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Sample records for automated simplified voxel-based

  1. Evaluation of absorbed doses in voxel-based and simplified models for small animals.

    PubMed

    Mohammadi, Akram; Kinase, Sakae; Saito, Kimiaki

    2012-07-01

    Internal dosimetry in non-human biota is desirable from the viewpoint of radiation protection of the environment. The International Commission on Radiological Protection (ICRP) proposed Reference Animals and Plants using simplified models, such as ellipsoids and spheres and calculated absorbed fractions (AFs) for whole bodies. In this study, photon and electron AFs in whole bodies of voxel-based rat and frog models have been calculated and compared with AFs in the reference models. It was found that the voxel-based and the reference frog (or rat) models can be consistent for the whole-body AFs within a discrepancy of 25%, as the source was uniformly distributed in the whole body. The specific absorbed fractions (SAFs) and S values were also evaluated in whole bodies and all organs of the voxel-based frog and rat models as the source was distributed in the whole body or skeleton. The results demonstrated that the whole-body SAFs reflect SAFs of all individual organs as the source was uniformly distributed per mass within the whole body by about 30% uncertainties with exceptions for body contour (up to -40%) for both electrons and photons due to enhanced radiation leakages, and for the skeleton for photons only (up to +185%) due to differences in the mass attenuation coefficients. For nuclides such as (90)Y and (90)Sr, which were concentrated in the skeleton, there were large differences between S values in the whole body and those in individual organs, however the whole-body S values for the reference models with the whole body as the source were remarkably similar to those for the voxel-based models with the skeleton as the source, within about 4 and 0.3%, respectively. It can be stated that whole-body SAFs or S values in simplified models without internal organs are not sufficient for accurate internal dosimetry because they do not reflect SAFs or S values of all individual organs as the source was not distributed uniformly in whole body. Thus, voxel-based models

  2. Singularity-free finite element model of bone through automated voxel-based reconstruction.

    PubMed

    Esposito, L; Bifulco, P; Gargiulo, P; Fraldi, M

    2016-02-01

    Computed tomography (CT) provides both anatomical and density information about tissues. Bone is segmented by raw images and Finite Element Method (FEM) voxel-based meshing technique is achieved by matching each CT voxel to a single finite element (FE). As a consequence of the automated model reconstruction, unstable elements - i.e. elements insufficiently anchored to the whole model and thus potentially involved in partial rigid body motion - can be generated, a crucial problem in obtaining consistent FE models, hindering mechanical analyses. Through the classification of instabilities on topological connections between elements, a numerical procedure is proposed in order to avoid unconstrained models.

  3. Voxel-based dose prediction with multi-patient atlas selection for automated radiotherapy treatment planning

    NASA Astrophysics Data System (ADS)

    McIntosh, Chris; Purdie, Thomas G.

    2017-01-01

    Automating the radiotherapy treatment planning process is a technically challenging problem. The majority of automated approaches have focused on customizing and inferring dose volume objectives to be used in plan optimization. In this work we outline a multi-patient atlas-based dose prediction approach that learns to predict the dose-per-voxel for a novel patient directly from the computed tomography planning scan without the requirement of specifying any objectives. Our method learns to automatically select the most effective atlases for a novel patient, and then map the dose from those atlases onto the novel patient. We extend our previous work to include a conditional random field for the optimization of a joint distribution prior that matches the complementary goals of an accurately spatially distributed dose distribution while still adhering to the desired dose volume histograms. The resulting distribution can then be used for inverse-planning with a new spatial dose objective, or to create typical dose volume objectives for the canonical optimization pipeline. We investigated six treatment sites (633 patients for training and 113 patients for testing) and evaluated the mean absolute difference in all DVHs for the clinical and predicted dose distribution. The results on average are favorable in comparison to our previous approach (1.91 versus 2.57). Comparing our method with and without atlas-selection further validates that atlas-selection improved dose prediction on average in whole breast (0.64 versus 1.59), prostate (2.13 versus 4.07), and rectum (1.46 versus 3.29) while it is less important in breast cavity (0.79 versus 0.92) and lung (1.33 versus 1.27) for which there is high conformity and minimal dose shaping. In CNS brain, atlas-selection has the potential to be impactful (3.65 versus 5.09), but selecting the ideal atlas is the most challenging.

  4. Automated Voxel-Based Analysis of Volumetric Dynamic Contrast-Enhanced CT Data Improves Measurement of Serial Changes in Tumor Vascular Biomarkers

    SciTech Connect

    Coolens, Catherine; Driscoll, Brandon; Chung, Caroline; Shek, Tina; Gorjizadeh, Alborz; Ménard, Cynthia; Jaffray, David

    2015-01-01

    Objectives: Development of perfusion imaging as a biomarker requires more robust methodologies for quantification of tumor physiology that allow assessment of volumetric tumor heterogeneity over time. This study proposes a parametric method for automatically analyzing perfused tissue from volumetric dynamic contrast-enhanced (DCE) computed tomography (CT) scans and assesses whether this 4-dimensional (4D) DCE approach is more robust and accurate than conventional, region-of-interest (ROI)-based CT methods in quantifying tumor perfusion with preliminary evaluation in metastatic brain cancer. Methods and Materials: Functional parameter reproducibility and analysis of sensitivity to imaging resolution and arterial input function were evaluated in image sets acquired from a 320-slice CT with a controlled flow phantom and patients with brain metastases, whose treatments were planned for stereotactic radiation surgery and who consented to a research ethics board-approved prospective imaging biomarker study. A voxel-based temporal dynamic analysis (TDA) methodology was used at baseline, at day 7, and at day 20 after treatment. The ability to detect changes in kinetic parameter maps in clinical data sets was investigated for both 4D TDA and conventional 2D ROI-based analysis methods. Results: A total of 7 brain metastases in 3 patients were evaluated over the 3 time points. The 4D TDA method showed improved spatial efficacy and accuracy of perfusion parameters compared to ROI-based DCE analysis (P<.005), with a reproducibility error of less than 2% when tested with DCE phantom data. Clinically, changes in transfer constant from the blood plasma into the extracellular extravascular space (K{sub trans}) were seen when using TDA, with substantially smaller errors than the 2D method on both day 7 post radiation surgery (±13%; P<.05) and by day 20 (±12%; P<.04). Standard methods showed a decrease in K{sub trans} but with large uncertainty (111.6 ± 150.5) %. Conclusions

  5. Voxel-Based LIDAR Analysis and Applications

    NASA Astrophysics Data System (ADS)

    Hagstrom, Shea T.

    One of the greatest recent changes in the field of remote sensing is the addition of high-quality Light Detection and Ranging (LIDAR) instruments. In particular, the past few decades have been greatly beneficial to these systems because of increases in data collection speed and accuracy, as well as a reduction in the costs of components. These improvements allow modern airborne instruments to resolve sub-meter details, making them ideal for a wide variety of applications. Because LIDAR uses active illumination to capture 3D information, its output is fundamentally different from other modalities. Despite this difference, LIDAR datasets are often processed using methods appropriate for 2D images and that do not take advantage of its primary virtue of 3-dimensional data. It is this problem we explore by using volumetric voxel modeling. Voxel-based analysis has been used in many applications, especially medical imaging, but rarely in traditional remote sensing. In part this is because the memory requirements are substantial when handling large areas, but with modern computing and storage this is no longer a significant impediment. Our reason for using voxels to model scenes from LIDAR data is that there are several advantages over standard triangle-based models, including better handling of overlapping surfaces and complex shapes. We show how incorporating system position information from early in the LIDAR point cloud generation process allows radiometrically-correct transmission and other novel voxel properties to be recovered. This voxelization technique is validated on simulated data using the Digital Imaging and Remote Sensing Image Generation (DIRSIG) software, a first-principles based ray-tracer developed at the Rochester Institute of Technology. Voxel-based modeling of LIDAR can be useful on its own, but we believe its primary advantage is when applied to problems where simpler surface-based 3D models conflict with the requirement of realistic geometry. To

  6. Simplified programming and control of automated radiosynthesizers through unit operations

    PubMed Central

    2013-01-01

    Background Many automated radiosynthesizers for producing positron emission tomography (PET) probes provide a means for the operator to create custom synthesis programs. The programming interfaces are typically designed with the engineer rather than the radiochemist in mind, requiring lengthy programs to be created from sequences of low-level, non-intuitive hardware operations. In some cases, the user is even responsible for adding steps to update the graphical representation of the system. In light of these unnecessarily complex approaches, we have created software to perform radiochemistry on the ELIXYS radiosynthesizer with the goal of being intuitive and easy to use. Methods Radiochemists were consulted, and a wide range of radiosyntheses were analyzed to determine a comprehensive set of basic chemistry unit operations. Based around these operations, we created a software control system with a client–server architecture. In an attempt to maximize flexibility, the client software was designed to run on a variety of portable multi-touch devices. The software was used to create programs for the synthesis of several 18F-labeled probes on the ELIXYS radiosynthesizer, with [18F]FDG detailed here. To gauge the user-friendliness of the software, program lengths were compared to those from other systems. A small sample group with no prior radiosynthesizer experience was tasked with creating and running a simple protocol. Results The software was successfully used to synthesize several 18F-labeled PET probes, including [18F]FDG, with synthesis times and yields comparable to literature reports. The resulting programs were significantly shorter and easier to debug than programs from other systems. The sample group of naive users created and ran a simple protocol within a couple of hours, revealing a very short learning curve. The client–server architecture provided reliability, enabling continuity of the synthesis run even if the computer running the client software

  7. A Comparative evaluation of voxel-based spatial mapping in diffusion tensor imaging.

    PubMed

    Cabeen, Ryan P; Bastin, Mark E; Laidlaw, David H

    2017-02-01

    This paper presents a comparative evaluation of methods for automated voxel-based spatial mapping in diffusion tensor imaging studies. Such methods are an essential step in computational pipelines and provide anatomically comparable measurements across a population in atlas-based studies. To better understand their strengths and weaknesses, we tested a total of eight methods for voxel-based spatial mapping in two types of diffusion tensor templates. The methods were evaluated with respect to scan-rescan reliability and an application to normal aging. The methods included voxel-based analysis with and without smoothing, two types of region-based analysis, and combinations thereof with skeletonization. The templates included a study-specific template created with DTI-TK and the IIT template serving as a standard template. To control for other factors in the pipeline, the experiments used a common dataset, acquired at 1.5T with a single shell high angular resolution diffusion MR imaging protocol, and tensor-based spatial normalization with DTI-TK. Scan-rescan reliability was assessed using the coefficient of variation (CV) and intraclass correlation (ICC) in eight subjects with three scans each. Sensitivity to normal aging was assessed in a population of 80 subjects aged 25-65 years old, and methods were compared with respect to the anatomical agreement of significant findings and the R(2) of the associated models of fractional anisotropy. The results show that reliability depended greatly on the method used for spatial mapping. The largest differences in reliability were found when adding smoothing and comparing voxel-based and region-based analyses. Skeletonization and template type were found to have either a small or negligible effect on reliability. The aging results showed agreement among the methods in nine brain areas, with some methods showing more sensitivity than others. Skeletonization and smoothing were not major factors affecting sensitivity to aging

  8. ODVBA: Optimally-Discriminative Voxel-Based Analysis

    PubMed Central

    Davatzikos, Christos

    2012-01-01

    Gaussian smoothing of images prior to applying voxel-based statistics is an important step in Voxel-Based Analysis and Statistical Parametric Mapping (VBA-SPM), and is used to account for registration errors, to Gaussianize the data, and to integrate imaging signals from a region around each voxel. However, it has also become a limitation of VBA-SPM based methods, since it is often chosen empirically and lacks spatial adaptivity to the shape and spatial extent of the region of interest, such as a region of atrophy or functional activity. In this paper, we propose a new framework, named Optimally-Discriminative Voxel-Based Analysis (ODVBA), for determining the optimal spatially adaptive smoothing of images, followed by applying voxel-based group analysis. In ODVBA, Nonnegative Discriminative Projection is applied regionally to get the direction that best discriminates between two groups, e.g., patients and controls; this direction is equivalent to local filtering by an optimal kernel whose coefficients define the optimally discriminative direction. By considering all the neighborhoods that contain a given voxel, we then compose this information to produce the statistic for each voxel. Finally, permutation tests are used to obtain a statistical parametric map of group differences. ODVBA has been evaluated using simulated data in which the ground truth is known and with data from an Alzheimer’s disease (AD) study. The experimental results have shown that the proposed ODVBA can precisely describe the shape and location of structural abnormality. PMID:21324774

  9. Simplified dengue virus microwell plaque assay using an automated quantification program.

    PubMed

    Boonyasuppayakorn, Siwaporn; Suroengrit, Aphinya; Srivarangkul, Pimsiri; Yuttithamnon, Wanchalerm; Pankaew, Saran; Saelee, Thanaphon; Prompetchara, Eakachai; Salakij, Saran; Bhattarakosol, Parvapan

    2016-11-01

    The plaque assay is essential for virion quantitation but the classic protocol requires considerable efforts. A simplified dengue 96-well plaque assay with automated quantitation program is an alternative to access the level of infectious virus. Dengue plaque assay was simplified using LLC/MK2 cells and virus mixing simultaneously before semisolid addition. Results were obtained using a flatbed scanner and analysis by the self-written program optimized to manual reads. The newly developed microwell system was accurate to the standard assay because 19 independent titrations from all subtypes obtained from both systems differed less than a log10 p.f.u./ml with no significance (p>0.05) with good correlation (R(2)=0.9058). Coefficient of variations within and between assays, indicating assay reliability and repeatability, were 19.29%, and 12.50%, respectively. This method serves various experimental designs in drug discovery that requires viral titers assessment. Effective concentrations (EC90) results showed no significant difference between 24- and 96-well assays (p>0.05). Compound screening for potential antivirals and clinical isolate titrations were successfully arranged. The method contains distinguished features including protocol simplicity, less reagent consumption in microwell format, convenient and affordable data acquisition and analysis system.

  10. Regional gray matter abnormalities in patients with schizophrenia determined with optimized voxel-based morphometry

    NASA Astrophysics Data System (ADS)

    Guo, XiaoJuan; Yao, Li; Jin, Zhen; Chen, Kewei

    2006-03-01

    This study examined regional gray matter abnormalities across the whole brain in 19 patients with schizophrenia (12 males and 7 females), comparing with 11 normal volunteers (7 males and 4 females). The customized brain templates were created in order to improve spatial normalization and segmentation. Then automated preprocessing of magnetic resonance imaging (MRI) data was conducted using optimized voxel-based morphometry (VBM). The statistical voxel based analysis was implemented in terms of two-sample t-test model. Compared with normal controls, regional gray matter concentration in patients with schizophrenia was significantly reduced in the bilateral superior temporal gyrus, bilateral middle frontal and inferior frontal gyrus, right insula, precentral and parahippocampal areas, left thalamus and hypothalamus as well as, however, significant increases in gray matter concentration were not observed across the whole brain in the patients. This study confirms and extends some earlier findings on gray matter abnormalities in schizophrenic patients. Previous behavior and fMRI researches on schizophrenia have suggested that cognitive capacity decreased and self-conscious weakened in schizophrenic patients. These regional gray matter abnormalities determined through structural MRI with optimized VBM may be potential anatomic underpinnings of schizophrenia.

  11. A voxel-based approach to gray matter asymmetries.

    PubMed

    Luders, E; Gaser, C; Jancke, L; Schlaug, G

    2004-06-01

    Voxel-based morphometry (VBM) was used to analyze gray matter (GM) asymmetries in a large sample (n = 60) of male and female professional musicians with and without absolute pitch (AP). We chose to examine these particular groups because previous studies using traditional region-of-interest (ROI) analyses have shown differences in hemispheric asymmetry related to AP and gender. Voxel-based methods may have advantages over traditional ROI-based methods since the analysis can be performed across the whole brain with minimal user bias. After determining that the VBM method was sufficiently sensitive for the detection of differences in GM asymmetries between groups, we found that male AP musicians were more leftward lateralized in the anterior region of the planum temporale (PT) than male non-AP musicians. This confirmed the results of previous studies using ROI-based methods that showed an association between PT asymmetry and the AP phenotype. We further observed that male non-AP musicians revealed an increased leftward GM asymmetry in the postcentral gyrus compared to female non-AP musicians, again corroborating results of a previously published study using ROI-based methods. By analyzing hemispheric GM differences across our entire sample, we were able to partially confirm findings of previous studies using traditional morphometric techniques, as well as more recent, voxel-based analyses. In addition, we found some unusually pronounced GM asymmetries in our musician sample not previously detected in subjects unselected for musical training. Since we were able to validate gender- and AP-related brain asymmetries previously described using traditional ROI-based morphometric techniques, the results of our analyses support the use of VBM for examinations of GM asymmetries.

  12. molSimplify: A toolkit for automating discovery in inorganic chemistry.

    PubMed

    Ioannidis, Efthymios I; Gani, Terry Z H; Kulik, Heather J

    2016-08-15

    We present an automated, open source toolkit for the first-principles screening and discovery of new inorganic molecules and intermolecular complexes. Challenges remain in the automatic generation of candidate inorganic molecule structures due to the high variability in coordination and bonding, which we overcome through a divide-and-conquer tactic that flexibly combines force-field preoptimization of organic fragments with alignment to first-principles-trained metal-ligand distances. Exploration of chemical space is enabled through random generation of ligands and intermolecular complexes from large chemical databases. We validate the generated structures with the root mean squared (RMS) gradients evaluated from density functional theory (DFT), which are around 0.02 Ha/au across a large 150 molecule test set. Comparison of molSimplify results to full optimization with the universal force field reveals that RMS DFT gradients are improved by 40%. Seamless generation of input files, preparation and execution of electronic structure calculations, and post-processing for each generated structure aids interpretation of underlying chemical and energetic trends. © 2016 Wiley Periodicals, Inc.

  13. Cerebral atrophy in myotonic dystrophy: a voxel based morphometric study.

    PubMed

    Antonini, G; Mainero, C; Romano, A; Giubilei, F; Ceschin, V; Gragnani, F; Morino, S; Fiorelli, M; Soscia, F; Di Pasquale, A; Caramia, F

    2004-11-01

    Brain involvement in myotonic dystrophy type 1 (DM1) is characterised by cortical atrophy and white matter lesions. We compared the magnetic resonance imaging derived grey matter maps of 22 DM1 patients with those of matched, healthy controls using voxel based morphometry to evaluate the extension of global and regional cortical atrophy in DM1, as well as its relationships with clinical and genetic features. Patients had significantly reduced brain tissue volumes. Grey matter volume was inversely correlated with age; this inverse correlation was significantly stronger in DM1 than in controls. Neither the clinical and genetic characteristics nor white matter lesions were correlated with cortical atrophy. Grey matter atrophy was located mainly in the bilateral frontal and parietal lobes, in the bilateral middle temporal gyrus, and in the left superior temporal and occipital gyrus.

  14. Voxel-based morphometry in autopsy proven PSP and CBD.

    PubMed

    Josephs, Keith A; Whitwell, Jennifer L; Dickson, Dennis W; Boeve, Bradley F; Knopman, David S; Petersen, Ronald C; Parisi, Joseph E; Jack, Clifford R

    2008-02-01

    The aim of this study was to compare the patterns of grey and white matter atrophy on MRI in autopsy confirmed progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD), and to determine whether the patterns vary depending on the clinical syndrome. Voxel-based morphometry was used to compare patterns of atrophy in 13 PSP and 11 CBD subjects and 24 controls. PSP and CBD subjects were also subdivided into those with a dominant dementia or extrapyramidal syndrome. PSP subjects showed brainstem atrophy with involvement of the cortex and underlying white matter. Frontoparietal grey and subcortical grey matter atrophy occurred in CBD. When subdivided, PSP subjects with an extrapyramidal syndrome had more brainstem atrophy and less cortical atrophy than CBD subjects with an extrapyramidal syndrome. PSP subjects with a dementia syndrome had more subcortical white matter atrophy than CBD subjects with a dementia syndrome. These results show regional differences between PSP and CBD that are useful in predicting the underlying pathology, and help to shed light on the in vivo distribution of regional atrophy in PSP and CBD.

  15. Finding significantly connected voxels based on histograms of connection strengths

    NASA Astrophysics Data System (ADS)

    Kasenburg, Niklas; Pedersen, Morten Vester; Darkner, Sune

    2016-03-01

    We explore a new approach for structural connectivity based segmentations of subcortical brain regions. Connectivity based segmentations are usually based on fibre connections from a seed region to predefined target regions. We present a method for finding significantly connected voxels based on the distribution of connection strengths. Paths from seed voxels to all voxels in a target region are obtained from a shortest-path tractography. For each seed voxel we approximate the distribution with a histogram of path scores. We hypothesise that the majority of estimated connections are false-positives and that their connection strength is distributed differently from true-positive connections. Therefore, an empirical null-distribution is defined for each target region as the average normalized histogram over all voxels in the seed region. Single histograms are then tested against the corresponding null-distribution and significance is determined using the false discovery rate (FDR). Segmentations are based on significantly connected voxels and their FDR. In this work we focus on the thalamus and the target regions were chosen by dividing the cortex into a prefrontal/temporal zone, motor zone, somatosensory zone and a parieto-occipital zone. The obtained segmentations consistently show a sparse number of significantly connected voxels that are located near the surface of the anterior thalamus over a population of 38 subjects.

  16. Voxel Based Morphometry in Optical Coherence Tomography: Validation & Core Findings

    PubMed Central

    Antony, Bhavna J.; Chen, Min; Carass, Aaron; Jedynak, Bruno M.; Al-Louzi, Omar; Solomon, Sharon D.; Saidha, Shiv; Calabresi, Peter A.; Prince, Jerry L.

    2016-01-01

    Optical coherence tomography (OCT) of the human retina is now becoming established as an important modality for the detection and tracking of various ocular diseases. Voxel based morphometry (VBM) is a long standing neuroimaging analysis technique that allows for the exploration of the regional differences in the brain. There has been limited work done in developing registration based methods for OCT, which has hampered the advancement of VBM analyses in OCT based population studies. Following on from our recent development of an OCT registration method, we explore the potential benefits of VBM analysis in cohorts of healthy controls (HCs) and multiple sclerosis (MS) patients. Specifically, we validate the stability of VBM analysis in two pools of HCs showing no significant difference between the two populations. Additionally, we also present a retrospective study of age and sex matched HCs and relapsing remitting MS patients, demonstrating results consistent with the reported literature while providing insight into the retinal changes associated with this MS subtype. PMID:27199503

  17. Simplifying the construction of domain-specific automatic programming systems: The NASA automated software development workstation project

    NASA Technical Reports Server (NTRS)

    Allen, Bradley P.; Holtzman, Peter L.

    1987-01-01

    An overview is presented of the Automated Software Development Workstation Project, an effort to explore knowledge-based approaches to increasing software productivity. The project focuses on applying the concept of domain specific automatic programming systems (D-SAPSs) to application domains at NASA's Johnson Space Center. A version of a D-SAPS developed in Phase 1 of the project for the domain of space station momentum management is described. How problems encountered during its implementation led researchers to concentrate on simplifying the process of building and extending such systems is discussed. Researchers propose to do this by attacking three observed bottlenecks in the D-SAPS development process through the increased automation of the acquisition of programming knowledge and the use of an object oriented development methodology at all stages of the program design. How these ideas are being implemented in the Bauhaus, a prototype workstation for D-SAPS development is discussed.

  18. Simplifying the construction of domain-specific automatic programming systems: The NASA automated software development workstation project

    NASA Technical Reports Server (NTRS)

    Allen, Bradley P.; Holtzman, Peter L.

    1988-01-01

    An overview is presented of the Automated Software Development Workstation Project, an effort to explore knowledge-based approaches to increasing software productivity. The project focuses on applying the concept of domain specific automatic programming systems (D-SAPSs) to application domains at NASA's Johnson Space Flight Center. A version of a D-SAPS developed in Phase 1 of the project for the domain of space station momentum management is described. How problems encountered during its implementation led researchers to concentrate on simplifying the process of building and extending such systems is discussed. Researchers propose to do this by attacking three observed bottlenecks in the D-SAPS development process through the increased automation of the acquisition of programming knowledge and the use of an object oriented development methodology at all stages of the program design. How these ideas are being implemented in the Bauhaus, a prototype workstation for D-SAPS development is discussed.

  19. Voxel-Based Lesion Symptom Mapping of Coarse Coding and Suppression Deficits in Patients With Right Hemisphere Damage

    PubMed Central

    Tompkins, Connie A.; Meigh, Kimberly M.; Prat, Chantel S.

    2015-01-01

    Purpose This study examined right hemisphere (RH) neuroanatomical correlates of lexical–semantic deficits that predict narrative comprehension in adults with RH brain damage. Coarse semantic coding and suppression deficits were related to lesions by voxel-based lesion symptom mapping. Method Participants were 20 adults with RH cerebrovascular accidents. Measures of coarse coding and suppression deficits were computed from lexical decision reaction times at short (175 ms) and long (1000 ms) prime-target intervals. Lesions were drawn on magnetic resonance imaging images and through normalization were registered on an age-matched brain template. Voxel-based lesion symptom mapping analysis was applied to build a general linear model at each voxel. Z score maps were generated for each deficit, and results were interpreted using automated anatomical labeling procedures. Results A deficit in coarse semantic activation was associated with lesions to the RH posterior middle temporal gyrus, dorsolateral prefrontal cortex, and lenticular nuclei. A maintenance deficit for coarsely coded representations involved the RH temporal pole and dorsolateral prefrontal cortex more medially. Ineffective suppression implicated lesions to the RH inferior frontal gyrus and subcortical regions, as hypothesized, along with the rostral temporal pole. Conclusion Beyond their scientific implications, these lesion–deficit correspondences may help inform the clinical diagnosis and enhance decisions about candidacy for deficit-focused treatment to improve narrative comprehension in individuals with RH damage. PMID:26425785

  20. Neural Correlates of Communication Skill and Symptom Severity in Autism: A Voxel-Based Morphometry Study

    ERIC Educational Resources Information Center

    Parks, Lauren K.; Hill, Dina E.; Thoma, Robert J.; Euler, Matthew J.; Lewine, Jeffrey D.; Yeo, Ronald A.

    2009-01-01

    Although many studies have compared the brains of normal controls and individuals with autism, especially older, higher-functioning individuals with autism, little is known of the neural correlates of the vast clinical heterogeneity characteristic of the disorder. In this study, we used voxel-based morphometry (VBM) to examine gray matter…

  1. Potential of Laboratory Execution Systems (LESs) to Simplify the Application of Business Process Management Systems (BPMSs) in Laboratory Automation.

    PubMed

    Neubert, Sebastian; Göde, Bernd; Gu, Xiangyu; Stoll, Norbert; Thurow, Kerstin

    2017-04-01

    Modern business process management (BPM) is increasingly interesting for laboratory automation. End-to-end workflow automation and improved top-level systems integration for information technology (IT) and automation systems are especially prominent objectives. With the ISO Standard Business Process Model and Notation (BPMN) 2.X, a system-independent and interdisciplinary accepted graphical process control notation is provided, allowing process analysis, while also being executable. The transfer of BPM solutions to structured laboratory automation places novel demands, for example, concerning the real-time-critical process and systems integration. The article discusses the potential of laboratory execution systems (LESs) for an easier implementation of the business process management system (BPMS) in hierarchical laboratory automation. In particular, complex application scenarios, including long process chains based on, for example, several distributed automation islands and mobile laboratory robots for a material transport, are difficult to handle in BPMSs. The presented approach deals with the displacement of workflow control tasks into life science specialized LESs, the reduction of numerous different interfaces between BPMSs and subsystems, and the simplification of complex process modelings. Thus, the integration effort for complex laboratory workflows can be significantly reduced for strictly structured automation solutions. An example application, consisting of a mixture of manual and automated subprocesses, is demonstrated by the presented BPMS-LES approach.

  2. Postprocessing of Voxel-Based Topologies for Additive Manufacturing Using the Computational Geometry Algorithms Library (CGAL)

    DTIC Science & Technology

    2015-06-01

    that a structure is built up by layers. Typically, additive manufacturing devices (3-dimensional [3-D] printers , e.g.), use the stereolithography (STL...begin with a standard, voxel-based topology optimization scheme and end with an STL file, ready for use in a 3-D printer or other additive manufacturing...S, Yvinec M. Cgal 4.6 - 3d alpha shapes. 2015 [accessed 2015 May 18]. http://doc.cgal.org/latest/Alpha_shapes_3/index.html#Chapter_3D_ Alpha_Shapes

  3. Spatial indices for measuring three-dimensional patterns in a voxel-based space

    NASA Astrophysics Data System (ADS)

    Jjumba, Anthony; Dragićević, Suzana

    2016-07-01

    Spatial indices are used to quantitatively describe the spatial arrangements of the features within a study region. However, most of the indices used are two-dimensional in their representation of the surface characteristics, and this is insufficient to quantify the three-dimensional properties of an area or geospatial features. With the increased availability of 3D data from laser scanning and other collection methods, a voxel-based representation of space is an important methodology that allows for an intuitive visualization of geospatial features and their analysis with 3D GIS techniques. The objective of this study is to conceptualize, develop, and implement indices that can characterize three-dimensional space and can be used to analyze the structure of spatial features in a landscape. The indices for three-dimensional space that are implemented are, namely, surface area volume, fractal dimension, lacunarity, and Moran's I which are all useful in the quantification of spatial organization found in ecological landscapes. In addition to providing the quantitative descriptors, the results indicate that a voxel-based representation provides a straightforward means of characterizing the form and composition of the spatial features using 3D indices.

  4. Towards a voxel-based geographic automata for the simulation of geospatial processes

    NASA Astrophysics Data System (ADS)

    Jjumba, Anthony; Dragićević, Suzana

    2016-07-01

    Many geographic processes evolve in a three dimensional space and time continuum. However, when they are represented with the aid of geographic information systems (GIS) or geosimulation models they are modelled in a framework of two-dimensional space with an added temporal component. The objective of this study is to propose the design and implementation of voxel-based automata as a methodological approach for representing spatial processes evolving in the four-dimensional (4D) space-time domain. Similar to geographic automata models which are developed to capture and forecast geospatial processes that change in a two-dimensional spatial framework using cells (raster geospatial data), voxel automata rely on the automata theory and use three-dimensional volumetric units (voxels). Transition rules have been developed to represent various spatial processes which range from the movement of an object in 3D to the diffusion of airborne particles and landslide simulation. In addition, the proposed 4D models demonstrate that complex processes can be readily reproduced from simple transition functions without complex methodological approaches. The voxel-based automata approach provides a unique basis to model geospatial processes in 4D for the purpose of improving representation, analysis and understanding their spatiotemporal dynamics. This study contributes to the advancement of the concepts and framework of 4D GIS.

  5. Voxel-Based Neighborhood for Spatial Shape Pattern Classification of Lidar Point Clouds with Supervised Learning.

    PubMed

    Plaza-Leiva, Victoria; Gomez-Ruiz, Jose Antonio; Mandow, Anthony; García-Cerezo, Alfonso

    2017-03-15

    Improving the effectiveness of spatial shape features classification from 3D lidar data is very relevant because it is largely used as a fundamental step towards higher level scene understanding challenges of autonomous vehicles and terrestrial robots. In this sense, computing neighborhood for points in dense scans becomes a costly process for both training and classification. This paper proposes a new general framework for implementing and comparing different supervised learning classifiers with a simple voxel-based neighborhood computation where points in each non-overlapping voxel in a regular grid are assigned to the same class by considering features within a support region defined by the voxel itself. The contribution provides offline training and online classification procedures as well as five alternative feature vector definitions based on principal component analysis for scatter, tubular and planar shapes. Moreover, the feasibility of this approach is evaluated by implementing a neural network (NN) method previously proposed by the authors as well as three other supervised learning classifiers found in scene processing methods: support vector machines (SVM), Gaussian processes (GP), and Gaussian mixture models (GMM). A comparative performance analysis is presented using real point clouds from both natural and urban environments and two different 3D rangefinders (a tilting Hokuyo UTM-30LX and a Riegl). Classification performance metrics and processing time measurements confirm the benefits of the NN classifier and the feasibility of voxel-based neighborhood.

  6. Voxel Based Representation of Full-Waveform Airborne Laser Scanner Data for Forestry Applications

    NASA Astrophysics Data System (ADS)

    Stelling, N.; Richter, K.

    2016-06-01

    The advantages of using airborne full-waveform laser scanner data in forest applications, e.g. for the description of the vertical vegetation structure or accurate biomass estimation, have been emphasized in many publications. To exploit the full potential offered by airborne full-waveform laser scanning data, the development of voxel based methods for data analysis is essential. In contrast to existing approaches based on the extraction of discrete 3D points by a Gaussian decomposition, it is very promising to derive the voxel attributes from the digitised waveform directly. For this purpose, the waveform data have to be transferred into a 3D voxel representation. This requires a series of radiometric and geometric transformations of the raw full-waveform laser scanner data. Thus, the paper deals with the geometric aspects and describes a processing chain from the raw waveform data to an attenuationcorrected volumetric forest stand reconstruction. The integration of attenuation-corrected waveform data into the voxel space is realised with an efficient parametric voxel traversal method operating on an octree data structure. The voxel attributes are derived from the amplitudes of the attenuation-corrected waveforms. Additionally, a new 3D filtering approach is presented to eliminate non-object voxel. Applying these methods to real full-waveform laser scanning data, a voxel based representation of a spruce was generated combining three flight strips from different viewing directions.

  7. Voxel-Based Neighborhood for Spatial Shape Pattern Classification of Lidar Point Clouds with Supervised Learning

    PubMed Central

    Plaza-Leiva, Victoria; Gomez-Ruiz, Jose Antonio; Mandow, Anthony; García-Cerezo, Alfonso

    2017-01-01

    Improving the effectiveness of spatial shape features classification from 3D lidar data is very relevant because it is largely used as a fundamental step towards higher level scene understanding challenges of autonomous vehicles and terrestrial robots. In this sense, computing neighborhood for points in dense scans becomes a costly process for both training and classification. This paper proposes a new general framework for implementing and comparing different supervised learning classifiers with a simple voxel-based neighborhood computation where points in each non-overlapping voxel in a regular grid are assigned to the same class by considering features within a support region defined by the voxel itself. The contribution provides offline training and online classification procedures as well as five alternative feature vector definitions based on principal component analysis for scatter, tubular and planar shapes. Moreover, the feasibility of this approach is evaluated by implementing a neural network (NN) method previously proposed by the authors as well as three other supervised learning classifiers found in scene processing methods: support vector machines (SVM), Gaussian processes (GP), and Gaussian mixture models (GMM). A comparative performance analysis is presented using real point clouds from both natural and urban environments and two different 3D rangefinders (a tilting Hokuyo UTM-30LX and a Riegl). Classification performance metrics and processing time measurements confirm the benefits of the NN classifier and the feasibility of voxel-based neighborhood. PMID:28294963

  8. Voxel based morphometry in optical coherence tomography: validation and core findings

    NASA Astrophysics Data System (ADS)

    Antony, Bhavna J.; Chen, Min; Carass, Aaron; Jedynak, Bruno M.; Al-Louzi, Omar; Solomon, Sharon D.; Saidha, Shiv; Calabresi, Peter A.; Prince, Jerry L.

    2016-03-01

    Optical coherence tomography (OCT) of the human retina is now becoming established as an important modality for the detection and tracking of various ocular diseases. Voxel based morphometry (VBM) is a long standing neuroimaging analysis technique that allows for the exploration of the regional differences in the brain. There has been limited work done in developing registration based methods for OCT, which has hampered the advancement of VBM analyses in OCT based population studies. Following on from our recent development of an OCT registration method, we explore the potential benefits of VBM analysis in cohorts of healthy controls (HCs) and multiple sclerosis (MS) patients. Specifically, we validate the stability of VBM analysis in two pools of HCs showing no significant difference between the two populations. Additionally, we also present a retrospective study of age and sex matched HCs and relapsing remitting MS patients, demonstrating results consistent with the reported literature while providing insight into the retinal changes associated with this MS subtype.

  9. Voxel-based morphometry in patients with cryptogenic occipital epilepsies. Preliminary data.

    PubMed

    Bilo, L; De Leva, M F; Meo, R; Tortora, F; Esposito, F; Aragri, A; Elefante, A

    2010-03-01

    We evaluated the differences in grey matter concentration (GMC) by voxel-based morphometry (VBM) in patients with cryptogenic occipital epilepsies. VBM analysis was performed in 11 patients with cryptogenic occipital epilepsies compared to 11 healthy controls. VBM analysis in patients revealed focal areas of reduced GMC in the occipital cortex and, more interestingly, increased GMC in the midbrain tegmentum and basal ganglia (globus pallidus and thalamus). VBM may disclose slight structural abnormalities in the brain of cryptogenic epilepsy patients, not evident with standard MRI. To the best of our knowledge, this is the first literature report describing areas of altered GMC in patients with occipital epilepsy. We hypothesize that these findings might be related to epileptic discharges and/or their diffusion and suggest that midbrain, globus pallidus and thalamus may be part of a functional network originating from the occipital areas.

  10. Voxel-based morphometry predicts shifts in dendritic spine density and morphology with auditory fear conditioning.

    PubMed

    Keifer, O P; Hurt, R C; Gutman, D A; Keilholz, S D; Gourley, S L; Ressler, K J

    2015-07-07

    Neuroimaging has provided compelling data about the brain. Yet the underlying mechanisms of many neuroimaging techniques have not been elucidated. Here we report a voxel-based morphometry (VBM) study of Thy1-YFP mice following auditory fear conditioning complemented by confocal microscopy analysis of cortical thickness, neuronal morphometric features and nuclei size/density. Significant VBM results included the nuclei of the amygdala, the insula and the auditory cortex. There were no significant VBM changes in a control brain area. Focusing on the auditory cortex, confocal analysis showed that fear conditioning led to a significantly increased density of shorter and wider dendritic spines, while there were no spine differences in the control area. Of all the morphology metrics studied, the spine density was the only one to show significant correlation with the VBM signal. These data demonstrate that learning-induced structural changes detected by VBM may be partially explained by increases in dendritic spine density.

  11. A voxel-based neural approach (VBNA) to identify lung nodules in the ANODE09 study

    NASA Astrophysics Data System (ADS)

    Retico, Alessandra; Bagagli, Francesco; Camarlinghi, Niccolo; Carpentieri, Carmela; Fantacci, Maria Evelina; Gori, Ilaria

    2009-02-01

    The computer-aided detection (CAD) system we applied on the ANODE09 dataset is devoted to identify pulmonary nodules in low-dose and thin-slice computed tomography (CT) images: we developed two different systems for internal (CADI) and juxtapleural nodules (CADJP) in the framework of the italian MAGIC-5 collaboration. The basic modules of CADI subsystem are: a 3D dot-enhancement algorithm for nodule candidate identification and an original approach, we referred as Voxel-Based Neural Approach (VBNA), to reduce the amount of false-positive findings based on a neural classifier working at the voxel level. To detect juxtapleural nodules we developed the CADJP subsystem based on a procedure enhancing regions where many pleura surface normals intersect, followed by a VBNA classification. We present both the FROC curves we obtained on the 5 annotated ANODE09 example dataset, and on all the ANODE09 50 test cases.

  12. Volumetric and voxel-based morphometry findings in autism subjects with and without macrocephaly.

    PubMed

    Bigler, Erin D; Abildskov, Tracy J; Petrie, Jo Ann; Johnson, Michael; Lange, Nicholas; Chipman, Jonathan; Lu, Jeffrey; McMahon, William; Lainhart, Janet E

    2010-01-01

    This study sought to replicate Herbert et al. (2003a), which found increased overall white matter (WM) volume in subjects with autism, even after controlling for head size differences. To avoid the possibility that greater WM volume in autism is merely an epiphenomena of macrocephaly overrepresentation associated with the disorder, the current study included control subjects with benign macrocephaly. The control group also included subjects with a reading disability to insure cognitive heterogeneity. WM volume in autism was significantly larger, even when controlling for brain volume, rate of macrocephaly, and other demographic variables. Autism and controls differed little on whole-brain WM voxel-based morphometry (VBM) analyses suggesting that the overall increase in WM volume was non-localized. Autism subjects exhibited a differential pattern of IQ relationships with brain volumetry findings from controls. Current theories of brain overgrowth and their importance in the development of autism are discussed in the context of these findings.

  13. Feasibility of voxel-based statistical analysis method for myocardial PET

    NASA Astrophysics Data System (ADS)

    Ram Yu, A.; Kim, Jin Su; Paik, Chang H.; Kim, Kyeong Min; Moo Lim, Sang

    2014-09-01

    Although statistical parametric mapping (SPM) analysis is widely used in neuroimaging studies, to our best knowledge, there was no application to myocardial PET data analysis. In this study, we developed the voxel based statistical analysis method for myocardial PET which provides statistical comparison results between groups in image space. PET Emission data of normal and myocardial infarction rats were acquired For the SPM analysis, a rat heart template was created. In addition, individual PET data was spatially normalized and smoothed. Two sample t-tests were performed to identify the myocardial infarct region. This developed SPM method was compared with conventional ROI methods. Myocardial glucose metabolism was decreased in the lateral wall of the left ventricle. In the result of ROI analysis, the mean value of the lateral wall was 29% decreased. The newly developed SPM method for myocardial PET could provide quantitative information in myocardial PET study.

  14. Volumetric and Voxel-Based Morphometry Findings in Autism Subjects With and Without Macrocephaly

    PubMed Central

    Bigler, Erin D.; Abildskov, Tracy J.; Petrie, Jo Ann; Johnson, Michael; Lange, Nicholas; Chipman, Jonathan; Lu, Jeffrey; McMahon, William; Lainhart, Janet E.

    2015-01-01

    This study sought to replicate Herbert et al. (2003a), which found increased overall white matter (WM) volume in subjects with autism, even after controlling for head size differences. To avoid the possibility that greater WM volume in autism is merely an epiphenomena of macrocephaly over-representation associated with the disorder, the current study included control subjects with benign macrocephaly. The control group also included subjects with a reading disability to insure cognitive heterogeneity. WM volume in autism was significantly larger, even when controlling for brain volume, rate of macrocephaly, and other demographic variables. Autism and controls differed little on whole-brain WM voxel-based morphometry (VBM) analyses suggesting that the overall increase in WM volume was non-localized. Autism subjects exhibited a differential pattern of IQ relationships with brain volumetry findings from controls. Current theories of brain overgrowth and their importance in the development of autism are discussed in the context of these findings. PMID:20446133

  15. A voxel-based finite element model for the prediction of bladder deformation

    SciTech Connect

    Chai Xiangfei; Herk, Marcel van; Hulshof, Maarten C. C. M.; Bel, Arjan

    2012-01-15

    Purpose: A finite element (FE) bladder model was previously developed to predict bladder deformation caused by bladder filling change. However, two factors prevent a wide application of FE models: (1) the labor required to construct a FE model with high quality mesh and (2) long computation time needed to construct the FE model and solve the FE equations. In this work, we address these issues by constructing a low-resolution voxel-based FE bladder model directly from the binary segmentation images and compare the accuracy and computational efficiency of the voxel-based model used to simulate bladder deformation with those of a classical FE model with a tetrahedral mesh. Methods: For ten healthy volunteers, a series of MRI scans of the pelvic region was recorded at regular intervals of 10 min over 1 h. For this series of scans, the bladder volume gradually increased while rectal volume remained constant. All pelvic structures were defined from a reference image for each volunteer, including bladder wall, small bowel, prostate (male), uterus (female), rectum, pelvic bone, spine, and the rest of the body. Four separate FE models were constructed from these structures: one with a tetrahedral mesh (used in previous study), one with a uniform hexahedral mesh, one with a nonuniform hexahedral mesh, and one with a low-resolution nonuniform hexahedral mesh. Appropriate material properties were assigned to all structures and uniform pressure was applied to the inner bladder wall to simulate bladder deformation from urine inflow. Performance of the hexahedral meshes was evaluated against the performance of the standard tetrahedral mesh by comparing the accuracy of bladder shape prediction and computational efficiency. Results: FE model with a hexahedral mesh can be quickly and automatically constructed. No substantial differences were observed between the simulation results of the tetrahedral mesh and hexahedral meshes (<1% difference in mean dice similarity coefficient to

  16. Diffuse Decreased Gray Matter in Patients with Idiopathic Craniocervical Dystonia: A Voxel-Based Morphometry Study

    PubMed Central

    Piccinin, Camila C.; Piovesana, Luiza G.; Santos, Maria C. A.; Guimarães, Rachel P.; De Campos, Brunno M.; Rezende, Thiago J. R.; Campos, Lidiane S.; Torres, Fabio R.; Amato-Filho, Augusto C.; França, Marcondes C.; Lopes-Cendes, Iscia; Cendes, Fernando; D’Abreu, Anelyssa

    2015-01-01

    Background: Recent studies have addressed the role of structures other than the basal ganglia in the pathophysiology of craniocervical dystonia (CCD). Neuroimaging studies have attempted to identify structural abnormalities in CCD but a clear pattern of alteration has not been established. We performed whole-brain evaluation using voxel-based morphometry (VBM) to identify patterns of gray matter (GM) changes in CCD. Methods: We compared 27 patients with CCD matched in age and gender to 54 healthy controls. VBM was used to compare GM volumes. We created a two-sample t-test corrected for subjects’ age, and we tested with a level of significance of p < 0.001 and false discovery rate (FDR) correction (p < 0.05). Results: Voxel-based morphometry demonstrated significant reductions of GM using p < 0.001 in the cerebellar vermis IV/V, bilaterally in the superior frontal gyrus, precuneus, anterior cingulate and paracingulate, insular cortex, lingual gyrus, and calcarine fissure; in the left hemisphere in the supplementary motor area, inferior frontal gyrus, inferior parietal gyrus, temporal pole, supramarginal gyrus, rolandic operculum, hippocampus, middle occipital gyrus, cerebellar lobules IV/V, superior, and middle temporal gyri; in the right hemisphere, the middle cingulate and precentral gyrus. Our study did not report any significant result using the FDR correction. We also detected correlations between GM volume and age, disease duration, duration of botulinum toxin treatment, and the Marsden–Fahn dystonia scale scores. Conclusion: We detected large clusters of GM changes chiefly in structures primarily involved in sensorimotor integration, motor planning, visuospatial function, and emotional processing. PMID:25620953

  17. Voxel-based analysis of grey and white matter degeneration in cervical spondylotic myelopathy

    PubMed Central

    Grabher, Patrick; Mohammadi, Siawoosh; Trachsler, Aaron; Friedl, Susanne; David, Gergely; Sutter, Reto; Weiskopf, Nikolaus; Thompson, Alan J.; Curt, Armin; Freund, Patrick

    2016-01-01

    In this prospective study, we made an unbiased voxel-based analysis to investigate above-stenosis spinal degeneration and its relation to impairment in patients with cervical spondylotic myelopathy (CSM). Twenty patients and 18 controls were assessed with high-resolution MRI protocols above the level of stenosis. Cross-sectional areas of grey matter (GM), white matter (WM), and posterior columns (PC) were measured to determine atrophy. Diffusion indices assessed tract-specific integrity of PC and lateral corticospinal tracts (CST). Regression analysis was used to reveal relationships between MRI measures and clinical impairment. Patients showed mainly sensory impairment. Atrophy was prominent within the cervical WM (13.9%, p = 0.004), GM (7.2%, p = 0.043), and PC (16.1%, p = 0.005). Fractional anisotropy (FA) was reduced in the PC (−11.98%, p = 0.006) and lateral CST (−12.96%, p = 0.014). In addition, radial (+28.47%, p = 0.014), axial (+14.72%, p = 0.005), and mean (+16.50%, p = 0.001) diffusivities were increased in the PC. Light-touch score was associated with atrophy (R2 = 0.3559, p = 0.020) and FA (z score 3.74, p = 0.003) in the PC, as was functional independence and FA in the lateral CST (z score 3.68, p = 0.020). This study demonstrates voxel-based degeneration far above the stenosis at a level not directly affected by the compression and provides unbiased readouts of tract-specific changes that relate to impairment. PMID:27095134

  18. A voxel-based mouse for internal dose calculations using Monte Carlo simulations (MCNP)

    NASA Astrophysics Data System (ADS)

    Bitar, A.; Lisbona, A.; Thedrez, P.; Sai Maurel, C.; LeForestier, D.; Barbet, J.; Bardies, M.

    2007-02-01

    Murine models are useful for targeted radiotherapy pre-clinical experiments. These models can help to assess the potential interest of new radiopharmaceuticals. In this study, we developed a voxel-based mouse for dosimetric estimates. A female nude mouse (30 g) was frozen and cut into slices. High-resolution digital photographs were taken directly on the frozen block after each section. Images were segmented manually. Monoenergetic photon or electron sources were simulated using the MCNP4c2 Monte Carlo code for each source organ, in order to give tables of S-factors (in Gy Bq-1 s-1) for all target organs. Results obtained from monoenergetic particles were then used to generate S-factors for several radionuclides of potential interest in targeted radiotherapy. Thirteen source and 25 target regions were considered in this study. For each source region, 16 photon and 16 electron energies were simulated. Absorbed fractions, specific absorbed fractions and S-factors were calculated for 16 radionuclides of interest for targeted radiotherapy. The results obtained generally agree well with data published previously. For electron energies ranging from 0.1 to 2.5 MeV, the self-absorbed fraction varies from 0.98 to 0.376 for the liver, and from 0.89 to 0.04 for the thyroid. Electrons cannot be considered as 'non-penetrating' radiation for energies above 0.5 MeV for mouse organs. This observation can be generalized to radionuclides: for example, the beta self-absorbed fraction for the thyroid was 0.616 for I-131; absorbed fractions for Y-90 for left kidney-to-left kidney and for left kidney-to-spleen were 0.486 and 0.058, respectively. Our voxel-based mouse allowed us to generate a dosimetric database for use in preclinical targeted radiotherapy experiments.

  19. Dyslexia and Voxel-Based Morphometry: Correlations between Five Behavioural Measures of Dyslexia and Gray and White Matter Volumes

    ERIC Educational Resources Information Center

    Tamboer, Peter; Scholte, H. Steven; Vorst, Harrie C. M.

    2015-01-01

    In voxel-based morphometry studies of dyslexia, the relation between causal theories of dyslexia and gray matter (GM) and white matter (WM) volume alterations is still under debate. Some alterations are consistently reported, but others failed to reach significance. We investigated GM alterations in a large sample of Dutch students (37 dyslexics…

  20. The Neural Basis of Reversible Sentence Comprehension: Evidence from Voxel-Based Lesion Symptom Mapping in Aphasia

    ERIC Educational Resources Information Center

    Thothathiri, Malathi; Kimberg, Daniel Y.; Schwartz, Myrna F.

    2012-01-01

    We explored the neural basis of reversible sentence comprehension in a large group of aphasic patients (n = 79). Voxel-based lesion symptom mapping revealed a significant association between damage in temporo-parietal cortex and impaired sentence comprehension. This association remained after we controlled for phonological working memory. We…

  1. A voxel-based multiscale model to simulate the radiation response of hypoxic tumors

    SciTech Connect

    Espinoza, I.; Peschke, P.; Karger, C. P.

    2015-01-15

    Purpose: In radiotherapy, it is important to predict the response of tumors to irradiation prior to the treatment. This is especially important for hypoxic tumors, which are known to be highly radioresistant. Mathematical modeling based on the dose distribution, biological parameters, and medical images may help to improve this prediction and to optimize the treatment plan. Methods: A voxel-based multiscale tumor response model for simulating the radiation response of hypoxic tumors was developed. It considers viable and dead tumor cells, capillary and normal cells, as well as the most relevant biological processes such as (i) proliferation of tumor cells, (ii) hypoxia-induced angiogenesis, (iii) spatial exchange of cells leading to tumor growth, (iv) oxygen-dependent cell survival after irradiation, (v) resorption of dead cells, and (vi) spatial exchange of cells leading to tumor shrinkage. Oxygenation is described on a microscopic scale using a previously published tumor oxygenation model, which calculates the oxygen distribution for each voxel using the vascular fraction as the most important input parameter. To demonstrate the capabilities of the model, the dependence of the oxygen distribution on tumor growth and radiation-induced shrinkage is investigated. In addition, the impact of three different reoxygenation processes is compared and tumor control probability (TCP) curves for a squamous cells carcinoma of the head and neck (HNSSC) are simulated under normoxic and hypoxic conditions. Results: The model describes the spatiotemporal behavior of the tumor on three different scales: (i) on the macroscopic scale, it describes tumor growth and shrinkage during radiation treatment, (ii) on a mesoscopic scale, it provides the cell density and vascular fraction for each voxel, and (iii) on the microscopic scale, the oxygen distribution may be obtained in terms of oxygen histograms. With increasing tumor size, the simulated tumors develop a hypoxic core. Within the

  2. Voxel-Based 3-D Tree Modeling from Lidar Images for Extracting Tree Structual Information

    NASA Astrophysics Data System (ADS)

    Hosoi, F.

    2014-12-01

    Recently, lidar (light detection and ranging) has been used to extracting tree structural information. Portable scanning lidar systems can capture the complex shape of individual trees as a 3-D point-cloud image. 3-D tree models reproduced from the lidar-derived 3-D image can be used to estimate tree structural parameters. We have proposed the voxel-based 3-D modeling for extracting tree structural parameters. One of the tree parameters derived from the voxel modeling is leaf area density (LAD). We refer to the method as the voxel-based canopy profiling (VCP) method. In this method, several measurement points surrounding the canopy and optimally inclined laser beams are adopted for full laser beam illumination of whole canopy up to the internal. From obtained lidar image, the 3-D information is reproduced as the voxel attributes in the 3-D voxel array. Based on the voxel attributes, contact frequency of laser beams on leaves is computed and LAD in each horizontal layer is obtained. This method offered accurate LAD estimation for individual trees and woody canopy trees. For more accurate LAD estimation, the voxel model was constructed by combining airborne and portable ground-based lidar data. The profiles obtained by the two types of lidar complemented each other, thus eliminating blind regions and yielding more accurate LAD profiles than could be obtained by using each type of lidar alone. Based on the estimation results, we proposed an index named laser beam coverage index, Ω, which relates to the lidar's laser beam settings and a laser beam attenuation factor. It was shown that this index can be used for adjusting measurement set-up of lidar systems and also used for explaining the LAD estimation error using different types of lidar systems. Moreover, we proposed a method to estimate woody material volume as another application of the voxel tree modeling. In this method, voxel solid model of a target tree was produced from the lidar image, which is composed of

  3. An MR image-guided, voxel-based partial volume correction method for PET images

    PubMed Central

    Wang, Hesheng; Fei, Baowei

    2012-01-01

    Purpose: Partial volume effect in positron emission tomography (PET) can cause incorrect quantification of radiopharmaceutical uptake in functional imaging. A PET partial volume correction method is presented to attenuate partial volume blurring and to yield voxel-based corrected PET images. Methods: By modeling partial volume effect as a convolution of point spread function of the PET scanner, the reconstructed PET images are corrected by iterative deconvolution with an edge-preserving smoothness constraint. The constraint is constructed to restore discontinuities extracted from coregistered MR images but maintains the smoothness in radioactivity distribution. The correction is implemented in a Bayesian deconvolution framework and is solved by a conjugate gradient method. The performance of the method was compared with the geometric transfer matrix (GTM) method on a simulated dataset. The method was evaluated on synthesized brain FDG–PET data and phantom MRI–PET experiments. Results: The true PET activity of objects with a size of greater than the full-width at half maximum of the point spread function has been effectively restored in the simulated data. The partial volume correction method is quantitatively comparable to the GTM method. For synthesized FDG–PET with true activity 0 μci/cc for cerebrospinal fluid (CSF), 228 μci/cc for white matter (WM), and 621 μci/cc for gray matter (GM), the method has improved the radioactivity quantification from 186 ± 16 μci/cc to 30 ± 7 μci/cc in CSF, 317 ± 15 μci/cc to 236 ± 10 μci/cc for WM, 438 ± 4 μci/cc to 592 ± 5 μci/cc for GM. Both visual and quantitative assessments show improvement of partial volume correction in the synthesized and phantom experiments. Conclusions: The partial volume correction method improves the quantification of PET images. The method is comparable to the GTM method but does not need MR image segmentation or prior tracer distribution information. The

  4. Skeletal dosimetry in a voxel-based rat phantom for internal exposures to photons and electrons

    SciTech Connect

    Xie Tianwu; Han Dao; Liu Yang; Sun Wenjuan; Liu Qian

    2010-05-15

    Purpose: The skeleton makes a significant contribution to the whole body absorbed dose evaluation of rats, since the bone marrow and bone surface in the skeleton express high radiosensitivity and are considered to be important dose-limiting tissues. The bone marrow can be categorized as red bone marrow (RBM) and yellow bone marrow (YBM). It is important to investigate the bone marrow in skeletal dosimetry. Methods: Cryosectional color images of the skeleton of a 156 g rat were segmented into mineral bone (including cortical bone and trabecular bone), RBM, and YBM. These three tissue types were identified at 40 different bone sites and integrated into a previously developed voxel-based rat computational phantom. Photon and electron skeletal absorbed fractions were then calculated using the MCNPX Monte Carlo code. Results: Absorbed fraction (AF) and specific absorbed fraction (SAF) for mineral bone, RBM, and YBM at the 40 different bone sites were established for monoenergetic photon and electron sources placed in 18 organs and seven bone sites. Discrete photon energy was varied from 0.01 to 5.0 MeV in 21 discrete steps, while 21 discrete electron energies were studied, from 0.1 to 10.0 MeV. The trends and values found were consistent with the results of other researchers [M. G. Stabin, T. E. Peterson, G. E. Holburn, and M. A. Emmons, ''Voxel-based mouse and rat models for internal dose calculations,'' J. Nucl. Med. 47, 655-659 (2006)]. S-factors for the radionuclides {sup 169}Er, {sup 143}Pr, {sup 89}Sr, {sup 32}P, and {sup 90}Y, located in 18 organs and seven bone sites for the skeleton, were calculated and are provided in detail. Conclusions: For internal dose calculations, the AF data reveal that the mineral bone in the rat skeletal system is responsible for significant attenuation of gamma rays, especially at low energies. The photon SAF curves of RBM show that, for photon energies greater than 0.6 MeV, there is an increase in secondary photons emitted from the

  5. Regional gray matter density associated with emotional intelligence: evidence from voxel-based morphometry.

    PubMed

    Takeuchi, Hikaru; Taki, Yasuyuki; Sassa, Yuko; Hashizume, Hiroshi; Sekiguchi, Atsushi; Fukushima, Ai; Kawashima, Ryuta

    2011-09-01

    Emotional Intelligence (EI) is the ability to monitor one's own and others' emotions and the ability to use the gathered information to guide one's thinking and action. EI is thought to be important for social life making it a popular subject of research. However, despite the existence of previous functional imaging studies on EI, the relationship between regional gray matter morphology and EI has never been investigated. We used voxel-based morphometry (VBM) and a questionnaire (Emotional Intelligence Scale) to measure EI to identify the gray matter correlates of each factor of individual EI (Intrapersonal factor, Interpersonal factor, Situation Management factor). We found significant negative relationships between the Intrapersonal factor and regional gray matter density (rGMD) (1-a) in an anatomical cluster that included the right anterior insula, (1-b) in the right cerebellum, (1-c) in an anatomical cluster that extends from the cuneus to the precuneus, (1-d) and in an anatomical cluster that extends from the medial prefrontal cortex to the left lateral fronto-polar cortex. We also found significant positive correlations between the Interpersonal factor and rGMD in the right superior temporal sulcus, and significant negative correlations between the Situation Management factor and rGMD in the ventromedial prefrontal cortex. These findings suggest that each factor of EI in healthy young people is related to the specific brain regions known to be involved in the networks of social cognition and self-related recognition, and in the somatic marker circuitry.

  6. Gray matter correlates of creative potential: A latent variable voxel-based morphometry study

    PubMed Central

    Jauk, Emanuel; Neubauer, Aljoscha C.; Dunst, Beate; Fink, Andreas; Benedek, Mathias

    2015-01-01

    There is increasing research interest in the structural and functional brain correlates underlying creative potential. Recent investigations found that interindividual differences in creative potential relate to volumetric differences in brain regions belonging to the default mode network, such as the precuneus. Yet, the complex interplay between creative potential, intelligence, and personality traits and their respective neural bases is still under debate. We investigated regional gray matter volume (rGMV) differences that can be associated with creative potential in a heterogeneous sample of N = 135 individuals using voxel-based morphometry (VBM). By means of latent variable modeling and consideration of recent psychometric advancements in creativity research, we sought to disentangle the effects of ideational originality and fluency as two independent indicators of creative potential. Intelligence and openness to experience were considered as common covariates of creative potential. The results confirmed and extended previous research: rGMV in the precuneus was associated with ideational originality, but not with ideational fluency. In addition, we found ideational originality to be correlated with rGMV in the caudate nucleus. The results indicate that the ability to produce original ideas is tied to default-mode as well as dopaminergic structures. These structural brain correlates of ideational originality were apparent throughout the whole range of intellectual ability and thus not moderated by intelligence. In contrast, structural correlates of ideational fluency, a quantitative marker of creative potential, were observed only in lower intelligent individuals in the cuneus/lingual gyrus. PMID:25676914

  7. Parahippocampal gray matter alterations in Spinocerebellar Ataxia Type 2 identified by voxel based morphometry.

    PubMed

    Mercadillo, Roberto E; Galvez, Víctor; Díaz, Rosalinda; Hernández-Castillo, Carlos Roberto; Campos-Romo, Aurelio; Boll, Marie-Catherine; Pasaye, Erick H; Fernandez-Ruiz, Juan

    2014-12-15

    Spinocerebellar Ataxia Type 2 (SCA2) is a genetic disorder causing cerebellar degeneration that result in motor and cognitive alterations. Voxel-based morphometry (VBM) analyses have found neurodegenerative patterns associated to SCA2, but they show some discrepancies. Moreover, behavioral deficits related to non-cerebellar functions are scarcely discussed in those reports. In this work we use behavioral and cognitive tests and VBM to identify and confirm cognitive and gray matter alterations in SCA2 patients compared with control subjects. Also, we discuss the cerebellar and non-cerebellar functions affected by this disease. Our results confirmed gray matter reduction in the cerebellar vermis, pons, and insular, frontal, parietal and temporal cortices. However, our analysis also found unreported loss of gray matter in the parahippocampal gyrus bilaterally. Motor performance test ratings correlated with total gray and white matter reductions, but executive performance and clinical features such as CAG repetitions and disease progression did not show any correlation. This pattern of cerebellar and non-cerebellar morphological alterations associated with SCA2 has to be considered to fully understand the motor and non-motor deficits that include language production and comprehension and some social skill changes that occur in these patients.

  8. Regional brain structural abnormality in ischemic stroke patients: a voxel-based morphometry study

    PubMed Central

    Wu, Ping; Zhou, Yu-mei; Zeng, Fang; Li, Zheng-jie; Luo, Lu; Li, Yong-xin; Fan, Wei; Qiu, Li-hua; Qin, Wei; Chen, Lin; Bai, Lin; Nie, Juan; Zhang, San; Xiong, Yan; Bai, Yu; Yin, Can-xin; Liang, Fan-rong

    2016-01-01

    Our previous study used regional homogeneity analysis and found that activity in some brain areas of patients with ischemic stroke changed significantly. In the current study, we examined structural changes in these brain regions by taking structural magnetic resonance imaging scans of 11 ischemic stroke patients and 15 healthy participants, and analyzing the data using voxel-based morphometry. Compared with healthy participants, patients exhibited higher gray matter density in the left inferior occipital gyrus and right anterior white matter tract. In contrast, gray matter density in the right cerebellum, left precentral gyrus, right middle frontal gyrus, and left middle temporal gyrus was less in ischemic stroke patients. The changes of gray matter density in the middle frontal gyrus were negatively associated with the clinical rating scales of the Fugl-Meyer Motor Assessment (r = –0.609, P = 0.047) and the left middle temporal gyrus was negatively correlated with the clinical rating scales of the nervous functional deficiency scale (r = –0.737, P = 0.010). Our findings can objectively identify the functional abnormality in some brain regions of ischemic stroke patients. PMID:27857744

  9. Brain correlates of pro-social personality traits: a voxel-based morphometry study.

    PubMed

    Coutinho, Joana F; Sampaio, Adriana; Ferreira, Miguel; Soares, José M; Gonçalves, Oscar F

    2013-09-01

    Of the five personality dimensions described by the Big Five Personality Model (Costa and McCrae 1992), Extraversion and Agreeableness are the traits most commonly associated with a pro-social orientation. In this study we tested whether a pro-social orientation, as expressed in terms of Extraversion and Agreeableness, is associated with a specific grey matter phenotype. Fifty-two healthy participants underwent magnetic resonance imaging (MRI) and completed the NEO-Five Factor Inventory (NEO-FFI), a self-report measure of the Big Five personality traits. Voxel-based morphometry (VBM) was used to investigate the correlation between brain structure and the personality traits of Agreeableness and Extraversion. We found that Extraversion was negatively correlated with grey matter density in the middle frontal and orbitofrontal gyri while Agreeableness was negatively correlated with grey matter density in the inferior parietal, middle occipital and posterior cingulate gyri. No positive correlations were found. These results suggest that pro-social personality traits seem to be associated with decreases in grey matter density in more frontal regions for Extraversion, and more posterior regions for Agreeableness.

  10. Structural Correlates of Functional Language Dominance: A Voxel-Based Morphometry Study

    PubMed Central

    Deppe, Michael; Kanowski, Martin; Ölschläger, Christian; Albers, Johannes M.; Schlaug, Gottfried; Knecht, Stefan

    2015-01-01

    BACKGROUND AND PURPOSE The goal of this study was to explore the structural correlates of functional language dominance by directly comparing the brain morphology of healthy subjects with left- and right-hemisphere language dominance. METHODS Twenty participants were selected based on their language dominance from a cohort of subjects with known language lateralization. Structural differences between both groups were assessed by voxel-based morphometry, a technique that automatically identifies differences in the local gray matter volume between groups using high-resolution T1-weighted magnetic resonance images. RESULTS The main findings can be summarized as follows: (1) Subjects with right-hemisphere language dominance had significantly larger gray matter volume in the right hippocampus than subjects with left-hemisphere language dominance. (2) Leftward structural asymmetries in the posterior superior temporal cortex, including the planum temporale (PT), were observed in both groups. CONCLUSIONS Our study does not support the still prevalent view that asymmetries of the PT are related in a direct way to functional language lateralization. The structural differences found in the hippocampus underline the importance of the medial temporal lobe in the neural language network. They are discussed in the context of recent findings attributing a critical role of the hippocampus in the development of language lateralization. PMID:19453831

  11. Voxel-based Morphometry of Brain MRI in Normal Aging and Alzheimer's Disease.

    PubMed

    Matsuda, Hiroshi

    2013-02-01

    Voxel-based morphometry (VBM) using structural brain MRI has been widely used for assessment of normal aging and Alzheimer's disease (AD). VBM of MRI data comprises segmentation into gray matter, white matter, and cerebrospinal fluid partitions, anatomical standardization of all the images to the same stereotactic space using linear affine transformation and further non-linear warping, smoothing, and finally performing a statistical analysis. Two techniques for VBM are commonly used, optimized VBM using statistical parametric mapping (SPM) 2 or SPM5 with non-linear warping based on discrete cosine transforms and SPM8 plus non-linear warping based on diffeomorphic anatomical registration using exponentiated Lie algebra (DARTEL). In normal aging, most cortical regions prominently in frontal and insular areas have been reported to show age-related gray matter atrophy. In contrast, specific structures such as amygdala, hippocampus, and thalamus have been reported to be preserved in normal aging. On the other hand, VBM studies have demonstrated progression of atrophy mapping upstream to Braak's stages of neurofibrillary tangle deposition in AD. The earliest atrophy takes place in medial temporal structures. Stand-alone VBM software using SPM8 plus DARTEL running on Windows has been newly developed as an adjunct to the clinical assessment of AD. This software provides a Z-score map as a consequence of comparison of a patient's MRI with a normal database.

  12. Temporal discrimination of sub- and suprasecond time intervals: a voxel-based lesion mapping analysis.

    PubMed

    Gooch, Cynthia M; Wiener, Martin; Hamilton, A Cris; Coslett, H Branch

    2011-01-01

    We used voxel-based lesion-symptom mapping (VLSM) to determine which brain areas are necessary for discriminating time intervals above and below 1 s. VLSM compares behavioral scores of patients that have damage to a given voxel to those that do not on a voxel-by-voxel basis to determine which voxels are critical for the given behavior. Forty-seven subjects with unilateral hemispheric lesions performed a temporal discrimination task in which a standard stimulus was compared on each trial to a test stimulus. In different blocks of trials, standard stimuli were either 600 or 2000 ms. Behavioral measures included the point of subjective equality, a measure of accuracy, and the coefficient of variation, a measure of variability. Lesions of the right middle and inferior frontal gyri were associated with decrements in performance on both durations. In addition, lesions of the left temporal lobe and right precentral gyrus were associated exclusively with impaired performance for subsecond stimuli. In line with results from other studies, these data suggest that different circuits are necessary for timing intervals in these ranges, and that right frontal areas are particularly important to timing.

  13. Networks underlying trait impulsivity: Evidence from voxel-based lesion-symptom mapping.

    PubMed

    McDonald, Valerie; Hauner, Katherina K; Chau, Aileen; Krueger, Frank; Grafman, Jordan

    2017-02-01

    Impulsivity is considered a multidimensional construct that encompasses a range of behaviors, including poor impulse control, premature decision-making, and the inability to delay gratification. In order to determine the extent to which impulsivity and its components share a common network, a voxel-based lesion-symptom mapping (VLSM) analysis was performed in a large sample of patients (N = 131) with focal, penetrating traumatic brain injuries (pTBI). Impulsivity was assessed using the Barratt Impulsiveness Scale (BIS-11), a standard self-report measure that allows for unique estimates of global impulsivity and its factor analysis-derived components (e.g., "motor impulsivity"). Heightened global impulsivity was associated with damage to multiple areas in bilateral prefrontal cortex (PFC), left superior, middle and inferior temporal gyrus, and left hippocampus. Moreover, a cluster was identified within the left PFC associated specifically with motor impulsivity (defined as "acting without thinking"). The results were consistent with the existing literature on bilateral prefrontal cortical involvement in behavioral impulsivity, but also provided new evidence for a more complex neuroanatomical representation of this construct, characterized by left-lateralized temporal and hippocampal involvement, as well as a left-lateralized prefrontal network specifically associated with motor impulsivity. Hum Brain Mapp 38:656-665, 2017. © 2016 Wiley Periodicals, Inc.

  14. The Neuroanatomical Basis of Panic Disorder and Social Phobia in Schizophrenia: A Voxel Based Morphometric Study

    PubMed Central

    Picado, Marisol; Carmona, Susanna; Hoekzema, Elseline; Pailhez, Guillem; Bergé, Daniel; Mané, Anna; Fauquet, Jordi; Hilferty, Joseph; Moreno, Ana; Cortizo, Romina; Vilarroya, Oscar; Bulbena, Antoni

    2015-01-01

    Objective It is known that there is a high prevalence of certain anxiety disorders among schizophrenic patients, especially panic disorder and social phobia. However, the neural underpinnings of the comorbidity of such anxiety disorders and schizophrenia remain unclear. Our study aims to determine the neuroanatomical basis of the co-occurrence of schizophrenia with panic disorder and social phobia. Methods Voxel-based morphometry was used in order to examine brain structure and to measure between-group differences, comparing magnetic resonance images of 20 anxious patients, 20 schizophrenic patients, 20 schizophrenic patients with comorbid anxiety, and 20 healthy control subjects. Results Compared to the schizophrenic patients, we observed smaller grey-matter volume (GMV) decreases in the dorsolateral prefrontal cortex and precentral gyrus in the schizophrenic-anxiety group. Additionally, the schizophrenic group showed significantly reduced GMV in the dorsolateral prefrontal cortex, precentral gyrus, orbitofrontal cortex, temporal gyrus and angular/inferior parietal gyrus when compared to the control group. Conclusions Our findings suggest that the comorbidity of schizophrenia with panic disorder and social phobia might be characterized by specific neuroanatomical and clinical alterations that may be related to maladaptive emotion regulation related to anxiety. Even thought our findings need to be replicated, our study suggests that the identification of neural abnormalities involved in anxiety, schizophrenia and schizophrenia-anxiety may lead to an improved diagnosis and management of these conditions. PMID:25774979

  15. Voxel-based analyses of magnetization transfer imaging of the brain in hepatic encephalopathy

    PubMed Central

    Miese, Falk R; Wittsack, Hans-Jörg; Kircheis, Gerald; Holstein, Arne; Mathys, Christian; Mödder, Ulrich; Cohnen, Mathias

    2009-01-01

    AIM: To evaluate the spatial distribution of cerebral abnormalities in cirrhotic subjects with and without hepatic encephalopathy (HE) found with magnetization transfer imaging (MTI). METHODS: Nineteen cirrhotic patients graded from neurologically normal to HE grade 2 and 18 healthy control subjects underwent magnetic resonance imaging. They gave institutional-review-board-approved written consent. Magnetization transfer ratio (MTR) maps were generated from MTI. We tested for significant differences compared to the control group using statistical non-parametric mapping (SnPM) for a voxel-based evaluation. RESULTS: The MTR of grey and white matter was lower in subjects with more severe HE. Changes were found in patients with cirrhosis without neurological deficits in the basal ganglia and bilateral white matter. The loss in magnetization transfer increased in severity and spatial extent in patients with overt HE. Patients with HE grade 2 showed an MTR decrease in white and grey matter: the maximum loss of magnetization transfer effect was located in the basal ganglia [SnPM (pseudo-)t = 17.98, P = 0.0001]. CONCLUSION: The distribution of MTR changes in HE points to an early involvement of basal ganglia and white matter in HE. PMID:19891014

  16. Grey matter volume alterations in CADASIL: a voxel-based morphometry study.

    PubMed

    Rossi Espagnet, Maria Camilla; Romano, Andrea; Carducci, Filippo; Calabria, Luigi Fausto; Fiorillo, Martina; Orzi, Francesco; Bozzao, Alessandro

    2012-04-01

    CADASIL is a hereditary disease characterized by cerebral subcortical microangiopathy leading to early onset cerebral strokes and progressive severe cognitive impairment. Until now, only few studies have investigated the extent and localization of grey matter (GM) involvement. The purpose of our study was to evaluate GM volume alterations in CADASIL patients compared to healthy subjects. We also looked for correlations between global and regional white matter (WM) lesion load and GM volume alterations. 14 genetically proved CADASIL patients and 12 healthy subjects were enrolled in our study. Brain MRI (1.5 T) was acquired in all subjects. Optimized-voxel based morphometry method was applied for the comparison of brain volumes between CADASIL patients and controls. Global and lobar WM lesion loads were calculated for each patient and used as covariate-of-interest for regression analyses with SPM-8. Compared to controls, patients showed GM volume reductions in bilateral temporal lobes (p < 0.05; FDR-corrected). Regression analysis in the patient group revealed a correlation between total WM lesion load and temporal GM atrophy (p < 0.05; uncorrected), not between temporal lesion load and GM atrophy. Temporal GM volume reduction was demonstrated in CADASIL patients compared to controls; it was related to WM lesion load involving the whole brain but not to lobar and, specifically, temporal WM lesion load. Complex interactions between sub-cortical and cortical damage should be hypothesized.

  17. Regional gray matter density is associated with achievement motivation: evidence from voxel-based morphometry.

    PubMed

    Takeuchi, Hikaru; Taki, Yasuyuki; Nouchi, Rui; Sekiguchi, Atsushi; Kotozaki, Yuka; Miyauchi, Carlos Makoto; Yokoyama, Ryoichi; Iizuka, Kunio; Hashizume, Hiroshi; Nakagawa, Seishu; Kunitoki, Keiko; Sassa, Yuko; Kawashima, Ryuta

    2014-01-01

    Achievement motivation can be defined as a recurrent need to improve one's past performance. Despite previous functional imaging studies on motivation-related functional activation, the relationship between regional gray matter (rGM) morphology and achievement motivation has never been investigated. We used voxel-based morphometry and a questionnaire (achievement motivation scale) to measure individual achievement motivation and investigated the association between rGM density (rGMD) and achievement motivation [self-fulfillment achievement motivation (SFAM) and competitive achievement motivation (CAM) across the brain in healthy young adults (age 21.0 ± 1.8 years, men (n = 94), women (n = 91)]. SFAM and rGMD significantly and negatively correlated in the orbitofrontal cortex (OFC). CAM and rGMD significantly and positively correlated in the right putamen, insula, and precuneus. These results suggest that the brain areas that play central roles in externally modulated motivation (OFC and putamen) also contribute to SFAM and CAM, respectively, but in different ways. Furthermore, the brain areas in which rGMD correlated with CAM are related to cognitive processes associated with distressing emotions and social cognition, and these cognitive processes may characterize CAM.

  18. Different brain structures associated with artistic and scientific creativity: a voxel-based morphometry study

    PubMed Central

    Shi, Baoguo; Cao, Xiaoqing; Chen, Qunlin; Zhuang, Kaixiang; Qiu, Jiang

    2017-01-01

    Creativity is the ability to produce original and valuable ideas or behaviors. In real life, artistic and scientific creativity promoted the development of human civilization; however, to date, no studies have systematically investigated differences in the brain structures responsible for artistic and scientific creativity in a large sample. Using voxel-based morphometry (VBM), this study identified differences in regional gray matter volume (GMV) across the brain between artistic and scientific creativity (assessed by the Creative Achievement Questionnaire) in 356 young, healthy subjects. The results showed that artistic creativity was significantly negatively associated with the regional GMV of the supplementary motor area (SMA) and anterior cingulate cortex (ACC). In contrast, scientific creativity was significantly positively correlated with the regional GMV of the left middle frontal gyrus (MFG) and left inferior occipital gyrus (IOG). Overall, artistic creativity was associated with the salience network (SN), whereas scientific creativity was associated with the executive attention network and semantic processing. These results may provide an effective marker that can be used to predict and evaluate individuals’ creative performance in the fields of science and art. PMID:28220826

  19. Gray Matter Volume Decreases in Elderly Patients with Schizophrenia: A Voxel-based Morphometry Study

    PubMed Central

    Schuster, Caroline; Schuller, Anne Marie; Paulos, Carlos; Namer, Izzie; Pull, Charles; Danion, Jean Marie; Foucher, Jack René

    2012-01-01

    Background: Aged patients (>50 years old) with residual schizophrenic symptoms differ from young patients. They represent a subpopulation with a more unfavorable Kraepelinian course and have an increased risk (up to 30%) for dementia of unknown origin. However, our current understanding of age-related brain changes in schizophrenia is derived from studies that included less than 17% of patients who were older than 50 years of age. This study investigated the anatomical distribution of gray matter (GM) brain deficits in aged patients with ongoing schizophrenia. Methods: Voxel-based morphometry was applied to 3D-T1 magnetic resonance images obtained from 27 aged patients with schizophrenia (mean age of 60 years) and 40 age-matched normal controls. Results: Older patients with schizophrenia showed a bilateral reduction of GM volume in the thalamus, the prefrontal cortex, and in a large posterior region centered on the occipito-temporo-parietal junction. Only the latter region showed accelerated GM volume loss with increasing age. None of these results could be accounted for by institutionalization, antipsychotic medication, or cognitive scores. Conclusions: This study replicated most common findings in patients with schizophrenia with regard to thalamic and frontal GM deficits. However, it uncovered an unexpected large region of GM atrophy in the posterior tertiary cortices. The latter observation may be specific to this aged and chronically symptomatic subpopulation, as atrophy in this region is rarely reported in younger patients and is accelerated with age. PMID:21205677

  20. VIDA: A Voxel-Based Dosimetry Method for Targeted Radionuclide Therapy Using Geant4

    PubMed Central

    Dewaraja, Yuni K.; Abramson, Richard G.; Stabin, Michael G.

    2015-01-01

    Abstract We have developed the Voxel-Based Internal Dosimetry Application (VIDA) to provide patient-specific dosimetry in targeted radionuclide therapy performing Monte Carlo simulations of radiation transport with the Geant4 toolkit. The code generates voxel-level dose rate maps using anatomical and physiological data taken from individual patients. Voxel level dose rate curves are then fit and integrated to yield a spatial map of radiation absorbed dose. In this article, we present validation studies using established dosimetry results, including self-dose factors (DFs) from the OLINDA/EXM program for uniform activity in unit density spheres and organ self- and cross-organ DFs in the Radiation Dose Assessment Resource (RADAR) reference adult phantom. The comparison with reference data demonstrated agreement within 5% for self-DFs to spheres and reference phantom source organs for four common radionuclides used in targeted therapy (131I, 90Y, 111In, 177Lu). Agreement within 9% was achieved for cross-organ DFs. We also present dose estimates to normal tissues and tumors from studies of two non-Hodgkin Lymphoma patients treated by 131I radioimmunotherapy, with comparison to results generated independently with another dosimetry code. A relative difference of 12% or less was found between methods for mean absorbed tumor doses accounting for tumor regression. PMID:25594357

  1. Effect of Experimental Thyrotoxicosis on Brain Gray Matter: A Voxel-Based Morphometry Study

    PubMed Central

    Göbel, Anna; Heldmann, Marcus; Göttlich, Martin; Dirk, Anna-Luise; Brabant, Georg; Münte, Thomas F.

    2015-01-01

    Background Hyper-as well hypothyroidism have an effect on behavior and brain function. Moreover, during development thyroid hormones influence brain structure. Objectives This study aimed to demonstrate an effect of experimentally induced hyperthyroidism on brain gray matter in healthy adult humans. Methods High-resolution 3D T1-weighted images were acquired in 29 healthy young subjects prior to as well as after receiving 250 µg of T4 per day for 8 weeks. Voxel-based morphometry analysis was performed using Statistical Parametric Mapping 8 (SPM8). Results Laboratory testing confirmed the induction of hyperthyroidism. In the hyperthyroid condition, gray matter volumes were increased in the right posterior cerebellum (lobule VI) and decreased in the bilateral visual cortex and anterior cerebellum (lobules I-IV) compared to the euthyroid condition. Conclusions Our study provides evidence that short periods of hyperthyroidism induce distinct alterations in brain structures of cerebellar regions that have been associated with sensorimotor functions as well as working memory in the literature. PMID:26601082

  2. The correlation between gray matter volume and perceived social support: a voxel-based morphometry study.

    PubMed

    Che, XianWei; Wei, DongTao; Li, WenFu; Li, HaiJiang; Qiao, Lei; Qiu, Jiang; Zhang, QingLin; Liu, YiJun

    2014-01-01

    Social support refers to interpersonal exchanges that include the combinations of aid, affirmation and affection. Perceived social support is a kind of subjective judgment of one's availability of social support. In spite of the importance of perceived social support to health, however, its neural substrate remains unknown. To address this question, voxel-based morphometry was employed to investigate the neural bases of individual differences in responses to the Perceived Social Support Scale (PSSS) in healthy volunteers (144 men and 203 women; mean age = 19.9; SD = 1.33, age range : 17-27). As a result, multiple regression analysis revealed that the PSSS scores were significantly and positively correlated with gray matter volume in a cluster that mainly included areas in posterior parts of posterior cingulate cortex, bilateral lingual cortex, left occipital lobe and cuneus. Highly-supported individuals had larger gray matter volume in these brain regions, implying a relatively high level of ability to engage in self-referential processes and social cognition. Our results provide a biological basis for exploring perceived social support particularly in relationship to various health parameters and outcomes.

  3. Neural correlates of post-conventional moral reasoning: a voxel-based morphometry study.

    PubMed

    Prehn, Kristin; Korczykowski, Marc; Rao, Hengyi; Fang, Zhuo; Detre, John A; Robertson, Diana C

    2015-01-01

    Going back to Kohlberg, moral development research affirms that people progress through different stages of moral reasoning as cognitive abilities mature. Individuals at a lower level of moral reasoning judge moral issues mainly based on self-interest (personal interests schema) or based on adherence to laws and rules (maintaining norms schema), whereas individuals at the post-conventional level judge moral issues based on deeper principles and shared ideals. However, the extent to which moral development is reflected in structural brain architecture remains unknown. To investigate this question, we used voxel-based morphometry and examined the brain structure in a sample of 67 Master of Business Administration (MBA) students. Subjects completed the Defining Issues Test (DIT-2) which measures moral development in terms of cognitive schema preference. Results demonstrate that subjects at the post-conventional level of moral reasoning were characterized by increased gray matter volume in the ventromedial prefrontal cortex and subgenual anterior cingulate cortex, compared with subjects at a lower level of moral reasoning. Our findings support an important role for both cognitive and emotional processes in moral reasoning and provide first evidence for individual differences in brain structure according to the stages of moral reasoning first proposed by Kohlberg decades ago.

  4. Short Latency Gray Matter Changes in Voxel-Based Morphometry following High Frequent Visual Stimulation

    PubMed Central

    Theysohn, Nina; Diener, Hans-Christoph; Katsarava, Zaza; Obermann, Mark; Holle, Dagny

    2017-01-01

    Magnetic resonance imaging studies using voxel-based morphometry (VBM) detected structural changes in the human brain within periods of months or weeks. The underlying molecular mechanisms of VBM findings remain unresolved. We showed that simple visual stimulation by an alternating checkerboard leads to instant, short-lasting alterations of the primary and secondary visual cortex detected by VBM. The rapidness of occurrence (i.e., within 10 minutes) rather excludes most of the proposed physiological mechanism such as neural or glial cell genesis/degeneration or synapse turnover. We therefore favour cerebral fluid shifts to be the underlying correlate of the here observed VBM gray matter changes. Fast onset gray matter changes might be one important explanation for the inconsistency of VBM study results that often raise concern in regard to the validity of presented data. This study shows that changes detectable by VBM may occur within a few minutes after physiological stimulation and must be considered in future VBM experiments to avoid misinterpretation of results. PMID:28293437

  5. Voxel-based morphometry evaluation of patients with photosensitive juvenile myoclonic epilepsy.

    PubMed

    Lin, Katia; Jackowski, Andrea Parolin; Carrete, Henrique; de Araújo Filho, Gerardo Maria; Silva, Henrique Hattori; Guaranha, Mirian Salvadori Bittar; Guilhoto, Laura Maria Figueiredo Ferreira; Bressan, Rodrigo Affonseca; Yacubian, Elza Márcia Targas

    2009-10-01

    We aim to investigate structural brain abnormalities in juvenile myoclonic epilepsy (JME) patients with photosensitivity (PS). Sixty JME patients, 19 (32%) of whom were photosensitive, were submitted to 1.5T magnetic resonance voxel-based morphometry (VBM). The control group (CTL) consisted of 30 sex-matched healthy volunteers. JME patients with (JME-PS) and without (JME-NPS) PS did not differ in their duration of disease, treatment or seizure control. VBM revealed significantly reduced bilateral gray matter volume (GMV) in thalami, insula cortices and cerebellar hemispheres; while significantly increased GMV was observed in the right superior frontal, orbitofrontal and medial frontal gyri of the JME group compared to CTL. JME-PS had reduced bilateral GMV of visual cortices when compared with CTL; while it was not seen among JME-NPS patients. Reduced left hippocampus and left inferior frontal gyrus volume was observed among JME-PS compared with JME-NPS. This study demonstrates structural abnormalities beyond the limits of the frontal lobes and provides evidence for the role of the occipital cortex in human PS, reinforcing the existence of functional-anatomic ictogenic networks in JME and the concept of 'system epilepsies'.

  6. An incremental-iterative method for modeling damage evolution in voxel-based microstructure models

    NASA Astrophysics Data System (ADS)

    Zhu, Qi-Zhi; Yvonnet, Julien

    2015-02-01

    Numerical methods motivated by rapid advances in image processing techniques have been intensively developed during recent years and increasingly applied to simulate heterogeneous materials with complex microstructure. The present work aims at elaborating an incremental-iterative numerical method for voxel-based modeling of damage evolution in quasi-brittle microstructures. The iterative scheme based on the Lippmann-Schwinger equation in the real space domain (Yvonnet, in Int J Numer Methods Eng 92:178-205, 2012) is first cast into an incremental form so as to implement nonlinear material models efficiently. In the proposed scheme, local strain increments at material grid points are computed iteratively by a mapping operation through a transformation array, while local stresses are determined using a constitutive model that accounts for material degradation by damage. For validation, benchmark studies and numerical simulations using microtomographic data of concrete are performed. For each test, numerical predictions by the incremental-iterative scheme and the finite element method, respectively, are presented and compared for both global responses and local damage distributions. It is emphasized that the proposed incremental-iterative formulation can be straightforwardly applied in the framework of other Lippmann-Schwinger equation-based schemes, like the fast Fourier transform method.

  7. Voxel-Based Morphometry ALE meta-analysis of Bipolar Disorder

    NASA Astrophysics Data System (ADS)

    Magana, Omar; Laird, Robert

    2012-03-01

    A meta-analysis was performed independently to view the changes in gray matter (GM) on patients with Bipolar disorder (BP). The meta-analysis was conducted on a Talairach Space using GingerALE to determine the voxels and their permutation. In order to achieve the data acquisition, published experiments and similar research studies were uploaded onto the online Voxel-Based Morphometry database (VBM). By doing so, coordinates of activation locations were extracted from Bipolar disorder related journals utilizing Sleuth. Once the coordinates of given experiments were selected and imported to GingerALE, a Gaussian was performed on all foci points to create the concentration points of GM on BP patients. The results included volume reductions and variations of GM between Normal Healthy controls and Patients with Bipolar disorder. A significant amount of GM clusters were obtained in Normal Healthy controls over BP patients on the right precentral gyrus, right anterior cingulate, and the left inferior frontal gyrus. In future research, more published journals could be uploaded onto the database and another VBM meta-analysis could be performed including more activation coordinates or a variation of age groups.

  8. Parallel solutions for voxel-based simulations of reaction-diffusion systems.

    PubMed

    D'Agostino, Daniele; Pasquale, Giulia; Clematis, Andrea; Maj, Carlo; Mosca, Ettore; Milanesi, Luciano; Merelli, Ivan

    2014-01-01

    There is an increasing awareness of the pivotal role of noise in biochemical processes and of the effect of molecular crowding on the dynamics of biochemical systems. This necessity has given rise to a strong need for suitable and sophisticated algorithms for the simulation of biological phenomena taking into account both spatial effects and noise. However, the high computational effort characterizing simulation approaches, coupled with the necessity to simulate the models several times to achieve statistically relevant information on the model behaviours, makes such kind of algorithms very time-consuming for studying real systems. So far, different parallelization approaches have been deployed to reduce the computational time required to simulate the temporal dynamics of biochemical systems using stochastic algorithms. In this work we discuss these aspects for the spatial TAU-leaping in crowded compartments (STAUCC) simulator, a voxel-based method for the stochastic simulation of reaction-diffusion processes which relies on the Sτ-DPP algorithm. In particular we present how the characteristics of the algorithm can be exploited for an effective parallelization on the present heterogeneous HPC architectures.

  9. VIDA: a voxel-based dosimetry method for targeted radionuclide therapy using Geant4.

    PubMed

    Kost, Susan D; Dewaraja, Yuni K; Abramson, Richard G; Stabin, Michael G

    2015-02-01

    We have developed the Voxel-Based Internal Dosimetry Application (VIDA) to provide patient-specific dosimetry in targeted radionuclide therapy performing Monte Carlo simulations of radiation transport with the Geant4 toolkit. The code generates voxel-level dose rate maps using anatomical and physiological data taken from individual patients. Voxel level dose rate curves are then fit and integrated to yield a spatial map of radiation absorbed dose. In this article, we present validation studies using established dosimetry results, including self-dose factors (DFs) from the OLINDA/EXM program for uniform activity in unit density spheres and organ self- and cross-organ DFs in the Radiation Dose Assessment Resource (RADAR) reference adult phantom. The comparison with reference data demonstrated agreement within 5% for self-DFs to spheres and reference phantom source organs for four common radionuclides used in targeted therapy ((131)I, (90)Y, (111)In, (177)Lu). Agreement within 9% was achieved for cross-organ DFs. We also present dose estimates to normal tissues and tumors from studies of two non-Hodgkin Lymphoma patients treated by (131)I radioimmunotherapy, with comparison to results generated independently with another dosimetry code. A relative difference of 12% or less was found between methods for mean absorbed tumor doses accounting for tumor regression.

  10. Neurostructural correlates of two subtypes of specific phobia: a voxel-based morphometry study.

    PubMed

    Hilbert, Kevin; Evens, Ricarda; Maslowski, Nina Isabel; Wittchen, Hans-Ulrich; Lueken, Ulrike

    2015-02-28

    The animal and blood-injection-injury (BII) subtypes of specific phobia are both characterized by subjective fear but distinct autonomic reactions to threat. Previous functional neuroimaging studies have related these characteristic responses to shared and non-shared neural underpinnings. However, no comparative structural data are available. This study aims to fill this gap by comparing the two subtypes and also comparing them with a non-phobic control group. Gray and white matter data of 33 snake phobia subjects (SP), 26 dental phobia subjects (DP), and 37 healthy control (HC) subjects were analyzed with voxel-based morphometry. Especially DP differed from HC and SP by showing significantly increased grey matter volumes in widespread areas including the right subgenual anterior cingulate gyrus, left insula, left orbitofrontal and left prefrontal (PFC) cortices. In addition, white matter volume was significantly increased in the left PFC in DP compared with SP. These results are in line with functional changes observed in dental phobia and point toward those brain circuits associated with emotional processing and regulation. Future studies should aim to further delineate functional and structural connectivity alterations in specific phobia.

  11. The brain structure correlates of individual differences in trait mindfulness: a voxel-based morphometry study.

    PubMed

    Lu, H; Song, Y; Xu, M; Wang, X; Li, X; Liu, J

    2014-07-11

    Mindfulness is the state of being attentive to and aware of what is taking place in the present, which is beneficial for reducing stress-related symptoms and improving mental and physical health. Previous studies have demonstrated that meditation practice can improve individuals' mindfulness through modifying functions and structures of multiple brain regions, including the anterior cingulate cortex (ACC), insula, fronto-limbic network, posterior cingulate cortex (PCC), and temporal-parietal junction. However, little is known about the neuroanatomical correlates of trait mindfulness. In the current study, we used voxel-based morphometry to investigate the neural correlates of individual differences in trait mindfulness by correlating the gray matter (GM) volume of each voxel across the whole brain with trait mindfulness measured by the Mindful Attention Awareness Scale in a large sample of young adults (N=247). We found that individuals who were more mindful of the present had greater GM volume in the right hippocampus/amygdala and bilateral ACC, but less GM volume in bilateral PCC and the left orbitofrontal cortex. These results suggest that trait mindfulness is associated with brain regions involved in executive attention, emotion regulation, and self-referential processing, through which mindfulness may exert its beneficial effects on psychological and physical well-being.

  12. An automatic framework for quantitative validation of voxel based morphometry measures of anatomical brain asymmetry.

    PubMed

    Pepe, Antonietta; Dinov, Ivo; Tohka, Jussi

    2014-10-15

    The study of anatomical brain asymmetries has been a topic of great interest in the neuroimaging community in the past decades. However, the accuracy of brain asymmetry measurements has been rarely investigated. In this study, we propose a fully automatic methodology for the quantitative validation of brain tissue asymmetries as measured by Voxel Based Morphometry (VBM) from structural magnetic resonance (MR) images. Starting from a real MR image, the methodology generates simulated 3D MR images with a known and realistic pattern of inter-hemispheric asymmetry that models the left-occipital right-frontal petalia of a normal brain and the related rightward bending of the inter-hemispheric fissure. As an example, we generated a dataset of 64 simulated MR images and applied this dataset for the quantitative validation of optimized VBM measures of asymmetries in brain tissue composition. Our results suggested that VBM analysis strongly depended on the spatial normalization of the individual brain images, the selected template space, and the amount of spatial smoothing applied. The most accurate asymmetry detections were achieved by 9-degrees of freedom registration to the symmetrical template space with 4 to 8mm spatial smoothing.

  13. 77 FR 48527 - National Customs Automation Program (NCAP) Test Concerning Automated Commercial Environment (ACE...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-14

    ... Automated Commercial Environment (ACE) Simplified Entry: Modification of Participant Selection Criteria and... (NCAP) test concerning the simplified entry functionality in the Automated Commercial Environment (ACE...) National Customs Automation Program (NCAP) test concerning Automated Commercial Environment...

  14. Sensitivity study of voxel-based PET image comparison to image registration algorithms

    SciTech Connect

    Yip, Stephen Chen, Aileen B.; Berbeco, Ross; Aerts, Hugo J. W. L.

    2014-11-01

    Purpose: Accurate deformable registration is essential for voxel-based comparison of sequential positron emission tomography (PET) images for proper adaptation of treatment plan and treatment response assessment. The comparison may be sensitive to the method of deformable registration as the optimal algorithm is unknown. This study investigated the impact of registration algorithm choice on therapy response evaluation. Methods: Sixteen patients with 20 lung tumors underwent a pre- and post-treatment computed tomography (CT) and 4D FDG-PET scans before and after chemoradiotherapy. All CT images were coregistered using a rigid and ten deformable registration algorithms. The resulting transformations were then applied to the respective PET images. Moreover, the tumor region defined by a physician on the registered PET images was classified into progressor, stable-disease, and responder subvolumes. Particularly, voxels with standardized uptake value (SUV) decreases >30% were classified as responder, while voxels with SUV increases >30% were progressor. All other voxels were considered stable-disease. The agreement of the subvolumes resulting from difference registration algorithms was assessed by Dice similarity index (DSI). Coefficient of variation (CV) was computed to assess variability of DSI between individual tumors. Root mean square difference (RMS{sub rigid}) of the rigidly registered CT images was used to measure the degree of tumor deformation. RMS{sub rigid} and DSI were correlated by Spearman correlation coefficient (R) to investigate the effect of tumor deformation on DSI. Results: Median DSI{sub rigid} was found to be 72%, 66%, and 80%, for progressor, stable-disease, and responder, respectively. Median DSI{sub deformable} was 63%–84%, 65%–81%, and 82%–89%. Variability of DSI was substantial and similar for both rigid and deformable algorithms with CV > 10% for all subvolumes. Tumor deformation had moderate to significant impact on DSI for progressor

  15. Voxel-based clustered imaging by multiparameter diffusion tensor images for glioma grading

    PubMed Central

    Inano, Rika; Oishi, Naoya; Kunieda, Takeharu; Arakawa, Yoshiki; Yamao, Yukihiro; Shibata, Sumiya; Kikuchi, Takayuki; Fukuyama, Hidenao; Miyamoto, Susumu

    2014-01-01

    Gliomas are the most common intra-axial primary brain tumour; therefore, predicting glioma grade would influence therapeutic strategies. Although several methods based on single or multiple parameters from diagnostic images exist, a definitive method for pre-operatively determining glioma grade remains unknown. We aimed to develop an unsupervised method using multiple parameters from pre-operative diffusion tensor images for obtaining a clustered image that could enable visual grading of gliomas. Fourteen patients with low-grade gliomas and 19 with high-grade gliomas underwent diffusion tensor imaging and three-dimensional T1-weighted magnetic resonance imaging before tumour resection. Seven features including diffusion-weighted imaging, fractional anisotropy, first eigenvalue, second eigenvalue, third eigenvalue, mean diffusivity and raw T2 signal with no diffusion weighting, were extracted as multiple parameters from diffusion tensor imaging. We developed a two-level clustering approach for a self-organizing map followed by the K-means algorithm to enable unsupervised clustering of a large number of input vectors with the seven features for the whole brain. The vectors were grouped by the self-organizing map as protoclusters, which were classified into the smaller number of clusters by K-means to make a voxel-based diffusion tensor-based clustered image. Furthermore, we also determined if the diffusion tensor-based clustered image was really helpful for predicting pre-operative glioma grade in a supervised manner. The ratio of each class in the diffusion tensor-based clustered images was calculated from the regions of interest manually traced on the diffusion tensor imaging space, and the common logarithmic ratio scales were calculated. We then applied support vector machine as a classifier for distinguishing between low- and high-grade gliomas. Consequently, the sensitivity, specificity, accuracy and area under the curve of receiver operating characteristic

  16. Brain volumetric abnormalities in patients with anorexia and bulimia nervosa: a voxel-based morphometry study.

    PubMed

    Amianto, Federico; Caroppo, Paola; D'Agata, Federico; Spalatro, Angela; Lavagnino, Luca; Caglio, Marcella; Righi, Dorico; Bergui, Mauro; Abbate-Daga, Giovanni; Rigardetto, Roberto; Mortara, Paolo; Fassino, Secondo

    2013-09-30

    Recent studies focussing on neuroimaging features of eating disorders have observed that anorexia nervosa (AN) is characterized by significant grey matter (GM) atrophy in many brain regions, especially in the cerebellum and anterior cingulate cortex. To date, no studies have found GM atrophy in bulimia nervosa (BN) or have directly compared patients with AN and BN. We used voxel-based morphometry (VBM) to characterize brain abnormalities in AN and BN patients, comparing them with each other and with a control group, and correlating brain volume with clinical features. We recruited 17 AN, 13 BN and 14 healthy controls. All subjects underwent high-resolution magnetic resonance imaging (MRI) with a T1-weighted 3D image. VBM analysis was carried out with the FSL-VBM 4.1 tool. We found no global atrophy, but regional GM reduction in AN with respect to controls and BN in the cerebellum, fusiform area, supplementary motor area, and occipital cortex, and in the caudate in BN compared to AN and controls. Both groups of patients had a volumetric increase bilaterally in somatosensory regions with respect to controls, in areas that are typically involved in the sensory-motor integration of body stimuli and in mental representation of the body image. Our VBM study documented, for the first time in BN patients, the presence of volumetric alterations and replicated previous findings in AN patients. We evidenced morphological differences between AN and BN, demonstrating in the latter atrophy of the caudate nucleus, a region involved in reward mechanisms and processes of self-regulation, perhaps involved in the genesis of the binge-eating behaviors of this disorder.

  17. Voxel-Based Dose Reconstruction for Total Body Irradiation With Helical TomoTherapy

    SciTech Connect

    Chao Ming; Penagaricano, Jose; Yan Yulong; Moros, Eduardo G.; Corry, Peter; Ratanatharathorn, Vaneerat

    2012-04-01

    Purpose: We have developed a megavoltage CT (MVCT)-based dose reconstruction strategy for total body irradiation (TBI) with helical TomoTherapy (HT) using a deformable registration model to account for the patient's interfraction changes. The proposed technique serves as an efficient tool for delivered dose verification and, potentially, plan adaptation. Methods and Materials: Four patients with acute myelogenous leukemia treated with TBI using HT were selected for this study. The prescription was 12 Gy, 2 Gy/fraction, twice per day, given at least 6 h apart. The original plan achieved coverage of 80% of the clinical target volume (CTV) by the 12 Gy isodose surface. MVCTs were acquired prior to each treatment. Regions of interest were contoured on each MVCT. The dose for each fraction was calculated based on the MVCT using the HT planned adaptive station. B-spline deformable registration was conducted to establish voxel-to-voxel correspondence between the MVCT and the planning CT. The resultant deformation vector was employed to map the reconstructed dose from each fraction to the same point as the plan dose, and a voxel-to-voxel summed dose from all six fractions was obtained. The reconstructed dose distribution and its dosimetric parameters were compared with those of the original treatment plan. Results: While changes in CTV contours occurred in all patients, the reconstructed dose distribution showed that the dose-volume histogram for CTV coverage was close (<1.5%) to that of the original plan. For sensitive structures, the differences between the reconstructed and the planned doses were less than 3.0%. Conclusion: Voxel-based dose reconstruction strategy that takes into account interfraction anatomical changes using MVCTs is a powerful tool for treatment verification of the delivered doses. This proposed technique can also be applied to adaptive TBI therapy using HT.

  18. Voxel-based lesion-symptom mapping of stroke lesions underlying somatosensory deficits

    PubMed Central

    Meyer, Sarah; Kessner, Simon S.; Cheng, Bastian; Bönstrup, Marlene; Schulz, Robert; Hummel, Friedhelm C.; De Bruyn, Nele; Peeters, Andre; Van Pesch, Vincent; Duprez, Thierry; Sunaert, Stefan; Schrooten, Maarten; Feys, Hilde; Gerloff, Christian; Thomalla, Götz; Thijs, Vincent; Verheyden, Geert

    2015-01-01

    The aim of this study was to investigate the relationship between stroke lesion location and the resulting somatosensory deficit. We studied exteroceptive and proprioceptive somatosensory symptoms and stroke lesions in 38 patients with first-ever acute stroke. The Erasmus modified Nottingham Sensory Assessment was used to clinically evaluate somatosensory functioning in the arm and hand within the first week after stroke onset. Additionally, more objective measures such as the perceptual threshold of touch and somatosensory evoked potentials were recorded. Non-parametric voxel-based lesion-symptom mapping was performed to investigate lesion contribution to different somatosensory deficits in the upper limb. Additionally, structural connectivity of brain areas that demonstrated the strongest association with somatosensory symptoms was determined, using probabilistic fiber tracking based on diffusion tensor imaging data from a healthy age-matched sample. Voxels with a significant association to somatosensory deficits were clustered in two core brain regions: the central parietal white matter, also referred to as the sensory component of the superior thalamic radiation, and the parietal operculum close to the insular cortex, representing the secondary somatosensory cortex. Our objective recordings confirmed findings from clinical assessments. Probabilistic tracking connected the first region to thalamus, internal capsule, brain stem, postcentral gyrus, cerebellum, and frontal pathways, while the second region demonstrated structural connections to thalamus, insular and primary somatosensory cortex. This study reveals that stroke lesions in the sensory fibers of the superior thalamocortical radiation and the parietal operculum are significantly associated with multiple exteroceptive and proprioceptive deficits in the arm and hand. PMID:26900565

  19. Structural neural correlates of multitasking: A voxel-based morphometry study.

    PubMed

    Zhang, Rui-Ting; Yang, Tian-Xiao; Wang, Yi; Sui, Yuxiu; Yao, Jingjing; Zhang, Chen-Yuan; Cheung, Eric F C; Chan, Raymond C K

    2016-12-01

    Multitasking refers to the ability to organize assorted tasks efficiently in a short period of time, which plays an important role in daily life. However, the structural neural correlates of multitasking performance remain unclear. The present study aimed at exploring the brain regions associated with multitasking performance using global correlation analysis. Twenty-six healthy participants first underwent structural brain scans and then performed the modified Six Element Test, which required participants to attempt six subtasks in 10 min while obeying a specific rule. Voxel-based morphometry of the whole brain was used to detect the structural correlates of multitasking ability. Grey matter volume of the anterior cingulate cortex (ACC) was positively correlated with the overall performance and time monitoring in multitasking. In addition, white matter volume of the anterior thalamic radiation (ATR) was also positively correlated with time monitoring during multitasking. Other related brain regions associated with multitasking included the superior frontal gyrus, the inferior occipital gyrus, the lingual gyrus, and the inferior longitudinal fasciculus. No significant correlation was found between grey matter volume of the prefrontal cortex (Brodmann Area 10) and multitasking performance. Using a global correlation analysis to examine various aspects of multitasking performance, this study provided new insights into the structural neural correlates of multitasking ability. In particular, the ACC was identified as an important brain region that played both a general and a specific time-monitoring role in multitasking, extending the role of the ACC from lesioned populations to healthy populations. The present findings also support the view that the ATR may influence multitasking performance by affecting time-monitoring abilities.

  20. Structural Abnormalities in Childhood Absence Epilepsy: Voxel-Based Analysis Using Diffusion Tensor Imaging

    PubMed Central

    Qiu, Wenchao; Gao, Yuan; Yu, Chuanyong; Miao, Ailiang; Tang, Lu; Huang, Shuyang; Hu, Zheng; Xiang, Jing; Wang, Xiaoshan

    2016-01-01

    Purpose: Childhood absence epilepsy (CAE) is a common syndrome of idiopathic generalized epilepsy. However, little is known about the brain structural changes in this type of epilepsy, especially in the default mode network (DMN) regions. This study aims at using the diffusion tensor imaging (DTI) technique to quantify structural abnormalities of DMN nodes in CAE patients. Method: DTI data were acquired in 14 CAE patients (aged 8.64 ± 2.59 years, seven females and seven males) and 16 age- and sex-matched healthy controls. The data were analyzed using voxel-based analysis (VBA) and statistically compared between patients and controls. Pearson correlation was explored between altered DTI metrics and clinical parameters. The difference of brain volumes between patients and controls were also tested using unpaired t-test. Results: Patients showed significant increase of mean diffusivity (MD) and radial diffusivity (RD) in left medial prefrontal cortex (MPFC), and decrease of fractional anisotropy (FA) in left precuneus and axial diffusivity (AD) in both left MPFC and precuneus. In correlation analysis, MD value from left MPFC was positively associated with duration of epilepsy. Neither the disease duration nor the seizure frequency showed significant correlation with FA values. Between-group comparison of brain volumes got no significant difference. Conclusion: The findings indicate that structural impairments exist in DMN regions in children suffering from absence epilepsy and MD values positively correlate with epilepsy duration. This may contribute to understanding the pathological mechanisms of chronic neurological deficits and promote the development of new therapies for this disorder. PMID:27733824

  1. A Voxel-Based Morphometric MRI Study in Young Adults with Borderline Personality Disorder

    PubMed Central

    Jin, Xinhu; Zhong, Mingtian; Yao, Shuqiao; Cao, Xiyu; Tan, Changlian; Gan, Jun; Zhu, Xiongzhao; Yi, Jinyao

    2016-01-01

    Background Increasing evidence has documented subtle changes in brain morphology and function in patients with borderline personality disorder (BPD). However, results of magnetic resonance imaging volumetry in patients with BPD are inconsistent. In addition, few researchers using voxel-based morphometry (VBM) have focused on attachment and childhood trauma in BPD. This preliminary study was performed to investigate structural brain changes and their relationships to attachment and childhood trauma in a homogenous sample of young adults with BPD. Method We examined 34 young adults with BPD and 34 healthy controls (HCs) to assess regionally specific differences in gray matter volume (GMV) and gray matter concentration (GMC). Multiple regressions between brain volumes measured by VBM and attachment style questionnaire (ASQ) and childhood trauma questionnaire (CTQ) scores were performed. Results Compared with HCs, subjects with BPD showed significant bilateral increases in GMV in the middle cingulate cortex (MCC)/posterior cingulate cortex (PCC)/precuneus. GMC did not differ significantly between groups. In multiple regression models, ASQ insecure attachment scores were correlated negatively with GMV in the precuneus/MCC and middle occipital gyrus in HCs, HCs with more severe insecure attachment showed smaller volumes in precuneus/MCC and middle occipital gyrus, whereas no negative correlations between insecure attachment and GMV in any region were found in BPD group. In addition, CTQ total scores were not correlated with GMV in any region in the two groups respectively. Conclusions Our findings fit with those of previous reports of larger precuneus GMV in patients with BPD, and suggest that GMV in the precuneus/MCC and middle occipital gyrus is associated inversely with insecure attachment style in HCs. Our finding of increased GMV in the MCC and PCC in patients with BPD compared with HCs has not been reported in previous VBM studies. PMID:26808504

  2. Sports and brain morphology - a voxel-based morphometry study with endurance athletes and martial artists.

    PubMed

    Schlaffke, L; Lissek, S; Lenz, M; Brüne, M; Juckel, G; Hinrichs, T; Platen, P; Tegenthoff, M; Schmidt-Wilcke, T

    2014-02-14

    Physical exercises and motor skill learning have been shown to induce changes in regional brain morphology, this has been demonstrated for various activities and tasks. Also individuals with special skills show differences in regional brain morphology. This has been indicated for professional musicians, London taxi drivers, as well as for athletes like dancers, golfers and judokas. However little is known about whether sports with different metabolic profiles (aerobic vs. anaerobic) are associated with different patterns of altered brain morphology. In this cross-sectional study we investigated two groups of high-performance athletes, one group performing sports that are thought to be mainly aerobic, and one group performing sports known to have intermittent phases of anaerobic metabolism. Using high-resolution structural imaging and voxel-based morphometry (VBM), we investigated a group of 26 male athletes consisting of 13 martial artists and 13 endurance athletes as well as a group of non-exercising men (n=13). VBM analyses revealed higher gray matter (GM) volumes in the supplementary motor area/dorsal premotor cortex (BA 6) in both athlete groups as compared to the control group. In addition, endurance athletes showed significantly higher GM volume in the medial temporal lobe (MTL), specifically in the hippocampus and parahippocampal gyrus, which was not seen in the martial arts group. Our data suggest that high-performance sports are associated with changes in regional brain morphology in areas implicated in motor planning and motor learning. In addition high-level endurance sports seem to affect MTL structures, areas that have previously been shown to be modulated by aerobic exercise.

  3. Neuroanatomical phenotype of Klinefelter syndrome in childhood: a voxel-based morphometry study.

    PubMed

    Bryant, Daniel M; Hoeft, Fumiko; Lai, Song; Lackey, John; Roeltgen, David; Ross, Judith; Reiss, Allan L

    2011-05-04

    Klinefelter syndrome (KS) is a genetic disorder characterized by a supernumerary X chromosome. As such, KS offers a naturally occurring human model for the study of both X-chromosome gene expression and androgen on brain development. Previous neuroimaging studies have revealed neuroanatomical variations associated with KS, but have differed widely with respect to subject inclusion criteria, including mosaicism, pubertal status, and history of testosterone replacement therapy (TRT), all factors likely to influence neurodevelopment. We conducted a voxel-based morphometry study of regional gray and white matter (GM and WM, respectively) volumes in 31 KS males (mean age, 9.69 ± 1.70 years) and 36 typically developing (TD) male controls (10.99 ± 1.72 years). None of the participants with KS had received TRT, and all were prepubertal and had nonmosaic 47,XXY karyotypes. After controlling for age, males with KS showed trends (0.05 < p < 0.10) for significantly reduced total gray matter volume (TGMV) and total white matter volume (TWMV), relative to TD males. After controlling for TGMV and age, the KS group had significantly increased sensorimotor and parietal-occipital GM and significantly reduced amygdalar, hippocampal, insular, temporal, and inferior frontal GM relative to TD controls. After controlling for TWMV and age, the KS group had significantly increased left parietal WM as well as significantly reduced frontal and temporal WM. These findings are indicative of a characteristic prepubertal neuroanatomical phenotype that may be associated with cognitive-behavioral features of KS. This work offers new insight into the relationships among X-chromosome gene expression, neuroanatomy, and cognitive-behavioral functions impaired in KS, including language and attention.

  4. Voxel-based dose calculation in radiocolloid therapy of cystic craniopharyngiomas

    NASA Astrophysics Data System (ADS)

    Treuer, H.; Hoevels, M.; Luyken, K.; Gierich, A.; Hellerbach, A.; Lachtermann, B.; Visser-Vandewalle, V.; Ruge, M.; Wirths, J.

    2015-02-01

    Very high doses are administered in radiocolloid therapy of cystic craniopharyngiomas. However individual dose planning is not common yet mainly due to insufficient image resolution. Our aim was to investigate whether currently available high-resolution image data can be used for voxel-based dose calculation for short-ranged β-emitters (32P,90Y,186Re) and to assess the achievable accuracy. We developed a convolution algorithm based on voxelized dose activity distributions and dose-spread kernels. Results for targets with 5-40 mm diameter were compared with high-resolution Monte Carlo calculations in spherical phantoms. Voxel size was 0.35 mm. Homogeneous volume and surface activity distributions were used. Dose-volume histograms of targets and shell structures were compared and γ index (dose tolerance 5%, distance to agreement 0.35 mm) was calculated for dose profiles along the principal axes. For volumetric activity distributions 89.3% ± 11.9% of all points passed the γ test (mean γ 0.53  ±  0.16). For surface distributions 33.6% ± 14.8% of all points passed the γ test (mean γ 2.01  ±  0.60). The shift of curves in dose-volume histograms was -1.7 Gy ± 7.6 Gy (-4.4 Gy ± 24.1 Gy for 186Re) in volumetric distributions and 46.3% ± 32.8% in surface distributions. The results show that individual dose planning for radiocolloid therapy of cystic craniopharyngiomas based on high-resolution voxelized image data is feasible and yields highly accurate results for volumetric activity distributions and reasonable dose estimates for surface distributions.

  5. Regional Grey Matter Structure Differences between Transsexuals and Healthy Controls—A Voxel Based Morphometry Study

    PubMed Central

    Simon, Lajos; Kozák, Lajos R.; Simon, Viktória; Czobor, Pál; Unoka, Zsolt; Szabó, Ádám; Csukly, Gábor

    2013-01-01

    Gender identity disorder (GID) refers to transsexual individuals who feel that their assigned biological gender is incongruent with their gender identity and this cannot be explained by any physical intersex condition. There is growing scientific interest in the last decades in studying the neuroanatomy and brain functions of transsexual individuals to better understand both the neuroanatomical features of transsexualism and the background of gender identity. So far, results are inconclusive but in general, transsexualism has been associated with a distinct neuroanatomical pattern. Studies mainly focused on male to female (MTF) transsexuals and there is scarcity of data acquired on female to male (FTM) transsexuals. Thus, our aim was to analyze structural MRI data with voxel based morphometry (VBM) obtained from both FTM and MTF transsexuals (n = 17) and compare them to the data of 18 age matched healthy control subjects (both males and females). We found differences in the regional grey matter (GM) structure of transsexual compared with control subjects, independent from their biological gender, in the cerebellum, the left angular gyrus and in the left inferior parietal lobule. Additionally, our findings showed that in several brain areas, regarding their GM volume, transsexual subjects did not differ significantly from controls sharing their gender identity but were different from those sharing their biological gender (areas in the left and right precentral gyri, the left postcentral gyrus, the left posterior cingulate, precuneus and calcarinus, the right cuneus, the right fusiform, lingual, middle and inferior occipital, and inferior temporal gyri). These results support the notion that structural brain differences exist between transsexual and healthy control subjects and that majority of these structural differences are dependent on the biological gender. PMID:24391851

  6. Voxel-based morphometry and intellectual assessment in patients with congenital bilateral perisylvian syndrome.

    PubMed

    Yasuda, Clarissa L; Guimarães, Catarina A; Guerreiro, Marilisa M; Boscariol, Mirela; Oliveira, Ecila P M; Teixeira, Karine C; Costa, André L F; Beltramini, Guilherme C; Cendes, Fernando

    2014-07-01

    Congenital bilateral perisylvian syndrome (CBPS) presents with heterogeneous clinical manifestations such as pseudobulbar palsy, language disorder, variable cognitive deficits, epilepsy, and perisylvian abnormalities (most frequently polymicrogyria) on imaging studies. We investigated the relationship between seizures and extent of gray matter (GM) and white matter (WM) abnormalities using voxel-based morphometry (VBM) of brain magnetic resonance imaging (MRI) as well the association between seizures, structural abnormalities and cognitive ability. In this cross-sectional study, we evaluated 51 healthy volunteers and 18 patients with CBPS with epilepsy (seizure group, n = 7) and without (non-seizure group, n = 11). We used VBM (SPM8/DARTEL) to investigate areas with excess and atrophy of both gray and white matter, comparing groups of patients with controls. Intellectual ability of patients was assessed by the WISC-III or WAIS-III. Both groups with CBPS and the control group were homogeneous with respect to gender (p = 0.07) and age (p = 0.065). Besides perisylvian polymicrogyria, the seizure group exhibited areas with GM and WM reduction including temporal, frontal, parietal and occipital lobes. In contrast, we identified fewer areas with GM and WM reduction in the non-seizure group. The seizure group presented worse intellectual performance (performance IQ and global IQ) than the non-seizure group. The seizure group presented with a more widespread pattern of cortical and sub-cortical abnormalities, as well as worse cognition. Our results suggest that patients with CBPS and epilepsy appear to have widespread neuronal damage that goes beyond the areas with MRI-visible perisylvian polymicrogyria.

  7. Brain structure in post-traumatic stress disorder: A voxel-based morphometry analysis.

    PubMed

    Tan, Liwen; Zhang, Li; Qi, Rongfeng; Lu, Guangming; Li, Lingjiang; Liu, Jun; Li, Weihui

    2013-09-15

    This study compared the difference in brain structure in 12 mine disaster survivors with chronic post-traumatic stress disorder, 7 cases of improved post-traumatic stress disorder symptoms, and 14 controls who experienced the same mine disaster but did not suffer post-traumatic stress disorder, using the voxel-based morphometry method. The correlation between differences in brain structure and post-traumatic stress disorder symptoms was also investigated. Results showed that the gray matter volume was the highest in the trauma control group, followed by the symptoms-improved group, and the lowest in the chronic post-traumatic stress disorder group. Compared with the symptoms-improved group, the gray matter volume in the lingual gyrus of the right occipital lobe was reduced in the chronic post-traumatic stress disorder group. Compared with the trauma control group, the gray matter volume in the right middle occipital gyrus and left middle frontal gyrus was reduced in the symptoms-improved group. Compared with the trauma control group, the gray matter volume in the left superior parietal lobule and right superior frontal gyrus was reduced in the chronic post-traumatic stress disorder group. The gray matter volume in the left superior parietal lobule was significantly positively correlated with the State-Trait Anxiety Inventory subscale score in the symptoms-improved group and chronic post-traumatic stress disorder group (r = 0.477, P = 0.039). Our findings indicate that (1) chronic post-traumatic stress disorder patients have gray matter structural damage in the prefrontal lobe, occipital lobe, and parietal lobe, (2) after post-traumatic stress, the disorder symptoms are improved and gray matter structural damage is reduced, but cannot recover to the trauma-control level, and (3) the superior parietal lobule is possibly associated with chronic post-traumatic stress disorder. Post-traumatic stress disorder patients exhibit gray matter abnormalities.

  8. Voxel-based Morphometric MRI Post-processing in MRI-negative Epilepsies

    PubMed Central

    Wang, ZI; Jones, SE; Jaisani, Z; Najm, IM; Prayson, RA; Burgess, RC; Krishnan, B; Ristic, A; Wong, CH; Bingaman, W; Gonzalez-Martinez, JA; Alexopoulos, AV

    2015-01-01

    Objective In the presurgical workup of MRI-negative (MRI−, or “nonlesional”) pharmacoresistant focal epilepsy (PFE) patients, discovering a previously undetected lesion can drastically change the evaluation and likely improve surgical outcome. Our study utilizes a voxel-based MRI post-processing technique, implemented in a morphometric analysis program (MAP), to facilitate detection of subtle abnormalities in a consecutive cohort of MRI− surgical candidates. Methods Included in this retrospective study was a consecutive cohort of 150 MRI-surgical patients. MAP was performed on T1-weighted MRI, with comparison to a scanner-specific normal database. Review and analysis of MAP were performed blinded to patients’ clinical information. The pertinence of MAP+ areas was confirmed by surgical outcome and pathology. Results MAP showed a 43% positive rate, sensitivity of 0.9 and specificity of 0.67. Overall, patients with MAP+ region completely resected had the best seizure outcomes, followed by the MAP− patients, and patients who had no/partial resection of the MAP+ region had the worst outcome (p<0.001). Subgroup analysis revealed that visually identified subtle findings are more likely correct if also MAP+. False-positive rate in 52 normal controls was 2%. Surgical pathology of the resected MAP+ areas contained mainly non-balloon-cell FCD. Multiple MAP+ regions were present in 7% of patients. Conclusions MAP can be a practical and valuable tool to: (1) guide the search for subtle MRI abnormalities, and (2) confirm visually identified questionable abnormalities in patients with PFE due to suspected FCD. A MAP+ region, when concordant with the patient’s electro-clinical presentation, should provide a legitimate target for surgical exploration. PMID:25807928

  9. A fast algorithm for voxel-based deterministic simulation of X-ray imaging

    NASA Astrophysics Data System (ADS)

    Li, Ning; Zhao, Hua-Xia; Cho, Sang-Hyun; Choi, Jung-Gil; Kim, Myoung-Hee

    2008-04-01

    Deterministic method based on ray tracing technique is known as a powerful alternative to the Monte Carlo approach for virtual X-ray imaging. The algorithm speed is a critical issue in the perspective of simulating hundreds of images, notably to simulate tomographic acquisition or even more, to simulate X-ray radiographic video recordings. We present an algorithm for voxel-based deterministic simulation of X-ray imaging using voxel-driven forward and backward perspective projection operations and minimum bounding rectangles (MBRs). The algorithm is fast, easy to implement, and creates high-quality simulated radiographs. As a result, simulated radiographs can typically be obtained in split seconds with a simple personal computer. Program summaryProgram title: X-ray Catalogue identifier: AEAD_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEAD_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 416 257 No. of bytes in distributed program, including test data, etc.: 6 018 263 Distribution format: tar.gz Programming language: C (Visual C++) Computer: Any PC. Tested on DELL Precision 380 based on a Pentium D 3.20 GHz processor with 3.50 GB of RAM Operating system: Windows XP Classification: 14, 21.1 Nature of problem: Radiographic simulation of voxelized objects based on ray tracing technique. Solution method: The core of the simulation is a fast routine for the calculation of ray-box intersections and minimum bounding rectangles, together with voxel-driven forward and backward perspective projection operations. Restrictions: Memory constraints. There are three programs in all. A. Program for test 3.1(1): Object and detector have axis-aligned orientation; B. Program for test 3.1(2): Object in arbitrary orientation; C. Program for test 3.2: Simulation of X-ray video

  10. Influence of Group on Individual Subject Maps in SPM Voxel Based Morphometry

    PubMed Central

    Michael, Andrew M.; Evans, Eli; Moore, Gregory J.

    2016-01-01

    Voxel based morphometry (VBM) is a widely utilized neuroimaging technique for spatially normalizing brain structural MRI (sMRI) onto a common template. The DARTEL technique of VBM takes into account the spatial intensity distribution of sMRIs to construct a study specific group template. The group template is then used to create final individual normalized tissue maps (FINTM) for each subject in the group. In this study, we investigate the effect of group on FINTM, i.e., we evaluate the variability of a constant subject's FINTM when other subjects in the group are iteratively changed. We examine this variability under the following scenarios: (1) when the demographics of the iterative groups are similar, (2) when the average age of the iterative groups is increased, and (3) when the number of subjects with a brain disorder (here we use subjects with autism) is increased. Our results show that when subject demographics of the group remains similar the mean standard deviation (SD) of FINTM gray matter (GM) of the constant subject was around 0.01. As the average age of the group is increased, mean SD of GM increased to around 0.03 and at certain brain locations variability was as high as 0.23. A similar increase in variability was observed when the number of autism subjects in the group was increased where mean SD was around 0.02. Further, we find that autism vs. control GM differences are in the range of −0.05 to +0.05 for more than 97% of the voxels and note that the magnitude of the differences are comparable to GM variability. Finally, we report that opting not to modulate during normalization or increasing the size of the smoothing kernel can decrease FINTM variability but at the loss of subject-specific features. Based on the findings of this study, we outline precautions that should be considered by investigators to reduce the impact of group on FINTM and thereby derive more meaningful group differences when comparing two cohorts of subjects. PMID:27994534

  11. Influence of Group on Individual Subject Maps in SPM Voxel Based Morphometry.

    PubMed

    Michael, Andrew M; Evans, Eli; Moore, Gregory J

    2016-01-01

    Voxel based morphometry (VBM) is a widely utilized neuroimaging technique for spatially normalizing brain structural MRI (sMRI) onto a common template. The DARTEL technique of VBM takes into account the spatial intensity distribution of sMRIs to construct a study specific group template. The group template is then used to create final individual normalized tissue maps (FINTM) for each subject in the group. In this study, we investigate the effect of group on FINTM, i.e., we evaluate the variability of a constant subject's FINTM when other subjects in the group are iteratively changed. We examine this variability under the following scenarios: (1) when the demographics of the iterative groups are similar, (2) when the average age of the iterative groups is increased, and (3) when the number of subjects with a brain disorder (here we use subjects with autism) is increased. Our results show that when subject demographics of the group remains similar the mean standard deviation (SD) of FINTM gray matter (GM) of the constant subject was around 0.01. As the average age of the group is increased, mean SD of GM increased to around 0.03 and at certain brain locations variability was as high as 0.23. A similar increase in variability was observed when the number of autism subjects in the group was increased where mean SD was around 0.02. Further, we find that autism vs. control GM differences are in the range of -0.05 to +0.05 for more than 97% of the voxels and note that the magnitude of the differences are comparable to GM variability. Finally, we report that opting not to modulate during normalization or increasing the size of the smoothing kernel can decrease FINTM variability but at the loss of subject-specific features. Based on the findings of this study, we outline precautions that should be considered by investigators to reduce the impact of group on FINTM and thereby derive more meaningful group differences when comparing two cohorts of subjects.

  12. A voxel based comparative analysis using magnetization transfer imaging and T1-weighted magnetic resonance imaging in progressive supranuclear palsy

    PubMed Central

    Sandhya, Mangalore; Saini, Jitender; Pasha, Shaik Afsar; Yadav, Ravi; Pal, Pramod Kumar

    2014-01-01

    Aims: In progressive supranuclear palsy (PSP) tissue damage occurs in specific cortical and subcortical regions. Voxel based analysis using T1-weighted images depict quantitative gray matter (GM) atrophy changes. Magnetization transfer (MT) imaging depicts qualitative changes in the brain parenchyma. The purpose of our study was to investigate whether MT imaging could indicate abnormalities in PSP. Settings and Design: A total of 10 patients with PSP (9 men and 1 woman) and 8 controls (5 men and 3 women) were studied with T1-weighted magnetic resonance imaging (MRI) and 3DMT imaging. Voxel based analysis of T1-weighted MRI was performed to investigate brain atrophy while MT was used to study qualitative abnormalities in the brain tissue. We used SPM8 to investigate group differences (with two sample t-test) using the GM and white matter (WM) segmented data. Results: T1-weighted imaging and MT are equally sensitive to detect changes in GM and WM in PSP. Magnetization transfer ratio images and magnetization-prepared rapid acquisition of gradient echo revealed extensive bilateral volume and qualitative changes in the orbitofrontal, prefrontal cortex and limbic lobe and sub cortical GM. The prefrontal structures involved were the rectal gyrus, medial, inferior frontal gyrus (IFG) and middle frontal gyrus (MFG). The anterior cingulate, cingulate gyrus and lingual gyrus of limbic lobe and subcortical structures such as caudate, thalamus, insula and claustrum were also involved. Cerebellar involvement mainly of anterior lobe was also noted. Conclusions: The findings suggest that voxel based MT imaging permits a whole brain unbiased investigation of central nervous system structural integrity in PSP. PMID:25024571

  13. Neurofunctional maps of the 'maternal brain' and the effects of oxytocin: a multimodal voxel-based meta-analysis.

    PubMed

    Rocchetti, Matteo; Radua, Joaquim; Paloyelis, Yannis; Xenaki, Lida-Alkisti; Frascarelli, Marianna; Caverzasi, Edgardo; Politi, Pierluigi; Fusar-Poli, Paolo

    2014-10-01

    Several studies have tried to understand the possible neurobiological basis of mothering. The putative involvement of oxytocin, in this regard, has been deeply investigated. Performing a voxel-based meta-analysis, we aimed at testing the hypothesis of overlapping brain activation in functional magnetic resonance imaging (fMRI) studies investigating the mother-infant interaction and the oxytocin modulation of emotional stimuli in humans. We performed two systematic literature searches: fMRI studies investigating the neurofunctional correlates of the 'maternal brain' by employing mother-infant paradigms; and fMRI studies employing oxytocin during emotional tasks. A unimodal voxel-based meta-analysis was performed on each database, whereas a multimodal voxel-based meta-analytical tool was adopted to assess the hypothesis that the neurofunctional effects of oxytocin are detected in brain areas implicated in the 'maternal brain.' We found greater activation in the bilateral insula extending to the inferior frontal gyrus, basal ganglia and thalamus during mother-infant interaction and greater left insular activation associated with oxytocin administration versus placebo. Left insula extending to basal ganglia and frontotemporal gyri as well as bilateral thalamus and amygdala showed consistent activation across the two paradigms. Right insula also showed activation across the two paradigms, and dorsomedial frontal cortex activation in mothers but deactivation with oxytocin. Significant activation in areas involved in empathy, emotion regulation, motivation, social cognition and theory of mind emerged from our multimodal meta-analysis, supporting the need for further studies directly investigating the neurobiology of oxytocin in the mother-infant relationship.

  14. Structural Differences in Gray Matter between Glider Pilots and Non-Pilots. A Voxel-Based Morphometry Study

    PubMed Central

    Ahamed, Tosif; Kawanabe, Motoaki; Ishii, Shin; Callan, Daniel E.

    2014-01-01

    Glider flying is a unique skill that requires pilots to control an aircraft at high speeds in three dimensions and amidst frequent full-body rotations. In the present study, we investigated the neural correlates of flying a glider using voxel-based morphometry. The comparison between gray matter densities of 15 glider pilots and a control group of 15 non-pilots exhibited significant gray matter density increases in left ventral premotor cortex, anterior cingulate cortex, and the supplementary eye field. We posit that the identified regions might be associated with cognitive and motor processes related to flying, such as joystick control, visuo-vestibular interaction, and oculomotor control. PMID:25506339

  15. The neural basis of reversible sentence comprehension: evidence from voxel-based lesion symptom mapping in aphasia.

    PubMed

    Thothathiri, Malathi; Kimberg, Daniel Y; Schwartz, Myrna F

    2012-01-01

    We explored the neural basis of reversible sentence comprehension in a large group of aphasic patients (n = 79). Voxel-based lesion symptom mapping revealed a significant association between damage in temporo-parietal cortex and impaired sentence comprehension. This association remained after we controlled for phonological working memory. We hypothesize that this region plays an important role in the thematic or what-where processing of sentences. In contrast, we detected weak or no association between reversible sentence comprehension and the ventrolateral pFC, which includes Broca's area, even for syntactically complex sentences. This casts doubt on theories that presuppose a critical role for this region in syntactic computations.

  16. Decreased gray matter volume is associated with the subtypes of psychotic symptoms in patients with antipsychotic-naïve mild or moderate Alzheimer's disease: A voxel-based morphometry study.

    PubMed

    Lee, Young-Min; Chung, Young-In; Park, Je-Min; Lee, Byung-Dae; Moon, Eunsoo; Jeong, Hee-Jeong; Kim, Ji-Hoon; Kim, Hak-Jin; Mun, Chi-Woong; Kim, Tae-Hyung; Kim, Young-Hoon; Kim, Eun-Joo

    2016-03-30

    The purpose of this study was to investigate the association between brain regional gray matter volume and two subtypes of psychotic symptoms, namely paranoid and misidentification subtypes, in antipsychotic-naïve mild or moderate Alzheimer's disease (AD) patients. Forty AD patients with psychotic symptoms and 25 AD patients without psychotic symptoms were assessed for cognitive and functional impairment. Presence and subtype of psychotic symptoms were assessed by using the delusion and hallucination subscale of the Korean Neuropsychiatric Inventory (K-NPI). Structural MRI images were acquired on a 3 T scanner, and were analyzed using voxel-based morphometry (VBM) for automated analysis. The misidentification subtype is associated with more severe gray matter atrophy, and paranoid subtype is associated with less severe gray matter atrophy compared to non-psychosis group. These results suggest that the misidentification, the paranoid subtype and the non-psychosis group have a distinct neural correlation.

  17. Generation of postured voxel-based human models for the study of step voltage excited by lightning current

    NASA Astrophysics Data System (ADS)

    Gao, J.; Munteanu, I.; Müller, W. F. O.; Weiland, T.

    2011-07-01

    With the development of medical technique and computational electromagnetics, high resolution anatomic human models have already been widely developed and used in computation of electromagnetic fields induced in human body. Although these so called voxel-based human models are powerful tools for research on electromagnetic safety, their unchangeable standing posture makes it impossible to simulate a realistic scenario in which people have a lot of different postures. This paper describes a poser program package which was developed as an improved version of the free-from deformation technique to overcome this problem. It can set rotation angles of different human joints and then deform the original human model to make it have different postures. The original whole-body human model can be deformed smoothly, continuity of internal tissues and organs is maintained and the mass of different tissues and organs can be conserved in a reasonable level. As a typical application of the postured human models, this paper also studies the effect of the step voltage due to a lightning strike on the human body. Two voxel-based human body models with standing and walking posture were developed and integrated into simulation models to compute the current density distribution in the human body shocked by the step voltage. In order to speed up the transient simulation, the reduced c technique was used, leading to a speedup factor of around 20. The error introduced by the reduced c technique is discussed and simulation results are presented in detail.

  18. Anterior temporal involvement in semantic word retrieval: voxel-based lesion-symptom mapping evidence from aphasia

    PubMed Central

    Kimberg, Daniel Y.; Walker, Grant M.; Faseyitan, Olufunsho; Brecher, Adelyn; Dell, Gary S.; Coslett, H. Branch

    2009-01-01

    Analysis of error types provides useful information about the stages and processes involved in normal and aphasic word production. In picture naming, semantic errors (horse for goat) generally result from something having gone awry in lexical access such that the right concept was mapped to the wrong word. This study used the new lesion analysis technique known as voxel-based lesion-symptom mapping to investigate the locus of lesions that give rise to semantic naming errors. Semantic errors were obtained from 64 individuals with post-stroke aphasia, who also underwent high-resolution structural brain scans. Whole brain voxel-based lesion-symptom mapping was carried out to determine where lesion status predicted semantic error rate. The strongest associations were found in the left anterior to mid middle temporal gyrus. This area also showed strong and significant effects in further analyses that statistically controlled for deficits in pre-lexical, conceptualization processes that might have contributed to semantic error production. This study is the first to demonstrate a specific and necessary role for the left anterior temporal lobe in mapping concepts to words in production. We hypothesize that this role consists in the conveyance of fine-grained semantic distinctions to the lexical system. Our results line up with evidence from semantic dementia, the convergence zone framework and meta-analyses of neuroimaging studies on word production. At the same time, they cast doubt on the classical linkage of semantic error production to lesions in and around Wernicke's area. PMID:19942676

  19. MAX meets ADAM: a dosimetric comparison between a voxel-based and a mathematical model for external exposure to photons.

    PubMed

    Kramer, R; Vieira, J W; Khoury, H J; de Andrade Lima, F

    2004-03-21

    The International Commission on Radiological Protection intends to revise the organ and tissue equivalent dose conversion coefficients published in various reports. For this purpose the mathematical human medical internal radiation dose (MIRD) phantoms, actually in use, have to be replaced by recently developed voxel-based phantoms. This study investigates the dosimetric consequences, especially with respect to the effective male dose, if not only a MIRD phantom is replaced by a voxel phantom, but also if the tissue compositions and the radiation transport codes are changed. This task will be resolved by systematically replacing in the mathematical ADAM/GSF exposure model, first the radiation transport code, then the tissue composition and finally the phantom anatomy, in order to arrive at the voxel-based MAX/EGS4 exposure model. The results show that the combined effect of these replacements can decrease the effective male dose by up to 25% for external exposures to photons for incident energies above 30 keV for different field geometries, mainly because of increased shielding by a heterogeneous skeleton and by the overlying adipose and muscle tissue, and also because of the positions internal organs have in a realistically designed human body compared to their positions in the mathematically constructed phantom.

  20. Voxel-based analysis of Alzheimer's disease PET imaging using a triplet of radiotracers: PIB, FDDNP, and FDG.

    PubMed

    Shin, Jonghan; Lee, Sang-Yoon; Kim, Seog Ju; Kim, So-Hee; Cho, Seong-Jin; Kim, Young-Bo

    2010-08-15

    Beta amyloid plaques, neurofibrillary tangles, and impaired glucose metabolism are among the most prevalent pathological characteristics of Alzheimer's disease (AD). However, separate visualization of these three AD-related pathologies in living humans has not been conducted. Here, we show that positron emission tomography (PET) imaging using the three radiotracers (11)C-Pittsburgh compound B (PIB), 2-(1-{6-[(2-(18)F-fluoroethyl)(methyl)amino]-2-naphthyl}ethylidene) malononitrile (FDDNP), and 2-[18F]fluoro-2-deoxy-d-glucose (FDG), in the same subjects, with and without AD, can provide valuable information on the pathological patterns of the distribution of tracers for amyloid plaque, neurofibrillary tangle, and glucose hypometabolism in AD. Voxel-based analysis of PIB-PET in patients with AD compared with normal control subjects showed that patients with AD have highly significant PIB retention in brain regions known to have high amyloid plaque deposition (e.g., frontal, parietal, temporal, and posterior cingulate/precuneus cortices). In contrast, voxel-based analysis of FDDNP-PET showed significantly high FDDNP binding in some brain regions known to have high tangle accumulation in patients with AD compared with age-matched normal subjects (e.g., entorhinal cortex, inferior temporal gyrus, and secondary visual cortex). In addition, because FDDNP binds both plaques and tangles but PIB binds plaques specifically, we examined subtracted PET data (FDDNP minus PIB) acquired from the same patients with AD using an SPM analysis. We found that the hippocampal formation was the most significant brain region in the voxel mapping of FDDNP minus PIB in the same patients with AD. Voxel-based analysis of FDG-PET in the same subjects revealed that brain regions with glucose hypometabolism in patients with AD overlap with regions of high PIB binding. In conclusion, PET imaging using these three radiotracers in the same subjects may contribute toward developing and testing disease

  1. Neuronal injury in the motor cortex after chronic stroke and lower limb motor impairment: a voxel-based lesion symptom mapping study.

    PubMed

    Reynolds, Alexandria M; Peters, Denise M; Vendemia, Jennifer M C; Smith, Lenwood P; Sweet, Raymond C; Baylis, Gordon C; Krotish, Debra; Fritz, Stacy L

    2014-04-01

    Many studies have examined motor impairments using voxel-based lesion symptom mapping, but few are reported regarding the corresponding relationship between cerebral cortex injury and lower limb motor impairment analyzed using this technique. This study correlated neuronal injury in the cerebral cortex of 16 patients with chronic stroke based on a voxel-based lesion symptom mapping analysis. Neuronal injury in the corona radiata, caudate nucleus and putamen of patients with chronic stroke could predict walking speed. The behavioral measure scores were consistent with motor deficits expected after damage to the cortical motor system due to stroke. These findings suggest that voxel-based lesion symptom mapping may provide a more accurate prognosis of motor recovery from chronic stroke according to neuronal injury in cerebral motor cortex.

  2. Neuronal injury in the motor cortex after chronic stroke and lower limb motor impairment: a voxel-based lesion symptom mapping study

    PubMed Central

    Reynolds, Alexandria M.; Peters, Denise M.; Vendemia, Jennifer M. C.; Smith, Lenwood P.; Sweet, Raymond C.; Baylis, Gordon C.; Krotish, Debra; Fritz, Stacy L.

    2014-01-01

    Many studies have examined motor impairments using voxel-based lesion symptom mapping, but few are reported regarding the corresponding relationship between cerebral cortex injury and lower limb motor impairment analyzed using this technique. This study correlated neuronal injury in the cerebral cortex of 16 patients with chronic stroke based on a voxel-based lesion symptom mapping analysis. Neuronal injury in the corona radiata, caudate nucleus and putamen of patients with chronic stroke could predict walking speed. The behavioral measure scores were consistent with motor deficits expected after damage to the cortical motor system due to stroke. These findings suggest that voxel-based lesion symptom mapping may provide a more accurate prognosis of motor recovery from chronic stroke according to neuronal injury in cerebral motor cortex. PMID:25206888

  3. Gray Matter Atrophy within the Default Mode Network of Fibromyalgia: A Meta-Analysis of Voxel-Based Morphometry Studies

    PubMed Central

    2016-01-01

    Over the years, studies have demonstrated morphological changes in the brain of fibromyalgia (FMS). We aimed to conduct a coordinate-based meta-analytic research through systemic review on voxel-based morphometry (VBM) imaging results to identify consistent gray matter (GM) difference between FMS patients and healthy subjects. We performed a comprehensive literature search in PubMed (January 2000–December 2015) and included six VBM publication on FMS. Stereotactic data were extracted from 180 patients of FMS and 123 healthy controls. By means of activation likelihood estimation (ALE) technique, regional GM reduction in left medial prefrontal cortex and right dorsal posterior cingulate cortex was identified. Both regions are within the default mode network. In conclusion, the gray matter deficit is related to the both affective and nonaffective components of pain processing. This result also provided the neuroanatomical correlates for emotional and cognitive symptoms in FMS. PMID:28105430

  4. Larger right posterior parietal volume in action video game experts: a behavioral and voxel-based morphometry (VBM) study.

    PubMed

    Tanaka, Satoshi; Ikeda, Hanako; Kasahara, Kazumi; Kato, Ryo; Tsubomi, Hiroyuki; Sugawara, Sho K; Mori, Makoto; Hanakawa, Takashi; Sadato, Norihiro; Honda, Manabu; Watanabe, Katsumi

    2013-01-01

    Recent studies suggest that action video game players exhibit superior performance in visuospatial cognitive tasks compared with non-game players. However, the neural basis underlying this visuospatial cognitive performance advantage remains largely unknown. The present human behavioral and imaging study compared gray matter volume in action video game experts and non-experts using structural magnetic resonance imaging and voxel-based morphometry analysis. The results revealed significantly larger gray matter volume in the right posterior parietal cortex in experts compared with non-experts. Furthermore, the larger gray matter volume in the right posterior parietal cortex significantly correlated with individual performance in a visual working memory task in experts. These results suggest that differences in brain structure may be linked to extensive video game play, leading to superior visuospatial cognitive performance in action video game experts.

  5. Whole-brain gray matter volume abnormalities in patients with generalized anxiety disorder: voxel-based morphometry.

    PubMed

    Moon, Chung-Man; Kim, Gwang-Won; Jeong, Gwang-Woo

    2014-02-12

    Patients with generalized anxiety disorder (GAD) experience psychological distress because of excessive and uncontrollable anxiety in everyday life. Only a few morphological studies have so far focused on specific brain regions of interest as well as the gray matter volume changes in GAD patients. This study evaluated gray matter volume alterations in whole-brain areas between GAD patients and healthy controls, and sex differences between the specific brain areas with significant volume changes in GAD patients using voxel-based morphometry. Twenty-two patients with GAD (13 men and nine women), who were diagnosed using the DSM-IV-TR, and 22 age-matched healthy controls (13 men and nine women) participated in this study. The high-resolution MRI data were processed using voxel-based morphometry analysis on the basis of diffeomorphic anatomical registration through an exponentiated Lie algebra algorithm in Statistical Parametric Mapping 8. There was no significant difference in the total intracranial volume between GAD patients and controls, but a significant difference was observed between sexes (P<0.05). Patients with GAD showed significant volume reductions in the hippocampus, midbrain, thalamus, insula, and superior temporal gyrus compared with the controls. As for the sex comparison, female patients showed a significant increase in the volume of the dorsolateral prefrontal cortex relative to male patients. Also, the volume of the dorsolateral prefrontal cortex in female patients was correlated positively with the Hamilton Anxiety Rating Scale score (γ=0.68, P=0.04). The specific morphological variations in patient with GAD will be helpful to understand the neural mechanism associated with a symptom of GAD. Furthermore, the findings would be valuable for the diagnostic accuracy of GAD using morphometric MRI analysis.

  6. Regional specificity of MRI contrast parameter changes in normal ageing revealed by voxel-based quantification (VBQ).

    PubMed

    Draganski, B; Ashburner, J; Hutton, C; Kherif, F; Frackowiak, R S J; Helms, G; Weiskopf, N

    2011-04-15

    Normal ageing is associated with characteristic changes in brain microstructure. Although in vivo neuroimaging captures spatial and temporal patterns of age-related changes of anatomy at the macroscopic scale, our knowledge of the underlying (patho)physiological processes at cellular and molecular levels is still limited. The aim of this study is to explore brain tissue properties in normal ageing using quantitative magnetic resonance imaging (MRI) alongside conventional morphological assessment. Using a whole-brain approach in a cohort of 26 adults, aged 18-85years, we performed voxel-based morphometric (VBM) analysis and voxel-based quantification (VBQ) of diffusion tensor, magnetization transfer (MT), R1, and R2* relaxation parameters. We found age-related reductions in cortical and subcortical grey matter volume paralleled by changes in fractional anisotropy (FA), mean diffusivity (MD), MT and R2*. The latter were regionally specific depending on their differential sensitivity to microscopic tissue properties. VBQ of white matter revealed distinct anatomical patterns of age-related change in microstructure. Widespread and profound reduction in MT contrasted with local FA decreases paralleled by MD increases. R1 reductions and R2* increases were observed to a smaller extent in overlapping occipito-parietal white matter regions. We interpret our findings, based on current biophysical models, as a fingerprint of age-dependent brain atrophy and underlying microstructural changes in myelin, iron deposits and water. The VBQ approach we present allows for systematic unbiased exploration of the interaction between imaging parameters and extends current methods for detection of neurodegenerative processes in the brain. The demonstrated parameter-specific distribution patterns offer insights into age-related brain structure changes in vivo and provide essential baseline data for studying disease against a background of healthy ageing.

  7. Simplifying Podcasting

    ERIC Educational Resources Information Center

    Panday, Prachi Parashar

    2009-01-01

    The article intends to simplify the different aspects of podcasting. The article covers types of podcasts; the pedagogical benefits of podcasting; the connection between theory and podcasting; answers to questions, queries, and apprehensions. Before trying out a new tool, it is important to understand why we do things the way we do. A crucial part…

  8. Early Gray-Matter and White-Matter Concentration in Infancy Predict Later Language Skills: A Whole Brain Voxel-Based Morphometry Study

    ERIC Educational Resources Information Center

    Can, Dilara Deniz; Richards, Todd; Kuhl, Patricia K.

    2013-01-01

    Magnetic Resonance Imaging (MRI) brain scans were obtained from 19 infants at 7 months. Expressive and receptive language performance was assessed at 12 months. Voxel-based morphometry (VBM) identified brain regions where gray-matter and white-matter concentrations at 7 months correlated significantly with children's language scores at 12 months.…

  9. A voxel-based investigation for MRI-only radiotherapy of the brain using ultra short echo times

    NASA Astrophysics Data System (ADS)

    Edmund, Jens M.; Kjer, Hans M.; Van Leemput, Koen; Hansen, Rasmus H.; Andersen, Jon AL; Andreasen, Daniel

    2014-12-01

    Radiotherapy (RT) based on magnetic resonance imaging (MRI) as the only modality, so-called MRI-only RT, would remove the systematic registration error between MR and computed tomography (CT), and provide co-registered MRI for assessment of treatment response and adaptive RT. Electron densities, however, need to be assigned to the MRI images for dose calculation and patient setup based on digitally reconstructed radiographs (DRRs). Here, we investigate the geometric and dosimetric performance for a number of popular voxel-based methods to generate a so-called pseudo CT (pCT). Five patients receiving cranial irradiation, each containing a co-registered MRI and CT scan, were included. An ultra short echo time MRI sequence for bone visualization was used. Six methods were investigated for three popular types of voxel-based approaches; (1) threshold-based segmentation, (2) Bayesian segmentation and (3) statistical regression. Each approach contained two methods. Approach 1 used bulk density assignment of MRI voxels into air, soft tissue and bone based on logical masks and the transverse relaxation time T2 of the bone. Approach 2 used similar bulk density assignments with Bayesian statistics including or excluding additional spatial information. Approach 3 used a statistical regression correlating MRI voxels with their corresponding CT voxels. A similar photon and proton treatment plan was generated for a target positioned between the nasal cavity and the brainstem for all patients. The CT agreement with the pCT of each method was quantified and compared with the other methods geometrically and dosimetrically using both a number of reported metrics and introducing some novel metrics. The best geometrical agreement with CT was obtained with the statistical regression methods which performed significantly better than the threshold and Bayesian segmentation methods (excluding spatial information). All methods agreed significantly better with CT than a reference water MRI

  10. Permutation and parametric tests for effect sizes in voxel-based morphometry of gray matter volume in brain structural MRI.

    PubMed

    Dickie, David A; Mikhael, Shadia; Job, Dominic E; Wardlaw, Joanna M; Laidlaw, David H; Bastin, Mark E

    2015-12-01

    Permutation testing has been widely implemented in voxel-based morphometry (VBM) tools. However, this type of non-parametric inference has yet to be thoroughly compared with traditional parametric inference in VBM studies of brain structure. Here we compare both types of inference and investigate what influence the number of permutations in permutation testing has on results in an exemplar study of how gray matter proportion changes with age in a group of working age adults. High resolution T1-weighted volume scans were acquired from 80 healthy adults aged 25-64years. Using a validated VBM procedure and voxel-based permutation testing for Pearson product-moment coefficient, the effect sizes of changes in gray matter proportion with age were assessed using traditional parametric and permutation testing inference with 100, 500, 1000, 5000, 10000 and 20000 permutations. The statistical significance was set at P<0.05 and false discovery rate (FDR) was used to correct for multiple comparisons. Clusters of voxels with statistically significant (PFDR<0.05) declines in gray matter proportion with age identified with permutation testing inference (N≈6000) were approximately twice the size of those identified with parametric inference (N=3221voxels). Permutation testing with 10000 (N=6251voxels) and 20000 (N=6233voxels) permutations produced clusters that were generally consistent with each other. However, with 1000 permutations there were approximately 20% more statistically significant voxels (N=7117voxels) than with ≥10000 permutations. Permutation testing inference may provide a more sensitive method than traditional parametric inference for identifying age-related differences in gray matter proportion. Based on the results reported here, at least 10000 permutations should be used in future univariate VBM studies investigating age related changes in gray matter to avoid potential false findings. Additional studies using permutation testing in large imaging databanks

  11. Permutation and parametric tests for effect sizes in voxel-based morphometry of grey matter volume in brain structural MRI

    PubMed Central

    Dickie, David A.; Mikhael, Shadia; Job, Dominic E.; Wardlaw, Joanna M.; Laidlaw, David H.; Bastin, Mark E.

    2015-01-01

    Permutation testing has been widely implemented in voxel-based morphometry (VBM) tools. However, this type of non-parametric inference has yet to be thoroughly compared with traditional parametric inference in VBM studies of brain structure. Here we compare both types of inference and investigate what influence the number of permutations in permutation testing has on results in an exemplar study of how grey matter proportion changes with age in a group of working age adults. High resolution T1-weighted volume scans were acquired from 80 healthy adults aged 25–64 years. Using a validated VBM procedure and voxel-based permutation testing for Pearson product-moment coefficient, the effect sizes of changes in grey matter proportion with age were assessed using traditional parametric and permutation testing inference with 100, 500, 1000, 5000, 10000 and 20000 permutations. The statistical significance was set at P < 0.05 and false discovery rate (FDR) used to correct for multiple comparisons. Clusters of voxels with statistically significant (PFDR < 0.05) declines in grey matter proportion with age identified with permutation testing inference (N ≈ 6000) were approximately twice the size of those identified with parametric inference (N = 3221 voxels). Permutation testing with 10000 (N = 6251 voxels) and 20000 (N = 6233 voxels) permutations produced clusters that were generally consistent with each other. However, with ≥ 1000 permutations there were approximately 20% more statistically significant voxels (N = 7117 voxels) than with 10000 permutations. Permutation testing inference may provide a more sensitive method than traditional parametric inference for identifying age-related differences in grey matter proportion. Based on the results reported here, at least 10000 permutations should be used in future univariate VBM studies investigating age related changes in grey matter to avoid potential false findings. Additional studies using permutation testing in large

  12. Increased Grey Matter Associated with Long-Term Sahaja Yoga Meditation: A Voxel-Based Morphometry Study

    PubMed Central

    Hernández, Sergio Elías; Suero, José; Barros, Alfonso; González-Mora, José Luis; Rubia, Katya

    2016-01-01

    Objectives To investigate regional differences in grey matter volume associated with the practice of Sahaja Yoga Meditation. Design Twenty three experienced practitioners of Sahaja Yoga Meditation and twenty three non-meditators matched on age, gender and education level, were scanned using structural Magnetic Resonance Imaging and their grey matter volume were compared using Voxel-Based Morphometry. Results Grey matter volume was larger in meditators relative to non-meditators across the whole brain. In addition, grey matter volume was larger in several predominantly right hemispheric regions: in insula, ventromedial orbitofrontal cortex, inferior temporal and parietal cortices as well as in left ventrolateral prefrontal cortex and left insula. No areas with larger grey matter volume were found in non-meditators relative to meditators. Conclusions The study shows that long-term practice of Sahaja Yoga Meditation is associated with larger grey matter volume overall, and with regional enlargement in several right hemispheric cortical and subcortical brain regions that are associated with sustained attention, self-control, compassion and interoceptive perception. The increased grey matter volume in these attention and self-control mediating regions suggests use-dependent enlargement with regular practice of this meditation. PMID:26938433

  13. Differences in regional brain volume related to the extraversion-introversion dimension--a voxel based morphometry study.

    PubMed

    Forsman, Lea J; de Manzano, Orjan; Karabanov, Anke; Madison, Guy; Ullén, Fredrik

    2012-01-01

    Extraverted individuals are sociable, behaviorally active, and happy. We report data from a voxel based morphometry study investigating, for the first time, if regional volume in gray and white matter brain regions is related to extraversion. For both gray and white matter, all correlations between extraversion and regional brain volume were negative, i.e. the regions were larger in introverts. Gray matter correlations were found in regions that included the right prefrontal cortex and the cortex around the right temporo-parietal junction--regions that are known to be involved in behavioral inhibition, introspection, and social-emotional processing, e.g. evaluation of social stimuli and reasoning about the mental states of others. White matter correlations extended from the brainstem to widespread cortical regions, and were largely due to global effects, i.e. a larger total white matter volume in introverts. We speculate that these white matter findings may reflect differences in ascending modulatory projections affecting cortical regions involved in behavioral regulation.

  14. Entorhinal volume, aerobic fitness, and recognition memory in healthy young adults: a voxel-based morphometry study1

    PubMed Central

    Whiteman, Andrew S.; Young, Daniel E.; Budson, Andrew E.; Stern, Chantal E.; Schon, Karin

    2015-01-01

    Converging evidence supports the hypothesis effects of aerobic exercise and environmental enrichment are beneficial for cognition, in particular for hippocampus-supported learning and memory. Recent work in humans suggests exercise training induces changes in hippocampal volume, but it is not known if aerobic exercise and fitness also impact the entorhinal cortex. In animal models, aerobic exercise increases expression of growth factors, including brain derived neurotrophic factor (BDNF). This exercise-enhanced expression of growth hormones may boost synaptic plasticity, and neuronal survival and differentiation, potentially supporting function and structure in brain areas including but not limited to the hippocampus. Here, using voxel based morphometry and a standard graded treadmill test to determine cardio-respiratory fitness (Bruce protocol; VO2 max), we examined if entorhinal and hippocampal volumes were associated with cardio-respiratory fitness in healthy young adults (N = 33). In addition, we examined if volumes were modulated by recognition memory performance and by serum BDNF, a putative marker of synaptic plasticity. Our results show a positive association between volume in right entorhinal cortex and cardio-respiratory fitness. In addition, average gray matter volume in the entorhinal cortex, bilaterally, was positively associated with memory performance. These data extend prior work on the cerebral effects of aerobic exercise and fitness to the entorhinal cortex in healthy young adults thus providing compelling evidence for a relationship between aerobic fitness and structure of the medial temporal lobe memory system. PMID:26631814

  15. Zero in the brain: A voxel-based lesion-symptom mapping study in right hemisphere damaged patients.

    PubMed

    Benavides-Varela, Silvia; Passarini, Laura; Butterworth, Brian; Rolma, Giuseppe; Burgio, Francesca; Pitteri, Marco; Meneghello, Francesca; Shallice, Tim; Semenza, Carlo

    2016-04-01

    Transcoding numerals containing zero is more problematic than transcoding numbers formed by non-zero digits. However, it is currently unknown whether this is due to zeros requiring brain areas other than those traditionally associated with number representation. Here we hypothesize that transcoding zeros entails visuo-spatial and integrative processes typically associated with the right hemisphere. The investigation involved 22 right-brain-damaged patients and 20 healthy controls who completed tests of reading and writing Arabic numbers. As expected, the most significant deficit among patients involved a failure to cope with zeros. Moreover, a voxel-based lesion-symptom mapping (VLSM) analysis showed that the most common zero-errors were maximally associated to the right insula which was previously related to sensorimotor integration, attention, and response selection, yet for the first time linked to transcoding processes. Error categories involving other digits corresponded to the so-called Neglect errors, which however, constituted only about 10% of the total reading and 3% of the writing mistakes made by the patients. We argue that damage to the right hemisphere impairs the mechanism of parsing, and the ability to set-up empty-slot structures required for processing zeros in complex numbers; moreover, we suggest that the brain areas located in proximity to the right insula play a role in the integration of the information resulting from the temporary application of transcoding procedures.

  16. Cerebral gray matter volume variation in female-to-male transsexuals: a voxel-based morphometric study.

    PubMed

    Kim, Tae-Hoon; Kim, Seok-Kwun; Jeong, Gwang-Woo

    2015-12-16

    Several studies seem to support the hypothesis that brain anatomy is associated with transsexualism. However, these studies were still limited because few neuroanatomical findings have been obtained from female-to-male (FtM) transsexuals. This study compared the cerebral regional volumes of gray matter (GM) between FtM transsexuals and female controls using a voxel-based morphometry. Twelve FtM transsexuals who had undergone sex-reassignment surgery and 15 female controls participated in this study. Both groups were age matched and right-handed, with no history of neurological illness. Fifteen female controls were recruited to determine whether GM volumes in FtM transsexuals more closely resembled individuals who shared their biological sex. MRI data were processed using SPM 8 with the diffeomorphic anatomical registration through exponentiated Lie algebra (DARTEL). FtM transsexuals showed significantly larger volumes of the thalamus, hypothalamus, midbrain, gyrus rectus, head of caudate nucleus, precentral gyrus, and subcallosal area compared with the female controls. However, the female controls showed a significantly larger volume in the superior temporal gyrus including Heschl's gyrus and Rolandic operculum. These findings confirm that the volume difference in brain substructures in FtM transsexuals is likely to be associated with transsexualism and that transsexualism is probably associated with distinct cerebral structures, determining gender identity.

  17. Contralesional Cortical Structural Reorganization Contributes to Motor Recovery after Sub-Cortical Stroke: A Longitudinal Voxel-Based Morphometry Study

    PubMed Central

    Cai, Jianxin; Ji, Qiling; Xin, Ruiqiang; Zhang, Dianping; Na, Xu; Peng, Ruchen; Li, Kuncheng

    2016-01-01

    Although changes in brain gray matter after stroke have been identified in some neuroimaging studies, lesion heterogeneity and individual variability make the detection of potential neuronal reorganization difficult. This study attempted to investigate the potential structural cortical reorganization after sub-cortical stroke using a longitudinal voxel-based gray matter volume (GMV) analysis. Eleven right-handed patients with first-onset, subcortical, ischemic infarctions involving the basal ganglia regions underwent structural magnetic resonance imaging in addition to National Institutes of Health Stroke Scale (NIHSS) and Motricity Index (MI) assessments in the acute (<5 days) and chronic stages (1 year later). The GMVs were calculated and compared between the two stages using nonparametric permutation paired t-tests. Moreover, the Spearman correlations between the GMV changes and clinical recoveries were analyzed. Compared with the acute stage, significant decreases in GMV were observed in the ipsilesional (IL) precentral gyrus (PreCG), paracentral gyrus (ParaCG), and contralesional (CL) cerebellar lobule VII in the chronic stage. Additionally, significant increases in GMV were found in the CL orbitofrontal cortex (OFC) and middle (MFG) and inferior frontal gyri (IFG). Furthermore, severe GMV atrophy in the IL PreCG predicted poorer clinical recovery, and greater GMV increases in the CL OFG and MFG predicted better clinical recovery. Our findings suggest that structural reorganization of the CL “cognitive” cortices might contribute to motor recovery after sub-cortical stroke. PMID:27536229

  18. A voxel-based morphometry study of gray matter correlates of facial emotion recognition in bipolar disorder.

    PubMed

    Neves, Maila de Castro L; Albuquerque, Maicon Rodrigues; Malloy-Diniz, Leandro; Nicolato, Rodrigo; Silva Neves, Fernando; de Souza-Duran, Fábio Luis; Busatto, Geraldo; Corrêa, Humberto

    2015-08-30

    Facial emotion recognition (FER) is one of the many cognitive deficits reported in bipolar disorder (BD) patients. The aim of this study was to investigate neuroanatomical correlates of FER impairments in BD type I (BD-I). Participants comprised 21 euthymic BD-I patients without Axis I DSM IV-TR comorbidities and 21 healthy controls who were assessed using magnetic resonance imaging and the Penn Emotion Recognition Test (ER40). Preprocessing of images used DARTEL (diffeomorphic anatomical registration through exponentiated Lie algebra) for optimized voxel-based morphometry in SPM8. Compared with healthy subjects, BD-I patients performed poorly in on the ER40 and had reduced gray matter volume (GMV) in the left orbitofrontal cortex, superior portion of the temporal pole and insula. In the BD-I group, the statistical maps indicated a direct correlation between FER on the ER40 and right middle cingulate gyrus GMV. Our findings are consistent with the previous studies regarding the overlap of multiple brain networks of social cognition and BD neurobiology, particularly components of the anterior-limbic neural network.

  19. Impact of image acquisition on voxel-based-morphometry investigations of age-related structural brain changes.

    PubMed

    Streitbürger, Daniel-Paolo; Pampel, André; Krueger, Gunnar; Lepsien, Jöran; Schroeter, Matthias L; Mueller, Karsten; Möller, Harald E

    2014-02-15

    A growing number of magnetic resonance imaging studies employ voxel-based morphometry (VBM) to assess structural brain changes. Recent reports have shown that image acquisition parameters may influence VBM results. For systematic evaluation, gray-matter-density (GMD) changes associated with aging were investigated by VBM employing acquisitions with different radiofrequency head coils (12-channel matrix coil vs. 32-channel array), different pulse sequences (MP-RAGE vs. MP2RAGE), and different voxel dimensions (1mm vs. 0.8mm). Thirty-six healthy subjects, classified as young, middle-aged, or elderly, participated in the study. Two-sample and paired t-tests revealed significant effects of acquisition parameters (coil, pulse sequence, and resolution) on the estimated age-related GMD changes in cortical and subcortical regions. Potential advantages in tissue classification and segmentation were obtained for MP2RAGE. The 32-channel coil generally outperformed the 12-channel coil, with more benefit for MP2RAGE. Further improvement can be expected from higher resolution if the loss in SNR is accounted for. Use of inconsistent acquisition parameters in VBM analyses is likely to introduce systematic bias. Overall, acquisition and protocol changes require careful adaptations of the VBM analysis strategy before generalized conclusion can be drawn.

  20. Gray matter changes in right superior temporal gyrus in criminal psychopaths. Evidence from voxel-based morphometry.

    PubMed

    Müller, Jürgen L; Gänssbauer, Susanne; Sommer, Monika; Döhnel, Katrin; Weber, Tatjana; Schmidt-Wilcke, Tobias; Hajak, Göran

    2008-08-30

    "Psychopathy" according to the PCL-R describes a specific subgroup of antisocial personality disorder with a high risk for criminal relapses. Lesion and imaging studies point towards frontal or temporal brain regions connected with disturbed social behavior, antisocial personality disorder (APD) and psychopathy. Morphologically, some studies described a reduced prefrontal brain volume, whereas others reported on temporal lobe atrophy. To further investigate whether participants with psychopathy according to the Psychopathy Checklist-Revised Version (PCL-R) show abnormalities in brain structure, we used voxel-based morphometry (VBM) to investigate region-specific changes in gray matter in 17 forensic male inpatients with high PCL-R scores (PCL-R>28) and 17 male control subjects with low PCL-R scores (PCL<10). We found significant gray matter reductions in frontal and temporal brain regions in psychopaths compared with controls. In particular, we found a highly significant volume loss in the right superior temporal gyrus. This is the first study to show that psychopathy is associated with a decrease in gray matter in both frontal and temporal brain regions, in particular in the right superior temporal gyrus, supporting the hypothesis that a disturbed frontotemporal network is critically involved in the pathogenesis of psychopathy.

  1. Damage to Fronto-Parietal Networks Impairs Motor Imagery Ability after Stroke: A Voxel-Based Lesion Symptom Mapping Study

    PubMed Central

    Oostra, Kristine M.; Van Bladel, Anke; Vanhoonacker, Ann C. L.; Vingerhoets, Guy

    2016-01-01

    Background: Mental practice with motor imagery has been shown to promote motor skill acquisition in healthy subjects and patients. Although lesions of the common motor imagery and motor execution neural network are expected to impair motor imagery ability, functional equivalence appears to be at least partially preserved in stroke patients. Aim: To identify brain regions that are mandatory for preserved motor imagery ability after stroke. Method: Thirty-seven patients with hemiplegia after a first time stroke participated. Motor imagery ability was measured using a Motor Imagery questionnaire and temporal congruence test. A voxelwise lesion symptom mapping approach was used to identify neural correlates of motor imagery in this cohort within the first year post-stroke. Results: Poor motor imagery vividness was associated with lesions in the left putamen, left ventral premotor cortex and long association fibers linking parieto-occipital regions with the dorsolateral premotor and prefrontal areas. Poor temporal congruence was otherwise linked to lesions in the more rostrally located white matter of the superior corona radiata. Conclusion: This voxel-based lesion symptom mapping study confirms the association between white matter tract lesions and impaired motor imagery ability, thus emphasizing the importance of an intact fronto-parietal network for motor imagery. Our results further highlight the crucial role of the basal ganglia and premotor cortex when performing motor imagery tasks. PMID:26869894

  2. Association between regional white and gray matter volume and ambiguity tolerance: Evidence from voxel-based morphometry.

    PubMed

    Tong, Dandan; Yang, Wenjing; Zhang, Qinglin; Li, Wenfu; Wei, Dongtao; Che, Xianwei; Zhang, Meng; Hitchman, Glenn; Qiu, Jiang; Liu, Yijun; Cao, Guikang

    2015-08-01

    The concept of tolerance of ambiguity (AT) is defined as the way in which an individual tends to perceive and deal with confusing, vague, and unclear situations. AT is generally considered as an important personality trait, but the neural mechanisms underlying individual differences in AT have never been investigated. Using voxel-based morphometry and MSTAT-II scale, we investigated the correlations between AT and regional white matter volume (rWMV) and regional gray matter volume (rGMV) in 351 young healthy subjects. We found AT to be positively correlated with rGMV in the dorsolateral prefrontal cortex (DLPFC), and negatively correlated with rGMV in the precuneus. These results indicate that increased rGMV in the left DLPFC may lead to characteristics of ambiguous stimuli consideration from multiple contexts and risk taking. Decreased rGMV in the left precuneus may be associated with a high tolerance for ambiguity, which attributes uncertainty to self-related factors.

  3. Relating inter-individual differences in verbal creative thinking to cerebral structures: an optimal voxel-based morphometry study.

    PubMed

    Zhu, Feifei; Zhang, Qinglin; Qiu, Jiang

    2013-01-01

    Creativity can be defined the capacity of an individual to produce something original and useful. An important measurable component of creativity is divergent thinking. Despite existing studies on creativity-related cerebral structural basis, no study has used a large sample to investigate the relationship between individual verbal creativity and regional gray matter volumes (GMVs) and white matter volumes (WMVs). In the present work, optimal voxel-based morphometry (VBM) was employed to identify the structure that correlates verbal creativity (measured by the verbal form of Torrance Tests of Creative Thinking) across the brain in young healthy subjects. Verbal creativity was found to be significantly positively correlated with regional GMV in the left inferior frontal gyrus (IFG), which is believed to be responsible for language production and comprehension, new semantic representation, and memory retrieval, and in the right IFG, which may involve inhibitory control and attention switching. A relationship between verbal creativity and regional WMV in the left and right IFG was also observed. Overall, a highly verbal creative individual with superior verbal skills may demonstrate a greater computational efficiency in the brain areas involved in high-level cognitive processes including language production, semantic representation and cognitive control.

  4. Voxel-based morphometry in opera singers: Increased gray-matter volume in right somatosensory and auditory cortices.

    PubMed

    Kleber, Boris; Veit, Ralf; Moll, Christina Valérie; Gaser, Christian; Birbaumer, Niels; Lotze, Martin

    2016-06-01

    In contrast to instrumental musicians, professional singers do not train on a specific instrument but perfect a motor system that has already been extensively trained during speech motor development. Previous functional imaging studies suggest that experience with singing is associated with enhanced somatosensory-based vocal motor control. However, experience-dependent structural plasticity in vocal musicians has rarely been studied. We investigated voxel-based morphometry (VBM) in 27 professional classical singers and compared gray matter volume in regions of the "singing-network" to an age-matched group of 28 healthy volunteers with no special singing experience. We found right hemispheric volume increases in professional singers in ventral primary somatosensory cortex (larynx S1) and adjacent rostral supramarginal gyrus (BA40), as well as in secondary somatosensory (S2) and primary auditory cortices (A1). Moreover, we found that earlier commencement with vocal training correlated with increased gray-matter volume in S1. However, in contrast to studies with instrumental musicians, this correlation only emerged in singers who began their formal training after the age of 14years, when speech motor development has reached its first plateau. Structural data thus confirm and extend previous functional reports suggesting a pivotal role of somatosensation in vocal motor control with increased experience in singing. Results furthermore indicate a sensitive period for developing additional vocal skills after speech motor coordination has matured.

  5. A Voxel-Based Morphometry Study of the Brain of University Students Majoring in Music and Nonmusic Disciplines

    PubMed Central

    Sato, Kanako; Kirino, Eiji; Tanaka, Shoji

    2015-01-01

    The brain changes flexibly due to various experiences during the developmental stages of life. Previous voxel-based morphometry (VBM) studies have shown volumetric differences between musicians and nonmusicians in several brain regions including the superior temporal gyrus, sensorimotor areas, and superior parietal cortex. However, the reported brain regions depend on the study and are not necessarily consistent. By VBM, we investigated the effect of musical training on the brain structure by comparing university students majoring in music with those majoring in nonmusic disciplines. All participants were right-handed healthy Japanese females. We divided the nonmusic students into two groups and therefore examined three groups: music expert (ME), music hobby (MH), and nonmusic (NM) group. VBM showed that the ME group had the largest gray matter volumes in the right inferior frontal gyrus (IFG; BA 44), left middle occipital gyrus (BA 18), and bilateral lingual gyrus. These differences are considered to be caused by neuroplasticity during long and continuous musical training periods because the MH group showed intermediate volumes in these regions. PMID:26494943

  6. Voxel-based morphometric analysis in hypothyroidism using diffeomorphic anatomic registration via an exponentiated lie algebra algorithm approach.

    PubMed

    Singh, S; Modi, S; Bagga, D; Kaur, P; Shankar, L R; Khushu, S

    2013-03-01

    The present study aimed to investigate whether brain morphological differences exist between adult hypothyroid subjects and age-matched controls using voxel-based morphometry (VBM) with diffeomorphic anatomic registration via an exponentiated lie algebra algorithm (DARTEL) approach. High-resolution structural magnetic resonance images were taken in ten healthy controls and ten hypothyroid subjects. The analysis was conducted using statistical parametric mapping. The VBM study revealed a reduction in grey matter volume in the left postcentral gyrus and cerebellum of hypothyroid subjects compared to controls. A significant reduction in white matter volume was also found in the cerebellum, right inferior and middle frontal gyrus, right precentral gyrus, right inferior occipital gyrus and right temporal gyrus of hypothyroid patients compared to healthy controls. Moreover, no meaningful cluster for greater grey or white matter volume was obtained in hypothyroid subjects compared to controls. Our study is the first VBM study of hypothyroidism in an adult population and suggests that, compared to controls, this disorder is associated with differences in brain morphology in areas corresponding to known functional deficits in attention, language, motor speed, visuospatial processing and memory in hypothyroidism.

  7. The association between the brain and mind pops: a voxel-based morphometry study in 256 Chinese college students.

    PubMed

    Zhang, Lei; Li, Wenfu; Wei, Dongtao; Yang, Wenjing; Yang, Ning; Qiao, Lei; Qiu, Jiang; Zuo, Xi-Nian; Zhang, Qinglin

    2016-06-01

    Mind pops or involuntary semantic memories refer to words, phrases, images, or melodies that suddenly pop into one's mind without any deliberate attempt to recall them. Despite their prevalence in everyday life, research on mind pops has started only recently. Notably, mind pops are very similar to clinical involuntary phenomena such as hallucinations in schizophrenia, suggesting their potential role in pathology. The present study aimed to investigate the relationship between mind pops and the brain morphometry measured in 302 healthy young adults; after exclusions, 256 participants were included in our analyses. Specifically, the Mind Popping Questionnaire (MPQ) was employed to measure the degree of individual mind pops, whereas the Voxel-Based Morphometry (VBM) was used to compute the volumes of both gray and white matter tissues. Multiple regression analyses on MPQ and VBM metrics indicated that high-frequency mind pops were significantly associated with smaller gray matter volume in the left middle temporal gyrus as well as with larger gray and white matter volume in the right medial prefrontal cortex. This increase in mind pops is also linked to higher creativity and the personality trait of 'openness'. These data not only suggest a key role of the two regions in generating self-related thoughts, but also open a possible link between brain and creativity or personality.

  8. Grey matter density decreases as well as increases in patients with classic galactosemia: A voxel-based morphometry study.

    PubMed

    Timmers, Inge; van der Korput, Lisanne D; Jansma, Bernadette M; Rubio-Gozalbo, M Estela

    2016-10-01

    Brain impairments have been observed in patients with classic galactosemia, an inherited metabolic disorder resulting in a particular neuro-cognitive profile. Neuroimaging studies showed abnormalities such as diffuse white mater (WM) abnormalities and grey matter (GM) atrophy. Our current study analysed grey matter density using voxel-based morphometry (VBM) and compared the brains of eight adolescent patients with classic galactosemia with eight healthy gender- and aged-matched controls. GM density differences were found in several regions. Decreased GM density was found in the patients in the bilateral putamen and bilateral occipital cortex. Increased GM density in the patients, on the other hand, was found in the bilateral inferior frontal and medial prefrontal cortex. The anatomical profile of the abnormalities is in line with the neuro-cognitive profile of patients with classic galactosemia, including motor dysfunction, speech and language difficulties and higher order cognitive problems. Less favourable GM densities in patients (either increased or decreased compared to controls) correlated with younger age, a worse visual working memory performance, and an older age at initiation of the galactose-restricted diet. To conclude, this explorative study is the first to analyse the GM using VBM in this population, and demonstrates a mixed profile of both increased and decreased GM density in these patients.

  9. Voxel-based approach to generate entire human metacarpal bone with microscopic architecture for finite element analysis.

    PubMed

    Tang, C Y; Tsui, C P; Tang, Y M; Wei, L; Wong, C T; Lam, K W; Ip, W Y; Lu, W W J; Pang, M Y C

    2014-01-01

    With the development of micro-computed tomography (micro-CT) technology, it is possible to construct three-dimensional (3D) models of human bone without destruction of samples and predict mechanical behavior of bone using finite element analysis (FEA). However, due to large number of elements required for constructing the FE models of entire bone, this demands a substantial computational effort and the analysis usually needs a high level of computer. In this article, a voxel-based approach for generation of FE models of entire bone with microscopic architecture from micro-CT image data is proposed. To enable the FE analyses of entire bone to be run even on a general personal computer, grayscale intensity thresholds were adopted to reduce the amount of elements. Human metacarpal bone (MCP) bone was used as an example for demonstrating the applicability of the proposed method. The micro-CT images of the MCP bone were combined and converted into 3D array of pixels. Dual grayscale intensity threshold parameters were used to distinguish the pixels of bone tissues from those of surrounding soft tissues and improve predictive accuracy for the FE analyses with different sizes of elements. The method of selecting an appropriate value of the second grayscale intensity threshold was also suggested to minimize the area error for the reconstructed cross-sections of a FE structure. Experimental results showed that the entire FE MCP bone with microscopic architecture could be modeled and analyzed on a personal computer with reasonable accuracy.

  10. A Voxel-Based Morphometry Study of the Brain of University Students Majoring in Music and Nonmusic Disciplines.

    PubMed

    Sato, Kanako; Kirino, Eiji; Tanaka, Shoji

    2015-01-01

    The brain changes flexibly due to various experiences during the developmental stages of life. Previous voxel-based morphometry (VBM) studies have shown volumetric differences between musicians and nonmusicians in several brain regions including the superior temporal gyrus, sensorimotor areas, and superior parietal cortex. However, the reported brain regions depend on the study and are not necessarily consistent. By VBM, we investigated the effect of musical training on the brain structure by comparing university students majoring in music with those majoring in nonmusic disciplines. All participants were right-handed healthy Japanese females. We divided the nonmusic students into two groups and therefore examined three groups: music expert (ME), music hobby (MH), and nonmusic (NM) group. VBM showed that the ME group had the largest gray matter volumes in the right inferior frontal gyrus (IFG; BA 44), left middle occipital gyrus (BA 18), and bilateral lingual gyrus. These differences are considered to be caused by neuroplasticity during long and continuous musical training periods because the MH group showed intermediate volumes in these regions.

  11. Gray matter density reduction in the insula in fire survivors with posttraumatic stress disorder: a voxel-based morphometric study.

    PubMed

    Chen, Shulin; Xia, Weiwei; Li, Lingjiang; Liu, Jun; He, Zhong; Zhang, Zishu; Yan, Lirong; Zhang, Jinli; Hu, Dewen

    2006-01-30

    Voxel-based morphometry (VBM) is an objective whole-brain technique for characterizing regional cerebral volume and tissue concentration differences in structural magnetic resonance images. In the current study, we used VBM to examine possible cerebral gray matter abnormalities in patients with posttraumatic stress disorder (PTSD) due to fire. The subjects included 12 victims of a fire disaster with PTSD and 12 matched victims of the same fire without PTSD. Magnetic resonance images were obtained on a 1.5-Tesla General Electric scanner at Central South University, and an entire brain volume of 248 contiguous slices was obtained for each subject. Then, gray matter density in patients with PTSD and control groups was compared by using a VBM approach in SPM2. Group analysis was thresholded at P<0.001, uncorrected, at the voxel level. The following three regions of reduced gray matter volume were found in patients with PTSD compared with controls: left hippocampus, left anterior cingulate cortex (ACC), and bilateral insular cortex. It was concluded that there are structural abnormalities of the hippocampus, the ACC and the insular cortex in patients with PTSD due to fire.

  12. Entorhinal volume, aerobic fitness, and recognition memory in healthy young adults: A voxel-based morphometry study.

    PubMed

    Whiteman, Andrew S; Young, Daniel E; Budson, Andrew E; Stern, Chantal E; Schon, Karin

    2016-02-01

    Converging evidence supports the hypothesis effects of aerobic exercise and environmental enrichment are beneficial for cognition, in particular for hippocampus-supported learning and memory. Recent work in humans suggests that exercise training induces changes in hippocampal volume, but it is not known if aerobic exercise and fitness also impact the entorhinal cortex. In animal models, aerobic exercise increases expression of growth factors, including brain derived neurotrophic factor (BDNF). This exercise-enhanced expression of growth hormones may boost synaptic plasticity, and neuronal survival and differentiation, potentially supporting function and structure in brain areas including but not limited to the hippocampus. Here, using voxel based morphometry and a standard graded treadmill test to determine cardio-respiratory fitness (Bruce protocol; ·VO2 max), we examined if entorhinal and hippocampal volumes were associated with cardio-respiratory fitness in healthy young adults (N=33). In addition, we examined if volumes were modulated by recognition memory performance and by serum BDNF, a putative marker of synaptic plasticity. Our results show a positive association between volume in right entorhinal cortex and cardio-respiratory fitness. In addition, average gray matter volume in the entorhinal cortex, bilaterally, was positively associated with memory performance. These data extend prior work on the cerebral effects of aerobic exercise and fitness to the entorhinal cortex in healthy young adults thus providing compelling evidence for a relationship between aerobic fitness and structure of the medial temporal lobe memory system.

  13. Grey matter changes associated with deficit awareness in mild cognitive impairment: a voxel-based morphometry study.

    PubMed

    Ford, Andrew H; Almeida, Osvaldo P; Flicker, Leon; Garrido, Griselda J; Greenop, Kathryn R; Foster, Jonathan K; Etherton-Beer, Christopher; van Bockxmeer, Frank M; Lautenschlager, Nicola T

    2014-01-01

    Reduced awareness of cognitive deficits in mild cognitive impairment (MCI) is associated with poorer outcomes although little is known about the anatomical correlates of this. We examined the association of insight and grey matter volume using a voxel-based morphometry approach in 65 volunteers with MCI and 55 healthy age-matched controls. Participants with MCI had multiple areas of subtle grey matter volume loss compared with controls, although these did not survive correction for multiple comparisons. These were predominantly in the temporal and anterior portions of the brain. Individuals with MCI did not differ from each other on a number of demographic and cognitive variables according to level of insight. Reduced awareness of cognitive deficits was associated with few differences in grey matter volume apart from a subtle loss of grey matter in the medial frontal gyri. Given the modest nature of these findings, the routine assessment of insight in non-clinical populations of individuals with MCI is therefore not supported. Prospective data in larger samples, however, would be helpful to clarify this further and determine if impaired insight predicts brain atrophy and cognitive decline.

  14. Cluster analysis for identifying sub-types of tinnitus: a positron emission tomography and voxel-based morphometry study.

    PubMed

    Schecklmann, Martin; Lehner, Astrid; Poeppl, Timm B; Kreuzer, Peter M; Hajak, Göran; Landgrebe, Michael; Langguth, Berthold

    2012-11-16

    Tinnitus is a heterogeneous disorder with respect to its etiology and phenotype. Thus, the identification of sub-types implicates high relevance for treatment recommendations. For this aim, we used cluster analysis of patients for which clinical data, positron-emission tomography (PET) data and voxel-based morphometry (VBM) data were available. 44 patients with chronic tinnitus were included in this analysis. On a phenotypical level, we used tinnitus distress, duration, and laterality for clustering. To correct PET and VBM data for age, gender, and hearing, we built up a design matrix including these variables as regressors and extracted the residuals. We applied Ward's clustering method and forced cluster analysis to divide the data into two groups for both imaging and phenotypical data. On a phenotypical level the clustered groups differed only in tinnitus laterality (uni- vs. bilateral tinnitus), but not in tinnitus duration, distress, age, gender, and hearing. For grey matter volume, groups differed mainly in frontal, cingulate, temporal, and thalamic areas. For glucose metabolism, groups differed in temporal and parietal areas. The correspondence of classification was near chance level for the interrelationship of all three data set clusters. Thus, we showed that clustering according to imaging data is feasible and might depict a new approach for identifying tinnitus sub-types. However, it remains an open question to what extent the phenotypical and imaging levels may be interrelated. This article is part of a Special Issue entitled: Tinnitus Neuroscience.

  15. The pedunculopontine nucleus is related to visual hallucinations in Parkinson's disease: preliminary results of a voxel-based morphometry study.

    PubMed

    Janzen, J; van 't Ent, D; Lemstra, A W; Berendse, H W; Barkhof, F; Foncke, E M J

    2012-01-01

    Visual hallucinations (VH) are common in Parkinson's disease (PD) and lead to a poor quality of life. For a long time, dopaminergic therapy was considered to be the most important risk factor for the development of VH in PD. Recently, the cholinergic system, including the pedunculopontine nucleus (PPN), has been implicated in the pathophysiology of VH. The aim of the present study was to investigate grey matter density of the PPN region and one of its projection areas, the thalamus. Thirteen non-demented PD patients with VH were compared to 16 non-demented PD patients without VH, 13 demented PD patients (PDD) with VH and 11 patients with dementia with Lewy bodies (DLB). Isotropic 3-D T1-weighted MRI images (3T) were analysed using voxel-based morphometry (VBM) with the PPN region and thalamus as ROIs. PD and PDD patients with VH showed grey matter reductions of the PPN region and the thalamus compared to PD patients without VH. VH in PD(D) patients are associated with atrophy of the PPN region and its thalamic target area, suggesting that a cholinergic deficit may be involved in the development of VH in PD(D).

  16. Absorbed dose estimates to structures of the brain and head using a high-resolution voxel-based head phantom.

    PubMed

    Evans, J F; Blue, T E; Gupta, N

    2001-05-01

    The purpose of this article is to demonstrate the viability of using a high-resolution 3-D head phantom in Monte Carlo N-Particle (MCNP) for boron neutron capture therapy (BNCT) structure dosimetry. This work describes a high-resolution voxel-based model of a human head and its use for calculating absorbed doses to the structures of the brain. The Zubal head phantom is a 3-D model of a human head that can be displayed and manipulated on a computer. Several changes were made to the original head phantom which now contains over 29 critical structures of the brain and head. The modified phantom is a 85 x 109 x 120 lattice of voxels, where each voxel is 2.2 x 2.2 x 1.4 mm3. This model was translated into MCNP lattice format. As a proof of principle study, two MCNP absorbed dose calculations were made (left and right lateral irradiations) using a uniformly distributed neutron disk source with an 1/E energy spectrum. Additionally, the results of these two calculations were combined to estimate the absorbed doses from a bilateral irradiation. Radiobiologically equivalent (RBE) doses were calculated for all structures and were normalized to 12.8 Gy-Eq. For a left lateral irradiation, the left motor cortex receives the limiting RBE dose. For a bilateral irradiation, the insula cortices receive the limiting dose. Among the nonencephalic structures, the parotid glands receive RBE doses that were within 15% of the limiting dose.

  17. Mapping grey matter reductions in schizophrenia: an anatomical likelihood estimation analysis of voxel-based morphometry studies.

    PubMed

    Fornito, A; Yücel, M; Patti, J; Wood, S J; Pantelis, C

    2009-03-01

    Voxel-based morphometry (VBM) is a popular tool for mapping neuroanatomical changes in schizophrenia patients. Several recent meta-analyses have identified the brain regions in which patients most consistently show grey matter reductions, although they have not examined whether such changes reflect differences in grey matter concentration (GMC) or grey matter volume (GMV). These measures assess different aspects of grey matter integrity, and may therefore reflect different pathological processes. In this study, we used the Anatomical Likelihood Estimation procedure to analyse significant differences reported in 37 VBM studies of schizophrenia patients, incorporating data from 1646 patients and 1690 controls, and compared the findings of studies using either GMC or GMV to index grey matter differences. Analysis of all studies combined indicated that grey matter reductions in a network of frontal, temporal, thalamic and striatal regions are among the most frequently reported in literature. GMC reductions were generally larger and more consistent than GMV reductions, and were more frequent in the insula, medial prefrontal, medial temporal and striatal regions. GMV reductions were more frequent in dorso-medial frontal cortex, and lateral and orbital frontal areas. These findings support the primacy of frontal, limbic, and subcortical dysfunction in the pathophysiology of schizophrenia, and suggest that the grey matter changes observed with MRI may not necessarily result from a unitary pathological process.

  18. On the construction of a ground truth framework for evaluating voxel-based diffusion tensor MRI analysis methods.

    PubMed

    Van Hecke, Wim; Sijbers, Jan; De Backer, Steve; Poot, Dirk; Parizel, Paul M; Leemans, Alexander

    2009-07-01

    Although many studies are starting to use voxel-based analysis (VBA) methods to compare diffusion tensor images between healthy and diseased subjects, it has been demonstrated that VBA results depend heavily on parameter settings and implementation strategies, such as the applied coregistration technique, smoothing kernel width, statistical analysis, etc. In order to investigate the effect of different parameter settings and implementations on the accuracy and precision of the VBA results quantitatively, ground truth knowledge regarding the underlying microstructural alterations is required. To address the lack of such a gold standard, simulated diffusion tensor data sets are developed, which can model an array of anomalies in the diffusion properties of a predefined location. These data sets can be employed to evaluate the numerous parameters that characterize the pipeline of a VBA algorithm and to compare the accuracy, precision, and reproducibility of different post-processing approaches quantitatively. We are convinced that the use of these simulated data sets can improve the understanding of how different diffusion tensor image post-processing techniques affect the outcome of VBA. In turn, this may possibly lead to a more standardized and reliable evaluation of diffusion tensor data sets of large study groups with a wide range of white matter altering pathologies. The simulated DTI data sets will be made available online (http://www.dti.ua.ac.be).

  19. Voxel-based registration of simulated and real patient CBCT data for accurate dental implant pose estimation

    NASA Astrophysics Data System (ADS)

    Moreira, António H. J.; Queirós, Sandro; Morais, Pedro; Rodrigues, Nuno F.; Correia, André Ricardo; Fernandes, Valter; Pinho, A. C. M.; Fonseca, Jaime C.; Vilaça, João. L.

    2015-03-01

    The success of dental implant-supported prosthesis is directly linked to the accuracy obtained during implant's pose estimation (position and orientation). Although traditional impression techniques and recent digital acquisition methods are acceptably accurate, a simultaneously fast, accurate and operator-independent methodology is still lacking. Hereto, an image-based framework is proposed to estimate the patient-specific implant's pose using cone-beam computed tomography (CBCT) and prior knowledge of implanted model. The pose estimation is accomplished in a threestep approach: (1) a region-of-interest is extracted from the CBCT data using 2 operator-defined points at the implant's main axis; (2) a simulated CBCT volume of the known implanted model is generated through Feldkamp-Davis-Kress reconstruction and coarsely aligned to the defined axis; and (3) a voxel-based rigid registration is performed to optimally align both patient and simulated CBCT data, extracting the implant's pose from the optimal transformation. Three experiments were performed to evaluate the framework: (1) an in silico study using 48 implants distributed through 12 tridimensional synthetic mandibular models; (2) an in vitro study using an artificial mandible with 2 dental implants acquired with an i-CAT system; and (3) two clinical case studies. The results shown positional errors of 67+/-34μm and 108μm, and angular misfits of 0.15+/-0.08° and 1.4°, for experiment 1 and 2, respectively. Moreover, in experiment 3, visual assessment of clinical data results shown a coherent alignment of the reference implant. Overall, a novel image-based framework for implants' pose estimation from CBCT data was proposed, showing accurate results in agreement with dental prosthesis modelling requirements.

  20. Regional Gray Matter Volume Is Associated with Restrained Eating in Healthy Chinese Young Adults: Evidence from Voxel-Based Morphometry

    PubMed Central

    Su, Yanhua; Jackson, Todd; Wei, Dongtao; Qiu, Jiang; Chen, Hong

    2017-01-01

    Highlight Participants were non-clinical young adults with different restrained eating levels.We assessed relations of restrained eating (RE) with regional gray matter volume (rGMV).High RE scores were related to larger GMV in specific areas related to reward.High RE scores were also linked to less GMV in regions related to response inhibition. Objective: Dieting is a popular method of weight control. However, few dieters are able to maintain initial weight losses over an extended period of time. Why do most restrained dieters fail to lose weight? Alterations in brain structures associated with restrained eating (RE) represent one potentially important mechanism that contributes to difficulties in maintaining weight loss within this group. To evaluate this contention, we investigated associations between intentional, sustained restriction of food intake to lose or maintain body weight, and regional gray matter volume (rGMV) within a large non-clinical young adult, sample. Methods: Participants (150 women, 108 men) completed measures of RE and demographics prior to undergoing an MRI scan. Voxel-based morphometry (VBM) evaluated strengths of association between RE scores and rGMV. Results: Higher RE levels corresponded to more rGMV in regions linked to risk of overeating and binge-eating including the left insula and orbitofrontal cortex (OFC). Conversely, RE had significant negative correlations with rGMV in the left and right posterior cingulum gyrus, regions linked to inhibitory control and potential risk for future weight gain. Conclusions: Together, findings suggested individual differences in RE among young adults correspond to GMV variability in regions linked to overweight and obesity risk.

  1. Voxel-based magnetic resonance imaging investigation of poor and preserved clinical insight in people with schizophrenia

    PubMed Central

    Sapara, Adegboyega; Ffytche, Dominic H; Cooke, Michael A; Williams, Steven CR; Kumari, Veena

    2016-01-01

    AIM To define regional grey-matter abnormalities in schizophrenia patients with poor insight (Insight-), relative to patients with preserved clinical insight (Insight+), and healthy controls. METHODS Forty stable schizophrenia outpatients (20 Insight- and 20 Insight+) and 20 healthy controls underwent whole brain magnetic resonance imaging (MRI). Insight in all patients was assessed using the Birchwood Insight Scale (BIS; a self-report measure). The two patient groups were pre-selected to match on most clinical and demographic parameters but, by design, they had markedly distinct BIS scores. Voxel-based morphometry employed in SPM8 was used to examine group differences in grey matter volumes across the whole brain. RESULTS The three participant groups were comparable in age [F(2,57) = 0.34, P = 0.71] and the patient groups did not differ in age at illness onset [t(38) = 0.87, P = 0.39]. Insight- and Insight+ patient groups also did not differ in symptoms on the Positive and Negative Syndromes scale (PANSS): Positive symptoms [t(38) = 0.58, P = 0.57], negative symptoms [t(38) = 0.61, P = 0.55], general psychopathology [t(38) = 1.30, P = 0.20] and total PANSS scores [t(38) = 0.21, P = 0.84]. The two patient groups, as expected, varied significantly in the level of BIS-assessed insight [t(38) = 12.11, P < 0.001]. MRI results revealed lower fronto-temporal, parahippocampal, occipital and cerebellar grey matter volumes in Insight- patients, relative to Insight+ patients and healthy controls (for all clusters, family-wise error corrected P < 0.05). Insight+ patient and healthy controls did not differ significantly (P > 0.20) from each other. CONCLUSION Our findings demonstrate a clear association between poor clinical insight and smaller fronto-temporal, occipital and cerebellar grey matter volumes in stable long-term schizophrenia patients. PMID:27679770

  2. Dyslexia and voxel-based morphometry: correlations between five behavioural measures of dyslexia and gray and white matter volumes.

    PubMed

    Tamboer, Peter; Scholte, H Steven; Vorst, Harrie C M

    2015-10-01

    In voxel-based morphometry studies of dyslexia, the relation between causal theories of dyslexia and gray matter (GM) and white matter (WM) volume alterations is still under debate. Some alterations are consistently reported, but others failed to reach significance. We investigated GM alterations in a large sample of Dutch students (37 dyslexics and 57 non-dyslexics) with two analyses: group differences in local GM and total GM and WM volume and correlations between GM and WM volumes and five behavioural measures. We found no significant group differences after corrections for multiple comparisons although total WM volume was lower in the group of dyslexics when age was partialled out. We presented an overview of uncorrected clusters of voxels (p < 0.05, cluster size k > 200) with reduced or increased GM volume. We found four significant correlations between factors of dyslexia representing various behavioural measures and the clusters found in the first analysis. In the whole sample, a factor related to performances in spelling correlated negatively with GM volume in the left posterior cerebellum. Within the group of dyslexics, a factor related to performances in Dutch-English rhyme words correlated positively with GM volume in the left and right caudate nucleus and negatively with increased total WM volume. Most of our findings were in accordance with previous reports. A relatively new finding was the involvement of the caudate nucleus. We confirmed the multiple cognitive nature of dyslexia and suggested that experience greatly influences anatomical alterations depending on various subtypes of dyslexia, especially in a student sample.

  3. Selection of voxel size and photon number in voxel-based Monte Carlo method: criteria and applications.

    PubMed

    Li, Dong; Chen, Bin; Ran, Wei Yu; Wang, Guo Xiang; Wu, Wen Juan

    2015-01-01

    The voxel-based Monte Carlo method (VMC) is now a gold standard in the simulation of light propagation in turbid media. For complex tissue structures, however, the computational cost will be higher when small voxels are used to improve smoothness of tissue interface and a large number of photons are used to obtain accurate results. To reduce computational cost, criteria were proposed to determine the voxel size and photon number in 3-dimensional VMC simulations with acceptable accuracy and computation time. The selection of the voxel size can be expressed as a function of tissue geometry and optical properties. The photon number should be at least 5 times the total voxel number. These criteria are further applied in developing a photon ray splitting scheme of local grid refinement technique to reduce computational cost of a nonuniform tissue structure with significantly varying optical properties. In the proposed technique, a nonuniform refined grid system is used, where fine grids are used for the tissue with high absorption and complex geometry, and coarse grids are used for the other part. In this technique, the total photon number is selected based on the voxel size of the coarse grid. Furthermore, the photon-splitting scheme is developed to satisfy the statistical accuracy requirement for the dense grid area. Result shows that local grid refinement technique photon ray splitting scheme can accelerate the computation by 7.6 times (reduce time consumption from 17.5 to 2.3 h) in the simulation of laser light energy deposition in skin tissue that contains port wine stain lesions.

  4. Approach to voxel-based carbon stock quanticiation using LiDAR data in tropical rainforest, Brunei

    NASA Astrophysics Data System (ADS)

    Kim, Eunji; Piao, Dongfan; Lee, Jongyeol; Lee, Woo-Kyun; Yoon, Mihae; Moon, Jooyeon

    2016-04-01

    Forest is an important means to adapt climate change as the only carbon sink recognized by the international community (KFS 2009). According to the Intergovernmental Panel on Climate Change (IPCC) 5th Assessment Report (AR5), Agriculture, Forestry, and Other Land Use (AFOLU) sectors including forestry contributed 24% of total anthropogenic emissions in 2010 (IPCC 2014; Tubiello et al. 2015). While all sectors excluding AFOLU have increased Greenhouse Gas (GHG) emissions, land use sectors including forestry remains similar level as before due to decreasing deforestation and increasing reforestation. In earlier researches, optical imagery has been applied for analysis (Jakubowski et al. 2013). Optical imagery collects spectral information in 2D. It is difficult to effectively quantify forest stocks, especially in dense forest (Cui et al. 2012). To detect individual trees information from remotely sensed data, Light detection and ranging (LiDAR) has been used (Hyyppäet al. 2001; Persson et al. 2002; Chen et al. 2006). Moreover, LiDAR has the ability to actively acquire vertical tree information such as tree height using geo-registered 3D points (Kwak et al. 2007). In general, however, geo-register 3D point was used with a raster format which contains only 2D information by missing all the 3D data. Therefore, this research aimed to use the volumetric pixel (referred as "voxel") approach using LiDAR data in tropical rainforest, Brunei. By comparing the parameters derived from voxel based LiDAR data and field measured data, we examined the relationships between them for the quantification of forest carbon. This study expects to be more helpful to take advantage of the strategic application of climate change adaption.

  5. Effects of Hormone Therapy on Brain Volumes Changes of Postmenopausal Women Revealed by Optimally-Discriminative Voxel-Based Morphometry

    PubMed Central

    Zhang, Tianhao; Casanova, Ramon; Resnick, Susan M.; Manson, JoAnn E.; Baker, Laura D.; Padual, Claudia B.; Kuller, Lewis H.; Bryan, R. Nick; Espeland, Mark A.; Davatzikos, Christos

    2016-01-01

    Backgrounds The Women's Health Initiative Memory Study Magnetic Resonance Imaging (WHIMS-MRI) provides an opportunity to evaluate how menopausal hormone therapy (HT) affects the structure of older women’s brains. Our earlier work based on region of interest (ROI) analysis demonstrated potential structural changes underlying adverse effects of HT on cognition. However, the ROI-based analysis is limited in statistical power and precision, and cannot provide fine-grained mapping of whole-brain changes. Methods We aimed to identify local structural differences between HT and placebo groups from WHIMS-MRI in a whole-brain refined level, by using a novel method, named Optimally-Discriminative Voxel-Based Analysis (ODVBA). ODVBA is a recently proposed imaging pattern analysis approach for group comparisons utilizing a spatially adaptive analysis scheme to accurately locate areas of group differences, thereby providing superior sensitivity and specificity to detect the structural brain changes over conventional methods. Results Women assigned to HT treatments had significant Gray Matter (GM) losses compared to the placebo groups in the anterior cingulate and the adjacent medial frontal gyrus, and the orbitofrontal cortex, which persisted after multiple comparison corrections. There were no regions where HT was significantly associated with larger volumes compared to placebo, although a trend of marginal significance was found in the posterior cingulate cortical area. The CEE-Alone and CEE+MPA groups, although compared with different placebo controls, demonstrated similar effects according to the spatial patterns of structural changes. Conclusions HT had adverse effects on GM volumes and risk for cognitive impairment and dementia in older women. These findings advanced our understanding of the neurobiological underpinnings of HT effects. PMID:26974440

  6. From Cortical and Subcortical Grey Matter Abnormalities to Neurobehavioral Phenotype of Angelman Syndrome: A Voxel-Based Morphometry Study

    PubMed Central

    Aghakhanyan, Gayane; Bonanni, Paolo; Randazzo, Giovanna; Nappi, Sara; Tessarotto, Federica; De Martin, Lara; Frijia, Francesca; De Marchi, Daniele; De Masi, Francesco; Kuppers, Beate; Lombardo, Francesco; Caramella, Davide; Montanaro, Domenico

    2016-01-01

    Angelman syndrome (AS) is a rare neurogenetic disorder due to loss of expression of maternal ubiquitin-protein ligase E3A (UBE3A) gene. It is characterized by severe developmental delay, speech impairment, movement or balance disorder and typical behavioral uniqueness. Affected individuals show normal magnetic resonance imaging (MRI) findings, although mild dysmyelination may be observed. In this study, we adopted a quantitative MRI analysis with voxel-based morphometry (FSL-VBM) method to investigate disease-related changes in the cortical/subcortical grey matter (GM) structures. Since 2006 to 2013 twenty-six AS patients were assessed by our multidisciplinary team. From those, sixteen AS children with confirmed maternal 15q11-q13 deletions (mean age 7.7 ± 3.6 years) and twenty-one age-matched controls were recruited. The developmental delay and motor dysfunction were assessed using Bayley III and Gross Motor Function Measure (GMFM). Principal component analysis (PCA) was applied to the clinical and neuropsychological datasets. High-resolution T1-weighted images were acquired and FSL-VBM approach was applied to investigate differences in the local GM volume and to correlate clinical and neuropsychological changes in the regional distribution of GM. We found bilateral GM volume loss in AS compared to control children in the striatum, limbic structures, insular and orbitofrontal cortices. Voxel-wise correlation analysis with the principal components of the PCA output revealed a strong relationship with GM volume in the superior parietal lobule and precuneus on the left hemisphere. The anatomical distribution of cortical/subcortical GM changes plausibly related to several clinical features of the disease and may provide an important morphological underpinning for clinical and neurobehavioral symptoms in children with AS. PMID:27626634

  7. Auras and clinical features in temporal lobe epilepsy: a new approach on the basis of voxel-based morphometry.

    PubMed

    Santana, Maria Teresa Castilho Garcia; Jackowski, Andrea Parolin; da Silva, Henrique Hattori; Caboclo, Luis Otávio Sales Ferreira; Centeno, Ricardo Silva; Bressan, Rodrigo A; Carrete, Henrique; Yacubian, Elza Márcia Targas

    2010-05-01

    MRI investigations in patients with temporal lobe epilepsy (TLE) with mesial temporal sclerosis (MTS) have demonstrated structural abnormalities extending beyond ipsilateral hippocampus which may be studied through voxel-based morphometry (VBM). We investigated brain morphology related to clinical features in patients with refractory TLE with MTS using VBM. One hundred patients with unilateral TLE with MTS (59 left) and 30 controls were enrolled. VBM5 was employed to analyze (1) hemispheric damage, (2) influence of initial precipitating injury (IPI): 23 patients with febrile seizures and 19 with status epilepticus, and (3) types of auras classified as: mesial, including psychic auras (19 patients); anterior mesio-lateral, as autonomic symptoms, specially epigastric auras (27 patients) and neocortical, which included auditory, vertiginous, somatosensory and visual auras (16 patients). (1) Left TLE patients presented more widespread gray matter volume (GMV) reductions affecting ipsilateral hippocampus, temporal neocortex, insula and also left uncus, precentral gyrus, thalamus, parietal lobule, cuneus and bilateral cingulum. (2) Febrile seizures group presented ipsilateral GMV reductions in hippocampus, neocortical temporal, frontal and occipital cortices, insula and cingulum. Status epilepticus group presented more widespread GMV reductions involving temporal and extratemporal lobes. (3) Patients with mesial auras showed significant ipsilateral GMV reductions in hippocampus and amygdala, particularly right TLE group, who presented greater extension of GMV reduction in the entorhinal cortex. Significant reductions in hippocampus, amygdala and insula were seen in patients with anterior mesio-lateral auras. This study evaluated a large number of TLE-MTS patients showing structural damage extending beyond hippocampus, and different types of IPI associated with the extension of brain damage. Subtypes of auras are related to different clusters of areas of GMV reductions in

  8. Global brain atrophy and corticospinal tract alterations in ALS, as investigated by voxel-based morphometry of 3-D MRI.

    PubMed

    Kassubek, Jan; Unrath, Alexander; Huppertz, Hans-Jürgen; Lulé, Dorothée; Ethofer, Thomas; Sperfeld, Anne-Dorte; Ludolph, Albert C

    2005-12-01

    In ALS, advanced magnetic resonance imaging (MRI) techniques are increasingly used to investigate the underlying pathology. In this study, the technique of voxel-based morphometry (VBM) was applied to 3-D MRI data in ALS patients to localize regional grey and white matter changes. Twenty-two ALS patients (mean age 58+/-9 years) with clinically definite ALS by revised El Escorial criteria were studied. None of the patients had any signs of associated frontotemporal dementia. High-resolution 3-D MRI data sets of the whole brain, collected on a 1.5 T scanner, were analysed by statistical parametric mapping (SPM) and VBM in comparison to an age-matched normal data base consisting of 22 healthy volunteers (mean age 59+/-11 years), for grey matter and white matter segments separately. Global brain atrophy was assessed by calculation of brain parenchymal fractions (BPF). In ALS patients, BPF were significantly reduced compared to controls (p = 0.0003), indicating global brain atrophy. Regional decreases of grey matter density were found in the ALS patients at corrected p<0.01 in the right-hemispheric primary motor cortex (area of the highest Z-score) and in the left medial frontal gyrus. Furthermore, regional white matter alterations were observed along the corticospinal tracts bilaterally and in multiple smaller areas including corpus callosum, cerebellum, frontal and occipital subcortical regions. Besides considerable global atrophy in ALS, the topography of ALS-associated cerebral morphological changes could be mapped using VBM, in particular white matter signal changes along the bilateral corticospinal tracts, but also in extra-motor areas. VBM might be a potential tool to visualize disease progression in future longitudinal studies.

  9. Desperately seeking grey matter volume changes in sleep apnea: A methodological review of magnetic resonance brain voxel-based morphometry studies.

    PubMed

    Celle, Sébastien; Delon-Martin, Chantal; Roche, Frédéric; Barthélémy, Jean-Claude; Pépin, Jean-Louis; Dojat, Michel

    2016-02-01

    Cognitive impairment related to obstructive sleep apnea might be explained by subtle changes in brain anatomy. This has been mainly investigated using magnetic resonance brain scans coupled with a voxel-based morphometry analysis. However, this approach is prone to several methodological pitfalls that may explain the large discrepancy in the results reported in the literature. We critically reviewed twelve papers addressing grey matter volume modifications in association with obstructive sleep apnea. Finally, based on strict methodological criteria, only three studies reported robust, but conflicting, results. No clear evidence has emerged and exploring brain alteration due to obstructive sleep apnea should thus be considered as an open field. We provide recommendations for designing additional robust voxel-based morphometry studies, notably the use of larger cohorts, which is the only way to solve the underpowered issue and the underestimated role of confounders in neuroimaging studies.

  10. CT-Based Attenuation Correction in Brain SPECT/CT Can Improve the Lesion Detectability of Voxel-Based Statistical Analyses

    PubMed Central

    Kato, Hiroki; Shimosegawa, Eku; Fujino, Koichi; Hatazawa, Jun

    2016-01-01

    Background Integrated SPECT/CT enables non-uniform attenuation correction (AC) using built-in CT instead of the conventional uniform AC. The effect of CT-based AC on voxel-based statistical analyses of brain SPECT findings has not yet been clarified. Here, we assessed differences in the detectability of regional cerebral blood flow (CBF) reduction using SPECT voxel-based statistical analyses based on the two types of AC methods. Subjects and Methods N-isopropyl-p-[123I]iodoamphetamine (IMP) CBF SPECT images were acquired for all the subjects and were reconstructed using 3D-OSEM with two different AC methods: Chang’s method (Chang’s AC) and the CT-based AC method. A normal database was constructed for the analysis using SPECT findings obtained for 25 healthy normal volunteers. Voxel-based Z-statistics were also calculated for SPECT findings obtained for 15 patients with chronic cerebral infarctions and 10 normal subjects. We assumed that an analysis with a higher specificity would likely produce a lower mean absolute Z-score for normal brain tissue, and a more sensitive voxel-based statistical analysis would likely produce a higher absolute Z-score for in old infarct lesions, where the CBF was severely decreased. Results The inter-subject variation in the voxel values in the normal database was lower using CT-based AC, compared with Chang’s AC, for most of the brain regions. The absolute Z-score indicating a SPECT count reduction in infarct lesions was also significantly higher in the images reconstructed using CT-based AC, compared with Chang’s AC (P = 0.003). The mean absolute value of the Z-score in the 10 intact brains was significantly lower in the images reconstructed using CT-based AC than in those reconstructed using Chang’s AC (P = 0.005). Conclusions Non-uniform CT-based AC by integrated SPECT/CT significantly improved sensitivity and the specificity of the voxel-based statistical analyses for regional SPECT count reductions, compared with

  11. A voxel-based morphometry study of grey matter loss in fragile X-associated tremor/ataxia syndrome.

    PubMed

    Hashimoto, Ryu-ichiro; Javan, Alireza K; Tassone, Flora; Hagerman, Randi J; Rivera, Susan M

    2011-03-01

    Fragile X-associated tremor/ataxia syndrome is a neurodegenerative disorder that primarily affects older male premutation carriers of the fragile X mental retardation gene. Although its core symptoms are mainly characterized by motor problems such as intention tremor and gait ataxia, cognitive decline and psychiatric problems are also commonly observed. Past radiological and histological approaches have focused on prominent neurodegenerative changes in specific brain structures including the cerebellum and limbic areas. However, quantitative investigations of the regional structural abnormalities have not been performed over the whole brain. In this study, we adopted the voxel-based morphometry method together with regions of interest analysis for the cerebellum to examine the pattern of regional grey matter change in the male premutation carriers with and without fragile X-associated tremor/ataxia syndrome. In a comparison with healthy controls, we found striking grey matter loss of the patients with fragile X-associated tremor/ataxia syndrome in multiple regions over the cortical and subcortical structures. In the cerebellum, the anterior lobe and the superior posterior lobe were profoundly reduced in both vermis and hemispheres. In the cerebral cortex, clusters of highly significant grey matter reduction were found in the extended areas in the medial surface of the brain, including the dorsomedial prefrontal cortex, anterior cingulate cortex and precuneus. The other prominent grey matter loss was found in the lateral prefrontal cortex, orbitofrontal cortex, amygdala and insula. Although the voxel-wise comparison between the asymptomatic premutation group and healthy controls did not reach significant difference, a regions of interest analysis revealed significant grey matter reduction in anterior subregions of the cerebellar vermis and hemisphere in the asymptomatic premutation group. Correlation analyses using behavioural scales of the premutation groups showed

  12. Voxel-based morphometry at ultra-high fields. A comparison of 7T and 3T MRI data

    PubMed Central

    Seiger, Rene; Hahn, Andreas; Hummer, Allan; Kranz, Georg S; Ganger, Sebastian; Küblböck, Martin; Kraus, Christoph; Sladky, Ronald; Kasper, Siegfried; Windischberger, Christian; Lanzenberger, Rupert

    2017-01-01

    Recent technological progress enables MRI recordings at ultra-high fields of 7 Tesla and above leading to brain images of higher resolution and increased signal-to-noise ratio. Despite these benefits, imaging at 7T exhibits distinct challenges due to B1 field inhomogeneities, causing decreased image quality and problems in data analysis. Although several strategies have been proposed, a systematic investigation of bias-corrected 7T data for voxel-based morphometry (VBM) is still missing and it is an ongoing matter of debate if VBM at 7T can be carried out properly. Here, an optimized VBM study was conducted, evaluating the impact of field strength (3T vs 7T) and pulse sequence (MPRAGE vs MP2RAGE) on gray matter volume (GMV) estimates. More specifically, twenty-two participants were measured under the conditions 3T MPRAGE, 7T MPRAGE and 7T MP2RAGE. Due to the fact that 7T MPRAGE data exhibited strong intensity inhomogeneities, an alternative preprocessing pipeline was proposed and applied for that data. VBM analysis revealed higher GMV estimates for 7T predominantly in superior cortical areas, caudate nucleus, cingulate cortex and the hippocampus. On the other hand, 3T yielded higher estimates especially in inferior cortical areas of the brain, cerebellum, thalamus and putamen compared to 7T. Besides minor exceptions, these results were observed for 7T MPRAGE as well for the 7T MP2RAGE measurements. Results gained in the inferior parts of the brain should be taken with caution, as native GM segmentations displayed misclassifications in these regions for both 7T sequences. This was supported by the test-retest measurements showing highest variability in these inferior regions of the brain for 7T also for the advanced MP2RAGE sequence. Hence, our data support the use of 7T MRI for VBM analysis in cortical areas, but direct comparison between field strengths and sequences requires careful assessment. Similarly, analysis of inferior cortical regions, cerebellum and

  13. Active brain changes after initiating fingolimod therapy in multiple sclerosis patients using individual voxel-based analyses for diffusion tensor imaging

    PubMed Central

    Senda, Joe; Watanabe, Hirohisa; Endo, Kuniyuki; Yasui, Keizo; Hawsegawa, Yasuhiro; Yoneyama, Noritaka; Tsuboi, Takashi; Hara, Kazuhiro; Ito, Mizuki; Atsuta, Naoki; Epifanio Jr, Bagarinao; Katsuno, Masahisa; Naganawa, Shinji; Sobue, Gen

    2016-01-01

    ABSTRACT Voxel-based analysis (VBA) of diffusion tensor images (DTI) and voxel-based morphometry (VBM) in patients with multiple sclerosis (MS) can sensitively detect occult tissue damage that underlies pathological changes in the brain. In the present study, both at the start of fingolimod and post-four months clinical remission, we assessed four patients with MS who were evaluated with VBA of DTI, VBM, and fluid-attenuated inversion recovery (FLAIR). DTI images for all four patients showed widespread areas of increased mean diffusivity (MD) and decreased fractional anisotropy (FA) that were beyond the high-intensity signal areas across images. After four months of continuous fingolimod therapy, DTI abnormalities progressed; in particular, MD was significantly increased, while brain volume and high-intensity signals were unchanged. These findings suggest that VBA of DTI (e.g., MD) may help assess MS demyelination as neuroinflammatory conditions, even though clinical manifestations of MS appear to be in complete remission during fingolimod. PMID:28008201

  14. Voxel-based analysis of the immediate early gene, c-jun, in the honey bee brain after a sucrose stimulus.

    PubMed

    McNeill, M S; Robinson, G E

    2015-06-01

    Immediate early genes (IEGs) have served as useful markers of brain neuronal activity in mammals, and more recently in insects. The mammalian canonical IEG, c-jun, is part of regulatory pathways conserved in insects and has been shown to be responsive to alarm pheromone in honey bees. We tested whether c-jun was responsive in honey bees to another behaviourally relevant stimulus, sucrose, in order to further identify the brain regions involved in sucrose processing. To identify responsive regions, we developed a new method of voxel-based analysis of c-jun mRNA expression. We found that c-jun is expressed in somata throughout the brain. It was rapidly induced in response to sucrose stimuli, and it responded in somata near the antennal and mechanosensory motor centre, mushroom body calices and lateral protocerebrum, which are known to be involved in sucrose processing. c-jun also responded to sucrose in somata near the lateral suboesophageal ganglion, dorsal optic lobe, ventral optic lobe and dorsal posterior protocerebrum, which had not been previously identified by other methods. These results demonstrate the utility of voxel-based analysis of mRNA expression in the insect brain.

  15. Empirical comparison of maximal voxel and non-isotropic adjusted cluster extent results in a voxel-based morphometry study of comorbid learning disability with schizophrenia.

    PubMed

    Moorhead, T William J; Job, Dominic E; Spencer, Michael D; Whalley, Heather C; Johnstone, Eve C; Lawrie, Stephen M

    2005-11-15

    We present an empirical comparison of cluster extent and maximal voxel results in a voxel-based morphometry (VBM) study of brain structure. The cluster extents are adjusted for underlying deviation from uniform smoothness. We implement this comparison on a four-group cohort that has previously shown evidence of a neuro-developmental component in schizophrenia (Moorhead, T.W.J., Job, D.E., Whalley, H.C., Sanderson, T.L., Johnstone, E.C. and Lawrie, S.M. 2004. Voxel-based morphometry of comorbid schizophrenia and learning disability: analyses in normalized and native spaces using parametric and nonparametric statistical methods. NeuroImage 22: 188-202.). We find that adjusted cluster extent results provide information on the nature of deficits that occur in the schizophrenia affected groups, and these important structural differences are not all shown in maximal voxel results. The maximal voxel and cluster extent results are corrected for multiple comparisons using Random Fields (RF) methods. In order to apply the cluster extent measures, we propose a post-hoc method for determining the primary threshold in the analysis. Unadjusted cluster extent results are reported, for these, no allowance is made for non-isotropic smoothness, and comparison with the adjusted extent results shows that the unadjusted results can be either conservative or anti-conservative depending upon the underlying tissue distributions.

  16. 78 FR 66039 - Modification of National Customs Automation Program Test Concerning Automated Commercial...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-04

    ... Concerning Automated Commercial Environment (ACE) Cargo Release (Formerly Known as Simplified Entry) AGENCY... Automated Commercial Environment (ACE). Originally, the test was known as the Simplified Entry Test because... Environment (ACE) Simplified Entry (SE test) functionality is authorized under Sec. 101.9(b) of title 19...

  17. Evaluation of brain perfusion in specific Brodmann areas in Frontotemporal dementia and Alzheimer disease using automated 3-D voxel based analysis

    NASA Astrophysics Data System (ADS)

    Valotassiou, V.; Papatriantafyllou, J.; Sifakis, N.; Karageorgiou, C.; Tsougos, I.; Tzavara, C.; Zerva, C.; Georgoulias, P.

    2009-05-01

    Introduction. Brain perfusion studies with single-photon emission computed tomography (SPECT) have been applied in demented patients to provide better discrimination between frontotemporal dementia (FTD) and Alzheimer's disease (AD). Aim. To assess the perfusion of specific Brodmann (Br) areas of the brain cortex in FTD and AD patients, using NeuroGam processing program to provide 3D voxel-by-voxel cerebral SPECT analysis. Material and methods. We studied 34 consecutive patients. We used the established criteria for the diagnosis of dementia and the specific established criteria for the diagnosis of FTD and AD. All the patients had a neuropsychological evaluation with a battery of tests including the mini-mental state examination (MMSE).Twenty-six patients (16 males, 10 females, mean age 68.76±6.51 years, education 11.81±4.25 years, MMSE 16.69±9.89) received the diagnosis of FTD and 8 patients (all females, mean age 71.25±10.48 years, education 10±4.6 years, MMSE 12.5±3.89) the diagnosis of AD. All the patients underwent a brain SPECT. We applied the NeuroGam Software for the evaluation of brain perfusion in specific Br areas in the left (L) and right (R) hemispheres. Results. Statistically significant hypoperfusion in FTD compared to AD patients, was found in the following Br areas: 11L (p<0.0001), 11R, 20L, 20R, 32L, 38L, 38R, 44L (p<0.001), 32R, 36L, 36R, 45L, 45R, 47R (p<0.01), 9L, 21L, 39R, 44R, 46R, 47L (p<0.05). On the contrary, AD patients presented significant (p<0.05) hypoperfusion in 7R and 39R Br areas. Conclusion. NeuroGam processing program of brain perfusion SPECT could result in enhanced accuracy for the differential diagnosis between AD and FTD patients.

  18. Automation of Cyber Penetration Testing Using the Detect, Identify, Predict, React Intelligence Automation Model

    DTIC Science & Technology

    2013-09-01

    With increased computing power available, intelligent automation is a clear choice for simplifying the lives of both administrators and developers...with manual cyber penetration [1]. With increased computing power available, intelligent automation is a clear choice for simplifying the lives... power intensive, and basic automation has the limitation of only finding the specific vulnerabilities which it is programmed to find. Penetration

  19. Early gray-matter and white-matter concentration in infancy predict later language skills: A whole brain voxel-based morphometry study

    PubMed Central

    Can, Dilara Deniz; Richards, Todd; Kuhl, Patricia

    2012-01-01

    Magnetic Resonance Imaging (MRI) brain scans were obtained from 19 infants at 7 months. Expressive and receptive language performance was assessed at 12 months. Voxel-based morphometry (VBM) identified brain regions where gray-matter and white-matter concentrations at 7 months correlated significantly with children’s language scores at 12 months. Early gray-matter concentration in the right cerebellum, early white-matter concentration in the right cerebellum, and early white-matter concentration in the left posterior limb of the internal capsule (PLIC)/cerebral peduncle were positively and strongly associated with infants’ receptive language ability at 12 months. Early gray-matter concentration in the right hippocampus was positively and strongly correlated with infants’ expressive language ability at 12 months. Our results suggest that the cerebellum, PLIC/cerebral peduncle, and the hippocampus may be associated with early language development. Potential links between these structural predictors and infants’ linguistic functions are discussed. PMID:23274797

  20. Numerical Transcoding Proficiency in 10-Year-Old Schoolchildren is Associated with Gray Matter Inter-Individual Differences: A Voxel-Based Morphometry Study

    PubMed Central

    Lubin, Amélie; Rossi, Sandrine; Simon, Grégory; Lanoë, Céline; Leroux, Gaëlle; Poirel, Nicolas; Pineau, Arlette; Houdé, Olivier

    2013-01-01

    Are individual differences in numerical performance sustained by variations in gray matter volume in schoolchildren? To our knowledge, this challenging question for neuroeducation has not yet been investigated in typical development. We used the Voxel-Based Morphometry method to search for possible structural brain differences between two groups of 10-year-old schoolchildren (N = 22) whose performance differed only in numerical transcoding between analog and symbolic systems. The results indicated that children with low numerical proficiency have less gray matter volume in the parietal (particularly in the left intraparietal sulcus and the bilateral angular gyri) and occipito-temporal areas. All the identified regions have previously been shown to be functionally involved in transcoding between analog and symbolic numerical systems. Our data contribute to a better understanding of the intertwined relationships between mathematics learning and brain structure in healthy schoolchildren. PMID:23630510

  1. Numerical Transcoding Proficiency in 10-Year-Old Schoolchildren is Associated with Gray Matter Inter-Individual Differences: A Voxel-Based Morphometry Study.

    PubMed

    Lubin, Amélie; Rossi, Sandrine; Simon, Grégory; Lanoë, Céline; Leroux, Gaëlle; Poirel, Nicolas; Pineau, Arlette; Houdé, Olivier

    2013-01-01

    Are individual differences in numerical performance sustained by variations in gray matter volume in schoolchildren? To our knowledge, this challenging question for neuroeducation has not yet been investigated in typical development. We used the Voxel-Based Morphometry method to search for possible structural brain differences between two groups of 10-year-old schoolchildren (N = 22) whose performance differed only in numerical transcoding between analog and symbolic systems. The results indicated that children with low numerical proficiency have less gray matter volume in the parietal (particularly in the left intraparietal sulcus and the bilateral angular gyri) and occipito-temporal areas. All the identified regions have previously been shown to be functionally involved in transcoding between analog and symbolic numerical systems. Our data contribute to a better understanding of the intertwined relationships between mathematics learning and brain structure in healthy schoolchildren.

  2. Magnetic resonance imaging for monitoring therapeutic response in a transgenic mouse model of Alzheimer’s disease using voxel-based analysis of amyloid plaques

    PubMed Central

    Kim, Jae-Hun; Ha, Tae Lin; Im, Geun Ho; Yang, Jehoon; Seo, Sang Won; Chung, Julius Juhyun; Chae, Sun Young; Lee, In Su

    2014-01-01

    In this study, we have shown the potential of a voxel-based analysis for imaging amyloid plaques and its utility in monitoring therapeutic response in Alzheimer’s disease (AD) mice using manganese oxide nanoparticles conjugated with an antibody of Aβ1-40 peptide (HMON-abAβ40). T1-weighted MR brain images of a drug-treated AD group (n=7), a nontreated AD group (n=7), and a wild-type group (n=7) were acquired using a 7.0 T MRI system before (D−1), 24-h (D+1) after, and 72-h (D+3) after injection with an HMON-abAβ40 contrast agent. For the treatment of AD mice, DAPT was injected intramuscularly into AD transgenic mice (50 mg/kg of body weight). For voxel-based analysis, the skull-stripped mouse brain images were spatially normalized, and these voxels’ intensities were corrected to reduce voxel intensity differences across scans in different mice. Statistical analysis showed higher normalized MR signal intensity in the frontal cortex and hippocampus of AD mice over wild-type mice on D+1 and D+3 (P<0.01, uncorrected for multiple comparisons). After the treatment of AD mice, the normalized MR signal intensity in the frontal cortex and hippocampus decreased significantly in comparison with nontreated AD mice on D+1 and D+3 (P<0.01, uncorrected for multiple comparisons). These results were confirmed by histological analysis using a thioflavin staining. This unique strategy allows us to detect brain regions that are subjected to amyloid plaque deposition and has the potential for human applications in monitoring therapeutic response for drug development in AD. PMID:24518227

  3. Density abnormalities in normal-appearing gray matter in the middle-aged brain with white matter hyperintense lesions: a DARTEL-enhanced voxel-based morphometry study

    PubMed Central

    Peng, Yan; Li, Shenhong; Zhuang, Ying; Liu, Xiaojia; Wu, Lin; Gong, Honghan; Liu, Dewu; Zhou, Fuqing

    2016-01-01

    Background and purpose Little is known about the structural alterations within gray matter (GM) in middle-aged subjects with white matter hyperintense (WMH) lesions. Here, we aimed to examine the anatomical changes within the GM and their relationship to WMH lesion loads in middle-aged subjects. Participants and methods Twenty-three middle-aged subjects with WMH lesions (WMH group) and 23 demographically matched healthy control subjects participated in the study. A Diffeomorphic Anatomical Registration Through Exponentiated Liealgebra-enhanced voxel-based morphometry was used to measure the GM density, and the correlations between WMH lesion volume and extracted GM values in abnormal regions were identified by voxel-based morphometry analysis. Results Compared with the healthy control subjects, the WMH group had a significantly decreased GM density in the left middle frontal gyrus, bilateral anterior cingulate cortex, left and right premotor cortex, and left and right middle cingulate cortex and an increased GM density in the bilateral cerebellum anterior lobe, left middle temporal gyrus, right temporoparietal junction, left and right prefrontal cortex (PFC), and left inferior parietal lobule. A relationship was observed between the normalized WMH lesion volume and the decreased GM density, including the left middle frontal gyrus (ρ=−0.629, P=0.002), bilateral anterior cingulate cortex (ρ=−0.507, P=0.019), right middle cingulate cortex (ρ=−0.484, P=0.026), and right premotor cortex (ρ=−0.438, P=0.047). The WMH lesion loads also negatively correlated with increased GM density in the right temporoparietal junction (ρ=−0.484, P=0.026), left PFC (ρ=−0.469, P=0.032), and right PFC (ρ=−0.438, P=0.047). Conclusion We observed that lesion load-associated structural plasticity corresponds to bidirectional changes in regional GM density in the WMH group. PMID:27274211

  4. White matter abnormalities associated with auditory hallucinations in schizophrenia: a combined study of voxel-based analyses of diffusion tensor imaging and structural magnetic resonance imaging.

    PubMed

    Seok, Jeong-Ho; Park, Hae-Jeong; Chun, Ji-Won; Lee, Seung-Koo; Cho, Hyun Sang; Kwon, Jun Soo; Kim, Jae-Jin

    2007-11-15

    White matter (WM) abnormalities in schizophrenia may offer important clues to a better understanding of the disconnectivity associated with the disorder. The aim of this study was to elucidate a WM basis of auditory hallucinations in schizophrenia through the simultaneous investigation of WM tract integrity and WM density. Diffusion tensor images (DTIs) and structural T1 magnetic resonance images (MRIs) were taken from 15 hallucinating schizophrenic patients, 15 non-hallucinating schizophrenic patients and 22 normal controls. Voxel-based analyses and post-hoc region of interest analyses were obtained to compare the three groups on fractional anisotropy (FA) derived from DTI as well as WM density derived from structural MRIs. In both the hallucinating and non-hallucinating groups, FA of the WM regions was significantly decreased in the left superior longitudinal fasciculus (SLF), whereas WM density was significantly increased in the left inferior longitudinal fasciculus (ILF). The mean FA value of the left frontal part of the SLF was positively correlated with the severity score of auditory hallucinations in the hallucinating patient group. Our findings show that WM changes were mainly observed in the frontal and temporal areas, suggesting that disconnectivity in the left fronto-temporal area may contribute to the pathophysiology of schizophrenia. In addition, pathologic WM changes in this region may be an important step in the development of auditory hallucinations in schizophrenia.

  5. Structural and functional brain changes in early- and mid-stage primary open-angle glaucoma using voxel-based morphometry and functional magnetic resonance imaging.

    PubMed

    Jiang, Ming-Ming; Zhou, Qing; Liu, Xiao-Yong; Shi, Chang-Zheng; Chen, Jian; Huang, Xiang-He

    2017-03-01

    To investigate structural and functional brain changes in patients with primary open-angle glaucoma (POAG) by using voxel-based morphometry based on diffeomorphic anatomical registration through exponentiated Lie algebra (VBM-DARTEL) and blood oxygenation level dependent functional magnetic resonance imaging (BOLD-fMRI), respectively.Thirteen patients diagnosed with POAG and 13 age- and sex-matched healthy controls were enrolled in the study. For each participant, high-resolution structural brain imaging and blood flow imaging were acquired on a 3.0-Tesla magnetic resonance imaging (MRI) scanner. Structural and functional changes between the POAG and control groups were analyzed. An analysis was carried out to identify correlations between structural and functional changes acquired in the previous analysis and the retinal nerve fiber layer (RNFL).Patients in the POAG group showed a significant (P < 0.001) volume increase in the midbrain, left brainstem, frontal gyrus, cerebellar vermis, left inferior parietal lobule, caudate nucleus, thalamus, precuneus, and Brodmann areas 7, 18, and 46. Moreover, significant (P < 0.001) BOLD signal changes were observed in the right supramarginal gyrus, frontal gyrus, superior frontal gyrus, left inferior parietal lobule, left cuneus, and left midcingulate area; many of these regions had high correlations with the RNFL.Patients with POAG undergo widespread and complex changes in cortical brain structure and blood flow. (ClinicalTrials.gov number: NCT02570867).

  6. Linear and curvilinear correlations of brain gray matter volume and density with age using voxel-based morphometry with the Akaike information criterion in 291 healthy children.

    PubMed

    Taki, Yasuyuki; Hashizume, Hiroshi; Thyreau, Benjamin; Sassa, Yuko; Takeuchi, Hikaru; Wu, Kai; Kotozaki, Yuka; Nouchi, Rui; Asano, Michiko; Asano, Kohei; Fukuda, Hiroshi; Kawashima, Ryuta

    2013-08-01

    We examined linear and curvilinear correlations of gray matter volume and density in cortical and subcortical gray matter with age using magnetic resonance images (MRI) in a large number of healthy children. We applied voxel-based morphometry (VBM) and region-of-interest (ROI) analyses with the Akaike information criterion (AIC), which was used to determine the best-fit model by selecting which predictor terms should be included. We collected data on brain structural MRI in 291 healthy children aged 5-18 years. Structural MRI data were segmented and normalized using a custom template by applying the diffeomorphic anatomical registration using exponentiated lie algebra (DARTEL) procedure. Next, we analyzed the correlations of gray matter volume and density with age in VBM with AIC by estimating linear, quadratic, and cubic polynomial functions. Several regions such as the prefrontal cortex, the precentral gyrus, and cerebellum showed significant linear or curvilinear correlations between gray matter volume and age on an increasing trajectory, and between gray matter density and age on a decreasing trajectory in VBM and ROI analyses with AIC. Because the trajectory of gray matter volume and density with age suggests the progress of brain maturation, our results may contribute to clarifying brain maturation in healthy children from the viewpoint of brain structure.

  7. Increased medial temporal lobe and striatal grey-matter volume in a rare disorder of androgen excess: a voxel-based morphometry (VBM) study

    PubMed Central

    Mueller, Sven C.; Merke, Deborah P.; Leschek, Ellen W.; Fromm, Steven; VanRyzin, Carol; Ernst, Monique

    2016-01-01

    Major questions remain about how sex hormones influence human brain development and cognition. Studies in humans and animals suggest a strong impact of androgen on the structure and function of the medial temporal lobe (MTL) and striatum. Using voxel-based morphometry (DARTEL), we compared MTL and striatal structures in 13 [mean age (±s.d.) 12.7 ± 3.2 yr, mean bone age 14.8 ± 3.2 yr] boys with familial male precocious puberty (FMPP), characterized by early excess androgen secretion, and 39 healthy age-matched boys (mean age 14.3 ± 2.5 yr). The FMPP group showed significantly larger grey-matter volume (GMV) in parahippocampal and fusiform gyri as well as putamen relative to controls. By comparison, larger GMV for controls relative to patients was only apparent in the precentral gyrus. Exploratory regression analyses that examined the impact of age on the current findings revealed a significant increase of GMV in the putamen with age in patients suffering from excess androgen but not in controls. Finally, current levels of free testosterone were obtained in the patient group. Analyses revealed a significant negative association indicating that FMPP boys with low levels of bioavailable testosterone exhibited high GMV in the bilateral striatum. The findings suggest a critical influence of androgen on human brain development and are discussed in relation to male-dominant psychiatric childhood disorders. PMID:20860880

  8. Greater intake of vitamins B6 and B12 spares gray matter in healthy elderly: a voxel-based morphometry study.

    PubMed

    Erickson, Kirk I; Suever, Barbara L; Prakash, Ruchika Shaurya; Colcombe, Stanley J; McAuley, Edward; Kramer, Arthur F

    2008-03-14

    Previous studies have reported that high concentrations of homocysteine and lower concentrations of vitamins B6, B12, and folate increase the risk for cognitive decline and pathology in aging populations. In this cross-sectional study, high resolution magnetic resonance imaging (MRI) scans and a 3-day food diary were collected on 32 community-dwelling adults between the ages of 59 and 79. We examined the relation between vitamins B6, B12, and folate intake on cortical volume using an optimized voxel-based morphometry (VBM) method and global gray and white matter volume after correcting for age, sex, body mass index, calorie intake, and education. All participants met or surpassed the recommended daily intake for these vitamins. In the VBM analysis, we found that adults with greater vitamin B6 intake had greater gray matter volume along the medial wall, anterior cingulate cortex, medial parietal cortex, middle temporal gyrus, and superior frontal gyrus, whereas people with greater B12 intake had greater volume in the left and right superior parietal sulcus. These effects were driven by vitamin supplementation and were negated when only examining vitamin intake from diet. Folate had no effect on brain volume. Furthermore, there was no relationship between vitamins B6, B12, or folate intake on global brain volume measures, indicating that VBM methods are more sensitive for detecting localized differences in gray matter volume than global measures. These results are discussed in relation to a growing literature on vitamin intake on age-related neurocognitive deterioration.

  9. Voxel-based morphometry of the marmoset brain: In vivo detection of volume loss in the substantia nigra of the MPTP-treated Parkinson's disease model.

    PubMed

    Hikishima, K; Ando, K; Komaki, Y; Kawai, K; Yano, R; Inoue, T; Itoh, T; Yamada, M; Momoshima, S; Okano, H J; Okano, H

    2015-08-06

    Movement dysfunction in Parkinson's disease (PD) is caused by the degeneration of dopaminergic (DA) neurons in the substantia nigra (SN). Here, we established a method for voxel-based morphometry (VBM) and automatic tissue segmentation of the marmoset monkey brain using a 7-T animal scanner and applied the method to assess DA degeneration in a PD model, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated animals, with tyrosine-hydroxylase staining. The most significant decreases of local tissue volume were detected in the bilateral SN of MPTP-treated marmoset brains (-53.0% in right and -46.5% in left) and corresponded with the location of DA neurodegeneration found in histology (-65.4% in right). In addition to the SN, the decreases were also confirmed in the locus coeruleus, and lateral hypothalamus. VBM using 7-T MRI was effective in detecting volume loss in the SN of the PD-model marmoset. This study provides a potential basis for the application of VBM with ultra-high field MRI in the clinical diagnosis of PD. The developed method may also offer value in automatic whole-brain evaluation of structural changes for the marmoset monkey.

  10. A comparison of gray and white matter density in patients with Parkinson's disease dementia and dementia with Lewy bodies using voxel-based morphometry.

    PubMed

    Lee, Ji E; Park, Bosuk; Song, Sook K; Sohn, Young H; Park, Hae-Jeong; Lee, Phil Hyu

    2010-01-15

    Despite clinical and neuropsychological similarities between Parkinson's disease dementia (PDD) and dementia with Lewy bodies (DLB), recent studies have demonstrated that structural and pathological changes are more severe in DLB than in PDD. We used voxel-based morphometry using a 3-T MRI scanner to compare gray and white matter densities in 20 patients with probable PDD and 18 patients with probable DLB, who had similar overall severity of dementia and similar demographic characteristics. The gray matter density was significantly decreased in the left occipital, parietal, and striatal areas in patients with DLB compared with patients with PDD. The white matter density was significantly decreased in bilateral occipital and left occipito-parietal areas in patients with DLB compared with those with PDD. The degree of white and gray matter atrophy was similar in patients with DLB; in contrast, there was markedly less atrophy in the white matter than in the gray matter in patients with PDD. On analyzing the change of WM density relative to that of GM density in patients with DLB compared to those with PDD, the area of WM atrophy in the occipital areas was more extensive than that of GM atrophy. Our data demonstrate that atrophy of both gray and white matter was more severe in patients with DLB and that white matter atrophy relative to gray matter atrophy was less severe in patients with PDD. These data may reflect a difference in the underlying nature of PDD and DLB.

  11. Voxel-based morphometry and arterial spin labeling fMRI reveal neuropathic and neuroplastic features of brain processing of itch in end-stage renal disease.

    PubMed

    Papoiu, Alexandru D P; Emerson, Nichole M; Patel, Tejesh S; Kraft, Robert A; Valdes-Rodriguez, Rodrigo; Nattkemper, Leigh A; Coghill, Robert C; Yosipovitch, Gil

    2014-10-01

    Pruritus of end-stage renal disease (ESRD) is a multifactorial symptom of complex etiology not yet fully understood. In this study we have investigated the cerebral perfusion patterns at rest in ESRD patients on hemodialysis, compared with those in healthy volunteers. We have also studied the brain responses evoked by experimental itch induction in ESRD, after stimulating the two distinct histamine and cowhage itch pathways, and compared them with the responses evoked in healthy volunteers. To identify potential structural alterations in ESRD patients compared with a group of age-matched healthy volunteers, we calculated the density of gray matter for the entire brain using a voxel-based morphometric analysis. Our results indicated that gray matter density was significantly reduced in ESRD patients in the frontal, parietal, temporal, and occipital cortices, as well as in the S1, precuneus, and insula, whereas the brain stem, hippocampus, amygdala, midcingulate cortex, and nucleus accumbens displayed an increased gray matter density. Functionally, we found a significantly higher brain perfusion at baseline associated with ESRD pruritus in the anterior cingulate, insula, claustrum, hippocampus, and nucleus accumbens. The brain responses evoked by cowhage itch, which are mediated by protease-activated receptors (PAR2), displayed significant differences compared with responses in healthy individuals and were correlated with perceived itch intensity in a dual, complex manner. The inverse correlations in particular suggested that a negative feedback mechanism modulated itch intensity, when elicited in a preexistent chronic itch background.

  12. Structural and functional brain changes in early- and mid-stage primary open-angle glaucoma using voxel-based morphometry and functional magnetic resonance imaging

    PubMed Central

    Jiang, Ming-Ming; Zhou, Qing; Liu, Xiao-Yong; Shi, Chang-Zheng; Chen, Jian; Huang, Xiang-He

    2017-01-01

    Abstract To investigate structural and functional brain changes in patients with primary open-angle glaucoma (POAG) by using voxel-based morphometry based on diffeomorphic anatomical registration through exponentiated Lie algebra (VBM-DARTEL) and blood oxygenation level dependent functional magnetic resonance imaging (BOLD-fMRI), respectively. Thirteen patients diagnosed with POAG and 13 age- and sex-matched healthy controls were enrolled in the study. For each participant, high-resolution structural brain imaging and blood flow imaging were acquired on a 3.0-Tesla magnetic resonance imaging (MRI) scanner. Structural and functional changes between the POAG and control groups were analyzed. An analysis was carried out to identify correlations between structural and functional changes acquired in the previous analysis and the retinal nerve fiber layer (RNFL). Patients in the POAG group showed a significant (P < 0.001) volume increase in the midbrain, left brainstem, frontal gyrus, cerebellar vermis, left inferior parietal lobule, caudate nucleus, thalamus, precuneus, and Brodmann areas 7, 18, and 46. Moreover, significant (P < 0.001) BOLD signal changes were observed in the right supramarginal gyrus, frontal gyrus, superior frontal gyrus, left inferior parietal lobule, left cuneus, and left midcingulate area; many of these regions had high correlations with the RNFL. Patients with POAG undergo widespread and complex changes in cortical brain structure and blood flow. (ClinicalTrials.gov number: NCT02570867). PMID:28248867

  13. Supersize my brain: A cross-sectional voxel-based morphometry study on the association between self-reported dietary restraint and regional grey matter volumes.

    PubMed

    van der Laan, Laura N; Charbonnier, Lisette; Griffioen-Roose, Sanne; Kroese, Floor M; van Rijn, Inge; Smeets, Paul A M

    2016-05-01

    Restrained eaters do not eat less than their unrestrained counterparts. Proposed underlying mechanisms are that restrained eaters are more reward sensitive and that they have worse inhibitory control. Although fMRI studies assessed these mechanisms, it is unknown how brain anatomy relates to dietary restraint. Voxel-based morphometry was performed on anatomical scans from 155 normal-weight females to investigate how regional grey matter volume correlates with restraint. A positive correlation was found in several areas, including the parahippocampal gyrus, hippocampus, striatum and the amygdala (bilaterally, p<0.05, corrected). A negative correlation was found in several areas, including the inferior frontal gyrus, superior frontal gyrus, supplementary motor area, middle cingulate cortex and precentral gyrus (p<0.05, corrected). That higher restraint relates to higher grey matter volume in reward-related areas and lower grey matter volume in regions involved in inhibition, provides a neuroanatomical underpinning of theories relating restraint to increased reward sensitivity and reduced inhibitory capacity.

  14. Grey matter volume abnormalities in patients with bipolar I depressive disorder and unipolar depressive disorder: a voxel-based morphometry study.

    PubMed

    Cai, Yi; Liu, Jun; Zhang, Li; Liao, Mei; Zhang, Yan; Wang, Lifeng; Peng, Hongjun; He, Zhong; Li, Zexuan; Li, Weihui; Lu, Shaojia; Ding, Yuqiang; Li, Lingjiang

    2015-02-01

    Bipolar disorder and unipolar depressive disorder (UD) may be different in brain structure. In the present study, we performed voxel-based morphometry (VBM) to quantify the grey matter volumes in 23 patients with bipolar I depressive disorder (BP1) and 23 patients with UD, and 23 age-, gender-, and education-matched healthy controls (HCs) using magnetic resonance imaging. We found that compared with the HC and UD groups, the BP1 group showed reduced grey matter volumes in the right inferior frontal gyrus and middle cingulate gyrus, while the UD group showed reduced volume in the right inferior frontal gyrus compared to HCs. In addition, correlation analyses revealed that the grey matter volumes of these regions were negatively correlated with the Hamilton depression rating scores. Taken together, the results of our study suggest that decreased grey matter volume of the right inferior frontal gyrus is a common abnormality in BP1 and UD, and decreased grey matter volume in the right middle cingulate gyrus may be specific to BP1.

  15. The Gray Matter Volume of the Amygdala Is Correlated with the Perception of Melodic Intervals: A Voxel-Based Morphometry Study

    PubMed Central

    Li, Xueting; Beuckelaer, Alain De; Guo, Jiahui; Ma, Feilong; Xu, Miao; Liu, Jia

    2014-01-01

    Music is not simply a series of organized pitches, rhythms, and timbres, it is capable of evoking emotions. In the present study, voxel-based morphometry (VBM) was employed to explore the neural basis that may link music to emotion. To do this, we identified the neuroanatomical correlates of the ability to extract pitch interval size in a music segment (i.e., interval perception) in a large population of healthy young adults (N = 264). Behaviorally, we found that interval perception was correlated with daily emotional experiences, indicating the intrinsic link between music and emotion. Neurally, and as expected, we found that interval perception was positively correlated with the gray matter volume (GMV) of the bilateral temporal cortex. More important, a larger GMV of the bilateral amygdala was associated with better interval perception, suggesting that the amygdala, which is the neural substrate of emotional processing, is also involved in music processing. In sum, our study provides one of first neuroanatomical evidence on the association between the amygdala and music, which contributes to our understanding of exactly how music evokes emotional responses. PMID:24923421

  16. White matter volume in the brainstem and inferior parietal lobule is related to motor performance in children with autism spectrum disorder: A voxel-based morphometry study.

    PubMed

    Hanaie, Ryuzo; Mohri, Ikuko; Kagitani-Shimono, Kuriko; Tachibana, Masaya; Matsuzaki, Junko; Hirata, Ikuko; Nagatani, Fumiyo; Watanabe, Yoshiyuki; Fujita, Norihiko; Taniike, Masako

    2016-09-01

    Many studies have reported poor motor performance in autism spectrum disorder (ASD); however, the underlying brain mechanisms remain unclear. Recent neuroimaging studies have suggested that abnormalities of the white matter (WM) are related to the features of ASD. In this study, we used voxel-based morphometry (VBM) to investigate which WM regions correlate with motor performance in children with ASD, and whether the WM volume in those brain regions differed between children with ASD and typically developing (TD) children. The subjects included 19 children with ASD and 20 TD controls. Motor performance was assessed using the Movement Assessment Battery for Children 2 (M-ABC 2). Children with ASD showed poorer motor performance than did the controls. There was a significant positive correlation between the total test score on the M-ABC 2 and the volume of WM in the brainstem and WM adjacent to the left supramarginal gyrus (SMG). In addition, compared with the TD controls, children with ASD had a decreased volume of WM in the brainstem and adjacent to the left intraparietal sulcus, which is close to the SMG. These findings suggest that structural changes in the WM in the brainstem and left inferior parietal lobule may contribute to poor motor performance in children with ASD. Autism Res 2016, 9: 981-992. © 2016 International Society for Autism Research, Wiley Periodicals, Inc.

  17. Wavelet denoising in voxel-based parametric estimation of small animal PET images: a systematic evaluation of spatial constraints and noise reduction algorithms.

    PubMed

    Su, Yi; Shoghi, Kooresh I

    2008-11-07

    Voxel-based estimation of PET images, generally referred to as parametric imaging, can provide invaluable information about the heterogeneity of an imaging agent in a given tissue. Due to high level of noise in dynamic images, however, the estimated parametric image is often noisy and unreliable. Several approaches have been developed to address this challenge, including spatial noise reduction techniques, cluster analysis and spatial constrained weighted nonlinear least-square (SCWNLS) methods. In this study, we develop and test several noise reduction techniques combined with SCWNLS using simulated dynamic PET images. Both spatial smoothing filters and wavelet-based noise reduction techniques are investigated. In addition, 12 different parametric imaging methods are compared using simulated data. With the combination of noise reduction techniques and SCWNLS methods, more accurate parameter estimation can be achieved than with either of the two techniques alone. A less than 10% relative root-mean-square error is achieved with the combined approach in the simulation study. The wavelet denoising based approach is less sensitive to noise and provides more accurate parameter estimation at higher noise levels. Further evaluation of the proposed methods is performed using actual small animal PET datasets. We expect that the proposed method would be useful for cardiac, neurological and oncologic applications.

  18. Componential Network for the Recognition of Tool-Associated Actions: Evidence from Voxel-based Lesion-Symptom Mapping in Acute Stroke Patients.

    PubMed

    Martin, Markus; Dressing, Andrea; Bormann, Tobias; Schmidt, Charlotte S M; Kümmerer, Dorothee; Beume, Lena; Saur, Dorothee; Mader, Irina; Rijntjes, Michel; Kaller, Christoph P; Weiller, Cornelius

    2016-08-06

    The study aimed to elucidate areas involved in recognizing tool-associated actions, and to characterize the relationship between recognition and active performance of tool use.We performed voxel-based lesion-symptom mapping in a prospective cohort of 98 acute left-hemisphere ischemic stroke patients (68 male, age mean ± standard deviation, 65 ± 13 years; examination 4.4 ± 2 days post-stroke). In a video-based test, patients distinguished correct tool-related actions from actions with spatio-temporal (incorrect grip, kinematics, or tool orientation) or conceptual errors (incorrect tool-recipient matching, e.g., spreading jam on toast with a paintbrush). Moreover, spatio-temporal and conceptual errors were determined during actual tool use.Deficient spatio-temporal error discrimination followed lesions within a dorsal network in which the inferior parietal lobule (IPL) and the lateral temporal cortex (sLTC) were specifically relevant for assessing functional hand postures and kinematics, respectively. Conversely, impaired recognition of conceptual errors resulted from damage to ventral stream regions including anterior temporal lobe. Furthermore, LTC and IPL lesions impacted differently on action recognition and active tool use, respectively.In summary, recognition of tool-associated actions relies on a componential network. Our study particularly highlights the dissociable roles of LTC and IPL for the recognition of action kinematics and functional hand postures, respectively.

  19. Cerebral asymmetry and the effects of sex and handedness on brain structure: a voxel-based morphometric analysis of 465 normal adult human brains.

    PubMed

    Good, C D; Johnsrude, I; Ashburner, J; Henson, R N; Friston, K J; Frackowiak, R S

    2001-09-01

    We used voxel-based morphometry (VBM) to examine human brain asymmetry and the effects of sex and handedness on brain structure in 465 normal adults. We observed significant asymmetry of cerebral grey and white matter in the occipital, frontal, and temporal lobes (petalia), including Heschl's gyrus, planum temporale (PT) and the hippocampal formation. Males demonstrated increased leftward asymmetry within Heschl's gyrus and PT compared to females. There was no significant interaction between asymmetry and handedness and no main effect of handedness. There was a significant main effect of sex on brain morphology, even after accounting for the larger global volumes of grey and white matter in males. Females had increased grey matter volume adjacent to the depths of both central sulci and the left superior temporal sulcus, in right Heschl's gyrus and PT, in right inferior frontal and frontomarginal gyri and in the cingulate gyrus. Females had significantly increased grey matter concentration extensively and relatively symmetrically in the cortical mantle, parahippocampal gyri, and in the banks of the cingulate and calcarine sulci. Males had increased grey matter volume bilaterally in the mesial temporal lobes, entorhinal and perirhinal cortex, and in the anterior lobes of the cerebellum, but no regions of increased grey matter concentration.

  20. Gray matter atrophy in patients with Parkinson’s disease and those with mild cognitive impairment: a voxel-based morphometry study

    PubMed Central

    Zhang, Jing; Zhang, Yun-Ting; Hu, Wei-Dong; Li, Li; Liu, Guang-Yao; Bai, Yu-Ping

    2015-01-01

    Purpose: Mild cognitive impairment is common in Parkinson’s disease, but the underlying pathological mechanism has not been fully understood. To examine the gray matter changes in patients with Parkinson’s disease and those with mild cognitive impairment (MCI) using voxel based Morphometry (VBM). Methods: Magnetic resonance images were obtained from 35 patients with PD and 20 age and sex-matched healthy control subjects. In the PD group, 14 subjects had no MCI and 21 had MCI. MRI 3D structural images were acquired and analyzed by means of the optimized VBM procedure with Statistical Parametric Mapping (SPM5). Results: Widespread areas of cortical atrophy were found in patients with PD compared with normal controls (in both temporal, occipital, parietal, frontal lobes and right limbic lobes, posterior lobes of the cerebellum and left caudate nucleus). Gray matter reductions were found in bilateral fusiform gyrus and lingual gyrus, left anterior cingulate cortex and insula, and right superior temporal gyrus, orbitofrontal cortex, central gyrus and precuneus in patients with PD with MCI compared with normal controls. Inpatients with PD with MCI, areas of reduced gray matter were found in both precentral gyrus and middle temporal gyrus, right cuneus, precuneus, and orbitofrontal cortex, and left fusiform gyrus compared with those without MCI. Conclusions: These findings suggest that PD is associated with the gray matter atrophy in the neocortical areas, and that cognitive impairment in patients with PD may be associated with gray matter changes in the parieto-occipital association cortex, right orbitofrontal cortex, and middle temporal gyrus. PMID:26629027

  1. Voxel-Based Morphometry in Individuals at Genetic High Risk for Schizophrenia and Patients with Schizophrenia during Their First Episode of Psychosis

    PubMed Central

    Bai, Chuan; Zhou, Qian; Wei, Shengnan; Jiang, Xiaowei; Geng, Haiyang; Zhou, Yifang; Tang, Yanqing; Wang, Fei

    2016-01-01

    Background Understanding morphologic changes in vulnerable and early disease state of schizophrenia (SZ) may provide further insight into the development of psychosis. Method Whole brain voxel-based morphometry was performed to identify gray matter (GM) regional differences in 60 individuals with SZ during their first psychotic episode (FE-SZ), 31 individuals at genetic high risk for SZ (GHR-SZ) individuals, and 71 healthy controls. Results Significant differences were found in several regions including the prefrontal cortex, parietal lobe, temporal lobe, hippocampus, occipital lobe, and cerebellum among the three groups (p<0.05, corrected). Compared to the HC group, the FE-SZ group had significantly decreased GM volumes in several regions including the cerebellum, hippocampus, fusiform gyrus, lingual gyrus, supramarginal gyrus, and superior, middle, and inferior temporal gyri and significantly increased GM volumes in the middle frontal gyrus and inferior operculum frontal gyrus (p<0.05). The GHR-SZ group had significant decreases in GM volumes in the supramaginal gyrus, precentral gyrus, and rolandic operculum and significant increases in GM volumes in the cerebellum, fusiform gyrus, middle frontal gyrus, inferior operculum frontal gyrus, and superior, middle, and inferior temporal gyri when compared to the HC group (p<0.05). Compared to the GHR-SZ group, the FE-SZ group had significant decreases in GM volumes in several regions including the cerebellum, fusiform gyrus, supramarginal gyrus, and superior, middle, and inferior temporal gyri (p<0.05). Conclusions The findings herein implicate the involvement of multisensory integration in SZ development and pathophysiology. Additionally, the patterns of observed differences suggest possible indicators of disease, vulnerability, and resiliency in SZ. PMID:27723806

  2. Speech repetition as a window on the neurobiology of auditory-motor integration for speech: A voxel-based lesion symptom mapping study.

    PubMed

    Rogalsky, Corianne; Poppa, Tasha; Chen, Kuan-Hua; Anderson, Steven W; Damasio, Hanna; Love, Tracy; Hickok, Gregory

    2015-05-01

    For more than a century, speech repetition has been used as an assay for gauging the integrity of the auditory-motor pathway in aphasia, thought classically to involve a linkage between Wernicke's area and Broca's area via the arcuate fasciculus. During the last decade, evidence primarily from functional imaging in healthy individuals has refined this picture both computationally and anatomically, suggesting the existence of a cortical hub located at the parietal-temporal boundary (area Spt) that functions to integrate auditory and motor speech networks for both repetition and spontaneous speech production. While functional imaging research can pinpoint the regions activated in repetition/auditory-motor integration, lesion-based studies are needed to infer causal involvement. Previous lesion studies of repetition have yielded mixed results with respect to Spt's critical involvement in speech repetition. The present study used voxel-based lesion symptom mapping (VLSM) to investigate the neuroanatomy of repetition of both real words and non-words in a sample of 47 patients with focal left hemisphere brain damage. VLSMs identified a large voxel cluster spanning gray and white matter in the left temporal-parietal junction, including area Spt, where damage was significantly related to poor non-word repetition. Repetition of real words implicated a very similar dorsal network including area Spt. Cortical regions including Spt were implicated in repetition performance even when white matter damage was factored out. In addition, removing variance associated with speech perception abilities did not alter the overall lesion pattern for either task. Together with past functional imaging work, our results suggest that area Spt is integral in both word and non-word repetition, that its contribution is above and beyond that made by white matter pathways, and is not driven by perceptual processes alone. These findings are highly consistent with the claim that Spt is an area of

  3. White and Gray Matter Volume Changes and Correlation with Visual Evoked Potential in Patients with Optic Neuritis: A Voxel-Based Morphometry Study

    PubMed Central

    Huang, Xin; Zhang, Qiang; Hu, Pei-Hong; Zhong, Yu-Lin; Zhang, Ying; Wei, Rong; Xu, Ting-Ting; Shao, Yi

    2016-01-01

    Background The aim of this study was to investigate potential morphological alterations of gray and white matter in patients with optic neuritis (ON) and their relationship with behavioral performance, using voxel-based morphometry (VBM). Material/Methods Twelve (4 males, 8 females) patients with ON and 12 (4 males, 8 females) age-, sex-, and education-matched healthy controls (HCs) underwent magnetic resonance imaging (MRI). Imaging data were analyzed using two-sample t tests to identify group differences in gray and white matter volume (GMV, WMV). Correlation analysis was used to explore relationships between observed GMV and WMV of different areas and visual evoked potential (VEP) in ON. Results Compared with HCs, ON patients had: significantly decreased GMV in the left postcentral gyrus, left inferior frontal gyrus, left anterior cingulate, left and right middle frontal gyrus, and right inferior parietal lobule; decreased WMV in the left middle frontal gyrus, right superior frontal gyrus, left precentral gyrus and right inferior parietal lobule; and increased WMV in the left fusiform gyrus and left inferior parietal lobule. VEP latency of the right eye in ON correlated positively with WMV signal value of the left fusiform gyrus (r=0.726, p=0.008), and negatively with GMV signal value of the right inferior parietal lobule (r=−0.611, p=0.035). Duration of ON correlated negatively with WMV signal value of the right superior frontal gyrus (r=−0.662, p=0.019), while best-corrected visual acuity (VA) of the right eye correlated negatively with WMV signal value of the left middle frontal gyrus (r=−0.704, p=0.011). Conclusions These results suggest significant brain involvement in ON, which may reflect the underlying pathologic mechanism. Correlational results demonstrate that VEP in ON is closely associated with WMV and GMV atrophy in many brain regions. PMID:27045330

  4. Brain changes in children and adolescents with obsessive-compulsive disorder before and after treatment: a voxel-based morphometric MRI study.

    PubMed

    Lázaro, Luisa; Bargalló, Nuria; Castro-Fornieles, Josefina; Falcón, Carles; Andrés, Susana; Calvo, Rosa; Junqué, Carme

    2009-05-15

    The aim of this study is to determine whether children and adolescents with treatment-naïve obsessive-compulsive disorder (OCD) present brain structure differences in comparison with healthy subjects, and to evaluate brain changes after treatment and clinical improvement. Initial and 6 months' follow-up evaluations were performed in 15 children and adolescents (age range=9-17 years, mean=13.7, S.D.=2.5; 8 male, 7 female) with DSM-IV OCD and 15 healthy subjects matched for age, sex and estimated intellectual level. An evaluation with psychopathological scales and magnetic resonance imaging (MRI) was carried out at admission and after 6 months' follow-up. Axial three-dimensional T1-weighted images were obtained in a 1.5 T scanner and analysed using optimized voxel-based morphometry (VBM) and longitudinal VBM approaches. Compared with controls, OCD patients presented significantly less gray matter volume bilaterally in right and left parietal lobes and right parietal white matter (P=0.001 FWE corrected) at baseline evaluation. After 6 months of treatment, and with a clear clinical improvement, the differences between OCD patients and controls in the parietal lobes in gray and white matter were no longer statistically significant. During follow-up in the longitudinal study, an increase in gray matter volume in the right striatum of OCD patients was observed, though the difference was not statistically significant. Children and adolescents with untreated OCD present gray and white matter decreases in lateral parietal cortices, but this abnormality is reversible after clinical improvement.

  5. Brain Tissue Volumes and Perfusion Change with the Number of Optic Neuritis Attacks in Relapsing Neuromyelitis Optica: A Voxel-Based Correlation Study.

    PubMed

    Sánchez-Catasús, Carlos A; Cabrera-Gomez, José; Almaguer Melián, William; Giroud Benítez, José Luis; Rodríguez Rojas, Rafael; Bayard, Jorge Bosch; Galán, Lídice; Sánchez, Reinaldo Galvizu; Fuentes, Nancy Pavón; Valdes-Sosa, Pedro

    2013-01-01

    Recent neuroimaging studies show that brain abnormalities in neuromyelitis optica (NMO) are more frequent than earlier described. Yet, more research considering multiple aspects of NMO is necessary to better understand these abnormalities. A clinical feature of relapsing NMO (RNMO) is that the incremental disability is attack-related. Therefore, association between the attack-related process and neuroimaging might be expected. On the other hand, the immunopathological analysis of NMO lesions has suggested that CNS microvasculature could be an early disease target, which could alter brain perfusion. Brain tissue volume changes accompanying perfusion alteration could also be expected throughout the attack-related process. The aim of this study was to investigate in RNMO patients, by voxel-based correlation analysis, the assumed associations between regional brain white (WMV) and grey matter volumes (GMV) and/or perfusion on one side, and the number of optic neuritis (ON) attacks, myelitis attacks and/or total attacks on the other side. For this purpose, high resolution T1-weighted MRI and perfusion SPECT imaging were obtained in 15 RNMO patients. The results showed negative regional correlations of WMV, GMV and perfusion with the number of ON attacks, involving important components of the visual system, which could be relevant for the comprehension of incremental visual disability in RNMO. We also found positive regional correlation of perfusion with the number of ON attacks, mostly overlapping the brain area where the WMV showed negative correlation. This provides evidence that brain microvasculature is an early disease target and suggests that perfusion alteration could be important in the development of brain structural abnormalities in RNMO.

  6. Behavioral impulsivity mediates the relationship between decreased frontal gray matter volume and harmful alcohol drinking: A voxel-based morphometry study.

    PubMed

    Gröpper, Sonja; Spengler, Stephanie; Stuke, Heiner; Gawron, Christiane K; Parnack, Jenny; Gutwinski, Stefan; Wiers, Corinde E; Bermpohl, Felix

    2016-12-01

    Alcohol use disorder (AUD) with harmful drinking patterns is on the one hand characterized by impulsive behavior and is on the other hand known to involve structural brain alterations with lower gray matter volume (GMV), especially in the prefrontal cortex (PFC). So far it is unclear whether frontal brain volumes are associated to harmful alcohol drinking and impulsivity, while controlling simultaneously for a wide array of important confounding factors, which are related to alcohol consumption. We used voxel-based morphometry in 99 adults ranging within a continuum of normal to harmful drinking behavior and alcohol dependence, measured by the 'Alcohol Use Disorders Identification Test', to examine whether the severity of harmful drinking is correlated with structural markers, in particular in the PFC and whether such markers are linked to self-reported impulsivity. We included alcohol and nicotine lifetime exposure, age, education, and BMI as covariates to control that GMV decreases were not related to those factors. Harmful drinking was associated with lower GMV in the right frontal pole, left inferior frontal gyrus, and bilateral inferior parietal lobe. GMV loss in the PFC regions was correlated with increased impulsivity. Follow-up mediation analyses showed that the relationship between GMV in the frontal pole and harmful drinking was mediated by impulsivity. Our findings show that PFC reductions are associated with harmful drinking and impulsivity. Our data suggest that reduced frontal pole GM, independent of a number of alcohol drinking associated covariates, e.g. lifetime alcohol consumption, is related to impaired top-down control of alcohol drinking behavior.

  7. Using Voxel-Based Morphometry to Examine the Relationship between Regional Brain Volumes and Memory Performance in Amnestic Mild Cognitive Impairment.

    PubMed

    Meyer, Patric; Feldkamp, Hanna; Hoppstädter, Michael; King, Andrea V; Frölich, Lutz; Wessa, Michèle; Flor, Herta

    2013-01-01

    Alzheimer's disease (AD) is a slowly progressive neurodegenerative disorder, in which morphological alterations of brain tissue develop many years before the first neuropsychological and clinical changes occur. Among the first and most prominent symptoms are deficiencies of declarative memory functions. This stage of precursory symptoms to AD has been described as amnestic mild cognitive impairment (aMCI) and is discussed as a potential AD prodrome. As therapy in the later stages of AD has been shown to be of limited impact, aMCI would be the key target for early intervention. For that purpose a comprehensive neuropsychological and anatomical characterization of this group is necessary. Previous neuropsychological investigations identified tests which are highly sensitive in diagnosing aMCI and very early AD. However, the sensitivity of those neuropsychological tests to the particular structural neuropathology in aMCI remains to be specified. To this end, we investigated 25 patients with single-domain aMCI. All participants underwent extensive neuropsychological testing and anatomical scanning with structural magnetic resonance imaging. Voxel-based morphometry (VBM) was performed to identify brain regions that show a significant correlation between regional brain volume and behavioral measures of memory and executive functioning. We found that performance in a variety of mnemonic tests was directly related to the integrity of the medial temporal lobe cortex (MTLC). Moreover, impairment of memory sub-functions in aMCI might be detected earlier than overt structural damage. By this, these findings contribute to the identification of cerebral structures associated with memory deficits in aMCI.

  8. Neuroanatomical differences in brain areas implicated in perceptual and other core features of autism revealed by cortical thickness analysis and voxel-based morphometry.

    PubMed

    Hyde, Krista L; Samson, Fabienne; Evans, Alan C; Mottron, Laurent

    2010-04-01

    Autism spectrum disorder is a complex neurodevelopmental variant thought to affect 1 in 166 [Fombonne (2003): J Autism Dev Disord 33:365-382]. Individuals with autism demonstrate atypical social interaction, communication, and repetitive behaviors, but can also present enhanced abilities, particularly in auditory and visual perception and nonverbal reasoning. Structural brain differences have been reported in autism, in terms of increased total brain volume (particularly in young children with autism), and regional gray/white matter differences in both adults and children with autism, but the reports are inconsistent [Amaral et al. (2008): Trends Neurosci 31:137-145]. These inconsistencies may be due to differences in diagnostic/inclusion criteria, and age and Intelligence Quotient of participants. Here, for the first time, we used two complementary magnetic resonance imaging techniques, cortical thickness analyses, and voxel-based morphometry (VBM), to investigate the neuroanatomical differences between a homogenous group of young adults with autism of average intelligence but delayed or atypical language development (often referred to as "high-functioning autism"), relative to a closely matched group of typically developing controls. The cortical thickness and VBM techniques both revealed regional structural brain differences (mostly in terms of gray matter increases) in brain areas implicated in social cognition, communication, and repetitive behaviors, and thus in each of the core atypical features of autism. Gray matter increases were also found in auditory and visual primary and associative perceptual areas. We interpret these results as the first structural brain correlates of atypical auditory and visual perception in autism, in support of the enhanced perceptual functioning model [Mottron et al. (2006): J Autism Dev Disord 36:27-43].

  9. A voxel-based analysis of FDG-PET in traumatic brain injury: regional metabolism and relationship between the thalamus and cortical areas.

    PubMed

    García-Panach, Javier; Lull, Nuria; Lull, Juan José; Ferri, Joan; Martínez, Carlos; Sopena, Pablo; Robles, Montserrat; Chirivella, Javier; Noé, Enrique

    2011-09-01

    The objective was to study the correlations and the differences in glucose metabolism between the thalamus and cortical structures in a sample of severe traumatic brain injury (TBI) patients with different neurological outcomes. We studied 49 patients who had suffered a severe TBI and 10 healthy control subjects using 18F-fluorodeoxyglucose positron emission tomography (18F-FDG-PET). The patients were divided into three groups: a vegetative or minimally-conscious state (MCS&VS) group (n=17), which included patients who were in a vegetative or a minimally conscious state; an In-post-traumatic amnesia (In-PTA) group (n=12), which included patients in PTA; and an Out-PTA group (n=20), which included patients who had recovered from PTA. SPM5 software was used to determine the metabolic differences between the groups. FDG-PET images were normalized and four regions of interest were generated around the thalamus, precuneus, and the frontal and temporal lobes. The groups were parameterized using Student's t-test. Principal component analysis was used to obtain an intensity-estimated-value per subject to correlate the function between the structures. Differences in glucose metabolism in all structures were related to the neurological outcome, and the most severe patients showed the most severe hypometabolism. We also found a significant correlation between the cortico-thalamo-cortical metabolism in all groups. Voxel-based analysis suggests a functional correlation between these four areas, and decreased metabolism was associated with less favorable outcomes. Higher levels of activation of the cortico-cortical connections appear to be related to better neurological condition. Differences in the thalamo-cortical correlations between patients and controls may be related to traumatic dysfunction due to focal or diffuse lesions.

  10. Speech repetition as a window on the neurobiology of auditory-motor integration for speech: A voxel-based lesion symptom mapping study

    PubMed Central

    Rogalsky, Corianne; Poppa, Tasha; Chen, Kuan-Hua; Anderson, Steven W.; Damasio, Hanna; Love, Tracy; Hickok, Gregory

    2015-01-01

    For more than a century, speech repetition has been used as an assay for gauging the integrity of the auditory-motor pathway in aphasia, thought classically to involve a linkage between Wernicke’s area and Broca’s area via the arcuate fasciculus. During the last decade, evidence primarily from functional imaging in healthy individuals has refined this picture both computationally and anatomically, suggesting the existence of a cortical hub located at the parietal-temporal boundary (area Spt) that functions to integrate auditory and motor speech networks for both repetition and spontaneous speech production. While functional imaging research can pinpoint the regions activated in repetition/auditory-motor integration, lesion-based studies are needed to infer causal involvement. Previous lesion studies of repetition have yielded mixed results with respect to Spt’s critical involvement in speech repetition. The present study used voxel-based lesion symptom mapping (VLSM) to investigate the neuroanatomy of repetition of both real words and non-words in a sample of 47 patients with focal left hemisphere brain damage. VLSMs identified a large voxel cluster spanning gray and white matter in the left temporal-parietal junction, including area Spt, where damage was significantly related to poor non-word repetition. Repetition of real words implicated a very similar dorsal network including area Spt. Cortical regions including Spt were implicated in repetition performance even when white matter damage was factored out. In addition, removing variance associated with speech perception abilities did not alter the overall lesion pattern for either task. Together with past functional imaging work, our results suggest that area Spt is integral in both word and non-word repetition, that its contribution is above and beyond that made by white matter pathways, and is not driven by perceptual processes alone. These findings are highly consistent with the claim that Spt is an area

  11. Mapping the “What” and “Where” Visual Cortices and Their Atrophy in Alzheimer's Disease: Combined Activation Likelihood Estimation with Voxel-Based Morphometry

    PubMed Central

    Deng, Yanjia; Shi, Lin; Lei, Yi; Liang, Peipeng; Li, Kuncheng; Chu, Winnie C. W.; Wang, Defeng

    2016-01-01

    The human cortical regions for processing high-level visual (HLV) functions of different categories remain ambiguous, especially in terms of their conjunctions and specifications. Moreover, the neurobiology of declined HLV functions in patients with Alzheimer's disease (AD) has not been fully investigated. This study provides a functionally sorted overview of HLV cortices for processing “what” and “where” visual perceptions and it investigates their atrophy in AD and MCI patients. Based upon activation likelihood estimation (ALE), brain regions responsible for processing five categories of visual perceptions included in “what” and “where” visions (i.e., object, face, word, motion, and spatial visions) were analyzed, and subsequent contrast analyses were performed to show regions with conjunctive and specific activations for processing these visual functions. Next, based on the resulting ALE maps, the atrophy of HLV cortices in AD and MCI patients was evaluated using voxel-based morphometry. Our ALE results showed brain regions for processing visual perception across the five categories, as well as areas of conjunction and specification. Our comparisons of gray matter (GM) volume demonstrated atrophy of three “where” visual cortices in late MCI group and extensive atrophy of HLV cortices (25 regions in both “what” and “where” visual cortices) in AD group. In addition, the GM volume of atrophied visual cortices in AD and MCI subjects was found to be correlated to the deterioration of overall cognitive status and to the cognitive performances related to memory, execution, and object recognition functions. In summary, these findings may add to our understanding of HLV network organization and of the evolution of visual perceptual dysfunction in AD as the disease progresses. PMID:27445770

  12. Structural Changes Induced by Daily Music Listening in the Recovering Brain after Middle Cerebral Artery Stroke: A Voxel-Based Morphometry Study

    PubMed Central

    Särkämö, Teppo; Ripollés, Pablo; Vepsäläinen, Henna; Autti, Taina; Silvennoinen, Heli M.; Salli, Eero; Laitinen, Sari; Forsblom, Anita; Soinila, Seppo; Rodríguez-Fornells, Antoni

    2014-01-01

    Music is a highly complex and versatile stimulus for the brain that engages many temporal, frontal, parietal, cerebellar, and subcortical areas involved in auditory, cognitive, emotional, and motor processing. Regular musical activities have been shown to effectively enhance the structure and function of many brain areas, making music a potential tool also in neurological rehabilitation. In our previous randomized controlled study, we found that listening to music on a daily basis can improve cognitive recovery and improve mood after an acute middle cerebral artery stroke. Extending this study, a voxel-based morphometry (VBM) analysis utilizing cost function masking was performed on the acute and 6-month post-stroke stage structural magnetic resonance imaging data of the patients (n = 49) who either listened to their favorite music [music group (MG), n = 16] or verbal material [audio book group (ABG), n = 18] or did not receive any listening material [control group (CG), n = 15] during the 6-month recovery period. Although all groups showed significant gray matter volume (GMV) increases from the acute to the 6-month stage, there was a specific network of frontal areas [left and right superior frontal gyrus (SFG), right medial SFG] and limbic areas [left ventral/subgenual anterior cingulate cortex (SACC) and right ventral striatum (VS)] in patients with left hemisphere damage in which the GMV increases were larger in the MG than in the ABG and in the CG. Moreover, the GM reorganization in the frontal areas correlated with enhanced recovery of verbal memory, focused attention, and language skills, whereas the GM reorganization in the SACC correlated with reduced negative mood. This study adds on previous results, showing that music listening after stroke not only enhances behavioral recovery, but also induces fine-grained neuroanatomical changes in the recovering brain. PMID:24860466

  13. Self-regulation therapy increases frontal gray matter in children with fetal alcohol spectrum disorder: evaluation by voxel-based morphometry

    PubMed Central

    Soh, Debra W.; Skocic, Jovanka; Nash, Kelly; Stevens, Sara; Turner, Gary R.; Rovet, Joanne

    2015-01-01

    Children with fetal alcohol spectrum disorder show executive function (EF) deficits, particularly in self-regulation skills, and abnormalities in brain regions critical for these skills. None of the validated EF interventions for these children has been evaluated with regards to impacts on brain structure. Twenty-nine children with FASD were assigned to either an immediate-treatment (TX) or delayed-treatment control (DTC) group (DTC). Nineteen typically developing children served as healthy controls (CT). All received a structural MRI scan and baseline neuropsychological testing, following which the TX group underwent 12 weekly 1.5-h sessions of the Alert Program for Self-Regulation®. After treatment or a period of ~14 weeks, all received a repeat scan and post-intervention testing. Whole-brain and region-of-interest analyses using voxel-based morphometry evaluated group differences and changes over time in gray matter (GM). Exploratory analyses revealed significant group changes: (1) At baseline, combined TX and DTC groups demonstrated global GM reductions compared with the CT group. (2) Region-of-interest analysis using a frontal mask, comparing post-intervention to pre-intervention results, showed significantly increased GM in the left middle frontal gyrus (BA10), right frontal pole (BA11), and right anterior cingulate (BA32) in the TX group. Similar results were not found in the DTC or CT groups. (3) At post-intervention, both TX and CT groups showed larger GM volumes than the DTC group in the left superior frontal gyrus (BA9), which was smaller in the FASD group at baseline. These results suggested that Alert led to improvements in post-intervention testing of self-regulation skills and typical brain development in treated children. PMID:25788884

  14. Common and distinct patterns of grey-matter volume alteration in major depression and bipolar disorder: evidence from voxel-based meta-analysis.

    PubMed

    Wise, T; Radua, J; Via, E; Cardoner, N; Abe, O; Adams, T M; Amico, F; Cheng, Y; Cole, J H; de Azevedo Marques Périco, C; Dickstein, D P; Farrow, T F D; Frodl, T; Wagner, G; Gotlib, I H; Gruber, O; Ham, B J; Job, D E; Kempton, M J; Kim, M J; Koolschijn, P C M P; Malhi, G S; Mataix-Cols, D; McIntosh, A M; Nugent, A C; O'Brien, J T; Pezzoli, S; Phillips, M L; Sachdev, P S; Salvadore, G; Selvaraj, S; Stanfield, A C; Thomas, A J; van Tol, M J; van der Wee, N J A; Veltman, D J; Young, A H; Fu, C H; Cleare, A J; Arnone, D

    2016-05-24

    Finding robust brain substrates of mood disorders is an important target for research. The degree to which major depression (MDD) and bipolar disorder (BD) are associated with common and/or distinct patterns of volumetric changes is nevertheless unclear. Furthermore, the extant literature is heterogeneous with respect to the nature of these changes. We report a meta-analysis of voxel-based morphometry (VBM) studies in MDD and BD. We identified studies published up to January 2015 that compared grey matter in MDD (50 data sets including 4101 individuals) and BD (36 data sets including 2407 individuals) using whole-brain VBM. We used statistical maps from the studies included where available and reported peak coordinates otherwise. Group comparisons and conjunction analyses identified regions in which the disorders showed common and distinct patterns of volumetric alteration. Both disorders were associated with lower grey-matter volume relative to healthy individuals in a number of areas. Conjunction analysis showed smaller volumes in both disorders in clusters in the dorsomedial and ventromedial prefrontal cortex, including the anterior cingulate cortex and bilateral insula. Group comparisons indicated that findings of smaller grey-matter volumes relative to controls in the right dorsolateral prefrontal cortex and left hippocampus, along with cerebellar, temporal and parietal regions were more substantial in major depression. These results suggest that MDD and BD are characterised by both common and distinct patterns of grey-matter volume changes. This combination of differences and similarities has the potential to inform the development of diagnostic biomarkers for these conditions.Molecular Psychiatry advance online publication, 24 May 2016; doi:10.1038/mp.2016.72.

  15. How reliable are gray matter disruptions in specific reading disability across multiple countries and languages? Insights from a large-scale voxel-based morphometry study.

    PubMed

    Jednoróg, Katarzyna; Marchewka, Artur; Altarelli, Irene; Monzalvo Lopez, Ana Karla; van Ermingen-Marbach, Muna; Grande, Marion; Grabowska, Anna; Heim, Stefan; Ramus, Franck

    2015-05-01

    The neural basis of specific reading disability (SRD) remains only partly understood. A dozen studies have used voxel-based morphometry (VBM) to investigate gray matter volume (GMV) differences between SRD and control children, however, recent meta-analyses suggest that few regions are consistent across studies. We used data collected across three countries (France, Poland, and Germany) with the aim of both increasing sample size (236 SRD and controls) to obtain a clearer picture of group differences, and of further assessing the consistency of the findings across languages. VBM analysis reveals a significant group difference in a single cluster in the left thalamus. Furthermore, we observe correlations between reading accuracy and GMV in the left supramarginal gyrus and in the left cerebellum, in controls only. Most strikingly, we fail to replicate all the group differences in GMV reported in previous studies, despite the superior statistical power. The main limitation of this study is the heterogeneity of the sample drawn from different countries (i.e., speaking languages with varying orthographic transparencies) and selected based on different assessment batteries. Nevertheless, analyses within each country support the conclusions of the cross-linguistic analysis. Explanations for the discrepancy between the present and previous studies may include: (1) the limited suitability of VBM to reveal the subtle brain disruptions underlying SRD; (2) insufficient correction for multiple statistical tests and flexibility in data analysis, and (3) publication bias in favor of positive results. Thus the study echoes widespread concerns about the risk of false-positive results inherent to small-scale VBM studies.

  16. Association of creative achievement with cognitive flexibility by a combined voxel-based morphometry and resting-state functional connectivity study.

    PubMed

    Chen, Qunlin; Yang, Wenjing; Li, Wenfu; Wei, Dongtao; Li, Haijiang; Lei, Qiao; Zhang, Qinglin; Qiu, Jiang

    2014-11-15

    Although researchers generally concur that creativity involves the production of novel and useful products, the neural basis of creativity remains elusive due to the complexity of the cognitive processes involved. Recent studies have shown that highly creative individuals displayed more cognitive flexibility. However, direct evidence supporting the relationship between creativity and cognitive flexibility has rarely been investigated using both structural and functional neuroimaging techniques. We used a combined voxel-based morphometry and resting-state functional connectivity (rsFC) analysis to investigate the relationship between individual creativity ability assessed by the creative achievement questionnaire (CAQ), and regional gray matter volume (GMV), as well as intrinsic functional connectivity. Results showed that CAQ scores negatively correlated with GMV in the rostral anterior cingulate cortex (ACC) and the bilateral dorsal ACC (dACC) extending to supplementary motor area, but positively correlated with GMV in the bilateral superior frontal gyrus and ventral medial prefrontal cortex (vmPFC). Further functional connectivity analysis revealed that higher creative achievement was inversely associated with the strength of rsFC between the dACC and medial superior frontal gyrus (mSFG), right middle frontal gyrus, and left orbito-frontal insula. Moreover, the association between the dACC-mSFG connectivity and CAQ scores was mediated by cognitive flexibility, assessed by a task-switching paradigm. These findings indicate that individual differences in creative achievement are associated with both brain structure and corresponding intrinsic functional connectivity involved in cognitive flexibility and deliberate creative processing. Furthermore, dACC-mSFG connectivity may affect creative achievement through its impact on cognitive flexibility.

  17. A voxel-based morphometry (VBM) analysis of regional grey and white matter volume abnormalities within the speech production network of children who stutter.

    PubMed

    Beal, Deryk S; Gracco, Vincent L; Brettschneider, Jane; Kroll, Robert M; De Nil, Luc F

    2013-09-01

    It is well documented that neuroanatomical differences exist between adults who stutter and their fluently speaking peers. Specifically, adults who stutter have been found to have more grey matter volume (GMV) in speech relevant regions including inferior frontal gyrus, insula and superior temporal gyrus (Beal et al., 2007; Song et al., 2007). Despite stuttering having its onset in childhood only one study has investigated the neuroanatomical differences between children who do and do not stutter. Chang et al. (2008) reported children who stutter had less GMV in the bilateral inferior frontal gyri and middle temporal gyrus relative to fluently speaking children. Thus it appears that children who stutter present with unique neuroanatomical abnormalities as compared to those of adults who stutter. In order to better understand the neuroanatomical correlates of stuttering earlier in its development, near the time of onset, we used voxel-based morphometry to examine volumetric differences between 11 children who stutter and 11 fluent children. Children who stutter had less GMV in the bilateral inferior frontal gyri and left putamen but more GMV in right Rolandic operculum and superior temporal gyrus relative to fluent children. Children who stutter also had less white matter volume bilaterally in the forceps minor of the corpus callosum. We discuss our findings of widespread anatomic abnormalities throughout the cortical network for speech motor control within the context of the speech motor skill limitations identified in people who stutter (Namasivayam and van Lieshout, 2008; Smits-Bandstra et al., 2006).

  18. Including anatomical and functional information in MC simulation of PET and SPECT brain studies. Brain-VISET: a voxel-based iterative method.

    PubMed

    Marti-Fuster, Berta; Esteban, Oscar; Thielemans, Kris; Setoain, Xavier; Santos, Andres; Ros, Domenec; Pavia, Javier

    2014-10-01

    Monte Carlo (MC) simulation provides a flexible and robust framework to efficiently evaluate and optimize image processing methods in emission tomography. In this work we present Brain-VISET (Voxel-based Iterative Simulation for Emission Tomography), a method that aims to simulate realistic [ (99m) Tc]-SPECT and [ (18) F]-PET brain databases by including anatomical and functional information. To this end, activity and attenuation maps generated using high-resolution anatomical images from patients were used as input maps in a MC projector to simulate SPECT or PET sinograms. The reconstructed images were compared with the corresponding real SPECT or PET studies in an iterative process where the activity inputs maps were being modified at each iteration. Datasets of 30 refractory epileptic patients were used to assess the new method. Each set consisted of structural images (MRI and CT) and functional studies (SPECT and PET), thereby allowing the inclusion of anatomical and functional variability in the simulation input models. SPECT and PET sinograms were obtained using the SimSET package and were reconstructed with the same protocols as those employed for the clinical studies. The convergence of Brain-VISET was evaluated by studying the behavior throughout iterations of the correlation coefficient, the quotient image histogram and a ROI analysis comparing simulated with real studies. The realism of generated maps was also evaluated. Our findings show that Brain-VISET is able to generate realistic SPECT and PET studies and that four iterations is a suitable number of iterations to guarantee a good agreement between simulated and real studies.

  19. Effects of Omega-3 Fatty Acid Supplementation on Cognitive Functions and Neural Substrates: A Voxel-Based Morphometry Study in Aged Mice

    PubMed Central

    Cutuli, Debora; Pagani, Marco; Caporali, Paola; Galbusera, Alberto; Laricchiuta, Daniela; Foti, Francesca; Neri, Cristina; Spalletta, Gianfranco; Caltagirone, Carlo; Petrosini, Laura; Gozzi, Alessandro

    2016-01-01

    Human and experimental studies have revealed putative neuroprotective and pro-cognitive effects of omega-3 polyunsaturated fatty acids (n-3 PUFA) in aging, evidencing positive correlations between peripheral n-3 PUFA levels and regional grey matter (GM) volume, as well as negative correlations between dietary n-3 PUFA levels and cognitive deficits. We recently showed that n-3 PUFA supplemented aged mice exhibit better hippocampal-dependent mnesic functions, along with enhanced cellular plasticity and reduced neurodegeneration, thus supporting a role of n-3 PUFA supplementation in preventing cognitive decline during aging. To corroborate these initial results and develop new evidence on the effects of n-3 PUFA supplementation on brain substrates at macro-scale level, here we expanded behavioral analyses to the emotional domain (anxiety and coping skills), and carried out a fine-grained regional GM volumetric mapping by using high-resolution MRI-based voxel-based morphometry. The behavioral effects of 8 week n-3 PUFA supplementation were measured on cognitive (discriminative, spatial and social) and emotional (anxiety and coping) abilities of aged (19 month-old at the onset of study) C57B6/J mice. n-3 PUFA supplemented mice showed better mnesic performances as well as increased active coping skills. Importantly, these effects were associated with enlarged regional hippocampal, retrosplenial and prefrontal GM volumes, and with increased post mortem n-3 PUFA brain levels. These findings indicate that increased dietary n-3 PUFA intake in normal aging can improve fronto-hippocampal GM structure and function, an effect present also when the supplementation starts at late age. Our data are consistent with a protective role of n-3 PUFA supplementation in counteracting cognitive decline, emotional dysfunctions and brain atrophy. PMID:26973513

  20. Relationship between Clinical Parameters and Brain Structure in Sporadic Amyotrophic Lateral Sclerosis Patients According to Onset Type: A Voxel-Based Morphometric Study

    PubMed Central

    de Leon, Mony; Wang, Xiuyuan; Kim, Hyun Young; Lee, Young-Jun; Kim, Yeon-Ha; Kim, Seung Hyun

    2017-01-01

    Background and purpose Amyotrophic lateral sclerosis (ALS) is a rapidly progressing, phenotypically heterogeneous neurodegenerative disease affecting mainly the motor neuron system. The present voxel-based morphometry (VBM) study investigated whether patterns of brain atrophy differ among sporadic ALS subtypes. Material and methods Sporadic ALS patients (n = 62) with normal cognition and age-matched healthy controls (n = 57) were included in the study. ALS patients were divided into limb- and bulbar-onset groups according to clinical manifestations at symptom onset (n = 48 and 14, respectively). Clinical measures were ALS Functional Rating Scale-Revised (ALSFRS-R) score, disease duration, and forced vital capacity (FVC). Patterns of brain atrophy between ALS subgroups were compared by VBM. Results In limb-onset ALS patients, atrophy was largely confined to the motor cortex and adjacent pre- and postcentral regions. However, in the bulbar-onset group, affected regions were more widespread and included these same areas but also extended to the bilateral frontotemporal and left superior temporal and supramarginal gyri, and multiple regression analysis revealed that their ALSFRS-R scores were associated with extensive loss of gray matter while FVC was related to atrophy in subcortical regions of the left superior temporal gyrus. In limb-onset ALS patients, disease duration was related to the degree of atrophy in the motor and adjacent areas. Conclusion Sporadic ALS subtypes show different patterns of brain atrophy. Neural networks related to limb and bulbar motor functions in each ALS subtype may underlie their distinct patterns of cerebral atrophy. That is, more extensive cortical and subcortical atrophy is correlated with greater ALSFRS-R severity and shorter disease duration in the bulbar-onset subtype and may explain the poor prognosis of these patients. PMID:28095425

  1. When the Single Matters more than the Group (II): Addressing the Problem of High False Positive Rates in Single Case Voxel Based Morphometry Using Non-parametric Statistics.

    PubMed

    Scarpazza, Cristina; Nichols, Thomas E; Seramondi, Donato; Maumet, Camille; Sartori, Giuseppe; Mechelli, Andrea

    2016-01-01

    In recent years, an increasing number of studies have used Voxel Based Morphometry (VBM) to compare a single patient with a psychiatric or neurological condition of interest against a group of healthy controls. However, the validity of this approach critically relies on the assumption that the single patient is drawn from a hypothetical population with a normal distribution and variance equal to that of the control group. In a previous investigation, we demonstrated that family-wise false positive error rate (i.e., the proportion of statistical comparisons yielding at least one false positive) in single case VBM are much higher than expected (Scarpazza et al., 2013). Here, we examine whether the use of non-parametric statistics, which does not rely on the assumptions of normal distribution and equal variance, would enable the investigation of single subjects with good control of false positive risk. We empirically estimated false positive rates (FPRs) in single case non-parametric VBM, by performing 400 statistical comparisons between a single disease-free individual and a group of 100 disease-free controls. The impact of smoothing (4, 8, and 12 mm) and type of pre-processing (Modulated, Unmodulated) was also examined, as these factors have been found to influence FPRs in previous investigations using parametric statistics. The 400 statistical comparisons were repeated using two independent, freely available data sets in order to maximize the generalizability of the results. We found that the family-wise error rate was 5% for increases and 3.6% for decreases in one data set; and 5.6% for increases and 6.3% for decreases in the other data set (5% nominal). Further, these results were not dependent on the level of smoothing and modulation. Therefore, the present study provides empirical evidence that single case VBM studies with non-parametric statistics are not susceptible to high false positive rates. The critical implication of this finding is that VBM can be used

  2. Impact of brain tumour location on emotion and personality: a voxel-based lesion-symptom mapping study on mentalization processes.

    PubMed

    Campanella, Fabio; Shallice, Tim; Ius, Tamara; Fabbro, Franco; Skrap, Miran

    2014-09-01

    Patients affected by brain tumours may show behavioural and emotional regulation deficits, sometimes showing flattened affect and sometimes experiencing a true 'change' in personality. However, little evidence is available to the surgeon as to what changes are likely to occur with damage at specific sites, as previous studies have either relied on single cases or provided only limited anatomical specificity, mostly reporting associations rather than dissociations of symptoms. We investigated these aspects in patients undergoing surgery for the removal of cerebral tumours. We argued that many of the problems described can be ascribed to the onset of difficulties in one or more of the different levels of the process of mentalizing (i.e. abstracting and reflecting upon) emotion and intentions, which impacts on everyday behaviour. These were investigated in terms of (i) emotion recognition; (ii) Theory of Mind; (iii) alexithymia; and (iv) self-maturity (personality disorder). We hypothesized that temporo/limbic areas would be critical for processing emotion and intentions at a more perceptual level, while frontal lobe structures would be more critical when higher levels of mentalization/abstraction are required. We administered four different tasks, Task 1: emotion recognition of Ekman faces; Task 2: the Eyes Test (Theory of Mind); Task 3: Toronto Alexithymia Scale; and Task 4: Temperament and Character Inventory (a personality inventory), both immediately before and few days after the operation for the removal of brain tumours in a series of 71 patients (age range: 18-75 years; 33 female) with lesions located in the left or right frontal, temporal and parietal lobes. Lobe-based and voxel-based analysis confirmed that tasks requiring interpretation of emotions and intentions at more basic (less mentalized) levels (Tasks 1 and 2) were more affected by temporo/insular lesions, with emotion recognition (Task 1) being maximally impaired by anterior temporal and amygdala

  3. Small-world and scale-free organization of voxel-based resting-state functional connectivity in the human brain.

    PubMed

    van den Heuvel, M P; Stam, C J; Boersma, M; Hulshoff Pol, H E

    2008-11-15

    The brain is a complex dynamic system of functionally connected regions. Graph theory has been successfully used to describe the organization of such dynamic systems. Recent resting-state fMRI studies have suggested that inter-regional functional connectivity shows a small-world topology, indicating an organization of the brain in highly clustered sub-networks, combined with a high level of global connectivity. In addition, a few studies have investigated a possible scale-free topology of the human brain, but the results of these studies have been inconclusive. These studies have mainly focused on inter-regional connectivity, representing the brain as a network of brain regions, requiring an arbitrary definition of such regions. However, using a voxel-wise approach allows for the model-free examination of both inter-regional as well as intra-regional connectivity and might reveal new information on network organization. Especially, a voxel-based study could give information about a possible scale-free organization of functional connectivity in the human brain. Resting-state 3 Tesla fMRI recordings of 28 healthy subjects were acquired and individual connectivity graphs were formed out of all cortical and sub-cortical voxels with connections reflecting inter-voxel functional connectivity. Graph characteristics from these connectivity networks were computed. The clustering-coefficient of these networks turned out to be much higher than the clustering-coefficient of comparable random graphs, together with a short average path length, indicating a small-world organization. Furthermore, the connectivity distribution of the number of inter-voxel connections followed a power-law scaling with an exponent close to 2, suggesting a scale-free network topology. Our findings suggest a combined small-world and scale-free organization of the functionally connected human brain. The results are interpreted as evidence for a highly efficient organization of the functionally connected

  4. Design, fabrication, and implementation of voxel-based 3D printed textured phantoms for task-based image quality assessment in CT

    NASA Astrophysics Data System (ADS)

    Solomon, Justin; Ba, Alexandre; Diao, Andrew; Lo, Joseph; Bier, Elianna; Bochud, François; Gehm, Michael; Samei, Ehsan

    2016-03-01

    In x-ray computed tomography (CT), task-based image quality studies are typically performed using uniform background phantoms with low-contrast signals. Such studies may have limited clinical relevancy for modern non-linear CT systems due to possible influence of background texture on image quality. The purpose of this study was to design and implement anatomically informed textured phantoms for task-based assessment of low-contrast detection. Liver volumes were segmented from 23 abdominal CT cases. The volumes were characterized in terms of texture features from gray-level co-occurrence and run-length matrices. Using a 3D clustered lumpy background (CLB) model, a fitting technique based on a genetic optimization algorithm was used to find the CLB parameters that were most reflective of the liver textures, accounting for CT system factors of spatial blurring and noise. With the modeled background texture as a guide, a cylinder phantom (165 mm in diameter and 30 mm height) was designed, containing 20 low-contrast spherical signals (6 mm in diameter at targeted contrast levels of ~3.2, 5.2, 7.2, 10, and 14 HU, 4 repeats per signal). The phantom was voxelized and input into a commercial multi-material 3D printer (Object Connex 350), with custom software for voxel-based printing. Using principles of digital half-toning and dithering, the 3D printer was programmed to distribute two base materials (VeroWhite and TangoPlus, nominal voxel size of 42x84x30 microns) to achieve the targeted spatial distribution of x-ray attenuation properties. The phantom was used for task-based image quality assessment of a clinically available iterative reconstruction algorithm (Sinogram Affirmed Iterative Reconstruction, SAFIRE) using a channelized Hotelling observer paradigm. Images of the textured phantom and a corresponding uniform phantom were acquired at six dose levels and observer model performance was estimated for each condition (5 contrasts x 6 doses x 2 reconstructions x 2

  5. Impact of cerebellar atrophy on cortical gray matter and cerebellar peduncles as assessed by voxel-based morphometry and high angular resolution diffusion imaging

    PubMed Central

    Dayan, Michael; Olivito, Giusy; Molinari, Marco; Cercignani, Mara; Bozzali, Marco; Leggio, Maria

    2016-01-01

    Summary In recent years the cerebellum has been attributed a more important role in higher-level functions than previously believed. We examined a cohort of patients suffering from cerebellar atrophy resulting in ataxia, with two main objectives: first to investigate which regions of the cerebrum were affected by the cerebellar degeneration, and second to assess whether diffusion magnetic resonance imaging (dMRI) metrics within the medial (MCP) and superior cerebellar peduncle (SCP) – namely fractional anisotropy (FA) and radial diffusivity (RD) – could be used as a biomarker in patients with this condition. Structural and dMRI data of seven patients with cerebellar atrophy (2 with spinocerebellar atrophy type 2, 1 with Friedreich’s ataxia, 4 with idiopathic cerebellar ataxia) and no visible cortical lesions or cortical atrophy were investigated with Freesurfer and voxel-based morphometry (VBM) of gray matter (GM) as well as MCP and SCP FA maps. Correlations of MCP and SCP mean FA with ataxia scores and subscores were also evaluated. Freesurfer showed that patients had significantly reduced volume of the thalamus, ventral diencephalon and pallidum. VBM also demonstrated significantly lower local GM volumes in patients, notably in the head of the caudate nucleus, posterior cingulate gyrus and orbitofrontal cortex bilaterally, as well as in Broca’s area in the left hemisphere, and a significant increase in RD in the MCP and SCP of both hemispheres. A significant correlation was found between MCP mean FA and total ataxia score (R=−0.7, p=0.03), and subscores for kinetic functions (R=−0.74, p=0.03) and oculomotor disorders (R=−0.70, p=0.04). The regions of the cerebrum found to have significantly lower local GM volumes have been described to be involved in higher-level cerebellar functions such as initiation of voluntary movements, emotional control, memory retrieval and general cognition. Our findings corroborate recent research pointing to a more

  6. Simplified Explosive Joining of Tubes to Fittings

    NASA Technical Reports Server (NTRS)

    Bement, L. J.; Bailey, J. W.; Perry, R.; Finch, M. S.

    1987-01-01

    Technique simplifies tube-to-fitting joining, as compared to fusion welding, and provides improvement on standard procedures used to join tubes explosively to tube fittings. Special tool inserted into tube to be joined. Tool allows strip of ribbon explosive to be placed right at joint. Ribbon explosive and mild detonating fuse allows use of smaller charge. Assembled tool storable, and process amenable to automation. Assembly of components, insertion of tool into weld site, and joining operation mechanized without human contact. Used to assemble components in nuclear reactors or in other environments hostile to humans.

  7. Systematic review automation technologies.

    PubMed

    Tsafnat, Guy; Glasziou, Paul; Choong, Miew Keen; Dunn, Adam; Galgani, Filippo; Coiera, Enrico

    2014-07-09

    Systematic reviews, a cornerstone of evidence-based medicine, are not produced quickly enough to support clinical practice. The cost of production, availability of the requisite expertise and timeliness are often quoted as major contributors for the delay. This detailed survey of the state of the art of information systems designed to support or automate individual tasks in the systematic review, and in particular systematic reviews of randomized controlled clinical trials, reveals trends that see the convergence of several parallel research projects.We surveyed literature describing informatics systems that support or automate the processes of systematic review or each of the tasks of the systematic review. Several projects focus on automating, simplifying and/or streamlining specific tasks of the systematic review. Some tasks are already fully automated while others are still largely manual. In this review, we describe each task and the effect that its automation would have on the entire systematic review process, summarize the existing information system support for each task, and highlight where further research is needed for realizing automation for the task. Integration of the systems that automate systematic review tasks may lead to a revised systematic review workflow. We envisage the optimized workflow will lead to system in which each systematic review is described as a computer program that automatically retrieves relevant trials, appraises them, extracts and synthesizes data, evaluates the risk of bias, performs meta-analysis calculations, and produces a report in real time.

  8. Systematic review automation technologies

    PubMed Central

    2014-01-01

    Systematic reviews, a cornerstone of evidence-based medicine, are not produced quickly enough to support clinical practice. The cost of production, availability of the requisite expertise and timeliness are often quoted as major contributors for the delay. This detailed survey of the state of the art of information systems designed to support or automate individual tasks in the systematic review, and in particular systematic reviews of randomized controlled clinical trials, reveals trends that see the convergence of several parallel research projects. We surveyed literature describing informatics systems that support or automate the processes of systematic review or each of the tasks of the systematic review. Several projects focus on automating, simplifying and/or streamlining specific tasks of the systematic review. Some tasks are already fully automated while others are still largely manual. In this review, we describe each task and the effect that its automation would have on the entire systematic review process, summarize the existing information system support for each task, and highlight where further research is needed for realizing automation for the task. Integration of the systems that automate systematic review tasks may lead to a revised systematic review workflow. We envisage the optimized workflow will lead to system in which each systematic review is described as a computer program that automatically retrieves relevant trials, appraises them, extracts and synthesizes data, evaluates the risk of bias, performs meta-analysis calculations, and produces a report in real time. PMID:25005128

  9. Principal component analysis-T1ρ voxel based relaxometry of the articular cartilage: a comparison of biochemical patterns in osteoarthritis and anterior cruciate ligament subjects

    PubMed Central

    Russell, Colin; Randolph, Allison; Li, Xiaojuan; Majumdar, Sharmila

    2016-01-01

    Background Quantitative MR, including T1ρ mapping, has been extensively used to probe early biochemical changes in knee articular cartilage of subjects with osteoarthritis (OA) and others at risk for cartilage degeneration, such as those with anterior cruciate ligament (ACL) injury and reconstruction. However, limited studies have been performed aimed to assess the spatial location and patterns of T1ρ. In this study we used a novel voxel-based relaxometry (VBR) technique coupled with principal component analysis (PCA) to extract relevant features so as to describe regional patterns and to investigate their similarities and differences in T1ρ maps in subjects with OA and subjects six months after ACL reconstruction (ACLR). Methods T1ρ quantitative MRI images were collected for 180 subjects from two separate cohorts. The OA cohort included 93 osteoarthritic patients and 25 age-matched controls. The ACLR-6M cohort included 52 patients with unilateral ACL tears who were imaged 6 months after ACL reconstruction, and 10 age-matched controls. Non-rigid registration on a single template and local Z-score conversion were adopted for T1ρ spatial and intensity normalization of all the images in the dataset. PCA was used as a data dimensionality reduction to obtain a description of all subjects in a 10-dimensional feature space. Logistic linear regression was used to identify distinctive features of OA and ACL subjects Results Global prolongation of the Z-score was observed in both OA and ACL subjects compared to controls [higher values in 1st principal component (PC1); P=0.01]. In addition, relaxation time differences between superficial and deep cartilage layers of the lateral tibia and trochlea were observed to be significant distinctive features between OA and ACL subjects. OA subjects demonstrated similar values between the two cartilage layers [higher value in 2nd principal component (PC2); P=0.008], while ACL reconstructed subjects showed T1ρ prolongation

  10. Simplified Vicarious Radiometric Calibration

    NASA Technical Reports Server (NTRS)

    Stanley, Thomas; Ryan, Robert; Holekamp, Kara; Pagnutti, Mary

    2010-01-01

    A measurement-based radiance estimation approach for vicarious radiometric calibration of spaceborne multispectral remote sensing systems has been developed. This simplified process eliminates the use of radiative transfer codes and reduces the number of atmospheric assumptions required to perform sensor calibrations. Like prior approaches, the simplified method involves the collection of ground truth data coincident with the overpass of the remote sensing system being calibrated, but this approach differs from the prior techniques in both the nature of the data collected and the manner in which the data are processed. In traditional vicarious radiometric calibration, ground truth data are gathered using ground-viewing spectroradiometers and one or more sun photometer( s), among other instruments, located at a ground target area. The measured data from the ground-based instruments are used in radiative transfer models to estimate the top-of-atmosphere (TOA) target radiances at the time of satellite overpass. These TOA radiances are compared with the satellite sensor readings to radiometrically calibrate the sensor. Traditional vicarious radiometric calibration methods require that an atmospheric model be defined such that the ground-based observations of solar transmission and diffuse-to-global ratios are in close agreement with the radiative transfer code estimation of these parameters. This process is labor-intensive and complex, and can be prone to errors. The errors can be compounded because of approximations in the model and inaccurate assumptions about the radiative coupling between the atmosphere and the terrain. The errors can increase the uncertainty of the TOA radiance estimates used to perform the radiometric calibration. In comparison, the simplified approach does not use atmospheric radiative transfer models and involves fewer assumptions concerning the radiative transfer properties of the atmosphere. This new technique uses two neighboring uniform

  11. Simplified fast neutron dosimeter

    DOEpatents

    Sohrabi, Mehdi

    1979-01-01

    Direct fast-neutron-induced recoil and alpha particle tracks in polycarbonate films may be enlarged for direct visual observation and automated counting procedures employing electrochemical etching techniques. Electrochemical etching is, for example, carried out in a 28% KOH solution at room temperature by applying a 2000 V peak-to-peak voltage at 1 kHz frequency. Such recoil particle amplification can be used for the detection of wide neutron dose ranges from 1 mrad. to 1000 rads. or higher, if desired.

  12. Voxel-based Gaussian naïve Bayes classification of ischemic stroke lesions in individual T1-weighted MRI scans

    PubMed Central

    Griffis, Joseph C.; Allendorfer, Jane B.; Szaflarski, Jerzy P.

    2015-01-01

    Background Manual lesion delineation by an expert is the standard for lesion identification in MRI scans, but is time-consuming and can introduce subjective bias. Alternative methods often require multi-modal MRI data, user interaction, scans from a control population, and/or arbitrary statistical thresholding. New Method We present an approach for automatically identifying stroke lesions in individual T1-weighted MRI scans using naïve Bayes classification. Probabilistic tissue segmentation and image algebra were used to create feature maps encoding information about missing and abnormal tissue. Leave-one-case-out training and cross-validation was used to obtain out-of-sample predictions for each of 30 cases with left hemisphere stroke lesions. Results Our method correctly predicted lesion locations for 30/30 un-trained cases. Post-processing with smoothing (8mm FWHM) and cluster-extent thresholding (100 voxels) was found to improve performance. Comparison with Existing Method Quantitative evaluations of post-processed out-of-sample predictions on 30 cases revealed high spatial overlap (mean Dice similarity coefficient = 0.66) and volume agreement (mean percent volume difference = 28.91; Pearson’s r = 0.97) with manual lesion delineations. Conclusions Our automated approach agrees with manual tracing. It provides an alternative to automated methods that require multi-modal MRI data, additional control scans, or user interaction to achieve optimal performance. Our fully trained classifier has applications in neuroimaging and clinical contexts. PMID:26432931

  13. Diffusion tensor imaging of nigral degeneration in Parkinson's disease: A region-of-interest and voxel-based study at 3 T and systematic review with meta-analysis.

    PubMed

    Schwarz, Stefan T; Abaei, Maryam; Gontu, Vamsi; Morgan, Paul S; Bajaj, Nin; Auer, Dorothee P

    2013-01-01

    There is increasing interest in developing a reliable, affordable and accessible disease biomarker of Parkinson's disease (PD) to facilitate disease modifying PD-trials. Imaging biomarkers using magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI) can describe parameters such as fractional anisotropy (FA), mean diffusivity (MD) or apparent diffusion coefficient (ADC). These parameters, when measured in the substantia nigra (SN), have not only shown promising but also varying and controversial results. To clarify the potential diagnostic value of nigral DTI in PD and its dependency on selection of region-of-interest, we undertook a high resolution DTI study at 3 T. 59 subjects (32 PD patients, 27 age and sex matched healthy controls) were analysed using manual outlining of SN and substructures, and voxel-based analysis (VBA). We also performed a systematic literature review and meta-analysis to estimate the effect size (DES) of disease related nigral DTI changes. We found a regional increase in nigral mean diffusivity in PD (mean ± SD, PD 0.80 ± 0.10 vs. controls 0.73 ± 0.06 · 10(- 3) mm(2)/s, p = 0.002), but no difference using a voxel based approach. No significant disease effect was seen using meta-analysis of nigral MD changes (10 studies, DES = + 0.26, p = 0.17, I(2) = 30%). None of the nigral regional or voxel based analyses of this study showed altered fractional anisotropy. Meta-analysis of 11 studies on nigral FA changes revealed a significant PD induced FA decrease. There was, however, a very large variation in results (I(2) = 86%) comparing all studies. After exclusion of five studies with unusual high values of nigral FA in the control group, an acceptable heterogeneity was reached, but there was non-significant disease effect (DES = - 0.5, p = 0.22, I(2) = 28%). The small PD related nigral MD changes in conjunction with the negative findings on VBA and meta-analysis limit the usefulness of nigral MD

  14. 78 FR 44142 - Modification of Two National Customs Automation Program (NCAP) Tests Concerning Automated...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-23

    ...) Tests Concerning Automated Commercial Environment (ACE) Document Image System (DIS) and Simplified Entry... certain Automated Commercial Environment (ACE) participants to submit electronic images of a specific set... requirements, and test development and evaluation methods. DATES: The modified DIS test will commence...

  15. 78 FR 53466 - Modification of Two National Customs Automation Program (NCAP) Tests Concerning Automated...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-29

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HOMELAND SECURITY U.S. Customs and Border Protection Modification of Two National Customs Automation Program (NCAP) Tests Concerning Automated Commercial Environment (ACE) Document Image System (DIS) and Simplified...

  16. Simplify and Succeed

    NASA Technical Reports Server (NTRS)

    Levine, Art

    2002-01-01

    In the early 70's the management at the American Stock Exchange wanted a set of automated displays installed on the trading floor. The purpose of the displays was to announce to the public all changes related to the trading of equities. I had exactly three months to get the work done. Because of local building codes, I was told that the displays that met the specifications would not be available until nine months after the order was placed. This was not acceptable to the Exchange's management. The project team was in a quandary. I called a meeting to discuss the situation and develop a report explaining why we needed more time. Jokingly, I suggested, 'Why not use picket signs?' The Exchange had just gone through some painful labor negotiations. To anyone who had been involved in those negotiations, the thought of a picket sign should have sounded, I thought, like gallows humor. This was not acceptable to the Exchange's management. To my surprise, the rest of the project team took the idea seriously.

  17. Genetic Variation in the Catechol-O-Methyl Transferase Val108/158Met Is Linked to the Caudate and Posterior Cingulate Cortex Volume in Healthy Subjects: Voxel-Based Morphometry Analysis of Brain Magnetic Resonance Imaging

    PubMed Central

    Watanabe, Keita; Kakeda, Shingo; Yoshimura, Reiji; Ide, Satoru; Hayashi, Kenji; Katsuki, Asuka; Umene-Nakano, Wakako; Watanabe, Rieko; Abe, Osamu; Korogi, Yukunori

    2015-01-01

    The effect of the catechol-O-methyltransferase (COMT) Val158Met polymorphism on brain morphology has been investigated but remains controversial. We hypothesized that a comparison between Val/Val and Val/Met individuals, which may represent the most different combinations concerning the effects of the COMT genotype, may reveal new findings. We investigated the brain morphology using 3-Tesla magnetic resonance imaging in 27 Val/Val and 22 Val/Met individuals. Voxel-based morphometry revealed that the volumes of the bilateral caudate and posterior cingulate cortex were significantly smaller in Val/Val individuals than in Val/Met individuals [right caudate: false discovery rate (FDR)-corrected p = 0.048; left caudate: FDR-corrected p = 0.048; and bilateral posterior cingulate cortex: FDR-corrected p = 0.048]. This study demonstrates that interacting functional variants of COMT affect gray matter regional volumes in healthy subjects. PMID:26566126

  18. A simplified cellular automation model for city traffic

    SciTech Connect

    Simon, P.M.; Nagel, K. |

    1997-12-31

    The authors systematically investigate the effect of blockage sites in a cellular automata model for traffic flow. Different scheduling schemes for the blockage sites are considered. None of them returns a linear relationship between the fraction of green time and the throughput. The authors use this information for a fast implementation of traffic in Dallas.

  19. Chronic spatial working memory deficit associated with the superior longitudinal fasciculus: a study using voxel-based lesion-symptom mapping and intraoperative direct stimulation in right prefrontal glioma surgery.

    PubMed

    Kinoshita, Masashi; Nakajima, Riho; Shinohara, Harumichi; Miyashita, Katsuyoshi; Tanaka, Shingo; Okita, Hirokazu; Nakada, Mitsutoshi; Hayashi, Yutaka

    2016-10-01

    OBJECTIVE Although the right prefrontal region is regarded as a silent area, chronic deficits of the executive function, including working memory (WM), could occur after resection of a right prefrontal glioma. This may be overlooked by postoperative standard examinations, and the disabilities could affect the patient's professional life. The right prefrontal region is a part of the frontoparietal network and is subserved by the superior longitudinal fasciculus (SLF); however, the role of the SLF in spatial WM is unclear. This study investigated a persistent spatial WM deficit in patients who underwent right prefrontal glioma resection, and evaluated the relationship between the spatial WM deficit and the SLF. METHODS Spatial WM was examined in 24 patients who underwent prefrontal glioma resection (right, n = 14; left, n = 10) and in 14 healthy volunteers using a spatial 2-back task during the long-term postoperative period. The neural correlates of spatial WM were evaluated using lesion mapping and voxel-based lesion-symptom mapping. In addition, the spatial 2-back task was performed during surgery under direct subcortical electrical stimulation in 2 patients with right prefrontal gliomas. RESULTS Patients with a right prefrontal lesion had a significant chronic spatial WM deficit. Voxel-based lesion-symptom mapping analysis revealed a significant correlation between spatial WM deficit and the region that overlapped the first and second segments of the SLF (SLF I and SLF II). Two patients underwent awake surgery and had difficulties providing the correct responses in the spatial 2-back task with direct subcortical electrical stimulation on the SLF I, which was preserved and confirmed by postoperative diffusion tensor imaging tractography. These patients exhibited no spatial WM deficits during the postoperative immediate and long-term periods. CONCLUSIONS Spatial WM deficits may persist in patients who undergo resection of the tumor located in the right prefrontal

  20. Simplified Decoding of Convolutional Codes

    NASA Technical Reports Server (NTRS)

    Truong, T. K.; Reed, I. S.

    1986-01-01

    Some complicated intermediate steps shortened or eliminated. Decoding of convolutional error-correcting digital codes simplified by new errortrellis syndrome technique. In new technique, syndrome vector not computed. Instead, advantage taken of newly-derived mathematical identities simplify decision tree, folding it back on itself into form called "error trellis." This trellis graph of all path solutions of syndrome equations. Each path through trellis corresponds to specific set of decisions as to received digits. Existing decoding algorithms combined with new mathematical identities reduce number of combinations of errors considered and enable computation of correction vector directly from data and check bits as received.

  1. A voxel-based morphometric magnetic resonance imaging study of the brain detects age-related gray matter volume changes in healthy subjects of 21–45 years old

    PubMed Central

    El-Beltagi, Ahmed; Cherian, Jigi; Gejo, Grace; Al-Jazzaf, Abrar; Ismail, Mohammad

    2015-01-01

    Previous and more recent work of analyzing structural changes in the brain suggest that certain brain regions such as the frontal lobe are among the brain regions profoundly affected by the aging process across males and females. Also, a unified model of structural changes in a normally aging brain is still lacking. The present study investigated age-related structural brain changes in gray matter from young to early middle-age adulthood for males and females. Magnetic resonance images of 215 normal and healthy participants between the ages of 21–45 years were acquired. Changes in gray matter were assessed using voxel-based morphometry and gray matter volumetric analysis. The results showed significant decrease in gray matter volume between the youngest and oldest groups in the following brain regions: frontal, temporal, and parietal lobes. Grey matter loss in the frontal lobe was among the most widespread of all brain regions across the comparison groups that showed significant age-related changes in grey matter for both males and females. This work provides a unique pattern of age-related decline of normal and healthy adult males and females that can aid in the future development of a unified model of normal brain aging. PMID:26306927

  2. Relationship between the catechol-O-methyl transferase Val108/158Met genotype and brain volume in treatment-naive major depressive disorder: Voxel-based morphometry analysis.

    PubMed

    Watanabe, Keita; Kakeda, Shingo; Yoshimura, Reiji; Abe, Osamu; Ide, Satoru; Hayashi, Kenji; Katsuki, Asuka; Umene-Nakano, Wakako; Watanabe, Rieko; Nakamura, Jun; Korogi, Yukunori

    2015-09-30

    Catechol-O-methyltransferase (COMT) is a methylation enzyme engaged in the degradation of dopamine and noradrenaline by catalyzing the transfer of a methyl group from S-adenosylmethionine. An association was found between the Valine (Val) 108/158Methionine (Met) COMT polymorphism (rs4680) and major depressive disorder (MDD). The authors prospectively investigated the relationship between the Val108/158Met COMT genotype and voxel-based morphometry (VBM) findings for patients with first-episode and treatment-naïve MDD and healthy subjects (HS). Participants comprised 30 MDD patients and 48 age- and sex-matched HS who were divided according to the COMT genotype. Effects of diagnosis, COMT genotype, and the genotype-diagnosis interaction in relation to brain morphology in the Val/Met and Val/Val individuals were evaluated using a VBM analysis of high-resolution magnetic resonance imaging findings. Among the Val/Met individuals, the volume of the bilateral caudate was significantly smaller for MDD patients than for HS. In the Val/Val individuals, the caudate volume was comparable between MDD patients and HS. Significant genotype-diagnosis interaction effects on brain morphology were noted in the right caudate.

  3. SEA - A Simplified Employee Assessment

    SciTech Connect

    Busby, L

    2001-04-23

    This paper presents a proposal for modifying the current employee annual evaluation process in SCAD. It purports to simplify that process, primarily by breaking up the resultant document into a set of more or less independent components. It claims to reduce the overall time and effort required from each actor.

  4. Simplifying the Water Poverty Index

    ERIC Educational Resources Information Center

    Cho, Danny I.; Ogwang, Tomson; Opio, Christopher

    2010-01-01

    In this paper, principal components methodology is used to derive simplified and cost effective indexes of water poverty. Using a well known data set for 147 countries from which an earlier five-component water poverty index comprising of "Resources," "Access," "Capacity," "Use" and "Environment" was constructed, we find that a simplified…

  5. 75 FR 28223 - Simplified Proceedings

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-20

    ...''). Trials are held before the Commission's Administrative Law Judges and appellate review is provided by a... proposing a rule to simplify the procedures for handling certain civil penalty proceedings. DATES: Written... civil penalty for the alleged violation described in the citation or order. The procedures for this...

  6. Simplified High-Power Inverter

    NASA Technical Reports Server (NTRS)

    Edwards, D. B.; Rippel, W. E.

    1984-01-01

    Solid-state inverter simplified by use of single gate-turnoff device (GTO) to commutate multiple silicon controlled rectifiers (SCR's). By eliminating conventional commutation circuitry, GTO reduces cost, size and weight. GTO commutation applicable to inverters of greater than 1-kilowatt capacity. Applications include emergency power, load leveling, drives for traction and stationary polyphase motors, and photovoltaic-power conditioning.

  7. Automated Inadvertent Intruder Application

    SciTech Connect

    Koffman, Larry D.; Lee, Patricia L.; Cook, James R.; Wilhite, Elmer L.

    2008-01-15

    results. The application was extended to calculate full decay chains for a given parent so that an intruder calculation could be performed without any input from transport calculations, i.e. the intruder analysis was decoupled from groundwater analysis. Once this full decay chain capability was in place, the application was extended to perform a transient calculation of the dose to an intruder over a specified time range, from which the maximum dose in time was determined. Use of the transient calculation to find the maximum dose in time was a significant step forward in automating and simplifying the inadvertent intruder analysis. In conclusion: an automated application has been developed to perform inadvertent intruder analysis for SRS low-level waste facilities. The application performs a transient analysis to find the maximum dose in time for each parent considered. Due to its ease of use and the standardization of input and methods, the Automated Inadvertent Intruder Application has been adopted as standard practice for inadvertent intruder analysis at SRS.

  8. Automation or De-automation

    NASA Astrophysics Data System (ADS)

    Gorlach, Igor; Wessel, Oliver

    2008-09-01

    In the global automotive industry, for decades, vehicle manufacturers have continually increased the level of automation of production systems in order to be competitive. However, there is a new trend to decrease the level of automation, especially in final car assembly, for reasons of economy and flexibility. In this research, the final car assembly lines at three production sites of Volkswagen are analysed in order to determine the best level of automation for each, in terms of manufacturing costs, productivity, quality and flexibility. The case study is based on the methodology proposed by the Fraunhofer Institute. The results of the analysis indicate that fully automated assembly systems are not necessarily the best option in terms of cost, productivity and quality combined, which is attributed to high complexity of final car assembly systems; some de-automation is therefore recommended. On the other hand, the analysis shows that low automation can result in poor product quality due to reasons related to plant location, such as inadequate workers' skills, motivation, etc. Hence, the automation strategy should be formulated on the basis of analysis of all relevant aspects of the manufacturing process, such as costs, quality, productivity and flexibility in relation to the local context. A more balanced combination of automated and manual assembly operations provides better utilisation of equipment, reduces production costs and improves throughput.

  9. An automated mapping satellite system (MAPSAT)

    NASA Technical Reports Server (NTRS)

    Colvocoresses, A. P.

    1982-01-01

    Digital data from highly stabilized stereo linear arrays are amenable to simplified processing to produce both planimetric imagery and elevation data. A satellite, called MAPSAT, including this concept was proposed to accomplish automated mapping in near real time. Image maps as large as 1:50,000 scale with contours as close as 20-m interval may be produced from MAPSAT data.

  10. A simplified In Situ cosmogenic 14C extraction system

    USGS Publications Warehouse

    Pigati, J.S.; Lifton, N.A.; Timothy, Jull A.J.; Quade, Jay

    2010-01-01

    We describe the design, construction, and testing of a new, simplified in situ radiocarbon extraction system at the University of Arizona. Blank levels for the new system are low ((234 ?? 11) ?? 103 atoms (1 ??; n = 7)) and stable. The precision of a given measurement depends on the concentration of 14C, but is typically <5% for concentrations of 100 ?? 103 atoms g-1 or more. The new system is relatively small and easy to construct, costs significantly less than the original in situ 14C extraction system at Arizona, and lends itself to future automation. ?? 2010 by the Arizona Board of Regents on behalf of the University of Arizona.

  11. Automation pilot

    NASA Technical Reports Server (NTRS)

    1983-01-01

    An important concept of the Action Information Management System (AIMS) approach is to evaluate office automation technology in the context of hands on use by technical program managers in the conduct of human acceptance difficulties which may accompany the transition to a significantly changing work environment. The improved productivity and communications which result from application of office automation technology are already well established for general office environments, but benefits unique to NASA are anticipated and these will be explored in detail.

  12. Simplifying plasma chemistry via ILDM

    NASA Astrophysics Data System (ADS)

    Rehman, T.; Kemaneci, E.; Graef, W.; van Dijk, J.

    2016-02-01

    A plasma fluid model containing a large number of chemical species and reactions yields a high computational load. One of the methods to overcome this difficulty is to apply Chemical Reduction Techniques as used in combustion engineering. The chemical reduction technique that we study here is ILDM (Intrinsic Lower Dimensional Manifold). The ILDM method is used to simplify an argon plasma model and then a comparison is made with a CRM (Collisional Radiative Model).

  13. Office automation.

    PubMed

    Arenson, R L

    1986-03-01

    By now, the term "office automation" should have more meaning for those readers who are not intimately familiar with the subject. Not all of the preceding material pertains to every department or practice, but certainly, word processing and simple telephone management are key items. The size and complexity of the organization will dictate the usefulness of electronic mail and calendar management, and the individual radiologist's personal needs and habits will determine the usefulness of the home computer. Perhaps the most important ingredient for success in the office automation arena relates to the ability to integrate information from various systems in a simple and flexible manner. Unfortunately, this is perhaps the one area that most office automation systems have ignored or handled poorly. In the personal computer world, there has been much emphasis recently on integration of packages such as spreadsheet, database management, word processing, graphics, time management, and communications. This same philosophy of integration has been applied to a few office automation systems, but these are generally vendor-specific and do not allow for a mixture of foreign subsystems. During the next few years, it is likely that a few vendors will emerge as dominant in this integrated office automation field and will stress simplicity and flexibility as major components.

  14. Habitat automation

    NASA Technical Reports Server (NTRS)

    Swab, Rodney E.

    1992-01-01

    A habitat, on either the surface of the Moon or Mars, will be designed and built with the proven technologies of that day. These technologies will be mature and readily available to the habitat designer. We believe an acceleration of the normal pace of automation would allow a habitat to be safer and more easily maintained than would be the case otherwise. This document examines the operation of a habitat and describes elements of that operation which may benefit from an increased use of automation. Research topics within the automation realm are then defined and discussed with respect to the role they can have in the design of the habitat. Problems associated with the integration of advanced technologies into real-world projects at NASA are also addressed.

  15. New tissue priors for improved automated classification of subcortical brain structures on MRI☆

    PubMed Central

    Lorio, S.; Fresard, S.; Adaszewski, S.; Kherif, F.; Chowdhury, R.; Frackowiak, R.S.; Ashburner, J.; Helms, G.; Weiskopf, N.; Lutti, A.; Draganski, B.

    2016-01-01

    Despite the constant improvement of algorithms for automated brain tissue classification, the accurate delineation of subcortical structures using magnetic resonance images (MRI) data remains challenging. The main difficulties arise from the low gray-white matter contrast of iron rich areas in T1-weighted (T1w) MRI data and from the lack of adequate priors for basal ganglia and thalamus. The most recent attempts to obtain such priors were based on cohorts with limited size that included subjects in a narrow age range, failing to account for age-related gray-white matter contrast changes. Aiming to improve the anatomical plausibility of automated brain tissue classification from T1w data, we have created new tissue probability maps for subcortical gray matter regions. Supported by atlas-derived spatial information, raters manually labeled subcortical structures in a cohort of healthy subjects using magnetization transfer saturation and R2* MRI maps, which feature optimal gray-white matter contrast in these areas. After assessment of inter-rater variability, the new tissue priors were tested on T1w data within the framework of voxel-based morphometry. The automated detection of gray matter in subcortical areas with our new probability maps was more anatomically plausible compared to the one derived with currently available priors. We provide evidence that the improved delineation compensates age-related bias in the segmentation of iron rich subcortical regions. The new tissue priors, allowing robust detection of basal ganglia and thalamus, have the potential to enhance the sensitivity of voxel-based morphometry in both healthy and diseased brains. PMID:26854557

  16. Automated office blood pressure.

    PubMed

    Myers, Martin G; Godwin, Marshall

    2012-05-01

    Manual blood pressure (BP) is gradually disappearing from clinical practice with the mercury sphygmomanometer now considered to be an environmental hazard. Manual BP is also subject to measurement error on the part of the physician/nurse and patient-related anxiety which can result in poor quality BP measurements and office-induced (white coat) hypertension. Automated office (AO) BP with devices such as the BpTRU (BpTRU Medical Devices, Coquitlam, BC) has already replaced conventional manual BP in many primary care practices in Canada and has also attracted interest in other countries where research studies using AOBP have been undertaken. The basic principles of AOBP include multiple readings taken with a fully automated recorder with the patient resting alone in a quiet room. When these principles are followed, office-induced hypertension is eliminated and AOBP exhibits a much stronger correlation with the awake ambulatory BP as compared with routine manual BP measurements. Unlike routine manual BP, AOBP correlates as well with left ventricular mass as does the awake ambulatory BP. AOBP also simplifies the definition of hypertension in that the cut point for a normal AOBP (< 135/85 mm Hg) is the same as for the awake ambulatory BP and home BP. This article summarizes the currently available evidence supporting the use of AOBP in routine clinical practice and proposes an algorithm in which AOBP replaces manual BP for the diagnosis and management of hypertension.

  17. Simplified propagation of standard uncertainties

    SciTech Connect

    Shull, A.H.

    1997-06-09

    An essential part of any measurement control program is adequate knowledge of the uncertainties of the measurement system standards. Only with an estimate of the standards` uncertainties can one determine if the standard is adequate for its intended use or can one calculate the total uncertainty of the measurement process. Purchased standards usually have estimates of uncertainty on their certificates. However, when standards are prepared and characterized by a laboratory, variance propagation is required to estimate the uncertainty of the standard. Traditional variance propagation typically involves tedious use of partial derivatives, unfriendly software and the availability of statistical expertise. As a result, the uncertainty of prepared standards is often not determined or determined incorrectly. For situations meeting stated assumptions, easier shortcut methods of estimation are now available which eliminate the need for partial derivatives and require only a spreadsheet or calculator. A system of simplifying the calculations by dividing into subgroups of absolute and relative uncertainties is utilized. These methods also incorporate the International Standards Organization (ISO) concepts for combining systematic and random uncertainties as published in their Guide to the Expression of Measurement Uncertainty. Details of the simplified methods and examples of their use are included in the paper.

  18. Simplifying microbial electrosynthesis reactor design

    PubMed Central

    Giddings, Cloelle G. S.; Nevin, Kelly P.; Woodward, Trevor; Lovley, Derek R.; Butler, Caitlyn S.

    2015-01-01

    Microbial electrosynthesis, an artificial form of photosynthesis, can efficiently convert carbon dioxide into organic commodities; however, this process has only previously been demonstrated in reactors that have features likely to be a barrier to scale-up. Therefore, the possibility of simplifying reactor design by both eliminating potentiostatic control of the cathode and removing the membrane separating the anode and cathode was investigated with biofilms of Sporomusa ovata. S. ovata reduces carbon dioxide to acetate and acts as the microbial catalyst for plain graphite stick cathodes as the electron donor. In traditional ‘H-cell’ reactors, where the anode and cathode chambers were separated with a proton-selective membrane, the rates and columbic efficiencies of microbial electrosynthesis remained high when electron delivery at the cathode was powered with a direct current power source rather than with a potentiostat-poised cathode utilized in previous studies. A membrane-less reactor with a direct-current power source with the cathode and anode positioned to avoid oxygen exposure at the cathode, retained high rates of acetate production as well as high columbic and energetic efficiencies. The finding that microbial electrosynthesis is feasible without a membrane separating the anode from the cathode, coupled with a direct current power source supplying the energy for electron delivery, is expected to greatly simplify future reactor design and lower construction costs. PMID:26029199

  19. 76 FR 69755 - National Customs Automation Program Test Concerning Automated Commercial Environment (ACE...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-09

    ... Commercial Environment (ACE) Simplified Entry AGENCY: U.S. Customs and Border Protection, Department of... Commercial Environment (ACE) entry capability. This new capability will include functionality specific to the... was on trade compliance and the development of the Automated Commercial Environment (ACE), the...

  20. Automating Finance

    ERIC Educational Resources Information Center

    Moore, John

    2007-01-01

    In past years, higher education's financial management side has been riddled with manual processes and aging mainframe applications. This article discusses schools which had taken advantage of an array of technologies that automate billing, payment processing, and refund processing in the case of overpayment. The investments are well worth it:…

  1. Simplifier cut core inductor design

    NASA Technical Reports Server (NTRS)

    Mclyman, W. T.

    1976-01-01

    Advantages of specifying C cores and cut toroids fabricated from grain oriented silicon steels for use in high frequency power converters and pulse width modulated switching regulators are discussed. A method for rating cores assigns to each core a number which is the product of its window and core cross section area, called 'Area Product A sub p.' A correlation between the A sub p numbers and current density for a given temperature rise was developed. Also, straight line relationships were developed for A sub p and volume, A sub p and surface area, and A sub p and weight. These relationships can be used to simplify and standardize the process of inductor design. They also make it possible to design inductors of small bulk and volume or to optimize efficiency.

  2. Simplified Methodology for Calculating Building Heating Loads.

    DTIC Science & Technology

    1980-11-01

    an inexpensive, accurate, and reliable simplified methodology , termed the "Modified Bin Method ", for 2 calculating building heating loads. In doing so...I AD-AI01 725 AIR FORCE INST OF TECH WRIGMT-PATTERSON AFB OH F/6 13/1 SIMPLIFIED METHODOLOGY FOR CALCULATING BUILDING HEATING LOADS.(U) NOV 80 S 0...University The Graduate School ," Department of Architectural Engineering 4, Simplified Methodology for Calculating Building Heating Loads, -A /. ’.- A

  3. Simplified modal method for slanted grating

    NASA Astrophysics Data System (ADS)

    Li, Shubin; Zhou, Changhe; Jia, Wei

    2017-01-01

    We report the simplified modal method for the slanted grating based on the accurate dispersion equation. The vividly physical insight is presented to interpret the diffraction process for slanted grating. We also present that the simplified modal method with the two-lowest mode condition is effective for a large slanted angle up to 26°. By examining the eignefunction, the mode index, and the two-lowest mode condition, we provide new evidences to verify the assumption that a slanted grating with subwavelength period can be analyzed as an equivalent rectangular grating using the simplified modal method, which is right and convenient to use for a small slanted angle up to 20°. Numerical simulations of the simplified modal method are coincident with rigorous coupled wave analysis for small slanted angle gratings. Thus the simplified modal method can be used for small slanted angle grating since the equivalence of slanted grating and rectangular grating is verified due to its vivid physical analysis.

  4. 48 CFR 453.213 - Simplified Acquisition and other simplified purchase procedures (AD-838).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 4 2011-10-01 2011-10-01 false Simplified Acquisition and other simplified purchase procedures (AD-838). 453.213 Section 453.213 Federal Acquisition Regulations... Acquisition and other simplified purchase procedures (AD-838). Form AD-838, Purchase Order, is prescribed...

  5. 48 CFR 453.213 - Simplified Acquisition and other simplified purchase procedures (AD-838).

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false Simplified Acquisition and other simplified purchase procedures (AD-838). 453.213 Section 453.213 Federal Acquisition Regulations... Acquisition and other simplified purchase procedures (AD-838). Form AD-838, Purchase Order, is prescribed...

  6. Simplified Application of Material Efficiency Green Metrics to Synthesis Plans: Pedagogical Case Studies Selected from "Organic Syntheses"

    ERIC Educational Resources Information Center

    Andraos, John

    2015-01-01

    This paper presents a simplified approach for the application of material efficiency metrics to linear and convergent synthesis plans encountered in organic synthesis courses. Computations are facilitated and automated using intuitively designed Microsoft Excel spreadsheets without invoking abstract mathematical formulas. The merits of this…

  7. Simplified method for nonlinear structural analysis

    NASA Technical Reports Server (NTRS)

    Kaufman, A.

    1983-01-01

    A simplified inelastic analysis computer program was developed for predicting the stress-strain history of a thermomechanically cycled structure from an elastic solution. The program uses an iterative and incremental procedure to estimate the plastic strains from the material stress-strain properties and a simulated plasticity hardening model. The simplified method was exercised on a number of problems involving uniaxial and multiaxial loading, isothermal and nonisothermal conditions, and different materials and plasticity models. Good agreement was found between these analytical results and nonlinear finite element solutions for these problems. The simplified analysis program used less than 1 percent of the CPU time required for a nonlinear finite element analysis.

  8. Veitch diagram plotter simplifies Boolean functions

    NASA Technical Reports Server (NTRS)

    Rubin, D. K.

    1964-01-01

    This device for simplifying the plotting of a Veitch diagram consists of several overlays for blocking out the unwanted squares. This method of plotting the various input combinations to a computer is used in conjunction with the Boolean functions.

  9. Simplified Derivation Of Geometrical Dynamic Range Compression

    NASA Astrophysics Data System (ADS)

    Altman, W. P.

    1982-08-01

    A simplified derivation is presented which illustrates the effects of unmatched fields of view for a lidar system. The resultant equations are easily evaluated on a programmable calculator, and comparison with previous calculations are numerically similar.

  10. Simplified solution for stresses and deformation

    NASA Technical Reports Server (NTRS)

    Hamrock, B. J.; Brewe, D. E.

    1981-01-01

    Conventional contact deformation analysis for ball bearings, gears, and cams involves tedious iterative procedures or the use of design charts. A simplified approach that makes the elastic deformation at the center of contact easy to calculate was previously reported. The range of validity in which these equations can be used is extended. A simplified approach to the calculation of the location and magnitude of subsurface stresses developed in machine element applications is included.

  11. Simplified Quantum Logic with Trapped Ions

    DTIC Science & Technology

    2016-06-23

    PHYSICAL REVIEW A ATOMIC , MOLECULAR, AND OPTICAL PHYSICS THIRD SERIES, VOLUME 55, NUMBER 4 APRIL 1997Simplified quantum logic with trapped ions C...Received 17 December 1996! We describe a simplified scheme for quantum logic with a collection of laser-cooled trapped atomic ions. Building on the...in a system of laser-cooled trapped atomic ions. In the simplest form of the ion trap quantum computer, two internal electronic levels of each ion in

  12. Simplified models for LHC new physics searches

    NASA Astrophysics Data System (ADS)

    Alves, Daniele; Arkani-Hamed, Nima; Arora, Sanjay; Bai, Yang; Baumgart, Matthew; Berger, Joshua; Buckley, Matthew; Butler, Bart; Chang, Spencer; Cheng, Hsin-Chia; Cheung, Clifford; Sekhar Chivukula, R.; Cho, Won Sang; Cotta, Randy; D'Alfonso, Mariarosaria; El Hedri, Sonia; Essig (Editor, Rouven; Evans, Jared A.; Fitzpatrick, Liam; Fox, Patrick; Franceschini, Roberto; Freitas, Ayres; Gainer, James S.; Gershtein, Yuri; Gray, Richard; Gregoire, Thomas; Gripaios, Ben; Gunion, Jack; Han, Tao; Haas, Andy; Hansson, Per; Hewett, JoAnne; Hits, Dmitry; Hubisz, Jay; Izaguirre, Eder; Kaplan, Jared; Katz, Emanuel; Kilic, Can; Kim, Hyung-Do; Kitano, Ryuichiro; Koay, Sue Ann; Ko, Pyungwon; Krohn, David; Kuflik, Eric; Lewis, Ian; Lisanti (Editor, Mariangela; Liu, Tao; Liu, Zhen; Lu, Ran; Luty, Markus; Meade, Patrick; Morrissey, David; Mrenna, Stephen; Nojiri, Mihoko; Okui, Takemichi; Padhi, Sanjay; Papucci, Michele; Park, Michael; Park, Myeonghun; Perelstein, Maxim; Peskin, Michael; Phalen, Daniel; Rehermann, Keith; Rentala, Vikram; Roy, Tuhin; Ruderman, Joshua T.; Sanz, Veronica; Schmaltz, Martin; Schnetzer, Stephen; Schuster (Editor, Philip; Schwaller, Pedro; Schwartz, Matthew D.; Schwartzman, Ariel; Shao, Jing; Shelton, Jessie; Shih, David; Shu, Jing; Silverstein, Daniel; Simmons, Elizabeth; Somalwar, Sunil; Spannowsky, Michael; Spethmann, Christian; Strassler, Matthew; Su, Shufang; Tait (Editor, Tim; Thomas, Brooks; Thomas, Scott; Toro (Editor, Natalia; Volansky, Tomer; Wacker (Editor, Jay; Waltenberger, Wolfgang; Yavin, Itay; Yu, Felix; Zhao, Yue; Zurek, Kathryn; LHC New Physics Working Group

    2012-10-01

    This document proposes a collection of simplified models relevant to the design of new-physics searches at the Large Hadron Collider (LHC) and the characterization of their results. Both ATLAS and CMS have already presented some results in terms of simplified models, and we encourage them to continue and expand this effort, which supplements both signature-based results and benchmark model interpretations. A simplified model is defined by an effective Lagrangian describing the interactions of a small number of new particles. Simplified models can equally well be described by a small number of masses and cross-sections. These parameters are directly related to collider physics observables, making simplified models a particularly effective framework for evaluating searches and a useful starting point for characterizing positive signals of new physics. This document serves as an official summary of the results from the ‘Topologies for Early LHC Searches’ workshop, held at SLAC in September of 2010, the purpose of which was to develop a set of representative models that can be used to cover all relevant phase space in experimental searches. Particular emphasis is placed on searches relevant for the first ˜50-500 pb-1 of data and those motivated by supersymmetric models. This note largely summarizes material posted at http://lhcnewphysics.org/, which includes simplified model definitions, Monte Carlo material, and supporting contacts within the theory community. We also comment on future developments that may be useful as more data is gathered and analyzed by the experiments.

  13. Simplified Models for LHC New Physics Searches

    SciTech Connect

    Alves, Daniele; Arkani-Hamed, Nima; Arora, Sanjay; Bai, Yang; Baumgart, Matthew; Berger, Joshua; Buckley, Matthew; Butler, Bart; Chang, Spencer; Cheng, Hsin-Chia; Cheung, Clifford; Chivukula, R.Sekhar; Cho, Won Sang; Cotta, Randy; D'Alfonso, Mariarosaria; El Hedri, Sonia; Essig, Rouven,; Evans, Jared A.; Fitzpatrick, Liam; Fox, Patrick; Franceschini, Roberto; /more authors..

    2012-06-01

    This document proposes a collection of simplified models relevant to the design of new-physics searches at the LHC and the characterization of their results. Both ATLAS and CMS have already presented some results in terms of simplified models, and we encourage them to continue and expand this effort, which supplements both signature-based results and benchmark model interpretations. A simplified model is defined by an effective Lagrangian describing the interactions of a small number of new particles. Simplified models can equally well be described by a small number of masses and cross-sections. These parameters are directly related to collider physics observables, making simplified models a particularly effective framework for evaluating searches and a useful starting point for characterizing positive signals of new physics. This document serves as an official summary of the results from the 'Topologies for Early LHC Searches' workshop, held at SLAC in September of 2010, the purpose of which was to develop a set of representative models that can be used to cover all relevant phase space in experimental searches. Particular emphasis is placed on searches relevant for the first {approx} 50-500 pb{sup -1} of data and those motivated by supersymmetric models. This note largely summarizes material posted at http://lhcnewphysics.org/, which includes simplified model definitions, Monte Carlo material, and supporting contacts within the theory community. We also comment on future developments that may be useful as more data is gathered and analyzed by the experiments.

  14. Automated integer programming based separation of arteries and veins from thoracic CT images.

    PubMed

    Payer, Christian; Pienn, Michael; Bálint, Zoltán; Shekhovtsov, Alexander; Talakic, Emina; Nagy, Eszter; Olschewski, Andrea; Olschewski, Horst; Urschler, Martin

    2016-12-01

    Automated computer-aided analysis of lung vessels has shown to yield promising results for non-invasive diagnosis of lung diseases. To detect vascular changes which affect pulmonary arteries and veins differently, both compartments need to be identified. We present a novel, fully automatic method that separates arteries and veins in thoracic computed tomography images, by combining local as well as global properties of pulmonary vessels. We split the problem into two parts: the extraction of multiple distinct vessel subtrees, and their subsequent labeling into arteries and veins. Subtree extraction is performed with an integer program (IP), based on local vessel geometry. As naively solving this IP is time-consuming, we show how to drastically reduce computational effort by reformulating it as a Markov Random Field. Afterwards, each subtree is labeled as either arterial or venous by a second IP, using two anatomical properties of pulmonary vessels: the uniform distribution of arteries and veins, and the parallel configuration and close proximity of arteries and bronchi. We evaluate algorithm performance by comparing the results with 25 voxel-based manual reference segmentations. On this dataset, we show good performance of the subtree extraction, consisting of very few non-vascular structures (median value: 0.9%) and merged subtrees (median value: 0.6%). The resulting separation of arteries and veins achieves a median voxel-based overlap of 96.3% with the manual reference segmentations, outperforming a state-of-the-art interactive method. In conclusion, our novel approach provides an opportunity to become an integral part of computer aided pulmonary diagnosis, where artery/vein separation is important.

  15. Simplifying operations with an uplink/downlink integration toolkit

    NASA Technical Reports Server (NTRS)

    Murphy, Susan C.; Miller, Kevin J.; Guerrero, Ana Maria; Joe, Chester; Louie, John J.; Aguilera, Christine

    1994-01-01

    display actual values from the telemetry data stream. This toolkit was designed to greatly simplify the user's ability to access and view telemetry data, and also provide a means to view this data in the context of the commands and ground events that are used to interpret it. A closed-loop system can prove especially useful in small missions with limited resources requiring automated monitoring tools. This paper will discuss the toolkit implementation, including design trade-offs and future plans for enhancing the automated capabilities.

  16. Simplified Warfarin Dose-response Pharmacodynamic Models

    PubMed Central

    Kim, Seongho; Gaweda, Adam E.; Wu, Dongfeng; Li, Lang; Rai, Shesh N.; Brier, Michael E.

    2014-01-01

    Warfarin is a frequently used oral anticoagulant for long-term prevention and treatment of thromboembolic events. Due to its narrow therapeutic range and large inter-individual dose-response variability, it is highly desirable to personalize warfarin dosing. However, the complexity of the conventional kinetic-pharmacodynamic (K-PD) models hampers the development of the personalized dose management. To avert this challenge, we propose simplified PD models for warfarin dose-response relationship, which is motivated by ideas from control theory. The simplified models were further applied to longitudinal data of 37 patients undergoing anticoagulation treatment using the standard two-stage approach and then compared with the conventional K-PD models. Data analysis shows that all models have a similar predictive ability, but the simplified models are most parsimonious. PMID:25750489

  17. Hypersonic Vehicle Propulsion System Simplified Model Development

    NASA Technical Reports Server (NTRS)

    Stueber, Thomas J.; Raitano, Paul; Le, Dzu K.; Ouzts, Peter

    2007-01-01

    This document addresses the modeling task plan for the hypersonic GN&C GRC team members. The overall propulsion system modeling task plan is a multi-step process and the task plan identified in this document addresses the first steps (short term modeling goals). The procedures and tools produced from this effort will be useful for creating simplified dynamic models applicable to a hypersonic vehicle propulsion system. The document continues with the GRC short term modeling goal. Next, a general description of the desired simplified model is presented along with simulations that are available to varying degrees. The simulations may be available in electronic form (FORTRAN, CFD, MatLab,...) or in paper form in published documents. Finally, roadmaps outlining possible avenues towards realizing simplified model are presented.

  18. SIMPLIFIED LAPAROSCOPIC CHOLECYSTECTOMY WITH TWO INCISIONS

    PubMed Central

    ABAID, Rafael Antoniazzi; CECCONELLO, Ivan; ZILBERSTEIN, Bruno

    2014-01-01

    Background Laparoscopic cholecystectomy has traditionally been performed with four incisions to insert four trocars, in a simple, efficient and safe way. Aim To describe a simplified technique of laparoscopic cholecystectomy with two incisions, using basic conventional instrumental. Technique In one incision in the umbilicus are applied two trocars and in epigastrium one more. The use of two trocars on the same incision, working in "x" does not hinder the procedure and does not require special instruments. Conclusion Simplified laparoscopic cholecystectomy with two incisions is feasible and easy to perform, allowing to operate with ergonomy and safety, with good cosmetic result. PMID:25004296

  19. Simplify, simplify

    PubMed Central

    Berenbaum, May R; Seufferheld, Manfredo J; Margam, Venu M; Strycharz, Joseph P; Yoon, Kyong S; Sun, Weilin; Reenan, Robert; Lee, Si Hyeock; Clark, John M

    2011-01-01

    The body louse, with its recently sequenced genome, is now primed to serve as a powerful model organism for addressing fundamental questions relating to how insects interact with their environment. One characteristic of the body louse that facilitates this research is the size of its genome—the smallest insect genome sequenced to date. This diminutive genome must nonetheless control an organism that senses and responds to its environment, reacting to threats of corporal and genomic integrity. Additionally, the body louse transmits several important human diseases compared to its very close relative, the head louse, which does not. Therefore, these two organisms comprise an excellent model system for studying molecular mechanisms associated with vector competence. To understand more fully the development of vector/pathogen interactions, we have developed an in vitro bioassay system and determined that the body louse genome appears to contain the genes necessary for RNAi. The body louse will therefore be useful for determining the set of conditions permissive to the evolution of vector competence. PMID:21655436

  20. Autonomy and Automation

    NASA Technical Reports Server (NTRS)

    Shively, Jay

    2017-01-01

    A significant level of debate and confusion has surrounded the meaning of the terms autonomy and automation. Automation is a multi-dimensional concept, and we propose that Remotely Piloted Aircraft Systems (RPAS) automation should be described with reference to the specific system and task that has been automated, the context in which the automation functions, and other relevant dimensions. In this paper, we present definitions of automation, pilot in the loop, pilot on the loop and pilot out of the loop. We further propose that in future, the International Civil Aviation Organization (ICAO) RPAS Panel avoids the use of the terms autonomy and autonomous when referring to automated systems on board RPA. Work Group 7 proposes to develop, in consultation with other workgroups, a taxonomy of Levels of Automation for RPAS.

  1. Simplified Recipes for Day Care Centers.

    ERIC Educational Resources Information Center

    Asmussen, Patricia D.

    The spiral-bound collection of 156 simplified recipes is designed to help those who prepare food for groups of children at day care centers. The recipes provide for 25 child-size servings to meet the nutritional needs and appetites of children from 2 to 6 years of age. The first section gives general information on ladle and scoop sizes, weights…

  2. Simplified Fabrication of Helical Copper Antennas

    NASA Technical Reports Server (NTRS)

    Petro, Andrew

    2006-01-01

    A simplified technique has been devised for fabricating helical antennas for use in experiments on radio-frequency generation and acceleration of plasmas. These antennas are typically made of copper (for electrical conductivity) and must have a specific helical shape and precise diameter.

  3. Simplified procedures for designing composite bolted joints

    NASA Technical Reports Server (NTRS)

    Chamis, Christos C.

    1988-01-01

    Simplified procedures are described to design and analyze single and multi-bolt composite joints. Numerical examples illustrate the use of these methods. Factors affecting composite bolted joints are summarized. References are cited where more detailed discussion is presented on specific aspects of composite bolted joints. Design variables associated with these joints are summarized in the appendix.

  4. Simplified procedures for designing composite bolted joints

    NASA Technical Reports Server (NTRS)

    Chamis, Christos C.

    1990-01-01

    Simplified procedures are described to design and analyze single and multi-bolt composite joints. Numerical examples illustrate the use of these methods. Factors affecting composite bolted joints are summarized. References are cited where more detailed discussion is presented on specific aspects of composite bolted joints. Design variables associated with these joints are summarized in the appendix.

  5. Simplified modeling for infiltration and radon entry

    SciTech Connect

    Sherman, M.H.

    1992-08-01

    Air leakage in the envelopes of residential buildings is the primary mechanism for provided ventilation to those buildings. For radon the same mechanisms that drive the ventilation, drive the radon entry This paper attempts to provide a simplified physical model that can be used to understand the interactions between the building leakage distribution, the forces that drive infiltration and ventilation, and indoor radon concentrations, Combining both ventilation and entry modeling together allows an estimation of Radon concentration and exposure to be made and demonstrates how changes in the envelope or ventilation system would affect it. This paper will develop simplified modeling approaches for estimating both ventilation rate and radon entry rate based on the air tightness of the envelope and the driving forces. These approaches will use conventional leakage values (i.e. effective leakage area ) to quantify the air tightness and include natural and mechanical driving forces. This paper will introduce a simplified parameter, the Radon Leakage Area, that quantifies the resistance to radon entry. To be practical for dwellings, modeling of the occupant exposures to indoor pollutants must be simple to use and not require unreasonable input data. This paper presents the derivation of the simplified physical model, and applies that model to representative situations to explore the tendencies to be expected under different circumstances.

  6. Workflow automation architecture standard

    SciTech Connect

    Moshofsky, R.P.; Rohen, W.T.

    1994-11-14

    This document presents an architectural standard for application of workflow automation technology. The standard includes a functional architecture, process for developing an automated workflow system for a work group, functional and collateral specifications for workflow automation, and results of a proof of concept prototype.

  7. CRIE: An automated analyzer for Chinese texts.

    PubMed

    Sung, Yao-Ting; Chang, Tao-Hsing; Lin, Wei-Chun; Hsieh, Kuan-Sheng; Chang, Kuo-En

    2016-12-01

    Textual analysis has been applied to various fields, such as discourse analysis, corpus studies, text leveling, and automated essay evaluation. Several tools have been developed for analyzing texts written in alphabetic languages such as English and Spanish. However, currently there is no tool available for analyzing Chinese-language texts. This article introduces a tool for the automated analysis of simplified and traditional Chinese texts, called the Chinese Readability Index Explorer (CRIE). Composed of four subsystems and incorporating 82 multilevel linguistic features, CRIE is able to conduct the major tasks of segmentation, syntactic parsing, and feature extraction. Furthermore, the integration of linguistic features with machine learning models enables CRIE to provide leveling and diagnostic information for texts in language arts, texts for learning Chinese as a foreign language, and texts with domain knowledge. The usage and validation of the functions provided by CRIE are also introduced.

  8. An Empirical Evaluation of Automated Theorem Provers in Software Certification

    NASA Technical Reports Server (NTRS)

    Denney, Ewen; Fischer, Bernd; Schumann, Johann

    2004-01-01

    We describe a system for the automated certification of safety properties of NASA software. The system uses Hoare-style program verification technology to generate proof obligations which are then processed by an automated first-order theorem prover (ATP). We discuss the unique requirements this application places on the ATPs, focusing on automation, proof checking, and usability. For full automation, however, the obligations must be aggressively preprocessed and simplified, and we demonstrate how the individual simplification stages, which are implemented by rewriting, influence the ability of the ATPs to solve the proof tasks. Our results are based on 13 certification experiments that lead to more than 25,000 proof tasks which have each been attempted by Vampire, Spass, e-setheo, and Otter. The proofs found by Otter have been proof-checked by IVY.

  9. Automation in Clinical Microbiology

    PubMed Central

    Ledeboer, Nathan A.

    2013-01-01

    Historically, the trend toward automation in clinical pathology laboratories has largely bypassed the clinical microbiology laboratory. In this article, we review the historical impediments to automation in the microbiology laboratory and offer insight into the reasons why we believe that we are on the cusp of a dramatic change that will sweep a wave of automation into clinical microbiology laboratories. We review the currently available specimen-processing instruments as well as the total laboratory automation solutions. Lastly, we outline the types of studies that will need to be performed to fully assess the benefits of automation in microbiology laboratories. PMID:23515547

  10. Shoe-String Automation

    SciTech Connect

    Duncan, M.L.

    2001-07-30

    Faced with a downsizing organization, serious budget reductions and retirement of key metrology personnel, maintaining capabilities to provide necessary services to our customers was becoming increasingly difficult. It appeared that the only solution was to automate some of our more personnel-intensive processes; however, it was crucial that the most personnel-intensive candidate process be automated, at the lowest price possible and with the lowest risk of failure. This discussion relates factors in the selection of the Standard Leak Calibration System for automation, the methods of automation used to provide the lowest-cost solution and the benefits realized as a result of the automation.

  11. Automated three-dimensional spatial standardization and quantification of myocardial perfusion tomography: alternative to polar maps

    NASA Astrophysics Data System (ADS)

    Slomka, Piotr J.; Radau, Perry E.; Hurwitz, Gilbert; Dey, Damini

    2000-04-01

    We developed a novel clinical tool (PERFIT) for automated 3-D voxel-based quantification of myocardial perfusion, validated it with a wide spectrum of angiographically correlated cases, compared it to previous approaches, and tested its agreement with visual expert reading. A multistage, 3-D iterative inter- subject registration of patient images to normal stress and rest cardiac templates was applied, including automated masking of external activity before final fit. The reference templates were adjusted to the individual left ventricles by template erosion, for further shape correction. 125 angiographically correlated cases including multi-vessel disease, infarction, and dilated ventricles were tested. In addition, standard polar maps were generated automatically from the registered data. Results of consensus visual reading (V) and PERFIT (P) were compared. The iterative fitting was successful in 245/250 (99%) stress and rest images. PERFIT found defects on stress in 2/29 normal patients and 95/96 abnormal patients. Overall correlation between V and P findings was r equals 0.864. In all abnormal groups (n equals 96), PERFIT average defect sizes expressed as the percentage the myocardial volume were 9.6% for rest and 22.3% for stress, versus 11.4% (rest) and 23% (stress) for visual reading. Automatic quantification by PERFIT is consistent with visual analysis; it can be applied to the analysis whole spectrum of clinical images, and can aid physicians in interpretation of myocardial perfusion.

  12. Simplified models of mixed dark matter

    SciTech Connect

    Cheung, Clifford; Sanford, David E-mail: dsanford@caltech.edu

    2014-02-01

    We explore simplified models of mixed dark matter (DM), defined here to be a stable relic composed of a singlet and an electroweak charged state. Our setup describes a broad spectrum of thermal DM candidates that can naturally accommodate the observed DM abundance but are subject to substantial constraints from current and upcoming direct detection experiments. We identify ''blind spots'' at which the DM-Higgs coupling is identically zero, thus nullifying direct detection constraints on spin independent scattering. Furthermore, we characterize the fine-tuning in mixing angles, i.e. well-tempering, required for thermal freeze-out to accommodate the observed abundance. Present and projected limits from LUX and XENON1T force many thermal relic models into blind spot tuning, well-tempering, or both. This simplified model framework generalizes bino-Higgsino DM in the MSSM, singlino-Higgsino DM in the NMSSM, and scalar DM candidates that appear in models of extended Higgs sectors.

  13. An Accurate, Simplified Model Intrabeam Scattering

    SciTech Connect

    Bane, Karl LF

    2002-05-23

    Beginning with the general Bjorken-Mtingwa solution for intrabeam scattering (IBS) we derive an accurate, greatly simplified model of IBS, valid for high energy beams in normal storage ring lattices. In addition, we show that, under the same conditions, a modified version of Piwinski's IBS formulation (where {eta}{sub x,y}{sup 2}/{beta}{sub x,y} has been replaced by {Eta}{sub x,y}) asymptotically approaches the result of Bjorken-Mtingwa.

  14. Simplified analysis of complex conductivity data

    NASA Astrophysics Data System (ADS)

    Salomon, M.

    1981-03-01

    A simplified method is presented for the analysis of conductivity data for complex situations which involve ion pairing. The method was tested by comparing results with more elaborate analyses using published data for a number of salts in various solvents. The method is then used to analyze the conductivity data for several salts in thionyl chloride. These latter analyses are important for selecting electrolytes for lithium primary batteries.

  15. Simplified Learning Scheme For Analog Neural Network

    NASA Technical Reports Server (NTRS)

    Eberhardt, Silvio P.

    1991-01-01

    Synaptic connections adjusted one at a time in small increments. Simplified gradient-descent learning scheme for electronic neural-network processor less efficient than better-known back-propagation scheme, but offers two advantages: easily implemented in circuitry because data-access circuitry separated from learning circuitry; and independence of data-access circuitry makes possible to implement feedforward as well as feedback networks, including those of multiple-attractor type. Important in such applications as recognition of patterns.

  16. Simplified dichromated gelatin hologram recording process

    NASA Technical Reports Server (NTRS)

    Georgekutty, Tharayil G.; Liu, Hua-Kuang

    1987-01-01

    A simplified method for making dichromated gelatin (DCG) holographic optical elements (HOE) has been discovered. The method is much less tedious and it requires a period of processing time comparable with that for processing a silver halide hologram. HOE characteristics including diffraction efficiency (DE), linearity, and spectral sensitivity have been quantitatively investigated. The quality of the holographic grating is very high. Ninety percent or higher diffraction efficiency has been achieved in simple plane gratings made by this process.

  17. Simplified robot arm dynamics for control

    NASA Technical Reports Server (NTRS)

    Bejczy, A. K.; Paul, R. P.

    1981-01-01

    A brief summary and evaluation is presented on the use of symbolic state equation techniques in order to represent robot arm dynamics with sufficient accuracy for controlling arm motion. The use of homogeneous transformations and the Lagrangian formulation of mechanics offers a convenient frame for the derivation, analysis and simplification of complex robot dynamics equations. It is pointed out that simplified state equations can represent robot arm dynamics with good accuracy.

  18. Simplified Modeling of Active Magnetic Regenerators

    NASA Astrophysics Data System (ADS)

    Burdyny, Thomas

    Active magnetic regenerator (AMR) refrigeration is an alternative technology to conventional vapor-compression refrigerators that has the potential to operate at higher efficiencies. Based on the magnetocaloric effect, this technology uses the magnetization and demagnetization of environmentally neutral solid refrigerants to produce a cooling effect. To become competitive however, a large amount of research into the optimal device configurations, operating parameters and refrigerants is still needed. To aid in this research, a simplified model for predicting the general trends of AMR devices at a low computational cost is developed. The derivation and implementation of the model for an arbitrary AMR is presented. Simulations from the model are compared to experimental results from two different devices and show good agreement across a wide range of operating parameters. The simplified model is also used to study the impacts of Curie temperature spacing, material weighting and devices on the performance of multilayered regenerators. Future applications of the simplified AMR model include costing and optimization programs where the low computational demand of the model can be fully exploited.

  19. Automated DNA Sequencing System

    SciTech Connect

    Armstrong, G.A.; Ekkebus, C.P.; Hauser, L.J.; Kress, R.L.; Mural, R.J.

    1999-04-25

    Oak Ridge National Laboratory (ORNL) is developing a core DNA sequencing facility to support biological research endeavors at ORNL and to conduct basic sequencing automation research. This facility is novel because its development is based on existing standard biology laboratory equipment; thus, the development process is of interest to the many small laboratories trying to use automation to control costs and increase throughput. Before automation, biology Laboratory personnel purified DNA, completed cycle sequencing, and prepared 96-well sample plates with commercially available hardware designed specifically for each step in the process. Following purification and thermal cycling, an automated sequencing machine was used for the sequencing. A technician handled all movement of the 96-well sample plates between machines. To automate the process, ORNL is adding a CRS Robotics A- 465 arm, ABI 377 sequencing machine, automated centrifuge, automated refrigerator, and possibly an automated SpeedVac. The entire system will be integrated with one central controller that will direct each machine and the robot. The goal of this system is to completely automate the sequencing procedure from bacterial cell samples through ready-to-be-sequenced DNA and ultimately to completed sequence. The system will be flexible and will accommodate different chemistries than existing automated sequencing lines. The system will be expanded in the future to include colony picking and/or actual sequencing. This discrete event, DNA sequencing system will demonstrate that smaller sequencing labs can achieve cost-effective the laboratory grow.

  20. Identifying Requirements for Effective Human-Automation Teamwork

    SciTech Connect

    Jeffrey C. Joe; John O'Hara; Heather D. Medema; Johanna H. Oxstrand

    2014-06-01

    Previous studies have shown that poorly designed human-automation collaboration, such as poorly designed communication protocols, often leads to problems for the human operators, such as: lack of vigilance, complacency, and loss of skills. These problems often lead to suboptimal system performance. To address this situation, a considerable amount of research has been conducted to improve human-automation collaboration and to make automation function better as a “team player.” Much of this research is based on an understanding of what it means to be a good team player from the perspective of a human team. However, the research is often based on a simplified view of human teams and teamwork. In this study, we sought to better understand the capabilities and limitations of automation from the standpoint of human teams. We first examined human teams to identify the principles for effective teamwork. We next reviewed the research on integrating automation agents and human agents into mixed agent teams to identify the limitations of automation agents to conform to teamwork principles. This research resulted in insights that can lead to more effective human-automation collaboration by enabling a more realistic set of requirements to be developed based on the strengths and limitations of all agents.

  1. Computer automation of high current ion implanters

    NASA Astrophysics Data System (ADS)

    Woodard, Ollie; Lindsey, Paul; Cecil, Joseph; Pipe, Robert

    1985-01-01

    Complete computer automation of a high current ion implanter has been achieved. Special design considerations were necessary for automation including the development of a simplified ion source, a simplified beam transport control function, and a computer aided real-time feedback dosimetry control system. A special, versatile software architecture was also necessary to allow protected operation by unskilled operators, as well as diagnostic and maintenance modes accessible only to qualified personnel. Integral mounting of the DEC LSI-11 computer in the implanter frame provided additional challenges regarding EMI control and the electrical isolation required. The end result is a system in which all pertinent functions of the implanter are computer monitored and controlled continuously, allowing for automatic set-up, operation, on-line fault detection and diagnostics, with recovery software to correct many transient problems as they occur. This paper will discuss both general and specific solutions to the design problems encountered, and will review the system performance from a user point of view.

  2. Management Planning for Workplace Automation.

    ERIC Educational Resources Information Center

    McDole, Thomas L.

    Several factors must be considered when implementing office automation. Included among these are whether or not to automate at all, the effects of automation on employees, requirements imposed by automation on the physical environment, effects of automation on the total organization, and effects on clientele. The reasons behind the success or…

  3. Laboratory Automation and Middleware.

    PubMed

    Riben, Michael

    2015-06-01

    The practice of surgical pathology is under constant pressure to deliver the highest quality of service, reduce errors, increase throughput, and decrease turnaround time while at the same time dealing with an aging workforce, increasing financial constraints, and economic uncertainty. Although not able to implement total laboratory automation, great progress continues to be made in workstation automation in all areas of the pathology laboratory. This report highlights the benefits and challenges of pathology automation, reviews middleware and its use to facilitate automation, and reviews the progress so far in the anatomic pathology laboratory.

  4. Simplified solution of diffraction from a Lyot system

    NASA Astrophysics Data System (ADS)

    Wang, Yaujen; Vaughan, Arthur H.

    1988-01-01

    This paper presents a derivation of a simplified analytical solution of diffraction from a Lyot (1939) system designed for observation of the solar corona outside of eclipses. Applying the theorem of Papoulis (1986) to simplify the calculations, a simplified solution is derived which is found to be in reasonable agreement with the exact solution. The simplified solution suffices for the preliminary evaluation of the amount of diffraction reduction needed to meet certain system requirements and also serves as a guideline for further apodization.

  5. Simplified tools for evaluating domestic ventilation systems

    SciTech Connect

    Maansson, L.G.; Orme, M.

    1999-07-01

    Within an International Energy Agency (IEA) project, Annex 27, experts from 8 countries (Canada, France, Italy, Japan, The Netherlands, Sweden, UK and USA) have developed simplified tools for evaluating domestic ventilation systems during the heating season. Tools for building and user aspects, thermal comfort, noise, energy, life cycle cost, reliability and indoor air quality (IAQ) have been devised. The results can be used both for dwellings at the design stage and after construction. The tools lead to immediate answers and indications about the consequences of different choices that may arise during discussion with clients. This paper presents an introduction to these tools. Examples applications of the indoor air quality and energy simplified tools are also provided. The IAQ tool accounts for constant emission sources, CO{sub 2}, cooking products, tobacco smoke, condensation risks, humidity levels (i.e., for judging the risk for mould and house dust mites), and pressure difference (for identifying the risk for radon or land fill spillage entering the dwelling or problems with indoor combustion appliances). An elaborated set of design parameters were worked out that resulted in about 17,000 combinations. By using multi-variate analysis it was possible to reduce this to 174 combinations for IAQ. In addition, a sensitivity analysis was made using 990 combinations. The results from all the runs were used to develop a simplified tool, as well as quantifying equations relying on the design parameters. A computerized energy tool has also been developed within this project, which takes into account air tightness, climate, window airing pattern, outdoor air flow rate and heat exchange efficiency.

  6. Orbital transfer vehicle launch operations study: Automated technology knowledge base, volume 4

    NASA Technical Reports Server (NTRS)

    1986-01-01

    A simplified retrieval strategy for compiling automation-related bibliographies from NASA/RECON is presented. Two subsets of NASA Thesaurus subject terms were extracted: a primary list, which is used to obtain an initial set of citations; and a secondary list, which is used to limit or further specify a large initial set of citations. These subject term lists are presented in Appendix A as the Automated Technology Knowledge Base (ATKB) Thesaurus.

  7. An automated deformable image registration evaluation of confidence tool

    NASA Astrophysics Data System (ADS)

    Kirby, Neil; Chen, Josephine; Kim, Hojin; Morin, Olivier; Nie, Ke; Pouliot, Jean

    2016-04-01

    Deformable image registration (DIR) is a powerful tool for radiation oncology, but it can produce errors. Beyond this, DIR accuracy is not a fixed quantity and varies on a case-by-case basis. The purpose of this study is to explore the possibility of an automated program to create a patient- and voxel-specific evaluation of DIR accuracy. AUTODIRECT is a software tool that was developed to perform this evaluation for the application of a clinical DIR algorithm to a set of patient images. In brief, AUTODIRECT uses algorithms to generate deformations and applies them to these images (along with processing) to generate sets of test images, with known deformations that are similar to the actual ones and with realistic noise properties. The clinical DIR algorithm is applied to these test image sets (currently 4). From these tests, AUTODIRECT generates spatial and dose uncertainty estimates for each image voxel based on a Student’s t distribution. In this study, four commercially available DIR algorithms were used to deform a dose distribution associated with a virtual pelvic phantom image set, and AUTODIRECT was used to generate dose uncertainty estimates for each deformation. The virtual phantom image set has a known ground-truth deformation, so the true dose-warping errors of the DIR algorithms were also known. AUTODIRECT predicted error patterns that closely matched the actual error spatial distribution. On average AUTODIRECT overestimated the magnitude of the dose errors, but tuning the AUTODIRECT algorithms should improve agreement. This proof-of-principle test demonstrates the potential for the AUTODIRECT algorithm as an empirical method to predict DIR errors.

  8. 29 CFR 2700.104 - Discontinuance of simplified proceedings.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...) Procedure. If it becomes apparent at any time that a case is not appropriate for Simplified Proceedings, the... Simplified Proceedings and order the case to continue under conventional rules. (b) Party motion. At any time... Simplified Proceedings be discontinued and that the matter continue under conventional procedures. A...

  9. 29 CFR 2700.104 - Discontinuance of simplified proceedings.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...) Procedure. If it becomes apparent at any time that a case is not appropriate for Simplified Proceedings, the... Simplified Proceedings and order the case to continue under conventional rules. (b) Party motion. At any time... Simplified Proceedings be discontinued and that the matter continue under conventional procedures. A...

  10. Chronic Meningitis: Simplifying a Diagnostic Challenge.

    PubMed

    Baldwin, Kelly; Whiting, Chris

    2016-03-01

    Chronic meningitis can be a diagnostic dilemma for even the most experienced clinician. Many times, the differential diagnosis is broad and encompasses autoimmune, neoplastic, and infectious etiologies. This review will focus on a general approach to chronic meningitis to simplify the diagnostic challenges many clinicians face. The article will also review the most common etiologies of chronic meningitis in some detail including clinical presentation, diagnostic testing, treatment, and outcomes. By using a case-based approach, we will focus on the key elements of clinical presentation and laboratory analysis that will yield the most rapid and accurate diagnosis in these complicated cases.

  11. A Simplified Model of Intrabeam Scattering

    SciTech Connect

    Bane, Karl LF

    2002-06-03

    Beginning with the general Bjorken-Mtingwa solution, we derive a simplified model of intrabeam scattering (IBS), one valid for high energy beams in normal storage rings; our result is similar, though more accurate than a model due to Raubenheimer. In addition, we show that a modified version of Piwinski's IBS formulation (where {eta}{sub x,y}{sup 2}/{beta}{sub x,y} has been replaced by {Eta}{sub x,y}) at high energies asymptotically approaches the same result.

  12. Simplified dynamic buckling assessment of steel containments

    SciTech Connect

    Farrar, C.R.; Duffey, T.A.; Renick, D.H.

    1993-02-01

    A simplified, three-degree-of-freedom analytical procedure for performing a response spectrum buckling analysis of a thin containment shell is developed. Two numerical examples with R/t values which bound many existing steel containments are used to illustrate the procedure. The role of damping on incipient buckling acceleration level is evaluated for a regulatory seismic spectrum using the two numerical examples. The zero-period acceleration level that causes incipient buckling in either of the two containments increases 31% when damping is increased from 1% to 4% of critical. Comparisons with finite element results on incipient buckling levels are favorable.

  13. Simplified definition system: magnetic products fabrication

    SciTech Connect

    Morris, R.S.

    1981-06-01

    The Simplified Definition System, a product definition approach that differentiates between design and production agency manufacturing requirements, has been used in producing 50 types of magnetic products. This system was formed as a result of cooperative work and proposed modifications by engineers from Bendix Kansas City and Sandia National Laboratories Albuquerque (SNLA) to reduce product costs. The system places responsibility for production-related requirements with a production agency, a procedure that has realized both direct and indirect cost savings. This report is a documentation of the system's description and projected savings on magnetic products.

  14. A Simplified Scheme for Kinematic Source Inversion

    NASA Astrophysics Data System (ADS)

    Iglesias, A.; Castro-Artola, O.; Singh, S.; Hjorleifsdottir, V.; Legrand, D.

    2013-05-01

    It is well known that different kinematic source inversion schemes lead to non-unique solutions. For this reason, a simplified scheme, which yields the main characteristics of the rupture process, rather than the details, may be desirable. In this work we propose a modification of the frequency-domain inversion scheme of Cotton & Campillo (1995) to extract kinematic parameters using simplified geometries (ellipses). The forward problem is re-parameterized by including one or two ellipses in which the displacement is smoothly distributed. For the ellipses we invert for the position of the centers within the fault plane, the major and minor semi-axes, the maximum displacements, the angles of rotation and a parameter that controls the distribution of slip. A simulated annealing scheme is used to invert near-source displacements. We first test the method on synthetic displacement records corresponding to the Guerrero-Oaxaca earthquake (20/03/2012, Mw=7.5) by comparing the results obtained from the modified technique with the original method. In the next step, we use displacements obtained by double numerical integration of recorded accelerograms. We find that, in spite of the simple geometry, the modified method leads to a good fit between observed and synthetic displacements and recovers the main rupture characteristics.

  15. Automating checks of plan check automation.

    PubMed

    Halabi, Tarek; Lu, Hsiao-Ming

    2014-07-08

    While a few physicists have designed new plan check automation solutions for their clinics, fewer, if any, managed to adapt existing solutions. As complex and varied as the systems they check, these programs must gain the full confidence of those who would run them on countless patient plans. The present automation effort, planCheck, therefore focuses on versatility and ease of implementation and verification. To demonstrate this, we apply planCheck to proton gantry, stereotactic proton gantry, stereotactic proton fixed beam (STAR), and IMRT treatments.

  16. WANTED: Fully Automated Indexing.

    ERIC Educational Resources Information Center

    Purcell, Royal

    1991-01-01

    Discussion of indexing focuses on the possibilities of fully automated indexing. Topics discussed include controlled indexing languages such as subject heading lists and thesauri, free indexing languages, natural indexing languages, computer-aided indexing, expert systems, and the need for greater creativity to further advance automated indexing.…

  17. The Automated Office.

    ERIC Educational Resources Information Center

    Naclerio, Nick

    1979-01-01

    Clerical personnel may be able to climb career ladders as a result of office automation and expanded job opportunities in the word processing area. Suggests opportunities in an automated office system and lists books and periodicals on word processing for counselors and teachers. (MF)

  18. Planning for Office Automation.

    ERIC Educational Resources Information Center

    Sherron, Gene T.

    1982-01-01

    The steps taken toward office automation by the University of Maryland are described. Office automation is defined and some types of word processing systems are described. Policies developed in the writing of a campus plan are listed, followed by a section on procedures adopted to implement the plan. (Author/MLW)

  19. Work and Programmable Automation.

    ERIC Educational Resources Information Center

    DeVore, Paul W.

    A new industrial era based on electronics and the microprocessor has arrived, an era that is being called intelligent automation. Intelligent automation, in the form of robots, replaces workers, and the new products, using microelectronic devices, require significantly less labor to produce than the goods they replace. The microprocessor thus…

  20. Order Division Automated System.

    ERIC Educational Resources Information Center

    Kniemeyer, Justin M.; And Others

    This publication was prepared by the Order Division Automation Project staff to fulfill the Library of Congress' requirement to document all automation efforts. The report was originally intended for internal use only and not for distribution outside the Library. It is now felt that the library community at-large may have an interest in the…

  1. Automation and Cataloging.

    ERIC Educational Resources Information Center

    Furuta, Kenneth; And Others

    1990-01-01

    These three articles address issues in library cataloging that are affected by automation: (1) the impact of automation and bibliographic utilities on professional catalogers; (2) the effect of the LASS microcomputer software on the cost of authority work in cataloging at the University of Arizona; and (3) online subject heading and classification…

  2. Automated preliminary design of simplified wing structures to satisfy strength and flutter requirements

    NASA Technical Reports Server (NTRS)

    Stroud, W. J.; Dexter, C. B.; Stein, M.

    1972-01-01

    A simple structural model of an aircraft wing is used to show the effects of strength (stress) and flutter requirements on the design of minimum-weight aircraft-wing structures. The wing is idealized as an isotropic sandwich plate with a variable cover thickness distribution and a variable depth between covers. Plate theory is used for the structural analysis, and piston theory is used for the unsteady aerodynamics in the flutter analysis. Mathematical programming techniques are used to find the minimum-weight cover thickness distribution which satisfies flutter, strength, and minimum-gage constraints. The method of solution, some sample results, and the computer program used to obtain these results are presented. The results indicate that the cover thickness distribution obtained when designing for the strength requirement alone may be quite different from the cover thickness distribution obtained when designing for either the flutter requirement alone or for both the strength and flutter requirements concurrently. This conclusion emphasizes the need for designing for both flutter and strength from the outset.

  3. Automation in Immunohematology

    PubMed Central

    Bajpai, Meenu; Kaur, Ravneet; Gupta, Ekta

    2012-01-01

    There have been rapid technological advances in blood banking in South Asian region over the past decade with an increasing emphasis on quality and safety of blood products. The conventional test tube technique has given way to newer techniques such as column agglutination technique, solid phase red cell adherence assay, and erythrocyte-magnetized technique. These new technologies are adaptable to automation and major manufacturers in this field have come up with semi and fully automated equipments for immunohematology tests in the blood bank. Automation improves the objectivity and reproducibility of tests. It reduces human errors in patient identification and transcription errors. Documentation and traceability of tests, reagents and processes and archiving of results is another major advantage of automation. Shifting from manual methods to automation is a major undertaking for any transfusion service to provide quality patient care with lesser turnaround time for their ever increasing workload. This article discusses the various issues involved in the process. PMID:22988378

  4. Advances in inspection automation

    NASA Astrophysics Data System (ADS)

    Weber, Walter H.; Mair, H. Douglas; Jansen, Dion; Lombardi, Luciano

    2013-01-01

    This new session at QNDE reflects the growing interest in inspection automation. Our paper describes a newly developed platform that makes the complex NDE automation possible without the need for software programmers. Inspection tasks that are tedious, error-prone or impossible for humans to perform can now be automated using a form of drag and drop visual scripting. Our work attempts to rectify the problem that NDE is not keeping pace with the rest of factory automation. Outside of NDE, robots routinely and autonomously machine parts, assemble components, weld structures and report progress to corporate databases. By contrast, components arriving in the NDT department typically require manual part handling, calibrations and analysis. The automation examples in this paper cover the development of robotic thickness gauging and the use of adaptive contour following on the NRU reactor inspection at Chalk River.

  5. An automated mapping satellite system

    NASA Technical Reports Server (NTRS)

    Colvocoreses, A. P.

    1982-01-01

    Topographic maps are compiled by manually operated stereoplotters that recreate the geometry of two wide-angle overlapping stereo frame photographs. Continuous imaging systems such as strip cameras, electro-optical scanners, or linear arrays of detectors (push brooms) can also create stereo coverage from which topography can be compiled; however, the instability of an aircraft in the atmosphere makes this approach impractical. The benign environment of space permits a satellite to orbit the Earth with very high stability as long as no local perturbing forces are involved. Solid-state linear-array sensors have no moving parts and create no perturbing force on the satellite. Digital data from highly stabilized stereo linear arrays are amenable to simplified processing to produce both planimetric imagery and elevation data. A proposed satellite, called MAPSAT, could accomplish automated mapping in near real time. Image maps as large as 1:50,000 scale with contours as close as 20-m interval may be produced from MAPSAT data.

  6. Automated harvesting and processing of protein crystals through laser photoablation.

    PubMed

    Zander, Ulrich; Hoffmann, Guillaume; Cornaciu, Irina; Marquette, Jean-Pierre; Papp, Gergely; Landret, Christophe; Seroul, Gaël; Sinoir, Jérémy; Röwer, Martin; Felisaz, Frank; Rodriguez-Puente, Sonia; Mariaule, Vincent; Murphy, Peter; Mathieu, Magali; Cipriani, Florent; Márquez, José Antonio

    2016-04-01

    Currently, macromolecular crystallography projects often require the use of highly automated facilities for crystallization and X-ray data collection. However, crystal harvesting and processing largely depend on manual operations. Here, a series of new methods are presented based on the use of a low X-ray-background film as a crystallization support and a photoablation laser that enable the automation of major operations required for the preparation of crystals for X-ray diffraction experiments. In this approach, the controlled removal of the mother liquor before crystal mounting simplifies the cryocooling process, in many cases eliminating the use of cryoprotectant agents, while crystal-soaking experiments are performed through diffusion, precluding the need for repeated sample-recovery and transfer operations. Moreover, the high-precision laser enables new mounting strategies that are not accessible through other methods. This approach bridges an important gap in automation and can contribute to expanding the capabilities of modern macromolecular crystallography facilities.

  7. Automated harvesting and processing of protein crystals through laser photoablation

    PubMed Central

    Zander, Ulrich; Hoffmann, Guillaume; Cornaciu, Irina; Marquette, Jean-Pierre; Papp, Gergely; Landret, Christophe; Seroul, Gaël; Sinoir, Jérémy; Röwer, Martin; Felisaz, Frank; Rodriguez-Puente, Sonia; Mariaule, Vincent; Murphy, Peter; Mathieu, Magali; Cipriani, Florent; Márquez, José Antonio

    2016-01-01

    Currently, macromolecular crystallography projects often require the use of highly automated facilities for crystallization and X-ray data collection. However, crystal harvesting and processing largely depend on manual operations. Here, a series of new methods are presented based on the use of a low X-ray-background film as a crystallization support and a photoablation laser that enable the automation of major operations required for the preparation of crystals for X-ray diffraction experiments. In this approach, the controlled removal of the mother liquor before crystal mounting simplifies the cryocooling process, in many cases eliminating the use of cryoprotectant agents, while crystal-soaking experiments are performed through diffusion, precluding the need for repeated sample-recovery and transfer operations. Moreover, the high-precision laser enables new mounting strategies that are not accessible through other methods. This approach bridges an important gap in automation and can contribute to expanding the capabilities of modern macromolecular crystallography facilities. PMID:27050125

  8. Comparative performance evaluation of automated segmentation methods of hippocampus from magnetic resonance images of temporal lobe epilepsy patients

    PubMed Central

    Hosseini, Mohammad-Parsa; Nazem-Zadeh, Mohammad-Reza; Pompili, Dario; Jafari-Khouzani, Kourosh; Elisevich, Kost; Soltanian-Zadeh, Hamid

    2016-01-01

    Purpose: Segmentation of the hippocampus from magnetic resonance (MR) images is a key task in the evaluation of mesial temporal lobe epilepsy (mTLE) patients. Several automated algorithms have been proposed although manual segmentation remains the benchmark. Choosing a reliable algorithm is problematic since structural definition pertaining to multiple edges, missing and fuzzy boundaries, and shape changes varies among mTLE subjects. Lack of statistical references and guidance for quantifying the reliability and reproducibility of automated techniques has further detracted from automated approaches. The purpose of this study was to develop a systematic and statistical approach using a large dataset for the evaluation of automated methods and establish a method that would achieve results better approximating those attained by manual tracing in the epileptogenic hippocampus. Methods: A template database of 195 (81 males, 114 females; age range 32–67 yr, mean 49.16 yr) MR images of mTLE patients was used in this study. Hippocampal segmentation was accomplished manually and by two well-known tools (FreeSurfer and hammer) and two previously published methods developed at their institution [Automatic brain structure segmentation (ABSS) and LocalInfo]. To establish which method was better performing for mTLE cases, several voxel-based, distance-based, and volume-based performance metrics were considered. Statistical validations of the results using automated techniques were compared with the results of benchmark manual segmentation. Extracted metrics were analyzed to find the method that provided a more similar result relative to the benchmark. Results: Among the four automated methods, ABSS generated the most accurate results. For this method, the Dice coefficient was 5.13%, 14.10%, and 16.67% higher, Hausdorff was 22.65%, 86.73%, and 69.58% lower, precision was 4.94%, −4.94%, and 12.35% higher, and the root mean square (RMS) was 19.05%, 61.90%, and 65.08% lower than

  9. Combustion Safety Simplified Test Protocol Field Study

    SciTech Connect

    Brand, L.; Cautley, D.; Bohac, D.; Francisco, P.; Shen, L.; Gloss, S.

    2015-11-01

    Combustions safety is an important step in the process of upgrading homes for energy efficiency. There are several approaches used by field practitioners, but researchers have indicated that the test procedures in use are complex to implement and provide too many false positives. Field failures often mean that the house is not upgraded until after remediation or not at all, if not include in the program. In this report the PARR and NorthernSTAR DOE Building America Teams provide a simplified test procedure that is easier to implement and should produce fewer false positives. A survey of state weatherization agencies on combustion safety issues, details of a field data collection instrumentation package, summary of data collected over seven months, data analysis and results are included. The project team collected field data on 11 houses in 2015.

  10. Constructing Simplified Plans via Truth Criteria Approximation

    NASA Technical Reports Server (NTRS)

    Chien, S.; DeJong, G.

    1994-01-01

    This paper has presented an approach to dealing with the complexity of explanation-based learning plans in complex domains. This approach uses a simplified algorithm to construct plans, and employs later refinements to repair bugs in constructed plans. This algorithm has the theoretical properties of completeness and convergence upon soundness. This incremental reasoning planning and learning algorithm has been implemented using a partial-order constraint posting planner and empirically compared to a conventional exhaustive reasoning partial-order constraint-posting planner and learning algorithm. This comparison showed that 1) incremental reasoning significantly reduced learning costs compared to exhaustive reasoning, 2) Explanation-based Learning (EBL) reduced failures from incremental reasoning, 3) EBL with incremental reasoning required less search to solve problems than EBL with exhaustive reasoning.

  11. Nonlinear optimization simplified by hypersurface deformation

    SciTech Connect

    Stillinger, F.H.; Weber, T.A.

    1988-09-01

    A general strategy is advanced for simplifying nonlinear optimization problems, the ant-lion method. This approach exploits shape modifications of the cost-function hypersurface which distend basins surrounding low-lying minima (including global minima). By intertwining hypersurface deformations with steepest-descent displacements, the search is concentrated on a small relevant subset of all minima. Specific calculations demonstrating the value of this method are reported for the partitioning of two classes of irregular but nonrandom graphs, the prime-factor graphs and the pi graphs. We also indicate how this approach can be applied to the traveling salesman problem and to design layout optimization, and that it may be useful in combination with simulated annealing strategies.

  12. Aeroacoustic Analysis of a Simplified Landing Gear

    NASA Technical Reports Server (NTRS)

    Lockard, David P.; Khorrami, Mehdi, R.; Li, Fei

    2004-01-01

    A hybrid approach is used to investigate the noise generated by a simplified landing gear without small scale parts such as hydraulic lines and fasteners. The Ffowcs Williams and Hawkings equation is used to predict the noise at far-field observer locations from flow data provided by an unsteady computational fluid dynamics calculation. A simulation with 13 million grid points has been completed, and comparisons are made between calculations with different turbulence models. Results indicate that the turbulence model has a profound effect on the levels and character of the unsteadiness. Flow data on solid surfaces and a set of permeable surfaces surrounding the gear have been collected. Noise predictions using the porous surfaces appear to be contaminated by errors caused by large wake fluctuations passing through the surfaces. However, comparisons between predictions using the solid surfaces with the near-field CFD solution are in good agreement giving confidence in the far-field results.

  13. Effectiveness of simplified dentin bonding systems.

    PubMed

    Imai, T; Itoh, K; Tani, C; Manabe, A; Yamashita, T; Hisamitsu, H; Wakumoto, S

    1998-03-01

    The effectiveness of newly developed commercial dentin bonding systems (SB, MB II and KB) was evaluated by measuring the contraction gap width of a resin composite restored into a cylindrical dentin cavity prepared in an extracted human molar and by measuring the tensile bond strength to the flat dentin surface. In addition, calcium loss during dentin conditioning was analyzed using electron microanalyses. An experimental dentin bonding system composed of EDTA conditioning, GM solution priming and a bonding agent containing 10-MDP was employed as a control in which it was presumed that contraction gap formation was prevented completely. However, gap formation was observed using the three commercial simplified dentin bonding systems. SEM observation showed that the gap was formed between the resin composite and the top surface of the dentin cavity wall indicating that the fracture occurred at the adhesive interface, but never inside the dentin nor inside the resin composite.

  14. Simplified Model of Nonlinear Landau Damping

    SciTech Connect

    N. A. Yampolsky and N. J. Fisch

    2009-07-16

    The nonlinear interaction of a plasma wave with resonant electrons results in a plateau in the electron distribution function close to the phase velocity of the plasma wave. As a result, Landau damping of the plasma wave vanishes and the resonant frequency of the plasma wave downshifts. However, this simple picture is invalid when the external driving force changes the plasma wave fast enough so that the plateau cannot be fully developed. A new model to describe amplification of the plasma wave including the saturation of Landau damping and the nonlinear frequency shift is proposed. The proposed model takes into account the change of the plasma wave amplitude and describes saturation of the Landau damping rate in terms of a single fluid equation, which simplifies the description of the inherently kinetic nature of Landau damping. A proposed fluid model, incorporating these simplifications, is verified numerically using a kinetic Vlasov code.

  15. Entropy reduction via simplified image contourization

    NASA Technical Reports Server (NTRS)

    Turner, Martin J.

    1993-01-01

    The process of contourization is presented which converts a raster image into a set of plateaux or contours. These contours can be grouped into a hierarchical structure, defining total spatial inclusion, called a contour tree. A contour coder has been developed which fully describes these contours in a compact and efficient manner and is the basis for an image compression method. Simplification of the contour tree has been undertaken by merging contour tree nodes thus lowering the contour tree's entropy. This can be exploited by the contour coder to increase the image compression ratio. By applying general and simple rules derived from physiological experiments on the human vision system, lossy image compression can be achieved which minimizes noticeable artifacts in the simplified image.

  16. Space station ECLSS simplified integrated test

    NASA Technical Reports Server (NTRS)

    Schunk, Richard G.; Bagdigian, Robert M.; Carrasquillo, Robyn L.; Ogle, Kathyrn Y.; Wieland, Paul O.

    1989-01-01

    A discussion of the Space Station Simplified Integrated Test (SIT) was conducted. The first in a series of three integrated Environmental Control and Life Support (ECLS) system tests, the primary objectives of the SIT were to verify proper operation of ECLS subsystems functioning in an integrated fashion as well as to gather preliminary performance data for the partial ECLS system used in the test. A description of the SIT configuration, a summary of events, a discussion of anomalies that occurred during the test, and detailed results and analysis from individual measurements and water and gas samples taken during the test are included. The preprototype ECLS hardware used in the test is reported providing an overall process description and theory of operation for each hardware item.

  17. Simplifying the circuit of Josephson parametric converters

    NASA Astrophysics Data System (ADS)

    Abdo, Baleegh; Brink, Markus; Chavez-Garcia, Jose; Keefe, George

    Josephson parametric converters (JPCs) are quantum-limited three-wave mixing devices that can play various important roles in quantum information processing in the microwave domain, including amplification of quantum signals, transduction of quantum information, remote entanglement of qubits, nonreciprocal amplification, and circulation of signals. However, the input-output and biasing circuit of a state-of-the-art JPC consists of bulky components, i.e. two commercial off-chip broadband 180-degree hybrids, four phase-matched short coax cables, and one superconducting magnetic coil. Such bulky hardware significantly hinders the integration of JPCs in scalable quantum computing architectures. In my talk, I will present ideas on how to simplify the JPC circuit and show preliminary experimental results

  18. Miniaturized photoelectric angular sensor with simplified design

    NASA Astrophysics Data System (ADS)

    Dumbravescu, Niculae; Schiaua, Silviu

    1999-09-01

    In building the movable elements of robots, peripheral devices and measuring apparata, increasing the resolution of the angular sensor systems, based on incremental rotary encoders, is essential, together with decreasing the complexity, dimensions and weight. Especially when the angular sensor is integrated in a measuring system, belonging to a programmed light airplane for surveillance, the key issue is to reduce both dimensions and weight. This can be done using a simplified design, which consists in the following solutions: replacement of the fragile Cr on glass substrate, 1.5 mm thick (normally used for the fabrication of incremental disks), with light Cr on polycarbonate substrate, with only 0.15 mm thick; the absence of collimating optics (based on microlenses, used in IR emitter-photocell receiver assembly), as a result of the good coupling efficiency (due to the possible approaching of these elements at minimum 0.45 mm); the shrinkage of the disk's diameters to only 14 mm; the use of surface mounting devices and the related surface mounting technology, enabling to reduce dimensions and weight. The maximum number of slits on a 14 mm diameter dividing disk, usually obtained in a Cr on polycarbonate version, being approx. 1000, no problem occurs in our case, for 360 slits. The requested angular resolution (only 0.5 degrees for the light airplane), using the whole classical '4x digital multiplication' is not necessary, but a lower one of only 2x, resulting in a simplified electronics. The proposed design permitted, that an original arrangement, for building a small size, lightweight, heavy-duty incremental transducer based angular sensor system, to be obtained, useful not only in avionics, but also in robotics, or other special applications. Besides, extending the number of fixed gratings (masks) allows, that many primary signals to be derived, and a further increase in resolution of even 6 angular minutes to be obtained from the initial 360 slits.

  19. Using Automated Theorem Provers to Certify Auto-Generated Aerospace Software

    NASA Technical Reports Server (NTRS)

    Denney, Ewen; Fischer, Bernd; Schumann, Johann

    2004-01-01

    We describe a system for the automated certification of safety properties of NASA software. The system uses Hoare-style program verification technology to generate proof obligations which are then processed by an automated first-order theorem prover (ATP). For full automation, however, the obligations must be aggressively preprocessed and simplified We describe the unique requirements this places on the ATP and demonstrate how the individual simplification stages, which are implemented by rewriting, influence the ability of the ATP to solve the proof tasks. Experiments on more than 25,000 tasks were carried out using Vampire, Spass, and e-setheo.

  20. Managing laboratory automation

    PubMed Central

    Saboe, Thomas J.

    1995-01-01

    This paper discusses the process of managing automated systems through their life cycles within the quality-control (QC) laboratory environment. The focus is on the process of directing and managing the evolving automation of a laboratory; system examples are given. The author shows how both task and data systems have evolved, and how they interrelate. A BIG picture, or continuum view, is presented and some of the reasons for success or failure of the various examples cited are explored. Finally, some comments on future automation need are discussed. PMID:18925018

  1. Rapid Assemblers for Voxel-Based VLSI Robotics

    DTIC Science & Technology

    2014-02-12

    of Chemical and Biomolecular Engineering, Dr. Paul Steen and his research group have developed electro- osmosis droplet switches (EODS) that can move...throughout the electro- osmosis process. As the voltage changes the water moves from one side of the frit to the other, pushing up the droplet on one...the velocity was induced but in the opposite direction causing the other droplet to grow. These stills can be seen below. II Electro- Osmosis

  2. Automated Scoring of Constructed-Response Science Items: Prospects and Obstacles

    ERIC Educational Resources Information Center

    Liu, Ou Lydia; Brew, Chris; Blackmore, John; Gerard, Libby; Madhok, Jacquie; Linn, Marcia C.

    2014-01-01

    Content-based automated scoring has been applied in a variety of science domains. However, many prior applications involved simplified scoring rubrics without considering rubrics representing multiple levels of understanding. This study tested a concept-based scoring tool for content-based scoring, c-rater™, for four science items with rubrics…

  3. Automated diagnosis and prediction of Alzheimer disease using magnetic resonance image

    NASA Astrophysics Data System (ADS)

    Cai, Zifan; Di, Qian; Chen, Kewei; Reiman, Eric M.; Wang, Liang; Li, Kuncheng; Tang, Jie; Yao, Li; Zhao, Xiaojie

    2007-03-01

    Magnetic resonance image (MRI) has provided an imageological support into the clinical diagnosis and prediction of Alzheimer disease (AD) progress. Currently, the clinical use of MRI data on AD diagnosis is qualitative via visual inspection and less accurate. To provide assistance to physicians in improving the accuracy and sensitivity of the AD diagnose and the clinical outcome of the disease, we developed a computer-assisted analysis package that analyzed the MRI data of an individual patient in comparison with a group of normal controls. The package is based on the principle of the well established and widely used voxel-based morphometry (VBM) and SPM software. All analysis procedure is automated and streamlined. With only one mouse-click, the whole procedure was finished within 15 minutes. With the interactive display and anatomical automatic labeling toolbox, the final result and report supply the brain regional structure difference, the quantitative assessment and visual inspections by physicians and scientific researcher. The brain regions which affected by AD are consonant in the main with the clinical diagnosis, which are reviewed by physicians. In result, the computer package provides physician with an automatic and assistant tool for prediction using MRI. This package could be valuable tool assisting physicians in making their clinical diagnosis decisions.

  4. Rapid automated three-dimensional tracing of neurons from confocal image stacks.

    PubMed

    Al-Kofahi, Khalid A; Lasek, Sharie; Szarowski, Donald H; Pace, Christopher J; Nagy, George; Turner, James N; Roysam, Badrinath

    2002-06-01

    Algorithms are presented for fully automatic three-dimensional (3-D) tracing of neurons that are imaged by fluorescence confocal microscopy. Unlike previous voxel-based skeletonization methods, the present approach works by recursively following the neuronal topology, using a set of 4 x N2 directional kernels (e.g., N = 32), guided by a generalized 3-D cylinder model. This method extends our prior work on exploratory tracing of retinal vasculature to 3-D space. Since the centerlines are of primary interest, the 3-D extension can be accomplished by four rather than six sets of kernels. Additional modifications, such as dynamic adaptation of the correlation kernels, and adaptive step size estimation, were introduced for achieving robustness to photon noise, varying contrast, and apparent discontinuity and/or hollowness of structures. The end product is a labeling of all somas present, graph-theoretic representations of all dendritic/axonal structures, and image statistics such as soma volume and centroid, soma interconnectivity, the longest branch, and lengths of all graph branches originating from a soma. This method is able to work directly with unprocessed confocal images, without expensive deconvolution or other preprocessing. It is much faster that skeletonization, typically consuming less than a minute to trace a 70-MB image on a 500-MHz computer. These properties make it attractive for large-scale automated tissue studies that require rapid on-line image analysis, such as high-throughput neurobiology/angiogenesis assays, and initiatives such as the Human Brain Project.

  5. Automated decision stations

    NASA Technical Reports Server (NTRS)

    Tischendorf, Mark

    1990-01-01

    This paper discusses the combination of software robots and expert systems to automate everyday business tasks. Tasks which require people to repetitively interact with multiple systems screens as well as multiple systems.

  6. Automating the Media Center.

    ERIC Educational Resources Information Center

    Holloway, Mary A.

    1988-01-01

    Discusses the need to develop more efficient information retrieval skills by the use of new technology. Lists four stages used in automating the media center. Describes North Carolina's pilot programs. Proposes benefits and looks at the media center's future. (MVL)

  7. Planning for Office Automation.

    ERIC Educational Resources Information Center

    Mick, Colin K.

    1983-01-01

    Outlines a practical approach to planning for office automation termed the "Focused Process Approach" (the "what" phase, "how" phase, "doing" phase) which is a synthesis of the problem-solving and participatory planning approaches. Thirteen references are provided. (EJS)

  8. Xenon International Automated Control

    SciTech Connect

    2016-08-05

    The Xenon International Automated Control software monitors, displays status, and allows for manual operator control as well as fully automatic control of multiple commercial and PNNL designed hardware components to generate and transmit atmospheric radioxenon concentration measurements every six hours.

  9. Development of an automated fuzing station for the future armored resupply vehicle

    SciTech Connect

    Chesser, J.B.; Jansen, J.F.; Lloyd, P.D.; Varma, V.K.

    1995-03-01

    The US Army is developing the Advanced Field Artillery System (SGSD), a next generation armored howitzer. The Future Armored Resupply Vehicle (FARV) will be its companion ammunition resupply vehicle. The FARV with automate the supply of ammunition and fuel to the AFAS which will increase capabilities over the current system. One of the functions being considered for automation is ammunition processing. Oak Ridge National Laboratory is developing equipment to demonstrate automated ammunition processing. One of the key operations to be automated is fuzing. The projectiles are initially unfuzed, and a fuze must be inserted and threaded into the projectile as part of the processing. A constraint on the design solution is that the ammunition cannot be modified to simplify automation. The problem was analyzed to determine the alignment requirements. Using the results of the analysis, ORNL designed, built, and tested a test stand to verify the selected design solution.

  10. Automated Cyber Red Teaming

    DTIC Science & Technology

    2015-04-01

    possible attack paths for CRT. This report surveys the current state-of-the- art planning techniques, tools and frameworks, their performance at...6 3.3 State of the art Automated Planning ..................................................................... 7 3.3.1...automated planning to CRT problems. Finally, we recommend several state-of-the- art planning tools for trial and, more generally, when it is suitable to use

  11. Automating Index Preparation

    DTIC Science & Technology

    1987-03-23

    Automating Index Preparation* Pehong Chent Michael A. Harrison Computer Science Division University of CaliforniaI Berkeley, CA 94720 March 23, 1987...Abstract Index preparation is a tedious and time-consuming task. In this paper we indicate * how the indexing process can be automated in a way which...identified and analyzed. Specifically, we describe a framework for placing index commands in the document and a general purpose index processor which

  12. Automated Pilot Advisory System

    NASA Technical Reports Server (NTRS)

    Parks, J. L., Jr.; Haidt, J. G.

    1981-01-01

    An Automated Pilot Advisory System (APAS) was developed and operationally tested to demonstrate the concept that low cost automated systems can provide air traffic and aviation weather advisory information at high density uncontrolled airports. The system was designed to enhance the see and be seen rule of flight, and pilots who used the system preferred it over the self announcement system presently used at uncontrolled airports.

  13. Automated Lattice Perturbation Theory

    SciTech Connect

    Monahan, Christopher

    2014-11-01

    I review recent developments in automated lattice perturbation theory. Starting with an overview of lattice perturbation theory, I focus on the three automation packages currently "on the market": HiPPy/HPsrc, Pastor and PhySyCAl. I highlight some recent applications of these methods, particularly in B physics. In the final section I briefly discuss the related, but distinct, approach of numerical stochastic perturbation theory.

  14. Automated Status Notification System

    NASA Technical Reports Server (NTRS)

    2005-01-01

    NASA Lewis Research Center's Automated Status Notification System (ASNS) was born out of need. To prevent "hacker attacks," Lewis' telephone system needed to monitor communications activities 24 hr a day, 7 days a week. With decreasing staff resources, this continuous monitoring had to be automated. By utilizing existing communications hardware, a UNIX workstation, and NAWK (a pattern scanning and processing language), we implemented a continuous monitoring system.

  15. Automated Groundwater Screening

    SciTech Connect

    Taylor, Glenn A.; Collard, Leonard, B.

    2005-10-31

    The Automated Intruder Analysis has been extended to include an Automated Ground Water Screening option. This option screens 825 radionuclides while rigorously applying the National Council on Radiation Protection (NCRP) methodology. An extension to that methodology is presented to give a more realistic screening factor for those radionuclides which have significant daughters. The extension has the promise of reducing the number of radionuclides which must be tracked by the customer. By combining the Automated Intruder Analysis with the Automated Groundwater Screening a consistent set of assumptions and databases is used. A method is proposed to eliminate trigger values by performing rigorous calculation of the screening factor thereby reducing the number of radionuclides sent to further analysis. Using the same problem definitions as in previous groundwater screenings, the automated groundwater screening found one additional nuclide, Ge-68, which failed the screening. It also found that 18 of the 57 radionuclides contained in NCRP Table 3.1 failed the screening. This report describes the automated groundwater screening computer application.

  16. Metrology automation reliability

    NASA Astrophysics Data System (ADS)

    Chain, Elizabeth E.

    1996-09-01

    At Motorola's MOS-12 facility automated measurements on 200- mm diameter wafers proceed in a hands-off 'load-and-go' mode requiring only wafer loading, measurement recipe loading, and a 'run' command for processing. Upon completion of all sample measurements, the data is uploaded to the factory's data collection software system via a SECS II interface, eliminating the requirement of manual data entry. The scope of in-line measurement automation has been extended to the entire metrology scheme from job file generation to measurement and data collection. Data analysis and comparison to part specification limits is also carried out automatically. Successful integration of automated metrology into the factory measurement system requires that automated functions, such as autofocus and pattern recognition algorithms, display a high degree of reliability. In the 24- hour factory reliability data can be collected automatically on every part measured. This reliability data is then uploaded to the factory data collection software system at the same time as the measurement data. Analysis of the metrology reliability data permits improvements to be made as needed, and provides an accurate accounting of automation reliability. This reliability data has so far been collected for the CD-SEM (critical dimension scanning electron microscope) metrology tool, and examples are presented. This analysis method can be applied to such automated in-line measurements as CD, overlay, particle and film thickness measurements.

  17. Simplified Modeling of Oxidation of Hydrocarbons

    NASA Technical Reports Server (NTRS)

    Bellan, Josette; Harstad, Kenneth

    2008-01-01

    A method of simplified computational modeling of oxidation of hydrocarbons is undergoing development. This is one of several developments needed to enable accurate computational simulation of turbulent, chemically reacting flows. At present, accurate computational simulation of such flows is difficult or impossible in most cases because (1) the numbers of grid points needed for adequate spatial resolution of turbulent flows in realistically complex geometries are beyond the capabilities of typical supercomputers now in use and (2) the combustion of typical hydrocarbons proceeds through decomposition into hundreds of molecular species interacting through thousands of reactions. Hence, the combination of detailed reaction- rate models with the fundamental flow equations yields flow models that are computationally prohibitive. Hence, further, a reduction of at least an order of magnitude in the dimension of reaction kinetics is one of the prerequisites for feasibility of computational simulation of turbulent, chemically reacting flows. In the present method of simplified modeling, all molecular species involved in the oxidation of hydrocarbons are classified as either light or heavy; heavy molecules are those having 3 or more carbon atoms. The light molecules are not subject to meaningful decomposition, and the heavy molecules are considered to decompose into only 13 specified constituent radicals, a few of which are listed in the table. One constructs a reduced-order model, suitable for use in estimating the release of heat and the evolution of temperature in combustion, from a base comprising the 13 constituent radicals plus a total of 26 other species that include the light molecules and related light free radicals. Then rather than following all possible species through their reaction coordinates, one follows only the reduced set of reaction coordinates of the base. The behavior of the base was examined in test computational simulations of the combustion of

  18. Elements of EAF automation processes

    NASA Astrophysics Data System (ADS)

    Ioana, A.; Constantin, N.; Dragna, E. C.

    2017-01-01

    Our article presents elements of Electric Arc Furnace (EAF) automation. So, we present and analyze detailed two automation schemes: the scheme of electrical EAF automation system; the scheme of thermic EAF automation system. The application results of these scheme of automation consists in: the sensitive reduction of specific consummation of electrical energy of Electric Arc Furnace, increasing the productivity of Electric Arc Furnace, increase the quality of the developed steel, increasing the durability of the building elements of Electric Arc Furnace.

  19. Combustion Safety Simplified Test Protocol Field Study

    SciTech Connect

    Brand, L; Cautley, D.; Bohac, D.; Francisco, P.; Shen, L.; Gloss, S.

    2015-11-05

    "9Combustions safety is an important step in the process of upgrading homes for energy efficiency. There are several approaches used by field practitioners, but researchers have indicated that the test procedures in use are complex to implement and provide too many false positives. Field failures often mean that the house is not upgraded until after remediation or not at all, if not include in the program. In this report the PARR and NorthernSTAR DOE Building America Teams provide a simplified test procedure that is easier to implement and should produce fewer false positives. A survey of state weatherization agencies on combustion safety issues, details of a field data collection instrumentation package, summary of data collected over seven months, data analysis and results are included. The project provides several key results. State weatherization agencies do not generally track combustion safety failures, the data from those that do suggest that there is little actual evidence that combustion safety failures due to spillage from non-dryer exhaust are common and that only a very small number of homes are subject to the failures. The project team collected field data on 11 houses in 2015. Of these homes, two houses that demonstrated prolonged and excessive spillage were also the only two with venting systems out of compliance with the National Fuel Gas Code. The remaining homes experienced spillage that only occasionally extended beyond the first minute of operation. Combustion zone depressurization, outdoor temperature, and operation of individual fans all provide statistically significant predictors of spillage.

  20. Simplified liquid oxygen propellant conditioning concepts

    NASA Technical Reports Server (NTRS)

    Cleary, N. L.; Holt, K. A.; Flachbart, R. H.

    1995-01-01

    Current liquid oxygen feed systems waste propellant and use hardware, unnecessary during flight, to condition the propellant at the engine turbopumps prior to launch. Simplified liquid oxygen propellant conditioning concepts are being sought for future launch vehicles. During a joint program, four alternative propellant conditioning options were studied: (1) passive recirculation; (2) low bleed through the engine; (3) recirculation lines; and (4) helium bubbling. The test configuration for this program was based on a vehicle design which used a main recirculation loop that was insulated on the downcomer and uninsulated on the upcomer. This produces a natural convection recirculation flow. The test article for this program simulated a feedline which ran from the main recirculation loop to the turbopump. The objective was to measure the temperature profile of this test article. Several parameters were varied from the baseline case to determine their effects on the temperature profile. These parameters included: flow configuration, feedline slope, heat flux, main recirculation loop velocity, pressure, bleed rate, helium bubbling, and recirculation lines. The heat flux, bleed rate, and recirculation configurations produced the greatest changes from the baseline temperature profile. However, the temperatures in the feedline remained subcooled. Any of the options studied could be used in future vehicles.

  1. Simplified limits on resonances at the LHC

    NASA Astrophysics Data System (ADS)

    Chivukula, R. Sekhar; Ittisamai, Pawin; Mohan, Kirtimaan; Simmons, Elizabeth H.

    2016-11-01

    In the earliest stages of evaluating new collider data, especially if a small excess may be present, it would be useful to have a method for comparing the data with entire classes of models, to get an immediate sense of which classes could conceivably be relevant. In this paper, we propose a method that applies when the new physics invoked to explain the excess corresponds to the production and decay of a single, relatively narrow, s -channel resonance. A simplifed model of the resonance allows us to convert an estimated signal cross section into general bounds on the product of the branching ratios corresponding to the dominant production and decay modes. This quickly reveals whether a given class of models could possibly produce a signal of the required size at the LHC. Our work sets up a general framework, outlines how it operates for resonances with different numbers of production and decay modes, and analyzes cases of current experimental interest, including resonances decaying to dibosons, diphotons, dileptons, or dijets. If the LHC experiments were to report their searches for new resonances beyond the standard model in the simplified limits variable ζ defined in this paper, that would make it far easier to avoid blind alleys and home in on the most likely candidate models to explain any observed excesses.

  2. Simplified Optics and Controls for Laser Communications

    NASA Technical Reports Server (NTRS)

    Chen, Chien-Chung; Hemmati, Hamid

    2006-01-01

    A document discusses an architecture of a spaceborne laser communication system that provides for a simplified control subsystem that stabilizes the line of sight in a desired direction. Heretofore, a typical design for a spaceborne laser communication system has called for a high-bandwidth control loop, a steering mirror and associated optics, and a fast steering-mirror actuator to stabilize the line of sight in the presence of vibrations. In the present architecture, the need for this fast steering-mirror subsystem is eliminated by mounting the laser-communication optics on a disturbance-free platform (DFP) that suppresses coupling of vibrations to the optics by 60 dB. Taking advantage of microgravitation, in the DFP, the optical assembly is free-flying relative to the rest of the spacecraft, and a low-spring-constant pointing control subsystem exerts small forces to regulate the position and orientation of the optics via voice coils. All steering is effected via the DFP, which can be controlled in all six degrees of freedom relative to the spacecraft. A second control loop, closed around a position sensor and the spacecraft attitude-control system, moves the spacecraft as needed to prevent mechanical contact with the optical assembly.

  3. A clinically useful simplified blastocyst grading system.

    PubMed

    Richardson, Alison; Brearley, Sophie; Ahitan, Saran; Chamberlain, Sarah; Davey, Tracey; Zujovic, Lyndsey; Hopkisson, James; Campbell, Bruce; Raine-Fenning, Nick

    2015-10-01

    The aim of this study was to investigate whether a new simplified blastocyst grading system (A: fully expanded, clear inner cell mass, cohesive trophectoderm; B: not yet expanded, clear inner cell mass, cohesive trophectoderm; C: small inner cell mass ± irregular trophectoderm ± excluded/degenerate cells) was clinically useful. All day-5 single embryo transfers between 15 June 2009 and 29 June 2012 were reviewed. Implantation, clinical pregnancy and live birth rates were related to embryo quality. Five embryologists were asked to grade and decide the clinical fate of 80 images of day-5 embryos on two occasions 4-6 weeks apart. Implantation, clinical pregnancy and live birth rates decreased with deteriorating embryo quality. A highly significant (P < 0.01) difference was observed between the groups. Inter-observer agreement was substantial for grade allocation (K = 0.63) and clinical decision-making (K = 0.66). Intra-observer agreement ranged from substantial (K = 0.71) to almost perfect (K = 0.88) for grade allocation, and was almost perfect for clinical fate determination (K ≥ 0.84). This grading system is quick and easy to use, effectively predicts IVF outcome and has levels of agreement similar to, if not better than, those associated with more complex grading systems.

  4. Interferometric phase reconstruction using simplified coherence network

    NASA Astrophysics Data System (ADS)

    Zhang, Kui; Song, Ruiqing; Wang, Hui; Wu, Di; Wang, Hua

    2016-09-01

    Interferometric time-series analysis techniques, which extend the traditional differential radar interferometry, have demonstrated a strong capability for monitoring ground surface displacement. Such techniques are able to obtain the temporal evolution of ground deformation within millimeter accuracy by using a stack of synthetic aperture radar (SAR) images. In order to minimize decorrelation between stacked SAR images, the phase reconstruction technique has been developed recently. The main idea of this technique is to reform phase observations along a SAR stack by taking advantage of a maximum likelihood estimator which is defined on the coherence matrix estimated from each target. However, the phase value of a coherence matrix element might be considerably biased when its corresponding coherence is low. In this case, it will turn to an outlying sample affecting the corresponding phase reconstruction process. In order to avoid this problem, a new approach is developed in this paper. This approach considers a coherence matrix element to be an arc in a network. A so-called simplified coherence network (SCN) is constructed to decrease the negative impact of outlying samples. Moreover, a pointed iterative strategy is designed to resolve the transformed phase reconstruction problem defined on a SCN. For validation purposes, the proposed method is applied to 29 real SAR images. The results demonstrate that the proposed method has an excellent computational efficiency and could obtain more reliable phase reconstruction solutions compared to the traditional method using phase triangulation algorithm.

  5. Simplified Dynamic Analysis of Grinders Spindle Node

    NASA Astrophysics Data System (ADS)

    Demec, Peter

    2014-12-01

    The contribution deals with the simplified dynamic analysis of surface grinding machine spindle node. Dynamic analysis is based on the use of the transfer matrix method, which is essentially a matrix form of method of initial parameters. The advantage of the described method, despite the seemingly complex mathematical apparatus, is primarily, that it does not require for solve the problem of costly commercial software using finite element method. All calculations can be made for example in MS Excel, which is advantageous especially in the initial stages of constructing of spindle node for the rapid assessment of the suitability its design. After detailing the entire structure of spindle node is then also necessary to perform the refined dynamic analysis in the environment of FEM, which it requires the necessary skills and experience and it is therefore economically difficult. This work was developed within grant project KEGA No. 023TUKE-4/2012 Creation of a comprehensive educational - teaching material for the article Production technique using a combination of traditional and modern information technology and e-learning.

  6. Simplified lattice model for polypeptide fibrillar transitions

    NASA Astrophysics Data System (ADS)

    Xiao, Xuhui; Wu, Ming-Chya

    2014-10-01

    Polypeptide fibrillar transitions are studied using a simplified lattice model, modified from the three-state Potts model, where uniform residues as spins, placed on a cubic lattice, can interact with neighbors to form coil, helical, sheet, or fibrillar structure. Using the transfer matrix method and numerical calculations, we analyzed the partition function and construct phase diagrams. The model manifests phase transitions among coil, helix, sheet, and fibril through parameterizing bond coupling energy ɛh,ɛs,ɛf, structural entropies sh,ss,sf of helical, sheet, and fibrillar states, and number density ρ. The phase diagrams show the transition sequence is basically governed by ɛh, ɛs, and ɛf, while the transition temperature is determined by the competition among ɛh, ɛs, and ɛf, as well as sh, ss, sf, and ρ. Furthermore, the fibrillation is accompanied with an abrupt phase transition from coil, helix, or sheet to fibril even for short polypeptide length, resembling the feature of nucleation-growth process. The finite-size effect in specific heat at transitions for the nonfibrillation case can be described by the scaling form of lattice model. With rich phase-transition properties, our model provides a useful reference for protein aggregation experiments and modeling.

  7. Simplified Storm Surge Simulations Using Bernstein Polynomials

    NASA Astrophysics Data System (ADS)

    Beisiegel, Nicole; Behrens, Jörn

    2016-04-01

    Storm surge simulations are vital for forecasting, hazard assessment and eventually improving our understanding of Earth system processes. Discontinuous Galerkin (DG) methods have recently been explored in that context, because they are locally mass-conservative and in combination with suitable robust nodal filtering techniques (slope limiters) positivity-preserving and well-balanced for the still water state at rest. These filters manipulate interpolation point values in every time step in order to retain the desirable properties of the scheme. In particular, DG methods are able to represent prognostic variables such as the fluid height at high-order accuracy inside each element (triangle). For simulations that include wetting and drying, however, the high-order accuracy will destabilize the numerical model because point values on quadrature points may become negative during the computation if they do not coincide with interpolation points. This is why the model that we are presenting utilizes Bernstein polynomials as basis functions to model the wetting and drying. This has the advantage that negative pointvalues away from interpolation points are prevented, the model is stabilized and no additional time step restriction is introduced. Numerical tests show that the model is capable of simulating simplified storm surges. Furthermore, a comparison of model results with third-order Bernstein polynomials with results using traditional nodal Lagrange polynomials reveals an improvement in numerical convergence.

  8. Predictive processing simplified: The infotropic machine.

    PubMed

    Thornton, Chris

    2017-03-01

    On a traditional view of cognition, we see the agent acquiring stimuli, interpreting these in some way, and producing behavior in response. An increasingly popular alternative is the predictive processing framework. This sees the agent as continually generating predictions about the world, and responding productively to any errors made. Partly because of its heritage in the Bayesian brain theory, predictive processing has generally been seen as an inherently Bayesian process. The 'hierarchical prediction machine' which mediates it is envisaged to be a specifically Bayesian device. But as this paper shows, a specification for this machine can also be derived directly from information theory, using the metric of predictive payoff as an organizing concept. Hierarchical prediction machines can be built along purely information-theoretic lines, without referencing Bayesian theory in any way; this simplifies the account to some degree. The present paper describes what is involved and presents a series of working models. An experiment involving the conversion of a Braitenberg vehicle to use a controller of this type is also described.

  9. The Effect of Information Analysis Automation Display Content on Human Judgment Performance in Noisy Environments

    PubMed Central

    Bass, Ellen J.; Baumgart, Leigh A.; Shepley, Kathryn Klein

    2014-01-01

    Displaying both the strategy that information analysis automation employs to makes its judgments and variability in the task environment may improve human judgment performance, especially in cases where this variability impacts the judgment performance of the information analysis automation. This work investigated the contribution of providing either information analysis automation strategy information, task environment information, or both, on human judgment performance in a domain where noisy sensor data are used by both the human and the information analysis automation to make judgments. In a simplified air traffic conflict prediction experiment, 32 participants made probability of horizontal conflict judgments under different display content conditions. After being exposed to the information analysis automation, judgment achievement significantly improved for all participants as compared to judgments without any of the automation's information. Participants provided with additional display content pertaining to cue variability in the task environment had significantly higher aided judgment achievement compared to those provided with only the automation's judgment of a probability of conflict. When designing information analysis automation for environments where the automation's judgment achievement is impacted by noisy environmental data, it may be beneficial to show additional task environment information to the human judge in order to improve judgment performance. PMID:24847184

  10. An automated mapping satellite system ( Mapsat).

    USGS Publications Warehouse

    Colvocoresses, A.P.

    1982-01-01

    The favorable environment of space permits a satellite to orbit the Earth with very high stability as long as no local perturbing forces are involved. Solid-state linear-array sensors have no moving parts and create no perturbing force on the satellite. Digital data from highly stabilized stereo linear arrays are amenable to simplified processing to produce both planimetric imagery and elevation data. A satellite imaging system, called Mapsat, including this concept has been proposed to produce data from which automated mapping in near real time can be accomplished. Image maps as large as 1:50 000 scale with contours as close as a 20-m interval may be produced from Mapsat data. -from Author

  11. Simplified overturn stability monitoring of agricultural tractors.

    PubMed

    Nichol, C I; Sommer, H J; Murphy, D J

    2005-02-01

    Agricultural tractors are the most common source of farm work fatalities in the U.S., with overturns the most common type of incident. For the year 2001, there were 15 tractor-related fatalities in Pennsylvania, 9 of which were due to tractor rollover. A new device using low-cost sensors and microcomputers was developed around a simplified mathematical model of an agricultural tractor to inform the operator of potential tractor instability. This device communicates the current rollover potential, along with a recent history of rollover potential, to the operator of the tractor via a simple bar-graph display. The device uses a single-chip accelerometer to sense the current rollover potential and a small microprocessor to analyze the accelerometer data, compensate for variations due to temperature, and then send this information to a visual display. The use of these low-cost "off the shelf" components enabled the fabrication of a very inexpensive sensor system. Because agricultural tractors have a long service life, it was important to make the device low cost and flexible. This could enable it to be sold as an aftermarket add-on for a variety of tractor models. The device is also capable of interfacing with newer on-board tractor systems via a CAN bus to make it more attractive to tractor manufacturers who may want to incorporate this device into new models. Work is continuing on the development of an improved display to inform the tractor operator of possible instability, including display ergonomic studies, investigation of threshold levels for alerting an operator of potential instability, and investigation into audible warning signals.

  12. A Simplified HTTR Diffusion Theory Benchmark

    SciTech Connect

    Rodolfo M. Ferrer; Abderrafi M. Ougouag; Farzad Rahnema

    2010-10-01

    The Georgia Institute of Technology (GA-Tech) recently developed a transport theory benchmark based closely on the geometry and the features of the HTTR reactor that is operational in Japan. Though simplified, the benchmark retains all the principal physical features of the reactor and thus provides a realistic and challenging test for the codes. The purpose of this paper is twofold. The first goal is an extension of the benchmark to diffusion theory applications by generating the additional data not provided in the GA-Tech prior work. The second goal is to use the benchmark on the HEXPEDITE code available to the INL. The HEXPEDITE code is a Green’s function-based neutron diffusion code in 3D hexagonal-z geometry. The results showed that the HEXPEDITE code accurately reproduces the effective multiplication factor of the reference HELIOS solution. A secondary, but no less important, conclusion is that in the testing against actual HTTR data of a full sequence of codes that would include HEXPEDITE, in the apportioning of inevitable discrepancies between experiment and models, the portion of error attributable to HEXPEDITE would be expected to be modest. If large discrepancies are observed, they would have to be explained by errors in the data fed into HEXPEDITE. Results based on a fully realistic model of the HTTR reactor are presented in a companion paper. The suite of codes used in that paper also includes HEXPEDITE. The results shown here should help that effort in the decision making process for refining the modeling steps in the full sequence of codes.

  13. Simplified models for heat transfer in rooms

    NASA Astrophysics Data System (ADS)

    Graca, Guilherme C. C. Carrilho Da

    Buildings protect their occupants from the outside environment. As a semi-enclosed environment, buildings tend to contain the internally generated heat and air pollutants, as well as the solar and conductive heat gains that can occur in the facade. In the warmer months of the year this generally leads to overheating, creating a need for a cooling system. Ventilation air replaces contaminated air in the building and is often used as the dominant medium for heat transfer between indoor and outdoor environments. The goal of the research presented in this thesis is to develop a better understanding of the important parameters in the performance of ventilation systems and to develop simplified convective heat transfer models. The general approach used in this study seeks to capture the dominant physical processes for these problems with first order accuracy, and develop simple models that show the correct system behavior trends. Dimensional analysis, in conjunction with simple momentum and energy conservation, scaled model experiments and numerical simulations, is used to improve airflow and heat transfer rate predictions in both single and multi room ventilation systems. This study includes the three commonly used room ventilation modes: mixing, displacement and cross-ventilation. A new modeling approach to convective heat transfer between the building and the outside is presented: the concept of equivalent room heat transfer coefficient. The new model quantifies the reduction in heat transfer between ventilation air and internal room surfaces caused by limited thermal capacity and temperature variation of the air for the three modes studied. Particular emphasis is placed on cross-ventilation, and on the development of a simple model to characterize the airflow patterns that occur in this case. The implementation of the models in a building thermal simulation software tool is presented as well as comparisons between model predictions, experimental results and complex

  14. 12 CFR 217.144 - Simplified supervisory formula approach (SSFA).

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 12 Banks and Banking 2 2014-01-01 2014-01-01 false Simplified supervisory formula approach (SSFA... Simplified supervisory formula approach (SSFA). (a) General requirements for the SSFA. To use the SSFA to determine the risk weight for a securitization exposure, a Board-regulated institution must have data...

  15. 26 CFR 1.41-9 - Alternative simplified credit.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 1 2011-04-01 2009-04-01 true Alternative simplified credit. 1.41-9 Section 1.41-9 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY INCOME TAX INCOME TAXES Credits Against Tax § 1.41-9 Alternative simplified credit. For further guidance, see § 1.41-9T....

  16. 26 CFR 1.41-9 - Alternative simplified credit.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 1 2010-04-01 2010-04-01 true Alternative simplified credit. 1.41-9 Section 1.41-9 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY INCOME TAX INCOME TAXES Credits Against Tax § 1.41-9 Alternative simplified credit. For further guidance, see § 1.41-9T....

  17. Naturally Simplified Input, Comprehension, and Second Language Acquisition.

    ERIC Educational Resources Information Center

    Ellis, Rod

    This article examines the concept of simplification in second language (SL) learning, reviewing research on the simplified input that both naturalistic and classroom SL learners receive. Research indicates that simplified input, particularly if derived from naturally occurring interactions, does aid comprehension but has not been shown to…

  18. Communication: A simplified coupled-cluster Lagrangian for polarizable embedding

    SciTech Connect

    Krause, Katharina; Klopper, Wim

    2016-01-28

    A simplified coupled-cluster Lagrangian, which is linear in the Lagrangian multipliers, is proposed for the coupled-cluster treatment of a quantum mechanical system in a polarizable environment. In the simplified approach, the amplitude equations are decoupled from the Lagrangian multipliers and the energy obtained from the projected coupled-cluster equation corresponds to a stationary point of the Lagrangian.

  19. Simplified process model discovery based on role-oriented genetic mining.

    PubMed

    Zhao, Weidong; Liu, Xi; Dai, Weihui

    2014-01-01

    Process mining is automated acquisition of process models from event logs. Although many process mining techniques have been developed, most of them are based on control flow. Meanwhile, the existing role-oriented process mining methods focus on correctness and integrity of roles while ignoring role complexity of the process model, which directly impacts understandability and quality of the model. To address these problems, we propose a genetic programming approach to mine the simplified process model. Using a new metric of process complexity in terms of roles as the fitness function, we can find simpler process models. The new role complexity metric of process models is designed from role cohesion and coupling, and applied to discover roles in process models. Moreover, the higher fitness derived from role complexity metric also provides a guideline for redesigning process models. Finally, we conduct case study and experiments to show that the proposed method is more effective for streamlining the process by comparing with related studies.

  20. Automated diagnoses of attention deficit hyperactive disorder using magnetic resonance imaging.

    PubMed

    Eloyan, Ani; Muschelli, John; Nebel, Mary Beth; Liu, Han; Han, Fang; Zhao, Tuo; Barber, Anita D; Joel, Suresh; Pekar, James J; Mostofsky, Stewart H; Caffo, Brian

    2012-01-01

    Successful automated diagnoses of attention deficit hyperactive disorder (ADHD) using imaging and functional biomarkers would have fundamental consequences on the public health impact of the disease. In this work, we show results on the predictability of ADHD using imaging biomarkers and discuss the scientific and diagnostic impacts of the research. We created a prediction model using the landmark ADHD 200 data set focusing on resting state functional connectivity (rs-fc) and structural brain imaging. We predicted ADHD status and subtype, obtained by behavioral examination, using imaging data, intelligence quotients and other covariates. The novel contributions of this manuscript include a thorough exploration of prediction and image feature extraction methodology on this form of data, including the use of singular value decompositions (SVDs), CUR decompositions, random forest, gradient boosting, bagging, voxel-based morphometry, and support vector machines as well as important insights into the value, and potentially lack thereof, of imaging biomarkers of disease. The key results include the CUR-based decomposition of the rs-fc-fMRI along with gradient boosting and the prediction algorithm based on a motor network parcellation and random forest algorithm. We conjecture that the CUR decomposition is largely diagnosing common population directions of head motion. Of note, a byproduct of this research is a potential automated method for detecting subtle in-scanner motion. The final prediction algorithm, a weighted combination of several algorithms, had an external test set specificity of 94% with sensitivity of 21%. The most promising imaging biomarker was a correlation graph from a motor network parcellation. In summary, we have undertaken a large-scale statistical exploratory prediction exercise on the unique ADHD 200 data set. The exercise produced several potential leads for future scientific exploration of the neurological basis of ADHD.

  1. Automated diagnoses of attention deficit hyperactive disorder using magnetic resonance imaging

    PubMed Central

    Eloyan, Ani; Muschelli, John; Nebel, Mary Beth; Liu, Han; Han, Fang; Zhao, Tuo; Barber, Anita D.; Joel, Suresh; Pekar, James J.; Mostofsky, Stewart H.; Caffo, Brian

    2012-01-01

    Successful automated diagnoses of attention deficit hyperactive disorder (ADHD) using imaging and functional biomarkers would have fundamental consequences on the public health impact of the disease. In this work, we show results on the predictability of ADHD using imaging biomarkers and discuss the scientific and diagnostic impacts of the research. We created a prediction model using the landmark ADHD 200 data set focusing on resting state functional connectivity (rs-fc) and structural brain imaging. We predicted ADHD status and subtype, obtained by behavioral examination, using imaging data, intelligence quotients and other covariates. The novel contributions of this manuscript include a thorough exploration of prediction and image feature extraction methodology on this form of data, including the use of singular value decompositions (SVDs), CUR decompositions, random forest, gradient boosting, bagging, voxel-based morphometry, and support vector machines as well as important insights into the value, and potentially lack thereof, of imaging biomarkers of disease. The key results include the CUR-based decomposition of the rs-fc-fMRI along with gradient boosting and the prediction algorithm based on a motor network parcellation and random forest algorithm. We conjecture that the CUR decomposition is largely diagnosing common population directions of head motion. Of note, a byproduct of this research is a potential automated method for detecting subtle in-scanner motion. The final prediction algorithm, a weighted combination of several algorithms, had an external test set specificity of 94% with sensitivity of 21%. The most promising imaging biomarker was a correlation graph from a motor network parcellation. In summary, we have undertaken a large-scale statistical exploratory prediction exercise on the unique ADHD 200 data set. The exercise produced several potential leads for future scientific exploration of the neurological basis of ADHD. PMID:22969709

  2. Power subsystem automation study

    NASA Technical Reports Server (NTRS)

    Imamura, M. S.; Moser, R. L.; Veatch, M.

    1983-01-01

    Generic power-system elements and their potential faults are identified. Automation functions and their resulting benefits are defined and automation functions between power subsystem, central spacecraft computer, and ground flight-support personnel are partitioned. All automation activities were categorized as data handling, monitoring, routine control, fault handling, planning and operations, or anomaly handling. Incorporation of all these classes of tasks, except for anomaly handling, in power subsystem hardware and software was concluded to be mandatory to meet the design and operational requirements of the space station. The key drivers are long mission lifetime, modular growth, high-performance flexibility, a need to accommodate different electrical user-load equipment, onorbit assembly/maintenance/servicing, and potentially large number of power subsystem components. A significant effort in algorithm development and validation is essential in meeting the 1987 technology readiness date for the space station.

  3. Fully automated protein purification

    PubMed Central

    Camper, DeMarco V.; Viola, Ronald E.

    2009-01-01

    Obtaining highly purified proteins is essential to begin investigating their functional and structural properties. The steps that are typically involved in purifying proteins can include an initial capture, intermediate purification, and a final polishing step. Completing these steps can take several days and require frequent attention to ensure success. Our goal was to design automated protocols that will allow the purification of proteins with minimal operator intervention. Separate methods have been produced and tested that automate the sample loading, column washing, sample elution and peak collection steps for ion-exchange, metal affinity, hydrophobic interaction and gel filtration chromatography. These individual methods are designed to be coupled and run sequentially in any order to achieve a flexible and fully automated protein purification protocol. PMID:19595984

  4. Automated telescope scheduling

    NASA Technical Reports Server (NTRS)

    Johnston, Mark D.

    1988-01-01

    With the ever increasing level of automation of astronomical telescopes the benefits and feasibility of automated planning and scheduling are becoming more apparent. Improved efficiency and increased overall telescope utilization are the most obvious goals. Automated scheduling at some level has been done for several satellite observatories, but the requirements on these systems were much less stringent than on modern ground or satellite observatories. The scheduling problem is particularly acute for Hubble Space Telescope: virtually all observations must be planned in excruciating detail weeks to months in advance. Space Telescope Science Institute has recently made significant progress on the scheduling problem by exploiting state-of-the-art artificial intelligence software technology. What is especially interesting is that this effort has already yielded software that is well suited to scheduling groundbased telescopes, including the problem of optimizing the coordinated scheduling of more than one telescope.

  5. Automating the CMS DAQ

    SciTech Connect

    Bauer, G.; et al.

    2014-01-01

    We present the automation mechanisms that have been added to the Data Acquisition and Run Control systems of the Compact Muon Solenoid (CMS) experiment during Run 1 of the LHC, ranging from the automation of routine tasks to automatic error recovery and context-sensitive guidance to the operator. These mechanisms helped CMS to maintain a data taking efficiency above 90% and to even improve it to 95% towards the end of Run 1, despite an increase in the occurrence of single-event upsets in sub-detector electronics at high LHC luminosity.

  6. Automated Library System Specifications.

    DTIC Science & Technology

    1986-06-01

    AD-A78 95 AUTOMATED LIBRARY SYSTEM SPECIFICATIONS(U) ARMY LIBRARY /i MANAGEMENT OFFICE ALEXANDRIA VA ASSISTANT CHIEF OF STAFF FOR INFORMATION... MANAGEMENT M B BONNETT JUN 86 UNCLASSIFIED F/G 9/2 NLEElIIhllEEEEE IllEEEEEllllEI .1lm lliml * ~I fI.L25 MI, [OCM RL,;OCLUTO fl. ’N k~ AUTOMATED LIBRARY...SYSTEM SPECIFICATIONS .,I Prepared by Mary B. Bonnett ARMY LIBRARY MANAGEMENT OFFICE OFFICE OF THE ASSISTANT CHIEF OF STAFF FOR INFORMATION MANAGEMENT Lij

  7. Automated gas chromatography

    DOEpatents

    Mowry, Curtis D.; Blair, Dianna S.; Rodacy, Philip J.; Reber, Stephen D.

    1999-01-01

    An apparatus and process for the continuous, near real-time monitoring of low-level concentrations of organic compounds in a liquid, and, more particularly, a water stream. A small liquid volume of flow from a liquid process stream containing organic compounds is diverted by an automated process to a heated vaporization capillary where the liquid volume is vaporized to a gas that flows to an automated gas chromatograph separation column to chromatographically separate the organic compounds. Organic compounds are detected and the information transmitted to a control system for use in process control. Concentrations of organic compounds less than one part per million are detected in less than one minute.

  8. Automated knowledge generation

    NASA Technical Reports Server (NTRS)

    Myler, Harley R.; Gonzalez, Avelino J.

    1988-01-01

    The general objectives of the NASA/UCF Automated Knowledge Generation Project were the development of an intelligent software system that could access CAD design data bases, interpret them, and generate a diagnostic knowledge base in the form of a system model. The initial area of concentration is in the diagnosis of the process control system using the Knowledge-based Autonomous Test Engineer (KATE) diagnostic system. A secondary objective was the study of general problems of automated knowledge generation. A prototype was developed, based on object-oriented language (Flavors).

  9. Simplifying CEA through Excel, VBA, and Subeq

    NASA Technical Reports Server (NTRS)

    Foster, Ryan

    2004-01-01

    Many people use compound equilibrium programs for very different reasons, varying from refrigerators to light bulbs to rockets. A commonly used equilibrium program is CEA. CEA can take various inputs such as pressure, temperature, and volume along with numerous reactants and run them through equilibrium equations to obtain valuable output information, including products formed and their relative amounts. A little over a year ago, Bonnie McBride created the program subeq with the goal to simplify the calling of CEA. Subeq was also designed to be called by other programs, including Excel, through the use of Visual Basic for Applications (VBA). The largest advantage of using Excel is that it allows the user to input the information in a colorful and user-friendly environment while allowing VBA to run subeq, which is in the form of a FORTRAN DLL (Dynamic Link Library). Calling subeq in this form makes it much faster than if it were converted to VBA. Since subeq requires such large lists of reactant and product names, all of which can't be passed in as an array, subeq had to be changed to accept very long strings of reactants and products. To pass this string and adjust the transfer of input and output parameters, the subeq DLL had to be changed. One program that does this is Compaq Visual FORTRAN, which allows DLLs to be edited, debugged, and compiled. Compaq Visual FORTRAN uses FORTRAN 90/95, which has additional features to that of FORTRAN 77. My goals this summer include finishing up the excel spreadsheet of subeq, which I started last summer, and putting it on the Internet so that others can use it without having to download my spreadsheet. To finish up the spreadsheet I will need to work on debugging current options and problems. I will also work on making it as robust as possible, so that all errors that may arise will be clearly communicated to the user. New features will be added old ones will be changed as I receive comments from people using the spreadsheet

  10. A spectrum of applications of automated reasoning.

    SciTech Connect

    Wos, L.

    2002-02-01

    The likelihood of an automated reasoning program being of substantial assistance for a wide spectrum of applications rests with the nature of the options and parameters it offers on which to base needed strategies and methodologies. This article focuses on such a spectrum, featuring W. McCune's program OTTER, discussing widely varied successes in answering open questions, and touching on some of the strategies and methodologies that played a key role. The applications include finding a first proof, discovering single axioms, locating improved axiom systems, and simplifying existing proofs. The last application is directly pertinent to the recently found (by R. Thiele) Hilbert's twenty-fourth problem--which is extremely amenable to attack with the appropriate automated reasoning program, a problem concerned with proof simplification. The methodologies include those for seeking shorter proofs and for finding proofs that avoid unwanted lemmas or classes of term, a specific option for seeking proofs with smaller equational or formula complexity, and a different option to address the variable richness of a proof. The type of proof one obtains with the use of OTTER is Hilbert-style axiomatic, including details that permit one sometimes to gain new insights. We include questions still open and challenges that merit consideration.

  11. Automated reverse engineering of nonlinear dynamical systems.

    PubMed

    Bongard, Josh; Lipson, Hod

    2007-06-12

    Complex nonlinear dynamics arise in many fields of science and engineering, but uncovering the underlying differential equations directly from observations poses a challenging task. The ability to symbolically model complex networked systems is key to understanding them, an open problem in many disciplines. Here we introduce for the first time a method that can automatically generate symbolic equations for a nonlinear coupled dynamical system directly from time series data. This method is applicable to any system that can be described using sets of ordinary nonlinear differential equations, and assumes that the (possibly noisy) time series of all variables are observable. Previous automated symbolic modeling approaches of coupled physical systems produced linear models or required a nonlinear model to be provided manually. The advance presented here is made possible by allowing the method to model each (possibly coupled) variable separately, intelligently perturbing and destabilizing the system to extract its less observable characteristics, and automatically simplifying the equations during modeling. We demonstrate this method on four simulated and two real systems spanning mechanics, ecology, and systems biology. Unlike numerical models, symbolic models have explanatory value, suggesting that automated "reverse engineering" approaches for model-free symbolic nonlinear system identification may play an increasing role in our ability to understand progressively more complex systems in the future.

  12. Altering user' acceptance of automation through prior automation exposure.

    PubMed

    Bekier, Marek; Molesworth, Brett R C

    2016-08-22

    Air navigation service providers worldwide see increased use of automation as one solution to overcome the capacity constraints imbedded in the present air traffic management (ATM) system. However, increased use of automation within any system is dependent on user acceptance. The present research sought to determine if the point at which an individual is no longer willing to accept or cooperate with automation can be manipulated. Forty participants underwent training on a computer-based air traffic control programme, followed by two ATM exercises (order counterbalanced), one with and one without the aid of automation. Results revealed after exposure to a task with automation assistance, user acceptance of high(er) levels of automation ('tipping point') decreased; suggesting it is indeed possible to alter automation acceptance. Practitioner Summary: This paper investigates whether the point at which a user of automation rejects automation (i.e. 'tipping point') is constant or can be manipulated. The results revealed after exposure to a task with automation assistance, user acceptance of high(er) levels of automation decreased; suggesting it is possible to alter automation acceptance.

  13. Automated Derivation of Complex System Constraints from User Requirements

    NASA Technical Reports Server (NTRS)

    Muery, Kim; Foshee, Mark; Marsh, Angela

    2006-01-01

    International Space Station (ISS) payload developers submit their payload science requirements for the development of on-board execution timelines. The ISS systems required to execute the payload science operations must be represented as constraints for the execution timeline. Payload developers use a software application, User Requirements Collection (URC), to submit their requirements by selecting a simplified representation of ISS system constraints. To fully represent the complex ISS systems, the constraints require a level of detail that is beyond the insight of the payload developer. To provide the complex representation of the ISS system constraints, HOSC operations personnel, specifically the Payload Activity Requirements Coordinators (PARC), manually translate the payload developers simplified constraints into detailed ISS system constraints used for scheduling the payload activities in the Consolidated Planning System (CPS). This paper describes the implementation for a software application, User Requirements Integration (URI), developed to automate the manual ISS constraint translation process.

  14. Automating Small Libraries.

    ERIC Educational Resources Information Center

    Swan, James

    1996-01-01

    Presents a four-phase plan for small libraries strategizing for automation: inventory and weeding, data conversion, implementation, and enhancements. Other topics include selecting a system, MARC records, compatibility, ease of use, industry standards, searching capabilities, support services, system security, screen displays, circulation modules,…

  15. Automated conflict resolution issues

    NASA Technical Reports Server (NTRS)

    Wike, Jeffrey S.

    1991-01-01

    A discussion is presented of how conflicts for Space Network resources should be resolved in the ATDRSS era. The following topics are presented: a description of how resource conflicts are currently resolved; a description of issues associated with automated conflict resolution; present conflict resolution strategies; and topics for further discussion.

  16. Automated Accounting. Instructor Guide.

    ERIC Educational Resources Information Center

    Moses, Duane R.

    This curriculum guide was developed to assist business instructors using Dac Easy Accounting College Edition Version 2.0 software in their accounting programs. The module consists of four units containing assignment sheets and job sheets designed to enable students to master competencies identified in the area of automated accounting. The first…

  17. Automated Student Model Improvement

    ERIC Educational Resources Information Center

    Koedinger, Kenneth R.; McLaughlin, Elizabeth A.; Stamper, John C.

    2012-01-01

    Student modeling plays a critical role in developing and improving instruction and instructional technologies. We present a technique for automated improvement of student models that leverages the DataShop repository, crowd sourcing, and a version of the Learning Factors Analysis algorithm. We demonstrate this method on eleven educational…

  18. Personnel Department Automation.

    ERIC Educational Resources Information Center

    Wilkinson, David

    In 1989, the Austin Independent School District's Office of Research and Evaluation was directed to monitor the automation of personnel information and processes in the district's Department of Personnel. Earlier, a study committee appointed by the Superintendent during the 1988-89 school year identified issues related to Personnel Department…

  19. Validating Automated Speaking Tests

    ERIC Educational Resources Information Center

    Bernstein, Jared; Van Moere, Alistair; Cheng, Jian

    2010-01-01

    This paper presents evidence that supports the valid use of scores from fully automatic tests of spoken language ability to indicate a person's effectiveness in spoken communication. The paper reviews the constructs, scoring, and the concurrent validity evidence of "facility-in-L2" tests, a family of automated spoken language tests in Spanish,…

  20. Automated Essay Scoring

    ERIC Educational Resources Information Center

    Dikli, Semire

    2006-01-01

    The impacts of computers on writing have been widely studied for three decades. Even basic computers functions, i.e. word processing, have been of great assistance to writers in modifying their essays. The research on Automated Essay Scoring (AES) has revealed that computers have the capacity to function as a more effective cognitive tool (Attali,…

  1. Automated Microbial Genome Annotation

    SciTech Connect

    Land, Miriam

    2009-05-29

    Miriam Land of the DOE Joint Genome Institute at Oak Ridge National Laboratory gives a talk on the current state and future challenges of moving toward automated microbial genome annotation at the "Sequencing, Finishing, Analysis in the Future" meeting in Santa Fe, NM

  2. Automated Administrative Data Bases

    NASA Technical Reports Server (NTRS)

    Marrie, M. D.; Jarrett, J. R.; Reising, S. A.; Hodge, J. E.

    1984-01-01

    Improved productivity and more effective response to information requirements for internal management, NASA Centers, and Headquarters resulted from using automated techniques. Modules developed to provide information on manpower, RTOPS, full time equivalency, and physical space reduced duplication, increased communication, and saved time. There is potential for greater savings by sharing and integrating with those who have the same requirements.

  3. Automated Management Of Documents

    NASA Technical Reports Server (NTRS)

    Boy, Guy

    1995-01-01

    Report presents main technical issues involved in computer-integrated documentation. Problems associated with automation of management and maintenance of documents analyzed from perspectives of artificial intelligence and human factors. Technologies that may prove useful in computer-integrated documentation reviewed: these include conventional approaches to indexing and retrieval of information, use of hypertext, and knowledge-based artificial-intelligence systems.

  4. Building Automation Systems.

    ERIC Educational Resources Information Center

    Honeywell, Inc., Minneapolis, Minn.

    A number of different automation systems for use in monitoring and controlling building equipment are described in this brochure. The system functions include--(1) collection of information, (2) processing and display of data at a central panel, and (3) taking corrective action by sounding alarms, making adjustments, or automatically starting and…

  5. Guide to Library Automation.

    ERIC Educational Resources Information Center

    Toohill, Barbara G.

    Directed toward librarians and library administrators who wish to procure automated systems or services for their libraries, this guide offers practical suggestions, advice, and methods for determining requirements, estimating costs and benefits, writing specifications procuring systems, negotiating contracts, and installing systems. The advice…

  6. Microcontroller for automation application

    NASA Technical Reports Server (NTRS)

    Cooper, H. W.

    1975-01-01

    The description of a microcontroller currently being developed for automation application was given. It is basically an 8-bit microcomputer with a 40K byte random access memory/read only memory, and can control a maximum of 12 devices through standard 15-line interface ports.

  7. Automated EEG acquisition

    NASA Technical Reports Server (NTRS)

    Frost, J. D., Jr.; Hillman, C. E., Jr.

    1977-01-01

    Automated self-contained portable device can be used by technicians with minimal training. Data acquired from patient at remote site are transmitted to centralized interpretation center using conventional telephone equipment. There, diagnostic information is analyzed, and results are relayed back to remote site.

  8. ORIGAMI Automator Primer. Automated ORIGEN Source Terms and Spent Fuel Storage Pool Analysis

    SciTech Connect

    Wieselquist, William A.; Thompson, Adam B.; Bowman, Stephen M.; Peterson, Joshua L.

    2016-04-01

    Source terms and spent nuclear fuel (SNF) storage pool decay heat load analyses for operating nuclear power plants require a large number of Oak Ridge Isotope Generation and Depletion (ORIGEN) calculations. SNF source term calculations also require a significant amount of bookkeeping to track quantities such as core and assembly operating histories, spent fuel pool (SFP) residence times, heavy metal masses, and enrichments. The ORIGEN Assembly Isotopics (ORIGAMI) module in the SCALE code system provides a simple scheme for entering these data. However, given the large scope of the analysis, extensive scripting is necessary to convert formats and process data to create thousands of ORIGAMI input files (one per assembly) and to process the results into formats readily usable by follow-on analysis tools. This primer describes a project within the SCALE Fulcrum graphical user interface (GUI) called ORIGAMI Automator that was developed to automate the scripting and bookkeeping in large-scale source term analyses. The ORIGAMI Automator enables the analyst to (1) easily create, view, and edit the reactor site and assembly information, (2) automatically create and run ORIGAMI inputs, and (3) analyze the results from ORIGAMI. ORIGAMI Automator uses the standard ORIGEN binary concentrations files produced by ORIGAMI, with concentrations available at all time points in each assembly’s life. The GUI plots results such as mass, concentration, activity, and decay heat using a powerful new ORIGEN Post-Processing Utility for SCALE (OPUS) GUI component. This document includes a description and user guide for the GUI, a step-by-step tutorial for a simplified scenario, and appendices that document the file structures used.

  9. Simplified Models for Dark Matter Face their Consistent Completions

    SciTech Connect

    Goncalves, Dorival; Machado, Pedro N.; No, Jose Miguel

    2016-11-14

    Simplified dark matter models have been recently advocated as a powerful tool to exploit the complementarity between dark matter direct detection, indirect detection and LHC experimental probes. Focusing on pseudoscalar mediators between the dark and visible sectors, we show that the simplified dark matter model phenomenology departs significantly from that of consistent ${SU(2)_{\\mathrm{L}} \\times U(1)_{\\mathrm{Y}}}$ gauge invariant completions. We discuss the key physics simplified models fail to capture, and its impact on LHC searches. Notably, we show that resonant mono-Z searches provide competitive sensitivities to standard mono-jet analyses at $13$ TeV LHC.

  10. Simplified models for dark matter searches at the LHC

    SciTech Connect

    Abdallah, Jalal; Araujo, Henrique; Arbey, Alexandre; Ashkenazi, Adi; Belyaev, Alexander; Berger, Joshua; Boehm, Celine; Boveia, Antonio; Brennan, Amelia; Brooke, Jim; Buchmueller, Oliver; Buckley, Matthew; Busoni, Giorgio; Calibbi, Lorenzo; Chauhan, Sushil; Daci, Nadir; Davies, Gavin; De Bruyn, Isabelle; De Jong, Paul; De Roeck, Albert; de Vries, Kees; Del Re, Daniele; De Simone, Andrea; Di Simone, Andrea; Doglioni, Caterina; Dolan, Matthew; Dreiner, Herbi K.; Ellis, John; Eno, Sarah; Etzion, Erez; Fairbairn, Malcolm; Feldstein, Brian; Flaecher, Henning; Feng, Eric; Fox, Patrick; Genest, Marie-Hélène; Gouskos, Loukas; Gramling, Johanna; Haisch, Ulrich; Harnik, Roni; Hibbs, Anthony; Hoh, Siewyan; Hopkins, Walter; Ippolito, Valerio; Jacques, Thomas; Kahlhoefer, Felix; Khoze, Valentin V.; Kirk, Russell; Korn, Andreas; Kotov, Khristian; Kunori, Shuichi; Landsberg, Greg; Liem, Sebastian; Lin, Tongyan; Lowette, Steven; Lucas, Robyn; Malgeri, Luca; Malik, Sarah; McCabe, Christopher; Mete, Alaettin Serhan; Morgante, Enrico; Mrenna, Stephen; Nakahama, Yu; Newbold, Dave; Nordstrom, Karl; Pani, Priscilla; Papucci, Michele; Pataraia, Sophio; Penning, Bjoern; Pinna, Deborah; Polesello, Giacomo; Racco, Davide; Re, Emanuele; Riotto, Antonio Walter; Rizzo, Thomas; Salek, David; Sarkar, Subir; Schramm, Steven; Skubic, Patrick; Slone, Oren; Smirnov, Juri; Soreq, Yotam; Sumner, Timothy; Tait, Tim M. P.; Thomas, Marc; Tomalin, Ian; Tunnell, Christopher; Vichi, Alessandro; Volansky, Tomer; Weiner, Neal; West, Stephen M.; Wielers, Monika; Worm, Steven; Yavin, Itay; Zaldivar, Bryan; Zhou, Ning; Zurek, Kathryn

    2015-09-01

    This document a outlines a set of simplified models for dark matter and its interactions with Standard Model particles. It is intended to summarize the main characteristics that these simplified models have when applied to dark matter searches at the LHC, and to provide a number of useful expressions for reference. The list of models includes both s-channel and t-channel scenarios. For s-channel, spin-0 and spin-1 mediations are discussed, and also realizations where the Higgs particle provides a portal between the dark and visible sectors. The guiding principles underpinning the proposed simplified models are spelled out, and some suggestions for implementation are presented.

  11. Liquid-filled simplified hollow-core photonic crystal fiber

    NASA Astrophysics Data System (ADS)

    Liu, Shengnan; Gao, Wei; Li, Hongwei; Dong, Yongkang; Zhang, Hongying

    2014-12-01

    We report on a novel type of liquid-filled simplified hollow-core photonic crystal fibers (HC-PCFs), and investigate their transmission properties with various filling liquids, including water, ethanol and FC-40. The loss and dispersion characterizations are calculated for different fiber parameters including strut thickness and core diameter. The results show that there are still low-loss windows existing for liquid-filled simplified HC-PCFs, and the low-loss windows and dispersions can be easily tailored by filling different liquids. Such liquid-filled simplified HC-PCFs open up many possibilities for nonlinear fiber optics, optical, biochemical and medical sensing.

  12. Simplified models for dark matter searches at the LHC

    NASA Astrophysics Data System (ADS)

    Abdallah, Jalal; Araujo, Henrique; Arbey, Alexandre; Ashkenazi, Adi; Belyaev, Alexander; Berger, Joshua; Boehm, Celine; Boveia, Antonio; Brennan, Amelia; Brooke, Jim; Buchmueller, Oliver; Buckley, Matthew; Busoni, Giorgio; Calibbi, Lorenzo; Chauhan, Sushil; Daci, Nadir; Davies, Gavin; De Bruyn, Isabelle; De Jong, Paul; De Roeck, Albert; de Vries, Kees; Del Re, Daniele; De Simone, Andrea; Di Simone, Andrea; Doglioni, Caterina; Dolan, Matthew; Dreiner, Herbi K.; Ellis, John; Eno, Sarah; Etzion, Erez; Fairbairn, Malcolm; Feldstein, Brian; Flaecher, Henning; Feng, Eric; Fox, Patrick; Genest, Marie-Hélène; Gouskos, Loukas; Gramling, Johanna; Haisch, Ulrich; Harnik, Roni; Hibbs, Anthony; Hoh, Siewyan; Hopkins, Walter; Ippolito, Valerio; Jacques, Thomas; Kahlhoefer, Felix; Khoze, Valentin V.; Kirk, Russell; Korn, Andreas; Kotov, Khristian; Kunori, Shuichi; Landsberg, Greg; Liem, Sebastian; Lin, Tongyan; Lowette, Steven; Lucas, Robyn; Malgeri, Luca; Malik, Sarah; McCabe, Christopher; Mete, Alaettin Serhan; Morgante, Enrico; Mrenna, Stephen; Nakahama, Yu; Newbold, Dave; Nordstrom, Karl; Pani, Priscilla; Papucci, Michele; Pataraia, Sophio; Penning, Bjoern; Pinna, Deborah; Polesello, Giacomo; Racco, Davide; Re, Emanuele; Riotto, Antonio Walter; Rizzo, Thomas; Salek, David; Sarkar, Subir; Schramm, Steven; Skubic, Patrick; Slone, Oren; Smirnov, Juri; Soreq, Yotam; Sumner, Timothy; Tait, Tim M. P.; Thomas, Marc; Tomalin, Ian; Tunnell, Christopher; Vichi, Alessandro; Volansky, Tomer; Weiner, Neal; West, Stephen M.; Wielers, Monika; Worm, Steven; Yavin, Itay; Zaldivar, Bryan; Zhou, Ning; Zurek, Kathryn

    2015-09-01

    This document outlines a set of simplified models for dark matter and its interactions with Standard Model particles. It is intended to summarize the main characteristics that these simplified models have when applied to dark matter searches at the LHC, and to provide a number of useful expressions for reference. The list of models includes both ss-channel and tt-channel scenarios. For ss-channel, spin-0 and spin-1 mediations are discussed, and also realizations where the Higgs particle provides a portal between the dark and visible sectors. The guiding principles underpinning the proposed simplified models are spelled out, and some suggestions for implementation are presented.

  13. Automating spectral measurements

    NASA Astrophysics Data System (ADS)

    Goldstein, Fred T.

    2008-09-01

    This paper discusses the architecture of software utilized in spectroscopic measurements. As optical coatings become more sophisticated, there is mounting need to automate data acquisition (DAQ) from spectrophotometers. Such need is exacerbated when 100% inspection is required, ancillary devices are utilized, cost reduction is crucial, or security is vital. While instrument manufacturers normally provide point-and-click DAQ software, an application programming interface (API) may be missing. In such cases automation is impossible or expensive. An API is typically provided in libraries (*.dll, *.ocx) which may be embedded in user-developed applications. Users can thereby implement DAQ automation in several Windows languages. Another possibility, developed by FTG as an alternative to instrument manufacturers' software, is the ActiveX application (*.exe). ActiveX, a component of many Windows applications, provides means for programming and interoperability. This architecture permits a point-and-click program to act as automation client and server. Excel, for example, can control and be controlled by DAQ applications. Most importantly, ActiveX permits ancillary devices such as barcode readers and XY-stages to be easily and economically integrated into scanning procedures. Since an ActiveX application has its own user-interface, it can be independently tested. The ActiveX application then runs (visibly or invisibly) under DAQ software control. Automation capabilities are accessed via a built-in spectro-BASIC language with industry-standard (VBA-compatible) syntax. Supplementing ActiveX, spectro-BASIC also includes auxiliary serial port commands for interfacing programmable logic controllers (PLC). A typical application is automatic filter handling.

  14. Combining Automated Theorem Provers with Symbolic Algebraic Systems: Position Paper

    NASA Technical Reports Server (NTRS)

    Schumann, Johann; Koga, Dennis (Technical Monitor)

    1999-01-01

    In contrast to pure mathematical applications where automated theorem provers (ATPs) are quite capable, proof tasks arising form real-world applications from the area of Software Engineering show quite different characteristics: they usually do not only contain much arithmetic (albeit often quite simple one), but they also often contain reasoning about specific structures (e.g. graphics, sets). Thus, an ATP must be capable of performing reasoning together with a fair amount of simplification, calculation and solving. Therefore, powerful simplifiers and other (symbolic and semi-symbolic) algorithms seem to be ideally suited to augment ATPs. In the following we shortly describe two major points of interest in combining SASs (symbolic algebraic systems) with top-down automated theorem provers (here: SETHEO [Let92, GLMS94]).

  15. Implementing hospital library automation: the GaIN project. Georgia Interactive Network for Medical Information.

    PubMed Central

    Rankin, J A; McInnis, K A; Rosner, A L

    1995-01-01

    The GaIN (Georgia Interactive Network for Medical Information) Hospital Libraries' Local Automation Project was a one-year, grant-funded initiative to implement an integrated library system in three Georgia hospitals. The purpose of the project was to install the library systems, describe the steps in hospital library automation, and identify issues and barriers related to automation in small libraries. The participating hospitals included a small, a medium, and a large institution. The steps and time required for project implementation were documented in order to develop a decision checklist. Although library automation proved a desirable approach for improving collection accessibility, simplifying daily routines, and improving the library's image in the hospital, planners must be sure to consider equipment as well as software support, staffing for the conversion, and training of the library staff and end users. PMID:7581184

  16. Photographic and drafting techniques simplify method of producing engineering drawings

    NASA Technical Reports Server (NTRS)

    Provisor, H.

    1968-01-01

    Combination of photographic and drafting techniques has been developed to simplify the preparation of three dimensional and dimetric engineering drawings. Conventional photographs can be converted to line drawings by making copy negatives on high contrast film.

  17. Simplified circuit corrects faults in parallel binary information channels

    NASA Technical Reports Server (NTRS)

    Goldberg, J.

    1966-01-01

    Corrective circuit prevents the appearance of erroneous output signals from the possible failure of any single-channel element interconnected in parallel binary information channels. The circuit is simplified and economical because it does not use redundant channels.

  18. Automation and Intensity Modulated Radiation Therapy for Individualized High-Quality Tangent Breast Treatment Plans

    SciTech Connect

    Purdie, Thomas G.; Dinniwell, Robert E.; Fyles, Anthony; Sharpe, Michael B.

    2014-11-01

    Purpose: To demonstrate the large-scale clinical implementation and performance of an automated treatment planning methodology for tangential breast intensity modulated radiation therapy (IMRT). Methods and Materials: Automated planning was used to prospectively plan tangential breast IMRT treatment for 1661 patients between June 2009 and November 2012. The automated planning method emulates the manual steps performed by the user during treatment planning, including anatomical segmentation, beam placement, optimization, dose calculation, and plan documentation. The user specifies clinical requirements of the plan to be generated through a user interface embedded in the planning system. The automated method uses heuristic algorithms to define and simplify the technical aspects of the treatment planning process. Results: Automated planning was used in 1661 of 1708 patients receiving tangential breast IMRT during the time interval studied. Therefore, automated planning was applicable in greater than 97% of cases. The time for treatment planning using the automated process is routinely 5 to 6 minutes on standard commercially available planning hardware. We have shown a consistent reduction in plan rejections from plan reviews through the standard quality control process or weekly quality review multidisciplinary breast rounds as we have automated the planning process for tangential breast IMRT. Clinical plan acceptance increased from 97.3% using our previous semiautomated inverse method to 98.9% using the fully automated method. Conclusions: Automation has become the routine standard method for treatment planning of tangential breast IMRT at our institution and is clinically feasible on a large scale. The method has wide clinical applicability and can add tremendous efficiency, standardization, and quality to the current treatment planning process. The use of automated methods can allow centers to more rapidly adopt IMRT and enhance access to the documented

  19. Simplified method for numerical modeling of fiber lasers.

    PubMed

    Shtyrina, O V; Yarutkina, I A; Fedoruk, M P

    2014-12-29

    A simplified numerical approach to modeling of dissipative dispersion-managed fiber lasers is examined. We present a new numerical iteration algorithm for finding the periodic solutions of the system of nonlinear ordinary differential equations describing the intra-cavity dynamics of the dissipative soliton characteristics in dispersion-managed fiber lasers. We demonstrate that results obtained using simplified model are in good agreement with full numerical modeling based on the corresponding partial differential equations.

  20. Simplified Correction Of Errors In Reed-Solomon Codes

    NASA Technical Reports Server (NTRS)

    Truong, T. K.; Hsu, I. S.; Eastman, W. L.; Reed, I. S.

    1990-01-01

    New decoder realized by simplified pipeline architecture. Simplified procedure for correction of errors and erasures in Reed-Solomon codes expected to result in simpler decoding equipment. Development widens commercial applicability of Reed-Solomon codes, used to correct bursts of errors in digital communication and recording systems. Improved decoder less complex. Made more regular, simple, and suitable for implementation in both VLSI and software.

  1. Simplifier: a web tool to eliminate redundant NGS contigs

    PubMed Central

    Ramos, Rommel Thiago Jucá; Carneiro, Adriana Ribeiro; Azevedo, Vasco; Schneider, Maria Paula; Barh, Debmalya; Silva, Artur

    2012-01-01

    Modern genomic sequencing technologies produce a large amount of data with reduced cost per base; however, this data consists of short reads. This reduction in the size of the reads, compared to those obtained with previous methodologies, presents new challenges, including a need for efficient algorithms for the assembly of genomes from short reads and for resolving repetitions. Additionally after abinitio assembly, curation of the hundreds or thousands of contigs generated by assemblers demands considerable time and computational resources. We developed Simplifier, a stand-alone software that selectively eliminates redundant sequences from the collection of contigs generated by ab initio assembly of genomes. Application of Simplifier to data generated by assembly of the genome of Corynebacterium pseudotuberculosis strain 258 reduced the number of contigs generated by ab initio methods from 8,004 to 5,272, a reduction of 34.14%; in addition, N50 increased from 1 kb to 1.5 kb. Processing the contigs of Escherichia coli DH10B with Simplifier reduced the mate-paired library 17.47% and the fragment library 23.91%. Simplifier removed redundant sequences from datasets produced by assemblers, thereby reducing the effort required for finalization of genome assembly in tests with data from Prokaryotic organisms. Availability Simplifier is available at http://www.genoma.ufpa.br/rramos/softwares/simplifier.xhtmlIt requires Sun jdk 6 or higher. PMID:23275695

  2. S-channel dark matter simplified models and unitarity

    NASA Astrophysics Data System (ADS)

    Englert, Christoph; McCullough, Matthew; Spannowsky, Michael

    2016-12-01

    The ultraviolet structure of s-channel mediator dark matter simplified models at hadron colliders is considered. In terms of commonly studied s-channel mediator simplified models it is argued that at arbitrarily high energies the perturbative description of dark matter production in high energy scattering can break down. This is analogous to the well documented breakdown of an EFT description of dark matter collider production. With this in mind, to diagnose whether or not the use of simplified models at the LHC is valid, perturbative unitarity of the scattering amplitude in the processes relevant to LHC dark matter searches is studied. The results are as one would expect: at the LHC and future proton colliders the simplified model descriptions of dark matter production are in general valid. As a result of the general discussion, a simple class of 'Fermiophobic Scalar' simplified models is proposed, in which a scalar mediator couples to electroweak vector bosons. The Fermiophobic simplified model is well motivated and exhibits interesting collider and direct detection phenomenology.

  3. Automated campaign system

    NASA Astrophysics Data System (ADS)

    Vondran, Gary; Chao, Hui; Lin, Xiaofan; Beyer, Dirk; Joshi, Parag; Atkins, Brian; Obrador, Pere

    2006-02-01

    To run a targeted campaign involves coordination and management across numerous organizations and complex process flows. Everything from market analytics on customer databases, acquiring content and images, composing the materials, meeting the sponsoring enterprise brand standards, driving through production and fulfillment, and evaluating results; all processes are currently performed by experienced highly trained staff. Presented is a developed solution that not only brings together technologies that automate each process, but also automates the entire flow so that a novice user could easily run a successful campaign from their desktop. This paper presents the technologies, structure, and process flows used to bring this system together. Highlighted will be how the complexity of running a targeted campaign is hidden from the user through technologies, all while providing the benefits of a professionally managed campaign.

  4. Automated macromolecular crystallization screening

    DOEpatents

    Segelke, Brent W.; Rupp, Bernhard; Krupka, Heike I.

    2005-03-01

    An automated macromolecular crystallization screening system wherein a multiplicity of reagent mixes are produced. A multiplicity of analysis plates is produced utilizing the reagent mixes combined with a sample. The analysis plates are incubated to promote growth of crystals. Images of the crystals are made. The images are analyzed with regard to suitability of the crystals for analysis by x-ray crystallography. A design of reagent mixes is produced based upon the expected suitability of the crystals for analysis by x-ray crystallography. A second multiplicity of mixes of the reagent components is produced utilizing the design and a second multiplicity of reagent mixes is used for a second round of automated macromolecular crystallization screening. In one embodiment the multiplicity of reagent mixes are produced by a random selection of reagent components.

  5. Terminal automation system maintenance

    SciTech Connect

    Coffelt, D.; Hewitt, J.

    1997-01-01

    Nothing has improved petroleum product loading in recent years more than terminal automation systems. The presence of terminal automation systems (TAS) at loading racks has increased operational efficiency and safety and enhanced their accounting and management capabilities. However, like all finite systems, they occasionally malfunction or fail. Proper servicing and maintenance can minimize this. And in the unlikely event a TAS breakdown does occur, prompt and effective troubleshooting can reduce its impact on terminal productivity. To accommodate around-the-clock loading at racks, increasingly unattended by terminal personnel, TAS maintenance, servicing and troubleshooting has become increasingly demanding. It has also become increasingly important. After 15 years of trial and error at petroleum and petrochemical storage and transfer terminals, a number of successful troubleshooting programs have been developed. These include 24-hour {open_quotes}help hotlines,{close_quotes} internal (terminal company) and external (supplier) support staff, and {open_quotes}layered{close_quotes} support. These programs are described.

  6. Automated Chromosome Breakage Assessment

    NASA Technical Reports Server (NTRS)

    Castleman, Kenneth

    1985-01-01

    An automated karyotyping machine was built at JPL in 1972. It does computerized karyotyping, but it has some hardware limitations. The image processing hardware that was available at a reasonable price in 1972 was marginal, at best, for this job. In the meantime, NASA has developed an interest in longer term spaceflights and an interest in using chromosome breakage studies as a dosimeter for radiation or perhaps other damage that might occur to the tissues. This uses circulating lymphocytes as a physiological dosimeter looking for chromosome breakage on long-term spaceflights. For that reason, we have reactivated the automated karyotyping work at JPL. An update on that work, and a description of where it appears to be headed is presented.

  7. The automation of science.

    PubMed

    King, Ross D; Rowland, Jem; Oliver, Stephen G; Young, Michael; Aubrey, Wayne; Byrne, Emma; Liakata, Maria; Markham, Magdalena; Pir, Pinar; Soldatova, Larisa N; Sparkes, Andrew; Whelan, Kenneth E; Clare, Amanda

    2009-04-03

    The basis of science is the hypothetico-deductive method and the recording of experiments in sufficient detail to enable reproducibility. We report the development of Robot Scientist "Adam," which advances the automation of both. Adam has autonomously generated functional genomics hypotheses about the yeast Saccharomyces cerevisiae and experimentally tested these hypotheses by using laboratory automation. We have confirmed Adam's conclusions through manual experiments. To describe Adam's research, we have developed an ontology and logical language. The resulting formalization involves over 10,000 different research units in a nested treelike structure, 10 levels deep, that relates the 6.6 million biomass measurements to their logical description. This formalization describes how a machine contributed to scientific knowledge.

  8. Automated gas chromatography

    DOEpatents

    Mowry, C.D.; Blair, D.S.; Rodacy, P.J.; Reber, S.D.

    1999-07-13

    An apparatus and process for the continuous, near real-time monitoring of low-level concentrations of organic compounds in a liquid, and, more particularly, a water stream. A small liquid volume of flow from a liquid process stream containing organic compounds is diverted by an automated process to a heated vaporization capillary where the liquid volume is vaporized to a gas that flows to an automated gas chromatograph separation column to chromatographically separate the organic compounds. Organic compounds are detected and the information transmitted to a control system for use in process control. Concentrations of organic compounds less than one part per million are detected in less than one minute. 7 figs.

  9. Automated assembly in space

    NASA Technical Reports Server (NTRS)

    Srivastava, Sandanand; Dwivedi, Suren N.; Soon, Toh Teck; Bandi, Reddy; Banerjee, Soumen; Hughes, Cecilia

    1989-01-01

    The installation of robots and their use of assembly in space will create an exciting and promising future for the U.S. Space Program. The concept of assembly in space is very complicated and error prone and it is not possible unless the various parts and modules are suitably designed for automation. Certain guidelines are developed for part designing and for an easy precision assembly. Major design problems associated with automated assembly are considered and solutions to resolve these problems are evaluated in the guidelines format. Methods for gripping and methods for part feeding are developed with regard to the absence of gravity in space. The guidelines for part orientation, adjustments, compliances and various assembly construction are discussed. Design modifications of various fasteners and fastening methods are also investigated.

  10. Automated Assembly Center (AAC)

    NASA Technical Reports Server (NTRS)

    Stauffer, Robert J.

    1993-01-01

    The objectives of this project are as follows: to integrate advanced assembly and assembly support technology under a comprehensive architecture; to implement automated assembly technologies in the production of high-visibility DOD weapon systems; and to document the improved cost, quality, and lead time. This will enhance the production of DOD weapon systems by utilizing the latest commercially available technologies combined into a flexible system that will be able to readily incorporate new technologies as they emerge. Automated assembly encompasses the following areas: product data, process planning, information management policies and framework, three schema architecture, open systems communications, intelligent robots, flexible multi-ability end effectors, knowledge-based/expert systems, intelligent workstations, intelligent sensor systems, and PDES/PDDI data standards.

  11. The automated command transmission

    NASA Astrophysics Data System (ADS)

    Inoue, Y.; Satoh, S.

    A technique for automated command transmission (ACT) to GEO-stationed satellites is presented. The system is intended for easing the command center workload. The ACT system determines the relation of the commands to on-board units, connects the telemetry with on-board units, defines the control path on the spacecraft, identifies the correspondence of back-up units to primary units, and ascertains sunlight or eclipse conditions. The system also has the address of satellite and command decoders, the ID and content for the mission command sequence, group and inhibit codes, a listing of all available commands, and restricts the data to a command sequence. Telemetry supplies data for automated problem correction. All other missions operations are terminated during system recovery data processing after a crash. The ACT system is intended for use with the GMS spacecraft.

  12. Automated RSO Stability Analysis

    NASA Astrophysics Data System (ADS)

    Johnson, T.

    2016-09-01

    A methodology for assessing the attitude stability of a Resident Space Object (RSO) using visual magnitude data is presented and then scaled to run in an automated fashion across the entire satellite catalog. Results obtained by applying the methodology to the Commercial Space Operations Center (COMSpOC) catalog are presented and summarized, identifying objects that have changed stability. We also examine the timeline for detecting the transition from stable to unstable attitude

  13. Automation in Photogrammetry,

    DTIC Science & Technology

    1980-07-25

    Allam , 1978), and the OM-Bendix AS-lIB-X (Scarano and Bruma, 1976). The UNAMACE and GPM-2 employ analog (electronic) correlation technology. However...Survey (USGS) and the Surveys and Mapping Branch (Canada) have formed integrated systems based on the Gestalt GPM 2 (Brunson and Olson, 1978; Allam , 1978...ten years off, and the full automation of planimetric extraction may be more than 20 years in the future. REFERENCES Allam , M. M., 1978. The Role of

  14. Automated Nitrocellulose Analysis

    DTIC Science & Technology

    1978-12-01

    is acceptable. (4) As would be expected from the theory of osmosis , a high saline content in the dialysis recipient stream (countersolution) is of...Block 39, II different from Report; IS. SUPPLEMENTARY NOTES IS. KEY WOROS (Continue on rereri Analysis Automated analysis Dialysis Glyceryl...Technicon AutoAnalyzer, involves aspiration of a stirred nitrocellulose suspension, dialysis against 9 percent saline, and hydrolysis with 5N sodium

  15. Automated Cooperative Trajectories

    NASA Technical Reports Server (NTRS)

    Hanson, Curt; Pahle, Joseph; Brown, Nelson

    2015-01-01

    This presentation is an overview of the Automated Cooperative Trajectories project. An introduction to the phenomena of wake vortices is given, along with a summary of past research into the possibility of extracting energy from the wake by flying close parallel trajectories. Challenges and barriers to adoption of civilian automatic wake surfing technology are identified. A hardware-in-the-loop simulation is described that will support future research. Finally, a roadmap for future research and technology transition is proposed.

  16. Power subsystem automation study

    NASA Technical Reports Server (NTRS)

    Tietz, J. C.; Sewy, D.; Pickering, C.; Sauers, R.

    1984-01-01

    The purpose of the phase 2 of the power subsystem automation study was to demonstrate the feasibility of using computer software to manage an aspect of the electrical power subsystem on a space station. The state of the art in expert systems software was investigated in this study. This effort resulted in the demonstration of prototype expert system software for managing one aspect of a simulated space station power subsystem.

  17. Automated Microfluidics for Genomics

    DTIC Science & Technology

    2007-11-02

    the automation of it, see [4]. In the Genomation Laboratory at the Univ. of Washington (http://rcs.ee.washington.edu/GNL/genomation.html) and with Orca ...reproducible biology without contamination . The high throughput capability is competitive with large scale robotic batch processing. III. INSTRUMENTATION...essentially arbitrary low volume, and without any contact that might cause contamination . A. ACAPELLA-5K Core Processor The ACAPELLA-5K was designed with

  18. Automated RTOP Management System

    NASA Technical Reports Server (NTRS)

    Hayes, P.

    1984-01-01

    The structure of NASA's Office of Aeronautics and Space Technology electronic information system network from 1983 to 1985 is illustrated. The RTOP automated system takes advantage of existing hardware, software, and expertise, and provides: (1) computerized cover sheet and resources forms; (2) electronic signature and transmission; (3) a data-based information system; (4) graphics; (5) intercenter communications; (6) management information; and (7) text editing. The system is coordinated with Headquarters efforts in codes R,E, and T.

  19. Automated Microbial Metabolism Laboratory

    NASA Technical Reports Server (NTRS)

    1973-01-01

    Development of the automated microbial metabolism laboratory (AMML) concept is reported. The focus of effort of AMML was on the advanced labeled release experiment. Labeled substrates, inhibitors, and temperatures were investigated to establish a comparative biochemical profile. Profiles at three time intervals on soil and pure cultures of bacteria isolated from soil were prepared to establish a complete library. The development of a strategy for the return of a soil sample from Mars is also reported.

  20. Cavendish Balance Automation

    NASA Technical Reports Server (NTRS)

    Thompson, Bryan

    2000-01-01

    This is the final report for a project carried out to modify a manual commercial Cavendish Balance for automated use in cryostat. The scope of this project was to modify an off-the-shelf manually operated Cavendish Balance to allow for automated operation for periods of hours or days in cryostat. The purpose of this modification was to allow the balance to be used in the study of effects of superconducting materials on the local gravitational field strength to determine if the strength of gravitational fields can be reduced. A Cavendish Balance was chosen because it is a fairly simple piece of equipment for measuring gravity, one the least accurately known and least understood physical constants. The principle activities that occurred under this purchase order were: (1) All the components necessary to hold and automate the Cavendish Balance in a cryostat were designed. Engineering drawings were made of custom parts to be fabricated, other off-the-shelf parts were procured; (2) Software was written in LabView to control the automation process via a stepper motor controller and stepper motor, and to collect data from the balance during testing; (3)Software was written to take the data collected from the Cavendish Balance and reduce it to give a value for the gravitational constant; (4) The components of the system were assembled and fitted to a cryostat. Also the LabView hardware including the control computer, stepper motor driver, data collection boards, and necessary cabling were assembled; and (5) The system was operated for a number of periods, data collected, and reduced to give an average value for the gravitational constant.

  1. Autonomy, Automation, and Systems

    NASA Astrophysics Data System (ADS)

    Turner, Philip R.

    1987-02-01

    Aerospace industry interest in autonomy and automation, given fresh impetus by the national goal of establishing a Space Station, is becoming a major item of research and technology development. The promise of new technology arising from research in Artificial Intelligence (AI) has focused much attention on its potential in autonomy and automation. These technologies can improve performance in autonomous control functions that involve planning, scheduling, and fault diagnosis of complex systems. There are, however, many aspects of system and subsystem design in an autonomous system that impact AI applications, but do not directly involve AI technology. Development of a system control architecture, establishment of an operating system within the design, providing command and sensory data collection features appropriate to automated operation, and the use of design analysis tools to support system engineering are specific examples of major design issues. Aspects such as these must also receive attention and technology development support if we are to implement complex autonomous systems within the realistic limitations of mass, power, cost, and available flight-qualified technology that are all-important to a flight project.

  2. Automating existing stations

    SciTech Connect

    Little, J.E.

    1986-09-01

    The task was to automate 20 major compressor stations along ANR Pipeline Co.'s Southeastern and Southwestern pipelines in as many months. Meeting this schedule required standardized hardware and software design. Working with Bristol Babcock Co., ANR came up with an off-the-shelf station automation package suitable for a variety of compressor stations. The project involved 148 engines with 488,880-hp in the 20 stations. ANR Pipeline developed software for these engines and compressors, including horsepower prediction and efficiency. The system places processors ''intelligence'' at each station and engine to monitor and control operations. The station processor receives commands from the company's gas dispatch center at Detroit and informs dispatchers of alarms, conditions, and decision it makes. The automation system is controlled by the Detroit center through a central communications network. Operating orders from the center are sent to the station processor, which obeys orders using the most efficient means of operation at the station's disposal. In a malfunction, a control and communications backup system takes over. Commands and information are directly transmitted between the center and the individual compressor stations. Stations receive their orders based on throughput, with suction and discharge pressure overrides. Additionally, a discharge temperature override protects pipeline coatings.

  3. Automation in biological crystallization.

    PubMed

    Stewart, Patrick Shaw; Mueller-Dieckmann, Jochen

    2014-06-01

    Crystallization remains the bottleneck in the crystallographic process leading from a gene to a three-dimensional model of the encoded protein or RNA. Automation of the individual steps of a crystallization experiment, from the preparation of crystallization cocktails for initial or optimization screens to the imaging of the experiments, has been the response to address this issue. Today, large high-throughput crystallization facilities, many of them open to the general user community, are capable of setting up thousands of crystallization trials per day. It is thus possible to test multiple constructs of each target for their ability to form crystals on a production-line basis. This has improved success rates and made crystallization much more convenient. High-throughput crystallization, however, cannot relieve users of the task of producing samples of high quality. Moreover, the time gained from eliminating manual preparations must now be invested in the careful evaluation of the increased number of experiments. The latter requires a sophisticated data and laboratory information-management system. A review of the current state of automation at the individual steps of crystallization with specific attention to the automation of optimization is given.

  4. Automation in biological crystallization

    PubMed Central

    Shaw Stewart, Patrick; Mueller-Dieckmann, Jochen

    2014-01-01

    Crystallization remains the bottleneck in the crystallographic process leading from a gene to a three-dimensional model of the encoded protein or RNA. Automation of the individual steps of a crystallization experiment, from the preparation of crystallization cocktails for initial or optimization screens to the imaging of the experiments, has been the response to address this issue. Today, large high-throughput crystallization facilities, many of them open to the general user community, are capable of setting up thousands of crystallization trials per day. It is thus possible to test multiple constructs of each target for their ability to form crystals on a production-line basis. This has improved success rates and made crystallization much more convenient. High-throughput crystallization, however, cannot relieve users of the task of producing samples of high quality. Moreover, the time gained from eliminating manual preparations must now be invested in the careful evaluation of the increased number of experiments. The latter requires a sophisticated data and laboratory information-management system. A review of the current state of automation at the individual steps of crystallization with specific attention to the automation of optimization is given. PMID:24915074

  5. Automation of optical tweezers

    NASA Astrophysics Data System (ADS)

    Hsieh, Tseng-Ming; Chang, Bo-Jui; Hsu, Long

    2000-07-01

    Optical tweezers is a newly developed instrument, which makes possible the manipulation of micro-optical particles under a microscope. In this paper, we present the automation of an optical tweezers which consists of a modified optical tweezers, equipped with two motorized actuators to deflect a 1 W argon laser beam, and a computer control system including a joystick. The trapping of a single bead and a group of lactoacidofilus was shown, separately. With the aid of the joystick and two auxiliary cursers superimposed on the real-time image of a trapped bead, we demonstrated the simple and convenient operation of the automated optical tweezers. By steering the joystick and then pressing a button on it, we assign a new location for the trapped bead to move to. The increment of the motion 0.04 (mu) m for a 20X objective, is negligible. With a fast computer for image processing, the manipulation of the trapped bead is smooth and accurate. The automation of the optical tweezers is also programmable. This technique may be applied to accelerate the DNA hybridization in a gene chip. The combination of the modified optical tweezers with the computer control system provides a tool for precise manipulation of micro particles in many scientific fields.

  6. Design and Prototype of an Automated Column-Switching HPLC System for Radiometabolite Analysis

    PubMed Central

    Vasdev, Neil; Collier, Thomas Lee

    2016-01-01

    Column-switching high performance liquid chromatography (HPLC) is extensively used for the critical analysis of radiolabeled ligands and their metabolites in plasma. However, the lack of streamlined apparatus and consequently varying protocols remain as a challenge among positron emission tomography laboratories. We report here the prototype apparatus and implementation of a fully automated and simplified column-switching procedure to allow for the easy and automated determination of radioligands and their metabolites in up to 5 mL of plasma. The system has been used with conventional UV and coincidence radiation detectors, as well as with a single quadrupole mass spectrometer. PMID:27548189

  7. Design and Prototype of an Automated Column-Switching HPLC System for Radiometabolite Analysis.

    PubMed

    Vasdev, Neil; Collier, Thomas Lee

    2016-08-17

    Column-switching high performance liquid chromatography (HPLC) is extensively used for the critical analysis of radiolabeled ligands and their metabolites in plasma. However, the lack of streamlined apparatus and consequently varying protocols remain as a challenge among positron emission tomography laboratories. We report here the prototype apparatus and implementation of a fully automated and simplified column-switching procedure to allow for the easy and automated determination of radioligands and their metabolites in up to 5 mL of plasma. The system has been used with conventional UV and coincidence radiation detectors, as well as with a single quadrupole mass spectrometer.

  8. Automated Space Surveillance using the AN/FSY-3 Space Fence System

    NASA Astrophysics Data System (ADS)

    Hack, P.; Carbaugh, K.; Simon, K.

    2016-09-01

    The AN/FSY-3 Space Fence System is a highly automated space surveillance system enabled by a service-oriented, net-centric architecture and an advanced situational awareness user interface. The large radar power aperture, coupled with mission processing, automation and advanced visualization, permits rapid space catalog buildup and provides space object event alerts to operators in near-real time. Operator burden is minimized with intuitive three-dimensional track displays, simplified radar tasking and control, and orbital mechanics processing driven by the US Air Force Space Command (AFSPC) Astrodynamic Standards Software.

  9. Automated Proactive Fault Isolation: A Key to Automated Commissioning

    SciTech Connect

    Katipamula, Srinivas; Brambley, Michael R.

    2007-07-31

    In this paper, we present a generic model for automated continuous commissioing and then delve in detail into one of the processes, proactive testing for fault isolation, which is key to automating commissioning. The automated commissioining process uses passive observation-based fault detction and diagnostic techniques, followed by automated proactive testing for fault isolation, automated fault evaluation, and automated reconfiguration of controls together to continuously keep equipment controlled and running as intended. Only when hard failures occur or a physical replacement is required does the process require human intervention, and then sufficient information is provided by the automated commissioning system to target manual maintenance where it is needed. We then focus on fault isolation by presenting detailed logic that can be used to automatically isolate faults in valves, a common component in HVAC systems, as an example of how automated proactive fault isolation can be accomplished. We conclude the paper with a discussion of how this approach to isolating faults can be applied to other common HVAC components and their automated commmissioning and a summary of key conclusions of the paper.

  10. Automation in organizations: Eternal conflict

    NASA Technical Reports Server (NTRS)

    Dieterly, D. L.

    1981-01-01

    Some ideas on and insights into the problems associated with automation in organizations are presented with emphasis on the concept of automation, its relationship to the individual, and its impact on system performance. An analogy is drawn, based on an American folk hero, to emphasize the extent of the problems encountered when dealing with automation within an organization. A model is proposed to focus attention on a set of appropriate dimensions. The function allocation process becomes a prominent aspect of the model. The current state of automation research is mentioned in relation to the ideas introduced. Proposed directions for an improved understanding of automation's effect on the individual's efficiency are discussed. The importance of understanding the individual's perception of the system in terms of the degree of automation is highlighted.

  11. World-wide distribution automation systems

    SciTech Connect

    Devaney, T.M.

    1994-12-31

    A worldwide power distribution automation system is outlined. Distribution automation is defined and the status of utility automation is discussed. Other topics discussed include a distribution management system, substation feeder, and customer functions, potential benefits, automation costs, planning and engineering considerations, automation trends, databases, system operation, computer modeling of system, and distribution management systems.

  12. Automating CPM-GOMS

    NASA Technical Reports Server (NTRS)

    John, Bonnie; Vera, Alonso; Matessa, Michael; Freed, Michael; Remington, Roger

    2002-01-01

    CPM-GOMS is a modeling method that combines the task decomposition of a GOMS analysis with a model of human resource usage at the level of cognitive, perceptual, and motor operations. CPM-GOMS models have made accurate predictions about skilled user behavior in routine tasks, but developing such models is tedious and error-prone. We describe a process for automatically generating CPM-GOMS models from a hierarchical task decomposition expressed in a cognitive modeling tool called Apex. Resource scheduling in Apex automates the difficult task of interleaving the cognitive, perceptual, and motor resources underlying common task operators (e.g. mouse move-and-click). Apex's UI automatically generates PERT charts, which allow modelers to visualize a model's complex parallel behavior. Because interleaving and visualization is now automated, it is feasible to construct arbitrarily long sequences of behavior. To demonstrate the process, we present a model of automated teller interactions in Apex and discuss implications for user modeling. available to model human users, the Goals, Operators, Methods, and Selection (GOMS) method [6, 21] has been the most widely used, providing accurate, often zero-parameter, predictions of the routine performance of skilled users in a wide range of procedural tasks [6, 13, 15, 27, 28]. GOMS is meant to model routine behavior. The user is assumed to have methods that apply sequences of operators and to achieve a goal. Selection rules are applied when there is more than one method to achieve a goal. Many routine tasks lend themselves well to such decomposition. Decomposition produces a representation of the task as a set of nested goal states that include an initial state and a final state. The iterative decomposition into goals and nested subgoals can terminate in primitives of any desired granularity, the choice of level of detail dependent on the predictions required. Although GOMS has proven useful in HCI, tools to support the

  13. Automated Propellant Blending

    NASA Technical Reports Server (NTRS)

    Hohmann, Carl W. (Inventor); Harrington, Douglas W. (Inventor); Dutton, Maureen L. (Inventor); Tipton, Billy Charles, Jr. (Inventor); Bacak, James W. (Inventor); Salazar, Frank (Inventor)

    2000-01-01

    An automated propellant blending apparatus and method that uses closely metered addition of countersolvent to a binder solution with propellant particles dispersed therein to precisely control binder precipitation and particle aggregation is discussed. A profile of binder precipitation versus countersolvent-solvent ratio is established empirically and used in a computer algorithm to establish countersolvent addition parameters near the cloud point for controlling the transition of properties of the binder during agglomeration and finishing of the propellant composition particles. The system is remotely operated by computer for safety, reliability and improved product properties, and also increases product output.

  14. Automated fiber pigtailing machine

    DOEpatents

    Strand, Oliver T.; Lowry, Mark E.

    1999-01-01

    The Automated Fiber Pigtailing Machine (AFPM) aligns and attaches optical fibers to optoelectonic (OE) devices such as laser diodes, photodiodes, and waveguide devices without operator intervention. The so-called pigtailing process is completed with sub-micron accuracies in less than 3 minutes. The AFPM operates unattended for one hour, is modular in design and is compatible with a mass production manufacturing environment. This machine can be used to build components which are used in military aircraft navigation systems, computer systems, communications systems and in the construction of diagnostics and experimental systems.

  15. Automated fiber pigtailing machine

    DOEpatents

    Strand, O.T.; Lowry, M.E.

    1999-01-05

    The Automated Fiber Pigtailing Machine (AFPM) aligns and attaches optical fibers to optoelectronic (OE) devices such as laser diodes, photodiodes, and waveguide devices without operator intervention. The so-called pigtailing process is completed with sub-micron accuracies in less than 3 minutes. The AFPM operates unattended for one hour, is modular in design and is compatible with a mass production manufacturing environment. This machine can be used to build components which are used in military aircraft navigation systems, computer systems, communications systems and in the construction of diagnostics and experimental systems. 26 figs.

  16. Automated wire preparation system

    NASA Astrophysics Data System (ADS)

    McCulley, Deborah J.

    The first step toward an automated wire harness facility for the aerospace industry has been taken by implementing the Wire Vektor 2000 into the wire harness preparation area. An overview of the Wire Vektor 2000 is given, including the facilities for wire cutting, marking, and transporting, for wire end processing, and for system control. Production integration in the Wire Vektor 2000 system is addressed, considering the hardware/software debug system and the system throughput. The manufacturing changes that have to be made in implementing the Wire Vektor 2000 are discussed.

  17. Automated Propellant Blending

    NASA Technical Reports Server (NTRS)

    Hohmann, Carl W. (Inventor); Harrington, Douglas W. (Inventor); Dutton, Maureen L. (Inventor); Tipton, Billy Charles, Jr. (Inventor); Bacak, James W. (Inventor); Salazar, Frank (Inventor)

    1999-01-01

    An automated propellant blending apparatus and method uses closely metered addition of countersolvent to a binder solution with propellant particles dispersed therein to precisely control binder precipitation and particle aggregation. A profile of binder precipitation versus countersolvent-solvent ratio is established empirically and used in a computer algorithm to establish countersolvent addition parameters near the cloud point for controlling the transition of properties of the binder during agglomeration and finishing of the propellant composition particles. The system is remotely operated by computer for safety, reliability and improved product properties, and also increases product output.

  18. A simplified method for elastic-plastic-creep structural analysis

    NASA Technical Reports Server (NTRS)

    Kaufman, A.

    1984-01-01

    A simplified inelastic analysis computer program (ANSYPM) was developed for predicting the stress-strain history at the critical location of a thermomechanically cycled structure from an elastic solution. The program uses an iterative and incremental procedure to estimate the plastic strains from the material stress-strain properties and a plasticity hardening model. Creep effects are calculated on the basis of stress relaxation at constant strain, creep at constant stress or a combination of stress relaxation and creep accumulation. The simplified method was exercised on a number of problems involving uniaxial and multiaxial loading, isothermal and nonisothermal conditions, dwell times at various points in the cycles, different materials and kinematic hardening. Good agreement was found between these analytical results and nonlinear finite element solutions for these problems. The simplified analysis program used less than 1 percent of the CPU time required for a nonlinear finite element analysis.

  19. A simplified method for elastic-plastic-creep structural analysis

    NASA Technical Reports Server (NTRS)

    Kaufman, A.

    1985-01-01

    A simplified inelastic analysis computer program (ANSYPM) was developed for predicting the stress-strain history at the critical location of a thermomechanically cycled structure from an elastic solution. The program uses an iterative and incremental procedure to estimate the plastic strains from the material stress-strain properties and a plasticity hardening model. Creep effects are calculated on the basis of stress relaxation at constant strain, creep at constant stress or a combination of stress relaxation and creep accumulation. The simplified method was exercised on a number of problems involving uniaxial and multiaxial loading, isothermal and nonisothermal conditions, dwell times at various points in the cycles, different materials and kinematic hardening. Good agreement was found between these analytical results and nonlinear finite element solutions for these problems. The simplified analysis program used less than 1 percent of the CPU time required for a nonlinear finite element analysis.

  20. Simplified Analysis Model for Predicting Pyroshock Responses on Composite Panel

    NASA Astrophysics Data System (ADS)

    Iwasa, Takashi; Shi, Qinzhong

    A simplified analysis model based on the frequency response analysis and the wave propagation analysis was established for predicting Shock Response Spectrum (SRS) on the composite panel subjected to pyroshock loadings. The complex composite panel was modeled as an isotropic single layer panel defined in NASA Lewis Method. Through the conductance of an impact excitation test on a composite panel with no equipment mounted on, it was presented that the simplified analysis model could estimate the SRS as well as the acceleration peak values in both near and far field in an accurate way. In addition, through the simulation for actual pyroshock tests on an actual satellite system, the simplified analysis model was proved to be applicable in predicting the actual pyroshock responses, while bringing forth several technical issues to estimate the pyroshock test specifications in early design stages.

  1. Development of a simplified procedure for cyclic structural analysis

    NASA Technical Reports Server (NTRS)

    Kaufman, A.

    1984-01-01

    Development was extended of a simplified inelastic analysis computer program (ANSYMP) for predicting the stress-strain history at the critical location of a thermomechanically cycled structure from an elastic solution. The program uses an iterative and incremental procedure to estimate the plastic strains from the material stress-strain properties and a plasticity hardening model. Creep effects can be calculated on the basis of stress relaxation at constant strain, creep at constant stress, or a combination of stress relaxation and creep accumulation. The simplified method was exercised on a number of problems involving uniaxial and multiaxial loading, isothermal and nonisothermal conditions, dwell times at various points in the cycles, different materials, and kinematic hardening. Good agreement was found between these analytical results and nonlinear finite-element solutions for these problems. The simplified analysis program used less than 1 percent of the CPU time required for a nonlinear finite-element analysis.

  2. Optical chirp z-transform processor with a simplified architecture.

    PubMed

    Ngo, Nam Quoc

    2014-12-29

    Using a simplified chirp z-transform (CZT) algorithm based on the discrete-time convolution method, this paper presents the synthesis of a simplified architecture of a reconfigurable optical chirp z-transform (OCZT) processor based on the silica-based planar lightwave circuit (PLC) technology. In the simplified architecture of the reconfigurable OCZT, the required number of optical components is small and there are no waveguide crossings which make fabrication easy. The design of a novel type of optical discrete Fourier transform (ODFT) processor as a special case of the synthesized OCZT is then presented to demonstrate its effectiveness. The designed ODFT can be potentially used as an optical demultiplexer at the receiver of an optical fiber orthogonal frequency division multiplexing (OFDM) transmission system.

  3. Cylindrical Invisibility Cloak with Simplified Material Parameters is Inherently Visible

    NASA Astrophysics Data System (ADS)

    Yan, Min; Ruan, Zhichao; Qiu, Min

    2007-12-01

    It was proposed that perfect invisibility cloaks can be constructed for hiding objects from electromagnetic illumination [J. B. Pendry, D. Schurig, and D. R. Smith, Science 312, 1780 (2006)SCIEAS0036-807510.1126/science.1125907]. The cylindrical cloaks experimentally demonstrated [D. Schurig , Science 314, 977 (2006)SCIEAS0036-807510.1126/science.1133628] and theoretically proposed [W. Cai , Nat. Photon. 1, 224 (2007)1749-488510.1038/nphoton.2007.28] have however simplified material parameters in order to facilitate easier realization as well as to avoid infinities in optical constants. Here we show that the cylindrical cloaks with simplified material parameters inherently allow the zeroth-order cylindrical wave to pass through the cloak as if the cloak is made of a homogeneous isotropic medium, and thus visible. To all high-order cylindrical waves, our numerical simulation suggests that the simplified cloak inherits some properties of the ideal cloak, but finite scatterings exist.

  4. Automated System Marketplace 1995: The Changing Face of Automation.

    ERIC Educational Resources Information Center

    Barry, Jeff; And Others

    1995-01-01

    Discusses trends in the automated system marketplace with specific attention to online vendors and their customers: academic, public, school, and special libraries. Presents vendor profiles; tables and charts on computer systems and sales; and sidebars that include a vendor source list and the differing views on procuring an automated library…

  5. Simulation and simplified design studies of photovoltaic systems

    SciTech Connect

    Evans, D.L.; Facinelli, W.A.; Koehler, L.P.

    1980-09-01

    Results of TRNSYS simulations of photovoltaic systems with electrical storage are described. Studies of the sensitivity of system performance, in terms of the fraction of the electrical load supplied by the solar energy system, to variables such as array size, battery size, location, time of year, and load shape are reported. An accurate simplified method for predicting array output of max-power photovoltaic systems is presented. A second simplified method, which estimates the overall performance of max-power systems, is developed. Finally, a preliminary technique for predicting clamped-voltage system performance is discussed.

  6. A simplified dynamic model of the T700 turboshaft engine

    NASA Technical Reports Server (NTRS)

    Duyar, Ahmet; Gu, Zhen; Litt, Jonathan S.

    1992-01-01

    A simplified open-loop dynamic model of the T700 turboshaft engine, valid within the normal operating range of the engine, is developed. This model is obtained by linking linear state space models obtained at different engine operating points. Each linear model is developed from a detailed nonlinear engine simulation using a multivariable system identification and realization method. The simplified model may be used with a model-based real time diagnostic scheme for fault detection and diagnostics, as well as for open loop engine dynamics studies and closed loop control analysis utilizing a user generated control law.

  7. Simplifying Probability Elicitation and Uncertainty Modeling in Bayesian Networks

    SciTech Connect

    Paulson, Patrick R; Carroll, Thomas E; Sivaraman, Chitra; Neorr, Peter A; Unwin, Stephen D; Hossain, Shamina S

    2011-04-16

    In this paper we contribute two methods that simplify the demands of knowledge elicitation for particular types of Bayesian networks. The first method simplify the task of providing probabilities when the states that a random variable takes can be described by a new, fully ordered state set in which a state implies all the preceding states. The second method leverages Dempster-Shafer theory of evidence to provide a way for the expert to express the degree of ignorance that they feel about the estimates being provided.

  8. Simplified pregnant woman models for the fetus exposure assessment

    NASA Astrophysics Data System (ADS)

    Jala, Marjorie; Conil, Emmanuelle; Varsier, Nadège; Wiart, Joe; Hadjem, Abdelhamid; Moulines, Éric; Lévy-Leduc, Céline

    2013-05-01

    In this paper, we introduce a study that we carried out in order to validate the use of a simplified pregnant woman model for the assessment of the fetus exposure to radio frequency waves. This simplified model, based on the use of a homogeneous tissue to replace most of the inner organs of the virtual mother, would allow us to deal with many issues that are raised because of the lack of pregnant woman models for numerical dosimetry. Using specific absorption rate comparisons, we show that this model could be used to estimate the fetus exposure to plane waves.

  9. Simplified ontologies allowing comparison of developmental mammalian gene expression

    PubMed Central

    Kruger, Adele; Hofmann, Oliver; Carninci, Piero; Hayashizaki, Yoshihide; Hide, Winston

    2007-01-01

    Model organisms represent an important resource for understanding the fundamental aspects of mammalian biology. Mapping of biological phenomena between model organisms is complex and if it is to be meaningful, a simplified representation can be a powerful means for comparison. The Developmental eVOC ontologies presented here are simplified orthogonal ontologies describing the temporal and spatial distribution of developmental human and mouse anatomy. We demonstrate the ontologies by identifying genes showing a bias for developmental brain expression in human and mouse. PMID:17961239

  10. Space station advanced automation

    NASA Technical Reports Server (NTRS)

    Woods, Donald

    1990-01-01

    In the development of a safe, productive and maintainable space station, Automation and Robotics (A and R) has been identified as an enabling technology which will allow efficient operation at a reasonable cost. The Space Station Freedom's (SSF) systems are very complex, and interdependent. The usage of Advanced Automation (AA) will help restructure, and integrate system status so that station and ground personnel can operate more efficiently. To use AA technology for the augmentation of system management functions requires a development model which consists of well defined phases of: evaluation, development, integration, and maintenance. The evaluation phase will consider system management functions against traditional solutions, implementation techniques and requirements; the end result of this phase should be a well developed concept along with a feasibility analysis. In the development phase the AA system will be developed in accordance with a traditional Life Cycle Model (LCM) modified for Knowledge Based System (KBS) applications. A way by which both knowledge bases and reasoning techniques can be reused to control costs is explained. During the integration phase the KBS software must be integrated with conventional software, and verified and validated. The Verification and Validation (V and V) techniques applicable to these KBS are based on the ideas of consistency, minimal competency, and graph theory. The maintenance phase will be aided by having well designed and documented KBS software.

  11. Maneuver Automation Software

    NASA Technical Reports Server (NTRS)

    Uffelman, Hal; Goodson, Troy; Pellegrin, Michael; Stavert, Lynn; Burk, Thomas; Beach, David; Signorelli, Joel; Jones, Jeremy; Hahn, Yungsun; Attiyah, Ahlam; Illsley, Jeannette

    2009-01-01

    The Maneuver Automation Software (MAS) automates the process of generating commands for maneuvers to keep the spacecraft of the Cassini-Huygens mission on a predetermined prime mission trajectory. Before MAS became available, a team of approximately 10 members had to work about two weeks to design, test, and implement each maneuver in a process that involved running many maneuver-related application programs and then serially handing off data products to other parts of the team. MAS enables a three-member team to design, test, and implement a maneuver in about one-half hour after Navigation has process-tracking data. MAS accepts more than 60 parameters and 22 files as input directly from users. MAS consists of Practical Extraction and Reporting Language (PERL) scripts that link, sequence, and execute the maneuver- related application programs: "Pushing a single button" on a graphical user interface causes MAS to run navigation programs that design a maneuver; programs that create sequences of commands to execute the maneuver on the spacecraft; and a program that generates predictions about maneuver performance and generates reports and other files that enable users to quickly review and verify the maneuver design. MAS can also generate presentation materials, initiate electronic command request forms, and archive all data products for future reference.

  12. Agile automated vision

    NASA Astrophysics Data System (ADS)

    Fandrich, Juergen; Schmitt, Lorenz A.

    1994-11-01

    The microelectronic industry is a protagonist in driving automated vision to new paradigms. Today semiconductor manufacturers use vision systems quite frequently in their fabs in the front-end process. In fact, the process depends on reliable image processing systems. In the back-end process, where ICs are assembled and packaged, today vision systems are only partly used. But in the next years automated vision will become compulsory for the back-end process as well. Vision will be fully integrated into every IC package production machine to increase yields and reduce costs. Modem high-speed material processing requires dedicated and efficient concepts in image processing. But the integration of various equipment in a production plant leads to unifying handling of data flow and interfaces. Only agile vision systems can act with these contradictions: fast, reliable, adaptable, scalable and comprehensive. A powerful hardware platform is a unneglectable requirement for the use of advanced and reliable, but unfortunately computing intensive image processing algorithms. The massively parallel SIMD hardware product LANTERN/VME supplies a powerful platform for existing and new functionality. LANTERN/VME is used with a new optical sensor for IC package lead inspection. This is done in 3D, including horizontal and coplanarity inspection. The appropriate software is designed for lead inspection, alignment and control tasks in IC package production and handling equipment, like Trim&Form, Tape&Reel and Pick&Place machines.

  13. Automating quantum experiment control

    NASA Astrophysics Data System (ADS)

    Stevens, Kelly E.; Amini, Jason M.; Doret, S. Charles; Mohler, Greg; Volin, Curtis; Harter, Alexa W.

    2017-03-01

    The field of quantum information processing is rapidly advancing. As the control of quantum systems approaches the level needed for useful computation, the physical hardware underlying the quantum systems is becoming increasingly complex. It is already becoming impractical to manually code control for the larger hardware implementations. In this chapter, we will employ an approach to the problem of system control that parallels compiler design for a classical computer. We will start with a candidate quantum computing technology, the surface electrode ion trap, and build a system instruction language which can be generated from a simple machine-independent programming language via compilation. We incorporate compile time generation of ion routing that separates the algorithm description from the physical geometry of the hardware. Extending this approach to automatic routing at run time allows for automated initialization of qubit number and placement and additionally allows for automated recovery after catastrophic events such as qubit loss. To show that these systems can handle real hardware, we present a simple demonstration system that routes two ions around a multi-zone ion trap and handles ion loss and ion placement. While we will mainly use examples from transport-based ion trap quantum computing, many of the issues and solutions are applicable to other architectures.

  14. Classification of Automated Search Traffic

    NASA Astrophysics Data System (ADS)

    Buehrer, Greg; Stokes, Jack W.; Chellapilla, Kumar; Platt, John C.

    As web search providers seek to improve both relevance and response times, they are challenged by the ever-increasing tax of automated search query traffic. Third party systems interact with search engines for a variety of reasons, such as monitoring a web site’s rank, augmenting online games, or possibly to maliciously alter click-through rates. In this paper, we investigate automated traffic (sometimes referred to as bot traffic) in the query stream of a large search engine provider. We define automated traffic as any search query not generated by a human in real time. We first provide examples of different categories of query logs generated by automated means. We then develop many different features that distinguish between queries generated by people searching for information, and those generated by automated processes. We categorize these features into two classes, either an interpretation of the physical model of human interactions, or as behavioral patterns of automated interactions. Using the these detection features, we next classify the query stream using multiple binary classifiers. In addition, a multiclass classifier is then developed to identify subclasses of both normal and automated traffic. An active learning algorithm is used to suggest which user sessions to label to improve the accuracy of the multiclass classifier, while also seeking to discover new classes of automated traffic. Performance analysis are then provided. Finally, the multiclass classifier is used to predict the subclass distribution for the search query stream.

  15. Translation: Aids, Robots, and Automation.

    ERIC Educational Resources Information Center

    Andreyewsky, Alexander

    1981-01-01

    Examines electronic aids to translation both as ways to automate it and as an approach to solve problems resulting from shortage of qualified translators. Describes the limitations of robotic MT (Machine Translation) systems, viewing MAT (Machine-Aided Translation) as the only practical solution and the best vehicle for further automation. (MES)

  16. Robotics/Automated Systems Technicians.

    ERIC Educational Resources Information Center

    Doty, Charles R.

    Major resources exist that can be used to develop or upgrade programs in community colleges and technical institutes that educate robotics/automated systems technicians. The first category of resources is Economic, Social, and Education Issues. The Office of Technology Assessment (OTA) report, "Automation and the Workplace," presents analyses of…

  17. Opening up Library Automation Software

    ERIC Educational Resources Information Center

    Breeding, Marshall

    2009-01-01

    Throughout the history of library automation, the author has seen a steady advancement toward more open systems. In the early days of library automation, when proprietary systems dominated, the need for standards was paramount since other means of inter-operability and data exchange weren't possible. Today's focus on Application Programming…

  18. Automated Power-Distribution System

    NASA Technical Reports Server (NTRS)

    Ashworth, Barry; Riedesel, Joel; Myers, Chris; Miller, William; Jones, Ellen F.; Freeman, Kenneth; Walsh, Richard; Walls, Bryan K.; Weeks, David J.; Bechtel, Robert T.

    1992-01-01

    Autonomous power-distribution system includes power-control equipment and automation equipment. System automatically schedules connection of power to loads and reconfigures itself when it detects fault. Potential terrestrial applications include optimization of consumption of power in homes, power supplies for autonomous land vehicles and vessels, and power supplies for automated industrial processes.

  19. Automated design of aerospace structures

    NASA Technical Reports Server (NTRS)

    Fulton, R. E.; Mccomb, H. G.

    1974-01-01

    The current state-of-the-art in structural analysis of aerospace vehicles is characterized, automated design technology is discussed, and an indication is given of the future direction of research in analysis and automated design. Representative computer programs for analysis typical of those in routine use in vehicle design activities are described, and results are shown for some selected analysis problems. Recent and planned advances in analysis capability are indicated. Techniques used to automate the more routine aspects of structural design are discussed, and some recently developed automated design computer programs are described. Finally, discussion is presented of early accomplishments in interdisciplinary automated design systems, and some indication of the future thrust of research in this field is given.

  20. Simplified preliminary economic analysis for passive solar heating. Master's thesis

    SciTech Connect

    Baldetti, P.J.; Lockard, M.A.

    1983-09-01

    This report establishes economic feasibility criteria for considering the use of passive solar design. In light of the growing cost of supplying the energy demands of the Air Force, a method is needed to simplify the adaptation of passive solar heating and cooling in future building construction.

  1. Simplified physically based model of earthen embankment breaching

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A simplified physically based model has been developed to simulate the breaching processes of homogenous and composite earthen embankments owing to overtopping and piping. The breach caused by overtopping flow is approximated as a flat broad-crested weir with a trapezoidal cross section, downstream ...

  2. 77 FR 54482 - Allocation of Costs Under the Simplified Methods

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-05

    ... 26 CFR Part 1 [REG-126770-06] RIN 1545-BG07 Allocation of Costs Under the Simplified Methods AGENCY... contains proposed regulations on allocating costs to certain property produced by the taxpayer or acquired... of property that are required to capitalize certain costs to the property and that allocate...

  3. Simplified mechanistic models of gene regulation for analysis and design

    PubMed Central

    Hancock, Edward J.; Stan, Guy-Bart; Arpino, James A. J.; Papachristodoulou, Antonis

    2015-01-01

    Simplified mechanistic models of gene regulation are fundamental to systems biology and essential for synthetic biology. However, conventional simplified models typically have outputs that are not directly measurable and are based on assumptions that do not often hold under experimental conditions. To resolve these issues, we propose a ‘model reduction’ methodology and simplified kinetic models of total mRNA and total protein concentration, which link measurements, models and biochemical mechanisms. The proposed approach is based on assumptions that hold generally and include typical cases in systems and synthetic biology where conventional models do not hold. We use novel assumptions regarding the ‘speed of reactions’, which are required for the methodology to be consistent with experimental data. We also apply the methodology to propose simplified models of gene regulation in the presence of multiple protein binding sites, providing both biological insights and an illustration of the generality of the methodology. Lastly, we show that modelling total protein concentration allows us to address key questions on gene regulation, such as efficiency, burden, competition and modularity. PMID:26063825

  4. A simplified ductile-brittle transition temperature tester

    NASA Technical Reports Server (NTRS)

    Arias, A.

    1973-01-01

    The construction and operation of a versatile, simplified bend tester is described. The tester is usable at temperatures from - 192 to 650 C in air. Features of the tester include a single test chamber for cryogenic or elevated temperatures, specimen alining support rollers, and either manual or motorized operation.

  5. Some Observations on Cohesion and Coherence in Simplified Texts.

    ERIC Educational Resources Information Center

    Lautamatti, Liisa

    Analysis of several texts simplified to teach reading comprehension to college second language students shows that simplification affects both textual cohesion and coherence. Moreover, simplification restricts the amount of significant semantic information and creates a more transparent pattern of reference. The use of cohesive conjunctions varies…

  6. Simplified Load-Following Control for a Fuel Cell System

    NASA Technical Reports Server (NTRS)

    Vasquez, Arturo

    2010-01-01

    A simplified load-following control scheme has been proposed for a fuel cell power system. The scheme could be used to control devices that are important parts of a fuel cell system but are sometimes characterized as parasitic because they consume some of the power generated by the fuel cells.

  7. A Simplified Technique for Evaluating Human "CCR5" Genetic Polymorphism

    ERIC Educational Resources Information Center

    Falteisek, Lukáš; Cerný, Jan; Janštová, Vanda

    2013-01-01

    To involve students in thinking about the problem of AIDS (which is important in the view of nondecreasing infection rates), we established a practical lab using a simplified adaptation of Thomas's (2004) method to determine the polymorphism of HIV co-receptor CCR5 from students' own epithelial cells. CCR5 is a receptor involved in inflammatory…

  8. Investigations in a Simplified Bracketed Grid Approach to Metrical Structure

    ERIC Educational Resources Information Center

    Liu, Patrick Pei

    2010-01-01

    In this dissertation, I examine the fundamental mechanisms and assumptions of the Simplified Bracketed Grid Theory (Idsardi 1992) in two ways: first, by comparing it with Parametric Metrical Theory (Hayes 1995), and second, by implementing it in the analysis of several case studies in stress assignment and syllabification. Throughout these…

  9. Simplified seismic performance assessment and implications for seismic design

    NASA Astrophysics Data System (ADS)

    Sullivan, Timothy J.; Welch, David P.; Calvi, Gian Michele

    2014-08-01

    The last decade or so has seen the development of refined performance-based earthquake engineering (PBEE) approaches that now provide a framework for estimation of a range of important decision variables, such as repair costs, repair time and number of casualties. This paper reviews current tools for PBEE, including the PACT software, and examines the possibility of extending the innovative displacement-based assessment approach as a simplified structural analysis option for performance assessment. Details of the displacement-based s+eismic assessment method are reviewed and a simple means of quickly assessing multiple hazard levels is proposed. Furthermore, proposals for a simple definition of collapse fragility and relations between equivalent single-degree-of-freedom characteristics and multi-degree-of-freedom story drift and floor acceleration demands are discussed, highlighting needs for future research. To illustrate the potential of the methodology, performance measures obtained from the simplified method are compared with those computed using the results of incremental dynamic analyses within the PEER performance-based earthquake engineering framework, applied to a benchmark building. The comparison illustrates that the simplified method could be a very effective conceptual seismic design tool. The advantages and disadvantages of the simplified approach are discussed and potential implications of advanced seismic performance assessments for conceptual seismic design are highlighted through examination of different case study scenarios including different structural configurations.

  10. A Simplified Diagnostic Method for Elastomer Bond Durability

    NASA Technical Reports Server (NTRS)

    White, Paul

    2009-01-01

    A simplified method has been developed for determining bond durability under exposure to water or high humidity conditions. It uses a small number of test specimens with relatively short times of water exposure at elevated temperature. The method is also gravimetric; the only equipment being required is an oven, specimen jars, and a conventional laboratory balance.

  11. 48 CFR 1532.003 - Simplified acquisition procedures financing.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... procedures financing. 1532.003 Section 1532.003 Federal Acquisition Regulations System ENVIRONMENTAL... procedures financing. (a) Scope. This subpart provides for authorization of advance and interim payments on commercial item orders not exceeding the simplified acquisition threshold. Advance payments are payments...

  12. 48 CFR 1532.003 - Simplified acquisition procedures financing.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... procedures financing. 1532.003 Section 1532.003 Federal Acquisition Regulations System ENVIRONMENTAL... procedures financing. (a) Scope. This subpart provides for authorization of advance and interim payments on commercial item orders not exceeding the simplified acquisition threshold. Advance payments are payments...

  13. 48 CFR 1532.003 - Simplified acquisition procedures financing.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... procedures financing. 1532.003 Section 1532.003 Federal Acquisition Regulations System ENVIRONMENTAL... procedures financing. (a) Scope. This subpart provides for authorization of advance and interim payments on commercial item orders not exceeding the simplified acquisition threshold. Advance payments are payments...

  14. Measuring Phantom Recollection in the Simplified Conjoint Recognition Paradigm

    ERIC Educational Resources Information Center

    Stahl, Christoph; Klauer, Karl Christoph

    2009-01-01

    False memories are sometimes strong enough to elicit recollective experiences. This phenomenon has been termed Phantom Recollection (PR). The Conjoint Recognition (CR) paradigm has been used to empirically separate PR from other memory processes. Recently, a simplification of the CR procedure has been proposed. We herein extend the simplified CR…

  15. Psychometric Evaluation of the Simplified Chinese Version of Flourishing Scale

    ERIC Educational Resources Information Center

    Tang, Xiaoqing; Duan, Wenjie; Wang, Zhizhang; Liu, Tianyuan

    2016-01-01

    Objectives: The Flourishing Scale (FS) was developed to measure psychological well-being from the eudaimonic perspective, highlighting the flourishing of human functioning. This article evaluated the psychometric characteristics of the simplified Chinese version of FS among a Chinese community population. Method: A total of 433 participants from…

  16. Synthesis of (+)-crocacin D and simplified bioactive analogues.

    PubMed

    Pasqua, Adele E; Ferrari, Frank D; Crawford, James J; Whittingham, William G; Marquez, Rodolfo

    2015-03-01

    The total synthesis of (+)-crocacin D has been achieved in 15 steps (9 isolated intermediates) and 14% overall yield from commercially available starting materials and using (+)-crocacin C as a key intermediate. A number of simplified analogues and their biological activities are also reported.

  17. The new soliton solutions via modified Hereman's simplified method

    NASA Astrophysics Data System (ADS)

    Pınar, Zehra

    2017-02-01

    It is well recognized that new types of exact travelling wave solutions to nonlinear partial differential equations can be obtained modifications of the methods which are in hand. In this study, the new ansatz which was proposed by Wazwaz is considered to get new soliton solutions modifying the methodology which is known as Hereman's simplified method.

  18. Simplify Web Development for Faculty and Promote Instructional Design.

    ERIC Educational Resources Information Center

    Pedersen, David C.

    Faculty members are often overwhelmed with the prospect of implementing Web-based instruction. In an effort to simplify the process and incorporate some basic instructional design elements, the Educational Technology Team at Embry Riddle Aeronautical University created a course template for WebCT. Utilizing rapid prototyping, the template…

  19. 48 CFR 14.201-9 - Simplified contract format.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... CONTRACTING METHODS AND CONTRACT TYPES SEALED BIDDING Solicitation of Bids 14.201-9 Simplified contract format...) Contract line item number. (2) Description of supplies or services, or data sufficient to identify the..., but shall retain them in the contract file. Award by acceptance of a bid on the award portion of...

  20. 48 CFR 14.201-9 - Simplified contract format.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... CONTRACTING METHODS AND CONTRACT TYPES SEALED BIDDING Solicitation of Bids 14.201-9 Simplified contract format...) Contract line item number. (2) Description of supplies or services, or data sufficient to identify the..., but shall retain them in the contract file. Award by acceptance of a bid on the award portion of...

  1. 7 CFR 273.25 - Simplified Food Stamp Program.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 4 2011-01-01 2011-01-01 false Simplified Food Stamp Program. 273.25 Section 273.25 Agriculture Regulations of the Department of Agriculture (Continued) FOOD AND NUTRITION SERVICE, DEPARTMENT OF AGRICULTURE FOOD STAMP AND FOOD DISTRIBUTION PROGRAM CERTIFICATION OF ELIGIBLE HOUSEHOLDS Program...

  2. 7 CFR 273.25 - Simplified Food Stamp Program.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 4 2010-01-01 2010-01-01 false Simplified Food Stamp Program. 273.25 Section 273.25 Agriculture Regulations of the Department of Agriculture (Continued) FOOD AND NUTRITION SERVICE, DEPARTMENT OF AGRICULTURE FOOD STAMP AND FOOD DISTRIBUTION PROGRAM CERTIFICATION OF ELIGIBLE HOUSEHOLDS § 273.25...

  3. 7 CFR 273.25 - Simplified Food Stamp Program.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 4 2012-01-01 2012-01-01 false Simplified Food Stamp Program. 273.25 Section 273.25 Agriculture Regulations of the Department of Agriculture (Continued) FOOD AND NUTRITION SERVICE, DEPARTMENT OF AGRICULTURE FOOD STAMP AND FOOD DISTRIBUTION PROGRAM CERTIFICATION OF ELIGIBLE HOUSEHOLDS Program...

  4. 7 CFR 273.25 - Simplified Food Stamp Program.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 4 2013-01-01 2013-01-01 false Simplified Food Stamp Program. 273.25 Section 273.25 Agriculture Regulations of the Department of Agriculture (Continued) FOOD AND NUTRITION SERVICE, DEPARTMENT OF AGRICULTURE FOOD STAMP AND FOOD DISTRIBUTION PROGRAM CERTIFICATION OF ELIGIBLE HOUSEHOLDS Program...

  5. 7 CFR 273.25 - Simplified Food Stamp Program.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 4 2014-01-01 2014-01-01 false Simplified Food Stamp Program. 273.25 Section 273.25 Agriculture Regulations of the Department of Agriculture (Continued) FOOD AND NUTRITION SERVICE, DEPARTMENT OF AGRICULTURE FOOD STAMP AND FOOD DISTRIBUTION PROGRAM CERTIFICATION OF ELIGIBLE HOUSEHOLDS Program...

  6. Molded elastomer provides compact ferrite-core holder, simplifies assembly

    NASA Technical Reports Server (NTRS)

    Hayden, R. R.

    1964-01-01

    A ferrite-core holder, fabricated by casting an elastomer in a simple mold, simplifies the assembly of modular matrix units for computers. Use of the device permits the core leads to be multiply threaded and soldered to terminals, without requiring intermediate terminals.

  7. Automated Desalting Apparatus

    NASA Technical Reports Server (NTRS)

    Spencer, Maegan K.; Liu, De-Ling; Kanik, Isik; Beegle, Luther

    2010-01-01

    Because salt and metals can mask the signature of a variety of organic molecules (like amino acids) in any given sample, an automated system to purify complex field samples has been created for the analytical techniques of electrospray ionization/ mass spectroscopy (ESI/MS), capillary electrophoresis (CE), and biological assays where unique identification requires at least some processing of complex samples. This development allows for automated sample preparation in the laboratory and analysis of complex samples in the field with multiple types of analytical instruments. Rather than using tedious, exacting protocols for desalting samples by hand, this innovation, called the Automated Sample Processing System (ASPS), takes analytes that have been extracted through high-temperature solvent extraction and introduces them into the desalting column. After 20 minutes, the eluent is produced. This clear liquid can then be directly analyzed by the techniques listed above. The current apparatus including the computer and power supplies is sturdy, has an approximate mass of 10 kg, and a volume of about 20 20 20 cm, and is undergoing further miniaturization. This system currently targets amino acids. For these molecules, a slurry of 1 g cation exchange resin in deionized water is packed into a column of the apparatus. Initial generation of the resin is done by flowing sequentially 2.3 bed volumes of 2N NaOH and 2N HCl (1 mL each) to rinse the resin, followed by .5 mL of deionized water. This makes the pH of the resin near neutral, and eliminates cross sample contamination. Afterward, 2.3 mL of extracted sample is then loaded into the column onto the top of the resin bed. Because the column is packed tightly, the sample can be applied without disturbing the resin bed. This is a vital step needed to ensure that the analytes adhere to the resin. After the sample is drained, oxalic acid (1 mL, pH 1.6-1.8, adjusted with NH4OH) is pumped into the column. Oxalic acid works as a

  8. Automated Design Space Exploration with Aspen

    DOE PAGES

    Spafford, Kyle L.; Vetter, Jeffrey S.

    2015-01-01

    Architects and applications scientists often use performance models to explore a multidimensional design space of architectural characteristics, algorithm designs, and application parameters. With traditional performance modeling tools, these explorations forced users to first develop a performance model and then repeatedly evaluate and analyze the model manually. These manual investigations proved laborious and error prone. More importantly, the complexity of this traditional process often forced users to simplify their investigations. To address this challenge of design space exploration, we extend our Aspen (Abstract Scalable Performance Engineering Notation) language with three new language constructs: user-defined resources, parameter ranges, and a collection ofmore » costs in the abstract machine model. Then, we use these constructs to enable automated design space exploration via a nonlinear optimization solver. We show how four interesting classes of design space exploration scenarios can be derived from Aspen models and formulated as pure nonlinear programs. The analysis tools are demonstrated using examples based on Aspen models for a three-dimensional Fast Fourier Transform, the CoMD molecular dynamics proxy application, and the DARPA Streaming Sensor Challenge Problem. Our results show that this approach can compose and solve arbitrary performance modeling questions quickly and rigorously when compared to the traditional manual approach.« less

  9. On Simplifying Features in OpenStreetMap database

    NASA Astrophysics Data System (ADS)

    Qian, Xinlin; Tao, Kunwang; Wang, Liang

    2015-04-01

    Currently the visualization of OpenStreetMap data is using a tile server which stores map tiles that have been rendered from vector data in advance. However, tiled map are short of functionalities such as data editing and customized styling. To enable these advanced functionality, Client-side processing and rendering of geospatial data is needed. Considering the voluminous size of the OpenStreetMap data, simply sending region queries results of OSM database to client is prohibitive. To make the OSM data retrieved from database adapted for client receiving and rendering, It must be filtered and simplified at server-side to limit its volume. We propose a database extension for OSM database to make it possible to simplifying geospatial objects such as ways and relations during data queries. Several auxiliary tables and PL/pgSQL functions are presented to make the geospatial features can be simplified by omitting unimportant vertices. There are five components in the database extension: Vertices weight computation by polyline and polygon simplification algorithm, Vertices weight storage in auxiliary tables. filtering and selecting of vertices using specific threshold value during spatial queries, assembling of simplified geospatial objects using filtered vertices, vertices weight updating after geospatial objects editing. The database extension is implemented on an OSM APIDB using PL/pgSQL. The database contains a subset of OSM database. The experimental database contains geographic data of United Kingdom which is about 100 million vertices and roughly occupy 100GB disk. JOSM are used to retrieve the data from the database using a revised data accessing API and render the geospatial objects in real-time. When serving simplified data to client, The database allows user to set the bound of the error of simplification or the bound of responding time in each data query. Experimental results show the effectiveness and efficiency of the proposed methods in building a

  10. Home Automation System Based on Intelligent Transducer Enablers.

    PubMed

    Suárez-Albela, Manuel; Fraga-Lamas, Paula; Fernández-Caramés, Tiago M; Dapena, Adriana; González-López, Miguel

    2016-09-28

    This paper presents a novel home automation system named HASITE (Home Automation System based on Intelligent Transducer Enablers), which has been specifically designed to identify and configure transducers easily and quickly. These features are especially useful in situations where many transducers are deployed, since their setup becomes a cumbersome task that consumes a significant amount of time and human resources. HASITE simplifies the deployment of a home automation system by using wireless networks and both self-configuration and self-registration protocols. Thanks to the application of these three elements, HASITE is able to add new transducers by just powering them up. According to the tests performed in different realistic scenarios, a transducer is ready to be used in less than 13 s. Moreover, all HASITE functionalities can be accessed through an API, which also allows for the integration of third-party systems. As an example, an Android application based on the API is presented. Remote users can use it to interact with transducers by just using a regular smartphone or a tablet.

  11. Home Automation System Based on Intelligent Transducer Enablers

    PubMed Central

    Suárez-Albela, Manuel; Fraga-Lamas, Paula; Fernández-Caramés, Tiago M.; Dapena, Adriana; González-López, Miguel

    2016-01-01

    This paper presents a novel home automation system named HASITE (Home Automation System based on Intelligent Transducer Enablers), which has been specifically designed to identify and configure transducers easily and quickly. These features are especially useful in situations where many transducers are deployed, since their setup becomes a cumbersome task that consumes a significant amount of time and human resources. HASITE simplifies the deployment of a home automation system by using wireless networks and both self-configuration and self-registration protocols. Thanks to the application of these three elements, HASITE is able to add new transducers by just powering them up. According to the tests performed in different realistic scenarios, a transducer is ready to be used in less than 13 s. Moreover, all HASITE functionalities can be accessed through an API, which also allows for the integration of third-party systems. As an example, an Android application based on the API is presented. Remote users can use it to interact with transducers by just using a regular smartphone or a tablet. PMID:27690031

  12. Automating the analytical laboratory via the Chemical Analysis Automation paradigm

    SciTech Connect

    Hollen, R.; Rzeszutko, C.

    1997-10-01

    To address the need for standardization within the analytical chemistry laboratories of the nation, the Chemical Analysis Automation (CAA) program within the US Department of Energy, Office of Science and Technology`s Robotic Technology Development Program is developing laboratory sample analysis systems that will automate the environmental chemical laboratories. The current laboratory automation paradigm consists of islands-of-automation that do not integrate into a system architecture. Thus, today the chemist must perform most aspects of environmental analysis manually using instrumentation that generally cannot communicate with other devices in the laboratory. CAA is working towards a standardized and modular approach to laboratory automation based upon the Standard Analysis Method (SAM) architecture. Each SAM system automates a complete chemical method. The building block of a SAM is known as the Standard Laboratory Module (SLM). The SLM, either hardware or software, automates a subprotocol of an analysis method and can operate as a standalone or as a unit within a SAM. The CAA concept allows the chemist to easily assemble an automated analysis system, from sample extraction through data interpretation, using standardized SLMs without the worry of hardware or software incompatibility or the necessity of generating complicated control programs. A Task Sequence Controller (TSC) software program schedules and monitors the individual tasks to be performed by each SLM configured within a SAM. The chemist interfaces with the operation of the TSC through the Human Computer Interface (HCI), a logical, icon-driven graphical user interface. The CAA paradigm has successfully been applied in automating EPA SW-846 Methods 3541/3620/8081 for the analysis of PCBs in a soil matrix utilizing commercially available equipment in tandem with SLMs constructed by CAA.

  13. Automated Electrostatics Environmental Chamber

    NASA Technical Reports Server (NTRS)

    Calle, Carlos; Lewis, Dean C.; Buchanan, Randy K.; Buchanan, Aubri

    2005-01-01

    The Mars Electrostatics Chamber (MEC) is an environmental chamber designed primarily to create atmospheric conditions like those at the surface of Mars to support experiments on electrostatic effects in the Martian environment. The chamber is equipped with a vacuum system, a cryogenic cooling system, an atmospheric-gas replenishing and analysis system, and a computerized control system that can be programmed by the user and that provides both automation and options for manual control. The control system can be set to maintain steady Mars-like conditions or to impose temperature and pressure variations of a Mars diurnal cycle at any given season and latitude. In addition, the MEC can be used in other areas of research because it can create steady or varying atmospheric conditions anywhere within the wide temperature, pressure, and composition ranges between the extremes of Mars-like and Earth-like conditions.

  14. Robust automated knowledge capture.

    SciTech Connect

    Stevens-Adams, Susan Marie; Abbott, Robert G.; Forsythe, James Chris; Trumbo, Michael Christopher Stefan; Haass, Michael Joseph; Hendrickson, Stacey M. Langfitt

    2011-10-01

    This report summarizes research conducted through the Sandia National Laboratories Robust Automated Knowledge Capture Laboratory Directed Research and Development project. The objective of this project was to advance scientific understanding of the influence of individual cognitive attributes on decision making. The project has developed a quantitative model known as RumRunner that has proven effective in predicting the propensity of an individual to shift strategies on the basis of task and experience related parameters. Three separate studies are described which have validated the basic RumRunner model. This work provides a basis for better understanding human decision making in high consequent national security applications, and in particular, the individual characteristics that underlie adaptive thinking.

  15. Automating Frame Analysis

    SciTech Connect

    Sanfilippo, Antonio P.; Franklin, Lyndsey; Tratz, Stephen C.; Danielson, Gary R.; Mileson, Nicholas D.; Riensche, Roderick M.; McGrath, Liam

    2008-04-01

    Frame Analysis has come to play an increasingly stronger role in the study of social movements in Sociology and Political Science. While significant steps have been made in providing a theory of frames and framing, a systematic characterization of the frame concept is still largely lacking and there are no rec-ognized criteria and methods that can be used to identify and marshal frame evi-dence reliably and in a time and cost effective manner. Consequently, current Frame Analysis work is still too reliant on manual annotation and subjective inter-pretation. The goal of this paper is to present an approach to the representation, acquisition and analysis of frame evidence which leverages Content Analysis, In-formation Extraction and Semantic Search methods to provide a systematic treat-ment of a Frame Analysis and automate frame annotation.

  16. Automated mapping system patented

    NASA Astrophysics Data System (ADS)

    A patent on a satellite system dubbed Mapsat, which would be able to map the earth from space and would thereby reduce the time and cost of mapping on a smaller scale, has been issued to the U.S. Geological Survey.The Mapsat concept, invented by Alden F. Colvocoresses, a research cartographer at the USGS National Center, is based on Landsat technology but uses sensors that acquire higher-resolution image data in either a stereo or monoscopic mode. Stereo data can be processed relatively simply with automation to produce images for interpretation or to produce maps. Monoscopic and multispectral data can be processed in a computer to derive information on earth resources. Ground control, one of the most expensive phases of mapping, could be kept to a minimum.

  17. Automating the multiprocessing environment

    NASA Technical Reports Server (NTRS)

    Arpasi, Dale J.

    1989-01-01

    An approach to automate the programming and operation of tree-structured networks of multiprocessor systems is discussed. A conceptual, knowledge-based operating environment is presented, and requirements for two major technology elements are identified as follows: (1) An intelligent information translator is proposed for implementating information transfer between dissimilar hardware and software, thereby enabling independent and modular development of future systems and promoting a language-independence of codes and information; (2) A resident system activity manager, which recognizes the systems capabilities and monitors the status of all systems within the environment, is proposed for integrating dissimilar systems into effective parallel processing resources to optimally meet user needs. Finally, key computational capabilities which must be provided before the environment can be realized are identified.

  18. [From automation to robotics].

    PubMed

    1985-01-01

    The introduction of automation into the laboratory of biology seems to be unavoidable. But at which cost, if it is necessary to purchase a new machine for every new application? Fortunately the same image processing techniques, belonging to a theoretic framework called Mathematical Morphology, may be used in visual inspection tasks, both in car industry and in the biology lab. Since the market for industrial robotics applications is much higher than the market of biomedical applications, the price of image processing devices drops, and becomes sometimes less than the price of a complete microscope equipment. The power of the image processing methods of Mathematical Morphology will be illustrated by various examples, as automatic silver grain counting in autoradiography, determination of HLA genotype, electrophoretic gels analysis, automatic screening of cervical smears... Thus several heterogeneous applications may share the same image processing device, provided there is a separate and devoted work station for each of them.

  19. Berkeley automated supernova search

    SciTech Connect

    Kare, J.T.; Pennypacker, C.R.; Muller, R.A.; Mast, T.S.; Crawford, F.S.; Burns, M.S.

    1981-01-01

    The Berkeley automated supernova search employs a computer controlled 36-inch telescope and charge coupled device (CCD) detector to image 2500 galaxies per night. A dedicated minicomputer compares each galaxy image with stored reference data to identify supernovae in real time. The threshold for detection is m/sub v/ = 18.8. We plan to monitor roughly 500 galaxies in Virgo and closer every night, and an additional 6000 galaxies out to 70 Mpc on a three night cycle. This should yield very early detection of several supernovae per year for detailed study, and reliable premaximum detection of roughly 100 supernovae per year for statistical studies. The search should be operational in mid-1982.

  20. Protein fabrication automation

    PubMed Central

    Cox, J. Colin; Lape, Janel; Sayed, Mahmood A.; Hellinga, Homme W.

    2007-01-01

    Facile “writing” of DNA fragments that encode entire gene sequences potentially has widespread applications in biological analysis and engineering. Rapid writing of open reading frames (ORFs) for expressed proteins could transform protein engineering and production for protein design, synthetic biology, and structural analysis. Here we present a process, protein fabrication automation (PFA), which facilitates the rapid de novo construction of any desired ORF from oligonucleotides with low effort, high speed, and little human interaction. PFA comprises software for sequence design, data management, and the generation of instruction sets for liquid-handling robotics, a liquid-handling robot, a robust PCR scheme for gene assembly from synthetic oligonucleotides, and a genetic selection system to enrich correctly assembled full-length synthetic ORFs. The process is robust and scalable. PMID:17242375