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Sample records for two-tensor streamline tractography

  1. Resolving crossings in the corticospinal tract by two-tensor streamline tractography

    DEFF Research Database (Denmark)

    Qazi, Arish Asif; Radmanesh, Alireza; O'Donnell, Lauren

    2009-01-01

    An inherent drawback of the traditional diffusion tensor model is its limited ability to provide detailed information about multidirectional fiber architecture within a voxel. This leads to erroneous fiber tractography results in locations where fiber bundles cross each other. This may lead to th...

  2. Two-tensor streamline tractography through white matter intra-voxel fiber crossings

    DEFF Research Database (Denmark)

    Qazi, Arish Asif; Kindlmann, G; O'Donnell, L

    2008-01-01

    An inherent drawback of the traditional diffusion tensor model is its limited ability to provide detailed information about multidirectional fiber architecture within a voxel. This leads to erroneous fiber tractography results in locations where fiber bundles cross each other. In this paper, we p...

  3. Performance of unscented Kalman filter tractography in edema: Analysis of the two-tensor model.

    Science.gov (United States)

    Liao, Ruizhi; Ning, Lipeng; Chen, Zhenrui; Rigolo, Laura; Gong, Shun; Pasternak, Ofer; Golby, Alexandra J; Rathi, Yogesh; O'Donnell, Lauren J

    2017-01-01

    Diffusion MRI tractography is increasingly used in pre-operative neurosurgical planning to visualize critical fiber tracts. However, a major challenge for conventional tractography, especially in patients with brain tumors, is tracing fiber tracts that are affected by vasogenic edema, which increases water content in the tissue and lowers diffusion anisotropy. One strategy for improving fiber tracking is to use a tractography method that is more sensitive than the traditional single-tensor streamline tractography. We performed experiments to assess the performance of two-tensor unscented Kalman filter (UKF) tractography in edema. UKF tractography fits a diffusion model to the data during fiber tracking, taking advantage of prior information from the previous step along the fiber. We studied UKF performance in a synthetic diffusion MRI digital phantom with simulated edema and in retrospective data from two neurosurgical patients with edema affecting the arcuate fasciculus and corticospinal tracts. We compared the performance of several tractography methods including traditional streamline, UKF single-tensor, and UKF two-tensor. To provide practical guidance on how the UKF method could be employed, we evaluated the impact of using various seed regions both inside and outside the edematous regions, as well as the impact of parameter settings on the tractography sensitivity. We quantified the sensitivity of different methods by measuring the percentage of the patient-specific fMRI activation that was reached by the tractography. We expected that diffusion anisotropy threshold parameters, as well as the inclusion of a free water model, would significantly influence the reconstruction of edematous WM fiber tracts, because edema increases water content in the tissue and lowers anisotropy. Contrary to our initial expectations, varying the fractional anisotropy threshold and including a free water model did not affect the UKF two-tensor tractography output appreciably in

  4. Reconstruction of the arcuate fasciculus for surgical planning in the setting of peritumoral edema using two-tensor unscented Kalman filter tractography.

    Science.gov (United States)

    Chen, Zhenrui; Tie, Yanmei; Olubiyi, Olutayo; Rigolo, Laura; Mehrtash, Alireza; Norton, Isaiah; Pasternak, Ofer; Rathi, Yogesh; Golby, Alexandra J; O'Donnell, Lauren J

    2015-01-01

    Diffusion imaging tractography is increasingly used to trace critical fiber tracts in brain tumor patients to reduce the risk of post-operative neurological deficit. However, the effects of peritumoral edema pose a challenge to conventional tractography using the standard diffusion tensor model. The aim of this study was to present a novel technique using a two-tensor unscented Kalman filter (UKF) algorithm to track the arcuate fasciculus (AF) in brain tumor patients with peritumoral edema. Ten right-handed patients with left-sided brain tumors in the vicinity of language-related cortex and evidence of significant peritumoral edema were retrospectively selected for the study. All patients underwent 3-Tesla magnetic resonance imaging (MRI) including a diffusion-weighted dataset with 31 directions. Fiber tractography was performed using both single-tensor streamline and two-tensor UKF tractography. A two-regions-of-interest approach was applied to perform the delineation of the AF. Results from the two different tractography algorithms were compared visually and quantitatively. Using single-tensor streamline tractography, the AF appeared disrupted in four patients and contained few fibers in the remaining six patients. Two-tensor UKF tractography delineated an AF that traversed edematous brain areas in all patients. The volume of the AF was significantly larger on two-tensor UKF than on single-tensor streamline tractography (p tensor UKF tractography provides the ability to trace a larger volume AF than single-tensor streamline tractography in the setting of peritumoral edema in brain tumor patients.

  5. Performance of unscented Kalman filter tractography in edema: Analysis of the two-tensor model

    Directory of Open Access Journals (Sweden)

    Ruizhi Liao

    2017-01-01

    Overall, the main contribution of this study is to provide insight into how UKF tractography can work, using a two-tensor model, to begin to address the challenge of fiber tract reconstruction in edematous regions near brain tumors.

  6. Investigating the effects of streamline-based fiber tractography on matrix scaling in brain connective network.

    Science.gov (United States)

    Jan, Hengtai; Chao, Yi-Ping; Cho, Kuan-Hung; Kuo, Li-Wei

    2013-01-01

    Investigating the brain connective network using the modern graph theory has been widely applied in cognitive and clinical neuroscience research. In this study, we aimed to investigate the effects of streamline-based fiber tractography on the change of network properties and established a systematic framework to understand how an adequate network matrix scaling can be determined. The network properties, including degree, efficiency and betweenness centrality, show similar tendency in both left and right hemispheres. By employing the curve-fitting process with exponential law and measuring the residuals, the association between changes of network properties and threshold of track numbers is found and an adequate range of investigating the lateralization of brain network is suggested. The proposed approach can be further applied in clinical applications to improve the diagnostic sensitivity using network analysis with graph theory.

  7. MR tractography

    International Nuclear Information System (INIS)

    Kinosada, Yasutomi; Okuda, Yasuyuki; Ono, Mototsugu

    1993-01-01

    We developed a new noninvasive technique to visualize the anatomical structure of the nerve fiber system in vivo, and named this technique magnetic resonance (MR) tractography and the acquired image an MR tractogram. MR tractography has two steps. One is to obtain diffusion-weighted images sensitized along axes appropriate for depicting the intended nerve fibers with anisotropic water diffusion MR imaging. The other is to extract the anatomical structure of the nerve fiber system from a series of diffusion-weighted images by the maximum intensity projection method. To examine the clinical usefulness of the proposed technique, many contiguous, thin (3 mm) coronal two-dimensional sections of the brain were acquired sequentially in normal volunteers and selected patients with paralyses, on a 1.5 Tesla MR system (Signa, GE) with an ECG-gated Stejskal-Tanner pulse sequence. The structure of the nerve fiber system of normal volunteers was almost the same as the anatomy. The tractograms of patients with paralyses clearly showed the degeneration of nerve fibers and were correlated with clinical symptoms. MR tractography showed great promise for the study of neuroanatomy and neuroradiology. (author)

  8. AxTract: Toward microstructure informed tractography.

    Science.gov (United States)

    Girard, Gabriel; Daducci, Alessandro; Petit, Laurent; Thiran, Jean-Philippe; Whittingstall, Kevin; Deriche, Rachid; Wassermann, Demian; Descoteaux, Maxime

    2017-11-01

    Diffusion-weighted (DW) magnetic resonance imaging (MRI) tractography has become the tool of choice to probe the human brain's white matter in vivo. However, tractography algorithms produce a large number of erroneous streamlines (false positives), largely due to complex ambiguous tissue configurations. Moreover, the relationship between the resulting streamlines and the underlying white matter microstructure characteristics remains poorly understood. In this work, we introduce a new approach to simultaneously reconstruct white matter fascicles and characterize the apparent distribution of axon diameters within fascicles. To achieve this, our method, AxTract, takes full advantage of the recent development DW-MRI microstructure acquisition, modeling, and reconstruction techniques. This enables AxTract to separate parallel fascicles with different microstructure characteristics, hence reducing ambiguities in areas of complex tissue configuration. We report a decrease in the incidence of erroneous streamlines compared to the conventional deterministic tractography algorithms on simulated data. We also report an average increase in streamline density over 15 known fascicles of the 34 healthy subjects. Our results suggest that microstructure information improves tractography in crossing areas of the white matter. Moreover, AxTract provides additional microstructure information along the fascicle that can be studied alongside other streamline-based indices. Overall, AxTract provides the means to distinguish and follow white matter fascicles using their microstructure characteristics, bringing new insights into the white matter organization. This is a step forward in microstructure informed tractography, paving the way to a new generation of algorithms able to deal with intricate configurations of white matter fibers and providing quantitative brain connectivity analysis. Hum Brain Mapp 38:5485-5500, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  9. Learning from Tractography

    DEFF Research Database (Denmark)

    Kasenburg, Niklas

    Analysis of structural connections between brain regions enables us to gain insight into the structural architecture of the human brain and into how connections are affected by age or pathology. Tractography is the standard tool for automatic delineation of structural connections or tracts. Post......-processing of tractography results using expert prior knowledge is often performed to ensure a robust delineation. In this thesis, I present a shortest-path tractography (SPT) framework that can automatically incorporate any prior knowledge about the location of a tract. Furthermore, I show how such a prior can be learned...... of a connection and demonstrate their application in connectivity-based parcellation. Network models are a common way to represent structural connections of the whole brain. With supervised learning methods, features are extracted from these networks and are associated with a parameter of interest. Dimensionality...

  10. Real-time multi-peak tractography for instantaneous connectivity display

    Directory of Open Access Journals (Sweden)

    Maxime eChamberland

    2014-05-01

    Full Text Available The computerized process of reconstructing white matter tracts from diffusion MRI (dMRI data is often referred to as tractography. Tractography is nowadays central in structural connectivity since it is the only non-invasive technique to obtain information about brain wiring. Most publicly available tractography techniques and most studies are based on a fixed set of tractography parameters. However, the scale and curvature of fiber bundles can vary from region to region in the brain. Therefore, depending on the area of interest or subject (e.g. healthy control vs. tumor patient, optimal tracking parameters can be dramatically different. As a result, a slight change in tracking parameters may return different connectivity profiles and complicate the interpretation of the results. Having access to tractography parameters can thus be advantageous, as it will help in better isolating those which are sensitive to certain streamline features and potentially converge on optimal settings which are area-specific. In this work, we propose a real-time fiber tracking (RTT tool which can instantaneously compute and display streamlines. To achieve such real-time performance, we propose a novel evolution equation based on the upsampled principal directions, also called peaks, extracted at each voxel of the dMRI dataset. The technique runs on a single Computer Processing Unit (CPU without the need for Graphical Unit Processing (GPU programming. We qualitatively illustrate and quantitatively evaluate our novel multi-peak RTT technique on phantom and human datasets in comparison with the state of the art offline tractography from MRtrix, which is robust to fiber crossings. Finally, we show how our RTT tool facilitates neurosurgical planning and allows one to find fibers that infiltrate tumor areas, otherwise missing when using the standard default tracking parameters.

  11. BootGraph: probabilistic fiber tractography using bootstrap algorithms and graph theory.

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    Vorburger, Robert S; Reischauer, Carolin; Boesiger, Peter

    2013-02-01

    Bootstrap methods have recently been introduced to diffusion-weighted magnetic resonance imaging to estimate the measurement uncertainty of ensuing diffusion parameters directly from the acquired data without the necessity to assume a noise model. These methods have been previously combined with deterministic streamline tractography algorithms to allow for the assessment of connection probabilities in the human brain. Thereby, the local noise induced disturbance in the diffusion data is accumulated additively due to the incremental progression of streamline tractography algorithms. Graph based approaches have been proposed to overcome this drawback of streamline techniques. For this reason, the bootstrap method is in the present work incorporated into a graph setup to derive a new probabilistic fiber tractography method, called BootGraph. The acquired data set is thereby converted into a weighted, undirected graph by defining a vertex in each voxel and edges between adjacent vertices. By means of the cone of uncertainty, which is derived using the wild bootstrap, a weight is thereafter assigned to each edge. Two path finding algorithms are subsequently applied to derive connection probabilities. While the first algorithm is based on the shortest path approach, the second algorithm takes all existing paths between two vertices into consideration. Tracking results are compared to an established algorithm based on the bootstrap method in combination with streamline fiber tractography and to another graph based algorithm. The BootGraph shows a very good performance in crossing situations with respect to false negatives and permits incorporating additional constraints, such as a curvature threshold. By inheriting the advantages of the bootstrap method and graph theory, the BootGraph method provides a computationally efficient and flexible probabilistic tractography setup to compute connection probability maps and virtual fiber pathways without the drawbacks of

  12. Tracking errors in tractography of the gastrocnemius muscle. A comparison between the transverse and sagittal planes

    International Nuclear Information System (INIS)

    Aoki, Takako; Tohdoh, Yukihiro; Tawara, Noriyuki; Okuwaki, Toru; Horiuchi, Akira; Itagaki, Takuma; Niitsu, Mamoru

    2010-01-01

    In scans taken in conventional direction, tracking errors may occur when using a streamline-based algorithm for the tractography of the gastrocnemius muscle. To solve errors in tracking, we applied tractography to the musculotendinous junction and performed fiber tracking on the gastrocnemius muscle of 10 healthy subjects with their written informed consent. We employed a spin-echo diffusion tensor imaging (SE-DTI) sequence with 6-direction diffusion gradient sensitization and acquired DTI images at 1.5 tesla using a body array coil with parallel imaging. We compared tractography obtained in the transverse and sagittal planes using anatomical reference and found that the gastrocnemius muscle and musculotendinous junction were significantly better visualized on sagittal scans and in 3 regions of interest. We utilized Mann-Whitney U-test to determine significant differences between rates of concordance (P 2 value of skeletal muscle is around 50 ms, and TE should be as short as possible. A streamline-based algorithm is based on the continuity of a vector. It is easy to take running of the muscle fiber in sagittal scan. Therefore, tracking error is hard to occur. In conclusion, sagittal scanning may be one way to eliminate tracking errors in the tractography of the gastrocnemius muscle. Tracking errors were smaller with sagittal scans than transverse scans, and sagittal scans allow better fiber tracking. (author)

  13. Visualizing whole-brain DTI tractography with GPU-based Tuboids and LoD management.

    Science.gov (United States)

    Petrovic, Vid; Fallon, James; Kuester, Falko

    2007-01-01

    Diffusion Tensor Imaging (DTI) of the human brain, coupled with tractography techniques, enable the extraction of large-collections of three-dimensional tract pathways per subject. These pathways and pathway bundles represent the connectivity between different brain regions and are critical for the understanding of brain related diseases. A flexible and efficient GPU-based rendering technique for DTI tractography data is presented that addresses common performance bottlenecks and image-quality issues, allowing interactive render rates to be achieved on commodity hardware. An occlusion query-based pathway LoD management system for streamlines/streamtubes/tuboids is introduced that optimizes input geometry, vertex processing, and fragment processing loads, and helps reduce overdraw. The tuboid, a fully-shaded streamtube impostor constructed entirely on the GPU from streamline vertices, is also introduced. Unlike full streamtubes and other impostor constructs, tuboids require little to no preprocessing or extra space over the original streamline data. The supported fragment processing levels of detail range from texture-based draft shading to full raycast normal computation, Phong shading, environment mapping, and curvature-correct text labeling. The presented text labeling technique for tuboids provides adaptive, aesthetically pleasing labels that appear attached to the surface of the tubes. Furthermore, an occlusion query aggregating and scheduling scheme for tuboids is described that reduces the query overhead. Results for a tractography dataset are presented, and demonstrate that LoD-managed tuboids offer benefits over traditional streamtubes both in performance and appearance.

  14. Anti-symmetric rank-two tensor matter field on superspace for NT=2

    International Nuclear Information System (INIS)

    Spalenza, Wesley; Ney, Wander G.; Helayel-Neto, J.A.

    2004-01-01

    In this work, we discuss the interaction between anti-symmetric rank-two tensor matter and topological Yang-Mills fields. The matter field considered here is the rank-2 Avdeev-Chizhov tensor matter field in a suitably extended N T =2 SUSY. We start off from the N T =2, D=4 superspace formulation and we go over to Riemannian manifolds. The matter field is coupled to the topological Yang-Mills field. We show that both actions are obtained as Q-exact forms, which allows us to express the energy-momentum tensor as Q-exact observables

  15. Spinal diffusion tensor tractography for differentiation of intramedullary tumor-suspected lesions

    Energy Technology Data Exchange (ETDEWEB)

    Egger, K., E-mail: karl.egger@uniklinik-freiburg.de [Department of Neuroradiology, University Medical Center Freiburg, Breisacher Straße 64, 79106 Freiburg (Germany); Hohenhaus, M. [Department of Neurosurgery, University Medical Center Freiburg, Breisacher Straße 64, 79106 Freiburg (Germany); Van Velthoven, V. [Department of Neurosurgery, UZ Brussel, Laarbeeklaan 101, 1090 Brussel (Belgium); Heil, S.; Urbach, H. [Department of Neuroradiology, University Medical Center Freiburg, Breisacher Straße 64, 79106 Freiburg (Germany)

    2016-12-15

    Background and purpose: Primary MRI diagnosis of spinal intramedullary tumor-suspected lesions can be challenging and often requires spinal biopsy or resection with a substantial risk of neurological deficits. We evaluated whether Diffusion Tensor Imaging (DTI) tractography can facilitate the differential diagnosis. Materials and methods: Twenty-five consecutive patients with an intramedullary tumor-suspected lesion considered for spinal surgery were studied with a Diffusion-weighted multi-shot read out segmented EPI sequence (RESOLVE). White matter tracts (“streamlines”) were calculated using the FACT algorithm and visually co-registered to a T2-weighted 3D sequence. The fused images were assessed concerning spinal streamline appearance as normal, displaced or terminated. Definite diagnosis was verified by histological analysis or further clinical work-up. Results: All patients with normal appearing streamlines (n = 6) showed an acute inflammatory demyelinating pathology in the further clinical work-up. In 10 patients streamline displacing lesions were found from which 5 patients underwent a surgical treatment with histologically confirmed low-grade tumors like ependymomas and pilocytic astrocytomas. In nine patients streamlines were terminated, from which 6 patients received a histology proven diagnoses with a more heterogenous spectrum (3 cases of high grade tumor, 1 case of low grade tumor with intralesional hemorrhage and 2 cases with gliosis but no tumor cells). Conclusion: Using multi-shot DTI spinal tractography acute inflammatory lesions can be differentiated from other tumorous intramedullary lesions. The entity diagnosis of spinal tumors seems to be more challenging, primarily due to the variety of factors like invasivity, expansion or intralesional hemorrhage.

  16. Validation of in vitro probabilistic tractography

    DEFF Research Database (Denmark)

    Dyrby, Tim B.; Sogaard, L.V.; Parker, G.J.

    2007-01-01

    assessed the anatomical validity and reproducibility of in vitro multi-fiber probabilistic tractography against two invasive tracers: the histochemically detectable biotinylated dextran amine and manganese enhanced magnetic resonance imaging. Post mortern DWI was used to ensure that most of the sources...

  17. Gender differences in MR muscle tractography

    International Nuclear Information System (INIS)

    Okamoto, Yoshikazu; Minami, Manabu; Kunimatsu, Akira; Kono, Tatsuo; Sonobe, Jyunichi; Kujiraoka, Yuka

    2010-01-01

    Tractography of skeletal muscle can clearly reveal the 3-dimensional course of muscle fibers, and the procedure has great potential and could open new fields for diagnostic imaging. Studying this technique for clinical application, we noticed differences in the number of visualized tracts among volunteers and among muscles in the same volunteer. To comprehend why the number of visualized tracts varied so that we could acquire consistently high quality tractography of muscle fiber, we started to examine whether differences in individual parameters affected tractography visualization. The purpose of this study was to determine whether there are gender- and age-specific differences that differentiate the muscles by gender and age in MR tractography of skeletal muscle fiber. We divided 33 healthy volunteers by gender and age among 3 groups, A (13 younger men, aged 20 to 36 years), B (11 younger women, 25 to 39 years), and C (9 older men, 50 to 69), and we obtained from each volunteer tractographs of 8 fibers, including the bilateral gastrocnemius medialis (GCM), gastrocnemius lateralis (GCL), soleus (SOL), and anterior tibialis (AT) muscles. We classified the fibers into 5 grades depending on the extent of visualized tracts and used Mann-Whitney U-test to compare scores by gender (Group A versus B) and age (Group A versus C). Muscle tracts were significantly better visualized in women than men (median total visual score, 34 versus 24, P<0.05). In particular, the SOL muscles showed better visualization in the right (4.0 in women, 1.0 in men, P<0.05) and left (3.0 in women, 1.0 in men, P<0.05). Difference by age was not significant. The GCL was the highest scored muscle in all groups. Our results suggest that group differences, especially by gender, affected visualization of tractography of muscle fiber of the calf. (author)

  18. Connectivity between the superior colliculus and the amygdala in humans and macaque monkeys: virtual dissection with probabilistic DTI tractography

    Science.gov (United States)

    Koller, Kristin; Bultitude, Janet H.; Mullins, Paul; Ward, Robert; Mitchell, Anna S.; Bell, Andrew H.

    2015-01-01

    It has been suggested that some cortically blind patients can process the emotional valence of visual stimuli via a fast, subcortical pathway from the superior colliculus (SC) that reaches the amygdala via the pulvinar. We provide in vivo evidence for connectivity between the SC and the amygdala via the pulvinar in both humans and rhesus macaques. Probabilistic diffusion tensor imaging tractography revealed a streamlined path that passes dorsolaterally through the pulvinar before arcing rostrally to traverse above the temporal horn of the lateral ventricle and connect to the lateral amygdala. To obviate artifactual connectivity with crossing fibers of the stria terminalis, the stria was also dissected. The putative streamline between the SC and amygdala traverses above the temporal horn dorsal to the stria terminalis and is positioned medial to it in humans and lateral to it in monkeys. The topography of the streamline was examined in relation to lesion anatomy in five patients who had previously participated in behavioral experiments studying the processing of emotionally valenced visual stimuli. The pulvinar lesion interrupted the streamline in two patients who had exhibited contralesional processing deficits and spared the streamline in three patients who had no deficit. Although not definitive, this evidence supports the existence of a subcortical pathway linking the SC with the amygdala in primates. It also provides a necessary bridge between behavioral data obtained in future studies of neurological patients, and any forthcoming evidence from more invasive techniques, such as anatomical tracing studies and electrophysiological investigations only possible in nonhuman species. PMID:26224780

  19. Tractography of lumbar nerve roots: initial results

    Energy Technology Data Exchange (ETDEWEB)

    Balbi, Vincent; Budzik, Jean-Francois; Thuc, Vianney le; Cotten, Anne [Hopital Roger Salengro, Service de Radiologie et d' Imagerie musculo-squelettique, Lille Cedex (France); Duhamel, Alain [Universite de Lille 2, UDSL, Lille (France); Bera-Louville, Anne [Service de Rhumatologie, Hopital Roger Salengro, Lille (France)

    2011-06-15

    The aims of this preliminary study were to demonstrate the feasibility of in vivo diffusion tensor imaging (DTI) and fibre tracking (FT) of the lumbar nerve roots, and to assess potential differences in the DTI parameters of the lumbar nerves between healthy volunteers and patients suffering from disc herniation. Nineteen patients with unilateral sciatica related to posterolateral or foraminal disc herniation and 19 healthy volunteers were enrolled in this study. DTI with tractography of the L5 or S1 nerves was performed. Mean fractional anisotropy (FA) and mean diffusivity (MD) values were calculated from tractography images. FA and MD values could be obtained from DTI-FT images in all controls and patients. The mean FA value of the compressed lumbar nerve roots was significantly lower than the FA of the contralateral nerve roots (p=0.0001) and of the nerve roots of volunteers (p=0.0001). MD was significantly higher in compressed nerve roots than in the contralateral nerve root (p=0.0002) and in the nerve roots of volunteers (p=0.04). DTI with tractography of the lumbar nerves is possible. Significant changes in diffusion parameters were found in the compressed lumbar nerves. (orig.)

  20. Tractography of lumbar nerve roots: initial results

    International Nuclear Information System (INIS)

    Balbi, Vincent; Budzik, Jean-Francois; Thuc, Vianney le; Cotten, Anne; Duhamel, Alain; Bera-Louville, Anne

    2011-01-01

    The aims of this preliminary study were to demonstrate the feasibility of in vivo diffusion tensor imaging (DTI) and fibre tracking (FT) of the lumbar nerve roots, and to assess potential differences in the DTI parameters of the lumbar nerves between healthy volunteers and patients suffering from disc herniation. Nineteen patients with unilateral sciatica related to posterolateral or foraminal disc herniation and 19 healthy volunteers were enrolled in this study. DTI with tractography of the L5 or S1 nerves was performed. Mean fractional anisotropy (FA) and mean diffusivity (MD) values were calculated from tractography images. FA and MD values could be obtained from DTI-FT images in all controls and patients. The mean FA value of the compressed lumbar nerve roots was significantly lower than the FA of the contralateral nerve roots (p=0.0001) and of the nerve roots of volunteers (p=0.0001). MD was significantly higher in compressed nerve roots than in the contralateral nerve root (p=0.0002) and in the nerve roots of volunteers (p=0.04). DTI with tractography of the lumbar nerves is possible. Significant changes in diffusion parameters were found in the compressed lumbar nerves. (orig.)

  1. Assessment of Brain Damage and Plasticity in the Visual System Due to Early Occipital Lesion: Comparison of FDG-PET with Diffusion MRI Tractography

    Science.gov (United States)

    Jeong, Jeong-won; Tiwari, Vijay N.; Shin, Joseph; Chugani, Harry T.; Juhász, Csaba

    2015-01-01

    Purpose To determine the relation between glucose metabolic changes of the primary visual cortex, structural abnormalities of the corresponding visual tracts, and visual symptoms in children with Sturge-Weber syndrome (SWS). Materials and Methods In 10 children with unilateral SWS (ages 1.5–5.5 years), a region-of-interest analysis was applied in the bilateral medial occipital cortex on positron emission tomography (PET) and used to track diffusion-weighted imaging (DWI) streamlines corresponding to the central visual pathway. Normalized streamline volumes of individual SWS patients were compared with values from age-matched control groups as well as correlated with normalized glucose uptakes and visual field deficit. Results Lower glucose uptake and lower corresponding streamline volumes were detected in the affected occipital lobe in 9/10 patients, as compared to the contralateral side. Seven of these 9 patients had visual field deficit and normal or decreased streamline volumes on the unaffected side. The two other children had no visual symptoms and showed high contralateral visual streamline volumes. There was a positive correlation between the normalized ratios on DWI and PET, indicating that lower glucose metabolism was associated with lower streamline volume in the affected hemisphere (R = 0.70, P = 0.024). Conclusion We demonstrated that 18F-flurodeoxyglucose (FDG)-PET combined with DWI tractography can detect both brain damage on the side of the lesion and contralateral plasticity in children with early occipital lesions. PMID:24391057

  2. Anti-symmetric rank-two tensor matter field on superspace for N{sub T}=2

    Energy Technology Data Exchange (ETDEWEB)

    Spalenza, Wesley; Ney, Wander G; Helayel-Neto, J A

    2004-05-06

    In this work, we discuss the interaction between anti-symmetric rank-two tensor matter and topological Yang-Mills fields. The matter field considered here is the rank-2 Avdeev-Chizhov tensor matter field in a suitably extended N{sub T}=2 SUSY. We start off from the N{sub T}=2, D=4 superspace formulation and we go over to Riemannian manifolds. The matter field is coupled to the topological Yang-Mills field. We show that both actions are obtained as Q-exact forms, which allows us to express the energy-momentum tensor as Q-exact observables.

  3. Training shortest-path tractography: Automatic learning of spatial priors

    DEFF Research Database (Denmark)

    Kasenburg, Niklas; Liptrot, Matthew George; Reislev, Nina Linde

    2016-01-01

    Tractography is the standard tool for automatic delineation of white matter tracts from diffusion weighted images. However, the output of tractography often requires post-processing to remove false positives and ensure a robust delineation of the studied tract, and this demands expert prior...... knowledge. Here we demonstrate how such prior knowledge, or indeed any prior spatial information, can be automatically incorporated into a shortest-path tractography approach to produce more robust results. We describe how such a prior can be automatically generated (learned) from a population, and we...

  4. Streamline-based microfluidic device

    Science.gov (United States)

    Tai, Yu-Chong (Inventor); Zheng, Siyang (Inventor); Kasdan, Harvey (Inventor)

    2013-01-01

    The present invention provides a streamline-based device and a method for using the device for continuous separation of particles including cells in biological fluids. The device includes a main microchannel and an array of side microchannels disposed on a substrate. The main microchannel has a plurality of stagnation points with a predetermined geometric design, for example, each of the stagnation points has a predetermined distance from the upstream edge of each of the side microchannels. The particles are separated and collected in the side microchannels.

  5. Novel diffusion tensor imaging technique reveals developmental streamline volume changes in the corticospinal tract associated with leg motor control.

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    Kamson, David O; Juhász, Csaba; Chugani, Harry T; Jeong, Jeong-Won

    2015-04-01

    Diffusion tensor imaging (DTI) has expanded our knowledge of corticospinal tract (CST) anatomy and development. However, previous developmental DTI studies assessed the CST as a whole, overlooking potential differences in development of its components related to control of the upper and lower extremities. The present cross-sectional study investigated age-related changes, side and gender differences in streamline volume of the leg- and hand-related segments of the CST in children. DTI data of 31 children (1-14 years; mean age: 6±4 years; 17 girls) with normal conventional MRI were analyzed. Leg- and hand-related CST streamline volumes were quantified separately, using a recently validated novel tractography approach. CST streamline volumes on both sides were compared between genders and correlated with age. Higher absolute streamline volumes were found in the left leg-related CST compared to the right (p=0.001) without a gender effect (p=0.4), whereas no differences were found in the absolute hand-related CST volumes (p>0.4). CST leg-related streamline volumes, normalized to hemispheric white matter volumes, declined with age in the right hemisphere only (R=-.51; p=0.004). Absolute leg-related CST streamline volumes showed similar, but slightly weaker correlations. Hand-related absolute or normalized CST streamline volumes showed no age-related variations on either side. These results suggest differential development of CST segments controlling hand vs. leg movements. Asymmetric volume changes in the lower limb motor pathway may be secondary to gradually strengthening left hemispheric dominance and is consistent with previous data suggesting that footedness is a better predictor of hemispheric lateralization than handedness. Copyright © 2014 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

  6. Glioma surgery using intraoperative tractography and MEP monitoring

    International Nuclear Information System (INIS)

    Maesawa, Satoshi; Nakahara, Norimoto; Watanabe, Tadashi; Fujii, Masazumi; Yoshida, Jun

    2009-01-01

    In surgery of gliomas in motor-eloquent locations, it is essential to maximize resection while minimizing motor deficits. We attempted to identify the cortico-spinal tract (CST) by intraoperative-diffusion tensor imaging (DTI) tractography, combined with electrophysiological mapping using direct subcortical stimulation during tumor resection. Our techniques and preliminary results are reported. Tumors were removed from twelve patients with gliomas in and around the CST using high-field intraoperative MRI and neuronavigation system (BrainSUITE). DTI-based tractography was implemented for navigation of CST pre-and intraoperatively. When the CST was close to the manipulating area, direct subcortical stimulation was performed, and motor evoked potential (MEP)-responses were examined. Locations of CST indicated by pre- and intraoperative tractography (pre- or intra-CST-tractography), and locations identified by subcortical stimulation were recorded, and those correlations were examined. Imaging and functional outcomes were reviewed. Total resections were achieved in 10 patients (83.4%). Two patients developed transient deterioration of motor function (16.6%), and permanent paresis was seen in one (8.3%). The distance from intra-CST-tractography to corresponding sites by subcortical stimulation was 4.5 mm in average (standard deviation (SD)=4.2), and significantly shorter than from pre-CST-tractography. That distance correlated significantly with the intensity of subcortical stimulation. We observed that intraoperative DTI-tractography demonstrated the location of the pyramidal tract more accurately than preoperative one. The combination of intraoperative tractgraphy and MEP monitoring enhanced the quality of surgery for gliomas in motor-eloquent area. (author)

  7. Application of fiber tractography for neurosurgery

    International Nuclear Information System (INIS)

    Hashimoto, Naoya; Yoshimine, Toshiki

    2007-01-01

    This review describes about the fiber tractography (FT) for its basic principle, method, and application to neurosurgery involving usefulness, pitfall, validation needed and future perspective. MR diffusion weighted image exhibits the diffusion (Brownian movement) of water molecules and its multiple images taken by different angles of magnetic field can also give information of their diffusion anisotropy, whereby diffusion tensor image is yielded as FT owing to their high anisotropy, with use of appropriate softwares assuming an ellipsoid of anisotropic water (single tensor model). FT thus presents an image of a specific and functional neurofiber bundle. Recently, FT in neurosurgery has been recognized to have pitfalls in tracing the bundle at its crossing and branch, e.g., suggested avoidance of surgery of eloquent area navigated with FT alone. For this, developed and considered are the multi-tensor models based on multiple ellipsoids and on probabilistic one on probability, and combination of electrophysiological mapping is thought necessary as well. Application of FT is also actively in progress to understand neurological diseases like cerebral vascular lesion, hemiplegia, epilepsy, injury and many others. FT navigation without other validation is thus limited in neurosurgery, but FT is surely one of means to improve patients' prognosis and quality of life (QOL). (R.T.)

  8. Streamlining Smart Meter Data Analytics

    DEFF Research Database (Denmark)

    Liu, Xiufeng; Nielsen, Per Sieverts

    2015-01-01

    of the so-called big data possible. This can improve energy management, e.g., help utilities improve the management of energy and services, and help customers save money. As this regard, the paper focuses on building an innovative software solution to streamline smart meter data analytic, aiming at dealing......Today smart meters are increasingly used in worldwide. Smart meters are the advanced meters capable of measuring customer energy consumption at a fine-grained time interval, e.g., every 15 minutes. The data are very sizable, and might be from different sources, along with the other social......-economic metrics such as the geographic information of meters, the information about users and their property, geographic location and others, which make the data management very complex. On the other hand, data-mining and the emerging cloud computing technologies make the collection, management, and analysis...

  9. Outcomes of Diffusion Tensor Tractography-Integrated Stereotactic Radiosurgery

    Energy Technology Data Exchange (ETDEWEB)

    Koga, Tomoyuki, E-mail: kouga-tky@umin.ac.jp [Department of Neurosurgery, University of Tokyo Hospital, Tokyo (Japan); Maruyama, Keisuke; Kamada, Kyousuke; Ota, Takahiro; Shin, Masahiro [Department of Neurosurgery, University of Tokyo Hospital, Tokyo (Japan); Itoh, Daisuke [Department of Radiology, University of Tokyo Hospital, Tokyo (Japan); Kunii, Naoto [Department of Neurosurgery, University of Tokyo Hospital, Tokyo (Japan); Ino, Kenji; Terahara, Atsuro; Aoki, Shigeki; Masutani, Yoshitaka [Department of Radiology, University of Tokyo Hospital, Tokyo (Japan); Saito, Nobuhito [Department of Neurosurgery, University of Tokyo Hospital, Tokyo (Japan)

    2012-02-01

    Purpose: To analyze the effect of use of tractography of the critical brain white matter fibers created from diffusion tensor magnetic resonance imaging on reduction of morbidity associated with radiosurgery. Methods and Materials: Tractography of the pyramidal tract has been integrated since February 2004 if lesions are adjacent to it, the optic radiation since May 2006, and the arcuate fasciculus since October 2007. By visually confirming the precise location of these fibers, the dose to these fiber tracts was optimized. One hundred forty-four consecutive patients with cerebral arteriovenous malformations who underwent radiosurgery with this technique between February 2004 and December 2009 were analyzed. Results: Tractography was prospectively integrated in 71 of 155 treatments for 144 patients. The pyramidal tract was visualized in 45, the optic radiation in 22, and the arcuate fasciculus in 13 (two tracts in 9). During the follow-up period of 3 to 72 months (median, 23 months) after the procedure, 1 patient showed permanent worsening of pre-existing dysesthesia, and another patient exhibited mild transient hemiparesis 12 months later but fully recovered after oral administration of corticosteroid agents. Two patients had transient speech disturbance before starting integration of the arcuate fasciculus tractography, but no patient thereafter. Conclusion: Integrating tractography helped prevent morbidity of radiosurgery in patients with brain arteriovenous malformations.

  10. A diffusion tensor imaging tractography algorithm based on Navier-Stokes fluid mechanics.

    Science.gov (United States)

    Hageman, Nathan S; Toga, Arthur W; Narr, Katherine L; Shattuck, David W

    2009-03-01

    We introduce a fluid mechanics based tractography method for estimating the most likely connection paths between points in diffusion tensor imaging (DTI) volumes. We customize the Navier-Stokes equations to include information from the diffusion tensor and simulate an artificial fluid flow through the DTI image volume. We then estimate the most likely connection paths between points in the DTI volume using a metric derived from the fluid velocity vector field. We validate our algorithm using digital DTI phantoms based on a helical shape. Our method segmented the structure of the phantom with less distortion than was produced using implementations of heat-based partial differential equation (PDE) and streamline based methods. In addition, our method was able to successfully segment divergent and crossing fiber geometries, closely following the ideal path through a digital helical phantom in the presence of multiple crossing tracts. To assess the performance of our algorithm on anatomical data, we applied our method to DTI volumes from normal human subjects. Our method produced paths that were consistent with both known anatomy and directionally encoded color images of the DTI dataset.

  11. ACHP | News | ACHP Issues Program Comment to Streamline Communication

    Science.gov (United States)

    Program Comment to Streamline Communication Facilities Construction and Modification ACHP Issues Program Comment to Streamline Communication Facilities Construction and Modification The Advisory Council on

  12. Accelerated Logistics: Streamlining the Army's Supply Chain

    National Research Council Canada - National Science Library

    Wang, Mark

    2000-01-01

    ...) initiative, the Army has dramatically streamlined its supply chain, cutting order and ship times for repair parts by nearly two-thirds nationwide and over 75 percent at several of the major Forces Command (FORSCOM) installations...

  13. Creating customer value by streamlining business processes.

    Science.gov (United States)

    Vantrappen, H

    1992-02-01

    Much of the strategic preoccupation of senior managers in the 1990s is focusing on the creation of customer value. Companies are seeking competitive advantage by streamlining the three processes through which they interact with their customers: product creation, order handling and service assurance. 'Micro-strategy' is a term which has been coined for the trade-offs and decisions on where and how to streamline these three processes. The article discusses micro-strategies applied by successful companies.

  14. White matter mapping by DTI-based tractography for neurosurgery

    International Nuclear Information System (INIS)

    Kamada, Kyousuke

    2009-01-01

    To validate the corticospinal tract (CST) and arcuate fasciculus (AF) illustrated by diffusion tensor imaging (DTI), we used CST- and AF-tractography integrated neuronavigation and monopolar and bipolar direct fiber stimulation. Forty seven patients with brain lesions adjacent to the CST and AF were studied. During lesion resection, direct fiber stimulation was applied to the CST and AF to elicit motor responses (fiber-motor evoked potential (MEP)) and the impairment of language-related functions to identify the CST and AF. The minimum distance between the resection border and illustrated CST was measured on postoperative images. Direct fiber stimulation demonstrated that CST- and AF-tractography accurately reflected anatomical CST functioning. The cortical stimulation to the gyrus, including the language-functional MRI (fMRI) activation, evoked speech arrest, while the subcortical stimulation close to the AF reproducibly caused 'paranomia' without speech arrest. There were strong correlations between stimulus intensity for the fiber-MEP and the distance between eloquent fibers and the stimulus points. The convergent calculation formulated 1.8 mA as the electrical threshold of CST for the fiber-MEP, which was much smaller than that of the hand motor area. Validated tractography demonstrated the mean distance and intersection angle between CST and AF were 5 mm and 107 deg, respectively. In addition, the anisotropic diffusion-weighted image (ADWI) and CST-tractography clearly indicated the locations of the primary motor area (PMA) and the central sulcus and well reflected the anatomical characteristics of the corticospinal tract in the human brain. DTI-based tractography is a reliable way to map the white matter connections in the entire brain in clinical and basic neuroscience. By combining these techniques, investigating the cortico-subcortical connections in the human central nervous system could contribute to elucidating the neural networks of the human brain and

  15. White matter mapping by DTI-based tractography for neurosurgery

    International Nuclear Information System (INIS)

    Kamada, Kyousuke

    2011-01-01

    The purpose of this study was to validate the corticospinal tract (CST) and arcuate fasciculus (AF) illustrated by diffusion tensor imaging (DTI), we used CST- and AF-tractography integrated neuronavigation and monopolar and bipolar direct fiber stimulation. Forty seven patients with brain lesions adjacent to the CST and AF were studied. During lesion resection, direct fiber stimulation was applied to the CST and AF to elicit motor responses (fiber-MEP) and the impairment of language-related functions to identify the CST and AF. The minimum distance between the resection border and illustrated CST was measured on postoperative images. Direct fiber stimulation demonstrated that CST- and AF-tractography accurately reflected anatomical CST functioning. The cortical stimulation to the gyrus, including the language-fMRI activation, evoked speech arrest, while the subcortical stimulation close to the AF reproducibly caused 'paranomia' without speech arrest. There were strong correlations between stimulus intensity for the fiber-MEP and the distance between eloquent fibers and the stimulus points. The convergent calculation formulated 1.8 mA as the electrical threshold of CST for the fiber-MEP, which was much smaller than that of the hand motor area. Validated tractography demonstrated the mean distance and intersection angle between CST and AF were 5 mm and 107 deg, respectively. In addition, the anisotropic diffusion-weighted image (ADWI) and CST-tractography clearly indicated the locations of the primary motor area (PMA) and the central sulcus and well reflected the anatomical characteristics of the corticospinal tract in the human brain. DTI-based tractography is a reliable way to map the white matter connections in the entire brain in clinical and basic neuroscience. By combining these techniques, investigating the cortico-subcortical connections in the human central nervous system could contribute to elucidating the neural networks of the human brain and shed light

  16. Introduction to tractography-guided navigation: using 3-tesla magnetic resonance tractography in surgery for cerebral arteriovenous malformations.

    Science.gov (United States)

    Kikuta, K; Takagi, Y; Nozaki, K; Hashimoto, N

    2008-01-01

    To examine the effectiveness of magnetic resonance (MR) tractography in surgery for cerebral arteriovenous malformations (AVMs). A preoperative evaluation of major neural tracts around the nidus was carried out with 3-tesla (3 T) MR tractography in 25 consecutive patients with cerebral AVMs. The patients were 12 men and 13 women ranging in age from 4 to 60 years of age (mean age: 31.2 +/- 14.1 years). Twelve presented with hemorrhage. Images were obtained with T2-weighted turbo spin echo sequences, axial T1-weighted three-dimensional magnetization-prepared rapid acquisition gradient-echo (MPRAGE) sequences, three-dimensional time-of-flight MR angiography (3D TOF MRA), and thin-section diffusion-tensor imaging (DTI). The AVMs were obliterated in 22 of the 25 patients. A postoperative study of the MR tractography was carried out in 24 patients. In 21 patients, tracts were preserved and no postoperative neurological worsening was observed. Disruption of the tracts was found in 3 patients, and postoperative worsening was observed in 2 patients. However, no deterioration occurred in 1 patient with cerebellar AVM. Notwithstanding the limitations of this method, MR tractography can be considered useful for confirming the integrity of deviated tracts, for localizing deviated tracts, and for evaluating surgical risk, especially in cases of non-hemorrhagic AVM.

  17. Impact assessment: Eroding benefits through streamlining?

    Energy Technology Data Exchange (ETDEWEB)

    Bond, Alan, E-mail: alan.bond@uea.ac.uk [School of Environmental Sciences, University of East Anglia (United Kingdom); School of Geo and Spatial Sciences, North-West University (South Africa); Pope, Jenny, E-mail: jenny@integral-sustainability.net [Integral Sustainability (Australia); Curtin University Sustainability Policy Institute (Australia); Morrison-Saunders, Angus, E-mail: A.Morrison-Saunders@murdoch.edu.au [School of Geo and Spatial Sciences, North-West University (South Africa); Environmental Science, Murdoch University (Australia); Retief, Francois, E-mail: francois.retief@nwu.ac.za [School of Geo and Spatial Sciences, North-West University (South Africa); Gunn, Jill A.E., E-mail: jill.gunn@usask.ca [Department of Geography and Planning and School of Environment and Sustainability, University of Saskatchewan (Canada)

    2014-02-15

    This paper argues that Governments have sought to streamline impact assessment in recent years (defined as the last five years) to counter concerns over the costs and potential for delays to economic development. We hypothesise that this has had some adverse consequences on the benefits that subsequently accrue from the assessments. This hypothesis is tested using a framework developed from arguments for the benefits brought by Environmental Impact Assessment made in 1982 in the face of the UK Government opposition to its implementation in a time of economic recession. The particular benefits investigated are ‘consistency and fairness’, ‘early warning’, ‘environment and development’, and ‘public involvement’. Canada, South Africa, the United Kingdom and Western Australia are the jurisdictions tested using this framework. The conclusions indicate that significant streamlining has been undertaken which has had direct adverse effects on some of the benefits that impact assessment should deliver, particularly in Canada and the UK. The research has not examined whether streamlining has had implications for the effectiveness of impact assessment, but the causal link between streamlining and benefits does sound warning bells that merit further investigation. -- Highlights: • Investigation of the extent to which government has streamlined IA. • Evaluation framework was developed based on benefits of impact assessment. • Canada, South Africa, the United Kingdom, and Western Australia were examined. • Trajectory in last five years is attrition of benefits of impact assessment.

  18. Impact assessment: Eroding benefits through streamlining?

    International Nuclear Information System (INIS)

    Bond, Alan; Pope, Jenny; Morrison-Saunders, Angus; Retief, Francois; Gunn, Jill A.E.

    2014-01-01

    This paper argues that Governments have sought to streamline impact assessment in recent years (defined as the last five years) to counter concerns over the costs and potential for delays to economic development. We hypothesise that this has had some adverse consequences on the benefits that subsequently accrue from the assessments. This hypothesis is tested using a framework developed from arguments for the benefits brought by Environmental Impact Assessment made in 1982 in the face of the UK Government opposition to its implementation in a time of economic recession. The particular benefits investigated are ‘consistency and fairness’, ‘early warning’, ‘environment and development’, and ‘public involvement’. Canada, South Africa, the United Kingdom and Western Australia are the jurisdictions tested using this framework. The conclusions indicate that significant streamlining has been undertaken which has had direct adverse effects on some of the benefits that impact assessment should deliver, particularly in Canada and the UK. The research has not examined whether streamlining has had implications for the effectiveness of impact assessment, but the causal link between streamlining and benefits does sound warning bells that merit further investigation. -- Highlights: • Investigation of the extent to which government has streamlined IA. • Evaluation framework was developed based on benefits of impact assessment. • Canada, South Africa, the United Kingdom, and Western Australia were examined. • Trajectory in last five years is attrition of benefits of impact assessment

  19. TractoR: Magnetic Resonance Imaging and Tractography with R

    Directory of Open Access Journals (Sweden)

    Chris A. Clark

    2011-10-01

    Full Text Available Statistical techniques play a major role in contemporary methods for analyzing magnetic resonance imaging (MRI data. In addition to the central role that classical statistical methods play in research using MRI, statistical modeling and machine learning techniques are key to many modern data analysis pipelines. Applications for these techniques cover a broad spectrum of research, including many preclinical and clinical studies, and in some cases these methods are working their way into widespread routine use. In this manuscript we describe a software tool called TractoR (for “Tractography with R”, a collection of packages for the R language and environment, along with additional infrastructure for straightforwardly performing common image processing tasks. TractoR provides general purpose functions for reading, writing and manipulating MR images, as well as more specific code for fitting signal models to diffusion MRI data and performing tractography, a technique for visualizing neural connectivity.

  20. Evaluation of diffusion-tensor imaging-based global search and tractography for tumor surgery close to the language system.

    Directory of Open Access Journals (Sweden)

    Mirco Richter

    Full Text Available Pre-operative planning and intra-operative guidance in neurosurgery require detailed information about the location of functional areas and their anatomo-functional connectivity. In particular, regarding the language system, post-operative deficits such as aphasia can be avoided. By combining functional magnetic resonance imaging and diffusion tensor imaging, the connectivity between functional areas can be reconstructed by tractography techniques that need to cope with limitations such as limited resolution and low anisotropic diffusion close to functional areas. Tumors pose particular challenges because of edema, displacement effects on brain tissue and infiltration of white matter. Under these conditions, standard fiber tracking methods reconstruct pathways of insufficient quality. Therefore, robust global or probabilistic approaches are required. In this study, two commonly used standard fiber tracking algorithms, streamline propagation and tensor deflection, were compared with a previously published global search, Gibbs tracking and a connection-oriented probabilistic tractography approach. All methods were applied to reconstruct neuronal pathways of the language system of patients undergoing brain tumor surgery, and control subjects. Connections between Broca and Wernicke areas via the arcuate fasciculus (AF and the inferior fronto-occipital fasciculus (IFOF were validated by a clinical expert to ensure anatomical feasibility, and compared using distance- and diffusion-based similarity metrics to evaluate their agreement on pathway locations. For both patients and controls, a strong agreement between all methods was observed regarding the location of the AF. In case of the IFOF however, standard fiber tracking and Gibbs tracking predominantly identified the inferior longitudinal fasciculus that plays a secondary role in semantic language processing. In contrast, global search resolved connections in almost every case via the IFOF which

  1. Global tractography with embedded anatomical priors for quantitative connectivity analysis

    Directory of Open Access Journals (Sweden)

    Alia eLemkaddem

    2014-11-01

    Full Text Available The main assumption of fiber-tracking algorithms is that fiber trajectories are represented by paths of highest diffusion, which is usually accomplished by following the principal diffusion directions estimated in every voxel from the measured diffusion MRI data. The state-of-the-art approaches, known as global tractography, reconstruct all the fiber tracts of the whole brain simultaneously by solving a global energy minimization problem. The tractograms obtained with these algorithms outperform any previous technique but, unfortunately, the price to pay is an increased computational cost which is not suitable in many practical settings, both in terms of time and memory requirements. Furthermore, existing global tractography algorithms suffer from an important shortcoming that is crucial in the context of brain connectivity analyses. As no anatomical priors are used during in the reconstruction process, the recovered fiber tracts are not guaranteed to connect cortical regions and, as a matter of fact, most of them stop prematurely in the white matter. This does not only unnecessarily slow down the estimation procedure and potentially biases any subsequent analysis but also, most importantly, prevents the de facto quantification of brain connectivity. In this work, we propose a novel approach for global tractography that is specifically designed for connectivity analysis applications by explicitly enforcing anatomical priors of the tracts in the optimization and considering the effective contribution of each of them, i.e. volume, to the acquired diffusion MRI image. We evaluated our approach on both a realistic diffusion MRI phantom and in-vivo data, and also compared its performance to existing tractography aloprithms.

  2. MRI and MR tractography in bilateral hypertrophic olivary degeneration

    Directory of Open Access Journals (Sweden)

    Debraj Sen

    2014-01-01

    Full Text Available Hypertrophic olivary degeneration is a trans-synaptic neuronal degeneration associated with hypertrophy of the inferior olivary nucleus due to a lesion in the triangle of Guillain-Mollaret. Familiarity with this entity on magnetic resonance imaging (MRI is essential to avoid other erroneous ominous diagnoses. We present a case of bilateral hypertrophic olivary degeneration and discuss the etiopathogenesis and MRI findings in this entity. The contributory role of MR tractography in the diagnosis is also highlighted.

  3. MRI and MR tractography in bilateral hypertrophic olivary degeneration.

    Science.gov (United States)

    Sen, Debraj; Gulati, Yoginder S; Malik, Virender; Mohimen, Aneesh; Sibi, Eranki; Reddy, Deepak Chandra

    2014-10-01

    Hypertrophic olivary degeneration is a trans-synaptic neuronal degeneration associated with hypertrophy of the inferior olivary nucleus due to a lesion in the triangle of Guillain-Mollaret. Familiarity with this entity on magnetic resonance imaging (MRI) is essential to avoid other erroneous ominous diagnoses. We present a case of bilateral hypertrophic olivary degeneration and discuss the etiopathogenesis and MRI findings in this entity. The contributory role of MR tractography in the diagnosis is also highlighted.

  4. MRI and MR tractography in bilateral hypertrophic olivary degeneration

    International Nuclear Information System (INIS)

    Sen, Debraj; Gulati, Yoginder S.; Malik, Virender; Mohimen, Aneesh; Sibi, Eranki; Reddy, Deepak Chandra

    2014-01-01

    Hypertrophic olivary degeneration is a trans-synaptic neuronal degeneration associated with hypertrophy of the inferior olivary nucleus due to a lesion in the triangle of Guillain-Mollaret. Familiarity with this entity on magnetic resonance imaging (MRI) is essential to avoid other erroneous ominous diagnoses. We present a case of bilateral hypertrophic olivary degeneration and discuss the etiopathogenesis and MRI findings in this entity. The contributory role of MR tractography in the diagnosis is also highlighted

  5. Target identification for stereotactic thalamotomy using diffusion tractography.

    Directory of Open Access Journals (Sweden)

    Zsigmond Tamás Kincses

    Full Text Available BACKGROUND: Stereotactic targets for thalamotomy are usually derived from population-based coordinates. Individual anatomy is used only to scale the coordinates based on the location of some internal guide points. While on conventional MR imaging the thalamic nuclei are indistinguishable, recently it has become possible to identify individual thalamic nuclei using different connectivity profiles, as defined by MR diffusion tractography. METHODOLOGY AND PRINCIPAL FINDINGS: Here we investigated the inter-individual variation of the location of target nuclei for thalamotomy: the putative ventralis oralis posterior (Vop and the ventral intermedius (Vim nucleus as defined by probabilistic tractography. We showed that the mean inter-individual distance of the peak Vop location is 7.33 mm and 7.42 mm for Vim. The mean overlap between individual Vop nuclei was 40.2% and it was 31.8% for Vim nuclei. As a proof of concept, we also present a patient who underwent Vop thalamotomy for untreatable tremor caused by traumatic brain injury and another patient who underwent Vim thalamotomy for essential tremor. The probabilistic tractography indicated that the successful tremor control was achieved with lesions in the Vop and Vim respectively. CONCLUSIONS: Our data call attention to the need for a better appreciation of the individual anatomy when planning stereotactic functional neurosurgery.

  6. Streamlining the Bankability Process using International Standards

    Energy Technology Data Exchange (ETDEWEB)

    Kurtz, Sarah [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Repins, Ingrid L [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Kelly, George [Sunset Technology, Mount Airy, MD; Ramu, Govind [SunPower, San Jose, California; Heinz, Matthias [TUV Rheinland, Cologne, Germany; Chen, Yingnan [CGC (China General Certification Center), Beijing; Wohlgemuth, John [PowerMark, Union Hall, VA; Lokanath, Sumanth [First Solar, Tempe, Arizona; Daniels, Eric [Suncycle USA, Frederick MD; Hsi, Edward [Swiss RE, Zurich, Switzerland; Yamamichi, Masaaki [RTS, Trumbull, CT

    2017-09-27

    NREL has supported the international efforts to create a streamlined process for documenting bankability and/or completion of each step of a PV project plan. IECRE was created for this purpose in 2014. This poster describes the goals, current status of this effort, and how individuals and companies can become involved.

  7. Hydrodynamic Drag on Streamlined Projectiles and Cavities

    KAUST Repository

    Jetly, Aditya

    2016-04-19

    The air cavity formation resulting from the water-entry of solid objects has been the subject of extensive research due to its application in various fields such as biology, marine vehicles, sports and oil and gas industries. Recently we demonstrated that at certain conditions following the closing of the air cavity formed by the initial impact of a superhydrophobic sphere on a free water surface a stable streamlined shape air cavity can remain attached to the sphere. The formation of superhydrophobic sphere and attached air cavity reaches a steady state during the free fall. In this thesis we further explore this novel phenomenon to quantify the drag on streamlined shape cavities. The drag on the sphere-cavity formation is then compared with the drag on solid projectile which were designed to have self-similar shape to that of the cavity. The solid projectiles of adjustable weight were produced using 3D printing technique. In a set of experiments on the free fall of projectile we determined the variation of projectiles drag coefficient as a function of the projectiles length to diameter ratio and the projectiles specific weight, covering a range of intermediate Reynolds number, Re ~ 104 – 105 which are characteristic for our streamlined cavity experiments. Parallel free fall experiment with sphere attached streamlined air cavity and projectile of the same shape and effective weight clearly demonstrated the drag reduction effect due to the stress-free boundary condition at cavity liquid interface. The streamlined cavity experiments can be used as the upper bound estimate of the drag reduction by air layers naturally sustained on superhydrophobic surfaces in contact with water. In the final part of the thesis we design an experiment to test the drag reduction capacity of robust superhydrophobic coatings deposited on the surface of various model vessels.

  8. Quantitative diffusion tensor deterministic and probabilistic fiber tractography in relapsing-remitting multiple sclerosis

    International Nuclear Information System (INIS)

    Hu Bing; Ye Binbin; Yang Yang; Zhu Kangshun; Kang Zhuang; Kuang Sichi; Luo Lin; Shan Hong

    2011-01-01

    Purpose: Our aim was to study the quantitative fiber tractography variations and patterns in patients with relapsing-remitting multiple sclerosis (RRMS) and to assess the correlation between quantitative fiber tractography and Expanded Disability Status Scale (EDSS). Material and methods: Twenty-eight patients with RRMS and 28 age-matched healthy volunteers underwent a diffusion tensor MR imaging study. Quantitative deterministic and probabilistic fiber tractography were generated in all subjects. And mean numbers of tracked lines and fiber density were counted. Paired-samples t tests were used to compare tracked lines and fiber density in RRMS patients with those in controls. Bivariate linear regression model was used to determine the relationship between quantitative fiber tractography and EDSS in RRMS. Results: Both deterministic and probabilistic tractography's tracked lines and fiber density in RRMS patients were less than those in controls (P < .001). Both deterministic and probabilistic tractography's tracked lines and fiber density were found negative correlations with EDSS in RRMS (P < .001). The fiber tract disruptions and reductions in RRMS were directly visualized on fiber tractography. Conclusion: Changes of white matter tracts can be detected by quantitative diffusion tensor fiber tractography, and correlate with clinical impairment in RRMS.

  9. Automatic target validation based on neuroscientific literature mining for tractography

    Directory of Open Access Journals (Sweden)

    Xavier eVasques

    2015-05-01

    Full Text Available Target identification for tractography studies requires solid anatomical knowledge validated by an extensive literature review across species for each seed structure to be studied. Manual literature review to identify targets for a given seed region is tedious and potentially subjective. Therefore, complementary approaches would be useful. We propose to use text-mining models to automatically suggest potential targets from the neuroscientific literature, full-text articles and abstracts, so that they can be used for anatomical connection studies and more specifically for tractography. We applied text-mining models to three structures: two well studied structures, since validated deep brain stimulation targets, the internal globus pallidus and the subthalamic nucleus and, the nucleus accumbens, an exploratory target for treating psychiatric disorders. We performed a systematic review of the literature to document the projections of the three selected structures and compared it with the targets proposed by text-mining models, both in rat and primate (including human. We ran probabilistic tractography on the nucleus accumbens and compared the output with the results of the text-mining models and literature review. Overall, text-mining the literature could find three times as many targets as two man-weeks of curation could. The overall efficiency of the text-mining against literature review in our study was 98% recall (at 36% precision, meaning that over all the targets for the three selected seeds, only one target has been missed by text-mining. We demonstrate that connectivity for a structure of interest can be extracted from a very large amount of publications and abstracts. We believe this tool will be useful in helping the neuroscience community to facilitate connectivity studies of particular brain regions. The text mining tools used for the study are part of the HBP Neuroinformatics Platform, publicly available at http://connectivity-brainer.rhcloud.com/.

  10. Diffusion imaging and tractography of congenital brain malformations

    International Nuclear Information System (INIS)

    Wahl, Michael; Barkovich, A.J.; Mukherjee, Pratik

    2010-01-01

    Diffusion imaging is an MRI modality that measures the microscopic molecular motion of water in order to investigate white matter microstructure. The modality has been used extensively in recent years to investigate the neuroanatomical basis of congenital brain malformations. We review the basic principles of diffusion imaging and of specific techniques, including diffusion tensor imaging (DTI) and high angular resolution diffusion imaging (HARDI). We show how DTI and HARDI, and their application to fiber tractography, has elucidated the aberrant connectivity underlying a number of congenital brain malformations. Finally, we discuss potential uses for diffusion imaging of developmental disorders in the clinical and research realms. (orig.)

  11. Streamlining Research by Using Existing Tools

    OpenAIRE

    Greene, Sarah M.; Baldwin, Laura-Mae; Dolor, Rowena J.; Thompson, Ella; Neale, Anne Victoria

    2011-01-01

    Over the past two decades, the health research enterprise has matured rapidly, and many recognize an urgent need to translate pertinent research results into practice, to help improve the quality, accessibility, and affordability of U.S. health care. Streamlining research operations would speed translation, particularly for multi-site collaborations. However, the culture of research discourages reusing or adapting existing resources or study materials. Too often, researchers start studies and...

  12. Identification of the pyramidal tract by neuronavigation based on intraoperative magnetic resonance tractography: correlation with subcortical stimulation

    Energy Technology Data Exchange (ETDEWEB)

    Bozzao, Alessandro; Romano, Andrea; Calabria, Luigi Fausto; Coppola, Valeria; Fantozzi, Luigi Maria [University of Rome Sapienza, Department of Neuroradiology, Rome (Italy); Angelini, Albina; D' Andrea, Giancarlo; Mastronardi, Luciano; Ferrante, Luigi [University of Rome Sapienza, Department of Neurosurgery, Rome (Italy)

    2010-10-15

    To demonstrate the accuracy of magnetic resonance tractography (MRT) in localizing the cortical spinal tract (CST) close to brain tumours by using intraoperative electric subcortical stimulation. Nine patients with intra-axial brain tumours underwent neurosurgery. Planning was based on analysis of the course of streamlines compatible with the CST. After tumour removal, intraoperative MRT was reacquired. Sites at various distance from the CST were repeatedly stimulated to assess whether registered motor evoked potential (MEP) could be elicited. All patients were assessed clinically both pre- and postoperatively. The motor function was preserved in all patients. In all patients intraoperative MRT demonstrated shift of the bundle position caused by the surgical procedure. The distance between the estimated intraoperative CST and the point of elicited MEP was 1 cm or less in all nine patients. At distances greater than 2 cm, no patient reported positive MEP. Intraoperative MRT is a reliable technique for localization of CST. In all patients MEP were elicited by direct subcortical electrical stimulation at a distance below 1 cm from the CST as represented by MRT. Brain shifting might impact this evaluation since CST position may change during surgery in the range of 8 mm. (orig.)

  13. Identification of the pyramidal tract by neuronavigation based on intraoperative magnetic resonance tractography: correlation with subcortical stimulation

    International Nuclear Information System (INIS)

    Bozzao, Alessandro; Romano, Andrea; Calabria, Luigi Fausto; Coppola, Valeria; Fantozzi, Luigi Maria; Angelini, Albina; D'Andrea, Giancarlo; Mastronardi, Luciano; Ferrante, Luigi

    2010-01-01

    To demonstrate the accuracy of magnetic resonance tractography (MRT) in localizing the cortical spinal tract (CST) close to brain tumours by using intraoperative electric subcortical stimulation. Nine patients with intra-axial brain tumours underwent neurosurgery. Planning was based on analysis of the course of streamlines compatible with the CST. After tumour removal, intraoperative MRT was reacquired. Sites at various distance from the CST were repeatedly stimulated to assess whether registered motor evoked potential (MEP) could be elicited. All patients were assessed clinically both pre- and postoperatively. The motor function was preserved in all patients. In all patients intraoperative MRT demonstrated shift of the bundle position caused by the surgical procedure. The distance between the estimated intraoperative CST and the point of elicited MEP was 1 cm or less in all nine patients. At distances greater than 2 cm, no patient reported positive MEP. Intraoperative MRT is a reliable technique for localization of CST. In all patients MEP were elicited by direct subcortical electrical stimulation at a distance below 1 cm from the CST as represented by MRT. Brain shifting might impact this evaluation since CST position may change during surgery in the range of 8 mm. (orig.)

  14. Oculomotor nerve palsy evaluated by diffusion-tensor tractography

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, Kei; Kizu, Osamu; Ito, Hirotoshi; Nishimura, Tsunehiko [Kyoto Prefectural University of Medicine, Department of Radiology, Kyoto (Japan); Shiga, Kensuke; Akiyama, Katsuhisa; Nakagawa, Masanori [Kyoto Prefectural University of Medicine, Department of Neurology, Kyoto (Japan)

    2006-06-15

    The aim of the study was to test the feasibility of the tractography technique based on diffusion-tensor imaging (DTI) for the assessment of small infarcts involving the brainstem. A patient who presented with an isolated left third cranial nerve palsy underwent magnetic resonance examination. Images were obtained by use of a whole-body, 1.5-T imager. Data were transferred to an off-line workstation for fiber tracking. The conventional diffusion-weighted imaging (DWI) performed using a 5 mm slice thickness could only depict an equivocal hyperintensity lesion located at the left paramedian midbrain. An additional thin-slice DTI was performed immediately after the initial DWI using a 3 mm slice thickness and was able to delineate the lesion more clearly. Image postprocessing of thin-slice DTI data revealed that the lesion location involved the course of the third cranial nerve tract, corresponding with the patient's clinical symptoms. The tractography technique can be applied to assess fine neuronal structures of the brainstem, enabling direct clinicoradiological correlation of small infarcts involving this region. (orig.)

  15. Oculomotor nerve palsy evaluated by diffusion-tensor tractography

    International Nuclear Information System (INIS)

    Yamada, Kei; Kizu, Osamu; Ito, Hirotoshi; Nishimura, Tsunehiko; Shiga, Kensuke; Akiyama, Katsuhisa; Nakagawa, Masanori

    2006-01-01

    The aim of the study was to test the feasibility of the tractography technique based on diffusion-tensor imaging (DTI) for the assessment of small infarcts involving the brainstem. A patient who presented with an isolated left third cranial nerve palsy underwent magnetic resonance examination. Images were obtained by use of a whole-body, 1.5-T imager. Data were transferred to an off-line workstation for fiber tracking. The conventional diffusion-weighted imaging (DWI) performed using a 5 mm slice thickness could only depict an equivocal hyperintensity lesion located at the left paramedian midbrain. An additional thin-slice DTI was performed immediately after the initial DWI using a 3 mm slice thickness and was able to delineate the lesion more clearly. Image postprocessing of thin-slice DTI data revealed that the lesion location involved the course of the third cranial nerve tract, corresponding with the patient's clinical symptoms. The tractography technique can be applied to assess fine neuronal structures of the brainstem, enabling direct clinicoradiological correlation of small infarcts involving this region. (orig.)

  16. Using Diffusion Tractography to Predict Cortical Connection Strength and Distance: A Quantitative Comparison with Tracers in the Monkey

    DEFF Research Database (Denmark)

    Donahue, Chad J.; Sotiropoulos, Stamatios N.; Jbabdi, Saad

    2016-01-01

    of tractography for analyzing interareal corticocortical connectivity in nonhuman primates and a framework for assessing future tractography methodological refinements objectively. SIGNIFICANCE STATEMENT Tractography based on diffusion MRI has great potential for a variety of applications, including estimation......Tractography based on diffusion MRI offers the promise of characterizing many aspects of long-distance connectivity in the brain, but requires quantitative validation to assess its strengths and limitations. Here, we evaluate tractography's ability to estimate the presence and strength...... of connections between areas of macaque neocortex by comparing its results with published data from retrograde tracer injections. Probabilistic tractography was performed on high-quality postmortem diffusion imaging scans from two Old World monkey brains. Tractography connection weights were estimated using...

  17. Streamlined approach to waste management at CRL

    International Nuclear Information System (INIS)

    Adams, L.; Campbell, B.

    2011-01-01

    Radioactive, mixed, hazardous and non-hazardous wastes have been and continue to be generated at Chalk River Laboratories (CRL) as a result of research and development activities and operations since the 1940s. Over the years, the wastes produced as a byproduct of activities delivering the core missions of the CRL site have been of many types, and today, over thirty distinct waste streams have been identified, all requiring efficient management. With the commencement of decommissioning of the legacy created as part of the development of the Canadian nuclear industry, the volumes and range of wastes to be managed have been increasing in the near term, and this trend will continue into the future. The development of a streamlined approach to waste management is a key to successful waste management at CRL. Waste management guidelines that address all of the requirements have become complex, and so have the various waste management groups receiving waste, with their many different processes and capabilities. This has led to difficulties for waste generators in understanding all of the requirements to be satisfied for the various CRL waste receivers, whose primary concerns are to be safe and in compliance with their acceptance criteria and license conditions. As a result, waste movement on site can often be very slow, especially for non-routine waste types. Recognizing an opportunity for improvement, the Waste Management organization at CRL has implemented a more streamlined approach with emphasis on early identification of waste type and possible disposition path. This paper presents a streamlined approach to waste identification and waste management at CRL, the implementation methodology applied and the early results achieved from this process improvement. (author)

  18. Lightroom 5 streamlining your digital photography process

    CERN Document Server

    Sylvan, Rob

    2014-01-01

    Manage your images with Lightroom and this beautifully illustrated guide Image management can soak up huge amounts of a photographer's time, but help is on hand. This complete guides teaches you how to use Adobe Lightroom 5 to import, manage, edit, and showcase large quantities of images with impressive results. The authors, both professional photographers and Lightroom experts, walk you through step by step, demonstrating real-world techniques as well as a variety of practical tips, tricks, and shortcuts that save you time. Streamline image management tasks like a pro, and get back to doing

  19. Streamlining environmental product declarations: a stage model

    Science.gov (United States)

    Lefebvre, Elisabeth; Lefebvre, Louis A.; Talbot, Stephane; Le Hen, Gael

    2001-02-01

    General public environmental awareness and education is increasing, therefore stimulating the demand for reliable, objective and comparable information about products' environmental performances. The recently published standard series ISO 14040 and ISO 14025 are normalizing the preparation of Environmental Product Declarations (EPDs) containing comprehensive information relevant to a product's environmental impact during its life cycle. So far, only a few environmentally leading manufacturing organizations have experimented the preparation of EPDs (mostly from Europe), demonstrating its great potential as a marketing weapon. However the preparation of EPDs is a complex process, requiring collection and analysis of massive amounts of information coming from disparate sources (suppliers, sub-contractors, etc.). In a foreseeable future, the streamlining of the EPD preparation process will require product manufacturers to adapt their information systems (ERP, MES, SCADA) in order to make them capable of gathering, and transmitting the appropriate environmental information. It also requires strong functional integration all along the product supply chain in order to ensure that all the information is made available in a standardized and timely manner. The goal of the present paper is two fold: first to propose a transitional model towards green supply chain management and EPD preparation; second to identify key technologies and methodologies allowing to streamline the EPD process and subsequently the transition toward sustainable product development

  20. Diffusion tensor imaging and tractography in clinical neuro sciences

    International Nuclear Information System (INIS)

    Zarei, M.; Johansen-Berg, H.; Matthews, P.M.

    2003-01-01

    Rapidly evolving MR technology has allowed better understanding of structure and function of the human brain. Diffusion weighted MRI was developed two decades ago and it is now well established in diagnosis of acute ischaemia in patients with stroke. Diffusion tensor MRI uses the same principles but takes a step further allowing US to measure magnitude of the diffusion along different directions. This lead to the development of diffusion tensor tractography, a technique by which major neural pathways in the living brain can be visualized. There is a growing interest in exploring possible use of these techniques in clinical neurology and psychiatry. This article aims to review the principles of this technique and recent discoveries which may help US to better understand neurological and psychiatric disorders

  1. Structural parcellation of the thalamus using shortest-path tractography

    DEFF Research Database (Denmark)

    Kasenburg, Niklas; Darkner, Sune; Hahn, Ute

    2016-01-01

    that parcellation of the thalamus results in p-value maps that are spatially coherent across subjects. Comparing to the state-of-the-art parcellation of Behrens et al. [1], we observe some agreement, but the soft segmentation exhibits better stability for voxels connected to multiple target regions.......We demonstrate how structural parcellation can be implemented using shortest-path tractography, thereby addressing some of the shortcomings of the conventional approaches. In particular, our algorithm quantifies, via p-values, the confidence that a voxel in the parcellated region is connected...... to each cortical target region. Calculation of these statistical measures is derived from a rank-based test on the histogram of tract-based scores from all the shortest paths found between the source voxel and each voxel within the target region. Using data from the Human Connectome Project, we show...

  2. Regional differences in fiber tractography predict neurodevelopmental outcomes in neonates with infantile Krabbe disease

    Directory of Open Access Journals (Sweden)

    A. Gupta

    2015-01-01

    Interpretation: Neonatal microstructural abnormalities correlate with neurodevelopmental treatment outcomes in patients treated for infantile Krabbe disease. DTI with quantitative tractography is an excellent biomarker for evaluating infants with Krabbe disease identified through newborn screening.

  3. The challenge of mapping the human connectome based on diffusion tractography.

    Science.gov (United States)

    Maier-Hein, Klaus H; Neher, Peter F; Houde, Jean-Christophe; Côté, Marc-Alexandre; Garyfallidis, Eleftherios; Zhong, Jidan; Chamberland, Maxime; Yeh, Fang-Cheng; Lin, Ying-Chia; Ji, Qing; Reddick, Wilburn E; Glass, John O; Chen, David Qixiang; Feng, Yuanjing; Gao, Chengfeng; Wu, Ye; Ma, Jieyan; Renjie, H; Li, Qiang; Westin, Carl-Fredrik; Deslauriers-Gauthier, Samuel; González, J Omar Ocegueda; Paquette, Michael; St-Jean, Samuel; Girard, Gabriel; Rheault, François; Sidhu, Jasmeen; Tax, Chantal M W; Guo, Fenghua; Mesri, Hamed Y; Dávid, Szabolcs; Froeling, Martijn; Heemskerk, Anneriet M; Leemans, Alexander; Boré, Arnaud; Pinsard, Basile; Bedetti, Christophe; Desrosiers, Matthieu; Brambati, Simona; Doyon, Julien; Sarica, Alessia; Vasta, Roberta; Cerasa, Antonio; Quattrone, Aldo; Yeatman, Jason; Khan, Ali R; Hodges, Wes; Alexander, Simon; Romascano, David; Barakovic, Muhamed; Auría, Anna; Esteban, Oscar; Lemkaddem, Alia; Thiran, Jean-Philippe; Cetingul, H Ertan; Odry, Benjamin L; Mailhe, Boris; Nadar, Mariappan S; Pizzagalli, Fabrizio; Prasad, Gautam; Villalon-Reina, Julio E; Galvis, Justin; Thompson, Paul M; Requejo, Francisco De Santiago; Laguna, Pedro Luque; Lacerda, Luis Miguel; Barrett, Rachel; Dell'Acqua, Flavio; Catani, Marco; Petit, Laurent; Caruyer, Emmanuel; Daducci, Alessandro; Dyrby, Tim B; Holland-Letz, Tim; Hilgetag, Claus C; Stieltjes, Bram; Descoteaux, Maxime

    2017-11-07

    Tractography based on non-invasive diffusion imaging is central to the study of human brain connectivity. To date, the approach has not been systematically validated in ground truth studies. Based on a simulated human brain data set with ground truth tracts, we organized an open international tractography challenge, which resulted in 96 distinct submissions from 20 research groups. Here, we report the encouraging finding that most state-of-the-art algorithms produce tractograms containing 90% of the ground truth bundles (to at least some extent). However, the same tractograms contain many more invalid than valid bundles, and half of these invalid bundles occur systematically across research groups. Taken together, our results demonstrate and confirm fundamental ambiguities inherent in tract reconstruction based on orientation information alone, which need to be considered when interpreting tractography and connectivity results. Our approach provides a novel framework for estimating reliability of tractography and encourages innovation to address its current limitations.

  4. Diffusion Tensor Tractography Imaging in a Case of Acute Brain Stem Infarct

    Directory of Open Access Journals (Sweden)

    Nilgül Yardımcı

    2009-03-01

    Full Text Available Diffusion tensor tractography enables graphical reconstruction of the white matter pathways in the brain and quantitative study of white matter integrity. With this method virtual dissection of the living human brain can be performed. This technique has many potential clinical applications in neurological disorders, including the investigation of stroke. We present tractography findings of a patient that had an acute ischemic infarct in the brain stem. We aimed to report the disintegration of the white matter tracts at the infarct location in vivo, as well as the associated clinical symptoms. The current use of tractography in neurological disorders shows that it has the potential to improve our understanding of the damage and recovery process in diseases of the brain and spinal cord. From a clinical point of view tractography might be used to test new hypotheses, and to provide important new insights into the organization of the brain and the effects of brain disorders

  5. Impact of Gradient Number and Voxel Size on Diffusion Tensor Imaging Tractography for Resective Brain Surgery

    NARCIS (Netherlands)

    Hoefnagels, Friso W. A.; de Witt Hamer, Philip C.; Pouwels, Petra J. W.; Barkhof, Frederik; Vandertop, W. Peter

    2017-01-01

    To explore quantitatively and qualitatively how the number of gradient directions (NGD) and spatial resolution (SR) affect diffusion tensor imaging (DTI) tractography in patients planned for brain tumor surgery, using routine clinical magnetic resonance imaging protocols. Of 67 patients with

  6. Seeing More by Showing Less: Orientation-Dependent Transparency Rendering for Fiber Tractography Visualization

    OpenAIRE

    Tax, Chantal M. W.; Chamberland, Maxime; van Stralen, Marijn; Viergever, Max A.; Whittingstall, Kevin; Fortin, David; Descoteaux, Maxime; Leemans, Alexander

    2015-01-01

    Fiber tractography plays an important role in exploring the architectural organization of fiber trajectories, both in fundamental neuroscience and in clinical applications. With the advent of diffusion MRI (dMRI) approaches that can also model "crossing fibers", the complexity of the fiber network as reconstructed with tractography has increased tremendously. Many pathways interdigitate and overlap, which hampers an unequivocal 3D visualization of the network and impedes an efficient study of...

  7. Trade-off between angular and spatial resolutions in in vivo fiber tractography

    OpenAIRE

    Vos, Sjoerd B.; Aksoy, Murat; Han, Zhaoying; Holdsworth, Samantha J.; Maclaren, Julian; Viergever, Max A.; Leemans, Alexander; Bammer, Roland

    2016-01-01

    Tractography is becoming an increasingly popular method to reconstruct white matter connections in vivo. The diffusion MRI data that tractography is based on requires a high angular resolution to resolve crossing fibers whereas high spatial resolution is required to distinguish kissing from crossing fibers. However, scan time increases with increasing spatial and angular resolutions, which can become infeasible in clinical settings. Here we investigated the trade-off between spatial and angul...

  8. Determining injuries from posterior and flank stab wounds using computed tomography tractography.

    Science.gov (United States)

    Bansal, Vishal; Reid, Chris M; Fortlage, Dale; Lee, Jeanne; Kobayashi, Leslie; Doucet, Jay; Coimbra, Raul

    2014-04-01

    Unlike anterior stab wounds (SW), in which local exploration may direct management, posterior SW can be challenging to evaluate. Traditional triple contrast computed tomography (CT) imaging is cumbersome and technician-dependent. The present study examines the role of CT tractography as a strategy to manage select patients with back and flank SW. Hemodynamically stable patients with back and flank SW were studied. After resuscitation, Betadine- or Visipaque®-soaked sterile sponges were inserted into each SW for the estimated depth of the wound. Patients underwent abdominal helical CT scanning, including intravenous contrast, as the sole abdominal imaging study. Images were reviewed by an attending radiologist and trauma surgeon. The tractogram was evaluated to determine SW trajectory and injury to intra- or retroperitoneal organs, vascular structures, the diaphragm, and the urinary tract. Complete patient demographics including operative management and injuries were collected. Forty-one patients underwent CT tractography. In 11 patients, tractography detected violation of the intra- or retroperitoneal cavity leading to operative exploration. Injuries detected included: the spleen (two), colon (one), colonic mesentery (one), kidney (kidney), diaphragm (kidney), pneumothorax (seven), hemothorax (two), iliac artery (one), and traumatic abdominal wall hernia (two). In all patients, none had negative CT findings that failed observation. In this series, CT tractography is a safe and effective imaging strategy to evaluate posterior torso SW. It is unknown whether CT tractography is superior to traditional imaging modalities. Other uses for CT tractography may include determining trajectory from missile wounds and tangential penetrating injuries.

  9. Assessment of Rotationally-Invariant Clustering Using Streamlet Tractography

    DEFF Research Database (Denmark)

    Liptrot, Matthew George; Lauze, François

    2016-01-01

    We present a novel visualisation-based strategy for the assessment of a recently proposed clustering technique for raw DWI volumes which derives rotationally-invariant metrics to classify voxels. The validity of the division of all brain tissue voxels into such classes was assessed using the rece......We present a novel visualisation-based strategy for the assessment of a recently proposed clustering technique for raw DWI volumes which derives rotationally-invariant metrics to classify voxels. The validity of the division of all brain tissue voxels into such classes was assessed using...... the recently developed streamlets visualisation technique, which aims to represent brain fibres by collections of many short streamlines. Under the assumption that streamlines seeded in a cluster should stay within it, we were able to assess how well perceptual tracing could occur across the boundaries...... of the clusters....

  10. Quantum mechanical streamlines. I - Square potential barrier

    Science.gov (United States)

    Hirschfelder, J. O.; Christoph, A. C.; Palke, W. E.

    1974-01-01

    Exact numerical calculations are made for scattering of quantum mechanical particles hitting a square two-dimensional potential barrier (an exact analog of the Goos-Haenchen optical experiments). Quantum mechanical streamlines are plotted and found to be smooth and continuous, to have continuous first derivatives even through the classical forbidden region, and to form quantized vortices around each of the nodal points. A comparison is made between the present numerical calculations and the stationary wave approximation, and good agreement is found between both the Goos-Haenchen shifts and the reflection coefficients. The time-independent Schroedinger equation for real wavefunctions is reduced to solving a nonlinear first-order partial differential equation, leading to a generalization of the Prager-Hirschfelder perturbation scheme. Implications of the hydrodynamical formulation of quantum mechanics are discussed, and cases are cited where quantum and classical mechanical motions are identical.

  11. A streamlined failure mode and effects analysis

    Energy Technology Data Exchange (ETDEWEB)

    Ford, Eric C., E-mail: eford@uw.edu; Smith, Koren; Terezakis, Stephanie; Croog, Victoria; Gollamudi, Smitha; Gage, Irene; Keck, Jordie; DeWeese, Theodore; Sibley, Greg [Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University, Baltimore, MD 21287 (United States)

    2014-06-15

    Purpose: Explore the feasibility and impact of a streamlined failure mode and effects analysis (FMEA) using a structured process that is designed to minimize staff effort. Methods: FMEA for the external beam process was conducted at an affiliate radiation oncology center that treats approximately 60 patients per day. A structured FMEA process was developed which included clearly defined roles and goals for each phase. A core group of seven people was identified and a facilitator was chosen to lead the effort. Failure modes were identified and scored according to the FMEA formalism. A risk priority number,RPN, was calculated and used to rank failure modes. Failure modes with RPN > 150 received safety improvement interventions. Staff effort was carefully tracked throughout the project. Results: Fifty-two failure modes were identified, 22 collected during meetings, and 30 from take-home worksheets. The four top-ranked failure modes were: delay in film check, missing pacemaker protocol/consent, critical structures not contoured, and pregnant patient simulated without the team's knowledge of the pregnancy. These four failure modes hadRPN > 150 and received safety interventions. The FMEA was completed in one month in four 1-h meetings. A total of 55 staff hours were required and, additionally, 20 h by the facilitator. Conclusions: Streamlined FMEA provides a means of accomplishing a relatively large-scale analysis with modest effort. One potential value of FMEA is that it potentially provides a means of measuring the impact of quality improvement efforts through a reduction in risk scores. Future study of this possibility is needed.

  12. Streamlining the license renewal review process

    International Nuclear Information System (INIS)

    Dozier, J.; Lee, S.; Kuo, P.T.

    2001-01-01

    The staff of the NRC has been developing three regulatory guidance documents for license renewal: the Generic Aging Lessons Learned (GALL) report, Standard Review Plan for License Renewal (SRP-LR), and Regulatory Guide (RG) for Standard Format and Content for Applications to Renew Nuclear Power Plant Operating Licenses. These documents are designed to streamline the license renewal review process by providing clear guidance for license renewal applicants and the NRC staff in preparing and reviewing license renewal applications. The GALL report systematically catalogs aging effects on structures and components; identifies the relevant existing plant programs; and evaluates the existing programs against the attributes considered necessary for an aging management program to be acceptable for license renewal. The GALL report also provides guidance for the augmentation of existing plant programs for license renewal. The revised SRP-LR allows an applicant to reference the GALL report to preclude further NRC staff evaluation if the plant's existing programs meet the criteria described in the GALL report. During the review process, the NRC staff will focus primarily on existing programs that should be augmented or new programs developed specifically for license renewal. The Regulatory Guide is expected to endorse the Nuclear Energy Institute (NEI) guideline, NEI 95-10, Revision 2, entitled 'Industry Guideline for Implementing the Requirements of 10 CFR Part 54 - The License Renewal Rule', which provides guidance for preparing a license renewal application. This paper will provide an introduction to the GALL report, SRP-LR, Regulatory Guide, and NEI 95-10 to show how these documents are interrelated and how they will be used to streamline the license renewal review process. This topic will be of interest to domestic power utilities considering license renewal and international ICONE participants seeking state-of-the-art information about license renewal in the United States

  13. A streamlined failure mode and effects analysis

    International Nuclear Information System (INIS)

    Ford, Eric C.; Smith, Koren; Terezakis, Stephanie; Croog, Victoria; Gollamudi, Smitha; Gage, Irene; Keck, Jordie; DeWeese, Theodore; Sibley, Greg

    2014-01-01

    Purpose: Explore the feasibility and impact of a streamlined failure mode and effects analysis (FMEA) using a structured process that is designed to minimize staff effort. Methods: FMEA for the external beam process was conducted at an affiliate radiation oncology center that treats approximately 60 patients per day. A structured FMEA process was developed which included clearly defined roles and goals for each phase. A core group of seven people was identified and a facilitator was chosen to lead the effort. Failure modes were identified and scored according to the FMEA formalism. A risk priority number,RPN, was calculated and used to rank failure modes. Failure modes with RPN > 150 received safety improvement interventions. Staff effort was carefully tracked throughout the project. Results: Fifty-two failure modes were identified, 22 collected during meetings, and 30 from take-home worksheets. The four top-ranked failure modes were: delay in film check, missing pacemaker protocol/consent, critical structures not contoured, and pregnant patient simulated without the team's knowledge of the pregnancy. These four failure modes hadRPN > 150 and received safety interventions. The FMEA was completed in one month in four 1-h meetings. A total of 55 staff hours were required and, additionally, 20 h by the facilitator. Conclusions: Streamlined FMEA provides a means of accomplishing a relatively large-scale analysis with modest effort. One potential value of FMEA is that it potentially provides a means of measuring the impact of quality improvement efforts through a reduction in risk scores. Future study of this possibility is needed

  14. A streamlined failure mode and effects analysis.

    Science.gov (United States)

    Ford, Eric C; Smith, Koren; Terezakis, Stephanie; Croog, Victoria; Gollamudi, Smitha; Gage, Irene; Keck, Jordie; DeWeese, Theodore; Sibley, Greg

    2014-06-01

    Explore the feasibility and impact of a streamlined failure mode and effects analysis (FMEA) using a structured process that is designed to minimize staff effort. FMEA for the external beam process was conducted at an affiliate radiation oncology center that treats approximately 60 patients per day. A structured FMEA process was developed which included clearly defined roles and goals for each phase. A core group of seven people was identified and a facilitator was chosen to lead the effort. Failure modes were identified and scored according to the FMEA formalism. A risk priority number,RPN, was calculated and used to rank failure modes. Failure modes with RPN > 150 received safety improvement interventions. Staff effort was carefully tracked throughout the project. Fifty-two failure modes were identified, 22 collected during meetings, and 30 from take-home worksheets. The four top-ranked failure modes were: delay in film check, missing pacemaker protocol/consent, critical structures not contoured, and pregnant patient simulated without the team's knowledge of the pregnancy. These four failure modes had RPN > 150 and received safety interventions. The FMEA was completed in one month in four 1-h meetings. A total of 55 staff hours were required and, additionally, 20 h by the facilitator. Streamlined FMEA provides a means of accomplishing a relatively large-scale analysis with modest effort. One potential value of FMEA is that it potentially provides a means of measuring the impact of quality improvement efforts through a reduction in risk scores. Future study of this possibility is needed.

  15. Age related diffusion and tractography changes in typically developing pediatric cervical and thoracic spinal cord

    Directory of Open Access Journals (Sweden)

    Mahdi Alizadeh

    Full Text Available Background and objective: Diffusion tensor imaging (DTI and diffusion tensor tractography (DTT are two techniques that can measure white matter integrity of the spinal cord. Recently, DTI indices have been shown to change with age. The purpose of this study is (a to evaluate the maturational states of the entire pediatric spinal cord using DTI and DTT indices including fractional anisotropy (FA, mean diffusivity (MD, mean length of white matter fiber tracts and tract density and (b to analyze the DTI and DTT parameters along the entire spinal cord as a function of spinal cord levels and age. Method: A total of 23 typically developing (TD pediatric subjects ranging in age from 6 to 16 years old (11.94 ± 3.26 (mean ± standard deviation, 13 females and 10 males were recruited, and scanned using 3.0 T MR scanner. Reduced FOV diffusion tensor images were acquired axially in the same anatomical location prescribed for the T2-weighted images to cover the entire spinal cord (C1-mid L1 levels. To mitigate motion induced artifacts, diffusion directional images were aligned with the reference image (b0 using a rigid body registration algorithm performed by in-house software developed in Matlab (MathWorks, Natick, Massachusetts. Diffusion tensor maps (FA and MD and streamline deterministic tractography were then generated from the motion corrected DTI dataset. DTI and DTT parameters were calculated by using ROIs drawn to encapsulate the whole cord along the entire spinal cord by an independent board certified neuroradiologist. These indices then were compared between two age groups (age group A = 6–11 years (n = 11 and age group B = 12–16 years (n = 12 based on similar standards and age definitions used for reporting spinal cord injury in the pediatric population. Standard least squared linear regression based on a restricted maximum likelihood (REML method was used to evaluate the relationship between age and DTI and

  16. When tractography meets tracer injections: a systematic study of trends and variation sources of diffusion-based connectivity.

    Science.gov (United States)

    Aydogan, Dogu Baran; Jacobs, Russell; Dulawa, Stephanie; Thompson, Summer L; Francois, Maite Christi; Toga, Arthur W; Dong, Hongwei; Knowles, James A; Shi, Yonggang

    2018-04-16

    Tractography is a powerful technique capable of non-invasively reconstructing the structural connections in the brain using diffusion MRI images, but the validation of tractograms is challenging due to lack of ground truth. Owing to recent developments in mapping the mouse brain connectome, high-resolution tracer injection-based axonal projection maps have been created and quickly adopted for the validation of tractography. Previous studies using tracer injections mainly focused on investigating the match in projections and optimal tractography protocols. Being a complicated technique, however, tractography relies on multiple stages of operations and parameters. These factors introduce large variabilities in tractograms, hindering the optimization of protocols and making the interpretation of results difficult. Based on this observation, in contrast to previous studies, in this work we focused on quantifying and ranking the amount of performance variation introduced by these factors. For this purpose, we performed over a million tractography experiments and studied the variability across different subjects, injections, anatomical constraints and tractography parameters. By using N-way ANOVA analysis, we show that all tractography parameters are significant and importantly performance variations with respect to the differences in subjects are comparable to the variations due to tractography parameters, which strongly underlines the importance of fully documenting the tractography protocols in scientific experiments. We also quantitatively show that inclusion of anatomical constraints is the most significant factor for improving tractography performance. Although this critical factor helps reduce false positives, our analysis indicates that anatomy-informed tractography still fails to capture a large portion of axonal projections.

  17. White matter pathways in persistent developmental stuttering: Lessons from tractography.

    Science.gov (United States)

    Kronfeld-Duenias, Vered; Civier, Oren; Amir, Ofer; Ezrati-Vinacour, Ruth; Ben-Shachar, Michal

    2018-03-01

    Fluent speech production relies on the coordinated processing of multiple brain regions. This highlights the role of neural pathways that connect distinct brain regions in producing fluent speech. Here, we aim to investigate the role of the white matter pathways in persistent developmental stuttering (PDS), where speech fluency is disrupted. We use diffusion weighted imaging and tractography to compare the white matter properties between adults who do and do not stutter. We compare the diffusion properties along 18 major cerebral white matter pathways. We complement the analysis with an overview of the methodology and a roadmap of the pathways implicated in PDS according to the existing literature. We report differences in the microstructural properties of the anterior callosum, the right inferior longitudinal fasciculus and the right cingulum in people who stutter compared with fluent controls. Persistent developmental stuttering is consistently associated with differences in bilateral distributed networks. We review evidence showing that PDS involves differences in bilateral dorsal fronto-temporal and fronto-parietal pathways, in callosal pathways, in several motor pathways and in basal ganglia connections. This entails an important role for long range white matter pathways in this disorder. Using a wide-lens analysis, we demonstrate differences in additional, right hemispheric pathways, which go beyond the replicable findings in the literature. This suggests that the affected circuits may extend beyond the known language and motor pathways. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Diffusion tensor tractography reveals muscle reconnection during axolotl limb regeneration.

    Directory of Open Access Journals (Sweden)

    Cheng-Han Wu

    Full Text Available Axolotls have amazing ability to regenerate their lost limbs. Our previous works showed that after amputation the remnant muscle ends remained at their original location whilst sending satellite cells into the regenerating parts to develop into early muscle fibers in the late differentiation stage. The parental and the newly formed muscle fibers were not connected until very late stage. The present study used non-invasive diffusion tensor imaging (DTI to monitor weekly axolotl upper arm muscles after amputation of their upper arms. DTI tractography showed that the regenerating muscle fibers became visible at 9-wpa (weeks post amputation, but a gap was observed between the regenerating and parental muscles. The gap was filled at 10-wpa, indicating reconnection of the fibers of both muscles. This was confirmed by histology. The DTI results indicate that 23% of the muscle fibers were reconnected at 10-wpa. In conclusion, DTI can be used to visualize axolotls' skeletal muscles and the results of muscle reconnection were in accordance with our previous findings. This non-invasive technique will allow researchers to identify the timeframe in which muscle fiber reconnection takes place and thus enable the study of the mechanisms underlying this reconnection.

  19. Probabilistic diffusion tractography reveals improvement of structural network in musicians.

    Directory of Open Access Journals (Sweden)

    Jianfu Li

    Full Text Available PURPOSE: Musicians experience a large amount of information transfer and integration of complex sensory, motor, and auditory processes when training and playing musical instruments. Therefore, musicians are a useful model in which to investigate neural adaptations in the brain. METHODS: Here, based on diffusion-weighted imaging, probabilistic tractography was used to determine the architecture of white matter anatomical networks in musicians and non-musicians. Furthermore, the features of the white matter networks were analyzed using graph theory. RESULTS: Small-world properties of the white matter network were observed in both groups. Compared with non-musicians, the musicians exhibited significantly increased connectivity strength in the left and right supplementary motor areas, the left calcarine fissure and surrounding cortex and the right caudate nucleus, as well as a significantly larger weighted clustering coefficient in the right olfactory cortex, the left medial superior frontal gyrus, the right gyrus rectus, the left lingual gyrus, the left supramarginal gyrus, and the right pallidum. Furthermore, there were differences in the node betweenness centrality in several regions. However, no significant differences in topological properties were observed at a global level. CONCLUSIONS: We illustrated preliminary findings to extend the network level understanding of white matter plasticity in musicians who have had long-term musical training. These structural, network-based findings may indicate that musicians have enhanced information transmission efficiencies in local white matter networks that are related to musical training.

  20. Case studies in geographic information systems for environmental streamlining

    Science.gov (United States)

    2012-05-31

    This 2012 summary report addresses the current use of geographic information systems (GIS) and related technologies by State Departments of Transportation (DOTs) for environmental streamlining and stewardship, particularly in relation to the National...

  1. Automated Whole Brain Tractography Affects Preoperative Surgical Decision Making.

    Science.gov (United States)

    Zakaria, Hesham; Haider, Sameah; Lee, Ian

    2017-09-06

    Surgery in and around eloquent brain structures poses a technical challenge when the goal of surgery is maximal safe resection. Magnetic resonance imaging (MRI) has revolutionized the diagnosis and treatment of neurological disorders, but tractography still remains limited in terms of utility because of the requisite manual labor and time required combined with the high risk of bias and inaccuracy. Automated whole brain tractography (AWBT) has simplified this workflow, overcoming historical barriers, and allowing for integration into modern neuronavigation. However, current literature showing the usefulness of this new technology is limited. In this study, we aimed to illustrate the utility of AWBT during cranial surgery and its ability to affect presurgical and intraoperative clinical decision making. We performed a retrospective chart review of cases that underwent AWBT for one year from July 2016 to July 2017. All patients underwent conventional anatomic MRI with and without contrast sequences, in addition to diffusion tensor imaging (DTI) on a 3 Tesla MRI scanner (Ingenia 3.0T, Philips, Amsterdam NL). Post-hoc AWBT processing was performed on a separate workstation. Patients were subsequently grouped into those that had undergone either language or motor mapping and those that did not. We compared both sets of patients to see any differences in patient age, sex, laterality of surgery, depth of resection from cortical surface, and smallest distance between the lesion and adjacent eloquent white matter tracts. We identified illustrative cases which demonstrated the ability of AWBT to affect surgical decision making. In this single-center series, we identified 73 total patients who underwent AWBT for intracranial surgery, of which 28 patients underwent either speech or language mapping. When comparing mapping to non-mapping patients, we found no difference with respect to age, gender, laterality of surgery, or whether the surgery was a revision. The distance

  2. Three-dimensional corticospinal tractography for brain tumor surgery

    International Nuclear Information System (INIS)

    Kamada, Kyousuke

    2009-01-01

    Maximal resection of the intracranial lesion like a brain tumor and concomitant identification of the unresectable region for avoiding the loss of motor and language functions are important before and during the operation. For these purposes, corticospinal tract (CST)-tractography (TG) based on diffusion tensor imaging (DTI) is widely used for nerve fiber tracking but it is conceivably essential to examine if the CST image in problem reflects the actually valid anatomical, functional CST. For the problem, in author's department, the intraoperative local relationship between the lesion and CST is monitored by a neuronavigation (NNA) system combined with CST-TG in case of patients who have the lesion close to CST and, when the resection site approaches CST, its surrounding white matter is electrically stimulated to evoke the myoelectric potential at upper and lower limbs. Here are reported examinations of the reliability of CST-TG by analysis of the positional relation of CST with the electric stimulating point and current value, and of the expansion of the subcortical stimulation current in the white matter. MRI data of such 40 patients as above by 1.5 or 3T machine were obtained with spin-echo/echo planer imaging and subsequent DTI data were processed by authors' VOLUME-ONE/dTV (http://volume-one.org). CST-TG-fused functional NNA was conducted by NNA system where 3D reconstructed image of CST-TG DTI and 3DMRI using digital imaging and communication medicine (DICOM) and the evoked functional myoelectric potential had been combined. This fusion was found useful for rapid decision of the position and timing of the electric stimulation at surgery, and highly reliable as CST-TG. Further, the stimulating threshold in the white matter was found lower than in the cortex. Future progress in imaging technology and separating algorithm of crossing fibers was expected for improved image of more complex central nervous system (CNS) structures. (K.T.)

  3. Probabilistic Tractography of the Cranial Nerves in Vestibular Schwannoma.

    Science.gov (United States)

    Zolal, Amir; Juratli, Tareq A; Podlesek, Dino; Rieger, Bernhard; Kitzler, Hagen H; Linn, Jennifer; Schackert, Gabriele; Sobottka, Stephan B

    2017-11-01

    Multiple recent studies have reported on diffusion tensor-based fiber tracking of cranial nerves in vestibular schwannoma, with conflicting results as to the accuracy of the method and the occurrence of cochlear nerve depiction. Probabilistic nontensor-based tractography might offer advantages in terms of better extraction of directional information from the underlying data in cranial nerves, which are of subvoxel size. Twenty-one patients with large vestibular schwannomas were recruited. The probabilistic tracking was run preoperatively and the position of the potential depictions of the facial and cochlear nerves was estimated postoperatively by 3 independent observers in a blinded fashion. The true position of the nerve was determined intraoperatively by the surgeon. Thereafter, the imaging-based estimated position was compared with the intraoperatively determined position. Tumor size, cystic appearance, and postoperative House-Brackmann score were analyzed with regard to the accuracy of the depiction of the nerves. The probabilistic tracking showed a connection that correlated to the position of the facial nerve in 81% of the cases and to the position of the cochlear nerve in 33% of the cases. Altogether, the resulting depiction did not correspond to the intraoperative position of any of the nerves in 3 cases. In a majority of cases, the position of the facial nerve, but not of the cochlear nerve, could be estimated by evaluation of the probabilistic tracking results. However, false depictions not corresponding to any nerve do occur and cannot be discerned as such from the image only. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. The Emerging Role of Tractography in Deep Brain Stimulation: Basic Principles and Current Applications

    Directory of Open Access Journals (Sweden)

    Nelson B. Rodrigues

    2018-01-01

    Full Text Available Diffusion tensor imaging (DTI is an MRI-based technique that delineates white matter tracts in the brain by tracking the diffusion of water in neural tissue. This methodology, known as “tractography”, has been extensively applied in clinical neuroscience to explore nervous system architecture and diseases. More recently, tractography has been used to assist with neurosurgical targeting in functional neurosurgery. This review provides an overview of DTI principles, and discusses current applications of tractography for improving and helping develop novel deep brain stimulation (DBS targets.

  5. Diffusion tensor MRI and fiber tractography of the sacral plexus in children with spina bifida

    DEFF Research Database (Denmark)

    Haakma, Wieke; Dik, Pieter; ten Haken, Bennie

    2014-01-01

    anatomical and microstructural properties of the sacral plexus of patients with spina bifida using diffusion tensor imaging and fiber tractography. MATERIALS AND METHODS: Ten patients 8 to 16 years old with spina bifida underwent diffusion tensor imaging on a 3 Tesla magnetic resonance imaging system...... diffusivity values at S1-S3 were significantly lower in patients. CONCLUSIONS: To our knowledge this 3 Tesla magnetic resonance imaging study showed for the first time sacral plexus asymmetry and disorganization in 10 patients with spina bifida using diffusion tensor imaging and fiber tractography...

  6. Streamline segment statistics of premixed flames with nonunity Lewis numbers

    Science.gov (United States)

    Chakraborty, Nilanjan; Wang, Lipo; Klein, Markus

    2014-03-01

    The interaction of flame and surrounding fluid motion is of central importance in the fundamental understanding of turbulent combustion. It is demonstrated here that this interaction can be represented using streamline segment analysis, which was previously applied in nonreactive turbulence. The present work focuses on the effects of the global Lewis number (Le) on streamline segment statistics in premixed flames in the thin-reaction-zones regime. A direct numerical simulation database of freely propagating thin-reaction-zones regime flames with Le ranging from 0.34 to 1.2 is used to demonstrate that Le has significant influences on the characteristic features of the streamline segment, such as the curve length, the difference in the velocity magnitude at two extremal points, and their correlations with the local flame curvature. The strengthenings of the dilatation rate, flame normal acceleration, and flame-generated turbulence with decreasing Le are principally responsible for these observed effects. An expression for the probability density function (pdf) of the streamline segment length, originally developed for nonreacting turbulent flows, captures the qualitative behavior for turbulent premixed flames in the thin-reaction-zones regime for a wide range of Le values. The joint pdfs between the streamline length and the difference in the velocity magnitude at two extremal points for both unweighted and density-weighted velocity vectors are analyzed and compared. Detailed explanations are provided for the observed differences in the topological behaviors of the streamline segment in response to the global Le.

  7. Streamlined Modeling for Characterizing Spacecraft Anomalous Behavior

    Science.gov (United States)

    Klem, B.; Swann, D.

    2011-09-01

    Anomalous behavior of on-orbit spacecraft can often be detected using passive, remote sensors which measure electro-optical signatures that vary in time and spectral content. Analysts responsible for assessing spacecraft operational status and detecting detrimental anomalies using non-resolved imaging sensors are often presented with various sensing and identification issues. Modeling and measuring spacecraft self emission and reflected radiant intensity when the radiation patterns exhibit a time varying reflective glint superimposed on an underlying diffuse signal contribute to assessment of spacecraft behavior in two ways: (1) providing information on body component orientation and attitude; and, (2) detecting changes in surface material properties due to the space environment. Simple convex and cube-shaped spacecraft, designed to operate without protruding solar panel appendages, may require an enhanced level of preflight characterization to support interpretation of the various physical effects observed during on-orbit monitoring. This paper describes selected portions of the signature database generated using streamlined signature modeling and simulations of basic geometry shapes apparent to non-imaging sensors. With this database, summarization of key observable features for such shapes as spheres, cylinders, flat plates, cones, and cubes in specific spectral bands that include the visible, mid wave, and long wave infrared provide the analyst with input to the decision process algorithms contained in the overall sensing and identification architectures. The models typically utilize baseline materials such as Kapton, paints, aluminum surface end plates, and radiators, along with solar cell representations covering the cylindrical and side portions of the spacecraft. Multiple space and ground-based sensors are assumed to be located at key locations to describe the comprehensive multi-viewing aspect scenarios that can result in significant specular reflection

  8. Feasibility of diffusion tensor imaging (DTI) with fibre tractography of the normal female pelvic floor

    International Nuclear Information System (INIS)

    Zijta, F.M.; Froeling, M.; Paardt, M.P. van der; Bipat, S.; Nederveen, A.J.; Stoker, J.; Lakeman, M.M.E.; Montauban van Swijndregt, A.D.; Strijkers, G.J.

    2011-01-01

    To prospectively determine the feasibility of diffusion tensor imaging (DTI) with fibre tractography as a tool for the three-dimensional (3D) visualisation of normal pelvic floor anatomy. Five young female nulliparous subjects (mean age 28 ± 3 years) underwent DTI at 3.0T. Two-dimensional diffusion-weighted axial spin-echo echo-planar (SP-EPI) pulse sequence of the pelvic floor was performed, with additional T2-TSE multiplanar sequences for anatomical reference. Fibre tractography for visualisation of predefined pelvic floor and pelvic wall muscles was performed offline by two observers, applying a consensus method. Three eigenvalues (λ1, λ2, λ3), fractional anisotropy (FA) and mean diffusivity (MD) were calculated from the fibre trajectories. In all subjects fibre tractography resulted in a satisfactory anatomical representation of the pubovisceral muscle, perineal body, anal - and urethral sphincter complex and internal obturator muscle. Mean FA values ranged from 0.23 ± 0.02 to 0.30 ± 0.04, MD values from 1.30 ± 0.08 to 1.73 ± 0.12 x 10- 3 mm 2 /s. Muscular structures in the superficial layer of the pelvic floor could not be satisfactorily identified. This study demonstrates the feasibility of visualising the complex three-dimensional pelvic floor architecture using 3T-DTI with fibre tractography. DTI of the deep female pelvic floor may provide new insights into pelvic floor disorders. (orig.)

  9. The challenge of mapping the human connectome based on diffusion tractography

    NARCIS (Netherlands)

    Maier-Hein, Klaus H; Neher, Peter F; Houde, Jean-Christophe; Côté, Marc-Alexandre; Garyfallidis, Eleftherios; Zhong, Jidan; Chamberland, Maxime; Yeh, Fang-Cheng; Lin, Ying-Chia; Ji, Qing; Reddick, Wilburn E; Glass, John O; Chen, David Qixiang; Feng, Yuanjing; Gao, Chengfeng; Wu, Ye; Ma, Jieyan; Renjie, H; Li, Qiang; Westin, Carl Fredrik; Deslauriers-Gauthier, Samuel; González, J Omar Ocegueda; Paquette, Michael; St-Jean, Samuel; Girard, Gabriel; Rheault, François; Sidhu, Jasmeen; Tax, Chantal M.W.; Guo, Fenghua; Mesri, Hamed Y.; Dávid, Szabolcs; Froeling, Martijn; Heemskerk, Anneriet M.; Leemans, Alexander; Boré, Arnaud; Pinsard, Basile; Bedetti, Christophe; Desrosiers, Matthieu; Brambati, Simona; Doyon, Julien; Sarica, Alessia; Vasta, Roberta; Cerasa, Antonio; Quattrone, Aldo; Yeatman, Jason; Khan, Ali R.; Hodges, Wes; Alexander, Simon; Romascano, David; Barakovic, Muhamed; Auría, Anna; Esteban, Oscar; Lemkaddem, Alia; Thiran, Jean-Philippe; Cetingul, H Ertan; Odry, Benjamin L; Mailhe, Boris; Nadar, Mariappan S; Pizzagalli, Fabrizio; Prasad, Gautam; Villalon-Reina, Julio E; Galvis, Justin; Thompson, Paul M.; Requejo, Francisco De Santiago; Laguna, Pedro Luque; Lacerda, Luis Miguel; Barrett, Rachel; Dell'Acqua, Flavio; Catani, Marco; Petit, Laurent; Caruyer, Emmanuel; Daducci, Alessandro; Dyrby, Tim B; Holland-Letz, Tim; Hilgetag, Claus C.; Stieltjes, Bram; Descoteaux, Maxime

    2017-01-01

    Tractography based on non-invasive diffusion imaging is central to the study of human brain connectivity. To date, the approach has not been systematically validated in ground truth studies. Based on a simulated human brain data set with ground truth tracts, we organized an open international

  10. The challenge of mapping the human connectome based on diffusion tractography

    DEFF Research Database (Denmark)

    Maier-Hein, Klaus H.; Neher, Peter F.; Houde, Jean-Christophe

    2017-01-01

    Tractography based on non-invasive diffusion imaging is central to the study of human brain connectivity. To date, the approach has not been systematically validated in ground truth studies. Based on a simulated human brain data set with ground truth tracts, we organized an open international tra...

  11. Seeing More by Showing Less : Orientation-Dependent Transparency Rendering for Fiber Tractography Visualization

    NARCIS (Netherlands)

    Tax, Chantal M. W.; Chamberland, Maxime; van Stralen, Marijn; Viergever, Max A.; Whittingstall, Kevin; Fortin, David; Descoteaux, Maxime; Leemans, Alexander

    2015-01-01

    Fiber tractography plays an important role in exploring the architectural organization of fiber trajectories, both in fundamental neuroscience and in clinical applications. With the advent of diffusion MRI (dMRI) approaches that can also model "crossing fibers", the complexity of the fiber network

  12. Probabilistic shortest path tractography in DTI using Gaussian Process ODE solvers

    DEFF Research Database (Denmark)

    Schober, Michael; Kasenburg, Niklas; Feragen, Aasa

    2014-01-01

    Tractography in diffusion tensor imaging estimates connectivity in the brain through observations of local diffusivity. These observations are noisy and of low resolution and, as a consequence, connections cannot be found with high precision. We use probabilistic numerics to estimate connectivity...

  13. Flexible ex vivo phantoms for validation of diffusion tensor tractography on a clinical scanner.

    Science.gov (United States)

    Watanabe, Makoto; Aoki, Shigeki; Masutani, Yoshitaka; Abe, Osamu; Hayashi, Naoto; Masumoto, Tomohiko; Mori, Harushi; Kabasawa, Hiroyuki; Ohtomo, Kuni

    2006-11-01

    The aim of this study was to develop ex vivo diffusion tensor (DT) flexible phantoms. Materials were bundles of textile threads of cotton, monofilament nylon, rayon, and polyester bunched with spiral wrapping bands and immersed in water. DT images were acquired on a 1.5-Tesla clinical magnetic resonance scanner using echo planar imaging sequences with 15 motion probing gradient directions. DT tractography with seeding and a line-tracking method was carried out by software originally developed on a PC-based workstation. We observed relatively high fractional anisotropy on the polyester phantom and were able to reconstruct tractography. Straight tracts along the bundle were displayed when it was arranged linearly. It was easy to bend arcuately or bifurcate at one end; and tracts followed the course of the bundle, whether it was curved or branched and had good agreement with direct visual observation. Tractography with the other fibers was unsuccessful. The polyester phantom revealed a diffusion anisotropic structure according to its shape and would be utilizable repeatedly under the same conditions, differently from living central neuronal system. It would be useful to validate DT sequences and to optimize an algorithm or parameters of DT tractography software. Additionally, the flexibility of the phantom would enable us to model human axonal projections.

  14. Flexible ex vivo phantoms for validation of diffusion tensor tractography on a clinical scanner

    International Nuclear Information System (INIS)

    Watanabe, Makoto; Aoki, Shigeki; Masutani, Yoshitaka; Abe, Osamu; Hayashi, Naoto; Masumoto, Tomohiko; Mori, Harushi; Kabasawa, Hiroyuki; Ohtomo, Kuni

    2006-01-01

    The aim of this study was to develop ex vivo diffusion tensor (DT) flexible phantoms. Materials were bundles of textile threads of cotton, monofilament nylon, rayon, and polyester bunched with spiral wrapping bands and immersed in water. DT images were acquired on a 1.5-Tesla clinical magnetic resonance scanner using echo planar imaging sequences with 15 motion probing gradient directions. DT tractography with seeding and a line-tracking method was carried out by software originally developed on a PC-based workstation. We observed relatively high fractional anisotropy on the polyester phantom and were able to reconstruct tractography. Straight tracts along the bundle were displayed when it was arranged linearly. It was easy to bend arcuately or bifurcate at one end; and tracts followed the course of the bundle, whether it was curved or branched and had good agreement with direct visual observation. Tractography with the other fibers was unsuccessful. The polyester phantom revealed a diffusion anisotropic structure according to its shape and would be utilizable repeatedly under the same conditions, differently from living central neuronal system. It would be useful to validate DT sequences and to optimize an algorithm or parameters of DT tractography software. Additionally, the flexibility of the phantom would enable us to model human axonal projections. (author)

  15. Feasibility of diffusion tensor imaging (DTI) with fibre tractography of the normal female pelvic floor

    Energy Technology Data Exchange (ETDEWEB)

    Zijta, F.M. [University of Amsterdam, Department of Radiology, Academic Medical Center, Amsterdam (Netherlands); Onze Lieve Vrouwe Gasthuis, Department of Radiology, Amsterdam (Netherlands); Froeling, M. [University of Amsterdam, Department of Radiology, Academic Medical Center, Amsterdam (Netherlands); Eindhoven University of Technology, Biomedical NMR, Department of Biomedical Engineering, Eindhoven (Netherlands); Paardt, M.P. van der; Bipat, S.; Nederveen, A.J.; Stoker, J. [University of Amsterdam, Department of Radiology, Academic Medical Center, Amsterdam (Netherlands); Lakeman, M.M.E. [University of Amsterdam, Department of Gynaecology, Academic Medical Center, Amsterdam (Netherlands); Montauban van Swijndregt, A.D. [Onze Lieve Vrouwe Gasthuis, Department of Radiology, Amsterdam (Netherlands); Strijkers, G.J. [Eindhoven University of Technology, Biomedical NMR, Department of Biomedical Engineering, Eindhoven (Netherlands)

    2011-06-15

    To prospectively determine the feasibility of diffusion tensor imaging (DTI) with fibre tractography as a tool for the three-dimensional (3D) visualisation of normal pelvic floor anatomy. Five young female nulliparous subjects (mean age 28 {+-} 3 years) underwent DTI at 3.0T. Two-dimensional diffusion-weighted axial spin-echo echo-planar (SP-EPI) pulse sequence of the pelvic floor was performed, with additional T2-TSE multiplanar sequences for anatomical reference. Fibre tractography for visualisation of predefined pelvic floor and pelvic wall muscles was performed offline by two observers, applying a consensus method. Three eigenvalues ({lambda}1, {lambda}2, {lambda}3), fractional anisotropy (FA) and mean diffusivity (MD) were calculated from the fibre trajectories. In all subjects fibre tractography resulted in a satisfactory anatomical representation of the pubovisceral muscle, perineal body, anal - and urethral sphincter complex and internal obturator muscle. Mean FA values ranged from 0.23 {+-} 0.02 to 0.30 {+-} 0.04, MD values from 1.30 {+-} 0.08 to 1.73 {+-} 0.12 x 10-{sup 3} mm{sup 2}/s. Muscular structures in the superficial layer of the pelvic floor could not be satisfactorily identified. This study demonstrates the feasibility of visualising the complex three-dimensional pelvic floor architecture using 3T-DTI with fibre tractography. DTI of the deep female pelvic floor may provide new insights into pelvic floor disorders. (orig.)

  16. Probabilistic Tractography Recovers a Rostrocaudal Trajectory of Connectivity Variability in the Human Insular Cortex

    Science.gov (United States)

    Cerliani, Leonardo; Thomas, Rajat M; Jbabdi, Saad; Siero, Jeroen CW; Nanetti, Luca; Crippa, Alessandro; Gazzola, Valeria; D'Arceuil, Helen; Keysers, Christian

    2012-01-01

    The insular cortex of macaques has a wide spectrum of anatomical connections whose distribution is related to its heterogeneous cytoarchitecture. Although there is evidence of a similar cytoarchitectural arrangement in humans, the anatomical connectivity of the insula in the human brain has not yet been investigated in vivo. In the present work, we used in vivo probabilistic white-matter tractography and Laplacian eigenmaps (LE) to study the variation of connectivity patterns across insular territories in humans. In each subject and hemisphere, we recovered a rostrocaudal trajectory of connectivity variation ranging from the anterior dorsal and ventral insula to the dorsal caudal part of the long insular gyri. LE suggested that regional transitions among tractography patterns in the insula occur more gradually than in other brain regions. In particular, the change in tractography patterns was more gradual in the insula than in the medial premotor region, where a sharp transition between different tractography patterns was found. The recovered trajectory of connectivity variation in the insula suggests a relation between connectivity and cytoarchitecture in humans resembling that previously found in macaques: tractography seeds from the anterior insula were mainly found in limbic and paralimbic regions and in anterior parts of the inferior frontal gyrus, while seeds from caudal insular territories mostly reached parietal and posterior temporal cortices. Regions in the putative dysgranular insula displayed more heterogeneous connectivity patterns, with regional differences related to the proximity with either putative granular or agranular regions. Hum Brain Mapp 33:2005–2034, 2012. © 2011 Wiley Periodicals, Inc. PMID:21761507

  17. Corticospinal MRI tractography in space-occupying brain lesions by diffusion tensor and kurtosis imaging methods

    Energy Technology Data Exchange (ETDEWEB)

    Leote, Joao [epartment of Neurosurgery, Hospital Garcia de Orta, Almada (Portugal); Institute of Biophysics and Biomedical Engineering, Faculty of Sciences of the University of Lisbon, Lisboa (Portugal); Nunes, Rita; Cerqueira, Luis; Ferreira, Hugo Alexandre [Institute of Biophysics and Biomedical Engineering, Faculty of Sciences of the University of Lisbon, Lisboa (Portugal)

    2015-05-18

    Recently, DKI-based tractography has been developed, showing improved crossing-fiber resolution in comparison to deterministic DTI-based tractography in healthy subjects. In this work, DTI and DKI-based tractography methods were compared regarding the assessment of the corticospinal tract in patients presenting space-occupying brain lesions near cortical motor areas. Nine patients (4 males) aged 23 to 62 years old, with space-occupying brain lesions (e.g. tumors) were studied for pre-surgical planning using a 1.5T MRI scanner and a 12-channel head coil. In 5 patients diffusion data was acquired along 64 directions and in 4 patients along 32 directions both with b-values 0, 1000 and 2000 s/mm2. Corticospinal tracts were estimated using deterministic DTI and DKI methods and also using probabilistic DTI. The superior cerebellar peduncles and the motor cortical areas, ipsilateral and contralateral to the lesions, were used as seed regions-of-interest for fiber tracking. Tracts courses and volumes were documented and compared between methods. Results showed that it was possible to estimate fiber tracts using deterministic DTI and DKI methods in 8/9 patients, and using the probabilistic DTI method in all patients. Overall, it was observed that DKI-based tractography showed more voluminous fiber tracts than when using deterministic DTI. The DKI method also showed curvilinear fibers mainly above lesions margins, which were not visible with deterministic DTI in 5 patients. Similar tracts were observed when using probabilistic DTI in 3 of those patients. Results suggest that the DKI method contribute with additional information about the corticospinal tract course in comparison with the DTI method, especially with subcortical lesions and near lesions’ margins. Therefore, this study suggests that DKI-based tractography could be useful in MRI and hybrid PET-MRI pre-surgical planning protocols for improved corticospinal tract evaluation.

  18. Development of a web-based graphical user interface to design brain fiber models for tractography validation

    OpenAIRE

    González Vela, Guillem

    2017-01-01

    Diffusion Magnetic Resonance Imaging (MRI) is an advanced MRI technique which can provide brain white matter tissue microscopic information. From this information, the connectivity map of axons in the brain can be obtained using tractography algorithms. However, this cartography of the brain wiring is known to suffer from several biases. Phantomas is an open source library created with the aim of evaluating tractography. It allows the creation of in silico brain phantoms and simulates i...

  19. 48 CFR 12.602 - Streamlined evaluation of offers.

    Science.gov (United States)

    2010-10-01

    ... offers. 12.602 Section 12.602 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION... for Commercial Items 12.602 Streamlined evaluation of offers. (a) When evaluation factors are used... evaluation factors. (b) Offers shall be evaluated in accordance with the criteria contained in the...

  20. Application-Tailored I/O with Streamline

    NARCIS (Netherlands)

    de Bruijn, W.J.; Bos, H.J.; Bal, H.E.

    2011-01-01

    Streamline is a stream-based OS communication subsystem that spans from peripheral hardware to userspace processes. It improves performance of I/O-bound applications (such as webservers and streaming media applications) by constructing tailor-made I/O paths through the operating system for each

  1. Contrasting Connectivity of the Vim and Vop Nuclei of the Motor Thalamus Demonstrated by Probabilistic Tractography

    DEFF Research Database (Denmark)

    Hyam, Jonathan A; Owen, Sarah L F; Kringelbach, Morten L.

    2011-01-01

    BACKGROUND:: Targeting of the motor thalamus for the treatment of tremor has traditionally been achieved by a combination of anatomical atlases and neuro-imaging, intra-operative clinical assessment, and physiological recordings. OBJECTIVE:: To evaluate whether thalamic nuclei targeted in tremor...... surgery could be identified by virtue of their differing connections using non-invasive neuro-imaging, thereby providing an extra factor to aid successful targeting. METHODS:: Diffusion tensor tractography was performed in seventeen healthy control subjects using diffusion data acquired at 1.5T magnetic...... resonance imaging (60 directions, b-value=1000 s/mm, 2x2x2 mm voxels). The ventralis intermedius (Vim) and ventralis oralis posterior (Vop) nuclei were identified by a stereotactic neurosurgeon and these sites were used as seeds for probabilistic tractography. The expected cortical connections...

  2. Mapping remodeling of thalamocortical projections in the living reeler mouse brain by diffusion tractography

    Science.gov (United States)

    Harsan, Laura-Adela; Dávid, Csaba; Reisert, Marco; Schnell, Susanne; Hennig, Jürgen; von Elverfeldt, Dominik; Staiger, Jochen F.

    2013-01-01

    A major challenge in neuroscience is to accurately decipher in vivo the entire brain circuitry (connectome) at a microscopic level. Currently, the only methodology providing a global noninvasive window into structural brain connectivity is diffusion tractography. The extent to which the reconstructed pathways reflect realistic neuronal networks depends, however, on data acquisition and postprocessing factors. Through a unique combination of approaches, we designed and evaluated herein a framework for reliable fiber tracking and mapping of the living mouse brain connectome. One important wiring scheme, connecting gray matter regions and passing fiber-crossing areas, was closely examined: the lemniscal thalamocortical (TC) pathway. We quantitatively validated the TC projections inferred from in vivo tractography with correlative histological axonal tracing in the same wild-type and reeler mutant mice. We demonstrated noninvasively that changes in patterning of the cortical sheet, such as highly disorganized cortical lamination in reeler, led to spectacular compensatory remodeling of the TC pathway. PMID:23610438

  3. Cognitive Function and 3-Tesla Magnetic Resonance Imaging Tractography of White Matter Hyperintensities in Elderly Persons

    OpenAIRE

    Reginold, William; Luedke, Angela C.; Tam, Angela; Itorralba, Justine; Fernandez-Ruiz, Juan; Reginold, Jennifer; Islam, Omar; Garcia, Angeles

    2015-01-01

    Background/Aims: This study used 3-Tesla magnetic resonance imaging (MRI) tractography to determine if there was an association between tracts crossing white matter hyperintensities (WMH) and cognitive function in elderly persons. Methods: Brain T2-weighted fluid-attenuated inversion recovery (FLAIR) and diffusion tensor MRI scans were acquired in participants above the age of 60 years. Twenty-six persons had WMH identified on T2 FLAIR scans. They completed a battery of neuropsychological tes...

  4. Diffusion tensor imaging and fiber tractography in cervical compressive myelopathy: preliminary results

    International Nuclear Information System (INIS)

    Lee, Joon Woo; Kim, Jae Hyoung; Park, Jong Bin; Lee, Guen Young; Kang, Heung Sik; Park, Kun Woo; Yeom, Jin S.

    2011-01-01

    To assess diffusion tensor imaging (DTI) parameters in cervical compressive myelopathy (CCM) patients compared to normal volunteers, to relate them with myelopathy severity, and to relate tractography patterns with postoperative neurologic improvement. Twenty patients suffering from CCM were prospectively enrolled (M:F = 13:7, mean age, 49.6 years; range 22-67 years) from September 2009 to March 2010. Sensitivity encoding (SENSE) single-shot echo-planar imaging (EPI) was used for the sagittal DTI. Twenty sex- and age-matched normal volunteers underwent the same scanning procedure. Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values in the spinal cord were compared between the patients and normal volunteers and were related to myelopathy severity based on Japanese Orthopedic Association (JOA) scores. Tractography patterns were related to myelopathy severity and postoperative improvement. There were significant differences between patients and normal volunteers in terms of FA (0.498 ± 0.114 vs. 0.604 ± 0.057; p = 0.001) and ADC (1.442 ± 0.389 vs. 1.169 ± 0.098; p = 0.001). DTI parameters and tractography patterns were not related to myelopathy severity. In ten patients in the neurologically worse group, postoperative neurologic improvement was seen in four of five patients with intact fiber tracts, but only one of five patients with interrupted fiber tracts exhibited neurologic improvement. DTI parameters in CCM patients were significantly different from those in normal volunteers but were not significantly related to myelopathy severity. The patterns of tractography appear to correlate with postoperative neurologic improvement. (orig.)

  5. Impact of Gradient Number and Voxel Size on Diffusion Tensor Imaging Tractography for Resective Brain Surgery.

    Science.gov (United States)

    Hoefnagels, Friso W A; de Witt Hamer, Philip C; Pouwels, Petra J W; Barkhof, Frederik; Vandertop, W Peter

    2017-09-01

    To explore quantitatively and qualitatively how the number of gradient directions (NGD) and spatial resolution (SR) affect diffusion tensor imaging (DTI) tractography in patients planned for brain tumor surgery, using routine clinical magnetic resonance imaging protocols. Of 67 patients with intracerebral lesions who had 2 different DTI scans, 3 DTI series were reconstructed to compare the effects of NGD and SR. Tractographies for 4 clinically relevant tracts (corticospinal tract, superior longitudinal fasciculus, optic radiation, and inferior fronto-occipital fasciculus) were constructed with a probabilistic tracking algorithm and automated region of interest placement and compared for 3 quantitative measurements: tract volume, median fiber density, and mean fractional anisotropy, using linear mixed-effects models. The mean tractography volume and intersubject reliability were visually compared across scanning protocols, to assess the clinical relevance of the quantitative differences. Both NGD and SR significantly influenced tract volume, median fiber density, and mean fractional anisotropy, but not to the same extent. In particular, higher NGD increased tract volume and median fiber density. More importantly, these effects further increased when tracts were affected by disease. The effects were tract specific, but not dependent on threshold. The superior longitudinal fasciculus and inferior fronto-occipital fasciculus showed the most significant differences. Qualitative assessment showed larger tract volumes given a fixed confidence level, and better intersubject reliability for the higher NGD protocol. SR in the range we considered seemed less relevant than NGD. This study indicates that, under time constraints of clinical imaging, a higher number of diffusion gradients is more important than spatial resolution for superior DTI probabilistic tractography in patients undergoing brain tumor surgery. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. MR diffusion histology and micro-tractography reveal mesoscale features of the human cerebellum.

    Science.gov (United States)

    Dell'Acqua, Flavio; Bodi, Istvan; Slater, David; Catani, Marco; Modo, Michel

    2013-12-01

    After 140 years from the discovery of Golgi's black reaction, the study of connectivity of the cerebellum remains a fascinating yet challenging task. Current histological techniques provide powerful methods for unravelling local axonal architecture, but the relatively low volume of data that can be acquired in a reasonable amount of time limits their application to small samples. State-of-the-art in vivo magnetic resonance imaging (MRI) methods, such as diffusion tractography techniques, can reveal trajectories of the major white matter pathways, but their correspondence with underlying anatomy is yet to be established. Hence, a significant gap exists between these two approaches as neither of them can adequately describe the three-dimensional complexity of fibre architecture at the level of the mesoscale (from a few millimetres to micrometres). In this study, we report the application of MR diffusion histology and micro-tractography methods to reveal the combined cytoarchitectural organisation and connectivity of the human cerebellum at a resolution of 100-μm (2 nl/voxel volume). Results show that the diffusion characteristics for each layer of the cerebellar cortex correctly reflect the known cellular composition and its architectural pattern. Micro-tractography also reveals details of the axonal connectivity of individual cerebellar folia and the intra-cortical organisation of the different cerebellar layers. The direct correspondence between MR diffusion histology and micro-tractography with immunohistochemistry indicates that these approaches have the potential to complement traditional histology techniques by providing a non-destructive, quantitative and three-dimensional description of the microstructural organisation of the healthy and pathological tissue.

  7. Preoperative Identification of Facial Nerve in Vestibular Schwannomas Surgery Using Diffusion Tensor Tractography

    OpenAIRE

    Choi, Kyung-Sik; Kim, Min-Su; Kwon, Hyeok-Gyu; Jang, Sung-Ho; Kim, Oh-Lyong

    2014-01-01

    Objective Facial nerve palsy is a common complication of treatment for vestibular schwannoma (VS), so preserving facial nerve function is important. The preoperative visualization of the course of facial nerve in relation to VS could help prevent injury to the nerve during the surgery. In this study, we evaluate the accuracy of diffusion tensor tractography (DTT) for preoperative identification of facial nerve. Methods We prospectively collected data from 11 patients with VS, who underwent pr...

  8. Parotid gland tumours: MR tractography to assess contact with the facial nerve.

    Science.gov (United States)

    Attyé, Arnaud; Karkas, Alexandre; Troprès, Irène; Roustit, Matthieu; Kastler, Adrian; Bettega, Georges; Lamalle, Laurent; Renard, Félix; Righini, Christian; Krainik, Alexandre

    2016-07-01

    To assess the feasibility of intraparotid facial nerve (VIIn) tractographic reconstructions in estimating the presence of a contact between the VIIn and the tumour, in patients requiring surgical resection of parotid tumours. Patients underwent MR scans with VIIn tractography calculated with the constrained spherical deconvolution model. The parameters of the diffusion sequence were: b-value of 1000 s/mm(2); 32 directions; voxel size: 2 mm isotropic; scan time: 9'31'. The potential contacts between VIIn branches and tumours were estimated with different initial fractional anisotropy (iFA) cut-offs compared to surgical data. Surgeons were blinded to the tractography reconstructions and identified both nerves and contact with tumours using nerve stimulation and reference photographs. Twenty-six patients were included in this study and the mean patient age was 55.2 years. Surgical direct assessment of VIIn allowed identifying 0.1 as the iFA threshold with the best sensitivity to detect tumour contact. In all patients with successful VIIn identification by tractography, surgeons confirmed nerve courses as well as lesion location in parotid glands. Mean VIIn branch FA values were significantly lower in cases with tumour contact (t-test; p ≤ 0.01). This study showed the feasibility of intraparotid VIIn tractography to identify nerve contact with parotid tumours. • Diffusion imaging is an efficient method for highlighting the intraparotid VIIn. • Visualization of the VIIn may help to better manage patients before surgery. • We bring new insights to future trials for patients with VIIn dysfunction. • We aimed to provide radio-anatomical references for further studies.

  9. Cognitive Function and 3-Tesla Magnetic Resonance Imaging Tractography of White Matter Hyperintensities in Elderly Persons

    Directory of Open Access Journals (Sweden)

    William Reginold

    2015-10-01

    Full Text Available Background/Aims: This study used 3-Tesla magnetic resonance imaging (MRI tractography to determine if there was an association between tracts crossing white matter hyperintensities (WMH and cognitive function in elderly persons. Methods: Brain T2-weighted fluid-attenuated inversion recovery (FLAIR and diffusion tensor MRI scans were acquired in participants above the age of 60 years. Twenty-six persons had WMH identified on T2 FLAIR scans. They completed a battery of neuropsychological tests and were classified as normal controls (n = 15 or with Alzheimer's dementia (n = 11. Tractography was generated by the Fiber Assignment by Continuous Tracking method. All tracts that crossed WMH were segmented. The average fractional anisotropy and average mean diffusivity of these tracts were quantified. We studied the association between cognitive test scores with the average mean diffusivity and average fractional anisotropy of tracts while controlling for age, total WMH volume and diagnosis. Results: An increased mean diffusivity of tracts crossing WMH was associated with worse performance on the Wechsler Memory Scale-III Longest Span Forward (p = 0.02. There was no association between the fractional anisotropy of tracts and performance on cognitive testing. Conclusion: The mean diffusivity of tracts crossing WMH measured by tractography is a novel correlate of performance on the Wechsler Memory Scale-III Longest Span Forward in elderly persons.

  10. Cognitive Function and 3-Tesla Magnetic Resonance Imaging Tractography of White Matter Hyperintensities in Elderly Persons.

    Science.gov (United States)

    Reginold, William; Luedke, Angela C; Tam, Angela; Itorralba, Justine; Fernandez-Ruiz, Juan; Reginold, Jennifer; Islam, Omar; Garcia, Angeles

    2015-01-01

    This study used 3-Tesla magnetic resonance imaging (MRI) tractography to determine if there was an association between tracts crossing white matter hyperintensities (WMH) and cognitive function in elderly persons. Brain T2-weighted fluid-attenuated inversion recovery (FLAIR) and diffusion tensor MRI scans were acquired in participants above the age of 60 years. Twenty-six persons had WMH identified on T2 FLAIR scans. They completed a battery of neuropsychological tests and were classified as normal controls (n = 15) or with Alzheimer's dementia (n = 11). Tractography was generated by the Fiber Assignment by Continuous Tracking method. All tracts that crossed WMH were segmented. The average fractional anisotropy and average mean diffusivity of these tracts were quantified. We studied the association between cognitive test scores with the average mean diffusivity and average fractional anisotropy of tracts while controlling for age, total WMH volume and diagnosis. An increased mean diffusivity of tracts crossing WMH was associated with worse performance on the Wechsler Memory Scale-III Longest Span Forward (p = 0.02). There was no association between the fractional anisotropy of tracts and performance on cognitive testing. The mean diffusivity of tracts crossing WMH measured by tractography is a novel correlate of performance on the Wechsler Memory Scale-III Longest Span Forward in elderly persons.

  11. Multimodality 3D Superposition and Automated Whole Brain Tractography: Comprehensive Printing of the Functional Brain.

    Science.gov (United States)

    Konakondla, Sanjay; Brimley, Cameron J; Sublett, Jesna Mathew; Stefanowicz, Edward; Flora, Sarah; Mongelluzzo, Gino; Schirmer, Clemens M

    2017-09-29

    Whole brain tractography using diffusion tensor imaging (DTI) sequences can be used to map cerebral connectivity; however, this can be time-consuming due to the manual component of image manipulation required, calling for the need for a standardized, automated, and accurate fiber tracking protocol with automatic whole brain tractography (AWBT). Interpreting conventional two-dimensional (2D) images, such as computed tomography (CT) and magnetic resonance imaging (MRI), as an intraoperative three-dimensional (3D) environment is a difficult task with recognized inter-operator variability. Three-dimensional printing in neurosurgery has gained significant traction in the past decade, and as software, equipment, and practices become more refined, trainee education, surgical skills, research endeavors, innovation, patient education, and outcomes via valued care is projected to improve. We describe a novel multimodality 3D superposition (MMTS) technique, which fuses multiple imaging sequences alongside cerebral tractography into one patient-specific 3D printed model. Inferences on cost and improved outcomes fueled by encouraging patient engagement are explored.

  12. Seeing More by Showing Less: Orientation-Dependent Transparency Rendering for Fiber Tractography Visualization.

    Directory of Open Access Journals (Sweden)

    Chantal M W Tax

    Full Text Available Fiber tractography plays an important role in exploring the architectural organization of fiber trajectories, both in fundamental neuroscience and in clinical applications. With the advent of diffusion MRI (dMRI approaches that can also model "crossing fibers", the complexity of the fiber network as reconstructed with tractography has increased tremendously. Many pathways interdigitate and overlap, which hampers an unequivocal 3D visualization of the network and impedes an efficient study of its organization. We propose a novel fiber tractography visualization approach that interactively and selectively adapts the transparency rendering of fiber trajectories as a function of their orientation to enhance the visibility of the spatial context. More specifically, pathways that are oriented (locally or globally along a user-specified opacity axis can be made more transparent or opaque. This substantially improves the 3D visualization of the fiber network and the exploration of tissue configurations that would otherwise be largely covered by other pathways. We present examples of fiber bundle extraction and neurosurgical planning cases where the added benefit of our new visualization scheme is demonstrated over conventional fiber visualization approaches.

  13. Joint statistics and conditional mean strain rates of streamline segments

    International Nuclear Information System (INIS)

    Schaefer, P; Gampert, M; Peters, N

    2013-01-01

    Based on four different direct numerical simulations of turbulent flows with Taylor-based Reynolds numbers ranging from Re λ = 50 to 300 among which are two homogeneous isotropic decaying, one forced and one homogeneous shear flow, streamlines are identified and the obtained space curves are parameterized with the pseudo-time as well as the arclength. Based on local extrema of the absolute value of the velocity along the streamlines, the latter are partitioned into segments following Wang (2010 J. Fluid Mech. 648 183–203). Streamline segments are then statistically analyzed based on both parameterizations using the joint probability density function of the pseudo-time lag τ (arclength l, respectively) between and the velocity difference Δu at the extrema: P(τ,Δu), (P(l,Δu)). We distinguish positive and negative streamline segments depending on the sign of the velocity difference Δu. Differences as well as similarities in the statistical description for both parameterizations are discussed. In particular, it turns out that the normalized probability distribution functions (pdfs) (of both parameterizations) of the length of positive, negative and all segments assume a universal shape for all Reynolds numbers and flow types and are well described by a model derived in Schaefer P et al (2012 Phys. Fluids 24 045104). Particular attention is given to the conditional mean velocity difference at the ending points of the segments, which can be understood as a first-order structure function in the context of streamline segment analysis. It determines to a large extent the stretching (compression) of positive (negative) streamline segments and corresponds to the convective velocity in phase space in the transport model equation for the pdf. While based on the random sweeping hypothesis a scaling ∝ (u rms ετ) 1/3 is found for the parameterization based on the pseudo-time, the parameterization with the arclength l yields a much larger than expected l 1/3 scaling. A

  14. An Evaluation of the Acquisition Streamlining Methods at the Fleet and Industrial Supply Center Pearl Harbor Hawaii

    National Research Council Canada - National Science Library

    Henry, Mark

    1999-01-01

    ...) Pearl Harbor's implementation of acquisition streamlining initiatives and recommends viable methods of streamlining the acquisition process at FISC Pearl Harbor and other Naval Supply Systems Command...

  15. Streamlining: Reducing costs and increasing STS operations effectiveness

    Science.gov (United States)

    Petersburg, R. K.

    1985-01-01

    The development of streamlining as a concept, its inclusion in the space transportation system engineering and operations support (STSEOS) contract, and how it serves as an incentive to management and technical support personnel is discussed. The mechanics of encouraging and processing streamlining suggestions, reviews, feedback to submitters, recognition, and how individual employee performance evaluations are used to motivation are discussed. Several items that were implemented are mentioned. Information reported and the methodology of determining estimated dollar savings are outlined. The overall effect of this activity on the ability of the McDonnell Douglas flight preparation and mission operations team to support a rapidly increasing flight rate without a proportional increase in cost is illustrated.

  16. Streamline topology: Patterns in fluid flows and their bifurcations

    DEFF Research Database (Denmark)

    Brøns, Morten

    2007-01-01

    Using dynamical systems theory, we consider structures such as vortices and separation in the streamline patterns of fluid flows. Bifurcation of patterns under variation of external parameters is studied using simplifying normal form transformations. Flows away from boundaries, flows close to fix...... walls, and axisymmetric flows are analyzed in detail. We show how to apply the ideas from the theory to analyze numerical simulations of the vortex breakdown in a closed cylindrical container....

  17. Damage Detection with Streamlined Structural Health Monitoring Data

    OpenAIRE

    Li, Jian; Deng, Jun; Xie, Weizhi

    2015-01-01

    The huge amounts of sensor data generated by large scale sensor networks in on-line structural health monitoring (SHM) systems often overwhelms the systems’ capacity for data transmission and analysis. This paper presents a new concept for an integrated SHM system in which a streamlined data flow is used as a unifying thread to integrate the individual components of on-line SHM systems. Such an integrated SHM system has a few desirable functionalities including embedded sensor data compressio...

  18. Zephyr: A secure Internet process to streamline engineering

    Energy Technology Data Exchange (ETDEWEB)

    Jordan, C.W.; Niven, W.A.; Cavitt, R.E. [and others

    1998-05-12

    Lawrence Livermore National Laboratory (LLNL) is implementing an Internet-based process pilot called `Zephyr` to streamline engineering and commerce using the Internet. Major benefits have accrued by using Zephyr in facilitating industrial collaboration, speeding the engineering development cycle, reducing procurement time, and lowering overall costs. Programs at LLNL are potentializing the efficiencies introduced since implementing Zephyr. Zephyr`s pilot functionality is undergoing full integration with Business Systems, Finance, and Vendors to support major programs at the Laboratory.

  19. A Streamlined Artificial Variable Free Version of Simplex Method

    OpenAIRE

    Inayatullah, Syed; Touheed, Nasir; Imtiaz, Muhammad

    2015-01-01

    This paper proposes a streamlined form of simplex method which provides some great benefits over traditional simplex method. For instance, it does not need any kind of artificial variables or artificial constraints; it could start with any feasible or infeasible basis of an LP. This method follows the same pivoting sequence as of simplex phase 1 without showing any explicit description of artificial variables which also makes it space efficient. Later in this paper, a dual version of the new ...

  20. Dividing Streamline Formation Channel Confluences by Physical Modeling

    Directory of Open Access Journals (Sweden)

    Minarni Nur Trilita

    2010-02-01

    Full Text Available Confluence channels are often found in open channel network system and is the most important element. The incoming flow from the branch channel to the main cause various forms and cause vortex flow. Phenomenon can cause erosion of the side wall of the channel, the bed channel scour and sedimentation in the downstream confluence channel. To control these problems needed research into the current width of the branch channel. The incoming flow from the branch channel to the main channel flow bounded by a line distributors (dividing streamline. In this paper, the wide dividing streamline observed in the laboratory using a physical model of two open channels, a square that formed an angle of 30º. Observations were made with a variety of flow coming from each channel. The results obtained in the laboratory observation that the width of dividing streamline flow is influenced by the discharge ratio between the channel branch with the main channel. While the results of a comparison with previous studies showing that the observation in the laboratory is smaller than the results of previous research.

  1. Investigating the tradeoffs between spatial resolution and diffusion sampling for brain mapping with diffusion tractography: time well spent?

    Science.gov (United States)

    Calabrese, Evan; Badea, Alexandra; Coe, Christopher L; Lubach, Gabriele R; Styner, Martin A; Johnson, G Allan

    2014-11-01

    Interest in mapping white matter pathways in the brain has peaked with the recognition that altered brain connectivity may contribute to a variety of neurologic and psychiatric diseases. Diffusion tractography has emerged as a popular method for postmortem brain mapping initiatives, including the ex-vivo component of the human connectome project, yet it remains unclear to what extent computer-generated tracks fully reflect the actual underlying anatomy. Of particular concern is the fact that diffusion tractography results vary widely depending on the choice of acquisition protocol. The two major acquisition variables that consume scan time, spatial resolution, and diffusion sampling, can each have profound effects on the resulting tractography. In this analysis, we determined the effects of the temporal tradeoff between spatial resolution and diffusion sampling on tractography in the ex-vivo rhesus macaque brain, a close primate model for the human brain. We used the wealth of autoradiography-based connectivity data available for the rhesus macaque brain to assess the anatomic accuracy of six time-matched diffusion acquisition protocols with varying balance between spatial and diffusion sampling. We show that tractography results vary greatly, even when the subject and the total acquisition time are held constant. Further, we found that focusing on either spatial resolution or diffusion sampling at the expense of the other is counterproductive. A balanced consideration of both sampling domains produces the most anatomically accurate and consistent results. Copyright © 2014 Wiley Periodicals, Inc.

  2. Preoperative DTI and probabilistic tractography in an amputee with deep brain stimulation for lower limb stump pain.

    Science.gov (United States)

    Owen, S L F; Heath, J; Kringelbach, M L; Stein, J F; Aziz, T Z

    2007-10-01

    This study aimed to find out whether preoperative diffusion tensor imaging (DTI) and probabilistic tractography could help with surgical planning for deep brain stimulation in the periaqueductal/periventricular grey area (PAG/PVG) in a patient with lower leg stump pain. A preoperative DTI was obtained from the patient, who then received DBS surgery in the PAG/PVG area with good pain relief. The postoperative MRI scan showing electrode placement was used to calculate four seed areas to represent the contacts on the Medtronic 3387 electrode. Probabilistic tractography was then performed from the pre-operative DTI image. Tracts were seen to connect to many areas within the pain network from the four different contacts. These initial findings suggest that preoperative DTI scanning and probabilistic tractography may be able to assist surgical planning in the future.

  3. SU-F-J-160: Clinical Evaluation of Targeting Accuracy in Radiosurgery Using Tractography

    Energy Technology Data Exchange (ETDEWEB)

    Juh, R; Han, J; Kim, C; Oh, C [Seoul National University Bundang Hospital, Seongnamsi, GyeonggiDo (Korea, Republic of); Suh, T [The catholic university of Korea, Seoul (Korea, Republic of)

    2016-06-15

    Purpose: Focal radiosurgery is a common treatment modality for trigeminal neuralgia (TN), a neuropathic facial pain condition. Assessment of treatment effectiveness is primarily clinical, given the paucity of investigational tools to assess trigeminal nerve changes. The efficiency of radiosurgery is related to its highly precise targeting. We assessed clinically the targeting accuracy of radiosurgery with Gamma knife. We hypothesized that trigeminal tractography provides more information than 2D-MR imaging, allowing detection of unique, focal changes in the target area after radiosurgery. Methods: Sixteen TN patients (2 females, 4 males, average age 65.3 years) treated with Gamma Knife radiosurgery, 40 Gy/50% isodose line underwent 1.5Tesla MR trigeminal nerve. Target accuracy was assessed from deviation of the coordinates of the target compared with the center of enhancement on post MRI. Radiation dose delivered at the borders of contrast enhancement was evaluated. Results: The median deviation of the coordinates between the intended target and the center of contrast enhancement was within 1mm. The radiation doses fitting within the borders of the contrast enhancement the target ranged from 37.5 to 40 Gy. Trigeminal tractography accurately detected the radiosurgical target. Radiosurgery resulted in 47% drop in FA values at the target with no significant change in FA outside the target, suggesting that radiosurgery primarily affects myelin. Tractography was more sensitive, since FA changes were detected regardless of trigeminal nerve enhancement. Conclusion: The median deviation found in clinical assessment of gamma knife treatment for TN Is low and compatible with its high rate of efficiency. DTI parameters accurately detect the effects of focal radiosurgery on the trigeminal nerve, serving as an in vivo imaging tool to study TN. This study is a proof of principle for further assessment of DTI parameters to understand the pathophysiology of TN and treatment

  4. Joint Multi-Fiber NODDI Parameter Estimation and Tractography using the Unscented Information Filter

    Directory of Open Access Journals (Sweden)

    Yogesh eRathi

    2016-04-01

    Full Text Available Tracing white matter fiber bundles is an integral part of analyzing brain connectivity. An accurate estimate of the underlying tissue parameters is also paramount in several neuroscience applications. In this work, we propose to use a joint fiber model estimation and tractography algorithm that uses the NODDI (neurite orientation dispersion diffusion imaging model to estimate fiber orientation dispersion consistently and smoothly along the fiber tracts along with estimating the intracellular and extracellular volume fractions from the diffusion signal. While the NODDI model has been used in earlier works to estimate the microstructural parameters at each voxel independently, for the first time, we propose to integrate it into a tractography framework. We extend this framework to estimate the NODDI parameters for two crossing fibers, which is imperative to trace fiber bundles through crossings as well as to estimate the microstructural parameters for each fiber bundle separately. We propose to use the unscented information filter (UIF to accurately estimate the model parameters and perform tractography. The proposed approach has significant computational performance improvements as well as numerical robustness over the unscented Kalman filter (UKF. Our method not only estimates the confidence in the estimated parameters via the covariance matrix, but also provides the Fisher-information matrix of the state variables (model parameters, which can be quite useful to measure model complexity. Results from in-vivo human brain data sets demonstrate the ability of our algorithm to trace through crossing fiber regions, while estimating orientation dispersion and other biophysical model parameters in a consistent manner along the tracts.

  5. Correlation between language function and the left arcuate fasciculus detected by diffusion tensor imaging tractography after brain tumor surgery.

    Science.gov (United States)

    Hayashi, Yutaka; Kinoshita, Masashi; Nakada, Mitsutoshi; Hamada, Jun-ichiro

    2012-11-01

    Disturbance of the arcuate fasciculus in the dominant hemisphere is thought to be associated with language-processing disorders, including conduction aphasia. Although the arcuate fasciculus can be visualized in vivo with diffusion tensor imaging (DTI) tractography, its involvement in functional processes associated with language has not been shown dynamically using DTI tractography. In the present study, to clarify the participation of the arcuate fasciculus in language functions, postoperative changes in the arcuate fasciculus detected by DTI tractography were evaluated chronologically in relation to postoperative changes in language function after brain tumor surgery. Preoperative and postoperative arcuate fasciculus area and language function were examined in 7 right-handed patients with a brain tumor in the left hemisphere located in proximity to part of the arcuate fasciculus. The arcuate fasciculus was depicted, and its area was calculated using DTI tractography. Language functions were measured using the Western Aphasia Battery (WAB). After tumor resection, visualization of the arcuate fasciculus was increased in 5 of the 7 patients, and the total WAB score improved in 6 of the 7 patients. The relative ratio of postoperative visualized area of the arcuate fasciculus to preoperative visualized area of the arcuate fasciculus was increased in association with an improvement in postoperative language function (p = 0.0039). The role of the left arcuate fasciculus in language functions can be evaluated chronologically in vivo by DTI tractography after brain tumor surgery. Because increased postoperative visualization of the fasciculus was significantly associated with postoperative improvement in language functions, the arcuate fasciculus may play an important role in language function, as previously thought. In addition, postoperative changes in the arcuate fasciculus detected by DTI tractography could represent a predicting factor for postoperative language

  6. Diffusion tensor magnetic resonance imaging and fiber tractography of the sacral plexus in children with spina bifida

    DEFF Research Database (Denmark)

    Haakma, Wieke; Dik, Pieter; ten Haken, Bennie

    2014-01-01

    anatomical and microstructural properties of the sacral plexus of patients with spina bifida using diffusion tensor imaging and fiber tractography. MATERIALS AND METHODS: Ten patients 8 to 16 years old with spina bifida underwent diffusion tensor imaging on a 3 Tesla magnetic resonance imaging system...... diffusivity values at S1-S3 were significantly lower in patients. CONCLUSIONS: To our knowledge this 3 Tesla magnetic resonance imaging study showed for the first time sacral plexus asymmetry and disorganization in 10 patients with spina bifida using diffusion tensor imaging and fiber tractography...

  7. Streamlining digital signal processing a tricks of the trade guidebook

    CERN Document Server

    2012-01-01

    Streamlining Digital Signal Processing, Second Edition, presents recent advances in DSP that simplify or increase the computational speed of common signal processing operations and provides practical, real-world tips and tricks not covered in conventional DSP textbooks. It offers new implementations of digital filter design, spectrum analysis, signal generation, high-speed function approximation, and various other DSP functions. It provides:Great tips, tricks of the trade, secrets, practical shortcuts, and clever engineering solutions from seasoned signal processing professionalsAn assortment.

  8. A streamlined ribosome profiling protocol for the characterization of microorganisms

    DEFF Research Database (Denmark)

    Latif, Haythem; Szubin, Richard; Tan, Justin

    2015-01-01

    Ribosome profiling is a powerful tool for characterizing in vivo protein translation at the genome scale, with multiple applications ranging from detailed molecular mechanisms to systems-level predictive modeling. Though highly effective, this intricate technique has yet to become widely used...... in the microbial research community. Here we present a streamlined ribosome profiling protocol with reduced barriers to entry for microbial characterization studies. Our approach provides simplified alternatives during harvest, lysis, and recovery of monosomes and also eliminates several time-consuming steps...

  9. Streamlined library programming how to improve services and cut costs

    CERN Document Server

    Porter-Reynolds, Daisy

    2014-01-01

    In their roles as community centers, public libraries offer many innovative and appealing programs; but under current budget cuts, library resources are stretched thin. With slashed budgets and limited staff hours, what can libraries do to best serve their publics? This how-to guide provides strategies for streamlining library programming in public libraries while simultaneously maintaining-or even improving-quality delivery. The wide variety of principles and techniques described can be applied on a selective basis to libraries of all sizes. Based upon the author's own extensive experience as

  10. Topology of streamlines and vorticity contours for two - dimensional flows

    DEFF Research Database (Denmark)

    Andersen, Morten

    on the vortex filament by the localised induction approximation the stream function is slightly modified and an extra parameter is introduced. In this setting two new flow topologies arise, but not more than two critical points occur for any combination of the parameters. The analysis of the closed form show...... by a point vortex above a wall in inviscid fluid. There is no reason to a priori expect equivalent results of the three vortex definitions. However, the study is mainly motivated by the findings of Kudela & Malecha (Fluid Dyn. Res. 41, 2009) who find good agreement between the vorticity and streamlines...

  11. Evaluation of two streamlined life cycle assessment methods

    International Nuclear Information System (INIS)

    Hochschomer, Elisabeth; Finnveden, Goeran; Johansson, Jessica

    2002-02-01

    Two different methods for streamlined life cycle assessment (LCA) are described: the MECO-method and SLCA. Both methods are tested on an already made case-study on cars fuelled with petrol or ethanol, and electric cars with electricity produced from hydro power or coal. The report also contains some background information on LCA and streamlined LCA, and a deschption of the case study used. The evaluation of the MECO and SLCA-methods are based on a comparison of the results from the case study as well as practical aspects. One conclusion is that the SLCA-method has some limitations. Among the limitations are that the whole life-cycle is not covered, it requires quite a lot of information and there is room for arbitrariness. It is not very flexible instead it difficult to develop further. We are therefore not recommending the SLCA-method. The MECO-method does in comparison show several attractive features. It is also interesting to note that the MECO-method produces information that is complementary compared to a more traditional quantitative LCA. We suggest that the MECO method needs some further development and adjustment to Swedish conditions

  12. Study of streamline flow in the portal system

    International Nuclear Information System (INIS)

    Atkins, H.L.; Deitch, J.S.; Oster, Z.H.; Perkes, E.A.

    1985-01-01

    The study was undertaken to determine if streamline flow occurs in the portal vein, thus separating inflow from the superior mesenteric artery (SMA) and the inferior mesenteric artery. Previously published data on this subject is inconsistent. Patients undergoing abdominal angiography received two administrations of Tc-99m sulfur colloid, first via the SMA during angiography and, after completion of the angiographic procedure, via a peripheral vein (IV). Anterior images of the liver were recorded over a three minute acquisition before and after the IV injection without moving the patient. The image from the SMA injection was subtracted from the SMA and IV image to provide a pure IV image. Analysis of R to L ratios for selected regions of interest as well as whole lobes was carried out and the shift of R to L (SMA to IV) determined. Six patients had liver metastases from the colon, four had cirrhosis and four had no known liver disease. The shift in the ratio was highly variable without a consistent pattern. Large changes in some patients could be attributed to hepatic artery flow directed to metastases. No consistent evidence for streamlining of portal flow was discerned

  13. MARCHIAFAVA-BIGNAMI DISEASE (MBD AND DIFFUSION TENSOR IMAGE (DTI TRACTOGRAPHY

    Directory of Open Access Journals (Sweden)

    Priscilla Chukwueke

    2015-06-01

    Full Text Available Marchiafava-Bignami Disease (MBD is a rare central nervous system (CNS disease characterized by demyelination of the corpus callosum. It is mostly found in men with alcohol use disorder and malnutrition with cases reported worldwide across all races. The onset of the disease may be sudden presenting with stupor, coma or seizures while some may present with gait abnormality (spasticity, psychiatric problems, hemiparesis, aphasia, apraxia and incontinence with a resultant high morbidity and mortality rates. Case description: patient is a 30 year old left handed African-American, who presented with c/o altered mental status, urinary incontinence, slurred speech and left-sided weakness. The diagnosis of MBD was confirmed with DTI Tractography which showed significantly diminished commissural fibers extending to the right central semiovale lesion, near absent or significantly diminished commissural fiber extending through the corpus callosum indicating demyelination. Discussion: MBD is often an incidental diagnosis with high morbidity and mortality. This is different from previous casas because of earlier onset as opposed to onset around age 45, rapid recovery and minimal disability as he could walk independently before discharge from hospital. This case also shows added benefit of the DTI tractography in the diagnosis of MBD.

  14. Diffusion tensor imaging with quantitative evaluation and fiber tractography of lumbar nerve roots in sciatica.

    Science.gov (United States)

    Shi, Yin; Zong, Min; Xu, Xiaoquan; Zou, Yuefen; Feng, Yang; Liu, Wei; Wang, Chuanbing; Wang, Dehang

    2015-04-01

    To quantitatively evaluate nerve roots by measuring fractional anisotropy (FA) values in healthy volunteers and sciatica patients, visualize nerve roots by tractography, and compare the diagnostic efficacy between conventional magnetic resonance imaging (MRI) and DTI. Seventy-five sciatica patients and thirty-six healthy volunteers underwent MR imaging using DTI. FA values for L5-S1 lumbar nerve roots were calculated at three levels from DTI images. Tractography was performed on L3-S1 nerve roots. ROC analysis was performed for FA values. The lumbar nerve roots were visualized and FA values were calculated in all subjects. FA values decreased in compressed nerve roots and declined from proximal to distal along the compressed nerve tracts. Mean FA values were more sensitive and specific than MR imaging for differentiating compressed nerve roots, especially in the far lateral zone at distal nerves. DTI can quantitatively evaluate compressed nerve roots, and DTT enables visualization of abnormal nerve tracts, providing vivid anatomic information and localization of probable nerve compression. DTI has great potential utility for evaluating lumbar nerve compression in sciatica. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  15. Susceptibility tensor imaging and tractography of collagen fibrils in the articular cartilage.

    Science.gov (United States)

    Wei, Hongjiang; Gibbs, Eric; Zhao, Peida; Wang, Nian; Cofer, Gary P; Zhang, Yuyao; Johnson, G Allan; Liu, Chunlei

    2017-11-01

    To investigate the B 0 orientation-dependent magnetic susceptibility of collagen fibrils within the articular cartilage and to determine whether susceptibility tensor imaging (STI) can detect the 3D collagen network within cartilage. Multiecho gradient echo datasets (100-μm isotropic resolution) were acquired from fixed porcine articular cartilage specimens at 9.4 T. The susceptibility tensor was calculated using phase images acquired at 12 or 15 different orientations relative to B 0 . The susceptibility anisotropy of the collagen fibril was quantified and diffusion tensor imaging (DTI) was compared against STI. 3D tractography was performed to visualize and track the collagen fibrils with DTI and STI. STI experiments showed the distinct and significant anisotropic magnetic susceptibility of collagen fibrils within the articular cartilage. STI can be used to measure and quantify susceptibility anisotropy maps. Furthermore, STI provides orientation information of the underlying collagen network via 3D tractography. The findings of this study demonstrate that STI can characterize the orientation variation of collagen fibrils where diffusion anisotropy fails. We believe that STI could serve as a sensitive and noninvasive marker to study the collagen fibrils microstructure. Magn Reson Med 78:1683-1690, 2017. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

  16. Fiber architecture in remodeled myocardium revealed with a quantitative diffusion CMR tractography framework and histological validation.

    Science.gov (United States)

    Mekkaoui, Choukri; Huang, Shuning; Chen, Howard H; Dai, Guangping; Reese, Timothy G; Kostis, William J; Thiagalingam, Aravinda; Maurovich-Horvat, Pal; Ruskin, Jeremy N; Hoffmann, Udo; Jackowski, Marcel P; Sosnovik, David E

    2012-10-12

    The study of myofiber reorganization in the remote zone after myocardial infarction has been performed in 2D. Microstructural reorganization in remodeled hearts, however, can only be fully appreciated by considering myofibers as continuous 3D entities. The aim of this study was therefore to develop a technique for quantitative 3D diffusion CMR tractography of the heart, and to apply this method to quantify fiber architecture in the remote zone of remodeled hearts. Diffusion Tensor CMR of normal human, sheep, and rat hearts, as well as infarcted sheep hearts was performed ex vivo. Fiber tracts were generated with a fourth-order Runge-Kutta integration technique and classified statistically by the median, mean, maximum, or minimum helix angle (HA) along the tract. An index of tract coherence was derived from the relationship between these HA statistics. Histological validation was performed using phase-contrast microscopy. In normal hearts, the subendocardial and subepicardial myofibers had a positive and negative HA, respectively, forming a symmetric distribution around the midmyocardium. However, in the remote zone of the infarcted hearts, a significant positive shift in HA was observed. The ratio between negative and positive HA variance was reduced from 0.96 ± 0.16 in normal hearts to 0.22 ± 0.08 in the remote zone of the remodeled hearts (p layers of the myocardium. Tractography-based quantification, performed here for the first time in remodeled hearts, may provide a framework for assessing regional changes in the left ventricle following infarction.

  17. Using Tractography to Distinguish SWEDD from Parkinson’s Disease Patients Based on Connectivity

    Directory of Open Access Journals (Sweden)

    Mansu Kim

    2016-01-01

    Full Text Available Background. It is critical to distinguish between Parkinson’s disease (PD and scans without evidence of dopaminergic deficit (SWEDD, because the two groups are different and require different therapeutic approaches. Objective. The aim of this study was to distinguish SWEDD patients from PD patients using connectivity information derived from diffusion tensor imaging tractography. Methods. Diffusion magnetic resonance images of SWEDD (n=37 and PD (n=40 were obtained from a research database. Tractography, the process of obtaining neural fiber information, was performed using custom software. Group-wise differences between PD and SWEDD patients were quantified using the number of connected fibers between two regions, and correlation analyses were performed based on clinical scores. A support vector machine classifier (SVM was applied to distinguish PD and SWEDD based on group-wise differences. Results. Four connections showed significant group-wise differences and correlated with the Unified Parkinson’s Disease Rating Scale sponsored by the Movement Disorder Society. The SVM classifier attained 77.92% accuracy in distinguishing between SWEDD and PD using these identified connections. Conclusions. The connections and regions identified represent candidates for future research investigations.

  18. Detection of the arcuate fasciculus in congenital amusia depends on the tractography algorithm

    Directory of Open Access Journals (Sweden)

    Joyce L Chen

    2015-01-01

    Full Text Available The advent of diffusion magnetic resonance imaging allows researchers to virtually dissect white matter fibre pathways in the brain in vivo. This, for example, allows us to characterize and quantify how fibre tracts differ across populations in health and disease, and change as a function of training. Based on diffusion MRI, prior literature reports the absence of the arcuate fasciculus (AF in some control individuals and as well in those with congenital amusia. The complete absence of such a major anatomical tract is surprising given the subtle impairments that characterize amusia. Thus, we hypothesize that failure to detect the AF in this population may relate to the tracking algorithm used, and is not necessarily reflective of their phenotype. Diffusion data in control and amusic individuals were analyzed using three different tracking algorithms: deterministic and probabilistic, the latter either modeling two or one fibre populations. Across the three algorithms, we replicate prior findings of a left greater than right AF volume, but do not find group differences or an interaction. We detect the AF in all individuals using the probabilistic 2-fibre model, however, tracking failed in some control and amusic individuals when deterministic tractography was applied. These findings show that the ability to detect the AF in our sample is dependent on the type of tractography algorithm. This raises the question of whether failure to detect the AF in prior studies may be unrelated to the underlying anatomy or phenotype.

  19. Detection of the arcuate fasciculus in congenital amusia depends on the tractography algorithm.

    Science.gov (United States)

    Chen, Joyce L; Kumar, Sukhbinder; Williamson, Victoria J; Scholz, Jan; Griffiths, Timothy D; Stewart, Lauren

    2015-01-01

    The advent of diffusion magnetic resonance imaging (MRI) allows researchers to virtually dissect white matter fiber pathways in the brain in vivo. This, for example, allows us to characterize and quantify how fiber tracts differ across populations in health and disease, and change as a function of training. Based on diffusion MRI, prior literature reports the absence of the arcuate fasciculus (AF) in some control individuals and as well in those with congenital amusia. The complete absence of such a major anatomical tract is surprising given the subtle impairments that characterize amusia. Thus, we hypothesize that failure to detect the AF in this population may relate to the tracking algorithm used, and is not necessarily reflective of their phenotype. Diffusion data in control and amusic individuals were analyzed using three different tracking algorithms: deterministic and probabilistic, the latter either modeling two or one fiber populations. Across the three algorithms, we replicate prior findings of a left greater than right AF volume, but do not find group differences or an interaction. We detect the AF in all individuals using the probabilistic 2-fiber model, however, tracking failed in some control and amusic individuals when deterministic tractography was applied. These findings show that the ability to detect the AF in our sample is dependent on the type of tractography algorithm. This raises the question of whether failure to detect the AF in prior studies may be unrelated to the underlying anatomy or phenotype.

  20. White matter tracts in first-episode psychosis: A DTI tractography study of the uncinate fasciculus

    Science.gov (United States)

    Price, Gary; Cercignani, Mara; Parker, Geoffrey J.M.; Altmann, Daniel R.; Barnes, Thomas R.E.; Barker, Gareth J.; Joyce, Eileen M.; Ron, Maria A.

    2008-01-01

    A model of disconnectivity involving abnormalities in the cortex and connecting white matter pathways may explain the symptoms and cognitive abnormalities of schizophrenia. Recently, diffusion imaging tractography has made it possible to study white matter pathways in detail, and we present here a study of patients with first-episode psychosis using this technique. We studied the uncinate fasciculus (UF), the largest white matter tract that connects the frontal and temporal lobes, two brain regions significantly implicated in schizophrenia. Nineteen patients with first-episode schizophrenia and 23 controls were studied using a probabilistic tractography algorithm (PICo). Fractional anisotropy (FA) and probability of connection were obtained for every voxel in the tract, and the group means and distributions of these variables were compared. The spread of the FA distribution in the upper tail, as measured by the squared coefficient of variance (SCV), was reduced in the left UF in the patient group, indicating that the number of voxels with high FA values was reduced in the core of the tract and suggesting the presence of changes in fibre alignment and tract coherence in the patient group. The SCV of FA was lower in females across both groups and there was no correlation between the SCV of FA and clinical ratings. PMID:17988894

  1. Quantifying diffusion MRI tractography of the corticospinal tract in brain tumors with deterministic and probabilistic methods.

    Science.gov (United States)

    Bucci, Monica; Mandelli, Maria Luisa; Berman, Jeffrey I; Amirbekian, Bagrat; Nguyen, Christopher; Berger, Mitchel S; Henry, Roland G

    2013-01-01

    Diffusion MRI tractography has been increasingly used to delineate white matter pathways in vivo for which the leading clinical application is presurgical mapping of eloquent regions. However, there is rare opportunity to quantify the accuracy or sensitivity of these approaches to delineate white matter fiber pathways in vivo due to the lack of a gold standard. Intraoperative electrical stimulation (IES) provides a gold standard for the location and existence of functional motor pathways that can be used to determine the accuracy and sensitivity of fiber tracking algorithms. In this study we used intraoperative stimulation from brain tumor patients as a gold standard to estimate the sensitivity and accuracy of diffusion tensor MRI (DTI) and q-ball models of diffusion with deterministic and probabilistic fiber tracking algorithms for delineation of motor pathways. We used preoperative high angular resolution diffusion MRI (HARDI) data (55 directions, b = 2000 s/mm(2)) acquired in a clinically feasible time frame from 12 patients who underwent a craniotomy for resection of a cerebral glioma. The corticospinal fiber tracts were delineated with DTI and q-ball models using deterministic and probabilistic algorithms. We used cortical and white matter IES sites as a gold standard for the presence and location of functional motor pathways. Sensitivity was defined as the true positive rate of delineating fiber pathways based on cortical IES stimulation sites. For accuracy and precision of the course of the fiber tracts, we measured the distance between the subcortical stimulation sites and the tractography result. Positive predictive rate of the delineated tracts was assessed by comparison of subcortical IES motor function (upper extremity, lower extremity, face) with the connection of the tractography pathway in the motor cortex. We obtained 21 cortical and 8 subcortical IES sites from intraoperative mapping of motor pathways. Probabilistic q-ball had the best

  2. Preoperative Navigated Transcranial Magnetic Stimulation and Tractography to Guide Endoscopic Cystoventriculostomy: A Technical Note and Case Report.

    Science.gov (United States)

    Hendrix, Philipp; Senger, Sebastian; Griessenauer, Christoph J; Simgen, Andreas; Linsler, Stefan; Oertel, Joachim

    2018-01-01

    To report a technique for endoscopic cystoventriculostomy guided by preoperative navigated transcranial magnetic stimulation (nTMS) and tractography in a patient with a large speech eloquent arachnoid cyst. A 74-year old woman presented with a seizure and subsequent persistent anomic aphasia from a progressive left-sided parietal arachnoid cyst. An endoscopic cystoventriculostomy and endoscope-assisted ventricle catheter placement were performed. Surgery was guided by preoperative nTMS and tractography to avoid eloquent language, motor, and visual pathways. Preoperative nTMS motor and language mapping were used to guide tractography of motor and language white matter tracts. The ideal locations of entry point and cystoventriculostomy as well as trajectory for stent-placement were determined preoperatively with a pseudo-3-dimensional model visualizing eloquent language, motor, and visual cortical and subcortical information. The early postoperative course was uneventful. At her 3-month follow-up visit, her language impairments had completely recovered. Additionally, magnetic resonance imaging demonstrated complete collapse of the arachnoid cyst. The combination of nTMS and tractography supports the identification of a safe trajectory for cystoventriculostomy in eloquent arachnoid cysts. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. MR neurography of the median nerve at 3.0 T: Optimization of diffusion tensor imaging and fiber tractography

    International Nuclear Information System (INIS)

    Guggenberger, Roman; Eppenberger, Patrick; Markovic, Daniel; Nanz, Daniel; Chhabra, Avneesh; Pruessmann, Klaas P.; Andreisek, Gustav

    2012-01-01

    Objectives: The purpose of this study was to systematically assess the optimal b-value and reconstruction parameters for DTI and fiber tractography of the median nerve at 3.0 T. Methods: Local ethical board approved study with 45 healthy volunteers (15 men, 30 women; mean age, 41 ± 3.4 years) who underwent DTI of the right wrist at 3.0 T. A single-shot echo-planar-imaging sequence (TR/TE 10123/40 ms) was acquired at four different b-values (800, 1000, 1200, and 1400 s/mm 2 ). Two independent readers performed post processing and fiber-tractography. Fractional anisotropy (FA) maps were calculated. Fiber tracts of the median nerve were generated using four different algorithms containing different FA thresholds and different angulation tolerances. Data were evaluated quantitatively and qualitatively. Results: Tracking algorithms using a minimum FA threshold of 0.2 and a maximum angulation of 10° were significantly better than other algorithms. Fiber tractography generated significantly longer fibers in DTI acquisitions with higher b-values (1200 and 1400 s/mm 2 versus 800 s/mm 2 ; p 2 (p 2 for DTI of the median nerve at 3.0 T. Optimal reconstruction parameters for fiber tractography should encompass a minimum FA threshold of 0.2 and a maximum angulation tolerance of 10.

  4. Diffusion tensor imaging (DTI) and tractography of the brachial plexus: feasibility and initial experience in neoplastic conditions

    Energy Technology Data Exchange (ETDEWEB)

    Vargas, Maria Isabel; Nguyen, Duy; Delavelle, Jacqueline [Geneva University Hospital, Department of Neuroradiology, DISIM, Geneve 14 (Switzerland); Viallon, Magalie [Geneva University Hospital and University of Geneva, Radiology, Geneva (Switzerland); Becker, Minerva [Geneva University Hospital and University of Geneva, Unit of Head and Neck Radiology, Geneva (Switzerland)

    2010-03-15

    The objective of this study was to assess the feasibility and potential clinical applications of diffusion tensor imaging (DTI) and tractography in the normal and pathologic brachial plexus prospectively. Six asymptomatic volunteers and 12 patients with symptoms related to the brachial plexus underwent DTI on a 1.5T system in addition to the routine anatomic plexus imaging protocol. Maps of the apparent diffusion coefficient (ADC) and of fractional anisotropy (FA), as well as tractography of the brachial plexus were obtained. Images were evaluated by two experienced neuroradiologists in a prospective fashion. Three patients underwent surgery, and nine patients underwent conservative medical treatment. Reconstructed DTI (17/18) were of good quality (one case could not be reconstructed due to artifacts). In all volunteers and in 11 patients, the roots and the trunks were clearly delineated with tractography. Mean FA and mean ADC values were as follows: 0.30{+-}0.079 and 1.70{+-}0.35 mm{sup 2}/s in normal fibers, 0.22{+-}0.04 and 1.49{+-}0.49 mm{sup 2}/s in benign neurogenic tumors, and 0.24{+-}0.08 and 1.51{+-}0.52 mm{sup 2}/s in malignant tumors, respectively. Although there was no statistically significant difference in FA and ADC values of normal fibers and fibers at the level of pathology, tractography revealed major differences regarding fiber architecture. In benign neurogenic tumors (n=4), tractography revealed fiber displacement alone (n=2) or fiber displacement and encasement by the tumor (n=2), whereas in the malignant tumors, either fiber disruption/destruction with complete disorganization (n=6) or fiber displacement (n=1) were seen. In patients with fiber displacement alone, surgery confirmed the tractography findings, and excision was successful without sequelae. Our preliminary data suggest that DTI with tractography is feasible in a clinical routine setting. DTI may demonstrate normal tracts, tract displacement, deformation, infiltration, disruption

  5. Diffusion tensor imaging (DTI) and tractography of the brachial plexus: feasibility and initial experience in neoplastic conditions

    International Nuclear Information System (INIS)

    Vargas, Maria Isabel; Nguyen, Duy; Delavelle, Jacqueline; Viallon, Magalie; Becker, Minerva

    2010-01-01

    The objective of this study was to assess the feasibility and potential clinical applications of diffusion tensor imaging (DTI) and tractography in the normal and pathologic brachial plexus prospectively. Six asymptomatic volunteers and 12 patients with symptoms related to the brachial plexus underwent DTI on a 1.5T system in addition to the routine anatomic plexus imaging protocol. Maps of the apparent diffusion coefficient (ADC) and of fractional anisotropy (FA), as well as tractography of the brachial plexus were obtained. Images were evaluated by two experienced neuroradiologists in a prospective fashion. Three patients underwent surgery, and nine patients underwent conservative medical treatment. Reconstructed DTI (17/18) were of good quality (one case could not be reconstructed due to artifacts). In all volunteers and in 11 patients, the roots and the trunks were clearly delineated with tractography. Mean FA and mean ADC values were as follows: 0.30±0.079 and 1.70±0.35 mm 2 /s in normal fibers, 0.22±0.04 and 1.49±0.49 mm 2 /s in benign neurogenic tumors, and 0.24±0.08 and 1.51±0.52 mm 2 /s in malignant tumors, respectively. Although there was no statistically significant difference in FA and ADC values of normal fibers and fibers at the level of pathology, tractography revealed major differences regarding fiber architecture. In benign neurogenic tumors (n=4), tractography revealed fiber displacement alone (n=2) or fiber displacement and encasement by the tumor (n=2), whereas in the malignant tumors, either fiber disruption/destruction with complete disorganization (n=6) or fiber displacement (n=1) were seen. In patients with fiber displacement alone, surgery confirmed the tractography findings, and excision was successful without sequelae. Our preliminary data suggest that DTI with tractography is feasible in a clinical routine setting. DTI may demonstrate normal tracts, tract displacement, deformation, infiltration, disruption, and disorganization of

  6. Streamlining of the Decontamination and Demolition Document Preparation Process

    International Nuclear Information System (INIS)

    Durand, Nick; Meincke, Carol; Peek, Georgianne

    1999-01-01

    During the past five years, the Sandia National Labo- ratories Decontamination, Decommissioning, Demolition, and Reuse (D3R) Program has evolved and become more focused and efficient. Historical approaches to project documentation, requirements, and drivers are discussed detailing key assumptions, oversight authority, and proj- ect approvals. Discussion of efforts to streamline the D3R project planning and preparation process include the in- corporation of the principles of graded approach, Total Quality Management, and the Observational Method (CH2MHILL April 1989).1 Process improvements were realized by clearly defining regulatory requirements for each phase of a project, establishing general guidance for the program and combining project-specific documents to eliminate redundant and unneeded information. Proc- ess improvements to cost, schedule, and quality are dis- cussed in detail for several projects

  7. The Zig-zag Instability of Streamlined Bodies

    Science.gov (United States)

    Guillet, Thibault; Coux, Martin; Quere, David; Clanet, Christophe

    2017-11-01

    When a floating bluff body, like a sphere, impacts water with a vertical velocity, its trajectory is straight and the depth of its dive increases with its initial velocity. Even though we observe the same phenomenon at low impact speed for axisymmetric streamlined bodies, the trajectory is found to deviate from the vertical when the velocity overcomes a critical value. This instability results from a competition between the destabilizing torque of the lift and the stabilizing torque of the Archimede's force. Balancing these torques yields a prediction on the critical velocity above which the instability appears. This theoretical value is found to depend on the position of the gravity center of the projectile and predicts with a full agreement the behaviour observed in our different experiments. Project funded by DGA.

  8. Streamlining air import operations by trade facilitation measures

    Directory of Open Access Journals (Sweden)

    Yuri da Cunha Ferreira

    2017-12-01

    Full Text Available Global operations are subject to considerable uncertainties. Due to the Trade Facilitation Agreement that became effective in February 2017, the study of measures to streamline customs controls is urgent. This study aims to assess the impact of trade facilitation measures on import flows. An experimental study was performed in the largest cargo airport in South America through discrete-event simulation and design of experiments. Operation impacts of three trade facilitation measures are assessed on import flow by air. We shed light in the following trade facilitation measures: the use of X-ray equipment for physical inspection; increase of the number of qualified companies in the trade facilitation program; performance targets for customs officials. All trade facilitation measures used indicated potential to provide more predictability, cost savings, time reduction, and increase in security in international supply chain.

  9. State Models to Incentivize and Streamline Small Hydropower Development

    Energy Technology Data Exchange (ETDEWEB)

    Curtis, Taylor [National Renewable Energy Lab. (NREL), Golden, CO (United States); Levine, Aaron [National Renewable Energy Lab. (NREL), Golden, CO (United States); Johnson, Kurt [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2017-10-31

    In 2016, the hydropower fleet in the United States produced more than 6 percent (approximately 265,829 gigawatt-hours [GWh]) of the total net electricity generation. The median-size hydroelectric facility in the United States is 1.6 MW and 75 percent of total facilities have a nameplate capacity of 10 MW or less. Moreover, the U.S. Department of Energy's Hydropower Vision study identified approximately 79 GW hydroelectric potential beyond what is already developed. Much of the potential identified is at low-impact new stream-reaches, existing conduits, and non-powered dams with a median project size of 10 MW or less. To optimize the potential and value of small hydropower development, state governments are crafting policies that provide financial assistance and expedite state and federal review processes for small hydroelectric projects. This report analyzes state-led initiatives and programs that incentivize and streamline small hydroelectric development.

  10. Streamlined bioreactor-based production of human cartilage tissues.

    Science.gov (United States)

    Tonnarelli, B; Santoro, R; Adelaide Asnaghi, M; Wendt, D

    2016-05-27

    Engineered tissue grafts have been manufactured using methods based predominantly on traditional labour-intensive manual benchtop techniques. These methods impart significant regulatory and economic challenges, hindering the successful translation of engineered tissue products to the clinic. Alternatively, bioreactor-based production systems have the potential to overcome such limitations. In this work, we present an innovative manufacturing approach to engineer cartilage tissue within a single bioreactor system, starting from freshly isolated human primary chondrocytes, through the generation of cartilaginous tissue grafts. The limited number of primary chondrocytes that can be isolated from a small clinically-sized cartilage biopsy could be seeded and extensively expanded directly within a 3D scaffold in our perfusion bioreactor (5.4 ± 0.9 doublings in 2 weeks), bypassing conventional 2D expansion in flasks. Chondrocytes expanded in 3D scaffolds better maintained a chondrogenic phenotype than chondrocytes expanded on plastic flasks (collagen type II mRNA, 18-fold; Sox-9, 11-fold). After this "3D expansion" phase, bioreactor culture conditions were changed to subsequently support chondrogenic differentiation for two weeks. Engineered tissues based on 3D-expanded chondrocytes were more cartilaginous than tissues generated from chondrocytes previously expanded in flasks. We then demonstrated that this streamlined bioreactor-based process could be adapted to effectively generate up-scaled cartilage grafts in a size with clinical relevance (50 mm diameter). Streamlined and robust tissue engineering processes, as the one described here, may be key for the future manufacturing of grafts for clinical applications, as they facilitate the establishment of compact and closed bioreactor-based production systems, with minimal automation requirements, lower operating costs, and increased compliance to regulatory guidelines.

  11. Streamlining cardiovascular clinical trials to improve efficiency and generalisability.

    Science.gov (United States)

    Zannad, Faiez; Pfeffer, Marc A; Bhatt, Deepak L; Bonds, Denise E; Borer, Jeffrey S; Calvo-Rojas, Gonzalo; Fiore, Louis; Lund, Lars H; Madigan, David; Maggioni, Aldo Pietro; Meyers, Catherine M; Rosenberg, Yves; Simon, Tabassome; Stough, Wendy Gattis; Zalewski, Andrew; Zariffa, Nevine; Temple, Robert

    2017-08-01

    Controlled trials provide the most valid determination of the efficacy and safety of an intervention, but large cardiovascular clinical trials have become extremely costly and complex, making it difficult to study many important clinical questions. A critical question, and the main objective of this review, is how trials might be simplified while maintaining randomisation to preserve scientific integrity and unbiased efficacy assessments. Experience with alternative approaches is accumulating, specifically with registry-based randomised controlled trials that make use of data already collected. This approach addresses bias concerns while still capitalising on the benefits and efficiencies of a registry. Several completed or ongoing trials illustrate the feasibility of using registry-based controlled trials to answer important questions relevant to daily clinical practice. Randomised trials within healthcare organisation databases may also represent streamlined solutions for some types of investigations, although data quality (endpoint assessment) is likely to be a greater concern in those settings. These approaches are not without challenges, and issues pertaining to informed consent, blinding, data quality and regulatory standards remain to be fully explored. Collaboration among stakeholders is necessary to achieve standards for data management and analysis, to validate large data sources for use in randomised trials, and to re-evaluate ethical standards to encourage research while also ensuring that patients are protected. The rapidly evolving efforts to streamline cardiovascular clinical trials have the potential to lead to major advances in promoting better care and outcomes for patients with cardiovascular disease. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  12. Parametric imaging of collagen structural changes in human osteoarthritic cartilage using optical polarization tractography

    Science.gov (United States)

    Ravanfar, Mohammadreza; Pfeiffer, Ferris M.; Bozynski, Chantelle C.; Wang, Yuanbo; Yao, Gang

    2017-12-01

    Collagen degeneration is an important pathological feature of osteoarthritis. The purpose of this study is to investigate whether the polarization-sensitive optical coherence tomography (PSOCT)-based optical polarization tractography (OPT) can be useful in imaging collagen structural changes in human osteoarthritic cartilage samples. OPT eliminated the banding artifacts in conventional PSOCT by calculating the depth-resolved local birefringence and fiber orientation. A close comparison between OPT and PSOCT showed that OPT provided improved visualization and characterization of the zonal structure in human cartilage. Experimental results obtained in this study also underlined the importance of knowing the collagen fiber orientation in conventional polarized light microscopy assessment. In addition, parametric OPT imaging was achieved by quantifying the surface roughness, birefringence, and fiber dispersion in the superficial zone of the cartilage. These quantitative parametric images provided complementary information on the structural changes in cartilage, which can be useful for a comprehensive evaluation of collagen damage in osteoarthritic cartilage.

  13. Diffusion tensor imaging with quantitative evaluation and fiber tractography of lumbar nerve roots in sciatica

    International Nuclear Information System (INIS)

    Shi, Yin; Zong, Min; Xu, Xiaoquan; Zou, Yuefen; Feng, Yang; Liu, Wei; Wang, Chuanbing; Wang, Dehang

    2015-01-01

    Highlights: •In the present study, we first elected ROIs corresponding to the proximal, medial, and distal levels of the lumbar foraminal zone. •The ROC analysis for FA values of distal nerves indicated a high level of reliability in the diagnosis of sciatica. •The declining trend of FA values from proximal to distal along the nerve tract may correlate with the disparity of axonal regeneration at different levels. •DTI is able to quantitatively evaluate compressed nerve roots and has a higher sensitivity and specificity for diagnosing sciatica than conventional MR imaging. •DTT enables visualization of abnormal nerve tracts, providing vivid anatomic information and probable localization of nerve compression. -- Abstract: Objective: To quantitatively evaluate nerve roots by measuring fractional anisotropy (FA) values in healthy volunteers and sciatica patients, visualize nerve roots by tractography, and compare the diagnostic efficacy between conventional magnetic resonance imaging (MRI) and DTI. Materials and methods: Seventy-five sciatica patients and thirty-six healthy volunteers underwent MR imaging using DTI. FA values for L5–S1 lumbar nerve roots were calculated at three levels from DTI images. Tractography was performed on L3–S1 nerve roots. ROC analysis was performed for FA values. Results: The lumbar nerve roots were visualized and FA values were calculated in all subjects. FA values decreased in compressed nerve roots and declined from proximal to distal along the compressed nerve tracts. Mean FA values were more sensitive and specific than MR imaging for differentiating compressed nerve roots, especially in the far lateral zone at distal nerves. Conclusions: DTI can quantitatively evaluate compressed nerve roots, and DTT enables visualization of abnormal nerve tracts, providing vivid anatomic information and localization of probable nerve compression. DTI has great potential utility for evaluating lumbar nerve compression in sciatica

  14. Diffusion tensor imaging with quantitative evaluation and fiber tractography of lumbar nerve roots in sciatica

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Yin; Zong, Min; Xu, Xiaoquan; Zou, Yuefen; Feng, Yang; Liu, Wei; Wang, Chuanbing; Wang, Dehang, E-mail: njmu_wangdehang@126.com

    2015-04-15

    Highlights: •In the present study, we first elected ROIs corresponding to the proximal, medial, and distal levels of the lumbar foraminal zone. •The ROC analysis for FA values of distal nerves indicated a high level of reliability in the diagnosis of sciatica. •The declining trend of FA values from proximal to distal along the nerve tract may correlate with the disparity of axonal regeneration at different levels. •DTI is able to quantitatively evaluate compressed nerve roots and has a higher sensitivity and specificity for diagnosing sciatica than conventional MR imaging. •DTT enables visualization of abnormal nerve tracts, providing vivid anatomic information and probable localization of nerve compression. -- Abstract: Objective: To quantitatively evaluate nerve roots by measuring fractional anisotropy (FA) values in healthy volunteers and sciatica patients, visualize nerve roots by tractography, and compare the diagnostic efficacy between conventional magnetic resonance imaging (MRI) and DTI. Materials and methods: Seventy-five sciatica patients and thirty-six healthy volunteers underwent MR imaging using DTI. FA values for L5–S1 lumbar nerve roots were calculated at three levels from DTI images. Tractography was performed on L3–S1 nerve roots. ROC analysis was performed for FA values. Results: The lumbar nerve roots were visualized and FA values were calculated in all subjects. FA values decreased in compressed nerve roots and declined from proximal to distal along the compressed nerve tracts. Mean FA values were more sensitive and specific than MR imaging for differentiating compressed nerve roots, especially in the far lateral zone at distal nerves. Conclusions: DTI can quantitatively evaluate compressed nerve roots, and DTT enables visualization of abnormal nerve tracts, providing vivid anatomic information and localization of probable nerve compression. DTI has great potential utility for evaluating lumbar nerve compression in sciatica.

  15. The Safe Area in the Parieto-Occipital Lobe in the Human Brain: Diffusion Tensor Tractography.

    Science.gov (United States)

    Jang, Sung Ho; Kim, Seong Ho; Kwon, Hyeok Gyu

    2015-06-01

    A recent study reported on the relatively safe area in the frontal lobe for performance of neurological interventions; however, no study on the posterior safe area has been reported. In this study, using diffusion tensor tractography, we attempted to identify the safe area in the parieto-occipital lobe in healthy subjects. A total of 47 healthy subjects were recruited for this study. Eleven neural tracts were reconstructed in and around the parieto-occipital area of the brain using diffusion tensor tractography. The safe area, which is free from any trajectory of 10 neural tracts, was measured anteriorly and medially from the line of the most posterior and lateral margin of the brain at 5 axial levels (from the cerebral cortex to the corona radiata). The anterior boundaries of the safe area in the upper cerebral cortex, lower cerebral cortex, centrum semiovale, upper corona radiata, and lower corona radiata levels were located at 31.0, 32.6, 32.7, 35.1, and 35.2 mm anteriorly from the line of the most posterior margin of the brain, respectively, and the medial boundaries were located at an average of 34.7, 38.1, 39.2, 36.1, and 33.6 mm medially from the line of the most lateral margin of the brain, respectively. According to our findings, the safe area was located in the posterolateral portion of the parieto-occipital lobe in the shape of a triangle. However, we found no safe area in the deep white matter around the lateral ventricle. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. Measuring Connectivity in the Primary Visual Pathway in Human Albinism Using Diffusion Tensor Imaging and Tractography.

    Science.gov (United States)

    Grigorian, Anahit; McKetton, Larissa; Schneider, Keith A

    2016-08-11

    In albinism, the number of ipsilaterally projecting retinal ganglion cells (RGCs) is significantly reduced. The retina and optic chiasm have been proposed as candidate sites for misrouting. Since a correlation between the number of lateral geniculate nucleus (LGN) relay neurons and LGN size has been shown, and based on previously reported reductions in LGN volumes in human albinism, we suggest that fiber projections from LGN to the primary visual cortex (V1) are also reduced. Studying structural differences in the visual system of albinism can improve the understanding of the mechanism of misrouting and subsequent clinical applications. Diffusion data and tractography are useful for mapping the OR (optic radiation). This manuscript describes two algorithms for OR reconstruction in order to compare brain connectivity in albinism and controls.An MRI scanner with a 32-channel head coil was used to acquire structural scans. A T1-weighted 3D-MPRAGE sequence with 1 mm(3) isotropic voxel size was used to generate high-resolution images for V1 segmentation. Multiple proton density (PD) weighted images were acquired coronally for right and left LGN localization. Diffusion tensor imaging (DTI) scans were acquired with 64 diffusion directions. Both deterministic and probabilistic tracking methods were run and compared, with LGN as the seed mask and V1 as the target mask. Though DTI provides relatively poor spatial resolution, and accurate delineation of OR may be challenging due to its low fiber density, tractography has been shown to be advantageous both in research and clinically. Tract based spatial statistics (TBSS) revealed areas of significantly reduced white matter integrity within the OR in patients with albinism compared to controls. Pairwise comparisons revealed a significant reduction in LGN to V1 connectivity in albinism compared to controls. Comparing both tracking algorithms revealed common findings, strengthening the reliability of the technique.

  17. Fiber architecture in remodeled myocardium revealed with a quantitative diffusion CMR tractography framework and histological validation

    Directory of Open Access Journals (Sweden)

    Mekkaoui Choukri

    2012-10-01

    Full Text Available Abstract Background The study of myofiber reorganization in the remote zone after myocardial infarction has been performed in 2D. Microstructural reorganization in remodeled hearts, however, can only be fully appreciated by considering myofibers as continuous 3D entities. The aim of this study was therefore to develop a technique for quantitative 3D diffusion CMR tractography of the heart, and to apply this method to quantify fiber architecture in the remote zone of remodeled hearts. Methods Diffusion Tensor CMR of normal human, sheep, and rat hearts, as well as infarcted sheep hearts was performed ex vivo. Fiber tracts were generated with a fourth-order Runge-Kutta integration technique and classified statistically by the median, mean, maximum, or minimum helix angle (HA along the tract. An index of tract coherence was derived from the relationship between these HA statistics. Histological validation was performed using phase-contrast microscopy. Results In normal hearts, the subendocardial and subepicardial myofibers had a positive and negative HA, respectively, forming a symmetric distribution around the midmyocardium. However, in the remote zone of the infarcted hearts, a significant positive shift in HA was observed. The ratio between negative and positive HA variance was reduced from 0.96 ± 0.16 in normal hearts to 0.22 ± 0.08 in the remote zone of the remodeled hearts (p Conclusions A significant reorganization of the 3D fiber continuum is observed in the remote zone of remodeled hearts. The positive (rightward shift in HA in the remote zone is greatest in the subepicardium, but involves all layers of the myocardium. Tractography-based quantification, performed here for the first time in remodeled hearts, may provide a framework for assessing regional changes in the left ventricle following infarction.

  18. Streamlined islands and the English Channel megaflood hypothesis

    Science.gov (United States)

    Collier, J. S.; Oggioni, F.; Gupta, S.; García-Moreno, D.; Trentesaux, A.; De Batist, M.

    2015-12-01

    Recognising ice-age catastrophic megafloods is important because they had significant impact on large-scale drainage evolution and patterns of water and sediment movement to the oceans, and likely induced very rapid, short-term effects on climate. It has been previously proposed that a drainage system on the floor of the English Channel was initiated by catastrophic flooding in the Pleistocene but this suggestion has remained controversial. Here we examine this hypothesis through an analysis of key landform features. We use a new compilation of multi- and single-beam bathymetry together with sub-bottom profiler data to establish the internal structure, planform geometry and hence origin of a set of 36 mid-channel islands. Whilst there is evidence of modern-day surficial sediment processes, the majority of the islands can be clearly demonstrated to be formed of bedrock, and are hence erosional remnants rather than depositional features. The islands display classic lemniscate or tear-drop outlines, with elongated tips pointing downstream, typical of streamlined islands formed during high-magnitude water flow. The length-to-width ratio for the entire island population is 3.4 ± 1.3 and the degree-of-elongation or k-value is 3.7 ± 1.4. These values are comparable to streamlined islands in other proven Pleistocene catastrophic flood terrains and are distinctly different to values found in modern-day rivers. The island geometries show a correlation with bedrock type: with those carved from Upper Cretaceous chalk having larger length-to-width ratios (3.2 ± 1.3) than those carved into more mixed Paleogene terrigenous sandstones, siltstones and mudstones (3.0 ± 1.5). We attribute these differences to the former rock unit having a lower skin friction which allowed longer island growth to achieve minimum drag. The Paleogene islands, although less numerous than the Chalk islands, also assume more perfect lemniscate shapes. These lithologies therefore reached island

  19. Streamlining Collaboration for the Gravitational-wave Astronomy Community

    Science.gov (United States)

    Koranda, S.

    2016-12-01

    In the morning hours of September 14, 2015 the LaserInterferometer Gravitational-wave Observatory (LIGO) directlydetected gravitational waves from inspiraling and coalescingblack holes, confirming a major prediction of AlbertEinstein's general theory of relativity and beginning the eraof gravitational-wave astronomy. With the LIGO detectors in the United States, the Virgo andGEO detectors in Europe, and the KAGRA detector in Japan thegravitational-wave astrononmy community is opening a newwindow on our Universe. Realizing the full science potentialof LIGO and the other interferometers requires globalcollaboration not only within the gravitational-wave astronomycommunity but also with the astronomers and astrophysicists acrossmultipe disciplines working to realize and leverage the powerof multi-messenger astronomy. Enabling thousands of researchers from around the world andacross multiple projects to efficiently collaborate, share,and analyze data and provide streamlined access to services,computing, and tools requires new and scalable approaches toidentity and access management (IAM). We will discuss LIGO'sIAM journey that began in 2007 and how today LIGO leveragesinternal identity federations like InCommon and eduGAIN toprovide scalable and managed access for the gravitational-waveastronomy community. We will discuss the steps both largeand small research organizations and projects take as theirIAM infrastructure matures from ad-hoc silos of independent services to fully integrated and federated services thatstreamline collaboration so that scientists can focus onresearch and not managing passwords.

  20. Damage Detection with Streamlined Structural Health Monitoring Data

    Directory of Open Access Journals (Sweden)

    Jian Li

    2015-04-01

    Full Text Available The huge amounts of sensor data generated by large scale sensor networks in on-line structural health monitoring (SHM systems often overwhelms the systems’ capacity for data transmission and analysis. This paper presents a new concept for an integrated SHM system in which a streamlined data flow is used as a unifying thread to integrate the individual components of on-line SHM systems. Such an integrated SHM system has a few desirable functionalities including embedded sensor data compression, interactive sensor data retrieval, and structural knowledge discovery, which aim to enhance the reliability, efficiency, and robustness of on-line SHM systems. Adoption of this new concept will enable the design of an on-line SHM system with more uniform data generation and data handling capacity for its subsystems. To examine this concept in the context of vibration-based SHM systems, real sensor data from an on-line SHM system comprising a scaled steel bridge structure and an on-line data acquisition system with remote data access was used in this study. Vibration test results clearly demonstrated the prominent performance characteristics of the proposed integrated SHM system including rapid data access, interactive data retrieval and knowledge discovery of structural conditions on a global level.

  1. Damage detection with streamlined structural health monitoring data.

    Science.gov (United States)

    Li, Jian; Deng, Jun; Xie, Weizhi

    2015-04-15

    The huge amounts of sensor data generated by large scale sensor networks in on-line structural health monitoring (SHM) systems often overwhelms the systems' capacity for data transmission and analysis. This paper presents a new concept for an integrated SHM system in which a streamlined data flow is used as a unifying thread to integrate the individual components of on-line SHM systems. Such an integrated SHM system has a few desirable functionalities including embedded sensor data compression, interactive sensor data retrieval, and structural knowledge discovery, which aim to enhance the reliability, efficiency, and robustness of on-line SHM systems. Adoption of this new concept will enable the design of an on-line SHM system with more uniform data generation and data handling capacity for its subsystems. To examine this concept in the context of vibration-based SHM systems, real sensor data from an on-line SHM system comprising a scaled steel bridge structure and an on-line data acquisition system with remote data access was used in this study. Vibration test results clearly demonstrated the prominent performance characteristics of the proposed integrated SHM system including rapid data access, interactive data retrieval and knowledge discovery of structural conditions on a global level.

  2. An integrated billing application to streamline clinician workflow.

    Science.gov (United States)

    Vawdrey, David K; Walsh, Colin; Stetson, Peter D

    2014-01-01

    Between 2008 and 2010, our academic medical center transitioned to electronic provider documentation using a commercial electronic health record system. For attending physicians, one of the most frustrating aspects of this experience was the system's failure to support their existing electronic billing workflow. Because of poor system integration, it was difficult to verify the supporting documentation for each bill and impractical to track whether billable notes had corresponding charges. We developed and deployed in 2011 an integrated billing application called "iCharge" that streamlines clinicians' documentation and billing workflow, and simultaneously populates the inpatient problem list using billing diagnosis codes. Each month, over 550 physicians use iCharge to submit approximately 23,000 professional service charges for over 4,200 patients. On average, about 2.5 new problems are added to each patient's problem list. This paper describes the challenges and benefits of workflow integration across disparate applications and presents an example of innovative software development within a commercial EHR framework.

  3. Lessons learned in streamlining the preparation of SNM standard solutions

    International Nuclear Information System (INIS)

    Clark, J.P.; Johnson, S.R.

    1986-01-01

    Improved safeguard measurements have produced a demand for greater quantities of reliable SNM solution standards. At the Savannah River Plant (SRP), the demand for these standards has been met by several innovations to improve the productivity and reliability of standards preparations. With the use of computer controlled balance, large batches of SNM stock solutions are prepared on a gravimetric basis. Accurately dispensed quantities of the stock solution are weighed and stored in bottles. When needed, they are quantitatively transferred to tared containers, matrix adjusted to target concentrations, weighed, and measured for density at 25 0 C. Concentrations of SNM are calculated both gravimetrically and volumetrically. Calculated values are confirmed analytically before the standards are used in measurement control program (MCP) activities. The lessons learned include: MCP goals include error identification and management. Strategy modifications are required to improve error management. Administrative controls can minimize certain types of errors. Automation can eliminate redundancy and streamline preparations. Prudence and simplicity enhance automation success. The effort expended to increase productivity has increased the reliability of standards and provided better documentation for quality assurance

  4. VISMASHUP: streamlining the creation of custom visualization applications

    Energy Technology Data Exchange (ETDEWEB)

    Ahrens, James P [Los Alamos National Laboratory; Santos, Emanuele [UNIV OF UTAH; Lins, Lauro [UNIV OF UTAH; Freire, Juliana [UNIV OF UTAH; Silva, Cl' audio T [UNIV OF UTAH

    2010-01-01

    Visualization is essential for understanding the increasing volumes of digital data. However, the process required to create insightful visualizations is involved and time consuming. Although several visualization tools are available, including tools with sophisticated visual interfaces, they are out of reach for users who have little or no knowledge of visualization techniques and/or who do not have programming expertise. In this paper, we propose VISMASHUP, a new framework for streamlining the creation of customized visualization applications. Because these applications can be customized for very specific tasks, they can hide much of the complexity in a visualization specification and make it easier for users to explore visualizations by manipulating a small set of parameters. We describe the framework and how it supports the various tasks a designer needs to carry out to develop an application, from mining and exploring a set of visualization specifications (pipelines), to the creation of simplified views of the pipelines, and the automatic generation of the application and its interface. We also describe the implementation of the system and demonstrate its use in two real application scenarios.

  5. Microdiversification in genome-streamlined ubiquitous freshwater Actinobacteria.

    Science.gov (United States)

    Neuenschwander, Stefan M; Ghai, Rohit; Pernthaler, Jakob; Salcher, Michaela M

    2018-01-01

    Actinobacteria of the acI lineage are the most abundant microbes in freshwater systems, but there are so far no pure living cultures of these organisms, possibly because of metabolic dependencies on other microbes. This, in turn, has hampered an in-depth assessment of the genomic basis for their success in the environment. Here we present genomes from 16 axenic cultures of acI Actinobacteria. The isolates were not only of minute cell size, but also among the most streamlined free-living microbes, with extremely small genome sizes (1.2-1.4 Mbp) and low genomic GC content. Genome reduction in these bacteria might have led to auxotrophy for various vitamins, amino acids and reduced sulphur sources, thus creating dependencies to co-occurring organisms (the 'Black Queen' hypothesis). Genome analyses, moreover, revealed a surprising degree of inter- and intraspecific diversity in metabolic pathways, especially of carbohydrate transport and metabolism, and mainly encoded in genomic islands. The striking genotype microdiversification of acI Actinobacteria might explain their global success in highly dynamic freshwater environments with complex seasonal patterns of allochthonous and autochthonous carbon sources. We propose a new order within Actinobacteria ('Candidatus Nanopelagicales') with two new genera ('Candidatus Nanopelagicus' and 'Candidatus Planktophila') and nine new species.

  6. A streamlined artificial variable free version of simplex method.

    Directory of Open Access Journals (Sweden)

    Syed Inayatullah

    Full Text Available This paper proposes a streamlined form of simplex method which provides some great benefits over traditional simplex method. For instance, it does not need any kind of artificial variables or artificial constraints; it could start with any feasible or infeasible basis of an LP. This method follows the same pivoting sequence as of simplex phase 1 without showing any explicit description of artificial variables which also makes it space efficient. Later in this paper, a dual version of the new method has also been presented which provides a way to easily implement the phase 1 of traditional dual simplex method. For a problem having an initial basis which is both primal and dual infeasible, our methods provide full freedom to the user, that whether to start with primal artificial free version or dual artificial free version without making any reformulation to the LP structure. Last but not the least, it provides a teaching aid for the teachers who want to teach feasibility achievement as a separate topic before teaching optimality achievement.

  7. A streamlined artificial variable free version of simplex method.

    Science.gov (United States)

    Inayatullah, Syed; Touheed, Nasir; Imtiaz, Muhammad

    2015-01-01

    This paper proposes a streamlined form of simplex method which provides some great benefits over traditional simplex method. For instance, it does not need any kind of artificial variables or artificial constraints; it could start with any feasible or infeasible basis of an LP. This method follows the same pivoting sequence as of simplex phase 1 without showing any explicit description of artificial variables which also makes it space efficient. Later in this paper, a dual version of the new method has also been presented which provides a way to easily implement the phase 1 of traditional dual simplex method. For a problem having an initial basis which is both primal and dual infeasible, our methods provide full freedom to the user, that whether to start with primal artificial free version or dual artificial free version without making any reformulation to the LP structure. Last but not the least, it provides a teaching aid for the teachers who want to teach feasibility achievement as a separate topic before teaching optimality achievement.

  8. Diffusion tensor tractography of the arcuate fasciculus in patients with brain tumors: Comparison between deterministic and probabilistic models.

    Science.gov (United States)

    Li, Zhixi; Peck, Kyung K; Brennan, Nicole P; Jenabi, Mehrnaz; Hsu, Meier; Zhang, Zhigang; Holodny, Andrei I; Young, Robert J

    2013-02-01

    The purpose of this study was to compare the deterministic and probabilistic tracking methods of diffusion tensor white matter fiber tractography in patients with brain tumors. We identified 29 patients with left brain tumors probabilistic method based on an extended Monte Carlo Random Walk algorithm. Tracking was controlled using two ROIs corresponding to Broca's and Wernicke's areas. Tracts in tumoraffected hemispheres were examined for extension between Broca's and Wernicke's areas, anterior-posterior length and volume, and compared with the normal contralateral tracts. Probabilistic tracts displayed more complete anterior extension to Broca's area than did FACT tracts on the tumor-affected and normal sides (p probabilistic tracts than FACT tracts (p probabilistic tracts than FACT tracts (p = 0.01). Probabilistic tractography reconstructs the arcuate fasciculus more completely and performs better through areas of tumor and/or edema. The FACT algorithm tends to underestimate the anterior-most fibers of the arcuate fasciculus, which are crossed by primary motor fibers.

  9. Quantitative Tractography and Volumetric MRI in Blast and Blunt Force TBI: Predictors of Neurocognitive and Behavioral Outcome

    Science.gov (United States)

    2016-10-01

    no conflicts of interest. Funding This work was supported by grants awarded by the Veterans Affairs: a Career Development Award to D.S. (2–065-10S...Benner, T., Soensen, A. G., & Wedeen, V. J. (2007). Diffusion toolkit : a software package for diffusion imaging data processing and tractography. Proc Intl...by the Veterans Affairs ( Career Development Awards [CDA]: LD-W, DS; Merit Award, LD-W) as well as the Department of Defense (Investigator-Initiated

  10. Periventricular Nodular Heterotopia: Detection of Abnormal Microanatomic Fiber Structures with Whole-Brain Diffusion MR Imaging Tractography.

    Science.gov (United States)

    Farquharson, Shawna; Tournier, J-Donald; Calamante, Fernando; Mandelstam, Simone; Burgess, Rosemary; Schneider, Michal E; Berkovic, Samuel F; Scheffer, Ingrid E; Jackson, Graeme D; Connelly, Alan

    2016-12-01

    Purpose To investigate whether it is possible in patients with periventricular nodular heterotopia (PVNH) to detect abnormal fiber projections that have only previously been reported in the histopathology literature. Materials and Methods Whole-brain diffusion-weighted (DW) imaging data from 14 patients with bilateral PVNH and 14 age- and sex-matched healthy control subjects were prospectively acquired by using 3.0-T magnetic resonance (MR) imaging between August 1, 2008, and December 5, 2012. All participants provided written informed consent. The DW imaging data were processed to generate whole-brain constrained spherical deconvolution (CSD)-based tractography data and super-resolution track-density imaging (TDI) maps. The tractography data were overlaid on coregistered three-dimensional T1-weighted images to visually assess regions of heterotopia. A panel of MR imaging researchers independently assessed each case and indicated numerically (no = 1, yes = 2) as to the presence of abnormal fiber tracks in nodular tissue. The Fleiss κ statistical measure was applied to assess the reader agreement. Results Abnormal fiber tracks emanating from one or more regions of heterotopia were reported by all four readers in all 14 patients with PVNH (Fleiss κ = 1). These abnormal structures were not visible on the tractography data from any of the control subjects and were not discernable on the conventional T1-weighted images of the patients with PVNH. Conclusion Whole-brain CSD-based fiber tractography and super-resolution TDI mapping reveals abnormal fiber projections in nodular tissue suggestive of abnormal organization of white matter (with abnormal fibers both within nodules and projecting to the surrounding white matter) in patients with bilateral PVNH. © RSNA, 2016.

  11. Diffusion tensor tractography-based analysis of the cingulum: clinical utility and findings in traumatic brain injury with chronic sequels

    International Nuclear Information System (INIS)

    Kurki, Timo; Himanen, Leena; Vuorinen, Elina; Myllyniemi, Anna; Saarenketo, Anna-Riitta; Kauko, Tommi; Brandstack, Nina; Tenovuo, Olli

    2014-01-01

    To evaluate the clinical utility of quantitative diffusion tensor tractography (DTT) and tractography-based core analysis (TBCA) of the cingulum by defining the reproducibility, normal values, and findings in traumatic brain injury (TBI). Eighty patients with TBI and normal routine MRI and 78 controls underwent MRI at 3T. To determine reproducibility, 12 subjects were scanned twice. Superior (SC) and inferior (IC) cingulum were analyzed separately by DTT (fractional anisotropy (FA) thresholds 0.15 and 0.30). TBCA was performed from volumes defined by tractography with gradually changed FA thresholds. FA values were correlated with clinical and neuropsychological data. The lowest coefficient of variation was obtained at DTT threshold 0.30 (2.0 and 2.4 % for SC and IC, respectively), but in proportion to standard deviations of normal controls, the reproducibility of TBCA was better in SC and similar to that of DTT in IC. In patients with TBI, volume reduction with loss of peripheral fibers was relatively common; mean FA was mostly normal in these tractograms. The frequency of FA reductions (>2 SD) was in DTT smaller than in TBCA, in which FA decrease was present in 42 (13.1 %) of the 320 measurements. Central FA values in SC predicted visuoperceptual ability, and those in left IC predicted cognitive speed, language, and communication ability (p < 0.05). Tractography-based measurements have sufficient reproducibility for demonstration of severe abnormalities of the cingulum. TBCA is preferential for clinical FA analysis, because it measures corresponding areas in patients and controls without inaccuracies due to trauma-induced structural changes. (orig.)

  12. Diffusion tensor tractography-based analysis of the cingulum: clinical utility and findings in traumatic brain injury with chronic sequels

    Energy Technology Data Exchange (ETDEWEB)

    Kurki, Timo [Turku University Hospital, Department of Radiology, Turku (Finland); MRI Unit, Terveystalo Pulssi Medical Centre, Turku (Finland); Himanen, Leena; Vuorinen, Elina; Myllyniemi, Anna; Saarenketo, Anna-Riitta [NeuTera Neuropsychologist Centre, Turku (Finland); Kauko, Tommi [University of Turku, Department of Biostatistics, Turku (Finland); Brandstack, Nina [Turku University Hospital, Department of Radiology, Turku (Finland); Helsinki University Hospital, Department of Radiology, Helsinki (Finland); Tenovuo, Olli [Turku University Hospital and University of Turku, Department of Rehabilitation and Brain Trauma, Turku (Finland)

    2014-10-15

    To evaluate the clinical utility of quantitative diffusion tensor tractography (DTT) and tractography-based core analysis (TBCA) of the cingulum by defining the reproducibility, normal values, and findings in traumatic brain injury (TBI). Eighty patients with TBI and normal routine MRI and 78 controls underwent MRI at 3T. To determine reproducibility, 12 subjects were scanned twice. Superior (SC) and inferior (IC) cingulum were analyzed separately by DTT (fractional anisotropy (FA) thresholds 0.15 and 0.30). TBCA was performed from volumes defined by tractography with gradually changed FA thresholds. FA values were correlated with clinical and neuropsychological data. The lowest coefficient of variation was obtained at DTT threshold 0.30 (2.0 and 2.4 % for SC and IC, respectively), but in proportion to standard deviations of normal controls, the reproducibility of TBCA was better in SC and similar to that of DTT in IC. In patients with TBI, volume reduction with loss of peripheral fibers was relatively common; mean FA was mostly normal in these tractograms. The frequency of FA reductions (>2 SD) was in DTT smaller than in TBCA, in which FA decrease was present in 42 (13.1 %) of the 320 measurements. Central FA values in SC predicted visuoperceptual ability, and those in left IC predicted cognitive speed, language, and communication ability (p < 0.05). Tractography-based measurements have sufficient reproducibility for demonstration of severe abnormalities of the cingulum. TBCA is preferential for clinical FA analysis, because it measures corresponding areas in patients and controls without inaccuracies due to trauma-induced structural changes. (orig.)

  13. Industrial Compositional Streamline Simulation for Efficient and Accurate Prediction of Gas Injection and WAG Processes

    Energy Technology Data Exchange (ETDEWEB)

    Margot Gerritsen

    2008-10-31

    Gas-injection processes are widely and increasingly used for enhanced oil recovery (EOR). In the United States, for example, EOR production by gas injection accounts for approximately 45% of total EOR production and has tripled since 1986. The understanding of the multiphase, multicomponent flow taking place in any displacement process is essential for successful design of gas-injection projects. Due to complex reservoir geometry, reservoir fluid properties and phase behavior, the design of accurate and efficient numerical simulations for the multiphase, multicomponent flow governing these processes is nontrivial. In this work, we developed, implemented and tested a streamline based solver for gas injection processes that is computationally very attractive: as compared to traditional Eulerian solvers in use by industry it computes solutions with a computational speed orders of magnitude higher and a comparable accuracy provided that cross-flow effects do not dominate. We contributed to the development of compositional streamline solvers in three significant ways: improvement of the overall framework allowing improved streamline coverage and partial streamline tracing, amongst others; parallelization of the streamline code, which significantly improves wall clock time; and development of new compositional solvers that can be implemented along streamlines as well as in existing Eulerian codes used by industry. We designed several novel ideas in the streamline framework. First, we developed an adaptive streamline coverage algorithm. Adding streamlines locally can reduce computational costs by concentrating computational efforts where needed, and reduce mapping errors. Adapting streamline coverage effectively controls mass balance errors that mostly result from the mapping from streamlines to pressure grid. We also introduced the concept of partial streamlines: streamlines that do not necessarily start and/or end at wells. This allows more efficient coverage and avoids

  14. Stream-lined Gating Systems with Improved Yield - Dimensioning and Experimental Validation

    DEFF Research Database (Denmark)

    Tiedje, Niels Skat; Skov-Hansen, Søren Peter

    the two types of lay-outs are cast in production. It is shown that flow in the stream-lined lay-out is well controlled and that the quality of the castings is as at least equal to that of castings produced with a traditional lay-out. Further, the yield is improved by 4 % relative to a traditional lay-out.......The paper describes how a stream-lined gating system where the melt is confined and controlled during filling can be designed. Commercial numerical modelling software has been used to compare the stream-lined design with a traditional gating system. These results are confirmed by experiments where...

  15. Three-dimensional white matter tractography by diffusion tensor imaging in ischaemic stroke involving the corticospinal tract

    International Nuclear Information System (INIS)

    Kunimatsu, A.; Aoki, S.; Masutani, Y.; Abe, O.; Mori, H.; Ohtomo, K.

    2003-01-01

    Diffusion tensor MR imaging (DTI) provides information on diffusion anisotropy, which can be expressed with three-dimensional (3D) white matter tractography. We used 3D white matter tractography to show the corticospinal tract in eight patients with acute or early subacute ischaemic stroke involving the posterior limb of the internal capsule or corona radiata and to assess involvement of the tract. Infarcts and the tract were shown simultaneously, providing information on their spatial relationships. In five of the eight patients, 3D fibre tract maps showed the corticospinal tract in close proximity to the infarct but not to pass through it. All these patients recovered well, with maximum improvement from the lowest score on manual muscle testing (MMT) up to the full score through rehabilitation. In the other three patients the corticospinal tract was shown running through the infarct; reduction in MMT did not necessarily improve favourably or last longer, other than in one patient. As 3D white matter tractography can show spatial relationships between the corticospinal tract and an infarct, it might be helpful in prognosis of gross motor function. (orig.)

  16. Three-dimensional white matter tractography by diffusion tensor imaging in ischaemic stroke involving the corticospinal tract

    Energy Technology Data Exchange (ETDEWEB)

    Kunimatsu, A.; Aoki, S.; Masutani, Y.; Abe, O.; Mori, H.; Ohtomo, K. [Department of Radiology, Graduate School of Medicine, Tokyo University, 7-3-1 Hongo, Bunkyo-ku, 113-8655, Tokyo (Japan)

    2003-08-01

    Diffusion tensor MR imaging (DTI) provides information on diffusion anisotropy, which can be expressed with three-dimensional (3D) white matter tractography. We used 3D white matter tractography to show the corticospinal tract in eight patients with acute or early subacute ischaemic stroke involving the posterior limb of the internal capsule or corona radiata and to assess involvement of the tract. Infarcts and the tract were shown simultaneously, providing information on their spatial relationships. In five of the eight patients, 3D fibre tract maps showed the corticospinal tract in close proximity to the infarct but not to pass through it. All these patients recovered well, with maximum improvement from the lowest score on manual muscle testing (MMT) up to the full score through rehabilitation. In the other three patients the corticospinal tract was shown running through the infarct; reduction in MMT did not necessarily improve favourably or last longer, other than in one patient. As 3D white matter tractography can show spatial relationships between the corticospinal tract and an infarct, it might be helpful in prognosis of gross motor function. (orig.)

  17. Migration Pathways of Thalamic Neurons and Development of Thalamocortical Connections in Humans Revealed by Diffusion MR Tractography.

    Science.gov (United States)

    Wilkinson, Molly; Kane, Tara; Wang, Rongpin; Takahashi, Emi

    2017-12-01

    The thalamus plays an important role in signal relays in the brain, with thalamocortical (TC) neuronal pathways linked to various sensory/cognitive functions. In this study, we aimed to see fetal and postnatal development of the thalamus including neuronal migration to the thalamus and the emergence/maturation of the TC pathways. Pathways from/to the thalami of human postmortem fetuses and in vivo subjects ranging from newborns to adults with no neurological histories were studied using high angular resolution diffusion MR imaging (HARDI) tractography. Pathways likely linked to neuronal migration from the ventricular zone and ganglionic eminence (GE) to the thalami were both successfully detected. Between the ventricular zone and thalami, more tractography pathways were found in anterior compared with posterior regions, which was well in agreement with postnatal observations that the anterior TC segment had more tract count and volume than the posterior segment. Three different pathways likely linked to neuronal migration from the GE to the thalami were detected. No hemispheric asymmetry of the TC pathways was quantitatively observed during development. These results suggest that HARDI tractography is useful to identify multiple differential neuronal migration pathways in human brains, and regional differences in brain development in fetal ages persisted in postnatal development. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  18. Abscess of the medulla oblongata in a toddler: case report and technical considerations based on magnetic resonance imaging tractography.

    Science.gov (United States)

    Arzoglou, Vasileios; D'Angelo, Luca; Koutzoglou, Michael; Di Rocco, Concezio

    2011-08-01

    We report a unique case of a toddler (the only one reported) successfully operated on for a medulla oblongata abscess and comment on the influence of neuroimaging modalities in the preoperative planning of the surgical approach. We report a case of a 20-month-old child with a solitary medulla oblongata abscess. The abscess appeared to be in close proximity to the anterior medulla oblongata, but preoperative planning based on diffusion tensor imaging (DTI) tractography motivated us to try to remove this lesion through a midline suboccipital approach. The ventral medulla oblongata abscess was surgically removed via a telovelar approach. At the anterior wall of the 4th ventricle, a fenestration was made with pus release and evacuation of the cavity. The child was discharged 1 week later with an uneventful and full recovery. Modern imaging modalities of the nervous system can be very helpful in preoperative planning. Functional visualization of the nervous system provided by modern imaging techniques, such as the DTI tractography, can alter the classic topographic concept of surgical approach. In the case presented, approaching an anterior medulla oblongata abscess based on DTI tractography data, through a suboccipital midline transventricular approach, proved to be an effective and safe technique.

  19. Tractography of the corticospinal tracts in infants with focal perinatal injury: comparison with normal controls and to motor development

    International Nuclear Information System (INIS)

    Roze, Elise; Harris, Polly A.; Ball, Gareth; Braga, Rodrigo M.; Allsop, Joanna M.; Counsell, Serena J.; Elorza, Leire Zubiaurre; Merchant, Nazakat; Arichi, Tomoki; Edwards, A.D.; Cowan, Frances M.; Porter, Emma; Rutherford, Mary A.

    2012-01-01

    Our aims were to (1) assess the corticospinal tracts (CSTs) in infants with focal injury and healthy term controls using probabilistic tractography and (2) to correlate the conventional magnetic resonance imaging (MRI) and tractography findings in infants with focal injury with their later motor function. We studied 20 infants with focal lesions and 23 controls using MRI and diffusion tensor imaging. Tract volume, fractional anisotropy (FA), apparent diffusion coefficient (ADC) values, axial diffusivity and radial diffusivity (RD) of the CSTs were determined. Asymmetry indices (AIs) were calculated by comparing ipsilateral to contralateral CSTs. Motor outcome was assessed using a standardized neurological examination. Conventional MRI was able to predict normal motor development (n = 9) or hemiplegia (n = 6). In children who developed a mild motor asymmetry (n = 5), conventional MRI predicted a hemiplegia in two and normal motor development in three infants. The AIs for tract volume, FA, ADC and RD showed a significant difference between controls and infants who developed a hemiplegia, and RD also showed a significant difference in AI between controls and infants who developed a mild asymmetry. Conventional MRI was able to predict subsequent normal motor development or hemiplegia following focal injury in newborn infants. Measures of RD obtained from diffusion tractography may offer additional information for predicting a subsequent asymmetry in motor function. (orig.)

  20. A DTI-based tractography study of effects on brain structure associated with prenatal alcohol exposure in newborns

    Science.gov (United States)

    Taylor, Paul A.; Jacobson, Sandra W.; van der Kouwe, André; Molteno, Christopher D.; Chen, Gang; Wintermark, Pia; Alhamud, Alkathafi; Jacobson, Joseph L.; Meintjes, Ernesta M.

    2014-01-01

    Prenatal alcohol exposure is known to have severe, long-term consequences for brain and behavioral development already detectable in infancy and childhood. Resulting features of fetal alcohol spectrum disorders (FASD) include cognitive and behavioral effects, as well as facial anomalies and growth deficits. Diffusion tensor imaging (DTI) and tractography were used to analyze white matter development in 11 newborns (age since conception <45 weeks) whose mothers were recruited during pregnancy. Comparisons were made with 9 age-matched controls born to abstainers or light drinkers from the same Cape Coloured (mixed ancestry) community near Cape Town, South Africa. DTI parameters, T1 relaxation time, proton density and volumes were used to quantify and investigate group differences in white matter (WM) in the newborn brains. Probabilistic tractography was used to estimate and to delineate similar tract locations among the subjects for transcallosal pathways, cortico-spinal projection fibers and cortico-cortical association fibers. In each of these WM networks, the axial diffusivity AD was the parameter that showed the strongest association with maternal drinking. The strongest relations were observed in medial and inferior WM, regions in which the myelination process typically begins. In contrast to studies of older individuals with prenatal alcohol exposure, FA did not exhibit a consistent and significant relation with alcohol exposure. To our knowledge, this is the first DTI-tractography study of prenatally alcohol exposed newborns. PMID:25182535

  1. MR tractography; Visualization of structure of nerve fiber system from diffusion weighted images with maximum intensity projection method

    Energy Technology Data Exchange (ETDEWEB)

    Kinosada, Yasutomi; Okuda, Yasuyuki (Mie Univ., Tsu (Japan). School of Medicine); Ono, Mototsugu (and others)

    1993-02-01

    We developed a new noninvasive technique to visualize the anatomical structure of the nerve fiber system in vivo, and named this technique magnetic resonance (MR) tractography and the acquired image an MR tractogram. MR tractography has two steps. One is to obtain diffusion-weighted images sensitized along axes appropriate for depicting the intended nerve fibers with anisotropic water diffusion MR imaging. The other is to extract the anatomical structure of the nerve fiber system from a series of diffusion-weighted images by the maximum intensity projection method. To examine the clinical usefulness of the proposed technique, many contiguous, thin (3 mm) coronal two-dimensional sections of the brain were acquired sequentially in normal volunteers and selected patients with paralyses, on a 1.5 Tesla MR system (Signa, GE) with an ECG-gated Stejskal-Tanner pulse sequence. The structure of the nerve fiber system of normal volunteers was almost the same as the anatomy. The tractograms of patients with paralyses clearly showed the degeneration of nerve fibers and were correlated with clinical symptoms. MR tractography showed great promise for the study of neuroanatomy and neuroradiology. (author).

  2. Correlation between pennation angle and image quality of skeletal muscle fibre tractography using deterministic diffusion tensor imaging.

    Science.gov (United States)

    Okamoto, Yoshikazu; Okamoto, Toru; Yuka, Kujiraoka; Hirano, Yuji; Isobe, Tomonori; Minami, Manabu

    2012-12-01

    The aim of this study was to ascertain whether a correlation existed between muscle pennation angle and the ability to successfully perform tractography of the lower leg muscle fibres with deterministic diffusion tensor imaging (DTI) in normal volunteers. Fourteen volunteers aged 20-39 (mean 28.2 years old) were recruited. All volunteers were scanned using DTI, and six fibre tractographs were constructed from one lower leg of each volunteer, and the 'fibre density' was calculated in each of the tractographs. The pennation angle is the angle formed by the muscle fibre and the aponeurosis. The average pennation angle (AVPA) and standard deviation of the pennation angle (SDPA) were also measured for each muscle by ultrasonography in the same region as the MRI scan. For all 84 tractography images, the correlation coefficient between the fibre density and AVPA or SDPA was calculated. Fibre density and AVPA showed a moderate negative correlation (R = -0.72), and fibre density and SDPA showed a weak negative correlation (R = -0.47). With respect to comparisons within each muscle, AVPA and fibre density showed a moderate negative correlation in the gastrocnemius lateralis muscle (R = -0.57). Our data suggest that a larger, more variable pennation angle resulted in worse skeletal muscle tractography using deterministic DTI. © 2012 The Authors. Journal of Medical Imaging and Radiation Oncology © 2012 The Royal Australian and New Zealand College of Radiologists.

  3. Streamlining of the RELAP5-3D Code

    International Nuclear Information System (INIS)

    Mesina, George L; Hykes, Joshua; Guillen, Donna Post

    2007-01-01

    RELAP5-3D is widely used by the nuclear community to simulate general thermal hydraulic systems and has proven to be so versatile that the spectrum of transient two-phase problems that can be analyzed has increased substantially over time. To accommodate the many new types of problems that are analyzed by RELAP5-3D, both the physics and numerical methods of the code have been continuously improved. In the area of computational methods and mathematical techniques, many upgrades and improvements have been made decrease code run time and increase solution accuracy. These include vectorization, parallelization, use of improved equation solvers for thermal hydraulics and neutron kinetics, and incorporation of improved library utilities. In the area of applied nuclear engineering, expanded capabilities include boron and level tracking models, radiation/conduction enclosure model, feedwater heater and compressor components, fluids and corresponding correlations for modeling Generation IV reactor designs, and coupling to computational fluid dynamics solvers. Ongoing and proposed future developments include improvements to the two-phase pump model, conversion to FORTRAN 90, and coupling to more computer programs. This paper summarizes the general improvements made to RELAP5-3D, with an emphasis on streamlining the code infrastructure for improved maintenance and development. With all these past, present and planned developments, it is necessary to modify the code infrastructure to incorporate modifications in a consistent and maintainable manner. Modifying a complex code such as RELAP5-3D to incorporate new models, upgrade numerics, and optimize existing code becomes more difficult as the code grows larger. The difficulty of this as well as the chance of introducing errors is significantly reduced when the code is structured. To streamline the code into a structured program, a commercial restructuring tool, FOR( ) STRUCT, was applied to the RELAP5-3D source files. The

  4. Streamlined, Inexpensive 3D Printing of the Brain and Skull.

    Science.gov (United States)

    Naftulin, Jason S; Kimchi, Eyal Y; Cash, Sydney S

    2015-01-01

    Neuroimaging technologies such as Magnetic Resonance Imaging (MRI) and Computed Tomography (CT) collect three-dimensional data (3D) that is typically viewed on two-dimensional (2D) screens. Actual 3D models, however, allow interaction with real objects such as implantable electrode grids, potentially improving patient specific neurosurgical planning and personalized clinical education. Desktop 3D printers can now produce relatively inexpensive, good quality prints. We describe our process for reliably generating life-sized 3D brain prints from MRIs and 3D skull prints from CTs. We have integrated a standardized, primarily open-source process for 3D printing brains and skulls. We describe how to convert clinical neuroimaging Digital Imaging and Communications in Medicine (DICOM) images to stereolithography (STL) files, a common 3D object file format that can be sent to 3D printing services. We additionally share how to convert these STL files to machine instruction gcode files, for reliable in-house printing on desktop, open-source 3D printers. We have successfully printed over 19 patient brain hemispheres from 7 patients on two different open-source desktop 3D printers. Each brain hemisphere costs approximately $3-4 in consumable plastic filament as described, and the total process takes 14-17 hours, almost all of which is unsupervised (preprocessing = 4-6 hr; printing = 9-11 hr, post-processing = Printing a matching portion of a skull costs $1-5 in consumable plastic filament and takes less than 14 hr, in total. We have developed a streamlined, cost-effective process for 3D printing brain and skull models. We surveyed healthcare providers and patients who confirmed that rapid-prototype patient specific 3D models may help interdisciplinary surgical planning and patient education. The methods we describe can be applied for other clinical, research, and educational purposes.

  5. Streamlined, Inexpensive 3D Printing of the Brain and Skull.

    Directory of Open Access Journals (Sweden)

    Jason S Naftulin

    Full Text Available Neuroimaging technologies such as Magnetic Resonance Imaging (MRI and Computed Tomography (CT collect three-dimensional data (3D that is typically viewed on two-dimensional (2D screens. Actual 3D models, however, allow interaction with real objects such as implantable electrode grids, potentially improving patient specific neurosurgical planning and personalized clinical education. Desktop 3D printers can now produce relatively inexpensive, good quality prints. We describe our process for reliably generating life-sized 3D brain prints from MRIs and 3D skull prints from CTs. We have integrated a standardized, primarily open-source process for 3D printing brains and skulls. We describe how to convert clinical neuroimaging Digital Imaging and Communications in Medicine (DICOM images to stereolithography (STL files, a common 3D object file format that can be sent to 3D printing services. We additionally share how to convert these STL files to machine instruction gcode files, for reliable in-house printing on desktop, open-source 3D printers. We have successfully printed over 19 patient brain hemispheres from 7 patients on two different open-source desktop 3D printers. Each brain hemisphere costs approximately $3-4 in consumable plastic filament as described, and the total process takes 14-17 hours, almost all of which is unsupervised (preprocessing = 4-6 hr; printing = 9-11 hr, post-processing = <30 min. Printing a matching portion of a skull costs $1-5 in consumable plastic filament and takes less than 14 hr, in total. We have developed a streamlined, cost-effective process for 3D printing brain and skull models. We surveyed healthcare providers and patients who confirmed that rapid-prototype patient specific 3D models may help interdisciplinary surgical planning and patient education. The methods we describe can be applied for other clinical, research, and educational purposes.

  6. Streamlined, Inexpensive 3D Printing of the Brain and Skull

    Science.gov (United States)

    Cash, Sydney S.

    2015-01-01

    Neuroimaging technologies such as Magnetic Resonance Imaging (MRI) and Computed Tomography (CT) collect three-dimensional data (3D) that is typically viewed on two-dimensional (2D) screens. Actual 3D models, however, allow interaction with real objects such as implantable electrode grids, potentially improving patient specific neurosurgical planning and personalized clinical education. Desktop 3D printers can now produce relatively inexpensive, good quality prints. We describe our process for reliably generating life-sized 3D brain prints from MRIs and 3D skull prints from CTs. We have integrated a standardized, primarily open-source process for 3D printing brains and skulls. We describe how to convert clinical neuroimaging Digital Imaging and Communications in Medicine (DICOM) images to stereolithography (STL) files, a common 3D object file format that can be sent to 3D printing services. We additionally share how to convert these STL files to machine instruction gcode files, for reliable in-house printing on desktop, open-source 3D printers. We have successfully printed over 19 patient brain hemispheres from 7 patients on two different open-source desktop 3D printers. Each brain hemisphere costs approximately $3–4 in consumable plastic filament as described, and the total process takes 14–17 hours, almost all of which is unsupervised (preprocessing = 4–6 hr; printing = 9–11 hr, post-processing = Printing a matching portion of a skull costs $1–5 in consumable plastic filament and takes less than 14 hr, in total. We have developed a streamlined, cost-effective process for 3D printing brain and skull models. We surveyed healthcare providers and patients who confirmed that rapid-prototype patient specific 3D models may help interdisciplinary surgical planning and patient education. The methods we describe can be applied for other clinical, research, and educational purposes. PMID:26295459

  7. Managing Written Directives: A Software Solution to Streamline Workflow.

    Science.gov (United States)

    Wagner, Robert H; Savir-Baruch, Bital; Gabriel, Medhat S; Halama, James R; Bova, Davide

    2017-06-01

    A written directive is required by the U.S. Nuclear Regulatory Commission for any use of 131 I above 1.11 MBq (30 μCi) and for patients receiving radiopharmaceutical therapy. This requirement has also been adopted and must be enforced by the agreement states. As the introduction of new radiopharmaceuticals increases therapeutic options in nuclear medicine, time spent on regulatory paperwork also increases. The pressure of managing these time-consuming regulatory requirements may heighten the potential for inaccurate or incomplete directive data and subsequent regulatory violations. To improve on the paper-trail method of directive management, we created a software tool using a Health Insurance Portability and Accountability Act (HIPAA)-compliant database. This software allows for secure data-sharing among physicians, technologists, and managers while saving time, reducing errors, and eliminating the possibility of loss and duplication. Methods: The software tool was developed using Visual Basic, which is part of the Visual Studio development environment for the Windows platform. Patient data are deposited in an Access database on a local HIPAA-compliant secure server or hard disk. Once a working version had been developed, it was installed at our institution and used to manage directives. Updates and modifications of the software were released regularly until no more significant problems were found with its operation. Results: The software has been used at our institution for over 2 y and has reliably kept track of all directives. All physicians and technologists use the software daily and find it superior to paper directives. They can retrieve active directives at any stage of completion, as well as completed directives. Conclusion: We have developed a software solution for the management of written directives that streamlines and structures the departmental workflow. This solution saves time, centralizes the information for all staff to share, and decreases

  8. The anatomy of fronto-occipital connections from early blunt dissections to contemporary tractography.

    Science.gov (United States)

    Forkel, Stephanie J; Thiebaut de Schotten, Michel; Kawadler, Jamie M; Dell'Acqua, Flavio; Danek, Adrian; Catani, Marco

    2014-07-01

    The occipital and frontal lobes are anatomically distant yet functionally highly integrated to generate some of the most complex behaviour. A series of long associative fibres, such as the fronto-occipital networks, mediate this integration via rapid feed-forward propagation of visual input to anterior frontal regions and direct top-down modulation of early visual processing. Despite the vast number of anatomical investigations a general consensus on the anatomy of fronto-occipital connections is not forthcoming. For example, in the monkey the existence of a human equivalent of the 'inferior fronto-occipital fasciculus' (iFOF) has not been demonstrated. Conversely, a 'superior fronto-occipital fasciculus' (sFOF), also referred to as 'subcallosal bundle' by some authors, is reported in monkey axonal tracing studies but not in human dissections. In this study our aim is twofold. First, we use diffusion tractography to delineate the in vivo anatomy of the sFOF and the iFOF in 30 healthy subjects and three acallosal brains. Second, we provide a comprehensive review of the post-mortem and neuroimaging studies of the fronto-occipital connections published over the last two centuries, together with the first integral translation of Onufrowicz's original description of a human fronto-occipital fasciculus (1887) and Muratoff's report of the 'subcallosal bundle' in animals (1893). Our tractography dissections suggest that in the human brain (i) the iFOF is a bilateral association pathway connecting ventro-medial occipital cortex to orbital and polar frontal cortex, (ii) the sFOF overlaps with branches of the superior longitudinal fasciculus (SLF) and probably represents an 'occipital extension' of the SLF, (iii) the subcallosal bundle of Muratoff is probably a complex tract encompassing ascending thalamo-frontal and descending fronto-caudate connections and is therefore a projection rather than an associative tract. In conclusion, our experimental findings and review of the

  9. Streamlining genomes: toward the generation of simplified and stabilized microbial systems

    NARCIS (Netherlands)

    Leprince, A.; Passel, van M.W.J.; Martins Dos Santos, V.A.P.

    2012-01-01

    At the junction between systems and synthetic biology, genome streamlining provides a solid foundation both for increased understanding of cellular circuitry, and for the tailoring of microbial chassis towards innovative biotechnological applications. Iterative genomic deletions (targeted and

  10. West Virginia Peer Exchange : Streamlining Highway Safety Improvement Program Project Delivery - An RSPCB Peer Exchange

    Science.gov (United States)

    2014-09-01

    The West Virginia Division of Highways (WV DOH) hosted a Peer Exchange to share information and experiences for streamlining Highway Safety Improvement Program (HSIP) project delivery. The event was held September 23 to 24, 2014 in Charleston, West V...

  11. 77 FR 50691 - Request for Information (RFI): Guidance on Data Streamlining and Reducing Undue Reporting Burden...

    Science.gov (United States)

    2012-08-22

    .... Attention: HIV Data Streamlining. FOR FURTHER INFORMATION CONTACT: Andrew D. Forsyth Ph.D. or Vera... of HIV/AIDS programs that vary in their specifications (e.g., numerators, denominators, time frames...

  12. West Virginia peer exchange : streamlining highway safety improvement program project delivery.

    Science.gov (United States)

    2015-01-01

    The West Virginia Division of Highways (WV DOH) hosted a Peer Exchange to share information and experiences : for streamlining Highway Safety Improvement Program (HSIP) project delivery. The event was held September : 22 to 23, 2014 in Charleston, We...

  13. A higher-order tensor vessel tractography for segmentation of vascular structures.

    Science.gov (United States)

    Cetin, Suheyla; Unal, Gozde

    2015-10-01

    A new vascular structure segmentation method, which is based on a cylindrical flux-based higher order tensor (HOT), is presented. On a vessel structure, the HOT naturally models branching points, which create challenges for vessel segmentation algorithms. In a general linear HOT model embedded in 3D, one has to work with an even order tensor due to an enforced antipodal-symmetry on the unit sphere. However, in scenarios such as in a bifurcation, the antipodally-symmetric tensor embedded in 3D will not be useful. In order to overcome that limitation, we embed the tensor in 4D and obtain a structure that can model asymmetric junction scenarios. During construction of a higher order tensor (e.g. third or fourth order) in 4D, the orientation vectors lie on the unit 3-sphere, in contrast to the unit 2-sphere in 3D tensor modeling. This 4D tensor is exploited in a seed-based vessel segmentation algorithm, where the principal directions of the 4D HOT is obtained by decomposition, and used in a HOT tractography approach. We demonstrate quantitative validation of the proposed algorithm on both synthetic complex tubular structures as well as real cerebral vasculature in Magnetic Resonance Angiography (MRA) datasets and coronary arteries from Computed Tomography Angiography (CTA) volumes.

  14. Pre-surgical planning and MR-tractography utility in brain tumour resection

    Energy Technology Data Exchange (ETDEWEB)

    Romano, A.; Fantozzi, L.M.; Bozzao, A. [University Sapienza, Department of Neuroradiology, S. Andrea Hospital, Rome (Italy); D' Andrea, G.; Mastronardi, L.; Ferrante, L. [University Sapienza, Department of Neurosurgery, S. Andrea Hospital, Rome (Italy); Minniti, G. [University Sapienza, Department of Radiotherapy, S. Andrea Hospital, Rome (Italy)

    2009-12-15

    The purposes of this study were (1) to evaluate the possible identification of trajectories of fibre tracts, (2) to examine the useful of a neuronavigation system for pre-surgical planning, (3) to assess pre- and post-surgery patients' clinical condition and (4) to evaluate the impact of this information on surgical planning and procedure. Twenty-eight right-handed patients were prospectively and consecutively studied. All the patients were clinically assessed by a neurologist in both pre- and post-surgical phases. Separately the pyramidal tract, optic radiation and arcuate fasciculus were reconstructed. The trajectories were considered suitable for surgical planning if there were no interruptions of any of the layers at the level of the lesion. Dedicated software 'merged' the acquired images with the tractographic processing, and the whole dataset was sent to the neuronavigation system. The assessment of the 37 visualised trajectories close to the tumour resulted in a modification of the surgical approach to corticotomy in six patients (21%); the impact on the definition of the resection margins during surgery was 64% (18 cases). The overall impact percentage on the surgical procedure was 82%. In 27 cases, the symptoms had not changed. MR-tractography provides the neurosurgeon with a new anatomical view that has an impact on the surgical resection planning for brain neoplasms. (orig.)

  15. A Review of Traumatic Axonal Injury following Whiplash Injury As Demonstrated by Diffusion Tensor Tractography

    Directory of Open Access Journals (Sweden)

    Sung Ho Jang

    2018-02-01

    Full Text Available Whiplash is a bony or soft tissue injury resulting from an acceleration–deceleration energy transfer in the neck. Although patients with whiplash injury often complain of cerebral symptoms, and previous studies have reported evidence indicating brain injury, such an association has not been clearly elucidated. Traumatic axonal injury (TAI is tearing of axons due to indirect shearing forces during acceleration, deceleration, and rotation of the brain or to direct head trauma. Diffusion tensor imaging (DTI has a unique advantage to detect TAI in patients whose conventional brain CT or magnetic resonance imaging (MRI results were negative following head trauma. Since the introduction of DTI, six studies using diffusion tensor tractography (DTT based on DTI data have reported TAI in patients with whiplash injury, even though conventional brain CT or MRI results were negative. A precise TAI diagnosis in whiplash patients is clinically important for proper management and prognosis. Among the methods employed to diagnose TAI in the six previous studies, the common diagnostic approach for neural tract TAI in individual patients with whiplash injury were (1 whiplash injury history due to car accident; (2 development of new clinical symptoms and signs after whiplash injury; (3 evidence of neural tract TAI in DTT results, mainly via configurational analysis; and (4 coincidence of newly developed clinical manifestations and the function of injured neural tracts. All six studies were individual patient case studies; therefore, further prospective studies involving larger number of subjects should be encouraged.

  16. Correlation of quantitative sensorimotor tractography with clinical grade of cerebral palsy

    International Nuclear Information System (INIS)

    Trivedi, Richa; Gupta, Rakesh K.; Agarwal, Shruti; Rathore, Ram K.S.; Shah, Vipul; Goyel, Puneet; Paliwal, Vimal K.

    2010-01-01

    The purpose of this study was to determine whether tract-specific diffusion tensor imaging measures in somatosensory and motor pathways correlate with clinical grades as defined using the Gross Motor Function Classification System (GMFCS) in cerebral palsy (CP) children. Quantitative diffusion tensor tractography was performed on 39 patients with spastic quadriparesis (mean age = 8 years) and 14 age/sex-matched controls. All patients were graded on the basis of GMFCS scale into grade II (n = 12), grade IV (n = 22), and grade V (n = 5) CP and quantitative analysis reconstruction of somatosensory and motor tracts performed. Significant inverse correlation between clinical grade and fractional anisotropy (FA) was observed in both right and left motor and sensory tracts. A significant direct correlation of mean diffusivity values from both motor and sensory tracts was also observed with clinical grades. Successive decrease in FA values was observed in all tracts except for left motor tracts moving from age/sex-matched controls to grade V through grades II and IV. We conclude that white matter tracts from both the somatosensory and the motor cortex play an important role in the pathophysiology of motor disability in patients with CP. (orig.)

  17. Testing the connections within face processing circuitry in Capgras delusion with diffusion imaging tractography

    Directory of Open Access Journals (Sweden)

    Maria A. Bobes

    2016-01-01

    Full Text Available Although Capgras delusion (CD patients are capable of recognizing familiar faces, they present a delusional belief that some relatives have been replaced by impostors. CD has been explained as a selective disruption of a pathway processing affective values of familiar faces. To test the integrity of connections within face processing circuitry, diffusion tensor imaging was performed in a CD patient and 10 age-matched controls. Voxel-based morphometry indicated gray matter damage in right frontal areas. Tractography was used to examine two important tracts of the face processing circuitry: the inferior fronto-occipital fasciculus (IFOF and the inferior longitudinal (ILF. The superior longitudinal fasciculus (SLF and commissural tracts were also assessed. CD patient did not differ from controls in the commissural fibers, or the SLF. Right and left ILF, and right IFOF were also equivalent to those of controls. However, the left IFOF was significantly reduced respect to controls, also showing a significant dissociation with the ILF, which represents a selective impairment in the fiber-tract connecting occipital and frontal areas. This suggests a possible involvement of the IFOF in affective processing of faces in typical observers and in covert recognition in some cases with prosopagnosia.

  18. Hemispheric Asymmetry of Human Brain Anatomical Network Revealed by Diffusion Tensor Tractography

    Directory of Open Access Journals (Sweden)

    Ni Shu

    2015-01-01

    Full Text Available The topological architecture of the cerebral anatomical network reflects the structural organization of the human brain. Recently, topological measures based on graph theory have provided new approaches for quantifying large-scale anatomical networks. However, few studies have investigated the hemispheric asymmetries of the human brain from the perspective of the network model, and little is known about the asymmetries of the connection patterns of brain regions, which may reflect the functional integration and interaction between different regions. Here, we utilized diffusion tensor imaging to construct binary anatomical networks for 72 right-handed healthy adult subjects. We established the existence of structural connections between any pair of the 90 cortical and subcortical regions using deterministic tractography. To investigate the hemispheric asymmetries of the brain, statistical analyses were performed to reveal the brain regions with significant differences between bilateral topological properties, such as degree of connectivity, characteristic path length, and betweenness centrality. Furthermore, local structural connections were also investigated to examine the local asymmetries of some specific white matter tracts. From the perspective of both the global and local connection patterns, we identified the brain regions with hemispheric asymmetries. Combined with the previous studies, we suggested that the topological asymmetries in the anatomical network may reflect the functional lateralization of the human brain.

  19. Diffusion Tensor Imaging Tractography in Pure Neuritic Leprosy: First Experience Report and Review of the Literature

    Directory of Open Access Journals (Sweden)

    Michele R. Colonna

    2016-01-01

    Full Text Available Five years after both right ulnar and median nerve decompression for paraesthesias and palsy, a patient, coming from Nigeria but living in Italy, came to our unit claiming to have persistent pain and combined median and ulnar palsy. Under suspicion of leprosy, skin and left sural nerve biopsy were performed. Skin tests were negative, but Schwann cells resulted as positive for acid-fast bacilli (AFB, leading to the diagnosis of Pure Neuritic Leprosy (PNL. The patient was given PB multidrug therapy and recovered from pain in two months. After nine months both High Resolution Ultrasonography (HRUS and Magnetic Resonance Imaging (MRI were performed, revealing thickening of the nerves. Since demyelination is common in PNL, the Authors started to use Diffusion Tensor Imaging Tractography (DTIT to get better morphological and functional data about myelination than does the traditional imaging. DTIT proved successful in showing myelin discontinuity, reorganization, and myelination, and the Authors suggest that it can give more information about the evolution of the disease, as well as further indications for surgery (nerve decompression, nerve transfers, and babysitting for distal effector protection, and should be added to traditional imaging tools in leprosy.

  20. Diffusion tensor imaging and tractography for assessment of renal allograft dysfunction - initial results

    Energy Technology Data Exchange (ETDEWEB)

    Hueper, Katja; Gutberlet, M.; Rodt, T.; Wacker, F.; Galanski, M.; Hartung, D. [Institute for Diagnostic and Interventional Radiology, Hannover Medical School - Germany, Hannover (Germany); Gwinner, W. [Clinic for Nephrology, Hannover Medical School - Germany, Hannover (Germany); Lehner, F. [Clinic for General, Abdominal and Transplant Surgery, Hannover Medical School - Germany, Hannover (Germany)

    2011-11-15

    To evaluate MR diffusion tensor imaging (DTI) as non-invasive diagnostic tool for detection of acute and chronic allograft dysfunction and changes of organ microstructure. 15 kidney transplanted patients with allograft dysfunction and 14 healthy volunteers were examined using a fat-saturated echo-planar DTI-sequence at 1.5 T (6 diffusion directions, b = 0, 600 s/mm{sup 2}). Mean apparent diffusion coefficient (ADC) and mean fractional anisotropy (FA) were calculated separately for the cortex and for the medulla and compared between healthy and transplanted kidneys. Furthermore, the correlation between diffusion parameters and estimated GFR was determined. The ADC in the cortex and in the medulla were lower in transplanted than in healthy kidneys (p < 0.01). Differences were more distinct for FA, especially in the renal medulla, with a significant reduction in allografts (p < 0.001). Furthermore, in transplanted patients a correlation between mean FA in the medulla and estimated GFR was observed (r = 0.72, p < 0.01). Tractography visualized changes in renal microstructure in patients with impaired allograft function. Changes in allograft function and microstructure can be detected and quantified using DTI. However, to prove the value of DTI for standard clinical application especially correlation of imaging findings and biopsy results is necessary. (orig.)

  1. Connectomic disturbances in attention-deficit/hyperactivity disorder: a whole-brain tractography analysis.

    Science.gov (United States)

    Hong, Soon-Beom; Zalesky, Andrew; Fornito, Alex; Park, Subin; Yang, Young-Hui; Park, Min-Hyeon; Song, In-Chan; Sohn, Chul-Ho; Shin, Min-Sup; Kim, Bung-Nyun; Cho, Soo-Churl; Han, Doug Hyun; Cheong, Jae Hoon; Kim, Jae-Won

    2014-10-15

    Few studies have sought to identify, in a regionally unbiased way, the precise cortical and subcortical regions that are affected by white matter abnormalities in attention-deficit/hyperactivity disorder (ADHD). This study aimed to derive a comprehensive, whole-brain characterization of connectomic disturbances in ADHD. Using diffusion tensor imaging, whole-brain tractography, and an imaging connectomics approach, we characterized altered white matter connectivity in 71 children and adolescents with ADHD compared with 26 healthy control subjects. White matter differences were further delineated between patients with (n = 40) and without (n = 26) the predominantly hyperactive/impulsive subtype of ADHD. A significant network comprising 25 distinct fiber bundles linking 23 different brain regions spanning frontal, striatal, and cerebellar brain regions showed altered white matter structure in ADHD patients (p attentional disturbances. Attention-deficit/hyperactivity disorder subtypes were differentiated by a right-lateralized network (p attentional performance underscore the functional importance of these connectomic disturbances for the clinical phenotype of ADHD. A distributed pattern of white matter microstructural integrity separately involving frontal, striatal, and cerebellar brain regions, rather than direct frontostriatal connectivity, appears to be disrupted in children and adolescents with ADHD. Copyright © 2014 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

  2. Correlation of quantitative sensorimotor tractography with clinical grade of cerebral palsy

    Energy Technology Data Exchange (ETDEWEB)

    Trivedi, Richa; Gupta, Rakesh K. [Sanjay Gandhi Postgraduate Institute of Medical Sciences, Department of Radiodiagnosis, Lucknow (India); Agarwal, Shruti; Rathore, Ram K.S. [Indian Institute of Technology, Department of Mathematics and Statistics, Kanpur (India); Shah, Vipul [Bhargava Nursing Home, Pediatric Orthopedic Surgery unit, Lucknow (India); Goyel, Puneet [Sanjay Gandhi Postgraduate Institute of Medical Sciences, Department of Anesthesiology, Lucknow (India); Paliwal, Vimal K. [Sanjay Gandhi Postgraduate Institute of Medical Sciences, Department of Neurology, Lucknow (India)

    2010-08-15

    The purpose of this study was to determine whether tract-specific diffusion tensor imaging measures in somatosensory and motor pathways correlate with clinical grades as defined using the Gross Motor Function Classification System (GMFCS) in cerebral palsy (CP) children. Quantitative diffusion tensor tractography was performed on 39 patients with spastic quadriparesis (mean age = 8 years) and 14 age/sex-matched controls. All patients were graded on the basis of GMFCS scale into grade II (n = 12), grade IV (n = 22), and grade V (n = 5) CP and quantitative analysis reconstruction of somatosensory and motor tracts performed. Significant inverse correlation between clinical grade and fractional anisotropy (FA) was observed in both right and left motor and sensory tracts. A significant direct correlation of mean diffusivity values from both motor and sensory tracts was also observed with clinical grades. Successive decrease in FA values was observed in all tracts except for left motor tracts moving from age/sex-matched controls to grade V through grades II and IV. We conclude that white matter tracts from both the somatosensory and the motor cortex play an important role in the pathophysiology of motor disability in patients with CP. (orig.)

  3. Limb apraxia in a patient with cerebral infarct: diffusion tensor tractography study.

    Science.gov (United States)

    Hong, Ji Heon; Lee, Jun; Cho, Yoon Woo; Byun, Woo Mok; Cho, Hee Kyung; Son, Su Min; Jang, Sung Ho

    2012-01-01

    We report on a patient with ideomotor apraxia (IMA) and limb-kinetic apraxia (LKA) following cerebral infarct, which demonstrated neural tract injuries by diffusion tensor tractography (DTT). A 67-year-old male was diagnosed as cerebral infarct in the left frontal cortex (anterior portion of the precentral gyrus and prefrontal cortex) and centrum semiovale. The patient presented with severe paralysis of the right upper extremity and mild weakness of the right lower extremity at onset. At the time of DTT scanning (5 months after onset), the patient was able to move all joint muscles of the right upper extremity against gravity, except for the finger extensors, which he could extend partially against gravity. The patient showed intact ideational plan for motor performance; however, his movements were slow, clumsy, and mutilated when executing grasp-release movements of his affected hand. The patient's score on the ideomotor apraxia test was 20 (cut-off score < 32). DTTs for premotor cortex fibers, supplementary motor area fibers, and superior longitudinal fasciculus of the left hemisphere showed partial injuries, compared with those of the right side, and these injuries appeared to be responsible for IMA and LKA in this patient.

  4. Segmentation of the Canine Corpus Callosum using Diffusion Tensor Imaging Tractography

    Science.gov (United States)

    Pierce, T.T.; Calabrese, E.; White, L.E.; Chen, S.D.; Platt, S.R.; Provenzale, J.M.

    2014-01-01

    Background We set out to determine functional white matter (WM) connections passing through the canine corpus callosum useful for subsequent studies of canine brains that serve as models for human WM pathway disease. Based on prior studies, we anticipated that the anterior corpus callosum would send projections to the anterior cerebral cortex while progressively posterior segments would send projections to more posterior cortex. Methods A post mortem canine brain was imaged using a 7T MRI producing 100 micron isotropic resolution DTI analyzed by tractography. Using ROIs within cortical locations, which were confirmed by a Nissl stain that identified distinct cortical architecture, we successfully identified 6 important WM pathways. We also compared fractional anisotropy (FA), apparent diffusion coefficient (ADC), radial diffusivity (RD), and axial diffusivity (AD) in tracts passing through the genu and splenium. Results Callosal fibers were organized based upon cortical destination, i.e. fibers from the genu project to the frontal cortex. Histologic results identified the motor cortex based on cytoarchitectonic criteria that allowed placement of ROIs to discriminate between frontal and parietal lobes. We also identified cytoarchitecture typical of the orbital frontal, anterior frontal, and occipital regions and placed ROIs accordingly. FA, ADC, RD and AD values were all higher in posterior corpus callosum fiber tracts. Conclusions Using 6 cortical ROIs, we identified 6 major white matter tracts that reflect major functional divisions of the cerebral hemispheres and we derived quantitative values that can be used for study of canine models of human WM pathological states. PMID:24370161

  5. Utility of diffusion tensor imaging tractography in decision making for extratemporal resective epilepsy surgery.

    Science.gov (United States)

    Radhakrishnan, Ashalatha; James, Jija S; Kesavadas, Chandrasekharan; Thomas, Bejoy; Bahuleyan, Biji; Abraham, Mathew; Radhakrishnan, Kurupath

    2011-11-01

    To assess the utility of diffusion tensor imaging tractography (DTIT) in decision making in patients considered for extratemporal resective epilepsy surgery. We subjected 49 patients with drug-resistant focal seizures due to lesions located in frontal, parietal and occipital lobes to DTIT to map the white matter fiber anatomy in relation to the planned resection zone, in addition to routine presurgical evaluation. We stratified our patients preoperatively into different grades of risk for anticipated neurological deficits as judged by the distance of the white matter tracts from the resection zones and functional cortical areas. Thirty-seven patients underwent surgery; surgery was abandoned in 12 (24.5%) patients because of the high risk of postoperative neurological deficit. DTIT helped us to modify the surgical procedures in one-fourth of occipital, one-third of frontal, and two-thirds of parietal and multilobar resections. Overall, DTIT assisted us in surgical decision making in two-thirds of our patients. DTIT is a noninvasive imaging strategy that can be used effectively in planning resection of epileptogenic lesions at or close to eloquent cortical areas. DTIT helps in predicting postoperative neurological outcome and thereby assists in surgical decision making and in preoperative counseling of patients with extratemporal focal epilepsies. Copyright © 2011 Elsevier B.V. All rights reserved.

  6. Pre-surgical planning and MR-tractography utility in brain tumour resection

    International Nuclear Information System (INIS)

    Romano, A.; Fantozzi, L.M.; Bozzao, A.; D'Andrea, G.; Mastronardi, L.; Ferrante, L.; Minniti, G.

    2009-01-01

    The purposes of this study were (1) to evaluate the possible identification of trajectories of fibre tracts, (2) to examine the useful of a neuronavigation system for pre-surgical planning, (3) to assess pre- and post-surgery patients' clinical condition and (4) to evaluate the impact of this information on surgical planning and procedure. Twenty-eight right-handed patients were prospectively and consecutively studied. All the patients were clinically assessed by a neurologist in both pre- and post-surgical phases. Separately the pyramidal tract, optic radiation and arcuate fasciculus were reconstructed. The trajectories were considered suitable for surgical planning if there were no interruptions of any of the layers at the level of the lesion. Dedicated software 'merged' the acquired images with the tractographic processing, and the whole dataset was sent to the neuronavigation system. The assessment of the 37 visualised trajectories close to the tumour resulted in a modification of the surgical approach to corticotomy in six patients (21%); the impact on the definition of the resection margins during surgery was 64% (18 cases). The overall impact percentage on the surgical procedure was 82%. In 27 cases, the symptoms had not changed. MR-tractography provides the neurosurgeon with a new anatomical view that has an impact on the surgical resection planning for brain neoplasms. (orig.)

  7. Combining diffusion magnetic resonance tractography with stereology highlights increased cross-cortical integration in primates.

    Science.gov (United States)

    Charvet, Christine J; Hof, Patrick R; Raghanti, Mary Ann; Van Der Kouwe, Andre J; Sherwood, Chet C; Takahashi, Emi

    2017-04-01

    The isocortex of primates is disproportionately expanded relative to many other mammals, yet little is known about what the expansion of the isocortex entails for differences in cellular composition and connectivity patterns in primates. Across the depth of the isocortex, neurons exhibit stereotypical patterns of projections. Upper-layer neurons (i.e., layers II-IV) project within and across cortical areas, whereas many lower-layer pyramidal neurons (i.e., layers V-VI) favor connections to subcortical regions. To identify evolutionary changes in connectivity patterns, we quantified upper (i.e., layers II-IV)- and lower (i.e., layers V-VI)-layer neuron numbers in primates and other mammals such as rodents and carnivores. We also used MR tractography based on high-angular resolution diffusion imaging and diffusion spectrum imaging to compare anterior-to-posterior corticocortical tracts between primates and other mammals. We found that primates possess disproportionately more upper-layer neurons as well as an expansion of anterior-to-posterior corticocortical tracts compared with other mammals. Taken together, these findings demonstrate that primates deviate from other mammals in exhibiting increased cross-cortical connectivity. J. Comp. Neurol. 525:1075-1093, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  8. Altered brain structural connectivity in post-traumatic stress disorder: a diffusion tensor imaging tractography study.

    Science.gov (United States)

    Long, Zhiliang; Duan, Xujun; Xie, Bing; Du, Handan; Li, Rong; Xu, Qiang; Wei, Luqing; Zhang, Shao-xiang; Wu, Yi; Gao, Qing; Chen, Huafu

    2013-09-25

    Post-traumatic stress disorder (PTSD) is characterized by dysfunction of several discrete brain regions such as medial prefrontal gyrus with hypoactivation and amygdala with hyperactivation. However, alterations of large-scale whole brain topological organization of structural networks remain unclear. Seventeen patients with PTSD in motor vehicle accident survivors and 15 normal controls were enrolled in our study. Large-scale structural connectivity network (SCN) was constructed using diffusion tensor tractography, followed by thresholding the mean factional anisotropy matrix of 90 brain regions. Graph theory analysis was then employed to investigate their aberrant topological properties. Both patient and control group showed small-world topology in their SCNs. However, patients with PTSD exhibited abnormal global properties characterized by significantly decreased characteristic shortest path length and normalized characteristic shortest path length. Furthermore, the patient group showed enhanced nodal centralities predominately in salience network including bilateral anterior cingulate and pallidum, and hippocampus/parahippocamus gyrus, and decreased nodal centralities mainly in medial orbital part of superior frontal gyrus. The main limitation of this study is the small sample of PTSD patients, which may lead to decrease the statistic power. Consequently, this study should be considered an exploratory analysis. These results are consistent with the notion that PTSD can be understood by investigating the dysfunction of large-scale, spatially distributed neural networks, and also provide structural evidences for further exploration of neurocircuitry models in PTSD. © 2013 Elsevier B.V. All rights reserved.

  9. MR muscle tractography study on VX2 soft-tissue tumor in rabbits

    International Nuclear Information System (INIS)

    Li Yonggang; Guo Liang; Xie Daohai; Hu Chunhogn; Guo Maofeng; Zhu Wei; Chen Jianhua; Xing Jianming; Wang Renfa

    2008-01-01

    Objective: To determine if diffusion tensor imaging (DTI) and muscle fiber tracts of muscle disease are feasible. Methods: Twenty Newzealand white rabbits were implanted with 0.2 ml VX 2 tumor tissue suspension in the right proximal thighs. MRI and DTI were performed on these rabbits and DTI of muscle fiber tracts in the muscles around the lesions were reconstructed. The fractional anisotropy(FA) and volume ratio anisotropy(VrA) of the tumor and the normal muscle were analyzed. The correlation study between MRI and pathological findings was done. Results: All experimental animal models of rabbit VX 2 soft tissue tumors were successfully established. The difference of FA between the central parenchyma area and the necrosis area, the peripheral area of the tumor, the adjacent and contralateral normal muscle was statistically significant (P 0.05). The difference of FA and VrA between the adjacent and contralateral normal muscle was not statistically significant (P>0.05). The arrangement of normal muscle was regular on DTI of muscle tract. The muscle around the tumor lesions was infiltrated and destructed, which demonstrated irregular and interrupted muscle fiber on muscle tractography. Conclusion: DTI is advantageous to demonstrate the structure of soft tissue tumors and its border, which should be helpful in the structure and function research of muscle, as well as in the diagnosis of muscle diseases. (authors)

  10. Effectiveness of and obstacles to antibiotic streamlining to amoxicillin monotherapy in bacteremic pneumococcal pneumonia.

    Science.gov (United States)

    Blot, Mathieu; Pivot, Diane; Bourredjem, Abderrahmane; Salmon-Rousseau, Arnaud; de Curraize, Claire; Croisier, Delphine; Chavanet, Pascal; Binquet, Christine; Piroth, Lionel

    2017-09-01

    Antibiotic streamlining is pivotal to reduce the emergence of resistant bacteria. However, whether streamlining is frequently performed and safe in difficult situations, such as bacteremic pneumococcal pneumonia (BPP), has still to be assessed. All adult patients admitted to Dijon Hospital (France) from 2005 to 2013 who had BPP without complications, and were alive on the third day were enrolled. Clinical, biological, radiological, microbiological and therapeutic data were recorded. A first analysis was conducted to assess factors associated with being on amoxicillin on the third day. A second analysis, adjusting for a propensity score, was performed to determine whether 30-day mortality was associated with streamlining to amoxicillin monotherapy. Of the 196 patients hospitalized for BPP, 161 were still alive on the third day and were included in the study. Treatment was streamlined to amoxicillin in 60 patients (37%). Factors associated with not streamlining were severe pneumonia (OR 3.11, 95%CI [1.23-7.87]) and a first-line antibiotic combination (OR 3.08, 95%CI [1.34-7.09]). By contrast, starting with amoxicillin monotherapy correlated inversely with the risk of subsequent treatment with antibiotics other than amoxicillin (OR 0.06, 95%CI [0.01-0.30]). The Cox model adjusted for the propensity-score analysis showed that streamlining to amoxicillin during BPP was not significantly associated with a higher risk of 30-day mortality (HR 0.38, 95%CI [0.08-1.87]). Streamlining to amoxicillin is insufficiently implemented during BPP. This strategy is safe and potentially associated with ecological and economic benefits; therefore, it should be further encouraged, particularly when antibiotic combinations are started for severe pneumonia. Copyright © 2017. Published by Elsevier B.V.

  11. [Tractography of the uncinate fasciculus and the posterior cingulate fasciculus in patients with mild cognitive impairment and Alzheimer disease].

    Science.gov (United States)

    Larroza, A; Moratal, D; D'ocón Alcañiz, V; Arana, E

    2014-01-01

    Brain tractography is a non-invasive medical imaging technique which enables in vivo visualisation and various types of quantitative studies of white matter fibre tracts connecting different parts of the brain. We completed a quantitative study using brain tractography with diffusion tensor imaging in patients with mild cognitive impairment, patients with Alzheimer disease, and normal controls, in order to analyse the reproducibility and validity of the results. Fractional anisotropy (FA) and mean diffusivity (MD) were measured across the uncinate fasciculus and the posterior cingulate fasciculus in images, obtained from a database and a research centre, representing 52 subjects distributed among the 3 study groups. Two observers took the measurements twice in order to evaluate intra- and inter-observer reproducibility. Measurements of FA and MD of the uncinate fasciculus delivered an intraclass correlation coefficient above 0.9; ICC was above 0.68 for the posterior cingulate fasciculus. Patients with Alzheimer disease showed lower values of FA and higher MD values in the right uncinate fasciculus in images from the research centre. A comparison of the measurements from the 2 centres revealed significant differences. We established a reproducible methodology for performing tractography of the tracts in question. FA and MD indexes may serve as early indicators of Alzheimer disease. The type of equipment and the method used to acquire images must be considered because they may alter results as shown by comparing the 2 data sets in this study. Copyright © 2012 Sociedad Española de Neurología. Published by Elsevier Espana. All rights reserved.

  12. Tensor and non-tensor tractography for the assessment of the corticospinal tract of children with motor disorders: a comparative study.

    Science.gov (United States)

    Stefanou, Maria-Ioanna; Lumsden, Daniel E; Ashmore, Jonathan; Ashkan, Keyoumars; Lin, Jean-Pierre; Charles-Edwards, Geoffrey

    2016-10-01

    Non-invasive measures of corticospinal tract (CST) integrity may help to guide clinical interventions, particularly in children and young people (CAYP) with motor disorders. We compared diffusion tensor imaging (DTI) metrics extracted from the CST generated by tensor and non-tensor based tractography algorithms. For a group of 25 CAYP undergoing clinical evaluation, the CST was reconstructed using (1) deterministic tensor-based tractography algorithm, (2) probabilistic tensor-based, and (3) constrained spherical deconvolution (CSD)-derived tractography algorithms. Choice of tractography algorithm significantly altered the results of tracking. Larger tracts were consistently defined with CSD, with differences in FA but not MD values for tracts to the pre- or post-central gyrus. Differences between deterministic and probabilistic tensor-based algorithms were minimal. Non-tensor reconstructed tracts appeared to be more anatomically representative. Examining metrics along the tract, difference in FA values appeared to be greatest in voxels with predominantly single-fibre orientations. Less pronounced differences were seen outwith of these regions. With an increasing interest in the applications of tractography analysis at all stages of movement disorder surgery, it is important that clinicians remain alert to the consequences of choice of tractography algorithm on subsequently generated tracts, including differences in volumes, anatomical reconstruction, and DTI metrics, the latter of which will have global as well as more regional effects. Tract-wide analysis of DTI based metrics is of limited utility, and a more segmental approach to analysis may be appropriate, particularly if disruption to a focal region of a white matter pathway is anticipated.

  13. Disrupted topological organization of structural networks revealed by probabilistic diffusion tractography in Tourette syndrome children.

    Science.gov (United States)

    Wen, Hongwei; Liu, Yue; Rekik, Islem; Wang, Shengpei; Zhang, Jishui; Zhang, Yue; Peng, Yun; He, Huiguang

    2017-08-01

    Tourette syndrome (TS) is a childhood-onset neurobehavioral disorder. Although previous TS studies revealed structural abnormalities in distinct corticobasal ganglia circuits, the topological alterations of the whole-brain white matter (WM) structural networks remain poorly understood. Here, we used diffusion MRI probabilistic tractography and graph theoretical analysis to investigate the topological organization of WM networks in 44 drug-naive TS children and 41 age- and gender-matched healthy children. The WM networks were constructed by estimating inter-regional connectivity probability and the topological properties were characterized using graph theory. We found that both TS and control groups showed an efficient small-world organization in WM networks. However, compared to controls, TS children exhibited decreased global and local efficiency, increased shortest path length and small worldness, indicating a disrupted balance between local specialization and global integration in structural networks. Although both TS and control groups showed highly similar hub distributions, TS children exhibited significant decreased nodal efficiency, mainly distributed in the default mode, language, visual, and sensorimotor systems. Furthermore, two separate networks showing significantly decreased connectivity in TS group were identified using network-based statistical (NBS) analysis, primarily composed of the parieto-occipital cortex, precuneus, and paracentral lobule. Importantly, we combined support vector machine and multiple kernel learning frameworks to fuse multiple levels of network topological features for classification of individuals, achieving high accuracy of 86.47%. Together, our study revealed the disrupted topological organization of structural networks related to pathophysiology of TS, and the discriminative topological features for classification are potential quantitative neuroimaging biomarkers for clinical TS diagnosis. Hum Brain Mapp 38:3988-4008, 2017

  14. Neuroanatomical correlates of developmental dyscalculia: combined evidence from morphometry and tractography

    Directory of Open Access Journals (Sweden)

    Elena Rykhlevskaia

    2009-11-01

    Full Text Available Poor mathematical abilities adversely affect academic and career opportunities. The neuroanatomical basis of developmental dyscalculia (DD, a specific learning deficit with prevalence rates exceeding 5%, is poorly understood. We used structural MRI and diffusion tensor imaging (DTI to examine macro- and micro-structural impairments in 7-9 year old children with DD, compared to a group of typically developing (TD children matched on age, gender, intelligence, reading abilities and working memory capacity. Voxel-based morphometry (VBM revealed reduced grey matter (GM bilaterally in superior parietal lobule, intra-parietal sulcus, fusiform gyrus, parahippocampal gyrus and right anterior temporal cortex in children with DD. VBM analysis also showed reduced white matter (WM volume in right temporal-parietal cortex. DTI revealed reduced fractional anisotropy (FA in this WM region, pointing to significant right hemisphere micro-structural impairments. Furthermore, FA in this region was correlated with numerical operations but not verbal mathematical reasoning or word reading. Atlas-based tract mapping identified the inferior longitudinal fasciculus, inferior fronto-occipital fasciculus and caudal forceps major as key pathways impaired in DD. DTI tractography suggests that long-range WM projection fibers linking the right fusiform gyrus with temporal-parietal WM are a specific source of vulnerability in DD. Network and classification analysis suggest that DD in children may be characterized by multiple dysfunctional circuits arising from a core WM deficit. Our findings link GM and WM abnormalities in children with DD and they point to macro- and micro-structural abnormalities in right hemisphere temporal-parietal WM, and pathways associated with it, as key neuroanatomical correlates of DD.

  15. Tractography of the brainstem in major depressive disorder using diffusion tensor imaging.

    Directory of Open Access Journals (Sweden)

    Yun Ju C Song

    Full Text Available BACKGROUND: The brainstem is the main region that innervates neurotransmitter release to the Hypothalamic-Pituitary Adrenal (HPA axis and fronto-limbic circuits, two key brain circuits found to be dysfunctional in Major Depressive Disorder (MDD. However, the brainstem's role in MDD has only been evaluated in limited reports. Using Diffusion Tensor Imaging (DTI, we investigated whether major brainstem white matter tracts that relate to these two circuits differ in MDD patients compared to healthy controls. METHODS: MDD patients (n = 95 and age- and gender-matched controls (n = 34 were assessed using probabilistic tractography of DTI to delineate three distinct brainstem tracts: the nigrostriatal tract (connecting brainstem to striatum, solitary tract (connecting brainstem to amygdala and corticospinal tract (connecting brainstem to precentral cortex. Fractional anisotropy (FA was used to measure the white matter integrity of these tracts, and measures were compared between MDD and control participants. RESULTS: MDD participants were characterized by a significant and specific decrease in white matter integrity of the right solitary tract (p<0.009 using independent t-test, which is a "bottom up" afferent pathway that connects the brainstem to the amygdala. This decrease was not related to symptom severity. CONCLUSIONS: The results provide new evidence to suggest that structural connectivity between the brainstem and the amygdala is altered in MDD. These results are interesting in light of predominant theories regarding amygdala-mediated emotional reactivity observed in functional imaging studies of MDD. The characterization of altered white matter integrity in the solitary tract in MDD supports the possibility of dysfunctional brainstem-amygdala connectivity impacting vulnerable circuits in MDD.

  16. Segmentation of the canine corpus callosum using diffusion-tensor imaging tractography.

    Science.gov (United States)

    Pierce, Theodore T; Calabrese, Evan; White, Leonard E; Chen, Steven D; Platt, Simon R; Provenzale, James M

    2014-01-01

    We set out to determine functional white matter (WM) connections passing through the canine corpus callosum; these WM connections would be useful for subsequent studies of canine brains that serve as models for human WM pathway disease. Based on prior studies, we anticipated that the anterior corpus callosum would send projections to the anterior cerebral cortex whereas progressively posterior segments would send projections to more posterior cortex. A postmortem canine brain was imaged using a 7-T MRI system producing 100-μm-isotropic-resolution diffusion-tensor imaging analyzed by tractography. Using regions of interest (ROIs) within cortical locations, which were confirmed by a Nissl stain that identified distinct cortical architecture, we successfully identified six important WM pathways. We also compared fractional anisotropy (FA), apparent diffusion coefficient (ADC), radial diffusivity, and axial diffusivity in tracts passing through the genu and splenium. Callosal fibers were organized on the basis of cortical destination (e.g., fibers from the genu project to the frontal cortex). Histologic results identified the motor cortex on the basis of cytoarchitectonic criteria that allowed placement of ROIs to discriminate between frontal and parietal lobes. We also identified cytoarchitecture typical of the orbital frontal, anterior frontal, and occipital regions and placed ROIs accordingly. FA, ADC, radial diffusivity, and axial diffusivity values were all higher in posterior corpus callosum fiber tracts. Using six cortical ROIs, we identified six major WM tracts that reflect major functional divisions of the cerebral hemispheres, and we derived quantitative values that can be used for study of canine models of human WM pathologic states.

  17. The optimal trackability threshold of fractional anisotropy for diffusion tensor tractography of the corticospinal tract

    International Nuclear Information System (INIS)

    Kunimatsu, Akira; Aoki, Shigeki; Masutani, Yoshitaka; Abe, Osamu; Hayashi, Naoto; Mori, Harushi; Masumoto, Tomohiko; Ohtomo, Kuni

    2004-01-01

    In order to ensure that three-dimensional diffusion tensor tractography (3D-DTT) of the corticospinal tract (CST), is performed accurately and efficiently, we set out to find the optimal lower threshold of fractional anisotropy (FA) below which tract elongation is terminated (trackability threshold). Thirteen patients with acute or early subacute ischemic stroke causing motor deficits were enrolled in this study. We performed 3D-DTT of the CST with diffusion tensor MR (magnetic resonance) imaging. We segmented the CST and established a cross-section of the CST in a transaxial plane as a region of interest. Thus, we selectively measured the FA values of the right and left corticospinal tracts at the level of the cerebral peduncle, the posterior limb of the internal capsule, and the centrum semiovale. The FA values of the CST were also measured on the affected side at the level where the clinically relevant infarction was present in isotropic diffusion-weighted imaging. 3D-DTT allowed us to selectively measure the FA values of the CST. Among the 267 regions of interest we measured, the minimum FA value was 0.22. The FA values of the CST were smaller and more variable in the centrum semiovale than in the other regions. The mean minus twice the standard deviation of the FA values of the CST in the centrum semiovale was calculated at 0.22 on the normal unaffected side and 0.16 on the affected side. An FA value of about 0.20 was found to be the optimal trackability threshold. (author)

  18. Reproducibility of corticospinal diffusion tensor tractography in normal subjects and hemiparetic stroke patients

    International Nuclear Information System (INIS)

    Lin, Chao-Chun; Tsai, Miao-Yu; Lo, Yu-Chien; Liu, Yi-Jui; Tsai, Po-Pang; Wu, Chiao-Ying; Lin, Chia-Wei; Shen, Wu-Chung; Chung, Hsiao-Wen

    2013-01-01

    Purpose: The reproducibility of corticospinal diffusion tensor tractography (DTT) for a guideline is important before longitudinal monitoring of the therapy effects in stroke patients. This study aimed to establish the reproducibility of corticospinal DTT indices in healthy subjects and chronic hemiparetic stroke patients. Materials and methods: Written informed consents were obtained from 10 healthy subjects (mean age 25.8 ± 6.8 years), who underwent two scans in one session plus the third scan one week later, and from 15 patients (mean age 47.5 ± 9.1 years, 6–60 months after the onset of stroke, NIHSS scores between 9 and 20) who were scanned thrice on separate days within one month. Diffusion-tensor imaging was performed at 3 T with 25 diffusion directions. Corticospinal tracts were reconstructed using fiber assignment by continuous tracking without and with motion/eddy-current corrections. Intra- and inter-rater as well as intra- and inter-session variations of the DTT derived indices (fiber number, apparent diffusion coefficient (ADC), and fractional anisotropy (FA)) were assessed. Results: Intra-session and inter-session coefficients of variations (CVs) are small for FA (1.13–2.09%) and ADC (0.45–1.64%), but much larger for fiber number (8.05–22.4%). Inter-session CVs in the stroke side of patients (22.4%) are higher than those in the normal sides (18.0%) and in the normal subjects (14.7%). Motion/eddy-current correction improved inter-session reproducibility only for the fiber number of the infarcted corticospinal tract (CV reduced from 22.4% to 14.1%). Conclusion: The fiber number derived from corticospinal DTT shows substantially lower precision than ADC and FA, with infarcted tracts showing lower reproducibility than the healthy tissues

  19. Traumatic brain injury and the post-concussion syndrome: A diffusion tensor tractography study

    International Nuclear Information System (INIS)

    D’souza, Maria M; Trivedi, Richa; Singh, Kavita; Grover, Hemal; Choudhury, Ajay; Kaur, Prabhjot; Kumar, Pawan; Tripathi, Rajendra Prashad

    2015-01-01

    The aim of the present study is to evaluate diffusion tensor tractography (DTT) as a tool for detecting diffuse axonal injury in patients of acute, mild, and moderate traumatic brain injury (TBI), using two diffusion variables: Fractional anisotropy (FA) and mean diffusivity (MD). The correlation of these indices with the severity of post-concussive symptoms was also assessed. Nineteen patients with acute, mild, or moderate TBI and twelve age- and sex-matched healthy controls were recruited. Following Magnetic Resonance Imaging (MRI) on a 3.0-T scanner, DTT was performed using the ‘fiber assignment by continuous tracking’ (FACT) algorithm for fiber reconstruction. Appropriate statistical tools were used to see the difference in FA and MD values between the control and patient groups. In the latter group, the severity of post-concussive symptoms was assessed six months following trauma, using the Rivermead Postconcussion Symptoms Questionnaire (RPSQ). The patients displayed significant reduction in FA compared to the controls (P < 0.05) in several tracts, notably the corpus callosum, fornix, bilateral uncinate fasciculus, and bilateral superior thalamic radiations. Changes in MD were statistically significant in the left uncinate, inferior longitudinal fasciculus, and left posterior thalamic radiation. A strong correlation between these indices and the RPSQ scores was observed in several white matter tracts. Diffusion tensor imaging (DTI)-based quantitative analysis in acute, mild, and moderate TBI can identify axonal injury neuropathology, over and above that visualized on conventional MRI scans. Furthermore, the significant correlation observed between FA and MD indices and the severity of post-concussive symptoms could make it a useful predictor of the long-term outcome

  20. Somatotopic location of corticospinal tract at pons in human brain: a diffusion tensor tractography study.

    Science.gov (United States)

    Hong, Ji Heon; Son, Su Min; Jang, Sung Ho

    2010-07-01

    No diffusion tensor tractography (DTT) study has yet investigated the somatotopic location of the corticospinal tract (CST) at the pons. In the current study, we used DTT to investigate the somatotopic location of the CST at the pons in the human brain. We recruited 25 healthy volunteers for this study. Diffusion tensor images (DTIs) were scanned using 1.5-T; CSTs for the hand and leg were obtained using FMRIB software. Normalized DTT was reconstructed using the Montreal Neurological Institute echo-planar imaging template supplied with the SPM. Individual DTI data were calculated as a pixel unit at the upper and lower pons. Relative average location of the highest probability point of the CST for the hand was 47.70%, with the standard from the midline to the most lateral point of the upper pons, and 35.87% at the lower pons. For the leg, the CST was located at 56.82% at the upper pons and 40.63% at the lower pons. For the anteroposterior direction from the most anterior point of the pons to the most anterior point of the fourth ventricle, the CST for the hand was located at 42.30% at the upper pons and 36.18% at the lower pons. For the leg, the CST was located at 45.68% and 39.01%, respectively. We found that the hand somatotopy of the CST was located at the antero-medial portion at the pons and that the leg somatotopy of the CST was located postero-laterally to the hand somatotopy of the CST. Copyright (c) 2010 Elsevier Inc. All rights reserved.

  1. Streamlets for visualisation and data exploration

    DEFF Research Database (Denmark)

    Liptrot, Matthew George

    Streamlets for visualisation and data exploration Matthew Liptrot, Image Group, Department of Computer Science, University of Copenhagen, Denmark Target Audience Anyone using streamlines for interpreting tractography from diffusion-weighted MRI Purpose The purpose of streamline tractography...

  2. Streamline-concentration balance model for in-situ uranium leaching and site restoration

    International Nuclear Information System (INIS)

    Bommer, P.M.; Schechter, R.S.; Humenick, M.J.

    1981-03-01

    This work presents two computer models. One describes in-situ uranium leaching and the other describes post leaching site restoration. Both models use a streamline generator to set up the flow field over the reservoir. The leaching model then uses the flow data in a concentration balance along each streamline coupled with the appropriate reaction kinetics to calculate uranium production. The restoration model uses the same procedure except that binary cation exchange is used as the restoring mechanism along each streamline and leaching cation clean up is simulated. The mathematical basis for each model is shown in detail along with the computational schemes used. Finally, the two models have been used with several data sets to point out their capabilities and to illustrate important leaching and restoration parameters and schemes

  3. Self streamlining wind tunnel: Further low speed testing and final design studies for the transonic facility

    Science.gov (United States)

    Wolf, S. W. D.

    1978-01-01

    Work was continued with the low speed self streamlining wind tunnel (SSWT) using the NACA 0012-64 airfoil in an effort to explain the discrepancies between the NASA Langley low turbulence pressure tunnel (LTPT) and SSWT results obtained with the airfoil stalled. Conventional wind tunnel corrections were applied to straight wall SSWT airfoil data, to illustrate the inadequacy of standard correction techniques in circumstances of high blockage. Also one SSWT test was re-run at different air speeds to investigate the effects of such changes (perhaps through changes in Reynold's number and freestream turbulence levels) on airfoil data and wall contours. Mechanical design analyses for the transonic self-streamlining wind tunnel (TSWT) were completed by the application of theoretical airfoil flow field data to the elastic beam and streamline analysis. The control system for the transonic facility, which will eventually allow on-line computer operation of the wind tunnel, was outlined.

  4. Streamline-concentration balance model for in situ uranium leaching and site restoration

    International Nuclear Information System (INIS)

    Bommer, P.M.

    1979-01-01

    This work presents two computer models. One describes in situ uranium leaching and the other describes post leaching site restoration. Both models use a streamline generator to set up the flow field over the reservoir. The leaching model then uses the flow data in a concentration balance along each streamline coupled with the appropriate reaction kinetics to calculate uranium production. The restoration model uses the same procedure ecept that binary cation exchange is used as the restoring mechanism along each streamline and leaching cation clean up is stimulated. The mathematical basis for each model is shown in detail along with the computational schemes used. Finally, the two models have been used with several data sets to point out their capabilities and to illustrate important leaching and restoration parameters and schemes

  5. Unique encoding for streamline topologies of incompressible and inviscid flows in multiply connected domains

    Energy Technology Data Exchange (ETDEWEB)

    Sakajo, T [Department of Mathematics, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502 (Japan); Sawamura, Y; Yokoyama, T, E-mail: sakajo@math.kyoto-u.ac.jp [JST CREST, Kawaguchi, Saitama 332-0012 (Japan)

    2014-06-01

    This study considers the flow of incompressible and inviscid fluid in two-dimensional multiply connected domains. For such flows, encoding algorithms to assign a unique sequence of words to any structurally stable streamline topology based on the theory presented by Yokoyama and Sakajo (2013 Proc. R. Soc. A 469 20120558) are proposed. As an application, we utilize the algorithms to characterize the evolution of an incompressible and viscid flow around a flat plate inclined to the uniform flow in terms of the change of the word representations for their instantaneous streamline topologies. (papers)

  6. Streamline Patterns and their Bifurcations near a wall with Navier slip Boundary Conditions

    DEFF Research Database (Denmark)

    Tophøj, Laust; Møller, Søren; Brøns, Morten

    2006-01-01

    We consider the two-dimensional topology of streamlines near a surface where the Navier slip boundary condition applies. Using transformations to bring the streamfunction in a simple normal form, we obtain bifurcation diagrams of streamline patterns under variation of one or two external parameters....... Topologically, these are identical with the ones previously found for no-slip surfaces. We use the theory to analyze the Stokes flow inside a circle, and show how it can be used to predict new bifurcation phenomena. ©2006 American Institute of Physics...

  7. Analysis of Streamline Separation at Infinity Using Time-Discrete Markov Chains.

    Science.gov (United States)

    Reich, W; Scheuermann, G

    2012-12-01

    Existing methods for analyzing separation of streamlines are often restricted to a finite time or a local area. In our paper we introduce a new method that complements them by allowing an infinite-time-evaluation of steady planar vector fields. Our algorithm unifies combinatorial and probabilistic methods and introduces the concept of separation in time-discrete Markov-Chains. We compute particle distributions instead of the streamlines of single particles. We encode the flow into a map and then into a transition matrix for each time direction. Finally, we compare the results of our grid-independent algorithm to the popular Finite-Time-Lyapunov-Exponents and discuss the discrepancies.

  8. Prediction of motor outcomes and activities of daily living function using diffusion tensor tractography in acute hemiparetic stroke patients.

    Science.gov (United States)

    Imura, Takeshi; Nagasawa, Yuki; Inagawa, Tetsuji; Imada, Naoki; Izumi, Hiroaki; Emoto, Katsuya; Tani, Itaru; Yamasaki, Hiroyuki; Ota, Yuichiro; Oki, Shuichi; Maeda, Tadanori; Araki, Osamu

    2015-05-01

    [Purpose] The efficacy of diffusion tensor imaging in the prediction of motor outcomes and activities of daily living function remains unclear. We evaluated the most appropriate diffusion tensor parameters and methodology to determine whether the region of interest- or tractography-based method was more useful for predicting motor outcomes and activities of daily living function in stroke patients. [Subjects and Methods] Diffusion tensor imaging data within 10 days after stroke onset were collected and analyzed for 25 patients. The corticospinal tract was analyzed. Fractional anisotropy, number of fibers, and apparent diffusion coefficient were used as diffusion tensor parameters. Motor outcomes and activities of daily living function were evaluated on the same day as diffusion tensor imaging and at 1 month post-onset. [Results] The fractional anisotropy value of the affected corticospinal tract significantly correlated with the motor outcome and activities of daily living function within 10 days post-onset and at 1 month post-onset. Tthere were no significant correlations between other diffusion tensor parameters and motor outcomes or activities of daily living function. [Conclusion] The fractional anisotropy value of the affected corticospinal tract obtained using the tractography-based method was useful for predicting motor outcomes and activities of daily living function in stroke patients.

  9. [Assessment of motor and sensory pathways of the brain using diffusion-tensor tractography in children with cerebral palsy].

    Science.gov (United States)

    Memedyarov, A M; Namazova-Baranova, L S; Ermolina, Y V; Anikin, A V; Maslova, O I; Karkashadze, M Z; Klochkova, O A

    2014-01-01

    Diffusion tensor tractography--a new method of magnetic resonance imaging, that allows to visualize the pathways of the brain and to study their structural-functional state. The authors investigated the changes in motor and sensory pathways of brain in children with cerebral palsy using routine magnetic resonance imaging and diffusion-tensor tractography. The main group consisted of 26 patients with various forms of cerebral palsy and the comparison group was 25 people with normal psychomotor development (aged 2 to 6 years) and MR-picture of the brain. Magnetic resonance imaging was performed on the scanner with the induction of a magnetic field of 1,5 Tesla. Coefficients of fractional anisotropy and average diffusion coefficient estimated in regions of the brain containing the motor and sensory pathways: precentral gyrus, posterior limb of the internal capsule, thalamus, posterior thalamic radiation and corpus callosum. Statistically significant differences (p cerebral palsy in relation to the comparison group. All investigated regions, the coefficients of fractional anisotropy in children with cerebral palsy were significantly lower, and the average diffusion coefficient, respectively, higher. These changes indicate a lower degree of ordering of the white matter tracts associated with damage and subsequent development of gliosis of varying severity in children with cerebral palsy. It is shown that microstructural damage localized in both motor and sensory tracts that plays a leading role in the development of the clinical picture of cerebral palsy.

  10. Diffusion tensor tractography of the mammillothalamic tract in the human brain using a high spatial resolution DTI technique.

    Science.gov (United States)

    Kamali, Arash; Zhang, Caroline C; Riascos, Roy F; Tandon, Nitin; Bonafante-Mejia, Eliana E; Patel, Rajan; Lincoln, John A; Rabiei, Pejman; Ocasio, Laura; Younes, Kyan; Hasan, Khader M

    2018-03-27

    The mammillary bodies as part of the hypothalamic nuclei are in the central limbic circuitry of the human brain. The mammillary bodies are shown to be directly or indirectly connected to the amygdala, hippocampus, and thalami as the major gray matter structures of the human limbic system. Although it is not primarily considered as part of the human limbic system, the thalamus is shown to be involved in many limbic functions of the human brain. The major direct connection of the thalami with the hypothalamic nuclei is known to be through the mammillothalamic tract. Given the crucial role of the mammillothalamic tracts in memory functions, diffusion tensor imaging may be helpful in better visualizing the surgical anatomy of this pathway noninvasively. This study aimed to investigate the utility of high spatial resolution diffusion tensor tractography for mapping the trajectory of the mammillothalamic tract in the human brain. Fifteen healthy adults were studied after obtaining written informed consent. We used high spatial resolution diffusion tensor imaging data at 3.0 T. We delineated, for the first time, the detailed trajectory of the mammillothalamic tract of the human brain using deterministic diffusion tensor tractography.

  11. Abnormal brain connectivity in first-episode psychosis: A diffusion MRI tractography study of the corpus callosum

    Science.gov (United States)

    Price, Gary; Cercignani, Mara; Parker, Geoffrey J.M.; Altmann, Daniel R.; Barnes, Thomas R.E.; Barker, Gareth J.; Joyce, Eileen M.; Ron, Maria A.

    2007-01-01

    A model of disconnectivity involving abnormalities in the cortex and connecting white matter pathways may explain the clinical manifestations of schizophrenia. Recently, diffusion imaging tractography has made it possible to study white matter pathways in detail and we present here a study of patients with first-episode psychosis using this technique. We selected the corpus callosum for this study because there is evidence that it is abnormal in schizophrenia. In addition, the topographical organization of its fibers makes it possible to relate focal abnormalities to specific cortical regions. Eighteen patients with first-episode psychosis and 21 healthy subjects took part in the study. A probabilistic tractography algorithm (PICo) was used to study fractional anisotropy (FA). Seed regions were placed in the genu and splenium to track fiber tracts traversing these regions, and a multi-threshold approach to study the probability of connection was used. Multiple linear regressions were used to explore group differences. FA, a measure of tract coherence, was reduced in tracts crossing the genu, and to a lesser degree the splenium, in patients compared with controls. FA was also lower in the genu in females across both groups, but there was no gender-by-group interaction. The FA reduction in patients may be due to aberrant myelination or axonal abnormalities, but the similar tract volumes in the two groups suggest that severe axonal loss is unlikely at this stage of the illness. PMID:17275337

  12. Diffusion tractography imaging-guided frameless linear accelerator stereotactic radiosurgical thalamotomy for tremor: case report.

    Science.gov (United States)

    Kim, Won; Sharim, Justin; Tenn, Stephen; Kaprealian, Tania; Bordelon, Yvette; Agazaryan, Nzhde; Pouratian, Nader

    2018-01-01

    Essential tremor and Parkinson's disease-associated tremor are extremely prevalent within the field of movement disorders. The ventral intermediate (VIM) nucleus of the thalamus has been commonly used as both a neuromodulatory and neuroablative target for the treatment of these forms of tremor. With both deep brain stimulation and Gamma Knife radiosurgery, there is an abundance of literature regarding the surgical planning, targeting, and outcomes of these methodologies. To date, there have been no reports of frameless, linear accelerator (LINAC)-based thalomotomies for tremor. The authors report the case of a patient with tremor-dominant Parkinson's disease, with poor tremor improvement with medication, who was offered LINAC-based thalamotomy. High-resolution 0.9-mm isotropic MR images were obtained, and simulation was performed via CT with 1.5-mm contiguous slices. The VIM thalamic nucleus was determined using diffusion tensor imaging (DTI)-based segmentation on FSL using probabilistic tractography. The supplemental motor and premotor areas were the cortical target masks. The authors centered their isocenter within the region of the DTI-determined target and treated the patient with 140 Gy in a single fraction. The DTI-determined target had coordinates of 14.2 mm lateral and 8.36 mm anterior to the posterior commissure (PC), and 3 mm superior to the anterior commissure (AC)-PC line, which differed by 3.30 mm from the original target determined by anatomical considerations (15.5 mm lateral and 7 mm anterior to the PC, and 0 mm superior to the AC-PC line). There was faint radiographic evidence of lesioning at the 3-month follow-up within the target zone, which continued to consolidate on subsequent scans. The patient experienced continued right upper-extremity resting tremor improvement starting at 10 months until it was completely resolved at 22 months of follow-up. Frameless LINAC-based thalamotomy guided by DTI-based thalamic segmentation is a feasible method

  13. The Superior Fronto-Occipital Fasciculus in the Human Brain Revealed by Diffusion Spectrum Imaging Tractography: An Anatomical Reality or a Methodological Artifact?

    Science.gov (United States)

    Bao, Yue; Wang, Yong; Wang, Wei; Wang, Yibao

    2017-01-01

    The existence of the superior fronto-occipital fasciculus (SFOF) in the human brain remains controversial. The aim of the present study was to clarify the existence, course, and terminations of the SFOF. High angular diffusion spectrum imaging (DSI) analysis was performed on six healthy adults and on a template of 842 subjects from the Human Connectome Project. To verify tractography results, we performed fiber microdissections of four post-mortem human brains. Based on DSI tractography, we reconstructed the SFOF in the subjects and the template from the Human Connectome Project that originated from the rostral and medial parts of the superior and middle frontal gyri. By tractography, we found that the fibers formed a compact fascicle at the level of the anterior horn of the lateral ventricle coursing above the head of caudate nucleus, medial to the corona radiate and under the corpus callosum (CC), and terminated at the parietal region via the lower part of the caudate nucleus. We consider that this fiber bundle observed by tractography is the SFOF, although it terminates mainly at the parietal region, rather than occipital lobe. By contrast, we were unable to identify a fiber bundle corresponding to the SFOF in our fiber dissection study. Although we did not provide definite evidence of the SFOF in the human brain, these findings may be useful for future studies in this field. PMID:29321729

  14. The Superior Fronto-Occipital Fasciculus in the Human Brain Revealed by Diffusion Spectrum Imaging Tractography: An Anatomical Reality or a Methodological Artifact?

    Directory of Open Access Journals (Sweden)

    Yue Bao

    2017-12-01

    Full Text Available The existence of the superior fronto-occipital fasciculus (SFOF in the human brain remains controversial. The aim of the present study was to clarify the existence, course, and terminations of the SFOF. High angular diffusion spectrum imaging (DSI analysis was performed on six healthy adults and on a template of 842 subjects from the Human Connectome Project. To verify tractography results, we performed fiber microdissections of four post-mortem human brains. Based on DSI tractography, we reconstructed the SFOF in the subjects and the template from the Human Connectome Project that originated from the rostral and medial parts of the superior and middle frontal gyri. By tractography, we found that the fibers formed a compact fascicle at the level of the anterior horn of the lateral ventricle coursing above the head of caudate nucleus, medial to the corona radiate and under the corpus callosum (CC, and terminated at the parietal region via the lower part of the caudate nucleus. We consider that this fiber bundle observed by tractography is the SFOF, although it terminates mainly at the parietal region, rather than occipital lobe. By contrast, we were unable to identify a fiber bundle corresponding to the SFOF in our fiber dissection study. Although we did not provide definite evidence of the SFOF in the human brain, these findings may be useful for future studies in this field.

  15. The Value of Neurosurgical and Intraoperative Magnetic Resonance Imaging and Diffusion Tensor Imaging Tractography in Clinically Integrated Neuroanatomy Modules: A Cross-Sectional Study

    Science.gov (United States)

    Familiari, Giuseppe; Relucenti, Michela; Heyn, Rosemarie; Baldini, Rossella; D'Andrea, Giancarlo; Familiari, Pietro; Bozzao, Alessandro; Raco, Antonino

    2013-01-01

    Neuroanatomy is considered to be one of the most difficult anatomical subjects for students. To provide motivation and improve learning outcomes in this area, clinical cases and neurosurgical images from diffusion tensor imaging (DTI) tractographies produced using an intraoperative magnetic resonance imaging apparatus (MRI/DTI) were presented and…

  16. 弥散张量成像的脑神经示踪重建及临床应用研究%Three-dimensional reconstruction of cranial nerves and clinical exploration based on diffusion tensor tractography

    Institute of Scientific and Technical Information of China (English)

    马峻; 苏少波; 赵岩; 李勇刚; 岳树源

    2014-01-01

    目的 探讨应用弥散张量成像进行脑神经(CNs)纤维束示踪、可视化重建的可行性,并尝试将其应用于颅底肿瘤术前规划.方法 利用3.0T磁共振对10例健康志愿者,10例颅底肿瘤患者进行稳态采集快速成像、弥散张量成像扫描,3D Slicer软件完成脑神经纤维示踪、重建,病变患者重建肿瘤三维影像,通过手术观察及神经电生理监测确认脑神经的位置.结果 CNⅡ、Ⅲ、Ⅴ、Ⅵ、Ⅶ~Ⅷ、Ⅹ、Ⅻ成像良好,肿瘤、水肿与相关脑神经的三维空间关系通过纤维示踪与三维重建得以呈现,经过手术验证准确无误.结论联合应用弥散张量成像及3D Slicer软件是正常及病理状态下脑神经可视化重建切实可行的方案,具有良好的临床应用前景.%Objective To investigate the feasibility of 3-dimensional reconstruction of cranial nerves (CNs) via diffusion imaging tractography,and attempt to apply in the preoperative plan of skull base tumor.Methods 3-Tesla magnetic resonance imaging scans,including 3D-FSPGR,FIESTA and DTI,were used to collect information of 10 healthy subjects and 10 skull base tumor patients.DTI data were integrated into the 3D-Slicer for fiber tracking,overlapped anatomic images to determine course of nerves.3D reconstructions of tumors were achieved to perform neighbor,encasing,invading relationship between lesion and nerves whose location was then recorded during surgery by surgical observation and neurophysiological monitoring.Results Detailed fibers of the cranialnerves were depicted.Optic pathway showed perfect 3D streamline body,especially the posterior of optic chiasm.Oculomotor nerve coursed from the brainstem to the cavernous sinus distally,which also had high fidelity.Trigeminal nerve allowed visualization of gasserian ganglion as cisternal segment.Cisternal parts of abducent nerve,facial/ vestibulocochlear nerve,vagus nerve,hypoglossal nerve were also imaged well.Moreover,the 3D

  17. Southern Ocean overturning across streamlines in an eddying simulation of the Antarctic Circumpolar Current

    Directory of Open Access Journals (Sweden)

    A. M. Treguier

    2007-12-01

    Full Text Available An eddying global model is used to study the characteristics of the Antarctic Circumpolar Current (ACC in a streamline-following framework. Previous model-based estimates of the meridional circulation were calculated using zonal averages: this method leads to a counter-intuitive poleward circulation of the less dense waters, and underestimates the eddy effects. We show that on the contrary, the upper ocean circulation across streamlines agrees with the theoretical view: an equatorward mean flow partially cancelled by a poleward eddy mass flux. Two model simulations, in which the buoyancy forcing above the ACC changes from positive to negative, suggest that the relationship between the residual meridional circulation and the surface buoyancy flux is not as straightforward as assumed by the simplest theoretical models: the sign of the residual circulation cannot be inferred from the surface buoyancy forcing only. Among the other processes that likely play a part in setting the meridional circulation, our model results emphasize the complex three-dimensional structure of the ACC (probably not well accounted for in streamline-averaged, two-dimensional models and the distinct role of temperature and salinity in the definition of the density field. Heat and salt transports by the time-mean flow are important even across time-mean streamlines. Heat and salt are balanced in the ACC, the model drift being small, but the nonlinearity of the equation of state cannot be ignored in the density balance.

  18. Streamlining the Online Course Development Process by Using Project Management Tools

    Science.gov (United States)

    Abdous, M'hammed; He, Wu

    2008-01-01

    Managing the design and production of online courses is challenging. Insufficient instructional design and inefficient management often lead to issues such as poor course quality and course delivery delays. In an effort to facilitate, streamline, and improve the overall design and production of online courses, this article discusses how we…

  19. Less is More : Better Compliance and Increased Revenues by Streamlining Business Registration in Uganda

    OpenAIRE

    Sander, Cerstin

    2003-01-01

    A pilot of a streamlined business registration system in Entebbe, Uganda, reduced compliance costs for enterprises by 75 percent, raised registration numbers and fee revenue by 40 percent and reduced the cost of administering the system. It also reduced opportunities for corruption, improved relations between businesses and the local authorities and resulted in better compliance.

  20. Zephyr: A secure Internet-based process to streamline engineering procurements using the World Wide Web

    Energy Technology Data Exchange (ETDEWEB)

    Jordan, C.W.; Cavitt, R.E.; Niven, W.A.; Warren, F.E.; Taylor, S.S.; Sharick, T.M.; Vickers, D.L.; Mitschkowetz, N.; Weaver, R.L.

    1996-08-13

    Lawrence Livermore National Laboratory (LLNL) is piloting an Internet- based paperless process called `Zephyr` to streamline engineering procurements. Major benefits have accrued by using Zephyr in reducing procurement time, speeding the engineering development cycle, facilitating industrial collaboration, and reducing overall costs. Programs at LLNL are benefiting by the efficiencies introduced since implementing Zephyr`s engineering and commerce on the Internet.

  1. Streamline topologies near simple degenerate critical points in two-dimensional flow away from boundaries

    DEFF Research Database (Denmark)

    Brøns, Morten; Hartnack, Johan Nicolai

    1998-01-01

    Streamline patterns and their bifurcations in two-dimensional incompressible flow are investigated from a topological point of view. The velocity field is expanded at a point in the fluid, and the expansion coefficients are considered as bifurcation parameters. A series of non-linear coordinate c...

  2. Streamline topologies near simple degenerate critical points in two-dimensional flow away from boundaries

    DEFF Research Database (Denmark)

    Brøns, Morten; Hartnack, Johan Nicolai

    1999-01-01

    Streamline patterns and their bifurcations in two-dimensional incompressible flow are investigated from a topological point of view. The velocity field is expanded at a point in the fluid, and the expansion coefficients are considered as bifurcation parameters. A series of nonlinear coordinate ch...

  3. The design of the Comet streamliner: An electric land speed record motorcycle

    Science.gov (United States)

    McMillan, Ethan Alexander

    The development of the land speed record electric motorcycle streamliner, the Comet, is discussed herein. Its design process includes a detailed literary review of past and current motorcycle streamliners in an effort to highlight the main components of such a vehicle's design, while providing baseline data for performance comparisons. A new approach to balancing a streamliner at low speeds is also addressed, a system henceforth referred to as landing gear, which has proven an effective means for allowing the driver to control the low speed instabilities of the vehicle with relative ease compared to tradition designs. This is accompanied by a dynamic stability analysis conducted on a test chassis that was developed for the primary purpose of understanding the handling dynamics of streamliners, while also providing a test bed for the implementation of the landing gear system and a means to familiarize the driver to the operation and handling of such a vehicle. Data gathered through the use of GPS based velocity tracking, accelerometers, and a linear potentiometer provided a means to validate a dynamic stability analysis of the weave and wobble modes of the vehicle through linearization of a streamliner model developed in the BikeSIM software suite. Results indicate agreement between the experimental data and the simulation, indicating that the conventional recumbent design of a streamliner chassis is in fact highly stable throughout the performance envelope beyond extremely low speeds. A computational fluid dynamics study was also performed, utilized in the development of the body of the Comet to which a series of tests were conducted in order to develop a shape that was both practical to transport and highly efficient. By creating a hybrid airfoil from a NACA 0018 and NACA 66-018, a drag coefficient of 0.1 and frontal area of 0.44 m2 has been found for the final design. Utilizing a performance model based on the proposed vehicle's motor, its rolling resistance, and

  4. Comparing a diffusion tensor and non-tensor approach to white matter fiber tractography in chronic stroke.

    Science.gov (United States)

    Auriat, A M; Borich, M R; Snow, N J; Wadden, K P; Boyd, L A

    2015-01-01

    Diffusion tensor imaging (DTI)-based tractography has been used to demonstrate functionally relevant differences in white matter pathway status after stroke. However, it is now known that the tensor model is insensitive to the complex fiber architectures found in the vast majority of voxels in the human brain. The inability to resolve intra-voxel fiber orientations may have important implications for the utility of standard DTI-based tract reconstruction methods. Intra-voxel fiber orientations can now be identified using novel, tensor-free approaches. Constrained spherical deconvolution (CSD) is one approach to characterize intra-voxel diffusion behavior. In the current study, we performed DTI- and CSD-based tract reconstruction of the corticospinal tract (CST) and corpus callosum (CC) to test the hypothesis that characterization of complex fiber orientations may improve the robustness of fiber tract reconstruction and increase the sensitivity to identify functionally relevant white matter abnormalities in individuals with chronic stroke. Diffusion weighted magnetic resonance imaging was performed in 27 chronic post-stroke participants and 12 healthy controls. Transcallosal pathways and the CST bilaterally were reconstructed using DTI- and CSD-based tractography. Mean fractional anisotropy (FA), apparent diffusion coefficient (ADC), axial diffusivity (AD), and radial diffusivity (RD) were calculated across the tracts of interest. The total number and volume of reconstructed tracts was also determined. Diffusion measures were compared between groups (Stroke, Control) and methods (CSD, DTI). The relationship between post-stroke motor behavior and diffusion measures was evaluated. Overall, CSD methods identified more tracts than the DTI-based approach for both CC and CST pathways. Mean FA, ADC, and RD differed between DTI and CSD for CC-mediated tracts. In these tracts, we discovered a difference in FA for the CC between stroke and healthy control groups using CSD but

  5. Comparing a diffusion tensor and non-tensor approach to white matter fiber tractography in chronic stroke

    Directory of Open Access Journals (Sweden)

    A.M. Auriat

    2015-01-01

    Full Text Available Diffusion tensor imaging (DTI-based tractography has been used to demonstrate functionally relevant differences in white matter pathway status after stroke. However, it is now known that the tensor model is insensitive to the complex fiber architectures found in the vast majority of voxels in the human brain. The inability to resolve intra-voxel fiber orientations may have important implications for the utility of standard DTI-based tract reconstruction methods. Intra-voxel fiber orientations can now be identified using novel, tensor-free approaches. Constrained spherical deconvolution (CSD is one approach to characterize intra-voxel diffusion behavior. In the current study, we performed DTI- and CSD-based tract reconstruction of the corticospinal tract (CST and corpus callosum (CC to test the hypothesis that characterization of complex fiber orientations may improve the robustness of fiber tract reconstruction and increase the sensitivity to identify functionally relevant white matter abnormalities in individuals with chronic stroke. Diffusion weighted magnetic resonance imaging was performed in 27 chronic post-stroke participants and 12 healthy controls. Transcallosal pathways and the CST bilaterally were reconstructed using DTI- and CSD-based tractography. Mean fractional anisotropy (FA, apparent diffusion coefficient (ADC, axial diffusivity (AD, and radial diffusivity (RD were calculated across the tracts of interest. The total number and volume of reconstructed tracts was also determined. Diffusion measures were compared between groups (Stroke, Control and methods (CSD, DTI. The relationship between post-stroke motor behavior and diffusion measures was evaluated. Overall, CSD methods identified more tracts than the DTI-based approach for both CC and CST pathways. Mean FA, ADC, and RD differed between DTI and CSD for CC-mediated tracts. In these tracts, we discovered a difference in FA for the CC between stroke and healthy control groups

  6. Diffusion tensor tractography of normal and compressed spinal cord: a preliminary study at 3.0 T MR

    International Nuclear Information System (INIS)

    Wang Wei; Chang Shixin; Hao Nanxin; Du Yushan; Wang Yibin; Zong Genlin; Cao Kaiming; Lu Jianping; Zhao Cheng; Qin Wen

    2007-01-01

    Objective: To study the feasibility and clinical values of diffusion tensor tractography (DTT) in the spinal cord at 3.0 T MR. Methods: Forty patients with spinal cord compression including cervical cord herniation and cervical spondylosis (30 cases), tumors in spinal canal (9 cases) and old injury in cervical vertebrae (1 cases) and 20 healthy volunteers participated in this study. Single-shot spin- echo echo-planar diffusion tensor sequence for tractography of the spinal cord was performed. The fibers of spinal cord were visualized by using fiber tracking software. Results: On the DTT maps, the normal spinal cord was depicted as a fiber tract showing color-encoded cephalocaudally, which indicated anisotropy in the cephalocaudal direction. By setting two ROI, the main spinal cord fiber tracts, such as corticospinal or spinothalamic tract, were visualized. The tracts from two sides of the brain did not completely cross. It was asymmetric in the number of tracts on the two sides in most normal subjects (8/10). The tracts of all patients with cord compression were seen oppressed or damaged in different degrees. The DTT in patients with cervical spondylosis and extramedullary-intradural neurolemmoma demonstrated that tracts were oppressed but not damaged. The DTT in one ependymoma showed that tract was markedly compressed and slightly damaged. Conclusion: DTT is a promising tool for demonstrating the spinal cord tracts and abnormalities, can provide useful information for the localization of compression and evaluation of the impairment extent on the white matter tracts of the spinal cord. (authors)

  7. DTI fiber tractography of cerebro-cerebellar pathways and clinical evaluation of ataxia in childhood posterior fossa tumor survivors.

    Science.gov (United States)

    Oh, Myung Eun; Driever, Pablo Hernáiz; Khajuria, Rajiv K; Rueckriegel, Stefan Mark; Koustenis, Elisabeth; Bruhn, Harald; Thomale, Ulrich-Wilhelm

    2017-01-01

    Pediatric posterior fossa (PF) tumor survivors experience long-term motor deficits. Specific cerebrocerebellar connections may be involved in incidence and severity of motor dysfunction. We examined the relationship between long-term ataxia as well as fine motor function and alteration of differential cerebellar efferent and afferent pathways using diffusion tensor imaging (DTI) and tractography. DTI-based tractography was performed in 19 patients (10 pilocytic astrocytoma (PA) and 9 medulloblastoma patients (MB)) and 20 healthy peers. Efferent Cerebello-Thalamo-Cerebral (CTC) and afferent Cerebro-Ponto-Cerebellar (CPC) tracts were reconstructed and analyzed concerning fractional anisotropy (FA) and volumetric measurements. Clinical outcome was assessed with the International Cooperative Ataxia Rating Scale (ICARS). Kinematic parameters of fine motor function (speed, automation, variability, and pressure) were obtained by employing a digitizing graphic tablet. ICARS scores were significantly higher in MB patients than in PA patients. Poorer ICARS scores and impaired fine motor function correlated significantly with volume loss of CTC pathway in MB patients, but not in PA patients. Patients with pediatric post-operative cerebellar mutism syndrome showed higher loss of CTC pathway volume and were more atactic. CPC pathway volume was significantly reduced in PA patients, but not in MB patients. Neither relationship was observed between the CPC pathway and ICARS or fine motor function. There was no group difference of FA values between the patients and healthy peers. Reduced CTC pathway volumes in our cohorts were associated with severity of long-term ataxia and impaired fine motor function in survivors of MBs. We suggest that the CTC pathway seems to play a role in extent of ataxia and fine motor dysfunction after childhood cerebellar tumor treatment. DTI may be a useful tool to identify relevant structures of the CTC pathway and possibly avoid surgically induced long

  8. Regional variation of white matter development in the cat brain revealed by ex vivo diffusion MR tractography.

    Science.gov (United States)

    Dai, Guangping; Das, Avilash; Hayashi, Emiko; Chen, Qin; Takahashi, Emi

    2016-11-01

    Three-dimensional reconstruction of developing fiber pathways is essential to assessing the developmental course of fiber pathways in the whole brain. We applied diffusion spectrum imaging (DSI) tractography to five juvenile ex vivo cat brains at postnatal day (P) 35, when the degree of myelination varies across brain regions. We quantified diffusion properties (fractional anisotropy [FA] and apparent diffusion coefficient [ADC]) and other measurements (number, volume, and voxel count) on reconstructed pathways for projection (cortico-spinal and thalamo-cortical), corpus callosal, limbic (cingulum and fornix), and association (cortico-cortical) pathways, and characterized regional differences in maturation patterns by assessing diffusion properties. FA values were significantly higher in cortico-cortical pathways within the right hemisphere compared to those within the left hemisphere, while the other measurements for the cortico-cortical pathways within the hemisphere did not show asymmetry. ADC values were not asymmetric in both types of pathways. Interestingly, tract count and volume were significantly larger in the left thalamo-cortical pathways compared to the right thalamo-cortical pathways. The bilateral thalamo-cortical pathways showed high FA values compared to the other fiber pathways. On the other hand, ADC values did not show any differences across pathways studied. These results demonstrate that DSI tractography successfully depicted regional variations of white matter tracts during development when myelination is incomplete. Low FA and high ADC values in the cingulum bundle suggest that the cingulum bundle is less mature than the others at this developmental stage. Copyright © 2016 ISDN. Published by Elsevier Ltd. All rights reserved.

  9. Mean streamline analysis for performance prediction of cross-flow fans

    International Nuclear Information System (INIS)

    Kim, Jae Won; Oh, Hyoung Woo

    2004-01-01

    This paper presents the mean streamline analysis using the empirical loss correlations for performance prediction of cross-flow fans. Comparison of overall performance predictions with test data of a cross-flow fan system with a simplified vortex wall scroll casing and with the published experimental characteristics for a cross-flow fan has been carried out to demonstrate the accuracy of the proposed method. Predicted performance curves by the present mean streamline analysis agree well with experimental data for two different cross-flow fans over the normal operating conditions. The prediction method presented herein can be used efficiently as a tool for the preliminary design and performance analysis of general-purpose cross-flow fans

  10. Calculation of heat transfer in transversely stream-lined tube bundles with chess arrangement

    International Nuclear Information System (INIS)

    Migaj, V.K.

    1978-01-01

    A semiempirical theory of heat transfer in transversely stream-lined chess-board tube bundles has been developed. The theory is based on a single cylinder model and involves external flow parameter evaluation on the basis of the solidification principle of a vortex zone. The effect of turbulence is estimated according to experimental results. The method is extended to both average and local heat transfer coefficients. Comparison with experiment shows satisfactory agreement

  11. Streamline processing of discrete nuclear spectra by means of authoregularized iteration process (the KOLOBOK code)

    International Nuclear Information System (INIS)

    Gadzhokov, V.; Penev, I.; Aleksandrov, L.

    1979-01-01

    A brief description of the KOLOBOK computer code designed for streamline processing of discrete nuclear spectra with symmetric Gaussian shape of the single line on computers of the ES series, models 1020 and above, is given. The program solves the stream of discrete-spectrometry generated nonlinear problems by means of authoregularized iteration process. The Fortran-4 text of the code is reported in an Appendix

  12. The Effects of Propulsive Jetting on Drag of a Streamlined body

    Science.gov (United States)

    Krieg, Michael; Mohseni, Kamran

    2017-11-01

    Recently an abundance of bioinspired underwater vehicles have emerged to leverage eons of evolution. Our group has developed a propulsion technique inspired by jellyfish and squid. Propulsive jets are generated by ingesting and expelling water from a flexible internal cavity. We have demonstrated thruster capabilities for maneuvering on AUV platforms, where the internal thruster geometry minimized forward drag; however, such a setup cannot characterize propulsive efficiency. Therefore, we created a new streamlined vehicle platform that produces unsteady jets for forward propulsion rather than maneuvering. The streamlined jetting body is placed in a water tunnel and held stationary while jetting frequency and background flow velocity are varied. For each frequency/velocity pair the flow field is measured around the surface and in the wake using PIV. Using the zero jetting frequency as a baseline for each background velocity, the passive body drag is related to the velocity distribution. For cases with active jetting the drag and jetting forces are estimated from the velocity field and compared to the passive case. For this streamlined body, the entrainment of surrounding flow into the propulsive jet can reduce drag forces in addition to the momentum transfer of the jet itself. Office of Naval Research.

  13. The role of streamline curvature in sand dune dynamics: evidence from field and wind tunnel measurements

    Science.gov (United States)

    Wiggs, Giles F. S.; Livingstone, Ian; Warren, Andrew

    1996-09-01

    Field measurements on an unvegetated, 10 m high barchan dune in Oman are compared with measurements over a 1:200 scale fixed model in a wind tunnel. Both the field and wind tunnel data demonstrate similar patterns of wind and shear velocity over the dune, confirming significant flow deceleration upwind of and at the toe of the dune, acceleration of flow up the windward slope, and deceleration between the crest and brink. This pattern, including the widely reported upwind reduction in shear velocity, reflects observations of previous studies. Such a reduction in shear velocity upwind of the dune should result in a reduction in sand transport and subsequent sand deposition. This is not observed in the field. Wind tunnel modelling using a near-surface pulse-wire probe suggests that the field method of shear velocity derivation is inadequate. The wind tunnel results exhibit no reduction in shear velocity upwind of or at the toe of the dune. Evidence provided by Reynolds stress profiles and turbulence intensities measured in the wind tunnel suggest that this maintenance of upwind shear stress may be a result of concave (unstable) streamline curvature. These additional surface stresses are not recorded by the techniques used in the field measurements. Using the occurrence of streamline curvature as a starting point, a new 2-D model of dune dynamics is deduced. This model relies on the establishment of an equilibrium between windward slope morphology, surface stresses induced by streamline curvature, and streamwise acceleration. Adopting the criteria that concave streamline curvature and streamwise acceleration both increase surface shear stress, whereas convex streamline curvature and deceleration have the opposite effect, the relationships between form and process are investigated in each of three morphologically distinct zones: the upwind interdune and concave toe region of the dune, the convex portion of the windward slope, and the crest-brink region. The

  14. InterviewStreamliner, a minimalist, free, open source, relational approach to computer-assisted qualitative data analysis software

    NARCIS (Netherlands)

    H.D. Pruijt (Hans)

    2010-01-01

    textabstractInterviewStreamliner is a free, open source, minimalist alternative to complex computer-assisted qualitative data analysis packages. It builds on the flexibility of relational database management technology.

  15. Brownfields Assessing Contractor Capabilities for Streamlined Site Investigation: Additional Information Regarding All Appropriate Inquiries and Hiring an Environmental Professional

    Science.gov (United States)

    This document assists Brownfields grantees and other decision makers as they assess the capabilities of contractors and consultants to determine their qualifications to provide streamlined and innovative strategies for the assessment and and cleanup.

  16. Report: Follow-Up Report: EPA Proposes to Streamline the Review, Management and Disposal of Hazardous Waste Pharmaceuticals

    Science.gov (United States)

    Report #15-P-0260, August 19, 2015. EPA states that it intends to issue a proposed rule, Management Standards for Hazardous Waste, which will attempt to streamline the approach to managing and disposing of hazardous and nonhazardous pharmaceutical waste.

  17. Surface-Based fMRI-Driven Diffusion Tractography in the Presence of Significant Brain Pathology: A Study Linking Structure and Function in Cerebral Palsy

    Science.gov (United States)

    Cunnington, Ross; Boyd, Roslyn N.; Rose, Stephen E.

    2016-01-01

    Diffusion MRI (dMRI) tractography analyses are difficult to perform in the presence of brain pathology. Automated methods that rely on cortical parcellation for structural connectivity studies often fail, while manually defining regions is extremely time consuming and can introduce human error. Both methods also make assumptions about structure-function relationships that may not hold after cortical reorganisation. Seeding tractography with functional-MRI (fMRI) activation is an emerging method that reduces these confounds, but inherent smoothing of fMRI signal may result in the inclusion of irrelevant pathways. This paper describes a novel fMRI-seeded dMRI-analysis pipeline based on surface-meshes that reduces these issues and utilises machine-learning to generate task specific white matter pathways, minimising the requirement for manually-drawn ROIs. We directly compared this new strategy to a standard voxelwise fMRI-dMRI approach, by investigating correlations between clinical scores and dMRI metrics of thalamocortical and corticomotor tracts in 31 children with unilateral cerebral palsy. The surface-based approach successfully processed more participants (87%) than the voxel-based approach (65%), and provided significantly more-coherent tractography. Significant correlations between dMRI metrics and five clinical scores of function were found for the more superior regions of these tracts. These significant correlations were stronger and more frequently found with the surface-based method (15/20 investigated were significant; R2 = 0.43–0.73) than the voxelwise analysis (2 sig. correlations; 0.38 & 0.49). More restricted fMRI signal, better-constrained tractography, and the novel track-classification method all appeared to contribute toward these differences. PMID:27487011

  18. Guessing right for the next war: streamlining, pooling, and right-timing force design decisions for an environment of uncertainty

    Science.gov (United States)

    2017-05-25

    key ingredients for not only how the Army fought World War II, but also how it continues to organize today. In essence , streamlining pares down every...Germans.1 The Battle of Mortain reflected the US Army in World War II at its best.2 It defined US Army success in the European theater of operations...continues to organize today.5 In essence , streamlining pared down every unit to its essentials based around a critical capability it provided to

  19. Assessment of arcuate fasciculus with diffusion-tensor tractography may predict the prognosis of aphasia in patients with left middle cerebral artery infarcts

    International Nuclear Information System (INIS)

    Hosomi, Akiko; Nagakane, Yoshinari; Kuriyama, Nagato; Mizuno, Toshiki; Nakagawa, Masanori; Yamada, Kei; Nishimura, Tsunehiko

    2009-01-01

    It is often clinically difficult to assess the severity of aphasia in the earliest stage of cerebral infarction. A method enabling objective assessment of verbal function is needed for this purpose. We examined whether diffusion tensor (DT) tractography is of clinical value in assessing aphasia. Thirteen right-handed patients with left middle cerebral artery infarcts who were scanned within 2 days after stroke onset were enrolled in this study. Magnetic resonance data of ten control subjects were also examined by DT tractography. Based on the severity of aphasia at discharge, patients were divided into two groups: six patients in the aphasic group and seven in the nonaphasic group. Fractional anisotropy (FA) and number of arcuate fasciculus fibers were evaluated. Asymmetry index was calculated for both FA and number of fibers. FA values for the arcuate fasciculus fibers did not differ between hemispheres in either the patient groups or the controls. Number of arcuate fasciculus fibers exhibited a significant leftward asymmetry in the controls and the nonaphasic group but not in the aphasic group. Asymmetry index of number of fibers was significantly lower (rightward) in the aphasic group than in the nonaphasic (P = 0.015) and control (P = 0.005) groups. Loss of leftward asymmetry in number of AF fibers predicted aphasia at discharge with a sensitivity of 0.83 and specificity of 0.86. Asymmetry of arcuate fasciculus fibers by DT tractography may deserve to be assessed in acute infarction for predicting the fate of vascular aphasia. (orig.)

  20. Assessment of arcuate fasciculus with diffusion-tensor tractography may predict the prognosis of aphasia in patients with left middle cerebral artery infarcts

    Energy Technology Data Exchange (ETDEWEB)

    Hosomi, Akiko; Nagakane, Yoshinari; Kuriyama, Nagato; Mizuno, Toshiki; Nakagawa, Masanori [Kyoto Prefectural University of Medicine, Department of Neurology, Graduate School of Medical Science, Kyoto (Japan); Yamada, Kei; Nishimura, Tsunehiko [Kyoto Prefectural University of Medicine, Department of Radiology, Graduate School of Medical Science, Kyoto (Japan)

    2009-09-15

    It is often clinically difficult to assess the severity of aphasia in the earliest stage of cerebral infarction. A method enabling objective assessment of verbal function is needed for this purpose. We examined whether diffusion tensor (DT) tractography is of clinical value in assessing aphasia. Thirteen right-handed patients with left middle cerebral artery infarcts who were scanned within 2 days after stroke onset were enrolled in this study. Magnetic resonance data of ten control subjects were also examined by DT tractography. Based on the severity of aphasia at discharge, patients were divided into two groups: six patients in the aphasic group and seven in the nonaphasic group. Fractional anisotropy (FA) and number of arcuate fasciculus fibers were evaluated. Asymmetry index was calculated for both FA and number of fibers. FA values for the arcuate fasciculus fibers did not differ between hemispheres in either the patient groups or the controls. Number of arcuate fasciculus fibers exhibited a significant leftward asymmetry in the controls and the nonaphasic group but not in the aphasic group. Asymmetry index of number of fibers was significantly lower (rightward) in the aphasic group than in the nonaphasic (P = 0.015) and control (P = 0.005) groups. Loss of leftward asymmetry in number of AF fibers predicted aphasia at discharge with a sensitivity of 0.83 and specificity of 0.86. Asymmetry of arcuate fasciculus fibers by DT tractography may deserve to be assessed in acute infarction for predicting the fate of vascular aphasia. (orig.)

  1. A novel approach of fMRI-guided tractography analysis within a group: construction of an fMRI-guided tractographic atlas.

    Science.gov (United States)

    Preti, Maria Giulia; Makris, Nikos; Laganà, Maria Marcella; Papadimitriou, George; Baglio, Francesca; Griffanti, Ludovica; Nemni, Raffaello; Cecconi, Pietro; Westin, Carl-Fredrik; Baselli, Giuseppe

    2012-01-01

    Diffusion Tensor Imaging (DTI) tractography and functional Magnetic Resonance Imaging (fMRI) investigate two complementary aspects of brain networks: white matter (WM) anatomical connectivity and gray matter (GM) function. However, integration standards have yet to be defined; namely, individual fMRI-driven tractography is usually applied and only few studies address group analysis. This work proposes an efficient method of fMRI-driven tractography at group level through the creation of a tractographic atlas starting from the GM areas activated by a verbal fluency task in 11 healthy subjects. The individual tracts were registered to the MNI space. Selection ROIs derived by GM masking and dilation of group activated areas were applied to obtain the fMRI-driven subsets within tracts. An atlas of the tracts recruited among the population was obtained by selecting for each subject the fMRI-guided tracts passing through the high probability voxels (the voxels recruited by the 90% of the subjects) and merging them together. The reliability of this approach was assessed by comparing it with the probabilistic atlas previously introduced in literature. The introduced method allowed to successfully reconstruct activated tracts, which comprehended corpus callosum, left cingulum and arcuate, a small portion of the right arcuate, both cortico-spinal tracts and inferior fronto-occipital fasciculi. Moreover, it proved to give results concordant with the previously introduced probabilistic approach, allowing in addition to reconstruct 3D trajectories of the activated fibers, which appear particularly helpful in the detection of WM connections.

  2. Preoperative Quantitative MR Tractography Compared with Visual Tract Evaluation in Patients with Neuropathologically Confirmed Gliomas Grades II and III: A Prospective Cohort Study

    International Nuclear Information System (INIS)

    Delgado, Anna F.; Nilsson, Markus; Latini, Francesco; Mårtensson, Johanna; Zetterling, Maria; Berntsson, Shala G.; Alafuzoff, Irina; Lätt, Jimmy; Larsson, Elna-Marie

    2016-01-01

    Background and Purpose. Low-grade gliomas show infiltrative growth in white matter tracts. Diffusion tensor tractography can noninvasively assess white matter tracts. The aim was to preoperatively assess tumor growth in white matter tracts using quantitative MR tractography (3T). The hypothesis was that suspected infiltrated tracts would have altered diffusional properties in infiltrated tract segments compared to noninfiltrated tracts. Materials and Methods. Forty-eight patients with suspected low-grade glioma were included after written informed consent and underwent preoperative diffusion tensor imaging in this prospective review-board approved study. Major white matter tracts in both hemispheres were tracked, segmented, and visually assessed for tumor involvement in thirty-four patients with gliomas grade II or III (astrocytomas or oligodendrogliomas) on postoperative neuropathological evaluation. Relative fractional anisotropy (rFA) and mean diffusivity (rMD) in tract segments were calculated and compared with visual evaluation and neuropathological diagnosis. Results. Tract segment infiltration on visual evaluation was associated with a lower rFA and high rMD in a majority of evaluated tract segments (89% and 78%, resp.). Grade II and grade III gliomas had similar infiltrating behavior. Conclusion. Quantitative MR tractography corresponds to visual evaluation of suspected tract infiltration. It may be useful for an objective preoperative evaluation of tract segment involvement

  3. Stable–streamlined and helical cavities following the impact of Leidenfrost spheres

    KAUST Repository

    Mansoor, Mohammad M.

    2017-06-23

    We report results from an experimental study on the formation of stable–streamlined and helical cavity wakes following the free-surface impact of Leidenfrost spheres. Similar to the observations of Mansoor et al. (J. Fluid Mech., vol. 743, 2014, pp. 295–326), we show that acoustic ripples form along the interface of elongated cavities entrained in the presence of wall effects as soon as the primary cavity pinch-off takes place. The crests of these ripples can act as favourable points for closure, producing multiple acoustic pinch-offs, which are found to occur in an acoustic pinch-off cascade. We show that these ripples pacify with time in the absence of physical contact between the sphere and the liquid, leading to extremely smooth cavity wake profiles. More importantly, the downward-facing jet at the apex of the cavity is continually suppressed due to a skin-friction drag effect at the colliding cavity-wall junction, which ultimately produces a stable–streamlined cavity wake. This streamlined configuration is found to experience drag coefficients an order of a magnitude lower than those acting on room-temperature spheres. A striking observation is the formation of helical cavities which occur for impact Reynolds numbers and are characterized by multiple interfacial ridges, stemming from and rotating synchronously about an evident contact line around the sphere equator. The contact line is shown to result from the degeneration of Kelvin–Helmholtz billows into turbulence which are observed forming along the liquid–vapour interface around the bottom hemisphere of the sphere. Using sphere trajectory measurements, we show that this helical cavity wake configuration has 40 %–55 % smaller force coefficients than those obtained in the formation of stable cavity wakes.

  4. Stable–streamlined and helical cavities following the impact of Leidenfrost spheres

    KAUST Repository

    Mansoor, Mohammad M.; Vakarelski, Ivan Uriev; Marston, J. O.; Truscott, T. T.; Thoroddsen, Sigurdur T

    2017-01-01

    We report results from an experimental study on the formation of stable–streamlined and helical cavity wakes following the free-surface impact of Leidenfrost spheres. Similar to the observations of Mansoor et al. (J. Fluid Mech., vol. 743, 2014, pp. 295–326), we show that acoustic ripples form along the interface of elongated cavities entrained in the presence of wall effects as soon as the primary cavity pinch-off takes place. The crests of these ripples can act as favourable points for closure, producing multiple acoustic pinch-offs, which are found to occur in an acoustic pinch-off cascade. We show that these ripples pacify with time in the absence of physical contact between the sphere and the liquid, leading to extremely smooth cavity wake profiles. More importantly, the downward-facing jet at the apex of the cavity is continually suppressed due to a skin-friction drag effect at the colliding cavity-wall junction, which ultimately produces a stable–streamlined cavity wake. This streamlined configuration is found to experience drag coefficients an order of a magnitude lower than those acting on room-temperature spheres. A striking observation is the formation of helical cavities which occur for impact Reynolds numbers and are characterized by multiple interfacial ridges, stemming from and rotating synchronously about an evident contact line around the sphere equator. The contact line is shown to result from the degeneration of Kelvin–Helmholtz billows into turbulence which are observed forming along the liquid–vapour interface around the bottom hemisphere of the sphere. Using sphere trajectory measurements, we show that this helical cavity wake configuration has 40 %–55 % smaller force coefficients than those obtained in the formation of stable cavity wakes.

  5. Theoretical Calculations on Sediment Transport on Titan, and the Possible Production of Streamlined Forms

    Science.gov (United States)

    Burr, D. M.; Emery, J. P.; Lorenz, R. D.

    2005-01-01

    The Cassini Imaging Science System (ISS) has been returning images of Titan, along with other Saturnian satellites. Images taken through the 938 nm methane window see down to Titan's surface. One of the purposes of the Cassini mission is to investigate possible fluid cycling on Titan. Lemniscate features shown recently and radar evidence of surface flow prompted us to consider theoretically the creation by methane fluid flow of streamlined forms on Titan. This follows work by other groups in theoretical consideration of fluid motion on Titan's surface.

  6. Injury of the inferior cerebellar peduncle in patients with mild traumatic brain injury: A diffusion tensor tractography study.

    Science.gov (United States)

    Jang, Sung Ho; Yi, Ji Hyun; Kwon, Hyeok Gyu

    2016-01-01

    No study on injury of the inferior cerebellar peduncle (ICP) in patients with mild traumatic brain injury (mTBI) has been reported. This study, using diffusion tensor tractography (DTT), attempted to demonstrate injury of the ICP in patients with mTBI. Three patients with mTBI resulting from a car accident and 18 normal healthy control subjects were enrolled in this study. Diffusion tensor imaging data were acquired at 2 months (patient 1) and 3 months (patients 2 and 3) after onset and the ICP was reconstructed. The Balance Error Scoring System was used for evaluation of balance at the same time diffusion tensor imaging scanning was performed. The ICPs were discontinued at the upper portion of the vertical cerebellar branch and the transverse cerebellar branch (patient 1) and the proximal portion of the transverse cerebellar branch (patients 2 and 3) compared to the normal control subjects. Regarding DTT parameters, in the three patients, the fibre number of the ICPs was decreased by more than 2 SD compared with those of subjects in the control group. Evaluation of the ICP using DTT would be useful in patients with a balance problem after mTBI.

  7. Anatomical parcellation of the brainstem and cerebellar white matter: a preliminary probabilistic tractography study at 3 T

    International Nuclear Information System (INIS)

    Habas, Christophe; Cabanis, Emmanuel A.

    2007-01-01

    The aims of this study were: (1) to test whether higher spatial resolution diffusion tensor images and a higher field strength (3 T) enable a more accurate delineation of the anatomical tract within the brainstem, and, in particular, (2) to try to distinguish the different components of the corticopontocerebellar paths in terms of their cortical origins. The main tracts of the brainstem of four volunteers were studied at 3 T using a probabilistic diffusion tensor imaging (DTI) axonal tracking. The resulting tractograms enabled anatomical well-delineated structures to be identified on the diffusion tensor coloured images. We tracked corticopontine, corticospinal, central tegmental, inferior and superior cerebellopeduncular, transverse, medial lemniscal and, possibly, longitudinal medial fibres. Moreover, DTI tracking allowed a broad delineation of the corticopontocerebellar paths. Diffusion tensor coloured images allow a rapid and reliable access to the white matter broad parcellation of the brainstem and of the cerebellum, which can be completed by fibre tracking. However, a more accurate and exhaustive depiction of the anatomical connectivity within the brainstem requires the application of more sophisticated techniques and tractography algorithms, such as diffusion spectrum imaging. (orig.)

  8. Segmentation of the Cingulum Bundle in the Human Brain: A New Perspective Based on DSI Tractography and Fiber Dissection Study.

    Science.gov (United States)

    Wu, Yupeng; Sun, Dandan; Wang, Yong; Wang, Yibao; Ou, Shaowu

    2016-01-01

    The cingulum bundle (CB) is a critical white matter fiber tract in the brain, which forms connections between the frontal lobe, parietal lobe and temporal lobe. In non-human primates, the CB is actually divided into distinct subcomponents on the basis of corticocortical connections. However, at present, no study has verified similar distinct subdivisions in the human brain. In this study, we reconstructed these distinct subdivisions in the human brain, and determined their exact cortical connections using high definition fiber tracking (HDFT) technique on 10 healthy adults and a 488-subject template from the Human Connectome Project (HCP-488). Fiber dissections were performed to verify tractography results. Five CB segments were identified. CB-I ran from the subrostral areas to the precuneus and splenium, encircling the corpus callosum (CC). CB-II arched around the splenium and extended anteriorly above the CC to the medial aspect of the superior frontal gyrus (SFG). CB-III connected the superior parietal lobule (SPL) and precuneus with the medial aspect of the SFG. CB-IV was a relatively minor subcomponent from the SPL and precuneus to the frontal region. CB-V, the para-hippocampal cingulum, stemmed from the medial temporal lobe and fanned out to the occipital lobes. Our findings not only provide a more accurate and detailed description on the associated architecture of the subcomponents within the CB, but also offer new insights into the functional role of the CB in the human brain.

  9. Segmentation of the cingulum bundle in the human brain: a new perspective based on DSI tractography and fiber dissection study

    Directory of Open Access Journals (Sweden)

    Yupeng Wu

    2016-09-01

    Full Text Available The cingulum bundle (CB is a critical white matter fiber tract in the brain, which forms connections between the frontal lobe, parietal lobe, and temporal lobe. In non-human primates, the CB is actually divided into distinct subcomponents on the basis of corticocortical connections. However, at present, no study has verified similar distinct subdivisions in the human brain. In this study, we reconstructed these distinct subdivisions in the human brain, and determined their exact cortical connections using high definition fiber tracking (HDFT technique on 10 healthy adults and a 488-subject template from the Human Connectome Project (HCP-488. Fiber dissections were performed to verify tractography results. Five CB segments were identified. CB-I ran from the subrostral areas to the precuneus and splenium, encircling the corpus callosum. CB-II arched around the splenium and extended anteriorly above the corpus callosum to the medial aspect of the superior frontal gyrus. CB-III connected the superior parietal lobule and precuneus with the medial aspect of the superior frontal gyrus. CB-IV was a relatively minor subcomponent from the superior parietal lobule and precuneus to the frontal region. CB-V, the para-hippocampal cingulum, stemmed from the medial temporal lobe and fanned out to the occipital lobes. Our findings not only provide a more accurate and detailed description on the associated architecture of the subcomponents within the CB, but also offer new insights into the functional role of the CB in the human brain.

  10. Anatomical parcellation of the brainstem and cerebellar white matter: a preliminary probabilistic tractography study at 3 T

    Energy Technology Data Exchange (ETDEWEB)

    Habas, Christophe; Cabanis, Emmanuel A. [UPMC Paris 6, Service de NeuroImagerie, Hopital des Quinze-Vingts, Paris (France)

    2007-10-15

    The aims of this study were: (1) to test whether higher spatial resolution diffusion tensor images and a higher field strength (3 T) enable a more accurate delineation of the anatomical tract within the brainstem, and, in particular, (2) to try to distinguish the different components of the corticopontocerebellar paths in terms of their cortical origins. The main tracts of the brainstem of four volunteers were studied at 3 T using a probabilistic diffusion tensor imaging (DTI) axonal tracking. The resulting tractograms enabled anatomical well-delineated structures to be identified on the diffusion tensor coloured images. We tracked corticopontine, corticospinal, central tegmental, inferior and superior cerebellopeduncular, transverse, medial lemniscal and, possibly, longitudinal medial fibres. Moreover, DTI tracking allowed a broad delineation of the corticopontocerebellar paths. Diffusion tensor coloured images allow a rapid and reliable access to the white matter broad parcellation of the brainstem and of the cerebellum, which can be completed by fibre tracking. However, a more accurate and exhaustive depiction of the anatomical connectivity within the brainstem requires the application of more sophisticated techniques and tractography algorithms, such as diffusion spectrum imaging. (orig.)

  11. Diffusion Tensor Imaging Tractography Reveals Disrupted White Matter Structural Connectivity Network in Healthy Adults with Insomnia Symptoms

    Directory of Open Access Journals (Sweden)

    Feng-Mei Lu

    2017-11-01

    Full Text Available Neuroimaging studies have revealed that insomnia is characterized by aberrant neuronal connectivity in specific brain regions, but the topological disruptions in the white matter (WM structural connectivity networks remain largely unknown in insomnia. The current study uses diffusion tensor imaging (DTI tractography to construct the WM structural networks and graph theory analysis to detect alterations of the brain structural networks. The study participants comprised 30 healthy subjects with insomnia symptoms (IS and 62 healthy subjects without IS. Both the two groups showed small-world properties regarding their WM structural connectivity networks. By contrast, increased local efficiency and decreased global efficiency were identified in the IS group, indicating an insomnia-related shift in topology away from regular networks. In addition, the IS group exhibited disrupted nodal topological characteristics in regions involving the fronto-limbic and the default-mode systems. To our knowledge, this is the first study to explore the topological organization of WM structural network connectivity in insomnia. More importantly, the dysfunctions of large-scale brain systems including the fronto-limbic pathways, salience network and default-mode network in insomnia were identified, which provides new insights into the insomnia connectome. Topology-based brain network analysis thus could be a potential biomarker for IS.

  12. High-definition fiber tractography for the evaluation of perilesional white matter tracts in high-grade glioma surgery.

    Science.gov (United States)

    Abhinav, Kumar; Yeh, Fang-Cheng; Mansouri, Alireza; Zadeh, Gelareh; Fernandez-Miranda, Juan C

    2015-09-01

    Conventional white matter (WM) imaging approaches, such as diffusion tensor imaging (DTI), have been used to preoperatively identify the location of affected WM tracts in patients with intracranial tumors in order to maximize the extent of resection and potentially reduce postoperative morbidity. DTI, however, has limitations that include its inability to resolve multiple crossing fibers and its susceptibility to partial volume effects. Therefore, recent focus has shifted to more advanced WM imaging techniques such as high-definition fiber tractography (HDFT). In this paper, we illustrate the application of HDFT, which in our preliminary experience has enabled accurate depiction of perilesional tracts in a 3-dimensional manner in multiple anatomical compartments including edematous zones around high-grade gliomas. This has facilitated accurate surgical planning. This is illustrated by using case examples of patients with glioblastoma multiforme. We also discuss future directions in the role of these techniques in surgery for gliomas. © The Author(s) 2015. Published by Oxford University Press on behalf of the Society for Neuro-Oncology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  13. Activation of less affected corticospinal tract and poor motor outcome in hemiplegic pediatric patients: a diffusion tensor tractography imaging study

    Directory of Open Access Journals (Sweden)

    Jin Hyun Kim

    2015-01-01

    Full Text Available The less affected hemisphere is important in motor recovery in mature brains. However, in terms of motor outcome in immature brains, no study has been reported on the less affected corticospinal tract in hemiplegic pediatric patients. Therefore, we examined the relationship between the condition of the less affected corticospinal tract and motor function in hemiplegic pediatric patients. Forty patients with hemiplegia due to perinatal or prenatal injury (13.7 ± 3.0 months and 40 age-matched typically developing controls were recruited. These patients were divided into two age-matched groups, the high functioning group (20 patients and the low functioning group (20 patients using functional level of hemiplegia scale. Diffusion tensor tractography images showed that compared with the control group, the patient group of the less affected corticospinal tract showed significantly increased fiber number and significantly decreased fractional anisotropy value. Significantly increased fiber number and significantly decreased fractional anisotropy value in the low functioning group were observed than in the high functioning group. These findings suggest that activation of the less affected hemisphere presenting as increased fiber number and decreased fractional anisotropy value is related to poor motor function in pediatric hemiplegic patients.

  14. Diffusion tensor tractography of the brainstem pyramidal tract; A study on the optimal reduction factor in parallel imaging

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Yun Jung; Park, Jong Bin; Kim, Jae Hyoung; Choi, Byung Se; Jung, Cheol Kyu [Dept. of of Radiology, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam (Korea, Republic of)

    2016-08-15

    Parallel imaging mitigates susceptibility artifacts that can adversely affect diffusion tensor tractography (DTT) of the pons depending on the reduction (R) factor. We aimed to find the optimal R factor for DTT of the pons that would allow us to visualize the largest possible number of pyramidal tract fibers. Diffusion tensor imaging was performed on 10 healthy subjects at 3 Tesla based on single-shot echo-planar imaging using the following parameters: b value, 1000 s/mm{sup 2}; gradient direction, 15; voxel size, 2 × 2 × 2 mm{sup 3}; and R factors, 1, 2, 3, 4, and 5. DTT of the right and left pyramidal tracts in the pons was conducted in all subjects. Signal-to-noise ratio (SNR), image distortion, and the number of fibers in the tracts were compared across R factors. SNR, image distortion, and fiber number were significantly different according to R factor. Maximal SNR was achieved with an R factor of 2. Image distortion was minimal with an R factor of 5. The number of visible fibers was greatest with an R factor of 3. R factor 3 is optimal for DTT of the pontine pyramidal tract. A balanced consideration of SNR and image distortion, which do not have the same dependence on the R factor, is necessary for DTT of the pons.

  15. Diffusion tensor MRI tractography reveals increased fractional anisotropy (FA) in arcuate fasciculus following music-cued motor training.

    Science.gov (United States)

    Moore, Emma; Schaefer, Rebecca S; Bastin, Mark E; Roberts, Neil; Overy, Katie

    2017-08-01

    Auditory cues are frequently used to support movement learning and rehabilitation, but the neural basis of this behavioural effect is not yet clear. We investigated the microstructural neuroplasticity effects of adding musical cues to a motor learning task. We hypothesised that music-cued, left-handed motor training would increase fractional anisotropy (FA) in the contralateral arcuate fasciculus, a fibre tract connecting auditory, pre-motor and motor regions. Thirty right-handed participants were assigned to a motor learning condition either with (Music Group) or without (Control Group) musical cues. Participants completed 20minutes of training three times per week over four weeks. Diffusion tensor MRI and probabilistic neighbourhood tractography identified FA, axial (AD) and radial (RD) diffusivity before and after training. Results revealed that FA increased significantly in the right arcuate fasciculus of the Music group only, as hypothesised, with trends for AD to increase and RD to decrease, a pattern of results consistent with activity-dependent increases in myelination. No significant changes were found in the left ipsilateral arcuate fasciculus of either group. This is the first evidence that adding musical cues to movement learning can induce rapid microstructural change in white matter pathways in adults, with potential implications for therapeutic clinical practice. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  16. Streamlining the process: A strategy for making NEPA work better and cost less

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, R.P.; Hansen, J.D. [Hansen Environmental Consultants, Englewood, CO (United States); Wolff, T.A. [Sandia National Labs., Albuquerque, NM (United States)

    1998-05-01

    When the National Environmental Policy Act (NEPA) was enacted in 1969, neither Congress nor the Federal Agencies affected anticipated that implementation of the NEPA process would result in the intolerable delays, inefficiencies, duplication of effort, commitments of excessive financial and personnel resources, and bureaucratic gridlock that have become institutionalized. The 1975 Council on Environmental Quality (CEQ) regulations, which were intended to make the NEPA process more efficient and more useful to decision makers and the public, have either been largely ignored or unintentionally subverted. Agency policy mandates, like those of former Secretary of Energy Hazel R. O`Leary, to ``make NEPA work better and cost less`` have, so far, been disappointingly ineffectual. Federal Agencies have reached the point where almost every constituent of the NEPA process must be subjected to crisis management. This paper focuses on a ten-point strategy for streamlining the NEPA process in order to achieve the Act`s objectives while easing the considerable burden on agencies, the public, and the judicial system. How the ten points are timed and implemented is critical to any successful streamlining.

  17. A new method for calculating volumetric sweeps efficiency using streamline simulation concepts

    International Nuclear Information System (INIS)

    Hidrobo, E A

    2000-01-01

    One of the purposes of reservoir engineering is to quantify the volumetric sweep efficiency for optimizing reservoir management decisions. The estimation of this parameter has always been a difficult task. Until now, sweep efficiency correlations and calculations have been limited to mostly homogeneous 2-D cases. Calculating volumetric sweep efficiency in a 3-D heterogeneous reservoir becomes difficult due to inherent complexity of multiple layers and arbitrary well configurations. In this paper, a new method for computing volumetric sweep efficiency for any arbitrary heterogeneity and well configuration is presented. The proposed method is based on Datta-Gupta and King's formulation of streamline time-of-flight (1995). Given the fact that the time-of-flight reflects the fluid front propagation at various times, then the connectivity in the time-of-flight represents a direct measure of the volumetric sweep efficiency. The proposed approach has been applied to synthetic as well as field examples. Synthetic examples are used to validate the volumetric sweep efficiency calculations using the streamline time-of-flight connectivity criterion by comparison with analytic solutions and published correlations. The field example, which illustrates the feasibility of the approach for large-scale field applications, is from the north Robertson unit, a low permeability carbonate reservoir in west Texas

  18. The impact of groundwater velocity fields on streamlines in an aquifer system with a discontinuous aquitard (Inner Mongolia, China)

    Science.gov (United States)

    Wu, Qiang; Zhao, Yingwang; Xu, Hua

    2018-04-01

    Many numerical methods that simulate groundwater flow, particularly the continuous Galerkin finite element method, do not produce velocity information directly. Many algorithms have been proposed to improve the accuracy of velocity fields computed from hydraulic potentials. The differences in the streamlines generated from velocity fields obtained using different algorithms are presented in this report. The superconvergence method employed by FEFLOW, a popular commercial code, and some dual-mesh methods proposed in recent years are selected for comparison. The applications to depict hydrogeologic conditions using streamlines are used, and errors in streamlines are shown to lead to notable errors in boundary conditions, the locations of material interfaces, fluxes and conductivities. Furthermore, the effects of the procedures used in these two types of methods, including velocity integration and local conservation, are analyzed. The method of interpolating velocities across edges using fluxes is shown to be able to eliminate errors associated with refraction points that are not located along material interfaces and streamline ends at no-flow boundaries. Local conservation is shown to be a crucial property of velocity fields and can result in more accurate streamline densities. A case study involving both three-dimensional and two-dimensional cross-sectional models of a coal mine in Inner Mongolia, China, are used to support the conclusions presented.

  19. Fiber tractography of the axonal pathways linking the basal ganglia and cerebellum in Parkinson disease: implications for targeting in deep brain stimulation.

    Science.gov (United States)

    Sweet, Jennifer A; Walter, Benjamin L; Gunalan, Kabilar; Chaturvedi, Ashutosh; McIntyre, Cameron C; Miller, Jonathan P

    2014-04-01

    Stimulation of white matter pathways near targeted structures may contribute to therapeutic effects of deep brain stimulation (DBS) for patients with Parkinson disease (PD). Two tracts linking the basal ganglia and cerebellum have been described in primates: the subthalamopontocerebellar tract (SPCT) and the dentatothalamic tract (DTT). The authors used fiber tractography to evaluate white matter tracts that connect the cerebellum to the region of the basal ganglia in patients with PD who were candidates for DBS. Fourteen patients with advanced PD underwent 3-T MRI, including 30-directional diffusion-weighted imaging sequences. Diffusion tensor tractography was performed using 2 regions of interest: ipsilateral subthalamic and red nuclei, and contralateral cerebellar hemisphere. Nine patients underwent subthalamic DBS, and the course of each tract was observed relative to the location of the most effective stimulation contact and the volume of tissue activated. In all patients 2 distinct tracts were identified that corresponded closely to the described anatomical features of the SPCT and DTT, respectively. The mean overall distance from the active contact to the DTT was 2.18 ± 0.35 mm, and the mean proportional distance relative to the volume of tissue activated was 1.35 ± 0.48. There was a nonsignificant trend toward better postoperative tremor control in patients with electrodes closer to the DTT. The SPCT and the DTT may be related to the expression of symptoms in PD, and this may have implications for DBS targeting. The use of tractography to identify the DTT might assist with DBS targeting in the future.

  20. Predicting pituitary stalk position by in vivo visualization of the hypothalamo-hypophyseal tract in craniopharyngioma using diffusion tensor imaging tractography.

    Science.gov (United States)

    Wang, Fuyu; Jiang, Jinli; Zhang, Jiashu; Wang, Qun

    2018-07-01

    The pituitary stalk (PS) is crucial to endocrine function and water-electrolyte equilibrium. Preservation of the PS during craniopharyngioma (CP) surgery is critical; however, in a pathological state, it is difficult to identify. The hypothalamo-hypophyseal tract (HHT) connects the hypothalamus and the posterior pituitary gland and projects through the PS. Thus, visualization of the HHT can help locate the PS. Preoperative visualization of the neural fasciculus has been widely achieved using diffusion tensor imaging (DTI) tractography. Therefore, this study evaluated the use of DTI tractography to identify and characterize the human HHT. We used DTI tractography to track the HHT in 10 patients with CP and compared the location of the tract with the intraoperative view of the PS in these patients. We successfully tracked the HHT in nine patients, indicating that delineating and quantifying the tracked HHT using this method is feasible. In addition, we found that the tract was consistent with the intraoperative view of the PS in seven out of eight patients (87.50%). Finally, we found that the mean number of tracts was 7.11 ± 12.28, the mean fractional anisotropy (FA) was 0.11 ± 0.04, and the mean tract length was 24.22 ± 9.39 mm. Taken together, our results demonstrate that the HHT can be visualized and characterized with DTI even in a clinical application, which may aid in preoperative identification of the PS. Characterization of the tracked HHT with this technique could also be used to advance our understanding of the HHT.

  1. Evaluation of the female pelvic floor in pelvic organ prolapse using 3.0-Tesla diffusion tensor imaging and fibre tractography

    Energy Technology Data Exchange (ETDEWEB)

    Zijta, F.M. [University of Amsterdam, Department of Radiology, Academic Medical Centre, Amsterdam (Netherlands); Onze Lieve Vrouwe Gasthuis, Amsterdam and Department of Radiology, Amsterdam (Netherlands); Academic Medical Center, Department of Radiology, Amsterdam, AZ (Netherlands); Lakeman, M.M.E.; Roovers, J.P. [University of Amsterdam the Netherlands and Biomedical NMR, Amsterdam and Department of Gynaecology, Academic Medical Centre, Amsterdam (Netherlands); Froeling, M. [University of Amsterdam, Department of Radiology, Academic Medical Centre, Amsterdam (Netherlands); Eindhoven University of Technology, Department of Biomedical Engineering, Eindhoven (Netherlands); Paardt, M.P. van der; Borstlap, C.S.V.; Bipat, S.; Nederveen, A.J.; Stoker, J. [University of Amsterdam, Department of Radiology, Academic Medical Centre, Amsterdam (Netherlands); Montauban van Swijndregt, A.D. [Onze Lieve Vrouwe Gasthuis, Amsterdam and Department of Radiology, Amsterdam (Netherlands); Strijkers, G.J. [Eindhoven University of Technology, Department of Biomedical Engineering, Eindhoven (Netherlands)

    2012-12-15

    To prospectively explore the clinical application of diffusion tensor imaging (DTI) and fibre tractography in evaluating the pelvic floor. Ten patients with pelvic organ prolapse, ten with pelvic floor symptoms and ten asymptomatic women were included. A two-dimensional (2D) spin-echo (SE) echo-planar imaging (EPI) sequence of the pelvic floor was acquired. Offline fibre tractography and morphological analysis of pelvic magnetic resonance imaging (MRI) were performed. Inter-rater agreement for quality assessment of fibre tracking results was evaluated using weighted kappa ({kappa}). From agreed tracking results, eigen values ({lambda}1, {lambda}2, {lambda}3), mean diffusivity (MD) and fractional anisotropy (FA) were calculated. MD and FA values were compared using ANOVA. Inter-rater reliability of DTI parameters was interpreted using the intra-class correlation coefficient (ICC). Substantial inter-rater agreement was found ({kappa} = 0.71 [95% CI 0.63-0.78]). Four anatomical structures were reliably identified. Substantial inter-rater agreement was found for MD and FA (ICC 0.60-0.91). No significant differences between groups were observed for anal sphincter, perineal body and puboperineal muscle. A significant difference in FA was found for internal obturator muscle between the prolapse group and the asymptomatic group (0.27 {+-} 0.05 vs 0.22 {+-} 0.03; P = 0.015). DTI with fibre tractography permits identification of part of the clinically relevant pelvic structures. Overall, no significant differences in DTI parameters were found between groups. circle Diffusion tensor MRI offers new insights into female pelvic floor problems. (orig.)

  2. Role of magnetic resonance tractography in the preoperative planning and intraoperative assessment of patients with intra-axial brain tumours.

    Science.gov (United States)

    Romano, A; Ferrante, M; Cipriani, V; Fasoli, F; Ferrante, L; D'Andrea, G; Fantozzi, L M; Bozzao, A

    2007-09-01

    This study was conducted to assess the possibility of identifying precise white matter tracts situated in proximity to intracranial tumours, to define the anatomical and topographical relations between the same white matter tracts and the tumour, to verify the possibility of integrating tractographic images in the context of a package of three-dimensional anatomical images to send to the neuronavigation system, to assess the impact of this information on surgical planning, and to analyse, both pre-and postoperatively, the patient's clinical conditions as an index of the functional integrity of the fibres themselves. Twenty-five patients underwent diffusion tensor study prior to neurosurgery. With the use of dedicated software, relative colour maps were obtained and the trajectories of the white matter tracts adjacent to the tumour were reconstructed in three dimensions. These were then processed for preoperative planning. Planning, which was performed with the neuronavigator, was based on analysis of the location of the course of the main white matter tracts adjacent to the lesion (pyramidal tract, optic radiation and arcuate fasciculus). Two neurosurgeons were asked whether the tractography images had modified the access and/or intraoperative approach to the tumour. All patients were clinically assessed both pre-and postoperatively 1 month after the procedure to define the presence of symptoms related to the involvement of the white matter tracts studied and therefore to assess the integrity of the fibres after the operation. In one patient, the tumour was situated away from all the tracts studied and did not compress them in any way. Overall, 40/75 tracts studied had no anatomical relation with the tumour, were not displaced by the tumour or could not be visualised in their entire course. Analysis of the remaining 35 white matter tracts led to an a priori change in the surgical approach for corticotomy in four patients (16%), with no disagreement between the two

  3. Longitudinal study on diffusion tensor imaging and diffusion tensor tractography following spinal cord contusion injury in rats.

    Science.gov (United States)

    Zhao, Can; Rao, Jia-Sheng; Pei, Xiao-Jiao; Lei, Jian-Feng; Wang, Zhan-Jing; Yang, Zhao-Yang; Li, Xiao-Guang

    2016-06-01

    Diffusion tensor imaging (DTI) as a potential technology has been used in spinal cord injury (SCI) studies, but the longitudinal evaluation of DTI parameters after SCI, and the correlation between DTI parameters and locomotor outcomes need to be defined. Adult Wistar rats (n = 6) underwent traumatic thoracic cord contusion by an NYU impactor. DTI and Basso-Beattie-Bresnahan datasets were collected pre-SCI and 1, 3, 7, 14, and 84 days post-SCI. Diffusion tensor tractography (DTT) of the spinal cord was also generated. Fractional anisotropy (FA) and connection rate of fibers at the injury epicenter and at 5 mm rostral/caudal to the epicenter were calculated. The variations of these parameters after SCI were observed by one-way analysis of variance and the correlations between these parameters and motor function were explored by Pearson's correlation. FA at the epicenter decreased most remarkably on day 1 post-SCI (from 0.780 ± 0.012 to 0.330 ± 0.015), and continued to decrease slightly by day 3 post-SCI (0.313 ± 0.015), while other parameters decreased significantly over the first 3 days after SCI. DTT showed residual fibers concentrated on ventral and ventrolateral sides of the cord. Moreover, FA at the epicenter exhibited the strongest correlation (r = 0.887, p = 0.000) with the locomotion performance. FA was sensitive to degeneration in white matter and DTT could directly reflect the distribution of the residual white matter. Moreover, days 1 to 3 post-SCI may be the optimal time window for SCI examination and therapy.

  4. Probabilistic diffusion tractography of the optic radiations and visual function in preterm infants at term equivalent age.

    Science.gov (United States)

    Bassi, Laura; Ricci, Daniela; Volzone, Anna; Allsop, Joanna M; Srinivasan, Latha; Pai, Aakash; Ribes, Carmen; Ramenghi, Luca A; Mercuri, Eugenio; Mosca, Fabio; Edwards, A David; Cowan, Frances M; Rutherford, Mary A; Counsell, Serena J

    2008-02-01

    Children born prematurely have a high incidence of visual disorders which cannot always be explained by focal retinal or brain lesions. The aim of this study was to test the hypothesis that visual function in preterm infants is related to the microstructural development of white matter in the optic radiations. We used diffusion tensor imaging (DTI) with probabilistic diffusion tractography to delineate the optic radiations at term equivalent age and compared the fractional anisotropy (FA) to a contemporaneous evaluation of visual function. Thirty-seven preterm infants (19 male) born at median (range) 28(+4) (24(+1)-32(+3)) weeks gestational age, were examined at a post-menstrual age of 42 (39(+6)-43) weeks. MRI and DTI were acquired on a 3 Tesla MR system with DTI obtained in 15 non-collinear directions with a b value of 750 s/mm(2). Tracts were generated from a seed mask placed in the white matter lateral to the lateral geniculate nucleus and mean FA values of these tracts were determined. Visual assessment was performed using a battery of nine items assessing different aspects of visual abilities. Ten infants had evidence of cerebral lesions on conventional MRI. Multiple regression analysis demonstrated that the visual assessment score was independently correlated with FA values, but not gestational age at birth, post-menstrual age at scan or the presence of lesions on conventional MRI. The occurrence of mild retinopathy of prematurity did not affect the FA measures or visual scores. We then performed a secondary analysis using tract-based spatial statistics to determine whether global brain white matter development was related to visual function and found that only FA in the optic radiations was correlated with visual assessment score. Our results suggest that in preterm infants at term equivalent age visual function is directly related to the development of white matter in the optic radiations.

  5. Piriformis muscle syndrome with assessment of sciatic nerve using diffusion tensor imaging and tractography: a case report

    Energy Technology Data Exchange (ETDEWEB)

    Wada, Keizo; Goto, Tomohiro; Takasago, Tomoya; Hamada, Daisuke; Sairyo, Koichi [The University of Tokushima Graduate School, Department of Orthopedics, Institute of Health Biosciences, Tokushima (Japan)

    2017-10-15

    Piriformis muscle syndrome (PMS) is difficult to diagnose by objective evaluation of sciatic nerve injury. Here we report a case of PMS diagnosed by diffusion tensor imaging (DTI) and tractography of the sciatic nerve, which can assess and visualize the extent of nerve injury. The patient was a 53-year-old man with a 2-year history of continuous pain and numbness in the left leg. His symptoms worsened when sitting. Physical examination, including sensorimotor neurologic tests, the deep tendon reflex test, and the straight leg raise test, revealed no specific findings. The hip flexion adduction and internal rotation test and resisted contraction maneuvers for the piriformis muscle were positive. There were no abnormal findings on magnetic resonance imaging (MRI) of the lumbar spine. The transverse diameter of piriformis muscle was slightly thicker in affected side on MRI of the pelvis. A single DTI sequence was performed during MRI of the pelvis. Fractional anisotropy (FA) and the apparent diffusion coefficient (ADC) of the sciatic nerve were quantified at three levels using the fiber-tracking method. FA values were significantly lower and ADC values were significantly higher distal to the piriformis muscle. We performed endoscopic-assisted resection of the piriformis tendon. Intraoperatively, the motor-evoked potentials in the left gastrocnemius were improved by resection of the piriformis tendon. The patient's symptoms improved immediately after surgery. There was no significant difference in FA or ADC at any level between the affected side and the unaffected side 3 months postoperatively. MRI-DTI may aid the diagnosis of PMS. (orig.)

  6. New insights into the developing rabbit brain using diffusion tensor tractography and generalized q-sampling MRI.

    Directory of Open Access Journals (Sweden)

    Seong Yong Lim

    Full Text Available The use of modern neuroimaging methods to characterize the complex anatomy of brain development at different stages reveals an enormous wealth of information in understanding this highly ordered process and provides clues to detect neurological and neurobehavioral disorders that have their origin in early structural and functional cerebral maturation. Non-invasive diffusion tensor magnetic resonance imaging (DTI is able to distinguish cerebral microscopic structures, especially in the white matter regions. However, DTI is unable to resolve the complicated neural structure, i.e., the fiber crossing that is frequently observed during the maturation process. To overcome this limitation, several methods have been proposed. One such method, generalized q-sampling imaging (GQI, can be applied to a variety of datasets, including the single shell, multi-shell or grid sampling schemes that are believed to be able to resolve the complicated crossing fibers. Rabbits have been widely used for neurodevelopment research because they exhibit human-like timing of perinatal brain white matter maturation. Here, we present a longitudinal study using both DTI and GQI to demonstrate the changes in cerebral maturation of in vivo developing rabbit brains over a period of 40 weeks. Fractional anisotropy (FA of DTI and generalized fractional anisotropy (GFA of GQI indices demonstrated that the white matter anisotropy increased with age, with GFA exhibiting an increase in the hippocampus as well. Normalized quantitative anisotropy (NQA of GQI also revealed an increase in the hippocampus, allowing us to observe the changes in gray matter as well. Regional and whole brain DTI tractography also demonstrated refinement in fiber pathway architecture with maturation. We concluded that DTI and GQI results were able to characterize the white matter anisotropy changes, whereas GQI provided further information about the gray matter hippocampus area. This developing rabbit brain

  7. Piriformis muscle syndrome with assessment of sciatic nerve using diffusion tensor imaging and tractography: a case report.

    Science.gov (United States)

    Wada, Keizo; Goto, Tomohiro; Takasago, Tomoya; Hamada, Daisuke; Sairyo, Koichi

    2017-10-01

    Piriformis muscle syndrome (PMS) is difficult to diagnose by objective evaluation of sciatic nerve injury. Here we report a case of PMS diagnosed by diffusion tensor imaging (DTI) and tractography of the sciatic nerve, which can assess and visualize the extent of nerve injury. The patient was a 53-year-old man with a 2-year history of continuous pain and numbness in the left leg. His symptoms worsened when sitting. Physical examination, including sensorimotor neurologic tests, the deep tendon reflex test, and the straight leg raise test, revealed no specific findings. The hip flexion adduction and internal rotation test and resisted contraction maneuvers for the piriformis muscle were positive. There were no abnormal findings on magnetic resonance imaging (MRI) of the lumbar spine. The transverse diameter of piriformis muscle was slightly thicker in affected side on MRI of the pelvis. A single DTI sequence was performed during MRI of the pelvis. Fractional anisotropy (FA) and the apparent diffusion coefficient (ADC) of the sciatic nerve were quantified at three levels using the fiber-tracking method. FA values were significantly lower and ADC values were significantly higher distal to the piriformis muscle. We performed endoscopic-assisted resection of the piriformis tendon. Intraoperatively, the motor-evoked potentials in the left gastrocnemius were improved by resection of the piriformis tendon. The patient's symptoms improved immediately after surgery. There was no significant difference in FA or ADC at any level between the affected side and the unaffected side 3 months postoperatively. MRI-DTI may aid the diagnosis of PMS.

  8. Piriformis muscle syndrome with assessment of sciatic nerve using diffusion tensor imaging and tractography: a case report

    International Nuclear Information System (INIS)

    Wada, Keizo; Goto, Tomohiro; Takasago, Tomoya; Hamada, Daisuke; Sairyo, Koichi

    2017-01-01

    Piriformis muscle syndrome (PMS) is difficult to diagnose by objective evaluation of sciatic nerve injury. Here we report a case of PMS diagnosed by diffusion tensor imaging (DTI) and tractography of the sciatic nerve, which can assess and visualize the extent of nerve injury. The patient was a 53-year-old man with a 2-year history of continuous pain and numbness in the left leg. His symptoms worsened when sitting. Physical examination, including sensorimotor neurologic tests, the deep tendon reflex test, and the straight leg raise test, revealed no specific findings. The hip flexion adduction and internal rotation test and resisted contraction maneuvers for the piriformis muscle were positive. There were no abnormal findings on magnetic resonance imaging (MRI) of the lumbar spine. The transverse diameter of piriformis muscle was slightly thicker in affected side on MRI of the pelvis. A single DTI sequence was performed during MRI of the pelvis. Fractional anisotropy (FA) and the apparent diffusion coefficient (ADC) of the sciatic nerve were quantified at three levels using the fiber-tracking method. FA values were significantly lower and ADC values were significantly higher distal to the piriformis muscle. We performed endoscopic-assisted resection of the piriformis tendon. Intraoperatively, the motor-evoked potentials in the left gastrocnemius were improved by resection of the piriformis tendon. The patient's symptoms improved immediately after surgery. There was no significant difference in FA or ADC at any level between the affected side and the unaffected side 3 months postoperatively. MRI-DTI may aid the diagnosis of PMS. (orig.)

  9. The streamline upwind Petrov-Galerkin stabilising method for the numerical solution of highly advective problems

    Directory of Open Access Journals (Sweden)

    Carlos Humberto Galeano Urueña

    2009-05-01

    Full Text Available This article describes the streamline upwind Petrov-Galerkin (SUPG method as being a stabilisation technique for resolving the diffusion-advection-reaction equation by finite elements. The first part of this article has a short analysis of the importance of this type of differential equation in modelling physical phenomena in multiple fields. A one-dimensional description of the SUPG me- thod is then given to extend this basis to two and three dimensions. The outcome of a strongly advective and a high numerical complexity experiment is presented. The results show how the version of the implemented SUPG technique allowed stabilised approaches in space, even for high Peclet numbers. Additional graphs of the numerical experiments presented here can be downloaded from www.gnum.unal.edu.co.

  10. Analytical Work in Support of the Design and Operation of Two Dimensional Self Streamlining Test Sections

    Science.gov (United States)

    Judd, M.; Wolf, S. W. D.; Goodyer, M. J.

    1976-01-01

    A method has been developed for accurately computing the imaginary flow fields outside a flexible walled test section, applicable to lifting and non-lifting models. The tolerances in the setting of the flexible walls introduce only small levels of aerodynamic interference at the model. While it is not possible to apply corrections for the interference effects, they may be reduced by improving the setting accuracy of the portions of wall immediately above and below the model. Interference effects of the truncation of the length of the streamlined portion of a test section are brought to an acceptably small level by the use of a suitably long test section with the model placed centrally.

  11. Streamlining interventional radiology admissions: The role of the interventional radiology clinic and physician's assistant

    International Nuclear Information System (INIS)

    White, R.I. Jr.; Rizer, D.M.; Shuman, K.; White, E.J.; Adams, P.; Doyle, K.; Kinnison, M.

    1987-01-01

    During a 5-year period (1982-1987), 376 patients were admitted to an interventional radiology service where they were managed by the senior physician and interventional radiology fellows. Sixty-eight percent of patients were admitted for angioplasty and 32% for elective embolotherapy/diagnostic angiography. A one-half-day, twice weekly interventional radiology clinic and employment of a physician's assistant who performed preadmission history and physicals and wrote orders accounted, in part, for a decrease in hospital stay length from 3.74 days (1982-1983) to 2.41 days (1986-1987). The authors conclude that use of the clinic and the physician's assistant streamlines patient flow and the admitting process and is partially responsible for a decreased length of stay for patients admitted to an interventional radiology service

  12. Streamlining and Standardizing Due Diligence to Ensure Quality of PV Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Kurtz, Sarah [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-11-28

    Those investing in PV power plants would like to have confidence that the plants will provide the anticipated return on investment. While due diligence is capably performed by independent engineers today, as PV systems mature, there will be benefit in standardization and streamlining of this process. The IECRE has defined technical information that is needed as a basis for each transaction step such as approving a design to begin construction, documenting readiness to operate, quantifying performance after a year of operation, and assessing the health of the plant in preparation for sale of the plant. The technical requirements have been defined by IEC Technical Committee 82 and have been designed to be both effective and efficient in completing the assessments. This workshop will describe these new tools that are now available to the community and will include a panel/audience discussion about how and when they can be most effectively used.

  13. Roof Box Shape Streamline Adaptation and the Impact towards Fuel Consumption

    Directory of Open Access Journals (Sweden)

    Abdul Latif M.F.

    2017-01-01

    Full Text Available The fuel price hike is currently a sensational national issue in Malaysia. Since the rationalization of fuel subsidies many were affected especially the middle income family. Vehicle aerodynamic were directly related to the fuel consumption, were extra frontal area result a higher drag force hence higher fuel consumption. Roof box were among the largest contributor to the extra drag, thus the roof box shape rationalization were prominent to reduce the extra drag. The idea of adopting water drop shape to the roof box design shows prominent result. The roof box has been simulated using MIRA virtual wind tunnel modelling via commercial computational fluid dynamic (CFD package. This streamline shape drastically reduce the drag force by 34% resulting to a 1.7% fuel saving compare to the conventional boxy roof box. This is an effort to reduce the carbon foot print for a sustainable green world.

  14. Easy XMM-Newton Data Analysis with the Streamlined ABC Guide!

    Science.gov (United States)

    Valencic, Lynne A.; Snowden, Steven L.; Pence, William D.

    2016-01-01

    The US XMM-Newton GOF has streamlined the time-honored XMM-Newton ABC Guide, making it easier to find and use what users may need to analyze their data. It takes into account what type of data a user might have, if they want to reduce the data on their own machine or over the internet with Web Hera, and if they prefer to use the command window or a GUI. The GOF has also included an introduction to analyzing EPIC and RGS spectra, and PN Timing mode data. The guide is provided for free to students, educators, and researchers for educational and research purposes. Try it out at: http://heasarc.gsfc.nasa.gov/docs/xmm/sl/intro.html

  15. Psychological distress and streamlined BreastScreen follow-up assessment versus standard assessment.

    Science.gov (United States)

    Sherman, Kerry A; Winch, Caleb J; Borecky, Natacha; Boyages, John

    2013-11-04

    To establish whether altered protocol characteristics of streamlined StepDown breast assessment clinics heightened or reduced the psychological distress of women in attendance compared with standard assessment. Willingness to attend future screening was also compared between the assessment groups. Observational, prospective study of women attending either a mammogram-only StepDown or a standard breast assessment clinic. Women completed questionnaires on the day of assessment and 1 month later. Women attending StepDown (136 women) or standard assessment clinics (148 women) at a BreastScreen centre between 10 November 2009 and 7 August 2010. Breast cancer worries; positive and negative psychological consequences of assessment (Psychological Consequences Questionnaire); breast cancer-related intrusion and avoidance (Impact of Event Scale); and willingness to attend, and uneasiness about, future screening. At 1-month follow-up, no group differences were evident between those attending standard and StepDown clinics on breast cancer worries (P= 0.44), positive (P= 0.88) and negative (P = 0.65) consequences, intrusion (P = 0.64), and avoidance (P = 0.87). Willingness to return for future mammograms was high, and did not differ between groups (P = 0.16), although higher levels of unease were associated with lessened willingness to rescreen (P = 0.04). There was no evidence that attending streamlined StepDown assessments had different outcomes in terms of distress than attending standard assessment clinics for women with a BreastScreen-detected abnormality. However, unease about attending future screening was generally associated with less willingness to do so in both groups; thus, there is a role for psycho-educational intervention to address these concerns.

  16. Use of Vortex Generators to Reduce Distortion for Mach 1.6 Streamline-Traced Supersonic Inlets

    Science.gov (United States)

    Baydar, Ezgihan; Lu, Frank; Slater, John W.; Trefny, Chuck

    2016-01-01

    Reduce the total pressure distortion at the engine-fan face due to low-momentum flow caused by the interaction of an external terminal shock at the turbulent boundary layer along a streamline-traced external-compression (STEX) inlet for Mach 1.6.

  17. Proposed Model for a Streamlined, Cohesive, and Optimized K-12 STEM Curriculum with a Focus on Engineering

    Science.gov (United States)

    Locke, Edward

    2009-01-01

    This article presents a proposed model for a clear description of K-12 age-possible engineering knowledge content, in terms of the selection of analytic principles and predictive skills for various grades, based on the mastery of mathematics and science pre-requisites, as mandated by national or state performance standards; and a streamlined,…

  18. Alterations in the microstructure of white matter in children and adolescents with Tourette syndrome measured using tract-based spatial statistics and probabilistic tractography.

    Science.gov (United States)

    Sigurdsson, Hilmar P; Pépés, Sophia E; Jackson, Georgina M; Draper, Amelia; Morgan, Paul S; Jackson, Stephen R

    2018-04-12

    Tourette syndrome (TS) is a neurodevelopmental disorder characterised by repetitive and intermittent motor and vocal tics. TS is thought to reflect fronto-striatal dysfunction and the aetiology of the disorder has been linked to widespread alterations in the functional and structural integrity of the brain. The aim of this study was to assess white matter (WM) abnormalities in a large sample of young patients with TS in comparison to a sample of matched typically developing control individuals (CS) using diffusion MRI. The study included 35 patients with TS (3 females; mean age: 14.0 ± 3.3) and 35 CS (3 females; mean age: 13.9 ± 3.3). Diffusion MRI data was analysed using tract-based spatial statistics (TBSS) and probabilistic tractography. Patients with TS demonstrated both marked and widespread decreases in axial diffusivity (AD) together with altered WM connectivity. Moreover, we showed that tic severity and the frequency of premonitory urges (PU) were associated with increased connectivity between primary motor cortex (M1) and the caudate nuclei, and increased information transfer between M1 and the insula, respectively. This is to our knowledge the first study to employ both TBSS and probabilistic tractography in a sample of young patients with TS. Our results contribute to the limited existing literature demonstrating altered connectivity in TS and confirm previous results suggesting in particular, that altered insular function contributes to increased frequency of PU. Copyright © 2018. Published by Elsevier Ltd.

  19. Diffusion tensor imaging fiber tracking with reliable tracking orientation and flexible step size☆

    Science.gov (United States)

    Yao, Xufeng; Wang, Manning; Chen, Xinrong; Nie, Shengdong; Li, Zhexu; Xu, Xiaoping; Zhang, Xuelong; Song, Zhijian

    2013-01-01

    We propose a method of reliable tracking orientation and flexible step size fiber tracking. A new directional strategy was defined to select one optimal tracking orientation from each directional set, which was based on the single-tensor model and the two-tensor model. The directional set of planar voxels contained three tracking directions: two from the two-tensor model and one from the single-tensor model. The directional set of linear voxels contained only one principal vector. In addition, a flexible step size, rather than fixable step sizes, was implemented to improve the accuracy of fiber tracking. We used two sets of human data to assess the performance of our method; one was from a healthy volunteer and the other from a patient with low-grade glioma. Results verified that our method was superior to the single-tensor Fiber Assignment by Continuous Tracking and the two-tensor eXtended Streamline Tractography for showing detailed images of fiber bundles. PMID:25206444

  20. Evaluation of left-right asymmetry of pyramidal tracts in preterm neonates by diffusion tensor imaging and tractography

    International Nuclear Information System (INIS)

    Ogita, Kaori

    2010-01-01

    Diffusion Tensor Tractography (DTT) is a new noninvasive brain imaging technique to detect the neural tract and is expected to be instrumental in diagnosing diseases with white matter involvement. Assessing the pyramidal tract with DTT will be useful in diagnosing motor dysfunction. However, the pyramidal tract (PT) has not been fully investigated with this technique especially in neonates. The aim of this study is to clarify the normal characteristics, especially the latevility, of the PT in healthy neonates. Fourteen preterm neonates were examined with DTT before being discharged from the neonatal intensive care unit (NICU). Free software dTV and Volume-One were used to depict the PT and analyze the fractional anisotrophy (FA) value, a parameter used in Diffusion Tensor Imaging (DTI). In the beginning, the FA at the medulla oblongata as the initial region of interest was determined to be 0.18 or more to depict the PT by DTT. The FA values at the level of the posterior limb of the Internal Capsule (IC), the Corona Radiate (CR), and the Centrum Semiovale (CS) of the depicted PT were measured and compared with the contralateral. The upper limit of the level of the FA at the medulla oblongata value capable of depicting the PT was measured and compared with the contralateral. All data was analyzed using the Mann-Whitney test. A p-value of less than 0.05 was considered to indicate significant difference. The FA value of the left CS was higher than that of the right in all 14 cases, and the FA value of the left CA was higher than that of the right in 13 cases. The upper limit of the FA value of the medulla oblongata as the initial region of interest to depict the left side of the PT was higher than for the right side of the PT in all 14 cases. We clarified the laterality of the PT in healthy neonates using DTT. This laterality must be taken into consideration when involvement of the PT is diagnosed using this technique. (author)

  1. The value of 3 T MR diffusion tensor fiber tractography study of association fasciculus of normative human in vivo primarily

    International Nuclear Information System (INIS)

    Sun Xuejin; Dai Jianping; Gao Peiyi; Li Shaowu; Ai Lin; Chen Hongyan; Tian Shengyong; Pang Ruilin

    2006-01-01

    Objective: To exhibit the fibers of association fascicules, aims at demonstrating the association fibers of brain with diffusion tensor fiber tracking technique. Methods: Conventionality MRI, diffusion tensor imaging (DTI) and diffusion tensor fiber tractography (DT-FT) were performed in twenty healthy subjects, including eighteen right-handed (sixteen men and four women) and two left-handed (one male and one female) by 3 T Siemens Trio 2003 T MRI. To select arcuate fascicules, inferior longitudinal fascicules, frontalwoceipital fascicules, corpus callosum, posterior limb of internal capsule and external capsule as seeds used to track fibers. Results: Diffusion tensor fiber tracking exhibited bundles of external capsule left mean fibers were 308 bundles, right fibers were 307 bundles (t=0.138, P>0.05), frontal-occipital tracks left mean fibers were 115 bundles, right fibers were 110 bundles(t=1.174, P>0.05), and their fractional anisotropy (FA) valueexternal capsule mean FA left was 0.361, the right was 0.362 (t=-0.184, P>0.05). Frontal-occipital tracks mean fractional anisotropy left was 0.352, the right was 0.351 (t=-0.816, P>0.05). The difference between both sides were statistically insignificant (P>0.05). The posterior limb of internal capsule left mean fibers were 249 bundles, right fibers were 257 bundles (t=-0.818, P>0.05), arcuate fascietfiesleft mean fibers were 198 bundles, right fibers were 204 bundles (t=-0.465, P>0.05 ) fibers difference between both sides were statistically insignificant (P>0.05), but the individual difference was significant, and their fractional anisotropy difference between both sides (posterior limb of internal capsule mean FA left was 0.450, the right was 0.444 (t=2.771, P 0.05). Mean FA left was 0.369, the right was 0.370(t=-0.178, P>0.05) ,difference between both sides was statistically insignificant (P>0.05). But the individual difference was significant. Some of them were the left larger than the right side. The frontal

  2. Filaments in curved streamlines: rapid formation of Staphylococcus aureus biofilm streamers

    International Nuclear Information System (INIS)

    Kevin Kim, Minyoung; Drescher, Knut; Shun Pak, On; Stone, Howard A; Bassler, Bonnie L

    2014-01-01

    Biofilms are surface-associated conglomerates of bacteria that are highly resistant to antibiotics. These bacterial communities can cause chronic infections in humans by colonizing, for example, medical implants, heart valves, or lungs. Staphylococcus aureus, a notorious human pathogen, causes some of the most common biofilm-related infections. Despite the clinical importance of S. aureus biofilms, it remains mostly unknown how physical effects, in particular flow, and surface structure influence biofilm dynamics. Here we use model microfluidic systems to investigate how environmental factors, such as surface geometry, surface chemistry, and fluid flow affect biofilm development of S. aureus. We discovered that S. aureus rapidly forms flow-induced, filamentous biofilm streamers, and furthermore if surfaces are coated with human blood plasma, streamers appear within minutes and clog the channels more rapidly than if the channels are uncoated. To understand how biofilm streamer filaments reorient in flows with curved streamlines to bridge the distances between corners, we developed a mathematical model based on resistive force theory of slender filaments. Understanding physical aspects of biofilm formation of S. aureus may lead to new approaches for interrupting biofilm formation of this pathogen. (paper)

  3. Challenges and Obstacles of e-Government Streamlining: A Case Study

    Directory of Open Access Journals (Sweden)

    Anupam K. Nath

    2014-05-01

    Full Text Available e-Government streamlining has been a challenge since its inception in the domain of e-business. Business organizations face challenges while trying to collaborate with partners through the use of information technology in order to ensure efficient delivery of services. One of the major reasons for these inefficient services has been political bureaucracies among government organizations. To meet this challenge, a transparent and networked environment is required where government organizations can effectively partner with other relevant organizations. Using a case study analysis, we intend to identify not just the challenges in government organizations while providing services which require collaborative effort, but also the obstacles in adopting new technology for collaboration. We believe that the outcome of our research could provide a generalized guideline for government agencies where there is need for digital collaboration. Our findings will thus help government organizations to address the challenges in digital collaboration, and also help them implement new technology successfully to ensure efficient delivery of services.

  4. Surrogate Based Optimization of Aerodynamic Noise for Streamlined Shape of High Speed Trains

    Directory of Open Access Journals (Sweden)

    Zhenxu Sun

    2017-02-01

    Full Text Available Aerodynamic noise increases with the sixth power of the running speed. As the speed increases, aerodynamic noise becomes predominant and begins to be the main noise source at a certain high speed. As a result, aerodynamic noise has to be focused on when designing new high-speed trains. In order to perform the aerodynamic noise optimization, the equivalent continuous sound pressure level (SPL has been used in the present paper, which could take all of the far field observation probes into consideration. The Non-Linear Acoustics Solver (NLAS approach has been utilized for acoustic calculation. With the use of Kriging surrogate model, a multi-objective optimization of the streamlined shape of high-speed trains has been performed, which takes the noise level in the far field and the drag of the whole train as the objectives. To efficiently construct the Kriging model, the cross validation approach has been adopted. Optimization results reveal that both the equivalent continuous sound pressure level and the drag of the whole train are reduced in a certain extent.

  5. Localized Plasticity in the Streamlined Genomes of Vinyl Chloride Respiring Dehalococcoides

    Energy Technology Data Exchange (ETDEWEB)

    McMurdie, Paul J.; Behrens, Sebastien F.; Muller, Jochen A.; Goke, Jonathan; Ritalahti, Kirsti M.; Wagner, Ryan; Goltsman, Eugene; Lapidus, Alla; Holmes, Susan; Loffler, Frank E.; Spormann, Alfred M.

    2009-06-30

    Vinyl chloride (VC) is a human carcinogen and widespread priority pollutant. Here we report the first, to our knowledge, complete genome sequences of microorganisms able to respire VC, Dehalococcoides sp. strains VS and BAV1. Notably, the respective VC reductase encoding genes, vcrAB and bvcAB, were found embedded in distinct genomic islands (GEIs) with different predicted integration sites, suggesting that these genes were acquired horizontally and independently by distinct mechanisms. A comparative analysis that included two previously sequenced Dehalococcoides genomes revealed a contextually conserved core that is interrupted by two high plasticity regions (HPRs) near the Ori. These HPRs contain the majority of GEIs and strain-specific genes identified in the four Dehalococcoides genomes, an elevated number of repeated elements including insertion sequences (IS), as well as 91 of 96 rdhAB, genes that putatively encode terminal reductases in organohalide respiration. Only three core rdhA orthologous groups were identified, and only one of these groups is supported by synteny. The low number of core rdhAB, contrasted with the high rdhAB numbers per genome (up to 36 in strain VS), as well as their colocalization with GEIs and other signatures for horizontal transfer, suggests that niche adaptation via organohalide respiration is a fundamental ecological strategy in Dehalococccoides. This adaptation has been exacted through multiple mechanisms of recombination that are mainly confined within HPRs of an otherwise remarkably stable, syntenic, streamlined genome among the smallest of any free-living microorganism.

  6. Symbiotic adaptation drives genome streamlining of the cyanobacterial sponge symbiont "Candidatus Synechococcus pongiarum"

    KAUST Repository

    Gao, Zhao-Ming

    2014-04-01

    "Candidatus Synechococcus spongiarum" is a cyanobacterial symbiont widely distributed in sponges, but its functions at the genome level remain unknown. Here, we obtained the draft genome (1.66 Mbp, 90% estimated genome recovery) of "Ca. Synechococcus spongiarum" strain SH4 inhabiting the Red Sea sponge Carteriospongia foliascens. Phylogenomic analysis revealed a high dissimilarity between SH4 and free-living cyanobacterial strains. Essential functions, such as photosynthesis, the citric acid cycle, and DNA replication, were detected in SH4. Eukaryoticlike domains that play important roles in sponge-symbiont interactions were identified exclusively in the symbiont. However, SH4 could not biosynthesize methionine and polyamines and had lost partial genes encoding low-molecular-weight peptides of the photosynthesis complex, antioxidant enzymes, DNA repair enzymes, and proteins involved in resistance to environmental toxins and in biosynthesis of capsular and extracellular polysaccharides. These genetic modifications imply that "Ca. Synechococcus spongiarum" SH4 represents a low-light-adapted cyanobacterial symbiont and has undergone genome streamlining to adapt to the sponge\\'s mild intercellular environment. 2014 Gao et al.

  7. Supply chain cost improvement opportunities through streamlining cross-border operations

    Directory of Open Access Journals (Sweden)

    Jan Hendrik Havenga

    2013-09-01

    Full Text Available The Cross-Border Road Transport Agency (CBRTA in South Africa aims to encourage and facilitate trade between South Africa and its neighbouring countries. The CBRTA sponsored a study by Stellenbosch University (SU to determine the logistics cost impact of cross-border delays between South Africa and its major neighbouring trading partners, and prioritise opportunities for improvement. SU is the proprietor of both a comprehensive freight demand model and a logistics cost model for South Africa, which enable extractions and extensions of freight flows and related costs for specific purposes. Through the application of these models, the following information is identified and presented in this paper: South Africa’s most important border posts (based on traffic flows; a product profile for imports and exports through these border posts; the modal split (road and rail; the annual logistics costs incurred on the corridors feeding the border posts, as well as the additional costs incurred due to border delays. The research has proved that the streamlining of border-post operations that take a total supply chain view (i.e. of both border operations and those that could be moved from the border is beneficial.

  8. Development of a Streamlined Work Flow for Handling Patients' Genetic Testing Insurance Authorizations.

    Science.gov (United States)

    Uhlmann, Wendy R; Schwalm, Katie; Raymond, Victoria M

    2017-08-01

    Obtaining genetic testing insurance authorizations for patients is a complex, time-involved process often requiring genetic counselor (GC) and physician involvement. In an effort to mitigate this complexity and meet the increasing number of genetic testing insurance authorization requests, GCs formed a novel partnership with an industrial engineer (IE) and a patient services associate (PSA) to develop a streamlined work flow. Eight genetics clinics and five specialty clinics at the University of Michigan were surveyed to obtain benchmarking data. Tasks needed for genetic testing insurance authorization were outlined and time-saving work flow changes were introduced including 1) creation of an Excel password-protected shared database between GCs and PSAs, used for initiating insurance authorization requests, tracking and follow-up 2) instituting the PSAs sending GCs a pre-clinic email noting each patients' genetic testing insurance coverage 3) inclusion of test medical necessity documentation in the clinic visit summary note instead of writing a separate insurance letter and 4) PSAs development of a manual with insurance providers and genetic testing laboratories information. These work flow changes made it more efficient to request and track genetic testing insurance authorizations for patients, enhanced GCs and PSAs communication, and reduced tasks done by clinicians.

  9. Streamlining Workflow for Endovascular Mechanical Thrombectomy: Lessons Learned from a Comprehensive Stroke Center.

    Science.gov (United States)

    Wang, Hongjin; Thevathasan, Arthur; Dowling, Richard; Bush, Steven; Mitchell, Peter; Yan, Bernard

    2017-08-01

    Recently, 5 randomized controlled trials confirmed the superiority of endovascular mechanical thrombectomy (EMT) to intravenous thrombolysis in acute ischemic stroke with large-vessel occlusion. The implication is that our health systems would witness an increasing number of patients treated with EMT. However, in-hospital delays, leading to increased time to reperfusion, are associated with poor clinical outcomes. This review outlines the in-hospital workflow of the treatment of acute ischemic stroke at a comprehensive stroke center and the lessons learned in reduction of in-hospital delays. The in-hospital workflow for acute ischemic stroke was described from prehospital notification to femoral arterial puncture in preparation for EMT. Systematic review of literature was also performed with PubMed. The implementation of workflow streamlining could result in reduction of in-hospital time delays for patients who were eligible for EMT. In particular, time-critical measures, including prehospital notification, the transfer of patients from door to computed tomography (CT) room, initiation of intravenous thrombolysis in the CT room, and the mobilization of neurointervention team in parallel with thrombolysis, all contributed to reduction in time delays. We have identified issues resulting in in-hospital time delays and have reported possible solutions to improve workflow efficiencies. We believe that these measures may help stroke centers initiate an EMT service for eligible patients. Copyright © 2017 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  10. Streamlining Appointment, Promotion, and Tenure Procedures to Promote Early-Career Faculty Success.

    Science.gov (United States)

    Smith, Shannon B; Hollerbach, Ann; Donato, Annemarie Sipkes; Edlund, Barbara J; Atz, Teresa; Kelechi, Teresa J

    2016-01-01

    A critical component of the progression of a successful academic career is being promoted in rank. Early-career faculty are required to have an understanding of appointment, promotion, and tenure (APT) guidelines, but many factors often impede this understanding, thwarting a smooth and planned promotion pathway for professional advancement. This article outlines the steps taken by an APT committee to improve the promotion process from instructor to assistant professor. Six sigma's DMAIC improvement model was selected as the guiding operational framework to remove variation in the promotion process. After faculty handbook revisions were made, several checklists developed, and a process review rubric was implemented; recently promoted faculty were surveyed on satisfaction with the process. Faculty opinions captured in the survey suggest increased transparency in the process and perceived support offered by the APT committee. Positive outcomes include a strengthened faculty support framework, streamlined promotion processes, and improved faculty satisfaction. Changes to the APT processes resulted in an unambiguous and standardized pathway for successful promotion. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Streamlining the Design-to-Build Transition with Build-Optimization Software Tools.

    Science.gov (United States)

    Oberortner, Ernst; Cheng, Jan-Fang; Hillson, Nathan J; Deutsch, Samuel

    2017-03-17

    Scaling-up capabilities for the design, build, and test of synthetic biology constructs holds great promise for the development of new applications in fuels, chemical production, or cellular-behavior engineering. Construct design is an essential component in this process; however, not every designed DNA sequence can be readily manufactured, even using state-of-the-art DNA synthesis methods. Current biological computer-aided design and manufacture tools (bioCAD/CAM) do not adequately consider the limitations of DNA synthesis technologies when generating their outputs. Designed sequences that violate DNA synthesis constraints may require substantial sequence redesign or lead to price-premiums and temporal delays, which adversely impact the efficiency of the DNA manufacturing process. We have developed a suite of build-optimization software tools (BOOST) to streamline the design-build transition in synthetic biology engineering workflows. BOOST incorporates knowledge of DNA synthesis success determinants into the design process to output ready-to-build sequences, preempting the need for sequence redesign. The BOOST web application is available at https://boost.jgi.doe.gov and its Application Program Interfaces (API) enable integration into automated, customized DNA design processes. The herein presented results highlight the effectiveness of BOOST in reducing DNA synthesis costs and timelines.

  12. Comparative Analysis of Wolbachia Genomes Reveals Streamlining and Divergence of Minimalist Two-Component Systems

    Science.gov (United States)

    Christensen, Steen; Serbus, Laura Renee

    2015-01-01

    Two-component regulatory systems are commonly used by bacteria to coordinate intracellular responses with environmental cues. These systems are composed of functional protein pairs consisting of a sensor histidine kinase and cognate response regulator. In contrast to the well-studied Caulobacter crescentus system, which carries dozens of these pairs, the streamlined bacterial endosymbiont Wolbachia pipientis encodes only two pairs: CckA/CtrA and PleC/PleD. Here, we used bioinformatic tools to compare characterized two-component system relays from C. crescentus, the related Anaplasmataceae species Anaplasma phagocytophilum and Ehrlichia chaffeensis, and 12 sequenced Wolbachia strains. We found the core protein pairs and a subset of interacting partners to be highly conserved within Wolbachia and these other Anaplasmataceae. Genes involved in two-component signaling were positioned differently within the various Wolbachia genomes, whereas the local context of each gene was conserved. Unlike Anaplasma and Ehrlichia, Wolbachia two-component genes were more consistently found clustered with metabolic genes. The domain architecture and key functional residues standard for two-component system proteins were well-conserved in Wolbachia, although residues that specify cognate pairing diverged substantially from other Anaplasmataceae. These findings indicate that Wolbachia two-component signaling pairs share considerable functional overlap with other α-proteobacterial systems, whereas their divergence suggests the potential for regulatory differences and cross-talk. PMID:25809075

  13. Symbiotic adaptation drives genome streamlining of the cyanobacterial sponge symbiont "Candidatus Synechococcus pongiarum"

    KAUST Repository

    Gao, Zhao-Ming; Wang, Yong; Tian, Ren-Mao; Wong, Yue Him; Batang, Zenon B.; Al-Suwailem, Abdulaziz M.; Bajic, Vladimir B.; Qian, Pei-Yuan

    2014-01-01

    "Candidatus Synechococcus spongiarum" is a cyanobacterial symbiont widely distributed in sponges, but its functions at the genome level remain unknown. Here, we obtained the draft genome (1.66 Mbp, 90% estimated genome recovery) of "Ca. Synechococcus spongiarum" strain SH4 inhabiting the Red Sea sponge Carteriospongia foliascens. Phylogenomic analysis revealed a high dissimilarity between SH4 and free-living cyanobacterial strains. Essential functions, such as photosynthesis, the citric acid cycle, and DNA replication, were detected in SH4. Eukaryoticlike domains that play important roles in sponge-symbiont interactions were identified exclusively in the symbiont. However, SH4 could not biosynthesize methionine and polyamines and had lost partial genes encoding low-molecular-weight peptides of the photosynthesis complex, antioxidant enzymes, DNA repair enzymes, and proteins involved in resistance to environmental toxins and in biosynthesis of capsular and extracellular polysaccharides. These genetic modifications imply that "Ca. Synechococcus spongiarum" SH4 represents a low-light-adapted cyanobacterial symbiont and has undergone genome streamlining to adapt to the sponge's mild intercellular environment. 2014 Gao et al.

  14. A streamlined DNA tool for global identification of heavily exploited coastal shark species (genus Rhizoprionodon.

    Directory of Open Access Journals (Sweden)

    Danillo Pinhal

    Full Text Available Obtaining accurate species-specific landings data is an essential step toward achieving sustainable shark fisheries. Globally distributed sharpnose sharks (genus Rhizoprionodon exhibit life-history characteristics (rapid growth, early maturity, annual reproduction that suggests that they could be fished in a sustainable manner assuming an investment in monitoring, assessment and careful management. However, obtaining species-specific landings data for sharpnose sharks is problematic because they are morphologically very similar to one another. Moreover, sharpnose sharks may also be confused with other small sharks (either small species or juveniles of large species once they are processed (i.e., the head and fins are removed. Here we present a highly streamlined molecular genetics approach based on seven species-specific PCR primers in a multiplex format that can simultaneously discriminate body parts from the seven described sharpnose shark species commonly occurring in coastal fisheries worldwide. The species-specific primers are based on nucleotide sequence differences among species in the nuclear ribosomal internal transcribed spacer 2 locus (ITS2. This approach also distinguishes sharpnose sharks from a wide range of other sharks (52 species and can therefore assist in the regulation of coastal shark fisheries around the world.

  15. Robust Preconditioning Estimates for Convection-Dominated Elliptic Problems via a Streamline Poincaré--Friedrichs Inequality

    Czech Academy of Sciences Publication Activity Database

    Axelsson, Owe; Karátson, J.; Kovács, B.

    2014-01-01

    Roč. 52, č. 6 (2014), s. 2957-2976 ISSN 0036-1429 R&D Projects: GA MŠk ED1.1.00/02.0070 Institutional support: RVO:68145535 Keywords : streamline diffusion finite element method * solving convection-dominated elliptic problems * convergence is robust Subject RIV: BA - General Mathematics Impact factor: 1.788, year: 2014 http://epubs.siam.org/doi/abs/10.1137/130940268

  16. Quantitative evaluation of the white matter tracts of the limbic system segmented by diffusion tensor tractography with schizophrenia. A preliminary study

    International Nuclear Information System (INIS)

    Aoki, Shigeki; Yamada, Haruyasu; Abe, Osamu

    2005-01-01

    In this study, the clinical feasibility of combined technique with diffusion tensor tractography (DTT) and fractional anisotropy (FA) analysis in patients with schizophrenia is evaluated. Fourteen patients with schizophrenia and 15 age-matched volunteers were studied on a 1.5 T MR imager. DTT of the fornix, anterior and posterior cingulum, and uncinate fasciculus were visualized by dTV (free software by Masutani Y, URL: http://www.ut-radiology.umin.jp/people/masutani/dTV.htm) and VOLUME-ONE. Region of interest (ROIs) were semi-automatically placed on the tracts and FA values were calculated. FA values on the anterior cingulum, fornix and uncinate fasciculus of the schizophrenia patients were significantly lower than those of the volunteers. This combined method may be useful in evaluating subtle changes in the white matter tracts in patients with schizophrenia. (author)

  17. Abnormal topological organization in white matter structural networks revealed by diffusion tensor tractography in unmedicated patients with obsessive-compulsive disorder.

    Science.gov (United States)

    Zhong, Zhaoxi; Zhao, Tengda; Luo, Jia; Guo, Zhihua; Guo, Meng; Li, Ping; Sun, Jing; He, Yong; Li, Zhanjiang

    2014-06-03

    Obsessive-compulsive disorder (OCD) is a chronic psychiatric disorder defined by recurrent thoughts, intrusive and distressing impulses, or images and ritualistic behaviors. Although focal diverse regional abnormalities white matter integrity in specific brain regions have been widely studied in populations with OCD, alterations in the structural connectivities among them remain poorly understood. The aim was to investigate the abnormalities in the topological efficiency of the white matter networks and the correlation between the network metrics and Yale-Brown Obsessive-Compulsive Scale scores in unmedicated OCD patients, using diffusion tensor tractography and graph theoretical approaches. This study used diffusion tensor imaging and deterministic tractography to map the white matter structural networks in 26 OCD patients and 39 age- and gender-matched healthy controls; and then applied graph theoretical methods to investigate abnormalities in the global and regional properties of the white matter network in these patients. The patients and control participants both showed small-world organization of the white matter networks. However, the OCD patients exhibited significant abnormal global topology, including decreases in global efficiency (t = -2.32, p = 0.02) and increases in shortest path length, Lp (t = 2.30, p = 0.02), the normalized weighted shortest path length, λ (t = 2.08, p=0.04), and the normalized clustering coefficient, γ (t = 2.26, p = 0.03), of their white matter structural networks compared with healthy controls. Further, the OCD patients showed a reduction in nodal efficiency predominately in the frontal regions, the parietal regions and caudate nucleus. The normalized weighted shortest path length of the network metrics was significantly negatively correlated with obsessive subscale of the Yale-Brown Obsessive-Compulsive Scale (r = -0.57, p = 0.0058). These findings demonstrate the abnormal topological efficiency in the white matter networks

  18. Altered integrity of the right arcuate fasciculus as a trait marker of schizophrenia: a sibling study using tractography-based analysis of the whole brain.

    Science.gov (United States)

    Wu, Chen-Hao; Hwang, Tzung-Jeng; Chen, Yu-Jen; Hsu, Yun-Chin; Lo, Yu-Chun; Liu, Chih-Min; Hwu, Hai-Gwo; Liu, Chen-Chung; Hsieh, Ming H; Chien, Yi Ling; Chen, Chung-Ming; Tseng, Wen-Yih Isaac

    2015-03-01

    Trait markers of schizophrenia aid the dissection of the heterogeneous phenotypes into distinct subtypes and facilitate the genetic underpinning of the disease. The microstructural integrity of the white matter tracts could serve as a trait marker of schizophrenia, and tractography-based analysis (TBA) is the current method of choice. Manual tractography is time-consuming and limits the analysis to preselected fiber tracts. Here, we sought to identify a trait marker of schizophrenia from among 74 fiber tracts across the whole brain using a novel automatic TBA method. Thirty-one patients with schizophrenia, 31 unaffected siblings and 31 healthy controls were recruited to undergo diffusion spectrum magnetic resonance imaging at 3T. Generalized fractional anisotropy (GFA), an index reflecting tract integrity, was computed for each tract and compared among the three groups. Ten tracts were found to exhibit significant differences between the groups with a linear, stepwise order from controls to siblings to patients; they included the right arcuate fasciculus, bilateral fornices, bilateral auditory tracts, left optic radiation, the genu of the corpus callosum, and the corpus callosum to the bilateral dorsolateral prefrontal cortices, bilateral temporal poles, and bilateral hippocampi. Posthoc between-group analyses revealed that the GFA of the right arcuate fasciculus was significantly decreased in both the patients and unaffected siblings compared to the controls. Furthermore, the GFA of the right arcuate fasciculus exhibited a trend toward positive symptom scores. In conclusion, the right arcuate fasciculus may be a candidate trait marker and deserves further study to verify any genetic association. © 2014 Wiley Periodicals, Inc.

  19. Altered structural connectivity of pain-related brain network in burning mouth syndrome-investigation by graph analysis of probabilistic tractography.

    Science.gov (United States)

    Wada, Akihiko; Shizukuishi, Takashi; Kikuta, Junko; Yamada, Haruyasu; Watanabe, Yusuke; Imamura, Yoshiki; Shinozaki, Takahiro; Dezawa, Ko; Haradome, Hiroki; Abe, Osamu

    2017-05-01

    Burning mouth syndrome (BMS) is a chronic intraoral pain syndrome featuring idiopathic oral pain and burning discomfort despite clinically normal oral mucosa. The etiology of chronic pain syndrome is unclear, but preliminary neuroimaging research has suggested the alteration of volume, metabolism, blood flow, and diffusion at multiple brain regions. According to the neuromatrix theory of Melzack, pain sense is generated in the brain by the network of multiple pain-related brain regions. Therefore, the alteration of pain-related network is also assumed as an etiology of chronic pain. In this study, we investigated the brain network of BMS brain by using probabilistic tractography and graph analysis. Fourteen BMS patients and 14 age-matched healthy controls underwent 1.5T MRI. Structural connectivity was calculated in 83 anatomically defined regions with probabilistic tractography of 60-axis diffusion tensor imaging and 3D T1-weighted imaging. Graph theory network analysis was used to evaluate the brain network at local and global connectivity. In BMS brain, a significant difference of local brain connectivity was recognized at the bilateral rostral anterior cingulate cortex, right medial orbitofrontal cortex, and left pars orbitalis which belong to the medial pain system; however, no significant difference was recognized at the lateral system including the somatic sensory cortex. A strengthened connection of the anterior cingulate cortex and medial prefrontal cortex with the basal ganglia, thalamus, and brain stem was revealed. Structural brain network analysis revealed the alteration of the medial system of the pain-related brain network in chronic pain syndrome.

  20. Improving and streamlining the workflow in the graphic arts and printing industry

    Science.gov (United States)

    Tuijn, Chris

    2003-01-01

    In order to survive in the economy of today, an ever-increasing productivity is required from all the partners participating in a specific business process. This is not different for the printing industry. One of the ways to remain profitable is, on one hand, to reduce costs by automation and aiming for large-scale projects and, on the other hand, to specialize and become an expert in the area in which one is active. One of the ways to realize these goals is by streamlining the communication of the different partners and focus on the core business. If we look at the graphic arts and printing industry, we can identify different important players that eventually help in the realization of printed material. For the printing company (as is the case for any other company), the most important player is the customer. This role can be adopted by many different players including publishers, companies, non-commercial institutions, private persons etc. Sometimes, the customer will be the content provider as well but this is not always the case. Often, the content is provided by other organizations such as design and prepress agencies, advertising companies etc. In most printing organizations, the customer has one contact person often referred to as the CSR (Customers Service Representative). Other people involved at the printing organization include the sales representatives, prepress operators, printing operators, postpress operators, planners, the logistics department, the financial department etc. In the first part of this article, we propose a solution that will improve the communication between all the different actors in the graphic arts and printing industry considerably and will optimize and streamline the overall workflow as well. This solution consists of an environment in which the customer can communicate with the CSR to ask for a quote based on a specific product intent; the CSR will then (after the approval from the customer's side) organize the work and brief

  1. A streamlined risk screening method for managing reutilization of abandoned factories in Taiwan

    Directory of Open Access Journals (Sweden)

    I-Chun Chen

    2017-05-01

    Full Text Available An integrated management strategy that considers the competing relationships between land values and associated risks in the process of land-use conversion is needed to assess and manage the reutilization of brownfields. However, the often large number of individual brownfields renders it difficult to conduct a completed risk assessment for all sites, and a streamlined risk screening method would facilitate prioritization of the redevelopment of those factories. This methodology takes into account the spatial heterogeneity of contaminated lands and produces risk mapping that compiles complex risk-related information. Using abandoned factories in Taiwan as a case study, the method considers 40 points (50% accumulated probability as the threshold of acceptable risk. Emergency risk should be over 90% of accumulated probability. For the sustainability of brownfield reutilization in Taiwan, this research uses a risk matrix to identify the low, middle, and high risk for brownfield reutilization. It can indicate zones with a high risk level or low economic incentive as areas of concern for future decision making. In Taiwan, high-risk sites with high incentive account for only 21.3% of the sites. In contrast, the sites with the lowest incentive and low risk account for 57.6% of the sites. To avoid failure in the brownfield market, three strategies are suggested: (1 flexible land management with urban planning is a feasible option for protecting the receptor's health; (2 the government could provide the tool or brownfield funds to reduce the uncertainty of investment risk; and (3 risk monitoring and management can reduce the possible pitfalls associated with brownfield reutilization.

  2. Providing Data Management Support to NASA Airborne Field Studies through Streamlined Usability Design

    Science.gov (United States)

    Beach, A. L., III; Northup, E. A.; Early, A. B.; Chen, G.

    2016-12-01

    Airborne field studies are an effective way to gain a detailed understanding of atmospheric processes for scientific research on climate change and air quality relevant issues. One major function of airborne project data management is to maintain seamless data access within the science team. This allows individual instrument principal investigators (PIs) to process and validate their own data, which requires analysis of data sets from other PIs (or instruments). The project's web platform streamlines data ingest, distribution processes, and data format validation. In May 2016, the NASA Langley Research Center (LaRC) Atmospheric Science Data Center (ASDC) developed a new data management capability to help support the Korea U.S.-Air Quality (KORUS-AQ) science team. This effort is aimed at providing direct NASA Distributed Active Archive Center (DAAC) support to an airborne field study. Working closely with the science team, the ASDC developed a scalable architecture that allows investigators to easily upload and distribute their data and documentation within a secure collaborative environment. The user interface leverages modern design elements to intuitively guide the PI through each step of the data management process. In addition, the new framework creates an abstraction layer between how the data files are stored and how the data itself is organized(i.e. grouping files by PI). This approach makes it easy for PIs to simply transfer their data to one directory, while the system itself can automatically group/sort data as needed. Moreover, the platform is "server agnostic" to a certain degree, making deployment and customization more straightforward as hardware needs change. This flexible design will improve development efficiency and can be leveraged for future field campaigns. This presentation will examine the KORUS-AQ data portal as a scalable solution that applies consistent and intuitive usability design practices to support ingest and management of airborne

  3. Vortex Generators in a Streamline-Traced, External-Compression Supersonic Inlet

    Science.gov (United States)

    Baydar, Ezgihan; Lu, Frank K.; Slater, John W.; Trefny, Charles J.

    2017-01-01

    Vortex generators within a streamline-traced, external-compression supersonic inlet for Mach 1.66 were investigated to determine their ability to increase total pressure recovery and reduce total pressure distortion. The vortex generators studied were rectangular vanes arranged in counter-rotating and co-rotating arrays. The vane geometric factors of interest included height, length, spacing, angle-of-incidence, and positions upstream and downstream of the inlet terminal shock. The flow through the inlet was simulated numerically through the solution of the steady-state, Reynolds-averaged Navier-Stokes equations on multi-block, structured grids using the Wind-US flow solver. The vanes were simulated using a vortex generator model. The inlet performance was characterized by the inlet total pressure recovery and the radial and circumferential total pressure distortion indices at the engine face. Design of experiments and statistical analysis methods were applied to quantify the effect of the geometric factors of the vanes and search for optimal vane arrays. Co-rotating vane arrays with negative angles-of-incidence positioned on the supersonic diffuser were effective in sweeping low-momentum flow from the top toward the sides of the subsonic diffuser. This distributed the low-momentum flow more evenly about the circumference of the subsonic diffuser and reduced distortion. Co-rotating vane arrays with negative angles-of-incidence or counter-rotating vane arrays positioned downstream of the terminal shock were effective in mixing higher-momentum flow with lower-momentum flow to increase recovery and decrease distortion. A strategy of combining a co-rotating vane array on the supersonic diffuser with a counter-rotating vane array on the subsonic diffuser was effective in increasing recovery and reducing distortion.

  4. Inter-laboratory validation of an inexpensive streamlined method to measure inorganic arsenic in rice grain.

    Science.gov (United States)

    Chaney, Rufus L; Green, Carrie E; Lehotay, Steven J

    2018-05-04

    With the establishment by CODEX of a 200 ng/g limit of inorganic arsenic (iAs) in polished rice grain, more analyses of iAs will be necessary to ensure compliance in regulatory and trade applications, to assess quality control in commercial rice production, and to conduct research involving iAs in rice crops. Although analytical methods using high-performance liquid chromatography-inductively coupled plasma-mass spectrometry (HPLC-ICP-MS) have been demonstrated for full speciation of As, this expensive and time-consuming approach is excessive when regulations are based only on iAs. We report a streamlined sample preparation and analysis of iAs in powdered rice based on heated extraction with 0.28 M HNO 3 followed by hydride generation (HG) under control of acidity and other simple conditions. Analysis of iAs is then conducted using flow-injection HG and inexpensive ICP-atomic emission spectroscopy (AES) or other detection means. A key innovation compared with previous methods was to increase the acidity of the reagent solution with 4 M HCl (prior to reduction of As 5+ to As 3+ ), which minimized interferences from dimethylarsinic acid. An inter-laboratory method validation was conducted among 12 laboratories worldwide in the analysis of six shared blind duplicates and a NIST Standard Reference Material involving different types of rice and iAs levels. Also, four laboratories used the standard HPLC-ICP-MS method to analyze the samples. The results between the methods were not significantly different, and the Horwitz ratio averaged 0.52 for the new method, which meets official method validation criteria. Thus, the simpler, more versatile, and less expensive method may be used by laboratories for several purposes to accurately determine iAs in rice grain. Graphical abstract Comparison of iAs results from new and FDA methods.

  5. ExoMars Trace Gas Orbiter Instrument Modelling Approach to Streamline Science Operations

    Science.gov (United States)

    Munoz Fernandez, Michela; Frew, David; Ashman, Michael; Cardesin Moinelo, Alejandro; Garcia Beteta, Juan Jose; Geiger, Bernhard; Metcalfe, Leo; Nespoli, Federico; Muniz Solaz, Carlos

    2018-05-01

    ExoMars Trace Gas Orbiter (TGO) science operations activities are centralised at ESAC's Science Operations Centre (SOC). The SOC receives the inputs from the principal investigators (PIs) in order to implement and deliver the spacecraft pointing requests and instrument timelines to the Mission Operations Centre (MOC). The high number of orbits per planning cycle has made it necessary to abstract the planning interactions between the SOC and the PI teams at the observation level. This paper describes the modelling approach we have conducted for TGOís instruments to streamline science operations. We have created dynamic observation types that scale to adapt to the conditions specified by the PI teams including observation timing, and pointing block parameters calculated from observation geometry. This approach is considered and improvement with respect to previous missions where the generation of the observation pointing and commanding requests was performed manually by the instrument teams. Automation software assists us to effectively handle the high density of planned orbits with increasing volume of scientific data and to successfully meet opportunistic scientific goals and objectives. Our planning tool combines the instrument observation definition files provided by the PIs together with the flight dynamics products to generate the Pointing Requests and the instrument timeline (ITL). The ITL contains all the validated commands at the TC sequence level and computes the resource envelopes (data rate, power, data volume) within the constraints. At the SOC, our main goal is to maximise the science output while minimising the number of iterations among the teams, ensuring that the timeline does not violate the state transitions allowed in the Mission Operations Rules and Constraints Document.

  6. Connecting streamlined subglacial bedforms with the geological/geographical environment in which they are located.

    Science.gov (United States)

    Dowling, Tom; Möller, Per; Greenwood, Sarah; Spagnolo, Matteo; Åkesson, Maria; Fraser, Stephen; Hughs, Anna; Clark, Chris

    2016-04-01

    Much work has qualitatively shown that there appears to be a relationship between the morphology of streamlined subglacial bedforms (drumlinoids) and the geological/geographical environment in which said bedforms are located upon, particularly in terms of bedrock influence. However, the one quantitative study that has been carried out on this connectivity (Greenwood and Clark, 2010) found that there appears to be a connection between bedrock type and morphology only at a local scale. At a regional scale the most important geological factor seemed to be the properties of the substrate, usually till. In order to investigate these connections further, self-organising maps (SOM) are used to investigate the role of contextual geology/geography in drumlinoid morphology. The SOM method allows the statistical exploration of data that cannot normally be evaluated by traditional means; categorical data (e.g. bedrock type) can be used in the same analysis as continuous/vector data (e.g. drift depth). Here, three large morphological data sets from Sweden (20 041), Britain (36 104) and Ireland (13 454) are combined with bedrock type, drift depth, basal elevation and distance to esker to see if there are any relationships to be found between them. The results indicate that there are pervasive, statistically significant, and weak to very weak correlations between contextual geological/geographical factors and drumlinoid morphology. The most important contextual factor appears to be 'drift depth', followed by 'distance to esker'. Therefore, models of drumlinoid formation and any efforts to use such features for palaeo-ice reconstruction must take into account the geological and geographical environment in which they are situated. The logical extension of this is that models of ice-sheet growth and retreat must also take into account and be sensitive to the type of substratum present beneath the ice. Further research into the effect of drift properties on the flow of ice is needed.

  7. Brownfields Assessing Contractor Capabilities for Streamlined Site Investigations -- Additional Information Regarding All Appropriate Inquiries and Hiring an Environmental Professional (November 2006)

    Science.gov (United States)

    Guidance for Brownfields grantees and other decision makers to assess the capabilities of contractors and consultants to determine their qualifications to provide streamlined and innovative strategies for the assessment and cleanup of brownfields.

  8. An improved design of axially driven permanent maglev centrifugal pump with streamlined impeller.

    Science.gov (United States)

    Qian, K X; Zeng, P; Ru, W M; Yuan, H Y

    2007-01-01

    streamlined design of the impeller.

  9. Detection of hand and leg motor tract injury using novel diffusion tensor MRI tractography in children with central motor dysfunction.

    Science.gov (United States)

    Jeong, Jeong-Won; Lee, Jessica; Kamson, David O; Chugani, Harry T; Juhász, Csaba

    2015-09-01

    To examine whether an objective segmenation of corticospinal tract (CST) associated with hand and leg movements can be used to detect central motor weakness in the corresponding extremities in a pediatric population. This retrospective study included diffusion tensor imaging (DTI) of 25 children with central paresis affecting at least one limb (age: 9.0±4.2years, 15 boys, 5/13/7 children with left/right/both hemispheric lesions including ischemia, cyst, and gliosis), as well as 42 pediatric control subjects with no motor dysfunction (age: 9.0±5.5years, 21 boys, 31 healthy/11 non-lesional epilepsy children). Leg- and hand-related CST pathways were segmented using DTI-maximum a posteriori (DTI-MAP) classification. The resulting CST volumes were then divided by total supratentorial white matter volume, resulting in a marker called "normalized streamline volume ratio (NSVR)" to quantify the degree of axonal loss in separate CST pathways associated with leg and hand motor functions. A receiver operating characteristic curve was applied to measure the accuracy of this marker to identify extremities with motor weakness. NSVR values of hand/leg CST selectively achieved the following values of accuracy/sensitivity/specificity: 0.84/0.84/0.57, 0.82/0.81/0.55, 0.78/0.75/0.55, 0.79/0.81/0.54 at a cut-off of 0.03/0.03/0.03/0.02 for right hand CST, left hand CST, right leg CST, and left leg CST, respectively. Motor weakness of hand and leg was most likely present at the cut-off values of hand and leg NSVR (i.e., 0.029/0.028/0.025/0.020 for left-hand/right-hand/left-leg/right-leg). The control group showed a moderate age-related increase in absolute CST volumes and a biphasic age-related variation of the normalized CST volumes, which were lacking in the paretic children. This study demonstrates that DTI-MAP classification may provide a new imaging tool to quantify axonal loss in children with central motor dysfunction. Using this technique, we found that early-life brain

  10. Large-scale renewable energy project barriers: Environmental impact assessment streamlining efforts in Japan and the EU

    International Nuclear Information System (INIS)

    Schumacher, Kim

    2017-01-01

    Environmental Impact Assessment (EIA) procedures have been identified as a major barrier to renewable energy (RE) development with regards to large-scale projects (LS-RE). However EIA laws have also been neglected by many decision-makers who have been underestimating its impact on RE development and the stifling potential they possess. As a consequence, apart from acknowledging the shortcomings of the systems currently in place, few governments momentarily have concrete plans to reform their EIA laws. By looking at recent EIA streamlining efforts in two industrialized regions that underwent major transformations in their energy sectors, this paper attempts to assess how such reform efforts can act as a means to support the balancing of environmental protection and climate change mitigation with socio-economic challenges. Thereby this paper fills this intellectual void by identifying the strengths and weaknesses of the Japanese EIA law by contrasting it with the recently revised EIA Directive of the European Union (EU). This enables the identification of the regulatory provisions that impact RE development the most and the determination of how structured EIA law reforms would affect domestic RE project development. The main focus lies on the evaluation of regulatory streamlining efforts in the Japanese and EU contexts through the application of a mixed-methods approach, consisting of in-depth literary and legal reviews, followed by a comparative analysis and a series of semi-structured interviews. Highlighting several legal inconsistencies in combination with the views of EIA professionals, academics and law- and policymakers, allowed for a more comprehensive assessment of what streamlining elements of the reformed EU EIA Directive and the proposed Japanese EIA framework modifications could either promote or stifle further RE deployment. - Highlights: •Performs an in-depth review of EIA reforms in OECD territories •First paper to compare Japan and the European

  11. Patient and physician attitudes regarding risk and benefit in streamlined development programmes for antibacterial drugs: a qualitative analysis.

    Science.gov (United States)

    Holland, Thomas L; Mikita, Stephen; Bloom, Diane; Roberts, Jamie; McCall, Jonathan; Collyar, Deborah; Santiago, Jonas; Tiernan, Rosemary; Toerner, Joseph

    2016-11-10

    To explore patient, caregiver and physician perceptions and attitudes regarding the balance of benefit and risk in using antibacterial drugs developed through streamlined development processes. Semistructured focus groups and in-depth interviews were conducted to elicit perceptions and attitudes about the use of antibacterial drugs to treat multidrug-resistant infections. Participants were given background information about antibiotic resistance, streamlined drug development programmes and FDA drug approval processes. Audio recordings of focus groups/interviews were reviewed and quotes excerpted and categorised to identify key themes. Two primary stakeholder groups were engaged: one comprising caregivers, healthy persons and patients who had recovered from or were at risk of resistant infection (N=67; 11 focus groups); and one comprising physicians who treat resistant infections (N=23). Responses from focus groups/interviews indicated widespread awareness among patients/caregivers and physicians of the seriousness of the problem of antibacterial resistance. Both groups were willing to accept a degree of uncertainty regarding the balance of risk and benefit in a new therapy where a serious unmet need exists, but also expressed a desire for rigorous monitoring and rapid, transparent reporting of safety/effectiveness data. Both groups wanted to ensure that >1 physician had input on whether to treat patients with antibiotics developed through a streamlined process. Some patients/caregivers unfamiliar with exigencies of critical care suggested a relatively large multidisciplinary team, while physicians believed individual expert consultations would be preferable. Both groups agreed that careful oversight and stewardship of antibacterial drugs are needed to ensure patient safety, preserve efficacy and prevent abuse. Groups comprising patients/caregivers and physicians were aware of serious issues posed by resistant infections and the lack of effective antibacterial drug

  12. Bioprofiling of unknown antibiotics in herbal extracts: Development of a streamlined direct bioautography using Bacillus subtilis linked to mass spectrometry.

    Science.gov (United States)

    Jamshidi-Aidji, Maryam; Morlock, Gertrud E

    2015-11-13

    Working in the field of profiling and identification of bioactive compounds in herbal extracts is faced with the challenge that common chromatographic methods do not directly link to bioactive compounds. Direct bioautography, the combination of TLC/HPTLC with bioassays, linked to structure elucidating techniques is demonstrated to overcome this challenge. The combination of TLC and Bacillus subtilis bioassay was already demonstrated to detect the antibiotics in samples. However, previous studies in this field were faced with some challenges, like being time-consuming, leading not to a homogenous plate background or being restricted to a non-acidic mobile phase. In this study, these aspects were investigated and a streamlined HPTLC-B. subtilis bioassay was developed that generated a homogenous plate background, which was crucial to yield a good baseline for biodensitometry. Two commonly used broths for B. subtilis and a self-designed medium were compared with regard to their capability of detection and baseline noise. The workflow developed allowed the use of acidic mobile phases for the first time. To prove this, 20 herbal extracts were screened for antimicrobial substances developed in parallel with an acidic mobile phase. The main antimicrobial substance in Salvia officinalis tincture detected was further characterized by microchemical reactions, Aliivibrio fischeri, β-glucosidase and acetylcholinesterase (bio)assays as well as mass spectrometry. Scientists looking for new herbal-based medicine may benefit from this time-saving and streamlined bioactivity profiling. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. The benefits of life cycle inventory parametric models in streamlining data collection. A case study in the wooden pallet sector

    DEFF Research Database (Denmark)

    Niero, Monia; Di Felice, F.; Ren, J.

    2014-01-01

    LCA methodology is time and resource consuming particularly when it comes to data collection and handling, therefore companies, particularly Small and Medium Enterprises (SMEs), are inclined to use streamlined approaches to shorten the resource-consuming life cycle inventory (LCI) phase. An effec......LCA methodology is time and resource consuming particularly when it comes to data collection and handling, therefore companies, particularly Small and Medium Enterprises (SMEs), are inclined to use streamlined approaches to shorten the resource-consuming life cycle inventory (LCI) phase...... study of a SME in the wooden pallet sector, investigating to what extent the use of parametric LCI models can be beneficial both in evaluating the environmental impacts of similar products and in providing a preliminary assessment of the potential environmental impacts of new products. We developed...... an LCI parametric model describing the LCI of a range of wooden pallets and tested its effectiveness with a reference product, namely a non-reversible pallet with four-way blocks. The identified parameters refer to the technical characteristics of the product system, e.g. the number and dimension...

  14. Cardiogenic induction of pluripotent stem cells streamlined through a conserved SDF-1/VEGF/BMP2 integrated network.

    Directory of Open Access Journals (Sweden)

    Anca Chiriac

    Full Text Available BACKGROUND: Pluripotent stem cells produce tissue-specific lineages through programmed acquisition of sequential gene expression patterns that function as a blueprint for organ formation. As embryonic stem cells respond concomitantly to diverse signaling pathways during differentiation, extraction of a pro-cardiogenic network would offer a roadmap to streamline cardiac progenitor output. METHODS AND RESULTS: To resolve gene ontology priorities within precursor transcriptomes, cardiogenic subpopulations were here generated according to either growth factor guidance or stage-specific biomarker sorting. Innate expression profiles were independently delineated through unbiased systems biology mapping, and cross-referenced to filter transcriptional noise unmasking a conserved progenitor motif (55 up- and 233 down-regulated genes. The streamlined pool of 288 genes organized into a core biological network that prioritized the "Cardiovascular Development" function. Recursive in silico deconvolution of the cardiogenic neighborhood and associated canonical signaling pathways identified a combination of integrated axes, CXCR4/SDF-1, Flk-1/VEGF and BMP2r/BMP2, predicted to synchronize cardiac specification. In vitro targeting of the resolved triad in embryoid bodies accelerated expression of Nkx2.5, Mef2C and cardiac-MHC, enhanced beating activity, and augmented cardiogenic yield. CONCLUSIONS: Transcriptome-wide dissection of a conserved progenitor profile thus revealed functional highways that coordinate cardiogenic maturation from a pluripotent ground state. Validating the bioinformatics algorithm established a strategy to rationally modulate cell fate, and optimize stem cell-derived cardiogenesis.

  15. Diffusion tractography and graph theory analysis reveal the disrupted rich-club organization of white matter structural networks in early Tourette Syndrome children

    Science.gov (United States)

    Wen, Hongwei; Liu, Yue; Wang, Shengpei; Zhang, Jishui; Peng, Yun; He, Huiguang

    2017-03-01

    Tourette syndrome (TS) is a childhood-onset neurobehavioral disorder. At present, the topological disruptions of the whole brain white matter (WM) structural networks remain poorly understood in TS children. Considering the unique position of the topologically central role of densely interconnected brain hubs, namely the rich club regions, therefore, we aimed to investigate whether the rich club regions and their related connections would be particularly vulnerable in early TS children. In our study, we used diffusion tractography and graph theoretical analyses to explore the rich club structures in 44 TS children and 48 healthy children. The structural networks of TS children exhibited significantly increased normalized rich club coefficient, suggesting that TS is characterized by increased structural integrity of this centrally embedded rich club backbone, potentially resulting in increased global communication capacity. In addition, TS children showed a reorganization of rich club regions, as well as significantly increased density and decreased number in feeder connections. Furthermore, the increased rich club coefficients and feeder connections density of TS children were significantly positively correlated to tic severity, indicating that TS may be characterized by a selective alteration of the structural connectivity of the rich club regions, tending to have higher bridging with non-rich club regions, which may increase the integration among tic-related brain circuits with more excitability but less inhibition for information exchanges between highly centered brain regions and peripheral areas. In all, our results suggest the disrupted rich club organization in early TS children and provide structural insights into the brain networks.

  16. Does the use of hormonal contraceptives cause microstructural changes in cerebral white matter? Preliminary results of a DTI and tractography study.

    Science.gov (United States)

    De Bondt, Timo; Van Hecke, Wim; Veraart, Jelle; Leemans, Alexander; Sijbers, Jan; Sunaert, Stefan; Jacquemyn, Yves; Parizel, Paul M

    2013-01-01

    To evaluate the effect of monophasic combined oral contraceptive pill (COCP) and menstrual cycle phase in healthy young women on white matter (WM) organization using diffusion tensor imaging (DTI). Thirty young women were included in the study; 15 women used COCP and 15 women had a natural cycle. All subjects underwent DTI magnetic resonance imaging during the follicular and luteal phase of their cycle, or in different COCP cycle phases. DTI parameters were obtained in different WM structures by performing diffusion tensor fibre tractography. Fractional anisotropy and mean diffusivity were calculated for different WM structures. Hormonal plasma concentrations were measured in peripheral venous blood samples and correlated with the DTI findings. We found a significant difference in mean diffusivity in the fornix between the COCP and the natural cycle group. Mean diffusivity values in the fornix were negatively correlated with luteinizing hormone and estradiol blood concentrations. An important part in the limbic system, the fornix, regulates emotional processes. Differences in diffusion parameters in the fornix may contribute to behavioural alternations related to COCP use. This finding also suggests that the use of oral contraceptives needs to be taken into account when designing DTI group studies.

  17. Microfluidic DNA microarrays in PMMA chips: streamlined fabrication via simultaneous DNA immobilization and bonding activation by brief UV exposure

    DEFF Research Database (Denmark)

    Sabourin, David; Petersen, J; Snakenborg, Detlef

    2010-01-01

    This report presents and describes a simple and scalable method for producing functional DNA microarrays within enclosed polymeric, PMMA, microfluidic devices. Brief (30 s) exposure to UV simultaneously immobilized poly(T)poly(C)-tagged DNA probes to the surface of unmodified PMMA and activated...... the surface for bonding below the glass transition temperature of the bulk PMMA. Functionality and validation of the enclosed PMMA microarrays was demonstrated as 18 patients were correctly genotyped for all eight mutation sites in the HBB gene interrogated. The fabrication process therefore produced probes...... with desired hybridization properties and sufficient bonding between PMMA layers to allow construction of microfluidic devices. The streamlined fabrication method is suited to the production of low-cost microfluidic microarray-based diagnostic devices and, as such, is equally applicable to the development...

  18. Altered microstructural connectivity of the superior and middle cerebellar peduncles are related to motor dysfunction in children with diffuse periventricular leucomalacia born preterm: A DTI tractography study

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Shanshan, E-mail: jelly_66@126.com; Fan, Guo Guang, E-mail: cjr.fanguoguang@vip.163.com; Xu, Ke, E-mail: cjr.xuke@vip.163.com; Wang, Ci, E-mail: xiangxuehai19850224@yahoo.cn

    2014-06-15

    Purpose: To investigate the microstructural integrity of superior cerebellar peduncles (SCP) and middle cerebellar peduncles (MCP) by using DTI tractography method, and further to detect whether the microstructural integrity of these major cerebellar pathways is related to motor function in children with diffuse periventricular leucomalacia (PVL) born preterm. Materials and methods: 46 children with diffuse PVL (30 males and 16 females; age range 3–48 months; mean age 22.4 ± 6.7 months; mean gestational age 30.5 ± 2.2 weeks) and 40 healthy controls (27 males and 13 females; age range 3.5–48 months; mean age 22.1 ± 5.8 months) were enrolled in this study. DTI outcome measurements, fractional anisotropy (FA), for the SCP, MCP and cortical spinal tract (CST) were calculated. The gross motor function classification system (GMFCS) was used for assessing motor functions. Results: Compared to the controls, patients with diffuse PVL had a significantly lower FA in bilateral SCP, MCP and CST. There was a significant negative correlation between GMFCS levels and FA in bilateral SCP, MCP and CST in the patients group. In addition, significant inverse correlation of FA value was found between not only the contralateral but also the ipsilateral CST and SCP/MCP. Conclusions: These findings suggest that the injury of SCP and MCP may contribute to the motor dysfunction of diffuse PVL. Moreover, the correlations we found between supratentorial and subtentorial injured white matter extend our knowledge about the cerebro-cerebellar white matter interaction in children with diffuse PVL.

  19. Hemispheric asymmetries in dorsal language pathway white-matter tracts: A magnetic resonance imaging tractography and functional magnetic resonance imaging study.

    Science.gov (United States)

    Silva, Guilherme; Citterio, Alberto

    2017-10-01

    Introduction Previous studies have shown that the arcuate fasciculus has a leftward asymmetry in right-handers that could be correlated with the language lateralisation defined by functional magnetic resonance imaging. Nonetheless, information about the asymmetry of the other fibres that constitute the dorsal language pathway is scarce. Objectives This study investigated the asymmetry of the white-matter tracts involved in the dorsal language pathway through the diffusion tensor imaging (DTI) technique, in relation to language hemispheric dominance determined by task-dependent functional magnetic resonance imaging (fMRI). Methods We selected 11 patients (10 right-handed) who had been studied with task-dependent fMRI for language areas and DTI and who had no language impairment or structural abnormalities that could compromise magnetic resonance tractography of the fibres involved in the dorsal language pathway. Laterality indices (LI) for fMRI and for the volumes of each tract were calculated. Results In fMRI, all the right-handers had left hemispheric lateralisation, and the ambidextrous subject presented right hemispheric dominance. The arcuate fasciculus LI was strongly correlated with fMRI LI ( r = 0.739, p = 0.009), presenting the same lateralisation of fMRI in seven subjects (including the right hemispheric dominant). It was not asymmetric in three cases and had opposite lateralisation in one case. The other tracts presented predominance for rightward lateralisation, especially superior longitudinal fasciculus (SLF) II/III (nine subjects), but their LI did not correlate (directly or inversely) with fMRI LI. Conclusion The fibres that constitute the dorsal language pathway have an asymmetric distribution in the cerebral hemispheres. Only the asymmetry of the arcuate fasciculus is correlated with fMRI language lateralisation.

  20. Modeling transcranial magnetic stimulation from the induced electric fields to the membrane potentials along tractography-based white matter fiber tracts

    Science.gov (United States)

    De Geeter, Nele; Dupré, Luc; Crevecoeur, Guillaume

    2016-04-01

    Objective. Transcranial magnetic stimulation (TMS) is a promising non-invasive tool for modulating the brain activity. Despite the widespread therapeutic and diagnostic use of TMS in neurology and psychiatry, its observed response remains hard to predict, limiting its further development and applications. Although the stimulation intensity is always maximum at the cortical surface near the coil, experiments reveal that TMS can affect deeper brain regions as well. Approach. The explanation of this spread might be found in the white matter fiber tracts, connecting cortical and subcortical structures. When applying an electric field on neurons, their membrane potential is altered. If this change is significant, more likely near the TMS coil, action potentials might be initiated and propagated along the fiber tracts towards deeper regions. In order to understand and apply TMS more effectively, it is important to capture and account for this interaction as accurately as possible. Therefore, we compute, next to the induced electric fields in the brain, the spatial distribution of the membrane potentials along the fiber tracts and its temporal dynamics. Main results. This paper introduces a computational TMS model in which electromagnetism and neurophysiology are combined. Realistic geometry and tissue anisotropy are included using magnetic resonance imaging and targeted white matter fiber tracts are traced using tractography based on diffusion tensor imaging. The position and orientation of the coil can directly be retrieved from the neuronavigation system. Incorporating these features warrants both patient- and case-specific results. Significance. The presented model gives insight in the activity propagation through the brain and can therefore explain the observed clinical responses to TMS and their inter- and/or intra-subject variability. We aspire to advance towards an accurate, flexible and personalized TMS model that helps to understand stimulation in the connected

  1. Altered microstructural connectivity of the superior and middle cerebellar peduncles are related to motor dysfunction in children with diffuse periventricular leucomalacia born preterm: A DTI tractography study

    International Nuclear Information System (INIS)

    Wang, Shanshan; Fan, Guo Guang; Xu, Ke; Wang, Ci

    2014-01-01

    Purpose: To investigate the microstructural integrity of superior cerebellar peduncles (SCP) and middle cerebellar peduncles (MCP) by using DTI tractography method, and further to detect whether the microstructural integrity of these major cerebellar pathways is related to motor function in children with diffuse periventricular leucomalacia (PVL) born preterm. Materials and methods: 46 children with diffuse PVL (30 males and 16 females; age range 3–48 months; mean age 22.4 ± 6.7 months; mean gestational age 30.5 ± 2.2 weeks) and 40 healthy controls (27 males and 13 females; age range 3.5–48 months; mean age 22.1 ± 5.8 months) were enrolled in this study. DTI outcome measurements, fractional anisotropy (FA), for the SCP, MCP and cortical spinal tract (CST) were calculated. The gross motor function classification system (GMFCS) was used for assessing motor functions. Results: Compared to the controls, patients with diffuse PVL had a significantly lower FA in bilateral SCP, MCP and CST. There was a significant negative correlation between GMFCS levels and FA in bilateral SCP, MCP and CST in the patients group. In addition, significant inverse correlation of FA value was found between not only the contralateral but also the ipsilateral CST and SCP/MCP. Conclusions: These findings suggest that the injury of SCP and MCP may contribute to the motor dysfunction of diffuse PVL. Moreover, the correlations we found between supratentorial and subtentorial injured white matter extend our knowledge about the cerebro-cerebellar white matter interaction in children with diffuse PVL

  2. Comparative assessment of therapeutic response to physiotherapy with or without botulinum toxin injection using diffusion tensor tractography and clinical scores in term diplegic cerebral palsy children.

    Science.gov (United States)

    Chaturvedi, Saurabh K; Rai, Yogita; Chourasia, Ankita; Goel, Puneet; Paliwal, Vimal K; Garg, Ravindra K; Rathore, Ram Kishore S; Pandey, Chandra M; Gupta, Rakesh K

    2013-08-01

    The present study was to compare the effects of combined therapy [botulinum (BTX) plus physiotherapy] with physiotherapy alone using diffusion tensor imaging (DTI) derived fractional anisotropy (FA) values of motor and sensory fiber bundles and clinical grade of the disability to see the value of BTX in term children with spastic diplegic cerebral palsy (CP). Clinically diagnosed 36 children participated in the study. All these children were born at term, and had no history of seizures. The study was randomly categorized into two groups: group I (n=18) - physiotherapy alone and group II (n=18) - physiotherapy plus BTX injection. Quantitative diffusion tensor tractography on all these children was performed on motor and sensory fiber bundles on baseline as well as after 6months of therapy. Motor function and clinical grades were also measured by gross motor function measures (GMFM) scale on both occasions. We observed significant change in FA value in motor and sensory fiber bundle as well as in GMFM scores at 6months compared to baseline study in both the groups. However, delta change and relative delta change in FA values of sensory and motor fiber bundle as well as GMFM score between group I and group II was statistically insignificant. We conclude that addition of BTX to physiotherapy regimen does not influence the outcome at 6months with similar insult in children with term diplegic spastic CP. This information may influence management of diplegic CP especially in developing countries, where BTX is beyond the reach of these children. Copyright © 2012 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

  3. New insights in the homotopic and heterotopic connectivity of the frontal portion of the human corpus callosum revealed by microdissection and diffusion tractography.

    Science.gov (United States)

    De Benedictis, Alessandro; Petit, Laurent; Descoteaux, Maxime; Marras, Carlo Efisio; Barbareschi, Mattia; Corsini, Francesco; Dallabona, Monica; Chioffi, Franco; Sarubbo, Silvio

    2016-12-01

    Extensive studies revealed that the human corpus callosum (CC) plays a crucial role in providing large-scale bi-hemispheric integration of sensory, motor and cognitive processing, especially within the frontal lobe. However, the literature lacks of conclusive data regarding the structural macroscopic connectivity of the frontal CC. In this study, a novel microdissection approach was adopted, to expose the frontal fibers of CC from the dorsum to the lateral cortex in eight hemispheres and in one entire brain. Post-mortem results were then combined with data from advanced constrained spherical deconvolution in 130 healthy subjects. We demonstrated as the frontal CC provides dense inter-hemispheric connections. In particular, we found three types of fronto-callosal fibers, having a dorso-ventral organization. First, the dorso-medial CC fibers subserve homotopic connections between the homologous medial cortices of the superior frontal gyrus. Second, the ventro-lateral CC fibers subserve homotopic connections between lateral frontal cortices, including both the middle frontal gyrus and the inferior frontal gyrus, as well as heterotopic connections between the medial and lateral frontal cortices. Third, the ventro-striatal CC fibers connect the medial and lateral frontal cortices with the contralateral putamen and caudate nucleus. We also highlighted an intricate crossing of CC fibers with the main association pathways terminating in the lateral regions of the frontal lobes. This combined approach of ex vivo microdissection and in vivo diffusion tractography allowed demonstrating a previously unappreciated three-dimensional architecture of the anterior frontal CC, thus clarifying the functional role of the CC in mediating the inter-hemispheric connectivity. Hum Brain Mapp 37:4718-4735, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  4. Synchronous changes of cortical thickness and corresponding white matter microstructure during brain development accessed by diffusion MRI tractography from parcellated cortex

    Directory of Open Access Journals (Sweden)

    Tina eJeon

    2015-12-01

    Full Text Available Cortical thickness (CT changes during normal brain development is associated with complicated cellular and molecular processes including synaptic pruning and apoptosis. In parallel, the microstructural enhancement of developmental white matter (WM axons with their neuronal bodies in the cerebral cortex has been widely reported with measurements of metrics derived from diffusion tensor imaging (DTI, especially fractional anisotropy (FA. We hypothesized that the changes of CT and microstructural enhancement of corresponding axons are highly interacted during development. DTI and T1-weighted images of 50 healthy children and adolescents between the ages of 7 to 25 years were acquired. With the parcellated cortical gyri transformed from T1-weighted images to DTI space as the tractography seeds, probabilistic tracking was performed to delineate the WM fibers traced from specific parcellated cortical regions. CT was measured at certain cortical regions and FA was measured from the WM fibers traced from same cortical regions. The CT of all frontal cortical gyri, includeing Brodmann areas 4, 6, 8, 9, 10, 11, 44, 45, 46 and 47, decreased significantly and heterogeneously; concurrently, significant and heterogeneous increases of FA of WM traced from corresponding regions were found. We further revealed significant correlation between the slopes of the CT decrease and the slopes of corresponding WM FA increase in all frontal cortical gyri, suggesting coherent cortical pruning and corresponding WM microstructural enhancement. Such correlation was not found in cortical regions other than frontal cortex. The molecular and cellular mechanisms of these synchronous changes may be associated with overlapping signaling pathways of axonal guidance, synaptic pruning, neuronal apoptosis and more prevalent interstitial neurons in the prefrontal cortex. Revealing the coherence of cortical and WM structural changes during development may open a new window for

  5. STREAMLINED APPROACH FOR ENVIRONMENTAL RESTORATION PLAN FOR CORRECTIVE ACTION UNIT 116: AREA 25 TEST CELL C FACILITY NEVADA TEST SITE, NEVADA

    International Nuclear Information System (INIS)

    2006-01-01

    This Streamlined Approach for Environmental Restoration Plan identifies the activities required for the closure of Corrective Action Unit 116, Area 25 Test Cell C Facility. The Test Cell C Facility is located in Area 25 of the Nevada Test Site approximately 25 miles northwest of Mercury, Nevada

  6. Streamlined Approach for Environmental Restoration Plan for Corrective Action Unit 574: Neptune, Nevada National Security Site, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    NSTec Environmental Restoration

    2011-08-31

    This Streamlined Approach for Environmental Restoration (SAFER) Plan identifies the activities required for closure of Corrective Action Unit (CAU) 574, Neptune. CAU 574 is included in the Federal Facility Agreement and Consent Order (FFACO) (1996 [as amended March 2010]) and consists of the following two Corrective Action Sites (CASs) located in Area 12 of the Nevada National Security Site: (1) CAS 12-23-10, U12c.03 Crater (Neptune); (2) CAS 12-45-01, U12e.05 Crater (Blanca). This plan provides the methodology for the field activities that will be performed to gather the necessary information for closure of the two CASs. There is sufficient information and process knowledge regarding the expected nature and extent of potential contaminants to recommend closure of CAU 574 using the SAFER process. Based on historical documentation, personnel interviews, site process knowledge, site visits, photographs, field screening, analytical results, the results of the data quality objective (DQO) process (Section 3.0), and an evaluation of corrective action alternatives (Appendix B), closure in place with administrative controls is the expected closure strategy for CAU 574. Additional information will be obtained by conducting a field investigation to verify and support the expected closure strategy and provide a defensible recommendation that no further corrective action is necessary. This will be presented in a Closure Report that will be prepared and submitted to the Nevada Division of Environmental Protection (NDEP) for review and approval.

  7. Streamlined Membrane Proteome Preparation for Shotgun Proteomics Analysis with Triton X-100 Cloud Point Extraction and Nanodiamond Solid Phase Extraction

    Directory of Open Access Journals (Sweden)

    Minh D. Pham

    2016-05-01

    Full Text Available While mass spectrometry (MS plays a key role in proteomics research, characterization of membrane proteins (MP by MS has been a challenging task because of the presence of a host of interfering chemicals in the hydrophobic protein extraction process, and the low protease digestion efficiency. We report a sample preparation protocol, two-phase separation with Triton X-100, induced by NaCl, with coomassie blue added for visualizing the detergent-rich phase, which streamlines MP preparation for SDS-PAGE analysis of intact MP and shot-gun proteomic analyses. MP solubilized in the detergent-rich milieu were then sequentially extracted and fractionated by surface-oxidized nanodiamond (ND at three pHs. The high MP affinity of ND enabled extensive washes for removal of salts, detergents, lipids, and other impurities to ensure uncompromised ensuing purposes, notably enhanced proteolytic digestion and down-stream mass spectrometric (MS analyses. Starting with a typical membranous cellular lysate fraction harvested with centrifugation/ultracentrifugation, MP purities of 70%, based on number (not weight of proteins identified by MS, was achieved; the weight-based purity can be expected to be much higher.

  8. The potential of high resolution melting analysis (hrma) to streamline, facilitate and enrich routine diagnostics in medical microbiology.

    Science.gov (United States)

    Ruskova, Lenka; Raclavsky, Vladislav

    2011-09-01

    Routine medical microbiology diagnostics relies on conventional cultivation followed by phenotypic techniques for identification of pathogenic bacteria and fungi. This is not only due to tradition and economy but also because it provides pure culture needed for antibiotic susceptibility testing. This review focuses on the potential of High Resolution Melting Analysis (HRMA) of double-stranded DNA for future routine medical microbiology. Search of MEDLINE database for publications showing the advantages of HRMA in routine medical microbiology for identification, strain typing and further characterization of pathogenic bacteria and fungi in particular. The results show increasing numbers of newly-developed and more tailor-made assays in this field. For microbiologists unfamiliar with technical aspects of HRMA, we also provide insight into the technique from the perspective of microbial characterization. We can anticipate that the routine availability of HRMA in medical microbiology laboratories will provide a strong stimulus to this field. This is already envisioned by the growing number of medical microbiology applications published recently. The speed, power, convenience and cost effectiveness of this technology virtually predestine that it will advance genetic characterization of microbes and streamline, facilitate and enrich diagnostics in routine medical microbiology without interfering with the proven advantages of conventional cultivation.

  9. Evaluation of 3D tensor tractography of pyramidal tract depicted by 3T MRI in patients with lacunar infarcts. For prediction of motor function outcome

    International Nuclear Information System (INIS)

    Igase, Keiji; Arai, Masamori; Matsubara, Ichiro; Goishi, Jyunji; Sadamoto, Kazuhiko; Kumon, Yoshiaki; Nagato, Shigeyuki; Seno, Toshimoto; Ohnishi, Takanori

    2007-01-01

    3D tensor tractography (DTT) has been applied to central nervous system (CNS) diseases to depict neuronal fibers. In this study with 3 tesla MRI, we have evaluated DTT to predict outcome of motor function in patients with lacunar infarcts. Fifteen patients with New lacunar infarcts, underwent DTTs with at least one in the acute (mean 1.4 days) and another in the subacute phase (mean 18.7 days). Patients were separated to 2 groups, recovery and non-recovery. Patients in former group had almost complete recovery in motor function 3 month later, while those to latter had a residual hemiparesis. Motor function was assessed with MMT score, which was uniquely stratefied into 12 levels by a modified MMT (manual muscle testing) protocol. DTT was implemented with 3 tesla MRI (Signa Excite; GE) and analyzed with dTV. IISR which was produced by the Department of Radiology, Tokyo University. The pyramidal tract was delineated by setting each region of interest (ROI), with the cerebral peduncle as the seed point and the motor cortex as the target point. The number of pyramidal fibers was identified as drawn lines obtained from a result display. The ratio of the number of fibers (RF) was calculated based on the number of fibers in the injured side relative to the number of fibers in the intact side x 100. In acute phase mean RFs the recovery (70.8±21.6%) and non-recovery (63.5±23.4%) groups were not significantly different. RF of recovery group in subacute phase was 100.5±28.3%, which was significantly higher with that in acute phase, meanwhile there was no significance difference between RFs of non-recovery group in two phases. In addition there was a significant correlation (R 2 =0.89) between MMT score 3 month later and RF in subacute phase in all patients group. There seems to be a correlation between long-term recovery of motor function and increased numbers in pyramidal fibers defected by DTT. Therefore, DTT may have a potential use in predicting the outcome of patients

  10. Disruption of Accumbens and Thalamic White Matter Connectivity Revealed by Diffusion Tensor Tractography in Young Men with Genetic Risk for Obesity

    Directory of Open Access Journals (Sweden)

    Gaia Olivo

    2018-02-01

    Full Text Available Background: Neurovascular coupling is associated with white matter (WM structural integrity, and it is regulated by specific subtypes of dopaminergic receptors. An altered activity of such receptors, highly expressed in reward-related regions, has been reported in carriers of obesity-risk alleles of the fat mass and obesity associated (FTO gene. Among the reward-related regions, the thalamus and the nucleus accumbens are particularly vulnerable to blood pressure dysregulation due to their peculiar anatomo-vascular characteristics, and have been consistently reported to be altered in early-stage obesity. We have thus hypothesized that a disruption in thalamus and nucleus accumbens WM microstructure, possibly on neurovascular basis, could potentially be a predisposing factor underlying the enhanced risk for obesity in the risk-allele carriers.Methods: We have tested WM integrity in 21 male participants genotyped on the FTO risk single nucleotide polymorphisms (SNP rs9939609, through a deterministic tractography analysis. Only homozygous participants (9 AA, 12 TT were included. 11 tracts were selected and categorized as following according to our hypothesis: “risk tracts”, “obesity-associated tracts”, and a control tract (forcpes major. We investigated whether an association existed between genotype, body mass index (BMI and WM microstructural integrity in the “risk-tracts” (anterior thalamic radiation and accumbofrontal fasciculus compared to other tracts. Moreover, we explored whether WM diffusivity could be related to specific personality traits in terms of punishment and reward sensitivity, as measure by the BIS/BAS questionnaire.Results: An effect of the genotype and an interaction effect of genotype and BMI were detected on the fractional anisotropy (FA of the “risk tracts”. Correlations between WM diffusivity parameters and measures of punishment and reward sensitivity were also detected in many WM tracts of both networks

  11. CFD Prediction on the Pressure Distribution and Streamlines around an Isolated Single-Storey House Considering the Effect of Topographic Characteristics

    Science.gov (United States)

    Abdullah, J.; Zaini, S. S.; Aziz, M. S. A.; Majid, T. A.; Deraman, S. N. C.; Yahya, W. N. W.

    2018-04-01

    Single-storey houses are classified as low rise building and vulnerable to damages under windstorm event. This study was carried out with the aim to investigate the pressure distribution and streamlines around an isolated house by considering the effect of terrain characteristics. The topographic features such as flat, depression, ridge, and valley, are considered in this study. This simulation were analysed with Ansys FLUENT 14.0 software package. The result showed the topography characteristics influence the value of pressure coefficient and streamlines especially when the house was located at ridge terrain. The findings strongly suggested that wind analysis should include all topographic features in the analysis in order to establish the true wind force exerted on any structure.

  12. Geologic storage of carbon dioxide and enhanced oil recovery. I. Uncertainty quantification employing a streamline based proxy for reservoir flow simulation

    International Nuclear Information System (INIS)

    Kovscek, A.R.; Wang, Y.

    2005-01-01

    Carbon dioxide (CO 2 ) is already injected into a limited class of reservoirs for oil recovery purposes; however, the engineering design question for simultaneous oil recovery and storage of anthropogenic CO 2 is significantly different from that of oil recovery alone. Currently, the volumes of CO 2 injected solely for oil recovery are minimized due to the purchase cost of CO 2 . If and when CO 2 emissions to the atmosphere are managed, it will be necessary to maximize simultaneously both economic oil recovery and the volumes of CO 2 emplaced in oil reservoirs. This process is coined 'cooptimization'. This paper proposes a work flow for cooptimization of oil recovery and geologic CO 2 storage. An important component of the work flow is the assessment of uncertainty in predictions of performance. Typical methods for quantifying uncertainty employ exhaustive flow simulation of multiple stochastic realizations of the geologic architecture of a reservoir. Such approaches are computationally intensive and thereby time consuming. An analytic streamline based proxy for full reservoir simulation is proposed and tested. Streamline trajectories represent the three-dimensional velocity field during multiphase flow in porous media and so are useful for quantifying the similarity and differences among various reservoir models. The proxy allows rational selection of a representative subset of equi-probable reservoir models that encompass uncertainty with respect to true reservoir geology. The streamline approach is demonstrated to be thorough and rapid

  13. Can streamlined multi-criteria decision analysis be used to implement shared decision making for colorectal cancer screening?

    Science.gov (United States)

    Dolan, James G.; Boohaker, Emily; Allison, Jeroan; Imperiale, Thomas F.

    2013-01-01

    Background Current US colorectal cancer screening guidelines that call for shared decision making regarding the choice among several recommended screening options are difficult to implement. Multi-criteria decision analysis (MCDA) is an established methodology well suited for supporting shared decision making. Our study goal was to determine if a streamlined form of MCDA using rank order based judgments can accurately assess patients’ colorectal cancer screening priorities. Methods We converted priorities for four decision criteria and three sub-criteria regarding colorectal cancer screening obtained from 484 average risk patients using the Analytic Hierarchy Process (AHP) in a prior study into rank order-based priorities using rank order centroids. We compared the two sets of priorities using Spearman rank correlation and non-parametric Bland-Altman limits of agreement analysis. We assessed the differential impact of using the rank order-based versus the AHP-based priorities on the results of a full MCDA comparing three currently recommended colorectal cancer screening strategies. Generalizability of the results was assessed using Monte Carlo simulation. Results Correlations between the two sets of priorities for the seven criteria ranged from 0.55 to 0.92. The proportions of absolute differences between rank order-based and AHP-based priorities that were more than ± 0.15 ranged from 1% to 16%. Differences in the full MCDA results were minimal and the relative rankings of the three screening options were identical more than 88% of the time. The Monte Carlo simulation results were similar. Conclusion Rank order-based MCDA could be a simple, practical way to guide individual decisions and assess population decision priorities regarding colorectal cancer screening strategies. Additional research is warranted to further explore the use of these methods for promoting shared decision making. PMID:24300851

  14. Streamlined Approach for Environmental Restoration Plan for Corrective Action Unit 408: Bomblet Target Area, Tonopah Test Range, Nevada

    International Nuclear Information System (INIS)

    NSTec Environmental Management

    2006-01-01

    This Streamlined Approach for Environmental Restoration Plan provides the details for the closure of Corrective Action Unit (CAU) 408, Bomblet Target Area. CAU 408 is located at the Tonopah Test Range and is currently listed in Appendix III of the Federal Facility Agreement and Consent Order of 1996. One Corrective Action Site (CAS) is included in CAU 408: (lg b ullet) CAS TA-55-002-TAB2, Bomblet Target Areas Based on historical documentation, personnel interviews, process knowledge, site visits, aerial photography, multispectral data, preliminary geophysical surveys, and the results of data quality objectives process (Section 3.0), clean closure will be implemented for CAU 408. CAU 408 closure activities will consist of identification and clearance of bomblet target areas, identification and removal of depleted uranium (DU) fragments on South Antelope Lake, and collection of verification samples. Any soil containing contaminants at concentrations above the action levels will be excavated and transported to an appropriate disposal facility. Based on existing information, contaminants of potential concern at CAU 408 include explosives. In addition, at South Antelope Lake, bomblets containing DU were tested. None of these contaminants is expected to be present in the soil at concentrations above the action levels; however, this will be determined by radiological surveys and verification sample results. The corrective action investigation and closure activities have been planned to include data collection and hold points throughout the process. Hold points are designed to allow decision makers to review the existing data and decide which of the available options are most suitable. Hold points include the review of radiological, geophysical, and analytical data and field observations

  15. Streamlined Approach for Environmental Restoration Plan for Corrective Action Unit 107: Low Impact Soil Sites, Nevada Test Site, Nevada

    International Nuclear Information System (INIS)

    2008-01-01

    This Streamlined Approach for Environmental Restoration Plan covers activities associated with Corrective Action Unit (CAU) 107 of the Federal Facility Agreement and Consent Order (FFACO, 1996 (as amended February 2008)). CAU 107 consists of the following Corrective Action Sites (CASs) located in Areas 1, 2, 3, 4, 5, 9, 10, and 18 of the Nevada Test Site. (1) CAS 01-23-02, Atmospheric Test Site - High Alt; (2) CAS 02-23-02, Contaminated Areas (2); (3) CAS 02-23-03, Contaminated Berm; (4) CAS 02-23-10, Gourd-Amber Contamination Area; (5) CAS 02-23-11, Sappho Contamination Area; (6) CAS 02-23-12, Scuttle Contamination Area; (7) CAS 03-23-24, Seaweed B Contamination Area; (8) CAS 03-23-27, Adze Contamination Area; (9) CAS 03-23-28, Manzanas Contamination Area; (10) CAS 03-23-29, Truchas-Chamisal Contamination Area; (11) CAS 04-23-02, Atmospheric Test Site T4-a; (12) CAS 05-23-06, Atmospheric Test Site; (13) CAS 09-23-06, Mound of Contaminated Soil; (14) CAS 10-23-04, Atmospheric Test Site M-10; and (15) CAS 18-23-02, U-18d Crater (Sulky). Based on historical documentation, personnel interviews, site process knowledge, site visits, photographs, engineering drawings, field screening, analytical results, and the results of data quality objectives process (Section 3.0), closure in place with administrative controls or no further action will be implemented for CAU 107. CAU 107 closure activities will consist of verifying that the current postings required under Title 10 Code of Federal Regulations (CFR) Part 835 are in place and implementing use restrictions (URs) at two sites, CAS 03-23-29 and CAS 18-23-02. The current radiological postings combined with the URs are adequate administrative controls to limit site access and worker dose

  16. Streamlined Approach for Environmental Restoration Plan for Corrective Action Unit 107: Low Impact Soil Sites, Nevada Test Site, Nevada

    International Nuclear Information System (INIS)

    2009-01-01

    This Streamlined Approach for Environmental Restoration Plan covers activities associated with Corrective Action Unit (CAU) 107 of the Federal Facility Agreement and Consent Order (1996 (as amended February 2008)). CAU 107 consists of the following Corrective Action Sites (CASs) located in Areas 1, 2, 3, 4, 5, 9, 10, and 18 of the Nevada Test Site. (sm b ullet) CAS 01-23-02, Atmospheric Test Site - High Alt(sm b ullet) CAS 02-23-02, Contaminated Areas (2)(sm b ullet) CAS 02-23-03, Contaminated Berm(sm b ullet) CAS 02-23-10, Gourd-Amber Contamination Area(sm b ullet) CAS 02-23-11, Sappho Contamination Area(sm b ullet) CAS 02-23-12, Scuttle Contamination Area(sm b ullet) CAS 03-23-24, Seaweed B Contamination Area(sm b ullet) CAS 03-23-27, Adze Contamination Area(sm b ullet) CAS 03-23-28, Manzanas Contamination Area(sm b ullet) CAS 03-23-29, Truchas-Chamisal Contamination Area(sm b ullet) CAS 04-23-02, Atmospheric Test Site T4-a(sm b ullet) CAS 05-23-06, Atmospheric Test Site(sm b ullet) CAS 09-23-06, Mound of Contaminated Soil(sm b ullet) CAS 10-23-04, Atmospheric Test Site M-10(sm b ullet) CAS 18-23-02, U-18d Crater (Sulky) Based on historical documentation, personnel interviews, site process knowledge, site visits, photographs, engineering drawings, field screening, analytical results, and the results of data quality objectives process (Section 3.0), closure in place with administrative controls or no further action will be implemented for CAU 107.

  17. Analysis Streamlining in ATLAS

    CERN Document Server

    Heinrich, Lukas; The ATLAS collaboration

    2018-01-01

    We present recent work within the ATLAS collaboration centrally provide tools to facilitate analysis management and highly automated container-based analysis execution in order to both enable non-experts to benefit from these best practices as well as the collaboration to track and re-execute analyses indpendently, e.g. during their review phase. Through integration with the ATLAS GLANCE system, users can request a pre-configured, but customizable version control setup, including continuous integration for automated build and testing as well as continuous Linux Container image building for software preservation purposes. As analyses typically require many individual steps, analysis workflow pipelines can then be defined using such images and the yadage workflow description language. The integration into the workflow exection service REANA allows the interactive or automated reproduction of the main analysis results by orchestrating a large number of container jobs using the Kubernetes. For long-term archival,...

  18. Streamlining the Hiring Process

    Science.gov (United States)

    DePrater, Karen

    2011-01-01

    Historically, education employees have been hired after a process that consists of these steps: Determining the need for a position, posting the vacancy, paper-screening applications, an interview with a panel or committee, background check, reference calling, and finally the selection of a candidate. This is a very time-consuming and costly…

  19. Tractographie globale sous contraintes anatomiques

    OpenAIRE

    Teillac , Achille

    2017-01-01

    This work aims at developing a method inferring white matter fibers reconstructed using a global spin-glass approach constrained by anatomical prior knowledge. Unlike usual methods building fibers independently from one another, our markovian approach reconstructs the whole tractogram in an unique process by minimizing the global energy depending on the spin glass configuration (position, orientation, length and connection(s)) and the match with the local diffusion process in order to increas...

  20. One stop or full stop? The continuing challenges for researchers despite the new streamlined NHS research governance process

    Directory of Open Access Journals (Sweden)

    France Emma F

    2010-05-01

    Full Text Available Abstract Background Obtaining the necessary approvals and permission for clinical research requires successful negotiation of the ethical and R&D layers of the NHS. Differences in structure and governance frameworks feature between the constituent nations of the UK (England, Scotland, Wales and Northern Ireland, which adds complexity to cross-national studies. Difficulties in carrying out research in the NHS in the UK due to bureaucratic and time-consuming governance processes have led to the development of a new system of application and co-ordination from 2009. This paper illustrates how this new system fails to be consistent and streamlined and is unlikely to become so unless changes are made to the implementation and management of the governance processes. Methods We present a case study of the research governance process at the survey stage of an investigation into the use, preferences and need for information by people making choices or decisions about health care. The method involved home-based, face-to-face interviewing in a questionnaire survey in relation to decisions about lymphoma treatment, Down's syndrome screening in pregnancy, and caring for people with dementia. Results Our experience of the ethics stage was very positive, noting an efficient process of application and a speedy decision, both in relation to the initial application and to subsequent substantial amendments. By contrast, the R&D stages were very slow, most with unexplained delays, but some offering contradictory advice and exhibiting a lack of clear guidance and training for NHS staff. The R&D arrangements in Scotland were far quicker and more likely to be successful than in England. Overall, the delays were so severe that substantial parts of the research could not be delivered as planned within the funding timescale. Conclusions If high-quality research in the NHS, particularly in England, is to be delivered in a timely and cost-effective way, R&D processes for

  1. One stop or full stop? The continuing challenges for researchers despite the new streamlined NHS research governance process.

    Science.gov (United States)

    Thompson, Andrew G H; France, Emma F

    2010-05-13

    Obtaining the necessary approvals and permission for clinical research requires successful negotiation of the ethical and R&D layers of the NHS. Differences in structure and governance frameworks feature between the constituent nations of the UK (England, Scotland, Wales and Northern Ireland), which adds complexity to cross-national studies. Difficulties in carrying out research in the NHS in the UK due to bureaucratic and time-consuming governance processes have led to the development of a new system of application and co-ordination from 2009. This paper illustrates how this new system fails to be consistent and streamlined and is unlikely to become so unless changes are made to the implementation and management of the governance processes. We present a case study of the research governance process at the survey stage of an investigation into the use, preferences and need for information by people making choices or decisions about health care. The method involved home-based, face-to-face interviewing in a questionnaire survey in relation to decisions about lymphoma treatment, Down's syndrome screening in pregnancy, and caring for people with dementia. Our experience of the ethics stage was very positive, noting an efficient process of application and a speedy decision, both in relation to the initial application and to subsequent substantial amendments. By contrast, the R&D stages were very slow, most with unexplained delays, but some offering contradictory advice and exhibiting a lack of clear guidance and training for NHS staff. The R&D arrangements in Scotland were far quicker and more likely to be successful than in England. Overall, the delays were so severe that substantial parts of the research could not be delivered as planned within the funding timescale. If high-quality research in the NHS, particularly in England, is to be delivered in a timely and cost-effective way, R&D processes for gaining research governance approval need improvement. Attention is

  2. Streamlined Approach for Environmental Restoration Plan for Corrective Action Unit 398: Area 25 Spill Sites, Nevada Test Site, Nevada; TOPICAL

    International Nuclear Information System (INIS)

    K. B. Campbell

    2001-01-01

    This Streamlined Approach for Environmental Restoration (SAFER) plan addresses the activities necessary to close Corrective Action Unit (CAU) 398: Area 25 Spill Sites. CAU 398, located in Area 25 of the Nevada Test Site, is currently listed in Appendix III of the Federal Facility Agreement and Consent Order (FFACO) (FFACO, 1996), and consists of the following 13 Corrective Action Sites (CASs) (Figure 1): (1) CAS 25-44-01 , a fuel spill on soil that covers a concrete pad. The origins and use of the spill material are unknown, but the spill is suspected to be railroad bedding material. (2) CAS 25-44-02, a spill of liquid to the soil from leaking drums. (3) CAS 25-44-03, a spill of oil from two leaking drums onto a concrete pad and surrounding soil. (4) CAS 25-44-04, a spill from two tanks containing sulfuric acid and sodium hydroxide used for a water demineralization process. (5) CAS 25-25-02, a fuel or oil spill from leaking drums that were removed in 1992. (6) CAS 25-25-03, an oil spill adjacent to a tipped-over drum. The source of the drum is not listed, although it is noted that the drum was removed in 1991. (7) CAS 25-25-04, an area on the north side of the Engine-Maintenance, Assembly, and Disassembly (E-MAD) facility, where oils and cooling fluids from metal machining operations were poured directly onto the ground. (8) CAS 25-25-05, an area of oil and/or hydraulic fluid spills beneath the heavy equipment once stored there. (9) CAS 25-25-06, an area of diesel fuel staining beneath two generators that have since been removed. (10) CAS 25-25-07, an area of hydraulic oil spills associated with a tunnel-boring machine abandoned inside X-Tunnel. (11) CAS 25-25-08, an area of hydraulic fluid spills associated with a tunnel-boring machine abandoned inside Y-Tunnel. (12) CAS 25-25-16, a diesel fuel spill from an above-ground storage tank located near Building 3320 at Engine Test Stand-1 (ETS-1) that was removed in 1998. (13) CAS 25-25-17, a hydraulic oil spill

  3. Streamlined Total Synthesis of Trioxacarcins and Its Application to the Design, Synthesis, and Biological Evaluation of Analogues Thereof. Discovery of Simpler Designed and Potent Trioxacarcin Analogues.

    Science.gov (United States)

    Nicolaou, K C; Chen, Pengxi; Zhu, Shugao; Cai, Quan; Erande, Rohan D; Li, Ruofan; Sun, Hongbao; Pulukuri, Kiran Kumar; Rigol, Stephan; Aujay, Monette; Sandoval, Joseph; Gavrilyuk, Julia

    2017-11-01

    A streamlined total synthesis of the naturally occurring antitumor agents trioxacarcins is described, along with its application to the construction of a series of designed analogues of these complex natural products. Biological evaluation of the synthesized compounds revealed a number of highly potent, and yet structurally simpler, compounds that are effective against certain cancer cell lines, including a drug-resistant line. A novel one-step synthesis of anthraquinones and chloro anthraquinones from simple ketone precursors and phenylselenyl chloride is also described. The reported work, featuring novel chemistry and cascade reactions, has potential applications in cancer therapy, including targeted approaches as in antibody-drug conjugates.

  4. Streamlined Approach for Environmental Restoration Plan for Corrective Action Unit 121: Storage Tanks and Miscellaneous Sites, Nevada Test Site, Nevada

    International Nuclear Information System (INIS)

    NSTec Environmental Restoration

    2007-01-01

    This Streamlined Approach for Environmental Restoration (SAFER) Plan identifies the activities required for the closure of Corrective Action Unit (CAU) 121, Storage Tanks and Miscellaneous Sites. CAU 121 is currently listed in Appendix III of the ''Federal Facility Agreement and Consent Order'' (FFACO, 1996) and consists of three Corrective Action Sites (CASs) located in Area 12 of the Nevada Test Site (NTS): CAS 12-01-01, Aboveground Storage Tank; CAS 12-01-02, Aboveground Storage Tank; and CAS 12-22-26, Drums; 2 AST's. CASs 12-01-01 and 12-01-02 are located to the west of the Area 12 Camp, and CAS 12-22-26 is located near the U-12g Tunnel, also known as G-tunnel, in Area 12 (Figure 1). The aboveground storage tanks (ASTs) present at CASs 12-01-01 and 12-01-02 will be removed and disposed of at an appropriate facility. Soil below the ASTs will be sampled to identify whether it has been impacted with chemicals or radioactivity above action levels. If impacted soil above action levels is present, the soil will be excavated and disposed of at an appropriate facility. The CAS 12-22-26 site is composed of two overlapping areas, one where drums had formerly been stored, and the other where an AST was used to dispense diesel for locomotives used at G-tunnel. This area is located above an underground radioactive materials area (URMA), and within an area that may have elevated background radioactivity because of containment breaches during nuclear tests and associated tunnel reentry operations. CAS 12-22-26 does not include the URMA or the elevated background radioactivity. An AST that had previously been used to store liquid magnesium chloride (MgCl) was properly disposed of several years ago, and releases from this tank are not an environmental concern. The diesel AST will be removed and disposed of at an appropriate facility. Soil at the former drum area and the diesel AST area will be sampled to identify whether it has been impacted by releases, from the drums or the

  5. Streamlined Approach for Environmental Restoration Plan for Corrective Action Unit 484: Surface Debris, Waste Sites, and Burn Area, Tonopah Test Range, Nevada

    International Nuclear Information System (INIS)

    Bechel Nevada

    2004-01-01

    This Streamlined Approach for Environmental Restoration plan details the activities necessary to close Corrective Action Unit (CAU) 484: Surface Debris, Waste Sites, and Burn Area (Tonopah Test Range). CAU 484 consists of sites located at the Tonopah Test Range, Nevada, and is currently listed in Appendix III of the Federal Facility Agreement and Consent Order. CAU 484 consists of the following six Corrective Action Sites: (1) CAS RG-52-007-TAML, Davis Gun Penetrator Test; (2) CAS TA-52-001-TANL, NEDS Detonation Area; (3) CAS TA-52-004-TAAL, Metal Particle Dispersion Test; (4) CAS TA-52-005-TAAL, Joint Test Assembly DU Sites; (5) CAS TA-52-006-TAPL, Depleted Uranium Site; and (6) CAS TA-54-001-TANL, Containment Tank and Steel Structure

  6. Streamlined approach for environmental restoration plan for corrective action unit 430, buried depleted uranium artillery round No. 1, Tonopah test range

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-09-01

    This plan addresses actions necessary for the restoration and closure of Corrective Action Unit (CAU) No. 430, Buried Depleted Uranium (DU) Artillery Round No. 1 (Corrective Action Site No. TA-55-003-0960), a buried and unexploded W-79 Joint Test Assembly (JTA) artillery test projectile with high explosives (HE), at the U.S. Department of Energy, Nevada Operations Office (DOE/NV) Tonopah Test Range (TTR) in south-central Nevada. It describes activities that will occur at the site as well as the steps that will be taken to gather adequate data to obtain a notice of completion from Nevada Division of Environmental Protection (NDEP). This plan was prepared under the Streamlined Approach for Environmental Restoration (SAFER) concept, and it will be implemented in accordance with the Federal Facility Agreement and Consent Order (FFACO) and the Resource Conservation and Recovery Act (RCRA) Industrial Sites Quality Assurance Project Plan.

  7. Streamlined Approach for Environmental Restoration Plan for Corrective Action Unit 113: Reactor Maintenance, Assembly, and Disassembly Building Nevada Test Site, Nevada

    International Nuclear Information System (INIS)

    Smith, J. L.

    2001-01-01

    This Streamlined Approach for Environmental Restoration (SAFER) Plan addresses the action necessary for the closure in place of Corrective Action Unit (CAU) 113 Area 25 Reactor Maintenance, Assembly, and Disassembly Facility (R-MAD). CAU 113 is currently listed in Appendix III of the Federal Facility Agreement and Consent Order (FFACO) (NDEP, 1996). The CAU is located in Area 25 of the Nevada Test Site (NTS) and consists of Corrective Action Site (CAS) 25-04-01, R-MAD Facility (Figures 1-2). This plan provides the methodology for closure in place of CAU 113. The site contains radiologically impacted and hazardous material. Based on preassessment field work, there is sufficient process knowledge to close in place CAU 113 using the SAFER process. At a future date when funding becomes available, the R-MAD Building (25-3110) will be demolished and inaccessible radiologic waste will be properly disposed in the Area 3 Radiological Waste Management Site (RWMS)

  8. Streamlined Approach for Environmental Restoration Plan for Corrective Action Unit 113: Reactor Maintenance, Assembly, and Disassembly Building Nevada Test Site, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    J. L. Smith

    2001-01-01

    This Streamlined Approach for Environmental Restoration (SAFER) Plan addresses the action necessary for the closure in place of Corrective Action Unit (CAU) 113 Area 25 Reactor Maintenance, Assembly, and Disassembly Facility (R-MAD). CAU 113 is currently listed in Appendix III of the Federal Facility Agreement and Consent Order (FFACO) (NDEP, 1996). The CAU is located in Area 25 of the Nevada Test Site (NTS) and consists of Corrective Action Site (CAS) 25-04-01, R-MAD Facility (Figures 1-2). This plan provides the methodology for closure in place of CAU 113. The site contains radiologically impacted and hazardous material. Based on preassessment field work, there is sufficient process knowledge to close in place CAU 113 using the SAFER process. At a future date when funding becomes available, the R-MAD Building (25-3110) will be demolished and inaccessible radiologic waste will be properly disposed in the Area 3 Radiological Waste Management Site (RWMS).

  9. Streamlined approach for environmental restoration plan for corrective action unit 430, buried depleted uranium artillery round No. 1, Tonopah test range

    International Nuclear Information System (INIS)

    1996-09-01

    This plan addresses actions necessary for the restoration and closure of Corrective Action Unit (CAU) No. 430, Buried Depleted Uranium (DU) Artillery Round No. 1 (Corrective Action Site No. TA-55-003-0960), a buried and unexploded W-79 Joint Test Assembly (JTA) artillery test projectile with high explosives (HE), at the U.S. Department of Energy, Nevada Operations Office (DOE/NV) Tonopah Test Range (TTR) in south-central Nevada. It describes activities that will occur at the site as well as the steps that will be taken to gather adequate data to obtain a notice of completion from Nevada Division of Environmental Protection (NDEP). This plan was prepared under the Streamlined Approach for Environmental Restoration (SAFER) concept, and it will be implemented in accordance with the Federal Facility Agreement and Consent Order (FFACO) and the Resource Conservation and Recovery Act (RCRA) Industrial Sites Quality Assurance Project Plan

  10. Rapid Evidence Assessment of the Literature (REAL(©)): streamlining the systematic review process and creating utility for evidence-based health care.

    Science.gov (United States)

    Crawford, Cindy; Boyd, Courtney; Jain, Shamini; Khorsan, Raheleh; Jonas, Wayne

    2015-11-02

    Systematic reviews (SRs) are widely recognized as the best means of synthesizing clinical research. However, traditional approaches can be costly and time-consuming and can be subject to selection and judgment bias. It can also be difficult to interpret the results of a SR in a meaningful way in order to make research recommendations, clinical or policy decisions, or practice guidelines. Samueli Institute has developed the Rapid Evidence Assessment of the Literature (REAL) SR process to address these issues. REAL provides up-to-date, rigorous, high quality SR information on health care practices, products, or programs in a streamlined, efficient and reliable manner. This process is a component of the Scientific Evaluation and Review of Claims in Health Care (SEaRCH™) program developed by Samueli Institute, which aims at answering the question of "What works?" in health care. The REAL process (1) tailors a standardized search strategy to a specific and relevant research question developed with various stakeholders to survey the available literature; (2) evaluates the quantity and quality of the literature using structured tools and rulebooks to ensure objectivity, reliability and reproducibility of reviewer ratings in an independent fashion and; (3) obtains formalized, balanced input from trained subject matter experts on the implications of the evidence for future research and current practice. Online tools and quality assurance processes are utilized for each step of the review to ensure a rapid, rigorous, reliable, transparent and reproducible SR process. The REAL is a rapid SR process developed to streamline and aid in the rigorous and reliable evaluation and review of claims in health care in order to make evidence-based, informed decisions, and has been used by a variety of organizations aiming to gain insight into "what works" in health care. Using the REAL system allows for the facilitation of recommendations on appropriate next steps in policy, funding

  11. Scientific Evaluation and Review of Claims in Health Care (SEaRCH): A Streamlined, Systematic, Phased Approach for Determining “What Works” in Healthcare

    Science.gov (United States)

    Crawford, Cindy; Hilton, Lara; Elfenbaum, Pamela

    2017-01-01

    Abstract Background: Answering the question of “what works” in healthcare can be complex and requires the careful design and sequential application of systematic methodologies. Over the last decade, the Samueli Institute has, along with multiple partners, developed a streamlined, systematic, phased approach to this process called the Scientific Evaluation and Review of Claims in Health Care (SEaRCH™). The SEaRCH process provides an approach for rigorously, efficiently, and transparently making evidence-based decisions about healthcare claims in research and practice with minimal bias. Methods: SEaRCH uses three methods combined in a coordinated fashion to help determine what works in healthcare. The first, the Claims Assessment Profile (CAP), seeks to clarify the healthcare claim and question, and its ability to be evaluated in the context of its delivery. The second method, the Rapid Evidence Assessment of the Literature (REAL©), is a streamlined, systematic review process conducted to determine the quantity, quality, and strength of evidence and risk/benefit for the treatment. The third method involves the structured use of expert panels (EPs). There are several types of EPs, depending on the purpose and need. Together, these three methods—CAP, REAL, and EP—can be integrated into a strategic approach to help answer the question “what works in healthcare?” and what it means in a comprehensive way. Discussion: SEaRCH is a systematic, rigorous approach for evaluating healthcare claims of therapies, practices, programs, or products in an efficient and stepwise fashion. It provides an iterative, protocol-driven process that is customized to the intervention, consumer, and context. Multiple communities, including those involved in health service and policy, can benefit from this organized framework, assuring that evidence-based principles determine which healthcare practices with the greatest promise are used for improving the public's health and

  12. Scientific Evaluation and Review of Claims in Health Care (SEaRCH): A Streamlined, Systematic, Phased Approach for Determining "What Works" in Healthcare.

    Science.gov (United States)

    Jonas, Wayne B; Crawford, Cindy; Hilton, Lara; Elfenbaum, Pamela

    2017-01-01

    Answering the question of "what works" in healthcare can be complex and requires the careful design and sequential application of systematic methodologies. Over the last decade, the Samueli Institute has, along with multiple partners, developed a streamlined, systematic, phased approach to this process called the Scientific Evaluation and Review of Claims in Health Care (SEaRCH™). The SEaRCH process provides an approach for rigorously, efficiently, and transparently making evidence-based decisions about healthcare claims in research and practice with minimal bias. SEaRCH uses three methods combined in a coordinated fashion to help determine what works in healthcare. The first, the Claims Assessment Profile (CAP), seeks to clarify the healthcare claim and question, and its ability to be evaluated in the context of its delivery. The second method, the Rapid Evidence Assessment of the Literature (REAL © ), is a streamlined, systematic review process conducted to determine the quantity, quality, and strength of evidence and risk/benefit for the treatment. The third method involves the structured use of expert panels (EPs). There are several types of EPs, depending on the purpose and need. Together, these three methods-CAP, REAL, and EP-can be integrated into a strategic approach to help answer the question "what works in healthcare?" and what it means in a comprehensive way. SEaRCH is a systematic, rigorous approach for evaluating healthcare claims of therapies, practices, programs, or products in an efficient and stepwise fashion. It provides an iterative, protocol-driven process that is customized to the intervention, consumer, and context. Multiple communities, including those involved in health service and policy, can benefit from this organized framework, assuring that evidence-based principles determine which healthcare practices with the greatest promise are used for improving the public's health and wellness.

  13. Diffusion Properties and 3D Architecture of Human Lower Leg Muscles Assessed with Ultra-High-Field-Strength Diffusion-Tensor MR Imaging and Tractography: Reproducibility and Sensitivity to Sex Difference and Intramuscular Variability.

    Science.gov (United States)

    Fouré, Alexandre; Ogier, Augustin C; Le Troter, Arnaud; Vilmen, Christophe; Feiweier, Thorsten; Guye, Maxime; Gondin, Julien; Besson, Pierre; Bendahan, David

    2018-05-01

    Purpose To demonstrate the reproducibility of the diffusion properties and three-dimensional structural organization measurements of the lower leg muscles by using diffusion-tensor imaging (DTI) assessed with ultra-high-field-strength (7.0-T) magnetic resonance (MR) imaging and tractography of skeletal muscle fibers. On the basis of robust statistical mapping analyses, this study also aimed at determining the sensitivity of the measurements to sex difference and intramuscular variability. Materials and Methods All examinations were performed with ethical review board approval; written informed consent was obtained from all volunteers. Reproducibility of diffusion tensor indexes assessment including eigenvalues, mean diffusivity, and fractional anisotropy (FA) as well as muscle volume and architecture (ie, fiber length and pennation angle) were characterized in lower leg muscles (n = 8). Intramuscular variability and sex differences were characterized in young healthy men and women (n = 10 in each group). Student t test, statistical parametric mapping, correlation coefficients (Spearman rho and Pearson product-moment) and coefficient of variation (CV) were used for statistical data analysis. Results High reproducibility of measurements (mean CV ± standard deviation, 4.6% ± 3.8) was determined in diffusion properties and architectural parameters. Significant sex differences were detected in FA (4.2% in women for the entire lower leg; P = .001) and muscle volume (21.7% in men for the entire lower leg; P = .008), whereas architecture parameters were almost identical across sex. Additional differences were found independently of sex in diffusion properties and architecture along several muscles of the lower leg. Conclusion The high-spatial-resolution DTI assessed with 7.0-T MR imaging allows a reproducible assessment of structural organization of superficial and deep muscles, giving indirect information on muscle function. © RSNA, 2018 Online supplemental material is

  14. Streamlined Approach for Environmental Restoration (SAFER) Plan for Corrective Action Unit 408: Bomblet Target Area Tonopah Test Range (TTR), Nevada, Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    Mark Krauss

    2010-03-01

    This Streamlined Approach for Environmental Restoration Plan addresses the actions needed to achieve closure of Corrective Action Unit (CAU) 408, Bomblet Target Area (TTR). Corrective Action Unit 408 is located at the Tonopah Test Range and is currently listed in Appendix III of the Federal Facility Agreement and Consent Order. Corrective Action Unit 408 comprises Corrective Action Site TA-55-002-TAB2, Bomblet Target Areas. Clean closure of CAU 408 will be accomplished by removal of munitions and explosives of concern within seven target areas and potential disposal pits. The target areas were used to perform submunitions related tests for the U.S. Department of Energy (DOE). The scope of CAU 408 is limited to submunitions released from DOE activities. However, it is recognized that the presence of other types of unexploded ordnance and munitions may be present within the target areas due to the activities of other government organizations. The CAU 408 closure activities consist of: • Clearing bomblet target areas within the study area. • Identifying and remediating disposal pits. • Collecting verification samples. • Performing radiological screening of soil. • Removing soil containing contaminants at concentrations above the action levels. Based on existing information, contaminants of potential concern at CAU 408 include unexploded submunitions, explosives, Resource Conservation Recovery Act metals, and depleted uranium. Contaminants are not expected to be present in the soil at concentrations above the action levels; however, this will be determined by radiological surveys and verification sample results.

  15. Streamlined approach for environmental restoration (SAFER) plan for corrective action unit 412: clean slate I plutonium dispersion (TTR) tonopah test range, Nevada, revision 0

    Energy Technology Data Exchange (ETDEWEB)

    Matthews, Patrick K.

    2015-04-01

    This Streamlined Approach for Environmental Restoration (SAFER) Plan addresses the actions needed to achieve closure for Corrective Action Unit (CAU) 412. CAU 412 is located on the Tonopah Test Range and consists of a single corrective action site (CAS), TA-23-01CS, Pu Contaminated Soil. There is sufficient information and historical documentation from previous investigations and the 1997 interim corrective action to recommend closure of CAU 412 using the SAFER process. Based on existing data, the presumed corrective action for CAU 412 is clean closure. However, additional data will be obtained during a field investigation to document and verify the adequacy of existing information and determine whether the CAU 412 closure objectives have been achieved. This SAFER Plan provides the methodology to gather the necessary information for closing the CAU.The following summarizes the SAFER activities that will support the closure of CAU 412:• Collect environmental samples from designated target populations to confirm or disprove the presence of contaminants of concern (COCs) as necessary to supplement existing information.• If no COCs are present, establish clean closure as the corrective action. • If COCs are present, the extent of contamination will be defined and further corrective actions will be evaluated with the stakeholders (NDEP, USAF).• Confirm the preferred closure option is sufficient to protect human health and the environment.

  16. Streamlined Approach for Environmental Restoration (SAFER) Plan for Corrective Action Unit 408: Bomblet Target Area Tonopah Test Range (TTR), Nevada, Revision 1

    International Nuclear Information System (INIS)

    Krauss, Mark

    2010-01-01

    This Streamlined Approach for Environmental Restoration Plan addresses the actions needed to achieve closure of Corrective Action Unit (CAU) 408, Bomblet Target Area (TTR). Corrective Action Unit 408 is located at the Tonopah Test Range and is currently listed in Appendix III of the Federal Facility Agreement and Consent Order. Corrective Action Unit 408 comprises Corrective Action Site TA-55-002-TAB2, Bomblet Target Areas. Clean closure of CAU 408 will be accomplished by removal of munitions and explosives of concern within seven target areas and potential disposal pits. The target areas were used to perform submunitions related tests for the U.S. Department of Energy (DOE). The scope of CAU 408 is limited to submunitions released from DOE activities. However, it is recognized that the presence of other types of unexploded ordnance and munitions may be present within the target areas due to the activities of other government organizations. The CAU 408 closure activities consist of: (1) Clearing bomblet target areas within the study area. (2) Identifying and remediating disposal pits. (3) Collecting verification samples. (4) Performing radiological screening of soil. (5) Removing soil containing contaminants at concentrations above the action levels. Based on existing information, contaminants of potential concern at CAU 408 include unexploded submunitions, explosives, Resource Conservation Recovery Act metals, and depleted uranium. Contaminants are not expected to be present in the soil at concentrations above the action levels; however, this will be determined by radiological surveys and verification sample results.

  17. Streamlined Approach for Environmental Restoration (SAFER) Plan for Corrective Action Unit 415: Project 57 No. 1 Plutonium Dispersion (NTTR), Nevada, Revision 0

    Energy Technology Data Exchange (ETDEWEB)

    Matthews, Patrick; Burmeister, Mark

    2014-04-01

    This Streamlined Approach for Environmental Restoration (SAFER) Plan addresses the actions needed to achieve closure for Corrective Action Unit (CAU) 415, Project 57 No. 1 Plutonium Dispersion (NTTR). CAU 415 is located on Range 4808A of the Nevada Test and Training Range (NTTR) and consists of one corrective action site: NAFR-23-02, Pu Contaminated Soil. The CAU 415 site consists of the atmospheric release of radiological contaminants to surface soil from the Project 57 safety experiment conducted in 1957. The safety experiment released plutonium (Pu), uranium (U), and americium (Am) to the surface soil over an area of approximately 1.9 square miles. This area is currently fenced and posted as a radiological contamination area. Vehicles and debris contaminated by the experiment were subsequently buried in a disposal trench within the surface-contaminated, fenced area and are assumed to have released radiological contamination to subsurface soils. Potential source materials in the form of pole-mounted electrical transformers were also identified at the site and will be removed as part of closure activities.

  18. BrAD-seq: Breath Adapter Directional sequencing: a streamlined, ultra-simple and fast library preparation protocol for strand specific mRNA library construction.

    Directory of Open Access Journals (Sweden)

    Brad Thomas Townsley

    2015-05-01

    Full Text Available Next Generation Sequencing (NGS is driving rapid advancement in biological understanding and RNA-sequencing (RNA-seq has become an indispensable tool for biology and medicine. There is a growing need for access to these technologies although preparation of NGS libraries remains a bottleneck to wider adoption. Here we report a novel method for the production of strand specific RNA-seq libraries utilizing inherent properties of double-stranded cDNA to capture and incorporate a sequencing adapter. Breath Adapter Directional sequencing (BrAD-seq reduces sample handling and requires far fewer enzymatic steps than most available methods to produce high quality strand-specific RNA-seq libraries. The method we present is optimized for 3-prime Digital Gene Expression (DGE libraries and can easily extend to full transcript coverage shotgun (SHO type strand-specific libraries and is modularized to accommodate a diversity of RNA and DNA input materials. BrAD-seq offers a highly streamlined and inexpensive option for RNA-seq libraries.

  19. Streamlined approach for environmental restoration work plan for Corrective Action Unit 126: Closure of aboveground storage tanks, Nevada Test Site, Nevada. Revision 1

    International Nuclear Information System (INIS)

    1998-07-01

    This plan addresses the closure of several aboveground storage tanks in Area 25 of the Nevada Test Site. The unit is currently identified as Corrective Action Unit 126 in the Federal Facility Agreement and Consent Order and is listed as having six Corrective Action Sites. This plan addresses the Streamlined Approach for Environmental Restoration closure for five of the six sites. Four of the CASs are located at the Engine Test Stand complex and one is located in the Central Support Area. The sites consist of aboveground tanks, two of which were used to store diesel fuel and one stored Nalcool (an antifreeze mixture). The remaining tanks were used as part of a water demineralization process and stored either sulfuric acid or sodium hydroxide, and one was used as a charcoal adsorption furnace. Closure will be completed by removal of the associated piping, tank supports and tanks using a front end loader, backhoe, and/or crane. When possible, the tanks will be salvaged as scrap metal. The piping that is not removed will be sealed using a cement grout

  20. Streamlined Approach for Environmental Restoration (SAFER) Plan for Corrective Action Unit 538: Spill Sites, Nevada Test Site, Nevada, Rev. No.: 0

    Energy Technology Data Exchange (ETDEWEB)

    Alfred Wickline

    2006-04-01

    This Streamlined Approach for Environmental Restoration (SAFER) Plan addresses the actions necessary for the closure of Corrective Action Unit (CAU) 538: Spill Sites, Nevada Test Site, Nevada. It has been developed in accordance with the ''Federal Facility Agreement and Consent Order'' (FFACO) (1996) that was agreed to by the State of Nevada, the U.S. Department of Energy (DOE), and the U.S. Department of Defense. A SAFER may be performed when the following criteria are met: (1) Conceptual corrective actions are clearly identified (although some degree of investigation may be necessary to select a specific corrective action before completion of the Corrective Action Investigation [CAI]). (2) Uncertainty of the nature, extent, and corrective action must be limited to an acceptable level of risk. (3) The SAFER Plan includes decision points and criteria for making data quality objective (DQO) decisions. The purpose of the investigation will be to document and verify the adequacy of existing information; to affirm the decision for either clean closure, closure in place, or no further action; and to provide sufficient data to implement the corrective action. The actual corrective action selected will be based on characterization activities implemented under this SAFER Plan. This SAFER Plan identifies decision points developed in cooperation with the Nevada Division of Environmental Protection (NDEP) and where DOE will reach consensus with NDEP before beginning the next phase of work.

  1. High-throughput, 384-well, LC-MS/MS CYP inhibition assay using automation, cassette-analysis technique, and streamlined data analysis.

    Science.gov (United States)

    Halladay, Jason S; Delarosa, Erlie Marie; Tran, Daniel; Wang, Leslie; Wong, Susan; Khojasteh, S Cyrus

    2011-08-01

    Here we describe a high capacity and high-throughput, automated, 384-well CYP inhibition assay using well-known HLM-based MS probes. We provide consistently robust IC(50) values at the lead optimization stage of the drug discovery process. Our method uses the Agilent Technologies/Velocity11 BioCel 1200 system, timesaving techniques for sample analysis, and streamlined data processing steps. For each experiment, we generate IC(50) values for up to 344 compounds and positive controls for five major CYP isoforms (probe substrate): CYP1A2 (phenacetin), CYP2C9 ((S)-warfarin), CYP2C19 ((S)-mephenytoin), CYP2D6 (dextromethorphan), and CYP3A4/5 (testosterone and midazolam). Each compound is incubated separately at four concentrations with each CYP probe substrate under the optimized incubation condition. Each incubation is quenched with acetonitrile containing the deuterated internal standard of the respective metabolite for each probe substrate. To minimize the number of samples to be analyzed by LC-MS/MS and reduce the amount of valuable MS runtime, we utilize timesaving techniques of cassette analysis (pooling the incubation samples at the end of each CYP probe incubation into one) and column switching (reducing the amount of MS runtime). Here we also report on the comparison of IC(50) results for five major CYP isoforms using our method compared to values reported in the literature.

  2. Streamlined Approach for Environmental Restoration (SAFER) Plan for Corrective Action Unit 575: Area 15 Miscellaneous Sites, Nevada National Security Site, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Matthews, Patrick [Navarro-Intera, LLC (N-I), Las Vegas, NV (United States)

    2014-12-01

    This Streamlined Approach for Environmental Restoration (SAFER) Plan addresses the actions needed to achieve closure for Corrective Action Unit (CAU) 575, Area 15 Miscellaneous Sites, identified in the Federal Facility Agreement and Consent Order (FFACO). CAU 575 comprises the following four corrective action sites (CASs) located in Area 15 of the Nevada National Security Site: 15-19-02, Waste Burial Pit, 15-30-01, Surface Features at Borehole Sites, 15-64-01, Decontamination Area, 15-99-03, Aggregate Plant This plan provides the methodology for field activities needed to gather the necessary information for closing each CAS. There is sufficient information and process knowledge from historical documentation and investigations of similar sites regarding the expected nature and extent of potential contaminants to recommend closure of CAU 575 using the SAFER process. Additional information will be obtained by conducting a field investigation to document and verify the adequacy of existing information, to affirm the predicted corrective action decisions, and to provide sufficient data to implement the corrective actions. This will be presented in a closure report that will be prepared and submitted to the Nevada Division of Environmental Protection (NDEP) for review and approval.

  3. Streamlined Approach for Environmental Restoration Plan for Corrective Action Unit 425: Area 9 Main Lake Construction Debris Disposal Area, Tonopah Test Range, Nevada; TOPICAL

    International Nuclear Information System (INIS)

    K. B. Campbell

    2002-01-01

    This Streamlined Approach for Environmental Restoration (SAFER) Plan addresses the action necessary for the closure of Corrective Action Unit (CAU) 425, Area 9 Main Lake Construction Debris Disposal Area. This CAU is currently listed in Appendix III of the Federal Facility Agreement and Consent Order (FFACO, 1996). This site will be cleaned up under the SAFER process since the volume of waste exceeds the 23 cubic meters (m(sup 3)) (30 cubic yards[yd(sup 3)]) limit established for housekeeping sites. CAU 425 is located on the Tonopah Test Range (TTR) and consists of one Corrective Action Site (CAS) 09-08-001-TA09, Construction Debris Disposal Area (Figure 1). CAS 09-08-001-TA09 is an area that was used to collect debris from various projects in and around Area 9. The site is located approximately 81 meters (m) (265 feet[ft]) north of Edwards Freeway northeast of Main Lake on the TTR. The site is composed of concrete slabs with metal infrastructure, metal rebar, wooden telephone poles, and concrete rubble from the Hard Target and early Tornado Rocket sled tests. Other items such as wood scraps, plastic pipes, soil, and miscellaneous nonhazardous items have also been identified in the debris pile. It is estimated that this site contains approximately 2280 m(sup 3) (3000 yd(sup 3)) of construction-related debris

  4. Comparison of streamlined liner of the pharynx airway (SLIPA TM with the laryngeal mask airway Proseal TM for lower abdominal laparoscopic surgeries in paralyzed, anesthetized patients

    Directory of Open Access Journals (Sweden)

    Ashraf Abualhassan Abdellatif

    2011-01-01

    Full Text Available Context: Supraglottic airway devices have been used as an alternative to tracheal intubation during laparoscopic surgery. Aims: The study was designed to compare the efficacy of Streamlined Liner of the Pharynx Airway (SLIPA for positive pressure ventilation and postoperative complications with the Laryngeal Mask Airway ProSeal (PLMA for patients undergoing lower abdominal laparoscopies under general anesthesia with controlled ventilation. Settings and Design: Prospective, crossover randomized controlled trial performed on patients undergoing lower abdominal laparoscopic surgeries. Methods: A total of 120 patients undergoing lower abdominal laparoscopic surgeries were randomly allocated into two equal groups; PLMA and SLIPA groups. Number of intubation attempts, insertion time, ease of insertion, and fiberoptic bronchoscopic view were recorded. Lung mechanics data were collected 5 minutes after securing the airway, then after abdominal insufflation. Blood traces and regurgitation were checked for; postoperative sore throat and other complications were recorded. Statistical Analysis: Arithmetic mean and standard deviation values were calculated and statistical analyses were performed for each group. Independent sample t-test was used to compare continuous variables exhibiting normal distribution, and Chi-squared test for noncontinuous variables. P value <0.05 was considered significant. Results: Insertion time, first insertion success rate, and ease of insertion were comparable in both groups. Fiberoptic bronchoscopic view was significantly better and epiglottic downfolding was significantly lower in SLIPA group. Sealing pressure and lung mechanics were similar. Gastric distension was not observed in both groups. Postoperative sore throat was significantly higher in PACU in PLMA group. Blood traces on the device were significantly more in SLIPA group. Conclusions: SLIPA can be used as a useful alternative to PLMA in patients undergoing lower

  5. Streamlined Approach for Environmental Restoration (SAFER) Plan for Corrective Action Unit 411. Double Tracks Plutonium Dispersion (Nellis), Nevada Test and Training Range, Nevada, Revision 0

    Energy Technology Data Exchange (ETDEWEB)

    Matthews, Patrick K. [Navarro-Intera, LLC (N-I), Las Vegas, NV (United States)

    2015-03-01

    This Streamlined Approach for Environmental Restoration (SAFER) Plan addresses the actions needed to achieve closure for Corrective Action Unit (CAU) 411, Double Tracks Plutonium Dispersion (Nellis). CAU 411 is located on the Nevada Test and Training Range and consists of a single corrective action site (CAS), NAFR-23-01, Pu Contaminated Soil. There is sufficient information and historical documentation from previous investigations and the 1996 interim corrective action to recommend closure of CAU 411 using the SAFER process. Based on existing data, the presumed corrective action for CAU 411 is clean closure. However, additional data will be obtained during a field investigation to document and verify the adequacy of existing information, and to determine whether the CAU 411 closure objectives have been achieved. This SAFER Plan provides the methodology to gather the necessary information for closing the CAU. The results of the field investigation will be presented in a closure report that will be prepared and submitted to the Nevada Division of Environmental Protection (NDEP) for review and approval. The site will be investigated based on the data quality objectives (DQOs) developed on November 20, 2014, by representatives of NDEP, the U.S. Air Force (USAF), and the U.S. Department of Energy (DOE), National Nuclear Security Administration Nevada Field Office. The DQO process was used to identify and define the type, amount, and quality of data needed to determine whether CAU 411 closure objectives have been achieved. The following text summarizes the SAFER activities that will support the closure of CAU 411; Collect environmental samples from designated target populations to confirm or disprove the presence of contaminants of concern (COCs) as necessary to supplement existing information; If COCs are no longer present, establish clean closure as the corrective action; If COCs are present, the extent of contamination will be defined and further corrective actions

  6. Streamlined Approach for Environmental Restoration Plan for Corrective Action Unit 326: Areas 6 and 27 Release Sites, Nevada Test Site, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    A. T. Urbon

    2001-09-01

    This Streamlined Approach for Environmental Restoration (SAFER) plan addresses the action necessary for the closure of Corrective Action Unit (CAU) 326, Areas 6 and 27 Release Sites. This CAU is currently listed in the January 2001, Appendix III of the Federal Facilities Agreement and Consent Order (FFACO) (FFACO, 1996). CAU 326 is located on the Nevada Test Site (NTS) and consists of the following four Corrective Action Sites (CASS) (Figure 1): CAS 06-25-01--Is a rupture in an underground pipe that carried heating oil (diesel) from the underground heating oil tank (Tank 6-CP-1) located to the west of Building CP-70 to the boiler in Building CP-1 in the Area 6 Control Point (CP) compound. CAS 06-25-02--A heating oil spill that is a result of overfilling an underground heating oil tank (Tank 6-DAF-5) located at the Area 6 Device Assembly Facility (DAF). CAS 06-25-04--A release of waste oil that occurred while removing used oil to from Tank 6-619-4. Tank 6-619-4 is located northwest of Building 6-619 at the Area 6 Gas Station. CAS 27-25-01--Consists of an excavation that was created in an attempt to remove impacted stained soil from the Site Maintenance Yard in Area 27. Approximately 53.5 cubic meters (m{sup 3}) (70 cubic yards [yd{sup 3}]) of soil impacted by total petroleum hydrocarbons (TPH) and polychlorinated biphenyls (PCBs) was excavated before the excavation activities were halted. The excavation activities were stopped because the volume of impacted soil exceeded estimated quantities and budget.

  7. Streamlined Approach for Environmental Restoration Plan for Corrective Action Unit 330: Areas 6, 22, and 23 Tanks and Spill Sites, Nevada Test Site, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    T. M. Fitzmaurice

    2001-08-01

    This Streamlined Approach for Environmental restoration (SAFER) plan addresses the action necessary for the closure of Corrective Action Unit (CAU) 330, Areas 6,22, and 23 Tanks and Spill Sites. The CAUs are currently listed in Appendix III of the Federal Facility Agreement and Consent Order (FFACO). This CAU is located at the Nevada Test Site (NTS) (Figure 1). CAU 330 consists of the following Corrective Action Sites (CASs): (1) CAS 06-02-04 - Consists of an underground tank and piping. This CAS is close to an area that was part of the Animal Investigation Program (AIP), conducted under the U.S. Public Health Service. Its purpose was to study and perform tests on the cattle and wild animals in and around the NTS that were exposed to radionuclides. It is unknown if this tank was part of these operations. (2) CAS 22-99-06 - Is a fuel spill that is believed to be a waste oil release which occurred when Camp Desert Rock was an active facility. This CAS was originally identified as being a small depression where liquids were poured onto the ground, located on the west side of Building T-1001. This building has been identified as housing a fire station, radio station, and radio net remote and telephone switchboard. (3) CAS 23-01-02 - Is a large aboveground storage tank (AST) farm that was constructed to provide gasoline and diesel storage in Area 23. The site consists of two ASTs, a concrete foundation, a surrounding earthen berm, associated piping, and unloading stations. (4) CAS 23-25-05 - Consists of an asphalt oil spill/tar release that contains a wash covered with asphalt oil/tar material, a half buried 208-liter (L) (55-gallon [gal]) drum, rebar, and concrete located in the vicinity.

  8. Streamlined Approach for Environmental Restoration Plan for Corrective Action Unit 330: Areas 6, 22, and 23 Tanks and Spill Sites, Nevada Test Site, Nevada; TOPICAL

    International Nuclear Information System (INIS)

    T. M. Fitzmaurice

    2001-01-01

    This Streamlined Approach for Environmental restoration (SAFER) plan addresses the action necessary for the closure of Corrective Action Unit (CAU) 330, Areas 6,22, and 23 Tanks and Spill Sites. The CAUs are currently listed in Appendix III of the Federal Facility Agreement and Consent Order (FFACO). This CAU is located at the Nevada Test Site (NTS) (Figure 1). CAU 330 consists of the following Corrective Action Sites (CASs): (1) CAS 06-02-04 - Consists of an underground tank and piping. This CAS is close to an area that was part of the Animal Investigation Program (AIP), conducted under the U.S. Public Health Service. Its purpose was to study and perform tests on the cattle and wild animals in and around the NTS that were exposed to radionuclides. It is unknown if this tank was part of these operations. (2) CAS 22-99-06 - Is a fuel spill that is believed to be a waste oil release which occurred when Camp Desert Rock was an active facility. This CAS was originally identified as being a small depression where liquids were poured onto the ground, located on the west side of Building T-1001. This building has been identified as housing a fire station, radio station, and radio net remote and telephone switchboard. (3) CAS 23-01-02 - Is a large aboveground storage tank (AST) farm that was constructed to provide gasoline and diesel storage in Area 23. The site consists of two ASTs, a concrete foundation, a surrounding earthen berm, associated piping, and unloading stations. (4) CAS 23-25-05 - Consists of an asphalt oil spill/tar release that contains a wash covered with asphalt oil/tar material, a half buried 208-liter (L) (55-gallon[gal]) drum, rebar, and concrete located in the vicinity

  9. Evaluation of performance of Streamlined Liner of the Pharynx Airway™, Laryngeal Mask Airway-ProSeal and endotracheal tube in prone position: A prospective, randomised study

    Directory of Open Access Journals (Sweden)

    Harihar Vishwanath Hegde

    2018-01-01

    Full Text Available Background and Aims: Airway used in prone position should be efficacious and safe. The Streamlined Liner of the Pharynx Airway (SLIPA™ and Laryngeal Mask Airway-ProSeal (PLMA provide better airway seal and protection against aspiration. We planned to evaluate the performance of SLIPA™, PLMA and endotracheal tube (ETT in prone position. Methods: 114 adult patients undergoing elective surgery in prone position under general anaesthesia were randomised into Group-T (ETT, Group-S (SLIPA™ and Group-P (PLMA. Airways were inserted in supine position and patients turned prone subsequently. Airway characteristics, ventilatory parameters and complications were noted. One-way analysis of variance, Mann–Whitney U-test and Chi-square or Fisher's exact test were used. Results: Tidal volumes, peak airway pressure and compliance were comparable at all times. Leak pressure was significantly higher (P < 0.001 in Group-T (mean leak pressure = 40 cmH2O when compared to Group-S and Group-P at all the times of recording, and there was no significant difference between Group-S and Group-P. The number of patients requiring airway/neck manipulation in prone position was significantly higher (P < 0.001 in Group-S (19 [55.9%] when the three groups were compared (none in Group-T and in comparison with Group-P (5 [14.7%], P < 0.001. On airway removal, the incidence of complications and airway reaction was significantly higher in Group-T. Group-S had a significantly higher incidence of dysphagia at 2 h postoperatively. Conclusion: ETT was most efficacious. SLIPA™ and PLMA were efficacious, safe and less stimulating to the airway during removal. More patients required SLIPA™ airway/neck manipulation.

  10. Streamlined Approach for Environmental Restoration Plan for Corrective Action Unit 326: Areas 6 and 27 Release Sites, Nevada Test Site, Nevada; TOPICAL

    International Nuclear Information System (INIS)

    A. T. Urbon

    2001-01-01

    This Streamlined Approach for Environmental Restoration (SAFER) plan addresses the action necessary for the closure of Corrective Action Unit (CAU) 326, Areas 6 and 27 Release Sites. This CAU is currently listed in the January 2001, Appendix III of the Federal Facilities Agreement and Consent Order (FFACO) (FFACO, 1996). CAU 326 is located on the Nevada Test Site (NTS) and consists of the following four Corrective Action Sites (CASS) (Figure 1): CAS 06-25-01-Is a rupture in an underground pipe that carried heating oil (diesel) from the underground heating oil tank (Tank 6-CP-1) located to the west of Building CP-70 to the boiler in Building CP-1 in the Area 6 Control Point (CP) compound. CAS 06-25-02-A heating oil spill that is a result of overfilling an underground heating oil tank (Tank 6-DAF-5) located at the Area 6 Device Assembly Facility (DAF). CAS 06-25-04-A release of waste oil that occurred while removing used oil to from Tank 6-619-4. Tank 6-619-4 is located northwest of Building 6-619 at the Area 6 Gas Station. CAS 27-25-01-Consists of an excavation that was created in an attempt to remove impacted stained soil from the Site Maintenance Yard in Area 27. Approximately 53.5 cubic meters (m(sup 3)) (70 cubic yards[yd(sup 3)]) of soil impacted by total petroleum hydrocarbons (TPH) and polychlorinated biphenyls (PCBs) was excavated before the excavation activities were halted. The excavation activities were stopped because the volume of impacted soil exceeded estimated quantities and budget

  11. Determination of triazine herbicides and their metabolites in multiple medicinal parts of traditional Chinese medicines using streamlined pretreatment and UFLC-ESI-MS/MS.

    Science.gov (United States)

    Liu, Congmin; Dou, Xiaowen; Zhang, Lei; Li, Qian; Qin, Jia'an; Duan, Yaping; Yang, Meihua

    2018-01-01

    A rapid, sensitive, and reliable ultra-fast liquid chromatography combined with electrospray ionization tandem mass spectrometry (UFLC-ESI-MS/MS) method was established and applied to simultaneous determination of 31 triazine herbicides and their metabolites in multiple medicinal parts of traditional Chinese medicines (TCMs). A streamlined pretreatment approach using one-step extraction and dilution was proposed, which provided high-throughput processing, excellent recovery, and negligible interference. Afterwards, multiple-reaction monitoring (MRM) and information-dependent acquisition (IDA) triggered enhanced product ion spectra (EPI) was adopted to identify and quantify the targets in a single analysis. The optimized method was then validated according to the guidelines of the European Commission for the following parameters: Matrix effects, specificity, accuracy, precision, linearity, range, and stability. The LOD and LOQ for the 31 triazine herbicides were 0.1-10 μg kg -1 and 0.5-25 μg kg -1 , respectively. Recoveries at three concentration levels were within 67.9-120.3% with an associated precision RSD <20%. Using the proposed approach, trazines herbicides were determined from 44 commercially available TCMs. The detection rate of triazine herbicides residues was 15.9% of the total samples. Among them, atrazine, simeton, and simetryn were found in the radix, herba, and seed TCMs with values far below the referenced maximum residue limits (MRLs), but no residues were detected in either the flos or fructus. Taken together, this method has the potential to provide a means for triazines screening in extensive matrices, thereby laying the foundation for pesticide registration on TCMs. Moreover, it has the potential to guide further triazine residue control in TCMs. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Streamline topology of axisymmetric flows

    DEFF Research Database (Denmark)

    Brøns, Morten

    Topological fluid mechanics in the sense of the present paper is the study and classification of flow patterns close to a critical point. Here we discuss the topology of steady viscous incompressible axisymmetric flows in the vicinity of the axis. Following previous studies the velocity field $v...... to the authors knowledge has not been used systematically to high orders in topological fluid mechanics. We compare the general results with experimental and computational results on the Vogel-Ronneberg flow. We show that the topology changes observed when recirculating bubbles on the vortex axis are created...... and interact follow the topological classification and that the complete set of patterns found is contained in a codimension-4 unfolding of the most simple singular configuration....

  13. Software Tools Streamline Project Management

    Science.gov (United States)

    2009-01-01

    Three innovative software inventions from Ames Research Center (NETMARK, Program Management Tool, and Query-Based Document Management) are finding their way into NASA missions as well as industry applications. The first, NETMARK, is a program that enables integrated searching of data stored in a variety of databases and documents, meaning that users no longer have to look in several places for related information. NETMARK allows users to search and query information across all of these sources in one step. This cross-cutting capability in information analysis has exponentially reduced the amount of time needed to mine data from days or weeks to mere seconds. NETMARK has been used widely throughout NASA, enabling this automatic integration of information across many documents and databases. NASA projects that use NETMARK include the internal reporting system and project performance dashboard, Erasmus, NASA s enterprise management tool, which enhances organizational collaboration and information sharing through document routing and review; the Integrated Financial Management Program; International Space Station Knowledge Management; Mishap and Anomaly Information Reporting System; and management of the Mars Exploration Rovers. Approximately $1 billion worth of NASA s projects are currently managed using Program Management Tool (PMT), which is based on NETMARK. PMT is a comprehensive, Web-enabled application tool used to assist program and project managers within NASA enterprises in monitoring, disseminating, and tracking the progress of program and project milestones and other relevant resources. The PMT consists of an integrated knowledge repository built upon advanced enterprise-wide database integration techniques and the latest Web-enabled technologies. The current system is in a pilot operational mode allowing users to automatically manage, track, define, update, and view customizable milestone objectives and goals. The third software invention, Query-Based Document Management (QBDM) is a tool that enables content or context searches, either simple or hierarchical, across a variety of databases. The system enables users to specify notification subscriptions where they associate "contexts of interest" and "events of interest" to one or more documents or collection(s) of documents. Based on these subscriptions, users receive notification when the events of interest occur within the contexts of interest for associated document or collection(s) of documents. Users can also associate at least one notification time as part of the notification subscription, with at least one option for the time period of notifications.

  14. Streamlining Smart Meter Data Analytics

    OpenAIRE

    Liu, Xiufeng; Nielsen, Per Sieverts

    2015-01-01

    Today smart meters are increasingly used in worldwide. Smart meters are the advanced meters capable of measuring customer energy consumption at a fine-grained time interval, e.g., every 15 minutes. The data are very sizable, and might be from different sources, along with the other social-economic metrics such as the geographic information of meters, the information about users and their property, geographic location and others, which make the data management very complex. On the other hand, ...

  15. Streamlined Approach for Environmental Restoration (SAFER) Plan for Corrective Action Unit 553: Areas 19, 20 Mud Pits and Cellars, Nevada Test Site, Nevada, Rev. No. 0

    International Nuclear Information System (INIS)

    Boehlecke, Robert F.

    2006-01-01

    This Streamlined Approach for Environmental Restoration (SAFER) Plan addresses the actions necessary for the closure of Corrective Action Unit (CAU) 553: Areas 19, 20 Mud Pits and Cellars, Nevada Test Site (NTS), Nevada. It has been developed in accordance with the ''Federal Facility Agreement and Consent Order'' (FFACO) (1996) that was agreed to by the State of Nevada, the U.S. Department of Energy (DOE), and the U.S. Department of Defense. A SAFER may be performed when the following criteria are met: (1) Conceptual corrective actions are clearly identified (although some degree of investigation may be necessary to select a specific corrective action before completion of the Corrective Action Investigation [CAI]); (2) Uncertainty of the nature, extent, and corrective action must be limited to an acceptable level of risk; (3) The SAFER Plan includes decision points and criteria for making data quality objective (DQO) decisions. The purpose of the investigation will be to document and verify the adequacy of existing information; to affirm the decision for clean closure, closure in place, or no further action; and to provide sufficient data to implement the corrective action. The actual corrective action selected will be based on characterization activities implemented under this SAFER Plan. This SAFER Plan identifies decision points developed in cooperation with the Nevada Department of Environmental Protection (NDEP), where the DOE, National Nuclear Security Administration Nevada Site Office (NNSA/NSO) will reach consensus with the NDEP before beginning the next phase of work. Corrective Action Unit 553 is located in Areas 19 and 20 of the NTS, approximately 65 miles (mi) northwest of Las Vegas, Nevada (Figure 1-1). Corrective Action Unit 553 is comprised of the four Corrective Action Sites (CASs) shown on Figure 1-1 and listed below: 19-99-01, Mud Spill; 19-99-11, Mud Spill; 20-09-09, Mud Spill; and 20-99-03, Mud Spill. There is sufficient information and process

  16. A flocking based method for brain tractography.

    Science.gov (United States)

    Aranda, Ramon; Rivera, Mariano; Ramirez-Manzanares, Alonso

    2014-04-01

    We propose a new method to estimate axonal fiber pathways from Multiple Intra-Voxel Diffusion Orientations. Our method uses the multiple local orientation information for leading stochastic walks of particles. These stochastic particles are modeled with mass and thus they are subject to gravitational and inertial forces. As result, we obtain smooth, filtered and compact trajectory bundles. This gravitational interaction can be seen as a flocking behavior among particles that promotes better and robust axon fiber estimations because they use collective information to move. However, the stochastic walks may generate paths with low support (outliers), generally associated to incorrect brain connections. In order to eliminate the outlier pathways, we propose a filtering procedure based on principal component analysis and spectral clustering. The performance of the proposal is evaluated on Multiple Intra-Voxel Diffusion Orientations from two realistic numeric diffusion phantoms and a physical diffusion phantom. Additionally, we qualitatively demonstrate the performance on in vivo human brain data. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Streamlined Approach for Environmental Restoration Work Plan for Corrective Action Unit 461: Joint Test Assembly Sites and Corrective Action Unit 495: Unconfirmed Joint Test Assembly Sites Tonopah Test Range, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Jeff Smith

    1998-08-01

    This Streamlined Approach for Environmental Restoration plan addresses the action necessary for the clean closure of Corrective Action Unit 461 (Test Area Joint Test Assembly Sites) and Corrective Action Unit 495 (Unconfirmed Joint Test Assembly Sites). The Corrective Action Units are located at the Tonopah Test Range in south central Nevada. Closure for these sites will be completed by excavating and evaluating the condition of each artillery round (if found); detonating the rounds (if necessary); excavating the impacted soil and debris; collecting verification samples; backfilling the excavations; disposing of the impacted soil and debris at an approved low-level waste repository at the Nevada Test Site

  18. Streamlined Approach for Environmental Restoration (SAFER) Plan for Corrective Action Unit 539: Area 25 and Area 26 Railroad Tracks, Nevada Test Site, Nevada, Revision 0

    Energy Technology Data Exchange (ETDEWEB)

    Mark Krauss

    2010-06-01

    This Streamlined Approach for Environmental Restoration (SAFER) Plan addresses the actions needed to achieve closure for Corrective Action Unit (CAU) 539, Areas 25 and 26 Railroad Tracks, as identified in the Federal Facility Agreement and Consent Order (FFACO). A modification to the FFACOwas approved in May 2010 to transfer the two Railroad Tracks corrective action sites (CASs) from CAU 114 into CAU539. The two CASs are located in Areas 25 and 26 of the Nevada Test Site: • 25-99-21, Area 25 Railroad Tracks • 26-99-05, Area 26 Railroad Tracks This plan provides the methodology for field activities needed to gather the necessary information for closing the two CASs. There is sufficient information and process knowledge from historical documentation and investigations of similar sites regarding the expected nature and extent of potential contaminants to recommend closure of the CAU 539 Railroad Tracks CASs using the SAFER process. Additional information will be obtained by conducting a field investigation before selecting the appropriate corrective action for each CAS. The results of the field investigation should support a defensible recommendation that no further corrective action is necessary. If it is determined that complete clean closure cannot be accomplished during the SAFER, then a hold point will have been reached and the Nevada Division of Environmental Protection (NDEP) will be consulted to determine whether the remaining contamination will be closed under the alternative corrective action of closure in place with use restrictions. This will be presented in a closure report that will be prepared and submitted to the NDEP for review and approval. The sites will be investigated based on the data quality objectives (DQOs) developed on December 14, 2009, by representatives of U.S.Department of Energy (DOE), National Nuclear Security Administration Nevada Site Office; Navarro Nevada Environmental Services, LLC (NNES); and National Security Technologies

  19. Streamlined Approach for Environmental Restoration (SAFER) Plan for Corrective Action Unit 356: Mud Pits and Disposal Sites, Nevada Test Site, Nevada (Revision No. 0, August 2001); FINAL

    International Nuclear Information System (INIS)

    2001-01-01

    This Streamlined Approach for Environmental Restoration (SAFER) Plan addresses the actions necessary for the characterization and closure of Corrective Action Unit (CAU) 356, Mud Pits and Disposal Sites, as identified in the Federal Facility Agreement and Consent Order (FFACO). The CAU, located on the Nevada Test Site in Nevada, consists of seven Corrective Action Sites (CASs): CAS 03-04-01, Area 3 Change House Septic System; CAS 03-09-01, Mud Pit Spill Over; CAS 03-09-03, Mud Pit; CAS 03-09-04, Mud Pit; CAS 03-09-05, Mud Pit; CAS 20-16-01, Landfill; CAS 20-22-21, Drums. Sufficient information and process knowledge from historical documentation and investigations are the basis for the development of the phased approach chosen to address the data collection activities prior to implementing the preferred closure alternative for each CAS. The Phase I investigation will determine through collection of environmental samples from targeted populations (i.e., mud/soil cuttings above textural discontinuity) if contaminants of potential concern (COPCs) are present in concentrations exceeding preliminary action levels (PALs) at each of the CASs. If COPCs are present above PALs, a Phase II investigation will be implemented to determine the extent of contamination to support the appropriate corrective action alternative to complete closure of the site. Groundwater impacts from potentially migrating contaminants are not expected due to the depths to groundwater and limiting hydrologic drivers of low precipitation and high evaporation rates. Future land-use scenarios limit future uses to industrial activities; therefore, future residential uses are not considered. Potential exposure routes to site workers from contaminants of concern in septage and soils include oral ingestion, inhalation, or dermal contact (absorption) through in-advertent disturbance of contaminated structures and/or soils. Diesel within drilling muds is expected to be the primary COPC based on process

  20. Streamlined Approach for Environmental Restoration (SAFER) Plan for Corrective Action Unit 465: Hydronuclear Nevada National Security Site, Nevada, with ROTC 1, Revision 0

    Energy Technology Data Exchange (ETDEWEB)

    Patrick Matthews

    2011-11-01

    This Streamlined Approach for Environmental Restoration (SAFER) Plan addresses the actions needed to achieve closure for Corrective Action Unit (CAU) 465, Hydronuclear, identified in the Federal Facility Agreement and Consent Order (FFACO). Corrective Action Unit 465 comprises the following four corrective action sites (CASs) located in Areas 6 and 27 of the Nevada National Security Site: (1) 00-23-01, Hydronuclear Experiment; (2) 00-23-02, Hydronuclear Experiment; (3) 00-23-03, Hydronuclear Experiment; (4) 06-99-01, Hydronuclear. The sites will be investigated based on the data quality objectives (DQOs) developed on July 6, 2011, by representatives of the Nevada Division of Environmental Protection (NDEP) and the U.S. Department of Energy (DOE), National Nuclear Security Administration Nevada Site Office. The DQO process was used to identify and define the type, amount, and quality of data needed to determine and implement appropriate corrective actions for each CAS in CAU 465. For CAU 465, two potential release components have been identified. The subsurface release component includes potential releases of radiological and nonradiological contaminants from the subsurface hydronuclear experiments and disposal boreholes. The surface release component consists of other potential releases of radiological and nonradiological contaminants to surface soils that may have occurred during the pre- and post-test activities. This plan provides the methodology for collection of the necessary information for closing each CAS component. There is sufficient information and process knowledge from historical documentation, contaminant characteristics, existing regional and site groundwater models, and investigations of similar sites regarding the expected nature and extent of potential contaminants to recommend closure of CAU 465 using the SAFER process. For potential subsurface releases, flow and transport models will be developed to integrate existing data into a conservative

  1. Streamlined Approach for Environmental Restoration Plan for Corrective Action Unit 116: Area 25 Test Cell C Facility, Nevada Test Site, Nevada, Revision 1

    International Nuclear Information System (INIS)

    2008-01-01

    This Streamlined Approach for Environmental Restoration (SAFER) Plan identifies the activities required for the closure of Corrective Action Unit (CAU) 116, Area 25 Test Cell C Facility. The Test Cell C (TCC) Facility is located in Area 25 of the Nevada Test Site (NTS) approximately 25 miles northwest of Mercury, Nevada (Figure 1). CAU 116 is currently listed in Appendix III of the Federal Facility Agreement and Consent Order (FFACO) of 1996 (as amended February 2008) and consists of two Corrective Action Sites (CASs): (1) CAS 25-23-20, Nuclear Furnace Piping; and (2) CAS 25-41-05, Test Cell C Facility. CAS 25-41-05 is described in the FFACO as the TCC Facility but actually includes Building 3210 and attached concrete shield wall only. CAU 116 will be closed by demolishing Building 3210, the attached concrete shield wall, and the nuclear furnace piping. In addition, as a best management practice (BMP), Building 3211 (moveable shed) will be demolished due to its close proximity to Building 3210. This will aid in demolition and disposal operations. Radiological surveys will be performed on the demolition debris to determine the proper disposal pathway. As much of the demolition debris as space allows will be placed into the Building 3210 basement structure. After filling to capacity with demolition debris, the basement structure will be mounded or capped and closed with administrative controls. Prior to beginning demolition activities and according to an approved Sampling and Analysis Plan (SAP), representative sampling of surface areas that are known, suspected, or have the potential to contain hazardous constituents such as lead or polychlorinated biphenyls (PCBs) will be performed throughout all buildings and structures. Sections 2.3.2, 4.2.2.2, 4.2.2.3, 4.3, and 6.2.6.1 address the methodologies employed that assure the solid debris placed in the basement structure will not contain contaminants of concern (COCs) above hazardous waste levels. The anticipated post

  2. Streamlined Approach for Environmental Restoration (SAFER) Plan for Corrective Action Unit 544: Cellars, Mud Pits, and Oil Spills, Nevada Test Site, Nevada, Revision 0

    Energy Technology Data Exchange (ETDEWEB)

    Mark Krauss

    2010-07-01

    This Streamlined Approach for Environmental Restoration (SAFER) Plan addresses the actions needed to achieve closure for Corrective Action Unit (CAU) 544, Cellars, Mud Pits, and Oil Spills, identified in the Federal Facility Agreement and Consent Order (FFACO). Corrective Action Unit 544 comprises the following 20 corrective action sites (CASs) located in Areas 2, 7, 9, 10, 12, 19, and 20 of the Nevada Test Site (NTS): • 02-37-08, Cellar & Mud Pit • 02-37-09, Cellar & Mud Pit • 07-09-01, Mud Pit • 09-09-46, U-9itsx20 PS #1A Mud Pit • 10-09-01, Mud Pit • 12-09-03, Mud Pit • 19-09-01, Mud Pits (2) • 19-09-03, Mud Pit • 19-09-04, Mud Pit • 19-25-01, Oil Spill • 19-99-06, Waste Spill • 20-09-01, Mud Pits (2) • 20-09-02, Mud Pit • 20-09-03, Mud Pit • 20-09-04, Mud Pits (2) • 20-09-06, Mud Pit • 20-09-07, Mud Pit • 20-09-10, Mud Pit • 20-25-04, Oil Spills • 20-25-05, Oil Spills This plan provides the methodology for field activities needed to gather the necessary information for closing each CAS. There is sufficient information and process knowledge from historical documentation and investigations of similar sites regarding the expected nature and extent of potential contaminants to recommend closure of CAU 544 using the SAFER process. Using the approach approved for previous mud pit investigations (CAUs 530–535), 14 mud pits have been identified that • are either a single mud pit or a system of mud pits, • are not located in a radiologically posted area, and • have no evident biasing factors based on visual inspections. These 14 mud pits are recommended for no further action (NFA), and further field investigations will not be conducted. For the sites that do not meet the previously approved closure criteria, additional information will be obtained by conducting a field investigation before selecting the appropriate corrective action for each CAS. The results of the field investigation will support a defensible

  3. Addressing the path-length-dependency confound in white matter tract segmentation

    DEFF Research Database (Denmark)

    Liptrot, Matthew George; Sidaros, Karam; Dyrby, Tim B.

    2014-01-01

    of streamlines emitted per voxel, and a threshold applied at each iteration. As few as 20 streamlines per seed-voxel, and a robust range of ICE-T thresholds, were shown to sufficiently segment the desired tract network. Outside this range, the tract network either approximated the complete white-matter...... complexity, and therefore cannot be handled using linear correction methods. ICE-T is an easy-to-implement framework that acts as a wrapper around most probabilistic streamline tractography methods, iteratively growing the tractography seed regions. Tract networks segmented with ICE-T can subsequently...... consider this or a similar approach when using tractography to provide tract segmentations for tract based analysis, or for brain network analysis....

  4. Smart management of sample dilution using an artificial neural network to achieve streamlined processes and saving resources: the automated nephelometric testing of serum free light chain as case study.

    Science.gov (United States)

    Ialongo, Cristiano; Pieri, Massimo; Bernardini, Sergio

    2017-02-01

    Saving resources is a paramount issue for the modern laboratory, and new trainable as well as smart technologies can be used to allow the automated instrumentation to manage samples more efficiently in order to achieve streamlined processes. In this regard the serum free light chain (sFLC) testing represents an interesting challenge, as it usually causes using a number of assays before achieving an acceptable result within the analytical range. An artificial neural network based on the multi-layer perceptron (MLP-ANN) was used to infer the starting dilution status of sFLC samples based on the information available through the laboratory information system (LIS). After the learning phase, the MLP-ANN simulation was applied to the nephelometric testing routinely performed in our laboratory on a BN ProSpec® System analyzer (Siemens Helathcare) using the N Latex FLC kit. The MLP-ANN reduced the serum kappa free light chain (κ-FLC) and serum lambda free light chain (λ-FLC) wasted tests by 69.4% and 70.8% with respect to the naïve stepwise dilution scheme used by the automated analyzer, and by 64.9% and 66.9% compared to a "rational" dilution scheme based on a 4-step dilution. Although it was restricted to follow-up samples, the MLP-ANN showed good predictive performance, which alongside the possibility to implement it in any automated system, made it a suitable solution for achieving streamlined laboratory processes and saving resources.

  5. Establishment of expanded and streamlined pipeline of PITCh knock-in - a web-based design tool for MMEJ-mediated gene knock-in, PITCh designer, and the variations of PITCh, PITCh-TG and PITCh-KIKO.

    Science.gov (United States)

    Nakamae, Kazuki; Nishimura, Yuki; Takenaga, Mitsumasa; Nakade, Shota; Sakamoto, Naoaki; Ide, Hiroshi; Sakuma, Tetsushi; Yamamoto, Takashi

    2017-05-04

    The emerging genome editing technology has enabled the creation of gene knock-in cells easily, efficiently, and rapidly, which has dramatically accelerated research in the field of mammalian functional genomics, including in humans. We recently developed a microhomology-mediated end-joining-based gene knock-in method, termed the PITCh system, and presented various examples of its application. Since the PITCh system only requires very short microhomologies (up to 40 bp) and single-guide RNA target sites on the donor vector, the targeting construct can be rapidly prepared compared with the conventional targeting vector for homologous recombination-based knock-in. Here, we established a streamlined pipeline to design and perform PITCh knock-in to further expand the availability of this method by creating web-based design software, PITCh designer ( http://www.mls.sci.hiroshima-u.ac.jp/smg/PITChdesigner/index.html ), as well as presenting an experimental example of versatile gene cassette knock-in. PITCh designer can automatically design not only the appropriate microhomologies but also the primers to construct locus-specific donor vectors for PITCh knock-in. By using our newly established pipeline, a reporter cell line for monitoring endogenous gene expression, and transgenesis (TG) or knock-in/knockout (KIKO) cell line can be produced systematically. Using these new variations of PITCh, an exogenous promoter-driven gene cassette expressing fluorescent protein gene and drug resistance gene can be integrated into a safe harbor or a specific gene locus to create transgenic reporter cells (PITCh-TG) or knockout cells with reporter knock-in (PITCh-KIKO), respectively.

  6. Establishment of expanded and streamlined pipeline of PITCh knock-in – a web-based design tool for MMEJ-mediated gene knock-in, PITCh designer, and the variations of PITCh, PITCh-TG and PITCh-KIKO

    Science.gov (United States)

    Nakamae, Kazuki; Nishimura, Yuki; Takenaga, Mitsumasa; Sakamoto, Naoaki; Ide, Hiroshi; Sakuma, Tetsushi; Yamamoto, Takashi

    2017-01-01

    ABSTRACT The emerging genome editing technology has enabled the creation of gene knock-in cells easily, efficiently, and rapidly, which has dramatically accelerated research in the field of mammalian functional genomics, including in humans. We recently developed a microhomology-mediated end-joining-based gene knock-in method, termed the PITCh system, and presented various examples of its application. Since the PITCh system only requires very short microhomologies (up to 40 bp) and single-guide RNA target sites on the donor vector, the targeting construct can be rapidly prepared compared with the conventional targeting vector for homologous recombination-based knock-in. Here, we established a streamlined pipeline to design and perform PITCh knock-in to further expand the availability of this method by creating web-based design software, PITCh designer (http://www.mls.sci.hiroshima-u.ac.jp/smg/PITChdesigner/index.html), as well as presenting an experimental example of versatile gene cassette knock-in. PITCh designer can automatically design not only the appropriate microhomologies but also the primers to construct locus-specific donor vectors for PITCh knock-in. By using our newly established pipeline, a reporter cell line for monitoring endogenous gene expression, and transgenesis (TG) or knock-in/knockout (KIKO) cell line can be produced systematically. Using these new variations of PITCh, an exogenous promoter-driven gene cassette expressing fluorescent protein gene and drug resistance gene can be integrated into a safe harbor or a specific gene locus to create transgenic reporter cells (PITCh-TG) or knockout cells with reporter knock-in (PITCh-KIKO), respectively. PMID:28453368

  7. Streamlining of plant patches in streams

    DEFF Research Database (Denmark)

    Jensen, Kaj Sand; Pedersen, Morten Lauge

    2008-01-01

    . Sediment elevation within patches (avg. 4.1 cm) increased significantly with patch length, but did not differ between unstable sand or more stable coarse sediment for the same patch length. Shape of canopy and root area did not change significantly with sediment type. 4. Pressure drag on the canopy...

  8. Streamline Your Project: A Lifecycle Model.

    Science.gov (United States)

    Viren, John

    2000-01-01

    Discusses one approach to project organization providing a baseline lifecycle model for multimedia/CBT development. This variation of the standard four-phase model of Analysis, Design, Development, and Implementation includes a Pre-Analysis phase, called Definition, and a Post-Implementation phase, known as Maintenance. Each phase is described.…

  9. Gust loading on streamlined bridge decks

    DEFF Research Database (Denmark)

    Larose, Guy; Mann, Jakob

    1998-01-01

    The current analytical description of the buffeting action of wind on long-span bridges is based on the strip assumption. However, recent experiments on closed-box girder bridge decks have shown that this assumption is not valid and is the source of an important part of the error margin...... of the analytical prediction methods. In this paper, an analytical model that departs from the strip assumption is used to describe the gust loading on a thin airfoil. A parallel is drawn between the analytical model and direct measurements of gust loading on motionless closed-box girder bridge decks. Empirical...

  10. Environmental protection: Streamlining petroleum exploration and production

    International Nuclear Information System (INIS)

    Hunt, A.M.

    1991-01-01

    The petroleum industry is inherently subject to a tremendous degree of volatility through fluctuation in world market prices and vagaries of world politics. A more recent stressful demand on the existing domestic petroleum exploration and production system has been the burgeoning number of environmental regulations imposed on this segment of the industry. Prudent and acceptable oil-field practices must now include agency-regulated environmental protection measures. Many independent producers are unfamiliar not only with the regulatory agencies, but also with the jargon and ambiguities, of regulations that very widely from state to state. Whereas some companies perceive only the restrictions and added cost of regulatory compliance, other companies have sought to optimize benefits while minimizing financial burdens by approaching this modern necessity more creatively, thereby discovering numerous means to become even more competitive. The domestic oil field of the 1990s will be increasingly affected by environmental regulation and public opinion. A number of companies have taken a proactive position on environmental issues. Industry examples include Louisiana Land and Exploration Company's history of wetlands conservation and Chevron's SMART (Save Money and Reduce Toxics). The future of the quality of life of this nation, and indeed the planet as a whole, lies in our capability to deal concurrently with the issues of a petroleum-based economy while protecting the natural environment that sustains life

  11. Streamlining Compliance Validation Through Automation Processes

    Science.gov (United States)

    2014-03-01

    INTENTIONALLY LEFT BLANK xv LIST OF ACRONYMS AND ABBREVIATIONS ACAS Assured Compliance Assessment Suite AMP Apache- MySQL -PHP ANSI American...enemy. Of course , a common standard for DoD security personnel to write and share compliance validation content would prevent duplicate work and aid in...process and consume much of the SCAP content available. Finally, it is free and easy to install as part of the Apache/ MySQL /PHP (AMP) [37

  12. Streamlined project closeout for construction at KYTC.

    Science.gov (United States)

    2017-09-01

    Project closeout is the period between the end of construction and when a contract is finalized. During closeout, resources are held in encumbered funds intended for the project and in the contractors bonding capacity. Although the Kentucky Transp...

  13. Streamlining geospatial metadata in the Semantic Web

    Science.gov (United States)

    Fugazza, Cristiano; Pepe, Monica; Oggioni, Alessandro; Tagliolato, Paolo; Carrara, Paola

    2016-04-01

    In the geospatial realm, data annotation and discovery rely on a number of ad-hoc formats and protocols. These have been created to enable domain-specific use cases generalized search is not feasible for. Metadata are at the heart of the discovery process and nevertheless they are often neglected or encoded in formats that either are not aimed at efficient retrieval of resources or are plainly outdated. Particularly, the quantum leap represented by the Linked Open Data (LOD) movement did not induce so far a consistent, interlinked baseline in the geospatial domain. In a nutshell, datasets, scientific literature related to them, and ultimately the researchers behind these products are only loosely connected; the corresponding metadata intelligible only to humans, duplicated on different systems, seldom consistently. Instead, our workflow for metadata management envisages i) editing via customizable web- based forms, ii) encoding of records in any XML application profile, iii) translation into RDF (involving the semantic lift of metadata records), and finally iv) storage of the metadata as RDF and back-translation into the original XML format with added semantics-aware features. Phase iii) hinges on relating resource metadata to RDF data structures that represent keywords from code lists and controlled vocabularies, toponyms, researchers, institutes, and virtually any description one can retrieve (or directly publish) in the LOD Cloud. In the context of a distributed Spatial Data Infrastructure (SDI) built on free and open-source software, we detail phases iii) and iv) of our workflow for the semantics-aware management of geospatial metadata.

  14. How streamlining telecommunications can cut IT expense.

    Science.gov (United States)

    McIntyre, Greg

    2016-02-01

    Hospitals and health systems can save IT expenses by implementing more efficient processes in accordance with the principles of effective telecommunications expense management. This approach involves three primary steps: Inventory of existing infrastructure. Charge verification. Optimization of rates and design for continual improvement.

  15. Streamlining Education System Through Waqf Enlargement

    Directory of Open Access Journals (Sweden)

    Imam Bahroni

    2016-06-01

    Full Text Available This paper is aimed at discussing the development of education systembased on the Waqf Empowerment. It is an experience of Gontor ModernIntegrated Islamic Institution to maintain its existence through the activitiesof Waqf Enlargement. The spirit of self-reliance which has been implementedby Gontor through various economic enterprise activities inside the campus isthe total processes of educational activities, carried out by students andteachers themselves. They act as the subjects and objects of the education atthe same time. They teach themselves through various activities, creativitiesand social interaction for their character and personality building. Thislearning process is purposely undertaken in Gontor, because the basicprinciple of this system is to actualize the community orientation throughwhich the students in the campus guided and prepared to have a spirit ofself reliance. So when they back to the society to undertake the real life theyconfidently take their role to develop their society for the sake of Allah andunity of muslim ummah.

  16. Streamlining Field Data Collection With Mobile Apps

    Science.gov (United States)

    Camp, Reid J.; Wheaton, Joseph M.

    2014-12-01

    Fieldwork is a major component of nearly every geoscience discipline. Over the past 3 decades, scientists have amassed an array of specialized instrumentation and equipment to help them measure and monitor a staggering assortment of geophysical phenomena.

  17. Streamlined Darwin methods for particle beam injectors

    International Nuclear Information System (INIS)

    Boyd, J.K.

    1987-01-01

    Physics issues that involve inductive effects, such as beam fluctuations, electromagnetic (EM) instability, or interactions with a cavity require a time-dependent simulation. The most elaborate time-dependent codes self-consistently solve Maxwell's equations and the force equation for a large number of macroparticles. Although these full EM particle-in-cell (PIC) codes have been used to study a broad range of phenomena, including beam injectors, they have several drawbacks. In an explicit solution of Maxwell's equations, the time step is restricted by a Courant condition. A second disadvantage is the production of anomalously large numerical fluctuations, caused by representing many real particles by a single computational macroparticle. Last, approximate models of internal boundaries can create nonphysical radiation in a full EM simulation. In this work, many of the problems of a fully electromagnetic simulation are avoided by using the Darwin field model. The Darwin field model is the magnetoinductive limit of Maxwell's equations, and it retains the first-order relativistic correction to the particle Lagrangian. It includes the part of the displacement current necessary to satisfy the charge-continuity equation. This feature is important for simulation of nonneutral beams. Because the Darwin model does not include the solenoidal vector component of the displacement current, it cannot be used to study high-frequency phenomena or effects caused by rapid current changes. However, because wave motion is not followed, the Courant condition of a fully electromagnetic code can be exceeded. In addition, inductive effects are modeled without creating nonphysical radiation

  18. Streamlined Darwin simulation of nonneutral plasmas

    International Nuclear Information System (INIS)

    Hewett, D.W.; Boyd, J.K.

    1987-01-01

    Efficient, new algorithms that require less formal manipulation than previous implementations have been formulated for the numerical solution of the Darwin model. These new procedures reduce the effort required to achieve some of the advantages that the Darwin model offers. Because the Courant--Friedrichs--Lewy stability limit for radiation modes is eliminated, the Darwin model has the advantage of a substantially larger time-step. Further, without radiation modes, simulation results are less sensitive to enhanced particle fluctation noise. We discuss methods for calculating the magnetic field that avoid formal vector decomposition and offer a new procedure for finding the inductive electric field. This procedure avoids vector decomposition of plasma source terms and circumvents some source gradient issues that slow convergence. As a consequence, the numerical effort required for each of the field time-steps is reduced, and more importantly, the need to specify several nonintuitive boundary conditions is eliminated. copyright 1987 Academic Press, Inc

  19. Mobile technology: streamlining practice and improving care

    OpenAIRE

    Blake, Holly

    2013-01-01

    The use of mobile phones in care delivery has the potential to improve the way in which care is delivered. When implemented effectively, mobile technologies can empower patients and enhance communication between patients and their health-care providers. When barriers are recognised and addressed, mobile technologies can change working lives, facilitating rapid access to information and supporting efficiency in practice.

  20. Assessing Contractor Capabilities for Streamlined Site Investigations

    Science.gov (United States)

    The purpose of this document is to familiarize and encourage brownfields decision makers to investigate and employ innovative methods for characterizing their sites, to assist brownfields decision makers in assessing contractors' capabilities.

  1. 76 FR 75825 - Streamlining Inherited Regulations

    Science.gov (United States)

    2011-12-05

    ... easier. DATES: Comments must be submitted by March 5, 2012. Commenters will have 30 additional days... 1700 G Street NW., Washington, DC 20006, on official business days between the hours of 10 a.m. and 5 p... deadline for most of these rules. At the same time, the Bureau wants to start reviewing the inherited...

  2. Reliability centered maintenance streamlining through lessons learned

    International Nuclear Information System (INIS)

    Strong, D.K.

    1991-01-01

    In late 1986, PSE and G concluded that the Nuclear Department would develop a consistent approach to maintenance at Artificial Island (Salem and Hope Creak nuclear units). Preventive maintenance (PM) would be the heart of this approach. In the last six months of 1987 departments affected by the maintenance program participated on working groups that developed the Artificial Island maintenance philosophy. The central theme of the maintenance philosophy is the RCM (reliability centered maintenance) process. A pilot project tested the process in 1988. In 1989 the Central PM Group formed and in 1990 was given responsibility and authority to analyze, approve, implement, and control PM program changes. RCM is the central theme of the PM improvement effort but not the whole effort. Other important pieces included in this paper are: development of a common PM program, improvement of work instructions, development of predictive maintenance techniques into programs, development of a PM basis database, development of PM feedback from failure trends, root cause analysis, maintenance performance indicators, technicians, and engineers

  3. Hydrodynamic Drag on Streamlined Projectiles and Cavities

    KAUST Repository

    Jetly, Aditya

    2016-01-01

    The air cavity formation resulting from the water-entry of solid objects has been the subject of extensive research due to its application in various fields such as biology, marine vehicles, sports and oil and gas industries. Recently we

  4. Streamlining the path from physics to medicine

    CERN Multimedia

    2013-01-01

    We all know them: the well-established cases of knowledge transfer from physics to medicine in which CERN has played an important role. From technology for PET scanners to dedicated accelerator designs for cancer therapy, we have contributed a lot over the years. But until recently, the pathway has been a little ad hoc, depending largely on enthusiastic individuals. That’s about to change.   CERN’s commitment to formalising the transfer of knowledge to the field of medicine has been growing over recent years. Notable successes are the establishment of a new conference series, ICTR-PHE, that brings together medical practitioners and members of the physics community, and the establishment of cancer therapy centres like CNAO in Italy and MedAustron in Austria, built on CERN accelerator technology. These are important, but there’s still more that we can and should do. To this end, we’ve created a new Office for CERN Medical Applications, whose first head w...

  5. Streamlining Policy Creation in Policy Frameworks

    NARCIS (Netherlands)

    M.A. Hills (Mark); N. Martí-Oliet; M. Palomino

    2012-01-01

    textabstract{\\it Policy frameworks} provide a technique for improving reuse in program analysis: the same language frontend, and a core analysis semantics, can be shared among multiple analysis policies for the same language, while analysis domains (such as units of measurement) can be shared among

  6. Streamlining project delivery through risk analysis.

    Science.gov (United States)

    2015-08-01

    Project delivery is a significant area of concern and is subject to several risks throughout Plan Development : Process (PDP). These risks are attributed to major areas of project development, such as environmental : analysis, right-of-way (ROW) acqu...

  7. Optimal Parameter Updating in Assisted History Matching Using Streamlines as a Guide Mise à jour optimale des paramètres dans un processus de calage d’historique en s’aidant des lignes de courants

    Directory of Open Access Journals (Sweden)

    Kazemi A.

    2013-05-01

    Full Text Available It is becoming more and more common to use assisted history matching methods to find different combinations of reservoir simulation models that agree with production data. Models with a large number of cells contain millions of unknown parameters and selecting the correct property values can be difficult. In practice, not all are important but finding which parts of the reservoir require updating is a challenge. In this work, we investigate methods of history matching by focusing on sub-sets of the full array model parameters and we use streamlines to help us choose where the model requires change. We identify localities in the reservoir that affect particular wells and we update reservoir properties (net:gross and permeability within. We control changes using the pilot point method combined with a Neighbourhood Algorithm. We apply these approaches to the Nelson field (North Sea, UK where uncertainty of the shale distribution controls predictions. The field is divided into localities based on the performance of the worst well predictions. We history match to improve production rates. The localities that require change are sufficiently separate that we can modify them one at a time. We also compare our result with a more ad hoc approach where the whole area around the well is modified. We find that, for the wells of interest, the streamline guided approach gives a 70% improvement in the history match from our starting model and around 40% reduction of misfit in prediction. This improvement is twice that of modifying the properties all around the well. L’utilisation de méthodes de calage d’historique assisté est de plus en plus fréquente pour déterminer différentes combinaisons de modèles de réservoir reproduisant les données de production. Les modèles comprenant un grand nombre de cellules contiennent des millions de paramètres inconnus, et leur attribuer des valeurs appropriées peut s’avérer difficile. En pratique, tous les

  8. Diffusion Tensor Tractography Reveals Disrupted Structural Connectivity during Brain Aging

    Science.gov (United States)

    Lin, Lan; Tian, Miao; Wang, Qi; Wu, Shuicai

    2017-10-01

    Brain aging is one of the most crucial biological processes that entail many physical, biological, chemical, and psychological changes, and also a major risk factor for most common neurodegenerative diseases. To improve the quality of life for the elderly, it is important to understand how the brain is changed during the normal aging process. We compared diffusion tensor imaging (DTI)-based brain networks in a cohort of 75 healthy old subjects by using graph theory metrics to describe the anatomical networks and connectivity patterns, and network-based statistic (NBS) analysis was used to identify pairs of regions with altered structural connectivity. The NBS analysis revealed a significant network comprising nine distinct fiber bundles linking 10 different brain regions showed altered white matter structures in young-old group compare with middle-aged group (p < .05, family-wise error-corrected). Our results might guide future studies and help to gain a better understanding of brain aging.

  9. A Random Riemannian Metric for Probabilistic Shortest-Path Tractography

    DEFF Research Database (Denmark)

    Hauberg, Søren; Schober, Michael; Liptrot, Matthew George

    2015-01-01

    of the diffusion tensor as a “random Riemannian metric”, where a geodesic is a distribution over tracts. We approximate this distribution with a Gaussian process and present a probabilistic numerics algorithm for computing the geodesic distribution. We demonstrate SPT improvements on data from the Human Connectome...

  10. Tractography segmentation using a hierarchical Dirichlet processes mixture model.

    Science.gov (United States)

    Wang, Xiaogang; Grimson, W Eric L; Westin, Carl-Fredrik

    2011-01-01

    In this paper, we propose a new nonparametric Bayesian framework to cluster white matter fiber tracts into bundles using a hierarchical Dirichlet processes mixture (HDPM) model. The number of clusters is automatically learned driven by data with a Dirichlet process (DP) prior instead of being manually specified. After the models of bundles have been learned from training data without supervision, they can be used as priors to cluster/classify fibers of new subjects for comparison across subjects. When clustering fibers of new subjects, new clusters can be created for structures not observed in the training data. Our approach does not require computing pairwise distances between fibers and can cluster a huge set of fibers across multiple subjects. We present results on several data sets, the largest of which has more than 120,000 fibers. Copyright © 2010 Elsevier Inc. All rights reserved.

  11. Intraoperative tractography and neuronavigation of the pyramidal tract

    International Nuclear Information System (INIS)

    Nimsky, C.; Ganslandt, O.; Weigel, D.; Keller, B. von; Stadlbauer, A.; Akutsu, H.; Hammen, T.; Buchfelder, M.

    2008-01-01

    Diffusion tensor imaging (DTI) based fiber tracking was applied to visualize the course of the pyramidal tract in the surgical field by microscope-based navigation. In 70 patients with lesions adjacent to the pyramidal tract, DTI data were integrated in a navigational setup. Diffusion data (b=0) were rigidly registered with standard T1-weighted 3-D images. Fiber tracking was performed applying a tensor-deflection algorithm using a multiple volume of interest approach as seed regions for tracking. fMRI data identifying the motor gyrus were applied as selection criteria to define the fibers of interest. After tracking, a 3-D object was generated representing the pyramidal tract. In selected cases, the intraoperative image data (1.5 T intraoperative MRI) were used to update the navigation system. In all patients the pyramidal tract could be visualized in the operative field applying the heads-up display of the operating microscope. In 8 patients (11%) a new or aggravated postoperative paresis could be observed, which was transient in 5 of them; thus, only in 3 patients (4.2%) was there a new permanent neurological deficit. Intraoperative imaging depicted a shifting of the pyramidal tract which amounted up to 15 mm; even the direction of shifting was variable and could not be predicted before surgery, so that mathematical models trying to predict brain shift behaviour are of restricted value only. DTI fiber tracking data can be reliably integrated into navigational systems providing intraoperative visualization of the pyramidal tract. This technique allowed the resection of lesions adjacent to the pyramidal tract with low morbidity. (author)

  12. Tractography-based Parcellation of the Human Middle Temporal Gyrus

    Science.gov (United States)

    Xu, Jinping; Wang, Jiaojian; Fan, Lingzhong; Li, Hai; Zhang, Wen; Hu, Qingmao; Jiang, Tianzi

    2015-01-01

    The middle temporal gyrus (MTG) participates in a variety of functions, suggesting the existence of distinct functional subregions. In order to further delineate the functions of this brain area, we parcellated the MTG based on its distinct anatomical connectivity profiles and identified four distinct subregions, including the anterior (aMTG), middle (mMTG), posterior (pMTG), and sulcus (sMTG). Both the anatomical connectivity patterns and the resting-state functional connectivity patterns revealed distinct connectivity profiles for each subregion. The aMTG was primarily involved in the default mode network, sound recognition, and semantic retrieval. The mMTG was predominantly involved in the semantic memory and semantic control networks. The pMTG seems to be a part of the traditional sensory language area. The sMTG appears to be associated with decoding gaze direction and intelligible speech. Interestingly, the functional connectivity with Brodmann’s Area (BA) 40, BA 44, and BA 45 gradually increased from the anterior to the posterior MTG, a finding which indicated functional topographical organization as well as implying that language processing is functionally segregated in the MTG. These proposed subdivisions of the MTG and its functions contribute to understanding the complex functions of the MTG at the subregional level. PMID:26689815

  13. Mapping topographic structure in white matter pathways with level set trees.

    Directory of Open Access Journals (Sweden)

    Brian P Kent

    Full Text Available Fiber tractography on diffusion imaging data offers rich potential for describing white matter pathways in the human brain, but characterizing the spatial organization in these large and complex data sets remains a challenge. We show that level set trees--which provide a concise representation of the hierarchical mode structure of probability density functions--offer a statistically-principled framework for visualizing and analyzing topography in fiber streamlines. Using diffusion spectrum imaging data collected on neurologically healthy controls (N = 30, we mapped white matter pathways from the cortex into the striatum using a deterministic tractography algorithm that estimates fiber bundles as dimensionless streamlines. Level set trees were used for interactive exploration of patterns in the endpoint distributions of the mapped fiber pathways and an efficient segmentation of the pathways that had empirical accuracy comparable to standard nonparametric clustering techniques. We show that level set trees can also be generalized to model pseudo-density functions in order to analyze a broader array of data types, including entire fiber streamlines. Finally, resampling methods show the reliability of the level set tree as a descriptive measure of topographic structure, illustrating its potential as a statistical descriptor in brain imaging analysis. These results highlight the broad applicability of level set trees for visualizing and analyzing high-dimensional data like fiber tractography output.

  14. Sensitivity analysis of human brain structural network construction

    Directory of Open Access Journals (Sweden)

    Kuang Wei

    2017-12-01

    Full Text Available Network neuroscience leverages diffusion-weighted magnetic resonance imaging and tractography to quantify structural connectivity of the human brain. However, scientists and practitioners lack a clear understanding of the effects of varying tractography parameters on the constructed structural networks. With diffusion images from the Human Connectome Project (HCP, we characterize how structural networks are impacted by the spatial resolution of brain atlases, total number of tractography streamlines, and grey matter dilation with various graph metrics. We demonstrate how injudicious combinations of highly refined brain parcellations and low numbers of streamlines may inadvertently lead to disconnected network models with isolated nodes. Furthermore, we provide solutions to significantly reduce the likelihood of generating disconnected networks. In addition, for different tractography parameters, we investigate the distributions of values taken by various graph metrics across the population of HCP subjects. Analyzing the ranks of individual subjects within the graph metric distributions, we find that the ranks of individuals are affected differently by atlas scale changes. Our work serves as a guideline for researchers to optimize the selection of tractography parameters and illustrates how biological characteristics of the brain derived in network neuroscience studies can be affected by the choice of atlas parcellation schemes. Diffusion tractography has been proven to be a promising noninvasive technique to study the network properties of the human brain. However, how various tractography and network construction parameters affect network properties has not been studied using a large cohort of high-quality data. We utilize data provided by the Human Connectome Project to characterize the changes to network properties induced by varying the brain parcellation atlas scales, the number of reconstructed tractography tracks, and the degree of grey

  15. Effectiveness of the Community Treatment Order in streamlining psychiatric services.

    Science.gov (United States)

    Awara, Mahmoud A; Jaffar, Khalid; Roberts, Pauline

    2013-04-01

    The implementation of the Community Treatment Order (CTO) has created controversy surrounding its beneficence. The study aims at examining the effectiveness of the CTO in reducing the rate and duration of revolving door admissions for patients who were made subject to this Order. All patients who were made subject to CTO between November 2008 and August 2009 in South Essex were involved in the study where patients acted as their own control through comparing their pre-CTO, during CTO and post-CTO's admission rate and duration. There was a significant reduction in the rate and duration of admissions in the period during and post-CTO state. The CTO proved to be effective in reducing revolving door admissions and it has a beneficial carryover effect in the post-CTO state.

  16. Streamlined approach to mapping the magnetic induction of skyrmionic materials

    International Nuclear Information System (INIS)

    Chess, Jordan J.; Montoya, Sergio A.; Harvey, Tyler R.; Ophus, Colin; Couture, Simon; Lomakin, Vitaliy; Fullerton, Eric E.; McMorran, Benjamin J.

    2017-01-01

    Highlights: • A method to reconstruction the phase of electrons after pasting though a sample that requires a single defocused image is presented. • Restrictions as to when it is appropriate to apply this method are described. • The relative error associated with this method is compared to conventional transport of intensity equation analysis. - Abstract: Recently, Lorentz transmission electron microscopy (LTEM) has helped researchers advance the emerging field of magnetic skyrmions. These magnetic quasi-particles, composed of topologically non-trivial magnetization textures, have a large potential for application as information carriers in low-power memory and logic devices. LTEM is one of a very few techniques for direct, real-space imaging of magnetic features at the nanoscale. For Fresnel-contrast LTEM, the transport of intensity equation (TIE) is the tool of choice for quantitative reconstruction of the local magnetic induction through the sample thickness. Typically, this analysis requires collection of at least three images. Here, we show that for uniform, thin, magnetic films, which includes many skyrmionic samples, the magnetic induction can be quantitatively determined from a single defocused image using a simplified TIE approach.

  17. Streamlined Calibration of the ATLAS Muon Spectrometer Precision Chambers

    CERN Document Server

    Levin, DS; The ATLAS collaboration; Dai, T; Diehl, EB; Ferretti, C; Hindes, JM; Zhou, B

    2009-01-01

    The ATLAS Muon Spectrometer is comprised of nearly 1200 optically Monitored Drifttube Chambers (MDTs) containing 354,000 aluminum drift tubes. The chambers are configured in barrel and endcap regions. The momentum resolution required for the LHC physics reach (dp/p = 3% and 10% at 100 GeV and 1 TeV) demands rigorous MDT drift tube calibration with frequent updates. These calibrations (RT functions) convert the measured drift times to drift radii and are a critical component to the spectrometer performance. They are sensitive to the MDT gas composition: Ar 93%, CO2 7% at 3 bar, flowing through the detector at arate of 100,000 l hr−1. We report on the generation and application of Universal RT calibrations derived from an inline gas system monitor chamber. Results from ATLAS cosmic ray commissioning data are included. These Universal RTs are intended for muon track reconstuction in LHC startup phase.

  18. Unexpectedly Streamlined Mitochondrial Genome of the Euglenozoan Euglena gracilis

    Czech Academy of Sciences Publication Activity Database

    Dobáková, Eva; Flegontov, Pavel; Skalický, Tomáš; Lukeš, Julius

    2015-01-01

    Roč. 7, č. 12 (2015), s. 3358-3367 ISSN 1759-6653 R&D Projects: GA ČR GA15-21974S Institutional support: RVO:60077344 Keywords : Euglena gracilis * mitochondrial genome * transcription * RNA editing Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.098, year: 2015

  19. General Services Administration Streamlines the Procurement of Construction Services

    Science.gov (United States)

    2010-05-01

    successful. The system must be changed to increase performance, and have a sustainable performance measurement system that results in an increase...currently employ, and what is needed to employ a sustainable performance measurement system that has accompanying increase in performance and value

  20. Aligning BIM with FM: streamlining the process for future projects

    Directory of Open Access Journals (Sweden)

    Colleen Kasprzak

    2012-12-01

    Full Text Available A study performed by the National Institute of Standards and Technology (NIST, USA in 2004 found that owners account for approximately $10.6 billion of the $15.8 billion total inadequate interoperability costs of U.S. capital facility projects in 2002. Because of these inefficiency costs, it becomes vital that information produced during the design and construction phases of a project be transferred into operations with maximum leverage to the end users. However, very few owners have defined these informational needs or developed an integration strategy into existing maintenance management systems. To increase operational efficiency, an organization must first develop an understanding of their operating systems, as well as identify how Building Information Modeling (BIM will add value to their daily tasks. The Pennsylvania State University (PSU has a unique opportunity to diversely implement BIM processes because not only does the University act as an owner, but also as designer and construction manager on the majority of projects. The struggle that PSU faces is one that is unique only to owners with a large, existing, multifaceted building inventory. This paper outlines the current initiative by the Office of Physical Plant (OPP, the asset manager at PSU, to develop an information exchange framework between BIM and FM applications to be used internally. As a result of this research, PSU has been able to define owner operational requirements for future projects and develop a flexible integration framework to support additional BIM tasks and information exchanges.

  1. Streamlining the Process of Acquiring Secure Open Architecture Software Systems

    Science.gov (United States)

    2013-10-08

    Microsoft.NET, Enterprise Java Beans, GNU Lesser General Public License (LGPL) libraries, and data communication protocols like the Hypertext Transfer...NetBeans development environments),  customer relationship management (SugarCRM),  database management systems (PostgreSQL, MySQL ),  operating

  2. Streamlining CASTOR to manage the LHC data torrent

    International Nuclear Information System (INIS)

    Presti, G Lo; Curull, X Espinal; Cano, E; Fiorini, B; Ieri, A; Murray, S; Ponce, S; Sindrilaru, E

    2014-01-01

    This contribution describes the evolution of the main CERN storage system, CASTOR, as it manages the bulk data stream of the LHC and other CERN experiments, achieving over 90 PB of stored data by the end of LHC Run 1. This evolution was marked by the introduction of policies to optimize the tape sub-system throughput, going towards a cold storage system where data placement is managed by the experiments' production managers. More efficient tape migrations and recalls have been implemented and deployed where bulk meta-data operations greatly reduce the overhead due to small files. A repack facility is now integrated in the system and it has been enhanced in order to automate the repacking of several tens of petabytes, required in 2014 in order to prepare for the next LHC run. Finally the scheduling system has been evolved to integrate the internal monitoring. To efficiently manage the service a solid monitoring infrastructure is required, able to analyze the logs produced by the different components (about 1 kHz of log messages). A new system has been developed and deployed, which uses a transport messaging layer provided by the CERN-IT Agile Infrastructure and exploits technologies including Hadoop and HBase. This enables efficient data mining by making use of MapReduce techniques, and real-time data aggregation and visualization. The outlook for the future is also presented. Directions and possible evolution will be discussed in view of the restart of data taking activities.

  3. Streamlining Transportation Corridor Planning Processess: Freight and Traffic Information

    Energy Technology Data Exchange (ETDEWEB)

    Franzese, Oscar [ORNL

    2010-08-01

    The traffic investigation is one of the most important parts of an Environmental Impact Statement of projects involving the construction of new roadway facilities and/or the improvement of existing ones. The focus of the traffic analysis is on the determination of anticipated traffic flow characteristics of the proposed project, by the application of analytical methods that can be grouped under the umbrella of capacity analysis methodologies. In general, the main traffic parameter used in EISs to describe the quality of traffic flow is the Level of Service (LOS). The current state of the practice in terms of the traffic investigations for EISs has two main shortcomings. The first one is related to the information that is necessary to conduct the traffic analysis, and specifically to the lack of integration among the different transportation models and the sources of information that, in general, reside in GIS databases. A discussion of the benefits of integrating CRS&SI technologies and the transportation models used in the EIS traffic investigation is included. The second shortcoming is in the presentation of the results, both in terms of the appearance and formatting, as well as content. The presentation of traffic results (current and proposed) is discussed. This chapter also addresses the need of additional data, in terms of content and coverage. Regarding the former, other traffic parameters (e.g., delays) that are more meaningful to non-transportation experts than LOS, as well as additional information (e.g., freight flows) that can impact traffic conditions and safety are discussed. Spatial information technologies can decrease the negative effects of, and even eliminate, these shortcomings by making the relevant information that is input to the models more complete and readily available, and by providing the means to communicate the results in a more clear and efficient manner. The benefits that the application and use of CRS&SI technologies can provide to improve and expedite the traffic investigation part of the EIS process are presented.

  4. Streamline and Improve the Targeting of Education Tax Benefits

    Science.gov (United States)

    Institute for College Access & Success, 2014

    2014-01-01

    This one-page document presents The Institute for College Access & Success' (TICAS') recommendations for ways to improve the targeting of higher education tax benefits. The TICAS white paper, "Aligning the Means and the Ends: How to Improve Federal Student Aid and Increase College Access and Success," recommends almost entirely…

  5. A framework for streamlining research workflow in neuroscience and psychology

    Directory of Open Access Journals (Sweden)

    Jonas eKubilius

    2014-01-01

    Full Text Available Successful accumulation of knowledge is critically dependent on the ability to verify and replicate every part of scientific conduct. However, such principles are difficult to enact when researchers continue to resort on ad hoc workflows and with poorly maintained code base. In this paper I examine the needs of neuroscience and psychology community, and introduce psychopy_ext, a unifying framework that seamlessly integrates popular experiment building, analysis and manuscript preparation tools by choosing reasonable defaults and implementing relatively rigid patterns of workflow. This structure allows for automation of multiple tasks, such as generated user interfaces, unit testing, control analyses of stimuli, single-command access to descriptive statistics, and publication quality plotting. Taken together, psychopy_ext opens an exciting possibility for faster, more robust code development and collaboration for researchers.

  6. Darwin core based data streamlining with digimus 2.0

    Digital Repository Service at National Institute of Oceanography (India)

    Kakodkar, A.P.; Kerkar, S.S.; Varghese, N.S.; Kavlekar, D.P.; Achuthankutty, C.T.

    smaller datasets into a larger information system requires uniformity of data based on a single data standard. In the developing world smaller datasets are maintained by individual researchers or small college and university groups. To standardize data...

  7. Acquisition Documentation Streamlining, the SEP, and the PESHE

    Science.gov (United States)

    2012-05-21

    identifying any other ESOH requirements (e.g., ban on use of Ozone Depleting Substances or hexavalent chrome )  "Description/Comments:" Use 2-3...limitations on use of hexavalent chrome )  "Description/Comments:" Use 2-3 paragraphs to describe the strategy for integrating ESOH into SE processes...optional tasks) and identifying any other ESOH requirements (e.g., ban on use of Ozone Depleting Substances or hexavalent chrome )  "Description

  8. 76 FR 24339 - Streamlining Service Delivery and Improving Customer Service

    Science.gov (United States)

    2011-05-02

    ... accessed by the Internet or mobile phone and improved processes that deliver services faster and more... ``Conversations with America'' to Further Improve Customer Service). However, with advances in technology and... major initiative (signature initiative) that will use technology to improve the customer experience; (b...

  9. Streamlining and automation of radioanalytical methods at a commercial laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Harvey, J.T.; Dillard, J.W. [IT Corp., Knoxville, TN (United States)

    1993-12-31

    Through the careful planning and design of laboratory facilities and incorporation of modern instrumentation and robotics systems, properly trained and competent laboratory associates can efficiently and safely handle radioactive and mixed waste samples. This paper addresses the potential improvements radiochemistry and mixed waste laboratories can achieve utilizing robotics for automated sample analysis. Several examples of automated systems for sample preparation and analysis will be discussed.

  10. Streamlining policies for enhancing rice production in Africa: Past ...

    African Journals Online (AJOL)

    There is a consensus that African development confronts several challenges, which include alleviating widespread poverty and unemployment, providing basic foods for the people, containing the HIV/AIDS pandemic, eliminating gender disparities and ensuring sustainable management of natural resources. In order to ...

  11. Halal Supply Chain Management Streamlined Practices: Issues and Challenges

    Science.gov (United States)

    Hijrah Abd Kadir, Muhammad; Zuraidah Raja Mohd Rasi, Raja; Omar, Siti Sarah; Manap, Zariq Imran Abdul

    2016-11-01

    The quickly developing worldwide halal in business sector has given a remarkable window of chance, which empowers Malaysia to the renowned halal centre in worldwide (known as Halal-hubs). Malaysia also has proactively taken a lead in halal activities, which is presently considered as the benchmark for a halal framework worldwide. Malaysia also set up the Halal Industry Development Corporation (HDC) which driving a wide range of halal activities since the demand of halal food has increased significantly which is very crucial for a Muslim in ensuring its authenticity and integrity. Even in parallel to this developments, many studies has been conducted because there are many issues still occurs in the food industry. The issue of consumer awareness and understanding the halal principles, mixing of halal and non- halal products, halal certification and logo compliance with Shariah law and lack of regulation and enforcement need the serious attention by all parties along the supply chain. The challenges occur mainly in the halal food segregation and halal traceability of the products. The unit of analysis in this study different halal stakeholders group which are JAKIM, Halal Development Centre (HDC), Raw Material Manufacturers, Retailers and Government Agencies. This paper attempt discusses the issues and challenges occurs in the halal supply chain and faced by the practitioners as well as the relevant parties involved in the industry especially for food products manufacturers. The study would like to give a basic information about the issues and challenges in the contribution of Halal Supply Chain Management (HSCM) as well as for the future studies.

  12. STREAMLINING THE POWERS AND DUTIES OF A RECEIVER ...

    African Journals Online (AJOL)

    Mofasony

    form of transaction involves a company on the one hand and a financial ... In what can be regarded as an assault on the separate legal personality principle, the Court of .... and render accounts to that other who made the appointment.

  13. Streamlining antibiotic therapy with procalcitonin protocols: consensus and controversies.

    Science.gov (United States)

    Haubitz, Sebastian; Mueller, Beat; Schuetz, Philipp

    2013-04-01

    Accumulating evidence supports procalcitonin (PCT) as an accurate surrogate biomarker for likelihood and severity of bacterial infections. In community-acquired pneumonia and other respiratory infections, PCT-guided antibiotic therapy algorithms resulted in reduced antibiotic exposure while maintaining a similar or even better level of safety compared with standard care. Reductions in antibiotic use translate into lower treatment costs, decreased risk of side effects and decreased bacterial multiresistance. This is especially important, as acute respiratory infections represent the most frequent reason for antibiotic prescriptions worldwide. Still, there is some controversy about the benefits of PCT measurement in sepsis patients in the intensive care unit and for nonrespiratory infections. Highly sensitive PCT assays are readily available in many hospitals today, and point-of-care assays with high enough sensitivity for antibiotic guidance are expected to be available soon. Herein, the authors provide an overview of recent studies evaluating PCT in different clinical situations and an outlook of currently enrolling or upcoming interventional trials.

  14. Streamlined, Inexpensive 3D Printing of the Brain and Skull

    OpenAIRE

    Naftulin, Jason S.; Kimchi, Eyal Y.; Cash, Sydney S.

    2015-01-01

    Neuroimaging technologies such as Magnetic Resonance Imaging (MRI) and Computed Tomography (CT) collect three-dimensional data (3D) that is typically viewed on two-dimensional (2D) screens. Actual 3D models, however, allow interaction with real objects such as implantable electrode grids, potentially improving patient specific neurosurgical planning and personalized clinical education. Desktop 3D printers can now produce relatively inexpensive, good quality prints. We describe our process for...

  15. Streamlining machine learning in mobile devices for remote sensing

    Science.gov (United States)

    Coronel, Andrei D.; Estuar, Ma. Regina E.; Garcia, Kyle Kristopher P.; Dela Cruz, Bon Lemuel T.; Torrijos, Jose Emmanuel; Lim, Hadrian Paulo M.; Abu, Patricia Angela R.; Victorino, John Noel C.

    2017-09-01

    Mobile devices have been at the forefront of Intelligent Farming because of its ubiquitous nature. Applications on precision farming have been developed on smartphones to allow small farms to monitor environmental parameters surrounding crops. Mobile devices are used for most of these applications, collecting data to be sent to the cloud for storage, analysis, modeling and visualization. However, with the issue of weak and intermittent connectivity in geographically challenged areas of the Philippines, the solution is to provide analysis on the phone itself. Given this, the farmer gets a real time response after data submission. Though Machine Learning is promising, hardware constraints in mobile devices limit the computational capabilities, making model development on the phone restricted and challenging. This study discusses the development of a Machine Learning based mobile application using OpenCV libraries. The objective is to enable the detection of Fusarium oxysporum cubense (Foc) in juvenile and asymptomatic bananas using images of plant parts and microscopic samples as input. Image datasets of attached, unattached, dorsal, and ventral views of leaves were acquired through sampling protocols. Images of raw and stained specimens from soil surrounding the plant, and sap from the plant resulted to stained and unstained samples respectively. Segmentation and feature extraction techniques were applied to all images. Initial findings show no significant differences among the different feature extraction techniques. For differentiating infected from non-infected leaves, KNN yields highest average accuracy, as opposed to Naive Bayes and SVM. For microscopic images using MSER feature extraction, KNN has been tested as having a better accuracy than SVM or Naive-Bayes.

  16. ADVANCING TECHNOLOGY AND METHODOLOGY TO STREAMLINE ENVIRONMENTAL COMPLIANCE

    Energy Technology Data Exchange (ETDEWEB)

    Ben Grunewald; Paul Jehn

    2002-11-15

    By early 2000, fifteen oil and gas State Agencies were using RBDMS or a RBDMS utility to handle a significant amount or all of their data management needs. There are three additional State slated to begin implementation this year. There are an additional twelve State agencies that are not utilizing this technology that have proven to be very useful for so many other States. This project will allow for the base RBDMS install in all State oil and gas agency that desire it.

  17. The LISST-SL streamlined isokinetic suspended-sediment profiler

    Science.gov (United States)

    Gray, John R.; Agrawal, Yogesh C.; Pottsmith, H. Charles

    2004-01-01

    The new manually deployed Laser In Situ Scattering Transmissometer-StreamLined profiler (LISST-SL) represents a major technological advance for suspended-sediment measurements in rivers. The LISST-SL is being designed to provide real-time data on sediment concentrations and particle-size distributions. A pressure sensor and current meter provide real-time depth and ambient velocity data, respectively. The velocity data are also used to control pumpage across an internal laser so that the intake velocity is constantly adjusted to match the ambient stream velocity. Such isokinetic withdrawal is necessary for obtaining representative sedimentary measurements in streamflow, and ensures compliance with established practices. The velocity and sediment-concentration data are used to compute fluxes for up to 32 particle-size classes at points, verticals, or in the entire stream cross section. All data are stored internally, as well as transmitted via a 2-wire conductor to the operator using a specially developed communication protocol. The LISST-SL's performance will be measured and compared to published sedimentological accuracy criteria, and a performance summary will be placed on-line.

  18. On Stagnation points and streamline topology in vortex flows

    DEFF Research Database (Denmark)

    Aref, Hassan; Brøns, Morten

    1997-01-01

    The problem of locating stagnation points in the flow produced by a system of N interacting point vortices in two dimensions is considered. The general solution, which follows from an 1864 theorem by Siebeck, that the stagnation points are the foci of a certain plane curve of class N-1 that has a...

  19. On stagnation points and streamline topology in vortex flows

    DEFF Research Database (Denmark)

    Aref, Hassan; Brøns, Morten

    1998-01-01

    The problem of locating stagnation points in the flow produced by a system of N vortices in two dimensions is considered. The general solution follows from a 1864 theorem by Siebeck, that the stagnation points are the foci of a certain plane curve of class N-1 that has all lines connecting vortic...

  20. Streamlining resummed QCD calculations using Monte Carlo integration

    Energy Technology Data Exchange (ETDEWEB)

    Farhi, David; Feige, Ilya; Freytsis, Marat; Schwartz, Matthew D. [Center for the Fundamental Laws of Nature, Harvard University,17 Oxford St., Cambridge, MA 02138 (United States)

    2016-08-18

    Some of the most arduous and error-prone aspects of precision resummed calculations are related to the partonic hard process, having nothing to do with the resummation. In particular, interfacing to parton-distribution functions, combining various channels, and performing the phase space integration can be limiting factors in completing calculations. Conveniently, however, most of these tasks are already automated in many Monte Carlo programs, such as MADGRAPH http://dx.doi.org/10.1007/JHEP07(2014)079, ALPGEN http://dx.doi.org/10.1088/1126-6708/2003/07/001 or SHERPA http://dx.doi.org/10.1088/1126-6708/2009/02/007. In this paper, we show how such programs can be used to produce distributions of partonic kinematics with associated color structures representing the hard factor in a resummed distribution. These distributions can then be used to weight convolutions of jet, soft and beam functions producing a complete resummed calculation. In fact, only around 1000 unweighted events are necessary to produce precise distributions. A number of examples and checks are provided, including e{sup +}e{sup −} two- and four-jet event shapes, n-jettiness and jet-mass related observables at hadron colliders at next-to-leading-log (NLL) matched to leading order (LO). Attached code can be used to modify MADGRAPH to export the relevant LO hard functions and color structures for arbitrary processes.

  1. 75 FR 4031 - Streamlining Hard-Copy Postage Statement Processing

    Science.gov (United States)

    2010-01-26

    ... finalized postage statements from PostalOne! facilities are available online at the Business Customer...! facilities only. Copies of finalized postage statements are available online at the Business Customer Gateway... postage statements from PostalOne! facilities are available online at the Business Customer Gateway. 2. At...

  2. Using Pre-Statistical Analysis to Streamline Monitoring Assessments

    International Nuclear Information System (INIS)

    Reed, J.K.

    1999-01-01

    A variety of statistical methods exist to aid evaluation of groundwater quality and subsequent decision making in regulatory programs. These methods are applied because of large temporal and spatial extrapolations commonly applied to these data. In short, statistical conclusions often serve as a surrogate for knowledge. However, facilities with mature monitoring programs that have generated abundant data have inherently less uncertainty because of the sheer quantity of analytical results. In these cases, statistical tests can be less important, and ''expert'' data analysis should assume an important screening role.The WSRC Environmental Protection Department, working with the General Separations Area BSRI Environmental Restoration project team has developed a method for an Integrated Hydrogeological Analysis (IHA) of historical water quality data from the F and H Seepage Basins groundwater remediation project. The IHA combines common sense analytical techniques and a GIS presentation that force direct interactive evaluation of the data. The IHA can perform multiple data analysis tasks required by the RCRA permit. These include: (1) Development of a groundwater quality baseline prior to remediation startup, (2) Targeting of constituents for removal from RCRA GWPS, (3) Targeting of constituents for removal from UIC, permit, (4) Targeting of constituents for reduced, (5)Targeting of monitoring wells not producing representative samples, (6) Reduction in statistical evaluation, and (7) Identification of contamination from other facilities

  3. Streamlining the Design Tradespace for Earth Imaging Constellations

    Science.gov (United States)

    Nag, Sreeja; Hughes, Steven P.; Le Moigne, Jacqueline J.

    2016-01-01

    Satellite constellations and Distributed Spacecraft Mission (DSM) architectures offer unique benefits to Earth observation scientists and unique challenges to cost estimators. The Cost and Risk (CR) module of the Tradespace Analysis Tool for Constellations (TAT-C) being developed by NASA Goddard seeks to address some of these challenges by providing a new approach to cost modeling, which aggregates existing Cost Estimating Relationships (CER) from respected sources, cost estimating best practices, and data from existing and proposed satellite designs. Cost estimation through this tool is approached from two perspectives: parametric cost estimating relationships and analogous cost estimation techniques. The dual approach utilized within the TAT-C CR module is intended to address prevailing concerns regarding early design stage cost estimates, and offer increased transparency and fidelity by offering two preliminary perspectives on mission cost. This work outlines the existing cost model, details assumptions built into the model, and explains what measures have been taken to address the particular challenges of constellation cost estimating. The risk estimation portion of the TAT-C CR module is still in development and will be presented in future work. The cost estimate produced by the CR module is not intended to be an exact mission valuation, but rather a comparative tool to assist in the exploration of the constellation design tradespace. Previous work has noted that estimating the cost of satellite constellations is difficult given that no comprehensive model for constellation cost estimation has yet been developed, and as such, quantitative assessment of multiple spacecraft missions has many remaining areas of uncertainty. By incorporating well-established CERs with preliminary approaches to approaching these uncertainties, the CR module offers more complete approach to constellation costing than has previously been available to mission architects or Earth scientists seeking to leverage the capabilities of multiple spacecraft working in support of a common goal.

  4. SWOT ANALYSIS-MANAGEMENT TECHNIQUES TO STREAMLINE PUBLIC BUSINESS MANAGEMENT

    OpenAIRE

    Rodica IVORSCHI

    2012-01-01

    SWOT analysis is the most important management techniques for understanding the strategic position of an organization. Objective SWOT analysis is to recommend strategies to ensure the best alignment between internal and external environment, and choosing the right strategy can be benefi cial organization in order to adapt their strengths to opportunities, minimize risks and eliminate weaknesses.

  5. SWOT ANALYSIS-MANAGEMENT TECHNIQUES TO STREAMLINE PUBLIC BUSINESS MANAGEMENT

    Directory of Open Access Journals (Sweden)

    Rodica IVORSCHI

    2012-06-01

    Full Text Available SWOT analysis is the most important management techniques for understanding the strategic position of an organization.Objective SWOT analysis is to recommend strategies to ensure the best alignment between internal and external environment, and choosing the right strategy can be beneficial organization in order to adapt their strengths to opportunities, minimize risks and eliminate weaknesses.

  6. Streamlining and automation of radioanalytical methods at a commercial laboratory

    International Nuclear Information System (INIS)

    Harvey, J.T.; Dillard, J.W.

    1993-01-01

    Through the careful planning and design of laboratory facilities and incorporation of modern instrumentation and robotics systems, properly trained and competent laboratory associates can efficiently and safely handle radioactive and mixed waste samples. This paper addresses the potential improvements radiochemistry and mixed waste laboratories can achieve utilizing robotics for automated sample analysis. Several examples of automated systems for sample preparation and analysis will be discussed

  7. ERP (enterprise resource planning) systems can streamline healthcare business functions.

    Science.gov (United States)

    Jenkins, E K; Christenson, E

    2001-05-01

    Enterprise resource planning (ERP) software applications are designed to facilitate the systemwide integration of complex processes and functions across a large enterprise consisting of many internal and external constituents. Although most currently available ERP applications generally are tailored to the needs of the manufacturing industry, many large healthcare systems are investigating these applications. Due to the significant differences between manufacturing and patient care, ERP-based systems do not easily translate to the healthcare setting. In particular, the lack of clinical standardization impedes the use of ERP systems for clinical integration. Nonetheless, an ERP-based system can help a healthcare organization integrate many functions, including patient scheduling, human resources management, workload forecasting, and management of workflow, that are not directly dependent on clinical decision making.

  8. Asian high tech streamlines traditional industry | CRDI - Centre de ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    control systems and to make them affordable to small enterprises. Today, Eutech is a multinational provider of business services such as building management, workflow solutions, web publishing, and hospital information systems.

  9. Streamlined approach to mapping the magnetic induction of skyrmionic materials

    Energy Technology Data Exchange (ETDEWEB)

    Chess, Jordan J., E-mail: jchess@uoregon.edu [Department of Physics, University of Oregon, Eugene, OR 97403 (United States); Montoya, Sergio A. [Center for Memory and Recording Research, University of California, San Diego, CA 92093 (United States); Department of Electrical and Computer Engineering, University of California, San Diego, La Jolla, CA 92093 (United States); Harvey, Tyler R. [Department of Physics, University of Oregon, Eugene, OR 97403 (United States); Ophus, Colin [National Center for Electron Microscopy, Molecular Foundry, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Couture, Simon; Lomakin, Vitaliy; Fullerton, Eric E. [Center for Memory and Recording Research, University of California, San Diego, CA 92093 (United States); Department of Electrical and Computer Engineering, University of California, San Diego, La Jolla, CA 92093 (United States); McMorran, Benjamin J. [Department of Physics, University of Oregon, Eugene, OR 97403 (United States)

    2017-06-15

    Highlights: • A method to reconstruction the phase of electrons after pasting though a sample that requires a single defocused image is presented. • Restrictions as to when it is appropriate to apply this method are described. • The relative error associated with this method is compared to conventional transport of intensity equation analysis. - Abstract: Recently, Lorentz transmission electron microscopy (LTEM) has helped researchers advance the emerging field of magnetic skyrmions. These magnetic quasi-particles, composed of topologically non-trivial magnetization textures, have a large potential for application as information carriers in low-power memory and logic devices. LTEM is one of a very few techniques for direct, real-space imaging of magnetic features at the nanoscale. For Fresnel-contrast LTEM, the transport of intensity equation (TIE) is the tool of choice for quantitative reconstruction of the local magnetic induction through the sample thickness. Typically, this analysis requires collection of at least three images. Here, we show that for uniform, thin, magnetic films, which includes many skyrmionic samples, the magnetic induction can be quantitatively determined from a single defocused image using a simplified TIE approach.

  10. Asian high tech streamlines traditional industry | IDRC - International ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2010-10-28

    Oct 28, 2010 ... "Synapse, our software monitoring system, optimizes the process by monitoring temperatures," explains Gunasingham. ... workflow solutions, web publishing, and hospital information systems. ... IDRC Digital Library

  11. Real-time information systems: Streamlining the energy industry

    International Nuclear Information System (INIS)

    Purgason, R.S.

    1994-01-01

    The convergence of computing and telecommunications is impacting the energy business. New services bred in this merger will now allow companies to efficiently re-engineer the way they buy and sell energy, fostering greater efficiencies in all segments of the gas processing and related energy businesses

  12. Streamlining the Acquisition Process: A DCAA Field-Grade Perspective

    Science.gov (United States)

    2014-03-01

    Initial Capabilities Document IFRS International Financial Reporting Standards IPT Integrated Product Team IRR Independent Reference Review...the responsibilities, programmed focus, strategic plan and recent events impacting the organization. B. DEFENSE CONTRACT AUDIT AGENCY 1. DCAA...material misstatements, whether caused by error or fraud. The type of audit requested by the contracting officer will directly impact both the

  13. Mapping population-based structural connectomes.

    Science.gov (United States)

    Zhang, Zhengwu; Descoteaux, Maxime; Zhang, Jingwen; Girard, Gabriel; Chamberland, Maxime; Dunson, David; Srivastava, Anuj; Zhu, Hongtu

    2018-05-15

    Advances in understanding the structural connectomes of human brain require improved approaches for the construction, comparison and integration of high-dimensional whole-brain tractography data from a large number of individuals. This article develops a population-based structural connectome (PSC) mapping framework to address these challenges. PSC simultaneously characterizes a large number of white matter bundles within and across different subjects by registering different subjects' brains based on coarse cortical parcellations, compressing the bundles of each connection, and extracting novel connection weights. A robust tractography algorithm and streamline post-processing techniques, including dilation of gray matter regions, streamline cutting, and outlier streamline removal are applied to improve the robustness of the extracted structural connectomes. The developed PSC framework can be used to reproducibly extract binary networks, weighted networks and streamline-based brain connectomes. We apply the PSC to Human Connectome Project data to illustrate its application in characterizing normal variations and heritability of structural connectomes in healthy subjects. Copyright © 2018 Elsevier Inc. All rights reserved.

  14. IM-CRDS for the analysis of matrix-bound water isotopes: a streamlined (and updated) tool for ecohydrologists to probe small-scale variability in plants Yasuhara, S. (syasuhara@picarro.com)1,Carter, J.A. (jcarter@picarro.com)1, Dennis, K.J. (kdennis@picarro.com)1 1Picarro Inc., 3105 Patrick Henry Drive, Santa Clara, CA 95054

    Science.gov (United States)

    Yasuhara, S.

    2013-12-01

    The ability to measure the isotopic composition of matrix-bound water is valuable to many facets of earth and environmental sciences. For example, ecohydrologists use stable isotopes of oxygen and hydrogen in plant and soil water, in combination with measurements of atmospheric water vapor, surface water and precipitation, to estimate budgets of evapotranspiration. Likewise, water isotopes of oceanic water, brines and other waters with high total dissolved solids (TDS, e.g., juices) are relevant to studying large-scale oceanic circulation, small-scale mixing, groundwater contamination, the balance of evaporation to precipitation, and the provenance of food. Conventionally matrix-bound water has been extracted using cryogenic distillation, whereby water is distilled from the material in question (e.g., a leaf sample) by heating under vacuum and collecting the resultant water vapor using liquid nitrogen. The water can then be analyzed for its stable isotopic composition by a variety of methods, including isotope ratio mass spectrometry and laser techniques, such as Cavity Ring-Down Spectroscopy (CRDS). Here we present recent improvements in an alternative, and stream-lined, solution for integrated sample extraction and isotopic measurement using a Picarro Induction Module (IM) coupled to commercially-available CRDS analyzer from Picarro. This technique is also valuable for waters with high TDS, which can have detrimental effects on flash vaporization process, typically used for the introduction of water to Picarro CRDS water isotope analyzers. The IM works by inductively heating a sample held within a metal sample holder in a glass vial flushed with dry air. Tested samples include leaves, stems, twigs, calibration water, juices, and salt water. The heating process evolves water vapor which is then swept through the system at approximately 150 standard cubic centimeters per minute. The evolved water vapor passes through an activated charcoal cartridge for removal of

  15. Early diagnosis of Balo's concentric sclerosis by diffusion tensor tractography: a case report and literature review

    Directory of Open Access Journals (Sweden)

    Juan Alberto Nader Kawachi

    2016-03-01

    Full Text Available La esclerosis concéntrica de Baló es una variante infrecuente de enfermedad desmielinizante relacionada con la esclerosis múltiple, inicialmente considerada de progresión fatal. En estudios recientes se reportan variantes no fatales de esclerosis concéntrica de Baló en los que se enfatiza la importancia del diagnóstico por medio de la imagen por resonancia magnética, utilizando además la espectroscopia y las secuencias de difusión y perfusión. En los últimos años se ha logrado reproducir la imagen tridimensional de un fascículo en particular y observar la presencia de lesiones por medio de la tractografía por imagen por resonancia magnética mediante la técnica de tensor de difusión. Presentamos el caso de una mujer joven con síntomas neurológicos focales agudos, incluyendo paresia de extremidades derechas, cuyo diagnóstico por biopsia fue de esclerosis concéntrica de Baló, confirmando el resultado de los estudios de imagen. La paciente recibió tratamiento con bolos de metilprednisolona, obteniendo remisión clínica completa a largo plazo. A nuestro entender, este es el primer reporte que describe los hallazgos de la esclerosis concéntrica de Baló utilizando la técnica de tensor de difusión. Consideramos que dicha técnica permitirá en el futuro la detección temprana de la enfermedad, su tratamiento oportuno y permitirá establecer nuevos criterios de clasificación y estratificación. Este caso demuestra la existencia de variantes benignas de esclerosis concéntrica de Baló, que tienen buena respuesta a la terapia con glucocorticoides y donde se logra la recuperación funcional.

  16. Automated longitudinal intra-subject analysis (ALISA) for diffusion MRI tractography

    DEFF Research Database (Denmark)

    Aarnink, Saskia H; Vos, Sjoerd B; Leemans, Alexander

    2014-01-01

    the inter-subject and intra-subject automation in this situation are intended for subjects without gross pathology. In this work, we propose such an automated longitudinal intra-subject analysis (dubbed ALISA) approach, and assessed whether ALISA could preserve the same level of reliability as obtained....... The major disadvantage of manual FT segmentations, unfortunately, is that placing regions-of-interest for tract selection can be very labor-intensive and time-consuming. Although there are several methods that can identify specific WM fiber bundles in an automated way, manual FT segmentations across...... multiple subjects performed by a trained rater with neuroanatomical expertise are generally assumed to be more accurate. However, for longitudinal DTI analyses it may still be beneficial to automate the FT segmentation across multiple time points, but then for each individual subject separately. Both...

  17. Diffusion tractography of the subcortical auditory system in a postmortem human brain

    OpenAIRE

    Sitek, Kevin

    2017-01-01

    The subcortical auditory system is challenging to identify with standard human brain imaging techniques: MRI signal decreases toward the center of the brain as well as at higher resolution, both of which are necessary for imaging small brainstem auditory structures.Using high-resolution diffusion-weighted MRI, we asked:Can we identify auditory structures and connections in high-resolution ex vivo images?Which structures and connections can be mapped in vivo?

  18. Optic radiation structure and anatomy in the normally developing brain determined using diffusion MRI and tractography.

    Science.gov (United States)

    Dayan, Michael; Munoz, Monica; Jentschke, Sebastian; Chadwick, Martin J; Cooper, Janine M; Riney, Kate; Vargha-Khadem, Faraneh; Clark, Chris A

    2015-01-01

    The optic radiation (OR) is a component of the visual system known to be myelin mature very early in life. Diffusion tensor imaging (DTI) and its unique ability to reconstruct the OR in vivo were used to study structural maturation through analysis of DTI metrics in a cohort of 90 children aged 5-18 years. As the OR is at risk of damage during epilepsy surgery, we measured its position relative to characteristic anatomical landmarks. Anatomical distances, DTI metrics and volume of the OR were investigated for age, gender and hemisphere effects. We observed changes in DTI metrics with age comparable to known trajectories in other white matter tracts. Left lateralization of DTI metrics was observed that showed a gender effect in lateralization. Sexual dimorphism of DTI metrics in the right hemisphere was also found. With respect to OR dimensions, volume was shown to be right lateralised and sexual dimorphism demonstrated for the extent of the left OR. The anatomical results presented for the OR have potentially important applications for neurosurgical planning.

  19. Motor pathway degeneration in young ataxia telangiectasia patients: A diffusion tractography study

    Directory of Open Access Journals (Sweden)

    Ishani Sahama

    2015-01-01

    Conclusions: Whole tract analysis of the corticomotor, corticospinal and somatosensory pathways in ataxia telangiectasia showed significant white matter degeneration along the entire length of motor circuits, highlighting that ataxia–telangiectasia gene mutation impacts the cerebellum and multiple other motor circuits in young patients.

  20. Diffusion tensor tractography of language functional areas and fiber pathways in normal human brain

    International Nuclear Information System (INIS)

    Sun Xuejin; Dai Jianping; Chen Hongyan; Gao Peiyi; Ai Lin; Tian Shengyong; Pang Ruilin

    2007-01-01

    Objective: To demonstrate the fiber pathways of Broca area to the other functional brain areas with diffusion tensor imaging and fiber tracking. Methods: Conventionality MRI, diffusion tensor imaging (DTI) and fiber tracking were performed using 3.0 T MRI in 20 healthy person. The fiber bundles and tracts were analyzed in Broca area and contralateral normal area. Results: The left-side fiber bundles were 428 and the right-side were 416 in B45 area, there were no statistically significant differences between both sides (t=0.216, P>0.05). The left-side fiber bundles were 432 and the right-side were 344 in B44 area,there were statistically significant (t=2.314, P 0.05). Differences of the arcuate fascicule between both sides were not statistically significant (t=-0.465, P>0.05), the mean FA on the left was higher than the right (t=1.912, P<0.05). DTI and fiber tracking exhibited that the fiber bundles from Broca area were distributed superoanteriorly to the lateral foreside of the frontal lobe, lateroinferiorly to the occipital lobe through external capsule, and went down through globus pallidus and internal capsule. Conclusion: The fiber tracts bewteen Broca area and other brain areas were the fundamental structures for performing language function of the human brain. (authors)

  1. Tractography-Based Score for Learning Effective Connectivity From Multimodal Imaging Data Using Dynamic Bayesian Networks.

    Science.gov (United States)

    Dang, Shilpa; Chaudhury, Santanu; Lall, Brejesh; Roy, Prasun K

    2018-05-01

    Effective connectivity (EC) is the methodology for determining functional-integration among the functionally active segregated regions of the brain. By definition EC is "the causal influence exerted by one neuronal group on another" which is constrained by anatomical connectivity (AC) (axonal connections). AC is necessary for EC but does not fully determine it, because synaptic communication occurs dynamically in a context-dependent fashion. Although there is a vast emerging evidence of structure-function relationship using multimodal imaging studies, till date only a few studies have done joint modeling of the two modalities: functional MRI (fMRI) and diffusion tensor imaging (DTI). We aim to propose a unified probabilistic framework that combines information from both sources to learn EC using dynamic Bayesian networks (DBNs). DBNs are probabilistic graphical temporal models that learn EC in an exploratory fashion. Specifically, we propose a novel anatomically informed (AI) score that evaluates fitness of a given connectivity structure to both DTI and fMRI data simultaneously. The AI score is employed in structure learning of DBN given the data. Experiments with synthetic-data demonstrate the face validity of structure learning with our AI score over anatomically uninformed counterpart. Moreover, real-data results are cross-validated by performing classification-experiments. EC inferred on real fMRI-DTI datasets is found to be consistent with previous literature and show promising results in light of the AC present as compared to other classically used techniques such as Granger-causality. Multimodal analyses provide a more reliable basis for differentiating brain under abnormal/diseased conditions than the single modality analysis.

  2. Detection of white matter injury in concussion using high-definition fiber tractography.

    Science.gov (United States)

    Shin, Samuel S; Pathak, Sudhir; Presson, Nora; Bird, William; Wagener, Lauren; Schneider, Walter; Okonkwo, David O; Fernandez-Miranda, Juan C

    2014-01-01

    Over the last few decades, structural imaging techniques of the human brain have undergone significant strides. High resolution provided by recent developments in magnetic resonance imaging (MRI) allows improved detection of injured regions in patients with moderate-to-severe traumatic brain injury (TBI). In addition, diffusion imaging techniques such as diffusion tensor imaging (DTI) has gained much interest recently due to its possible utility in detecting structural integrity of white matter pathways in mild TBI (mTBI) cases. However, the results from recent DTI studies in mTBI patients remain equivocal. Also, there are important shortcomings for DTI such as limited resolution in areas of multiple crossings and false tract formation. The detection of white matter damage in concussion remains challenging, and development of imaging biomarkers for mTBI is still in great need. In this chapter, we discuss our experience with high-definition fiber tracking (HDFT), a diffusion spectrum imaging-based technique. We also discuss ongoing developments and specific advantages HDFT may offer concussion patients. © 2014 S. Karger AG, Basel.

  3. Topological Measurements of DWI Tractography for Alzheimer’s Disease Detection

    Directory of Open Access Journals (Sweden)

    Nicola Amoroso

    2017-01-01

    Full Text Available Neurodegenerative diseases affect brain morphology and connectivity, making complex networks a suitable tool to investigate and model their effects. Because of its stereotyped pattern Alzheimer’s disease (AD is a natural benchmark for the study of novel methodologies. Several studies have investigated the network centrality and segregation changes induced by AD, especially with a single subject approach. In this work, a holistic perspective based on the application of multiplex network concepts is introduced. We define and assess a diagnostic score to characterize the brain topology and measure the disease effects on a mixed cohort of 52 normal controls (NC and 47 AD patients, from Alzheimer’s Disease Neuroimaging Initiative (ADNI. The proposed topological score allows an accurate NC-AD classification: the average area under the curve (AUC is 95% and the 95% confidence interval is 92%–99%. Besides, the combination of topological information and structural measures, such as the hippocampal volumes, was also investigated. Topology is able to capture the disease signature of AD and, as the methodology is general, it can find interesting applications to enhance our insight into disease with more heterogeneous patterns.

  4. Brain anatomical networks in world class gymnasts: a DTI tractography study.

    Science.gov (United States)

    Wang, Bin; Fan, Yuanyuan; Lu, Min; Li, Shumei; Song, Zheng; Peng, Xiaoling; Zhang, Ruibin; Lin, Qixiang; He, Yong; Wang, Jun; Huang, Ruiwang

    2013-01-15

    The excellent motor skills of world class gymnasts amaze everyone. People marvel at the way they precisely control their movements and wonder how the brain structure and function of these elite athletes differ from those of non-athletes. In this study, we acquired diffusion images from thirteen world class gymnasts and fourteen matched controls, constructed their anatomical networks, and calculated the topological properties of each network based on graph theory. From a connectivity-based analysis, we found that most of the edges with increased connection density in the champions were linked to brain regions that are located in the sensorimotor, attentional, and default-mode systems. From graph-based metrics, we detected significantly greater global and local efficiency but shorter characteristic path length in the anatomical networks of the champions compared with the controls. Moreover, in the champions we found a significantly higher nodal degree and greater regional efficiency in several brain regions that correspond to motor and attention functions. These included the left precentral gyrus, left postcentral gyrus, right anterior cingulate gyrus and temporal lobes. In addition, we revealed an increase in the mean fractional anisotropy of the corticospinal tract in the champions, possibly in response to long-term gymnastic training. Our study indicates that neuroanatomical adaptations and plastic changes occur in gymnasts' brain anatomical networks either in response to long-term intensive gymnastic training or as an innate predisposition or both. Our findings may help to explain gymnastic skills at the highest levels of performance and aid in understanding the neural mechanisms that distinguish expert gymnasts from novices. Copyright © 2012 Elsevier Inc. All rights reserved.

  5. Diffusion tensor tractography as a supplementary tool to conventional MRI for evaluating patients with myelopathy

    Directory of Open Access Journals (Sweden)

    Amal Amin A. El Maati

    2014-12-01

    Conclusion: Diffusion tensor imaging is a reliable method for the evaluation of the diffusion properties of normal and compressed spinal cords. Furthermore, this technique can be used as an important supplementary tool to conventional MRI for the quantification of fiber damage in spinal cord compression, thus has the potential to be of great utility for treatment planning and follow up.

  6. Probabilistic tractography recovers a rostrocaudal trajectory of connectivity variability in the human insular cortex

    NARCIS (Netherlands)

    Cerliani, Leonardo; Thomas, Rajat M.; Jbabdi, Saad; Siero, Jeroen C. W.; Nanetti, Luca; Crippa, Alessandro; Gazzola, Valeria; D'Arceuil, Helen; Keysers, Christian

    The insular cortex of macaques has a wide spectrum of anatomical connections whose distribution is related to its heterogeneous cytoarchitecture. Although there is evidence of a similar cytoarchitectural arrangement in humans, the anatomical connectivity of the insula in the human brain has not yet

  7. Uniformity and Deviation of Intra-axonal Cross-sectional Area Coverage of the Gray-to-White Matter Interface

    Directory of Open Access Journals (Sweden)

    Stefan Sommer

    2017-12-01

    Full Text Available Diffusion magnetic resonance imaging (dMRI is a compelling tool for investigating the structure and geometry of brain tissue based on indirect measurement of the diffusion anisotropy of water. Recent developments in global top-down tractogram optimizations enable the estimation of streamline weights, which characterize the connection between gray matter areas. In this work, the intra-axonal cross-sectional area coverage of the gray-to-white matter interface was examined by intersecting tractography streamlines with cortical regions of interest. The area coverage is the ratio of streamline weights divided by the surface area at the gray-to-white matter interface and assesses the estimated percentage which is covered by intra-axonal space. A high correlation (r = 0.935 between streamline weights and the cortical surface area was found across all regions of interest in all subjects. The variance across different cortical regions exhibits similarities to myelin maps. Additionally, we examined the effect of different diffusion gradient subsets at a lower, clinically feasible spatial resolution. Subsampling of the initial high-resolution diffusion dataset did not alter the tendency of the area coverage at the gray-to-white matter interface across cortical areas and subjects. However, single-shell acquisition schemes with lower b-values lead to a steady increase in area coverage in comparison to the full acquisition scheme at high resolution.

  8. Motor and cortico-striatal-thalamic connectivity alterations in intrauterine growth restriction.

    Science.gov (United States)

    Eixarch, Elisenda; Muñoz-Moreno, Emma; Bargallo, Nuria; Batalle, Dafnis; Gratacos, Eduard

    2016-06-01

    Intrauterine growth restriction is associated with short- and long-term neurodevelopmental problems. Structural brain changes underlying these alterations have been described with the use of different magnetic resonance-based methods that include changes in whole structural brain networks. However, evaluation of specific brain circuits and its correlation with related functions has not been investigated in intrauterine growth restriction. In this study, we aimed to investigate differences in tractography-related metrics in cortico-striatal-thalamic and motor networks in intrauterine growth restricted children and whether these parameters were related with their specific function in order to explore its potential use as an imaging biomarker of altered neurodevelopment. We included a group of 24 intrauterine growth restriction subjects and 27 control subjects that were scanned at 1 year old; we acquired T1-weighted and 30 directions diffusion magnetic resonance images. Each subject brain was segmented in 93 regions with the use of anatomical automatic labeling atlas, and deterministic tractography was performed. Brain regions included in motor and cortico-striatal-thalamic networks were defined based in functional and anatomic criteria. Within the streamlines that resulted from the whole brain tractography, those belonging to each specific circuit were selected and tractography-related metrics that included number of streamlines, fractional anisotropy, and integrity were calculated for each network. We evaluated differences between both groups and further explored the correlation of these parameters with the results of socioemotional, cognitive, and motor scales from Bayley Scale at 2 years of age. Reduced fractional anisotropy (cortico-striatal-thalamic, 0.319 ± 0.018 vs 0.315 ± 0.015; P = .010; motor, 0.322 ± 0.019 vs 0.319 ± 0.020; P = .019) and integrity cortico-striatal-thalamic (0.407 ± 0.040 vs 0.399 ± 0.034; P = .018; motor, 0.417 ± 0.044 vs 0

  9. Streamlining tasks and roles to expand treatment and care for HIV: randomised controlled trial protocol

    Directory of Open Access Journals (Sweden)

    van Vuuren Cloete

    2008-04-01

    Full Text Available Abstract Background A major barrier to accessing free government-provided antiretroviral treatment (ART in South Africa is the shortage of suitably skilled health professionals. Current South African guidelines recommend that only doctors should prescribe ART, even though most primary care is provided by nurses. We have developed an effective method of educational outreach to primary care nurses in South Africa. Evidence is needed as to whether primary care nurses, with suitable training and managerial support, can initiate and continue to prescribe and monitor ART in the majority of ART-eligible adults. Methods/design This is a protocol for a pragmatic cluster randomised trial to evaluate the effectiveness of a complex intervention based on and supporting nurse-led antiretroviral treatment (ART for South African patients with HIV/AIDS, compared to current practice in which doctors are responsible for initiating ART and continuing prescribing. We will randomly allocate 31 primary care clinics in the Free State province to nurse-led or doctor-led ART. Two groups of patients aged 16 years and over will be included: a 7400 registering with the programme with CD4 counts of ≤ 350 cells/mL (mainly to evaluate treatment initiation and b 4900 already receiving ART (to evaluate ongoing treatment and monitoring. The primary outcomes will be time to death (in the first group and viral suppression (in the second group. Patients' survival, viral load and health status indicators will be measured at least 6-monthly for at least one year and up to 2 years, using an existing province-wide clinical database linked to the national death register. Trial registration Controlled Clinical Trials ISRCTN46836853

  10. 47 CFR 63.03 - Streamlining procedures for domestic transfer of control applications.

    Science.gov (United States)

    2010-10-01

    ... Commission will treat the discontinuance request as sufficient to fulfill the pro forma post-transaction... of control applications. 63.03 Section 63.03 Telecommunication FEDERAL COMMUNICATIONS COMMISSION... to section 214 of the Communications Act of 1934, as amended, shall be subject to the following...

  11. Streamlined analysis technique for the evaluation of pellet clad interaction in PWR reload cores

    International Nuclear Information System (INIS)

    Beard, Ch.; Morita, T.; Brown, J.

    2007-01-01

    For some applications, an analysis is required to explicitly demonstrate that fuel failure due to pellet-clad interaction (PCI) is prevented by the core limits and the protection system for both Condition I (normal operation) operation and for Condition II (events of moderate frequency) events. This analysis needs to address the entire range of normal operation allowed by the Technical Specifications and all Condition II transients. The obvious approach which has been utilized for many years is a simulation of normal operation power maneuvers followed by explicit Condition II transients as a function of key core parameters. This is a sampling approach and has concerns about the overall coverage of the potential space. An alternative approach is the 3D FAC power distribution analysis methodology that was based upon the Westinghouse Relaxed Axial Offset Control Strategy (RAOC) evaluation process. The 3D FAC methodology uses a parametric representation of variables affecting the power distributions, defining a grid mesh over a space of Condition I and Condition II parameters. The operation space is defined by a power range, temperature range, rod position range, axial offset range, core protection limits and representative xenon distributions. Then the 3D FAC evaluation consists of systematically calculating the 3D power distribution and margin to the core and fuel limits for each mesh point of this multi-dimensional space. The PCI margin is obtained by the comparison of the 3D power distributions over the Condition II space and the 3D maximum allowed power, which is dependent on the fuel rod history. The fuel history model utilizes the power history developed in the 3-dimensional nuclear analysis code to define local powers for the specified fuel rods to be analyzed. It tracks the rod history and provides the maximum allowed power for the point. This model is appropriate for base load operation, extended reduced power operation, return to power operation and extensive load follow operation. The methodology allows for easy evaluation of the impact of changes to core protection setpoints and clearly defines the margin to the limits. (authors)

  12. Streamlined structure elucidation of an unknown compound in a pigment formulation.

    Science.gov (United States)

    Yüce, Imanuel; Morlock, Gertrud E

    2016-10-21

    A fast and reliable quality control is important for ink manufacturers to ensure a constant production grade of mixtures and chemical formulations, and unknown components attract their attention. Structure elucidating techniques seem time-consuming in combination with column-based methods, but especially the low solubility of pigment formulations is challenging the analysis. In contrast, layer chromatography is more tolerant with regard to pigment particles. One PLC plate for NMR and FTIR analyses and one HPTLC plate for recording of high resolution mass spectra, MS/MS spectra and for gathering information on polarity and spectral properties were needed to characterize a structure, exemplarily shown for an unknown component in pigment Red 57:1 to be 3-hydroxy-2-naphtoic acid. A preparative layer chromatography (PLC) workflow was developed that used an Automated Multiple Development 2 (AMD 2) system. The 0.5-mm PLC plate could still be operated in the AMD 2 system and allowed a smooth switch from the analytical to the preparative gradient separation. Through automated gradient development and the resulting focusing of bands, the sharpness of the PLC bands was improved. For NMR, the necessary high load of the target compound on the PLC plate was achieved via a selective solvent extraction that discriminated the polar sample matrix and thus increased the application volume of the extract that could maximally be applied without overloading. By doing so, the yield for NMR analysis was improved by a factor of 9. The effectivity gain through a simple, but thoroughly chosen extraction solvent is often overlooked, and for educational purpose, it was clearly illustrated and demonstrated by an extended solvent screening. Thus, PLC using an automated gradient development after a selective extraction was proven to be a new powerful combination for structural elucidation by NMR. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Streamlined energy-savings calculations for heat-island reduction strategies

    Energy Technology Data Exchange (ETDEWEB)

    Akbari, Hashem; Konopacki, Steven J.

    2003-03-15

    We have developed summary tables (sorted by heating- and cooling-degree-days) to estimate the potential of Heat-Island Reduction (HIR) strategies (i.e., solar-reflective roofs, shade trees, reflective pavements, and urban vegetation) to reduce cooling-energy use in buildings. The tables provide estimates of savings for both direct effect (reducing heat gain through the building shell) and indirect effect (reducing the ambient air temperature). In this analysis, we considered three building types that offer the most savings potential : residences, offices, and retail stores. Each building type was characterized in detail by Pre-1980 (old) or 1980+ (new) construction vintage and with natural gas or electricity as heating fuel. We defined prototypical-building characteristics for each building type and simulated the effects of HIR strategies on building cooling and heating energy use and peak power demand using the DOE-2.1E model and weather data for about 240 locations in the U.S. A statistical analysis of previously completed simulations for five cities was used to estimate the indirect savings. Our simulations included the effect of (1) solar-reflective roofing material on building [direct effect], (2) placement of deciduous shade trees near south and west walls of building [direct effect], and (3) ambient cooling achieved by urban reforestation and reflective building surfaces and pavements [indirect effect]. Upon completion of estimating the direct and indirect energy savings for all the selected locations, we integrated the results in tables arranged by heating- and cooling-degree-days. We considered 15 bins for heating-degree-days, and 11 bins for cooling-degree-days. Energy use and savings are presented per 1000 ft2 of roof area. In residences heated with gas and in climates with greater than 1000 cooling-degree-days, the annual electricity savings in Pre-1980 stock ranged from 650 to 1300 kWh/1000ft2; for 1980+ stock savings ranged 300 to 600 kWh/1000 ft2. For residences heated with electricity, the savings ranged from 350 to 1300 kWh/1000ft2 for Pre-1980 stock and 190-600 kWh/1000ft2 for 1980+ stocks. In climates with less than 1000 cooling-degree-days, the electricity savings were not significantly higher than winter heating penalties. For gas-heated office buildings, simulations indicated electricity savings in the range of 1100-1500 kWh/1000ft2 and 360-700 kWh/1000ft2, for Pre-1980 and 1980+ stocks, respectively. For electrically heated office buildings, simulations indicated electricity savings in the range of 700-1400 kWh/1000ft2 and 100-700 kW