Estimating generalized skew of the log-Pearson Type III distribution for annual peak floods in Illinois

USGS Publications Warehouse

Oberg, Kevin A.; Mades, Dean M.

1987-01-01

Four techniques for estimating generalized skew in Illinois were evaluated: (1) a generalized skew map of the US; (2) an isoline map; (3) a prediction equation; and (4) a regional-mean skew. Peak-flow records at 730 gaging stations having 10 or more annual peaks were selected for computing station skews. Station skew values ranged from -3.55 to 2.95, with a mean of -0.11. Frequency curves computed for 30 gaging stations in Illinois using the variations of the regional-mean skew technique are similar to frequency curves computed using a skew map developed by the US Water Resources Council (WRC). Estimates of the 50-, 100-, and 500-yr floods computed for 29 of these gaging stations using the regional-mean skew techniques are within the 50% confidence limits of frequency curves computed using the WRC skew map. Although the three variations of the regional-mean skew technique were slightly more accurate than the WRC map, there is no appreciable difference between flood estimates computed using the variations of the regional-mean technique and flood estimates computed using the WRC skew map. (Peters-PTT)

The contribute of DInSAR techniques to landslide hazard evaluation in mountain and hilly regions: a case study from Agno Valley (North-Eastern Italian Alps)

NASA Astrophysics Data System (ADS)

De Agostini, A.; Floris, M.; Pasquali, P.; Barbieri, M.; Cantone, A.; Riccardi, P.; Stevan, G.; Genevois, R.

2012-04-01

In the last twenty years, Differential Synthetic Aperture Radar Interferometry (DInSAR) techniques have been widely used to investigate geological processes, such as subsidence, earthquakes and landslides, through the evaluation of earth surface displacements caused by these processes. In the study of mass movements, contribution of interferometry can be limited due to the acquisition geometry of RADAR images and the rough morphology of mountain and hilly regions which represent typical landslide-prone areas. In this study, the advanced DInSAR techniques (i.e. Small Baseline Subset and Persistent Scatterers techniques), available in SARscape software, are used. These methods involve the use of multiple acquisitions stacks (large SAR temporal series) allowing improvements and refinements in landslide identification, characterization and hazard evaluation at the basin scale. Potential and limits of above mentioned techniques are outlined and discussed. The study area is the Agno Valley, located in the North-Eastern sector of Italian Alps and included in the Vicenza Province (Veneto Region, Italy). This area and the entire Vicenza Province were hit by an exceptional rainfall event on November 2010 that triggered more than 500 slope instabilities. The main aim of the work is to verify if spatial information available before the rainfall event, including ERS and ENVISAT RADAR data from 1992 to 2010, were able to predict the landslides occurred in the study area, in order to implement an effectiveness forecasting model. In the first step of the work a susceptibility analysis is carried out using landslide dataset from the IFFI project (Inventario Fenomeni Franosi in Italia, Landslide Italian Inventory) and related predisposing factors, which consist of morphometric (elevation, slope, aspect and curvature) and non-morphometric (land use, distance of roads and distance of river) factors available from the Veneto Region spatial database. Then, to test the prediction, the results of susceptibility analysis are compared with the location of landslides occurred in the study area during the November 2010 rainfall event. In the second step, results of DInSAR analysis (displacement maps over the time) are added on the prediction analysis to build up a map containing both spatial and temporal information on landslides and, as in the previous case, the prediction is tested by using November 2010 instabilities dataset. Comparison of the two tests allows to evaluate the contribution of interferometric techniques. Finally, morphometric factors and interferometric RADAR data are combined to design a preliminary analysis scheme that provide information on possible use of DInSAR techniques in landslide hazard evaluation of a given area.

Assessing the nonlinear response of fine particles to precursor emissions: Development and application of an extended response surface modeling technique v1.0

DOE PAGES

Zhao, B.; Wang, S. X.; Xing, J.; ...

2015-01-30

An innovative extended response surface modeling technique (ERSM v1.0) is developed to characterize the nonlinear response of fine particles (PM₂̣₅) to large and simultaneous changes of multiple precursor emissions from multiple regions and sectors. The ERSM technique is developed based on the conventional response surface modeling (RSM) technique; it first quantifies the relationship between PM₂̣₅ concentrations and the emissions of gaseous precursors from each single region using the conventional RSM technique, and then assesses the effects of inter-regional transport of PM₂̣₅ and its gaseous precursors on PM₂̣₅ concentrations in the target region. We apply this novel technique with a widelymore » used regional chemical transport model (CTM) over the Yangtze River delta (YRD) region of China, and evaluate the response of PM₂̣₅ and its inorganic components to the emissions of 36 pollutant–region–sector combinations. The predicted PM₂̣₅ concentrations agree well with independent CTM simulations; the correlation coefficients are larger than 0.98 and 0.99, and the mean normalized errors (MNEs) are less than 1 and 2% for January and August, respectively. It is also demonstrated that the ERSM technique could reproduce fairly well the response of PM₂̣₅ to continuous changes of precursor emission levels between zero and 150%. Employing this new technique, we identify the major sources contributing to PM₂̣₅ and its inorganic components in the YRD region. The nonlinearity in the response of PM₂̣₅ to emission changes is characterized and the underlying chemical processes are illustrated.« less

Radiological evaluation of dysphagia

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

Ott, D.J.; Gelfand, D.W.; Wu, W.C.

1986-11-21

Dysphagia is a common complaint in patients presenting for radiological or endoscopic examination of the esophagus and is usually due to functional or structural abnormalities of the esophageal body or esophagogastric region. The authors review the radiological evaluation of the esophagus and esophagogastric region in patients with esophageal dysphagia and discuss the roentgenographic techniques used, radiological efficacy for common structural disorders, and evaluation of esophageal motor function. Comparison is made with endoscopy in assessing dysphagia, with the conclusion that the radiological examination be used initially in patients with this complaint.

Access to destinations : annual accessibility measure for the Twin Cities Metropolitan Region.

DOT National Transportation Integrated Search

2012-11-01

This report summarizes previous phases of the Access to Destinations project and applies the techniques developed : over the course of the project to conduct an evaluation of accessibility in the Twin Cities metropolitan region for : 2010. It describ...

MAG4 versus alternative techniques for forecasting active region flare productivity.

PubMed

Falconer, David A; Moore, Ronald L; Barghouty, Abdulnasser F; Khazanov, Igor

2014-05-01

MAG4 is a technique of forecasting an active region's rate of production of major flares in the coming few days from a free magnetic energy proxy. We present a statistical method of measuring the difference in performance between MAG4 and comparable alternative techniques that forecast an active region's major-flare productivity from alternative observed aspects of the active region. We demonstrate the method by measuring the difference in performance between the "Present MAG4" technique and each of three alternative techniques, called "McIntosh Active-Region Class," "Total Magnetic Flux," and "Next MAG4." We do this by using (1) the MAG4 database of magnetograms and major flare histories of sunspot active regions, (2) the NOAA table of the major-flare productivity of each of 60 McIntosh active-region classes of sunspot active regions, and (3) five technique performance metrics (Heidke Skill Score, True Skill Score, Percent Correct, Probability of Detection, and False Alarm Rate) evaluated from 2000 random two-by-two contingency tables obtained from the databases. We find that (1) Present MAG4 far outperforms both McIntosh Active-Region Class and Total Magnetic Flux, (2) Next MAG4 significantly outperforms Present MAG4, (3) the performance of Next MAG4 is insensitive to the forward and backward temporal windows used, in the range of one to a few days, and (4) forecasting from the free-energy proxy in combination with either any broad category of McIntosh active-region classes or any Mount Wilson active-region class gives no significant performance improvement over forecasting from the free-energy proxy alone (Present MAG4). Quantitative comparison of performance of pairs of forecasting techniques Next MAG4 forecasts major flares more accurately than Present MAG4 Present MAG4 forecast outperforms McIntosh AR Class and total magnetic flux.

MAG4 versus alternative techniques for forecasting active region flare productivity

PubMed Central

Falconer, David A; Moore, Ronald L; Barghouty, Abdulnasser F; Khazanov, Igor

2014-01-01

MAG4 is a technique of forecasting an active region's rate of production of major flares in the coming few days from a free magnetic energy proxy. We present a statistical method of measuring the difference in performance between MAG4 and comparable alternative techniques that forecast an active region's major-flare productivity from alternative observed aspects of the active region. We demonstrate the method by measuring the difference in performance between the “Present MAG4” technique and each of three alternative techniques, called “McIntosh Active-Region Class,” “Total Magnetic Flux,” and “Next MAG4.” We do this by using (1) the MAG4 database of magnetograms and major flare histories of sunspot active regions, (2) the NOAA table of the major-flare productivity of each of 60 McIntosh active-region classes of sunspot active regions, and (3) five technique performance metrics (Heidke Skill Score, True Skill Score, Percent Correct, Probability of Detection, and False Alarm Rate) evaluated from 2000 random two-by-two contingency tables obtained from the databases. We find that (1) Present MAG4 far outperforms both McIntosh Active-Region Class and Total Magnetic Flux, (2) Next MAG4 significantly outperforms Present MAG4, (3) the performance of Next MAG4 is insensitive to the forward and backward temporal windows used, in the range of one to a few days, and (4) forecasting from the free-energy proxy in combination with either any broad category of McIntosh active-region classes or any Mount Wilson active-region class gives no significant performance improvement over forecasting from the free-energy proxy alone (Present MAG4). Key Points Quantitative comparison of performance of pairs of forecasting techniques Next MAG4 forecasts major flares more accurately than Present MAG4 Present MAG4 forecast outperforms McIntosh AR Class and total magnetic flux PMID:26213517

Evaluation of the class II region of the major histocompatibility complex of the greyhound with the genomic matching technique and sequence-based typing.

PubMed

Fliegner, R A; Holloway, S A; Lester, S; McLure, C A; Dawkins, R L

2008-08-01

The class II region of the major histocompatibility complex was evaluated in 25 greyhounds by sequence-based typing and the genomic matching technique (GMT). Two new DLA-DRB1 alleles were identified. Twenty-four dogs carried the DLA-DRB1*01201/DQA1*00401/DQB1*01303/DQB1*01701 haplotype, which carries two DQB1 alleles. One haplotype was identified from which DQB1 and DQA1 appeared to be deleted. The GMT enabled detection of DQB1 copy number, discrimination of the different class II haplotypes and the identification of new, possibly biologically relevant polymorphisms.

Evaluation of Fuzzy-Logic Framework for Spatial Statistics Preserving Methods for Estimation of Missing Precipitation Data

NASA Astrophysics Data System (ADS)

El Sharif, H.; Teegavarapu, R. S.

2012-12-01

Spatial interpolation methods used for estimation of missing precipitation data at a site seldom check for their ability to preserve site and regional statistics. Such statistics are primarily defined by spatial correlations and other site-to-site statistics in a region. Preservation of site and regional statistics represents a means of assessing the validity of missing precipitation estimates at a site. This study evaluates the efficacy of a fuzzy-logic methodology for infilling missing historical daily precipitation data in preserving site and regional statistics. Rain gauge sites in the state of Kentucky, USA, are used as a case study for evaluation of this newly proposed method in comparison to traditional data infilling techniques. Several error and performance measures will be used to evaluate the methods and trade-offs in accuracy of estimation and preservation of site and regional statistics.

In Search of Determinism-Sensitive Region to Avoid Artefacts in Recurrence Plots

NASA Astrophysics Data System (ADS)

Wendi, Dadiyorto; Marwan, Norbert; Merz, Bruno

As an effort to reduce parameter uncertainties in constructing recurrence plots, and in particular to avoid potential artefacts, this paper presents a technique to derive artefact-safe region of parameter sets. This technique exploits both deterministic (incl. chaos) and stochastic signal characteristics of recurrence quantification (i.e. diagonal structures). It is useful when the evaluated signal is known to be deterministic. This study focuses on the recurrence plot generated from the reconstructed phase space in order to represent many real application scenarios when not all variables to describe a system are available (data scarcity). The technique involves random shuffling of the original signal to destroy its original deterministic characteristics. Its purpose is to evaluate whether the determinism values of the original and the shuffled signal remain closely together, and therefore suggesting that the recurrence plot might comprise artefacts. The use of such determinism-sensitive region shall be accompanied by standard embedding optimization approaches, e.g. using indices like false nearest neighbor and mutual information, to result in a more reliable recurrence plot parameterization.

Use of the bolus tracking technique for the tomographic evaluation of the uretero-vesicular junction in dogs and assessment of dose records.

PubMed

Longo, Maurizio; Andreis, Maria Elena; Pettinato, Cinzia; Ravasio, Giuliano; Rabbogliatti, Vanessa; De Zani, Donatella; Di Giancamillo, Mauro; Zani, Davide Danilo

2016-03-29

The aim of the work is the application of a bolus tracking technique for tomographic evaluation of the uretero-vesicular junction in dogs. Ten adult dogs (8-14 years) with variable body weight (2,8-32 kg) were enrolled in the prospective study. The patients were placed in sternal recumbency with a 10° elevated pelvis and the visualization of the uretero-vesicular junction was obtained with the bolus tracking technique after intravenous administration of non-ionic contrast medium. In the post-contrast late phase a region of interest was placed within the lumen of the distal ureters and the density values were monitored before starting the helical scan. The uretero-vesicular junction was clearly visible in 100% of patients with the visualization of the endoluminal ureteral contrast enhancement and bladder washout. At the end of the tomographic study an evaluation of the dose records was performed and compared to human exposures reported in literature for the pelvic region. The effective dose estimated for each patient (37,5-138 mSv) proved to be elevated, when compared to those reported in human patients. The bolus tracking technique could be applied for the visualization of the uretero-vesicular junction in non-pathological patients, placing the region of interest in the distal ureters. The high effective doses recorded in our study support the need of specific thresholds for veterinary patients, pointing out the attention for paediatric patient's exposure also in veterinary imaging.

A histogram-based technique for rapid vector extraction from PIV photographs

NASA Technical Reports Server (NTRS)

Humphreys, William M., Jr.

1991-01-01

A new analysis technique, performed totally in the image plane, is proposed which rapidly extracts all available vectors from individual interrogation regions on PIV photographs. The technique avoids the need for using Fourier transforms with the associated computational burden. The data acquisition and analysis procedure is described, and results of a preliminary simulation study to evaluate the accuracy of the technique are presented. Recently obtained PIV photographs are analyzed.

Numerical optimization in Hilbert space using inexact function and gradient evaluations

NASA Technical Reports Server (NTRS)

Carter, Richard G.

1989-01-01

Trust region algorithms provide a robust iterative technique for solving non-convex unstrained optimization problems, but in many instances it is prohibitively expensive to compute high accuracy function and gradient values for the method. Of particular interest are inverse and parameter estimation problems, since function and gradient evaluations involve numerically solving large systems of differential equations. A global convergence theory is presented for trust region algorithms in which neither function nor gradient values are known exactly. The theory is formulated in a Hilbert space setting so that it can be applied to variational problems as well as the finite dimensional problems normally seen in trust region literature. The conditions concerning allowable error are remarkably relaxed: relative errors in the gradient error condition is automatically satisfied if the error is orthogonal to the gradient approximation. A technique for estimating gradient error and improving the approximation is also presented.

Evaluation of the robustness of the preprocessing technique improving reversible compressibility of CT images: Tested on various CT examinations

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

Jeon, Chang Ho; Kim, Bohyoung; Gu, Bon Seung

2013-10-15

Purpose: To modify the preprocessing technique, which was previously proposed, improving compressibility of computed tomography (CT) images to cover the diversity of three dimensional configurations of different body parts and to evaluate the robustness of the technique in terms of segmentation correctness and increase in reversible compression ratio (CR) for various CT examinations.Methods: This study had institutional review board approval with waiver of informed patient consent. A preprocessing technique was previously proposed to improve the compressibility of CT images by replacing pixel values outside the body region with a constant value resulting in maximizing data redundancy. Since the technique wasmore » developed aiming at only chest CT images, the authors modified the segmentation method to cover the diversity of three dimensional configurations of different body parts. The modified version was evaluated as follows. In randomly selected 368 CT examinations (352 787 images), each image was preprocessed by using the modified preprocessing technique. Radiologists visually confirmed whether the segmented region covers the body region or not. The images with and without the preprocessing were reversibly compressed using Joint Photographic Experts Group (JPEG), JPEG2000 two-dimensional (2D), and JPEG2000 three-dimensional (3D) compressions. The percentage increase in CR per examination (CR{sub I}) was measured.Results: The rate of correct segmentation was 100.0% (95% CI: 99.9%, 100.0%) for all the examinations. The median of CR{sub I} were 26.1% (95% CI: 24.9%, 27.1%), 40.2% (38.5%, 41.1%), and 34.5% (32.7%, 36.2%) in JPEG, JPEG2000 2D, and JPEG2000 3D, respectively.Conclusions: In various CT examinations, the modified preprocessing technique can increase in the CR by 25% or more without concerning about degradation of diagnostic information.« less

Evaluation of Meterorite Amono Acid Analysis Data Using Multivariate Techniques

NASA Technical Reports Server (NTRS)

McDonald, G.; Storrie-Lombardi, M.; Nealson, K.

1999-01-01

The amino acid distributions in the Murchison carbonaceous chondrite, Mars meteorite ALH84001, and ice from the Allan Hills region of Antarctica are shown, using a multivariate technique known as Principal Component Analysis (PCA), to be statistically distinct from the average amino acid compostion of 101 terrestrial protein superfamilies.

Molecular diagnosis of rhino-orbito-cerebral mucormycosis from fresh tissue samples.

PubMed

Zaman, Kamran; Rudramurthy, Shivaprakash Mandya; Das, Ashim; Panda, Naresh; Honnavar, Prasanna; Kaur, Harsimran; Chakrabarti, Arunaloke

2017-08-01

We aimed to evaluate a PCR-based technique for the diagnosis of mucormycosis and the identification of fungi from fresh tissue specimens in patients with rhino-orbito-cerebral-mucormycosis (ROCM). Fifty cases of ROCM were included in the study. Conventional identification was performed using microscopy and culture. Molecular diagnosis was performed by amplifying the ribosomal DNA using pan-fungal ITS primers and semi-nested Mucorales-specific primers of the 18S region. The amplified products were sequenced to identify the agents. The utility of PCR-RFLP of the 18S region of rDNA was evaluated to identify the Mucorales. The ROCM cases were diagnosed by the demonstration of aseptate ribbon-like hyphae in biopsy specimens collected from the patients. Isolation was possible in 24 (48 %) samples. The ITS2 PCR confirmed mucormycosis in 27 cases (54 %; CI 59.4-68.2). By comparison, Mucorales-specific PCR was able to amplify DNA and the sequence enabled the identification of Mucorales speciesin all the patients. PCR-RFLP of the 18S region of rDNA could only identify the agent to genus level. The molecular technique was able to identify Mucorales species in 26 (42 %) cases that were negative by culture. Mucorales-specific semi-nested PCR targeting the 18S region is a better technique than ITS2 PCR for diagnosis. PCR-RFLP of the 18S region helps in identification to genus level.

Damage Evaluation Based on a Wave Energy Flow Map Using Multiple PZT Sensors

PubMed Central

Liu, Yaolu; Hu, Ning; Xu, Hong; Yuan, Weifeng; Yan, Cheng; Li, Yuan; Goda, Riu; Alamusi; Qiu, Jinhao; Ning, Huiming; Wu, Liangke

2014-01-01

A new wave energy flow (WEF) map concept was proposed in this work. Based on it, an improved technique incorporating the laser scanning method and Betti's reciprocal theorem was developed to evaluate the shape and size of damage as well as to realize visualization of wave propagation. In this technique, a simple signal processing algorithm was proposed to construct the WEF map when waves propagate through an inspection region, and multiple lead zirconate titanate (PZT) sensors were employed to improve inspection reliability. Various damages in aluminum and carbon fiber reinforced plastic laminated plates were experimentally and numerically evaluated to validate this technique. The results show that it can effectively evaluate the shape and size of damage from wave field variations around the damage in the WEF map. PMID:24463430

Current Work on Telecommunications Policies and Structures.

ERIC Educational Resources Information Center

Ohlin, Thomas

The studies described in this paper were undertaken to evaluate the usefulness of information-exchange techniques for promoting the quality of life within given regions of a society. The first analysis describes the investigation of projects to enhance the functions of small businesses, joint regional planning, health care, education,…

An improved DPSM technique for modelling ultrasonic fields in cracked solids

NASA Astrophysics Data System (ADS)

Banerjee, Sourav; Kundu, Tribikram; Placko, Dominique

2007-04-01

In recent years Distributed Point Source Method (DPSM) is being used for modelling various ultrasonic, electrostatic and electromagnetic field modelling problems. In conventional DPSM several point sources are placed near the transducer face, interface and anomaly boundaries. The ultrasonic or the electromagnetic field at any point is computed by superimposing the contributions of different layers of point sources strategically placed. The conventional DPSM modelling technique is modified in this paper so that the contributions of the point sources in the shadow region can be removed from the calculations. For this purpose the conventional point sources that radiate in all directions are replaced by Controlled Space Radiation (CSR) sources. CSR sources can take care of the shadow region problem to some extent. Complete removal of the shadow region problem can be achieved by introducing artificial interfaces. Numerically synthesized fields obtained by the conventional DPSM technique that does not give any special consideration to the point sources in the shadow region and the proposed modified technique that nullifies the contributions of the point sources in the shadow region are compared. One application of this research can be found in the improved modelling of the real time ultrasonic non-destructive evaluation experiments.

Measurement of Beta Particles Induced Electron-Hole Pairs Recombination in Depletion Region of GaAs PN Junction

NASA Astrophysics Data System (ADS)

Chen, Hai-Yang; Jiang, Lan; Li, Da-Rang

2011-05-01

PN junctions and schottky diodes are widely employed as electron-hole pair collectors in electron beam induced current (EBIC) techniques and betavoltaic batteries, in which the recombination in depletion regions is ignored. We measured the beta particles induced electron-hole pairs recombination in the depletion region of a GaAs P+PN+ junction, based on comparisons between measured short currents and ideal values. The results show that only 20% electron-hole pairs in the depletion can be collected, causing the short current. This indicates an electron-hole pair diffusion length of 0.2μm in the depletion region. Hence, it is necessary to evaluate the recombination in the EBIC techniques and betavoltaic design.

Potential utilization of the absolute point cumulative semivariogram technique for the evaluation of distribution coefficient.

PubMed

Külahci, Fatih; Sen, Zekâi

2009-09-15

The classical solid/liquid distribution coefficient, K(d), for radionuclides in water-sediment systems is dependent on many parameters such as flow, geology, pH, acidity, alkalinity, total hardness, radioactivity concentration, etc. in a region. Considerations of all these effects require a regional analysis with an effective methodology, which has been based on the concept of the cumulative semivariogram concept in this paper. Although classical K(d) calculations are punctual and cannot represent regional pattern, in this paper a regional calculation methodology is suggested through the use of Absolute Point Cumulative SemiVariogram (APCSV) technique. The application of the methodology is presented for (137)Cs and (90)Sr measurements at a set of points in Keban Dam reservoir, Turkey.

The European Society of Regional Anaesthesia and Pain Therapy and the American Society of Regional Anesthesia and Pain Medicine Joint Committee Practice Advisory on Controversial Topics in Pediatric Regional Anesthesia.

PubMed

Ivani, Giorgio; Suresh, Santhanam; Ecoffey, Claude; Bosenberg, Adrian; Lonnqvist, Per-Anne; Krane, Elliot; Veyckemans, Francis; Polaner, David M; Van de Velde, Marc; Neal, Joseph M

2015-01-01

Some topics in the clinical management of regional anesthesia in children remain controversial. To evaluate and come to a consensus regarding some of these topics, The European Society of Regional Anaesthesia and Pain Therapy (ESRA) and the American Society of Regional Anesthesia and Pain Medicine (ASRA) developed a joint committee practice advisory on pediatric regional anesthesia (PRA). Representatives from both ASRA and ESRA comprised the joint committee practice advisory on PRA. Evidence-based recommendations were based on a systematic search of the literature. In cases where no literature was available, expert opinion was elicited. Experts selected controversial topics in PRA. The performance of PRA under general anesthesia or deep sedation is associated with acceptable safety and should be viewed as the standard of care (Evidence B2 and Evidence B3). Because of the difficulty interpreting a negative test dose, the use of test dosing should remain discretionary (Evidence B4). The use of either air-loss of resistance or saline-loss of resistance techniques is supported by expert opinion, but the literature supporting one technique over the other is sparse and controversial; when used appropriately, each technique may be safely used in children. There are no current evidence-based data that the use of RA increases the risk for acute compartment syndrome or delays its diagnosis in children. High-level evidence is not yet available for the topics evaluated, and most recommendations are based on Evidence B studies. The ESRA/ASRA recommendations intend to provide guidance for the safe practice of regional anesthesia in children.

An Analysis of Nondestructive Evaluation Techniques for Polymer Matrix Composite Sandwich Materials

NASA Technical Reports Server (NTRS)

Cosgriff, Laura M.; Roberts, Gary D.; Binienda, Wieslaw K.; Zheng, Diahua; Averbeck, Timothy; Roth, Donald J.; Jeanneau, Philippe

2006-01-01

Structural sandwich materials composed of triaxially braided polymer matrix composite material face sheets sandwiching a foam core are being utilized for applications including aerospace components and recreational equipment. Since full scale components are being made from these sandwich materials, it is necessary to develop proper inspection practices for their manufacture and in-field use. Specifically, nondestructive evaluation (NDE) techniques need to be investigated for analysis of components made from these materials. Hockey blades made from sandwich materials and a flat sandwich sample were examined with multiple NDE techniques including thermographic, radiographic, and shearographic methods to investigate damage induced in the blades and flat panel components. Hockey blades used during actual play and a flat polymer matrix composite sandwich sample with damage inserted into the foam core were investigated with each technique. NDE images from the samples were presented and discussed. Structural elements within each blade were observed with radiographic imaging. Damaged regions and some structural elements of the hockey blades were identified with thermographic imaging. Structural elements, damaged regions, and other material variations were detected in the hockey blades with shearography. Each technique s advantages and disadvantages were considered in making recommendations for inspection of components made from these types of materials.

Evaluation of TIGGE Ensemble Forecasts of Precipitation in Distinct Climate Regions in Iran

NASA Astrophysics Data System (ADS)

Aminyavari, Saleh; Saghafian, Bahram; Delavar, Majid

2018-04-01

The application of numerical weather prediction (NWP) products is increasing dramatically. Existing reports indicate that ensemble predictions have better skill than deterministic forecasts. In this study, numerical ensemble precipitation forecasts in the TIGGE database were evaluated using deterministic, dichotomous (yes/no), and probabilistic techniques over Iran for the period 2008-16. Thirteen rain gauges spread over eight homogeneous precipitation regimes were selected for evaluation. The Inverse Distance Weighting and Kriging methods were adopted for interpolation of the prediction values, downscaled to the stations at lead times of one to three days. To enhance the forecast quality, NWP values were post-processed via Bayesian Model Averaging. The results showed that ECMWF had better scores than other products. However, products of all centers underestimated precipitation in high precipitation regions while overestimating precipitation in other regions. This points to a systematic bias in forecasts and demands application of bias correction techniques. Based on dichotomous evaluation, NCEP did better at most stations, although all centers overpredicted the number of precipitation events. Compared to those of ECMWF and NCEP, UKMO yielded higher scores in mountainous regions, but performed poorly at other selected stations. Furthermore, the evaluations showed that all centers had better skill in wet than in dry seasons. The quality of post-processed predictions was better than those of the raw predictions. In conclusion, the accuracy of the NWP predictions made by the selected centers could be classified as medium over Iran, while post-processing of predictions is recommended to improve the quality.

Visual terrain mapping for traversable path planning of mobile robots

NASA Astrophysics Data System (ADS)

Shirkhodaie, Amir; Amrani, Rachida; Tunstel, Edward W.

2004-10-01

In this paper, we have primarily discussed technical challenges and navigational skill requirements of mobile robots for traversability path planning in natural terrain environments similar to Mars surface terrains. We have described different methods for detection of salient terrain features based on imaging texture analysis techniques. We have also presented three competing techniques for terrain traversability assessment of mobile robots navigating in unstructured natural terrain environments. These three techniques include: a rule-based terrain classifier, a neural network-based terrain classifier, and a fuzzy-logic terrain classifier. Each proposed terrain classifier divides a region of natural terrain into finite sub-terrain regions and classifies terrain condition exclusively within each sub-terrain region based on terrain visual clues. The Kalman Filtering technique is applied for aggregative fusion of sub-terrain assessment results. The last two terrain classifiers are shown to have remarkable capability for terrain traversability assessment of natural terrains. We have conducted a comparative performance evaluation of all three terrain classifiers and presented the results in this paper.

Soft computing-based terrain visual sensing and data fusion for unmanned ground robotic systems

NASA Astrophysics Data System (ADS)

Shirkhodaie, Amir

2006-05-01

In this paper, we have primarily discussed technical challenges and navigational skill requirements of mobile robots for traversability path planning in natural terrain environments similar to Mars surface terrains. We have described different methods for detection of salient terrain features based on imaging texture analysis techniques. We have also presented three competing techniques for terrain traversability assessment of mobile robots navigating in unstructured natural terrain environments. These three techniques include: a rule-based terrain classifier, a neural network-based terrain classifier, and a fuzzy-logic terrain classifier. Each proposed terrain classifier divides a region of natural terrain into finite sub-terrain regions and classifies terrain condition exclusively within each sub-terrain region based on terrain visual clues. The Kalman Filtering technique is applied for aggregative fusion of sub-terrain assessment results. The last two terrain classifiers are shown to have remarkable capability for terrain traversability assessment of natural terrains. We have conducted a comparative performance evaluation of all three terrain classifiers and presented the results in this paper.

Computerized mass detection in whole breast ultrasound images: reduction of false positives using bilateral subtraction technique

NASA Astrophysics Data System (ADS)

Ikedo, Yuji; Fukuoka, Daisuke; Hara, Takeshi; Fujita, Hiroshi; Takada, Etsuo; Endo, Tokiko; Morita, Takako

2007-03-01

The comparison of left and right mammograms is a common technique used by radiologists for the detection and diagnosis of masses. In mammography, computer-aided detection (CAD) schemes using bilateral subtraction technique have been reported. However, in breast ultrasonography, there are no reports on CAD schemes using comparison of left and right breasts. In this study, we propose a scheme of false positive reduction based on bilateral subtraction technique in whole breast ultrasound images. Mass candidate regions are detected by using the information of edge directions. Bilateral breast images are registered with reference to the nipple positions and skin lines. A false positive region is detected based on a comparison of the average gray values of a mass candidate region and a region with the same position and same size as the candidate region in the contralateral breast. In evaluating the effectiveness of the false positive reduction method, three normal and three abnormal bilateral pairs of whole breast images were employed. These abnormal breasts included six masses larger than 5 mm in diameter. The sensitivity was 83% (5/6) with 13.8 (165/12) false positives per breast before applying the proposed reduction method. By applying the method, false positives were reduced to 4.5 (54/12) per breast without removing a true positive region. This preliminary study indicates that the bilateral subtraction technique is effective for improving the performance of a CAD scheme in whole breast ultrasound images.

Evaluation of Ground-Motion Modeling Techniques for Use in Global ShakeMap - A Critique of Instrumental Ground-Motion Prediction Equations, Peak Ground Motion to Macroseismic Intensity Conversions, and Macroseismic Intensity Predictions in Different Tectonic Settings

USGS Publications Warehouse

Allen, Trevor I.; Wald, David J.

2009-01-01

Regional differences in ground-motion attenuation have long been thought to add uncertainty in the prediction of ground motion. However, a growing body of evidence suggests that regional differences in ground-motion attenuation may not be as significant as previously thought and that the key differences between regions may be a consequence of limitations in ground-motion datasets over incomplete magnitude and distance ranges. Undoubtedly, regional differences in attenuation can exist owing to differences in crustal structure and tectonic setting, and these can contribute to differences in ground-motion attenuation at larger source-receiver distances. Herein, we examine the use of a variety of techniques for the prediction of several ground-motion metrics (peak ground acceleration and velocity, response spectral ordinates, and macroseismic intensity) and compare them against a global dataset of instrumental ground-motion recordings and intensity assignments. The primary goal of this study is to determine whether existing ground-motion prediction techniques are applicable for use in the U.S. Geological Survey's Global ShakeMap and Prompt Assessment of Global Earthquakes for Response (PAGER). We seek the most appropriate ground-motion predictive technique, or techniques, for each of the tectonic regimes considered: shallow active crust, subduction zone, and stable continental region.

Evaluation of the Impact of AIRS Radiance and Profile Data Assimilation in Partly Cloudy Regions

NASA Technical Reports Server (NTRS)

Zavodsky, Bradley; Srikishen, Jayanthi; Jedlovec, Gary

2013-01-01

Improvements to global and regional numerical weather prediction have been demonstrated through assimilation of data from NASA s Atmospheric Infrared Sounder (AIRS). Current operational data assimilation systems use AIRS radiances, but impact on regional forecasts has been much smaller than for global forecasts. Retrieved profiles from AIRS contain much of the information that is contained in the radiances and may be able to reveal reasons for this reduced impact. Assimilating AIRS retrieved profiles in an identical analysis configuration to the radiances, tracking the quantity and quality of the assimilated data in each technique, and examining analysis increments and forecast impact from each data type can yield clues as to the reasons for the reduced impact. By doing this with regional scale models individual synoptic features (and the impact of AIRS on these features) can be more easily tracked. This project examines the assimilation of hyperspectral sounder data used in operational numerical weather prediction by comparing operational techniques used for AIRS radiances and research techniques used for AIRS retrieved profiles. Parallel versions of a configuration of the Weather Research and Forecasting (WRF) model with Gridpoint Statistical Interpolation (GSI) are run to examine the impact AIRS radiances and retrieved profiles. Statistical evaluation of a long-term series of forecast runs will be compared along with preliminary results of in-depth investigations for select case comparing the analysis increments in partly cloudy regions and short-term forecast impacts.

Evaluation of the Impact of Atmospheric Infrared Sounder (AIRS) Radiance and Profile Data Assimilation in Partly Cloudy Regions

NASA Technical Reports Server (NTRS)

Zavodsky, Bradley; Srikishen, Jayanthi; Jedlovec, Gary

2013-01-01

Improvements to global and regional numerical weather prediction have been demonstrated through assimilation of data from NASA s Atmospheric Infrared Sounder (AIRS). Current operational data assimilation systems use AIRS radiances, but impact on regional forecasts has been much smaller than for global forecasts. Retrieved profiles from AIRS contain much of the information that is contained in the radiances and may be able to reveal reasons for this reduced impact. Assimilating AIRS retrieved profiles in an identical analysis configuration to the radiances, tracking the quantity and quality of the assimilated data in each technique, and examining analysis increments and forecast impact from each data type can yield clues as to the reasons for the reduced impact. By doing this with regional scale models individual synoptic features (and the impact of AIRS on these features) can be more easily tracked. This project examines the assimilation of hyperspectral sounder data used in operational numerical weather prediction by comparing operational techniques used for AIRS radiances and research techniques used for AIRS retrieved profiles. Parallel versions of a configuration of the Weather Research and Forecasting (WRF) model with Gridpoint Statistical Interpolation (GSI) are run to examine the impact AIRS radiances and retrieved profiles. Statistical evaluation of 6 weeks of forecast runs will be compared along with preliminary results of in-depth investigations for select case comparing the analysis increments in partly cloudy regions and short-term forecast impacts.

Using Landsat digital data to detect moisture stress in corn-soybean growing regions

NASA Technical Reports Server (NTRS)

Thompson, D. R.; Wehmanen, O. A.

1980-01-01

As a part of a follow-on study to the moisture stress detection effort conducted in the Large Area Crop Inventory Experiment (LACIE), a technique utilizing transformed Landsat digital data was evaluated for detecting moisture stress in humid growing regions using sample segments from Iowa, Illinois, and Indiana. At known growth stages of corn and soybeans, segments were classified as undergoing moisture stress or not undergoing stress. The remote-sensing-based information was compared to a weekly ground-based index (Crop Moisture Index). This comparison demonstrated that the remote sensing technique could be used to monitor the growing conditions within a region where corn and soybeans are the major crop.

Evaluation of a total scalp electron irradiation technique.

PubMed

Able, C M; Mills, M D; McNeese, M D; Hogstrom, K R

1991-09-01

A dosimetric evaluation of a total scalp electron-beam irradiation technique that uses six stationary fields was performed. The initial treatment plan specified a) that there be a 3-mm gap between abutted fields and b) that the field junctions be shifted 1 cm after 50% of the prescribed dose had been delivered. Dosimetric measurements were made at the scalp surface, scalp-skull interface, and the skull-brain interface in an anthropomorphic head phantom using both film and thermoluminescent dosimeters (TLD-100). The measurements showed that the initial technique yields areas of increased and decreased dose ranging from -50% to +70% in the region of the field junctions. To reduce regions of nonuniform dose, the treatment protocol was changed by eliminating the gap between the coronal borders of abutted fields and by increasing the field shift from 1 cm to 2 cm for all borders. Subsequent measurements showed that these changes in treatment protocol resulted in a significantly more uniform dose to the scalp and decreased variation of doses near field junctions (-10% to +50%).

3D matching techniques using OCT fingerprint point clouds

NASA Astrophysics Data System (ADS)

Gutierrez da Costa, Henrique S.; Silva, Luciano; Bellon, Olga R. P.; Bowden, Audrey K.; Czovny, Raphael K.

2017-02-01

Optical Coherence Tomography (OCT) makes viable acquisition of 3D fingerprints from both dermis and epidermis skin layers and their interfaces, exposing features that can be explored to improve biometric identification such as the curvatures and distinctive 3D regions. Scanned images from eleven volunteers allowed the construction of the first OCT 3D fingerprint database, to our knowledge, containing epidermal and dermal fingerprints. 3D dermal fingerprints can be used to overcome cases of Failure to Enroll (FTE) due to poor ridge image quality and skin alterations, cases that affect 2D matching performance. We evaluate three matching techniques, including the well-established Iterative Closest Points algorithm (ICP), Surface Interpenetration Measure (SIM) and the well-known KH Curvature Maps, all assessed using a 3D OCT fingerprint database, the first one for this purpose. Two of these techniques are based on registration techniques and one on curvatures. These were evaluated, compared and the fusion of matching scores assessed. We applied a sequence of steps to extract regions of interest named (ROI) minutiae clouds, representing small regions around distinctive minutia, usually located at ridges/valleys endings or bifurcations. The obtained ROI is acquired from the epidermis and dermis-epidermis interface by OCT imaging. A comparative analysis of identification accuracy was explored using different scenarios and the obtained results shows improvements for biometric identification. A comparison against 2D fingerprint matching algorithms is also presented to assess the improvements.

A retrospective evaluation of traffic forecasting techniques.

DOT National Transportation Integrated Search

2016-08-01

Traffic forecasting techniquessuch as extrapolation of previous years traffic volumes, regional travel demand models, or : local trip generation rateshelp planners determine needed transportation improvements. Thus, knowing the accuracy of t...

Average discharge, perennial flow initiation, and channel initiation - small southern Appalachian basins

Treesearch

B. Lane Rivenbark; C. Rhett Jackson

2004-01-01

Regional average evapotranspiration estimates developed by water balance techniques are frequently used to estimate average discharge in ungaged strttams. However, the lower stream size range for the validity of these techniques has not been explored. Flow records were collected and evaluated for 16 small streams in the Southern Appalachians to test whether the...

The effects of missing data on global ozone estimates

NASA Technical Reports Server (NTRS)

Drewry, J. W.; Robbins, J. L.

1981-01-01

The effects of missing data and model truncation on estimates of the global mean, zonal distribution, and global distribution of ozone are considered. It is shown that missing data can introduce biased estimates with errors that are not accounted for in the accuracy calculations of empirical modeling techniques. Data-fill techniques are introduced and used for evaluating error bounds and constraining the estimate in areas of sparse and missing data. It is found that the accuracy of the global mean estimate is more dependent on data distribution than model size. Zonal features can be accurately described by 7th order models over regions of adequate data distribution. Data variance accounted for by higher order models appears to represent climatological features of columnar ozone rather than pure error. Data-fill techniques can prevent artificial feature generation in regions of sparse or missing data without degrading high order estimates over dense data regions.

Can state-of-the-art HVS-based objective image quality criteria be used for image reconstruction techniques based on ROI analysis?

NASA Astrophysics Data System (ADS)

Dostal, P.; Krasula, L.; Klima, M.

2012-06-01

Various image processing techniques in multimedia technology are optimized using visual attention feature of the human visual system. Spatial non-uniformity causes that different locations in an image are of different importance in terms of perception of the image. In other words, the perceived image quality depends mainly on the quality of important locations known as regions of interest. The performance of such techniques is measured by subjective evaluation or objective image quality criteria. Many state-of-the-art objective metrics are based on HVS properties; SSIM, MS-SSIM based on image structural information, VIF based on the information that human brain can ideally gain from the reference image or FSIM utilizing the low-level features to assign the different importance to each location in the image. But still none of these objective metrics utilize the analysis of regions of interest. We solve the question if these objective metrics can be used for effective evaluation of images reconstructed by processing techniques based on ROI analysis utilizing high-level features. In this paper authors show that the state-of-the-art objective metrics do not correlate well with subjective evaluation while the demosaicing based on ROI analysis is used for reconstruction. The ROI were computed from "ground truth" visual attention data. The algorithm combining two known demosaicing techniques on the basis of ROI location is proposed to reconstruct the ROI in fine quality while the rest of image is reconstructed with low quality. The color image reconstructed by this ROI approach was compared with selected demosaicing techniques by objective criteria and subjective testing. The qualitative comparison of the objective and subjective results indicates that the state-of-the-art objective metrics are still not suitable for evaluation image processing techniques based on ROI analysis and new criteria is demanded.

Something Old, Something New: MBA Program Evaluation Using Shift-Share Analysis and Google Trends

ERIC Educational Resources Information Center

Davis, Sarah M.; Rodriguez, A. E.

2014-01-01

Shift-share analysis is a decomposition technique that is commonly used to measure attributes of regional change. In this method, regional change is decomposed into its relevant functional and competitive parts. This paper introduces traditional shift-share method and its extensions with examples of its applicability and usefulness for program…

Assessment of biological leaf tissue using biospeckle laser imaging technique

NASA Astrophysics Data System (ADS)

Ansari, M. Z.; Mujeeb, A.; Nirala, A. K.

2018-06-01

We report on the application of an optical imaging technique, the biospeckle laser, as a potential tool to assess biological and medicinal plant leaves. The biospeckle laser technique is a non-invasive and non-destructive optical technique used to investigate biological objects. Just after their removal from plants, the torn leaves were used for biospeckle laser imaging. Quantitative evaluation of the biospeckle data using the inertia moment (IM) of the time history speckle pattern, showed that the IM can be utilized to provide a biospeckle signature to the plant leaves. It showed that leaves from different plants can have their own characteristic IM values. We further investigated the infected regions of the leaves that display a relatively lower biospeckle activity than the healthy tissue. It was easy to discriminate between the infected and healthy regions of the leaf tissue. The biospeckle technique can successfully be implemented as a potential tool for the taxonomy of quality leaves. Furthermore, the technique can help boost the quality of ayurvedic medicines.

Modeling of Convective-Stratiform Precipitation Processes: Sensitivity to Partitioning Methods and Numerical Advection Schemes

NASA Technical Reports Server (NTRS)

Lang, Steve; Tao, W.-K.; Simpson, J.; Ferrier, B.; Einaudi, Franco (Technical Monitor)

2001-01-01

Six different convective-stratiform separation techniques, including a new technique that utilizes the ratio of vertical and terminal velocities, are compared and evaluated using two-dimensional numerical simulations of a tropical [Tropical Ocean Global Atmosphere Coupled Ocean-Atmosphere Response Experiment (TOGA COARE)] and midlatitude continental [Preliminary Regional Experiment for STORM-Central (PRESTORM)] squall line. The simulations are made using two different numerical advection schemes: 4th order and positive definite advection. Comparisons are made in terms of rainfall, cloud coverage, mass fluxes, apparent heating and moistening, mean hydrometeor profiles, CFADs (Contoured Frequency with Altitude Diagrams), microphysics, and latent heating retrieval. Overall, it was found that the different separation techniques produced results that qualitatively agreed. However, the quantitative differences were significant. Observational comparisons were unable to conclusively evaluate the performance of the techniques. Latent heating retrieval was shown to be sensitive to the use of separation technique mainly due to the stratiform region for methods that found very little stratiform rain. The midlatitude PRESTORM simulation was found to be nearly invariant with respect to advection type for most quantities while for TOGA COARE fourth order advection produced numerous shallow convective cores and positive definite advection fewer cells that were both broader and deeper penetrating above the freezing level.

The boomerang osteotomy -- a new method of reduction malarplasty.

PubMed

Nakanishi, Yuji; Nagasao, Tomohisa; Shimizu, Yusuke; Miyamoto, Junpei; Kishi, Kazuo; Fukuta, Keizo

2012-05-01

To achieve optimal outcomes in reduction malarplasty, it is important to preserve the natural curvature of the cheek while reducing the zygoma prominence and the width of the midface. The present article introduces an effective technique that aims to achieve these purposes. Through an intraoral approach, boomerang-shaped bone incision lines are marked on the anterior aspect of the zygomatico-maxillary junction. The lines are placed medial to the most prominent part of the zygoma. The zygomatic arch is divided at its posterior part through a small incision made in the pre-auricular region. By performing these manoeuvres, a unit of bone-composed of a part of the zygoma body and zygomatic arch - is mobilised. The mobilised bone is shifted medially, reducing the width of the midface and making the zygoma region less prominent. After performing reduction malarplasty for 89 patients (10 males and 79 females) using this technique, clinical outcomes were evaluated. Outcomes of the treatment was optimal, with over 80% of the patients evaluating the results as excellent in terms of effectiveness in malar prominence, facial width and symmetry. Because the continuity of the main part of the zygoma body and zygomatic arch is preserved in our technique, medial transfer of the zygoma is enabled while preserving the natural curvature of the malar region and the superior-inferior position of the zygomatic arch. Because of these advantages, we recommend our technique as an effective technique of reduction malarplasty. Copyright © 2012 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

Passive monitoring techniques for evaluating atmospheric ozone and nitrogen exposure and deposition to California ecosystems

Treesearch

Mark E. Fenn; Andrzej Bytnerowicz; Susan L. Schilling

2018-01-01

Measuring the exposure of ecosystems to ecologically relevant pollutants is needed for evaluating ecosystem effects and to identify regions and resources at risk. In California, ozone (O3) and nitrogen (N) pollutants are of greatest concern for ecological effects. "Passive" monitoring methods have been developed to obtain spatially...

Detection and imaging of corrosion around wing skin fasteners using the dripless bubbler ultrasonic scanner

NASA Astrophysics Data System (ADS)

Hsu, David K.; Barnard, Daniel J.

1998-03-01

The galvanic action between steel fasteners and aluminum wing skins of aircraft often leads to hidden exfoliation corrosion around the countersink surface of the fastener heads. To detect and evaluate the severity of such corrosion defects, the Dripless Bubbler ultrasonic scanner was applied. This technique uses a focused beam of high frequency ultrasound in a closed-cycle, water-coupled scan of wing skin test panels containing corroded and uncorroded fasteners. With full waveform acquisition, not only the lateral extent but also the depth profile of the corrosions around the fastener heads were mapped out, subject to shadowing of defects at different depth. The technique is capable of providing quantitative assessment of the severity of the corrosion. In tests conducted to evaluate different techniques, the Dripless Bubbler has shown high probability of detection and low false call rate. The presence of paint on the surface did not degrade the performance of the technique. In addition, the Dripless Bubbler was also used on wing skin panels containing repair 'blend-out' regions that had 0.020' to 0.100' of metal removed from the surface by grinding. Corrosions around fasteners in the blend-out regions were also detected.

Waste minimization for commercial radioactive materials users generating low-level radioactive waste. Revision 1

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

Fischer, D.K.; Gitt, M.; Williams, G.A.

1991-07-01

The objective of this document is to provide a resource for all states and compact regions interested in promoting the minimization of low-level radioactive waste (LLW). This project was initiated by the Commonwealth of Massachusetts, and Massachusetts waste streams have been used as examples; however, the methods of analysis presented here are applicable to similar waste streams generated elsewhere. This document is a guide for states/compact regions to use in developing a system to evaluate and prioritize various waste minimization techniques in order to encourage individual radioactive materials users (LLW generators) to consider these techniques in their own independent evaluations.more » This review discusses the application of specific waste minimization techniques to waste streams characteristic of three categories of radioactive materials users: (1) industrial operations using radioactive materials in the manufacture of commercial products, (2) health care institutions, including hospitals and clinics, and (3) educational and research institutions. Massachusetts waste stream characterization data from key radioactive materials users in each category are used to illustrate the applicability of various minimization techniques. The utility group is not included because extensive information specific to this category of LLW generators is available in the literature.« less

Waste minimization for commercial radioactive materials users generating low-level radioactive waste

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

Fischer, D.K.; Gitt, M.; Williams, G.A.

1991-07-01

The objective of this document is to provide a resource for all states and compact regions interested in promoting the minimization of low-level radioactive waste (LLW). This project was initiated by the Commonwealth of Massachusetts, and Massachusetts waste streams have been used as examples; however, the methods of analysis presented here are applicable to similar waste streams generated elsewhere. This document is a guide for states/compact regions to use in developing a system to evaluate and prioritize various waste minimization techniques in order to encourage individual radioactive materials users (LLW generators) to consider these techniques in their own independent evaluations.more » This review discusses the application of specific waste minimization techniques to waste streams characteristic of three categories of radioactive materials users: (1) industrial operations using radioactive materials in the manufacture of commercial products, (2) health care institutions, including hospitals and clinics, and (3) educational and research institutions. Massachusetts waste stream characterization data from key radioactive materials users in each category are used to illustrate the applicability of various minimization techniques. The utility group is not included because extensive information specific to this category of LLW generators is available in the literature.« less

Use of macroinvertebrates to identify cultivated wetlands in the Prairie Pothole Region

USGS Publications Warehouse

Euliss, Ned H.; Mushet, David M.; Johnson, Douglas H.

2001-01-01

We evaluated the use of macroinvertebrates as a potential tool to identify dry and intensively farmed temporary and seasonal wetlands in the Prairie Pothole Region. The techniques we designed and evaluated used the dried remains of invertebrates or their egg banks in soils as indicators of wetlands. For both the dried remains of invertebrates and their egg banks, we weighted each taxon according to its affinity for wetlands or uplands. Our study clearly demonstrated that shells, exoskeletons, head capsules, eggs, and other remains of macroinvertebrates can be used to identify wetlands, even when they are dry, intensively farmed, and difficult to identify as wetlands using standard criteria (i.e., hydrology, hydrophytic vegetation, and hydric soils). Although both dried remains and egg banks identified wetlands, the combination was more useful, especially for identifying drained or filled wetlands. We also evaluated the use of coarse taxonomic groupings to stimulate use of the technique by nonspecialists and obtained satisfactory results in most situations.

MR measures of renal perfusion, oxygen bioavailability and total renal blood flow in a porcine model: noninvasive regional assessment of renal function.

PubMed

Wentland, Andrew L; Artz, Nathan S; Fain, Sean B; Grist, Thomas M; Djamali, Arjang; Sadowski, Elizabeth A

2012-01-01

Magnetic resonance imaging (MRI) may be a useful adjunct to current methods of evaluating renal function. MRI is a noninvasive imaging modality that has the ability to evaluate the kidneys regionally, which is lacking in current clinical methods. Other investigators have evaluated renal function with MRI-based measurements, such as with techniques to measure cortical and medullary perfusion, oxygen bioavailability and total renal blood flow (TRBF). However, use of all three techniques simultaneously, and therefore the relationships between these MRI-derived functional parameters, have not been reported previously. To evaluate the ability of these MRI techniques to track changes in renal function, we scanned 11 swine during a state of hyperperfusion with acetylcholine and a saline bolus and subsequently scanned during a state of hypoperfusion with the prolonged use of isoflurane anesthesia. For each time point, measurements of perfusion, oxygen bioavailability and TRBF were acquired. Measurements of perfusion and oxygen bioavailability were compared with measurements of TRBF for all swine across all time points. Cortical perfusion, cortical oxygen bioavailability, medullary oxygen bioavailability and TRBF significantly increased with the acetylcholine challenge. Cortical perfusion, medullary perfusion, cortical oxygen bioavailability and TRBF significantly decreased during isoflurane anesthesia. Cortical perfusion (Spearman's correlation coefficient = 0.68; P < 1 × 10(-6)) and oxygen bioavailability (Spearman's correlation coefficient = -0.60; P < 0.0001) correlated significantly with TRBF, whereas medullary perfusion and oxygen bioavailability did not correlate with TRBF. Our results demonstrate expected changes given the pharmacologically induced changes in renal function. Maintenance of the medullary oxygen bioavailability in low blood flow states may reflect the autoregulation particular to this region of the kidney. The ability to non-invasively measure all three parameters of kidney function in a single MRI examination and to evaluate the relationships between these functional parameters is potentially useful for evaluating the state of the human kidneys in situ in future studies.

Coupling Finite Element and Meshless Local Petrov-Galerkin Methods for Two-Dimensional Potential Problems

NASA Technical Reports Server (NTRS)

Chen, T.; Raju, I. S.

2002-01-01

A coupled finite element (FE) method and meshless local Petrov-Galerkin (MLPG) method for analyzing two-dimensional potential problems is presented in this paper. The analysis domain is subdivided into two regions, a finite element (FE) region and a meshless (MM) region. A single weighted residual form is written for the entire domain. Independent trial and test functions are assumed in the FE and MM regions. A transition region is created between the two regions. The transition region blends the trial and test functions of the FE and MM regions. The trial function blending is achieved using a technique similar to the 'Coons patch' method that is widely used in computer-aided geometric design. The test function blending is achieved by using either FE or MM test functions on the nodes in the transition element. The technique was evaluated by applying the coupled method to two potential problems governed by the Poisson equation. The coupled method passed all the patch test problems and gave accurate solutions for the problems studied.

Moral Education in Asia: Promotional Strategies and Evaluation Techniques. Reports of a High-Level Seminar and a Regional Workshop (Tokyo, Japan, 1978).

ERIC Educational Resources Information Center

United Nations Educational, Scientific, and Cultural Organization, Bangkok (Thailand). Regional Office for Education in Asia and Oceania.

This publication reports on a seminar and a workshop held in Tokyo, Japan, 1978 dealing with moral education in Asia. The seminar and workshop participants exchanged information and experiences, examined problems, and suggested guidelines for the implementation of regional programs in moral education. Participating countries include Afghanistan,…

SEASONAL AND REGIONAL VARIATIONS OF PRIMARY AND SECONDARY ORGANIC AEROSOLS OVER THE CONTINENTAL UNITED STATES: SEMI-EMPIRICAL ESTIMATES AND MODEL EVALUATION

EPA Science Inventory

Seasonal and regional variations of primary (OC_pri) and secondary (OC_sec) organic carbon aerosols across the continental U.S. for the year 2001 were examined by a semi-empirical technique using observed OC and elemental carbon (EC) data from 142 routine moni...

Effects of mechanical massage, manual lymphatic drainage and connective tissue manipulation techniques on fat mass in women with cellulite.

PubMed

Bayrakci Tunay, V; Akbayrak, T; Bakar, Y; Kayihan, H; Ergun, N

2010-02-01

To evaluate and compare the effectiveness of three different noninvasive treatment techniques on fat mass and regional fat thickness of the patients with cellulites. Sixty subjects were randomized into three groups. Group 1 (n = 20) treated with mechanical massage (MM), group 2 (n = 20) treated with manual lymphatic drainage (MLD) and group 3 (n = 20) treated with connective tissue manipulation (CTM) techniques. Subjects were evaluated by using standardized photographs, body composition analyzer (TBF 300) (body weight (BW), body mass index (BMI), fat %, fat mass (FM), fat free mass (FFM), total body water (TBW)), circumference measurement from thigh, waist-hip ratio (WHR), fat thickness measurements from abdomen, suprailium and thigh regions with skin fold caliper. All groups had an improvement in thinning of the subcutaneous fat after the treatment (P < 0.05). Thigh circumference decreased by an average of 0.5 cm in all groups and thigh fat thickness decreased 1.66 mm in Group 1, 2.21 mm in Group 2 and 3.03 mm in Group 3. Abdomen and suprailium fat thicknesses decreased 2.4 and 2.58 mm in Group 1, 1.78 and 2 mm in Group 2 and 1.23 and 0.64 mm in Group 3, respectively. The mean difference in waist-hip ratio was 0.1 cm in all groups. All the treatment techniques are effective in decreasing the regional fat values of the patients with cellulites.

Evaluation of culture-based techniques and 454 pyrosequencing for the analysis of fungal diversity in potting media and organic fertilizers.

PubMed

Al-Sadi, A M; Al-Mazroui, S S; Phillips, A J L

2015-08-01

Potting media and organic fertilizers (OFs) are commonly used in agricultural systems. However, there is a lack of studies on the efficiency of culture-based techniques in assessing the level of fungal diversity in these products. A study was conducted to investigate the efficiency of seven culture-based techniques and pyrosequencing for characterizing fungal diversity in potting media and OFs. Fungal diversity was evaluated using serial dilution, direct plating and baiting with carrot slices, potato slices, radish seeds, cucumber seeds and cucumber cotyledons. Identity of all the isolates was confirmed on the basis of the internal transcribed spacer region of the ribosomal RNA (ITS rRNA) sequence data. The direct plating technique was found to be superior over other culture-based techniques in the number of fungal species detected. It was also found to be simple and the least time consuming technique. Comparing the efficiency of direct plating with 454 pyrosequencing revealed that pyrosequencing detected 12 and 15 times more fungal species from potting media and OFs respectively. Analysis revealed that there were differences between potting media and OFs in the dominant phyla, classes, orders, families, genera and species detected. Zygomycota (52%) and Chytridiomycota (60%) were the predominant phyla in potting media and OFs respectively. The superiority of pyrosequencing over cultural methods could be related to the ability to detect obligate fungi, slow growing fungi and fungi that exist at low population densities. The evaluated methods in this study, especially direct plating and pyrosequencing, may be used as tools to help detect and reduce movement of unwanted fungi between countries and regions. © 2015 The Society for Applied Microbiology.

Phase processing for quantitative susceptibility mapping of regions with large susceptibility and lack of signal.

PubMed

Fortier, Véronique; Levesque, Ives R

2018-06-01

Phase processing impacts the accuracy of quantitative susceptibility mapping (QSM). Techniques for phase unwrapping and background removal have been proposed and demonstrated mostly in brain. In this work, phase processing was evaluated in the context of large susceptibility variations (Δχ) and negligible signal, in particular for susceptibility estimation using the iterative phase replacement (IPR) algorithm. Continuous Laplacian, region-growing, and quality-guided unwrapping were evaluated. For background removal, Laplacian boundary value (LBV), projection onto dipole fields (PDF), sophisticated harmonic artifact reduction for phase data (SHARP), variable-kernel sophisticated harmonic artifact reduction for phase data (V-SHARP), regularization enabled sophisticated harmonic artifact reduction for phase data (RESHARP), and 3D quadratic polynomial field removal were studied. Each algorithm was quantitatively evaluated in simulation and qualitatively in vivo. Additionally, IPR-QSM maps were produced to evaluate the impact of phase processing on the susceptibility in the context of large Δχ with negligible signal. Quality-guided unwrapping was the most accurate technique, whereas continuous Laplacian performed poorly in this context. All background removal algorithms tested resulted in important phase inaccuracies, suggesting that techniques used for brain do not translate well to situations where large Δχ and no or low signal are expected. LBV produced the smallest errors, followed closely by PDF. Results suggest that quality-guided unwrapping should be preferred, with PDF or LBV for background removal, for QSM in regions with large Δχ and negligible signal. This reduces the susceptibility inaccuracy introduced by phase processing. Accurate background removal remains an open question. Magn Reson Med 79:3103-3113, 2017. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

Advances in reduction techniques for tire contact problems

NASA Technical Reports Server (NTRS)

Noor, Ahmed K.

1995-01-01

Some recent developments in reduction techniques, as applied to predicting the tire contact response and evaluating the sensitivity coefficients of the different response quantities, are reviewed. The sensitivity coefficients measure the sensitivity of the contact response to variations in the geometric and material parameters of the tire. The tire is modeled using a two-dimensional laminated anisotropic shell theory with the effects of variation in geometric and material parameters, transverse shear deformation, and geometric nonlinearities included. The contact conditions are incorporated into the formulation by using a perturbed Lagrangian approach with the fundamental unknowns consisting of the stress resultants, the generalized displacements, and the Lagrange multipliers associated with the contact conditions. The elemental arrays are obtained by using a modified two-field, mixed variational principle. For the application of reduction techniques, the tire finite element model is partitioned into two regions. The first region consists of the nodes that are likely to come in contact with the pavement, and the second region includes all the remaining nodes. The reduction technique is used to significantly reduce the degrees of freedom in the second region. The effectiveness of the computational procedure is demonstrated by a numerical example of the frictionless contact response of the space shuttle nose-gear tire, inflated and pressed against a rigid flat surface. Also, the research topics which have high potential for enhancing the effectiveness of reduction techniques are outlined.

Field Data Collection: an Essential Element in Remote Sensing Applications

NASA Technical Reports Server (NTRS)

Pettinger, L. R.

1971-01-01

Field data collected in support of remote sensing projects are generally used for the following purposes: (1) calibration of remote sensing systems, (2) evaluation of experimental applications of remote sensing imagery on small test sites, and (3) designing and evaluating operational regional resource studies and inventories which are conducted using the remote sensing imagery obtained. Field data may be used to help develop a technique for a particular application, or to aid in the application of that technique to a resource evaluation or inventory problem for a large area. Scientists at the Forestry Remote Sensing Laboratory have utilized field data for both purposes. How meaningful field data has been collected in each case is discussed.

SLAM examination of solar cells and solar cell welds. [Scanning Laser Acoustic Microscope

NASA Technical Reports Server (NTRS)

Stella, P. M.; Vorres, C. L.; Yuhas, D. E.

1981-01-01

The scanning laser acoustic microscope (SLAM) has been evaluated for non-destructive examination of solar cells and interconnector bonds. Using this technique, it is possible to view through materials in order to reveal regions of discontinuity such as microcracks and voids. Of particular interest is the ability to evaluate, in a unique manner, the bonds produced by parallel gap welding. It is possible to not only determine the area and geometry of the bond between the tab and cell, but also to reveal any microcracks incurred during the welding. By correlating the SLAM results with conventional techniques of weld evaluation a more confident weld parameter optimization can be obtained.

Techniques for Tracking, Evaluating, and Reporting the Implementation of Nonpoint Source Control Measures - Forestry

EPA Pesticide Factsheets

This guidance is intended to assist state, regional, and local environmental professionals in tracking the implementation of best management practices (BMPs) used to control nonpoint source pollution generated by forestry practices.

Reduction technique for tire contact problems

NASA Technical Reports Server (NTRS)

Noor, Ahmed K.; Peters, Jeanne M.

1995-01-01

A reduction technique and a computational procedure are presented for predicting the tire contact response and evaluating the sensitivity coefficients of the different response quantities. The sensitivity coefficients measure the sensitivity of the contact response to variations in the geometric and material parameters of the tire. The tire is modeled using a two-dimensional laminated anisotropic shell theory with the effects of variation in geometric and material parameters, transverse shear deformation, and geometric nonlinearities included. The contact conditions are incorporated into the formulation by using a perturbed Lagrangian approach with the fundamental unknowns consisting of the stress resultants, the generalized displacements, and the Lagrange multipliers associated with the contact conditions. The elemental arrays are obtained by using a modified two-field, mixed variational principle. For the application of the reduction technique, the tire finite element model is partitioned into two regions. The first region consists of the nodes that are likely to come in contact with the pavement, and the second region includes all the remaining nodes. The reduction technique is used to significantly reduce the degrees of freedom in the second region. The effectiveness of the computational procedure is demonstrated by a numerical example of the frictionless contact response of the space shuttle nose-gear tire, inflated and pressed against a rigid flat surface.

Local bipolar-transistor gain measurement for VLSI devices

NASA Astrophysics Data System (ADS)

Bonnaud, O.; Chante, J. P.

1981-08-01

A method is proposed for measuring the gain of a bipolar transistor region as small as possible. The measurement then allows the evaluation particularly of the effect of the emitter-base junction edge and the technology-process influence of VLSI-technology devices. The technique consists in the generation of charge carriers in the transistor base layer by a focused laser beam in order to bias the device in as small a region as possible. To reduce the size of the conducting area, a transversal reverse base current is forced through the base layer resistance in order to pinch in the emitter current in the illuminated region. Transistor gain is deduced from small signal measurements. A model associated with this technique is developed, and this is in agreement with the first experimental results.

Studies and proposals on remote sensing programs for the evaluation and management of resources in Latin America (Columbia)

NASA Technical Reports Server (NTRS)

1982-01-01

A report is given on the situation in regard to diagnostic studies carried out on the use of remote sensing techniques at the regional level, and discussions held at international meetings on this topic. Studies and proposals presented by different organizations are discussed. It is concluded that a consultative body must be established at the regional level.

Sampling techniques and detection methods for developing risk assessments for root-knot nematode (Meloidogyne incognita) on lima bean (Phaseolus lunatus) in the Mid-Atlantic region

USDA-ARS?s Scientific Manuscript database

Lima bean, Phaseolus lunatus, is a cornerstone crop in the Mid-Atlantic region and Meloidogyne incognita, the southern root knot nematode (RKN), causes significant yield loss. The RKN has become more pervasive as toxic nematicides have been removed from the market, and risk evaluation research is ne...

Evaluation of Aster Images for Characterization and Mapping of Amethyst Mining Residues

NASA Astrophysics Data System (ADS)

Markoski, P. R.; Rolim, S. B. A.

2012-07-01

The objective of this work was to evaluate the potential of Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), subsystems VNIR (Visible and Near Infrared) and SWIR (Short Wave Infrared) images, for discrimination and mapping of amethyst mining residues (basalt) in the Ametista do Sul Region, Rio Grande do Sul State, Brazil. This region provides the most part of amethyst mining of the World. The basalt is extracted during the mining process and deposited outside the mine. As a result, mounts of residues (basalt) rise up. These mounts are many times smaller than ASTER pixel size (VNIR - 15 meters and SWIR - 30 meters). Thus, the pixel composition becomes a mixing of various materials, hampering its identification and mapping. Trying to solve this problem, multispectral algorithm Maximum Likelihood (MaxVer) and the hyperspectral technique SAM (Spectral Angle Mapper) were used in this work. Images from ASTER subsystems VNIR and SWIR were used to perform the classifications. SAM technique produced better results than MaxVer algorithm. The main error found by the techniques was the mixing between "shadow" and "mining residues/basalt" classes. With the SAM technique the confusion decreased because it employed the basalt spectral curve as a reference, while the multispectral techniques employed pixels groups that could have spectral mixture with other targets. The results showed that in tropical terrains as the study area, ASTER data can be efficacious for the characterization of mining residues.

Non-destructive evaluation of laboratory scale hydraulic fracturing using acoustic emission

NASA Astrophysics Data System (ADS)

Hampton, Jesse Clay

The primary objective of this research is to develop techniques to characterize hydraulic fractures and fracturing processes using acoustic emission monitoring based on laboratory scale hydraulic fracturing experiments. Individual microcrack AE source characterization is performed to understand the failure mechanisms associated with small failures along pre-existing discontinuities and grain boundaries. Individual microcrack analysis methods include moment tensor inversion techniques to elucidate the mode of failure, crack slip and crack normal direction vectors, and relative volumetric deformation of an individual microcrack. Differentiation between individual microcrack analysis and AE cloud based techniques is studied in efforts to refine discrete fracture network (DFN) creation and regional damage quantification of densely fractured media. Regional damage estimations from combinations of individual microcrack analyses and AE cloud density plotting are used to investigate the usefulness of weighting cloud based AE analysis techniques with microcrack source data. Two granite types were used in several sample configurations including multi-block systems. Laboratory hydraulic fracturing was performed with sample sizes ranging from 15 x 15 x 25 cm3 to 30 x 30 x 25 cm 3 in both unconfined and true-triaxially confined stress states using different types of materials. Hydraulic fracture testing in rock block systems containing a large natural fracture was investigated in terms of AE response throughout fracture interactions. Investigations of differing scale analyses showed the usefulness of individual microcrack characterization as well as DFN and cloud based techniques. Individual microcrack characterization weighting cloud based techniques correlated well with post-test damage evaluations.

A multilayered polyurethane foam technique for skin graft immobilization.

PubMed

Nakamura, Motoki; Ito, Erika; Kato, Hiroshi; Watanabe, Shoichi; Morita, Akimichi

2012-02-01

Several techniques are applicable for skin graft immobilization. Although the sponge dressing is a popular technique, pressure failure near the center of the graft is a weakness of the technique that can result in engraftment failure. To evaluate the efficacy of a new skin graft immobilization technique using multilayered polyurethane foam in vivo and in vitro. Twenty-six patients underwent a full-thickness skin graft. Multiple layers of a hydrocellular polyurethane foam dressing were used for skin graft immobilization. In addition, we created an in vitro skin graft model that allowed us to estimate immobilization pressure at the center and edges of skin grafts of various sizes. Overall mean graft survival was 88.9%. In the head and neck region (19 patients), mean graft survival was 93.6%. Based on the in vitro outcomes, this technique supplies effective pressure (<30 mmHg) to the center region of the skin graft. This multilayered polyurethane foam dressing is simple, safe, and effective for skin graft immobilization. © 2011 by the American Society for Dermatologic Surgery, Inc. Published by Wiley Periodicals, Inc.

Demonstrating Improvements from a NWP-based Satellite Precipitation Adjustment Technique in Tropical Mountainous Regions

NASA Astrophysics Data System (ADS)

Zhang, X.; Anagnostou, E. N.

2016-12-01

This research contributes to the improvement of high resolution satellite applications in tropical regions with mountainous topography. Such mountainous regions are usually covered by sparse networks of in-situ observations while quantitative precipitation estimation from satellite sensors exhibits strong underestimation of heavy orographically enhanced storm events. To address this issue, our research applies a satellite error correction technique based solely on high-resolution numerical weather predictions (NWP). Our previous work has demonstrated the accuracy of this method in two mid-latitude mountainous regions (Zhang et al. 2013*1, Zhang et al. 2016*2), while the current research focuses on a comprehensive evaluation in three topical mountainous regions: Colombia, Peru and Taiwan. In addition, two different satellite precipitation products, NOAA Climate Prediction Center morphing technique (CMORPH) and Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks-Cloud Classification System (PERSIANN-CCS), are considered. The study includes a large number of heavy precipitation events (68 events over the three regions) in the period 2004 to 2012. The NWP-based adjustments of the two satellite products are contrasted to their corresponding gauge-adjusted post-processing products. Preliminary results show that the NWP-based adjusted CMORPH product is consistently improved relative to both original and gauge-adjusted precipitation products for all regions and storms examined. The improvement of PERSIANN-CCS product is less significant and less consistent relative to the CMORPH performance improvements from the NWP-based adjustment. *1Zhang, Xinxuan, Emmanouil N. Anagnostou, Maria Frediani, Stavros Solomos, and George Kallos. "Using NWP simulations in satellite rainfall estimation of heavy precipitation events over mountainous areas." Journal of Hydrometeorology 14, no. 6 (2013): 1844-1858.*2 Zhang, Xinxuan, Emmanouil N. Anagnostou, and Humberto Vergara. "Hydrologic Evaluation of NWP-Adjusted CMORPH Estimates of Hurricane-Induced Precipitation in the Southern Appalachians." Journal of Hydrometeorology 17.4 (2016): 1087-1099.

Telecommunications network optimization

NASA Technical Reports Server (NTRS)

Lee, J.

1979-01-01

Analysis discusses STACOM (state criminal justic communication) network topology program used to design and evaluate digital telecommunications networks STACOM employs ESAU-WILLIAMS technique to search for direct links between system terminations and regional switching center. Inputs include traffic data, terminal locations, and functional requirements.

An Evaluation of the Relationship between Supervisory Techniques and Organizational Outcomes among the Supervisors in the Agricultural Extension Service in the Eastern Region Districts of Uganda. Summary of Research 81.

ERIC Educational Resources Information Center

Padde, Paul; And Others

A descriptive study examined the relationship between supervisory techniques and organizational outcomes among supervisors in the agricultural extension service in eight districts in eastern Uganda. Self-rating and rater forms of the Multifactor Leadership Questionnaire were sent to 220 extension agents, 8 field supervisors, and 8 deputy field…

User group attitudes toward forest management treatments on the Shawnee National Forest: application of a photo-evaluation technique

Treesearch

Jonathan M. Cohen; Jean C. Mangun; Mae A. Davenport; Andrew D. Carver

2008-01-01

Diverse public opinions, competing management goals, and polarized interest groups combine with problems of scale to create a complex management arena for managers in the Central Hardwood Forest region. A mixed-methods approach that incorporated quantitative analysis of data from a photo evaluation-attitude scale survey instrument was used to assess attitudes toward...

Nonlinear imaging (NIM) of barely visible impact damage (BVID) in composite panels using a semi and full air-coupled linear and nonlinear ultrasound technique

NASA Astrophysics Data System (ADS)

Malfense Fierro, Gian Piero; Meo, Michele

2018-03-01

Two non-contact methods were evaluated to address the reliability and reproducibility concerns affecting industry adoption of nonlinear ultrasound techniques for non-destructive testing and evaluation (NDT/E) purposes. A semi and a fully air-coupled linear and nonlinear ultrasound method was evaluated by testing for barely visible impact damage (BVID) in composite materials. Air coupled systems provide various advantages over contact driven systems; such as: ease of inspection, no contact and lubrication issues and a great potential for non-uniform geometry evaluation. The semi air-coupled setup used a suction attached piezoelectric transducer to excite the sample and an array of low-cost microphones to capture the signal over the inspection area, while the second method focused on a purely air-coupled setup, using an air-coupled transducer to excite the structure and capture the signal. One of the issues facing nonlinear and any air-coupled systems is transferring enough energy to stimulate wave propagation and in the case of nonlinear ultrasound; damage regions. Results for both methods provided nonlinear imaging (NIM) of damage regions using a sweep excitation methodology, with the semi aircoupled system providing clearer results.

SU-F-T-82: Dosimetric Evaluation of a Shield Used for Hemi-Body Skin Electron Irradiation

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

Rivers, C; Singh, A; AlDahlawi, I

Purpose: We had several mycosis fungoides patients with a limited disease to about half of the skin surface. A custom-made plywood shield was used to protect the non-targeted skin region with our total skin electron irradiation (TSEI) technique. We report a dosimetric evaluation for our “hemi-body” skin electron irradiation technique. Methods: The technique is similar to our clinical total skin electron irradiation (TSEI), performed with a six-pair dual field (Stanford technique) at an extended source-to-skin distance (SSD) of 377 cm, with the addition of a plywood shield placed 50 cm from the patient. The shield is made of three layersmore » of standard 5/8″ thick plywood (total thickness of 4.75 cm) that are clamped securely on an adjustable-height stand. Gafchromic EBT3 films were used in assessing the shield’s transmission factor and the extend of the dose penumbra region. To verify the dose delivered for hemi-body skin radiation in a real patient treatment, in-vivo dosimetry using Gafchromic EBT3 films were performed. Film pieces were taped on the patient skin to measure the dose received during the first two fractions, placed on the forehead and upper body (shielded region); and also at the level of pelvic area, left thigh, and left ankle. Results: The shield transmission factor was found to be 10%, and the width of the penumbra (80-to-20% dose fall-off) was about 12 cm. In-vivo dosimetry of a real case confirmed the expected shielded area dose. Conclusion: Hemi-Body skin electron irradiation at an extended SSD is feasible with the addition of a plywood shield at a distance from patient skin. The penumbra dose region and the shield’s transmission factor should be evaluated prior to clinical use. We have treated several hemi-body skin patients with our custom-made plywood shield, the current patient measurements are representative of these for other patients as well.« less

The Crustal Structure of the North-South Earthquake Belt in China Revealed from Deep Seismic Soundings and Gravity Data

NASA Astrophysics Data System (ADS)

Zhao, Yang; Guo, Lianghui; Shi, Lei; Li, Yonghua

2018-01-01

The North-South earthquake belt (NSEB) is one of the major earthquake regions in China. The studies of crustal structure play a great role in understanding tectonic evolution and in evaluating earthquake hazards in this region. However, some fundamental crustal parameters, especially crustal interface structure, are not clear in this region. In this paper, we reconstructed the crustal interface structure around the NSEB based on both the deep seismic sounding (DSS) data and the gravity data. We firstly reconstructed the crustal structure of crystalline basement (interface G), interface between upper and lower crusts (interface C) and Moho in the study area by compiling the results of 38 DSS profiles published previously. Then, we forwardly calculated the gravity anomalies caused by the interfaces G and C, and then subtracted them from the complete Bouguer gravity anomalies, yielding the regional gravity anomalies mainly due to the Moho interface. We then utilized a lateral-variable density interface inversion technique with constraints of the DSS data to invert the regional anomalies for the Moho depth model in the study area. The reliability of our Moho depth model was evaluated by comparing with other Moho depth models derived from other gravity inversion technique and receiver function analysis. Based on our Moho depth model, we mapped the crustal apparent density distribution in the study area for better understanding the geodynamics around the NSEB.

Short- and long-term results of an inpatient programme to manage Complex Regional Pain Syndrome in children and adolescents

PubMed Central

Cucchiaro, Giovanni; Craig, Kevin; Marks, Kerri; Cooley, Kristin; Cox, Thalitha Kay Black; Schwartz, Jennifer

2017-01-01

The aim of this retrospective study was to determine whether an inpatient approach and the use of regional anaesthesia techniques can accelerate the recovery to normal functions in children with Complex Regional Pain Syndrome (CRPS). This study looked at the data of patients admitted to the rehabilitation unit with a diagnosis of CRPS from January 2010 to April 2015. Variables such as hospital stay, medications administered, regional anaesthesia procedures, changes in functional status prior to treatment and at the time of discharge, psychological evaluation and diagnosis were evaluated. A total of 31 patients (21 females and 10 males) were admitted with a diagnosis of CRPS 1 and 2. In all, 97% of the patients received a peripheral or central nerve catheter for an average of 4 days with pain scores of Verbal Numeric Scale (VNS) score = 1.0 ± 0.7 and an average length of hospital stay of 8.2 ± 2.6 days. The modified Functional Independence Measure for Children (WeeFIM) scores and Canadian Association of Occupational Therapists tests significantly improved at the time of hospital discharge, as well as their pain scores, which decreased from 8.2 ± 2 to 1.6 ± 3. In conclusion, these data suggest that the use of regional anaesthesia techniques and an intensive inpatient rehabilitation programme could accelerate the recovery of children with CRPS. PMID:28491301

Statistical robustness of machine-learning estimates for characterizing a groundwater-surface water system, Southland, New Zealand

NASA Astrophysics Data System (ADS)

Friedel, M. J.; Daughney, C.

2016-12-01

The development of a successful surface-groundwater management strategy depends on the quality of data provided for analysis. This study evaluates the statistical robustness when using a modified self-organizing map (MSOM) technique to estimate missing values for three hypersurface models: synoptic groundwater-surface water hydrochemistry, time-series of groundwater-surface water hydrochemistry, and mixed-survey (combination of groundwater-surface water hydrochemistry and lithologies) hydrostratigraphic unit data. These models of increasing complexity are developed and validated based on observations from the Southland region of New Zealand. In each case, the estimation method is sufficiently robust to cope with groundwater-surface water hydrochemistry vagaries due to sample size and extreme data insufficiency, even when >80% of the data are missing. The estimation of surface water hydrochemistry time series values enabled the evaluation of seasonal variation, and the imputation of lithologies facilitated the evaluation of hydrostratigraphic controls on groundwater-surface water interaction. The robust statistical results for groundwater-surface water models of increasing data complexity provide justification to apply the MSOM technique in other regions of New Zealand and abroad.

Model Evaluation To Measuring Efficiencies of ICT Development In Indonesia Region Using DEA

NASA Astrophysics Data System (ADS)

Efendi, Syahril; Fadly Syahputra, M.; Anggia Muchtar, M.

2018-01-01

ICT Pura or digital city is a program designed by the Indonesian government with the main objective is to determine the level of readiness of each district and city in each province in the era of digital economy. It is necessarily to evaluate whether a city or a region that was successfully managing ICT better than other city and significantly contributes to the communities and living systems. Data envelopment analysis (DEA) is a well known technique to estimate efficiency and returns to scale through the construction of a best practice frontier, based on non-parametric mathematical programming approach. This paper addresses DEA BCC method to get index of efficiencies for all region in Indonesia covered by ICT Pura. Numerical result is given.

MR morphology of triangular fibrocartilage complex: correlation with quantitative MR and biomechanical properties.

PubMed

Bae, Won C; Ruangchaijatuporn, Thumanoon; Chang, Eric Y; Biswas, Reni; Du, Jiang; Statum, Sheronda; Chung, Christine B

2016-04-01

To evaluate pathology of the triangular fibrocartilage complex (TFCC) using high-resolution morphologic magnetic resonance (MR) imaging, and compare with quantitative MR and biomechanical properties. Five cadaveric wrists (22-70 years) were imaged at 3 T using morphologic (proton density weighted spin echo, PD FS, and 3D spoiled gradient echo, 3D SPGR) and quantitative MR sequences to determine T2 and T1rho properties. In eight geographic regions, morphology of TFC disc and laminae were evaluated for pathology and quantitative MR values. Samples were disarticulated and biomechanical indentation testing was performed on the distal surface of the TFC disc. On morphologic PD SE images, TFC disc pathology included degeneration and tears, while that of the laminae included degeneration, degeneration with superimposed tear, mucinous transformation, and globular calcification. Punctate calcifications were highly visible on 3D SPGR images and found only in pathologic regions. Disc pathology occurred more frequently in proximal regions of the disc than distal regions. Quantitative MR values were lowest in normal samples, and generally higher in pathologic regions. Biomechanical testing demonstrated an inverse relationship, with indentation modulus being high in normal regions with low MR values. The laminae studied were mostly pathologic, and additional normal samples are needed to discern quantitative changes. These results show technical feasibility of morphologic MR, quantitative MR, and biomechanical techniques to characterize pathology of the TFCC. Quantitative MRI may be a suitable surrogate marker of soft tissue mechanical properties, and a useful adjunct to conventional morphologic MR techniques.

Functional network alterations and their structural substrate in drug-resistant epilepsy

PubMed Central

Caciagli, Lorenzo; Bernhardt, Boris C.; Hong, Seok-Jun; Bernasconi, Andrea; Bernasconi, Neda

2014-01-01

The advent of MRI has revolutionized the evaluation and management of drug-resistant epilepsy by allowing the detection of the lesion associated with the region that gives rise to seizures. Recent evidence indicates marked chronic alterations in the functional organization of lesional tissue and large-scale cortico-subcortical networks. In this review, we focus on recent methodological developments in functional MRI (fMRI) analysis techniques and their application to the two most common drug-resistant focal epilepsies, i.e., temporal lobe epilepsy related to mesial temporal sclerosis and extra-temporal lobe epilepsy related to focal cortical dysplasia. We put particular emphasis on methodological developments in the analysis of task-free or “resting-state” fMRI to probe the integrity of intrinsic networks on a regional, inter-regional, and connectome-wide level. In temporal lobe epilepsy, these techniques have revealed disrupted connectivity of the ipsilateral mesiotemporal lobe, together with contralateral compensatory reorganization and striking reconfigurations of large-scale networks. In cortical dysplasia, initial observations indicate functional alterations in lesional, peri-lesional, and remote neocortical regions. While future research is needed to critically evaluate the reliability, sensitivity, and specificity, fMRI mapping promises to lend distinct biomarkers for diagnosis, presurgical planning, and outcome prediction. PMID:25565942

Monitoring Structure and Regional-Level Displacements for Lisbon Using Mltitemporal InSAR Techniques

NASA Astrophysics Data System (ADS)

Roque, Dora; Perissin, Daniele Falcao, Ana Paula; Fonseca, Ana Maria; Henriques, Maria Joao

2015-05-01

The city of Lisbon is the capital of Portugal and has been devastated by catastrophic events in the past, such as earthquakes and tsunamis. This study provides a regional analysis of displacements for the city and its neighbourhoods, between 2008 and 2010, through the application of mutitemporal InSAR techniques on Envisat ASAR images. Smaller areas with identified problems were subjected to a more refined processing. Besides, the behaviour of some key infrastructures, such as important buildings or railways, was carefully analysed in order to evaluate their safety. Subsidence was detected at the regional and small areas, in which the highest subsidence rates were verified on industrial parks or on landfills close to the river. Seasonal trends were found for the small areas, mainly related with structure thermal expansion or variations in underground water.

Lidar point density analysis: implications for identifying water bodies

USGS Publications Warehouse

Worstell, Bruce B.; Poppenga, Sandra K.; Evans, Gayla A.; Prince, Sandra

2014-01-01

Most airborne topographic light detection and ranging (lidar) systems operate within the near-infrared spectrum. Laser pulses from these systems frequently are absorbed by water and therefore do not generate reflected returns on water bodies in the resulting void regions within the lidar point cloud. Thus, an analysis of lidar voids has implications for identifying water bodies. Data analysis techniques to detect reduced lidar return densities were evaluated for test sites in Blackhawk County, Iowa, and Beltrami County, Minnesota, to delineate contiguous areas that have few or no lidar returns. Results from this study indicated a 5-meter radius moving window with fewer than 23 returns (28 percent of the moving window) was sufficient for delineating void regions. Techniques to provide elevation values for void regions to flatten water features and to force channel flow in the downstream direction also are presented.

Mapping accuracy via spectrally and structurally based filtering techniques: comparisons through visual observations

NASA Astrophysics Data System (ADS)

Chockalingam, Letchumanan

2005-01-01

The data of Gunung Ledang region of Malaysia acquired through LANDSAT are considered to map certain hydrogeolocial features. To map these significant features, image-processing tools such as contrast enhancement, edge detection techniques are employed. The advantages of these techniques over the other methods are evaluated from the point of their validity in properly isolating features of hydrogeolocial interest are discussed. As these techniques take the advantage of spectral aspects of the images, these techniques have several limitations to meet the objectives. To discuss these limitations, a morphological transformation, which generally considers the structural aspects rather than spectral aspects from the image, are applied to provide comparisons between the results derived from spectral based and the structural based filtering techniques.

Sandwich Panels Evaluated With Ultrasonic Spectroscopy

NASA Technical Reports Server (NTRS)

Cosgriff, Laura M.

2004-01-01

Enhanced, lightweight material systems, such as 17-4PH stainless steel sandwich panels are being developed for use as fan blades and fan containment systems for next-generation engines. The bond strength between the core and face sheets is critical in maintaining the structural integrity of the sandwich structure. To improve the inspection and production of these systems, researchers at the NASA Glenn Research Center are using nondestructive evaluation (NDE) techniques, such as ultrasonic spectroscopy, to evaluate the brazing quality between the face plates and the metallic foam core. The capabilities and limitations of a swept-frequency approach to ultrasonic spectroscopy were evaluated with respect to these sandwich structures. This report discusses results from three regions of a sandwich panel representing different levels of brazing quality between the outer face plates and a metallic foam core. Each region was investigated with ultrasonic spectroscopy. Then, on the basis of the NDE results, three shear specimens sectioned from the sandwich panel to contain each of these regions were mechanically tested.

Evaluation of Language Function under Awake Craniotomy

PubMed Central

KANNO, Aya; MIKUNI, Nobuhiro

2015-01-01

Awake craniotomy is the only established way to assess patients’ language functions intraoperatively and to contribute to their preservation, if necessary. Recent guidelines have enabled the approach to be used widely, effectively, and safely. Non-invasive brain functional imaging techniques, including functional magnetic resonance imaging and diffusion tensor imaging, have been used preoperatively to identify brain functional regions corresponding to language, and their accuracy has increased year by year. In addition, the use of neuronavigation that incorporates this preoperative information has made it possible to identify the positional relationships between the lesion and functional regions involved in language, conduct functional brain mapping in the awake state with electrical stimulation, and intraoperatively assess nerve function in real time when resecting the lesion. This article outlines the history of awake craniotomy, the current state of pre- and intraoperative evaluation of language function, and the clinical usefulness of such functional evaluation. When evaluating patients’ language functions during awake craniotomy, given the various intraoperative stresses involved, it is necessary to carefully select the tasks to be undertaken, quickly perform all examinations, and promptly evaluate the results. As language functions involve both input and output, they are strongly affected by patients’ preoperative cognitive function, degree of intraoperative wakefulness and fatigue, the ability to produce verbal articulations and utterances, as well as perform synergic movement. Therefore, it is essential to appropriately assess the reproducibility of language function evaluation using awake craniotomy techniques. PMID:25925758

Evaluation of Language Function under Awake Craniotomy.

PubMed

Kanno, Aya; Mikuni, Nobuhiro

2015-01-01

Awake craniotomy is the only established way to assess patients' language functions intraoperatively and to contribute to their preservation, if necessary. Recent guidelines have enabled the approach to be used widely, effectively, and safely. Non-invasive brain functional imaging techniques, including functional magnetic resonance imaging and diffusion tensor imaging, have been used preoperatively to identify brain functional regions corresponding to language, and their accuracy has increased year by year. In addition, the use of neuronavigation that incorporates this preoperative information has made it possible to identify the positional relationships between the lesion and functional regions involved in language, conduct functional brain mapping in the awake state with electrical stimulation, and intraoperatively assess nerve function in real time when resecting the lesion. This article outlines the history of awake craniotomy, the current state of pre- and intraoperative evaluation of language function, and the clinical usefulness of such functional evaluation. When evaluating patients' language functions during awake craniotomy, given the various intraoperative stresses involved, it is necessary to carefully select the tasks to be undertaken, quickly perform all examinations, and promptly evaluate the results. As language functions involve both input and output, they are strongly affected by patients' preoperative cognitive function, degree of intraoperative wakefulness and fatigue, the ability to produce verbal articulations and utterances, as well as perform synergic movement. Therefore, it is essential to appropriately assess the reproducibility of language function evaluation using awake craniotomy techniques.

Evaluating Acoustic Emission Signals as an in situ process monitoring technique for Selective Laser Melting (SLM)

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

Fisher, Karl A.; Candy, Jim V.; Guss, Gabe

2016-10-14

In situ real-time monitoring of the Selective Laser Melting (SLM) process has significant implications for the AM community. The ability to adjust the SLM process parameters during a build (in real-time) can save time, money and eliminate expensive material waste. Having a feedback loop in the process would allow the system to potentially ‘fix’ problem regions before a next powder layer is added. In this study we have investigated acoustic emission (AE) phenomena generated during the SLM process, and evaluated the results in terms of a single process parameter, of an in situ process monitoring technique.

Anatomical Regional Targeted (ART) BOTOX Injection Technique: A Novel Paradigm for Migraines and Chronic Headaches

PubMed Central

Sanniec, Kyle; Pezeshk, Ronnie; Chung, Michael

2016-01-01

Summary: Migraine headaches are a debilitating disease that causes significant socioeconomic problems. One of the speculated etiologies of the generation of migraines is peripheral nerve irritation at different trigger points. The use of Onabotulinum toxin A (BOTOX), although initially a novel approach, has now been determined to be a valid treatment for chronic headaches and migraines as described in the Phase III Research Evaluating Migraine Prophylaxis Therapy trials that prompted the approval by the Food and Drug Administration for treatment of chronic migraines. The injection paradigm established by this trial was one of a broad injection pattern across large muscle groups that did not always correspond to the anatomical locations of nerves. The senior author developed the Anatomical Regional Targeted BOTOX injection paradigm as an alternative to the current injection model. This technique targets both the anatomical location of nerves known to have causal effects with migraines and the region where the pain localizes, to provide relief across a wide distribution of the peripheral nerve. This article serves as a guide to the Anatomical Regional Targeted injection technique, which, to our knowledge, is the first comprehensive BOTOX injection paradigm described in the literature for treatment of migraines that targets nerves and nerve areas rather than purely muscle groups. This technique is based on the most up-to-date anatomical and scientific studies and large-volume migraine surgery experience. PMID:28293532

Method for evaluating toner adhesion on copier paper

Treesearch

C. Tim Scott; Roland Gleisner; Jeanne Dahlke-Bauman

2000-01-01

A new instrument and technique developed at the USDA Forest Service, Forest Products Laboratory to evaluate the adhesion of inks on paper was used to study toner loss on copier papers. This instrument creates a fold with a very small radius in the printed region of a paper specimen. This fold is repeatedly rolled through the specimen until the desired degree of wear is...

Whole-brain hippocampal sparing radiation therapy: Volume-modulated arc therapy vs intensity-modulated radiation therapy case study

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

Lee, Katrina, E-mail: Trinabena23@gmail.com; Lenards, Nishele; Holson, Janice

The hippocampus is responsible for memory and cognitive function. An ongoing phase II clinical trial suggests that sparing dose to the hippocampus during whole-brain radiation therapy can help preserve a patient's neurocognitive function. Progressive research and advancements in treatment techniques have made treatment planning more sophisticated but beneficial for patients undergoing treatment. The aim of this study is to evaluate and compare hippocampal sparing whole-brain (HS-WB) radiation therapy treatment planning techniques using volume-modulated arc therapy (VMAT) and intensity-modulated radiation therapy (IMRT). We randomly selected 3 patients to compare different treatment techniques that could be used for reducing dose to themore » hippocampal region. We created 2 treatment plans, a VMAT and an IMRT, from each patient's data set and planned on the Eclipse 11.0 treatment planning system (TPS). A total of 6 plans (3 IMRT and 3 VMAT) were created and evaluated for this case study. The physician contoured the hippocampus as per the Radiation Therapy Oncology Group (RTOG) 0933 protocol atlas. The organs at risk (OR) were contoured and evaluated for the plan comparison, which included the spinal cord, optic chiasm, the right and left eyes, lenses, and optic nerves. Both treatment plans produced adequate coverage on the planning target volume (PTV) while significantly reducing dose to the hippocampal region. The VMAT treatment plans produced a more homogenous dose distribution throughout the PTV while decreasing the maximum point dose to the target. However, both treatment techniques demonstrated hippocampal sparing when irradiating the whole brain.« less

Video Analytics Evaluation: Survey of Datasets, Performance Metrics and Approaches

DTIC Science & Technology

2014-09-01

training phase and a fusion of the detector outputs. 6.3.1 Training Techniques 1. Bagging: The basic idea of Bagging is to train multiple classifiers...can reduce more noise interesting points. Person detection and background subtraction methods were used to create hot regions. The hot regions were...detection algorithms are incorporated with MHT to construct one integrated detector /tracker. 6.8 IRDS-CASIA team IRDS-CASIA proposed a method to solve a

Time-series analysis of lung texture on bone-suppressed dynamic chest radiograph for the evaluation of pulmonary function: a preliminary study

NASA Astrophysics Data System (ADS)

Tanaka, Rie; Matsuda, Hiroaki; Sanada, Shigeru

2017-03-01

The density of lung tissue changes as demonstrated on imagery is dependent on the relative increases and decreases in the volume of air and lung vessels per unit volume of lung. Therefore, a time-series analysis of lung texture can be used to evaluate relative pulmonary function. This study was performed to assess a time-series analysis of lung texture on dynamic chest radiographs during respiration, and to demonstrate its usefulness in the diagnosis of pulmonary impairments. Sequential chest radiographs of 30 patients were obtained using a dynamic flat-panel detector (FPD; 100 kV, 0.2 mAs/pulse, 15 frames/s, SID = 2.0 m; Prototype, Konica Minolta). Imaging was performed during respiration, and 210 images were obtained over 14 seconds. Commercial bone suppression image-processing software (Clear Read Bone Suppression; Riverain Technologies, Miamisburg, Ohio, USA) was applied to the sequential chest radiographs to create corresponding bone suppression images. Average pixel values, standard deviation (SD), kurtosis, and skewness were calculated based on a density histogram analysis in lung regions. Regions of interest (ROIs) were manually located in the lungs, and the same ROIs were traced by the template matching technique during respiration. Average pixel value effectively differentiated regions with ventilatory defects and normal lung tissue. The average pixel values in normal areas changed dynamically in synchronization with the respiratory phase, whereas those in regions of ventilatory defects indicated reduced variations in pixel value. There were no significant differences between ventilatory defects and normal lung tissue in the other parameters. We confirmed that time-series analysis of lung texture was useful for the evaluation of pulmonary function in dynamic chest radiography during respiration. Pulmonary impairments were detected as reduced changes in pixel value. This technique is a simple, cost-effective diagnostic tool for the evaluation of regional pulmonary function.

First of all: Do not harm! Use of simulation for the training of regional anaesthesia techniques: Which skills can be trained without the patient as substitute for a mannequin.

PubMed

Sujatta, Susanne

2015-03-01

Character of clinical skills training is always influenced by technical improvement and cultural changes. Over the last years, two trends have changed the way of traditional apprenticeship-style training in regional anaesthesia: firstly, the development in ultrasound-guided regional anaesthesia, and secondly, the reduced acceptance of using patients as mannequins for invasive techniques. Against this background, simulation techniques are explored, ranging from simple low-fidelity part-task training models to train skills in needle application, to highly sophisticated virtual reality models – the full range is covered. This review tries to discuss all available options with benefits and neglects. The task in clinical practice will be in choosing the right level of sophistication for the desired approach and trainee level. However, the transfer of simulated skills to clinical practice has not been evaluated. It has to be proven whether simulation-trained skills could, as a last consequence, reduce the risk to patients. Copyright © 2015 Elsevier Ltd. All rights reserved.

WE-E-18A-07: MAGIC: Multi-Acquisition Gain Image Correction for Mobile X-Ray Systems with Intrinsic Localization Crosshairs

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

Park, Y; Sharp, G

2014-06-15

Purpose: Gain calibration for X-ray imaging systems with movable flat panel detectors (FPD) and intrinsic crosshairs is a challenge due to the geometry dependence of the heel effect and crosshair artifact. This study aims to develop a gain correction method for such systems by implementing the multi-acquisition gain image correction (MAGIC) technique. Methods: Raw flat-field images containing crosshair shadows and heel effect were acquired in 4 different FPD positions with fixed exposure parameters. The crosshair region was automatically detected and substituted with interpolated values from nearby exposed regions, generating a conventional single-image gain-map for each FPD position. Large kernel-based correctionmore » was applied to these images to correct the heel effect. A mask filter was used to invalidate the original cross-hair regions previously filled with the interpolated values. A final, seamless gain-map was created from the processed images by either the sequential filling (SF) or selective averaging (SA) techniques developed in this study. Quantitative evaluation was performed based on detective quantum efficiency improvement factor (DQEIF) for gain-corrected images using the conventional and proposed techniques. Results: Qualitatively, the MAGIC technique was found to be more effective in eliminating crosshair artifacts compared to the conventional single-image method. The mean DQEIF over the range of frequencies from 0.5 to 3.5 mm-1 were 1.09±0.06, 2.46±0.32, and 3.34±0.36 in the crosshair-artifact region and 2.35±0.31, 2.33±0.31, and 3.09±0.34 in the normal region, for the conventional, MAGIC-SF, and MAGIC-SA techniques, respectively. Conclusion: The introduced MAGIC technique is appropriate for gain calibration of an imaging system associated with a moving FPD and an intrinsic crosshair. The technique showed advantages over a conventional single image-based technique by successfully reducing residual crosshair artifacts, and higher image quality with respect to DQE.« less

LANDSAT and radar mapping of intrusive rocks in SE-Brazil

NASA Technical Reports Server (NTRS)

Parada, N. D. J. (Principal Investigator); Dossantos, A. R.; Dosanjos, C. E.; Moreira, J. C.; Barbosa, M. P.; Veneziani, P.

1982-01-01

The feasibility of intrusive rock mapping was investigated and criteria for regional geological mapping established at the scale of 1:500,00 in polycyclic and polymetamorphic areas using the logic method of photointerpretation of LANDSAT imagery and radar from the RADAMBRASIL project. The spectral behavior of intrusive rocks, was evaluated using the interactive multispectral image analysis system (Image-100). The region of Campos (city) in northern Rio de Janeiro State was selected as the study area and digital imagery processing and pattern recognition techniques were applied. Various maps at the 2:250,000 scale were obtained to evaluate the results of automatic data processing.

Advanced Ecosystem Mapping Techniques for Large Arctic Study Domains Using Calibrated High-Resolution Imagery

NASA Astrophysics Data System (ADS)

Macander, M. J.; Frost, G. V., Jr.

2015-12-01

Regional-scale mapping of vegetation and other ecosystem properties has traditionally relied on medium-resolution remote sensing such as Landsat (30 m) and MODIS (250 m). Yet, the burgeoning availability of high-resolution (<=2 m) imagery and ongoing advances in computing power and analysis tools raises the prospect of performing ecosystem mapping at fine spatial scales over large study domains. Here we demonstrate cutting-edge mapping approaches over a ~35,000 km² study area on Alaska's North Slope using calibrated and atmospherically-corrected mosaics of high-resolution WorldView-2 and GeoEye-1 imagery: (1) an a priori spectral approach incorporating the Satellite Imagery Automatic Mapper (SIAM) algorithms; (2) image segmentation techniques; and (3) texture metrics. The SIAM spectral approach classifies radiometrically-calibrated imagery to general vegetation density categories and non-vegetated classes. The SIAM classes were developed globally and their applicability in arctic tundra environments has not been previously evaluated. Image segmentation, or object-based image analysis, automatically partitions high-resolution imagery into homogeneous image regions that can then be analyzed based on spectral, textural, and contextual information. We applied eCognition software to delineate waterbodies and vegetation classes, in combination with other techniques. Texture metrics were evaluated to determine the feasibility of using high-resolution imagery to algorithmically characterize periglacial surface forms (e.g., ice-wedge polygons), which are an important physical characteristic of permafrost-dominated regions but which cannot be distinguished by medium-resolution remote sensing. These advanced mapping techniques provide products which can provide essential information supporting a broad range of ecosystem science and land-use planning applications in northern Alaska and elsewhere in the circumpolar Arctic.

Principles and Design of a Zeeman–Sisyphus Decelerator for Molecular Beams

PubMed Central

Tarbutt, M. R.

2016-01-01

Abstract We explore a technique for decelerating molecules using a static magnetic field and optical pumping. Molecules travel through a spatially varying magnetic field and are repeatedly pumped into a weak‐field seeking state as they move towards each strong field region, and into a strong‐field seeking state as they move towards weak field. The method is time‐independent and so is suitable for decelerating both pulsed and continuous molecular beams. By using guiding magnets at each weak field region, the beam can be simultaneously guided and decelerated. By tapering the magnetic field strength in the strong field regions, and exploiting the Doppler shift, the velocity distribution can be compressed during deceleration. We develop the principles of this deceleration technique, provide a realistic design, use numerical simulations to evaluate its performance for a beam of CaF, and compare this performance to other deceleration methods. PMID:27629547

Spectral-spatial hyperspectral image classification using super-pixel-based spatial pyramid representation

NASA Astrophysics Data System (ADS)

Fan, Jiayuan; Tan, Hui Li; Toomik, Maria; Lu, Shijian

2016-10-01

Spatial pyramid matching has demonstrated its power for image recognition task by pooling features from spatially increasingly fine sub-regions. Motivated by the concept of feature pooling at multiple pyramid levels, we propose a novel spectral-spatial hyperspectral image classification approach using superpixel-based spatial pyramid representation. This technique first generates multiple superpixel maps by decreasing the superpixel number gradually along with the increased spatial regions for labelled samples. By using every superpixel map, sparse representation of pixels within every spatial region is then computed through local max pooling. Finally, features learned from training samples are aggregated and trained by a support vector machine (SVM) classifier. The proposed spectral-spatial hyperspectral image classification technique has been evaluated on two public hyperspectral datasets, including the Indian Pines image containing 16 different agricultural scene categories with a 20m resolution acquired by AVIRIS and the University of Pavia image containing 9 land-use categories with a 1.3m spatial resolution acquired by the ROSIS-03 sensor. Experimental results show significantly improved performance compared with the state-of-the-art works. The major contributions of this proposed technique include (1) a new spectral-spatial classification approach to generate feature representation for hyperspectral image, (2) a complementary yet effective feature pooling approach, i.e. the superpixel-based spatial pyramid representation that is used for the spatial correlation study, (3) evaluation on two public hyperspectral image datasets with superior image classification performance.

MR Morphology of Triangular Fibrocartilage Complex: Correlation with Quantitative MR and Biomechanical Properties

PubMed Central

Bae, Won C.; Ruangchaijatuporn, Thumanoon; Chang, Eric Y; Biswas, Reni; Du, Jiang; Statum, Sheronda

2016-01-01

Objective To evaluate pathology of the triangular fibrocartilage complex (TFCC) using high resolution morphologic magnetic resonance (MR) imaging, and compare with quantitative MR and biomechanical properties. Materials and Methods Five cadaveric wrists (22 to 70 yrs) were imaged at 3T using morphologic (proton density weighted spin echo, PD FS, and 3D spoiled gradient echo, 3D SPGR) and quantitative MR sequences to determine T2 and T1rho properties. In eight geographic regions, morphology of TFC disc and laminae were evaluated for pathology and quantitative MR values. Samples were disarticulated and biomechanical indentation testing was performed on the distal surface of the TFC disc. Results On morphologic PD SE images, TFC disc pathology included degeneration and tears, while that of the laminae included degeneration, degeneration with superimposed tear, mucinous transformation, and globular calcification. Punctate calcifications were highly visible on 3D SPGR images and found only in pathologic regions. Disc pathology occurred more frequently in proximal regions of the disc than distal regions. Quantitative MR values were lowest in normal samples, and generally higher in pathologic regions. Biomechanical testing demonstrated an inverse relationship, with indentation modulus being high in normal regions with low MR values. The laminae studied were mostly pathologic, and additional normal samples are needed to discern quantitative changes. Conclusion These results show technical feasibility of morphologic MR, quantitative MR, and biomechanical techniques to characterize pathology of the TFCC. Quantitative MRI may be a suitable surrogate marker of soft tissue mechanical properties, and a useful adjunct to conventional morphologic MR techniques. PMID:26691643

Evaluation of the flood hydrology in the Colorado Front Range using precipitation, streamflow, and paleoflood data for the Big Thompson River basin

USGS Publications Warehouse

Jarrett, R.D.; Costa, J.E.

1988-01-01

A multidisciplinary study of precipitation and streamflow data and paleohydrologic studies of channel features was made to analyze the flood hydrology of foothill and mountain streams in the Front Range of Colorado, with emphasis on the Big Thompson River basin, because conventional hydrologic analyses do not adequately characterize the flood hydrology. In the foothills of Colorado, annual floodflows are derived from snowmelt at high elevations in the mountain regions, from rainfall at low elevation in the plains or plateau regions, or from a combination of rain falling on snow or mixed population hydrology. Above approximately 7,500 ft, snowmelt dominates; rain does not contribute to the flood potential. Regional flood-frequency relations were developed and compared with conventional flood-estimating technique results, including an evaluation of the magnitude and frequency of the probable maximum flood. Evaluation of streamflow data and paleoflood investigations provide an alternative for evaluating flood hydrology and the safety of dams. The study indicates the need for additional data collection and research to understand the complexities of the flood hydrology in mountainous regions, especially its effects on flood-plain management and the design of structures in the flood plain. (USGS)

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

Ebeida, Mohamed S.; Mitchell, Scott A.; Swiler, Laura P.

We introduce a novel technique, POF-Darts, to estimate the Probability Of Failure based on random disk-packing in the uncertain parameter space. POF-Darts uses hyperplane sampling to explore the unexplored part of the uncertain space. We use the function evaluation at a sample point to determine whether it belongs to failure or non-failure regions, and surround it with a protection sphere region to avoid clustering. We decompose the domain into Voronoi cells around the function evaluations as seeds and choose the radius of the protection sphere depending on the local Lipschitz continuity. As sampling proceeds, regions uncovered with spheres will shrink,more » improving the estimation accuracy. After exhausting the function evaluation budget, we build a surrogate model using the function evaluations associated with the sample points and estimate the probability of failure by exhaustive sampling of that surrogate. In comparison to other similar methods, our algorithm has the advantages of decoupling the sampling step from the surrogate construction one, the ability to reach target POF values with fewer samples, and the capability of estimating the number and locations of disconnected failure regions, not just the POF value. Furthermore, we present various examples to demonstrate the efficiency of our novel approach.« less

A methodology for automated CPA extraction using liver biopsy image analysis and machine learning techniques.

PubMed

Tsipouras, Markos G; Giannakeas, Nikolaos; Tzallas, Alexandros T; Tsianou, Zoe E; Manousou, Pinelopi; Hall, Andrew; Tsoulos, Ioannis; Tsianos, Epameinondas

2017-03-01

Collagen proportional area (CPA) extraction in liver biopsy images provides the degree of fibrosis expansion in liver tissue, which is the most characteristic histological alteration in hepatitis C virus (HCV). Assessment of the fibrotic tissue is currently based on semiquantitative staging scores such as Ishak and Metavir. Since its introduction as a fibrotic tissue assessment technique, CPA calculation based on image analysis techniques has proven to be more accurate than semiquantitative scores. However, CPA has yet to reach everyday clinical practice, since the lack of standardized and robust methods for computerized image analysis for CPA assessment have proven to be a major limitation. The current work introduces a three-stage fully automated methodology for CPA extraction based on machine learning techniques. Specifically, clustering algorithms have been employed for background-tissue separation, as well as for fibrosis detection in liver tissue regions, in the first and the third stage of the methodology, respectively. Due to the existence of several types of tissue regions in the image (such as blood clots, muscle tissue, structural collagen, etc.), classification algorithms have been employed to identify liver tissue regions and exclude all other non-liver tissue regions from CPA computation. For the evaluation of the methodology, 79 liver biopsy images have been employed, obtaining 1.31% mean absolute CPA error, with 0.923 concordance correlation coefficient. The proposed methodology is designed to (i) avoid manual threshold-based and region selection processes, widely used in similar approaches presented in the literature, and (ii) minimize CPA calculation time. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

IA-Regional-Radio - Social Network for Radio Recommendation

NASA Astrophysics Data System (ADS)

Dziczkowski, Grzegorz; Bougueroua, Lamine; Wegrzyn-Wolska, Katarzyna

This chapter describes the functions of a system proposed for the music hit recommendation from social network data base. This system carries out the automatic collection, evaluation and rating of music reviewers and the possibility for listeners to rate musical hits and recommendations deduced from auditor's profiles in the form of regional Internet radio. First, the system searches and retrieves probable music reviews from the Internet. Subsequently, the system carries out an evaluation and rating of those reviews. From this list of music hits, the system directly allows notation from our application. Finally, the system automatically creates the record list diffused each day depending on the region, the year season, the day hours and the age of listeners. Our system uses linguistics and statistic methods for classifying music opinions and data mining techniques for recommendation part needed for recorded list creation. The principal task is the creation of popular intelligent radio adaptive on auditor's age and region - IA-Regional-Radio.

The role of magnetic resonance imaging techniques in evaluation and management of the idiopathic inflammatory myopathies.

PubMed

Day, Jessica; Patel, Sandy; Limaye, Vidya

2017-04-01

Magnetic resonance imaging (MRI) is an important tool in the evaluation of neuromuscular disorders. MRI accurately demonstrates muscle oedema, atrophy, subcutaneous pathology and fatty infiltration and also highlights the distribution of muscle involvement. This review examines the role of MRI in evaluation of the idiopathic inflammatory myopathies (IIMs), a heterogeneous group of autoimmune conditions characterised by muscle inflammation and a variety of extra-muscular manifestations. MRI has a clear role in aiding diagnosis of these conditions, guiding muscle biopsy, differentiating subtypes of IIM using a pattern-based approach, and monitoring disease activity in a longitudinal fashion. Whole body MRI is an emerging technique that offers several advantages over regional MRI, but is not currently widely available. We will also consider newer MRI techniques which provide detailed information regarding the metabolism, function and structure of muscle, although their use is restricted to research purposes at present. Copyright © 2017 Elsevier Inc. All rights reserved.

Influence of Piezosurgery on Bone Healing around Titanium Implants: A Histological Study in Rats.

PubMed

Sirolli, Marcelo; Mafra, Carlos Eduardo Secco; Santos, Rodrigo Albuquerque Basílio Dos; Saraiva, Luciana; Holzhausen, Marinella; César, João Batista

2016-01-01

The aim of this study was to evaluate histomorphometrically the influence of two techniques of dental implant site preparation on bone healing around titanium implants. Fifteen male Wistar rats (±300 g) were used in the study. Each tibia was randomly assigned to receive the implant site preparation either with a conventional drilling technique (control - DRILL group) or with a piezoelectric device (PIEZO group). The animals were sacrificed after 30 days and then the following histomorphometric parameters were evaluated (percentage) separately for cortical and cancellous regions: proportion of mineralized tissue (PMT) adjacent to implant threads (500 μm adjacent); bone area within the threads (BA) and bone-implant contact (BIC). The results demonstrated that there were no statistically significant differences between both groups for cancellous BIC (p>0.05) and cortical PMT (p>0.05). On the other hand, a higher percentage of BA was observed in the PIEZO group in the cortical (71.50±6.91 and 78.28±4.38 for DRILL and PIEZO groups, respectively; p<0.05) and cancellous regions (9.62±4.06 and 19.94±14.18 for DRILL and PIEZO groups, respectively; p<0.05). The piezosurgery also showed higher PMT values in the cancellous zone (9.35±5.54 and 18.72±13.21 for DRILL and PIEZO groups, respectively; p<0.05). However, the DRILL group presented better results for BIC in cortical region (80.42±10.88 and 70.25±16.93 for DRILL and PIEZO groups, respectively; p<0.05). In conclusion, for the implant site preparation, the piezosurgery was beneficial to bone healing rates in the cancellous bone region, while the drill technique produced better results in the cortical bone.

SU-E-J-149: Establishing the Relationship Between Pre-Treatment Lung Ventilation, Dose, and Toxicity Outcome

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

Mistry, N; D'Souza, W; Sornsen de Koste, J

2014-06-01

Purpose: Recently, there has been an interest in incorporating functional information in treatment planning especially in thoracic tumors. The rationale is that healthy lung regions need to be spared from radiation if possible to help achieve better control on toxicity. However, it is still unclear whether high functioning regions need to be spared or have more capacity to deal with the excessive radiation as compared to the compromised regions of the lung. Our goal with this work is to establish the tools by which we can establish a relationship between pre-treatment lung function, dose, and radiographic outcomes of lung toxicity.more » Methods: Treatment planning was performed using a single phase of a 4DCT scan, and follow-up anatomical CT scans were performed every 3 months for most patients. In this study, we developed the pipeline of tools needed to analyze such a large dataset, while trying to establish a relationship between function, dose, and outcome. Pre-treatment lung function was evaluated using a recently published technique that evaluates Fractional Regional Ventilation (FRV). All images including the FRV map and the individual follow-up anatomical CT images were all spatially matched to the planning CT using a diffusion based Demons image registration algorithm. Change in HU value was used as a metric to capture the effects of lung toxicity. To validate the findings, a radiologist evaluated the follow-up anatomical CT images and scored lung toxicity. Results: Initial experience in 1 patient shows a relationship between the pre-treatment lung function, dose and toxicity outcome. The results are also correlated to the findings by the radiologist who was blinded to the analysis or dose. Conclusion: The pipeline we have established to study this enables future studies in large retrospective studies. However, the tools are dependent on the fidelity of 4DCT reconstruction for accurate evaluation of regional ventilation. Patent Pending for the technique presented in this work to evaluate FRV incorporating mass correction.« less

Assessment of the stress transmitted to dental implants connected to screw-retained bars using different casting techniques.

PubMed

Haselhuhn, Klaus; Marotti, Juliana; Tortamano, Pedro; Weiss, Claudia; Suleiman, Lubna; Wolfart, Stefan

2014-12-01

Passive fit of the prosthetic superstructure is important to avoid complications; however, evaluation of passive fit is not possible using conventional procedures. Thus, the aim of this study was to check and locate mechanical stress in bar restorations fabricated using two casting techniques. Fifteen patients received four implants in the interforaminal region of the mandible, and a bar was fabricated using either the cast-on abutment or lost-wax casting technique. The fit accuracy was checked according to the Sheffield's test criteria. Measurements were recorded on the master model with a gap-free, passive fit using foil strain gauges both before and after tightening the prosthetic screws. Data acquisition and processing was analyzed with computer software and submitted to statistical analysis (ANOVA). The greatest axial distortion was at position 42 with the cast-on abutment technique, with a mean distortion of 450 μm/m. The lowest axial distortion occurred at position 44 with the lost-wax casting technique, with a mean distortion of 100 μm/m. The minimal differences between the means of axial distortion do not indicate any significant differences between the techniques (P = 0.2076). Analysis of the sensor axial distortion in relation to the implant position produced a significant difference (P < 0.0001). Significantly higher measurements were recorded in the axial distortion analysis of the distal sensors of implants at the 34 and 44 regions than on the mesial positions at the 32 and 42 regions (P = 0.0481). The measuring technique recorded axial distortion in the implant-supported superstructures. Distortions were present at both casting techniques, with no significant difference between the sides.

Peak-flow characteristics of Wyoming streams

USGS Publications Warehouse

Miller, Kirk A.

2003-01-01

Peak-flow characteristics for unregulated streams in Wyoming are described in this report. Frequency relations for annual peak flows through water year 2000 at 364 streamflow-gaging stations in and near Wyoming were evaluated and revised or updated as needed. Analyses of historical floods, temporal trends, and generalized skew were included in the evaluation. Physical and climatic basin characteristics were determined for each gaging station using a geographic information system. Gaging stations with similar peak-flow and basin characteristics were grouped into six hydrologic regions. Regional statistical relations between peak-flow and basin characteristics were explored using multiple-regression techniques. Generalized least squares regression equations for estimating magnitudes of annual peak flows with selected recurrence intervals from 1.5 to 500 years were developed for each region. Average standard errors of estimate range from 34 to 131 percent. Average standard errors of prediction range from 35 to 135 percent. Several statistics for evaluating and comparing the errors in these estimates are described. Limitations of the equations are described. Methods for applying the regional equations for various circumstances are listed and examples are given.

Using remote sensing and GIS techniques to estimate discharge and recharge fluxes for the Death Valley regional groundwater flow system, USA

USGS Publications Warehouse

D'Agnese, F. A.; Faunt, C.C.; Turner, A.K.; ,

1996-01-01

The recharge and discharge components of the Death Valley regional groundwater flow system were defined by techniques that integrated disparate data types to develop a spatially complex representation of near-surface hydrological processes. Image classification methods were applied to multispectral satellite data to produce a vegetation map. The vegetation map was combined with ancillary data in a GIS to delineate different types of wetlands, phreatophytes and wet playa areas. Existing evapotranspiration-rate estimates were used to calculate discharge volumes for these area. An empirical method of groundwater recharge estimation was modified to incorporate data describing soil-moisture conditions, and a recharge potential map was produced. These discharge and recharge maps were readily converted to data arrays for numerical modelling codes. Inverse parameter estimation techniques also used these data to evaluate the reliability and sensitivity of estimated values.The recharge and discharge components of the Death Valley regional groundwater flow system were defined by remote sensing and GIS techniques that integrated disparate data types to develop a spatially complex representation of near-surface hydrological processes. Image classification methods were applied to multispectral satellite data to produce a vegetation map. This map provided a basis for subsequent evapotranspiration and infiltration estimations. The vegetation map was combined with ancillary data in a GIS to delineate different types of wetlands, phreatophytes and wet playa areas. Existing evapotranspiration-rate estimates were then used to calculate discharge volumes for these areas. A previously used empirical method of groundwater recharge estimation was modified by GIS methods to incorporate data describing soil-moisture conditions, and a recharge potential map was produced. These discharge and recharge maps were readily converted to data arrays for numerical modelling codes. Inverse parameter estimation techniques also used these data to evaluate the reliability and sensitivity of estimated values.

Evaluation of SIR-B imagery for geologic and geomorphic mapping, hydrology, and oceanography in Australia

NASA Technical Reports Server (NTRS)

Honey, F. R.; Simpson, C. J.; Huntington, J.; Horwitz, R.; Byrne, G.; Nilsson, C.

1984-01-01

The objectives of a study to evaluate the potential of Shuttle Imaging Radar-B (SIR-B) imagery for various applications are outlined. Specific goals include: the development of techniques for registration multiple acquisition, varied illumination, and incidence-angle SIR-B imagery, and a model for estimation of the relative contributions to the backscattered radiation of topography, surface roughness, and dielectric and conductivity components; (2) the evaluation of SIR-B imagery for delineation of agricultural lands affected by secondary salinity in the southwest and southeast agricultural regions of Australia; (3) the development of techniques for application of SIR-B imagery for geologic, geomorphologic and soils mapping and mineral exploration; and (4) the evaluation of the use of SIR-B imagery in determining ocean currents, current shear patterns, internal waves and bottom features for specific locations off the Australian coast.

Comparison of the artifacts caused by metallic implants in breast MRI using dual-echo dixon versus conventional fat-suppression techniques.

PubMed

Le, Yuan; Kipfer, Hal D; Majidi, Shadie S; Holz, Stephanie; Lin, Chen

2014-09-01

The purpose of this article is to evaluate and compare the artifacts caused by metal implants in breast MR images acquired with dual-echo Dixon and two conventional fat-suppression techniques. Two types of biopsy markers were embedded into a uniform fat-water emulsion. T1-weighted gradient-echo images were acquired on a clinical 3-T MRI scanner with three different fat-suppression techniques-conventional or quick fat saturation, spectrally selective adiabatic inversion recovery (SPAIR), and dual-echo Dixon-and the 3D volumes of artifacts were measured. Among the subjects of a clinical breast MRI study using the same scanner, five patients were found to have one or more metal implants. The artifacts in Dixon and SPAIR fat-suppressed images were evaluated by three radiologists, and the results were compared with those of the phantom study. In the phantom study, the artifacts appeared as interleaved bright and dark rings on SPAIR and quick-fat-saturation images, whereas they appeared as dark regions with a thin bright rim on Dixon images. The artifacts imaged with the Dixon technique had the smallest total volume. However, the reviewers found larger artifact diameters on patient images using the Dixon sequence because only the central region was recognized as an artifact on the SPAIR images. Metal implants introduce artifacts of different types and sizes, according to the different fat-suppression techniques used. The dual-echo Dixon technique produces a larger central void, allowing the implant to be easily identified, but presents a smaller overall artifact volume by obscuring less area in the image, according to a quantitative phantom study.

An evaluation of machine processing techniques of ERTS-1 data for user applications. [urban land use and soil association mapping in Indiana

NASA Technical Reports Server (NTRS)

Landgrebe, D.

1974-01-01

A broad study is described to evaluate a set of machine analysis and processing techniques applied to ERTS-1 data. Based on the analysis results in urban land use analysis and soil association mapping together with previously reported results in general earth surface feature identification and crop species classification, a profile of general applicability of this procedure is beginning to emerge. Put in the hands of a user who knows well the information needed from the data and also is familiar with the region to be analyzed it appears that significantly useful information can be generated by these methods. When supported by preprocessing techniques such as the geometric correction and temporal registration capabilities, final products readily useable by user agencies appear possible. In parallel with application, through further research, there is much potential for further development of these techniques both with regard to providing higher performance and in new situations not yet studied.

Monitoring the effects of knickpoint erosion on bridge pier and abutment structural damage due to scour.

DOT National Transportation Integrated Search

2012-04-01

The goal of this study was to conduct a field-oriented evaluation, coupled with advanced laboratory techniques, of channel : degradation in a stream of the Deep Loess Region of western Iowa, namely Mud Creek. The Midwestern United States is : an idea...

Historical Photographs: A County-Wide Organization.

ERIC Educational Resources Information Center

Safran, Franciska

This basic outline for the organization of photograph collections is designed for use by individual agencies as well as by people interested in a cooperative collection organization that can encompass a regional network. The working manual provides organizational techniques for the evaluation of historical, monetary, and other values of the…

Detection of cracks on tomatoes using hyperspectral near-infrared reflectance imaging system

USDA-ARS?s Scientific Manuscript database

The objective of this study was to evaluate the use of hyperspectral near-infrared (NIR) reflectance imaging techniques for detection of cuticle cracks on tomatoes. A hyperspectral near-infrared reflectance imaging system in the region of 1000-1700 nm was used to obtain hyperspectral reflectance ima...

Whole-brain hippocampal sparing radiation therapy: Volume-modulated arc therapy vs intensity-modulated radiation therapy case study.

PubMed

Lee, Katrina; Lenards, Nishele; Holson, Janice

2016-01-01

The hippocampus is responsible for memory and cognitive function. An ongoing phase II clinical trial suggests that sparing dose to the hippocampus during whole-brain radiation therapy can help preserve a patient׳s neurocognitive function. Progressive research and advancements in treatment techniques have made treatment planning more sophisticated but beneficial for patients undergoing treatment. The aim of this study is to evaluate and compare hippocampal sparing whole-brain (HS-WB) radiation therapy treatment planning techniques using volume-modulated arc therapy (VMAT) and intensity-modulated radiation therapy (IMRT). We randomly selected 3 patients to compare different treatment techniques that could be used for reducing dose to the hippocampal region. We created 2 treatment plans, a VMAT and an IMRT, from each patient׳s data set and planned on the Eclipse 11.0 treatment planning system (TPS). A total of 6 plans (3 IMRT and 3 VMAT) were created and evaluated for this case study. The physician contoured the hippocampus as per the Radiation Therapy Oncology Group (RTOG) 0933 protocol atlas. The organs at risk (OR) were contoured and evaluated for the plan comparison, which included the spinal cord, optic chiasm, the right and left eyes, lenses, and optic nerves. Both treatment plans produced adequate coverage on the planning target volume (PTV) while significantly reducing dose to the hippocampal region. The VMAT treatment plans produced a more homogenous dose distribution throughout the PTV while decreasing the maximum point dose to the target. However, both treatment techniques demonstrated hippocampal sparing when irradiating the whole brain. Copyright © 2016 American Association of Medical Dosimetrists. Published by Elsevier Inc. All rights reserved.

The use of adaptive statistical iterative reconstruction (ASiR) technique in evaluation of patients with cervical spine trauma: impact on radiation dose reduction and image quality

PubMed Central

Sheikh, Adnan

2016-01-01

Objective: The aim of this study was to evaluate the impact of adaptive statistical iterative reconstruction (ASiR) technique on the image quality and radiation dose reduction. The comparison was made with the traditional filtered back projection (FBP) technique. Methods: We retrospectively reviewed 78 patients, who underwent cervical spine CT for blunt cervical trauma between 1 June 2010 and 30 November 2010. 48 patients were imaged using traditional FBP technique and the remaining 30 patients were imaged using the ASiR technique. The patient demographics, radiation dose, objective image signal and noise were recorded; while subjective noise, sharpness, diagnostic acceptability and artefacts were graded by two radiologists blinded to the techniques. Results: We found that the ASiR technique was able to reduce the volume CT dose index, dose–length product and effective dose by 36%, 36.5% and 36.5%, respectively, compared with the FBP technique. There was no significant difference in the image noise (p = 0.39), signal (p = 0.82) and signal-to-noise ratio (p = 0.56) between the groups. The subjective image quality was minimally better in the ASiR group but not statistically significant. There was excellent interobserver agreement on the subjective image quality and diagnostic acceptability for both groups. Conclusion: The use of ASiR technique allowed approximately 36% radiation dose reduction in the evaluation of cervical spine without degrading the image quality. Advances in knowledge: The present study highlights that the ASiR technique is extremely helpful in reducing the patient radiation exposure while maintaining the image quality. It is highly recommended to utilize this novel technique in CT imaging of different body regions. PMID:26882825

The use of adaptive statistical iterative reconstruction (ASiR) technique in evaluation of patients with cervical spine trauma: impact on radiation dose reduction and image quality.

PubMed

Patro, Satya N; Chakraborty, Santanu; Sheikh, Adnan

2016-01-01

The aim of this study was to evaluate the impact of adaptive statistical iterative reconstruction (ASiR) technique on the image quality and radiation dose reduction. The comparison was made with the traditional filtered back projection (FBP) technique. We retrospectively reviewed 78 patients, who underwent cervical spine CT for blunt cervical trauma between 1 June 2010 and 30 November 2010. 48 patients were imaged using traditional FBP technique and the remaining 30 patients were imaged using the ASiR technique. The patient demographics, radiation dose, objective image signal and noise were recorded; while subjective noise, sharpness, diagnostic acceptability and artefacts were graded by two radiologists blinded to the techniques. We found that the ASiR technique was able to reduce the volume CT dose index, dose-length product and effective dose by 36%, 36.5% and 36.5%, respectively, compared with the FBP technique. There was no significant difference in the image noise (p = 0.39), signal (p = 0.82) and signal-to-noise ratio (p = 0.56) between the groups. The subjective image quality was minimally better in the ASiR group but not statistically significant. There was excellent interobserver agreement on the subjective image quality and diagnostic acceptability for both groups. The use of ASiR technique allowed approximately 36% radiation dose reduction in the evaluation of cervical spine without degrading the image quality. The present study highlights that the ASiR technique is extremely helpful in reducing the patient radiation exposure while maintaining the image quality. It is highly recommended to utilize this novel technique in CT imaging of different body regions.

Multi-Sectional Views Textural Based SVM for MS Lesion Segmentation in Multi-Channels MRIs

PubMed Central

Abdullah, Bassem A; Younis, Akmal A; John, Nigel M

2012-01-01

In this paper, a new technique is proposed for automatic segmentation of multiple sclerosis (MS) lesions from brain magnetic resonance imaging (MRI) data. The technique uses a trained support vector machine (SVM) to discriminate between the blocks in regions of MS lesions and the blocks in non-MS lesion regions mainly based on the textural features with aid of the other features. The classification is done on each of the axial, sagittal and coronal sectional brain view independently and the resultant segmentations are aggregated to provide more accurate output segmentation. The main contribution of the proposed technique described in this paper is the use of textural features to detect MS lesions in a fully automated approach that does not rely on manually delineating the MS lesions. In addition, the technique introduces the concept of the multi-sectional view segmentation to produce verified segmentation. The proposed textural-based SVM technique was evaluated using three simulated datasets and more than fifty real MRI datasets. The results were compared with state of the art methods. The obtained results indicate that the proposed method would be viable for use in clinical practice for the detection of MS lesions in MRI. PMID:22741026

An evaluation of the directed flow graph methodology

NASA Technical Reports Server (NTRS)

Snyder, W. E.; Rajala, S. A.

1984-01-01

The applicability of the Directed Graph Methodology (DGM) to the design and analysis of special purpose image and signal processing hardware was evaluated. A special purpose image processing system was designed and described using DGM. The design, suitable for very large scale integration (VLSI) implements a region labeling technique. Two computer chips were designed, both using metal-nitride-oxide-silicon (MNOS) technology, as well as a functional system utilizing those chips to perform real time region labeling. The system is described in terms of DGM primitives. As it is currently implemented, DGM is inappropriate for describing synchronous, tightly coupled, special purpose systems. The nature of the DGM formalism lends itself more readily to modeling networks of general purpose processors.

Machine learning techniques for medical diagnosis of diabetes using iris images.

PubMed

Samant, Piyush; Agarwal, Ravinder

2018-04-01

Complementary and alternative medicine techniques have shown their potential for the treatment and diagnosis of chronical diseases like diabetes, arthritis etc. On the same time digital image processing techniques for disease diagnosis is reliable and fastest growing field in biomedical. Proposed model is an attempt to evaluate diagnostic validity of an old complementary and alternative medicine technique, iridology for diagnosis of type-2 diabetes using soft computing methods. Investigation was performed over a close group of total 338 subjects (180 diabetic and 158 non-diabetic). Infra-red images of both the eyes were captured simultaneously. The region of interest from the iris image was cropped as zone corresponds to the position of pancreas organ according to the iridology chart. Statistical, texture and discrete wavelength transformation features were extracted from the region of interest. The results show best classification accuracy of 89.63% calculated from RF classifier. Maximum specificity and sensitivity were absorbed as 0.9687 and 0.988, respectively. Results have revealed the effectiveness and diagnostic significance of proposed model for non-invasive and automatic diabetes diagnosis. Copyright © 2018 Elsevier B.V. All rights reserved.

Results of NDE Technique Evaluation of Clad Hydrides

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

Kunerth, Dennis C.

2014-09-01

This report fulfills the M4 milestone, M4FT-14IN0805023, Results of NDE Technique Evaluation of Clad Hydrides, under Work Package Number FT-14IN080502. During service, zirconium alloy fuel cladding will degrade via corrosion/oxidation. Hydrogen, a byproduct of the oxidation process, will be absorbed into the cladding and eventually form hydrides due to low hydrogen solubility limits. The hydride phase is detrimental to the mechanical properties of the cladding and therefore it is important to be able to detect and characterize the presence of this constituent within the cladding. Presently, hydrides are evaluated using destructive examination. If nondestructive evaluation techniques can be used tomore » detect and characterize the hydrides, the potential exists to significantly increase test sample coverage while reducing evaluation time and cost. To demonstrate the viability this approach, an initial evaluation of eddy current and ultrasonic techniques were performed to demonstrate the basic ability to these techniques to detect hydrides or their effects on the microstructure. Conventional continuous wave eddy current techniques were applied to zirconium based cladding test samples thermally processed with hydrogen gas to promote the absorption of hydrogen and subsequent formation of hydrides. The results of the evaluation demonstrate that eddy current inspection approaches have the potential to detect both the physical damage induced by hydrides, e.g. blisters and cracking, as well as the combined effects of absorbed hydrogen and hydride precipitates on the electrical properties of the zirconium alloy. Similarly, measurements of ultrasonic wave velocities indicate changes in the elastic properties resulting from the combined effects of absorbed hydrogen and hydride precipitates as well as changes in geometry in regions of severe degradation. However, for both approaches, the signal responses intended to make the desired measurement incorporate a number of contributing parameters. These contributing factors need to be recognized and a means to control them or separate their contributions will be required to obtain the desired information.« less

Evaluation of a technique for satellite-derived area estimation of forest fires

NASA Technical Reports Server (NTRS)

Cahoon, Donald R., Jr.; Stocks, Brian J.; Levine, Joel S.; Cofer, Wesley R., III; Chung, Charles C.

1992-01-01

The advanced very high resolution radiometer (AVHRR), has been found useful for the location and monitoring of both smoke and fires because of the daily observations, the large geographical coverage of the imagery, the spectral characteristics of the instrument, and the spatial resolution of the instrument. This paper will discuss the application of AVHRR data to assess the geographical extent of burning. Methods have been developed to estimate the surface area of burning by analyzing the surface area effected by fire with AVHRR imagery. Characteristics of the AVHRR instrument, its orbit, field of view, and archived data sets are discussed relative to the unique surface area of each pixel. The errors associated with this surface area estimation technique are determined using AVHRR-derived area estimates of target regions with known sizes. This technique is used to evaluate the area burned during the Yellowstone fires of 1988.

Impact of pixel-based machine-learning techniques on automated frameworks for delineation of gross tumor volume regions for stereotactic body radiation therapy.

PubMed

Kawata, Yasuo; Arimura, Hidetaka; Ikushima, Koujirou; Jin, Ze; Morita, Kento; Tokunaga, Chiaki; Yabu-Uchi, Hidetake; Shioyama, Yoshiyuki; Sasaki, Tomonari; Honda, Hiroshi; Sasaki, Masayuki

2017-10-01

The aim of this study was to investigate the impact of pixel-based machine learning (ML) techniques, i.e., fuzzy-c-means clustering method (FCM), and the artificial neural network (ANN) and support vector machine (SVM), on an automated framework for delineation of gross tumor volume (GTV) regions of lung cancer for stereotactic body radiation therapy. The morphological and metabolic features for GTV regions, which were determined based on the knowledge of radiation oncologists, were fed on a pixel-by-pixel basis into the respective FCM, ANN, and SVM ML techniques. Then, the ML techniques were incorporated into the automated delineation framework of GTVs followed by an optimum contour selection (OCS) method, which we proposed in a previous study. The three-ML-based frameworks were evaluated for 16 lung cancer cases (six solid, four ground glass opacity (GGO), six part-solid GGO) with the datasets of planning computed tomography (CT) and 18 F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT images using the three-dimensional Dice similarity coefficient (DSC). DSC denotes the degree of region similarity between the GTVs contoured by radiation oncologists and those estimated using the automated framework. The FCM-based framework achieved the highest DSCs of 0.79±0.06, whereas DSCs of the ANN-based and SVM-based frameworks were 0.76±0.14 and 0.73±0.14, respectively. The FCM-based framework provided the highest segmentation accuracy and precision without a learning process (lowest calculation cost). Therefore, the FCM-based framework can be useful for delineation of tumor regions in practical treatment planning. Copyright © 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

EEG-fMRI evaluation of patients with mesial temporal lobe sclerosis.

PubMed

Avesani, Mirko; Giacopuzzi, Silvia; Bongiovanni, Luigi Giuseppe; Borelli, Paolo; Cerini, Roberto; Pozzi Mucelli, Roberto; Fiaschi, Antonio

2014-02-01

This preliminary study sought more information on blood oxygen level dependent (BOLD) activation, especially contralateral temporal/extratemporal spread, during continuous EEG-fMRI recordings in four patients with mesial temporal sclerosis (MTS). In two patients, EEG showed unilateral focal activity during the EEG-fMRI session concordant with the interictal focus previously identified with standard and video-poly EEG. In the other two patients EEG demonstrated a contralateral diffusion of the irritative focus. In the third patient (with the most drug-resistant form and also extratemporal clinical signs), there was an extratemporal diffusion over frontal regions, ipsilateral to the irritative focus. fMRI analysis confirmed a single activation in the mesial temporal region in two patients whose EEG showed unilateral focal activity, while it demonstrated a bilateral activation in the mesial temporal regions in the other two patients. In the third patient, fMRI demonstrated an activation in the supplementary motxor area. This study confirms the most significant activation with a high firing rate of the irritative focus, but also suggests the importance of using new techniques (such as EEG-fMRI to examine cerebral blood flow) to identify the controlateral limbic activation, and any other extratemporal activations, possible causes of drug resistance in MTS that may require a more precise pre-surgical evaluation with invasive techniques.

EEG-fMRI Evaluation of Patients with Mesial Temporal Lobe Sclerosis

PubMed Central

Avesani, Mirko; Giacopuzzi, Silvia; Bongiovanni, Luigi Giuseppe; Borelli, Paolo; Cerini, Roberto; Pozzi Mucelli, Roberto; Fiaschi, Antonio

2014-01-01

Summary This preliminary study sought more information on blood oxygen level dependent (BOLD) activation, especially contralateral temporal/extratemporal spread, during continuous EEG-fMRI recordings in four patients with mesial temporal sclerosis (MTS). In two patients, EEG showed unilateral focal activity during the EEG-fMRI session concordant with the interictal focus previously identified with standard and video-poly EEG. In the other two patients EEG demonstrated a contralateral diffusion of the irritative focus. In the third patient (with the most drug-resistant form and also extratemporal clinical signs), there was an extratemporal diffusion over frontal regions, ipsilateral to the irritative focus. fMRI analysis confirmed a single activation in the mesial temporal region in two patients whose EEG showed unilateral focal activity, while it demonstrated a bilateral activation in the mesial temporal regions in the other two patients. In the third patient, fMRI demonstrated an activation in the supplementary motxor area. This study confirms the most significant activation with a high firing rate of the irritative focus, but also suggests the importance of using new techniques (such as EEG-fMRI to examine cerebral blood flow) to identify the controlateral limbic activation, and any other extratemporal activations, possible causes of drug resistance in MTS that may require a more precise pre-surgical evaluation with invasive techniques. PMID:24571833

Evaluation of Methods Used for Estimating Selected Streamflow Statistics, and Flood Frequency and Magnitude, for Small Basins in North Coastal California

USGS Publications Warehouse

Mann, Michael P.; Rizzardo, Jule; Satkowski, Richard

2004-01-01

Accurate streamflow statistics are essential to water resource agencies involved in both science and decision-making. When long-term streamflow data are lacking at a site, estimation techniques are often employed to generate streamflow statistics. However, procedures for accurately estimating streamflow statistics often are lacking. When estimation procedures are developed, they often are not evaluated properly before being applied. Use of unevaluated or underevaluated flow-statistic estimation techniques can result in improper water-resources decision-making. The California State Water Resources Control Board (SWRCB) uses two key techniques, a modified rational equation and drainage basin area-ratio transfer, to estimate streamflow statistics at ungaged locations. These techniques have been implemented to varying degrees, but have not been formally evaluated. For estimating peak flows at the 2-, 5-, 10-, 25-, 50-, and 100-year recurrence intervals, the SWRCB uses the U.S. Geological Surveys (USGS) regional peak-flow equations. In this study, done cooperatively by the USGS and SWRCB, the SWRCB estimated several flow statistics at 40 USGS streamflow gaging stations in the north coast region of California. The SWRCB estimates were made without reference to USGS flow data. The USGS used the streamflow data provided by the 40 stations to generate flow statistics that could be compared with SWRCB estimates for accuracy. While some SWRCB estimates compared favorably with USGS statistics, results were subject to varying degrees of error over the region. Flow-based estimation techniques generally performed better than rain-based methods, especially for estimation of December 15 to March 31 mean daily flows. The USGS peak-flow equations also performed well, but tended to underestimate peak flows. The USGS equations performed within reported error bounds, but will require updating in the future as peak-flow data sets grow larger. Little correlation was discovered between estimation errors and geographic locations or various basin characteristics. However, for 25-percentile year mean-daily-flow estimates for December 15 to March 31, the greatest estimation errors were at east San Francisco Bay area stations with mean annual precipitation less than or equal to 30 inches, and estimated 2-year/24-hour rainfall intensity less than 3 inches.

Evaluating Three Insar Time-Series Methods to Assess Creep Motion, Case Study: Masouleh Landslide in North Iran

NASA Astrophysics Data System (ADS)

Mirzaee, S.; Motagh, M.; Akbari, B.; Wetzel, H. U.; Roessner, S.

2017-05-01

Masouleh is one of the ancient cities located in a high mountainous area in Gilan province of northern Iran. The region is threatened by a hazardous landslide, which was last activated in 1998, causing 32 dead and 45 injured. Significant temporal decorrelation caused by dense vegetation coverage within the landslide area makes the use of Synthetic Aperture Radar Interferometry (InSAR) for monitoring landslide movement very challenging. In this paper, we investigate the capability of three InSAR time-series techniques for evaluating creep motion on Masouleh landslide. The techniques are Persistent Scatterer Interferometry (PSI), Small BAseline Subset (SBAS) and SqueeSAR. The analysis is done using a dataset of 33 TerraSAR-X images in SpotLight (SL) mode covering a period of 15 months between June 2015 and September 2016. Results show the distinguished capability of SqueeSAR method in comparison to 2 other techniques for assessing landslide movement. The final number of scatterers in the landslide body detected by PSI and SBAS are about 70 and 120 respectively while this increases to about 345 in SqueeSAR. The coherence of interferograms improved by about 37% for SqueeSAR as compared to SBAS. The same rate of displacement was observed in those regions where all the methods were able to detect scatterers. Maximum rates of displacement detected by SqueeSAR technique in the northern edge, older and younger part of the landslide body are about -39, -65 and -22 mm/y, respectively.

An evaluation of the partial reflection technique and results from the winter 1971 - 1972 D region

NASA Technical Reports Server (NTRS)

Dasilva, L. C.; Bowhill, S. A.

1974-01-01

Fundamental physical and chemical processes, and measurement techniques on the D region are reviewed. Design considerations about a partial-reflection system are made, and the main characteristics of the partial-reflection system at the University of Illinois are presented. The nature of the partial reflections is discussed, particularly reflections produced by gradients in electron density and by random fluctuations in a locally homogeneous random medium. Possible reasons for disagreement between partial reflections and rocket measurements are discussed. Some suggestions are made to improve partial-reflection data reduction, including the use of only maximums of the reflections and deconvolution of the data. The results of partial-reflection measurements at Wallops Island, Virginia during the 1971-1972 winter are presented and compared to rocket measurements.

Optimum radars and filters for the passive sphere system

NASA Technical Reports Server (NTRS)

Luers, J. K.; Soltes, A.

1971-01-01

Studies have been conducted to determine the influence of the tracking radar and data reduction technique on the accuracy of the meteorological measurements made in the 30 to 100 kilometer altitude region by the ROBIN passive falling sphere. A survey of accuracy requirements was made of agencies interested in data from this region of the atmosphere. In light of these requirements, various types of radars were evaluated to determine the tracking system most applicable to the ROBIN, and methods were developed to compute the errors in wind and density that arise from noise errors in the radar supplied data. The effects of launch conditions on the measurements were also examined. Conclusions and recommendations have been made concerning the optimum tracking and data reduction techniques for the ROBIN falling sphere system.

A comparative quantitative analysis of the IDEAL (iterative decomposition of water and fat with echo asymmetry and least-squares estimation) and the CHESS (chemical shift selection suppression) techniques in 3.0 T L-spine MRI

NASA Astrophysics Data System (ADS)

Kim, Eng-Chan; Cho, Jae-Hwan; Kim, Min-Hye; Kim, Ki-Hong; Choi, Cheon-Woong; Seok, Jong-min; Na, Kil-Ju; Han, Man-Seok

2013-03-01

This study was conducted on 20 patients who had undergone pedicle screw fixation between March and December 2010 to quantitatively compare a conventional fat suppression technique, CHESS (chemical shift selection suppression), and a new technique, IDEAL (iterative decomposition of water and fat with echo asymmetry and least squares estimation). The general efficacy and usefulness of the IDEAL technique was also evaluated. Fat-suppressed transverse-relaxation-weighed images and longitudinal-relaxation-weighted images were obtained before and after contrast injection by using these two techniques with a 1.5T MR (magnetic resonance) scanner. The obtained images were analyzed for image distortion, susceptibility artifacts and homogenous fat removal in the target region. The results showed that the image distortion due to the susceptibility artifacts caused by implanted metal was lower in the images obtained using the IDEAL technique compared to those obtained using the CHESS technique. The results of a qualitative analysis also showed that compared to the CHESS technique, fewer susceptibility artifacts and more homogenous fat removal were found in the images obtained using the IDEAL technique in a comparative image evaluation of the axial plane images before and after contrast injection. In summary, compared to the CHESS technique, the IDEAL technique showed a lower occurrence of susceptibility artifacts caused by metal and lower image distortion. In addition, more homogenous fat removal was shown in the IDEAL technique.

Quantification of Regional Myocardial Oxygenation by Magnetic Resonance Imaging: Validation with Positron Emission Tomography

PubMed Central

McCommis, Kyle S.; Goldstein, Thomas A.; Abendschein, Dana R.; Herrero, Pilar; Misselwitz, Bernd; Gropler, Robert J.; Zheng, Jie

2011-01-01

Background A comprehensive evaluation of myocardial ischemia requires measures of both oxygen supply and demand. Positron emission tomography (PET) is currently the gold standard for such evaluations, but its use is limited due to its ionizing radiation, limited availability, and high cost. A cardiac magnetic resonance imaging (MRI) method was developed for assessing myocardial oxygenation. The purpose of this study was to evaluate and validate this technique compared to PET during pharmacologic stress in a canine model of coronary artery stenosis. Methods and Results Twenty-one beagles and small mongrel dogs without coronary artery stenosis (controls), or with moderate to severe acute coronary artery stenosis underwent MRI and PET imaging at rest and during dipyridamole vasodilation or dobutamine stress to induce a wide range of changes in cardiac perfusion and oxygenation. MRI first-pass perfusion imaging was performed to quantify myocardial blood flow (MBF) and volume (MBV). The MRI blood-oxygen-level-dependent (BOLD) technique was used to determine the myocardial oxygen extraction fraction (OEF) during pharmacologic hyperemia. Myocardial oxygen consumption (MVO2) was determined by Fick’s law. In the same dogs, 15O-water and 11C-acetate were used to measure MBF and MVO2, respectively, by PET. Regional assessments were performed for both MR and PET. MRI data correlated nicely with PET values for MBF (R2 = 0.79, P < 0.001), MVO2 (R2 = 0.74, P < 0.001), and OEF (R2 = 0.66, P < 0.01). Conclusions Cardiac MRI methods may provide an alternative to radionuclide imaging in settings of myocardial ischemia. Our newly developed quantitative MRI oxygenation imaging technique may be a valuable non-invasive tool to directly evaluate myocardial energetics and efficiency. PMID:19933371

Biomechanical testing simulation of a cadaver spine specimen: development and evaluation study.

PubMed

Ahn, Hyung Soo; DiAngelo, Denis J

2007-05-15

This article describes a computer model of the cadaver cervical spine specimen and virtual biomechanical testing. To develop a graphics-oriented, multibody model of a cadaver cervical spine and to build a virtual laboratory simulator for the biomechanical testing using physics-based dynamic simulation techniques. Physics-based computer simulations apply the laws of physics to solid bodies with defined material properties. This technique can be used to create a virtual simulator for the biomechanical testing of a human cadaver spine. An accurate virtual model and simulation would complement tissue-based in vitro studies by providing a consistent test bed with minimal variability and by reducing cost. The geometry of cervical vertebrae was created from computed tomography images. Joints linking adjacent vertebrae were modeled as a triple-joint complex, comprised of intervertebral disc joints in the anterior region, 2 facet joints in the posterior region, and the surrounding ligament structure. A virtual laboratory simulation of an in vitro testing protocol was performed to evaluate the model responses during flexion, extension, and lateral bending. For kinematic evaluation, the rotation of motion segment unit, coupling behaviors, and 3-dimensional helical axes of motion were analyzed. The simulation results were in correlation with the findings of in vitro tests and published data. For kinetic evaluation, the forces of the intervertebral discs and facet joints of each segment were determined and visually animated. This methodology produced a realistic visualization of in vitro experiment, and allowed for the analyses of the kinematics and kinetics of the cadaver cervical spine. With graphical illustrations and animation features, this modeling technique has provided vivid and intuitive information.

Advances in Applications of Hierarchical Bayesian Methods with Hydrological Models

NASA Astrophysics Data System (ADS)

Alexander, R. B.; Schwarz, G. E.; Boyer, E. W.

2017-12-01

Mechanistic and empirical watershed models are increasingly used to inform water resource decisions. Growing access to historical stream measurements and data from in-situ sensor technologies has increased the need for improved techniques for coupling models with hydrological measurements. Techniques that account for the intrinsic uncertainties of both models and measurements are especially needed. Hierarchical Bayesian methods provide an efficient modeling tool for quantifying model and prediction uncertainties, including those associated with measurements. Hierarchical methods can also be used to explore spatial and temporal variations in model parameters and uncertainties that are informed by hydrological measurements. We used hierarchical Bayesian methods to develop a hybrid (statistical-mechanistic) SPARROW (SPAtially Referenced Regression On Watershed attributes) model of long-term mean annual streamflow across diverse environmental and climatic drainages in 18 U.S. hydrological regions. Our application illustrates the use of a new generation of Bayesian methods that offer more advanced computational efficiencies than the prior generation. Evaluations of the effects of hierarchical (regional) variations in model coefficients and uncertainties on model accuracy indicates improved prediction accuracies (median of 10-50%) but primarily in humid eastern regions, where model uncertainties are one-third of those in arid western regions. Generally moderate regional variability is observed for most hierarchical coefficients. Accounting for measurement and structural uncertainties, using hierarchical state-space techniques, revealed the effects of spatially-heterogeneous, latent hydrological processes in the "localized" drainages between calibration sites; this improved model precision, with only minor changes in regional coefficients. Our study can inform advances in the use of hierarchical methods with hydrological models to improve their integration with stream measurements.

POF-Darts: Geometric adaptive sampling for probability of failure

DOE PAGES

Ebeida, Mohamed S.; Mitchell, Scott A.; Swiler, Laura P.; ...

2016-06-18

We introduce a novel technique, POF-Darts, to estimate the Probability Of Failure based on random disk-packing in the uncertain parameter space. POF-Darts uses hyperplane sampling to explore the unexplored part of the uncertain space. We use the function evaluation at a sample point to determine whether it belongs to failure or non-failure regions, and surround it with a protection sphere region to avoid clustering. We decompose the domain into Voronoi cells around the function evaluations as seeds and choose the radius of the protection sphere depending on the local Lipschitz continuity. As sampling proceeds, regions uncovered with spheres will shrink,more » improving the estimation accuracy. After exhausting the function evaluation budget, we build a surrogate model using the function evaluations associated with the sample points and estimate the probability of failure by exhaustive sampling of that surrogate. In comparison to other similar methods, our algorithm has the advantages of decoupling the sampling step from the surrogate construction one, the ability to reach target POF values with fewer samples, and the capability of estimating the number and locations of disconnected failure regions, not just the POF value. Furthermore, we present various examples to demonstrate the efficiency of our novel approach.« less

Developing nursing and midwifery research priorities: a Health Service Executive (HSE) North West study.

PubMed

Parlour, Randal; Slater, Paul

2014-06-01

The primary purpose of this study was to identify research priorities for nurses and midwives across the Health Service Executive (HSE) North West region. The rationale for the study was underlined during meetings of HSE North West Directors of Nursing and Midwifery in January 2011. It was agreed that a more strategic approach to generating synergy among nursing and midwifery research, evaluation, and evidence-based practice should be developed through the Nursing and Midwifery Planning and Development Unit. The research design was founded upon collaborative processes for consensus building that included the Delphi technique and nominal group technique. The study sample included a panel of experts. Data were collected between March 2011 and December 2011. Findings from this study validate the efficacy of the research methodology in enabling the effective identification of priority areas for research. These include: (a) an evaluation of the impact of postgraduate nursing and midwifery education programs focusing upon patient, professional, and organizational outcomes; (b) development and evaluation of an effective culture of nurse- and midwife-led audit across all services within a Regional Health Trust in Ireland; (c) an examination of the efficacy of approaches to clinical supervision within the context of the Irish health system; (d) an evaluation of the impact of an Advanced Nurse Practitioner role in supporting the effective management of long-term conditions within the context of Regional Health Trust primary care settings in Ireland; and (e) Supporting and developing an ethical framework for nursing and midwifery research within a Regional Health Trust in Ireland. It is anticipated that future work, outlined within this paper, will lead to important improvements in patient care and outcomes. Furthermore, this study provides evidence that a strong nursing and midwifery research agenda can be established upon genuine collaborations and partnerships across varying levels of research knowledge and skills, but with a shared purpose and shared values. © 2014 Sigma Theta Tau International.

Using remote sensing and GIS techniques to estimate discharge and recharge. fluxes for the Death Valley regional groundwater flow system, USA

USGS Publications Warehouse

D'Agnese, F. A.; Faunt, C.C.; Keith, Turner A.

1996-01-01

The recharge and discharge components of the Death Valley regional groundwater flow system were defined by remote sensing and GIS techniques that integrated disparate data types to develop a spatially complex representation of near-surface hydrological processes. Image classification methods were applied to multispectral satellite data to produce a vegetation map. This map provided a basis for subsequent evapotranspiration and infiltration estimations. The vegetation map was combined with ancillary data in a GIS to delineate different types of wetlands, phreatophytes and wet playa areas. Existing evapotranspiration-rate estimates were then used to calculate discharge volumes for these areas. A previously used empirical method of groundwater recharge estimation was modified by GIS methods to incorporate data describing soil-moisture conditions, and a recharge potential map was produced. These discharge and recharge maps were readily converted to data arrays for numerical modelling codes. Inverse parameter estimation techniques also used these data to evaluate the reliability and sensitivity of estimated values.

Evaluation of sperm quality of Erythrolamprus poecilogyrus sublineatus (Cope, 1860) (Serpentes, Dipsadidae).

PubMed

Silva, A C; Varela, A S; Cardoso, T F; Silva, E F; Loebmann, D; Corcini, C D

2017-01-01

Erythrolamprus poecilogyrus sublineatus (Cope, 1860), is a species widely distributed in the Pampa Domain, occurring in Rio Grande do Sul, Argentina and Uruguay, mainlyin the pampa region. In the coastal region of southern Brazil this is serpent is considered one of the most abundant. The purpose of the present study is to describe the techniques of sperm evaluation in vitro for E. poecilogyrus sublineatus in the coastal plain of Rio Grande do Sul, Brazil. After laparatomy the efferent vases were collected and the semen was diluted in 1ml Beltsville Thawing Solution. The characteristics of motility, membrane integrity, mitochondria, acrosome, DNA, cell viability and cellular functionality were evaluated. Fluorescent probes were used for the evaluation of sperm structure in epifluorescence microscope. With the techniques described, it was possible to identify intact and injured cells, enabling the determination of cell characteristics for the spring season (October and November). It was observed in the analyses that 80% of sperm cells were mobile and that 84.1 ± 8.0% of sperm membranes were intact. The standards found were of 48 ± 13.8% of intact acrosome, 73.6 ± 6.0 of perfect DNA and of 91.8 ± 4.0 of functional mitochondria. Thus, these values from the sperm analysis can be used as standards for the species Erythrolamprus poecilogyrus sublineatus.

Forest health monitoring: national status, trends, and analysis 2013

Treesearch

Kevin M. Potter; Barbara L. Conkling

2015-01-01

The annual national report of the Forest Health Monitoring (FHM) Program of the Forest Service, U.S. Department of Agriculture, presents forest health status and trends from a national or multi-State regional perspective using a variety of sources, introduces new techniques for analyzing forest health data, and summarizes results of recently completed Evaluation...

Forest health monitoring: National status, trends, and analysis 2012

Treesearch

Kevin M. Potter; Barbara L. Conkling

2014-01-01

The annual national report of the Forest Health Monitoring Program of the Forest Service, U.S. Department of Agriculture, presents forest health status and trends from a national or multi-State regional perspective using a variety of sources, introduces new techniques for analyzing forest health data, and summarizes results of recently completed Evaluation Monitoring...

Forest Health Monitoring: national status, trends, and analysis 2014

Treesearch

Kevin M. Potter; Barbara L. Conkling

2015-01-01

The annual national report of the Forest Health Monitoring (FHM) Program of the Forest Service, U.S. Department of Agriculture, presents forest health status and trends from a national or multi-State regional perspective using a variety of sources, introduces new techniques for analyzing forest health data, and summarizes results of recently completed Evaluation...

Forest health monitoring: national status, trends, and analysis 2011

Treesearch

Kevin M. Potter; Barbara L. Conkling

2013-01-01

The annual national report of the Forest Health Monitoring Program of the Forest Service, U.S. Department of Agriculture, presents forest health status and trends from a national or multi-State regional perspective using a variety of sources, introduces new techniques for analyzing forest health data, and summarizes results of recently completed Evaluation Monitoring...

Forest Health Monitoring: national status, trends, and analysis 2010

Treesearch

Kevin M. Potter; Barbara L. Conkling

2013-01-01

The annual national report of the Forest Health Monitoring Program of the Forest Service, U.S. Department of Agriculture, presents forest health status and trends from a national or multi-State regional perspective using a variety of sources, introduces new techniques for analyzing forest health data, and summarizes results of recently completed Evaluation Monitoring...

Effects of stimulation technique, anatomical region and time on human sweat lipid mediator profiles.

USDA-ARS?s Scientific Manuscript database

Few studies compare sampling protocol effect on sweat composition. Here we evaluate the impact of sweat stimulation mode and site of collection on lipid mediator composition. Sweat from healthy males (n = 7) was collected weekly for three weeks from the volar forearm following either pilocarpine ion...

Forest health monitoring: national status, trends, and analysis 2017

Treesearch

Kevin M. Potter; Barbara L. Conkling

2018-01-01

The annual national report of the Forest Health Monitoring (FHM) Program of the Forest Service, U.S. Department of Agriculture, presents forest health status and trends from a national or multi-State regional perspective using a variety of sources, introduces new techniques for analyzing forest health data, and summarizes results of recently completed Evaluation...

Interference detection and correction applied to incoherent-scatter radar power spectrum measurement

NASA Technical Reports Server (NTRS)

Ying, W. P.; Mathews, J. D.; Rastogi, P. K.

1986-01-01

A median filter based interference detection and correction technique is evaluated and the method applied to the Arecibo incoherent scatter radar D-region ionospheric power spectrum is discussed. The method can be extended to other kinds of data when the statistics involved in the process are still valid.

SEASONAL AND REGIONAL VARIATIONS OF PRIMARY AND SECONDARY ORGANIC AEROSOLS OVER THE CONTINENTAL UNITED STATES: OBSERVATION-BASED ESTIMATES AND MODEL EVALUATION

EPA Science Inventory

Due to the lack of an analytical technique for directly quantifying the atmospheric concentrations of primary (OC_pri) and secondary (OC_sec) organic carbon aerosols, different indirect methods have been developed to estimate their concentrations. In this stu...

Evaluating imputation and modeling in the North Central region

Treesearch

Ronald E. McRoberts

2000-01-01

The objectives of the North Central Research Station, USDA Forest Service, in developing procedures for annual forest inventories include establishing the capability of producing annual estimates of timber volume and related variables. The inventory system developed to accomplish these objectives features an annual sample of measured field plots and techniques for...

Summary appraisals of the Nation's ground-water resources; Ohio region

USGS Publications Warehouse

Bloyd, Richard M.

1974-01-01

Rapid advance of techniques in ground-water hydrology during recent years has provided methods which the hydrologist can use for evaluating planned ground-water development. Therefore, the manager can resolve the inherent problems that historically have bred caution when this part of our total water resource was considered for development.

RESOLVING FINE SCALE IN AIR TOXICS MODELING AND THE IMPORTANCE OF ITS SUB-GRID VARIABILITY FOR EXPOSURE ESTIMATES

EPA Science Inventory

This presentation explains the importance of the fine-scale features for air toxics exposure modeling. The paper presents a new approach to combine local-scale and regional model results for the National Air Toxic Assessment. The technique has been evaluated with a chemical tra...

Forest health monitoring: 2009 national technical report

Treesearch

Kevin M. Potter; Barbara L. Conkling

2012-01-01

The annual national technical report of the Forest Health Monitoring Program of the Forest Service, U.S. Department of Agriculture, presents forest health status and trends from a national or multi-State regional perspective using a variety of sources, introduces new techniques for analyzing forest health data, and summarizes results of recently completed Evaluation...

Single-phase Whole-body 64-MDCT Split-bolus Protocol for Pediatric Oncology: Diagnostic Efficacy and Dose Radiation.

PubMed

Scialpi, Michele; Schiavone, Raffaele; D'Andrea, Alfredo; Palumbo, Isabella; Magli, Michelle; Gravante, Sabrina; Falcone, Giuseppe; De Filippi, Claudio; Manganaro, Lucia; Palumbo, Barbara

2015-05-01

To evaluate the image quality and the diagnostic efficacy by single-phase whole-body 64-slice multidetector CT (MDCT) for pediatric oncology. Chest-abdomen-pelvis CT examinations with single-phase split-bolus technique were evaluated for T: detection and delineation of primary tumor (assessment of the extent of the lesion to neighboring tissues), N: regional lymph nodes and M: distant metastasis. Quality scores (5-point scale) were assessed by two radiologists on parenchymal and vascular enhancement. Accurate TNM staging in term of detection and delineation of primary tumor, regional lymph nodes and distant metastasis was obtained in all cases. On the image quality and severity artifact, the Kappa value for the interobserver agreement measure obtained from the analysis was 0.754, (p<0.001), characterizing a very good agreement between observers. Single-pass total body CT split-bolus technique reached the highest overall image quality and an accurate TNM staging in pediatric patients with cancer. Copyright© 2015 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

Inspiratory and expiratory computed tomographic volumetry for lung volume reduction surgery.

PubMed

Morimura, Yuki; Chen, Fengshi; Sonobe, Makoto; Date, Hiroshi

2013-06-01

Three-dimensional (3D) computed tomographic (CT) volumetry has been introduced into the field of thoracic surgery, and a combination of inspiratory and expiratory 3D-CT volumetry provides useful data on regional pulmonary function as well as the volume of individual lung lobes. We report herein a case of a 62-year-old man with severe emphysema who had undergone lung volume reduction surgery (LVRS) to assess this technique as a tool for the evaluation of regional lung function and volume before and after LVRS. His postoperative pulmonary function was maintained in good condition despite a gradual slight decrease 2 years after LVRS. This trend was also confirmed by a combination of inspiratory and expiratory 3D-CT volumetry. We confirm that a combination of inspiratory and expiratory 3D-CT volumetry might be effective for the preoperative assessment of LVRS in order to determine the amount of lung tissue to be resected as well as for postoperative evaluation. This novel technique could, therefore, be used more widely to assess local lung function.

Inspiratory and expiratory computed tomographic volumetry for lung volume reduction surgery

PubMed Central

Morimura, Yuki; Chen, Fengshi; Sonobe, Makoto; Date, Hiroshi

2013-01-01

Three-dimensional (3D) computed tomographic (CT) volumetry has been introduced into the field of thoracic surgery, and a combination of inspiratory and expiratory 3D-CT volumetry provides useful data on regional pulmonary function as well as the volume of individual lung lobes. We report herein a case of a 62-year-old man with severe emphysema who had undergone lung volume reduction surgery (LVRS) to assess this technique as a tool for the evaluation of regional lung function and volume before and after LVRS. His postoperative pulmonary function was maintained in good condition despite a gradual slight decrease 2 years after LVRS. This trend was also confirmed by a combination of inspiratory and expiratory 3D-CT volumetry. We confirm that a combination of inspiratory and expiratory 3D-CT volumetry might be effective for the preoperative assessment of LVRS in order to determine the amount of lung tissue to be resected as well as for postoperative evaluation. This novel technique could, therefore, be used more widely to assess local lung function. PMID:23460599

Mapping and spatiotemporal characterization of degraded forests in the Brazilian Amazon through remote sensing

NASA Astrophysics Data System (ADS)

de Souza, Carlos Moreira, Jr.

Large forested areas have recently been impoverished by degradation caused by selective logging, forest fires and fragmentation in the Amazon region, causing partial change of the original forest structure and composition. As opposed to deforestation that has been monitored with Landsat images since the late 70's, degraded forests have not been monitored in the Amazon region. In this dissertation, remote sensing techniques for identifying and mapping unambiguously degraded forests with Landsat images are proposed. The test area was the region of Sinop, located in the state of Mato Grosso, Brazil. This region was selected because a gradient of degraded forest environments exist and a robust time-series of Landsat images and forest transect data were available. First, statistical analyses were applied to identify the best set of spectral information extracted from Landsat images to detect several types of degraded forest environments. Fraction images derived from Spectral Mixture Analysis (SMA) were the best type of information for that purpose. A new spectral index based on fraction images---Normalized Difference Fraction Index (NDFI)---was proposed to enhance the detection of canopy damaged areas in degraded forests. Second, a contextual classification algorithm was implemented to separate unambiguously forest degradation caused by anthropogenic activities from natural forest disturbances. These techniques were validated using forest transects and high resolution aerial videography images and proved to be highly accurate. Next, these techniques were applied to a time-series data set of Landsat images, encompassing 20 years, to evaluate the relationship between forest degradation and deforestation. The most important finding of the forest change detection analysis was that forest degradation and deforestation are independent events in the study area, making worse the current forest impacts in the Amazon region. Finally, the techniques developed and tested in the Sinop region were successfully applied to forty Landsat images covering other regions of the Brazilian Amazon. Standard fractions and NDFI images were computed for these other regions and both physically and spatially consistent results were obtained. An automated decision tree classification using genetic algorithm was implemented successfully to classify land cover types and sub-classes of degraded forests. The remote sensing techniques proposed in this dissertation are fully automated and have the potential to be used in tropical forest monitoring programs.

Tumor or abnormality identification from magnetic resonance images using statistical region fusion based segmentation.

PubMed

Subudhi, Badri Narayan; Thangaraj, Veerakumar; Sankaralingam, Esakkirajan; Ghosh, Ashish

2016-11-01

In this article, a statistical fusion based segmentation technique is proposed to identify different abnormality in magnetic resonance images (MRI). The proposed scheme follows seed selection, region growing-merging and fusion of multiple image segments. In this process initially, an image is divided into a number of blocks and for each block we compute the phase component of the Fourier transform. The phase component of each block reflects the gray level variation among the block but contains a large correlation among them. Hence a singular value decomposition (SVD) technique is adhered to generate a singular value of each block. Then a thresholding procedure is applied on these singular values to identify edgy and smooth regions and some seed points are selected for segmentation. By considering each seed point we perform a binary segmentation of the complete MRI and hence with all seed points we get an equal number of binary images. A parcel based statistical fusion process is used to fuse all the binary images into multiple segments. Effectiveness of the proposed scheme is tested on identifying different abnormalities: prostatic carcinoma detection, tuberculous granulomas identification and intracranial neoplasm or brain tumor detection. The proposed technique is established by comparing its results against seven state-of-the-art techniques with six performance evaluation measures. Copyright © 2016 Elsevier Inc. All rights reserved.

[Preliminary evaluation on self-developed dentin porcelain color prediction system].

PubMed

Chen, L; Lu, C; Li, X L; Zhu, X M; Zhang, S; Tan, J G

2016-09-01

To apply the self-developed dentin porcelain color prediction system in the fabrication of porcelain-fused-to-metal-crown(PFMC), and to evaluate its accuracy in color-matching. Twenty upper central incisors were recruited according to preset criteria, and three PFMC were made for each tooth using three shade-matching techniques. Group A: PFMC were made according to the result of visual color selection; Group B: an spectrophotometer-based color-matching technique was used; Group C: PFMC were fabricated with dentin porcelain powder calculated by the prediction system according to the L(*), a(*), b(*) value measured by a spectrophotometer. Color differences(ΔE) (measured by spectrophotometer) of three groups of crowns were calculated in the cervical, middle, and incisal regions. The results were analyzed using one-way ANOVA. Mean color differences in body regions were: Group A: 3.53±1.80, Group B: 2.86±1.63, Group C: 3.77±1.40(P>0.05), and those in incisal regions were: Group A: 2.70 ± 1.13, Group B: 2.80 ± 0.90, Group C: 3.04 ± 1.03(P>0.05). In cervical region, Group C had greater color difference than Group B(2.78±1.14)(P<0.05). Group A(3.80±2.02) and Group B, Group A and Group C had similar color difference(P>0.05). PFMC fabricated using self-developed dentin porcelain color prediction system had similar color matching compared with conventional and instrument-based methods.

Development of the evaluation instrument use CIPP on the implementation of project assessment topic optik

NASA Astrophysics Data System (ADS)

Asfaroh, Jati Aurum; Rosana, Dadan; Supahar

2017-08-01

This research aims to develop an evaluation instrument models CIPP valid and reliable as well as determine the feasibility and practicality of an evaluation instrument models CIPP. An evaluation instrument models CIPP to evaluate the implementation of the project assessment topic optik to measure problem-solving skills of junior high school class VIII in the Yogyakarta region. This research is a model of development that uses 4-D. Subject of product trials are students in class VIII SMP N 1 Galur and SMP N 1 Sleman. Data collection techniques in this research using non-test techniques include interviews, questionnaires and observations. Validity in this research was analyzed using V'Aikens. Reliability analyzed using ICC. This research uses 7 raters are derived from two lecturers expert (expert judgment), two practitioners (science teacher) and three colleagues. The results of this research is the evaluation's instrument model of CIPP is used to evaluate the implementation of the implementation of the project assessment instruments. The validity result of evaluation instrument have V'Aikens values between 0.86 to 1, which means a valid and 0.836 reliability values into categories so well that it has been worth used as an evaluation instrument.

Brain Connectivity Networks and the Aesthetic Experience of Music.

PubMed

Reybrouck, Mark; Vuust, Peter; Brattico, Elvira

2018-06-12

Listening to music is above all a human experience, which becomes an aesthetic experience when an individual immerses himself/herself in the music, dedicating attention to perceptual-cognitive-affective interpretation and evaluation. The study of these processes where the individual perceives, understands, enjoys and evaluates a set of auditory stimuli has mainly been focused on the effect of music on specific brain structures, as measured with neurophysiology and neuroimaging techniques. The very recent application of network science algorithms to brain research allows an insight into the functional connectivity between brain regions. These studies in network neuroscience have identified distinct circuits that function during goal-directed tasks and resting states. We review recent neuroimaging findings which indicate that music listening is traceable in terms of network connectivity and activations of target regions in the brain, in particular between the auditory cortex, the reward brain system and brain regions active during mind wandering.

Automated Detection of Microaneurysms Using Scale-Adapted Blob Analysis and Semi-Supervised Learning

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

Adal, Kedir M.; Sidebe, Desire; Ali, Sharib

2014-01-07

Despite several attempts, automated detection of microaneurysm (MA) from digital fundus images still remains to be an open issue. This is due to the subtle nature of MAs against the surrounding tissues. In this paper, the microaneurysm detection problem is modeled as finding interest regions or blobs from an image and an automatic local-scale selection technique is presented. Several scale-adapted region descriptors are then introduced to characterize these blob regions. A semi-supervised based learning approach, which requires few manually annotated learning examples, is also proposed to train a classifier to detect true MAs. The developed system is built using onlymore » few manually labeled and a large number of unlabeled retinal color fundus images. The performance of the overall system is evaluated on Retinopathy Online Challenge (ROC) competition database. A competition performance measure (CPM) of 0.364 shows the competitiveness of the proposed system against state-of-the art techniques as well as the applicability of the proposed features to analyze fundus images.« less

Automated segmentation of knee and ankle regions of rats from CT images to quantify bone mineral density for monitoring treatments of rheumatoid arthritis

NASA Astrophysics Data System (ADS)

Cruz, Francisco; Sevilla, Raquel; Zhu, Joe; Vanko, Amy; Lee, Jung Hoon; Dogdas, Belma; Zhang, Weisheng

2014-03-01

Bone mineral density (BMD) obtained from a CT image is an imaging biomarker used pre-clinically for characterizing the Rheumatoid arthritis (RA) phenotype. We use this biomarker in animal studies for evaluating disease progression and for testing various compounds. In the current setting, BMD measurements are obtained manually by selecting the regions of interest from three-dimensional (3-D) CT images of rat legs, which results in a laborious and low-throughput process. Combining image processing techniques, such as intensity thresholding and skeletonization, with mathematical techniques in curve fitting and curvature calculations, we developed an algorithm for quick, consistent, and automatic detection of joints in large CT data sets. The implemented algorithm has reduced analysis time for a study with 200 CT images from 10 days to 3 days and has improved the robust detection of the obtained regions of interest compared with manual segmentation. This algorithm has been used successfully in over 40 studies.

Depth profiling of ion-induced damage in D9 alloy using X-ray diffraction

NASA Astrophysics Data System (ADS)

Dey, S.; Gayathri, N.; Mukherjee, P.

2018-04-01

The ion-induced depthwise damage profile in 35 MeV α-irradiated D9 alloy samples with doses of 5 × 1015 He2+/cm2, 6.4 × 1016 He2+/cm2 and 2 × 1017 He2+/cm2 has been assessed using X-ray diffraction technique. The microstructural characterisation has been done along the depth from beyond the stopping region (peak damage region) to the homogeneous damage region (surface) as simulated from SRIM. The parameters such as domain size and microstrain have been evaluated using two different X-ray diffraction line profile analysis techniques. The results indicate that at low dose the damage profile shows a prominent variation as a function of depth but, with increasing dose, it becomes more homogeneous along the depth. This suggests that enhanced defect diffusion and their annihilation in pre-existing and newly formed sinks play a significant role in deciding the final microstructure of the irradiated sample as a function of depth.

New optoelectronic methodology for nondestructive evaluation of MEMS at the wafer level

NASA Astrophysics Data System (ADS)

Furlong, Cosme; Ferguson, Curtis F.; Melson, Michael J.

2004-02-01

One of the approaches to fabrication of MEMS involves surface micromachining to define dies on single crystal silicon wafers, dicing of the wafers to separate the dies, and electronic packaging of the individual dies. Dicing and packaging of MEMS accounts for a large fraction of the fabrication costs, therefore, nondestructive evaluation at the wafer level, before dicing, can have significant implications on improving production yield and costs. In this paper, advances in development of optoelectronic holography (OEH) techniques for nondestructive, noninvasive, full-field of view evaluation of MEMS at the wafer level are described. With OEH techniques, quantitative measurements of shape and deformation of MEMS, as related to their performance and integrity, are obtained with sub-micrometer spatial resolution and nanometer measuring accuracy. To inspect an entire wafer with OEH methodologies, measurements of overlapping regions of interest (ROI) on a wafer are recorded and adjacent ROIs are stitched together through efficient 3D correlation analysis algorithms. Capabilities of the OEH techniques are illustrated with representative applications, including determination of optimal inspection conditions to minimize inspection time while achieving sufficient levels of accuracy and resolution.

Validation of voxel-based morphometry (VBM) based on MRI

NASA Astrophysics Data System (ADS)

Yang, Xueyu; Chen, Kewei; Guo, Xiaojuan; Yao, Li

2007-03-01

Voxel-based morphometry (VBM) is an automated and objective image analysis technique for detecting differences in regional concentration or volume of brain tissue composition based on structural magnetic resonance (MR) images. VBM has been used widely to evaluate brain morphometric differences between different populations, but there isn't an evaluation system for its validation until now. In this study, a quantitative and objective evaluation system was established in order to assess VBM performance. We recruited twenty normal volunteers (10 males and 10 females, age range 20-26 years, mean age 22.6 years). Firstly, several focal lesions (hippocampus, frontal lobe, anterior cingulate, back of hippocampus, back of anterior cingulate) were simulated in selected brain regions using real MRI data. Secondly, optimized VBM was performed to detect structural differences between groups. Thirdly, one-way ANOVA and post-hoc test were used to assess the accuracy and sensitivity of VBM analysis. The results revealed that VBM was a good detective tool in majority of brain regions, even in controversial brain region such as hippocampus in VBM study. Generally speaking, much more severity of focal lesion was, better VBM performance was. However size of focal lesion had little effects on VBM analysis.

Comparative Evaluation of Marginal and Internal Gap of Co-Cr Copings Fabricated from Conventional Wax Pattern, 3D Printed Resin Pattern and DMLS Tech: An In Vitro Study.

PubMed

Bhaskaran, Eswaran; Azhagarasan, N S; Miglani, Saket; Ilango, T; Krishna, G Phani; Gajapathi, B

2013-09-01

Accuracy of the fit of the restoration has always remained as one of the primary factors in determining success of the restoration. A well fitting restoration needs to be accurate both along its margins and internal surface. This study was conducted to comparatively evaluate the marginal gap and internal gap of cobalt-chromium (Co-Cr) copings fabricated by conventional casting procedures and with direct metal laser sintering (DMLS) technique. Among the total of 30 test samples 10 cast copings were made from inlay casting wax and 10 from 3D printed resin pattern. 10 copings were obtained from DMLS technique. All the 30 test samples were then cemented sequentially on stainless steel model using pressure indicating paste and evaluated for vertical marginal gap in 8 predetermined reference areas. All copings were then removed and partially sectioned and cemented sequentially on same master model for evaluation of internal gap at 4 predetermined reference areas. Both marginal gap and internal gap were measured in microns using video measuring system (VMS2010F). The results obtained for both marginal and internal gap were statistically analyzed and the values fall within the clinically acceptable range. The DMLS technique had an edge over the other two techniques used, as it exhibited minimal gap in the marginal region which is an area of chief concern.

Fat-suppressed three-dimensional fast spoiled gradient-recalled echo imaging: a modified FS 3D SPGR technique for assessment of patellofemoral joint chondromalacia.

PubMed

Wang, S F; Cheng, H C; Chang, C Y

1999-01-01

Fast fat-suppressed (FS) three-dimensional (3D) spoiled gradient-recalled echo (SPGR) imaging of 64 articular cartilage regions in 16 patellofemoral joints was evaluated to assess its feasibility in diagnosing patellofemoral chondromalacia. It demonstrated good correlation with arthroscopic reports and took about half of the examination time that FS 3D SPGR did. This modified, faster technique has the potential to diagnose patellofemoral chondromalacia with shorter examination time than FS 3D SPGR did.

An investigation of the marine boundary layer during cold air outbreak

NASA Technical Reports Server (NTRS)

Stage, S. A.

1986-01-01

Methods for use in the remote estimation of ocean surface sensible and latent heat fluxes were developed and evaluated. Three different techniques were developed for determining these fluxes. These methods are: (1) Obtaining surface sensible and latent heat fluxes from satellite measurements; (2)Obtaining surface sensible and latent heat fluxes from an MABL model; (3) A method using horizontal transfer coefficients. These techniques are not very sensitive to errors in the data and therefore appear to hold promise of producing useful answers. Questions remain about how closely the structure of the real atmosphere agrees with the assumptions made for each of these techniques, and, therefore about how well these techniques can perform in actual use. The value of these techniques is that they promise to provide methods for the determination of fluxes over regions where very few traditional measurement exist.

Olive mill wastewater treatment in Jordan: A Review

NASA Astrophysics Data System (ADS)

Bawab, Abeer Al; Ghannam, Noor; Abu-Mallouh, Saida; Bozeya, Ayat; Abu-Zurayk, Rund A.; Al-Ajlouni, Yazan A.; Alshawawreh, Fida'a.; Odeh, Fadwa; Abu-Dalo, Muna A.

2018-02-01

The environmental impact of olive mill wastewater (OMW) pollution is a public concern. OMW contains high levels of phenols, organic compounds, chemical oxygen demand (COD), biological oxygen demand (BOD), microorganisms, nutrients, and toxic compounds. The treatment of OMW has been investigated by many researchers in the Mediterranean region, using several treatment techniques to remove contaminants from OMW. These techniques include chemical, biological, physiochemical, and biophysical techniques. Surfactants and some adsorbents were used in chemical techniques, anaerobic and aerobic in biological techniques, while the combined treatment methods used Electroosmosis, ozonation and electrocoagulation processes as physiochemical methods, and ultrasonic irradiation combined with aerobic biodegradation as biophysical method. The effects of OMW, whether treated or untreated, have been evaluated on both plants’ growth and soil properties. The treatment methods as well as the environmental impact of OMW in Jordan were summarized in this review.

Application of earth resources technology satellite data to urban and regional planning: Test site, County of Los Angeles

NASA Technical Reports Server (NTRS)

Raje, S.; Mcknight, J.; Willoughby, G.; Economy, R. (Principal Investigator)

1974-01-01

The author has identified the following significant results. The County of Los Angeles photointerpreted ERTS film products to define problems of interest, coordinated ground truth over the complex test site including interfaces with secondary users as well as participated in on-line analyses of the GE multispectral information extraction systems. Interactive machine analyses were carried out, developing techniques and procedures as well as evaluating the outputs for community and regional planning. Extensive aircraft underflight coverage was provided that was valuable both in inputs preparation and outputs evaluation of the machine-aided analyses. One of the nonstandard ERTS images led to the discovery of a major new fault lineament on the northern slope of the Santa Monica Mountains.

A Study on Regional Frequency Analysis using Artificial Neural Network - the Sumjin River Basin

NASA Astrophysics Data System (ADS)

Jeong, C.; Ahn, J.; Ahn, H.; Heo, J. H.

2017-12-01

Regional frequency analysis means to make up for shortcomings in the at-site frequency analysis which is about a lack of sample size through the regional concept. Regional rainfall quantile depends on the identification of hydrologically homogeneous regions, hence the regional classification based on hydrological homogeneous assumption is very important. For regional clustering about rainfall, multidimensional variables and factors related geographical features and meteorological figure are considered such as mean annual precipitation, number of days with precipitation in a year and average maximum daily precipitation in a month. Self-Organizing Feature Map method which is one of the artificial neural network algorithm in the unsupervised learning techniques solves N-dimensional and nonlinear problems and be shown results simply as a data visualization technique. In this study, for the Sumjin river basin in South Korea, cluster analysis was performed based on SOM method using high-dimensional geographical features and meteorological factor as input data. then, for the results, in order to evaluate the homogeneity of regions, the L-moment based discordancy and heterogeneity measures were used. Rainfall quantiles were estimated as the index flood method which is one of regional rainfall frequency analysis. Clustering analysis using SOM method and the consequential variation in rainfall quantile were analyzed. This research was supported by a grant(2017-MPSS31-001) from Supporting Technology Development Program for Disaster Management funded by Ministry of Public Safety and Security(MPSS) of the Korean government.

[Therapeutic effect observation of post-stroke shoulder pain treated with the touching-periosteum needling technique of the meridian muscle region theory].

PubMed

Yuan, Haiguang; Liu, Zhibin; Feng, Weixing

2017-10-12

To evaluate the pain severity, the motor function of the upper limb and the quality of life in the patients of post-stroke shoulder pain treated with the touching-periosteum needling technique of the meridian muscle region theory. One hundred and six cases of post-stroke shoulder pain were randomized into an observation group and a control group, 53 cases in each one. In the observation group, the touching-periosteum needle technique and the rehabilitation training were used on the bases of the theory of meridian muscle region. The points were Jianyuci , Binaoci , Jianliaoci , Jianqianci , Quchi (LI 11), Shousanli (LI 10) and Waiguan (TE 5) on the affected side. The needles were inserted obliquely, at 45°degrees at those extra points to the tendon knots till the needle tips touching periosteum. The needles were manipulated to ensure the qi arrival and then retained for 30 min. The rehabilitation was applied, such as the anti-spasmodic posture, bridge-style movement on the bed, weight transition and balance training, joint activity maintenance training, passive and active movement of shoulder joint, the training for activities of daily living (ADL) and Bobath technique. In the control group, the routine acupuncture and the rehabilitation training were used. The acupints were Jianyu (LI 15), Binao (LI 14), Jianliao (TE 14), Jianqian (Extra), Quchi (LI 11), Shousanli (LI 10) and Waiguan (TE 5). The rehabilitation training was the same as the observation group. The treatment was given once every day, 6 treatments a week. After 20 treatments, the visual analogue scale (VAS), Fugl-Meyer (FMA) score and Barthel (MBI) score were adopted to evaluate the pain severity, the motor function of the upper limb and the ADL. The clinical therapeutic effects were evaluated in the two groups. The VAS scores were reduced after treatment as compared with those before treatment in the two groups, and FMA and MBI scores were all increased as compared with those before treatment, indicating the significant difference statistically ( P <0.05, P <0.01). After treatment, the improvements in the observation group were better than those in the control group (all P <0.05). The curative and remarkably effective rate was 69.8% (37/53) in the observation group, better than 47.2% (25/53) in the control group ( P <0.05). The touching-periosteum needling technique of the meridian muscle region theory obviously improves the pain severity, the motor function of the upper limb and the quality of life in patients of post-stroke shoulder pain. The therapeutic effects are better than the routine acupuncture.

Adaptive policy responses to water shortage mitigation in the arid regions--a systematic approach based on eDPSIR, DEMATEL, and MCDA.

PubMed

Azarnivand, Ali; Chitsaz, Nastaran

2015-02-01

Most of the arid and semi-arid regions are located in the developing countries, while the availability of water in adequate quantity and quality is an essential condition to approach sustainable development. In this research, "enhanced Driving force-Pressure-State-Impact-Response (eDPSIR)" sustainability framework was applied to deal with water shortage in Yazd, an arid province of Iran. Then, the Decision Making Trial and Evaluation Laboratory (DEMATEL) technique was integrated into the driven components of eDPSIR, to quantify the inter-linkages among fundamental anthropogenic indicators (i.e. causes and effects). The paper's structure included: (1) identifying the indicators of DPSIR along with structuring eDPSIR causal networks, (2) using the DEMATEL technique to evaluate the inter-relationships among the causes and effects along with determining the key indicators, (3) decomposing the problem into a system of hierarchies, (4) employing the analytic hierarchy process (AHP) technique to evaluate the weight of each criterion, and (5) applying complex proportional assessment with Grey interval numbers (COPRAS-G) method to obtain the most conclusive adaptive policy response. The systematic quantitative analysis of causes and effects revealed that the root sources of water shortage in the study area were the weak enforcement of law and regulations, decline of available freshwater resources for development, and desertification consequences. According to the results, mitigating the water shortage in Yazd could be feasible by implementation of such key adaptive policy-responses as providing effective law enforcement, updating the standards and regulations, providing social learning, and boosting stakeholders' collaboration.

Simulation in teaching regional anesthesia: current perspectives.

PubMed

Udani, Ankeet D; Kim, T Edward; Howard, Steven K; Mariano, Edward R

2015-01-01

The emerging subspecialty of regional anesthesiology and acute pain medicine represents an opportunity to evaluate critically the current methods of teaching regional anesthesia techniques and the practice of acute pain medicine. To date, there have been a wide variety of simulation applications in this field, and efficacy has largely been assumed. However, a thorough review of the literature reveals that effective teaching strategies, including simulation, in regional anesthesiology and acute pain medicine are not established completely yet. Future research should be directed toward comparative-effectiveness of simulation versus other accepted teaching methods, exploring the combination of procedural training with realistic clinical scenarios, and the application of simulation-based teaching curricula to a wider range of learner, from the student to the practicing physician.

Simulation in teaching regional anesthesia: current perspectives

PubMed Central

Udani, Ankeet D; Kim, T Edward; Howard, Steven K; Mariano, Edward R

2015-01-01

The emerging subspecialty of regional anesthesiology and acute pain medicine represents an opportunity to evaluate critically the current methods of teaching regional anesthesia techniques and the practice of acute pain medicine. To date, there have been a wide variety of simulation applications in this field, and efficacy has largely been assumed. However, a thorough review of the literature reveals that effective teaching strategies, including simulation, in regional anesthesiology and acute pain medicine are not established completely yet. Future research should be directed toward comparative-effectiveness of simulation versus other accepted teaching methods, exploring the combination of procedural training with realistic clinical scenarios, and the application of simulation-based teaching curricula to a wider range of learner, from the student to the practicing physician. PMID:26316812

Evaluation of macrozone dimensions by ultrasound and EBSD techniques

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

Moreau, Andre, E-mail: Andre.Moreau@cnrc-nrc.gc.ca; Toubal, Lotfi; Ecole de technologie superieure, 1100, rue Notre-Dame Ouest, Montreal, QC, Canada H3C 1K3

2013-01-15

Titanium alloys are known to have texture heterogeneities, i.e. regions much larger than the grain dimensions, where the local orientation distribution of the grains differs from one region to the next. The electron backscattering diffraction (EBSD) technique is the method of choice to characterize these macro regions, which are called macrozones. Qualitatively, the images obtained by EBSD show that these macrozones may be larger or smaller, elongated or equiaxed. However, often no well-defined boundaries are observed between the macrozones and it is very hard to obtain objective and quantitative estimates of the macrozone dimensions from these data. In the presentmore » work, we present a novel, non-destructive ultrasonic technique that provides objective and quantitative characteristic dimensions of the macrozones. The obtained dimensions are based on the spatial autocorrelation function of fluctuations in the sound velocity. Thus, a pragmatic definition of macrozone dimensions naturally arises from the ultrasonic measurement. This paper has three objectives: 1) to disclose the novel, non-destructive ultrasonic technique to measure macrozone dimensions, 2) to propose a quantitative and objective definition of macrozone dimensions adapted to and arising from the ultrasonic measurement, and which is also applicable to the orientation data obtained by EBSD, and 3) to compare the macrozone dimensions obtained using the two techniques on two samples of the near-alpha titanium alloy IMI834. In addition, it was observed that macrozones may present a semi-periodical arrangement. - Highlights: Black-Right-Pointing-Pointer Discloses a novel, ultrasonic NDT technique to measure macrozone dimensions Black-Right-Pointing-Pointer Proposes a quantitative and objective definition of macrozone dimensions Black-Right-Pointing-Pointer Compares macrozone dimensions obtained using EBSD and ultrasonics on 2 Ti samples Black-Right-Pointing-Pointer Observes that macrozones may have a semi-periodical arrangement.« less

Comparative study of shear wave-based elastography techniques in optical coherence tomography

NASA Astrophysics Data System (ADS)

Zvietcovich, Fernando; Rolland, Jannick P.; Yao, Jianing; Meemon, Panomsak; Parker, Kevin J.

2017-03-01

We compare five optical coherence elastography techniques able to estimate the shear speed of waves generated by one and two sources of excitation. The first two techniques make use of one piezoelectric actuator in order to produce a continuous shear wave propagation or a tone-burst propagation (TBP) of 400 Hz over a gelatin tissue-mimicking phantom. The remaining techniques utilize a second actuator located on the opposite side of the region of interest in order to create three types of interference patterns: crawling waves, swept crawling waves, and standing waves, depending on the selection of the frequency difference between the two actuators. We evaluated accuracy, contrast to noise ratio, resolution, and acquisition time for each technique during experiments. Numerical simulations were also performed in order to support the experimental findings. Results suggest that in the presence of strong internal reflections, single source methods are more accurate and less variable when compared to the two-actuator methods. In particular, TBP reports the best performance with an accuracy error <4.1%. Finally, the TBP was tested in a fresh chicken tibialis anterior muscle with a localized thermally ablated lesion in order to evaluate its performance in biological tissue.

Heidelberg retina tomograph measurements of the optic disc and parapapillary retina for detecting glaucoma analyzed by machine learning classifiers.

PubMed

Zangwill, Linda M; Chan, Kwokleung; Bowd, Christopher; Hao, Jicuang; Lee, Te-Won; Weinreb, Robert N; Sejnowski, Terrence J; Goldbaum, Michael H

2004-09-01

To determine whether topographical measurements of the parapapillary region analyzed by machine learning classifiers can detect early to moderate glaucoma better than similarly processed measurements obtained within the disc margin and to improve methods for optimization of machine learning classifier feature selection. One eye of each of 95 patients with early to moderate glaucomatous visual field damage and of each of 135 normal subjects older than 40 years participating in the longitudinal Diagnostic Innovations in Glaucoma Study (DIGS) were included. Heidelberg Retina Tomograph (HRT; Heidelberg Engineering, Dossenheim, Germany) mean height contour was measured in 36 equal sectors, both along the disc margin and in the parapapillary region (at a mean contour line radius of 1.7 mm). Each sector was evaluated individually and in combination with other sectors. Gaussian support vector machine (SVM) learning classifiers were used to interpret HRT sector measurements along the disc margin and in the parapapillary region, to differentiate between eyes with normal and glaucomatous visual fields and to compare the results with global and regional HRT parameter measurements. The area under the receiver operating characteristic (ROC) curve was used to measure diagnostic performance of the HRT parameters and to evaluate the cross-validation strategies and forward selection and backward elimination optimization techniques that were used to generate the reduced feature sets. The area under the ROC curve for mean height contour of the 36 sectors along the disc margin was larger than that for the mean height contour in the parapapillary region (0.97 and 0.85, respectively). Of the 36 individual sectors along the disc margin, those in the inferior region between 240 degrees and 300 degrees, had the largest area under the ROC curve (0.85-0.91). With SVM Gaussian techniques, the regional parameters showed the best ability to discriminate between normal eyes and eyes with glaucomatous visual field damage, followed by the global parameters, mean height contour measures along the disc margin, and mean height contour measures in the parapapillary region. The area under the ROC curve was 0.98, 0.94, 0.93, and 0.85, respectively. Cross-validation and optimization techniques demonstrated that good discrimination (99% of peak area under the ROC curve) can be obtained with a reduced number of HRT parameters. Mean height contour measurements along the disc margin discriminated between normal and glaucomatous eyes better than measurements obtained in the parapapillary region. Copyright Association for Research in Vision and Ophthalmology

Heidelberg Retina Tomograph Measurements of the Optic Disc and Parapapillary Retina for Detecting Glaucoma Analyzed by Machine Learning Classifiers

PubMed Central

Zangwill, Linda M.; Chan, Kwokleung; Bowd, Christopher; Hao, Jicuang; Lee, Te-Won; Weinreb, Robert N.; Sejnowski, Terrence J.; Goldbaum, Michael H.

2010-01-01

Purpose To determine whether topographical measurements of the parapapillary region analyzed by machine learning classifiers can detect early to moderate glaucoma better than similarly processed measurements obtained within the disc margin and to improve methods for optimization of machine learning classifier feature selection. Methods One eye of each of 95 patients with early to moderate glaucomatous visual field damage and of each of 135 normal subjects older than 40 years participating in the longitudinal Diagnostic Innovations in Glaucoma Study (DIGS) were included. Heidelberg Retina Tomograph (HRT; Heidelberg Engineering, Dossenheim, Germany) mean height contour was measured in 36 equal sectors, both along the disc margin and in the parapapillary region (at a mean contour line radius of 1.7 mm). Each sector was evaluated individually and in combination with other sectors. Gaussian support vector machine (SVM) learning classifiers were used to interpret HRT sector measurements along the disc margin and in the parapapillary region, to differentiate between eyes with normal and glaucomatous visual fields and to compare the results with global and regional HRT parameter measurements. The area under the receiver operating characteristic (ROC) curve was used to measure diagnostic performance of the HRT parameters and to evaluate the cross-validation strategies and forward selection and backward elimination optimization techniques that were used to generate the reduced feature sets. Results The area under the ROC curve for mean height contour of the 36 sectors along the disc margin was larger than that for the mean height contour in the parapapillary region (0.97 and 0.85, respectively). Of the 36 individual sectors along the disc margin, those in the inferior region between 240° and 300°, had the largest area under the ROC curve (0.85–0.91). With SVM Gaussian techniques, the regional parameters showed the best ability to discriminate between normal eyes and eyes with glaucomatous visual field damage, followed by the global parameters, mean height contour measures along the disc margin, and mean height contour measures in the parapapillary region. The area under the ROC curve was 0.98, 0.94, 0.93, and 0.85, respectively. Cross-validation and optimization techniques demonstrated that good discrimination (99% of peak area under the ROC curve) can be obtained with a reduced number of HRT parameters. Conclusions Mean height contour measurements along the disc margin discriminated between normal and glaucomatous eyes better than measurements obtained in the parapapillary region. PMID:15326133

A study on FlexMaster : a Ni-Ti rotary engine driven system for root canal preparation.

PubMed

Alam, M S; Bashar, A K; Begumr, J A; Kinoshita, J I

2006-07-01

In the present study, the effectiveness of recently introduced rotary Nickel Titanium FlexMaster engine driven system was evaluated for cleaning and shaping of root canals in extracted human teeth and compared with that done by the Nickel Titanium Flexofile hand instruments. A total of 40 root canals from 36 extracted mandibular and maxillary teeth with curvature ranging between 20 and 30 degree were divided into two groups, consisting 20 canals in each. FlexMaster instrumentation was done in 20 canals, using crown-down technique and manual filing with Flexofile was done in other 20 canals, using conventional and step-back techniques. 5.25% sodium hypochlorite (NaOCl) solution and 17% ethelene di-amine tetra-acetic acid (EDTA) were used alternatively for irrigation after canal preparation by each instrument size. Time needed for canal preparation of individual canal was recorded. A procedural error such as instrument breakage was also noted. After preparation, all the roots were cut longitudinally by using diamond burs in turbine handpiece and examined under scanning electron microscope. Apical region was quantified for debris and smear layer based on a 5-score numerical evaluation scale. The data established for scoring the debris and smear layer and preparation time of individual canal were analyzed statistically using the Mann-Whitney U test. Completely cleaned root canals were not found with any of the two instruments and none of the instruments maintained the original canal uniformity and regular dentine surface. Because significantly less debris was found in the apical region using the manual filing technique (p< 0.05). Thus the flexmaster system was found to produce less cleaner root canal walls than manual technique. Only one FlexMaster finishing file sized 30 was separated in the apical region during preparation of 30 degree curved canal. The time taken by FlexMaster was significantly better (p< 0.01) than that of hand instruments.

A study of reconstruction accuracy for a cardiac SPECT system with multi-segmental collimation

NASA Astrophysics Data System (ADS)

Yu, D.-C.; Chang, W.; Pan, T.-S.

1997-06-01

To improve the geometric efficiency of cardiac SPECT imaging, the authors previously proposed to use a multi-segmental collimation with a cylindrical geometry. The proposed collimator consists of multiple parallel-hole collimators with most of the segments directed toward a small central region, where the patient's heart should be positioned. This technique provides a significantly increased detection efficiency for the central region, but at the expense of reduced efficiency for the surrounding region. The authors have used computer simulations to evaluate the implication of this technique on the accuracy of the reconstructed cardiac images. Two imaging situations were simulated: 1) the heart well placed inside the central region, and 2) the heart shifted and partially outside the central region. A neighboring high-uptake liver was simulated for both imaging situations. The images were reconstructed and corrected for attenuation with ML-EM and OS-FM methods using a complete attenuation map. The results indicate that errors caused by projection truncation are not significant and are not strongly dependent on the activity of the liver when the heart is well positioned within the central region. When the heart is partially outside the central region, hybrid emission data (a combination of high-count projections from the central region and low-count projections from the background region) can be used to restore the activity of the truncated section of the myocardium. However, the variance of the image in the section of the myocardium outside the central region is increased by 2-3 times when 10% of the collimator segments are used to image the background region.

Augmenting Sand Simulation Environments through Subdivision and Particle Refinement

NASA Astrophysics Data System (ADS)

Clothier, M.; Bailey, M.

2012-12-01

Recent advances in computer graphics and parallel processing hardware have provided disciplines with new methods to evaluate and visualize data. These advances have proven useful for earth and planetary scientists as many researchers are using this hardware to process large amounts of data for analysis. As such, this has provided opportunities for collaboration between computer graphics and the earth sciences. Through collaboration with the Oregon Space Grant and IGERT Ecosystem Informatics programs, we are investigating techniques for simulating the behavior of sand. We are also collaborating with the Jet Propulsion Laboratory's (JPL) DARTS Lab to exchange ideas and gain feedback on our research. The DARTS Lab specializes in simulation of planetary vehicles, such as the Mars rovers. Their simulations utilize a virtual "sand box" to test how a planetary vehicle responds to different environments. Our research builds upon this idea to create a sand simulation framework so that planetary environments, such as the harsh, sandy regions on Mars, are more fully realized. More specifically, we are focusing our research on the interaction between a planetary vehicle, such as a rover, and the sand beneath it, providing further insight into its performance. Unfortunately, this can be a computationally complex problem, especially if trying to represent the enormous quantities of sand particles interacting with each other. However, through the use of high-performance computing, we have developed a technique to subdivide areas of actively participating sand regions across a large landscape. Similar to a Level of Detail (LOD) technique, we only subdivide regions of a landscape where sand particles are actively participating with another object. While the sand is within this subdivision window and moves closer to the surface of the interacting object, the sand region subdivides into smaller regions until individual sand particles are left at the surface. As an example, let's say there is a planetary rover interacting with our sand simulation environment. Sand that is actively interacting with a rover wheel will be represented as individual particles whereas sand that is further under the surface will be represented by larger regions of sand. The result of this technique allows for many particles to be represented without the computational complexity. In developing this method, we have further generalized these subdivision regions into any volumetric area suitable for use in the simulation. This is a further improvement of our method as it allows for more compact subdivision sand regions. This helps to fine tune the simulation so that more emphasis can be placed on regions of actively participating sand. We feel that through the generalization of our technique, our research can provide other opportunities within the earth and planetary sciences. Through collaboration with our academic colleagues, we continue to refine our technique and look for other opportunities to utilize our research.

The application of remote sensing techniques to selected inter and intra urban data acquisition problems

NASA Technical Reports Server (NTRS)

Horton, F. E.

1970-01-01

The utility of remote sensing techniques to urban data acquisition problems in several distinct areas was identified. This endeavor included a comparison of remote sensing systems for urban data collection, the extraction of housing quality data from aerial photography, utilization of photographic sensors in urban transportation studies, urban change detection, space photography utilization, and an application of remote sensing techniques to the acquisition of data concerning intra-urban commercial centers. The systematic evaluation of variable extraction for urban modeling and planning at several different scales, and the model derivation for identifying and predicting economic growth and change within a regional system of cities are also studied.

High-Resolution DCE-MRI of the Pituitary Gland Using Radial k-Space Acquisition with Compressed Sensing Reconstruction.

PubMed

Rossi Espagnet, M C; Bangiyev, L; Haber, M; Block, K T; Babb, J; Ruggiero, V; Boada, F; Gonen, O; Fatterpekar, G M

2015-08-01

The pituitary gland is located outside of the blood-brain barrier. Dynamic T1 weighted contrast enhanced sequence is considered to be the gold standard to evaluate this region. However, it does not allow assessment of intrinsic permeability properties of the gland. Our aim was to demonstrate the utility of radial volumetric interpolated brain examination with the golden-angle radial sparse parallel technique to evaluate permeability characteristics of the individual components (anterior and posterior gland and the median eminence) of the pituitary gland and areas of differential enhancement and to optimize the study acquisition time. A retrospective study was performed in 52 patients (group 1, 25 patients with normal pituitary glands; and group 2, 27 patients with a known diagnosis of microadenoma). Radial volumetric interpolated brain examination sequences with golden-angle radial sparse parallel technique were evaluated with an ROI-based method to obtain signal-time curves and permeability measures of individual normal structures within the pituitary gland and areas of differential enhancement. Statistical analyses were performed to assess differences in the permeability parameters of these individual regions and optimize the study acquisition time. Signal-time curves from the posterior pituitary gland and median eminence demonstrated a faster wash-in and time of maximum enhancement with a lower peak of enhancement compared with the anterior pituitary gland (P < .005). Time-optimization analysis demonstrated that 120 seconds is ideal for dynamic pituitary gland evaluation. In the absence of a clinical history, differences in the signal-time curves allow easy distinction between a simple cyst and a microadenoma. This retrospective study confirms the ability of the golden-angle radial sparse parallel technique to evaluate the permeability characteristics of the pituitary gland and establishes 120 seconds as the ideal acquisition time for dynamic pituitary gland imaging. © 2015 by American Journal of Neuroradiology.

High-Resolution DCE-MRI of the Pituitary Gland Using Radial k-Space Acquisition with Compressed Sensing Reconstruction

PubMed Central

Rossi Espagnet, M.C.; Bangiyev, L.; Haber, M.; Block, K.T.; Babb, J.; Ruggiero, V.; Boada, F.; Gonen, O.; Fatterpekar, G.M.

2015-01-01

BACKGROUNDANDPURPOSE The pituitary gland is located outside of the blood-brain barrier. Dynamic T1 weighted contrast enhanced sequence is considered to be the gold standard to evaluate this region. However, it does not allow assessment of intrinsic permeability properties of the gland. Our aim was to demonstrate the utility of radial volumetric interpolated brain examination with the golden-angle radial sparse parallel technique to evaluate permeability characteristics of the individual components (anterior and posterior gland and the median eminence) of the pituitary gland and areas of differential enhancement and to optimize the study acquisition time. MATERIALS AND METHODS A retrospective study was performed in 52 patients (group 1, 25 patients with normal pituitary glands; and group 2, 27 patients with a known diagnosis of microadenoma). Radial volumetric interpolated brain examination sequences with golden-angle radial sparse parallel technique were evaluated with an ROI-based method to obtain signal-time curves and permeability measures of individual normal structures within the pituitary gland and areas of differential enhancement. Statistical analyses were performed to assess differences in the permeability parameters of these individual regions and optimize the study acquisition time. RESULTS Signal-time curves from the posterior pituitary gland and median eminence demonstrated a faster wash-in and time of maximum enhancement with a lower peak of enhancement compared with the anterior pituitary gland (P < .005). Time-optimization analysis demonstrated that 120 seconds is ideal for dynamic pituitary gland evaluation. In the absence of a clinical history, differences in the signal-time curves allow easy distinction between a simple cyst and a microadenoma. CONCLUSIONS This retrospective study confirms the ability of the golden-angle radial sparse parallel technique to evaluate the permeability characteristics of the pituitary gland and establishes 120 seconds as the ideal acquisition time for dynamic pituitary gland imaging. PMID:25953760

Effectiveness of a specific manual approach to the suboccipital region in patients with chronic mechanical neck pain and rotation deficit in the upper cervical spine: study protocol for a randomized controlled trial.

PubMed

González Rueda, Vanessa; López de Celis, Carlos; Barra López, Martín Eusebio; Carrasco Uribarren, Andoni; Castillo Tomás, Sara; Hidalgo García, Cesar

2017-09-05

Mechanical neck pain is a highly prevalent problem in primary healthcare settings. Many of these patients have restricted mobility of the cervical spine. Several manual techniques have been recommended for restoring cervical mobility, but their effectiveness in these patients is unknown. The aim of the present study is to compare the effectiveness of two types of specific techniques of the upper neck region: the pressure maintained suboccipital inhibition technique (PMSIT) and the translatory dorsal glide mobilization (TDGM) C0-C1 technique, as adjuncts to a protocolized physiotherapy treatment of the neck region in subjects with chronic mechanical neck pain and rotation deficit in the upper cervical spine. A randomized, prospective, double-blind (patient and evaluator) clinical trial. The participants (n = 78) will be randomly distributed into three groups. The Control Group will receive a protocolized treatment for 3 weeks, the Mobilization Group will receive the same protocolized treatment and 6 sessions (2 per week) of the TDGM C0-C1 technique, and the Pressure Group will receive the same protocolized treatment and 6 sessions (2 per week) of the PMSIT technique. The intensity of pain (VAS), neck disability (NDI), the cervical range of motion (CROM), headache intensity (HIT-6) and the rating of clinical change (GROC scale) will be measured. The measurements will be performed at baseline, post-treatment and 3 months after the end of treatment, by the same physiotherapist blinded to the group assigned to the subject. We believe that an approach including manual treatment to upper cervical dysfunction will be more effective in these patients. Furthermore, the PMSIT technique acts mostly on the musculature, while the TDGM technique acts on the joint. We expect to clarify which component is more effective in improving the upper cervical mobility. ClinicalTrials.gov NCT02832232 . Registered on July 13th, 2016.

Damage Evaluation for Ti Alloys in Creep based on Incompatibility Field Measurement via EBSD Technique and Micro-Pillar Experiments Toward Identification of Roles of Dislocation Substructures on Fatigue Crack Initiation

DTIC Science & Technology

2011-02-07

Reproduction of a slip band with a PSB -ladder-like internal structure is attempted assuming initial conditions with and without corresponding strain...into heat at the PSB region, the present study extensively examined possible transition mechanisms toward the growth of grooves thereabout and that...arrangements even with the same dislocation density. (2)A slip band-like region having a substructure mimicking PSB ladder is demonstrated to be

Forest health monitoring: 2008 national technical report

Treesearch

Kevin M. Potter; Barbara L. Conkling

2012-01-01

The Forest Health Monitoring (FHM) Program’s annual national technical report has three objectives: (1) to present forest health status and trends from a national or a multi-State regional perspective using a variety of sources, (2) to introduce new techniques for analyzing forest health data, and (3) to report results of recently completed evaluation monitoring...

Artificial Regeneration of Blue and Coast Live Oaks in the Central Coast

Treesearch

Tim R. Plumb; Bennie Hannah

1991-01-01

The primary goal of this study was to find economical and effective planting techniques that will ensure the establishment and early survival of coast live oak (Quercus agrifolia Née) and blue oak (Q. douglasii H. and A.) in the Central Coast region of California. Eight treatments were evaluated ranging from unprotected seed spots...

Oak Woodland Artificial Regeneration - Correlating Soil Moisture to Seedling Survival

Treesearch

Tim R. Plumb; Karl Kraus

1991-01-01

The primary goal of this study was to find economical and effective planting techniques that will ensure the establishment and early survival of coast live oak (Quercus agrifolia Née) and blue oak (Q. douglasii H. and A.) in the Central Coast region of California. Eight treatments were evaluated ranging from unprotected seed spots...

Computational Tools for Probing Interactions in Multiple Linear Regression, Multilevel Modeling, and Latent Curve Analysis

ERIC Educational Resources Information Center

Preacher, Kristopher J.; Curran, Patrick J.; Bauer, Daniel J.

2006-01-01

Simple slopes, regions of significance, and confidence bands are commonly used to evaluate interactions in multiple linear regression (MLR) models, and the use of these techniques has recently been extended to multilevel or hierarchical linear modeling (HLM) and latent curve analysis (LCA). However, conducting these tests and plotting the…

Method of self-consistent evaluation of absolute emission probabilities of particles and gamma rays

NASA Astrophysics Data System (ADS)

Badikov, Sergei; Chechev, Valery

2017-09-01

In assumption of well installed decay scheme the method provides a) exact balance relationships, b) lower (compared to the traditional techniques) uncertainties of recommended absolute emission probabilities of particles and gamma rays, c) evaluation of correlations between the recommended emission probabilities (for the same and different decay modes). Application of the method for the decay data evaluation for even curium isotopes led to paradoxical results. The multidimensional confidence regions for the probabilities of the most intensive alpha transitions constructed on the basis of present and the ENDF/B-VII.1, JEFF-3.1, DDEP evaluations are inconsistent whereas the confidence intervals for the evaluated probabilities of single transitions agree with each other.

[Evaluation of eco-environmental quality based on artificial neural network and remote sensing techniques].

PubMed

Li, Hongyi; Shi, Zhou; Sha, Jinming; Cheng, Jieliang

2006-08-01

In the present study, vegetation, soil brightness, and moisture indices were extracted from Landsat ETM remote sensing image, heat indices were extracted from MODIS land surface temperature product, and climate index and other auxiliary geographical information were selected as the input of neural network. The remote sensing eco-environmental background value of standard interest region evaluated in situ was selected as the output of neural network, and the back propagation (BP) neural network prediction model containing three layers was designed. The network was trained, and the remote sensing eco-environmental background value of Fuzhou in China was predicted by using software MATLAB. The class mapping of remote sensing eco-environmental background values based on evaluation standard showed that the total classification accuracy was 87. 8%. The method with a scheme of prediction first and classification then could provide acceptable results in accord with the regional eco-environment types.

Fission gas bubble identification using MATLAB's image processing toolbox

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

Collette, R.; King, J.; Keiser, Jr., D.

Automated image processing routines have the potential to aid in the fuel performance evaluation process by eliminating bias in human judgment that may vary from person-to-person or sample-to-sample. In addition, this study presents several MATLAB based image analysis routines designed for fission gas void identification in post-irradiation examination of uranium molybdenum (U–Mo) monolithic-type plate fuels. Frequency domain filtration, enlisted as a pre-processing technique, can eliminate artifacts from the image without compromising the critical features of interest. This process is coupled with a bilateral filter, an edge-preserving noise removal technique aimed at preparing the image for optimal segmentation. Adaptive thresholding provedmore » to be the most consistent gray-level feature segmentation technique for U–Mo fuel microstructures. The Sauvola adaptive threshold technique segments the image based on histogram weighting factors in stable contrast regions and local statistics in variable contrast regions. Once all processing is complete, the algorithm outputs the total fission gas void count, the mean void size, and the average porosity. The final results demonstrate an ability to extract fission gas void morphological data faster, more consistently, and at least as accurately as manual segmentation methods.« less

Fission gas bubble identification using MATLAB's image processing toolbox

DOE PAGES

Collette, R.; King, J.; Keiser, Jr., D.; ...

2016-06-08

Automated image processing routines have the potential to aid in the fuel performance evaluation process by eliminating bias in human judgment that may vary from person-to-person or sample-to-sample. In addition, this study presents several MATLAB based image analysis routines designed for fission gas void identification in post-irradiation examination of uranium molybdenum (U–Mo) monolithic-type plate fuels. Frequency domain filtration, enlisted as a pre-processing technique, can eliminate artifacts from the image without compromising the critical features of interest. This process is coupled with a bilateral filter, an edge-preserving noise removal technique aimed at preparing the image for optimal segmentation. Adaptive thresholding provedmore » to be the most consistent gray-level feature segmentation technique for U–Mo fuel microstructures. The Sauvola adaptive threshold technique segments the image based on histogram weighting factors in stable contrast regions and local statistics in variable contrast regions. Once all processing is complete, the algorithm outputs the total fission gas void count, the mean void size, and the average porosity. The final results demonstrate an ability to extract fission gas void morphological data faster, more consistently, and at least as accurately as manual segmentation methods.« less

Fit of interim crowns fabricated using photopolymer-jetting 3D printing.

PubMed

Mai, Hang-Nga; Lee, Kyu-Bok; Lee, Du-Hyeong

2017-08-01

The fit of interim crowns fabricated using 3-dimensional (3D) printing is unknown. The purpose of this in vitro study was to evaluate the fit of interim crowns fabricated using photopolymer-jetting 3D printing and to compare it with that of milling and compression molding methods. Twelve study models were fabricated by making an impression of a metal master model of the mandibular first molar. On each study model, interim crowns (N=36) were fabricated using compression molding (molding group, n=12), milling (milling group, n=12), and 3D polymer-jetting methods. The crowns were prepared as follows: molding group, overimpression technique; milling group, a 5-axis dental milling machine; and polymer-jetting group using a 3D printer. The fit of interim crowns was evaluated in the proximal, marginal, internal axial, and internal occlusal regions by using the image-superimposition and silicone-replica techniques. The Mann-Whitney U test and Kruskal-Wallis tests were used to compare the results among groups (α=.05). Compared with the molding group, the milling and polymer-jetting groups showed more accurate results in the proximal and marginal regions (P<.001). In the axial regions, even though the mean discrepancy was smallest in the molding group, the data showed large deviations. In the occlusal region, the polymer-jetting group was the most accurate, and compared with the other groups, the milling group showed larger internal discrepancies (P<.001). Polymer-jet 3D printing significantly enhanced the fit of interim crowns, particularly in the occlusal region. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Three-dimensional venous visualization with phase-lag computed tomography angiography for reconstructive microsurgery.

PubMed

Sakakibara, Shunsuke; Onishi, Hiroyuki; Hashikawa, Kazunobu; Akashi, Masaya; Sakakibara, Akiko; Nomura, Tadashi; Terashi, Hiroto

2015-05-01

Most free flap reconstruction complications involve vascular compromise. Evaluation of vascular anatomy provides considerable information that can potentially minimize these complications. Previous reports have shown that contrast-enhanced computed tomography is effective for understanding three-dimensional arterial anatomy. However, most vascular complications result from venous thromboses, making imaging of venous anatomy highly desirable. The phase-lag computed tomography angiography (pl-CTA) technique involves 64-channel (virtually, 128-channel) multidetector CT and is used to acquire arterial images using conventional CTA. Venous images are three-dimensionally reconstructed using a subtraction technique involving combined venous phase and arterial phase images, using a computer workstation. This technique was used to examine 48 patients (12 lower leg reconstructions, 34 head and neck reconstructions, and 2 upper extremity reconstructions) without complications. The pl-CTA technique can be used for three-dimensional visualization of peripheral veins measuring approximately 1 mm in diameter. The pl-CTA information was especially helpful for secondary free flap reconstructions in the head and neck region after malignant tumor recurrence. In such cases, radical dissection of the neck was performed as part of the first operation, and many vessels, including veins, were resected and used in the first free-tissue transfer. The pl-CTA images also allowed visualization of varicose changes in the lower leg region and helped us avoid selecting those vessels for anastomosis. Thus, the pl-CTA-derived venous anatomy information was useful for exact evaluations during the planning of free-tissue transfers. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Quantification of human body fat tissue percentage by MRI.

PubMed

Müller, Hans-Peter; Raudies, Florian; Unrath, Alexander; Neumann, Heiko; Ludolph, Albert C; Kassubek, Jan

2011-01-01

The MRI-based evaluation of the quantity and regional distribution of adipose tissue is one objective measure in the investigation of obesity. The aim of this article was to report a comprehensive and automatic analytical method for the determination of the volumes of subcutaneous fat tissue (SFT) and visceral fat tissue (VFT) in either the whole human body or selected slices or regions of interest. Using an MRI protocol in an examination position that was convenient for volunteers and patients with severe diseases, 22 healthy subjects were examined. The software platform was able to merge MRI scans of several body regions acquired in separate acquisitions. Through a cascade of image processing steps, SFT and VFT volumes were calculated. Whole-body SFT and VFT distributions, as well as fat distributions of defined body slices, were analysed in detail. Complete three-dimensional datasets were analysed in a reproducible manner with as few operator-dependent interventions as possible. In order to determine the SFT volume, the ARTIS (Adapted Rendering for Tissue Intensity Segmentation) algorithm was introduced. The advantage of the ARTIS algorithm was the delineation of SFT volumes in regions in which standard region grow techniques fail. Using the ARTIS algorithm, an automatic SFT volume detection was feasible. MRI data analysis was able to determine SFT and VFT volume percentages using new analytical strategies. With the techniques described, it was possible to detect changes in SFT and VFT percentages of the whole body and selected regions. The techniques presented in this study are likely to be of use in obesity-related investigations, as well as in the examination of longitudinal changes in weight during various medical conditions. Copyright © 2010 John Wiley & Sons, Ltd.

MDCT evaluation of potential living renal donor, prior to laparoscopic donor nephrectomy: What the transplant surgeon wants to know?

PubMed Central

Ghonge, Nitin P; Gadanayak, Satyabrat; Rajakumari, Vijaya

2014-01-01

As Laparoscopic Donor Nephrectomy (LDN) offers several advantages for the donor such as lesser post-operative pain, fewer cosmetic concerns and faster recovery time, there is growing global trend towards LDN as compared to open nephrectomy. Comprehensive pre-LDN donor evaluation includes assessment of renal morphology including pelvi-calyceal and vascular system. Apart from donor selection, evaluation of the regional anatomy allows precise surgical planning. Due to limited visualization during laparoscopic renal harvesting, detailed pre-transplant evaluation of regional anatomy, including the renal venous anatomy is of utmost importance. MDCT is the modality of choice for pre-LDN evaluation of potential renal donors. Apart from appropriate scan protocol and post-processing methods, detailed understanding of surgical techniques is essential for the Radiologist for accurate image interpretation during pre-LDN MDCT evaluation of potential renal donors. This review article describes MDCT evaluation of potential living renal donor, prior to LDN with emphasis on scan protocol, post-processing methods and image interpretation. The article laid special emphasis on surgical perspectives of pre-LDN MDCT evaluation and addresses important points which transplant surgeons want to know. PMID:25489130

[Ultrasound-guided peripheral nerve block at wrist level for the treatment of idiopathic palmar hyperhidrosis with botulinum toxin].

PubMed

Olea, E; Fondarella, A; Sánchez, C; Iriarte, I; Almeida, M V; Martínez de Salinas, A

2013-12-01

Evaluation of pain and degree of satisfaction in patients undergoing ultrasound-assisted peripheral regional block for the treatment of idiopathic palmar hyperhidrosis with botulinum toxin. A descriptive, observational study of patients with palmar hyperhidrosis treated with botulinum toxin A, who underwent ultrasound-guided peripheral regional block of the median and ulnar nerves with 3 ml of mepivacaine 1% in each one. The radial nerve block was injected in the anatomical snuffbox. After establishing blocking, the dermatologist performed a mapping and injected around 100 IU of botulinum toxin across the whole palm. The pain experienced during the injection of botulinum toxin was evaluated by verbal numerical scale (from 0 to 10), along with the degree of satisfaction with the anesthetic technique, and the post-anesthetic complications. A total of 40 patients were enrolled in the study, 11 men and 29 women with no significant differences. The pain intensity assessed with verbal numerical scale was 1.03 (standard deviation of 1.37). No patients had a value greater than 5. The degree of patient satisfaction with the anesthetic technique was very good for 85% of the patients, and good for 7.5%. There were no complications related to type of anesthesia. The ultrasound-assisted peripheral regional block could be a simple, effective and safe technique for patients undergoing palmar injection of botulinum toxin. Pain intensity was very low, and it provided a very good level of satisfaction in most patients. Copyright © 2013 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Published by Elsevier España. All rights reserved.

Region of interest processing for iterative reconstruction in x-ray computed tomography

NASA Astrophysics Data System (ADS)

Kopp, Felix K.; Nasirudin, Radin A.; Mei, Kai; Fehringer, Andreas; Pfeiffer, Franz; Rummeny, Ernst J.; Noël, Peter B.

2015-03-01

The recent advancements in the graphics card technology raised the performance of parallel computing and contributed to the introduction of iterative reconstruction methods for x-ray computed tomography in clinical CT scanners. Iterative maximum likelihood (ML) based reconstruction methods are known to reduce image noise and to improve the diagnostic quality of low-dose CT. However, iterative reconstruction of a region of interest (ROI), especially ML based, is challenging. But for some clinical procedures, like cardiac CT, only a ROI is needed for diagnostics. A high-resolution reconstruction of the full field of view (FOV) consumes unnecessary computation effort that results in a slower reconstruction than clinically acceptable. In this work, we present an extension and evaluation of an existing ROI processing algorithm. Especially improvements for the equalization between regions inside and outside of a ROI are proposed. The evaluation was done on data collected from a clinical CT scanner. The performance of the different algorithms is qualitatively and quantitatively assessed. Our solution to the ROI problem provides an increase in signal-to-noise ratio and leads to visually less noise in the final reconstruction. The reconstruction speed of our technique was observed to be comparable with other previous proposed techniques. The development of ROI processing algorithms in combination with iterative reconstruction will provide higher diagnostic quality in the near future.

Inter-subject FDG PET Brain Networks Exhibit Multi-scale Community Structure with Different Normalization Techniques.

PubMed

Sperry, Megan M; Kartha, Sonia; Granquist, Eric J; Winkelstein, Beth A

2018-07-01

Inter-subject networks are used to model correlations between brain regions and are particularly useful for metabolic imaging techniques, like 18F-2-deoxy-2-(18F)fluoro-D-glucose (FDG) positron emission tomography (PET). Since FDG PET typically produces a single image, correlations cannot be calculated over time. Little focus has been placed on the basic properties of inter-subject networks and if they are affected by group size and image normalization. FDG PET images were acquired from rats (n = 18), normalized by whole brain, visual cortex, or cerebellar FDG uptake, and used to construct correlation matrices. Group size effects on network stability were investigated by systematically adding rats and evaluating local network connectivity (node strength and clustering coefficient). Modularity and community structure were also evaluated in the differently normalized networks to assess meso-scale network relationships. Local network properties are stable regardless of normalization region for groups of at least 10. Whole brain-normalized networks are more modular than visual cortex- or cerebellum-normalized network (p < 0.00001); however, community structure is similar at network resolutions where modularity differs most between brain and randomized networks. Hierarchical analysis reveals consistent modules at different scales and clustering of spatially-proximate brain regions. Findings suggest inter-subject FDG PET networks are stable for reasonable group sizes and exhibit multi-scale modularity.

A radiotherapy technique to limit dose to neural progenitor cell niches without compromising tumor coverage

PubMed Central

Redmond, Kristin J.; Achanta, Pragathi; Grossman, Stuart A.; Armour, Michael; Reyes, Juvenal; Kleinberg, Lawrence; Tryggestad, Erik; Quinones-Hinojosa, Alfredo

2015-01-01

Radiation therapy (RT) for brain tumors is associated with neurocognitive toxicity which may be a result of damage to neural progenitor cells (NPCs). We present a novel technique to limit the radiation dose to NPC without compromising tumor coverage. A study was performed in mice to examine the rationale and another was conducted in humans to determine its feasibility. C57BL/6 mice received localized radiation using a dedicated animal irradiation system with on-board CT imaging with either: (1) Radiation which spared NPC containing regions; (2) Radiation which did not spare these niches; or (3) Sham irradiation. Mice were sacrificed 24 h later and the brains were processed for immunohistochemical Ki-67 staining. For the human component of the study, 33 patients with primary brain tumors were evaluated. Two intensity modulated radiotherapy (IMRT) plans were retrospectively compared: a standard clinical plan and a plan which spares NPC regions while maintaining the same dose coverage of the tumor. The change in radiation dose to the contralateral NPC-containing regions was recorded. In the mouse model, non-NPC-sparing radiation treatment resulted in a significant decrease in the number of Ki67+ cells in dentate gyrus (DG) (P = 0.008) and subventricular zone (SVZ) (P = 0.005) compared to NPC-sparing radiation treatment. In NPC-sparing clinical plans, NPC regions received significantly lower radiation dose with no clinically relevant changes in tumor coverage. This novel radiation technique should significantly reduce radiation doses to NPC containing regions of the brain which may reduce neurocognitive deficits following RT for brain tumors. PMID:21327710

Surgical Approach and Anesthetic Modality for Carpal Tunnel Release: A Nationwide Database Study With Health Care Cost Implications.

PubMed

Foster, Brock D; Sivasundaram, Lakshmanan; Heckmann, Nathanael; Cohen, Jeremiah R; Pannell, William C; Wang, Jeffrey C; Ghiassi, Alidad

2017-03-01

Background: Carpal tunnel release (CTR) is commonly performed for carpal tunnel syndrome once conservative treatment has failed. Operative technique and anesthetic modality vary by surgeon preference and patient factors. However, CTR practices and anesthetic trends have, to date, not been described on a nationwide scale in the United States. Methods: The PearlDiver Patient Records Database was used to search Current Procedural Terminology codes for elective CTR from 2007 to 2011. Anesthetic modality (eg, general and regional anesthesia vs local anesthesia) and surgical approach (eg, endoscopic vs open) were recorded for this patient population. Cost analysis, patient demographics, regional variation, and annual changes in CTR surgery were evaluated. Results: We identified 86 687 patients who underwent carpal tunnel surgery during this 5-year time period. In this patient sample, 80.5% of CTR procedures were performed using general or regional anesthesia, compared with 19.5% of procedures performed using local anesthesia; 83.9% of all CTR were performed in an open fashion, and 16.1% were performed using an endoscopic technique. Endoscopic surgery was on average $794 more expensive than open surgery, and general or regional anesthesia was $654 more costly than local anesthesia. Conclusions: In the United States, open CTR under local anesthesia is the most cost-effective way to perform a CTR. However, only a small fraction of elective CTR procedures are performed with this technique, representing a potential area for significant health care cost savings. In addition, regional and age variations exist in procedure and anesthetic type utilized.

Imaging regional renal function parameters using radionuclide tracers

NASA Astrophysics Data System (ADS)

Qiao, Yi

A compartmental model is given for evaluating kidney function accurately and noninvasively. This model is cast into a parallel multi-compartment structure and each pixel region (picture element) of kidneys is considered as a single kidney compartment. The loss of radionuclide tracers from the blood to the kidney and from the kidney to the bladder are modelled in great detail. Both the uptake function and the excretion function of the kidneys can be evaluated pixel by pixel, and regional diagnostic information on renal function is obtained. Gamma Camera image data are required by this model and a screening test based renal function measurement is provided. The regional blood background is subtracted from the kidney region of interest (ROI) and the kidney regional rate constants are estimated analytically using the Kuhn-Pucker multiplier method in convex programming by considering the input/output behavior of the kidney compartments. The detailed physiological model of the peripheral compartments of the system, which is not available for most radionuclide tracers, is not required in the determination of the kidney regional rate constants and the regional blood background factors within the kidney ROI. Moreover, the statistical significance of measurements is considered to assure the improved statistical properties of the estimated kidney rate constants. The relations between various renal function parameters and the kidney rate constants are established. Multiple renal function measurements can be found from the renal compartmental model. The blood radioactivity curve and the regional (or total) radiorenogram determining the regional (or total) summed behavior of the kidneys are obtained analytically with the consideration of the statistical significance of measurements using convex programming methods for a single peripheral compartment system. In addition, a new technique for the determination of 'initial conditions' in both the blood compartment and the kidney compartment is presented. The blood curve and the radiorenogram are analyzed in great detail and a physiological analysis from the radiorenogram is given. Applications of Kuhn-Tucker multiplier methods are illustrated for the renal compartmental model in the field of nuclear medicine. Conventional kinetic data analysis methods, the maximum likehood method, and the weighted integration method are investigated and used for comparisons. Moreover, the effect of the blood background subtraction is shown by using the gamma camera images in man. Several functional images are calculated and the functional imaging technique is applied for evaluating renal function in man quantitatively and visually and compared with comments from a physician.

Automated detection of microaneurysms using robust blob descriptors

NASA Astrophysics Data System (ADS)

Adal, K.; Ali, S.; Sidibé, D.; Karnowski, T.; Chaum, E.; Mériaudeau, F.

2013-03-01

Microaneurysms (MAs) are among the first signs of diabetic retinopathy (DR) that can be seen as round dark-red structures in digital color fundus photographs of retina. In recent years, automated computer-aided detection and diagnosis (CAD) of MAs has attracted many researchers due to its low-cost and versatile nature. In this paper, the MA detection problem is modeled as finding interest points from a given image and several interest point descriptors are introduced and integrated with machine learning techniques to detect MAs. The proposed approach starts by applying a novel fundus image contrast enhancement technique using Singular Value Decomposition (SVD) of fundus images. Then, Hessian-based candidate selection algorithm is applied to extract image regions which are more likely to be MAs. For each candidate region, robust low-level blob descriptors such as Speeded Up Robust Features (SURF) and Intensity Normalized Radon Transform are extracted to characterize candidate MA regions. The combined features are then classified using SVM which has been trained using ten manually annotated training images. The performance of the overall system is evaluated on Retinopathy Online Challenge (ROC) competition database. Preliminary results show the competitiveness of the proposed candidate selection techniques against state-of-the art methods as well as the promising future for the proposed descriptors to be used in the localization of MAs from fundus images.

[Evaluation of ecosystem resilience in the regions across Qinghai-Tibet railway based on GIS].

PubMed

Gao, Jiang-bo; Zhao, Zhi-qiang; Li, Shuang-cheng

2008-11-01

Based on GIS technique and the methods of mean-squared deviation weight decision and catastrophe progression, a more clear definition and associated evaluation for ecosystem resilience were given, with a case study in the regions across Qinghai-Tibet railway by using the indices of plant community coverage, species diversity, and biomass. It was shown that the areas with high ecosystem resilience were mainly located in the Qilian Mountain meadow grassland, Huangshui Valley needle-leaved and deciduous broad-leaved forest, and south Tanggula Mountain kobresia swamp meadow, while those with the lowest resilience were in the central part of Qaidam Basin, and the Kunlun Mountains. Most areas in the regions had higher or medium ecosystem resilience, with a trend of that in the south of Kunlun Mountains, the resilience in the north of the railway was lower, while in the east of Qaidam Basin (especially in the Qinghai Lake area), the resilience was lower in the south than in the north of the railway. Through the evaluation of ecosystem resilience, the key issues in the process of ecological resilience could be found, and corresponding effective measures would be pointed out to manage alpine ecosystems. Moreover, combining with the evaluation of vulnerability, scientific basis for regional development could be provided to avoid or mitigate the negative effects of human activities on eco-environment.

[Comparative evaluation of six different body regions of the dog using analog and digital radiography].

PubMed

Meyer-Lindenberg, Andrea; Ebermaier, Christine; Wolvekamp, Pim; Tellhelm, Bernd; Meutstege, Freek J; Lang, Johann; Hartung, Klaus; Fehr, Michael; Nolte, Ingo

2008-01-01

In this study the quality of digital and analog radiography in dogs was compared. For this purpose, three conventional radiographs (varying in exposure) and three digital radiographs (varying in MUSI-contrast [MUSI = MUlti Scale Image Contrast], the main post-processing parameter) of six different body regions of the dog were evaluated (thorax, abdomen, skull, femur, hip joints, elbow). The quality of the radiographs was evaluated by eight veterinary specialists familiar with radiographic images using a questionnaire based on details of each body region significant in obtaining a radiographic diagnosis. In the first part of the study the overall quality of the radiographs was evaluated. Within one region, 89.5% (43/48) chose a digital radiograph as the best image. Divided into analog and digital groups, the digital image with the highest MUSI-contrast was most often considered the best, while the analog image considered the best varied between the one with the medium and the one with the longest exposure time. In the second part of the study, each image was rated for the visibility of specific, diagnostically important details. After summarisation of the scores for each criterion, divided into analog and digital imaging, the digital images were rated considerably superior to conventional images. The results of image comparison revealed that digital radiographs showed better image detail than radiographs taken with the analog technique in all six areas of the body.

Regional changes in extreme monsoon rainfall deficit and excess in India

NASA Astrophysics Data System (ADS)

Pal, Indrani; Al-Tabbaa, Abir

2010-04-01

With increasing concerns about climate change, the need to understand the nature and variability of monsoon climatic conditions and to evaluate possible future changes becomes increasingly important. This paper deals with the changes in frequency and magnitudes of extreme monsoon rainfall deficiency and excess in India from 1871 to 2005. Five regions across India comprising variable climates were selected for the study. Apart from changes in individual regions, changing tendencies in extreme monsoon rainfall deficit and excess were also determined for the Indian region as a whole. The trends and their significance were assessed using non-parametric Mann-Kendall technique. The results show that intra-region variability for extreme monsoon seasonal precipitation is large and mostly exhibited a negative tendency leading to increasing frequency and magnitude of monsoon rainfall deficit and decreasing frequency and magnitude of monsoon rainfall excess.

Is Anesthesia Technique Associated With a Higher Risk of Mortality or Complications Within 90 Days of Surgery for Geriatric Patients With Hip Fractures?

PubMed

Desai, Vimal; Chan, Priscilla H; Prentice, Heather A; Zohman, Gary L; Diekmann, Glenn R; Maletis, Gregory B; Fasig, Brian H; Diaz, Diana; Chung, Elena; Qiu, Chunyuan

2018-06-01

Postoperative mortality and complications after geriatric hip fracture surgery remain high despite efforts to improve perioperative care for these patients. One factor of particular interest is anesthetic technique, but prior studies on this are limited by sample selection, competing risks, and incomplete followup. (1) Among older patients undergoing surgery for hip fracture, does 90-day mortality differ depending on the type of anesthesia received? (2) Do 90-day emergency department returns and hospital readmissions differ based on anesthetic technique after geriatric hip fracture repairs? (3) Do 90-day Agency for Healthcare Research and Quality (AHRQ) outcomes differ according to anesthetic techniques used during hip fracture surgery? We conducted a retrospective study on geriatric patients (65 years or older) with hip fractures between 2009 and 2014 using the Kaiser Permanente Hip Fracture Registry. A total of 1995 (11%) of the surgically treated patients with hip fracture were excluded as a result of missing anesthesia information. The final study sample consisted of 16,695 patients. Of these, 2027 (12%) died and 98 (< 1%) terminated membership during followup, which were handled as competing events and censoring events, respectively. Ninety-day mortality, emergency department returns, hospital readmission, deep vein thrombosis (DVT) or pulmonary embolism (PE), myocardial infarction (MI), and pneumonia were evaluated using multivariable competing risk proportional subdistribution hazard regression according to type of anesthesia technique: general anesthesia, regional anesthesia, or conversion from regional to general. Of the 16,695 patients, 58% (N = 9629) received general anesthesia, 40% (N = 6597) received regional anesthesia, and 2.8% (N = 469) patients were converted from regional to general. Compared with regional anesthesia, patients treated with general anesthesia had a higher likelihood of overall 90-day mortality (hazard ratio [HR], 1.22; 95% confidence interval [CI], 1.11-1.35; p < 0.001); however, when stratified by before and after hospital discharge but within 90 days of surgery, this higher risk was only observed during the inpatient stay (HR, 3.83; 95% CI, 3.18-4.61; p < 0.001); no difference was observed after hospital discharge (HR, 1.04; 95% CI, 0.94-1.16; p = 0.408). Patients undergoing conversion from regional to general also had a higher overall mortality risk compared with those undergoing regional anesthesia (HR, 1.34; 95% CI 1.04-1.74; p = 0.026), but this risk was only observed during their inpatient stay (HR, 6.84; 95% CI, 4.21-11.11; p < 0.001) when stratifying by before and after hospital discharge. Patients undergoing general anesthesia had a higher risk for all-cause readmission when compared with regional anesthesia (HR, 1.09; 95% CI, 1.01-1.19; p = 0.026). No differences according to anesthesia type were observed for risk of 90-day AHRQ outcomes, including DVT/PE, MI, and pneumonia. We found the use of general anesthesia and conversion from regional to general anesthesia were associated with a higher risk of mortality during the in-hospital stay compared with regional anesthetic techniques, but this higher risk did not persist after hospital discharge. We also found general anesthesia to be associated with a higher risk of all-cause readmission compared with regional, but no other differences were observed in risk for complications. Our findings suggest regional anesthetic techniques may be preferred when possible in this patient population. Level III, therapeutic study.

Labia Minora, Labia Majora, and Clitoral Hood Alteration: Experience-Based Recommendations.

PubMed

Hunter, John G

2016-01-01

Aesthetic alteration of the genitalia is increasingly sought by women unhappy with the size, shape, and appearance of their vulva. Although the labia minora are usually the focus of concern, the entire anatomic region--minora, labia majora, clitoral hood, perineum, and mons pubis--should be evaluated in a preoperative assessment of women seeking labiaplasty. Labiaplasty is associated with high patient satisfaction and low complication rates. The three basic labia minora reduction techniques--edge excision, wedge excision, and central deepithelialization--as well as their advantages and disadvantages are discussed to assist the surgeon in tailoring technique selection to individual genital anatomy and aesthetic desires. We present key points of the preoperative anatomic evaluation, technique selection, operative risks, perioperative care, and potential complications for labia minora, labia majora, and clitoral hood alterations, based on a large operative experience. Labiaplasty competency should be part of the skill set of all plastic surgeons. © 2015 The American Society for Aesthetic Plastic Surgery, Inc. Reprints and permission: journals.permissions@oup.com.

Surface assessment of CaF2 deep-ultraviolet and vacuum-ultraviolet optical components by the quasi-Brewster angle technique.

PubMed

Wang, Jue; Maier, Robert L

2006-08-01

The requirements for optical components have drastically increased for the deep-ultraviolet and vacuum-ultraviolet spectral regions. Low optical loss, high laser damage threshold, and long lifetime fluoride optics are required for microlithographic applications. A nondestructive quasi-Brewster angle technique (qBAT) has been developed for evaluating the quality of optical surfaces including both top surface and subsurface information. By using effective medium approximation, the negative quasi-Brewster angle shift at wavelengths longer than 200 nm has been used to model the distribution of subsurface damage, whereas the positive quasi-Brewster angle shift for wavelengths shorter than 200 nm has been explained by subsurface contamination. The top surface roughness depicted by the qBAT is consistent with atomic force microscopy measurements. The depth and the microporous structure of the subsurface damage measured by the qBAT has been confirmed by magnetorheological finishing. The technique has been extended to evaluate both polished and antireflection-coated CaF(2) components.

Lung volume reduction of pulmonary emphysema: the radiologist task.

PubMed

Milanese, Gianluca; Silva, Mario; Sverzellati, Nicola

2016-03-01

Several lung volume reduction (LVR) techniques have been increasingly evaluated in patients with advanced pulmonary emphysema, especially in the last decade. Radiologist plays a pivotal role in the characterization of parenchymal damage and, thus, assessment of eligibility criteria. This review aims to discuss the most common LVR techniques, namely LVR surgery, endobronchial valves, and coils LVR, with emphasis on the role of computed tomography (CT). Several trials have recently highlighted the importance of regional quantification of emphysema by computerized CT-based segmentation of hyperlucent parenchyma, which is strongly recommended for candidates to any LVR treatment. In particular, emphysema distribution pattern and fissures integrity are evaluated to tailor the choice of the most appropriate LVR technique. Furthermore, a number of CT measures have been tested for the personalization of treatment, according to imaging detected heterogeneity of parenchymal disease. CT characterization of heterogeneous parenchymal abnormalities provides criteria for selection of the preferable treatment in each patient and improves outcome of LVR as reflected by better quality of life, higher exercise tolerance, and lower mortality.

25 years of neuroimaging in amyotrophic lateral sclerosis.

PubMed

Foerster, Bradley R; Welsh, Robert C; Feldman, Eva L

2013-09-01

Amyotrophic lateral sclerosis (ALS) is a fatal motor neuron disease for which a precise cause has not yet been identified. Standard CT or MRI evaluation does not demonstrate gross structural nervous system changes in ALS, so conventional neuroimaging techniques have provided little insight into the pathophysiology of this disease. Advanced neuroimaging techniques--such as structural MRI, diffusion tensor imaging and proton magnetic resonance spectroscopy--allow evaluation of alterations of the nervous system in ALS. These alterations include focal loss of grey and white matter and reductions in white matter tract integrity, as well as changes in neural networks and in the chemistry, metabolism and receptor distribution in the brain. Given their potential for investigation of both brain structure and function, advanced neuroimaging methods offer important opportunities to improve diagnosis, guide prognosis, and direct future treatment strategies in ALS. In this article, we review the contributions made by various advanced neuroimaging techniques to our understanding of the impact of ALS on different brain regions, and the potential role of such measures in biomarker development.

MRI-negative refractory partial epilepsy: role for diffusion tensor imaging in high field MRI.

PubMed

Chen, Qin; Lui, Su; Li, Chun-Xiao; Jiang, Li-Jun; Ou-Yang, Luo; Tang, He-Han; Shang, Hui-Fang; Huang, Xiao-Qi; Gong, Qi-Yong; Zhou, Dong

2008-07-01

Our aim is to use the high field MR scanner (3T) to verify whether diffusion tensor imaging (DTI) could help in locating the epileptogenic zone in patients with MRI-negative refractory partial epilepsy. Fifteen patients with refractory partial epilepsy who had normal conventional MRI, and 40 healthy volunteers were recruited for the study. DTI was performed on a 3T MR scanner, individual maps of mean diffusivity (MD) and fractional anisotropy (FA) were calculated, and Voxel-Based Analysis (VBA) was performed for individual comparison between patients and controls. Voxel-based analysis revealed significant MD increase in variant regions in 13 patients. The electroclinical seizure localization was concurred to seven patients. No patient exhibited regions of significant decreased MD. Regions of significant reduced FA were observed in five patients, with two of these concurring with electroclinical seizure localization. Two patients had regions of significant increase in FA, which were distinct from electroclinical seizure localization. Our study's results revealed that DTI is a responsive neuroradiologic technique that provides information about the epileptogenic areas in patients with MRI-negative refractory partial epilepsy. This technique may also helpful in pre-surgical evaluation.

Dermal exposure of applicators to chlorpyrifos on rice farms in Ghana.

PubMed

Atabila, Albert; Phung, Dung Tri; Hogarh, Jonathan N; Osei-Fosu, Paul; Sadler, Ross; Connell, Des; Chu, Cordia

2017-07-01

Studies evaluating dermal exposure to pesticides among applicators in tropical countries have largely been conducted using the patch dosimetry and hand wiping/washing techniques. This study used the more accurate whole-body dosimetry technique to evaluate dermal exposure to chlorpyrifos among applicators on rice farms in Ghana. The exposure levels were plotted as Cumulative Probability Distribution (CPD). Total Dermal Exposure (TDE) of chlorpyrifos among the median exposed and the 5% highly exposed groups during a spray event were 24 mg and 48 mg, respectively. When these were converted as a percentage of the quantity of active ingredient applied (Unit Exposure, UE), UE values of 0.03% and 0.06% were found among the median exposed and the 5% highly exposed groups, respectively. Overall, the hands were the most contaminated anatomical regions of the applicators, both in terms of proportion of TDE (39%) and skin loading (13 μg/cm 2 ). Also, the lower anatomical region was more contaminated (82% of TDE) compared to the upper anatomical region (18% of TDE). The levels of chlorpyrifos TDE among the applicators were found to be influenced by the quantity of insecticide applied and the height of the crops sprayed (p < 0.05). The pesticide UE data of the present study can be used to estimate the levels of dermal exposure under similar pesticide use scenarios among applicators. The findings of the present study suggest that protecting the hands and the lower anatomical regions with appropriate PPE may significantly reduce exposure among applicators. Copyright © 2017 Elsevier Ltd. All rights reserved.

Contrast-enhanced magnetic resonance imaging of pulmonary lesions: description of a technique aiming clinical practice.

PubMed

Koenigkam-Santos, Marcel; Optazaite, Elzbieta; Sommer, Gregor; Safi, Seyer; Heussel, Claus Peter; Kauczor, Hans-Ulrich; Puderbach, Michael

2015-01-01

To propose a technique for evaluation of pulmonary lesions using contrast-enhanced MRI; to assess morphological patterns of enhancement and correlate quantitative analysis with histopathology. Thirty-six patients were prospectively studied. Volumetric-interpolated T1W images were obtained during consecutive breath holds after bolus triggered contrast injection. Volume coverage of first three acquisitions was limited (higher temporal resolution) and last acquisition obtained at 4th min. Two radiologists individually evaluated the patterns of enhancement. Region-of-interest-based signal intensity (SI)-time curves were created to assess quantitative parameters. Readers agreed moderately to substantially concerning lesions' enhancement pattern. SI-time curves could be created for all lesions. In comparison to benign, malignant lesions showed higher values of maximum enhancement, early peak, slope and 4th min enhancement. Early peak >15% showed 100% sensitivity to detect malignancy, maximum enhancement >40% showed 100% specificity. The proposed technique is robust, simple to perform and can be applied in clinical scenario. It allows visual evaluation of enhancement pattern/progression together with creation of SI-time curves and assessment of derived quantitative parameters. Perfusion analysis was highly sensitive to detect malignancy, in accordance to what is recommended by most recent guidelines on imaging evaluation of pulmonary lesions. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

A novel method to remove GPR background noise based on the similarity of non-neighboring regions

NASA Astrophysics Data System (ADS)

Montiel-Zafra, V.; Canadas-Quesada, F. J.; Vera-Candeas, P.; Ruiz-Reyes, N.; Rey, J.; Martinez, J.

2017-09-01

Ground penetrating radar (GPR) is a non-destructive technique that has been widely used in many areas of research, such as landmine detection or subsurface anomalies, where it is required to locate targets embedded within a background medium. One of the major challenges in the research of GPR data remains the improvement of the image quality of stone materials by means of detection of true anisotropies since most of the errors are caused by an incorrect interpretation by the users. However, it is complicated due to the interference of the horizontal background noise, e.g., the air-ground interface, that reduces the high-resolution quality of radargrams. Thus, weak or deep anisotropies are often masked by this type of noise. In order to remove the background noise obtained by GPR, this work proposes a novel background removal method assuming that the horizontal noise shows repetitive two-dimensional regions along the movement of the GPR antenna. Specifically, the proposed method, based on the non-local similarity of regions over the distance, computes similarities between different regions of the same depth in order to identify most repetitive regions using a criterion to avoid closer regions. Evaluations are performed using a set of synthetic and real GPR data. Experimental results show that the proposed method obtains promising results compared to the classic background removal techniques and the most recently published background removal methods.

A Biomechanical Modeling Guided CBCT Estimation Technique

PubMed Central

Zhang, You; Tehrani, Joubin Nasehi; Wang, Jing

2017-01-01

Two-dimensional-to-three-dimensional (2D-3D) deformation has emerged as a new technique to estimate cone-beam computed tomography (CBCT) images. The technique is based on deforming a prior high-quality 3D CT/CBCT image to form a new CBCT image, guided by limited-view 2D projections. The accuracy of this intensity-based technique, however, is often limited in low-contrast image regions with subtle intensity differences. The solved deformation vector fields (DVFs) can also be biomechanically unrealistic. To address these problems, we have developed a biomechanical modeling guided CBCT estimation technique (Bio-CBCT-est) by combining 2D-3D deformation with finite element analysis (FEA)-based biomechanical modeling of anatomical structures. Specifically, Bio-CBCT-est first extracts the 2D-3D deformation-generated displacement vectors at the high-contrast anatomical structure boundaries. The extracted surface deformation fields are subsequently used as the boundary conditions to drive structure-based FEA to correct and fine-tune the overall deformation fields, especially those at low-contrast regions within the structure. The resulting FEA-corrected deformation fields are then fed back into 2D-3D deformation to form an iterative loop, combining the benefits of intensity-based deformation and biomechanical modeling for CBCT estimation. Using eleven lung cancer patient cases, the accuracy of the Bio-CBCT-est technique has been compared to that of the 2D-3D deformation technique and the traditional CBCT reconstruction techniques. The accuracy was evaluated in the image domain, and also in the DVF domain through clinician-tracked lung landmarks. PMID:27831866

Thermo-elastic nondestructive evaluation of fatigue damage in PMR-15 resin

NASA Astrophysics Data System (ADS)

Welter, J. T.; Sathish, S.; Tandon, G. P.; Schehl, N.; Cherry, M.; Nalladega, V.; Lindgren, E. A.; Hall, R.

2012-05-01

Thermoset polyimide resins are used as the polymer matrix in high temperature composites for aerospace applications such as engine shrouds. At these locations the components have to withstand high temperatures and significant vibration. A number of studies have investigated the effects of thermal exposure on mechanical properties of polyimide resins, and the effects of fatigue on thermoplastics have been discussed at length. However, the effects of fatigue on thermosets, in particular polyimides, have largely been overlooked. In this paper we present studies of nondestructive evaluation of fatigue damage in a thermoset polyimide resin, PMR-15, performed by measuring the changes in the evolution of heat in the samples during cyclic loading. The temperature changes are measured using a high sensitivity IR camera as a function of number of fatigue cycles. Interrupted fatigue tests were performed on four samples. The temperature rise during an increment of fatigue cycling shows two linear regions each with a different slope (region 1 and region 2). Region 1 remains constant for every increment of fatigue, while region 2 increases. The onset of region 2 occurs at the same increase in temperature due to hysteretic heating for all samples. Experimental observations are explained using a phenomenological two phase model based on crosslinking density variations in observed in other thermoset resins at microscopic scales. The results of these experiments are discussed in reference to utilizing this technique for detection and evaluation of fatigue in PMR-15 resin and composites.

Investigation of laser holographic interferometric techniques for structure inspection

NASA Technical Reports Server (NTRS)

Chu, W. P.

1973-01-01

The application of laser holographic interferometric techniques for nondestructive inspection of material structures commonly used in aerospace works is investigated. Two types of structures, composite plate and solid fuel rocket engine motor casing, were examined. In conducting the experiments, both CW HeNe gas lasers and Q-switched ruby lasers were used as light sources for holographic recording setups. Different stressing schemes were investigated as to their effectiveness in generating maximum deformation at regions of structural weakness such as flaws and disbonds. Experimental results on stressing schemes such as thermal stressing, pressurized stressing, transducer excitation, and mechanical impact are presented and evaluated.

Regionalizing land use impacts on farmland birds.

PubMed

Glemnitz, Michael; Zander, Peter; Stachow, Ulrich

2015-06-01

The environmental impacts of land use vary regionally. Differences in geomorphology, climate, landscape structure, and biotope inventories are regarded as the main causes of this variation. We present a methodological approach for identifying regional responses in land use type to large-scale changes and the implications for the provision of habitat for farmland birds. The methodological innovations of this approach are (i) the coupling of impact assessments with economic models, (ii) the linking of cropping techniques at the plot scale with the regional distribution of land use, and (iii) the integration of statistical or monitoring data on recent states. This approach allows for the regional differentiation of farmers' responses to changing external conditions and for matching the ecological impacts of land use changes with regional environmental sensitivities. An exemplary scenario analysis was applied for a case study of an area in Germany, assessing the impacts of increased irrigation and the promotion of energy cropping on farmland birds, evaluated as a core indicator for farmland biodiversity. The potential effects on farmland birds were analyzed based on the intrinsic habitat values of the crops and cropping techniques. The results revealed that the strongest decrease in habitat availability for farmland birds occurred in regions with medium-to-low agricultural yields. As a result of the limited cropping alternatives, the increase in maize production was highest in marginal regions for both examined scenarios. Maize production replaced many crops with good-to-medium habitat suitability for birds. The declines in habitat quality were strongest in regions that are not in focus for conservation efforts for farmland birds.

Preoperative and Postoperative CT Scan Assessment of Pterygomaxillary Junction in Patients Undergoing Le Fort I Osteotomy: Comparison of Pterygomaxillary Dysjunction Technique and Trimble Technique-A Pilot Study.

PubMed

Dadwal, Himani; Shanmugasundaram, S; Krishnakumar Raja, V B

2015-09-01

To determine the rate of complications and occurrence of pterygoid plate fractures comparing two techniques of Le Fort I osteotomy i.e., Classic Pterygomaxillary Dysjunction technique and Trimble technique and to know whether the dimensions of pterygomaxillary junction [determined preoperatively by computed tomography (CT) scan] have any influence on pterygomaxillary separation achieved during surgery. The study group consisted of eight South Indian patients with maxillary excess. A total of 16 sides were examined by CT. Preoperative CT was analyzed for all the patients. The thickness and width of the pterygomaxillary junction and the distance of the greater palatine canal from the pterygomaxillary junction was noted. Pterygomaxillary dysjunction was achieved by two techniques, the classic pterygomaxillary dysjunction technique (Group I) and Trimble technique (Group II). Patients were selected randomly and equally for both the techniques. Dysjunction was analyzed by postoperative CT. The average thickness of the pterygomaxillary junction on 16 sides was 4.5 ± 1.2 mm. Untoward pterygoid plate fractures occurred in Group I in 3 sides out of 8. In Trimble technique (Group II), no pterygoid plate fractures were noted. The average width of the pterygomaxillary junction was 7.8 ± 1.5 mm, distance of the greater palatine canal from pterygomaxillary junction was 7.4 ± 1.6 mm and the length of fusion of pterygomaxillary junction was 8.0 ± 1.9 mm. The Le Fort I osteotomy has become a standard procedure for correcting various dentofacial deformities. In an attempt to make Le Fort I osteotomy safer and avoid the problems associated with sectioning with an osteotome between the maxillary tuberosity and the pterygoid plates, Trimble suggested sectioning across the posterior aspect of the maxillary tuberosity itself. In our study, comparison between the classic pterygomaxillary dysjunction technique and the Trimble technique was made by using postoperative CT scan. It was found that unfavorable pterygoid plate fractures occurred only in dysjunction group and not in Trimble technique group. Preoperative CT scan assessment was done for all the patients to determine the dimension of the pterygomaxillary region. Preoperative CT scan proved to be helpful in not only determining the dimensions of the pterygomaxillary region but we also found out that thickness of the pterygomaxillary junction was an important parameter which may influence the separation at the pterygomaxillary region. No untoward fractures of the pterygoid plates were seen in Trimble technique (Group II) which makes it a safer technique than classic dysjunction technique. It was noted that pterygoid plate fractures occurred in patients in whom the thickness of the pterygomaxillary junction was <3.6 mm (preoperatively). Therefore, preoperative evaluation is important, on the basis of which we can decide upon the technique to be selected for safer and acceptable separation of pterygomaxillary region.

Development of multiple source data processing for structural analysis at a regional scale. [digital remote sensing in geology

NASA Technical Reports Server (NTRS)

Carrere, Veronique

1990-01-01

Various image processing techniques developed for enhancement and extraction of linear features, of interest to the structural geologist, from digital remote sensing, geologic, and gravity data, are presented. These techniques include: (1) automatic detection of linear features and construction of rose diagrams from Landsat MSS data; (2) enhancement of principal structural directions using selective filters on Landsat MSS, Spacelab panchromatic, and HCMM NIR data; (3) directional filtering of Spacelab panchromatic data using Fast Fourier Transform; (4) detection of linear/elongated zones of high thermal gradient from thermal infrared data; and (5) extraction of strong gravimetric gradients from digitized Bouguer anomaly maps. Processing results can be compared to each other through the use of a geocoded database to evaluate the structural importance of each lineament according to its depth: superficial structures in the sedimentary cover, or deeper ones affecting the basement. These image processing techniques were successfully applied to achieve a better understanding of the transition between Provence and the Pyrenees structural blocks, in southeastern France, for an improved structural interpretation of the Mediterranean region.

High voltage power transistor development

NASA Technical Reports Server (NTRS)

Hower, P. L.

1981-01-01

Design considerations, fabrication procedures, and methods of evaluation for high-voltage power-transistor development are discussed. Technique improvements such as controlling the electric field at the surface and perserving lifetimes in the collector region which have advanced the state of the art in high-voltage transistors are discussed. These improvements can be applied directly to the development of 1200 volt, 200 ampere transistors.

Equipment Level Fallout Radiation Effects Approach

DTIC Science & Technology

1989-02-10

Electromagnetic Pulse (EMP) mitigation Program to evaluate and, where possible, mitigate the effects of the nuclear attack. Fallout radiation has been identified as an environment which may effect the performance of the regional and national telecommunication system. This report presents the investigations in the network level fallout radiation methodology used to determine the effects of this environment. Alternative techniques are presented to improve the

A simple method of measuring the effective SRS coefficient in single-mode optical fibres and the range of its applicability

NASA Astrophysics Data System (ADS)

Shikhaliev, I. I.; Gainov, V. V.; Dorozhkin, A. N.; Nanii, O. E.; Konyshev, V. A.; Treshchikov, V. N.

2017-11-01

This paper describes techniques for measuring the SRS coefficient in a wide spectral range, including the region of small Stokes shifts. A simple, approximate method is proposed for evaluating the SRS coefficient near a gain peak. Spectral dependences of the SRS coefficient are presented for various telecom fibres.

BETR North America: A regionally segmented multimedia contaminant fate model for North America

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

MacLeod, M.; Woodfine, D.G.; Mackay, D.

We present the Berkeley-Trent North American contaminant fate model (BETR North America), a regionally segmented multimedia contaminant fate model based on the fugacity concept. The model is built on a framework that links contaminant fate models of individual regions, and is generally applicable to large, spatially heterogeneous areas. The North American environment is modeled as 24 ecological regions, within each region contaminant fate is described using a 7 compartment multimedia fugacity model including a vertically segmented atmosphere, freshwater, freshwater sediment, soil, coastal water and vegetation compartments. Inter-regional transport of contaminants in the atmosphere, freshwater and coastal water is described usingmore » a database of hydrological and meteorological data compiled with Geographical Information Systems (GIS) techniques. Steady-state and dynamic solutions to the 168 mass balance equations that make up the linked model for North America are discussed, and an illustrative case study of toxaphene transport from the southern United States to the Great Lakes Basin is presented. Regionally segmented models such as BETR North America can provide a critical link between evaluative models of long-range transport potential and contaminant concentrations observed in remote regions. The continent-scale mass balance calculated by the model provides a sound basis for evaluating long-range transport potential of organic pollutants, and formulation of continent scale management and regulatory strategies for chemicals.« less

Evaluation of hemodynamics changes during interventional stent placement using Doppler optical coherence tomography

NASA Astrophysics Data System (ADS)

Vuong, Barry; Genis, Helen; Wong, Ronnie; Ramjist, Joel; Jivraj, Jamil; Farooq, Hamza; Sun, Cuiru; Yang, Victor X. D.

2015-03-01

Carotid atherosclerosis is a critical medical concern that can lead to ischemic stroke. Local hemodynamic patterns have also been associated with the development of atherosclerosis, particularly in regions with disturbed flow patterns such as bifurcations. Traditionally, this disease was treated using carotid endarterectomy, however recently there is an increasing trend of carotid artery stenting due to its minimally invasive nature. It is well known that this interventional technique creates changes in vasculature geometry and hemodynamic patterns due to the interaction of stent struts with arterial lumen, and is associated with complications such as distal emboli and restenosis. Currently, there is no standard imaging technique to evaluate regional hemodynamic patterns found in stented vessels. Doppler optical coherence tomography (DOCT) provides an opportunity to identify in vivo hemodynamic changes in vasculature using high-resolution imaging. In this study, blood flow profiles were examined at the bifurcation junction in the internal carotid artery (ICA) in a porcine model following stent deployment. Doppler imaging was further conducted using pulsatile flow in a phantom model, and then compared to computational fluid dynamics (CFD) simulation of a virtual bifurcation to assist with the interpretation of emphin vivo results.

Dynamic drought risk assessment using crop model and remote sensing techniques

NASA Astrophysics Data System (ADS)

Sun, H.; Su, Z.; Lv, J.; Li, L.; Wang, Y.

2017-02-01

Drought risk assessment is of great significance to reduce the loss of agricultural drought and ensure food security. The normally drought risk assessment method is to evaluate its exposure to the hazard and the vulnerability to extended periods of water shortage for a specific region, which is a static evaluation method. The Dynamic Drought Risk Assessment (DDRA) is to estimate the drought risk according to the crop growth and water stress conditions in real time. In this study, a DDRA method using crop model and remote sensing techniques was proposed. The crop model we employed is DeNitrification and DeComposition (DNDC) model. The drought risk was quantified by the yield losses predicted by the crop model in a scenario-based method. The crop model was re-calibrated to improve the performance by the Leaf Area Index (LAI) retrieved from MODerate Resolution Imaging Spectroradiometer (MODIS) data. And the in-situ station-based crop model was extended to assess the regional drought risk by integrating crop planted mapping. The crop planted area was extracted with extended CPPI method from MODIS data. This study was implemented and validated on maize crop in Liaoning province, China.

Process evaluation of a walking programme delivered through the workplace in the South Pacific island Vanuatu.

PubMed

Siefken, Katja; Schofield, Grant; Schulenkorf, Nico

2015-06-01

The South Pacific region is experiencing significant rates of chronic diseases. Well-evaluated health promotion programmes are needed as a central piece of a strategic solution. Just as important as the evaluation itself is how that evaluation outcome can be communicated for future programme use by local programme planners. The objective of this study is to evaluate a physical activity (PA) programme that was designed for Pacific women in urban Vanuatu, and subsequently to develop new techniques to display data that support the understanding and communication of programme success and challenges. Data collection methods included quantitative Likert scale questions and qualitative open-ended questions. A new analysis technique visualises open-ended process evaluation data. We present themes using word sizes proportional to the frequency of the themes identified through thematic analysis. The Likert scale technique revealed little meaningful information; almost all participants rated most elements of the programme highly. This may be related to Pacific people being frequently inclined to assent with external ideas. Open-ended questions provided more significant insights. For example, we found a stronger change in eating habits (68.9%) than in exercise behaviour (28.2%). We present an evaluation of the first pedometer-based PA intervention in the Pacific and respond to the paucity of process evaluations that have been carried out in the context of low- and middle-income countries. Moreover, the new thematic data visualisation (TDV) approach may aid in understanding complex and cluttered data in a constructive and coordinated way; we present a new approach in health promotion research. © The Author(s) 2014.

Regional geothermal exploration in Egypt

NASA Technical Reports Server (NTRS)

Morgan, P.; Boulos, F. K.; Swanberg, C. A.

1983-01-01

A study is presented of the evaluation of the potential geothermal resources of Egypt using a thermal gradient/heat flow technique and a groundwater temperature/chemistry technique. Existing oil well bottom-hole temperature data, as well as subsurface temperature measurements in existing boreholes, were employed for the thermal gradient/heat flow investigation before special thermal gradient holes were drilled. The geographic range of the direct subsurface thermal measurements was extended by employing groundwater temperature and chemistry data. Results show the presence of a regional thermal high along the eastern margin of Egypt with a local thermal anomaly in this zone. It is suggested that the sandstones of the Nubian Formation may be a suitable reservoir for geothermal fluids. These findings indicate that temperatures of 150 C or higher may be found in this reservoir in the Gulf of Suez and Red Sea coastal zones where it lies at a depth of 4 km and deeper.

Evaluation of molecular markers for Phytophthora ramorum detection and identification: testing for specificity using a standardized library of isolates.

PubMed

Martin, F N; Coffey, M D; Zeller, K; Hamelin, R C; Tooley, P; Garbelotto, M; Hughes, K J D; Kubisiak, T; Bilodeau, G J; Levy, L; Blomquist, C; Berger, P H

2009-04-01

Given the importance of Phytophthora ramorum from a regulatory standpoint, it is imperative that molecular markers for pathogen detection are fully tested to evaluate their specificity in detection of the pathogen. In an effort to evaluate 11 reported diagnostic techniques, we assembled a standardized DNA library using accessions from the World Phytophthora Genetic Resource Collection for 315 isolates representing 60 described Phytophthora spp. as well as 11 taxonomically unclassified isolates. These were sent blind to collaborators in seven laboratories to evaluate published diagnostic procedures using conventional (based on internal transcribed spacer [ITS] and cytochrome oxidase gene [cox]1 and 2 spacer regions) and real-time polymerase chain reaction (based on ITS and cox1 and 2 spacer regions as well as beta-tubulin and elicitin genes). Single-strand conformation polymorphism (SSCP) analysis using an automated sequencer for data collection was also evaluated for identification of all species tested. In general, the procedures worked well, with varying levels of specificity observed among the different techniques. With few exceptions, all assays correctly identified all isolates of P. ramorum and low levels of false positives were observed for the mitochondrial cox spacer markers and most of the real-time assays based on nuclear markers (diagnostic specificity between 96.9 and 100%). The highest level of false positives was obtained with the conventional nested ITS procedure; however, this technique is not stand-alone and is used in conjunction with two other assays for diagnostic purposes. The results indicated that using multiple assays improved the accuracy of the results compared with looking at a single assay alone, in particular when the markers represented different genetic loci. The SSCP procedure accurately identified P. ramorum and was helpful in classification of a number of isolates to a species level. With one exception, all procedures accurately identified P. ramorum in blind evaluations of 60 field samples that included examples of plant infection by 11 other Phytophthora spp. The SSCP analysis identified eight of these species, with three identified to a species group.

Evaluation of reconstruction errors and identification of artefacts for JET gamma and neutron tomography

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

Craciunescu, Teddy, E-mail: teddy.craciunescu@jet.uk; Tiseanu, Ion; Zoita, Vasile

The Joint European Torus (JET) neutron profile monitor ensures 2D coverage of the gamma and neutron emissive region that enables tomographic reconstruction. Due to the availability of only two projection angles and to the coarse sampling, tomographic inversion is a limited data set problem. Several techniques have been developed for tomographic reconstruction of the 2-D gamma and neutron emissivity on JET, but the problem of evaluating the errors associated with the reconstructed emissivity profile is still open. The reconstruction technique based on the maximum likelihood principle, that proved already to be a powerful tool for JET tomography, has been usedmore » to develop a method for the numerical evaluation of the statistical properties of the uncertainties in gamma and neutron emissivity reconstructions. The image covariance calculation takes into account the additional techniques introduced in the reconstruction process for tackling with the limited data set (projection resampling, smoothness regularization depending on magnetic field). The method has been validated by numerically simulations and applied to JET data. Different sources of artefacts that may significantly influence the quality of reconstructions and the accuracy of variance calculation have been identified.« less

Ultrasonic contrast agents in transcranial perfusion sonography (TPS) for follow-up of patients with high grade gliomas.

PubMed

Ickenstein, G W; Valaikiene, J; Koch, H; Hau, P; Erban, P; Schlachetzki, F

2008-04-01

The aim of this study was to evaluate brain perfusion differences in patients with high grade gliomas after partial tumor resection and irradiation/chemotherapy between tumor and non-tumor hemisphere by transcranial perfusion sonography (TPS) employing a contrast burst imaging (CBI) technique. Six patients with glioblastoma (WHO Grade IV) in the temporoparietal region within the defined axial diencephalic scanning plane were examined by TPS during follow-up. All subjects had an adequate acoustic temporal bone window. Transtemporal insonation on brain tumor and non-tumor hemisphere was performed with a bolus-injection of sulphur hexafluoride-based contrast agent (10 mg i.v., 5mg/ml--SonoVue, Bracco, Altana, Switzerland). Recorded images were analysed off-line by Quanticon Software (3D-Echotech, Munich, Germany) and time intensity curve parameters [area under the curve (AUC, dB s), peak intensity (PI, dB), time to peak (TTP, s)] in five regions of interest (ROI) [thalamus anterior, thalamus posterior, nucleus lentiformis, white matter, whole hemisphere] were evaluated. Statistical analyses were performed. Perfusion differences between brain tumor and non-tumor hemispheres were detected with contrast burst imaging (CBI) technique with a significantly greater mean AUC (5343.69 dB s vs. 4625.04 dB s, p<0.028) and a significantly prolonged TTP (32.72 s vs. 28.91 s, p<0.046) in the tumor hemisphere. Within our study population, TTP and AUC seem to be the most robust parameters for the evaluation of cerebral perfusion differences assessed by transcranial perfusion sonography with CBI technique. We hypothesize that these results correlate with microvascular changes due to treatment regimens, such as microvessel necrosis after irradiation and chemotherapy. Above that, TPS may be of value for the long-term follow-up of brain tumor therapy concept.

Conceptual models in exploration geochemistry-The Basin and Range Province of the Western United States and Northern Mexico

USGS Publications Warehouse

Lovering, T.G.; McCarthy, J.H.

1978-01-01

This summary of geochemical exploration in the Basin and Range Province is another in the series of reviews of geochemical-exploration applications covering a large region; this series began in 1975 with a summary for the Canadian Cordillera and Canadian Shield, and was followed in 1976 by a similar summary for Scandinavia (Norden). Rather than adhering strictly to the type of conceptual models applied in those papers, we have made use of generalized landscape geochemistry models related to the nature of concealment of ore deposits. This study is part of a continuing effort to examine and evaluate geochemical-exploration practices in different areas of the world. Twenty case histories of the application of geochemical exploration in both district and regional settings illustrate recent developments in techniques and approaches. Along with other published reports these case histories, exemplifying generalized models of concealed deposits, provide data used to evaluate geochemical-exploration programs and specific sample media. Because blind deposits are increasingly sought in the Basin and Range Province, the use of new sample media or anomaly-enhancement techniques is a necessity. Analysis of vapors or gases emanating from blind deposits is a promising new technique. Certain fractions of stream sediments show anomalies that are weak or not detected in conventional minus 80-mesh fractions. Multi-element analysis of mineralized bedrock may show zoning patterns that indicate depth or direction of ore. Examples of the application of these and other, more conventional methods are indicated in the case histories. The final section of this paper contains a brief evaluation of the applications of all types of sample media to geochemical exploration in the arid environment of the Basin and Range Province. ?? 1978.

A nonlinear dynamics approach for incorporating wind-speed patterns into wind-power project evaluation.

PubMed

Huffaker, Ray; Bittelli, Marco

2015-01-01

Wind-energy production may be expanded beyond regions with high-average wind speeds (such as the Midwest U.S.A.) to sites with lower-average speeds (such as the Southeast U.S.A.) by locating favorable regional matches between natural wind-speed and energy-demand patterns. A critical component of wind-power evaluation is to incorporate wind-speed dynamics reflecting documented diurnal and seasonal behavioral patterns. Conventional probabilistic approaches remove patterns from wind-speed data. These patterns must be restored synthetically before they can be matched with energy-demand patterns. How to accurately restore wind-speed patterns is a vexing problem spurring an expanding line of papers. We propose a paradigm shift in wind power evaluation that employs signal-detection and nonlinear-dynamics techniques to empirically diagnose whether synthetic pattern restoration can be avoided altogether. If the complex behavior of observed wind-speed records is due to nonlinear, low-dimensional, and deterministic system dynamics, then nonlinear dynamics techniques can reconstruct wind-speed dynamics from observed wind-speed data without recourse to conventional probabilistic approaches. In the first study of its kind, we test a nonlinear dynamics approach in an application to Sugarland Wind-the first utility-scale wind project proposed in Florida, USA. We find empirical evidence of a low-dimensional and nonlinear wind-speed attractor characterized by strong temporal patterns that match up well with regular daily and seasonal electricity demand patterns.

Lung tumor segmentation in PET images using graph cuts.

PubMed

Ballangan, Cherry; Wang, Xiuying; Fulham, Michael; Eberl, Stefan; Feng, David Dagan

2013-03-01

The aim of segmentation of tumor regions in positron emission tomography (PET) is to provide more accurate measurements of tumor size and extension into adjacent structures, than is possible with visual assessment alone and hence improve patient management decisions. We propose a segmentation energy function for the graph cuts technique to improve lung tumor segmentation with PET. Our segmentation energy is based on an analysis of the tumor voxels in PET images combined with a standardized uptake value (SUV) cost function and a monotonic downhill SUV feature. The monotonic downhill feature avoids segmentation leakage into surrounding tissues with similar or higher PET tracer uptake than the tumor and the SUV cost function improves the boundary definition and also addresses situations where the lung tumor is heterogeneous. We evaluated the method in 42 clinical PET volumes from patients with non-small cell lung cancer (NSCLC). Our method improves segmentation and performs better than region growing approaches, the watershed technique, fuzzy-c-means, region-based active contour and tumor customized downhill. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Automated detection of microaneurysms using scale-adapted blob analysis and semi-supervised learning.

PubMed

Adal, Kedir M; Sidibé, Désiré; Ali, Sharib; Chaum, Edward; Karnowski, Thomas P; Mériaudeau, Fabrice

2014-04-01

Despite several attempts, automated detection of microaneurysm (MA) from digital fundus images still remains to be an open issue. This is due to the subtle nature of MAs against the surrounding tissues. In this paper, the microaneurysm detection problem is modeled as finding interest regions or blobs from an image and an automatic local-scale selection technique is presented. Several scale-adapted region descriptors are introduced to characterize these blob regions. A semi-supervised based learning approach, which requires few manually annotated learning examples, is also proposed to train a classifier which can detect true MAs. The developed system is built using only few manually labeled and a large number of unlabeled retinal color fundus images. The performance of the overall system is evaluated on Retinopathy Online Challenge (ROC) competition database. A competition performance measure (CPM) of 0.364 shows the competitiveness of the proposed system against state-of-the art techniques as well as the applicability of the proposed features to analyze fundus images. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

A Gradient-Field Pulsed Eddy Current Probe for Evaluation of Hidden Material Degradation in Conductive Structures Based on Lift-Off Invariance

PubMed Central

Li, Yong; Jing, Haoqing; Zainal Abidin, Ilham Mukriz; Yan, Bei

2017-01-01

Coated conductive structures are widely adopted in such engineering fields as aerospace, nuclear energy, etc. The hostile and corrosive environment leaves in-service coated conductive structures vulnerable to Hidden Material Degradation (HMD) occurring under the protection coating. It is highly demanded that HMD can be non-intrusively assessed using non-destructive evaluation techniques. In light of the advantages of Gradient-field Pulsed Eddy Current technique (GPEC) over other non-destructive evaluation methods in corrosion evaluation, in this paper the GPEC probe for quantitative evaluation of HMD is intensively investigated. Closed-form expressions of GPEC responses to HMD are formulated via analytical modeling. The Lift-off Invariance (LOI) in GPEC signals, which makes the HMD evaluation immune to the variation in thickness of the protection coating, is introduced and analyzed through simulations involving HMD with variable depths and conductivities. A fast inverse method employing magnitude and time of the LOI point in GPEC signals for simultaneously evaluating the conductivity and thickness of HMD region is proposed, and subsequently verified by finite element modeling and experiments. It has been found from the results that along with the proposed inverse method the GPEC probe is applicable to evaluation of HMD in coated conductive structures without much loss in accuracy. PMID:28441328

A Gradient-Field Pulsed Eddy Current Probe for Evaluation of Hidden Material Degradation in Conductive Structures Based on Lift-Off Invariance.

PubMed

Li, Yong; Jing, Haoqing; Zainal Abidin, Ilham Mukriz; Yan, Bei

2017-04-25

Coated conductive structures are widely adopted in such engineering fields as aerospace, nuclear energy, etc. The hostile and corrosive environment leaves in-service coated conductive structures vulnerable to Hidden Material Degradation (HMD) occurring under the protection coating. It is highly demanded that HMD can be non-intrusively assessed using non-destructive evaluation techniques. In light of the advantages of Gradient-field Pulsed Eddy Current technique (GPEC) over other non-destructive evaluation methods in corrosion evaluation, in this paper the GPEC probe for quantitative evaluation of HMD is intensively investigated. Closed-form expressions of GPEC responses to HMD are formulated via analytical modeling. The Lift-off Invariance (LOI) in GPEC signals, which makes the HMD evaluation immune to the variation in thickness of the protection coating, is introduced and analyzed through simulations involving HMD with variable depths and conductivities. A fast inverse method employing magnitude and time of the LOI point in GPEC signals for simultaneously evaluating the conductivity and thickness of HMD region is proposed, and subsequently verified by finite element modeling and experiments. It has been found from the results that along with the proposed inverse method the GPEC probe is applicable to evaluation of HMD in coated conductive structures without much loss in accuracy.

The superiority of indium ratio over blood pool subtraction in analysis of indium-111 platelet deposition on thoraco-abdominal prosthetic grafts

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

Ripley, S.; Wakefield, T.; Spaulding, S.

1985-05-01

In this investigation platelet deposition in polytetrafluroethylene (PTFE) thoracoabdominal grafts (TAC's) was evaluated using two different semi-quantitative techniques. Ten PTFE TAG's 6 mm in diameter and 30 cm in length were inserted into 10 mongrel dogs. One, 4 and 6 weeks after graft implantation the animals were injected with autologous In-111 platelets labelled by a modified Thakur technique. Platelet imaging in grafts was performed 48 hrs after injection. Blood pool was determined by Tc99m labelled RBC's (in vivo/in vitro technique). Semi-quantitative analysis was performed by subdividing the imaged graft into three major regions and selecting a reference region from eithermore » the native aorta or common iliac artery. Excess platelet deposition was determined by two methods: 1) the ratio of In-111 counts in the graft ROI''s to the reference region and 2) the percent In-111 excess using the Tc99m blood pool subtraction technique (TBPST). Animals were sacrificed 7 weeks after implantation and radioactivity in the excised grafts was determined using a well counter. A positive correlation was found to exist between the In-111 ratio percent analysis (IRPA) and the direct gamma counting (DCC) for all three segments of the prosthetic graft. Correlation coefficients for the thorax, midsegment and abdominal segments were 0.80, 0.73 and 0.48 respectivly. There was no correlation between TBPST and DGC. Using the IRPA technique the thrombogenicity of TAG's can be routinely assessed and is clinically applicable for patient use. TBPST should probably be limited to the extremities to avoid error due to free Tc99m counts from kidneys and ureters.« less

Pedunculopontine Nucleus Region Deep Brain Stimulation in Parkinson Disease: Surgical Techniques, Side Effects, and Postoperative Imaging

PubMed Central

Hamani, Clement; Lozano, Andres M.; Mazzone, Paolo A.M.; Moro, Elena; Hutchison, William; Silburn, Peter A.; Zrinzo, Ludvic; Alam, Mesbah; Goetz, Laurent; Pereira, Erlick; Rughani, Anand; Thevathasan, Wesley; Aziz, Tipu; Bloem, Bastiaan R.; Brown, Peter; Chabardes, Stephan; Coyne, Terry; Foote, Kelly; Garcia-Rill, Edgar; Hirsch, Etienne C.; Okun, Michael S.; Krauss, Joachim K.

2017-01-01

The pedunculopontine nucleus (PPN) region has received considerable attention in clinical studies as a target for deep brain stimulation (DBS) in Parkinson disease. These studies have yielded variable results with an overall impression of improvement in falls and freezing in many but not all patients treated. We evaluated the available data on the surgical anatomy and terminology of the PPN region in a companion paper. Here we focus on issues concerning surgical technique, imaging, and early side effects of surgery. The aim of this paper was to gain more insight into the reasoning for choosing specific techniques and to discuss short-comings of available studies. Our data demonstrate the wide range in almost all fields which were investigated. There are a number of important challenges to be resolved, such as identification of the optimal target, the choice of the surgical approach to optimize electrode placement, the impact on the outcome of specific surgical techniques, the reliability of intraoperative confirmation of the target, and methodological differences in postoperative validation of the electrode position. There is considerable variability both within and across groups, the overall experience with PPN DBS is still limited, and there is a lack of controlled trials. Despite these challenges, the procedure seems to provide benefit to selected patients and appears to be relatively safe. One important limitation in comparing studies from different centers and analyzing outcomes is the great variability in targeting and surgical techniques, as shown in our paper. The challenges we identified will be of relevance when designing future studies to better address several controversial issues. We hope that the data we accumulated may facilitate the development of surgical protocols for PPN DBS. PMID:27728909

Spatial and size-frequency distribution of Acropora (Cnidaria: Scleractinia) species in Chinchorro Bank, Mexican Caribbean: implications for management

NASA Astrophysics Data System (ADS)

Vega-Zepeda, A.; Hernández-Arana, H.; Carricart-Ganivet, J. P.

2007-09-01

The Mexican Government decreed Chinchorro Bank reef as a Biosphere Reserve in 1996. The aim of this study was to evaluate the spatial and size-frequency distribution of Acropora spp. in order to provide further knowledge and tools to enhance management. A field survey was conducted, within six regions, to locate and measure Acropora patches in the reef lagoon. Density, colony size and living tissue cover of Acropora colonies were evaluated using the line-intercept transect technique, combining direct observations and video transects. The results showed that Acropora spp. was preferentially distributed in the southern regions; where cover and density were high. Based on these results and considering that Acropora spp. produces landscape heterogeneity, which in turn generates shelter for other species, including some of considerable economic importance, then at least the South East region should be considered as a key area for Acropora species conservation, and should be included in the Chinchorro Bank management plan.

Mass preserving registration for lung CT

NASA Astrophysics Data System (ADS)

Gorbunova, Vladlena; Lo, Pechin; Loeve, Martine; Tiddens, Harm A.; Sporring, Jon; Nielsen, Mads; de Bruijne, Marleen

2009-02-01

In this paper, we evaluate a novel image registration method on a set of expiratory-inspiratory pairs of computed tomography (CT) lung scans. A free-form multi resolution image registration technique is used to match two scans of the same subject. To account for the differences in the lung intensities due to differences in inspiration level, we propose to adjust the intensity of lung tissue according to the local expansion or compression. An image registration method without intensity adjustment is compared to the proposed method. Both approaches are evaluated on a set of 10 pairs of expiration and inspiration CT scans of children with cystic fibrosis lung disease. The proposed method with mass preserving adjustment results in significantly better alignment of the vessel trees. Analysis of local volume change for regions with trapped air compared to normally ventilated regions revealed larger differences between these regions in the case of mass preserving image registration, indicating that mass preserving registration is better at capturing localized differences in lung deformation.

Flood inundation extent mapping based on block compressed tracing

NASA Astrophysics Data System (ADS)

Shen, Dingtao; Rui, Yikang; Wang, Jiechen; Zhang, Yu; Cheng, Liang

2015-07-01

Flood inundation extent, depth, and duration are important factors affecting flood hazard evaluation. At present, flood inundation analysis is based mainly on a seeded region-growing algorithm, which is an inefficient process because it requires excessive recursive computations and it is incapable of processing massive datasets. To address this problem, we propose a block compressed tracing algorithm for mapping the flood inundation extent, which reads the DEM data in blocks before transferring them to raster compression storage. This allows a smaller computer memory to process a larger amount of data, which solves the problem of the regular seeded region-growing algorithm. In addition, the use of a raster boundary tracing technique allows the algorithm to avoid the time-consuming computations required by the seeded region-growing. Finally, we conduct a comparative evaluation in the Chin-sha River basin, results show that the proposed method solves the problem of flood inundation extent mapping based on massive DEM datasets with higher computational efficiency than the original method, which makes it suitable for practical applications.

Water quality studied in areas of unconventional oil and gas development, including areas where hydraulic fracturing techniques are used, in the United States

USGS Publications Warehouse

Susong, David D.; Gallegos, Tanya J.; Oelsner, Gretchen P.

2012-01-01

The U.S. Geological Survey (USGS) John Wesley Powell Center for Analysis and Synthesis is hosting an interdisciplinary working group of USGS scientists to conduct a temporal and spatial analysis of surface-water and groundwater quality in areas of unconventional oil and gas development. The analysis uses existing national and regional datasets to describe water quality, evaluate water-quality changes over time where there are sufficient data, and evaluate spatial and temporal data gaps.

Ecological Sensitivity Evaluation of Tourist Region Based on Remote Sensing Image - Taking Chaohu Lake Area as a Case Study

NASA Astrophysics Data System (ADS)

Lin, Y.; Li, W. J.; Yu, J.; Wu, C. Z.

2018-04-01

Remote sensing technology is of significant advantages for monitoring and analysing ecological environment. By using of automatic extraction algorithm, various environmental resources information of tourist region can be obtained from remote sensing imagery. Combining with GIS spatial analysis and landscape pattern analysis, relevant environmental information can be quantitatively analysed and interpreted. In this study, taking the Chaohu Lake Basin as an example, Landsat-8 multi-spectral satellite image of October 2015 was applied. Integrated the automatic ELM (Extreme Learning Machine) classification results with the data of digital elevation model and slope information, human disturbance degree, land use degree, primary productivity, landscape evenness , vegetation coverage, DEM, slope and normalized water body index were used as the evaluation factors to construct the eco-sensitivity evaluation index based on AHP and overlay analysis. According to the value of eco-sensitivity evaluation index, by using of GIS technique of equal interval reclassification, the Chaohu Lake area was divided into four grades: very sensitive area, sensitive area, sub-sensitive areas and insensitive areas. The results of the eco-sensitivity analysis shows: the area of the very sensitive area was 4577.4378 km2, accounting for about 37.12 %, the sensitive area was 5130.0522 km2, accounting for about 37.12 %; the area of sub-sensitive area was 3729.9312 km2, accounting for 26.99 %; the area of insensitive area was 382.4399 km2, accounting for about 2.77 %. At the same time, it has been found that there were spatial differences in ecological sensitivity of the Chaohu Lake basin. The most sensitive areas were mainly located in the areas with high elevation and large terrain gradient. Insensitive areas were mainly distributed in slope of the slow platform area; the sensitive areas and the sub-sensitive areas were mainly agricultural land and woodland. Through the eco-sensitivity analysis of the study area, the automatic recognition and analysis techniques for remote sensing imagery are integrated into the ecological analysis and ecological regional planning, which can provide a reliable scientific basis for rational planning and regional sustainable development of the Chaohu Lake tourist area.

Rare Infratentorial and Supratentorial Localization of Juvenile Angiofibroma: A Case Report.

PubMed

Pašalić, Ivan; Trninić, Ines; Nemir, Jakob; Jednačak, Hrvoje; Žarković, Kamelija; Mrak, Goran

2016-01-01

Angiofibromas are rare tumors of the head and neck that mostly occur in the sphenopalatine region. We present a case of angiofibroma in a young male patient with an unusual and extremely rare localization, which to our knowledge has not been described before. It was situated in the tentorium and spread to the supratentorial and infratentorial regions. The patient initially presented with symptoms of increased intracranial pressure. After a diagnostic evaluation was done, the whole tumor was successfully removed using the supratentorial and infratentorial approach and the microsurgical technique. © 2016 S. Karger AG, Basel.

Gastrointestinal parasites of owls (Strigiformes) kept in captivity in the Southern region of Brazil.

PubMed

da Silva, Aleksandro S; Zanette, Régis A; Lara, Valéria M; Gressler, Luciane T; Carregaro, Adriano B; Santurio, Janio M; Monteiro, Silvia G

2009-01-01

The aim of this research was to study the gastrointestinal parasitism in 12 adult owls kept in captivity in the Southern region of Brazil. Cloacal contents of the species Rhinoptynx clamator, Tyto alba, Athene cunicularia, Megascops spp., and Bubo virginianus were evaluated. Feces and urine were collected and analyzed by the zinc sulfate centrifugal-flotation method and stained by the modified Ziehl-Neelsen technique. Eggs of Capillaria spp. and Strongylida, oocysts of Cryptosporidium spp., Eimeria spp., and Isospora spp. were observed. The birds showed no clinical signs, probably due to the mild nature of the infection.

Energy and Technology Review

NASA Astrophysics Data System (ADS)

Poggio, Andrew J.

1988-10-01

This issue of Energy and Technology Review contains: Neutron Penumbral Imaging of Laser-Fusion Targets--using our new penumbral-imaging diagnostic, we have obtained the first images that can be used to measure directly the deuterium-tritium burn region in laser-driven fusion targets; Computed Tomography for Nondestructive Evaluation--various computed tomography systems and computational techniques are used in nondestructive evaluation; Three-Dimensional Image Analysis for Studying Nuclear Chromatin Structure--we have developed an optic-electronic system for acquiring cross-sectional views of cell nuclei, and computer codes to analyze these images and reconstruct the three-dimensional structures they represent; Imaging in the Nuclear Test Program--advanced techniques produce images of unprecedented detail and resolution from Nevada Test Site data; and Computational X-Ray Holography--visible-light experiments and numerically simulated holograms test our ideas about an X-ray microscope for biological research.

Evaluating Application Resilience with XRay

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

Chen, Sui; Bronevetsky, Greg; Li, Bin

2015-05-07

The rising count and shrinking feature size of transistors within modern computers is making them increasingly vulnerable to various types of soft faults. This problem is especially acute in high-performance computing (HPC) systems used for scientific computing, because these systems include many thousands of compute cores and nodes, all of which may be utilized in a single large-scale run. The increasing vulnerability of HPC applications to errors induced by soft faults is motivating extensive work on techniques to make these applications more resiilent to such faults, ranging from generic techniques such as replication or checkpoint/restart to algorithmspecific error detection andmore » tolerance techniques. Effective use of such techniques requires a detailed understanding of how a given application is affected by soft faults to ensure that (i) efforts to improve application resilience are spent in the code regions most vulnerable to faults and (ii) the appropriate resilience technique is applied to each code region. This paper presents XRay, a tool to view the application vulnerability to soft errors, and illustrates how XRay can be used in the context of a representative application. In addition to providing actionable insights into application behavior XRay automatically selects the number of fault injection experiments required to provide an informative view of application behavior, ensuring that the information is statistically well-grounded without performing unnecessary experiments.« less

Gated blood pool tomography for the evaluation of global and regional left ventricular function in comparison to planar techniques and echocardiography.

PubMed

Canclini, S; Terzi, A; Rossini, P; Vignati, A; La Canna, G; Magri, G C; Pizzocaro, C; Giubbini, R

2001-01-01

Multigated radionuclide ventriculography (MUGA) is a simple and reliable tool for the assessment of global systolic and diastolic function and in several studies it is still considered a standard for the assessment of left ventricular ejection fraction. However the evaluation of regional wall motion by MUGA is critical due to two-dimensional imaging and its clinical use is progressively declining in favor of echocardiography. Tomographic MUGA (T-MUGA) is not widely adopted in clinical practice. The aim of this study was to compare T-MUGA to planar MUGA (P-MUGA) for the assessment of global ejection fraction and to transthoracic echocardiography for the evaluation of regional wall motion. A 16-segment model was adopted for the comparison with echo regional wall motion. For each one of the 16 segments the normal range of T-MUGA ejection fraction was quantified and a normal data file was defined; the average value -2.5 SD was used as the lower threshold to identify abnormal segments. In addition, amplitude images from Fourier analysis were quantified and considered abnormal according to three different thresholds (25, 50 and 75% of the maximum). In a study group of 33 consecutive patients the ejection fraction values of T-MUGA highly correlated with those of P-MUGA (r = 0.93). The regional ejection fraction (according to the normal database) and the amplitude analysis (50% threshold) allowed for the correct identification of 203/226 and 167/226 asynergic segments by echocardiography, and of 269/302 and 244/302 normal segments, respectively. Therefore sensitivity, specificity and overall accuracy to detect regional wall motion abnormalities were 90, 89, 89% and 74, 81, 79% for regional ejection fraction and amplitude analysis, respectively. T-MUGA is a reliable tool for regional wall motion evaluation, well correlated with echocardiography, less subjective and able to provide quantitative data.

Testing an advanced satellite technique for dust detection as a decision support system for the air quality assessment

NASA Astrophysics Data System (ADS)

Falconieri, Alfredo; Filizzola, Carolina; Femiano, Rossella; Marchese, Francesco; Sannazzaro, Filomena; Pergola, Nicola; Tramutoli, Valerio; Di Muro, Ersilia; Divietri, Mariella; Crisci, Anna Maria; Lovallo, Michele; Mangiamele, Lucia; Vaccaro, Maria Pia; Palma, Achille

2014-05-01

In order to correctly apply the European directive for air quality (2008/50/CE), local Authorities are often requested to discriminate the possible origin (natural/anthropic) of anomalous concentration of pollutants in the air (art.20 Directive 2008/50/CE). In this framework, it's been focused on PM10 and PM2,5 concentrations and sources. In fact, depending on their origin, appropriate counter-measures can be taken devoted to prevent their production (e.g. by traffic restriction) or simply to reduce their impact on citizen health (e.g. information campaigns). In this context suitable satellite techniques can be used in order to identify natural sources (particularly Saharan dust, but also volcanic ash or forest fire smoke) that can be responsible of over-threshold concentration of PM10/2,5 in populated areas. In the framework of the NIBS (Networking and Internationalization of Basilicata Space Technologies) project, funded by the Basilicata Region within the ERDF 2007-2013 program, the School of Engineering of University of Basilicata, the Institute of Methodologies for Environmental Analysis of National Research Council (IMAA-CNR) and the Regional Agency for the Protection of the Environment of Basilicata Region (ARPAB) have started a collaboration devoted to assess the potential of the use of advanced satellite techniques for Saharan dust events identification to support ARPAB activities related to the application of the European directive for air quality (2008/50/CE) in Basilicata region. In such a joint activity, the Robust Satellite Technique (RST) approach has been assessed and tested as a decision support system for monitoring and evaluating air quality at local and regional level. In particular, RST-DUST products, derived by processing high temporal resolution data provided by SEVIRI (Spinning Enhanced Visible and Infrared Imager) sensor on board Meteosat Second Generation platforms, have been analysed together with PM10 measurements performed by the ground-based stations operated by ARPAB. Such an inter-comparison was devoted to investigate possible PM10 over-threshold occurrences and to better evaluate their possible causes (i.e. anthropogenic and/or natural sources). The analysis demonstrated the added value of an independent, automatic and unsupervised satellite based system (capable of discriminating over-threshold PM10 data produced by natural source from the ones occurred because of anthropogenic causes) in supporting the decisions of the considered end-user (ARPAB) in a pre-operational context.

SU-E-T-433: Field-In-Field Irradiation for Breast Cancer with VERO-4DRT System: A Feasibility Study

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

Hayashi, N; Mizuno, T; Takada, Y

2015-06-15

Purpose: The Vero-4DRT system is a dedicated system for high precision radiation therapy. However, the field size is limited at 15 cm x 15 cm and shapes by using multi-leaf collimator (MLC) without X-Jaw and Y-Jaw. Therefore VERO-4DRT system is not available to simple wedged irradiation for breast cancer. In this study, we suppose FIF with ring and/or tilt/pan angles whole breast irradiation (FIFWBI). The purpose of this study is to verify the feasibility of FIFWBI with VERO-4DRT system. Methods: As fundamental evaluation, we performed commissioning test with phantom. The absorbed dose evaluation at several reference points and dose distributionmore » including split area were performed. We planned 10 demonstrative shapes in phantom for measuring these contents with i-plan workstation (BrainLAB). As clinical evaluation, the dose distribution and dose indexes were evaluated with actual patient data. Five patients with breast cancer were designed FIFWBI radiotherapy plan with split fields. Then, the dose distribution and dose indexes (including Dmax, Dmin, D95, D5 and Homogeneity index) were evaluated in these plans. Results: As the results of fundamental evaluation, all absorbed dose errors between calculated and measured doses were within 2%. The gamma passing rates with 2 mm/3% criteria in all cases were 96±2%. As the results of clinical evaluation, the values of Dmax, D95, D50, D5, and Homogeneity Index were 41.7±0.90 Gy, 49.4±0.34 Gy, 52.26±0.24 Gy, and 1.39±0.03, respectively. For Japanese breast cancer patients, this technique was feasible. However, the large split region was happened in FIFWBI in case of patient with large breast. Conclusion: We evaluated the FIFWBI technique with VERO-4DRT system. This technique is feasible for Japanese patients, but the patient with large breast should be disagreed with this technique.« less

Hypoalgesic effects of three different manual therapy techniques on cervical spine and psychological interaction: A randomized clinical trial.

PubMed

Alonso-Perez, Jose Luis; Lopez-Lopez, Almudena; La Touche, Roy; Lerma-Lara, Sergio; Suarez, Emilio; Rojas, Javier; Bishop, Mark D; Villafañe, Jorge Hugo; Fernández-Carnero, Josué

2017-10-01

The purpose of this study was to evaluate the extent to which psychological factors interact with a particular manual therapy (MT) technique to induce hypoalgesia in healthy subjects. Seventy-five healthy volunteers (36 female, 39 males), were recruited in this double-blind, controlled and parallel study. Subjects were randomly assigned to receive: High velocity low amplitude technique (HVLA), joint mobilization, or Cervical Lateral glide mobilization (CLGM). Pressure pain threshold (PPT) over C7 unilaterally, trapezius muscle and lateral epicondyle bilaterally, were measured prior to single technique MT was applied and immediately after to applied MT. Pain catastrophizing, depression, anxiety and kinesiophobia were evaluated before treatment. The results indicate that hypoalgesia was observed in all groups after treatment in the neck and elbow region (P < 0.05), but mobilization induces more hypoalgesic effects. Catastrophizing interacted with change over time in PPT, for changes in C7 and in manipulation group. All the MT techniques studied produced local and segmental hypoalgesic effects, supporting the results of previous studies studying the individual interventions. Interaction between catastrophizing and HVLA technique suggest that whether catastrophizing level is low or medium, the chance of success is high, but high levels of catastrophizing may result in poor outcome after HVLA intervention. ClinicalTrials.gov Registration Number: NCT02782585. Copyright © 2016 Elsevier Ltd. All rights reserved.

Intracranial Vascular Disease Evaluation With Combined Vessel Wall Imaging And Patient Specific Hemodynamics

NASA Astrophysics Data System (ADS)

Samson, Kurt; Mossa-Basha, Mahmud; Yuan, Chun; Canton, Maria De Gador; Aliseda, Alberto

2017-11-01

Intracranial vascular pathologies are evaluated with angiography, conventional digital subtraction angiography or non-invasive (MRI, CT). Current techniques present limitations on the resolution with which the vessel wall characteristics can be measured, presenting a major challenge to differential diagnostic of cerebral vasculopathies. A new combined approach is presented that incorporates patient-specific image-based CFD models with intracranial vessel-wall MRI (VWMRI). Comparisons of the VWMRI measurements, evaluated for the presence of wall enhancement and thin-walled regions, against CFD metrics such as wall shear stress (WSS), and oscillatory shear index (OSI) are used to understand how the new imaging technique developed can predict the influence of hemodynamics on the deterioration of the aneurysmal wall, leading to rupture. Additionally, histology of each resected aneurysm, evaluated for inflammatory infiltration and wall thickness features, is used to validate the analysis from VWMRI and CFD. This data presents a solid foundation on which to build a new framework for combined VWMRI-CFD to predict unstable wall changes in unruptured intracranial aneurysms, and support clinical monitoring and intervention decisions.

Radionuclide evaluation of lung trauma

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

Lull, R.J.; Tatum, J.L.; Sugerman, H.J.

1983-07-01

Nuclear medicine imaging procedures can play a significant role in evaluating the pulmonary complications that are seen in trauma patients. A quantitative method for measuring increased pulmonary capillary permeability that uses Tc-99m HSA allows early diagnosis of acute respiratory distress syndrome (ARDS) and accurately differentiates this condition from pneumonia or cardiogenic pulmonary edema. This technique may be of great value in following the response to therapy. The use of 133Xe to diagnose inhalation injury remains an important diagnostic tool, particularly at hospitals with specialized burn units. Regional decreases in ventilation-perfusion images reliably localize aspirated foreign bodies. Radionuclide techniques that aremore » used to demonstrate gastropulmonary aspiration remain controversial and require further clinical evaluation. Pulmonary perfusion imaging, although nonspecific, may provide the earliest clue for correct diagnosis of fat embolism, air embolism, contusion, or laceration. Furthermore, the possibility of perfusion abnormality due to these uncommon conditions must be remembered whenever trauma patients are evaluated for pulmonary thromboembolism with scintigraphy. Occasionally, liver or spleen scintigraphy may be the most appropriate procedure when penetrating chest trauma also involves these subdiaphragmatic organs.« less

Assessment of the performance of water harvesting systems in semi-arid regions

NASA Astrophysics Data System (ADS)

Lasage, Ralph

2016-04-01

Water harvesting is widely practiced and has the potential to improve water availability for domestic and agricultural use in semi-arid regions. New funds are becoming available to stimulate the implementation of water harvesting projects, for meeting the Sustainable Development Goals and to help communities to adapt to climate change. For this, it is important to understand which factors determine the success of water harvesting techniques under different conditions. For this, we review the literature, including information on the crop yield impacts of water harvesting projects in semi-arid Africa and Asia. Results show that large water harvesting structures (> 500 m3) are less expensive than small structures, when taking into account investment costs, storage capacity and lifetimes. We also find that water harvesting improves crop yields significantly, and that the relative impact of water harvesting on crop yields is largest in low rainfall years. We also see that the governance, technical knowledge and initial investment are more demanding for the larger structures than for smaller structures, which may affect their spontaneous adoption and long term sustainability when managed by local communities. To support the selection of appropriate techniques, we present a decision framework based on case specific characteristics. This framework can also be used when reporting and evaluating the performance of water harvesting techniques, which is up to now quite limited in peer reviewed literature. Based on Bouma, J., Hegde, S.E., Lasage, R., (2016). Assessing the returns to water harvesting: A meta-analysis. Agricultural Water Management 163, 100-109. Lasage, R., Verburg P.H., (2015). Evaluation of small scale water harvesting techniques for semi-arid environments. Journal of Arid Environments 118, 48-57.

Building Roof Segmentation from Aerial Images Using a Line-and Region-Based Watershed Segmentation Technique

PubMed Central

Merabet, Youssef El; Meurie, Cyril; Ruichek, Yassine; Sbihi, Abderrahmane; Touahni, Raja

2015-01-01

In this paper, we present a novel strategy for roof segmentation from aerial images (orthophotoplans) based on the cooperation of edge- and region-based segmentation methods. The proposed strategy is composed of three major steps. The first one, called the pre-processing step, consists of simplifying the acquired image with an appropriate couple of invariant and gradient, optimized for the application, in order to limit illumination changes (shadows, brightness, etc.) affecting the images. The second step is composed of two main parallel treatments: on the one hand, the simplified image is segmented by watershed regions. Even if the first segmentation of this step provides good results in general, the image is often over-segmented. To alleviate this problem, an efficient region merging strategy adapted to the orthophotoplan particularities, with a 2D modeling of roof ridges technique, is applied. On the other hand, the simplified image is segmented by watershed lines. The third step consists of integrating both watershed segmentation strategies into a single cooperative segmentation scheme in order to achieve satisfactory segmentation results. Tests have been performed on orthophotoplans containing 100 roofs with varying complexity, and the results are evaluated with the VINETcriterion using ground-truth image segmentation. A comparison with five popular segmentation techniques of the literature demonstrates the effectiveness and the reliability of the proposed approach. Indeed, we obtain a good segmentation rate of 96% with the proposed method compared to 87.5% with statistical region merging (SRM), 84% with mean shift, 82% with color structure code (CSC), 80% with efficient graph-based segmentation algorithm (EGBIS) and 71% with JSEG. PMID:25648706

A biomechanical modeling-guided simultaneous motion estimation and image reconstruction technique (SMEIR-Bio) for 4D-CBCT reconstruction

NASA Astrophysics Data System (ADS)

Huang, Xiaokun; Zhang, You; Wang, Jing

2018-02-01

Reconstructing four-dimensional cone-beam computed tomography (4D-CBCT) images directly from respiratory phase-sorted traditional 3D-CBCT projections can capture target motion trajectory, reduce motion artifacts, and reduce imaging dose and time. However, the limited numbers of projections in each phase after phase-sorting decreases CBCT image quality under traditional reconstruction techniques. To address this problem, we developed a simultaneous motion estimation and image reconstruction (SMEIR) algorithm, an iterative method that can reconstruct higher quality 4D-CBCT images from limited projections using an inter-phase intensity-driven motion model. However, the accuracy of the intensity-driven motion model is limited in regions with fine details whose quality is degraded due to insufficient projection number, which consequently degrades the reconstructed image quality in corresponding regions. In this study, we developed a new 4D-CBCT reconstruction algorithm by introducing biomechanical modeling into SMEIR (SMEIR-Bio) to boost the accuracy of the motion model in regions with small fine structures. The biomechanical modeling uses tetrahedral meshes to model organs of interest and solves internal organ motion using tissue elasticity parameters and mesh boundary conditions. This physics-driven approach enhances the accuracy of solved motion in the organ’s fine structures regions. This study used 11 lung patient cases to evaluate the performance of SMEIR-Bio, making both qualitative and quantitative comparisons between SMEIR-Bio, SMEIR, and the algebraic reconstruction technique with total variation regularization (ART-TV). The reconstruction results suggest that SMEIR-Bio improves the motion model’s accuracy in regions containing small fine details, which consequently enhances the accuracy and quality of the reconstructed 4D-CBCT images.

Evaluation of thresholding techniques for segmenting scaffold images in tissue engineering

NASA Astrophysics Data System (ADS)

Rajagopalan, Srinivasan; Yaszemski, Michael J.; Robb, Richard A.

2004-05-01

Tissue engineering attempts to address the ever widening gap between the demand and supply of organ and tissue transplants using natural and biomimetic scaffolds. The regeneration of specific tissues aided by synthetic materials is dependent on the structural and morphometric properties of the scaffold. These properties can be derived non-destructively using quantitative analysis of high resolution microCT scans of scaffolds. Thresholding of the scanned images into polymeric and porous phase is central to the outcome of the subsequent structural and morphometric analysis. Visual thresholding of scaffolds produced using stochastic processes is inaccurate. Depending on the algorithmic assumptions made, automatic thresholding might also be inaccurate. Hence there is a need to analyze the performance of different techniques and propose alternate ones, if needed. This paper provides a quantitative comparison of different thresholding techniques for segmenting scaffold images. The thresholding algorithms examined include those that exploit spatial information, locally adaptive characteristics, histogram entropy information, histogram shape information, and clustering of gray-level information. The performance of different techniques was evaluated using established criteria, including misclassification error, edge mismatch, relative foreground error, and region non-uniformity. Algorithms that exploit local image characteristics seem to perform much better than those using global information.

Helium-3 MR q-space imaging with radial acquisition and iterative highly constrained back-projection.

PubMed

O'Halloran, Rafael L; Holmes, James H; Wu, Yu-Chien; Alexander, Andrew; Fain, Sean B

2010-01-01

An undersampled diffusion-weighted stack-of-stars acquisition is combined with iterative highly constrained back-projection to perform hyperpolarized helium-3 MR q-space imaging with combined regional correction of radiofrequency- and T1-related signal loss in a single breath-held scan. The technique is tested in computer simulations and phantom experiments and demonstrated in a healthy human volunteer with whole-lung coverage in a 13-sec breath-hold. Measures of lung microstructure at three different lung volumes are evaluated using inhaled gas volumes of 500 mL, 1000 mL, and 1500 mL to demonstrate feasibility. Phantom results demonstrate that the proposed technique is in agreement with theoretical values, as well as with a fully sampled two-dimensional Cartesian acquisition. Results from the volunteer study demonstrate that the root mean squared diffusion distance increased significantly from the 500-mL volume to the 1000-mL volume. This technique represents the first demonstration of a spatially resolved hyperpolarized helium-3 q-space imaging technique and shows promise for microstructural evaluation of lung disease in three dimensions. Copyright (c) 2009 Wiley-Liss, Inc.

Radionuclide evaluation of left ventricular function with nonimaging probes.

PubMed

Wexler, J P; Blaufox, M D

1979-10-01

Portable nonimaging probes have been developed that can evaluate left ventricular function using radionuclide techniques. Two modes of data acquisition are possible with these probe systems, first-pass and gated. Precordial radiocardiograms obtained after a bolus injection can be used to determine cardiac output, pulmonary transit time, pulmonary blood volume, left ventricle ejection fraction, and left-to-right shunts. Gated techniques can be used to determine left ventricular ejection fraction and sytolic time intervals. Probe-determined indices of left ventricular function agree excellently with comparable measurements determined by conventional camera-computer methods as well as by invasive techniques. These have begun to be used in a preliminary manner in a variety of clinical problems associated with left ventricular dysfunction. This review discusses the types of probe systems available, the methods used in positioning them, and details the specifics of their data acquisition and processing capacity. The major criticisms of probe methods are that they are nonimaging and that they measure global rather than regional left ventricular function. In spite of these criticisms, probe systems, because of their portability, high sensitivity, and relatively low cost are useful supplements to conventional camera-computer systems for the measurement of parameters of left ventricular performance using radionuclide techniques.

A fusion of top-down and bottom-up modeling techniques to constrain regional scale carbon budgets

NASA Astrophysics Data System (ADS)

Goeckede, M.; Turner, D. P.; Michalak, A. M.; Vickers, D.; Law, B. E.

2009-12-01

The effort to constrain regional scale carbon budgets benefits from assimilating as many high quality data sources as possible in order to reduce uncertainties. Two of the most common approaches used in this field, bottom-up and top-down techniques, both have their strengths and weaknesses, and partly build on very different sources of information to train, drive, and validate the models. Within the context of the ORCA2 project, we follow both bottom-up and top-down modeling strategies with the ultimate objective of reconciling their surface flux estimates. The ORCA2 top-down component builds on a coupled WRF-STILT transport module that resolves the footprint function of a CO2 concentration measurement in high temporal and spatial resolution. Datasets involved in the current setup comprise GDAS meteorology, remote sensing products, VULCAN fossil fuel inventories, boundary conditions from CarbonTracker, and high-accuracy time series of atmospheric CO2 concentrations. Surface fluxes of CO2 are normally provided through a simple diagnostic model which is optimized against atmospheric observations. For the present study, we replaced the simple model with fluxes generated by an advanced bottom-up process model, Biome-BGC, which uses state-of-the-art algorithms to resolve plant-physiological processes, and 'grow' a biosphere based on biogeochemical conditions and climate history. This approach provides a more realistic description of biomass and nutrient pools than is the case for the simple model. The process model ingests various remote sensing data sources as well as high-resolution reanalysis meteorology, and can be trained against biometric inventories and eddy-covariance data. Linking the bottom-up flux fields to the atmospheric CO2 concentrations through the transport module allows evaluating the spatial representativeness of the BGC flux fields, and in that way assimilates more of the available information than either of the individual modeling techniques alone. Bayesian inversion is then applied to assign scaling factors that align the surface fluxes with the CO2 time series. Our project demonstrates how bottom-up and top-down techniques can be reconciled to arrive at a more robust and balanced spatial carbon budget. We will show how to evaluate existing flux products through regionally representative atmospheric observations, i.e. how well the underlying model assumptions represent processes on the regional scale. Adapting process model parameterizations sets for e.g. sub-regions, disturbance regimes, or land cover classes, in order to optimize the agreement between surface fluxes and atmospheric observations can lead to improved understanding of the underlying flux mechanisms, and reduces uncertainties in the regional carbon budgets.

Laser Scanning Systems and Techniques in Rockfall Source Identification and Risk Assessment: A Critical Review

NASA Astrophysics Data System (ADS)

Fanos, Ali Mutar; Pradhan, Biswajeet

2018-04-01

Rockfall poses risk to people, their properties and to transportation ways in mountainous and hilly regions. This catastrophe shows various characteristics such as vast distribution, sudden occurrence, variable magnitude, strong fatalness and randomicity. Therefore, prediction of rockfall phenomenon both spatially and temporally is a challenging task. Digital Terrain model (DTM) is one of the most significant elements in rockfall source identification and risk assessment. Light detection and ranging (LiDAR) is the most advanced effective technique to derive high-resolution and accurate DTM. This paper presents a critical overview of rockfall phenomenon (definition, triggering factors, motion modes and modeling) and LiDAR technique in terms of data pre-processing, DTM generation and the factors that can be obtained from this technique for rockfall source identification and risk assessment. It also reviews the existing methods that are utilized for the evaluation of the rockfall trajectories and their characteristics (frequency, velocity, bouncing height and kinetic energy), probability, susceptibility, hazard and risk. Detail consideration is given on quantitative methodologies in addition to the qualitative ones. Various methods are demonstrated with respect to their application scales (local and regional). Additionally, attention is given to the latest improvement, particularly including the consideration of the intensity of the phenomena and the magnitude of the events at chosen sites.

Identification of Type A, B, E, and F Botulinum Neurotoxin Genes and of Botulinum Neurotoxigenic Clostridia by Denaturing High-Performance Liquid Chromatography

PubMed Central

Franciosa, Giovanna; Pourshaban, Manoocheher; De Luca, Alessandro; Buccino, Anna; Dallapiccola, Bruno; Aureli, Paolo

2004-01-01

Denaturing high-performance liquid chromatography (DHPLC) is a recently developed technique for rapid screening of nucleotide polymorphisms in PCR products. We used this technique for the identification of type A, B, E, and F botulinum neurotoxin genes. PCR products amplified from a conserved region of the type A, B, E, and F botulinum toxin genes from Clostridium botulinum, neurotoxigenic C. butyricum type E, and C. baratii type F strains were subjected to both DHPLC analysis and sequencing. Unique DHPLC peak profiles were obtained with each different type of botulinum toxin gene fragment, consistent with nucleotide differences observed in the related sequences. We then evaluated the ability of this technique to identify botulinal neurotoxigenic organisms at the genus and species level. A specific short region of the 16S rRNA gene which contains genus-specific and in some cases species-specific heterogeneity was amplified from botulinum neurotoxigenic clostridia and from different food-borne pathogens and subjected to DHPLC analysis. Different peak profiles were obtained for each genus and species, demonstrating that the technique could be a reliable alternative to sequencing for the rapid identification of food-borne pathogens, specifically of botulinal neurotoxigenic clostridia most frequently implicated in human botulism. PMID:15240298

Ground truth data for test sites (SL-3). [solar radiation and thermal radiation brightness temperature measurements

NASA Technical Reports Server (NTRS)

1974-01-01

Field measurements performed simultaneously with Skylab overpasses in order to provide comparative calibration and performance evaluation measurements for the EREP sensors are presented. The solar radiation region from 400 to 1300 nanometers and the thermal radiation region from 8 to 14 micrometer region were investigated. The measurements of direct solar radiation were analyzed for atmospheric optical depth; the total and reflected solar radiation were analyzed for target reflectivity. These analyses were used in conjunction with a radiative transfer computer program in order to calculate the amount and spectral distribution of solar radiation at the apertures of the EREP sensors. The instrumentation and techniques employed, calibrations and analyses performed, and results obtained are discussed.

Discrimination of binocular color mixtures in dichromacy: evaluation of the Maxwell-Cornsweet conjecture

NASA Astrophysics Data System (ADS)

Knoblauch, Kenneth; McMahon, Matthew J.

1995-10-01

We tested the Maxwell-Cornsweet conjecture that differential spectral filtering of the two eyes can increase the dimensionality of a dichromat's color vision. Sex-linked dichromats wore filters that differentially passed long- and middle-wavelength regions of the spectrum to each eye. Monocularly, temporal modulation thresholds (1.5 Hz) for color mixtures from the Rayleigh region of the spectrum were accounted for by a single, univariant mechanism. Binocularly, univariance was rejected because, as in monocular viewing by trichromats, in no color direction could silent substitution of the color mixtures be obtained. Despite the filter-aided increase in dimension, estimated wavelength discrimination was quite poor in this spectral region, suggesting a limit to the effectiveness of this technique. binocular summation.

Forest health monitoring: national status, trends, and analysis 2015

Treesearch

Kevin M. Potter; Barbara L. Conkling

2016-01-01

The annual national report of the Forest Health Monitoring (FHM) Program of the Forest Service, U.S. Department of Agriculture, presents forest health status and trends from a national or multi- State regional perspective using a variety of sources, introduces new techniques for analyzing forest health data, and summarizes results of recently completed Evaluation...

Evaluation of Improved Engine Compartment Overheat Detection Techniques.

DTIC Science & Technology

1986-08-01

radiation properties (emissivity and reflectivity) of the surface. The first task of the numerical procedure is to investigate the radiosity (radiative heat...and radiosity are spatially uniform within each zone. 0 Radiative properties are spatially uniform and independent of direction. 0 The enclosure is...variation in the radiosity will be nonuniform in distribution in that region. The zone analysis method assumes the : . ,. temperature and radiation

Radioisotope studies in cardiology

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

Biersack, H.J.; Cox, P.H.

1985-01-01

In this text, reviews of all available techniques in this field have been collected, including methods that are still in the developmental stage. After a discussion of the pathophysiology of myocardial perfusion, metabolism, and recent developments in instrumentation, particular chapters are devoted to data processing, radipharmaceuticals, and labelled metabolites. Special references are made to cardiac blood-pool imaging, including evaluations of global and regional ventricular functions and reguritation volumes.

Evaluating Satellite Rainfall Estimates for Agro-hydrological Applications in Africa

NASA Astrophysics Data System (ADS)

Senay, G. B.; Verdin, J. P.; Korecha, D.; Asfaw, A.

2004-12-01

Regional water balance techniques are used to monitor and forecast crop performance and flooding potentials around the world. In the last few years, satellite rainfall estimates (RFE) have become available at continental scales, which made it possible to develop operational regional water balance models for the monitoring of crops performance and flooding potentials in Africa and other regions of the world as part of an environmental early warning system . The accuracy of RFE in absolute terms and importantly as it relates to agricultural and hydrological applications have not been evaluated systematically. This study evaluated a subset of the Africa-wide RFE product by comparing station-rainfall data and RFE from 1996 to 2002 using over 100 rain-gauge stations from Ethiopia at a dekadal (~10-day) time step. The results showed a general under-estimation of RFE compared to station rainfall values. The correlation between station rainfall data and RFE varied highly from place to place and between seasons. On the other hand, the correlation improved significantly when comparison was made between RFE-derived crop water satisfaction index (WRSI) and station-rainfall-derived WRSI, indicating the usefulness of the RFE for agro-hydrological applications.

Exploratory and spatial data analysis (EDA-SDA) for determining regional background levels and anomalies of potentially toxic elements in soils from Catorce-Matehuala, Mexico

USGS Publications Warehouse

Chiprés, J.A.; Castro-Larragoitia, J.; Monroy, M.G.

2009-01-01

The threshold between geochemical background and anomalies can be influenced by the methodology selected for its estimation. Environmental evaluations, particularly those conducted in mineralized areas, must consider this when trying to determinate the natural geochemical status of a study area, quantifying human impacts, or establishing soil restoration values for contaminated sites. Some methods in environmental geochemistry incorporate the premise that anomalies (natural or anthropogenic) and background data are characterized by their own probabilistic distributions. One of these methods uses exploratory data analysis (EDA) on regional geochemical data sets coupled with a geographic information system (GIS) to spatially understand the processes that influence the geochemical landscape in a technique that can be called a spatial data analysis (SDA). This EDA-SDA methodology was used to establish the regional background range from the area of Catorce-Matehuala in north-central Mexico. Probability plots of the data, particularly for those areas affected by human activities, show that the regional geochemical background population is composed of smaller subpopulations associated with factors such as soil type and parent material. This paper demonstrates that the EDA-SDA method offers more certainty in defining thresholds between geochemical background and anomaly than a numeric technique, making it a useful tool for regional geochemical landscape analysis and environmental geochemistry studies.

Automatic detection of diseased regions in knee cartilage

NASA Astrophysics Data System (ADS)

Qazi, Arish A.; Dam, Erik B.; Olsen, Ole F.; Nielsen, Mads; Christiansen, Claus

2007-03-01

Osteoarthritis (OA) is a degenerative joint disease characterized by articular cartilage degradation. A central problem in clinical trials is quantification of progression and early detection of the disease. The accepted standard for evaluating OA progression is to measure the joint space width from radiographs however; there the cartilage is not visible. Recently cartilage volume and thickness measures from MRI are becoming popular, but these measures don't account for the biochemical changes undergoing in the cartilage before cartilage loss even occurs and therefore are not optimal for early detection of OA. As a first step, we quantify cartilage homogeneity (computed as the entropy of the MR intensities) from 114 automatically segmented medial compartments of tibial cartilage sheets from Turbo 3D T 1 sequences, from subjects with no, mild or severe OA symptoms. We show that homogeneity is a more sensitive technique than volume quantification for detecting early OA and for separating healthy individuals from diseased. During OA certain areas of the cartilage are affected more and it is believed that these are the load-bearing regions located at the center of the cartilage. Based on the homogeneity framework we present an automatic technique that partitions the region on the cartilage that contributes to maximum homogeneity discrimination. These regions however, are more towards the noncentral regions of the cartilage. Our observation will provide valuable clues to OA research and may lead to improving treatment efficacy.

Identification of hydrothermal alteration minerals for exploring of porphyry copper deposit using ASTER data, SE Iran

NASA Astrophysics Data System (ADS)

Pour, Amin Beiranvnd; Hashim, Mazlan

2011-11-01

The NW-SE trending Central Iranian Volcanic Belt hosts many well-known porphyry copper deposits in Iran. It becomes an interesting area for remote sensing investigations to explore the new prospects of porphyry copper and vein type epithermal gold mineralization. Two copper mining districts in southeastern segment of the volcanic belt, including Meiduk and Sarcheshmeh have been selected in the present study. The performance of Principal Component Analysis, band ratio and Minimum Noise Fraction transformation has been evaluated for the visible and near infrared (VNIR) and, shortwave infrared (SWIR) subsystems of ASTER data. The image processing techniques indicated the distribution of iron oxides and vegetation in the VNIR subsystem. Hydrothermal alteration mineral zones associated with porphyry copper mineralization identified and discriminated based on distinctive shortwave infrared (SWIR) properties of the ASTER data in a regional scale. These techniques identified new prospects of porphyry copper mineralization in the study areas. The spatial distribution of hydrothermal alteration zones has been verified by in situ inspection, X-ray diffraction (XRD) analysis, and spectral reflectance measurements. Results indicated that the integration of the image processing techniques has a great ability to obtain significant and comprehensive information for the reconnaissance stages of porphyry copper exploration in a regional scale. The results of this research can assist exploration geologists to find new prospects of porphyry copper and gold deposits in the other virgin regions before costly detailed ground investigations. Consequently, the introduced image processing techniques can create an optimum idea about possible location of the new prospects.

Radioactive seed migration following parotid gland interstitial brachytherapy.

PubMed

Fan, Yi; Huang, Ming-Wei; Zhao, Yi-Jiao; Gao, Hong; Zhang, Jian-Guo

To evaluate the incidence and associated factors of pulmonary seed migration after parotid brachytherapy using a novel migrated seed detection technique. Patients diagnosed with parotid cancer who underwent permanent parotid brachytherapy from January 2006 to December 2011 were reviewed retrospectively. Head and neck CT scans and chest X-rays were evaluated during routine follow-up. Mimics software and Geomagic Studio software were used for seed reconstruction and migrated seed detection from the original implanted region, respectively. Postimplant dosimetry analysis was performed after seeds migration if the seeds were still in their emitting count. Adverse clinical sequelae from seed embolization to the lung were documented. The radioactive seed implants were identified on chest X-rays in 6 patients. The incidence rate of seed migration in 321 parotid brachytherapy patients was 1.87% (6/321) and that of individual seed migration was 0.04% (6/15218 seeds). All migrated seeds were originally from the retromandibular region. No adverse dosimetric consequences were found in the target region. Pulmonary symptoms were not reported by any patient in this study. In our patient set, migration of radioactive seeds with an initial radioactivity of 0.6-0.7 mCi to the chest following parotid brachytherapy was rare. Late migration of a single seed from the central target region did not affect the dosimetry significantly, and patients did not have severe short-term complications. This study proposed a novel technique to localize the anatomical origin of the migrated seeds during brachytherapy. Our evidence suggested that placement of seeds adjacent to blood vessels was associated with an increased likelihood of seed migration to the lungs. Copyright © 2017 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

Imaging of neural oscillations with embedded inferential and group prevalence statistics.

PubMed

Donhauser, Peter W; Florin, Esther; Baillet, Sylvain

2018-02-01

Magnetoencephalography and electroencephalography (MEG, EEG) are essential techniques for studying distributed signal dynamics in the human brain. In particular, the functional role of neural oscillations remains to be clarified. For that reason, imaging methods need to identify distinct brain regions that concurrently generate oscillatory activity, with adequate separation in space and time. Yet, spatial smearing and inhomogeneous signal-to-noise are challenging factors to source reconstruction from external sensor data. The detection of weak sources in the presence of stronger regional activity nearby is a typical complication of MEG/EEG source imaging. We propose a novel, hypothesis-driven source reconstruction approach to address these methodological challenges. The imaging with embedded statistics (iES) method is a subspace scanning technique that constrains the mapping problem to the actual experimental design. A major benefit is that, regardless of signal strength, the contributions from all oscillatory sources, which activity is consistent with the tested hypothesis, are equalized in the statistical maps produced. We present extensive evaluations of iES on group MEG data, for mapping 1) induced oscillations using experimental contrasts, 2) ongoing narrow-band oscillations in the resting-state, 3) co-modulation of brain-wide oscillatory power with a seed region, and 4) co-modulation of oscillatory power with peripheral signals (pupil dilation). Along the way, we demonstrate several advantages of iES over standard source imaging approaches. These include the detection of oscillatory coupling without rejection of zero-phase coupling, and detection of ongoing oscillations in deeper brain regions, where signal-to-noise conditions are unfavorable. We also show that iES provides a separate evaluation of oscillatory synchronization and desynchronization in experimental contrasts, which has important statistical advantages. The flexibility of iES allows it to be adjusted to many experimental questions in systems neuroscience.

Automated method to compute Evans index for diagnosis of idiopathic normal pressure hydrocephalus on brain CT images

NASA Astrophysics Data System (ADS)

Takahashi, Noriyuki; Kinoshita, Toshibumi; Ohmura, Tomomi; Matsuyama, Eri; Toyoshima, Hideto

2017-03-01

The early diagnosis of idiopathic normal pressure hydrocephalus (iNPH) considered as a treatable dementia is important. The iNPH causes enlargement of lateral ventricles (LVs). The degree of the enlargement of the LVs on CT or MR images is evaluated by using a diagnostic imaging criterion, Evans index. Evans index is defined as the ratio of the maximal width of frontal horns (FH) of the LVs to the maximal width of the inner skull (IS). Evans index is the most commonly used parameter for the evaluation of ventricular enlargement. However, manual measurement of Evans index is a time-consuming process. In this study, we present an automated method to compute Evans index on brain CT images. The algorithm of the method consisted of five major steps: standardization of CT data to an atlas, extraction of FH and IS regions, the search for the outmost points of bilateral FH regions, determination of the maximal widths of both the FH and the IS, and calculation of Evans index. The standardization to the atlas was performed by using linear affine transformation and non-linear wrapping techniques. The FH regions were segmented by using a three dimensional region growing technique. This scheme was applied to CT scans from 44 subjects, including 13 iNPH patients. The average difference in Evans index between the proposed method and manual measurement was 0.01 (1.6%), and the correlation coefficient of these data for the Evans index was 0.98. Therefore, this computerized method may have the potential to accurately compute Evans index for the diagnosis of iNPH on CT images.

Imaging of neural oscillations with embedded inferential and group prevalence statistics

PubMed Central

2018-01-01

Magnetoencephalography and electroencephalography (MEG, EEG) are essential techniques for studying distributed signal dynamics in the human brain. In particular, the functional role of neural oscillations remains to be clarified. For that reason, imaging methods need to identify distinct brain regions that concurrently generate oscillatory activity, with adequate separation in space and time. Yet, spatial smearing and inhomogeneous signal-to-noise are challenging factors to source reconstruction from external sensor data. The detection of weak sources in the presence of stronger regional activity nearby is a typical complication of MEG/EEG source imaging. We propose a novel, hypothesis-driven source reconstruction approach to address these methodological challenges. The imaging with embedded statistics (iES) method is a subspace scanning technique that constrains the mapping problem to the actual experimental design. A major benefit is that, regardless of signal strength, the contributions from all oscillatory sources, which activity is consistent with the tested hypothesis, are equalized in the statistical maps produced. We present extensive evaluations of iES on group MEG data, for mapping 1) induced oscillations using experimental contrasts, 2) ongoing narrow-band oscillations in the resting-state, 3) co-modulation of brain-wide oscillatory power with a seed region, and 4) co-modulation of oscillatory power with peripheral signals (pupil dilation). Along the way, we demonstrate several advantages of iES over standard source imaging approaches. These include the detection of oscillatory coupling without rejection of zero-phase coupling, and detection of ongoing oscillations in deeper brain regions, where signal-to-noise conditions are unfavorable. We also show that iES provides a separate evaluation of oscillatory synchronization and desynchronization in experimental contrasts, which has important statistical advantages. The flexibility of iES allows it to be adjusted to many experimental questions in systems neuroscience. PMID:29408902

Evaluation of cerebral maturation by visual and quantitative analysis of resting electroencephalography in children with primary nocturnal enuresis.

PubMed

Hallioğlu, O; Ozge, A; Comelekoglu, U; Topaloglu, A K; Kanik, A; Duzovali, O; Yilgor, E

2001-10-01

This study was undertaken to evaluate resting electroencephalographic (EEG) changes and their relations to cerebral maturation in children with primary nocturnal enuresis. Cerebral maturation is known to be important in the pathogenesis of this disorder. Twenty-five right-handed patients with primary nocturnal enuresis, aged 6 to 14 years, and 23 age- and sex-matched healthy children were included in this cross-sectional case-control study. The abnormalities detected using such techniques as hemispheral asymmetry, regional differences, and hyperventilation response in addition to visual and quantitative EEG analysis were examined statistically by multivariate analysis. A decrease in alpha activity in the left (dominant hemisphere) temporal lobe and in the frontal lobes bilaterally and an increase in delta activity in the right temporal region were observed. We concluded that insufficient cerebral maturation is an important factor in the pathogenesis of primary nocturnal enuresis, and EEG, as a noninvasive and inexpensive method, could be used in evaluating cerebral maturation.

Effectiveness of different rescanning techniques for scanned proton radiotherapy in lung cancer patients

NASA Astrophysics Data System (ADS)

Engwall, E.; Glimelius, L.; Hynning, E.

2018-05-01

Non-small cell lung cancer (NSCLC) is a tumour type thought to be well-suited for proton radiotherapy. However, the lung region poses many problems related to organ motion and can for actively scanned beams induce severe interplay effects. In this study we investigate four mitigating rescanning techniques: (1) volumetric rescanning, (2) layered rescanning, (3) breath-sampled (BS) layered rescanning, and (4) continuous breath-sampled (CBS) layered rescanning. The breath-sampled methods will spread the layer rescans over a full breathing cycle, resulting in an improved averaging effect at the expense of longer treatment times. In CBS, we aim at further improving the averaging by delivering as many rescans as possible within one breathing cycle. The interplay effect was evaluated for 4D robustly optimized treatment plans (with and without rescanning) for seven NSCLC patients in the treatment planning system RayStation. The optimization and final dose calculation used a Monte Carlo dose engine to account for the density heterogeneities in the lung region. A realistic treatment delivery time structure given from the IBA ScanAlgo simulation tool served as basis for the interplay evaluation. Both slow (2.0 s) and fast (0.1 s) energy switching times were simulated. For all seven studied patients, rescanning improves the dose conformity to the target. The general trend is that the breath-sampled techniques are superior to layered and volumetric rescanning with respect to both target coverage and variability in dose to OARs. The spacing between rescans in our breath-sampled techniques is set at planning, based on the average breathing cycle length obtained in conjunction with CT acquisition. For moderately varied breathing cycle lengths between planning and delivery (up to 15%), the breath-sampled techniques still mitigate the interplay effect well. This shows the potential for smooth implementation at the clinic without additional motion monitoring equipment.

Parameterization of 18th January 2011 earthquake in Dalbadin Region, Southwest Pakistan

NASA Astrophysics Data System (ADS)

Shafiq-Ur-Rehman; Azeem, Tahir; Abd el-aal, Abd el-aziz Khairy; Nasir, Asma

2013-12-01

An earthquake of magnitude 7.3 Mw occurred on 18th January 2011 in Southwestern Pakistan, Baluchistan province (Dalbadin Region). The area has complex tectonics due to interaction of Indian, Eurasian and Arabian plates. Both thrust and strike slip earthquakes are dominant in this region with minor, localized normal faulting events. This earthquake under consideration (Dalbadin Earthquake) posed constraints in depth and focal parameters due to lack of data for evaluation of parameters from Pakistan, Iran or Afghanistan region. Normal faulting mechanism has been proposed by many researchers for this earthquake. In the present study the earthquake was relocated using the technique of travel time residuals. Relocated coordinates and depth were utilized to calculate the focal mechanism solution with outcome of a dominant strike slip mechanism, which is contrary to normal faulting. Relocated coordinates and resulting mechanism are more reliable than many reporting agencies as evaluation in this study is augmented by data from local seismic monitoring network of Pakistan. The tectonics in the area is governed by active subduction along the Makran Subduction Zone. This particular earthquake has strike slip mechanism due to breaking of subducting oceanic plate. This earthquake is located where oceanic lithosphere is subducting along with relative movements between Lut and Helmand blocks. Magnitude of this event i.e. Mw = 7.3, re evaluated depth and a previous study of mechanism of earthquake in same region (Shafiq et al., 2011) also supports the strike slip movement.

Potential Analysis of Rainfall-induced Sediment Disaster

NASA Astrophysics Data System (ADS)

Chen, Jing-Wen; Chen, Yie-Ruey; Hsieh, Shun-Chieh; Tsai, Kuang-Jung; Chue, Yung-Sheng

2014-05-01

Most of the mountain regions in Taiwan are sedimentary and metamorphic rocks which are fragile and highly weathered. Severe erosion occurs due to intensive rainfall and rapid flow, the erosion is even worsen by frequent earthquakes and severely affects the stability of hillsides. Rivers are short and steep in Taiwan with large runoff differences in wet and dry seasons. Discharges respond rapidly with rainfall intensity and flood flows usually carry large amount of sediment. Because of the highly growth in economics and social change, the development in the slope land is inevitable in Taiwan. However, sediment disasters occur frequently in high and precipitous region during typhoon. To make the execution of the regulation of slope land development more efficiency, construction of evaluation model for sediment potential is very important. In this study, the Genetic Adaptive Neural Network (GANN) was implemented in texture analysis techniques for the classification of satellite images of research region before and after typhoon or extreme rainfall and to obtain surface information and hazard log data. By using GANN weight analysis, factors, levels and probabilities of disaster of the research areas are presented. Then, through geographic information system the disaster potential map is plotted to distinguish high potential regions from low potential regions. Finally, the evaluation processes for sediment disaster after rainfall due to slope land use are established. In this research, the automatic image classification and evaluation modules for sediment disaster after rainfall due to slope land disturbance and natural environment are established in MATLAB to avoid complexity and time of computation. After implementation of texture analysis techniques, the results show that the values of overall accuracy and coefficient of agreement of the time-saving image classification for different time periods are at intermediate-high level and above. The results of GANN show that the weight of building density is the largest in all slope land disturbance factors, followed by road density, orchard density, baren land density, vegetation density, and farmland density. The weight of geology is the largest in all natural environment factors, followed by slope roughness, slope, and elevation. Overlaying the locations of large sediment disaster in the past on the potential map predicted by GANN, we found that most damage areas were in the region with medium-high or high potential of landslide. Therefore, the proposed potential model of sediment disaster can be used in practice.

Noise characterization of broadband fiber Cherenkov radiation as a visible-wavelength source for optical coherence tomography and two-photon fluorescence microscopy.

PubMed

Tu, Haohua; Zhao, Youbo; Liu, Yuan; Liu, Yuan-Zhi; Boppart, Stephen

2014-08-25

Optical sources in the visible region immediately adjacent to the near-infrared biological optical window are preferred in imaging techniques such as spectroscopic optical coherence tomography of endogenous absorptive molecules and two-photon fluorescence microscopy of intrinsic fluorophores. However, existing sources based on fiber supercontinuum generation are known to have high relative intensity noise and low spectral coherence, which may degrade imaging performance. Here we compare the optical noise and pulse compressibility of three high-power fiber Cherenkov radiation sources developed recently, and evaluate their potential to replace the existing supercontinuum sources in these imaging techniques.

Remeasurement and compilation of excitation function of proton induced reactions on iron for activation techniques

NASA Astrophysics Data System (ADS)

Takács, S.; Vasváry, L.; Tárkányi, F.

1994-05-01

Excitation functions of proton induced reactions on natFe(p, xn) 56Co have been remeasured in the energy region up to 18 MeV using stacked foil technique and standard high resolution gamma-ray spectrometry at the Debrecen MGC-20E cyclotron. Compilation of the available data measured between 1959 and 1993 has been made. The corresponding excitation functions have been reviewed, critical comparison of all the available data was done to obtain the most accurate data set. The feasibility of the evaluated data set was checked by reproducing experimental calibration curves for TLA by calculation.

Airborne optical detection of oil on water.

NASA Technical Reports Server (NTRS)

Millard, J. P.; Arvesen, J. C.

1972-01-01

Airborne measurements were made over controlled oil-spill test sites to evaluate various techniques, utilizing reflected sunlight, for detecting oil on water. The results of these measurements show that (1) maximum contrast between oil and water is in the UV and red portions of the spectrum; (2) minimum contrast is in the blue-green; (3) differential polarization appears to be a very promising technique; (4) no characteristic absorption bands, which would permit one oil to be distinguished from another, were discovered in the spectral regions measured; (5) sky conditions greatly influence the contrast between oil and water; and (6) highest contrast was achieved under overcast sky conditions.

Marine Resources

NASA Technical Reports Server (NTRS)

Sherman, J. W., III

1975-01-01

The papers presented in the marine session may be broadly grouped into several classes: microwave region instruments compared to infrared and visible region sensors, satellite techniques compared to aircraft techniques, open ocean applications compared to coastal region applications, and basic research and understanding of ocean phenomena compared to research techniques that offer immediate applications.

[Multifocal visual electrophysiology in visual function evaluation].

PubMed

Peng, Shu-Ya; Chen, Jie-Min; Liu, Rui-Jue; Zhou, Shu; Liu, Dong-Mei; Xia, Wen-Tao

2013-08-01

Multifocal visual electrophysiology, consisting of multifocal electroretinography (mfERG) and multifocal visual evoked potential (mfVEP), can objectively evaluate retina function and retina-cortical conduction pathway status by stimulating many local retinal regions and obtaining each local response simultaneously. Having many advantages such as short testing time and high sensitivity, it has been widely used in clinical ophthalmology, especially in the diagnosis of retinal disease and glaucoma. It is a new objective technique in clinical forensic medicine involving visual function evaluation of ocular trauma in particular. This article summarizes the way of stimulation, the position of electrodes, the way of analysis, the visual function evaluation of mfERG and mfVEP, and discussed the value of multifocal visual electrophysiology in forensic medicine.

Comparison of scatter rejection and low-contrast performance of scan equalization digital radiography (SEDR), slot-scan digital radiography, and full-field digital radiography systems for chest phantom imaging

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

Liu Xinming; Shaw, Chris C.; Lai, Chao-Jen

Purpose: To investigate and compare the scatter rejection properties and low-contrast performance of the scan equalization digital radiography (SEDR) technique to the slot-scan and conventional full-field digital radiography techniques for chest imaging. Methods: A prototype SEDR system was designed and constructed with an a-Se flat-panel (FP) detector to improve image quality in heavily attenuating regions of an anthropomorphic chest phantom. Slot-scanning geometry was used to reject scattered radiation without attenuating primary x rays. The readout scheme of the FP was modified to erase accumulated scatter signals prior to image readout. A 24-segment beam width modulator was developed to regulate x-raymore » exposures regionally and compensate for the low x-ray flux in heavily attenuating regions. To measure the scatter-to-primary ratios (SPRs), a 2 mm thick lead plate with a 2-D array of aperture holes was used to measure the primary signals, which were then subtracted from those obtained without the lead plate to determine scatter components. A 2-D array of aluminum beads (3 mm in diameter) was used as the low-contrast objects to measure the contrast ratios (CRs) and contrast-to-noise ratios (CNRs) for evaluating the low-contrast performance in chest phantom images. A set of two images acquired with the same techniques were subtracted from each other to measure the noise levels. SPRs, CRs, and CNRs of the SEDR images were measured in four anatomical regions of chest phantom images and compared to those of slot-scan images and full-field images acquired with and without antiscatter grid. Results: The percentage reduction of SPR (percentage of SPRs reduced with scatter removal/rejection methods relative to that for nongrid full-field imaging) averaged over four anatomical regions was measured to be 80%, 83%, and 71% for SEDR, slot-scan, and full-field with grid, respectively. The average CR over four regions was found to improve over that for nongrid full-field imaging by 259%, 279%, and 145% for SEDR, slot-scan, and full-field with grid, respectively. The average CNR over four regions was found to improve over that for nongrid full-field imaging by 201% for SEDR as compared to 133% for the slot-scan technique and 14% for the antiscatter grid method. Conclusions: Both SEDR and slot-scan techniques outperformed the antiscatter grid method used in standard full-field radiography. For imaging with the same effective exposure, the SEDR technique offers no advantage over the slot-scan method in terms of SPRs and CRs. However, it improves CNRs significantly, especially in heavily attenuating regions. The improvement of low-contrast performance may help improve the detection of the lung nodules or other abnormalities and may offer SEDR the potential for dose reduction in chest radiography.« less

Computer-aided analysis of Skylab scanner data for land use mapping, forestry and water resource applications

NASA Technical Reports Server (NTRS)

Hoffer, R. M.

1975-01-01

Skylab data were obtained over a mountainous test site containing a complex association of cover types and rugged topography. The application of computer-aided analysis techniques to the multispectral scanner data produced a number of significant results. Techniques were developed to digitally overlay topographic data (elevation, slope, and aspect) onto the S-192 MSS data to provide a method for increasing the effectiveness and accuracy of computer-aided analysis techniques for cover type mapping. The S-192 MSS data were analyzed using computer techniques developed at Laboratory for Applications of Remote Sensing (LARS), Purdue University. Land use maps, forest cover type maps, snow cover maps, and area tabulations were obtained and evaluated. These results compared very well with information obtained by conventional techniques. Analysis of the spectral characteristics of Skylab data has conclusively proven the value of the middle infrared portion of the spectrum (about 1.3-3.0 micrometers), a wavelength region not previously available in multispectral satellite data.

The value of remote sensing techniques in supporting effective extrapolation across multiple marine spatial scales.

PubMed

Strong, James Asa; Elliott, Michael

2017-03-15

The reporting of ecological phenomena and environmental status routinely required point observations, collected with traditional sampling approaches to be extrapolated to larger reporting scales. This process encompasses difficulties that can quickly entrain significant errors. Remote sensing techniques offer insights and exceptional spatial coverage for observing the marine environment. This review provides guidance on (i) the structures and discontinuities inherent within the extrapolative process, (ii) how to extrapolate effectively across multiple spatial scales, and (iii) remote sensing techniques and data sets that can facilitate this process. This evaluation illustrates that remote sensing techniques are a critical component in extrapolation and likely to underpin the production of high-quality assessments of ecological phenomena and the regional reporting of environmental status. Ultimately, is it hoped that this guidance will aid the production of robust and consistent extrapolations that also make full use of the techniques and data sets that expedite this process. Copyright © 2017 Elsevier Ltd. All rights reserved.

Experimental Verification of Bayesian Planet Detection Algorithms with a Shaped Pupil Coronagraph

NASA Astrophysics Data System (ADS)

Savransky, D.; Groff, T. D.; Kasdin, N. J.

2010-10-01

We evaluate the feasibility of applying Bayesian detection techniques to discovering exoplanets using high contrast laboratory data with simulated planetary signals. Background images are generated at the Princeton High Contrast Imaging Lab (HCIL), with a coronagraphic system utilizing a shaped pupil and two deformable mirrors (DMs) in series. Estimates of the electric field at the science camera are used to correct for quasi-static speckle and produce symmetric high contrast dark regions in the image plane. Planetary signals are added in software, or via a physical star-planet simulator which adds a second off-axis point source before the coronagraph with a beam recombiner, calibrated to a fixed contrast level relative to the source. We produce a variety of images, with varying integration times and simulated planetary brightness. We then apply automated detection algorithms such as matched filtering to attempt to extract the planetary signals. This allows us to evaluate the efficiency of these techniques in detecting planets in a high noise regime and eliminating false positives, as well as to test existing algorithms for calculating the required integration times for these techniques to be applicable.

TH-EF-207A-04: A Dynamic Contrast Enhanced Cone Beam CT Technique for Evaluation of Renal Functions

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

Wang, Z; Shi, J; Yang, Y

Purpose: To develop a simple but robust method for the early detection and evaluation of renal functions using dynamic contrast enhanced cone beam CT technique. Methods: Experiments were performed on an integrated imaging and radiation research platform developed by our lab. Animals (n=3) were anesthetized with 20uL Ketamine/Xylazine cocktail, and then received 200uL injection of iodinated contrast agent Iopamidol via tail vein. Cone beam CT was acquired following contrast injection once per minute and up to 25 minutes. The cone beam CT was reconstructed with a dimension of 300×300×800 voxels of 130×130×130um voxel resolution. The middle kidney slices in themore » transvers and coronal planes were selected for image analysis. A double exponential function was used to fit the contrast enhanced signal intensity versus the time after contrast injection. Both pixel-based and region of interest (ROI)-based curve fitting were performed. Four parameters obtained from the curve fitting, namely the amplitude and flow constant for both contrast wash in and wash out phases, were investigated for further analysis. Results: Robust curve fitting was demonstrated for both pixel based (with R{sup 2}>0.8 for >85% pixels within the kidney contour) and ROI based (R{sup 2}>0.9 for all regions) analysis. Three different functional regions: renal pelvis, medulla and cortex, were clearly differentiated in the functional parameter map in the pixel based analysis. ROI based analysis showed the half-life T1/2 for contrast wash in and wash out phases were 0.98±0.15 and 17.04±7.16, 0.63±0.07 and 17.88±4.51, and 1.48±0.40 and 10.79±3.88 minutes for the renal pelvis, medulla and cortex, respectively. Conclusion: A robust method based on dynamic contrast enhanced cone beam CT and double exponential curve fitting has been developed to analyze the renal functions for different functional regions. Future study will be performed to investigate the sensitivity of this technique in the detection of radiation induced kidney dysfunction.« less

Remote sensing approach for hydrologic assessments of complex lake systems

NASA Astrophysics Data System (ADS)

Bhang, Kon Joon

Lake studies play an important role in understanding water management, ecology, climatology, etc. because most of earth processes are strongly related to water dynamics. Because the studies have only used on-site gage readings, it is almost impossible to access individual lakes and to evaluate regional scale hydrology as a whole system. Especially in the Prairie Pothole Region (PPR) of North America has millions of potholes and lakes. Measuring lake levels in this region is one of the critical issues in hydrology or other related sciences and applications. The remote sensing approach with the Geographic Information System (GIS) technique could be used to overcome the difficulty associated with on-site measurements. In this study, the SRTM data was used as a main topographic dataset because the dataset provides accurate and consistent elevation data on a worldwide basis. The first chapter introduced the whole idea of this study. In the second chapter, the elevation values of the C-band SRTM 30-meter DEM were compared with point-wise elevations from the Ice, Cloud and land Elevation Satellite (ICESat) laser altimetry for Otter Tail County, MN. The accuracy of SRTM DEM was measured as a function of land cover and geomorphologic characteristics. The typical mean vertical difference between the SRTM DEM and ICESat elevations in this study was determined for each classified land use type and the data properties were investigated. Also, the feasibility of using SRTM data for hydrologic applications, especially in a region of low relief exemplified by the Otter Tail basin in Minnesota, was examined in Chapter 3. For measuring lake levels, several lake-level estimation techniques using image processing and feature detection were tested with the Landsat imagery and SRTM data and the efficiency of the techniques were evaluated in Chapter 4. Lastly, the power law distribution of lake was simulated in Chapter 5. For the simulation, one-dimensional fractal landscapes were generated and precipitation and evaporation processes were added to the simulation algorithm to observe the effect of natural processes in lake formation. The simulation result for lake distribution was compared with real measurements and the lake distribution following the power law (linear scaling in logarithmic scale) distribution was shown.

Modification and evaluation of a Barnes-type objective analysis scheme for surface meteorological data

NASA Technical Reports Server (NTRS)

Smith, D. R.

1982-01-01

The Purdue Regional Objective Analysis of the Mesoscale (PROAM) is a Barness-type scheme for the analysis of surface meteorological data. Modifications are introduced to the original version in order to increase its flexibility and to permit greater ease of usage. The code was rewritten for an interactive computer environment. Furthermore, a multiple iteration technique suggested by Barnes was implemented for greater accuracy. PROAM was subjected to a series of experiments in order to evaluate its performance under a variety of analysis conditions. The tests include use of a known analytic temperature distribution in order to quantify error bounds for the scheme. Similar experiments were conducted using actual atmospheric data. Results indicate that the multiple iteration technique increases the accuracy of the analysis. Furthermore, the tests verify appropriate values for the analysis parameters in resolving meso-beta scale phenomena.

A computer simulation model to compute the radiation transfer of mountainous regions

NASA Astrophysics Data System (ADS)

Li, Yuguang; Zhao, Feng; Song, Rui

2011-11-01

In mountainous regions, the radiometric signal recorded at the sensor depends on a number of factors such as sun angle, atmospheric conditions, surface cover type, and topography. In this paper, a computer simulation model of radiation transfer is designed and evaluated. This model implements the Monte Carlo ray-tracing techniques and is specifically dedicated to the study of light propagation in mountainous regions. The radiative processes between sun light and the objects within the mountainous region are realized by using forward Monte Carlo ray-tracing methods. The performance of the model is evaluated through detailed comparisons with the well-established 3D computer simulation model: RGM (Radiosity-Graphics combined Model) based on the same scenes and identical spectral parameters, which shows good agreements between these two models' results. By using the newly developed computer model, series of typical mountainous scenes are generated to analyze the physical mechanism of mountainous radiation transfer. The results show that the effects of the adjacent slopes are important for deep valleys and they particularly affect shadowed pixels, and the topographic effect needs to be considered in mountainous terrain before accurate inferences from remotely sensed data can be made.

ICAO safety management systems (SMS) development in environmental contexts: A field study of greater China

NASA Astrophysics Data System (ADS)

Leib, Steven M.

This was a mixed-methods exploratory study to investigate association between environmental context and the implementation status of Safety Management Systems (SMS) at airports in Greater China. Using a framework of Institutional Theory, this study looked at three regions of Greater China and explored internal and external environments of SMS at airports within each region. It used ICAO standards to evaluate the implementation status of SMS at those airports based on the perceptions of 126 participants. This research also employed snowballing technique to spread a survey tool to participants in Greater China through several key gatekeepers, and then applied the Delphi method for interviews with key gatekeepers themselves. Analysis of the data suggested several associations between various sub-concepts of the external environment and different components of SMS in the three regions. In addition, the data suggested a relationship between the internal environment as a whole and the overall status of SMS implementation in each region. Lastly, the study makes several recommendations for future research regarding global standards implemented in local environments, the evaluation of SMS implementation status, and the theoretical implications of this study.

A Nonlinear Dynamics Approach for Incorporating Wind-Speed Patterns into Wind-Power Project Evaluation

PubMed Central

Huffaker, Ray; Bittelli, Marco

2015-01-01

Wind-energy production may be expanded beyond regions with high-average wind speeds (such as the Midwest U.S.A.) to sites with lower-average speeds (such as the Southeast U.S.A.) by locating favorable regional matches between natural wind-speed and energy-demand patterns. A critical component of wind-power evaluation is to incorporate wind-speed dynamics reflecting documented diurnal and seasonal behavioral patterns. Conventional probabilistic approaches remove patterns from wind-speed data. These patterns must be restored synthetically before they can be matched with energy-demand patterns. How to accurately restore wind-speed patterns is a vexing problem spurring an expanding line of papers. We propose a paradigm shift in wind power evaluation that employs signal-detection and nonlinear-dynamics techniques to empirically diagnose whether synthetic pattern restoration can be avoided altogether. If the complex behavior of observed wind-speed records is due to nonlinear, low-dimensional, and deterministic system dynamics, then nonlinear dynamics techniques can reconstruct wind-speed dynamics from observed wind-speed data without recourse to conventional probabilistic approaches. In the first study of its kind, we test a nonlinear dynamics approach in an application to Sugarland Wind—the first utility-scale wind project proposed in Florida, USA. We find empirical evidence of a low-dimensional and nonlinear wind-speed attractor characterized by strong temporal patterns that match up well with regular daily and seasonal electricity demand patterns. PMID:25617767

Comprehensive Review on Magnetic Resonance Imaging in Alzheimer's Disease.

PubMed

Dona, Olga; Thompson, Jeff; Druchok, Cheryl

2016-01-01

Alzheimer's disease (AD) is the most common cause of dementia in the elderly. However, definitive diagnosis of AD is only achievable postmortem and currently relies on clinical neurological evaluation. Magnetic resonance imaging (MRI) can evaluate brain changes typical of AD, including brain atrophy, presence of amyloid β (Aβ) plaques, and functional and biochemical abnormalities. Structural MRI (sMRI) has historically been used to assess the inherent brain atrophy present in AD. However, new techniques have recently emerged that have refined sMRI into a more precise tool to quantify the thickness and volume of AD-sensitive cerebral structures. Aβ plaques, a defining pathology of AD, are widely believed to contribute to the progressive cognitive decline in AD, but accurate assessment is only possible on autopsy. In vivo MRI of plaques, although currently limited to mouse models of AD, is a very promising technique. Measuring changes in activation and connectivity in AD-specific regions of the brain can be performed with functional MRI (fMRI). To help distinguish AD from diseases with similar symptoms, magnetic resonance spectroscopy (MRS) can be used to look for differing metabolite concentrations in vivo. Together, these MR techniques, evaluating various brain changes typical of AD, may help to provide a more definitive diagnosis and ease the assessment of the disease over time, noninvasively.

On the Validity of Econometric Techniques with Weak Instruments--Inference on Returns to Education Using Compulsory School Attendance Laws

ERIC Educational Resources Information Center

Cruz, Luiz M.; Moreira, Marcelo J.

2005-01-01

The authors evaluate Angrist and Krueger (1991) and Bound, Jaeger, and Baker (1995) by constructing reliable confidence regions around the 2SLS and LIML estimators for returns-to-schooling regardless of the quality of the instruments. The results indicate that the returns-to-schooling were between 8 and 25 percent in 1970 and between 4 and 14…

The Main Topics at the Oncoplastic Breast Surgery Course and Expert Panel.

PubMed

Emiroğlu, Mustafa; Kuru, Bekir; Gülçelik, Mehmet Ali; Atahan, M Kemal; Sezer, Atakan Y; Karaali, Cem; Güllüoğlu, Bahadır

2017-01-01

The Oncoplastic and Reconstructive Breast Surgery course was held in Izmir by the Izmir Breast Diseases Federation in collaboration with the Breast Diseases Federation of Turkey. The techniques of oncoplasty, the application details and experience in this subject were shared. In this text, the main topics and outcomes are briefly summarised. These evaluations can be considered highly valuable on both local and regional scales.

Effectiveness of a Treatment Involving Soft Tissue Techniques and/or Neural Mobilization Techniques in the Management of Tension-Type Headache: A Randomized Controlled Trial.

PubMed

Ferragut-Garcías, Alejandro; Plaza-Manzano, Gustavo; Rodríguez-Blanco, Cleofás; Velasco-Roldán, Olga; Pecos-Martín, Daniel; Oliva-Pascual-Vaca, Jesús; Llabrés-Bennasar, Bartomeu; Oliva-Pascual-Vaca, Ángel

2017-02-01

To evaluate the effects of a protocol involving soft tissue techniques and/or neural mobilization techniques in the management of patients with frequent episodic tension-type headache (FETTH) and those with chronic tension-type headache (CTTH). Randomized, double-blind, placebo-controlled before and after trial. Rehabilitation area of the local hospital and a private physiotherapy center. Patients (N=97; 78 women, 19 men) diagnosed with FETTH or CTTH were randomly assigned to groups A, B, C, or D. (A) Placebo superficial massage; (B) soft tissue techniques; (C) neural mobilization techniques; (D) a combination of soft tissue and neural mobilization techniques. The pressure pain threshold (PPT) in the temporal muscles (points 1 and 2) and supraorbital region (point 3), the frequency and maximal intensity of pain crisis, and the score in the Headache Impact Test-6 (HIT-6) were evaluated. All variables were assessed before the intervention, at the end of the intervention, and 15 and 30 days after the intervention. Groups B, C, and D had an increase in PPT and a reduction in frequency, maximal intensity, and HIT-6 values in all time points after the intervention as compared with baseline and group A (P<.001 for all cases). Group D had the highest PPT values and the lowest frequency and HIT-6 values after the intervention. The application of soft tissue and neural mobilization techniques to patients with FETTH or CTTH induces significant changes in PPT, the characteristics of pain crisis, and its effect on activities of daily living as compared with the application of these techniques as isolated interventions. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Macro- and micro-chaotic structures in the Hindmarsh-Rose model of bursting neurons

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

Barrio, Roberto, E-mail: rbarrio@unizar.es; Serrano, Sergio; Angeles Martínez, M.

2014-06-01

We study a plethora of chaotic phenomena in the Hindmarsh-Rose neuron model with the use of several computational techniques including the bifurcation parameter continuation, spike-quantification, and evaluation of Lyapunov exponents in bi-parameter diagrams. Such an aggregated approach allows for detecting regions of simple and chaotic dynamics, and demarcating borderlines—exact bifurcation curves. We demonstrate how the organizing centers—points corresponding to codimension-two homoclinic bifurcations—along with fold and period-doubling bifurcation curves structure the biparametric plane, thus forming macro-chaotic regions of onion bulb shapes and revealing spike-adding cascades that generate micro-chaotic structures due to the hysteresis.

Assessment of Ethylene Vinyl-Acetato Copolymer (EVA) Samples Bombarded by Gamma Radiation via Linearity Analyses

NASA Astrophysics Data System (ADS)

de Oliveira, L. N.; do Nascimento, E. O.; Schimidt, F.; Antonio, P. L.; Caldas, L. V. E.

2018-03-01

Materials with the potential to become dosimeters are of interest in radiation physics. In this research, the materials were analyzed and compared in relation to their linearity ranges. Samples of ethylene vinyl-acetate copolymer (EVA) were irradiated with doses from 10 Gy to 10 kGy using a 60Co Gamma-Cell system 220 and evaluated with the FTIR technique. The linearity analyses were applied through two methodologies, searching for linear regions in their response. The results show that both applied analyses indicate linear regions in defined dose interval. The radiation detectors EVA can be useful for radiation dosimetry in intermediate and high doses.

An evaluation of water quality in private drinking water wells near natural gas extraction sites in the Barnett Shale formation.

PubMed

Fontenot, Brian E; Hunt, Laura R; Hildenbrand, Zacariah L; Carlton, Doug D; Oka, Hyppolite; Walton, Jayme L; Hopkins, Dan; Osorio, Alexandra; Bjorndal, Bryan; Hu, Qinhong H; Schug, Kevin A

2013-09-03

Natural gas has become a leading source of alternative energy with the advent of techniques to economically extract gas reserves from deep shale formations. Here, we present an assessment of private well water quality in aquifers overlying the Barnett Shale formation of North Texas. We evaluated samples from 100 private drinking water wells using analytical chemistry techniques. Analyses revealed that arsenic, selenium, strontium and total dissolved solids (TDS) exceeded the Environmental Protection Agency's Drinking Water Maximum Contaminant Limit (MCL) in some samples from private water wells located within 3 km of active natural gas wells. Lower levels of arsenic, selenium, strontium, and barium were detected at reference sites outside the Barnett Shale region as well as sites within the Barnett Shale region located more than 3 km from active natural gas wells. Methanol and ethanol were also detected in 29% of samples. Samples exceeding MCL levels were randomly distributed within areas of active natural gas extraction, and the spatial patterns in our data suggest that elevated constituent levels could be due to a variety of factors including mobilization of natural constituents, hydrogeochemical changes from lowering of the water table, or industrial accidents such as faulty gas well casings.

Ischemia may be the primary cause of the neurologic deficits in classic migraine

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

Skyhoj Olsen, T.; Friberg, L.; Lassen, N.A.

1987-02-01

This study investigates whether the cerebral blood flow reduction occurring in attacks of classic migraine is sufficient to cause neurologic deficits. Regional cerebral blood flow measured with the xenon 133 intracarotid injection technique was analyzed in 11 patients in whom a low-flow area developed during attacks of classic migraine. When measured with this technique, regional cerebral blood flow in focal low-flow areas will be overestimated because of the effect of scattered radiation (Compton scatter) on the recordings. In this study, this effect was particularly taken into account when evaluating the degree of blood flow reduction. During attacks of classic migraine,more » cerebral blood flow reductions averaging 52% were observed focally in the 11 patients. Cerebral blood flow levels known to be insufficient for normal cortical function (less than 16 to 23 mL/100 g/min) were measured in seven patients during the attacks. This was probably also the case in the remaining four patients, but the effect of scattered radiation made a reliable evaluation of blood flow impossible. It is concluded that the blood flow reduction that occurs during attacks of classic migraine is sufficient to cause ischemia and neurologic deficits. Hence, this study suggests a vascular origin of the prodromal neurologic deficits that may accompany attacks of classic migraine.« less

Computer-aided classification of patients with dementia of Alzheimer's type based on cerebral blood flow determined with arterial spin labeling technique

NASA Astrophysics Data System (ADS)

Yamashita, Yasuo; Arimura, Hidetaka; Yoshiura, Takashi; Tokunaga, Chiaki; Magome, Taiki; Monji, Akira; Noguchi, Tomoyuki; Toyofuku, Fukai; Oki, Masafumi; Nakamura, Yasuhiko; Honda, Hiroshi

2010-03-01

Arterial spin labeling (ASL) is one of promising non-invasive magnetic resonance (MR) imaging techniques for diagnosis of Alzheimer's disease (AD) by measuring cerebral blood flow (CBF). The aim of this study was to develop a computer-aided classification system for AD patients based on CBFs measured by the ASL technique. The average CBFs in cortical regions were determined as functional image features based on the CBF map image, which was non-linearly transformed to a Talairach brain atlas by using a free-form deformation. An artificial neural network (ANN) was trained with the CBF functional features in 10 cortical regions, and was employed for distinguishing patients with AD from control subjects. For evaluation of the method, we applied the proposed method to 20 cases including ten AD patients and ten control subjects, who were scanned a 3.0-Tesla MR unit. As a result, the area under the receiver operating characteristic curve obtained by the proposed method was 0.893 based on a leave-one-out-by-case test in identification of AD cases among 20 cases. The proposed method would be feasible for classification of patients with AD.

The application of remote sensing techniques to inter and intra urban analysis

NASA Technical Reports Server (NTRS)

Horton, F. E.

1972-01-01

This is an effort to assess the applicability of air and spaceborne photography toward providing data inputs to urban and regional planning, management, and research. Through evaluation of remote sensing inputs to urban change detection systems, analyzing an effort to replicate an existing urban land use data file using remotely sensed data, estimating population and dwelling units from imagery, and by identifying and evaluating a system of urban places ultilizing space photography, it was determined that remote sensing can provide data concerning land use, changes in commercial structure, data for transportation planning, housing quality, residential dynamics, and population density.

The balance sheet technique. Volume I. The balance sheet analysis technique for preconstruction review of airports and highways

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

LaBelle, S.J.; Smith, A.E.; Seymour, D.A.

1977-02-01

The technique applies equally well to new or existing airports. The importance of accurate accounting of emissions, cannot be overstated. The regional oxidant modelling technique used in conjunction with a balance sheet review must be a proportional reduction technique. This type of emission balancing presumes equality of all sources in the analysis region. The technique can be applied successfully in the highway context, either in planning at the system level or looking only at projects individually. The project-by-project reviews could be used to examine each project in the same way as the airport projects are examined for their impact onmore » regional desired emission levels. The primary limitation of this technique is that it should not be used when simulation models have been used for regional oxidant air quality. In the case of highway projects, the balance sheet technique might appear to be limited; the real limitations are in the transportation planning process. That planning process is not well-suited to the needs of air quality forecasting. If the transportation forecasting techniques are insensitive to change in the variables that affect HC emissions, then no internal emission trade-offs can be identified, and the initial highway emission forecasts are themselves suspect. In general, the balance sheet technique is limited by the quality of the data used in the review. Additionally, the technique does not point out effective trade-off strategies, nor does it indicate when it might be worthwhile to ignore small amounts of excess emissions. Used in the context of regional air quality plans based on proportional reduction models, the balance sheet analysis technique shows promise as a useful method by state or regional reviewing agencies.« less

Techniques for Estimating the Magnitude and Frequency of Peak Flows on Small Streams in Minnesota Based on Data through Water Year 2005

USGS Publications Warehouse

Lorenz, David L.; Sanocki, Chris A.; Kocian, Matthew J.

2010-01-01

Knowledge of the peak flow of floods of a given recurrence interval is essential for regulation and planning of water resources and for design of bridges, culverts, and dams along Minnesota's rivers and streams. Statistical techniques are needed to estimate peak flow at ungaged sites because long-term streamflow records are available at relatively few places. Because of the need to have up-to-date peak-flow frequency information in order to estimate peak flows at ungaged sites, the U.S. Geological Survey (USGS) conducted a peak-flow frequency study in cooperation with the Minnesota Department of Transportation and the Minnesota Pollution Control Agency. Estimates of peak-flow magnitudes for 1.5-, 2-, 5-, 10-, 25-, 50-, 100-, and 500-year recurrence intervals are presented for 330 streamflow-gaging stations in Minnesota and adjacent areas in Iowa and South Dakota based on data through water year 2005. The peak-flow frequency information was subsequently used in regression analyses to develop equations relating peak flows for selected recurrence intervals to various basin and climatic characteristics. Two statistically derived techniques-regional regression equation and region of influence regression-can be used to estimate peak flow on ungaged streams smaller than 3,000 square miles in Minnesota. Regional regression equations were developed for selected recurrence intervals in each of six regions in Minnesota: A (northwestern), B (north central and east central), C (northeastern), D (west central and south central), E (southwestern), and F (southeastern). The regression equations can be used to estimate peak flows at ungaged sites. The region of influence regression technique dynamically selects streamflow-gaging stations with characteristics similar to a site of interest. Thus, the region of influence regression technique allows use of a potentially unique set of gaging stations for estimating peak flow at each site of interest. Two methods of selecting streamflow-gaging stations, similarity and proximity, can be used for the region of influence regression technique. The regional regression equation technique is the preferred technique as an estimate of peak flow in all six regions for ungaged sites. The region of influence regression technique is not appropriate for regions C, E, and F because the interrelations of some characteristics of those regions do not agree with the interrelations throughout the rest of the State. Both the similarity and proximity methods for the region of influence technique can be used in the other regions (A, B, and D) to provide additional estimates of peak flow. The peak-flow-frequency estimates and basin characteristics for selected streamflow-gaging stations and regional peak-flow regression equations are included in this report.

A study of data analysis techniques for the multi-needle Langmuir probe

NASA Astrophysics Data System (ADS)

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

2018-06-01

In this paper we evaluate two data analysis techniques for the multi-needle Langmuir probe (m-NLP). The instrument uses several cylindrical Langmuir probes, which are positively biased with respect to the plasma potential in order to operate in the electron saturation region. Since the currents collected by these probes can be sampled at kilohertz rates, the instrument is capable of resolving the ionospheric plasma structure down to the meter scale. The two data analysis techniques, a linear fit and a non-linear least squares fit, are discussed in detail using data from the Investigation of Cusp Irregularities 2 sounding rocket. It is shown that each technique has pros and cons with respect to the m-NLP implementation. Even though the linear fitting technique seems to be better than measurements from incoherent scatter radar and in situ instruments, m-NLPs can be longer and can be cleaned during operation to improve instrument performance. The non-linear least squares fitting technique would be more reliable provided that a higher number of probes are deployed.

Spatializing Open Data for the Assessment and the Improvement of Territorial and Social Cohesion

NASA Astrophysics Data System (ADS)

Scorza, F.; Las Casas, G. B.; Murgante, B.

2016-09-01

An integrated place-based approach for the improvement of territorial and social cohesion is the new instance for planning disciplines, coming from EU New Cohesion Policies. This paper considers the territorial impact assessment of regional development policies as a precondition in order to develop balanced and effective operative programs at national and regional levels. The contribution of `open data' appears to be mature in order to support this application and in this paper we present a spatial analysis technique for the evaluation of EU funds effects at territorial level, starting from open data by Open Cohesion. The application is focused on internal areas of Basilicata Region: Agri river Valley. A complex contest, where environmental and agricultural traditional vocations conflict with a recent development of oil extraction industries. Conclusions concern further applications and perspectives to improve and support regional development planning considering the exploitation of open data sources and spatial analysis.

Comparative analysis of optical coherence tomography signal and microhardness for demineralization evaluation of human tooth enamel

NASA Astrophysics Data System (ADS)

de Cara, Ana Claudia Ballet; Zezell, Denise Maria; Ana, Patricia A.; Deana, Alessandro Melo; Amaral, Marcello Magri; Dias Vieira, Nilson, Jr.; de Freitas, Anderson Zanardi

2012-06-01

The diagnosis of dental caries at an early stage enables the implementation of conservative treatments based on dental preservation. Several diagnostic methods have been developed, like visual-tactile and radiographic are the most commons but are limited for this application. The Optical Coherence Tomography is a technique that provides information of optical properties of enamel, which may change due to the decay process. The objective of this study was to evaluate the ability of OCT to detect different stages of demineralization of tooth enamel during the development of artificial caries lesions, taking as a reference standard for comparison sectional microhardness testing. Different stages of caries lesions were simulated using the pH cycling model suggested Feathestone and modified by Argenta. The samples were exposed to 0 (control group), 5, 10, 15, 20 and 25 days at a daily regimen of three hours demineralization followed by remineralization during 20 hours. It was used an OCT system with at 930nm. Sectional images were generated in all lesion region. The results obtained from the OCT technique presented similar behavior to microhardness, except for the group 25 days, due to inability to perform indentations reading in areas of more intense demineralization. A linear relationship was observed between the OCT and microhardness techniques for detection of demineralization in enamel. This relationship will allow the use of OCT technique in quantitative assessment of mineral loss and for the evaluation of incipient caries lesions.

Investigation of light induced effect on density of states of Pb doped CdSe thin films

NASA Astrophysics Data System (ADS)

Kaur, Jagdish; Singh, Baljinder; Tripathi, S. K.

2016-05-01

Thin films of Pb doped CdSe are deposited on the glass substrates by thermal evaporation technique using inert gas condensation method. The prepared thin films are light soaked under vacuum of 2×10-3 mbar for two hour. The absorption coefficient in the sub-band gap region has been studied using Constant Photocurrent Method (CPM). The absorption coefficient in the sub-band gap region follows an exponential Urbach tail. The value of Urbach energy and number density of defect states have been calculated from the absorption coefficient in the sub-band gap region and found to increase after light soaking treatment. The energy distribution of the occupied density of states below Fermi level has been evaluated using derivative procedure of the absorption coefficient.

Multi-year downscaling application of two-way coupled WRF v3.4 and CMAQ v5.0.2 over east Asia for regional climate and air quality modeling: model evaluation and aerosol direct effects

NASA Astrophysics Data System (ADS)

Hong, Chaopeng; Zhang, Qiang; Zhang, Yang; Tang, Youhua; Tong, Daniel; He, Kebin

2017-06-01

In this study, a regional coupled climate-chemistry modeling system using the dynamical downscaling technique was established by linking the global Community Earth System Model (CESM) and the regional two-way coupled Weather Research and Forecasting - Community Multi-scale Air Quality (WRF-CMAQ) model for the purpose of comprehensive assessments of regional climate change and air quality and their interactions within one modeling framework. The modeling system was applied over east Asia for a multi-year climatological application during 2006-2010, driven with CESM downscaling data under Representative Concentration Pathways 4.5 (RCP4.5), along with a short-term air quality application in representative months in 2013 that was driven with a reanalysis dataset. A comprehensive model evaluation was conducted against observations from surface networks and satellite observations to assess the model's performance. This study presents the first application and evaluation of the two-way coupled WRF-CMAQ model for climatological simulations using the dynamical downscaling technique. The model was able to satisfactorily predict major meteorological variables. The improved statistical performance for the 2 m temperature (T2) in this study (with a mean bias of -0.6 °C) compared with the Coupled Model Intercomparison Project Phase 5 (CMIP5) multi-models might be related to the use of the regional model WRF and the bias-correction technique applied for CESM downscaling. The model showed good ability to predict PM2. 5 in winter (with a normalized mean bias (NMB) of 6.4 % in 2013) and O3 in summer (with an NMB of 18.2 % in 2013) in terms of statistical performance and spatial distributions. Compared with global models that tend to underpredict PM2. 5 concentrations in China, WRF-CMAQ was able to capture the high PM2. 5 concentrations in urban areas. In general, the two-way coupled WRF-CMAQ model performed well for both climatological and air quality applications. The coupled modeling system with direct aerosol feedbacks predicted aerosol optical depth relatively well and significantly reduced the overprediction in downward shortwave radiation at the surface (SWDOWN) over polluted regions in China. The performance of cloud variables was not as good as other meteorological variables, and underpredictions of cloud fraction resulted in overpredictions of SWDOWN and underpredictions of shortwave and longwave cloud forcing. The importance of climate-chemistry interactions was demonstrated via the impacts of aerosol direct effects on climate and air quality. The aerosol effects on climate and air quality in east Asia (e.g., SWDOWN and T2 decreased by 21.8 W m-2 and 0.45 °C, respectively, and most pollutant concentrations increased by 4.8-9.5 % in January over China's major cities) were more significant than in other regions because of higher aerosol loadings that resulted from severe regional pollution, which indicates the need for applying online-coupled models over east Asia for regional climate and air quality modeling and to study the important climate-chemistry interactions. This work established a baseline for WRF-CMAQ simulations for a future period under the RCP4.5 climate scenario, which will be presented in a future paper.

Need for evaluative methodologies in land use, regional resource and waste management planning

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

Croke, E. J.

The transfer of planning methodology from the research community to the practitioner very frequently takes the form of analytical and evaluative techniques and procedures. In the end, these become operational in the form of data acquisition, management and display systems, computational schemes that are codified in the form of manuals and handbooks, and computer simulation models. The complexity of the socioeconomic and physical processes that govern environmental resource and waste management have reinforced the need for computer assisted, scientifically sophisticated planning models that are fully operational, dependent on an attainable data base and accessible in terms of the resources normallymore » available to practitioners of regional resource management, waste management, and land use planning. A variety of models and procedures that attempt to meet one or more of the needs of these practitioners are discussed.« less

Electrodeposition of gold nanoparticles on mesoporous TiO{sub 2} photoelectrode to enhance visible region photocurrent

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

Supriyono,; Krisnandi, Yuni Krisyuningsih; Gunlazuardi, Jarnuzi, E-mail: jarnuzi@ui.ac.id

2016-04-19

Electrodeposition of gold nanoparticles (Au NPs) on the mesoporous TiO{sub 2} photoelectrode to enchance visible region photocurrent have been investigated. Mesoporous TiO{sub 2} was prepared by a sol gel method and immobilized to the fluorine doped tin oxide (FTO) substrate by dip coating technique. Gold nanoparticles were electrodeposited on the TiO{sub 2} surface and the result FTO/TiO{sub 2}/Au was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), UV-Vis diffuse reflectance spectroscopy (DRS), and X-ray diffraction (XRD). The generated photocurrent was evaluated with an electrochemical workstation (e-DAQ/e-recorder 401) using 60 W wolfram lamp as visible lightmore » source. The photoelectrochemical evaluation indicated that the presence of gold nanoparticles on TiO{sub 2} photoelectrode shall enhance the photocurrent up to 50%.« less

Applications of Skylab data to land use and climatological analysis

NASA Technical Reports Server (NTRS)

Alexander, R. H. (Principal Investigator); Lewis, J. E., Jr.; Lins, H. F., Jr.; Jenner, C. B.; Outcalt, S. I.; Pease, R. W.

1976-01-01

The author has identified the following significant results. Skylab study in Central Atlantic Regional Ecological Test Site encompassed two separate but related tasks: (1) evaluation of photographic sensors S190A and B as sources of land use data for planning and managing land resources in major metropolitan regions, and (2) evaluation of the multispectral scanner S192 used in conjunction with associated data and analytical techniques as a data source on urban climates and the surface energy balance. Photographs from the Skylab S190B earth terrain camera were of greatest interest in the land use analysis task; they were of sufficiently high resolution to identify and map many level 2 and 3 land use categories. After being corrected to allow for atmosphere effects, output from thermal and visible bands of the S192 was employed in constructing computer map plots of albedo and surface temperature.

An evaluation of bilateral monitoring of cerebral oxygen saturation during pediatric cardiac surgery.

PubMed

Kussman, Barry D; Wypij, David; DiNardo, James A; Newburger, Jane; Jonas, Richard A; Bartlett, Jodi; McGrath, Ellen; Laussen, Peter C

2005-11-01

Cerebral oximetry is a technique that enables monitoring of regional cerebral oxygenation during cardiac surgery. In this study, we evaluated differences in bi-hemispheric measurement of cerebral oxygen saturation using near-infrared spectroscopy in 62 infants undergoing biventricular repair without aortic arch reconstruction. Left and right regional cerebral oxygen saturation index (rSO2i) were recorded continuously after the induction of anesthesia, and data were analyzed at 12 time points. Baseline rSO2i measurements were left 65 +/- 13 and right 66 +/- 13 (P = 0.17). Mean left and right rSO2i measurements were similar (< or =2 percentage points/absolute scale units) before, during, and after cardiopulmonary bypass, irrespective of the use of deep hypothermic circulatory arrest. Further longitudinal neurological outcome studies are required to determine whether uni- or bi-hemispheric monitoring is required in this patient population.

Preliminary Validation of the AFWA-NASA Blended Snowcover Product Over the Lower Great Lakes region

NASA Technical Reports Server (NTRS)

Hall, D. K.; Montesano, P. M.; Foster, J. L.; Riggs, G. A.; Kelly, R. E. J.; Czajkowski, K.

2007-01-01

A new snow product created using the standard Moderate-Resolution Imaging Spectroradiometer (MODIS) and Advanced Microwave Scanning Radiometer for EOS (AMSR-E) snow cover and snow-water equivalent products has been evaluated for the Lower Great Lakes region during the winter of 2002- 03. National Weather Service Co-Operative Observing Network stations and student-acquired snow data were used as ground truth. An interpolation scheme was used to map snow cover on the ground from the station measurements for each day of the study period. It is concluded that this technique does not represent the actual ground conditions adequately to permit evaluation of the new snow product in an absolute sense. However, use of the new product was found to improve the mapping of snow cover as compared to using either the MODIS or AMSR-E product, alone. Plans for further analysis are discussed.

Near-continuous non-contact cardiac pulse monitoring in a neonatal intensive care unit in near darkness

NASA Astrophysics Data System (ADS)

van Gastel, Mark; Balmaekers, Benoît; Bambang Oetomo, Sidarto; Verkruysse, Wim

2018-02-01

Currently, the cardiac activity of infants in the Neonatal Intensive Care Unit (NICU) is monitored with contact sensors. These techniques can cause injuries and infections, particularly in very premature infants with fragile skin. Recently, remote photoplethysmography (rPPG) showed its potential to measure cardiac activity with a camera without skin contact. The main limitations of this technique are its lack of robustness to subject motion and visible light requirements. The aim of this study is to investigate the feasibility of robust rPPG for NICU patients in near darkness. Video recordings using dedicated infrared illumination were made of 7 infants, age 30-33 weeks, at a NICU in Eindhoven, The Netherlands. The pulse rate can be detected with an average error of 1.5 BPM and 2.1 BPM when measured at the face and upper torso region, respectively. Overall, the correct pulse rate is detected for 87% of the time. A camera-based framework for robust pulse extraction in near darkness of NICU patients was proposed and successfully validated. The pulse rate could be reliably detected from all evaluated skin regions. Recordings with vigorous body movements, involving occlusion of the selected skin region, are still a challenge.

A variational method for automatic localization of the most pathological ROI in the knee cartilage

NASA Astrophysics Data System (ADS)

Qazi, Arish A.; Dam, Erik B.; Loog, Marco; Nielsen, Mads; Lauze, Francois; Christiansen, Claus

2008-03-01

Osteoarthritis (OA) is a degenerative joint disease characterized by degradation of the articular cartilage, and is a major cause of disability. At present, there is no cure for OA and currently available treatments are directed towards relief of symptoms. Recently it was shown that cartilage homogeneity visualized by MRI and representing the biochemical changes undergoing in the cartilage is a potential marker for early detection of knee OA. In this paper based on homogeneity we present an automatic technique, embedded in a variational framework, for localization of a region of interest in the knee cartilage that best indicates where the pathology of the disease is dominant. The technique is evaluated on 283 knee MR scans. We show that OA affects certain areas of the cartilage more distinctly, and these are more towards the peripheral region of the cartilage. We propose that this region in the cartilage corresponds anatomically to the area covered by the meniscus in healthy subjects. This finding may provide valuable clues in the pathology and the etiology of OA and thereby may improve treatment efficacy. Moreover our method is generic and may be applied to other organs as well.

Computer-aided diagnosis of cavernous malformations in brain MR images.

PubMed

Wang, Huiquan; Ahmed, S Nizam; Mandal, Mrinal

2018-06-01

Cavernous malformation or cavernoma is one of the most common epileptogenic lesions. It is a type of brain vessel abnormality that can cause serious symptoms such as seizures, intracerebral hemorrhage, and various neurological disorders. Manual detection of cavernomas by physicians in a large set of brain MRI slices is a time-consuming and labor-intensive task and often delays diagnosis. In this paper, we propose a computer-aided diagnosis (CAD) system for cavernomas based on T2-weighted axial plane MRI image analysis. The proposed technique first extracts the brain area based on atlas registration and active contour model, and then performs template matching to obtain candidate cavernoma regions. Texture, the histogram of oriented gradients and local binary pattern features of each candidate region are calculated, and principal component analysis is applied to reduce the feature dimensionality. Support vector machines (SVMs) are finally used to classify each region into cavernoma or non-cavernoma so that most of the false positives (obtained by template matching) are eliminated. The performance of the proposed CAD system is evaluated and experimental results show that it provides superior performance in cavernoma detection compared to existing techniques. Copyright © 2018 Elsevier Ltd. All rights reserved.

SU-E-I-37: Low-Dose Real-Time Region-Of-Interest X-Ray Fluoroscopic Imaging with a GPU-Accelerated Spatially Different Bilateral Filtering

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

Chung, H; Lee, J; Pua, R

2014-06-01

Purpose: The purpose of our study is to reduce imaging radiation dose while maintaining image quality of region of interest (ROI) in X-ray fluoroscopy. A low-dose real-time ROI fluoroscopic imaging technique which includes graphics-processing-unit- (GPU-) accelerated image processing for brightness compensation and noise filtering was developed in this study. Methods: In our ROI fluoroscopic imaging, a copper filter is placed in front of the X-ray tube. The filter contains a round aperture to reduce radiation dose to outside of the aperture. To equalize the brightness difference between inner and outer ROI regions, brightness compensation was performed by use of amore » simple weighting method that applies selectively to the inner ROI, the outer ROI, and the boundary zone. A bilateral filtering was applied to the images to reduce relatively high noise in the outer ROI images. To speed up the calculation of our technique for real-time application, the GPU-acceleration was applied to the image processing algorithm. We performed a dosimetric measurement using an ion-chamber dosimeter to evaluate the amount of radiation dose reduction. The reduction of calculation time compared to a CPU-only computation was also measured, and the assessment of image quality in terms of image noise and spatial resolution was conducted. Results: More than 80% of dose was reduced by use of the ROI filter. The reduction rate depended on the thickness of the filter and the size of ROI aperture. The image noise outside the ROI was remarkably reduced by the bilateral filtering technique. The computation time for processing each frame image was reduced from 3.43 seconds with single CPU to 9.85 milliseconds with GPU-acceleration. Conclusion: The proposed technique for X-ray fluoroscopy can substantially reduce imaging radiation dose to the patient while maintaining image quality particularly in the ROI region in real-time.« less

Evaluation of oesophageal transit velocity using the improved Demons technique.

PubMed

De Souza, Michele N; Xavier, Fernando E B; Secaf, Marie; Troncon, Luiz E A; de Oliveira, Ricardo B; Moraes, Eder R

2016-01-01

This paper presents a novel method to compute oesophageal transit velocity in a direct and automatized manner by the registration of scintigraphy images. A total of 36 images from nine healthy volunteers were processed. Four dynamic image series per volunteer were acquired after a minimum 8 h fast. Each acquisition was made following the ingestion of 5 ml saline labelled with about 26 MBq (700 µCi) technetium-99m phytate in a single swallow. Between the acquisitions, another two swallows of 5 ml saline were performed to clear the oesophagus. The composite acquired files were made of 240 frames of anterior and posterior views. Each frame is the accumulate count for 250 ms.At the end of acquisitions, the images were corrected for radioactive decay, the geometric mean was computed between the anterior and posterior views and the registration of a set of subsequent images was performed. Utilizing the improved Demons technique, we obtained from the deformation field the regional resultant velocity, which is directly related to the oesophagus transit velocity. The mean regional resulting velocities decreases progressively from the proximal to the distal oesophageal portions and, at the proximal portion, is virtually identical to the primary peristaltic pump typical velocity. Comparison between this parameter and 'time-activity' curves reveals consistency in velocities obtained using both methods, for the proximal portion. Application of the improved Demons technique, as an easy and automated method to evaluate velocities of oesophageal bolus transit, is feasible and seems to yield consistent data, particularly for the proximal oesophagus.

Full-Field Indentation Damage Measurement Using Digital Image Correlation

PubMed Central

López-Alba, Elías; Díaz-Garrido, Francisco A.

2017-01-01

A novel approach based on full-field indentation measurements to characterize and quantify the effect of contact in thin plates is presented. The proposed method has been employed to evaluate the indentation damage generated in the presence of bending deformation, resulting from the contact between a thin plate and a rigid sphere. For this purpose, the 3D Digital Image Correlation (3D-DIC) technique has been adopted to quantify the out of plane displacements at the back face of the plate. Tests were conducted using aluminum thin plates and a rigid bearing sphere to evaluate the influence of the thickness and the material behavior during contact. Information provided by the 3D-DIC technique has been employed to perform an indirect measurement of the contact area during the loading and unloading path of the test. A symmetrical distribution in the contact damage region due to the symmetry of the indenter was always observed. In the case of aluminum plates, the presence of a high level of plasticity caused shearing deformation as the load increased. Results show the full-field contact damage area for different plates’ thicknesses at different loads. The contact damage region was bigger when the thickness of the specimen increased, and therefore, bending deformation was reduced. With the proposed approach, the elastic recovery at the contact location was quantified during the unloading, as well as the remaining permanent indentation damage after releasing the load. Results show the information obtained by full-field measurements at the contact location during the test, which implies a substantial improvement compared with pointwise techniques. PMID:28773137

Numerical study of the vertical shading devices effect on the thermal performance of promotional apartments in hot dry climate of Algeria

NASA Astrophysics Data System (ADS)

Berkouk, Djihed; Bouzir, Tallal Abdel Karim; Mazouz, Said

2018-05-01

The bioclimatic architecture considers the local climatic conditions in order to reconcile maximally the comfort condition of the occupants. Through the several simulations effectuated by the TRNSYS software, this paper shows that the new architecture produced in the south of Algeria following the northern cities tendency is not fully adapted to the hot dry climate of the southern regions, such as the city of Biskra. In these regions, the passive techniques design influence strongly on the thermal architectural space performance. In this regard, diverse of the vertical shading devices size were proposed to evaluate the impact of this passive technique on the thermal performance of the promotional apartments situated in the city of Biskra. The comparative analysis between the simulation results says that the effectiveness of the vertical shading devices on the thermal performance spaces is reducing the indoor air temperature during the summer period. In addition, this analysis shows that promotional apartments are unsuitable for the desert climate.

Task-based evaluation of segmentation algorithms for diffusion-weighted MRI without using a gold standard

PubMed Central

Jha, Abhinav K.; Kupinski, Matthew A.; Rodríguez, Jeffrey J.; Stephen, Renu M.; Stopeck, Alison T.

2012-01-01

In many studies, the estimation of the apparent diffusion coefficient (ADC) of lesions in visceral organs in diffusion-weighted (DW) magnetic resonance images requires an accurate lesion-segmentation algorithm. To evaluate these lesion-segmentation algorithms, region-overlap measures are used currently. However, the end task from the DW images is accurate ADC estimation, and the region-overlap measures do not evaluate the segmentation algorithms on this task. Moreover, these measures rely on the existence of gold-standard segmentation of the lesion, which is typically unavailable. In this paper, we study the problem of task-based evaluation of segmentation algorithms in DW imaging in the absence of a gold standard. We first show that using manual segmentations instead of gold-standard segmentations for this task-based evaluation is unreliable. We then propose a method to compare the segmentation algorithms that does not require gold-standard or manual segmentation results. The no-gold-standard method estimates the bias and the variance of the error between the true ADC values and the ADC values estimated using the automated segmentation algorithm. The method can be used to rank the segmentation algorithms on the basis of both accuracy and precision. We also propose consistency checks for this evaluation technique. PMID:22713231

Southeast Regional Experiment Station

NASA Astrophysics Data System (ADS)

1994-08-01

This is the final report of the Southeast Regional Experiment Station project. The Florida Solar Energy Center (FSEC), a research institute of the University of Central Florida (UCF), has operated the Southeast Regional Experiment Station (SE RES) for the US Department of Energy (DOE) since September 1982. Sandia National Laboratories, Albuquerque (SNLA) provides technical program direction for both the SE RES and the Southwest Regional Experiment Station (SW RES) located at the Southwest Technology Development Institute at Las Cruces, New Mexico. This cooperative effort serves a critical role in the national photovoltaic program by conducting system evaluations, design assistance and technology transfer to enhance the cost-effective utilization and development of photovoltaic technology. Initially, the research focus of the SE RES program centered on utility-connected PV systems and associated issues. In 1987, the SE RES began evaluating amorphous silicon (a-Si) thin-film PV modules for application in utility-interactive systems. Stand-alone PV systems began receiving increased emphasis at the SE RES in 1986. Research projects were initiated that involved evaluation of vaccine refrigeration, water pumping and other stand-alone power systems. The results of this work have led to design optimization techniques and procedures for the sizing and modeling of PV water pumping systems. Later recent research at the SE RES included test and evaluation of batteries and charge controllers for stand-alone PV system applications. The SE RES project provided the foundation on which FSEC achieved national recognition for its expertise in PV systems research and related technology transfer programs. These synergistic products of the SE RES illustrate the high visibility and contributions the FSEC PV program offers to the DOE.

Applications of Mass Spectrometry Imaging for Safety Evaluation.

PubMed

Bonnel, David; Stauber, Jonathan

2017-01-01

Mass spectrometry imaging (MSI) was first derived from techniques used in physics, which were then incorporated into chemistry followed by application in biology. Developed over 50 years ago, and with different principles to detect and map compounds on a sample surface, MSI supports modern biology questions by detecting biological compounds within tissue sections. MALDI (matrix-assisted laser desorption/ionization) imaging trend analysis in this field shows an important increase in the number of publications since 2005, especially with the development of the MALDI imaging technique and its applications in biomarker discovery and drug distribution. With recent improvements of statistical tools, absolute and relative quantification protocols, as well as quality and reproducibility evaluations, MALDI imaging has become one of the most reliable MSI techniques to support drug discovery and development phases. MSI allows to potentially address important questions in drug development such as "What is the localization of the drug and its metabolites in the tissues?", "What is the pharmacological effect of the drug in this particular region of interest?", or "Is the drug and its metabolites related to an atypical finding?" However, prior to addressing these questions using MSI techniques, expertise needs to be developed to become proficient at histological procedures (tissue preparation with frozen of fixed tissues), analytical chemistry, matrix application, instrumentation, informatics, and mathematics for data analysis and interpretation.

Evaluation of support loss in micro-beam resonators: A revisit

NASA Astrophysics Data System (ADS)

Chen, S. Y.; Liu, J. Z.; Guo, F. L.

2017-12-01

This paper presents an analytical study on evaluation of support loss in micromechanical resonators undergoing in-plane flexural vibrations. Two-dimensional elastic wave theory is used to determine the energy transmission from the vibrating resonator to the support. Fourier transform and Green's function technique are adopted to solve the problem of wave motions on the surface of the support excited by the forces transmitted by the resonator onto the support. Analytical expressions of support loss in terms of quality factor, taking into account distributed normal stress and shear stress in the attachment region, and coupling between the normal stress and shear stress as well as material disparity between the support and the resonator, have been derived. Effects of geometry of micro-beam resonators, and material dissimilarity between support and resonator on support loss are examined. Numerical results show that 'harder resonator' and 'softer support' combination leads to larger support loss. In addition, the Perfectly Matched Layer (PML) numerical simulation technique is employed for validation of the proposed analytical model. Comparing with results of quality factor obtained by PML technique, we find that the present model agrees well with the results of PML technique and the pure-shear model overestimates support loss noticeably, especially for resonators with small aspect ratio and large material dissimilarity between the support and resonator.

Successful Treatment of Postpeak Stage Patients with Class II Division 1 Malocclusion Using Non-extraction and Multiloop Edgewise Archwire Therapy: A Report on 16 Cases

PubMed Central

Liu, Jun; Zou, Ling; Zhao, Zhi-he; Welburn, Neala; Yang, Pu; Tang, Tian; Li, Yu

2009-01-01

Aim To determine cephalometrically the mechanism of the treatment effects of non-extraction and multiloop edgewise archwire (MEAW) technique on postpeak Class II Division 1 patients. Methodology In this retrospective study, 16 postpeak Class II Division 1 patients successfully corrected using a non-extraction and MEAW technique were cephalometrically evaluated and compared with 16 matched control subjects treated using an extraction technique. Using CorelDRAW® software, standardized digital cephalograms pre- and post-active treatments were traced and a reference grid was set up. The superimpositions were based on the cranial base, the mandibular and the maxilla regions,and skeletal and dental changes were measured. Changes following treatment were evaluated using the paired-sample t-test. Student's t-test for unpaired samples was used to assess the differences in changes between the MEAW and the extraction control groups. Results The correction of the molar relationships comprised 54% skeletal change (mainly the advancement of the mandible) and 46% dental change. Correction of the anterior teeth relationships comprised 30% skeletal change and 70% dental change. Conclusion The MEAW technique can produce the desired vertical and sagittal movement of the tooth segment and then effectively stimulate mandibular advancement by utilizing the residual growth potential of the condyle. PMID:20690424

Handling of uncertainty due to interference fringe in FT-NIR transmittance spectroscopy - Performance comparison of interference elimination techniques using glucose-water system

NASA Astrophysics Data System (ADS)

Beganović, Anel; Beć, Krzysztof B.; Henn, Raphael; Huck, Christian W.

2018-05-01

The applicability of two elimination techniques for interferences occurring in measurements with cells of short pathlength using Fourier transform near-infrared (FT-NIR) spectroscopy was evaluated. Due to the growing interest in the field of vibrational spectroscopy in aqueous biological fluids (e.g. glucose in blood), aqueous solutions of D-(+)-glucose were prepared and split into a calibration set and an independent validation set. All samples were measured with two FT-NIR spectrometers at various spectral resolutions. Moving average smoothing (MAS) and fast Fourier transform filter (FFT filter) were applied to the interference affected FT-NIR spectra in order to eliminate the interference pattern. After data pre-treatment, partial least squares regression (PLSR) models using different NIR regions were constructed using untreated (interference affected) spectra and spectra treated with MAS and FFT filter. The prediction of the independent validation set revealed information about the performance of the utilized interference elimination techniques, as well as the different NIR regions. The results showed that the combination band of water at approx. 5200 cm-1 is of great importance since its performance was superior to the one of the so-called first overtone of water at approx. 6800 cm-1. Furthermore, this work demonstrated that MAS and FFT filter are fast and easy-to-use techniques for the elimination of interference fringes in FT-NIR transmittance spectroscopy.

Application of positron emission tomography to neuroimaging in sports sciences.

PubMed

Tashiro, Manabu; Itoh, Masatoshi; Fujimoto, Toshihiko; Masud, Md Mehedi; Watanuki, Shoichi; Yanai, Kazuhiko

2008-08-01

To investigate exercise-induced regional metabolic and perfusion changes in the human brain, various methods are available, such as positron emission tomography (PET), functional magnetic resonance imaging (fMRI), near-infrared spectroscopy (NIRS) and electroencephalography (EEG). In this paper, details of methods of metabolic measurement using PET, [(18)F]fluorodeoxyglucose ([(18)F]FDG) and [(15)O]radio-labelled water ([(15)O]H(2)O) will be explained. Functional neuroimaging in the field of neuroscience was started in the 1970s using an autoradiography technique on experimental animals. The first human functional neuroimaging exercise study was conducted in 1987 using a rough measurement system known as (133)Xe inhalation. Although the data was useful, more detailed and exact functional neuroimaging, especially with respect to spatial resolution, was achieved by positron emission tomography. Early studies measured the cerebral blood flow changes during exercise. Recently, PET was made more applicable to exercise physiology and psychology by the use of the tracer [(18)F]FDG. This technique allowed subjects to be scanned after an exercise task is completed but still obtain data from the exercise itself, which is similar to autoradiography studies. In this report, methodological information is provided with respect to the recommended protocol design, the selection of the scanning mode, how to evaluate the cerebral glucose metabolism and how to interpret the regional brain activity using voxel-by-voxel analysis and regions of interest techniques (ROI). Considering the important role of exercise in health promotion, further efforts in this line of research should be encouraged in order to better understand health behavior. Although the number of research papers is still limited, recent work has indicated that the [(18)F]FDG-PET technique is a useful tool to understand brain activity during exercise.

Microscopic observation of carrier-transport dynamics in quantum-structure solar cells using a time-of-flight technique

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

Toprasertpong, Kasidit; Fujii, Hiromasa; Sugiyama, Masakazu

2015-07-27

In this study, we propose a carrier time-of-flight technique to evaluate the carrier transport time across a quantum structure in an active region of solar cells. By observing the time-resolved photoluminescence signal with a quantum-well probe inserted under the quantum structure at forward bias, the carrier transport time can be efficiently determined at room temperature. The averaged drift velocity shows linear dependence on the internal field, allowing us to estimate the quantum structure as a quasi-bulk material with low effective mobility containing the information of carrier dynamics. We show that this direct and real-time observation is more sensitive to carriermore » transport than other conventional techniques, providing better insights into microscopic carrier transport dynamics to overcome a device design difficulty.« less

A cross correlation PIV technique using electro-optical image separation

NASA Astrophysics Data System (ADS)

Wirth, M.; Baritaud, T. A.

1996-11-01

A new approach for 2-dimensional flow field investigation by PIV has been developed for measurements with high spatial resolution without the well known directional ambiguity. This feature of the technique is especially important for measurements in flows with reversal regions or strong turbulent motion as in-cylinder engine measurements. The major aim of the work was to achieve the benefits of cross correlation PIV image evaluation at reasonable cost and under application of common single wavelength double pulsed laser systems as they are mainly used for PIV experiments. The development of the technique is based on polarization rotation of the light scattered by the seeding particles by means of a ferroelectric liquid crystal half wave plate (FLC). Measurement samples from low turbulent jets and the flow in the wake of a cylinder are being presented.

Modeling the biophysical impacts of global change in mountain biosphere reserves

USGS Publications Warehouse

Bugmann, H.K.M.; Bjornsen, F. Ewert; Haeberli, W.; Guisan, Antoine; Fagre, Daniel B.; Kaab, A.

2007-01-01

Mountains and mountain societies provide a wide range of goods and services to humanity, but they are particularly sensitive to the effects of global environmental change. Thus, the definition of appropriate management regimes that maintain the multiple functions of mountain regions in a time of greatly changing climatic, economic, and societal drivers constitutes a significant challenge. Management decisions must be based on a sound understanding of the future dynamics of these systems. The present article reviews the elements required for an integrated effort to project the impacts of global change on mountain regions, and recommends tools that can be used at 3 scientific levels (essential, improved, and optimum). The proposed strategy is evaluated with respect to UNESCO's network of Mountain Biosphere Reserves (MBRs), with the intention of implementing it in other mountain regions as well. First, methods for generating scenarios of key drivers of global change are reviewed, including land use/land cover and climate change. This is followed by a brief review of the models available for projecting the impacts of these scenarios on (1) cryospheric systems, (2) ecosystem structure and diversity, and (3) ecosystem functions such as carbon and water relations. Finally, the cross-cutting role of remote sensing techniques is evaluated with respect to both monitoring and modeling efforts. We conclude that a broad range of techniques is available for both scenario generation and impact assessments, many of which can be implemented without much capacity building across many or even most MBRs. However, to foster implementation of the proposed strategy, further efforts are required to establish partnerships between scientists and resource managers in mountain areas.

Constructing Synoptic Maps of Stratospheric Column Ozone from HALOE, SAGE and Balloonsonde Data Using Potential Vorticity Isentropic Coordinate Transformations

NASA Technical Reports Server (NTRS)

Hollandsworth, Stacey M.; Schoeberl, Mark R.; Morris, Gary A.; Long, Craig; Zhou, Shuntai; Miller, Alvin J.

1999-01-01

In this study we utilize potential vorticity - isentropic (PVI) coordinate transformations as a means of combining ozone data from different sources to construct daily, synthetic three-dimensional ozone fields. This methodology has been used successfully to reconstruct ozone maps in particular regions from aircraft data over the period of the aircraft campaign. We expand this method to create high-resolution daily global maps of profile ozone data, particularly in the lower stratosphere, where high-resolution ozone data are sparse. Ozone climatologies in PVI-space are constructed from satellite-based SAGE II and UARS/HALOE data, both of which-use solar occultation techniques to make high vertical resolution ozone profile measurements, but with low spatial resolution. A climatology from ground-based balloonsonde data is also created. The climatologies are used to establish the relationship between ozone and dynamical variability, which is defined by the potential vorticity (in the form of equivalent latitude) and potential temperature fields. Once a PVI climatology has been created from data taken by one or more instruments, high-resolution daily profile ozone field estimates are constructed based solely on the PVI fields, which are available on a daily basis from NCEP analysis. These profile ozone maps could be used for a variety of applications, including use in conjunction with total ozone maps to create a daily tropospheric ozone product, as input to forecast models, or as a tool for validating independent ozone measurements when correlative data are not available. This technique is limited to regions where the ozone is a long-term tracer and the flow is adiabatic. We evaluate the internal consistency of the technique by transforming the ozone back to physical space and comparing to the original profiles. Biases in the long-term average of the differences are used to identify regions where the technique is consistently introducing errors. Initial results show the technique is useful in the lower stratosphere at most latitudes throughout the year,and in the winter hemisphere in the middle stratosphere. The results are problematic in the summer hemisphere middle stratosphere due to increased ozone photochemistry and weak PV gradients. Alternate techniques in these regions will be discussed. An additional limitation is the quality and resolution of the meteorological data.

Visualization and Quantification of Nasal and Olfactory Deposition in a Sectional Adult Nasal Airway Cast.

PubMed

Xi, Jinxiang; Yuan, Jiayao Eddie; Zhang, Yu; Nevorski, Dannielle; Wang, Zhaoxuan; Zhou, Yue

2016-06-01

To compare drug deposition in the nose and olfactory region with different nasal devices and administration techniques. A Sar-Gel based colorimetry method will be developed to quantify local deposition rates. A sectional nasal airway cast was developed based on an MRI-based nasal airway model to visualize deposition patterns and measure regional dosages. Four nasal spray pumps and four nebulizers were tested with both standard and point-release administration techniques. Delivered dosages were measured using a high-precision scale. The colorimetry correlation for deposited mass was developed via image processing in Matlab and its performance was evaluated through comparison to experimental measurements. Results show that the majority of nasal spray droplets deposited in the anterior nose while only a small fraction (less than 4.6%) reached the olfactory region. For all nebulizers considered, more droplets went beyond the nasal valve, leading to distinct deposition patterns as a function of both the nebulizer type (droplet size and initial speed) and inhalation flow rate. With the point-release administration, up to 9.0% (±1.9%) of administered drugs were delivered to the olfactory region and 15.7 (±2.4%) to the upper nose using Pari Sinus. Standard nasal devices are inadequate to deliver clinically significant olfactory dosages without excess drug losses in other nasal epitheliums. The Sar-Gel based colorimetry method appears to provide a simple and practical approach to visualize and quantify regional deposition.

An Alternate Method for Estimating Dynamic Height from XBT Profiles Using Empirical Vertical Modes

NASA Technical Reports Server (NTRS)

Lagerloef, Gary S. E.

1994-01-01

A technique is presented that applies modal decomposition to estimate dynamic height (0-450 db) from Expendable BathyThermograph (XBT) temperature profiles. Salinity-Temperature-Depth (STD) data are used to establish empirical relationships between vertically integrated temperature profiles and empirical dynamic height modes. These are then applied to XBT data to estimate dynamic height. A standard error of 0.028 dynamic meters is obtained for the waters of the Gulf of Alaska- an ocean region subject to substantial freshwater buoyancy forcing and with a T-S relationship that has considerable scatter. The residual error is a substantial improvement relative to the conventional T-S correlation technique when applied to this region. Systematic errors between estimated and true dynamic height were evaluated. The 20-year-long time series at Ocean Station P (50 deg N, 145 deg W) indicated weak variations in the error interannually, but not seasonally. There were no evident systematic alongshore variations in the error in the ocean boundary current regime near the perimeter of the Alaska gyre. The results prove satisfactory for the purpose of this work, which is to generate dynamic height from XBT data for coanalysis with satellite altimeter data, given that the altimeter height precision is likewise on the order of 2-3 cm. While the technique has not been applied to other ocean regions where the T-S relation has less scatter, it is suggested that it could provide some improvement over previously applied methods, as well.

Quantitative metrics for evaluating parallel acquisition techniques in diffusion tensor imaging at 3 Tesla.

PubMed

Ardekani, Siamak; Selva, Luis; Sayre, James; Sinha, Usha

2006-11-01

Single-shot echo-planar based diffusion tensor imaging is prone to geometric and intensity distortions. Parallel imaging is a means of reducing these distortions while preserving spatial resolution. A quantitative comparison at 3 T of parallel imaging for diffusion tensor images (DTI) using k-space (generalized auto-calibrating partially parallel acquisitions; GRAPPA) and image domain (sensitivity encoding; SENSE) reconstructions at different acceleration factors, R, is reported here. Images were evaluated using 8 human subjects with repeated scans for 2 subjects to estimate reproducibility. Mutual information (MI) was used to assess the global changes in geometric distortions. The effects of parallel imaging techniques on random noise and reconstruction artifacts were evaluated by placing 26 regions of interest and computing the standard deviation of apparent diffusion coefficient and fractional anisotropy along with the error of fitting the data to the diffusion model (residual error). The larger positive values in mutual information index with increasing R values confirmed the anticipated decrease in distortions. Further, the MI index of GRAPPA sequences for a given R factor was larger than the corresponding mSENSE images. The residual error was lowest in the images acquired without parallel imaging and among the parallel reconstruction methods, the R = 2 acquisitions had the least error. The standard deviation, accuracy, and reproducibility of the apparent diffusion coefficient and fractional anisotropy in homogenous tissue regions showed that GRAPPA acquired with R = 2 had the least amount of systematic and random noise and of these, significant differences with mSENSE, R = 2 were found only for the fractional anisotropy index. Evaluation of the current implementation of parallel reconstruction algorithms identified GRAPPA acquired with R = 2 as optimal for diffusion tensor imaging.

Prioritization of water management for sustainability using hydrologic simulation model and multicriteria decision making techniques.

PubMed

Chung, Eun-Sung; Lee, Kil Seong

2009-03-01

The objective of this study is to develop an alternative evaluation index (AEI) in order to determine the priorities of a range of alternatives using both the hydrological simulation program in FORTRAN (HSPF) and multicriteria decision making (MCDM) techniques. In order to formulate the HSPF model, sensitivity analyses of water quantity (peak discharge and total volume) and quality (BOD peak concentrations and total loads) are conducted and a number of critical parameters were selected. To achieve a more precise simulation, the study watershed is divided into four regions for calibration and verification according to landuse, location, slope, and climate data. All evaluation criteria were selected using the Driver-Pressure-State-Impact-Response (DPSIR) model, a sustainability evaluation concept. The Analytic Hierarchy Process is used to estimate the weights of the criteria and the effects of water quantity and quality were quantified by HSPF simulation. In addition, AEIs that reflected residents' preferences for management objectives are proposed in order to induce the stakeholder to participate in the decision making process.

Low Dimensional Embedding of Climate Data for Radio Astronomical Site Testing in the Colombian Andes

NASA Astrophysics Data System (ADS)

Chaparro Molano, Germán; Ramírez Suárez, Oscar Leonardo; Restrepo Gaitán, Oscar Alberto; Marcial Martínez Mercado, Alexander

2017-10-01

We set out to evaluate the potential of the Colombian Andes for millimeter-wave astronomical observations. Previous studies for astronomical site testing in this region have suggested that nighttime humidity and cloud cover conditions make most sites unsuitable for professional visible-light observations. Millimeter observations can be done during the day, but require that the precipitable water vapor column above a site stays below ˜10 mm. Due to a lack of direct radiometric or radiosonde measurements, we present a method for correlating climate data from weather stations to sites with a low precipitable water vapor column. We use unsupervised learning techniques to low dimensionally embed climate data (precipitation, rain days, relative humidity, and sunshine duration) in order to group together stations with similar long-term climate behavior. The data were taken over a period of 30 years by 2046 weather stations across the Colombian territory. We find six regions with unusually dry, clear-sky conditions, ranging in elevations from 2200 to 3800 masl. We evaluate the suitability of each region using a quality index derived from a Bayesian probabilistic analysis of the station type and elevation distributions. Two of these regions show a high probability of having an exceptionally low precipitable water vapor column. We compared our results with global precipitable water vapor maps and find a plausible geographical correlation with regions with low water vapor columns (˜10 mm) at an accuracy of ˜20 km. Our methods can be applied to similar data sets taken in other countries as a first step toward astronomical site evaluation.

Objective spatiotemporal proxy-model comparisons of the Asian monsoon for the last millennium

NASA Astrophysics Data System (ADS)

Anchukaitis, K. J.; Cook, E. R.; Ammann, C. M.; Buckley, B. M.; D'Arrigo, R. D.; Jacoby, G.; Wright, W. E.; Davi, N.; Li, J.

2008-12-01

The Asian monsoon system can be studied using a complementary proxy/simulation approach which evaluates climate models using estimates of past precipitation and temperature, and which subsequently applies the best understanding of the physics of the climate system as captured in general circulation models to evaluate the broad-scale dynamics behind regional paleoclimate reconstructions. Here, we use a millennial-length climate field reconstruction of monsoon season summer (JJA) drought, developed from tree- ring proxies, with coupled climate simulations from NCAR CSM1.4 and CCSM3 to evaluate the cause of large- scale persistent droughts over the last one thousand years. Direct comparisons are made between the external forced response within the climate model and the spatiotemporal field reconstruction. In order to identify patterns of drought associated with internal variability in the climate system, we use a model/proxy analog technique which objectively selects epochs in the model that most closely reproduce those observed in the reconstructions. The concomitant ocean-atmosphere dynamics are then interpreted in order to identify and understand the internal climate system forcing of low frequency monsoon variability. We examine specific periods of extensive or intensive regional drought in the 15th, 17th, and 18th centuries, many of which are coincident with major cultural changes in the region.

Ultrasound Elastography for Estimation of Regional Strain of Multilayered Hydrogels and Tissue-Engineered Cartilage

PubMed Central

Chung, Chen-Yuan; Heebner, Joseph; Baskaran, Harihara; Welter, Jean F.; Mansour, Joseph M.

2015-01-01

Tissue-engineered (TE) cartilage constructs tend to develop inhomogeneously, thus, to predict the mechanical performance of the tissue, conventional biomechanical testing, which yields average material properties, is of limited value. Rather, techniques for evaluating regional and depth-dependent properties of TE cartilage, preferably non-destructively, are required. The purpose of this study was to build upon our previous results and to investigate the feasibility of using ultrasound elastography to non-destructively assess the depth-dependent biomechanical characteristics of TE cartilage while in a sterile bioreactor. As a proof-of-concept, and to standardize an assessment protocol, a well-characterized three-layered hydrogel construct was used as a surrogate for TE cartilage, and was studied under controlled incremental compressions. The strain field of the construct predicted by elastography was then validated by comparison with a poroelastic finite-element analysis (FEA). On average, the differences between the strains predicted by elastography and the FEA were within 10%. Subsequently engineered cartilage tissue was evaluated in the same test fixture. Results from these examinations showed internal regions where the local strain was 1–2 orders of magnitude greater than that near the surface. These studies document the feasibility of using ultrasound to evaluate the mechanical behaviors of maturing TE constructs in a sterile environment. PMID:26077987

NOAA Atmospheric Sciences Modeling Division support to the US Environmental Protection Agency

NASA Astrophysics Data System (ADS)

Poole-Kober, Evelyn M.; Viebrock, Herbert J.

1991-07-01

During FY-1990, the Atmospheric Sciences Modeling Division provided meteorological research and operational support to the U.S. Environmental Protection Agency. Basic meteorological operational support consisted of applying dispersion models and conducting dispersion studies and model evaluations. The primary research effort was the development and evaluation of air quality simulation models using numerical and physical techniques supported by field studies. Modeling emphasis was on the dispersion of photochemical oxidants and particulate matter on urban and regional scales, dispersion in complex terrain, and the transport, transformation, and deposition of acidic materials. Highlights included expansion of the Regional Acid Deposition Model/Engineering Model family to consist of the Tagged Species Engineering Model, the Non-Depleting Model, and the Sulfate Tracking Model; completion of the Acid-MODES field study; completion of the RADM2.1 evaluation; completion of the atmospheric processes section of the National Acid Precipitation Assessment Program 1990 Integrated Assessment; conduct of the first field study to examine the transport and entrainment processes of convective clouds; development of a Regional Oxidant Model-Urban Airshed Model interface program; conduct of an international sodar intercomparison experiment; incorporation of building wake dispersion in numerical models; conduct of wind-tunnel simulations of stack-tip downwash; and initiation of the publication of SCRAM NEWS.

Shallow landslide prediction and analysis with risk assessment using a spatial model in the coastal region in the state of São Paulo, Brazil

NASA Astrophysics Data System (ADS)

Camarinha, P. I. M.; Canavesi, V.; Alvalá, R. C. S.

2013-10-01

In Brazil, most of the disasters involving landslide occur in coastal regions, with population density concentrated on steep slopes. Thus, different approaches have been used to evaluate the landslide risk, although the greatest difficulty is related to the scarcity of spatial data with good quality. In this context, four cities located on the southeast coast of Brazil - Santos, Cubatão, Caraguatatuba and Ubatuba - in a region with the rough reliefs of the Serra do Mar and with a history of natural disasters were evaluated. Spatial prediction by fuzzy gamma technique was used for the landslide susceptibility mapping, considering environmental variables from data and software in the public domain. To validate the susceptibility mapping results, it was overlapped with risk sectors provided by the Geological Survey of Brazil (CPRM). A positive correlation was observed between the classes most susceptible and the location of these sectors. The results were also analyzed from the categorization of risk levels provided by CPRM. To compare the approach with other studies using landslide-scar maps, correlated indexes were evaluated, which also showed satisfactory results, thus indicating that the methodology presented is appropriate for risk assessment in urban areas and can be replicated to municipalities that do not have risk areas mapped.

Spatial assessment of Geo-environmental data by the integration of Remote Sensing and GIS techniques for Sitakund Region, Eastern foldbelt, Bangladesh.

NASA Astrophysics Data System (ADS)

Gazi, M. Y.; Rahman, M.; Islam, M. A.; Kabir, S. M. M.

2016-12-01

Techniques of remote sensing and geographic information systems (GIS) have been applied for the analysis and interpretation of the Geo-environmental assessment to Sitakund area, located within the administrative boundaries of the Chittagong district, Bangladesh. Landsat ETM+ image with a ground resolution of 30-meter and Digital Elevation Model (DEM) has been adopted in this study in order to produce a set of thematic maps. The diversity of the terrain characteristics had a major role in the diversity of recipes and types of soils that are based on the geological structure, also helped to diversity in land cover and use in the region. The geological situation has affected on the general landscape of the study area. The problem of research lies in the possibility of the estimating the techniques of remote sensing and geographic information systems in the evaluation of the natural data for the study area spatially as well as determine the appropriate in grades for the appearance of the ground and in line with the reality of the region. Software for remote sensing and geographic information systems were adopted in the analysis, classification and interpretation of the prepared thematic maps in order to get to the building of the Geo-environmental assessment map of the study area. Low risk geo-environmental land mostly covered area of Quaternary deposits especially with area of slope wash deposits carried by streams. Medium and high risk geo-environmental land distributed with area of other formation with the study area, mostly the high risk shows area of folds and faults. The study has assessed the suitability of lands for agricultural purpose and settlements in less vulnerable areas within this region.

Experimental study of cyclic creep and high-cycle fatigue of welded joints of St3 steel by the DIC technique

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

Kibitkin, Vladimir V., E-mail: vvk@ispms.tsc.ru; Solodushkin, Andrey I., E-mail: s.ai@sibmail.com; Pleshanov, Vasily S., E-mail: vsp@ispms.tsc.ru

In the paper the mechanisms of plastic deformation and fracture of welded joints of steel St3 were investigated at high-cycle fatigue and cyclic creep by the digital image correlation (DIC) technique. The evolution of strain rate is studied for the following regions: base metal, HAZ, and fusion zone. This strain rate evolution can be considered as a mechanical response of material. Three stages of deformation evolution are shown: deformation hardening (I), fatigue crack initiation (II), and the last stage is related to main crack (III). Two criteria are offered to evaluate the current mechanical state of welded joints.

Evaluation of publicly available documents to trace chiropractic technique systems that advocate radiography for subluxation analysis: a proposed genealogy.

PubMed

Young, Kenneth J

2014-12-01

The purpose of this study was to evaluate publicly available information of chiropractic technique systems that advocate radiography for subluxation detection to identify links between chiropractic technique systems and to describe claims made of the health effects of the osseous misalignment component of the chiropractic subluxation and radiographic paradigms. The Internet and publicly available documents were searched for information representing chiropractic technique systems that advocate radiography for subluxation detection. Key phrases including chiropractic, x-ray, radiography, and technique were identified from a Google search between April 2013 and March 2014. Phrases in Web sites and public documents were examined for any information about origins and potential links between these techniques, including the type of connection to BJ Palmer, who was the first chiropractor to advocate radiography for subluxation detection. Quotes were gathered to identify claims of health effects from osseous misalignment (subluxation) and paradigms of radiography. Techniques were grouped by region of the spine and how they could be traced back to B.J Palmer. A genealogy model and summary table of information on each technique were created. Patterns in year of origination and radiographic paradigms were noted, and percentages were calculated on elements of the techniques' characteristics in comparison to the entire group. Twenty-three techniques were identified on the Internet: 6 full spine, 17 upper cervical, and 2 techniques generating other lineage. Most of the upper cervical techniques (14/16) traced their origins to a time when the Palmer School was teaching upper cervical technique, and all the full spine techniques (6/6) originated before or after this phase. All the technique systems' documents attributed broad health effects to their methods. Many (21/23) of the techniques used spinal realignment on radiographs as one of their outcome measures. Chiropractic technique systems in this study (ie, those that advocate for radiography for subluxation misalignment detection) seem to be closely related by descent, their claims of a variety of health effects associated with chiropractic subluxation, and their radiographic paradigms.

Parametric studies and characterization measurements of x-ray lithography mask membranes

NASA Astrophysics Data System (ADS)

Wells, Gregory M.; Chen, Hector T. H.; Engelstad, Roxann L.; Palmer, Shane R.

1991-08-01

The techniques used in the experimental characterization of thin membranes are considered for their potential use as mask blanks for x-ray lithography. Among the parameters of interest for this evaluation are the film's stress, fracture strength, uniformity of thickness, absorption in the x-ray and visible spectral regions and the modulus and grain structure of the material. The experimental techniques used for measuring these properties are described. The accuracy and applicability of the assumptions used to derive the formulas that relate the experimental measurements to the parameters of interest are considered. Experimental results for silicon carbide and diamond films are provided. Another characteristic needed for an x-ray mask carrier is radiation stability. The number of x-ray exposures expected to be performed in the lifetime of an x-ray mask on a production line is on the order of 107. The dimensional stability requirements placed on the membranes during this period are discussed. Interferometric techniques that provide sufficient sensitivity for these stability measurements are described. A comparison is made between the different techniques that have been developed in term of the information that each technique provides, the accuracy of the various techniques, and the implementation issues that are involved with each technique.

Sensitivity analysis of brain morphometry based on MRI-derived surface models

NASA Astrophysics Data System (ADS)

Klein, Gregory J.; Teng, Xia; Schoenemann, P. T.; Budinger, Thomas F.

1998-07-01

Quantification of brain structure is important for evaluating changes in brain size with growth and aging and for characterizing neurodegeneration disorders. Previous quantification efforts using ex vivo techniques suffered considerable error due to shrinkage of the cerebrum after extraction from the skull, deformation of slices during sectioning, and numerous other factors. In vivo imaging studies of brain anatomy avoid these problems and allow repetitive studies following progression of brain structure changes due to disease or natural processes. We have developed a methodology for obtaining triangular mesh models of the cortical surface from MRI brain datasets. The cortex is segmented from nonbrain tissue using a 2D region-growing technique combined with occasional manual edits. Once segmented, thresholding and image morphological operations (erosions and openings) are used to expose the regions between adjacent surfaces in deep cortical folds. A 2D region- following procedure is then used to find a set of contours outlining the cortical boundary on each slice. The contours on all slices are tiled together to form a closed triangular mesh model approximating the cortical surface. This model can be used for calculation of cortical surface area and volume, as well as other parameters of interest. Except for the initial segmentation of the cortex from the skull, the technique is automatic and requires only modest computation time on modern workstations. Though the use of image data avoids many of the pitfalls of ex vivo and sectioning techniques, our MRI-based technique is still vulnerable to errors that may impact the accuracy of estimated brain structure parameters. Potential inaccuracies include segmentation errors due to incorrect thresholding, missed deep sulcal surfaces, falsely segmented holes due to image noise and surface tiling artifacts. The focus of this paper is the characterization of these errors and how they affect measurements of cortical surface area and volume.

Page layout analysis and classification for complex scanned documents

NASA Astrophysics Data System (ADS)

Erkilinc, M. Sezer; Jaber, Mustafa; Saber, Eli; Bauer, Peter; Depalov, Dejan

2011-09-01

A framework for region/zone classification in color and gray-scale scanned documents is proposed in this paper. The algorithm includes modules for extracting text, photo, and strong edge/line regions. Firstly, a text detection module which is based on wavelet analysis and Run Length Encoding (RLE) technique is employed. Local and global energy maps in high frequency bands of the wavelet domain are generated and used as initial text maps. Further analysis using RLE yields a final text map. The second module is developed to detect image/photo and pictorial regions in the input document. A block-based classifier using basis vector projections is employed to identify photo candidate regions. Then, a final photo map is obtained by applying probabilistic model based on Markov random field (MRF) based maximum a posteriori (MAP) optimization with iterated conditional mode (ICM). The final module detects lines and strong edges using Hough transform and edge-linkages analysis, respectively. The text, photo, and strong edge/line maps are combined to generate a page layout classification of the scanned target document. Experimental results and objective evaluation show that the proposed technique has a very effective performance on variety of simple and complex scanned document types obtained from MediaTeam Oulu document database. The proposed page layout classifier can be used in systems for efficient document storage, content based document retrieval, optical character recognition, mobile phone imagery, and augmented reality.

Intensity modulated radiotherapy and 3D conformal radiotherapy for whole breast irradiation: a comparative dosimetric study and introduction of a novel qualitative index for plan evaluation, the normal tissue index

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

Yim, Jackie; Suttie, Clare; Bromley, Regina

We report on a retrospective dosimetric study, comparing 3D conformal radiotherapy (3DCRT) and hybrid intensity modulated radiotherapy (hIMRT). We evaluated plans based on their planning target volume coverage, dose homogeneity, dose to organs at risk (OARs) and exposure of normal tissue to radiation. The Homogeneity Index (HI) was used to assess the dose homogeneity in the target region, and we describe a new index, the normal tissue index (NTI), to assess the dose in the normal tissue inside the tangent treatment portal. Plans were generated for 25 early-stage breast cancer patients, using a hIMRT technique. These were compared with themore » 3DCRT plans of the treatment previously received by the patients. Plan quality was evaluated using the HI, NTI and dose to OARs. The hIMRT technique was significantly more homogenous than the 3DCRT technique, while maintaining target coverage. The hIMRT technique was also superior at minimising the amount of tissue receiving D{sub 105%} and above (P < 0.0001). The ipsilateral lung and contralateral breast maximum were significantly lower in the hIMRT plans (P < 0.05 and P < 0.005), but the 3DCRT technique achieved a lower mean heart dose in left-sided breast cancer patients (P < 0.05). Hybrid intensity modulated radiotherapy plans achieved improved dose homogeneity compared to the 3DCRT plans and superior outcome with regard to dose to normal tissues. We propose that the addition of both HI and NTI in evaluating the quality of intensity modulated radiotherapy (IMRT) breast plans provides clinically relevant comparators which more accurately reflect the new paradigm of treatment goals and outcomes in the era of breast IMRT.« less

Evaluation of Publicly Available Documents to Trace Chiropractic Technique Systems That Advocate Radiography for Subluxation Analysis: A Proposed Genealogy

PubMed Central

Young, Kenneth J.

2014-01-01

Objective The purpose of this study was to evaluate publicly available information of chiropractic technique systems that advocate radiography for subluxation detection to identify links between chiropractic technique systems and to describe claims made of the health effects of the osseous misalignment component of the chiropractic subluxation and radiographic paradigms. Methods The Internet and publicly available documents were searched for information representing chiropractic technique systems that advocate radiography for subluxation detection. Key phrases including chiropractic, x-ray, radiography, and technique were identified from a Google search between April 2013 and March 2014. Phrases in Web sites and public documents were examined for any information about origins and potential links between these techniques, including the type of connection to BJ Palmer, who was the first chiropractor to advocate radiography for subluxation detection. Quotes were gathered to identify claims of health effects from osseous misalignment (subluxation) and paradigms of radiography. Techniques were grouped by region of the spine and how they could be traced back to B.J Palmer. A genealogy model and summary table of information on each technique were created. Patterns in year of origination and radiographic paradigms were noted, and percentages were calculated on elements of the techniques’ characteristics in comparison to the entire group. Results Twenty-three techniques were identified on the Internet: 6 full spine, 17 upper cervical, and 2 techniques generating other lineage. Most of the upper cervical techniques (14/16) traced their origins to a time when the Palmer School was teaching upper cervical technique, and all the full spine techniques (6/6) originated before or after this phase. All the technique systems’ documents attributed broad health effects to their methods. Many (21/23) of the techniques used spinal realignment on radiographs as one of their outcome measures. Conclusion Chiropractic technique systems in this study (ie, those that advocate for radiography for subluxation misalignment detection) seem to be closely related by descent, their claims of a variety of health effects associated with chiropractic subluxation, and their radiographic paradigms. PMID:25431540

WREP: A wavelet-based technique for extracting the red edge position from reflectance spectra for estimating leaf and canopy chlorophyll contents of cereal crops

NASA Astrophysics Data System (ADS)

Li, Dong; Cheng, Tao; Zhou, Kai; Zheng, Hengbiao; Yao, Xia; Tian, Yongchao; Zhu, Yan; Cao, Weixing

2017-07-01

Red edge position (REP), defined as the wavelength of the inflexion point in the red edge region (680-760 nm) of the reflectance spectrum, has been widely used to estimate foliar chlorophyll content from reflectance spectra. A number of techniques have been developed for REP extraction in the past three decades, but most of them require data-specific parameterization and the consistence of their performance from leaf to canopy levels remains poorly understood. In this study, we propose a new technique (WREP) to extract REPs based on the application of continuous wavelet transform to reflectance spectra. The REP is determined by the zero-crossing wavelength in the red edge region of a wavelet transformed spectrum for a number of scales of wavelet decomposition. The new technique is simple to implement and requires no parameterization from the user as long as continuous wavelet transforms are applied to reflectance spectra. Its performance was evaluated for estimating leaf chlorophyll content (LCC) and canopy chlorophyll content (CCC) of cereal crops (i.e. rice and wheat) and compared with traditional techniques including linear interpolation, linear extrapolation, polynomial fitting and inverted Gaussian. Our results demonstrated that WREP obtained the best estimation accuracy for both LCC and CCC as compared to traditional techniques. High scales of wavelet decomposition were favorable for the estimation of CCC and low scales for the estimation of LCC. The difference in optimal scale reveals the underlying mechanism of signature transfer from leaf to canopy levels. In addition, crop-specific models were required for the estimation of CCC over the full range. However, a common model could be built with the REPs extracted with Scale 5 of the WREP technique for wheat and rice crops when CCC was less than 2 g/m2 (R2 = 0.73, RMSE = 0.26 g/m2). This insensitivity of WREP to crop type indicates the potential for aerial mapping of chlorophyll content between growth seasons of cereal crops. The new REP extraction technique provides us a new insight for understanding the spectral changes in the red edge region in response to chlorophyll variation from leaf to canopy levels.

Using simulation and data envelopment analysis to evaluate Iraqi regions in producing strategic crops

NASA Astrophysics Data System (ADS)

Chaloob, Ibrahim Z.; Ramli, Razamin; Nawawi, Mohd Kamal Mohd

2014-12-01

Productivity of the agriculture sector in Iraq has yet to reach an acceptable level. In this paper, we introduce a practical method to help manage Iraqi agriculture sector to control resources and increase production to meet the modern century requirements of good crops. These important resources are identified as water, fertilizer, natural fertilizer, pesticides and labour. The current agricultural patterns in Iraq affect the strategic crops cultivation in the country and lessen agricultural production to some life-threatening limits. Data Envelopment Analysis (DEA), which is a non-parametric tool, is proposed to identify solutions that can maximize farmers' net benefit making an optimal use of the five resources. This model also improves optimal mix of the resources. In reference to the production of each one of the three strategic crops in Iraq, the DEA model is used to find the efficiency of one region among four others in its agriculture sector, with the main problem being the constraint in the number of lands available in the situation. Hence, the simulation technique is used to generate additional regions to the four main regions adopted. This is to resolve the constriction of DEA when the decision making unit is less than the number of variables (outputs and inputs). The result is expected to show the efficiency of each of the evaluated region.

Tailored ramp wave generation in gas gun experiments

NASA Astrophysics Data System (ADS)

Cotton, Matthew; Chapman, David; Winter, Ron; Harris, Ernie; Eakins, Daniel

2015-09-01

Gas guns are traditionally used as platforms to introduce a planar shock wave to a material using plate impact methods, generating states on the Hugoniot. The ability to deliver a ramp wave to a target during a gas gun experiment enables access to different regions of the equation-of-state surface, making it a valuable technique for characterising material behaviour. Previous techniques have relied on the use of multi-material impactors to generate a density gradient, which can be complex to manufacture. In this paper we describe the use of an additively manufactured steel component consisting of an array of tapered spikes which can deliver a ramp wave over ˜ 2 μs. The ability to tailor the input wave by varying the component design is discussed, an approach which makes use of the design freedom offered by additive manufacturing techniques to rapidly iterate the spike profile. Results from gas gun experiments are presented to evaluate the technique, and compared with 3D hydrodynamic simulations.

A methodological evaluation of volumetric measurement techniques including three-dimensional imaging in breast surgery.

PubMed

Hoeffelin, H; Jacquemin, D; Defaweux, V; Nizet, J L

2014-01-01

Breast surgery currently remains very subjective and each intervention depends on the ability and experience of the operator. To date, no objective measurement of this anatomical region can codify surgery. In this light, we wanted to compare and validate a new technique for 3D scanning (LifeViz 3D) and its clinical application. We tested the use of the 3D LifeViz system (Quantificare) to perform volumetric calculations in various settings (in situ in cadaveric dissection, of control prostheses, and in clinical patients) and we compared this system to other techniques (CT scanning and Archimedes' principle) under the same conditions. We were able to identify the benefits (feasibility, safety, portability, and low patient stress) and limitations (underestimation of the in situ volume, subjectivity of contouring, and patient selection) of the LifeViz 3D system, concluding that the results are comparable with other measurement techniques. The prospects of this technology seem promising in numerous applications in clinical practice to limit the subjectivity of breast surgery.

A Methodological Evaluation of Volumetric Measurement Techniques including Three-Dimensional Imaging in Breast Surgery

PubMed Central

Hoeffelin, H.; Jacquemin, D.; Defaweux, V.; Nizet, J L.

2014-01-01

Breast surgery currently remains very subjective and each intervention depends on the ability and experience of the operator. To date, no objective measurement of this anatomical region can codify surgery. In this light, we wanted to compare and validate a new technique for 3D scanning (LifeViz 3D) and its clinical application. We tested the use of the 3D LifeViz system (Quantificare) to perform volumetric calculations in various settings (in situ in cadaveric dissection, of control prostheses, and in clinical patients) and we compared this system to other techniques (CT scanning and Archimedes' principle) under the same conditions. We were able to identify the benefits (feasibility, safety, portability, and low patient stress) and limitations (underestimation of the in situ volume, subjectivity of contouring, and patient selection) of the LifeViz 3D system, concluding that the results are comparable with other measurement techniques. The prospects of this technology seem promising in numerous applications in clinical practice to limit the subjectivity of breast surgery. PMID:24511536

High resolution spectroscopic mapping imaging applied in situ to multilayer structures for stratigraphic identification of painted art objects

NASA Astrophysics Data System (ADS)

Karagiannis, Georgios Th.

2016-04-01

The development of non-destructive techniques is a reality in the field of conservation science. These techniques are usually not so accurate, as the analytical micro-sampling techniques, however, the proper development of soft-computing techniques can improve their accuracy. In this work, we propose a real-time fast acquisition spectroscopic mapping imaging system that operates from the ultraviolet to mid infrared (UV/Vis/nIR/mIR) area of the electromagnetic spectrum and it is supported by a set of soft-computing methods to identify the materials that exist in a stratigraphic structure of paint layers. Particularly, the system acquires spectra in diffuse-reflectance mode, scanning in a Region-Of-Interest (ROI), and having wavelength range from 200 up to 5000 nm. Also, a fuzzy c-means clustering algorithm, i.e., the particular soft-computing algorithm, produces the mapping images. The evaluation of the method was tested on a byzantine painted icon.

An evaluation of the PCR-RFLP technique to aid molecular-based monitoring of felids and canids in India

PubMed Central

2010-01-01

Background The order Carnivora is well represented in India, with 58 of the 250 species found globally, occurring here. However, small carnivores figure very poorly in research and conservation policies in India. This is mainly due to the dearth of tested and standardized techniques that are both cost effective and conducive to small carnivore studies in the field. In this paper we present a non-invasive genetic technique standardized for the study of Indian felids and canids with the use of PCR amplification and restriction enzyme digestion of scat collected in the field. Findings Using existing sequences of felids and canids from GenBank, we designed primers from the 16S rRNA region of the mitochondrial genome and tested these on ten species of felids and five canids. We selected restriction enzymes that would cut the selected region differentially for various species within each family. We produced a restriction digestion profile for the potential differentiation of species based on fragment patterns. To test our technique, we used felid PCR primers on scats collected from various habitats in India, representing varied environmental conditions. Amplification success with field collected scats was 52%, while 86% of the products used for restriction digestion could be accurately assigned to species. We verified this through sequencing. A comparison of costs across the various techniques currently used for scat assignment showed that this technique was the most practical and cost effective. Conclusions The species-specific key developed in this paper provides a means for detailed investigations in the future that focus on elusive carnivores in India and this approach provides a model for other studies in areas of Asia where many small carnivores co-occur. PMID:20525407

Soil Sampling Techniques For Alabama Grain Fields

NASA Technical Reports Server (NTRS)

Thompson, A. N.; Shaw, J. N.; Mask, P. L.; Touchton, J. T.; Rickman, D.

2003-01-01

Characterizing the spatial variability of nutrients facilitates precision soil sampling. Questions exist regarding the best technique for directed soil sampling based on a priori knowledge of soil and crop patterns. The objective of this study was to evaluate zone delineation techniques for Alabama grain fields to determine which method best minimized the soil test variability. Site one (25.8 ha) and site three (20.0 ha) were located in the Tennessee Valley region, and site two (24.2 ha) was located in the Coastal Plain region of Alabama. Tennessee Valley soils ranged from well drained Rhodic and Typic Paleudults to somewhat poorly drained Aquic Paleudults and Fluventic Dystrudepts. Coastal Plain s o i l s ranged from coarse-loamy Rhodic Kandiudults to loamy Arenic Kandiudults. Soils were sampled by grid soil sampling methods (grid sizes of 0.40 ha and 1 ha) consisting of: 1) twenty composited cores collected randomly throughout each grid (grid-cell sampling) and, 2) six composited cores collected randomly from a -3x3 m area at the center of each grid (grid-point sampling). Zones were established from 1) an Order 1 Soil Survey, 2) corn (Zea mays L.) yield maps, and 3) airborne remote sensing images. All soil properties were moderately to strongly spatially dependent as per semivariogram analyses. Differences in grid-point and grid-cell soil test values suggested grid-point sampling does not accurately represent grid values. Zones created by soil survey, yield data, and remote sensing images displayed lower coefficient of variations (8CV) for soil test values than overall field values, suggesting these techniques group soil test variability. However, few differences were observed between the three zone delineation techniques. Results suggest directed sampling using zone delineation techniques outlined in this paper would result in more efficient soil sampling for these Alabama grain fields.

Geothermometric evaluation of geothermal resources in southeastern Idaho

NASA Astrophysics Data System (ADS)

Neupane, G.; Mattson, E. D.; McLing, T. L.; Palmer, C. D.; Smith, R. W.; Wood, T. R.; Podgorney, R. K.

2016-01-01

Southeastern Idaho exhibits numerous warm springs, warm water from shallow wells, and hot water from oil and gas test wells that indicate a potential for geothermal development in the area. We have estimated reservoir temperatures from chemical composition of thermal waters in southeastern Idaho using an inverse geochemical modeling technique (Reservoir Temperature Estimator, RTEst) that calculates the temperature at which multiple minerals are simultaneously at equilibrium while explicitly accounting for the possible loss of volatile constituents (e.g., CO2), boiling and/or water mixing. The temperature estimates in the region varied from moderately warm (59 °C) to over 175 °C. Specifically, hot springs near Preston, Idaho, resulted in the highest reservoir temperature estimates in the region.

Evaluation of spectral channels and wavelength regions for separability of agricultural cover types

NASA Technical Reports Server (NTRS)

Dejesusparada, N. (Principal Investigator); Kumar, R.

1977-01-01

The author has identified the following significant results. Multispectral scanner data in twelve spectral channels in the wavelength range of 0.4 to 11.7 microns acquired in the middle of July for three flightlines were analyzed by applying automatic pattern recognition techniques. The same analysis was performed for the data acquired in mid August, over the same three flightlines, to investigate the effect of time on the results. The effect of deletion of each spectral channel, as well as each wavelength region on P sub c, is given. Values of P sub c for all possible combinations of wavelength regions in the subsets of one to twelve spectral channels are also given. The overall values of P sub c were found to be greater for the data of mid August than the data from mid July.

Advanced prediction technique for the low speed aerodynamics of V/STOL aircraft. Volume 2: User's manual

NASA Technical Reports Server (NTRS)

Beatty, T. D.; Worthey, M. K.

1984-01-01

A computerized prediction method known as the Vought V/STOL Aircraft Propulsive Effects computer program (VAPE) for propulsive induced forces and moments in transition and Short TakeOff and Landing (STOL) flight is improved and evaluated. The VAPE program is capable of evaluating: (1) effects of relative wind about an aircraft, (2) effects of propulsive lift jet entrainment, vorticity and flow blockage, (3) effects of engine inlet flow on the aircraft flow field, (4) engine inlet forces and moments including inlet separation, (5) ground effects in the STOL region of flight, and (6) viscous effects on lifting surfaces.

Depth resolved compositional analysis of aluminium oxide thin film using non-destructive soft x-ray reflectivity technique

NASA Astrophysics Data System (ADS)

Sinha, Mangalika; Modi, Mohammed H.

2017-10-01

In-depth compositional analysis of 240 Å thick aluminium oxide thin film has been carried out using soft x-ray reflectivity (SXR) and x-ray photoelectron spectroscopy technique (XPS). The compositional details of the film is estimated by modelling the optical index profile obtained from the SXR measurements over 60-200 Å wavelength region. The SXR measurements are carried out at Indus-1 reflectivity beamline. The method suggests that the principal film region is comprised of Al2O3 and AlOx (x = 1.6) phases whereas the interface region comprised of SiO2 and AlOx (x = 1.6) mixture. The soft x-ray reflectivity technique combined with XPS measurements explains the compositional details of principal layer. Since the interface region cannot be analyzed with the XPS technique in a non-destructive manner in such a case the SXR technique is a powerful tool for nondestructive compositional analysis of interface region.

Adaptation and micro-structure of Co-Cr alloy maxillary complete denture base plates fabricated by selective laser melting technique.

PubMed

Ye, Ye; Jiao, Ting; Zhu, Jiarui; Sun, Jian

2018-01-24

The purpose of the study was to evaluate the adaptation and micro-structure of Co-Cr alloy maxillary complete denture base plates fabricated by the selective laser melting (SLM) technique. Twenty pairs of edentulous casts were randomly and evenly divided into two groups, and manufacturing of the Co-Cr alloy maxillary complete denture base was conducted either by the SLM technique or by the conventional method. The base-cast sets were transversally sectioned into three sections at the distal canines, mesial of the first molars and the posterior palatal zone. The gap between the metal base and cast was measured in these three sections with a stereoscopic microscope, and the data were analysed using t tests. A total of five specimens of 5 mm diameter were fabricated with the Co-Cr alloy by SLM and the traditional casting technology. A scanning electron microscope (SEM) was used to evaluate the differences in microstructure between these specimens. There was no statistical difference between the three sections in all four groups (P > 0.05). At the region of the canines, the clearance value for the SLM Co-Cr alloy group was larger than that of the conventional method group (P < 0.05). At the mesial of the first molar region and the posterior palatal zone, there was no statistical difference between the gaps observed in the two groups (P > 0.05). The SLM Co-Cr alloy has a denser microstructure behaviour and less casting defect than the cast Co-Cr alloy. The SLM technique showed initial feasibility for the manufacture of dental bases of complete dentures, but large sample studies are needed to prove its reliability in clinical applications. The mechanical properties and microstructure of the denture frameworks prepared by selective laser melting indicate that these dentures are appropriate for clinical use.

Fully automated segmentation of left ventricle using dual dynamic programming in cardiac cine MR images

NASA Astrophysics Data System (ADS)

Jiang, Luan; Ling, Shan; Li, Qiang

2016-03-01

Cardiovascular diseases are becoming a leading cause of death all over the world. The cardiac function could be evaluated by global and regional parameters of left ventricle (LV) of the heart. The purpose of this study is to develop and evaluate a fully automated scheme for segmentation of LV in short axis cardiac cine MR images. Our fully automated method consists of three major steps, i.e., LV localization, LV segmentation at end-diastolic phase, and LV segmentation propagation to the other phases. First, the maximum intensity projection image along the time phases of the midventricular slice, located at the center of the image, was calculated to locate the region of interest of LV. Based on the mean intensity of the roughly segmented blood pool in the midventricular slice at each phase, end-diastolic (ED) and end-systolic (ES) phases were determined. Second, the endocardial and epicardial boundaries of LV of each slice at ED phase were synchronously delineated by use of a dual dynamic programming technique. The external costs of the endocardial and epicardial boundaries were defined with the gradient values obtained from the original and enhanced images, respectively. Finally, with the advantages of the continuity of the boundaries of LV across adjacent phases, we propagated the LV segmentation from the ED phase to the other phases by use of dual dynamic programming technique. The preliminary results on 9 clinical cardiac cine MR cases show that the proposed method can obtain accurate segmentation of LV based on subjective evaluation.

Evaluation of hyaluronan gel (Gengigel(®) ) as a topical applicant in the treatment of gingivitis.

PubMed

Sapna, Nadiger; Vandana, Kharidi Laxman

2011-08-01

  To clinically and histopathologically evaluate the anti-inflammatory effect of 0.2% hyaluronan gel alone and with mechanical therapy on gingivitis. The argyrophilic nucleolar organizer region staining technique was attempted to routinely determine its diagnostic and prognostic dependability for periodontal lesions.   In each of the 28 gingivitis patients, the four quadrants were subjected to different treatments: scaling, scaling + topical hyaluronan gel, only topical hyaluronan gel, and topical + intrasulcular hyaluronan gel. Clinical parameters were recorded at baseline, and on days 7, 14, and 21. Biopsies were taken from each quadrant, inflammatory infiltrates were graded, and the argyrophilic nucleolar organizer region count was measured before and after treatment.   A significant reduction was seen in clinical parameters, inflammatory infiltrates, and the argyrophilic nucleolar organizer region count within the groups. The effect of topical + intrasulcular gel was equivalent to scaling (P > 0.05). Topical + intrasulcular hyaluronan gel application demonstrated a better reduction than topical hyaluronan gel alone.   Hyaluronan gel is an effective topical agent for treating gingivitis, along with scaling and intrasulcular application. The argyrophilic nucleolar organizer region count can be used as a histopathological indicator in cases of non-responsive gingivitis to assess the severity of gingival inflammation. © 2011 Blackwell Publishing Asia Pty Ltd.

Simulation of climate characteristics and extremes of the Volta Basin using CCLM and RCA regional climate models

NASA Astrophysics Data System (ADS)

Darko, Deborah; Adjei, Kwaku A.; Appiah-Adjei, Emmanuel K.; Odai, Samuel N.; Obuobie, Emmanuel; Asmah, Ruby

2018-06-01

The extent to which statistical bias-adjusted outputs of two regional climate models alter the projected change signals for the mean (and extreme) rainfall and temperature over the Volta Basin is evaluated. The outputs from two regional climate models in the Coordinated Regional Climate Downscaling Experiment for Africa (CORDEX-Africa) are bias adjusted using the quantile mapping technique. Annual maxima rainfall and temperature with their 10- and 20-year return values for the present (1981-2010) and future (2051-2080) climates are estimated using extreme value analyses. Moderate extremes are evaluated using extreme indices (viz. percentile-based, duration-based, and intensity-based). Bias adjustment of the original (bias-unadjusted) models improves the reproduction of mean rainfall and temperature for the present climate. However, the bias-adjusted models poorly reproduce the 10- and 20-year return values for rainfall and maximum temperature whereas the extreme indices are reproduced satisfactorily for the present climate. Consequently, projected changes in rainfall and temperature extremes were weak. The bias adjustment results in the reduction of the change signals for the mean rainfall while the mean temperature signals are rather magnified. The projected changes for the original mean climate and extremes are not conserved after bias adjustment with the exception of duration-based extreme indices.

Utilizing Healthcare Developments, Demographic Data with Statistical Techniques to Estimate the Diarrhoea Prevalence in India.

PubMed

Srivastava, Shweta; Vatsalya, Vatsalya; Arora, Ashoo; Arora, Kashmiri L; Karch, Robert

2012-03-22

Diarrhoea is one of the leading causes of morbidity and mortality in developing countries in Africa and South Asia such as India. Prevalence of diarrheal diseases in those countries is higher than developed western world and largely has been associated with socio-economic and sanitary conditions. However, present available data has not been sufficiently evaluated to study the role of other factors like healthcare development, population density, sex and regional influence on diarrheal prevalence pattern. Study was performed to understand the relationship of diarrheal prevalence with specific measures namely; healthcare services development, demographics, population density, socio-economic conditions, sex, and regional prevalence patterns in India. Data from Annual national health reports and other epidemiological studies were included and statistically analyzed. Our results demonstrate significant correlation of the disease prevalence pattern with certain measures like healthcare centers, population growth rate, sex and region-specific morbidity. Available information on sanitation like water supply and toilet availability and socioeconomic conditions like poverty and literacy measures could only be associated as trends of significance. This study can be valuable for improvisation of appropriate strategies focused on important measures like healthcare resources, population growth and regional significances to evaluate prevalence patterns and management of the diarrhoea locally and globally.

A Many-Objective Approach to Developing Adaptive Water Supply Portfolios in the 'Research Triangle' Region of North Carolina

NASA Astrophysics Data System (ADS)

Zeff, H. B.; Kasprzyk, J. R.; Reed, P. M.; Characklis, G. W.

2012-12-01

This study uses many-objective evolutionary optimization to quantify the tradeoffs water utilities face when developing flexible water shortage response plans. Alternatives to infrastructure development, such as temporary demand management programs and inter-utility water transfer agreements, allow local water providers to develop portfolios of water supply options capable of adapting to changing hydrologic conditions and growing water demand. The extent to which these options are implemented will be determined by a number of conflicting operational and financial considerations. An integrated reservoir simulation model including four large water utilities in the 'Research Triangle' region of North Carolina is used to evaluate the potential tradeoffs resulting from regional demands on shared infrastructure, customer concerns, and the financial uncertainty caused by the intermittent and irregular nature of drought. Instead of providing one optimal solution, multi-objective evolutionary algorithms (MOEAs) use the concept of non-dominations to discover a set of portfolio options in which no solution is inferior to any other solution in all objectives. Interactive visual analytics enable water providers to explore these tradeoffs and develop water shortage response plans tailored to their individual circumstances. The simulation model is evaluated under a number of different formulations to help identify and visualize the impacts of water efficiency, revenue/cost variability, consumer effects, and inter-utility cooperation. The different problems are formulated by adding portfolio options and objectives in such a way that the lower dimensional problem formulations are sub-sets of the full formulation. The full formulation considers reservoir reliability, water use restriction frequency, total water transfer allotment, total costs, revenue/cost variability, and additional consumer losses during restrictions. The simulation results highlight the inadequacy of lower order, cost-benefit type analyses to evaluate water management techniques as they move beyond the construction of large storage infrastructure. This work can help water providers develop the analytical tools to evaluate complex, adaptive techniques that are becoming more attractive in an era of growing municipal demand, risking infrastructure costs, and uncertain hydrology.

Evaluation and comparison of methods to estimate irrigation withdrawal for the National Water Census Focus Area Study of the Apalachicola-Chattahoochee-Flint River Basin in southwestern Georgia

USGS Publications Warehouse

Painter, Jaime A.; Torak, Lynn J.; Jones, John W.

2015-09-30

Methods to estimate irrigation withdrawal using nationally available datasets and techniques that are transferable to other agricultural regions were evaluated by the U.S. Geological Survey as part of the Apalachicola-Chattahoochee-Flint (ACF) River Basin focus area study of the National Water Census (ACF–FAS). These methods investigated the spatial, temporal, and quantitative distributions of water withdrawal for irrigation in the southwestern Georgia region of the ACF–FAS, filling a vital need to inform science-based decisions regarding resource management and conservation. The crop– demand method assumed that only enough water is pumped onto a crop to satisfy the deficit between evapotranspiration and precipitation. A second method applied a geostatistical regimen of variography and conditional simulation to monthly metered irrigation withdrawal to estimate irrigation withdrawal where data do not exist. A third method analyzed Landsat satellite imagery using an automated approach to generate monthly estimates of irrigated lands. These methods were evaluated independently and compared collectively with measured water withdrawal information available in the Georgia part of the ACF–FAS, principally in the Chattahoochee-Flint River Basin. An assessment of each method’s contribution to the National Water Census program was also made to identify transfer value of the methods to the national program and other water census studies. None of the three methods evaluated represent a turnkey process to estimate irrigation withdrawal on any spatial (local or regional) or temporal (monthly or annual) extent. Each method requires additional information on agricultural practices during the growing season to complete the withdrawal estimation process. Spatial and temporal limitations inherent in identifying irrigated acres during the growing season, and in designing spatially and temporally representative monitor (meter) networks, can belie the ability of the methods to produce accurate irrigation-withdrawal estimates that can be used to produce dependable and consistent assessments of water availability and use for the National Water Census. Emerging satellite-data products and techniques for data analysis can generate high spatial-resolution estimates of irrigated-acres distributions with near-term temporal frequencies compatible with the needs of the ACF–FAS and the National Water Census.

Fission gas bubble identification using MATLAB's image processing toolbox

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

Collette, R.

Automated image processing routines have the potential to aid in the fuel performance evaluation process by eliminating bias in human judgment that may vary from person-to-person or sample-to-sample. This study presents several MATLAB based image analysis routines designed for fission gas void identification in post-irradiation examination of uranium molybdenum (U–Mo) monolithic-type plate fuels. Frequency domain filtration, enlisted as a pre-processing technique, can eliminate artifacts from the image without compromising the critical features of interest. This process is coupled with a bilateral filter, an edge-preserving noise removal technique aimed at preparing the image for optimal segmentation. Adaptive thresholding proved to bemore » the most consistent gray-level feature segmentation technique for U–Mo fuel microstructures. The Sauvola adaptive threshold technique segments the image based on histogram weighting factors in stable contrast regions and local statistics in variable contrast regions. Once all processing is complete, the algorithm outputs the total fission gas void count, the mean void size, and the average porosity. The final results demonstrate an ability to extract fission gas void morphological data faster, more consistently, and at least as accurately as manual segmentation methods. - Highlights: •Automated image processing can aid in the fuel qualification process. •Routines are developed to characterize fission gas bubbles in irradiated U–Mo fuel. •Frequency domain filtration effectively eliminates FIB curtaining artifacts. •Adaptive thresholding proved to be the most accurate segmentation method. •The techniques established are ready to be applied to large scale data extraction testing.« less

Influence of Freeze Concentration Technique on Aromatic and Phenolic Compounds, Color Attributes, and Sensory Properties of Cabernet Sauvignon Wine.

PubMed

Wu, Yan-Yan; Xing, Kai; Zhang, Xiao-Xu; Wang, Hui; Wang, Yong; Wang, Fang; Li, Jing-Ming

2017-06-02

Red wines produced in the Xinjiang region of China possess poor color density, and lack fruity notes and elegance. The freeze concentration technique, as a well-established concentration method for liquid food systems, was applied to the Cabernet Sauvignon ( Vitis vinifera L.) wine-making process, aiming to investigate its effect on wine quality improvement. Results showed that the freeze concentration treatment did not significantly alter the physicochemical properties of the wine, except for an increase of glycerol and alcoholic content. This technique increased ester contents, as well as decreasing the amount of volatile acids. Higher alcohol contents were also increased, but within an acceptable content range. All taken into consideration, the freeze concentration treated wine showed better fragrance characters according to sensory evaluation. The non-anthocyanin composition was altered by this application, however, the difference disappeared after the aging process. Fortunately, sensory evaluation showed that the treated wine possessed better mouthfeel properties. Anthocyanin contents were enhanced, and effectively stabilized the fresh wine color attributes, resulting in an improvement in appearance of the treated wine. All results considered, it can be concluded that freeze concentration treatment could be a good choice to improve wine quality.

Detection of an endangered aquatic heteropteran using environmental DNA in a wetland ecosystem

PubMed Central

Katano, Izumi; Sakata, Yusuke; Souma, Rio; Kosuge, Toshihiro; Nagano, Mariko; Ikeda, Kousuke; Yano, Koki; Tojo, Koji

2017-01-01

The use of environmental DNA (eDNA) has recently been employed to evaluate the distribution of various aquatic macroorganisms. Although this technique has been applied to a broad range of taxa, from vertebrates to invertebrates, its application is limited for aquatic insects such as aquatic heteropterans. Nepa hoffmanni (Heteroptera: Nepidae) is a small (approx. 23 mm) aquatic heteropteran that inhabits wetlands, can be difficult to capture and is endangered in Japan. The molecular tool eDNA was used to evaluate the species distribution of N. hoffmanni in comparison to that determined using hand-capturing methods in two regions of Japan. The eDNA of N. hoffmanni was detected at nearly all sites (10 eDNA-detected sites out of 14 sites), including sites where N. hoffmanni was not captured by hand (five eDNA-detected sites out of six captured sites). Thus, this species-specific eDNA technique can be applied to detect small, sparsely distributed heteropterans in wetland ecosystems. In conclusion, eDNA could be a valuable technique for the detection of aquatic insects inhabiting wetland habitats, and could make a significant contribution to providing distribution data necessary to species conservation. PMID:28791177

Use of the 1991 ASCOT field study data in a mesoscale model employing a four-dimensional data assimilation technique

NASA Astrophysics Data System (ADS)

Fast, Jerome D.; Osteen, B. Lance

In this study, a four-dimensional data assimilation technique based on Newtonian relaxation is incorporated into the Colorado State University (CSU) Regional Atmospheric Modeling System (RAMS) and evaluated using data taken from one experiment of the US Department of Energy's (DOE) 1991 Atmospheric Studies in COmplex Terrain (ASCOT) field study along the front range of the Rockies in Colorado. The main objective of this study is to determine the ability of the model to predict small-scale circulations influenced by terrain, such as drainage flows, and assess the impact of data assimilation on the numerical results. In contrast to previous studies in which the smallest horizontal grid spacing was 10 km and 8 km, data assimilation is applied in this study to domains with a horizontal grid spacing as small as 1 km. The prognostic forecasts made by RAMS are evaluated by comparing simulations that employ static initial conditions, with simulations that incorporate continuous data assimilation, and data assimilation for a fixed period of time (dynamic initialization). This paper will also elaborate on the application and limitation of the Newtonian relaxation technique in limited-area mesoscale models with a relatively small grid spacing.

Demonstration of a Probabilistic Technique for the Determination of Economic Viability of Very Large Transport Configurations

NASA Technical Reports Server (NTRS)

Mavris, Dimitri N.

1998-01-01

Over the past few years, modem aircraft design has experienced a paradigm shift from designing for performance to designing for affordability. This report contains a probabilistic approach that will allow traditional deterministic design methods to be extended to account for disciplinary, economic, and technological uncertainty. The probabilistic approach was facilitated by the Fast Probability Integration (FPI) technique; a technique which allows the designer to gather valuable information about the vehicle's behavior in the design space. This technique is efficient for assessing multi-attribute, multi-constraint problems in a more realistic fashion. For implementation purposes, this technique is applied to illustrate how both economic and technological uncertainty associated with a Very Large Transport aircraft concept may be assessed. The assessment is evaluated with the FPI technique to determine the cumulative probability distributions of the design space, as bound by economic objectives and performance constraints. These distributions were compared to established targets for a comparable large capacity aircraft, similar in size to the Boeing 747-400. The conventional baseline configuration design space was determined to be unfeasible and marginally viable, motivating the infusion of advanced technologies, including reductions in drag, specific fuel consumption, wing weight, and Research, Development, Testing, and Evaluation costs. The resulting system design space was qualitatively assessed with technology metric "k" factors. The infusion of technologies shifted the VLT design into regions of feasibility and greater viability. The study also demonstrated a method and relationship by which the impact of new technologies may be assessed in a more system focused approach.

Maxillary distraction osteogenesis in cleft lip and palate cases with midface hypoplasia using rigid external distractor: an alternative technique.

PubMed

Dua, Gaurav; Navin Kumar, Andrews; Roy, Indranil Deb; Roy, Supriyo Kumar

2014-05-01

Patients with operated cleft lip and palate present with a problem of midface hypoplasia, and such patients have been traditionally treated with orthognathic surgery. Such a procedure has its own limitations of relapse and hence a newer modality of distraction osteogenesis with histiogenesis can be chosen to overcome such limitations for midfacial advancement. The purpose of this study is to evaluate an alternative technique and its postoperative stability in maxillary distraction osteogenesis in patients of cleft lip and cleft palate using a rigid external device (RED). Nine patients with midface bone stock deficiency were selected for maxillary advancement. At the first surgery under general anesthesia, after Le Fort I osteotomy, RED system was used with the alternative technique. After distraction, evaluation was done for ease of the procedure, stability, and complications. Lateral cephalograms were evaluated at 3 stages: T1, pre-distraction; T2, post-distraction; and T3, 1 year post-distraction. A mean 13.4-mm midface advancement was shown with bone formation at the pterygomaxillary region without losing the vector and having a standby mode in case the wire broke during distraction The results were stable even at 1 year of follow-up. Maxillary position improved in relation to the cranial base. This study showed that the RED was versatile in midface advancement.

New calibration technique for water-vapor Raman lidar combined with the GNSS precipitable water vapor and the Meso-Scale Model

NASA Astrophysics Data System (ADS)

Kakihara, H.; Yabuki, M.; Kitafuji, F.; Tsuda, T.; Tsukamoto, M.; Hasegawa, T.; Hashiguchi, H.; Yamamoto, M.

2017-12-01

Atmospheric water vapor plays an important role in atmospheric chemistry and meteorology, with implications for climate change and severe weather. The Raman lidar technique is useful for observing water-vapor with high spatiotemporal resolutions. However, the calibration factor must be determined before observations. Because the calibration factor is generally evaluated by comparing Raman-signal results with those of independent measurement techniques (e.g., radiosonde), it is difficult to apply this technique to lidar sites where radiosonde observation cannot be carried out. In this study, we propose a new calibration technique for water-vapor Raman lidar using global navigation satellite system (GNSS)-derived precipitable water vapor (PWV) and Japan Meteorological Agency meso-scale model (MSM). The analysis was accomplished by fitting the GNSS-PWV to integrated water-vapor profiles combined with the MSM and the results of the lidar observations. The maximum height of the lidar signal applicable to this method was determined within 2.0 km by considering the signal noise mainly caused by low clouds. The MSM data was employed at higher regions that cannot apply the lidar data. This method can be applied to lidar signals lower than a limited height range due to weather conditions and lidar specifications. For example, Raman lidar using a laser operating in the ultraviolet C (UV-C) region has the advantage of daytime observation since there is no solar background radiation in the system. The observation range is, however, limited at altitudes lower than 1-3 km because of strong ozone absorption at the UV-C region. The new calibration technique will allow the utilization of various types of Raman lidar systems and provide many opportunities for calibration. We demonstrated the potential of this method by using the UV-C Raman lidar and GNSS observation data at the Shigaraki MU radar observatory (34°51'N, 136°06'E; 385m a.s.l.) of the Research Institute for Sustainable Humanosphere (RISH, Kyoto University, Japan, in June 2016. Differences of the calibration factor between the proposed method and the conventional method were 0.7% under optimal conditions such as clear skies and low ozone concentrations.

Benchmarking of state-of-the-art needle detection algorithms in 3D ultrasound data volumes

NASA Astrophysics Data System (ADS)

Pourtaherian, Arash; Zinger, Svitlana; de With, Peter H. N.; Korsten, Hendrikus H. M.; Mihajlovic, Nenad

2015-03-01

Ultrasound-guided needle interventions are widely practiced in medical diagnostics and therapy, i.e. for biopsy guidance, regional anesthesia or for brachytherapy. Needle guidance using 2D ultrasound can be very challenging due to the poor needle visibility and the limited field of view. Since 3D ultrasound transducers are becoming more widely used, needle guidance can be improved and simplified with appropriate computer-aided analyses. In this paper, we compare two state-of-the-art 3D needle detection techniques: a technique based on line filtering from literature and a system employing Gabor transformation. Both algorithms utilize supervised classification to pre-select candidate needle voxels in the volume and then fit a model of the needle on the selected voxels. The major differences between the two approaches are in extracting the feature vectors for classification and selecting the criterion for fitting. We evaluate the performance of the two techniques using manually-annotated ground truth in several ex-vivo situations of different complexities, containing three different needle types with various insertion angles. This extensive evaluation provides better understanding on the limitations and advantages of each technique under different acquisition conditions, which is leading to the development of improved techniques for more reliable and accurate localization. Benchmarking results that the Gabor features are better capable of distinguishing the needle voxels in all datasets. Moreover, it is shown that the complete processing chain of the Gabor-based method outperforms the line filtering in accuracy and stability of the detection results.

Impacts of soil moisture content on visual soil evaluation

NASA Astrophysics Data System (ADS)

Emmet-Booth, Jeremy; Forristal, Dermot; Fenton, Owen; Bondi, Giulia; Creamer, Rachel; Holden, Nick

2017-04-01

Visual Soil Examination and Evaluation (VSE) techniques offer tools for soil quality assessment. They involve the visual and tactile assessment of soil properties such as aggregate size and shape, porosity, redox morphology, soil colour and smell. An increasing body of research has demonstrated the reliability and utility of VSE techniques. However a number of limitations have been identified, including the potential impact of soil moisture variation during sampling. As part of a national survey of grassland soil quality in Ireland, an evaluation of the impact of soil moisture on two widely used VSE techniques was conducted. The techniques were Visual Evaluation of Soil Structure (VESS) (Guimarães et al., 2011) and Visual Soil Assessment (VSA) (Shepherd, 2009). Both generate summarising numeric scores that indicate soil structural quality, though employ different scoring mechanisms. The former requires the assessment of properties concurrently and the latter separately. Both methods were deployed on 20 sites across Ireland representing a range of soils. Additional samples were taken for soil volumetric water (θ) determination at 5-10 and 10-20 cm depth. No significant correlation was observed between θ 5-10 cm and either VSE technique. However, VESS scores were significantly related to θ 10-20 cm (rs = 0.40, sig = 0.02) while VSA scores were not (rs = -0.33, sig = 0.06). VESS and VSA scores can be grouped into quality classifications (good, moderate and poor). No significant mean difference was observed between θ 5-10 cm or θ 10-20 cm according to quality classification by either method. It was concluded that VESS scores may be affected by soil moisture variation while VSA appear unaffected. The different scoring mechanisms, where the separate assessment and scoring of individual properties employed by VSA, may limit soil moisture effects. However, moisture content appears not to affect overall structural quality classification by either method. References Guimarães, R.M.C., Ball, B.C. & Tormena, C.A. 2011. Improvements in the visual evaluation of soil structure, Soil Use and Management, 27, 3: 395-403 Shepherd, G.T. 2009. Visual Soil Assessment. Field guide for pastoral grazing and cropping on flat to rolling country. 2nd edn. Horizons regional council, New Zealand.

Intrathoracic airway wall detection using graph search and scanner PSF information

NASA Astrophysics Data System (ADS)

Reinhardt, Joseph M.; Park, Wonkyu; Hoffman, Eric A.; Sonka, Milan

1997-05-01

Measurements of the in vivo bronchial tree can be used to assess regional airway physiology. High-resolution CT (HRCT) provides detailed images of the lungs and has been used to evaluate bronchial airway geometry. Such measurements have been sued to assess diseases affecting the airways, such as asthma and cystic fibrosis, to measure airway response to external stimuli, and to evaluate the mechanics of airway collapse in sleep apnea. To routinely use CT imaging in a clinical setting to evaluate the in vivo airway tree, there is a need for an objective, automatic technique for identifying the airway tree in the CT images and measuring airway geometry parameters. Manual or semi-automatic segmentation and measurement of the airway tree from a 3D data set may require several man-hours of work, and the manual approaches suffer from inter-observer and intra- observer variabilities. This paper describes a method for automatic airway tree analysis that combines accurate airway wall location estimation with a technique for optimal airway border smoothing. A fuzzy logic, rule-based system is used to identify the branches of the 3D airway tree in thin-slice HRCT images. Raycasting is combined with a model-based parameter estimation technique to identify the approximate inner and outer airway wall borders in 2D cross-sections through the image data set. Finally, a 2D graph search is used to optimize the estimated airway wall locations and obtain accurate airway borders. We demonstrate this technique using CT images of a plexiglass tube phantom.

Urban Heat Island towards Urban Climate

NASA Astrophysics Data System (ADS)

Ningrum, Widya

2018-02-01

The urban heat island (UHI) is defined as the temperature difference between the urban and suburban areas and rural areas in the same region. Researchers have discussed several different techniques for evaluating the phenomenon. This paper reviews some of the causes and effects of urban heat islands, mainly on urban climate. Both directly and indirectly, the UHI influences multiple sectors. According to this, it is needed to develop a strategic mitigation between government and scientists to reduce the temperature.

Estimating A Reference Standard Segmentation With Spatially Varying Performance Parameters: Local MAP STAPLE

PubMed Central

Commowick, Olivier; Akhondi-Asl, Alireza; Warfield, Simon K.

2012-01-01

We present a new algorithm, called local MAP STAPLE, to estimate from a set of multi-label segmentations both a reference standard segmentation and spatially varying performance parameters. It is based on a sliding window technique to estimate the segmentation and the segmentation performance parameters for each input segmentation. In order to allow for optimal fusion from the small amount of data in each local region, and to account for the possibility of labels not being observed in a local region of some (or all) input segmentations, we introduce prior probabilities for the local performance parameters through a new Maximum A Posteriori formulation of STAPLE. Further, we propose an expression to compute confidence intervals in the estimated local performance parameters. We carried out several experiments with local MAP STAPLE to characterize its performance and value for local segmentation evaluation. First, with simulated segmentations with known reference standard segmentation and spatially varying performance, we show that local MAP STAPLE performs better than both STAPLE and majority voting. Then we present evaluations with data sets from clinical applications. These experiments demonstrate that spatial adaptivity in segmentation performance is an important property to capture. We compared the local MAP STAPLE segmentations to STAPLE, and to previously published fusion techniques and demonstrate the superiority of local MAP STAPLE over other state-of-the- art algorithms. PMID:22562727

Dosimetric changes with computed tomography automatic tube-current modulation techniques.

PubMed

Spampinato, Sofia; Gueli, Anna Maria; Milone, Pietro; Raffaele, Luigi Angelo

2018-04-06

The study is aimed at a verification of dose changes for a computed tomography automatic tube-current modulation (ATCM) technique. For this purpose, anthropomorphic phantom and Gafchromic ® XR-QA2 films were used. Radiochromic films were cut according to the shape of two thorax regions. The ATCM algorithm is based on noise index (NI) and three exam protocols with different NI were chosen, of which one was a reference. Results were compared with dose values displayed by the console and with Poisson statistics. The information obtained with radiochromic films has been normalized with respect to the NI reference value to compare dose percentage variations. Results showed that, on average, the information reported by the CT console and calculated values coincide with measurements. The study allowed verification of the dose information reported by the CT console for an ATCM technique. Although this evaluation represents an estimate, the method can be a starting point for further studies.

Carrier Propagation Dependence on Applied Potentials in Pentacene Organic Field Effect Transistors Investigated by Impedance Spectroscopy and Electrical Time-of-Flight Techniques

NASA Astrophysics Data System (ADS)

Lin, Jack; Weis, Martin; Taguchi, Dai; Manaka, Takaaki; Iwamoto, Mitsumasa

2011-04-01

Transient measurements of impedance spectroscopy and electrical time-of-flight (TOF) techniques were used for the evaluation of carrier propagation dependence on applied potentials in a pentacene organic field effect transistor (OFET). These techniques are based on carrier propagation, thus isolates the effect of charge density. The intrinsic mobility which is free from contact resistance effects was obtained by measurement of various channel lengths. The obtained intrinsic mobility shows good correspondence with steady-state current-voltage measurement's saturation mobility. However, their power law relations on mobility vs applied potential resulted in different exponents, suggesting different carrier propagation mechanisms, which is attributable to filling of traps or space charge field in the channel region. The hypothesis was verified by a modified electrical TOF experiment which demonstrated how the accumulated charges in the channel influence the effective mobility.

Change-based threat detection in urban environments with a forward-looking camera

NASA Astrophysics Data System (ADS)

Morton, Kenneth, Jr.; Ratto, Christopher; Malof, Jordan; Gunter, Michael; Collins, Leslie; Torrione, Peter

2012-06-01

Roadside explosive threats continue to pose a significant risk to soldiers and civilians in conflict areas around the world. These objects are easy to manufacture and procure, but due to their ad hoc nature, they are difficult to reliably detect using standard sensing technologies. Although large roadside explosive hazards may be difficult to conceal in rural environments, urban settings provide a much more complicated background where seemingly innocuous objects (e.g., piles of trash, roadside debris) may be used to obscure threats. Since direct detection of all innocuous objects would flag too many objects to be of use, techniques must be employed to reduce the number of alarms generated and highlight only a limited subset of possibly threatening regions for the user. In this work, change detection techniques are used to reduce false alarm rates and increase detection capabilities for possible threat identification in urban environments. The proposed model leverages data from multiple video streams collected over the same regions by first applying video aligning and then using various distance metrics to detect changes based on image keypoints in the video streams. Data collected at an urban warfare simulation range at an Eastern US test site was used to evaluate the proposed approach, and significant reductions in false alarm rates compared to simpler techniques are illustrated.

Microstructural Characterization of a Polycrystalline Nickel-Based Superalloy Processed via Tungsten-Intert-Gas-Shaped Metal Deposition

NASA Astrophysics Data System (ADS)

Clark, Daniel; Bache, Martin R.; Whittaker, Mark T.

2010-12-01

Recent trials have produced tungsten-inert-gas (TIG)-welded structures of a suitable scale to allow an evaluation of the technique as an economic and commercial process for the manufacture of complex aeroengine components. The employment of TIG welding is shown to have specific advantages over alternative techniques based on metal inert gas (MIG) systems. Investigations using the nickel-based superalloy 718 have shown that TIG induces a smaller weld pool with less compositional segregation. In addition, because the TIG process involves a pulsed power source, a faster cooling rate is achieved, although this rate, in turn, compromises the deposition rate. The microstructures produced by the two techniques differ significantly, with TIG showing an absence of the detrimental delta and Laves phases typically produced by extended periods at a high temperature using MIG. Instead, an anisotropic dendritic microstructure was evident with a preferred orientation relative to the axis of epitaxy. Niobium was segregated to the interdendritic regions. A fine-scale porosity was evident within the microstructure with a maximum diameter of approximately 5 μm. This porosity often was found in clusters and usually was associated with the interdendritic regions. Subsequent postdeposition heat treatment was shown to have no effect on preexisting porosity and to have a minimal effect on the microstructure.

TH-C-12A-03: Development of Expanded Field Irradiation Technique with Gimbaled X-Ray Head

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

Ono, T; Miyabe, Y; Yamada, M

2014-06-15

Purpose: The Vero4DRT has a maximum field size of 150×150 mm{sup 2}. The purposes of this study were to develop an expanded field irradiation technique using a unique gimbaled x-ray head of Vero4DRT and to evaluate its dosimetric characteristic. Methods: The expanded field irradiation consisted of four separate fields with 2.39 degree gimbal rotation around orthogonal two axes. The central beam axis for each field shifted 40 mm from the isocenter for longitudinal and lateral directions, and thus, the field size was expanded up to 230×230 mm{sup 2}. Adjacent region were created at the isocenter (center-adjacent expanded-field) and 20 mmmore » from isocenter (offadjacent expanded-field). To create flat dose distribution in the combined piecewise-fields, the overlapping and gaps regions on the isocenter plane were adjusted with the gimbal rotating and the MLC. To evaluate dosimetric characteristic of the expanded-field, films inserted in water-equivalent phantoms at 50, 100 and 150 mm depth were irradiated and the field size, penumbra, flatness and symmetry were analyzed.In addition, the expandedfield irradiation technique was applied to IMRT. A head and neck IMRT field, which was planned for the conventional linac (Varian Clinac iX), was reproduced with the expanded-field of the Vero4DRT. The simulated dose distribution for the expanded IMRT field was compared to the measured dose distribution. Results: The field size, penumbra, flatness and symmetry of center- and off- adjacent expanded-fields were 230.2–232.1 mm, 7.8–10.7 mm, 2.3–6.5% and –0.5–0.4% at 100 mm depth. The 82.1% area of the expanded IMRT dose distribution was within 5% difference between measurement and simulation, which was analyzed upper 50% dose area, and the 3%/3 mm gamma pass rate was 98.4%. Conclusions: The expandedfield technique was developed using the gimbaled x-ray head. To extend applied targets, such as whole breast irradiations or head and neck IMRT, the expanded-field technique would be effective.« less

Effects of skylight polarization, cloudiness, and view angle on the detection of oil on water.

NASA Technical Reports Server (NTRS)

Millard, J. P.; Arvesen, J. C.

1971-01-01

Three passive radiometric techniques, which use the contrast of sunlight reflected and backscattered from oil and water in specific wavelength regions, have potential application for remote sensing of oil spills. These techniques consist of measuring (1) total radiance, (2) the polarization components (normal and parallel) of radiance, and (3) the difference between the normal and parallel components. In this paper, the best view directions for these techniques are evaluated, conclusions are drawn as to the most promising technique, and explanations are developed to describe why previous total-radiance measurements yielded highest contrast between oil and water under overcast skies. The technique based on measurement of only the normal polorization component appears to be the most promising. The differential technique should be further investigated because of its potential to reduce the component of backscattered light from below the surface of the water. Measurements should be made about 45 deg nadir view angle in the direction opposite the sun. Overcast sky conditions provide a higher intensity of skylight relative to clear sky conditions and a lower intensity of backscatter within the water relative to surface reflectance. These factors result in higher contrast between oil and water under overcast skies.

Integrating multi-criteria evaluation techniques with geographic information systems for landfill site selection: a case study using ordered weighted average.

PubMed

Gorsevski, Pece V; Donevska, Katerina R; Mitrovski, Cvetko D; Frizado, Joseph P

2012-02-01

This paper presents a GIS-based multi-criteria decision analysis approach for evaluating the suitability for landfill site selection in the Polog Region, Macedonia. The multi-criteria decision framework considers environmental and economic factors which are standardized by fuzzy membership functions and combined by integration of analytical hierarchy process (AHP) and ordered weighted average (OWA) techniques. The AHP is used for the elicitation of attribute weights while the OWA operator function is used to generate a wide range of decision alternatives for addressing uncertainty associated with interaction between multiple criteria. The usefulness of the approach is illustrated by different OWA scenarios that report landfill suitability on a scale between 0 and 1. The OWA scenarios are intended to quantify the level of risk taking (i.e., optimistic, pessimistic, and neutral) and to facilitate a better understanding of patterns that emerge from decision alternatives involved in the decision making process. Copyright © 2011 Elsevier Ltd. All rights reserved.

25 years of neuroimaging in amyotrophic lateral sclerosis

PubMed Central

Foerster, Bradley R.; Welsh, Robert C.; Feldman, Eva L.

2014-01-01

Amyotrophic lateral sclerosis (ALS) is a fatal motor neuron disease for which a precise cause has not yet been identified. Standard CT or MRI evaluation does not demonstrate gross structural nervous system changes in ALS, so conventional neuroimaging techniques have provided little insight into the pathophysiology of this disease. Advanced neuroimaging techniques—such as structural MRI, diffusion tensor imaging and proton magnetic resonance spectroscopy—allow evaluation of alterations of the nervous system in ALS. These alterations include focal loss of grey and white matter and reductions in white matter tract integrity, as well as changes in neural networks and in the chemistry, metabolism and receptor distribution in the brain. Given their potential for investigation of both brain structure and function, advanced neuroimaging methods offer important opportunities to improve diagnosis, guide prognosis, and direct future treatment strategies in ALS. In this article, we review the contributions made by various advanced neuroimaging techniques to our understanding of the impact of ALS on different brain regions, and the potential role of such measures in biomarker development. PMID:23917850

[Regional anesthesia for carotid surgery : An overview of anatomy, techniques and their clinical relevance].

PubMed

Koköfer, A; Nawratil, J; Opperer, M

2017-04-01

Perioperative care for patients undergoing carotid endarterectomy (CEA) often presents a challenge to the anesthesia provider, as this patient group commonly suffers from a wide range of comorbidities. Although clinical trials could not demonstrate a significant benefit associated with regional anesthesia for outcomes such as insult, cardiac infarction or mortality, many authors concur that regional anesthetic techniques might be preferential in specific patient populations for this type of surgery. This article aims to present an overview of the currently used techniques for regional anesthesia in CEA, as well as discussing their influence on the perioperative outcome. After performing an extensive search of medical databases (Pubmed/Medline) the authors present a narrative analysis and interpretation of recent literature. Currently there is a clear trend towards ultrasound guided regional anesthesia and away from classic landmark based techniques. The literature seems to support the notion that superior and intermediate cervical blocks are safer and less invasive than deep blocks. With regional anesthetic techniques evolving to be more and more complex, the use of ultrasound is becoming increasingly indispensable in the operating theatre. For anesthesiologists with sufficient training and a profound knowledge of the respective anatomy, regional anesthesia seems to be a veritable alternative to general anesthesia for CEA.

Lots of legacy soil data are available, but which data do we need to collect for regional land use analysis?

NASA Astrophysics Data System (ADS)

Hendriks, Chantal; Stoorvogel, Jetse; Claessens, Lieven

2015-04-01

In the past, soil surveying techniques were mainly developed for qualitative regional land use analysis (RLUA) like land evaluation and land use planning. Conventional soil survey techniques usually describe soil types according to a soil classification scheme (e.g. Soil Taxonomy and World Reference Base). These soil surveys met the requirements of qualitative land evaluation and land use planning. However, during the last decades there is an increased need for quantitative RLUA resulting in an increased demand for quantitative soil data. The rapid developments in computing technology and the availability of auxiliary information (e.g. remote sensing and digital elevation models) allowed for the development of new soil surveying techniques like digital soil mapping. These new soil surveying techniques aim to produce continuous maps of quantitative functional soil properties. However, RLUA nowadays requires soil data that include a description of the spatial variability of the entire pedon in which correlations between soil properties are retained. Current surveying techniques do not fully fulfil these requirements resulting in a gap between the supply and demand of soil data in RLUA. The gap is caused by the fact that legacy soil data are collected for different purposes and inherently have different assumptions on e.g., soil variability. In this study, some of these assumptions are tested and verified using primary soil data collected during a recent field survey in Machakos and Makueni County (Kenya). Subsequently an ongoing RLUA, the Global Yield Gap Atlas (GYGA) project, is taken as a case study to evaluate the effect of different sources of soil data on the results of the RLUA. The results of the study show that various assumptions underlying the soil survey hamper the quality requirements of soil data for the specific objectives of the RLUA. To give a few examples: mapping soil properties individually ignores correlations between them, soil properties differed significantly between natural and agricultural land, discrete soil mapping units described by a representative soil profile showed internal variability. None of the legacy datasets fitted the requirements of the RLUA. However, resources to collect additional primary soil data are limited. Evaluating legacy data allows us to identify the soil data that we need to collect. Legacy data lack information on e.g. soil management and effective rooting depth, while these data are often required for RLUA. This results in the use of assumptions, estimations and simplifications in a RLUA. The choice of legacy data has a profound effect on the results of a RLUA. The GYGA case study shows for example that different sources of soil input data can lead to differences in simulated water-limited maize yields of up to 3 ton/ha.

Evaluating integration of inland bathymetry in the U.S. Geological Survey 3D Elevation Program, 2014

USGS Publications Warehouse

Miller-Corbett, Cynthia

2016-09-01

Inland bathymetry survey collections, survey data types, features, sources, availability, and the effort required to integrate inland bathymetric data into the U.S. Geological Survey 3D Elevation Program are assessed to help determine the feasibility of integrating three-dimensional water feature elevation data into The National Map. Available data from wading, acoustic, light detection and ranging, and combined technique surveys are provided by the U.S. Geological Survey, National Oceanic and Atmospheric Administration, U.S. Army Corps of Engineers, and other sources. Inland bathymetric data accessed through Web-hosted resources or contacts provide useful baseline parameters for evaluating survey types and techniques used for collection and processing, and serve as a basis for comparing survey methods and the quality of results. Historically, boat-mounted acoustic surveys have provided most inland bathymetry data. Light detection and ranging techniques that are beneficial in areas hard to reach by boat, that can collect dense data in shallow water to provide comprehensive coverage, and that can be cost effective for surveying large areas with good water clarity are becoming more common; however, optimal conditions and techniques for collecting and processing light detection and ranging inland bathymetry surveys are not yet well defined.Assessment of site condition parameters important for understanding inland bathymetry survey issues and results, and an evaluation of existing inland bathymetry survey coverage are proposed as steps to develop criteria for implementing a useful and successful inland bathymetry survey plan in the 3D Elevation Program. These survey parameters would also serve as input for an inland bathymetry survey data baseline. Integration and interpolation techniques are important factors to consider in developing a robust plan; however, available survey data are usually in a triangulated irregular network format or other format compatible with the 3D Elevation Program so that data can be integrated with a minimal level of effort. Geomorphic site conditions are known to affect the success and accuracy of light detection and ranging and other bathymetric surveys, and a baseline that includes geomorphic data is recommended to help in evaluation of limitations imposed by geomorphology for surveys completed in the variable physiographic provinces across the United States. The geographic distribution for existing surveys identifies regions where inland bathymetry data have been collected and, conversely, where little or no survey data seem to be available to provide hydrologic and hydraulic information. This distribution, in conjunction with local to regional data needs to characterize and monitor river and lake resources, provides another important set of criteria to propose and guide acquisition of new bathymetry data for the 3D Elevation Program. An initial evaluation of needs can be based on the importance of water resources that provide primary water supplies for communities, agriculture, energy, and ecological systems; the importance of flood plain analyses; and projected population growth across the United States.

Identification of Pork Contamination in Meatballs of Indonesia Local Market Using Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) Analysis

PubMed Central

Erwanto, Yuny; Abidin, Mohammad Zainal; Sugiyono, Eko Yasin Prasetyo Muslim; Rohman, Abdul

2014-01-01

This research applied and evaluated a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) using cytochrome b gene to detect pork contamination in meatballs from local markets in Surabaya and Yogyakarta regions, Indonesia. To confirm the effectiveness and specificity of this fragment, thirty nine DNA samples from different meatball shops were isolated and amplified, and then the PCR amplicon was digested by BseDI restriction enzyme to detect the presence of pork in meatballs. BseDI restriction enzyme was able to cleave porcine cytochrome b gene into two fragments (131 bp and 228 bp). Testing the meatballs from the local market showed that nine of twenty meatball shops in Yogyakarta region were detected to have pork contamination, but there was no pork contamination in meatball shops in Surabaya region. In conclusion, specific PCR amplification of cytochrome b gen and cleaved by BseDI restriction enzymes seems to be a powerful technique for the identification of pork presence in meatball because of its simplicity, specificity and sensitivity. Furthermore, pork contamination intended for commercial products of sausage, nugget, steak and meat burger can be checked. The procedure is also much cheaper than other methods based on PCR, immunodiffusion and other techniques that need expensive equipment. PMID:25178301

Identification of Pork Contamination in Meatballs of Indonesia Local Market Using Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) Analysis.

PubMed

Erwanto, Yuny; Abidin, Mohammad Zainal; Sugiyono, Eko Yasin Prasetyo Muslim; Rohman, Abdul

2014-10-01

This research applied and evaluated a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) using cytochrome b gene to detect pork contamination in meatballs from local markets in Surabaya and Yogyakarta regions, Indonesia. To confirm the effectiveness and specificity of this fragment, thirty nine DNA samples from different meatball shops were isolated and amplified, and then the PCR amplicon was digested by BseDI restriction enzyme to detect the presence of pork in meatballs. BseDI restriction enzyme was able to cleave porcine cytochrome b gene into two fragments (131 bp and 228 bp). Testing the meatballs from the local market showed that nine of twenty meatball shops in Yogyakarta region were detected to have pork contamination, but there was no pork contamination in meatball shops in Surabaya region. In conclusion, specific PCR amplification of cytochrome b gen and cleaved by BseDI restriction enzymes seems to be a powerful technique for the identification of pork presence in meatball because of its simplicity, specificity and sensitivity. Furthermore, pork contamination intended for commercial products of sausage, nugget, steak and meat burger can be checked. The procedure is also much cheaper than other methods based on PCR, immunodiffusion and other techniques that need expensive equipment.

Trepanation in South-Central Peru during the early late intermediate period (ca. AD 1000-1250).

PubMed

Kurin, Danielle S

2013-12-01

This study evaluates trepanations from five well-contextualized prehistoric sites in the south-central highlands of Andahuaylas, Peru. The emergence of trepanation in this region coincides with the collapse of the Wari Empire, ca. ad 1000. Thirty-two individuals from Andahuaylas, AMS radiocarbon dated to the early Late Intermediate Period (ca. ad 1000-1250), were found to have 45 total trepanations. Various surgical techniques were being employed concurrently throughout the region. Scraping trepanations evinced the highest survival rate; circular grooving, drilling and boring, and linear cutting were far less successful. Evidence of perioperative procedures like hair shaving, poultice application, and possible cranioplasty use aimed to ensure the survival of a trepanation recipient. Postmortem trepanations, also present in Andahuaylas, were likely executed on corpses as a means of better understanding cranial anatomy and improving techniques. Similarities in trepanation patterns throughout the region attest to common motivations to engage in surgery. Although moderate physical head trauma seems to be the impetus for intervention in many cases of trepanation, other motivations included physiological and possibly psychosomatic factors. Nevertheless, treatment was not for everyone. In Andahuaylas, trepanations were withheld from subadults, females, and those individuals who practiced cranial modification. Copyright © 2013 Wiley Periodicals, Inc.

Evaluating Dynamic Bivariate Correlations in Resting-state fMRI: A comparison study and a new approach

PubMed Central

Lindquist, Martin A.; Xu, Yuting; Nebel, Mary Beth; Caffo, Brain S.

2014-01-01

To date, most functional Magnetic Resonance Imaging (fMRI) studies have assumed that the functional connectivity (FC) between time series from distinct brain regions is constant across time. However, recently, there has been increased interest in quantifying possible dynamic changes in FC during fMRI experiments, as it is thought this may provide insight into the fundamental workings of brain networks. In this work we focus on the specific problem of estimating the dynamic behavior of pair-wise correlations between time courses extracted from two different regions of the brain. We critique the commonly used sliding-windows technique, and discuss some alternative methods used to model volatility in the finance literature that could also prove useful in the neuroimaging setting. In particular, we focus on the Dynamic Conditional Correlation (DCC) model, which provides a model-based approach towards estimating dynamic correlations. We investigate the properties of several techniques in a series of simulation studies and find that DCC achieves the best overall balance between sensitivity and specificity in detecting dynamic changes in correlations. We also investigate its scalability beyond the bivariate case to demonstrate its utility for studying dynamic correlations between more than two brain regions. Finally, we illustrate its performance in an application to test-retest resting state fMRI data. PMID:24993894

Electron energy distribution function in the divertor region of the COMPASS tokamak during neutral beam injection heating

NASA Astrophysics Data System (ADS)

Hasan, E.; Dimitrova, M.; Havlicek, J.; Mitošinková, K.; Stöckel, J.; Varju, J.; Popov, Tsv K.; Komm, M.; Dejarnac, R.; Hacek, P.; Panek, R.; the COMPASS Team

2018-02-01

This paper presents the results from swept probe measurements in the divertor region of the COMPASS tokamak in D-shaped, L-mode discharges, with toroidal magnetic field BT = 1.15 T, plasma current Ip = 180 kA and line-average electron densities varying from 2 to 8×1019 m-3. Using neutral beam injection heating, the electron energy distribution function is studied before and during the application of the beam. The current-voltage characteristics data are processed using the first-derivative probe technique. This technique allows one to evaluate the plasma potential and the real electron energy distribution function (respectively, the electron temperatures and densities). At the low average electron density of 2×1019 m-3, the electron energy distribution function is bi-Maxwellian with a low-energy electron population with temperatures 4-6 eV and a high-energy electron group 12-25 eV. As the line-average electron density is increased, the electron temperatures decrease. At line-average electron densities above 7×1019 m-3, the electron energy distribution function is found to be Maxwellian with a temperature of 6-8.5 eV. The effect of the neutral beam injection heating power in the divertor region is also studied.

DALMATIAN: An Algorithm for Automatic Cell Detection and Counting in 3D.

PubMed

Shuvaev, Sergey A; Lazutkin, Alexander A; Kedrov, Alexander V; Anokhin, Konstantin V; Enikolopov, Grigori N; Koulakov, Alexei A

2017-01-01

Current 3D imaging methods, including optical projection tomography, light-sheet microscopy, block-face imaging, and serial two photon tomography enable visualization of large samples of biological tissue. Large volumes of data obtained at high resolution require development of automatic image processing techniques, such as algorithms for automatic cell detection or, more generally, point-like object detection. Current approaches to automated cell detection suffer from difficulties originating from detection of particular cell types, cell populations of different brightness, non-uniformly stained, and overlapping cells. In this study, we present a set of algorithms for robust automatic cell detection in 3D. Our algorithms are suitable for, but not limited to, whole brain regions and individual brain sections. We used watershed procedure to split regional maxima representing overlapping cells. We developed a bootstrap Gaussian fit procedure to evaluate the statistical significance of detected cells. We compared cell detection quality of our algorithm and other software using 42 samples, representing 6 staining and imaging techniques. The results provided by our algorithm matched manual expert quantification with signal-to-noise dependent confidence, including samples with cells of different brightness, non-uniformly stained, and overlapping cells for whole brain regions and individual tissue sections. Our algorithm provided the best cell detection quality among tested free and commercial software.

Arsenic health risk assessment in drinking water and source apportionment using multivariate statistical techniques in Kohistan region, northern Pakistan.

PubMed

Muhammad, Said; Tahir Shah, M; Khan, Sardar

2010-10-01

The present study was conducted in Kohistan region, where mafic and ultramafic rocks (Kohistan island arc and Indus suture zone) and metasedimentary rocks (Indian plate) are exposed. Water samples were collected from the springs, streams and Indus river and analyzed for physical parameters, anions, cations and arsenic (As(3+), As(5+) and arsenic total). The water quality in Kohistan region was evaluated by comparing the physio-chemical parameters with permissible limits set by Pakistan environmental protection agency and world health organization. Most of the studied parameters were found within their respective permissible limits. However in some samples, the iron and arsenic concentrations exceeded their permissible limits. For health risk assessment of arsenic, the average daily dose, hazards quotient (HQ) and cancer risk were calculated by using statistical formulas. The values of HQ were found >1 in the samples collected from Jabba, Dubair, while HQ values were <1 in rest of the samples. This level of contamination should have low chronic risk and medium cancer risk when compared with US EPA guidelines. Furthermore, the inter-dependence of physio-chemical parameters and pollution load was also calculated by using multivariate statistical techniques like one-way ANOVA, correlation analysis, regression analysis, cluster analysis and principle component analysis. Copyright © 2010 Elsevier Ltd. All rights reserved.

Reliability of regional climate simulations

NASA Astrophysics Data System (ADS)

Ahrens, W.; Block, A.; Böhm, U.; Hauffe, D.; Keuler, K.; Kücken, M.; Nocke, Th.

2003-04-01

Quantification of uncertainty becomes more and more a key issue for assessing the trustability of future climate scenarios. In addition to the mean conditions, climate impact modelers focus in particular on extremes. Before generating such scenarios using e.g. dynamic regional climate models, a careful validation of present-day simulations should be performed to determine the range of errors for the quantities of interest under recent conditions as a raw estimate of their uncertainty in the future. Often, multiple aspects shall be covered together, and the required simulation accuracy depends on the user's demand. In our approach, a massive parallel regional climate model shall be used on the one hand to generate "long-term" high-resolution climate scenarios for several decades, and on the other hand to provide very high-resolution ensemble simulations of future dry spells or heavy rainfall events. To diagnosis the model's performance for present-day simulations, we have recently developed and tested a first version of a validation and visualization chain for this model. It is, however, applicable in a much more general sense and could be used as a common test bed for any regional climate model aiming at this type of simulations. Depending on the user's interest, integrated quality measures can be derived for near-surface parameters using multivariate techniques and multidimensional distance measures in a first step. At this point, advanced visualization techniques have been developed and included to allow for visual data mining and to qualitatively identify dominating aspects and regularities. Univariate techniques that are especially designed to assess climatic aspects in terms of statistical properties can then be used to quantitatively diagnose the error contributions of the individual used parameters. Finally, a comprehensive in-depth diagnosis tool allows to investigate, why the model produces the obtained near-surface results to answer the question if the model performs well from the modeler's point of view. Examples will be presented for results obtained using this approach for assessing the risk of potential total agricultural yield loss under drought conditions in Northeast Brazil and for evaluating simulation results for a 10-year period for Europe. To support multi-run simulations and result evaluation, the model will be embedded into an already existing simulation environment that provides further postprocessing tools for sensitivity studies, behavioral analysis and Monte-Carlo simulations, but also for ensemble scenario analysis in one of the next steps.

Carcinoma of the pancreatic head and periampullary region. Tumor staging with laparoscopy and laparoscopic ultrasonography.

PubMed Central

John, T G; Greig, J D; Carter, D C; Garden, O J

1995-01-01

OBJECTIVE: The authors performed a prospective evaluation of staging laparoscopy with laparoscopic ultrasonography in predicting surgical resectability in patients with carcinomas of the pancreatic head and periampullary region. SUMMARY BACKGROUND DATA: Pancreatic resection with curative intent is possible in a select minority of patients who have carcinomas of the pancreatic head and periampullary region. Patient selection is important to plan appropriate therapy and avoid unnecessary laparotomy in patients with unresectable disease. Laparoscopic ultrasonography is a novel technique that combines the proven benefits of staging laparoscopy with high resolution intraoperative ultrasound of the liver and pancreas, but which has yet to be evaluated critically in the staging of pancreatic malignancy. METHODS: A cohort of 40 consecutive patients referred to a tertiary referral center and with a diagnosis of potentially resectable pancreatic or periampullary cancer underwent staging laparoscopy with laparoscopic ultrasonography. The diagnostic accuracy of staging laparoscopy alone and in conjunction with laparoscopic ultrasonography was evaluated in predicting tumor resectability (absence of peritoneal or liver metastases; absence of malignant regional lymphadenopathy; tumor confined to pancreatic head or periampullary region). RESULTS: "Occult" metastatic lesions were demonstrated by staging laparoscopy in 14 patients (35%). Laparoscopic ultrasonography demonstrated factors confirming unresectable tumor in 23 patients (59%), provided staging information in addition to that of laparoscopy alone in 20 patients (53%), and changed the decision regarding tumor resectability in 10 patients (25%). Staging laparoscopy with laparoscopic ultrasonography was more specific and accurate in predicting tumor resectability than laparoscopy alone (88% and 89% versus 50% and 65%, respectively). CONCLUSIONS: Staging laparoscopy is indispensable in the detection of "occult" intra-abdominal metastases. Laparoscopic ultrasonography improves the accuracy of laparoscopic staging in patients with potentially resectable pancreatic and periampullary carcinomas. Images Figure 1. Figure 2. Figure 3. Figure 4. PMID:7857143

Identifying Cassini's Magnetospheric Location Using Magnetospheric Imaging Instrument (MIMI) Data and Machine Learning

NASA Astrophysics Data System (ADS)

Vandegriff, J. D.; Smith, G. L.; Edenbaum, H.; Peachey, J. M.; Mitchell, D. G.

2017-12-01

We analyzed data from Cassini's Magnetospheric Imaging Instrument (MIMI) and Magnetometer (MAG) and attempted to identify the region of Saturn's magnetosphere that Cassini was in at a given time using machine learning. MIMI data are from the Charge-Energy-Mass Spectrometer (CHEMS) instrument and the Low-Energy Magnetospheric Measurement System (LEMMS). We trained on data where the region is known based on a previous analysis of Cassini Plasma Spectrometer (CAPS) plasma data. Three magnetospheric regions are considered: Magnetosphere, Magnetosheath, and Solar Wind. MIMI particle intensities, magnetic field values, and spacecraft position are used as input attributes, and the output is the CAPS-based region, which is available from 2004 to 2012. We then use the trained classifier to identify Cassini's magnetospheric regions for times after 2012, when CAPS data is no longer available. Training accuracy is evaluated by testing the classifier performance on a time range of known regions that the classifier has never seen. Preliminary results indicate a 68% accuracy on such test data. Other techniques are being tested that may increase this performance. We present the data and algorithms used, and will describe the latest results, including the magnetospheric regions post-2012 identified by the algorithm.

Analysis of Land-Use Effects on Landscape Patterns and Biological Diversity in Pacific North Forests: 1972-1991

NASA Technical Reports Server (NTRS)

Wallin, David O.; Cohen, Warren B.; Bradshaw, G. A.; Spies, T. A.; Hansen, A.; Huff, M. H.; Lehmkuhl, J. F.; Raphael, M. G.; Ripple, W. J.

1998-01-01

While there is widespread recognition of the importance of preserving biological diversity there is considerable uncertainty about how to map current patterns of diversity and monitor changes through time. Ground-based approaches are impractical for examining regional patterns of biological diversity, for monitoring change, and they may actually overlook important higher-order phenomena. Thus, there is a critical need for innovative techniques to examine land-use effects on biological diversity at the landscape and regional scales. In this project, we have used satellite-based remote sensing to examine land-use effects on forest ecosystems in the Pacific NorthWest region (PNW) of the U.S.A. Rates and patterns of forest change throughout the region were quantified for the period from 1972 to 1993. This information was then used to map changes in the abundance and distribution of potential habitat for selected vertebrate species. The results of this project will be useful for identifying "keystone" stands that are important in maintaining habitat connectivity at the regional scale and for evaluating the impact of future land-use on vertebrate diversity throughout the region. The approaches developed here will also be useful in other forested regions throughout the world.

Techniques for obtaining regional radiation budgets from satellite radiometer observations, phase 4 and phase 5. Ph.D. Thesis. Final Report

NASA Technical Reports Server (NTRS)

Pina, J. F.; House, F. B.

1976-01-01

A scheme was developed which divides the earth-atmosphere system into 2060 elemental areas. The regions previously described are defined in terms of these elemental areas which are fixed in size and position as the satellite moves. One method, termed the instantaneous technique, yields values of the radiant emittance (We) and the radiant reflectance (Wr) which the regions have during the time interval of a single satellite pass. The number of observations matches the number of regions under study and a unique solution is obtained using matrix inversion. The other method (termed the best fit technique), yields time averages of We and Wr for large time intervals (e.g., months, seasons). The number of observations in this technique is much greater than the number of regions considered, and an approximate solution is obtained by the method of least squares.

Round and Oval Window Anatomic Variability: Its Implication for the Vibroplasty Technique.

PubMed

Mancheño, Marta; Aristegui, Miguel; Sañudo, Jose Ramon

2017-06-01

The objective of this study is to evaluate the anatomical variability of round and oval window regions and its relationship with their closest structures, to determine its implication on the fitting and stabilization of the middle ear implant Vibrant Soundbridge. Variations of the anatomy of round and oval window regions were assessed in a total of 85 human dissected temporal bones. Afterward, we evaluated the adaptation and subsequent stabilization of the floating mass transducer (FMT) of the Vibrant Soundbridge in 67 cases in round window (RW) and in 22 cases in oval window (OW), and the influence that the variability of the different anatomical features examined had on this stabilization. We also assessed access and surgeon's view of the RW niche through the facial recess approach. Stabilization of the FMT in the RW was achieved in 53 (79%) of the 67 cases; we found that the less favorable anatomical conditions for stabilization were: membrane smaller than 1.5 mm, presence of a high jugular bulb and a narrow or very narrow RW niche. Frequently, two or more of these conditions happened simultaneously. In seven cases (22%) access to the RW through facial recess approach did not allow positioning the FMT in place. OW stabilization succeeded in 18 (82%) of the 22 cases. Round and oval window vibroplasty are difficult surgical techniques. To place the FMT directly on the OW may be easier as we do not have to drill the niche. In both regions there are some anatomical conditions that hinder fitting the FMT and even make it impossible. Once fitted, the main problem is to achieve good stabilization of the device.

[Analysis of effect of prevention and control technique training of human important parasitic diseases in Jiangsu Province in 2017].

PubMed

Bi-Xian, Ni; Xiang-Zhen, Xu; Xiao-Ting, Wang; Ming-Xue, Sheng; Yang, Dai; Xiao-Lin, Jin

2017-07-24

To evaluate the effect of the prevention and control technique training of human important parasitic diseases for basic professional and technical personnel in Jiangsu Province in 2017. A workshop including theory courses and practical operations was carried out for the basic professional and technical personnel. At the end of the workshop, the effects were evaluated through the theoretical and microscopic examinations. There were 132 trainees from 13 cities, and all of them took part in the final examinations. The average score of total was 118.36. There were significant differences among different regions ( χ 2 = 13.38, P < 0.01). The pass rate of the theory test was 92.4% with the average score of 79.05. There were significant differences of theory scores among different regions ( χ 2 =14.51, P < 0.01). The theory score of Northern Jiangsu Province was significantly higher than the scores of Southern and Central Jiangsu Province ( P < 0.001, P = 0.009). The pass rate of microscopic examinations was 89.4% with the average score of 39.32. There was no significant difference of micro-scopic examination scores among different regions ( F = 2.37, P = 0.09). Among the total 7 species, the detection rate of Paragonimus westermani was the highest (75％) and the rates of Schistosoma japonicum and Fasciolopsis buski were only 51.5％ and 54.5% respectively. The detection rates of eggs of Trichuris trichiura , unfertilized Ascaris lumbricoides , Clonorchis sinensis and Taenia solium were 71.2%, 65.9%, 72.7% and 72.0% respectively. The training course has promoted the capability of prevention and control of parasitic diseases for basic technical personnel. Also it provides the technical supports for parasitic disease monitoring, control and risk assessment in the next step.

Sonoelastographic evaluation with the determination of compressibility ratio for symmetrical prostatic regions in the diagnosis of clinically significant prostate cancer

PubMed Central

Słapa, Rafał Z.; Jakubowski, Wiesław S.; Migda, Bartosz; Dmowski, Tadeusz

2014-01-01

Aim Sonoelastography is a technique that assesses tissue hardness/compressibility. Utility and sensitivity of the method in prostate cancer diagnostics were assessed compared to the current gold standard in prostate cancer diagnostics i.e. systematic biopsy. Material and methods The study involved 84 patients suspected of prostate cancer based on elevated PSA levels or abnormal per rectal examination findings. Sonoelastography was used to evaluate the prostate gland. In the case of regions with hardness two-fold greater than that of symmetric prostate area (strain ratio >2), targeted biopsy was used; which was followed by an ultrasound-guided 8- or 10-core systematic biopsy (regardless of sonoelastography-indicated sites) as a reference point. Results The mean age of patients was 69 years. PSA serum levels ranged between 1.02 and 885 ng/dl. The mean prostate volume was 62 ml (19–149 ml). Prostate cancer was found in 39 out of 84 individuals. Statistically significant differences in strain ratios between cancers and benign lesions were shown. Sonoelastography guided biopsy revealed 30 lesions – overall sensitivity 77% (sensitivity of the method – 81%). Sonoelastographic sensitivity increased depending on cancer stage according to the Gleason grading system: 6–60%, 7–75%, 8–83%, 9/10–100%. The estimated sensitivity of systematic biopsy was 92%. Conclusions Sonoelastography shows higher diagnostic sensitivity in prostate cancer diagnostics compared to conventional imaging techniques, i.e. grey-scale TRUS, Doppler ultrasound. It allows to reduce the number of collected tissue cores, and thus limit the incidence of complications as well as the costs involved. Sonoelastography using the determination of compressibility ratio for symmetrical prostatic regions may prove useful in the detection of clinically significant prostate cancer. PMID:26674065

Seasonal drought predictability in Portugal using statistical-dynamical techniques

NASA Astrophysics Data System (ADS)

Ribeiro, A. F. S.; Pires, C. A. L.

2016-08-01

Atmospheric forecasting and predictability are important to promote adaption and mitigation measures in order to minimize drought impacts. This study estimates hybrid (statistical-dynamical) long-range forecasts of the regional drought index SPI (3-months) over homogeneous regions from mainland Portugal, based on forecasts from the UKMO operational forecasting system, with lead-times up to 6 months. ERA-Interim reanalysis data is used for the purpose of building a set of SPI predictors integrating recent past information prior to the forecast launching. Then, the advantage of combining predictors with both dynamical and statistical background in the prediction of drought conditions at different lags is evaluated. A two-step hybridization procedure is performed, in which both forecasted and observed 500 hPa geopotential height fields are subjected to a PCA in order to use forecasted PCs and persistent PCs as predictors. A second hybridization step consists on a statistical/hybrid downscaling to the regional SPI, based on regression techniques, after the pre-selection of the statistically significant predictors. The SPI forecasts and the added value of combining dynamical and statistical methods are evaluated in cross-validation mode, using the R2 and binary event scores. Results are obtained for the four seasons and it was found that winter is the most predictable season, and that most of the predictive power is on the large-scale fields from past observations. The hybridization improves the downscaling based on the forecasted PCs, since they provide complementary information (though modest) beyond that of persistent PCs. These findings provide clues about the predictability of the SPI, particularly in Portugal, and may contribute to the predictability of crops yields and to some guidance on users (such as farmers) decision making process.

Importance of integrated results of different non-destructive techniques in order to evaluate defects in panel paintings: the contribution of infrared, optical and ultrasonic techniques

NASA Astrophysics Data System (ADS)

Sfarra, S.; Theodorakeas, P.; Ibarra-Castanedo, C.; Avdelidis, N. P.; Paoletti, A.; Paoletti, D.; Hrissagis, K.; Bendada, A.; Koui, M.; Maldague, X.

2011-06-01

The increasing deterioration of panel paintings can be due to physical processes that take place during exhibition or transit, or as a result of temperature and humidity fluctuations within a building, church or museum. In response to environmental alterations, a panel painting can expand or contract and a new equilibrium state is eventually reached. These adjustments though, are usually accompanied by a change in shape in order to accommodate to the new conditions. In this work, a holographic method for detecting detached regions and micro-cracks is described. Some of these defects are confirmed by Thermographic Signal Reconstruction (TSR) technique. In addition, Pulsed Phase Thermography (PPT) and Principal Component Thermography (PCT) allow to identify with greater contrast two artificial defects in Mylar which are crucial to understand the topic of interest: the discrimination between defect materials. Finally, traditional contact ultrasounds applications, are widely applied for the evaluation of the wood quality in several characterization procedures. Inspecting the specimen from the front side, the natural and artificial defects of the specimen are confirmed. Experimental results derived by the application of the integrated methods on an Italian panel painting reproduction, called The Angel specimen, are presented. The main advantages that these techniques can offer to the conservation and restoration of artworks are emphasized.

Cine EPID evaluation of two non-commercial techniques for DIBH

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

Jensen, Christopher; Urribarri, Jaime; Cail, Daniel

2014-02-15

Purpose: To evaluate the efficacy of two noncommercial techniques for deep inspiration breathhold (DIBH) treatment of left-sided breast cancer (LSBC) usingcine electronic portal imaging device (EPID) images. Methods: 23 875 EPID images of 65 patients treated for LSBC at two different cancer treatment centers were retrieved. At the Milford Regional Cancer Center, DIBH stability was maintained by visual alignment of inroom lasers and patient skin tattoos (TAT). At the South Shore Hospital, a distance-measuring laser device (RTSSD) was implemented. For both centers,cine EPID images were acquired at least once per week during beam-on. Chest wall position relative to image boundary wasmore » measured and tracked over the course of treatment for every patient and treatment fraction for which data were acquired. Results: Median intrabeam chest motion was 0.31 mm for the TAT method and 0.37 mm for the RTSSD method. The maximum excursions exceeded our treatment protocol threshold of 3 mm in 0.3% of cases (TAT) and 1.2% of cases (RTSSD). The authors did not observe a clinically significant difference between the two datasets. Conclusions: Both noncommercial techniques for monitoring the DIBH location provided DIBH stability within the predetermined treatment protocol parameters (<3 mm). The intreatment imaging offered by the EPID operating incine mode facilitates retrospective analysis and validation of both techniques.« less

Solar prediction analysis

NASA Technical Reports Server (NTRS)

Smith, Jesse B.

1992-01-01

Solar Activity prediction is essential to definition of orbital design and operational environments for space flight. This task provides the necessary research to better understand solar predictions being generated by the solar community and to develop improved solar prediction models. The contractor shall provide the necessary manpower and facilities to perform the following tasks: (1) review, evaluate, and assess the time evolution of the solar cycle to provide probable limits of solar cycle behavior near maximum end during the decline of solar cycle 22, and the forecasts being provided by the solar community and the techniques being used to generate these forecasts; and (2) develop and refine prediction techniques for short-term solar behavior flare prediction within solar active regions, with special emphasis on the correlation of magnetic shear with flare occurrence.

Determination of Probe Volume Dimensions in Coherent Measurement Techniques

NASA Technical Reports Server (NTRS)

Tedder, Sarah A.; Weikl, Markus C.; Seeger, Thomas; Leipertz, Alfred

2008-01-01

When investigating combustion phenomena with pump-probe techniques, the spatial resolution is given by the overlapping region of the laser beams and thus defines the probe volume size. The size of this probe volume becomes important when the length scales of interest are on the same order or smaller. In this work, we present a new approach to measure the probe volume in three dimensions (3-D), which can be used to determine the probe volume length, diameter, and shape. The optical arrangement and data evaluation are demonstrated for a dual-pump dual-broadband coherent anti-Stokes Raman scattering (CARS) setup which is used for combustion diagnostics. This new approach offers a simple, quick alternative with more capabilities than formerly used probe volume measurement methods.

A Multi-Region Magnetoimpedance-Based Bio-Analytical System for Ultrasensitive Simultaneous Determination of Cardiac Biomarkers Myoglobin and C-Reactive Protein.

PubMed

Yang, Zhen; Wang, Huanhuan; Guo, Pengfei; Ding, Yuanyuan; Lei, Chong; Luo, Yongsong

2018-06-01

Cardiac biomarkers (CBs) are substances that appear in the blood when the heart is damaged or stressed. Measurements of the level of CBs can be used in course of diagnostics or monitoring the state of the health of group risk persons. A multi-region bio-analytical system (MRBAS) based on magnetoimpedance (MI) changes was proposed for ultrasensitive simultaneous detection of CBs myoglobin (Mb) and C-reactive protein (CRP). The microfluidic device was designed and developed using standard microfabrication techniques for their usage in different regions, which were pre-modified with specific antibody for specified detection. Mb and CRP antigens labels attached to commercial Dynabeads with selected concentrations were trapped in different detection regions. The MI response of the triple sensitive element was carefully evaluated in initial state and in the presence of biomarkers. The results showed that the MI-based bio-sensing system had high selectivity and sensitivity for detection of CBs. Compared with the control region, ultrasensitive detections of CRP and Mb were accomplished with the detection limits of 1.0 pg/mL and 0.1 pg/mL, respectively. The linear detection range contained low concentration detection area and high concentration detection area, which were 1 pg/mL⁻10 ng/mL, 10⁻100 ng/mL for CRP, and 0.1 pg/mL⁻1 ng/mL, 1 n/mL⁻80 ng/mL for Mb. The measurement technique presented here provides a new methodology for multi-target biomolecules rapid testing.

A comparison of mandibular denture base deformation with different impression techniques for implant overdentures.

PubMed

Elsyad, Moustafa Abdou; El-Waseef, Fatma Ahmad; Al-Mahdy, Yasmeen Fathy; Fouad, Mohammed Mohammed

2013-08-01

This study aimed to evaluate mandibular denture base deformation along with three impression techniques used for implant-retained overdenture. Ten edentulous patients (five men and five women) received two implants in the canine region of the mandible and three duplicate mandibular overdentures which were constructed with mucostatic, selective pressure, and definitive pressure impression techniques. Ball abutments and respective gold matrices were used to connect the overdentures to the implants. Six linear strain gauges were bonded to the lingual polished surface of each duplicate overdenture at midline and implant areas to measure strain during maximal clenching and gum chewing. The strains recorded at midline were compressive while strains at implant areas were tensile. Clenching recorded significant higher strain when compared with gum chewing for all techniques. The mucostatic technique recorded the highest strain and the definite pressure technique recorded the lowest. There was no significant difference between the strain recorded with mucostatic technique and that registered with selective pressure technique. The highest strain was recorded at the level of ball abutment's top with the mucostatic technique during clenching. Definite pressure impression technique for implant-retained mandibular overdenture is associated with minimal denture deformation during function when compared with mucostatic and selective pressure techniques. Reinforcement of the denture base over the implants may be recommended to increase resistance of fracture when mucostatic or selective pressure impression technique is used. © 2012 John Wiley & Sons A/S.

QEEG and LORETA in Teenagers With Conduct Disorder and Psychopathic Traits.

PubMed

Calzada-Reyes, Ana; Alvarez-Amador, Alfredo; Galán-García, Lídice; Valdés-Sosa, Mitchell

2017-05-01

Few studies have investigated the impact of the psychopathic traits on the EEG of teenagers with conduct disorder (CD). To date, there is no other research studying low-resolution brain electromagnetic tomography (LORETA) technique using quantitative EEG (QEEG) analysis in adolescents with CD and psychopathic traits. To find electrophysiological differences specifically related to the psychopathic traits. The current investigation compares the QEEG and the current source density measures between adolescents with CD and psychopathic traits and adolescents with CD without psychopathic traits. The resting EEG activity and LORETA for the EEG fast spectral bands were evaluated in 42 teenagers with CD, 25 with and 17 without psychopathic traits according to the Antisocial Process Screening Device. All adolescents were assessed using the DSM-IV-TR criteria. The EEG visual inspection characteristics and the use of frequency domain quantitative analysis techniques (narrow band spectral parameters) are described. QEEG analysis showed a pattern of beta activity excess on the bilateral frontal-temporal regions and decreases of alpha band power on the left central-temporal and right frontal-central-temporal regions in the psychopathic traits group. Current source density calculated at 17.18 Hz showed an increase within fronto-temporo-striatal regions in the psychopathic relative to the nonpsychopathic traits group. These findings indicate that QEEG analysis and techniques of source localization may reveal differences in brain electrical activity among teenagers with CD and psychopathic traits, which was not obvious to visual inspection. Taken together, these results suggest that abnormalities in a fronto-temporo-striatal network play a relevant role in the neurobiological basis of psychopathic behavior.

Repeating ice-earthquakes beneath David Glacier from the 2012-2015 TAMNNET array

NASA Astrophysics Data System (ADS)

Walter, J. I.; Peng, Z.; Hansen, S. E.

2017-12-01

The continent of Antarctica has approximately the same surface area as the continental United States, though we know significantly less about its underlying geology and seismic activity. In recent years, improvements in seismic instrumentation, battery technology, and field deployment practices have allowed for continuous broadband stations throughout the dark Antarctic winter. We utilize broadband seismic data from a recent experiment (TAMNNET), which was originally proposed as a structural seismology experiment, for seismic event detection. Our target is to address fundamental questions about regional-scale crustal and environmental seismicity in the study region that comprises the Transantarctic Mountain area of Victoria and Oates Land. We identify most seismicity emanating from David Glacier, upstream of the Drygalski Ice Tongue, which has been documented by several other studies. In order to improve the catalog completeness for the David Glacier area, we utilize a matched-filter technique to identify potential missing earthquakes that may not have been originally detected. This technique utilizes existing cataloged waveforms as templates to scan through continuous data and to identify repeating or nearby earthquakes. With a more robust catalog, we evaluate relative changes in icequake positions, recurrence intervals, and other first-order information. In addition, we attempt to further refine locations of other regional seismicity using a variety of methods including body and surface wave polarization, beamforming, surface wave dispersion, and other seismological methods. This project highlights the usefulness of archiving raw datasets (i.e., passive seismic continuous data), so that researchers may apply new algorithms or techniques to test hypotheses not originally or specifically targeted by the original experimental design.

Implementation of local grid refinement (LGR) for the Lake Michigan Basin regional groundwater-flow model

USGS Publications Warehouse

Hoard, C.J.

2010-01-01

The U.S. Geological Survey is evaluating water availability and use within the Great Lakes Basin. This is a pilot effort to develop new techniques and methods to aid in the assessment of water availability. As part of the pilot program, a regional groundwater-flow model for the Lake Michigan Basin was developed using SEAWAT-2000. The regional model was used as a framework for assessing local-scale water availability through grid-refinement techniques. Two grid-refinement techniques, telescopic mesh refinement and local grid refinement, were used to illustrate the capability of the regional model to evaluate local-scale problems. An intermediate model was developed in central Michigan spanning an area of 454 square miles (mi2) using telescopic mesh refinement. Within the intermediate model, a smaller local model covering an area of 21.7 mi2 was developed and simulated using local grid refinement. Recharge was distributed in space and time using a daily output from a modified Thornthwaite-Mather soil-water-balance method. The soil-water-balance method derived recharge estimates from temperature and precipitation data output from an atmosphere-ocean coupled general-circulation model. The particular atmosphere-ocean coupled general-circulation model used, simulated climate change caused by high global greenhouse-gas emissions to the atmosphere. The surface-water network simulated in the regional model was refined and simulated using a streamflow-routing package for MODFLOW. The refined models were used to demonstrate streamflow depletion and potential climate change using five scenarios. The streamflow-depletion scenarios include (1) natural conditions (no pumping), (2) a pumping well near a stream; the well is screened in surficial glacial deposits, (3) a pumping well near a stream; the well is screened in deeper glacial deposits, and (4) a pumping well near a stream; the well is open to a deep bedrock aquifer. Results indicated that a range of 59 to 50 percent of the water pumped originated from the stream for the shallow glacial and deep bedrock pumping scenarios, respectively. The difference in streamflow reduction between the shallow and deep pumping scenarios was compensated for in the deep well by deriving more water from regional sources. The climate-change scenario only simulated natural conditions from 1991-2044, so there was no pumping stress simulated. Streamflows were calculated for the simulated period and indicated that recharge over the period generally increased from the start of the simulation until approximately 2017, and decreased from then to the end of the simulation. Streamflow was highly correlated with recharge so that the lowest streamflows occurred in the later stress periods of the model when recharge was lowest.

Dosimetry and field matching for radiotherapy to the breast and superclavicular fossa

NASA Astrophysics Data System (ADS)

Winfield, Elizabeth

Radiotherapy for early breast cancer aims to achieve local disease control and decrease loco-regional recurrence rates. Treatment may be directed to breast or chest wall alone or, include regional lymph nodes. When using tangential fields to treat the breast a separate anterior field directed to the axilla and supraclavicular fossa (SCF) is needed to treat nodal areas. The complex geometry of this region necessitates matching of adjacent radiation fields in three dimensions. The potential exists for zones of overdosage or underdosage along the match line. Cosmetic results may be compromised if treatment fields are not accurately aligned. Techniques for field matching vary between centres in the UK. A study of dosimetry across the match line region using different techniques, as reported in the multi-centre START Trial Quality Assurance (QA) programme, was undertaken. A custom-made anthropomorphic phantom was designed to assess dose distribution in three dimensions using film dosimetry. Methods with varying degrees of complexity were employed to match tangential and SCF beams. Various techniques combined half beam blocking and machine rotations to achieve geometric alignment. Matching of asymmetric beams allowed a single isocentre technique to be used. Where field matching was not undertaken a gap between tangential and SCF fields was employed. Results demonstrated differences between techniques in addition to variations within the same technique between different centres. Geometric alignment techniques produced more homogenous dose distributions in the match region than gap techniques or those techniques not correcting for field divergence. For this multi-centre assessment of match plane techniques film dosimetry used in conjunction with a breast shaped phantom provided relative dose information. This study has highlighted the difficulties of matching treatment fields to achieve homogenous dose distribution through the region of the match plane and the degree of inhomogeneity as a consequence of a gap between treatment fields.

Techniques for estimating flood-depth frequency relations for streams in West Virginia

USGS Publications Warehouse

Wiley, J.B.

1987-01-01

Multiple regression analyses are applied to data from 119 U.S. Geological Survey streamflow stations to develop equations that estimate baseline depth (depth of 50% flow duration) and 100-yr flood depth on unregulated streams in West Virginia. Drainage basin characteristics determined from the 100-yr flood depth analysis were used to develop 2-, 10-, 25-, 50-, and 500-yr regional flood depth equations. Two regions with distinct baseline depth equations and three regions with distinct flood depth equations are delineated. Drainage area is the most significant independent variable found in the central and northern areas of the state where mean basin elevation also is significant. The equations are applicable to any unregulated site in West Virginia where values of independent variables are within the range evaluated for the region. Examples of inapplicable sites include those in reaches below dams, within and directly upstream from bridge or culvert constrictions, within encroached reaches, in karst areas, and where streams flow through lakes or swamps. (Author 's abstract)

Magnetic resonance angiography with fresh blood imaging for identification of hemangiomas and blood vessels around hemangiomas in oral and maxillofacial regions.

PubMed

Oda, Masafumi; Tanaka, Tatsurou; Kito, Shinji; Matsumoto-Takeda, Shinobu; Otsuka, Kozue; Hayashi, Yuki; Wakasugi-Sato, Nao; Yoshioka, Izumi; Habu, Manabu; Kokuryo, Shinya; Kodama, Masaaki; Nogami, Shinnosuke; Miyamoto, Ikuya; Yamamoto, Noriaki; Ishikawa, Ayataka; Zhang, Min; Matsuo, Kou; Shiiba, Shunji; Seta, Yuji; Yamashita, Yoshihiro; Takahashi, Tetsu; Tominaga, Kazuhiro; Morimoto, Yasuhiro

2012-04-01

To evaluate fresh blood imaging (FBI), a magnetic resonance imaging technique that does not use contrast, for identifying hemangiomas and feeding arteries in the oral and maxillofacial regions. For 16 patients with hemangiomas, FBI visualizations of hemangiomas and feeding arteries in the oral and maxillofacial regions were compared with those from 3-dimensional (3D) phase-contrast magnetic resonance angiography (PC-MRA). Comparisons were based on the conspicuities of blood vessels and the 3D relationships of hemangiomas with the surrounding blood vessels. The conspicuity of hemangiomas, feeding arteries, and blood vessels were significantly better with FBI than with PC-MRA. After differentiating arteries from veins, 3D visualizations of hemangiomas and arteries or veins could be performed with FBI. FBI is a useful method in oral and maxillofacial regions for identifying the relationships between hemangiomas and the surrounding arteries or veins. Crown Copyright © 2012. Published by Mosby, Inc. All rights reserved.

Integrated resource inventory for southcentral Alaska (INTRISCA)

NASA Technical Reports Server (NTRS)

Burns, T.; Carson-Henry, C.; Morrissey, L. A.

1981-01-01

The Integrated Resource Inventory for Southcentral Alaska (INTRISCA) Project comprised an integrated set of activities related to the land use planning and resource management requirements of the participating agencies within the southcentral region of Alaska. One subproject involved generating a region-wide land cover inventory of use to all participating agencies. Toward this end, participants first obtained a broad overview of the entire region and identified reasonable expectations of a LANDSAT-based land cover inventory through evaluation of an earlier classification generated during the Alaska Water Level B Study. Classification of more recent LANDSAT data was then undertaken by INTRISCA participants. The latter classification produced a land cover data set that was more specifically related to individual agency needs, concurrently providing a comprehensive training experience for Alaska agency personnel. Other subprojects employed multi-level analysis techniques ranging from refinement of the region-wide classification and photointerpretation, to digital edge enhancement and integration of land cover data into a geographic information system (GIS).

Improved electrode positions for local impedance measurements in the lung-a simulation study.

PubMed

Orschulik, Jakob; Petkau, Rudolf; Wartzek, Tobias; Hochhausen, Nadine; Czaplik, Michael; Leonhardt, Steffen; Teichmann, Daniel

2016-12-01

Impedance spectroscopy can be used to analyze the dielectric properties of various materials. In the biomedical domain, it is used as bioimpedance spectroscopy (BIS) to analyze the composition of body tissue. Being a non-invasive, real-time capable technique, it is a promising modality, especially in the field of lung monitoring. Unfortunately, up to now, BIS does not provide any regional lung information as the electrodes are usually placed in hand-to-hand or transthoracic configurations. Even though transthoracic electrode configurations are in general capable of monitoring the lung, no focusing to specific regions is achieved. In order to resolve this issue, we use a finite element model (FEM) of the human body to study the effect of different electrode configurations on measured BIS data. We present evaluation results and show suitable electrode configurations for eight lung regions. We show that, using these optimized configurations, BIS measurements can be focused to desired regions allowing local lung analysis.

Smear Layer Evaluation on Root Canal Preparation with Manual and Rotary Techniques using EDTA as an Irrigant: A Scanning Electron Microscopy Study

PubMed Central

Manjunatha, M; Annapurna, Kini; Sudhakar, V; Sunil Kumar, VC; Hiremath, Vinay Kumar; Shah, Ankur

2013-01-01

Introduction: The aim of any root canal treatment is to achieve a canal free of micro organisms, residual pulp remnants, debris and smear layer for the long term success of the procedure. Manual and automated instrumentation techniques along with proper irrigation regime is used to arrive at the aforementioned goal. Many authors focused on the preparation capabilities of various manual and rotary instruments but very few investigators stressed on the actual cleaning abilities of these instruments. Aims and objectives: This study was undertaken to evaluate the cleaning efficiency of manual K flex files and rotary Pro File systems in the root canals using a scanning electron microscope. Material and Methods:Thirty single rooted mandibular first premolars were divided into two groups and randomized (the manual group-M and the ProFile group-P) with respect to the preparation technique. The Manual group was hand instrumented with stainless steel K- Flexofiles by means of a conventional filing technique. The Pro File group was instrumented according to the manufacturer's instructions using a rotary handpiece. All canals were shaped and cleaned under frequent irrigation with EDTA. Final irrigation was carried out with 3 mL of normal saline solution to neutralize the action of the irrigant. The roots were split, one half of each tooth was selected for further SEM technique analysis and examined under the scanning electron microscope. The canal walls were quantitatively evaluated for the amount of debris and smear layer. The apical, middle and coronal regions of the canal surface, were graded (1-5) for debris and smear layer. A statistical analysis was performed using a Mann-Whitney Rank Sum test. ProFile performed least effective cleaning. Manual K-Flexofiles led to a grooved pattern. Results and Conclusion: A statistically significant difference was observed (p<0.05) between the two instrumentation techniques concerning the amount of debris and smear layer at the apical level. The manually filed canals had less debris and smear layer than those using a rotary technique. It was concluded from this study that none of the instrumentation techniques employed, produced the canal walls which were free of surface debris and smear layer. The manual instrumentation technique was better in cleaning the canals compared to the ProFile rotary Ni-Ti instruments despite the step-back technique used for manual instrumentation. How to cite this article: Manjunatha M, Kini A, Sudhakar V, Sunil K V C, Hiremath V K, Shah A. Smear Layer Evaluation on Root Canal Preparation with Manual and Rotary Techniques using EDTA as an Irrigant: A Scanning Electron Microscopy Study. J Int Oral Health 2013; 5(1):66-78. PMID:24155580

Evaluation of multiple comparison correction procedures in drug assessment studies using LORETA maps.

PubMed

Alonso, Joan Francesc; Romero, Sergio; Mañanas, Miguel Ángel; Rojas, Mónica; Riba, Jordi; Barbanoj, Manel José

2015-10-01

The identification of the brain regions involved in the neuropharmacological action is a potential procedure for drug development. These regions are commonly determined by the voxels showing significant statistical differences after comparing placebo-induced effects with drug-elicited effects. LORETA is an electroencephalography (EEG) source imaging technique frequently used to identify brain structures affected by the drug. The aim of the present study was to evaluate different methods for the correction of multiple comparisons in the LORETA maps. These methods which have been commonly used in neuroimaging and also simulated studies have been applied on a real case of pharmaco-EEG study where the effects of increasing benzodiazepine doses on the central nervous system measured by LORETA were investigated. Data consisted of EEG recordings obtained from nine volunteers who received single oral doses of alprazolam 0.25, 0.5, and 1 mg, and placebo in a randomized crossover double-blind design. The identification of active regions was highly dependent on the selected multiple test correction procedure. The combined criteria approach known as cluster mass was useful to reveal that increasing drug doses led to higher intensity and spread of the pharmacologically induced changes in intracerebral current density.

Development of Raman microspectroscopy for automated detection and imaging of basal cell carcinoma

NASA Astrophysics Data System (ADS)

Larraona-Puy, Marta; Ghita, Adrian; Zoladek, Alina; Perkins, William; Varma, Sandeep; Leach, Iain H.; Koloydenko, Alexey A.; Williams, Hywel; Notingher, Ioan

2009-09-01

We investigate the potential of Raman microspectroscopy (RMS) for automated evaluation of excised skin tissue during Mohs micrographic surgery (MMS). The main aim is to develop an automated method for imaging and diagnosis of basal cell carcinoma (BCC) regions. Selected Raman bands responsible for the largest spectral differences between BCC and normal skin regions and linear discriminant analysis (LDA) are used to build a multivariate supervised classification model. The model is based on 329 Raman spectra measured on skin tissue obtained from 20 patients. BCC is discriminated from healthy tissue with 90+/-9% sensitivity and 85+/-9% specificity in a 70% to 30% split cross-validation algorithm. This multivariate model is then applied on tissue sections from new patients to image tumor regions. The RMS images show excellent correlation with the gold standard of histopathology sections, BCC being detected in all positive sections. We demonstrate the potential of RMS as an automated objective method for tumor evaluation during MMS. The replacement of current histopathology during MMS by a ``generalization'' of the proposed technique may improve the feasibility and efficacy of MMS, leading to a wider use according to clinical need.

RSRM TP-H1148 Main Grain Propellant Crack Initiation Evaluation

NASA Technical Reports Server (NTRS)

Earnest, Todd E.

2005-01-01

Pressurized TP-HI 148 propellant fracture toughness testing was performed to assess the potential for initiation of visually undetectable cracks in the RSRM forward segment transition region during motor ignition. Two separate test specimens were used in this evaluation. Testing was performed in cold-gas and hot-fire environments, and under both static and dynamic pressurization conditions. Analysis of test results demonstrates safety factors against initiation of visually undetectable cracks in excess of 8.0. The Reusable Solid Rocket Motor (RSRM) forward segment is cast with PBAN propellant (TP-HI 148) to form T an 1 1-point star configuration that transitions to a tapered center perforated bore (see Figure 1). The geometry of the transition region between the fin valleys and the bore causes a localized area of high strain during horizontal storage. Updated analyses using worst-case mechanical properties at 40 F and improved modeling techniques indicated a slight reduction in safety margins over previous predictions. Although there is no history of strain induced cracks or flaws in the transition region propellant, a proactive test effort was initiated to better understand the implications of the new analysis, primarily the resistance of TP-H1148 propellant to crack initiation' during RSRM ignition.

Quantitative kinetic analysis of lung nodules by temporal subtraction technique in dynamic chest radiography with a flat panel detector

NASA Astrophysics Data System (ADS)

Tsuchiya, Yuichiro; Kodera, Yoshie; Tanaka, Rie; Sanada, Shigeru

2007-03-01

Early detection and treatment of lung cancer is one of the most effective means to reduce cancer mortality; chest X-ray radiography has been widely used as a screening examination or health checkup. The new examination method and the development of computer analysis system allow obtaining respiratory kinetics by the use of flat panel detector (FPD), which is the expanded method of chest X-ray radiography. Through such changes functional evaluation of respiratory kinetics in chest has become available. Its introduction into clinical practice is expected in the future. In this study, we developed the computer analysis algorithm for the purpose of detecting lung nodules and evaluating quantitative kinetics. Breathing chest radiograph obtained by modified FPD was converted into 4 static images drawing the feature, by sequential temporal subtraction processing, morphologic enhancement processing, kinetic visualization processing, and lung region detection processing, after the breath synchronization process utilizing the diaphragmatic analysis of the vector movement. The artificial neural network used to analyze the density patterns detected the true nodules by analyzing these static images, and drew their kinetic tracks. For the algorithm performance and the evaluation of clinical effectiveness with 7 normal patients and simulated nodules, both showed sufficient detecting capability and kinetic imaging function without statistically significant difference. Our technique can quantitatively evaluate the kinetic range of nodules, and is effective in detecting a nodule on a breathing chest radiograph. Moreover, the application of this technique is expected to extend computer-aided diagnosis systems and facilitate the development of an automatic planning system for radiation therapy.

Prevalence, cause, and location of palatal fistula in operated complete unilateral cleft lip and palate: retrospective study.

PubMed

de Agostino Biella Passos, Vivian; de Carvalho Carrara, Cleide Felício; da Silva Dalben, Gisele; Costa, Beatriz; Gomide, Marcia Ribeiro

2014-03-01

To evaluate the prevalence of fistulas after palate repair and analyze their location and association with possible causal factors. Retrospective analysis of patient records and evaluation of preoperative initial photographs. Tertiary craniofacial center. Five hundred eighty-nine individuals with complete unilateral cleft lip and palate that underwent palate repair at the age of 12 to 36 months by the von Langenbeck technique, in a single stage, by the plastic surgery team of the hospital, from January 2003 to July 2007. The cleft width was visually classified by a single examiner as narrow, regular, or wide. The following regions of the palate were considered for the location: anterior, medium, transition (between hard and soft palate), and soft palate. Descriptive statistics and analysis of association between the occurrence of fistula and the different parameters were evaluated. Palatal fistulas were observed in 27% of the sample, with a greater proportion at the anterior region (37.11%). The chi-square statistical test revealed statistically significant association (P ≤ .05) between the fistulas and initial cleft width (P = .0003), intraoperative problems (P = .0037), and postoperative problems (P = .00002). The prevalence of palatal fistula was similar to mean values reported in the literature. Analysis of causal factors showed a positive association between palatal fistulas with wide and regular initial cleft width and intraoperative and postoperative problems. The anterior region presented the greatest occurrence of fistulas.

Asymmetry quantification from reflectance images of orthotic patients using structural similarity metrics

NASA Astrophysics Data System (ADS)

Boucher, Marc-Antoine; Watts, Nicolas; Gremillet, Frederic; Legare, Philippe; Kadoury, Samuel

2018-02-01

Pathologies like plantar fasciitis, a common soft tissue disorder of the foot, is frequently associated with older age, high BMI and little exercise. Like other pathologies associated with the foot, the knee or hip, foot orthoses can help the patient's posture and recent techniques allow the creation of personalized foot orthoses based on 3D foot model that are fitted with high accuracy to the foot surface. In order to assess the efficacy of the personalized orthoses on the patient's pose and balance, depth images with reflectance camera filters are acquired in order to evaluate the posture of the patient before and after the use of the orthoses. Images are analysed by clinicians to assess the region asymmetry and posture changes. However, this remains a subjective evaluation and a quantifiable measurement is required to follow patient progression. In this paper, we present a novel tool to assess and quantify the asymmetry of body regions using a color-based structural similarity metric calculated from paired regions. This provides a quantitative measure to evaluate the effect of the personalized orthoses on the patient. A user-friendly interface allows the user to select an area of the body and automatically generate a symmetry axis, along with a measure of asymmetry measuring reflectance variations from the skin. The tool was validated on 30 patients, demonstrating an 83% agreement rate compare to clinical observations.

Seismic Hazard Assessment for a Characteristic Earthquake Scenario: Probabilistic-Deterministic Method

NASA Astrophysics Data System (ADS)

mouloud, Hamidatou

2016-04-01

The objective of this paper is to analyze the seismic activity and the statistical treatment of seismicity catalog the Constantine region between 1357 and 2014 with 7007 seismic event. Our research is a contribution to improving the seismic risk management by evaluating the seismic hazard in the North-East Algeria. In the present study, Earthquake hazard maps for the Constantine region are calculated. Probabilistic seismic hazard analysis (PSHA) is classically performed through the Cornell approach by using a uniform earthquake distribution over the source area and a given magnitude range. This study aims at extending the PSHA approach to the case of a characteristic earthquake scenario associated with an active fault. The approach integrates PSHA with a high-frequency deterministic technique for the prediction of peak and spectral ground motion parameters in a characteristic earthquake. The method is based on the site-dependent evaluation of the probability of exceedance for the chosen strong-motion parameter. We proposed five sismotectonique zones. Four steps are necessary: (i) identification of potential sources of future earthquakes, (ii) assessment of their geological, geophysical and geometric, (iii) identification of the attenuation pattern of seismic motion, (iv) calculation of the hazard at a site and finally (v) hazard mapping for a region. In this study, the procedure of the earthquake hazard evaluation recently developed by Kijko and Sellevoll (1992) is used to estimate seismic hazard parameters in the northern part of Algeria.

Quantitative ex-vivo micro-computed tomographic imaging of blood vessels and necrotic regions within tumors.

PubMed

Downey, Charlene M; Singla, Arvind K; Villemaire, Michelle L; Buie, Helen R; Boyd, Steven K; Jirik, Frank R

2012-01-01

Techniques for visualizing and quantifying the microvasculature of tumors are essential not only for studying angiogenic processes but also for monitoring the effects of anti-angiogenic treatments. Given the relatively limited information that can be gleaned from conventional 2-D histological analyses, there has been considerable interest in methods that enable the 3-D assessment of the vasculature. To this end, we employed a polymerizing intravascular contrast medium (Microfil) and micro-computed tomography (micro-CT) in combination with a maximal spheres direct 3-D analysis method to visualize and quantify ex-vivo vessel structural features, and to define regions of hypoperfusion within tumors that would be indicative of necrosis. Employing these techniques we quantified the effects of a vascular disrupting agent on the tumor vasculature. The methods described herein for quantifying whole tumor vascularity represent a significant advance in the 3-D study of tumor angiogenesis and evaluation of novel therapeutics, and will also find potential application in other fields where quantification of blood vessel structure and necrosis are important outcome parameters.

New Embedded Denotes Fuzzy C-Mean Application for Breast Cancer Density Segmentation in Digital Mammograms

NASA Astrophysics Data System (ADS)

Othman, Khairulnizam; Ahmad, Afandi

2016-11-01

In this research we explore the application of normalize denoted new techniques in advance fast c-mean in to the problem of finding the segment of different breast tissue regions in mammograms. The goal of the segmentation algorithm is to see if new denotes fuzzy c- mean algorithm could separate different densities for the different breast patterns. The new density segmentation is applied with multi-selection of seeds label to provide the hard constraint, whereas the seeds labels are selected based on user defined. New denotes fuzzy c- mean have been explored on images of various imaging modalities but not on huge format digital mammograms just yet. Therefore, this project is mainly focused on using normalize denoted new techniques employed in fuzzy c-mean to perform segmentation to increase visibility of different breast densities in mammography images. Segmentation of the mammogram into different mammographic densities is useful for risk assessment and quantitative evaluation of density changes. Our proposed methodology for the segmentation of mammograms on the basis of their region into different densities based categories has been tested on MIAS database and Trueta Database.

Visual enhancement of unmixed multispectral imagery using adaptive smoothing

USGS Publications Warehouse

Lemeshewsky, G.P.; Rahman, Z.-U.; Schowengerdt, R.A.; Reichenbach, S.E.

2004-01-01

Adaptive smoothing (AS) has been previously proposed as a method to smooth uniform regions of an image, retain contrast edges, and enhance edge boundaries. The method is an implementation of the anisotropic diffusion process which results in a gray scale image. This paper discusses modifications to the AS method for application to multi-band data which results in a color segmented image. The process was used to visually enhance the three most distinct abundance fraction images produced by the Lagrange constraint neural network learning-based unmixing of Landsat 7 Enhanced Thematic Mapper Plus multispectral sensor data. A mutual information-based method was applied to select the three most distinct fraction images for subsequent visualization as a red, green, and blue composite. A reported image restoration technique (partial restoration) was applied to the multispectral data to reduce unmixing error, although evaluation of the performance of this technique was beyond the scope of this paper. The modified smoothing process resulted in a color segmented image with homogeneous regions separated by sharpened, coregistered multiband edges. There was improved class separation with the segmented image, which has importance to subsequent operations involving data classification.

Failure Analysis and Magnetic Evaluation of Tertiary Superheater Tube Used in Gas-Fired Boiler

NASA Astrophysics Data System (ADS)

Mohapatra, J. N.; Patil, Sujay; Sah, Rameshwar; Krishna, P. C.; Eswarappa, B.

2018-02-01

Failure analysis was carried out on a prematurely failed tertiary superheater tube used in gas-fired boiler. The analysis includes a comparative study of visual examination, chemical composition, hardness and microstructure at failed region, adjacent and far to failure as well as on fresh tube. The chemistry was found matching to the standard specification, whereas the hardness was low in failed tube compared to the fish mouth opening region and the fresh tube. Microscopic examination of failed sample revealed the presence of spheroidal carbides of Cr and Mo predominantly along the grain boundaries. The primary cause of failure is found to be localized heating. Magnetic hysteresis loop (MHL) measurements were carried out to correlate the magnetic parameters with microstructure and mechanical properties to establish a possible non-destructive evaluation (NDE) for health monitoring of the tubes. The coercivity of the MHL showed a very good correlation with microstructure and mechanical properties deterioration enabling a possible NDE technique for the health monitoring of the tubes.

Assessment of the current status of playground safety in the midwestern region of Turkey: an effort to provide a safe environment for children.

PubMed

Uskun, Ersin; Kişioğlu, Ahmet Nesimi; Altay, Tülin; Cikinlar, Rengül; Kocakaya, Asuman

2008-01-01

This study aimed to identify and evaluate the degree of conformity to the playground standards and the level of compliance with current safety specifications of the playgrounds in the midwestern region of Turkey. An observational technique was used at a total of 57 public playgrounds. A playground safety control form was prepared based on the United States National Program for Playground Safety and the Consumer Product Safety Commission security standards, since there is no national law covering playground equipment and safety in Turkey. The study evaluated the surroundings of the playground, arrangement of equipment in the playground, and characteristics of the equipment. The percentage of playgrounds surveyed with inadequate or hard surfacing was 80.7%. Fifty-two percent of the equipment was found to be inappropriate. Equipment was higher than the recommended heights. The results of our study unfortunately point out that playgrounds for children do not meet many of the safety criteria.

Utility of ultrasonography for diagnosis of superficial swellings in buffalo (Bubalus bubalis)

PubMed Central

ABOUELNASR, Khaled; EL-SHAFAEY, El-Sayed; MOSBAH, Esam; EL-KHODERY, Sabry

2016-01-01

We studied 72 buffalo with superficial swellings in the head (n=4), neck (n=5), chest wall (n=4), abdominal wall (n=28), limbs (n=16), gluteal region (n=8), perineal region (n=6) and udder (n=1). Ultrasonographically, the swellings varied according to type, duration, content and location. The clinical use of ultrasound to assess these superficial swellings allowed diagnosis of abscesses (n=21), hematomas (n=11), hernias (n=17), bursitis (n=13), urethral diverticula (n=6) and tumors (n=4). Ultrasonography could precisely discriminate each lesion type (sensitivity, 71–100%; specificity, 75–100%; odds ratio, 1.0–8.4; Confidence Interval, 74.2–20; and P value 0.001). The specificity for ultrasonographic evaluation of superficial swellings was 100% for hernias, urethral diverticula and tumors, whilst the lowest specificity was recorded for hematomas (75%) and abscesses (92%). In conclusion, ultrasonography provides a precise, non-invasive and fast technique for the evaluation, classification and subsequent treatment of a variety of superficial swellings in buffalo. PMID:27181085

Comparative analysis of feature extraction methods in satellite imagery

NASA Astrophysics Data System (ADS)

Karim, Shahid; Zhang, Ye; Asif, Muhammad Rizwan; Ali, Saad

2017-10-01

Feature extraction techniques are extensively being used in satellite imagery and getting impressive attention for remote sensing applications. The state-of-the-art feature extraction methods are appropriate according to the categories and structures of the objects to be detected. Based on distinctive computations of each feature extraction method, different types of images are selected to evaluate the performance of the methods, such as binary robust invariant scalable keypoints (BRISK), scale-invariant feature transform, speeded-up robust features (SURF), features from accelerated segment test (FAST), histogram of oriented gradients, and local binary patterns. Total computational time is calculated to evaluate the speed of each feature extraction method. The extracted features are counted under shadow regions and preprocessed shadow regions to compare the functioning of each method. We have studied the combination of SURF with FAST and BRISK individually and found very promising results with an increased number of features and less computational time. Finally, feature matching is conferred for all methods.

Investigation of four-dimensional computed tomography-based pulmonary ventilation imaging in patients with emphysematous lung regions

NASA Astrophysics Data System (ADS)

Yamamoto, Tokihiro; Kabus, Sven; Klinder, Tobias; Lorenz, Cristian; von Berg, Jens; Blaffert, Thomas; Loo, Billy W., Jr.; Keall, Paul J.

2011-04-01

A pulmonary ventilation imaging technique based on four-dimensional (4D) computed tomography (CT) has advantages over existing techniques. However, physiologically accurate 4D-CT ventilation imaging has not been achieved in patients. The purpose of this study was to evaluate 4D-CT ventilation imaging by correlating ventilation with emphysema. Emphysematous lung regions are less ventilated and can be used as surrogates for low ventilation. We tested the hypothesis: 4D-CT ventilation in emphysematous lung regions is significantly lower than in non-emphysematous regions. Four-dimensional CT ventilation images were created for 12 patients with emphysematous lung regions as observed on CT, using a total of four combinations of two deformable image registration (DIR) algorithms: surface-based (DIRsur) and volumetric (DIRvol), and two metrics: Hounsfield unit (HU) change (VHU) and Jacobian determinant of deformation (VJac), yielding four ventilation image sets per patient. Emphysematous lung regions were detected by density masking. We tested our hypothesis using the one-tailed t-test. Visually, different DIR algorithms and metrics yielded spatially variant 4D-CT ventilation images. The mean ventilation values in emphysematous lung regions were consistently lower than in non-emphysematous regions for all the combinations of DIR algorithms and metrics. VHU resulted in statistically significant differences for both DIRsur (0.14 ± 0.14 versus 0.29 ± 0.16, p = 0.01) and DIRvol (0.13 ± 0.13 versus 0.27 ± 0.15, p < 0.01). However, VJac resulted in non-significant differences for both DIRsur (0.15 ± 0.07 versus 0.17 ± 0.08, p = 0.20) and DIRvol (0.17 ± 0.08 versus 0.19 ± 0.09, p = 0.30). This study demonstrated the strong correlation between the HU-based 4D-CT ventilation and emphysema, which indicates the potential for HU-based 4D-CT ventilation imaging to achieve high physiologic accuracy. A further study is needed to confirm these results.

[Topographic anatomy of the hook region and its significance for the choice of the surgical technique for the cochlear implantation].

PubMed

Yanov, Yu K; Kuzovkov, V E; Lilenko, A S; Kostevich, I V; Sugarova, S B; Amonov, A Sh

The mode of the introduction of the active electrode of a cochlear implant into the cochlea remains a key issue as far as cochlear implantation is concerned. Especially much attention has recently been given to the relationship between the anatomical features of the basal region of the cochlea (the so-called 'fish hook') and the possibility to approach it. We have undertaken the attempt to optimize the approach to the tympanic canal (scala tympanica) of the cochlea with a view to reducing to a minimum the risk of an injury to the cochlear structures in the course of cochlear implantation. A total of 35 cadaveric temporal bones were examined to measure the fine structures of the hook region and evaluate the risk of their damages associated with various approaches to the tympanic canal.

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

Sato, M.; Kamide, Y.; Richmond, A.D.

A new technique is presented to estimate electric fields and currents in a localized region of the high-latitude ionosphere by combining two magnetogram-inversion algorithms. This paper describes the concept and practical procedures of the method as well as the first results of our efforts in which this new scheme is applied to northern Scandinavia, computing the ionospheric parameters on a small scale. Examining latitudinal profiles of these parameters and precipitating particles, it is found that the region of the most intense precipitation in the morning sector is located equatorward of the region of the strongest electric field. To evaluate themore » relative importance of ionospheric and magnetospheric effects, the field-aligned current is divided into two components: (del Sigma) dot E and Sigma del dot E. These two components give often the opposite directions in the resultant field-aligned currents. The relative strength of the two components appears to vary considerably with latitude.« less

Amazonas project: Application of remote sensing techniques for the integrated survey of natural resources in Amazonas. [Brazil

NASA Technical Reports Server (NTRS)

Dejesusparada, N. (Principal Investigator)

1981-01-01

The use of LANDSAT multispectral scanner and return beam vidicon imagery for surveying the natural resources of the Brazilian Amazonas is described. Purposes of the Amazonas development project are summarized. The application of LANDSAT imagery to identification of vegetation coverage and soil use, identification of soil types, geomorphology, and geology and highway planning is discussed. An evaluation of the worth of LANDSAT imagery in mapping the region is presented. Maps generated by the project are included.

An Evaluation of the Service Failure of Aluminum Nose Cones Using Four Test Techniques.

DTIC Science & Technology

1987-03-01

13 LIST OF ILLUSTRATIONS 1. Schematic of nose cone. 14 2. Subsize Charpy specimen. 15 3. Simulation test fixture. 16 4. Force displacement plot from...Figure 1. Schematic of nose cone. 14 LD 0.06 03-a 0.30L IL 1.602 Figure 2. Subsize Charpy specimen. i5 RAM DISPLACEMENT COLLART WV Ualz APPLIED FORCE...between threaded and tapered regions. In all, four measurements were made on each nose cone. The two material property measurements were made using Charpy

Aircraft remote sensing of soil moisture and hydrologic parameters, Taylor Creek, Florida, and Little River, Georgia, 1979 data report

NASA Technical Reports Server (NTRS)

Jackson, T. J.; Schmugge, T. J.; Allen, L. H., Jr.; Oneill, P.; Slack, R.; Wang, J.; Engman, E. T.

1981-01-01

Experiments were conducted to evaluate aircraft remote sensing techniques for hydrology in a wide range of physiographic and climatic regions using several sensor platforms. The data were collected in late 1978 and during 1979 in two humid areas--Taylor Creek, Fla., and Little River, Ga. Soil moisture measurements and climatic observations are presented as well as the remote sensing data collected using thermal infrared, passive microwave, and active microwave systems.

Whole-brain functional magnetic resonance imaging mapping of acute nociceptive responses induced by formalin in rats using atlas registration-based event-related analysis.

PubMed

Shih, Yen-Yu I; Chen, You-Yin; Chen, Chiao-Chi V; Chen, Jyh-Cheng; Chang, Chen; Jaw, Fu-Shan

2008-06-01

Nociceptive neuronal activation in subcortical regions has not been well investigated in functional magnetic resonance imaging (fMRI) studies. The present report aimed to use the blood oxygenation level-dependent (BOLD) fMRI technique to map nociceptive responses in both subcortical and cortical regions by employing a refined data processing method, the atlas registration-based event-related (ARBER) analysis technique. During fMRI acquisition, 5% formalin (50 mul) was injected into the left hindpaw to induce nociception. ARBER was then used to normalize the data among rats, and images were analyzed using automatic selection of the atlas-based region of interest. It was found that formalin-induced nociceptive processing increased BOLD signals in both cortical and subcortical regions. The cortical activation was distributed over the cingulate, motor, somatosensory, insular, and visual cortices, and the subcortical activation involved the caudate putamen, hippocampus, periaqueductal gray, superior colliculus, thalamus, and hypothalamus. With the aid of ARBER, the present study revealed a detailed activation pattern that possibly indicated the recruitment of various parts of the nociceptive system. The results also demonstrated the utilization of ARBER in establishing an fMRI-based whole-brain nociceptive map. The formalin induced nociceptive images may serve as a template of central nociceptive responses, which can facilitate the future use of fMRI in evaluation of new drugs and preclinical therapies for pain. (c) 2008 Wiley-Liss, Inc.

Sandwich technique, peripheral nerve stimulation, peripheral field stimulation and hybrid stimulation for inguinal region and genital pain.

PubMed

Shaw, Andrew; Sharma, Mayur; Zibly, Zion; Ikeda, Daniel; Deogaonkar, Milind

2016-12-01

Ilioinguinal neuralgia (IG) and genitofemoral (GF) neuralgia following inguinal hernia repair is a chronic and debilitating neuropathic condition. Recently, peripheral nerve stimulation has become an effective and minimally invasive option for the treatment of refractory pain. Here we present a retrospective case series of six patients who underwent placement of peripheral nerve stimulation electrodes using various techniques for treatment of refractory post-intervention inguinal region pain. Six patients with post-intervention inguinal, femoral or GF neuropathic pain were evaluated for surgery. Either octopolar percutaneous electrodes or combination of paddle and percutaneous electrodes were implanted in the area of their pain. Pain visual analog scores (VAS), surgical complication rate, preoperative symptom duration, degree of pain relief, preoperative and postoperative work status, postoperative changes in medication usage, and overall degree of satisfaction with this therapy was assessed. All six patients had an average improvement of 62% in the immediate post-operative follow-up. Four patients underwent stimulation for IG, one for femoral neuralgia, and another for GF neuralgia. Peripheral nerve stimulation provided at least 50% pain relief in all the six patients with post-intervention inguinal region pain. 85% of patients indicated they were completely satisfied with the therapy overall. There was one treatment failure with an acceptable complication rate. Peripheral nerve or field stimulation for post-intervention inguinal region pain is a safe and effective treatment for this refractory and complex problem for patients who have exhausted other management options.

Novel methods of imaging and analysis for the thermoregulatory sweat test.

PubMed

Carroll, Michael Sean; Reed, David W; Kuntz, Nancy L; Weese-Mayer, Debra Ellyn

2018-06-07

The thermoregulatory sweat test (TST) can be central to the identification and management of disorders affecting sudomotor function and small sensory and autonomic nerve fibers, but the cumbersome nature of the standard testing protocol has prevented its widespread adoption. A high resolution, quantitative, clean and simple assay of sweating could significantly improve identification and management of these disorders. Images from 89 clinical TSTs were analyzed retrospectively using two novel techniques. First, using the standard indicator powder, skin surface sweat distributions were determined algorithmically for each patient. Second, a fundamentally novel method using thermal imaging of forced evaporative cooling was evaluated through comparison with the standard technique. Correlation and receiver operating characteristic analyses were used to determine the degree of match between these methods, and the potential limits of thermal imaging were examined through cumulative analysis of all studied patients. Algorithmic encoding of sweating and non-sweating regions produces a more objective analysis for clinical decision making. Additionally, results from the forced cooling method correspond well with those from indicator powder imaging, with a correlation across spatial regions of -0.78 (CI: -0.84 to -0.71). The method works similarly across body regions, and frame-by-frame analysis suggests the ability to identify sweating regions within about 1 second of imaging. While algorithmic encoding can enhance the standard sweat testing protocol, thermal imaging with forced evaporative cooling can dramatically improve the TST by making it less time-consuming and more patient-friendly than the current approach.

Assessing regional environmental quality by integrated use of remote sensing, GIS, and spatial multi-criteria evaluation for prioritization of environmental restoration.

PubMed

Rahman, Md Rejaur; Shi, Z H; Chongfa, Cai

2014-11-01

This study was an attempt to analyse the regional environmental quality with the application of remote sensing, geographical information system, and spatial multiple criteria decision analysis and, to project a quantitative method applicable to identify the status of the regional environment of the study area. Using spatial multi-criteria evaluation (SMCE) approach with expert knowledge in this study, an integrated regional environmental quality index (REQI) was computed and classified into five levels of regional environment quality viz. worse, poor, moderate, good, and very good. During the process, a set of spatial criteria were selected (here, 15 criterions) together with the degree of importance of criteria in sustainability of the regional environment. Integrated remote sensing and GIS technique and models were applied to generate the necessary factors (criterions) maps for the SMCE approach. The ranking, along with expected value method, was used to standardize the factors and on the other hand, an analytical hierarchy process (AHP) was applied for calculating factor weights. The entire process was executed in the integrated land and water information system (ILWIS) software tool that supports SMCE. The analysis showed that the overall regional environmental quality of the area was at moderate level and was partly determined by elevation. Areas under worse and poor quality of environment indicated that the regional environmental status showed decline in these parts of the county. The study also revealed that the human activities, vegetation condition, soil erosion, topography, climate, and soil conditions have serious influence on the regional environment condition of the area. Considering the regional characteristics of environmental quality, priority, and practical needs for environmental restoration, the study area was further regionalized into four priority areas which may serve as base areas of decision making for the recovery, rebuilding, and protection of the environment.

Evaluation of human serum of severe rheumatoid arthritis by confocal Raman spectroscopy

NASA Astrophysics Data System (ADS)

Carvalho, C. S.; Raniero, L.; Santo, A. M. E.; Pinheiro, M. M.; Andrade, L. E. C.; Cardoso, M. A. G.; Junior, J. S.; Martin, A. A.

2010-02-01

Rheumatoid Arthritis is a systemic chronic inflammatory disease, recurrent and systemic, initiated by autoantibodies and maintained by inflammatory mechanisms cellular applicants. The evaluation of this disease to promote early diagnosis, need an associations of many tools, such as clinical, physical examination and thorough medical history. However, there is no satisfactory consensus due to its complexity. In the present work, confocal Raman spectroscopy was used to evaluate the biochemical composition of human serum of 40 volunteers, 24 patients with rheumatoid arthritis presenting clinical signs and symptoms, and 16 healthy donors. The technique of latex agglutination for the polystyrene covered with human immunoglobulin G and PCR (protein c-reactive) was performed for confirmation of possible false-negative results within the groups, facilitating the statistical interpretation and validation of the technique. This study aimed to verify the changes for the characteristics Raman peaks of biomolecules such as immunoglobulins amides and protein. The results were highly significant with a good separation between groups mentioned. The discriminant analysis was performed through the principal components and correctly identified 92% of the donors. Based on these results, we observed the behavior of arthritis autoimmune, evident in certain spectral regions that characterize the serological differences between the groups.

The NASA participation in the 1980 EPA PEPE/NEROS field measurements program

NASA Technical Reports Server (NTRS)

Remsberg, E.; Bendura, R.

1982-01-01

The Persistent Elevated Pollution Episode (PEPE)/Northeast Regional Oxidant Study (NEROS) Project consisted of a series of field measurements sponsored by the EPA during July and August, 1980. NASA participation in the Project had several purposes: (1) use remote sensing to help determine mixed layer height and ozone profiles regionally; and (2) provide opportunity for development, testing and evaluation of several NASA 'emerging' airborne remote sensing systems. NASA also provided information on the hazy pollution episodes throughout the summer of 1980 with satellite imagery. This paper describes findings on atmospheric aerosols, ozone profile and ozone column and discusses the instruments (airborne and ground-based sensors) and techniques used to obtain the relevant data. Associated archived data is also discussed.

Mass Movement Susceptibility Mapping Using Satellite Optical Imagery Compared With INSAR Monitoring: Zigui County, Three Gorges Region, China

NASA Astrophysics Data System (ADS)

Kincal, Cem; Singleton, Andrew; Liu, Peng; Li, Zhenhong; Drummond, Jane; Hoey, Trevor; Muller, Jan-Peter; Qu, Wei; Zeng, Qiming; Zhang, Jingfa; Du, Peijun

2010-10-01

Mass movements on steep slopes are a major hazard to communities and infrastructure in the Three Gorges region, China. Developing susceptibility maps of mass movements is therefore very important in both current and future land use planning. This study employed satellite optical imagery and an ASTER GDEM (15 m) to derive various parameters (namely geology; slope gradient; proximity to drainage networks and proximity to lineaments) in order to create a GIS-based map of mass movement susceptibility. This map was then evaluated using highly accurate deformation signals processed using the Persistent Scatterer (PS) InSAR technique. Areas of high susceptibility correspond well to points of high subsidence, which provides a strong support of our susceptibility map.

Hexahedral finite element mesh coarsening using pillowing technique

DOEpatents

Staten, Matthew L [Pittsburgh, PA; Woodbury, Adam C [Provo, UT; Benzley, Steven E [Provo, UT; Shepherd, Jason F [Edgewood, NM

2012-06-05

A techniques for coarsening a hexahedral mesh is described. The technique includes identifying a coarsening region within a hexahedral mesh to be coarsened. A boundary sheet of hexahedral elements is inserted into the hexahedral mesh around the coarsening region. A column of hexahedral elements is identified within the boundary sheet. The column of hexahedral elements is collapsed to create an extraction sheet of hexahedral elements contained within the coarsening region. Then, the extraction sheet of hexahedral elements is extracted to coarsen the hexahedral mesh.

CAD/CAM milled removable complete dentures: an in vitro evaluation of trueness.

PubMed

Srinivasan, Murali; Cantin, Yoann; Mehl, Albert; Gjengedal, Harald; Müller, Frauke; Schimmel, Martin

2017-07-01

This study aimed to compare the trueness of one type of CAD/CAM milled complete removable dental prostheses (CRDPs) with injection-molding and conventionally manufactured CRDPs. Thirty-three CRDPs were fabricated by three different manufacturing techniques (group CAD/CAM (AvaDent™): n = 11; group injection molding (Ivocap™): n = 11; group flask-pack-press: n = 11) using a single master reference model and incubated in artificial saliva for 21 days. The trueness of the entire intaglio surface along with five specific regions of interest (vestibular-flange, palate, tuberosities, alveolar crest, and post-dam areas) was compared. Non-parametric tests were used with a level of significance set at p < 0.05. At baseline, there was no difference in the trueness of the total intaglio surfaces between the groups. After incubation, only the conventional CRDPs showed a significant improvement in trueness of the entire intaglio surface (p = 0.0044), but improved trueness was confirmed for all three techniques in most individual regions of interest. The 80-20 % /2 median quantile of the CAD/CAM group demonstrated the highest variability of individual readings, probably due to the size of the milling instrument. However, for all three techniques, 80 % of all deviations of the complete intaglio surface after incubation in saliva were below 0.1 mm. In this in vitro study, the trueness of the intaglio surface of all three investigated techniques seems to remain within a clinically acceptable range. Additional research is warranted on material-related aspects, cost-effectiveness, clinical performance, patient-centered outcomes, as well as other CAD/CAM techniques for CRDP fabrication. The intaglio surface trueness is an essential aspect in the clinical performance of CRDPs.

Regional reliability of quantitative signal targeting with alternating radiofrequency (STAR) labeling of arterial regions (QUASAR).

PubMed

Tatewaki, Yasuko; Higano, Shuichi; Taki, Yasuyuki; Thyreau, Benjamin; Murata, Takaki; Mugikura, Shunji; Ito, Daisuke; Takase, Kei; Takahashi, Shoki

2014-01-01

Quantitative signal targeting with alternating radiofrequency labeling of arterial regions (QUASAR) is a recent spin labeling technique that could improve the reliability of brain perfusion measurements. Although it is considered reliable for measuring gray matter as a whole, it has never been evaluated regionally. Here we assessed this regional reliability. Using a 3-Tesla Philips Achieva whole-body system, we scanned four times 10 healthy volunteers, in two sessions 2 weeks apart, to obtain QUASAR images. We computed perfusion images and ran a voxel-based analysis within all brain structures. We also calculated mean regional cerebral blood flow (rCBF) within regions of interest configured for each arterial territory distribution. The mean CBF over whole gray matter was 37.74 with intraclass correlation coefficient (ICC) of .70. In white matter, it was 13.94 with an ICC of .30. Voxel-wise ICC and coefficient-of-variation maps showed relatively lower reliability in watershed areas and white matter especially in deeper white matter. The absolute mean rCBF values were consistent with the ones reported from PET, as was the relatively low variability in different feeding arteries. Thus, QUASAR reliability for regional perfusion is high within gray matter, but uncertain within white matter. © 2014 The Authors. Journal of Neuroimaging published by the American Society of Neuroimaging.

Regional Reliability of Quantitative Signal Targeting with Alternating Radiofrequency (STAR) Labeling of Arterial Regions (QUASAR)

PubMed Central

Tatewaki, Yasuko; Higano, Shuichi; Taki, Yasuyuki; Thyreau, Benjamin; Murata, Takaki; Mugikura, Shunji; Ito, Daisuke; Takase, Kei; Takahashi, Shoki

2014-01-01

BACKGROUND AND PURPOSE Quantitative signal targeting with alternating radiofrequency labeling of arterial regions (QUASAR) is a recent spin labeling technique that could improve the reliability of brain perfusion measurements. Although it is considered reliable for measuring gray matter as a whole, it has never been evaluated regionally. Here we assessed this regional reliability. METHODS Using a 3-Tesla Philips Achieva whole-body system, we scanned four times 10 healthy volunteers, in two sessions 2 weeks apart, to obtain QUASAR images. We computed perfusion images and ran a voxel-based analysis within all brain structures. We also calculated mean regional cerebral blood flow (rCBF) within regions of interest configured for each arterial territory distribution. RESULTS The mean CBF over whole gray matter was 37.74 with intraclass correlation coefficient (ICC) of .70. In white matter, it was 13.94 with an ICC of .30. Voxel-wise ICC and coefficient-of-variation maps showed relatively lower reliability in watershed areas and white matter especially in deeper white matter. The absolute mean rCBF values were consistent with the ones reported from PET, as was the relatively low variability in different feeding arteries. CONCLUSIONS Thus, QUASAR reliability for regional perfusion is high within gray matter, but uncertain within white matter. PMID:25370338

Evaluation of the Williams-type spring wheat model in North Dakota and Minnesota

NASA Technical Reports Server (NTRS)

Leduc, S. (Principal Investigator)

1982-01-01

The Williams type model, developed similarly to previous models of C.V.D. Williams, uses monthly temperature and precipitation data as well as soil and topological variables to predict the yield of the spring wheat crop. The models are statistically developed using the regression technique. Eight model characteristics are examined in the evaluation of the model. Evaluation is at the crop reporting district level, the state level and for the entire region. A ten year bootstrap test was the basis of the statistical evaluation. The accuracy and current indication of modeled yield reliability could show improvement. There is great variability in the bias measured over the districts, but there is a slight overall positive bias. The model estimates for the east central crop reporting district in Minnesota are not accurate. The estimate of yield for 1974 were inaccurate for all of the models.

Simulating Sand Behavior through Terrain Subdivision and Particle Refinement

NASA Astrophysics Data System (ADS)

Clothier, M.

2013-12-01

Advances in computer graphics, GPUs, and parallel processing hardware have provided researchers with new methods to visualize scientific data. In fact, these advances have spurred new research opportunities between computer graphics and other disciplines, such as Earth sciences. Through collaboration, Earth and planetary scientists have benefited by using these advances in hardware technology to process large amounts of data for visualization and analysis. At Oregon State University, we are collaborating with the Oregon Space Grant and IGERT Ecosystem Informatics programs to investigate techniques for simulating the behavior of sand. In addition, we have also been collaborating with the Jet Propulsion Laboratory's DARTS Lab to exchange ideas on our research. The DARTS Lab specializes in the simulation of planetary vehicles, such as the Mars rovers. One aspect of their work is testing these vehicles in a virtual "sand box" to test their performance in different environments. Our research builds upon this idea to create a sand simulation framework to allow for more complex and diverse environments. As a basis for our framework, we have focused on planetary environments, such as the harsh, sandy regions on Mars. To evaluate our framework, we have used simulated planetary vehicles, such as a rover, to gain insight into the performance and interaction between the surface sand and the vehicle. Unfortunately, simulating the vast number of individual sand particles and their interaction with each other has been a computationally complex problem in the past. However, through the use of high-performance computing, we have developed a technique to subdivide physically active terrain regions across a large landscape. To achieve this, we only subdivide terrain regions where sand particles are actively participating with another object or force, such as a rover wheel. This is similar to a Level of Detail (LOD) technique, except that the density of subdivisions are determined by their proximity to the interacting object or force with the sand. To illustrate an example, as a rover wheel moves forward and approaches a particular sand region, that region will continue to subdivide until individual sand particles are represented. Conversely, if the rover wheel moves away, previously subdivided sand regions will recombine. Thus, individual sand particles are available when an interacting force is present but stored away if there is not. As such, this technique allows for many particles to be represented without the computational complexity. We have also further generalized these subdivision regions in our sand framework into any volumetric area suitable for use in the simulation. This allows for more compact subdivision regions and has fine-tuned our framework so that more emphasis can be placed on regions of actively participating sand. We feel that this increases the framework's usefulness across scientific applications and can provide for other research opportunities within the earth and planetary sciences. Through continued collaboration with our academic partners, we continue to build upon our sand simulation framework and look for other opportunities to utilize this research.

Structural, optical absorption and photoluminescence spectral studies of Sm3+ ions in Alkaline-Earth Boro Tellurite glasses

NASA Astrophysics Data System (ADS)

Siva Rama Krishna Reddy, K.; Swapna, K.; Mahamuda, Sk.; Venkateswarlu, M.; Srinivas Prasad, M. V. V. K.; Rao, A. S.; Prakash, G. Vijaya

2018-05-01

Sm3+ ions doped Alkaline-Earth Boro Tellurite (AEBT) glasses were prepared by using conventional melt quenching technique and characterized using the spectroscopic techniques such as FT-IR, optical absorption, emission and decay spectral measurements to understand their utility in optoelectronic devices. From absorption spectra, the bonding parameters, nephelauxetic ratios were determined to know the nature of bonding between Sm3+ ions and its surrounding ligands. From the measured oscillator strengths, the Judd-Ofelt (J-O) intensity parameters were evaluated and in turn used to estimate various radiative parameters for the fluorescent levels of Sm3+ ions in AEBT glasses. The PL spectra of Sm3+ ions exhibit three emission bands corresponding to the transitions 4G5/2 → 6H5/2, 6H7/2 and 6H9/2 in the visible region for which the emission cross-sections and branching ratios were evaluated. The decay spectral profiles measured for 4G5/2 → 6H7/2 transition showed single exponential for lower concentration and non-exponential for higher concentration of doped rare earth ion in the as prepared glasses. Conversion of decay spectral profiles from single to non-exponential have been analyzed using Inokuti-Hirayama (I-H) model to understand the energy transfer mechanism involved in the decay process. CIE Chromaticity coordinates were measured using emission spectral data to identify the exact region of emission from the as-prepared glasses. From the evaluated radiative parameters, emission cross-sections and quantum efficiencies, it was observed that AEBT glass with 1 mol% of Sm3+ ions is more suitable for designing optoelectronic devices.

Human brain mapping: A systematic comparison of parcellation methods for the human cerebral cortex.

PubMed

Arslan, Salim; Ktena, Sofia Ira; Makropoulos, Antonios; Robinson, Emma C; Rueckert, Daniel; Parisot, Sarah

2018-04-15

The macro-connectome elucidates the pathways through which brain regions are structurally connected or functionally coupled to perform a specific cognitive task. It embodies the notion of representing and understanding all connections within the brain as a network, while the subdivision of the brain into interacting functional units is inherent in its architecture. As a result, the definition of network nodes is one of the most critical steps in connectivity network analysis. Although brain atlases obtained from cytoarchitecture or anatomy have long been used for this task, connectivity-driven methods have arisen only recently, aiming to delineate more homogeneous and functionally coherent regions. This study provides a systematic comparison between anatomical, connectivity-driven and random parcellation methods proposed in the thriving field of brain parcellation. Using resting-state functional MRI data from the Human Connectome Project and a plethora of quantitative evaluation techniques investigated in the literature, we evaluate 10 subject-level and 24 groupwise parcellation methods at different resolutions. We assess the accuracy of parcellations from four different aspects: (1) reproducibility across different acquisitions and groups, (2) fidelity to the underlying connectivity data, (3) agreement with fMRI task activation, myelin maps, and cytoarchitectural areas, and (4) network analysis. This extensive evaluation of different parcellations generated at the subject and group level highlights the strengths and shortcomings of the various methods and aims to provide a guideline for the choice of parcellation technique and resolution according to the task at hand. The results obtained in this study suggest that there is no optimal method able to address all the challenges faced in this endeavour simultaneously. Copyright © 2017 Elsevier Inc. All rights reserved.

Comparison of optical localization techniques for optical coherence tomography of the hand for multi-fraction orthovoltage radiotherapy or photodynamic therapy: white light vs. optical surface imaging (Conference Presentation)

NASA Astrophysics Data System (ADS)

Jakubovic, Raphael; Bains, Amitpal; Ramjist, Joel; Babic, Steve; Chin, Lee; Barnes, Elizabeth; Yang, Victor X. D.

2017-02-01

Non-melanoma skin cancer (NMSC) is considered the most commonly diagnosed cancer in the United States and Canada. Treatment options include radiotherapy, surgical excision, radiotherapy, topical therapies, electrocautery, and cryotherapy. For patients undergoing fractionated orthovoltage radiation therapy or photodynamic therapy (PDT), the lesions are typically delineated by clinical markup prior to treatment without providing any information about the underlying tissue thus increasing the risk of geographic miss. The development of biomarkers for response in NMSC is imperative considering the current treatment paradigm is based on clinical examination and biopsy confirmation. Therefore, a non-invasive image-based evaluation of skin structure would allow for faster and potentially more comprehensive microscopic evaluation of the treated region at the point of care. To address this, our group is investigating the use of optical coherence tomography (OCT) for pre- and post- treatment evaluation of NMSC lesions during radiation therapy and PDT. Localization of the OCT probe for follow-up is complex, especially in the context of treatment response where the lesion is not present, precluding accurate delineation of the planning treatment area. Further, comparison to standard white light pre-treatment images is limited by the scale of the OCT probe (6 mm X 6 mm) relative to target region. In this study we compare the set-up accuracy of a typical OCT probe to detect a theoretical lesion on a patient's hand. White light images, optical surface imaging (OSI) and OCT will be obtained at baseline and used for probe set up on subsequent scans. Set-up error will be quantified using advanced image processing techniques.

Improvement and performance evaluation of the perturbation source method for an exact Monte Carlo perturbation calculation in fixed source problems

NASA Astrophysics Data System (ADS)

Sakamoto, Hiroki; Yamamoto, Toshihiro

2017-09-01

This paper presents improvement and performance evaluation of the "perturbation source method", which is one of the Monte Carlo perturbation techniques. The formerly proposed perturbation source method was first-order accurate, although it is known that the method can be easily extended to an exact perturbation method. A transport equation for calculating an exact flux difference caused by a perturbation is solved. A perturbation particle representing a flux difference is explicitly transported in the perturbed system, instead of in the unperturbed system. The source term of the transport equation is defined by the unperturbed flux and the cross section (or optical parameter) changes. The unperturbed flux is provided by an "on-the-fly" technique during the course of the ordinary fixed source calculation for the unperturbed system. A set of perturbation particle is started at the collision point in the perturbed region and tracked until death. For a perturbation in a smaller portion of the whole domain, the efficiency of the perturbation source method can be improved by using a virtual scattering coefficient or cross section in the perturbed region, forcing collisions. Performance is evaluated by comparing the proposed method to other Monte Carlo perturbation methods. Numerical tests performed for a particle transport in a two-dimensional geometry reveal that the perturbation source method is less effective than the correlated sampling method for a perturbation in a larger portion of the whole domain. However, for a perturbation in a smaller portion, the perturbation source method outperforms the correlated sampling method. The efficiency depends strongly on the adjustment of the new virtual scattering coefficient or cross section.

Usefulness of myocardial parametric imaging to evaluate myocardial viability in experimental and in clinical studies.

PubMed

Korosoglou, G; Hansen, A; Bekeredjian, R; Filusch, A; Hardt, S; Wolf, D; Schellberg, D; Katus, H A; Kuecherer, H

2006-03-01

To evaluate whether myocardial parametric imaging (MPI) is superior to visual assessment for the evaluation of myocardial viability. Myocardial contrast echocardiography (MCE) was assessed in 11 pigs before, during, and after left anterior descending coronary artery occlusion and in 32 patients with ischaemic heart disease by using intravenous SonoVue administration. In experimental studies perfusion defect area assessment by MPI was compared with visually guided perfusion defect planimetry. Histological assessment of necrotic tissue was the standard reference. In clinical studies viability was assessed on a segmental level by (1) visual analysis of myocardial opacification; (2) quantitative estimation of myocardial blood flow in regions of interest; and (3) MPI. Functional recovery between three and six months after revascularisation was the standard reference. In experimental studies, compared with visually guided perfusion defect planimetry, planimetric assessment of infarct size by MPI correlated more significantly with histology (r2 = 0.92 versus r2 = 0.56) and had a lower intraobserver variability (4% v 15%, p < 0.05). In clinical studies, MPI had higher specificity (66% v 43%, p < 0.05) than visual MCE and good accuracy (81%) for viability detection. It was less time consuming (3.4 (1.6) v 9.2 (2.4) minutes per image, p < 0.05) than quantitative blood flow estimation by regions of interest and increased the agreement between observers interpreting myocardial perfusion (kappa = 0.87 v kappa = 0.75, p < 0.05). MPI is useful for the evaluation of myocardial viability both in animals and in patients. It is less time consuming than quantification analysis by regions of interest and less observer dependent than visual analysis. Thus, strategies incorporating this technique may be valuable for the evaluation of myocardial viability in clinical routine.

Method for automatically evaluating a transition from a batch manufacturing technique to a lean manufacturing technique

DOEpatents

Ivezic, Nenad; Potok, Thomas E.

2003-09-30

A method for automatically evaluating a manufacturing technique comprises the steps of: receiving from a user manufacturing process step parameters characterizing a manufacturing process; accepting from the user a selection for an analysis of a particular lean manufacturing technique; automatically compiling process step data for each process step in the manufacturing process; automatically calculating process metrics from a summation of the compiled process step data for each process step; and, presenting the automatically calculated process metrics to the user. A method for evaluating a transition from a batch manufacturing technique to a lean manufacturing technique can comprise the steps of: collecting manufacturing process step characterization parameters; selecting a lean manufacturing technique for analysis; communicating the selected lean manufacturing technique and the manufacturing process step characterization parameters to an automatic manufacturing technique evaluation engine having a mathematical model for generating manufacturing technique evaluation data; and, using the lean manufacturing technique evaluation data to determine whether to transition from an existing manufacturing technique to the selected lean manufacturing technique.

Visualizing Simulated Electrical Fields from Electroencephalography and Transcranial Electric Brain Stimulation: A Comparative Evaluation

PubMed Central

Eichelbaum, Sebastian; Dannhauer, Moritz; Hlawitschka, Mario; Brooks, Dana; Knösche, Thomas R.; Scheuermann, Gerik

2014-01-01

Electrical activity of neuronal populations is a crucial aspect of brain activity. This activity is not measured directly but recorded as electrical potential changes using head surface electrodes (electroencephalogram - EEG). Head surface electrodes can also be deployed to inject electrical currents in order to modulate brain activity (transcranial electric stimulation techniques) for therapeutic and neuroscientific purposes. In electroencephalography and noninvasive electric brain stimulation, electrical fields mediate between electrical signal sources and regions of interest (ROI). These fields can be very complicated in structure, and are influenced in a complex way by the conductivity profile of the human head. Visualization techniques play a central role to grasp the nature of those fields because such techniques allow for an effective conveyance of complex data and enable quick qualitative and quantitative assessments. The examination of volume conduction effects of particular head model parameterizations (e.g., skull thickness and layering), of brain anomalies (e.g., holes in the skull, tumors), location and extent of active brain areas (e.g., high concentrations of current densities) and around current injecting electrodes can be investigated using visualization. Here, we evaluate a number of widely used visualization techniques, based on either the potential distribution or on the current-flow. In particular, we focus on the extractability of quantitative and qualitative information from the obtained images, their effective integration of anatomical context information, and their interaction. We present illustrative examples from clinically and neuroscientifically relevant cases and discuss the pros and cons of the various visualization techniques. PMID:24821532

Evaluation of the deformation parameters of the northern part of Eg

NASA Astrophysics Data System (ADS)

Mohamed, Abdel-Monem S.; Radwan, Ali M.; Sharf, Mohamed; Hamimi, Zakaria; Hegazy, Esraa E.; Abou Aly, Nadia; Gomaa, Mahmoud

2016-06-01

The northern part of Egypt is a rapidly growing development accompanied by the increased levels of standard living particularly in its urban areas. From tectonic and seismic point of views, the northern part of Egypt is one of the interested regions. It shows an active geologic structure attributed to the tectonic movements of the African and Eurasian plates from one side and the Arabian plate from the other side. From historical point of view and recent instrumental records, the northern part of Egypt is one of the seismo-active regions in Egypt. The investigations of the seismic events and their interpretations had led to evaluate the seismic hazard for disaster mitigation, for the safety of the densely populated regions and the vital projects. In addition to the monitoring of the seismic events, the most powerful technique of Global Navigation Satellite System (GNSS) will be used in determining crustal deformation where a geodetic network covers the northern part of Egypt. Joining the GPS Permanent stations of the northern part of Egypt with the Southern part of Europe will give a clear picture about the recent crustal deformation and the African plate velocity. The results from the data sets are compared and combined in order to determine the main characteristics of the deformation and hazard estimation for specified regions. Final compiled output from the seismological and geodetic analysis will throw lights upon the geodynamical regime of these seismo-active regions. This work will throw lights upon the geodynamical regime and to delineate the crustal stress and strain fields in the study region. This also enables to evaluate the active tectonics and surface deformation with their directions from repeated geodetic observations. The results show that the area under study suffers from continuous seismic activity related to the crustal movements taken place along trends of major faults

Myocardial Blood Volume Is Associated with Myocardial Oxygen Consumption: An Experimental Study with CMR in a Canine Model

PubMed Central

McCommis, Kyle S.; Zhang, Haosen; Goldstein, Thomas A.; Misselwitz, Bernd; Abendschein, Dana R.; Gropler, Robert J.; Zheng, Jie

2009-01-01

OBJECTIVES To evaluate the feasibility of cardiovascular MR (CMR) to determine regional myocardial perfusion and O2 metabolism, and assess the role of myocardial blood volume (MBV) on oxygen supply. BACKGROUND Coronary artery disease presents as an imbalance of myocardial oxygen supply and demand. We have developed relevant CMR methods to determine the relationship of myocardial blood flow (MBF) and MBV to oxygen consumption (MVO2) during pharmacologic hyperemia. METHODS Twenty-one mongrel dogs were studied with varying stenosis severities imposed on the proximal left anterior descending (LAD) coronary artery. MBF and MBV were determined by CMR first-pass perfusion, while the oxygen extraction fraction (OEF) and MVO2 were determined by the myocardial Blood-Oxygen-Level-Dependent (BOLD) effect and Fick’s law, respectively. MR imaging was performed at rest, and during either dipyridamole-induced vasodilation or dobutamine-induced hyperemia. Regional differences in myocardial perfusion and oxygenation were then evaluated. RESULTS Dipyridamole and dobutamine both led to 145–200% increases in MBF and 50–80% increases in MBV in normal perfused myocardium. As expected, MVO2 increased more significantly with dobutamine (~175%) than dipyridamole (~40%). Coronary stenosis resulted in an attenuation of MBF, MBV, and MVO2 in both the LAD-subtended stenosis region and the left circumflex subtended remote region. Liner regression analysis showed that MBV reserve appears to be more correlated with MVO2 reserve during dobutamine stress than MBF reserve, particularly in the stenotic regions. Conversely, MBF reserve appears to be more correlated with MVO2 reserve during dipyridamole, although neither of these differences was significant. CONCLUSIONS Noninvasive evaluation of both myocardial perfusion and oxygenation by CMR facilitates direct monitoring of regional myocardial ischemia and provides a valuable tool for better understanding microvascular pathophysiology. These techniques could complement delayed enhancement and wall motion analysis protocols, making MRI a valuable “one-stop shop” for imaging of myocardial ischemia. PMID:19909936

Semi-automated segmentation of a glioblastoma multiforme on brain MR images for radiotherapy planning.

PubMed

Hori, Daisuke; Katsuragawa, Shigehiko; Murakami, Ryuuji; Hirai, Toshinori

2010-04-20

We propose a computerized method for semi-automated segmentation of the gross tumor volume (GTV) of a glioblastoma multiforme (GBM) on brain MR images for radiotherapy planning (RTP). Three-dimensional (3D) MR images of 28 cases with a GBM were used in this study. First, a sphere volume of interest (VOI) including the GBM was selected by clicking a part of the GBM region in the 3D image. Then, the sphere VOI was transformed to a two-dimensional (2D) image by use of a spiral-scanning technique. We employed active contour models (ACM) to delineate an optimal outline of the GBM in the transformed 2D image. After inverse transform of the optimal outline to the 3D space, a morphological filter was applied to smooth the shape of the 3D segmented region. For evaluation of our computerized method, we compared the computer output with manually segmented regions, which were obtained by a therapeutic radiologist using a manual tracking method. In evaluating our segmentation method, we employed the Jaccard similarity coefficient (JSC) and the true segmentation coefficient (TSC) in volumes between the computer output and the manually segmented region. The mean and standard deviation of JSC and TSC were 74.2+/-9.8% and 84.1+/-7.1%, respectively. Our segmentation method provided a relatively accurate outline for GBM and would be useful for radiotherapy planning.

CORDEX Coordinated Output for Regional Evaluation

NASA Astrophysics Data System (ADS)

Gutowski, William; Giorgi, Filippo; Lake, Irene

2017-04-01

The Science Advisory Team for the Coordinated Regional Downscaling Experiment (CORDEX) has developed a baseline framework of specified regions, resolutions and simulation periods intended to provide a foundation for ongoing regional CORDEX activities: the CORDEX Coordinated Output for Regional Evaluation, or CORDEX-CORE. CORDEX-CORE was conceived in part to be responsive to IPCC needs for coordinated simulations that could provide regional climate downscaling (RCD) that yields fine-scale climate information beyond that resolved by GCMs. For each CORDEX region, a matrix of GCM-RCD experiments is designed based on the need to cover as much as possible different dimensions of the uncertainty space (e.g., different emissions and land-use scenarios, GCMs, RCD models and techniques). An appropriate set of driving GCMs can allow a program of simulations that efficiently addresses key scientific issues within CORDEX, while facilitating comparison and transfer of results and lessons learned across different regions. The CORDEX-CORE program seeks to provide, as much as possible, homogeneity across domains, so it is envisioned that a standard set of regional climate models (RCMs) and empirical statistical downscaling (ESD) methods will downscale a standard set of GCMs over all or at least most CORDEX domains for a minimum set of scenarios (high and low end). The focus is on historical climate simulations for the 20th century and projections for 21st century, implying that data would be needed minimally for the period 1950-2100 (but ideally 1900-2100). This foundational ensemble can be regionally enriched with further contributions (additional GCM-RCD pairs) by individual groups over their selected domains of interest. The RCM model resolution for these core experiments will be in the range of 10-20 km, a resolution that has been shown to provide substantial added value for a variety of climate variables and that represents a significant forward step compared in the CORDEX program. This presentation presents the vision and structure of CORDEX-CORE while also soliciting discussion on plans for implementing the program.

Multimodal analgesia and regional anaesthesia.

PubMed

Tornero Tornero, C; Fernández Rodríguez, L E; Orduña Valls, J

Multimodal analgesia provides quality analgesia, with fewer side effects due to the use of combined analgesics or analgesic techniques. Regional anaesthesia plays a fundamental role in achieving this goal. The different techniques of regional anaesthesia that include both peripheral and central blocks in either a single dose or in continuous infusion help to modulate the nociceptive stimuli that access the central level. The emergence of the ultrasound as an effective system to perform regional anaesthesia techniques has allowed the development of new regional anaesthesia techniques that formerly could not be carried out since only neurostimulation or skin references were used. It is essential to take into account that even with effective blocking it is advisable to associate other drugs by other routes, in this way we will be able to reduce the required doses individually and attempt to achieve a synergistic, not purely additive, effect. Copyright © 2017 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.

Evaluation of hybrids algorithms for mass detection in digitalized mammograms

NASA Astrophysics Data System (ADS)

Cordero, José; Garzón Reyes, Johnson

2011-01-01

The breast cancer remains being a significant public health problem, the early detection of the lesions can increase the success possibilities of the medical treatments. The mammography is an image modality effective to early diagnosis of abnormalities, where the medical image is obtained of the mammary gland with X-rays of low radiation, this allows detect a tumor or circumscribed mass between two to three years before that it was clinically palpable, and is the only method that until now achieved reducing the mortality by breast cancer. In this paper three hybrids algorithms for circumscribed mass detection on digitalized mammograms are evaluated. In the first stage correspond to a review of the enhancement and segmentation techniques used in the processing of the mammographic images. After a shape filtering was applied to the resulting regions. By mean of a Bayesian filter the survivors regions were processed, where the characteristics vector for the classifier was constructed with few measurements. Later, the implemented algorithms were evaluated by ROC curves, where 40 images were taken for the test, 20 normal images and 20 images with circumscribed lesions. Finally, the advantages and disadvantages in the correct detection of a lesion of every algorithm are discussed.

Benefits of Atrial Substrate Modification Guided by Electrogram Similarity and Phase Mapping Techniques to Eliminate Rotors and Focal Sources Versus Conventional Defragmentation in Persistent Atrial Fibrillation.

PubMed

Lin, Yenn-Jiang; Lo, Men-Tzung; Chang, Shih-Lin; Lo, Li-Wei; Hu, Yu-Feng; Chao, Tze-Fan; Chung, Fa-Po; Liao, Jo-Nan; Lin, Chin-Yu; Kuo, Huan-Yu; Chang, Yi-Chung; Lin, Chen; Tuan, Ta-Chuan; Vincent Young, Hsu-Wen; Suenari, Kazuyoshi; Dan Do, Van Buu; Raharjo, Suunu Budhi; Huang, Norden E; Chen, Shih-Ann

2016-11-01

This prospective study compared the efficacy of atrial substrate modification guided by a nonlinear phase mapping technique with that of conventional substrate ablation. The optimal ablation strategy for persistent atrial fibrillation (AF) was unknown. In phase 1 study, we applied a cellular automation technique to simulate the electrical wave propagation to improve the phase mapping algorithm, involving analysis of high-similarity electrogram regions. In addition, we defined rotors and focal AF sources, using the physical parameters of the divergence and curvature forces. In phase 2 study, we enrolled 68 patients with persistent AF undergoing substrate modification into 2 groups, group-1 (n = 34) underwent similarity index (SI) and phase mapping techniques; group-2 (n = 34) received complex fractionated atrial electrogram ablation with commercially available software. Group-1 received real-time waveform similarity measurements in which a phase mapping algorithm was applied to localize the sources. We evaluated the single-procedure freedom from AF. In group-1, we identified an average of 2.6 ± 0.89 SI regions per chamber. These regions involved rotors and focal sources in 65% and 77% of patients in group-1, respectively. Group-1 patients had shorter ablation procedure times, higher termination rates, and significant reduction in AF recurrence compared to group-2 and a trend toward benefit for all atrial arrhythmias. Multivariate analysis showed that substrate mapping using nonlinear similarity and phase mapping was the independent predictor of freedom from AF recurrence (hazard ratio: 0.26; 95% confidence interval: 0.09 to 0.74; p = 0.01). Our study showed that for persistent AF ablation, a specified substrate modification guided by nonlinear phase mapping could eliminate localized re-entry and non-pulmonary focal sources after pulmonary vein isolation. Copyright © 2016 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Balloon-based interferometric techniques

NASA Technical Reports Server (NTRS)

Rees, David

1985-01-01

A balloon-borne triple-etalon Fabry-Perot Interferometer, observing the Doppler shifts of absorption lines caused by molecular oxygen and water vapor in the far red/near infrared spectrum of backscattered sunlight, has been used to evaluate a passive spaceborne remote sensing technique for measuring winds in the troposphere and stratosphere. There have been two successful high altitude balloon flights of the prototype UCL instrument from the National Scientific Balloon Facility at Palestine, TE (May 80, Oct. 83). The results from these flights have demonstrated that an interferometer with adequate resolution, stability and sensitivity can be built. The wind data are of comparable quality to those obtained from operational techniques (balloon and rocket sonde, cloud-top drift analysis, and from the gradient wind analysis of satellite radiance measurements). However, the interferometric data can provide a regular global grid, over a height range from 5 to 50 km in regions of clear air. Between the middle troposphere (5 km) and the upper stratosphere (40 to 50 km), an optimized instrument can make wind measurements over the daylit hemisphere with an accuracy of about 3 to 5 m/sec (2 sigma). It is possible to obtain full height profiles between altitudes of 5 and 50 km, with 4 km height resolution, and a spatial resolution of about 200 km, along the orbit track. Below an altitude of about 10 km, Fraunhofer lines of solar origin are possible targets of the Doppler wind analysis. Above an altitude of 50 km, the weakness of the backscattered solar spectrum (decreasing air density) is coupled with the low absorption crosssection of all atmospheric species in the spectral region up to 800 nm (where imaging photon detectors can be used), causing the along-the-track resolution (or error) to increase beyond values useful for operational purposes. Within the region of optimum performance (5 to 50 km), however, the technique is a valuable potential complement to existing wind measuring systems and can provide a low cost addition to powerful active (LIDAR) wind measuring systems now under development.

Facial recognition using multisensor images based on localized kernel eigen spaces.

PubMed

Gundimada, Satyanadh; Asari, Vijayan K

2009-06-01

A feature selection technique along with an information fusion procedure for improving the recognition accuracy of a visual and thermal image-based facial recognition system is presented in this paper. A novel modular kernel eigenspaces approach is developed and implemented on the phase congruency feature maps extracted from the visual and thermal images individually. Smaller sub-regions from a predefined neighborhood within the phase congruency images of the training samples are merged to obtain a large set of features. These features are then projected into higher dimensional spaces using kernel methods. The proposed localized nonlinear feature selection procedure helps to overcome the bottlenecks of illumination variations, partial occlusions, expression variations and variations due to temperature changes that affect the visual and thermal face recognition techniques. AR and Equinox databases are used for experimentation and evaluation of the proposed technique. The proposed feature selection procedure has greatly improved the recognition accuracy for both the visual and thermal images when compared to conventional techniques. Also, a decision level fusion methodology is presented which along with the feature selection procedure has outperformed various other face recognition techniques in terms of recognition accuracy.

Equivalent reduced model technique development for nonlinear system dynamic response

NASA Astrophysics Data System (ADS)

Thibault, Louis; Avitabile, Peter; Foley, Jason; Wolfson, Janet

2013-04-01

The dynamic response of structural systems commonly involves nonlinear effects. Often times, structural systems are made up of several components, whose individual behavior is essentially linear compared to the total assembled system. However, the assembly of linear components using highly nonlinear connection elements or contact regions causes the entire system to become nonlinear. Conventional transient nonlinear integration of the equations of motion can be extremely computationally intensive, especially when the finite element models describing the components are very large and detailed. In this work, the equivalent reduced model technique (ERMT) is developed to address complicated nonlinear contact problems. ERMT utilizes a highly accurate model reduction scheme, the System equivalent reduction expansion process (SEREP). Extremely reduced order models that provide dynamic characteristics of linear components, which are interconnected with highly nonlinear connection elements, are formulated with SEREP for the dynamic response evaluation using direct integration techniques. The full-space solution will be compared to the response obtained using drastically reduced models to make evident the usefulness of the technique for a variety of analytical cases.

Local Guided Wavefield Analysis for Characterization of Delaminations in Composites

NASA Technical Reports Server (NTRS)

Rogge, Matthew D.; Campbell Leckey, Cara A.

2012-01-01

Delaminations in composite laminates resulting from impact events may be accompanied by minimal indication of damage at the surface. As such, inspection techniques are required to ensure defects are within allowable limits. Conventional ultrasonic scanning techniques have been shown to effectively characterize the size and depth of delaminations but require physical contact with the structure. Alternatively, a noncontact scanning laser vibrometer may be used to measure guided wave propagation in the laminate structure. A local Fourier domain analysis method is presented for processing guided wavefield data to estimate spatially-dependent wavenumber values, which can be used to determine delamination depth. The technique is applied to simulated wavefields and results are analyzed to determine limitations of the technique with regards to determining defect size and depth. Finally, experimental wavefield data obtained in quasi-isotropic carbon fiber reinforced polymer (CFRP) laminates with impact damage is analyzed and wavenumber is measured to an accuracy of 8.5% in the region of shallow delaminations. Keywords: Ultrasonic wavefield imaging, Windowed Fourier transforms, Guided waves, Structural health monitoring, Nondestructive evaluation

Analysis of endodontist posture utilizing cinemetry, surface electromyography and ergonomic checklists.

PubMed

Onety, Geraldo Celso da Silva; Leonel, Daniel Vilela; Saquy, Paulo César; Silva, Gabriel Pádua da; Ferreira, Bruno; Varise, Tiago Gilioli; Sousa, Luiz Gustavo de; Verri, Edson Donizetti; Siéssere, Selma; Semprini, Marisa; Nepomuceno, Victor Rodrigues; Regalo, Simone Cecilio Hallak

2014-01-01

The postural risk factors for dentists include the ease of vision in the workplace, cold, vibration and mechanical pressure in tissues, incorrect posture, functional fixity, cognitive requirements and work-related organizational and psychosocial factors. The objective was to analyze the posture of endodontists at the workplace. Eighteen right-handed endodontists aged 25 to 60 years (34±3) participated in the study. Electromyography, kinemetry, ergonomic scales (RULA and Couto's checklist) and biophotogrammetry were used to analyze the posture of endodontists during root canal treatment of the maxillary right first and second molars using rotary and manual instrumentation. The variations observed in the electromyographic activities during the performance of rotary and manual techniques suggest that the fibers of the longissimus region, anterior and medium deltoid, medium trapezium, biceps, triceps brachii, brachioradialis and short thumb abductor muscles underwent adaptations to provide more accurate functional movements. Computerized kinemetry and biophotogrammetry showed that, as far as posture is concerned, rotary technique was more demanding than the manual technique. In conclusion, the group of endodontists evaluated in this study exhibited posture disorders regardless of whether the rotary or manual technique was used.

Techniques for High Contrast Imaging in Multi-Star Systems II: Multi-Star Wavefront Control

NASA Technical Reports Server (NTRS)

Sirbu, D.; Thomas, S.; Belikov, R.

2017-01-01

Direct imaging of exoplanets represents a challenge for astronomical instrumentation due to the high-contrast ratio and small angular separation between the host star and the faint planet. Multi-star systems pose additional challenges for coronagraphic instruments because of the diffraction and aberration leakage introduced by the additional stars, and as a result are not planned to be on direct imaging target lists. Multi-star wavefront control (MSWC) is a technique that uses a coronagraphic instrument's deformable mirror (DM) to create high-contrast regions in the focal plane in the presence of multiple stars. Our previous paper introduced the Super-Nyquist Wavefront Control (SNWC) technique that uses a diffraction grating to enable the DM to generate high-contrast regions beyond the nominal controllable region. These two techniques can be combined to generate high-contrast regions for multi-star systems at any angular separations. As a case study, a high-contrast wavefront control (WC) simulation that applies these techniques shows that the habitable region of the Alpha Centauri system can be imaged reaching 8 times 10(exp -9) mean contrast in 10 percent broadband light in one-sided dark holes from 1.6-5.5 lambda (wavelength) divided by D (distance).

Optoacoustic Imaging Detects Hormone-Related Physiological Changes of Breast Parenchyma.

PubMed

Abeyakoon, Oshaani; Morscher, Stefan; Dalhaus, Nina; Ford, Steven J; Mendichovszky, Iosif A; Manavaki, Roido; Wallis, Matthew; Moyle, Penelope; Woitek, Ramona; Patterson, Andrew; Torheim, Turid; Joseph, James; Gonzalez, Isabel Quiros; Bohndiek, Sarah; Gilbert, Fiona J

2018-06-07

 Optoacoustic imaging with ultrasound (OPUS) can assess in-vivo perfusion/oxygenation through surrogate measures of oxy, deoxy and total hemoglobin content in tissues. The primary aim of our study was to evaluate the ability of OPUS to detect physiological changes in the breast during the menstrual cycle and to determine qualitative/quantitative metrics of normal parenchymal tissue in pre-/post-menopausal women. The secondary aim was to assess the technique's repeatability.  We performed a prospective ethically approved study in volunteers using OPUS (700, 800 and 850 nm wavelengths) in the proliferative/follicular and secretory phase of the menstrual cycle. Regions of interest (ROIs) were drawn on the most superficial region of fibroglandular tissue and same-day intra-observer repeatability was assessed. We used t-tests to interrogate differences in the OPUS measurements due to hormonal changes and interclass correlation coefficients/Bland-Altman plots to evaluate the repeatability of mean ROI signal intensities.  22 pre-menopausal and 8 post-menopausal volunteers were recruited. 21 participants underwent repeatability examinations. OPUS intensity values were significantly higher (p < 0.0001) at all excitation wavelengths in the secretory compared to the proliferative/follicular phase. Post-menopausal volunteers showed similar optoacoustic values to the proliferative/follicular phase of pre-menopausal volunteers. The repeatability of the technique was comparable to other handheld ultrasound modalities.  OPUS detects changes in perfusion/vascularity related to the menstrual cycle and menopausal status of breast parenchyma. © Georg Thieme Verlag KG Stuttgart · New York.

Molecular cytogenetic analysis of Xq critical regions in premature ovarian failure

PubMed Central

2013-01-01

Background One of the frequent reasons for unsuccessful conception is premature ovarian failure/primary ovarian insufficiency (POF/POI) that is defined as the loss of functional follicles below the age of 40 years. Among the genetic causes the most common one involves the X chromosome, as in Turner syndrome, partial X deletion and X-autosome translocations. Here we report a case of a 27-year-old female patient referred to genetic counselling because of premature ovarian failure. The aim of this case study to perform molecular genetic and cytogenetic analyses in order to identify the exact genetic background of the pathogenic phenotype. Results For premature ovarian failure disease diagnostics we performed the Fragile mental retardation 1 gene analysis using Southern blot technique and Repeat Primed PCR in order to identify the relationship between the Fragile mental retardation 1 gene premutation status and the premature ovarion failure disease. At this early onset, the premature ovarian failure affected patient we detected one normal allele of Fragile mental retardation 1 gene and we couldn’t verify the methylated allele, therefore we performed the cytogenetic analyses using G-banding and fluorescent in situ hybridization methods and a high resolution molecular cytogenetic method, the array comparative genomic hybridization technique. For this patient applying the G-banding, we identified a large deletion on the X chromosome at the critical region (ChrX q21.31-q28) which is associated with the premature ovarian failure phenotype. In order to detect the exact breakpoints, we used a special cytogenetic array ISCA plus CGH array and we verified a 67.355 Mb size loss at the critical region which include total 795 genes. Conclusions We conclude for this case study that the karyotyping is definitely helpful in the evaluation of premature ovarian failure patients, to identify the non submicroscopic chromosomal rearrangement, and using the array CGH technique we can contribute to the most efficient detection and mapping of exact deletion breakpoints of the deleted Xq region. PMID:24359613

New insights into lung diseases using hyperpolarized gas MRI.

PubMed

Flors, L; Altes, T A; Mugler, J P; de Lange, E E; Miller, G W; Mata, J F; Ruset, I C; Hersman, F W

2015-01-01

Hyperpolarized (HP) gases are a new class of contrast agents that permit to obtain high temporal and spatial resolution magnetic resonance images (MRI) of the lung airspaces. HP gas MRI has become important research tool not only for morphological and functional evaluation of normal pulmonary physiology but also for regional quantification of pathologic changes occurring in several lung diseases. The purpose of this work is to provide an introduction to MRI using HP noble gases, describing both the basic principles of the technique and the new information about lung disease provided by clinical studies with this method. The applications of the technique in normal subjects, smoking related lung disease, asthma, and cystic fibrosis are reviewed. Copyright © 2014 SERAM. Published by Elsevier España, S.L.U. All rights reserved.