Production and delivery of a fluid mixture to an annular volume of a wellbore

DOEpatents

Hermes, Robert E [Los Alamos, NM; Bland, Ronald Gene [Houston, TX; Foley, Ron Lee [Magnolia, TX; Bloys, James B [Katy, TX; Gonzalez, Manuel E [Kingwood, NM; Daniel, John M [Germantown, TN; Robinson, Ian M [Guisborough, GB; Carpenter, Robert B [Tomball, TX

2012-01-24

The methods described herein generally relate to preparing and delivering a fluid mixture to a confined volume, specifically an annular volume located between two concentrically oriented casing strings within a hydrocarbon fluid producing well. The fluid mixtures disclosed herein are useful in controlling pressure in localized volumes. The fluid mixtures comprise at least one polymerizable monomer and at least one inhibitor. The processes and methods disclosed herein allow the fluid mixture to be stored, shipped and/or injected into localized volumes, for example, an annular volume defined by concentric well casing strings.

Measuring the volume of uterine fibroids using 2- and 3-dimensional ultrasound and comparison with histopathology.

PubMed

Zivković, Nikica; Zivković, Kreiimir; Despot, Albert; Paić, Josip; Zelić, Ana

2012-12-01

The aim of this study was clinical testing of the reliability and usability of three-dimensional (3D) and two-dimensional (2D) ultrasound (US) technology. The ultimate aim and purpose of this study was to establish ultrasound methods, standards and protocols for determining the volume of any gynecologic organ or tumor. The study included 31 women in reproductive age and postmenopause. All patients were examined with a RIC 5-9 3D-endovaginal probe (4.3-7.5 MHz) on a Voluson 730 Pro ultrasound device. The volume of myomas was measured by using the existing 2D and 3D ultrasound methods on the above mentioned device. All patients underwent myomectomy or hysterectomy due to clinically and ultrasonographically diagnosed uterine myomas indicating operative intervention. After the operation, the pathologist determined the volume of removed myomas by measuring them in a gauge bowl containing water, i.e. using Archimedes' principle (lift), serving as the control group with histopathologic diagnosis. A total of 155 myoma volumes were processed on 2D display, 31 myoma volumes were preoperatively measured on 3D display and 31 myoma volumes were measured by the pathologist. The values of US measurements for each US method were expressed as mean value of all measurements of myoma volumes. Statistical processing of the results and Student's t-test for independent samples revealed that the 2nd examined US method (measuring of myoma by using an ellipse and the longer tumor diameter) and 4th examined US method (measuring of myoma by using the longer and shorter tumor diameters together with establishing their mean values) in 2D US technique, as well as the 6th examined US method in 3D US technique showed no significant measurement differences in comparison with control measurement in a gauge bowl containing water (p < 0.05), indicating acceptability of the US methods for verifying tumor volumes. The standard error in determining the volume of myomas by the above US methods varied between 15% and 25%, so it is concluded that these three methods can be used in clinical practice to determine tumor volumes, in this case uterine myomas. The 3D MultiPlane method proved to be the most reliable method of determining the volume of uterine myomas.

Biases in measuring the brain: the trouble with the telencephalon.

PubMed

LaDage, Lara D; Roth, Timothy C; Pravosudov, Vladimir V

2009-01-01

When correlating behavior with particular brain regions thought responsible for the behavior, a different region of the brain is usually measured as a control region. This technique is often used to relate spatial processes with the hippocampus, while concomitantly controlling for overall brain changes by measuring the remainder of the telencephalon. We have identified two methods in the literature (the HOM and TTM) that estimate the volume of the telencephalon, although the majority of studies are ambiguous regarding the method employed in measuring the telencephalon. Of these two methods, the HOM might produce an artificial correlation between the telencephalon and the hippocampus, and this bias could result in a significant overestimation of the relative hippocampal volume and a significant underestimation of the telencephalon volume, both of which are regularly used in large comparative analyses. We suggest that future studies should avoid this method and all studies should explicitly delineate the procedures used when estimating brain volumes. Copyright 2009 S. Karger AG, Basel.

Microfluidic devices for the controlled manipulation of small volumes

DOEpatents

Ramsey, J Michael [Knoxville, TN; Jacobson, Stephen C [Knoxville, TN

2003-02-25

A method for conducting a broad range of biochemical analyses or manipulations on a series of nano- to subnanoliter reaction volumes and an apparatus for carrying out the same are disclosed. The method and apparatus are implemented on a fluidic microchip to provide high serial throughput. The method and device of the invention also lend themselves to multiple parallel analyses and manipulation to provide greater throughput for the generation of biochemical information. In particular, the disclosed device is a microfabricated channel device that can manipulate nanoliter or subnanoliter biochemical reaction volumes in a controlled manner to produce results at rates of 1 to 10 Hz per channel. The individual reaction volumes are manipulated in serial fashion analogous to a digital shift register. The method and apparatus according to this invention have application to such problems as screening molecular or cellular targets using single beads from split-synthesis combinatorial libraries, screening single cells for RNA or protein expression, genetic diagnostic screening at the single cell level, or performing single cell signal transduction studies.

Evaluation of innovative devices to control traffic entering from low-volume access points within a land closure.

DOT National Transportation Integrated Search

2014-04-01

This report describes the methodology and results of analyses performed to identify and evaluate : alternative methods to control traffic entering a lane closure on a two-lane, two-way road from low-volume : access points. Researchers documented the ...

Model-based flow rate control for an orfice-type low-volume air sampler

USDA-ARS?s Scientific Manuscript database

The standard method of measuring air suspended particulate matter concentration per volume of air consists of continuously drawing a defined volume of air across a filter over an extended period of time, then measuring the mass of the filtered particles and dividing it by the total volume sampled ov...

CADDIS Volume 4. Data Analysis: Advanced Analyses - Controlling for Natural Variability

EPA Pesticide Factsheets

Methods for controlling natural variability, predicting environmental conditions from biological observations method, biological trait data, species sensitivity distributions, propensity scores, Advanced Analyses of Data Analysis references.

Assessment of the Derivative-Moment Transformation method for unsteady-load estimation

NASA Astrophysics Data System (ADS)

Mohebbian, Ali; Rival, David

2011-11-01

It is often difficult, if not impossible, to measure the aerodynamic or hydrodynamic forces on a moving body. For this reason, a classical control-volume technique is typically applied to extract the unsteady forces instead. However, measuring the acceleration term within the volume of interest using PIV can be limited by optical access, reflections as well as shadows. Therefore in this study an alternative approach, termed the Derivative-Moment Transformation (DMT) method, is introduced and tested on a synthetic data set produced using numerical simulations. The test case involves the unsteady loading of a flat plate in a two-dimensional, laminar periodic gust. The results suggest that the DMT method can accurately predict the acceleration term so long as appropriate spatial and temporal resolutions are maintained. The major deficiency was found to be the determination of pressure in the wake. The effect of control-volume size was investigated suggesting that smaller domains work best by minimizing the associated error with the pressure field. When increasing the control-volume size, the number of calculations necessary for the pressure-gradient integration increases, in turn substantially increasing the error propagation.

Decreased frontal white-matter volume in chronic substance abuse.

PubMed

Schlaepfer, Thomas E; Lancaster, Eric; Heidbreder, Rebecca; Strain, Eric C; Kosel, Markus; Fisch, Hans-Ulrich; Pearlson, Godfrey D

2006-04-01

There is quite a body of work assessing functional brain changes in chronic substance abuse, much less is known about structural brain abnormalities in this patient population. In this study we used magnetic resonance imaging (MRI) to determine if structural brain differences exist in patients abusing illicit drugs compared to healthy controls. Sixteen substance abusers who abused heroin, cocaine and cannabis but not alcohol and 16 age-, sex- and race-matched controls were imaged on a MRI scanner. Contiguous, 5-mm-thick axial slices were acquired with simultaneous T2 and proton density sequences. Volumes were estimated for total grey and white matter, frontal grey and white matter, ventricles, and CSF using two different methods: a conventional segmentation and a stereological method based on the Cavalieri principle. Overall brain volume differences were corrected for by expressing the volumes of interest as a percentage of total brain volume. Volume measures obtained with the two methods were highly correlated (r=0.65, p<0.001). Substance abusers had significantly less frontal white-matter volume percentage than controls. There were no significant differences in any of the other brain volumes measured. This difference in frontal lobe white matter might be explained by a direct neurotoxic effect of drug use on white matter, a pre-existing abnormality in the development of the frontal lobe or a combination of both effects. This last explanation might be compelling based on the fact that newer concepts on shared aspects of some neuropsychiatric disorders focus on the promotion and inhibition of the process of myelination throughout brain development and subsequent degeneration.

Air Pollution Translations: A Bibliography with Abstracts - Volume 4.

ERIC Educational Resources Information Center

Environmental Protection Agency, Research Triangle Park, NC. Air Pollution Technical Information Center.

This volume is the fourth in a series of compilations presenting abstracts and indexes of translations of technical air pollution literature. The entries are grouped into 12 subject categories: Emission Sources, Control Methods, Measurement Methods, Air Quality Measurements, Atmospheric Interaction, Basic Science and Technology, Effects--Human…

Detection of gas leakage

DOEpatents

Thornberg, Steven [Peralta, NM; Brown, Jason [Albuquerque, NM

2012-06-19

A method of detecting leaks and measuring volumes as well as an apparatus, the Power-free Pump Module (PPM), that is a self-contained leak test and volume measurement apparatus that requires no external sources of electrical power during leak testing or volume measurement, where the invention is a portable, pneumatically-controlled instrument capable of generating a vacuum, calibrating volumes, and performing quantitative leak tests on a closed test system or device, all without the use of alternating current (AC) power. Capabilities include the ability is to provide a modest vacuum (less than 10 Torr), perform a pressure rise leak test, measure the gas's absolute pressure, and perform volume measurements. All operations are performed through a simple rotary control valve which controls pneumatically-operated manifold valves.

Detection of gas leakage

DOEpatents

Thornberg, Steven M; Brown, Jason

2015-02-17

A method of detecting leaks and measuring volumes as well as a device, the Power-free Pump Module (PPM), provides a self-contained leak test and volume measurement apparatus that requires no external sources of electrical power during leak testing or volume measurement. The PPM is a portable, pneumatically-controlled instrument capable of generating a vacuum, calibrating volumes, and performing quantitative leak tests on a closed test system or device, all without the use of alternating current (AC) power. Capabilities include the ability is to provide a modest vacuum (less than 10 Torr) using a venturi pump, perform a pressure rise leak test, measure the gas's absolute pressure, and perform volume measurements. All operations are performed through a simple rotary control valve which controls pneumatically-operated manifold valves.

Control theory based airfoil design for potential flow and a finite volume discretization

NASA Technical Reports Server (NTRS)

Reuther, J.; Jameson, A.

1994-01-01

This paper describes the implementation of optimization techniques based on control theory for airfoil design. In previous studies it was shown that control theory could be used to devise an effective optimization procedure for two-dimensional profiles in which the shape is determined by a conformal transformation from a unit circle, and the control is the mapping function. The goal of our present work is to develop a method which does not depend on conformal mapping, so that it can be extended to treat three-dimensional problems. Therefore, we have developed a method which can address arbitrary geometric shapes through the use of a finite volume method to discretize the potential flow equation. Here the control law serves to provide computationally inexpensive gradient information to a standard numerical optimization method. Results are presented, where both target speed distributions and minimum drag are used as objective functions.

Test functions for three-dimensional control-volume mixed finite-element methods on irregular grids

USGS Publications Warehouse

Naff, R.L.; Russell, T.F.; Wilson, J.D.; ,; ,; ,; ,; ,

2000-01-01

Numerical methods based on unstructured grids, with irregular cells, usually require discrete shape functions to approximate the distribution of quantities across cells. For control-volume mixed finite-element methods, vector shape functions are used to approximate the distribution of velocities across cells and vector test functions are used to minimize the error associated with the numerical approximation scheme. For a logically cubic mesh, the lowest-order shape functions are chosen in a natural way to conserve intercell fluxes that vary linearly in logical space. Vector test functions, while somewhat restricted by the mapping into the logical reference cube, admit a wider class of possibilities. Ideally, an error minimization procedure to select the test function from an acceptable class of candidates would be the best procedure. Lacking such a procedure, we first investigate the effect of possible test functions on the pressure distribution over the control volume; specifically, we look for test functions that allow for the elimination of intermediate pressures on cell faces. From these results, we select three forms for the test function for use in a control-volume mixed method code and subject them to an error analysis for different forms of grid irregularity; errors are reported in terms of the discrete L2 norm of the velocity error. Of these three forms, one appears to produce optimal results for most forms of grid irregularity.

Air Pollution Translations: A Bibliography with Abstracts - Volume 2.

ERIC Educational Resources Information Center

National Air Pollution Control Administration (DHEW), Raleigh, NC.

This volume is the second in a series of compilations presenting abstracts and indexes of translations of technical air pollution literature. The 444 entries are grouped into 12 subject categories: General; Emission Sources; Atmospheric Interaction; Measurement Methods; Control Methods; Effects--Human Health; Effects--Plants and Livestock;…

CADDIS Volume 4. Data Analysis: Advanced Analyses - Controlling for Natural Variability: SSD Plot Diagrams

EPA Pesticide Factsheets

Methods for controlling natural variability, predicting environmental conditions from biological observations method, biological trait data, species sensitivity distributions, propensity scores, Advanced Analyses of Data Analysis references.

Effects of different aerobic exercise programmes with nutritional intervention in sedentary adults with overweight/obesity and hypertension: EXERDIET-HTA study.

PubMed

Gorostegi-Anduaga, Ilargi; Corres, Pablo; MartinezAguirre-Betolaza, Aitor; Pérez-Asenjo, Javier; Aispuru, G Rodrigo; Fryer, Simon M; Maldonado-Martín, Sara

2018-03-01

Background Both exercise training and diet are recommended to prevent and control hypertension and overweight/obesity. Purpose The purpose of this study was to determine the effectiveness of different 16-week aerobic exercise programmes with hypocaloric diet on blood pressure, body composition, cardiorespiratory fitness and pharmacological treatment. Methods Overweight/obese, sedentary participants ( n = 175, aged 54.0 ± 8.2 years) with hypertension were randomly assigned into an attention control group (physical activity recommendations) or one of three supervised exercise groups (2 days/week: high-volume with 45 minutes of moderate-intensity continuous training (MICT), high-volume and high-intensity interval training (HIIT), alternating high and moderate intensities, and low-volume HIIT (20 minutes)). All variables were assessed pre- and post-intervention. All participants received the same hypocaloric diet. Results Following the intervention, there was a significant reduction in blood pressure and body mass in all groups with no between-group differences for blood pressure. However, body mass was significantly less reduced in the attention control group compared with all exercise groups (attention control -6.6%, high-volume MICT -8.3%, high-volume HIIT -9.7%, low-volume HIIT -6.9%). HIIT groups had significantly higher cardiorespiratory fitness than high-volume MICT, but there were no significant between-HIIT differences (attention control 16.4%, high-volume MICT 23.6%, high-volume HIIT 36.7%, low-volume HIIT 30.5%). Medication was removed in 7.6% and reduced in 37.7% of the participants. Conclusions The combination of hypocaloric diet with supervised aerobic exercise 2 days/week offers an optimal non-pharmacological tool in the management of blood pressure, cardiorespiratory fitness and body composition in overweight/obese and sedentary individuals with hypertension. High-volume HIIT seems to be better for reducing body mass compared with low-volume HIIT. The exercise-induced improvement in cardiorespiratory fitness is intensity dependent with low-volume HIIT as a time-efficient method in this population. ClinicalTrials.gov Registration: NCT02283047.

Brain volumes in psychotic youth with schizophrenia and mood disorders

PubMed Central

El-Sayed, Mohamed; Steen, R. Grant; Poe, Michele D.; Bethea, T. Carter; Gerig, Guido; Lieberman, Jeffrey; Sikich, Linmarie

2010-01-01

Background We sought to test the hypothesis that deficits in grey matter volume are characteristic of psychotic youth with early-onset schizophrenia-spectrum disorders (EOSS) but not of psychotic youth with early-onset mood disorders (EOMD). Methods We used magnetic resonance imaging to examine brain volume in 24 psychotic youth (13 male, 11 female) with EOSS (n = 12) or EOMD (n = 12) and 17 healthy controls (10 male, 7 female). We measured the volume of grey and white matter using an automated segmentation program. Results After adjustment for age and intracranial volume, whole brain volume was lower in the EOSS patients than in the healthy controls (p = 0.001) and EOMD patients (p = 0.002). The EOSS patients had a deficit in grey matter volume (p = 0.005), especially in the frontal (p = 0.003) and parietal (p = 0.006) lobes, with no significant differences in white matter volume. Limitations The main limitations of our study were its small sample size and the inclusion of patients with depression and mania in the affective group. Conclusion Adolescents with EOSS have grey matter deficits compared with healthy controls and psychotic adolescents with EOMD. Our results suggest that grey matter deficits are not generally associated with psychosis but may be specifically associated with schizophrenia. Larger studies with consistent methods are needed to reconcile the contradictory findings among imaging studies involving psychotic youth. PMID:20569649

High-throughput controllable generation of droplet arrays with low consumption

NASA Astrophysics Data System (ADS)

Lin, Yinyin; Wu, Zhongsheng; Gao, Yibo; Wu, Jinbo; Wen, Weijia

2018-06-01

We describe a controllable sliding method for fabricating millions of isolated femto- to nanoliter-sized droplets with defined volume, geometry and position and a speed of up to 375 kHz. In this work, without using a superhydrophobic or superoleophobic surface, arrays of droplets are instantly formed on the patterned substrate by sliding a strip of liquid, including water, low-surface-tension organic solvents and solution, along the substrate. To precisely control the volume of the droplets, we systemically investigate the effects of the size of the wettable pattern, the viscosity of the liquid and sliding speed, which were found to vary independently to tune the height and volume of the droplets. Through this method, we successfully fabricated an oriented single metal-organic framework crystal array with control over their XY positioning on the surface, as characterized by microscopy and X-ray diffraction (XRD) techniques.

7 CFR 58.442 - Laboratory and quality control tests.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 3 2010-01-01 2010-01-01 false Laboratory and quality control tests. 58.442 Section... Service 1 Operations and Operating Procedures § 58.442 Laboratory and quality control tests. (a) Chemical... Methods or by other methods giving equivalent results. (b) Weight or volume control. Representative...

7 CFR 58.442 - Laboratory and quality control tests.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 3 2011-01-01 2011-01-01 false Laboratory and quality control tests. 58.442 Section... Service 1 Operations and Operating Procedures § 58.442 Laboratory and quality control tests. (a) Chemical... Methods or by other methods giving equivalent results. (b) Weight or volume control. Representative...

ρ-VOF: An interface sharpening method for gas-liquid flow simulation

NASA Astrophysics Data System (ADS)

Wang, Jiantao; Liu, Gang; Jiang, Xiong; Mou, Bin

2018-05-01

The study on simulation of compressible gas-liquid flow remains open. Popular methods are either confined to incompressible flow regime, or inevitably induce smear of the free interface. A new finite volume method for compressible two-phase flow simulation is contributed for this subject. First, the “heterogeneous equilibrium” assumption is introduced to the control volume, by hiring free interface reconstruction technology, the distribution of each component in the control volume is achieved. Next, AUSM+-up (advection upstream splitting method) scheme is employed to calculate the convective fluxes and pressure fluxes, with the contact discontinuity characteristic considered, followed by the update of the whole flow field. The new method features on density-based pattern and interface reconstruction technology from VOF (volume of fluid), thus we name it “ρ-VOF method”. Inherited from AUSM families and VOF, ρ-VOF behaves as an all-speed method, capable of simulating shock in gas-liquid flow, and preserving the sharpness of the free interface. Gas-liquid shock tube is simulated to evaluate the method, from which good agreement is obtained between the predicted results and those of the cited literature, meanwhile, sharper free interface is identified. Finally, the capability and validity of ρ-VOF method can be concluded in compressible gas-liquid flow simulation.

Converging evidence for abnormalities of the prefrontal cortex and evaluation of midsagittal structures in pediatric PTSD: an MRI study

PubMed Central

Carrion, Victor G.; Weems, Carl F.; Watson, Christa; Eliez, Stephan; Menon, Vinod; Reiss, Allan L.

2009-01-01

Objective Volumetric imaging research has shown abnormal brain morphology in posttraumatic stress disorder (PTSD) when compared to controls. We present results on a study of brain morphology in the prefrontal cortex (PFC) and midline structures, via indices of gray matter volume and density, in pediatric PTSD. We hypothesized that both methods would demonstrate aberrant morphology in the PFC. Further, we hypothesized aberrant brainstem anatomy and reduced corpus collosum volume in children with PTSD. Methods Twenty-four children (aged 7-14) with history of interpersonal trauma and 24 age, and gender matched controls underwent structural magnetic resonance imaging. Images of the PFC and midline brain structures were first analyzed using volumetric image analysis. The PFC data were then compared with whole-brain voxel-based techniques using statistical parametric mapping (SPM). Results The PTSD group showed significant increased gray matter volume in the right and left inferior and superior quadrants of the prefrontal cortex and smaller gray matter volume in pons, and posterior vermis areas by volumetric image analysis. The voxel-byvoxel group comparisons demonstrated increased gray matter density mostly localized to ventral PFC as compared to the control group. Conclusions Abnormal frontal lobe morphology, as revealed by separate-complementary image analysis methods, and reduced pons and posterior vermis areas are associated with pediatric PTSD. Voxel-based morphometry may help to corroborate and further localize data obtained by volume of interest methods in PTSD. PMID:19349151

Calibration of a semi-automated segmenting method for quantification of adipose tissue compartments from magnetic resonance images of mice.

PubMed

Garteiser, Philippe; Doblas, Sabrina; Towner, Rheal A; Griffin, Timothy M

2013-11-01

To use an automated water-suppressed magnetic resonance imaging (MRI) method to objectively assess adipose tissue (AT) volumes in whole body and specific regional body components (subcutaneous, thoracic and peritoneal) of obese and lean mice. Water-suppressed MR images were obtained on a 7T, horizontal-bore MRI system in whole bodies (excluding head) of 26 week old male C57BL6J mice fed a control (10% kcal fat) or high-fat diet (60% kcal fat) for 20 weeks. Manual (outlined regions) versus automated (Gaussian fitting applied to threshold-weighted images) segmentation procedures were compared for whole body AT and regional AT volumes (i.e., subcutaneous, thoracic, and peritoneal). The AT automated segmentation method was compared to dual-energy X-ray (DXA) analysis. The average AT volumes for whole body and individual compartments correlated well between the manual outlining and the automated methods (R2>0.77, p<0.05). Subcutaneous, peritoneal, and total body AT volumes were increased 2-3 fold and thoracic AT volume increased more than 5-fold in diet-induced obese mice versus controls (p<0.05). MRI and DXA-based method comparisons were highly correlative (R2=0.94, p<0.0001). Automated AT segmentation of water-suppressed MRI data using a global Gaussian filtering algorithm resulted in a fairly accurate assessment of total and regional AT volumes in a pre-clinical mouse model of obesity. © 2013 Elsevier Inc. All rights reserved.

One-Dimensional Ablation with Pyrolysis Gas Flow Using a Full Newton's Method and Finite Control Volume Procedure

NASA Technical Reports Server (NTRS)

Amar, Adam J.; Blackwell, Ben F.; Edwards, Jack R.

2007-01-01

The development and verification of a one-dimensional material thermal response code with ablation is presented. The implicit time integrator, control volume finite element spatial discretization, and Newton's method for nonlinear iteration on the entire system of residual equations have been implemented and verified for the thermochemical ablation of internally decomposing materials. This study is a continuation of the work presented in "One-Dimensional Ablation with Pyrolysis Gas Flow Using a Full Newton's Method and Finite Control Volume Procedure" (AIAA-2006-2910), which described the derivation, implementation, and verification of the constant density solid energy equation terms and boundary conditions. The present study extends the model to decomposing materials including decomposition kinetics, pyrolysis gas flow through the porous char layer, and a mixture (solid and gas) energy equation. Verification results are presented for the thermochemical ablation of a carbon-phenolic ablator which involves the solution of the entire system of governing equations.

Higher order solution of the Euler equations on unstructured grids using quadratic reconstruction

NASA Technical Reports Server (NTRS)

Barth, Timothy J.; Frederickson, Paul O.

1990-01-01

High order accurate finite-volume schemes for solving the Euler equations of gasdynamics are developed. Central to the development of these methods are the construction of a k-exact reconstruction operator given cell-averaged quantities and the use of high order flux quadrature formulas. General polygonal control volumes (with curved boundary edges) are considered. The formulations presented make no explicit assumption as to complexity or convexity of control volumes. Numerical examples are presented for Ringleb flow to validate the methodology.

Semiautomatic regional segmentation to measure orbital fat volumes in thyroid-associated ophthalmopathy. A validation study.

PubMed

Comerci, M; Elefante, A; Strianese, D; Senese, R; Bonavolontà, P; Alfano, B; Bonavolontà, B; Brunetti, A

2013-08-01

This study was designed to validate a novel semi-automated segmentation method to measure regional intra-orbital fat tissue volume in Graves' ophthalmopathy. Twenty-four orbits from 12 patients with Graves' ophthalmopathy, 24 orbits from 12 controls, ten orbits from five MRI study simulations and two orbits from a digital model were used. Following manual region of interest definition of the orbital volumes performed by two operators with different levels of expertise, an automated procedure calculated intra-orbital fat tissue volumes (global and regional, with automated definition of four quadrants). In patients with Graves' disease, clinical activity score and degree of exophthalmos were measured and correlated with intra-orbital fat volumes. Operator performance was evaluated and statistical analysis of the measurements was performed. Accurate intra-orbital fat volume measurements were obtained with coefficients of variation below 5%. The mean operator difference in total fat volume measurements was 0.56%. Patients had significantly higher intra-orbital fat volumes than controls (p<0.001 using Student's t test). Fat volumes and clinical score were significantly correlated (p<0.001). The semi-automated method described here can provide accurate, reproducible intra-orbital fat measurements with low inter-operator variation and good correlation with clinical data.

System for detecting operating errors in a variable valve timing engine using pressure sensors

DOEpatents

Wiles, Matthew A.; Marriot, Craig D

2013-07-02

A method and control module includes a pressure sensor data comparison module that compares measured pressure volume signal segments to ideal pressure volume segments. A valve actuation hardware remedy module performs a hardware remedy in response to comparing the measured pressure volume signal segments to the ideal pressure volume segments when a valve actuation hardware failure is detected.

Pain and efficacy rating of a microprocessor-controlled metered injection system for local anaesthesia in minor hand surgery.

PubMed

Nimigan, André S; Gan, Bing Siang

2011-01-01

Purpose. Little attention has been given to syringe design and local anaesthetic administration methods. A microprocessor-controlled anaesthetic delivery device has become available that may minimize discomfort during injection. The purpose of this study was to document the pain experience associated with the use of this system and to compare it with use of a conventional syringe. Methods. A prospective, randomized clinical trial was designed. 40 patients undergoing carpal tunnel release were block randomized according to sex into a two groups: a traditional syringe group and a microprocessor-controlled device group. The primary outcome measure was surgical pain and local anaesthetic administration pain. Secondary outcomes included volume of anaesthetic used and injection time. Results. Analysis showed that equivalent anaesthesia was achieved in the microprocessor-controlled group despite using a significantly lower volume of local anaesthetic (P = .0002). This same group, however, has significantly longer injection times (P < .0001). Pain during the injection process or during surgery was not different between the two groups. Conclusions. This RCT comparing traditional and microprocessor controlled methods of administering local anaesthetic showed similar levels of discomfort in both groups. While the microprocessor-controlled group used less volume, the total time for the administration was significantly greater.

Adaptive control with self-tuning for non-invasive beat-by-beat blood pressure measurement.

PubMed

Nogawa, Masamichi; Ogawa, Mitsuhiro; Yamakoshi, Takehiro; Tanaka, Shinobu; Yamakoshi, Ken-ichi

2011-01-01

Up to now, we have successfully carried out the non-invasive beat-by-beat measurement of blood pressure (BP) in the root of finger, superficial temporal and radial artery based on the volume-compensation technique with reasonable accuracy. The present study concerns with improvement of control method for this beat-by-beat BP measurement. The measurement system mainly consists of a partial pressurization cuff with a pair of LED and photo-diode for the detection of arterial blood volume, and a digital self-tuning control method. Using healthy subjects, the performance and accuracy of this system were evaluated through comparison experiments with the system using a conventional empirically tuned PID controller. The significant differences of BP measured in finger artery were not showed in systolic (SBP), p=0.52, and diastolic BP (DBP), p=0.35. With the advantage of the adaptive control with self-tuning method, which can tune the control parameters without disturbing the control system, the application area of the non-invasive beat-by-beat measurement method will be broadened.

[Compatible biomass models of natural spruce (Picea asperata)].

PubMed

Wang, Jin Chi; Deng, Hua Feng; Huang, Guo Sheng; Wang, Xue Jun; Zhang, Lu

2017-10-01

By using nonlinear measurement error method, the compatible tree volume and above ground biomass equations were established based on the volume and biomass data of 150 sampling trees of natural spruce (Picea asperata). Two approaches, controlling directly under total aboveground biomass and controlling jointly from level to level, were used to design the compatible system for the total aboveground biomass and the biomass of four components (stem, bark, branch and foliage), and the total ground biomass could be estimated independently or estimated simultaneously in the system. The results showed that the R 2 of the one variable and bivariate compatible tree volume and aboveground biomass equations were all above 0.85, and the maximum value reached 0.99. The prediction effect of the volume equations could be improved significantly when tree height was included as predictor, while it was not significant in biomass estimation. For the compatible biomass systems, the one variable model based on controlling jointly from level to level was better than the model using controlling directly under total above ground biomass, but the bivariate models of the two methods were similar. Comparing the imitative effects of the one variable and bivariate compatible biomass models, the results showed that the increase of explainable variables could significantly improve the fitness of branch and foliage biomass, but had little effect on other components. Besides, there was almost no difference between the two methods of estimation based on the comparison.

Entomology for Agricultural Science II Core Curriculum. Instructor Guide, Volume 23, Number 2, and Student Reference, Volume 23, Number 3.

ERIC Educational Resources Information Center

DeFelice, Karen L.

This unit is a basic introduction to entomology. The instructor guide and the corresponding student reference contain seven lessons: (1) introduction to entomology; (2) insect collection; (3) insect identification; (4) methods of control; (5) chemical control measures; (6) safe use of insecticides; and (7) integrated pest management. Students…

Regional gray matter volumetric changes in autism associated with social and repetitive behavior symptoms

PubMed Central

Rojas, Donald C; Peterson, Eric; Winterrowd, Erin; Reite, Martin L; Rogers, Sally J; Tregellas, Jason R

2006-01-01

Background Although differences in brain anatomy in autism have been difficult to replicate using manual tracing methods, automated whole brain analyses have begun to find consistent differences in regions of the brain associated with the social cognitive processes that are often impaired in autism. We attempted to replicate these whole brain studies and to correlate regional volume changes with several autism symptom measures. Methods We performed MRI scans on 24 individuals diagnosed with DSM-IV autistic disorder and compared those to scans from 23 healthy comparison subjects matched on age. All participants were male. Whole brain, voxel-wise analyses of regional gray matter volume were conducted using voxel-based morphometry (VBM). Results Controlling for age and total gray matter volume, the volumes of the medial frontal gyri, left pre-central gyrus, right post-central gyrus, right fusiform gyrus, caudate nuclei and the left hippocampus were larger in the autism group relative to controls. Regions exhibiting smaller volumes in the autism group were observed exclusively in the cerebellum. Significant partial correlations were found between the volumes of the caudate nuclei, multiple frontal and temporal regions, the cerebellum and a measure of repetitive behaviors, controlling for total gray matter volume. Social and communication deficits in autism were also associated with caudate, cerebellar, and precuneus volumes, as well as with frontal and temporal lobe regional volumes. Conclusion Gray matter enlargement was observed in areas that have been functionally identified as important in social-cognitive processes, such as the medial frontal gyri, sensorimotor cortex and middle temporal gyrus. Additionally, we have shown that VBM is sensitive to associations between social and repetitive behaviors and regional brain volumes in autism. PMID:17166273

Use of the Electronic Medical Record to Assess Pancreas Size in Type 1 Diabetes

PubMed Central

Virostko, John; Hilmes, Melissa; Eitel, Kelsey; Moore, Daniel J.; Powers, Alvin C.

2016-01-01

Aims This study harnessed the electronic medical record to assess pancreas volume in patients with type 1 diabetes (T1D) and matched controls to determine whether pancreas volume is altered in T1D and identify covariates that influence pancreas volume. Methods This study included 25 patients with T1D and 25 age-, sex-, and weight-matched controls from the Vanderbilt University Medical Center enterprise data warehouse. Measurements of pancreas volume were made from medical imaging studies using magnetic resonance imaging (MRI) or computed tomography (CT). Results Patients with T1D had a pancreas volume 47% smaller than matched controls (41.16 ml vs. 77.77 ml, P < 0.0001) as well as pancreas volume normalized by subject body weight, body mass index, or body surface area (all P < 0.0001). Pancreatic volume was smaller with a longer duration of T1D across the patient population (N = 25, P = 0.04). Additionally, four individual patients receiving multiple imaging scans displayed progressive declines in pancreas volume over time (~ 6% of volume/year), whereas five controls scanned a year apart did not exhibit a decline in pancreas size (P = 0.03). The pancreas was uniformly smaller on the right and left side of the abdomen. Conclusions Pancreas volume declines with disease duration in patients with T1D, suggesting a protracted pathological process that may include the exocrine pancreas. PMID:27391588

Tailoring nanocrystalline diamond film properties

DOEpatents

Gruen, Dieter M [Downers Grove, IL; McCauley, Thomas G [Somerville, MA; Zhou, Dan [Orlando, FL; Krauss, Alan R [Naperville, IL

2003-07-15

A method for controlling the crystallite size and growth rate of plasma-deposited diamond films. A plasma is established at a pressure in excess of about 55 Torr with controlled concentrations of hydrogen up to about 98% by volume, of unsubstituted hydrocarbons up to about 3% by volume and an inert gas of one or more of the noble gases and nitrogen up to about 98% by volume. The volume ratio of inert gas to hydrogen is preferably maintained at greater than about 4, to deposit a diamond film on a suitable substrate. The diamond film is deposited with a predetermined crystallite size and at a predetermined growth rate.

The effects of erythrocyte deformability upon hematocrit assessed by the conductance method.

PubMed

Hayashi, Yoshihito; Katsumoto, Yoichi; Oshige, Ikuya; Omori, Shinji; Yasuda, Akio; Asami, Koji

2009-04-21

A comparative study of centrifugation and conductance methods for the estimation of cell volume fraction (phi) was performed to examine whether the strong forces exerted upon erythrocytes during centrifugation affect their volume, and the results are discussed in terms of erythrocyte deformability. Rabbit erythrocytes of four shapes (spherocytes, echinocytes, stomatocyte-like enlarged erythrocytes and discocytes) were prepared by controlling the pH of the suspending media. The packed cell volumes of the suspensions were measured by standard hematocrit determination methods using centrifugation in capillary tubes. Simultaneously, the same suspensions and their supernatants were used in dielectric spectroscopy measurements, and the low-frequency limits of their conductivities were used for the numerical estimation of phi. The hematocrit values of spherocytes and echinocytes were markedly less than the volume fractions obtained by the conductance method. Namely, the centrifugation reduced the cell volume. For enlarged erythrocytes and discocytes, however, the reduction of cell volume was not observed. These findings showed that phi obtained by the centrifugation method can be greatly affected by the deformability of the cells, but the level of the effect depends on the cell types. Consequently, phi obtained by the centrifugation method should be carefully interpreted.

Ceramic transactions - Materials processing and design: Grain-boundary-controlled properties of fine ceramics II. Volume 44

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

Niihara, Koichi; Ishizaki, Kozo; Isotani, Mitsuo

This volume contains selected papers presented at a workshop by the Japan Fine Ceramics Center, `Materials Processing and Design Through Better Control of Grain Boundaries: Emphasizing Fine Ceramics II,` which was held March 17-19, 1994, in Koda-cho, Aichi, Japan. The focus of the workshop was the application of grain boundary phenomena to materials processing and design. The topics covered included electronic materials, evaluation methods, structural materials, and interfaces. Also included is an illuminating overview of the current status of work on grain boundary assisted materials processing and design, particularly for fine ceramics. The volume`s chapter titles are: Electron Microscopy, Evaluation,more » Grain Boundary Control and Design, Functional Ceramics, Composite Materials, Synthesis and Sintering, and Mechanical Properties.« less

Low current plasmatron fuel converter having enlarged volume discharges

DOEpatents

Rabinovich, Alexander; Alexeev, Nikolai; Bromberg, Leslie; Cohn, Daniel R.; Samokhin, Andrei

2005-04-19

A novel apparatus and method is disclosed for a plasmatron fuel converter (""plasmatron"") that efficiently uses electrical energy to produce hydrogen rich gas. The volume and shape of the plasma discharge is controlled by a fluid flow established in a plasma discharge volume. A plasmatron according to this invention produces a substantially large effective plasma discharge volume allowing for substantially greater volumetric efficiency in the initiation of chemical reactions within a volume of bulk fluid reactant flowing through the plasmatron.

Low current plasmatron fuel converter having enlarged volume discharges

DOEpatents

Rabinovich, Alexander [Swampscott, MA; Alexeev, Nikolai [Moscow, RU; Bromberg, Leslie [Sharon, MA; Cohn, Daniel R [Chestnut Hill, MA; Samokhin, Andrei [Moscow, RU

2009-10-06

A novel apparatus and method is disclosed for a plasmatron fuel converter ("plasmatron") that efficiently uses electrical energy to produce hydrogen rich gas. The volume and shape of the plasma discharge is controlled by a fluid flow established in a plasma discharge volume. A plasmatron according to this invention produces a substantially large effective plasma discharge volume allowing for substantially greater volumetric efficiency in the initiation of chemical reactions within a volume of bulk fluid reactant flowing through the plasmatron.

Stratal Control Volumes and Stratal Control Trajectories: A New Method to Constrain, Understand and Reconcile Results from Stratigraphic Outcrop Analysis, Subsurface Analysis and Analogue and Numerical Modelling

NASA Astrophysics Data System (ADS)

Burgess, P. M.; Steel, R. J.

2016-12-01

Decoding a history of Earth's surface dynamics from strata requires robust quantitative understanding of supply and accommodation controls. The concept of stratigraphic solution sets has proven useful in this decoding, but application and development of this approach has so far been surprisingly limited. Stratal control volumes, areas and trajectories are new approaches defined here, building on previous ideas about stratigraphic solution sets, to help analyse and understand the sedimentary record of Earth surface dynamics. They may have particular application reconciling results from outcrop and subsurface analysis with results from analogue and numerical experiments. Stratal control volumes are sets of points in a three-dimensional volume, with axes of subsidence, sediment supply and eustatic rates of change, populated with probabilities derived from analysis of subsidence, supply and eustasy timeseries (Figure 1). These empirical probabilities indicate the likelihood of occurrence of any particular combination of control rates defined by any point in the volume. The stratal control volume can then by analysed to determine which parts of the volume represent relative sea-level fall and rise, where in the volume particular stacking patterns will occur, and how probable those stacking patterns are. For outcrop and subsurface analysis, using a stratal control area with eustasy and subsidence combined on a relative sea-level axis allows similar analysis, and may be preferable. A stratal control trajectory is a history of supply and accommodation creation rates, interpreted from outcrop or subsurface data, or observed in analogue and numerical experiments, and plotted as a series of linked points forming a trajectory through the stratal control volume (Figure 1) or area. Three examples are presented, one from outcrop and two theoretical. Much work remains to be done to build a properly representative database of stratal controls, but careful comparison of stratal control volume and trajectories constructed from outcrop analysis, subsurface analysis and experimental models may help the convergence, reconciliation and future evolution of these different approaches.

Gas permeability measurements for film envelope materials

DOEpatents

Ludtka, G.M.; Kollie, T.G.; Watkin, D.C.; Walton, D.G.

1998-05-12

Method and apparatus for measuring the permeability of polymer film materials such as used in super-insulation powder-filled evacuated panels (PEPs) reduce the time required for testing from several years to weeks or months. The method involves substitution of a solid non-outgassing body having a free volume of between 0% and 25% of its total volume for the usual powder in the PEP to control the free volume of the ``body-filled panel.`` Pressure versus time data for the test piece permit extrapolation to obtain long term performance of the candidate materials. 4 figs.

Gas permeability measurements for film envelope materials

DOEpatents

Ludtka, Gerard M.; Kollie, Thomas G.; Watkin, David C.; Walton, David G.

1998-01-01

Method and apparatus for measuring the permeability of polymer film materials such as used in super-insulation powder-filled evacuated panels (PEPs) reduce the time required for testing from several years to weeks or months. The method involves substitution of a solid non-outgassing body having a free volume of between 0% and 25% of its total volume for the usual powder in the PEP to control the free volume of the "body-filled panel". Pressure versus time data for the test piece permit extrapolation to obtain long term performance of the candidate materials.

Incorporation of Condensation Heat Transfer in a Flow Network Code

NASA Technical Reports Server (NTRS)

Anthony, Miranda; Majumdar, Alok

2002-01-01

Pure water is distilled from waste water in the International Space Station. The distillation assembly consists of an evaporator, a compressor and a condenser. Vapor is periodically purged from the condenser to avoid vapor accumulation. Purged vapor is condensed in a tube by coolant water prior to entering the purge pump. The paper presents a condensation model of purged vapor in a tube. This model is based on the Finite Volume Method. In the Finite Volume Method, the flow domain is discretized into multiple control volumes and a simultaneous analysis is performed.

High correlations between MRI brain volume measurements based on NeuroQuant® and FreeSurfer.

PubMed

Ross, David E; Ochs, Alfred L; Tate, David F; Tokac, Umit; Seabaugh, John; Abildskov, Tracy J; Bigler, Erin D

2018-05-30

NeuroQuant ® (NQ) and FreeSurfer (FS) are commonly used computer-automated programs for measuring MRI brain volume. Previously they were reported to have high intermethod reliabilities but often large intermethod effect size differences. We hypothesized that linear transformations could be used to reduce the large effect sizes. This study was an extension of our previously reported study. We performed NQ and FS brain volume measurements on 60 subjects (including normal controls, patients with traumatic brain injury, and patients with Alzheimer's disease). We used two statistical approaches in parallel to develop methods for transforming FS volumes into NQ volumes: traditional linear regression, and Bayesian linear regression. For both methods, we used regression analyses to develop linear transformations of the FS volumes to make them more similar to the NQ volumes. The FS-to-NQ transformations based on traditional linear regression resulted in effect sizes which were small to moderate. The transformations based on Bayesian linear regression resulted in all effect sizes being trivially small. To our knowledge, this is the first report describing a method for transforming FS to NQ data so as to achieve high reliability and low effect size differences. Machine learning methods like Bayesian regression may be more useful than traditional methods. Copyright © 2018 Elsevier B.V. All rights reserved.

Multiple model predictive control for optimal drug administration of mixed immunotherapy and chemotherapy of tumours.

PubMed

Sharifi, N; Ozgoli, S; Ramezani, A

2017-06-01

Mixed immunotherapy and chemotherapy of tumours is one of the most efficient ways to improve cancer treatment strategies. However, it is important to 'design' an effective treatment programme which can optimize the ways of combining immunotherapy and chemotherapy to diminish their imminent side effects. Control engineering techniques could be used for this. The method of multiple model predictive controller (MMPC) is applied to the modified Stepanova model to induce the best combination of drugs scheduling under a better health criteria profile. The proposed MMPC is a feedback scheme that can perform global optimization for both tumour volume and immune competent cell density by performing multiple constraints. Although current studies usually assume that immunotherapy has no side effect, this paper presents a new method of mixed drug administration by employing MMPC, which implements several constraints for chemotherapy and immunotherapy by considering both drug toxicity and autoimmune. With designed controller we need maximum 57% and 28% of full dosage of drugs for chemotherapy and immunotherapy in some instances, respectively. Therefore, through the proposed controller less dosage of drugs are needed, which contribute to suitable results with a perceptible reduction in medicine side effects. It is observed that in the presence of MMPC, the amount of required drugs is minimized, while the tumour volume is reduced. The efficiency of the presented method has been illustrated through simulations, as the system from an initial condition in the malignant region of the state space (macroscopic tumour volume) transfers into the benign region (microscopic tumour volume) in which the immune system can control tumour growth. Copyright © 2017 Elsevier B.V. All rights reserved.

A control-volume method for analysis of unsteady thrust augmenting ejector flows

NASA Technical Reports Server (NTRS)

Drummond, Colin K.

1988-01-01

A method for predicting transient thrust augmenting ejector characteristics is presented. The analysis blends classic self-similar turbulent jet descriptions with a control volume mixing region discretization to solicit transient effects in a new way. Division of the ejector into an inlet, diffuser, and mixing region corresponds with the assumption of viscous-dominated phenomenon in the latter. Inlet and diffuser analyses are simplified by a quasi-steady analysis, justified by the assumptions that pressure is the forcing function in those regions. Details of the theoretical foundation, the solution algorithm, and sample calculations are given.

Three-dimensional echocardiographic measurements using automated quantification software for big data processing.

PubMed

Feng, Cheng; Chen, Lixin; Li, Jian; Wang, Jiangtao; Dong, Fajin; Xu, Jinfeng

2017-01-01

To compare a full-automated software to quantify 3D transthoracic echocardiography namely, 3DE-HM (three-dimensional echocardiography HeartModel, Philips Healthcare) with the traditional manual quantitative method (3DE-manual) for assessing volumes of left atrial and ventricular volumes, and left ventricular ejection fraction (LVEF). 3D full volume images acquired from 156 subjects were collected and divided into 3 groups, which include 70 normal control cases (Group A), 17 patients with left ventricular remodeling after acute myocardial infarction (AMI) (Group B), and 69 patients with left atrial remodeling secondary to hypertension (Group C). The 3DE-HM method was used to quantify left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV), left atrial end-systolic volume (LAESV), and left ventricular ejection fraction (LVEF), respectively. The results were compared with those obtained with the 3DE-manual method for correlation and consistency analyses. The reproducibility of the 3DE-HM method was also evaluated. There was a high correlation between LVEDV, LVESV, LAESV and LVEF values obtained with the 3DE-HM method and those obtained using the 3DE-manual method (r = 0.72 to 0.97). The correlation was strongest for Group B, patients with left ventricular remodeling post-AMI also demonstrated the greatest degree of morphologic changes. There was a significant difference in all parameters measured with the 3DE-HM method in different groups (P < 0.05). The difference in the measurements of LVEDV and LVESV between the two methods was greatest in patients in Group B compared with patients with hypertension-induced left ventricular remodeling (Group C) and in normal controls (Group A) (P < 0.05). Lastly, the difference in the measurement of LAESV between the two methods was greater in patients with hypertension-induced left ventricular remodeling (Group C) than that in the control group (Group A) (P < 0.05). The post-processing time of the 3DE-HM data was significantly shorter than that using the 3DE-manual method (P < 0.05). There was no significant variability in repeated measurements at different time points using the 3DE-HM method either between subjects in different groups or within the same subject. 3DE-HM is a quick and feasible method for left ventricular quantification and is clinically applicable for evaluating patients with left atrial and left ventricular remodeling.

Forest control and regulation ... a comparison of traditional methods and alternatives

Treesearch

LeRoy C. Hennes; Michael J. Irving; Daniel I. Navon

1971-01-01

Two traditional techniques of forest control and regulation-formulas and area-volume check-are compared to linear programing, as used in a new computerized planning system called Timber Resource Allocation Method ( Timber RAM). Inventory data from a National Forest in California illustrate how each technique is used. The traditional methods are simpler to apply and...

Brain volume and fatigue in patients with postpoliomyelitis syndrome.

PubMed

Trojan, Daria A; Narayanan, Sridar; Francis, Simon J; Caramanos, Zografos; Robinson, Ann; Cardoso, Mauro; Arnold, Douglas L

2014-03-01

Acute paralytic poliomyelitis is associated with encephalitis. Early brain inflammation may produce permanent neuronal injury with brain atrophy, which may result in symptoms such as fatigue. Brain volume has not been assessed in postpoliomyelitis syndrome (PPS). To determine whether brain volume is decreased compared with that in normal controls, and whether brain volume is associated with fatigue in patients with PPS. A cross-sectional study. Tertiary university-affiliated hospital postpolio and multiple sclerosis (MS) clinics. Forty-nine ambulatory patients with PPS, 28 normal controls, and 53 ambulatory patients with MS. We studied the brains of all study subjects with magnetic resonance imaging by using a 1.5 T Siemens Sonata machine. The subjects completed the Fatigue Severity Scale. Multivariable linear regression models were computed to evaluate the contribution of PPS and MS compared with controls to explain brain volume. Normalized brain volume (NBV) was assessed with the automated program Structured Image Evaluation, using Normalization, of Atrophy method from the acquired magnetic resonance images. This method may miss brainstem atrophy. Technically adequate NBV measurements were available for 42 patients with PPS, 27 controls, and 49 patients with MS. The mean (standard deviation) age was 60.9 ± 7.6 years for patients with PPS, 47.0 ± 14.6 years for controls, and 46.2 ± 9.4 years for patients with MS. In a multivariable model adjusted for age and gender, NBV was not significantly different in patients with PPS compared with that in controls (P = .28). As expected, when using a similar model for patients with MS, NBV was significantly decreased compared with that in controls (P = .006). There was no significant association between NBV and fatigue in subjects with PPS (Spearman ρ = 0.23; P = .19). No significant whole-brain atrophy was found, and no association of brain volume with fatigue in PPS. Brain atrophy was confirmed in MS. It is possible that brainstem atrophy was not recognized by this study. Copyright © 2014 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

Spectral (Finite) Volume Method for Conservation Laws on Unstructured Grids II: Extension to Two Dimensional Scalar Equation

NASA Technical Reports Server (NTRS)

Wang, Z. J.; Liu, Yen; Kwak, Dochan (Technical Monitor)

2002-01-01

The framework for constructing a high-order, conservative Spectral (Finite) Volume (SV) method is presented for two-dimensional scalar hyperbolic conservation laws on unstructured triangular grids. Each triangular grid cell forms a spectral volume (SV), and the SV is further subdivided into polygonal control volumes (CVs) to supported high-order data reconstructions. Cell-averaged solutions from these CVs are used to reconstruct a high order polynomial approximation in the SV. Each CV is then updated independently with a Godunov-type finite volume method and a high-order Runge-Kutta time integration scheme. A universal reconstruction is obtained by partitioning all SVs in a geometrically similar manner. The convergence of the SV method is shown to depend on how a SV is partitioned. A criterion based on the Lebesgue constant has been developed and used successfully to determine the quality of various partitions. Symmetric, stable, and convergent linear, quadratic, and cubic SVs have been obtained, and many different types of partitions have been evaluated. The SV method is tested for both linear and non-linear model problems with and without discontinuities.

Design and Control of Chemical Grouting : Volume 1 - Construction Control

DOT National Transportation Integrated Search

1983-04-01

This report presents the results of a laboratory and field research program investigating innovative method for design and control of chemical grouting in soils. Chemical grouting practice is reviewed and standard evaluation and measurement technique...

The Effect of Bilateral Superior Laryngeal Nerve Lesion on Swallowing – A Novel Method to Quantitate Aspirated Volume and Pharyngeal Threshold in Videofluoroscopy

PubMed Central

DING, Peng; FUNG, George Shiu-Kai; LIN, Ming De; HOLMAN, Shaina D.; GERMAN, Rebecca Z.

2015-01-01

Purpose To determine the effect of bilateral superior laryngeal nerve (SLN) lesion on swallowing threshold volume and the occurrence of aspiration, using a novel measurement technique for videofluorscopic swallowing studies (VFSS). Methods and Materials We used a novel radiographic phantom to assess volume of the milk containing barium from fluoroscopy. The custom made phantom was firstly calibrated by comparing image intensity of the phantom with known cylinder depths. Secondly, known volume pouches of milk in a pig cadaver were compared to volumes calculated with the phantom. Using these standards, we calculated the volume of milk in the valleculae, esophagus and larynx, for 205 feeding sequences from four infant pigs feeding before and after had bilateral SLN lesions. Swallow safety was assessed using the IMPAS scale. Results The log-linear correlation between image intensity values from the phantom filled with barium milk and the known phantom cylinder depths was strong (R2>0.95), as was the calculated volumes of the barium milk pouches. The threshold volume of bolus in the valleculae during feeding was significantly larger after bilateral SLN lesion than in control swallows (p<0.001). The IMPAS score increased in the lesioned swallows relative to the controls (p<0.001). Conclusion Bilateral SLN lesion dramatically increased the aspiration incidence and the threshold volume of bolus in valleculae. The use of this phantom permits quantification of the aspirated volume of fluid. The custom made phantom and calibration allow for more accurate 3D volume estimation from 2D x-ray in VFSS. PMID:25270532

An integrated algorithm for hypersonic fluid-thermal-structural numerical simulation

NASA Astrophysics Data System (ADS)

Li, Jia-Wei; Wang, Jiang-Feng

2018-05-01

In this paper, a fluid-structural-thermal integrated method is presented based on finite volume method. A unified integral equations system is developed as the control equations for physical process of aero-heating and structural heat transfer. The whole physical field is discretized by using an up-wind finite volume method. To demonstrate its capability, the numerical simulation of Mach 6.47 flow over stainless steel cylinder shows a good agreement with measured values, and this method dynamically simulates the objective physical processes. Thus, the integrated algorithm proves to be efficient and reliable.

Real time control of a combined sewer system using radar-measured precipitation--results of the pilot study.

PubMed

Petruck, A; Holtmeier, E; Redder, A; Teichgräber, B

2003-01-01

Emschergenossenschaft and Lippeverband have developed a method to use radar-measured precipitation as an input for a real-time control of a combined sewer system containing several overflow structures. Two real-time control strategies have been developed and tested, one is solely volume-based, the other is volume and pollution-based. The system has been implemented in a pilot study in Gelsenkirchen, Germany. During the project the system was optimised and is now in constant operation. It was found, that the volume of combined sewage overflow could be reduced by 5 per cent per year. This was also found in simulations carried out in similar catchment areas. Most of the potential of improvement can already be achieved by local pollution-based control strategies.

Synthesis from Design Requirements of a Hybrid System for Transport Aircraft Longitudinal Control. Volume 1

NASA Technical Reports Server (NTRS)

Hynes, Charles S.; Hardy, Gordon H.; Sherry, Lance

2007-01-01

Volume I of this report presents a new method for synthesizing hybrid systems directly from design requirements, and applies the method to design of a hybrid system for longitudinal control of transport aircraft. The resulting system satisfies general requirement for safety and effectiveness specified a priori, enabling formal validation to be achieved. Volume II contains seven appendices intended to make the report accessible to readers with backgrounds in human factors, fli ght dynamics and control. and formal logic. Major design goals are (1) system desi g n integrity based on proof of correctness at the design level, (2), significant simplification and cost reduction in system development and certification, and (3) improved operational efficiency, with significant alleviation of human-factors problems encountered by pilots in current transport aircraft. This report provides for the first time a firm technical basis for criteria governing design and certification of avionic systems for transport aircraft. It should be of primary interest to designers of next-generation avionic systems.

Synthesis from Design Requirements of a Hybrid System for Transport Aircraft Longitudinal Control. Volume 2

NASA Technical Reports Server (NTRS)

Hynes, Charles S.; Hardy, Gordon H.; Sherry, Lance

2007-01-01

Volume I of this report presents a new method for synthesizing hybrid systems directly from desi gn requirements, and applies the method to design of a hybrid system for longitudinal control of transport aircraft. The resulting system satisfies general requirement for safety and effectiveness specified a priori, enabling formal validation to be achieved. Volume II contains seven appendices intended to make the report accessible to readers with backgrounds in human factors, flight dynamics and control, and formal logic. Major design goals are (1) system design integrity based on proof of correctness at the design level, (2) significant simplification and cost reduction in system development and certification, and (3) improved operational efficiency, with significant alleviation of human-factors problems encountered by pilots in current transport aircraft. This report provides for the first time a firm technical basis for criteria governing design and certification of avionic systems for transport aircraft. It should be of primary interest to designers of next-generation avionic systems.

Guidelines for Analysis of Communicable Disease Control Planning in Developing Countries. Volume 1: Communicable Diseases Control Planning. International Health Planning Methods Series.

ERIC Educational Resources Information Center

Chin, James

Intended to assist Agency for International Development (AID) officers, advisors, and health officials in incorporating health planning into national plans for economic development, this first of ten manuals in the International Health Planning Methods Series deals with planning and evaluation of communicable disease control programs. The first…

NLT and extrapolated DLT:3-D cinematography alternatives for enlarging the volume of calibration.

PubMed

Hinrichs, R N; McLean, S P

1995-10-01

This study investigated the accuracy of the direct linear transformation (DLT) and non-linear transformation (NLT) methods of 3-D cinematography/videography. A comparison of standard DLT, extrapolated DLT, and NLT calibrations showed the standard (non-extrapolated) DLT to be the most accurate, especially when a large number of control points (40-60) were used. The NLT was more accurate than the extrapolated DLT when the level of extrapolation exceeded 100%. The results indicated that when possible one should use the DLT with a control object, sufficiently large as to encompass the entire activity being studied. However, in situations where the activity volume exceeds the size of one's DLT control object, the NLT method should be considered.

Validation of Digital Systems in Avionics and Flight Control Applications Handbook. Volume 1.

DTIC Science & Technology

1983-07-01

will also be available to Airways Facilities, Systems Research and Development Service, Air Traffic Control Service, and Flight Standards elements...2114, March 12-14, 1979. 3. Validation Methods Research for Fault-Tolerant Avionics and Control Systems-- *r Working Group Meeting II, NASA...command generation with the multiple methods becoming avail- able for closure of the outer control loop necessitates research on alternative integration

3D numerical simulations of oblique droplet impact onto a deep liquid pool

NASA Astrophysics Data System (ADS)

Gelderblom, Hanneke; Reijers, Sten A.; Gielen, Marise; Sleutel, Pascal; Lohse, Detlef; Xie, Zhihua; Pain, Christopher C.; Matar, Omar K.

2017-11-01

We study the fluid dynamics of three-dimensional oblique droplet impact, which results in phenomena that include splashing and cavity formation. An adaptive, unstructured mesh modelling framework is employed here, which can modify and adapt unstructured meshes to better represent the underlying physics of droplet dynamics, and reduce computational effort without sacrificing accuracy. The numerical framework consists of a mixed control-volume and finite-element formulation, a volume-of-fluid-type method for the interface-capturing based on a compressive control-volume advection method. The framework also features second-order finite-element methods, and a force-balanced algorithm for the surface tension implementation, minimising the spurious velocities often found in many simulations involving capillary-driven flows. The numerical results generated using this framework are compared with high-speed images of the interfacial shapes of the deformed droplet, and the cavity formed upon impact, yielding good agreement. EPSRC, UK, MEMPHIS program Grant (EP/K003976/1), RAEng Research Chair (OKM).

Measurement of cerebral perfusion volume and 99mTc-HMPAO uptake using SPECT in controls and patients with Alzheimer's disease.

PubMed

Fleming, J S; Kemp, P M; Bolt, L; Goatman, K A

2002-11-01

Methods for quantifying the changes in brain function observed in single photon emission computed tomography (SPECT) using hexamethylenepropylene amine oxime (HMPAO) for patients with Alzheimer's disease have the potential of improving the diagnostic accuracy of the procedure and its ability to monitor response to treatment. The absolute percentage uptake of HMPAO and the cerebral perfusion volume (CPV) of the brain were assessed using SPECT in 26 patients with mild to moderate Alzheimer's disease (AD) and 24 control subjects. A subset of 15 control subjects, which was age-matched to the AD patients, was selected to allow fair statistical comparison of parameters between groups. The percentage of brain volume with reduced perfusion (R) and a volume loss index (VLI), given by /CPV, were also calculated. Eight of the control subjects were studied on a second occasion after a mean period of 6 months. There was no significant difference in percentage uptake between controls and AD patients, the mean value being 5.8%. Cerebral perfusion volume in controls was found to depend on sex (mean value in males and females being 1327 ml and 1222 ml, respectively) and on age. The volume loss index corrected for age and sex provided good discrimination between controls and AD subjects giving a sensitivity and specificity of 81% and 96%, respectively. The repeatability coefficient, the 95% confidence limit for the difference between repeat measurements, on controls was 67 ml (5%). The measurement of cerebral perfusion volume and related indices may be of value in identifying patients with early Alzheimer's disease and in following their response to treatment.

Focus control enhancement and on-product focus response analysis methodology

NASA Astrophysics Data System (ADS)

Kim, Young Ki; Chen, Yen-Jen; Hao, Xueli; Samudrala, Pavan; Gomez, Juan-Manuel; Mahoney, Mark O.; Kamalizadeh, Ferhad; Hanson, Justin K.; Lee, Shawn; Tian, Ye

2016-03-01

With decreasing CDOF (Critical Depth Of Focus) for 20/14nm technology and beyond, focus errors are becoming increasingly critical for on-product performance. Current on product focus control techniques in high volume manufacturing are limited; It is difficult to define measurable focus error and optimize focus response on product with existing methods due to lack of credible focus measurement methodologies. Next to developments in imaging and focus control capability of scanners and general tool stability maintenance, on-product focus control improvements are also required to meet on-product imaging specifications. In this paper, we discuss focus monitoring, wafer (edge) fingerprint correction and on-product focus budget analysis through diffraction based focus (DBF) measurement methodology. Several examples will be presented showing better focus response and control on product wafers. Also, a method will be discussed for a focus interlock automation system on product for a high volume manufacturing (HVM) environment.

Control of a HexaPOD treatment couch for robot-assisted radiotherapy.

PubMed

Hermann, Christian; Ma, Lei; Wilbert, Jürgen; Baier, Kurt; Schilling, Klaus

2012-10-01

Moving tumors, for example in the vicinity of the lungs, pose a challenging problem in radiotherapy, as healthy tissue should not be irradiated. Apart from gating approaches, one standard method is to irradiate the complete volume within which a tumor moves plus a safety margin containing a considerable volume of healthy tissue. This work deals with a system for tumor motion compensation using the HexaPOD® robotic treatment couch (Medical Intelligence GmbH, Schwabmünchen, Germany). The HexaPOD, carrying the patient during treatment, is instructed to perform translational movements such that the tumor motion, from the beams-eye view of the linear accelerator, is eliminated. The dynamics of the HexaPOD are characterized by time delays, saturations, and other non-linearities that make the design of control a challenging task. The focus of this work lies on two control methods for the HexaPOD that can be used for reference tracking. The first method uses a model predictive controller based on a model gained through system identification methods, and the second method uses a position control scheme useful for reference tracking. We compared the tracking performance of both methods in various experiments with real hardware using ideal reference trajectories, prerecorded patient trajectories, and human volunteers whose breathing motion was compensated by the system.

Design and Control of Chemical Grouting : Volume 4 - Executive Summary

DOT National Transportation Integrated Search

1983-04-01

This report focuses on the engineering practice of chemical grouting, summarizing the findings of a study to improve design and control techniques for chemical grouting in soils. Improved methods for the planning, control and evaluation of chemical g...

Automatic control of arterial carbon dioxide tension in mechanically ventilated patients.

PubMed

Fernando, Tyrone; Cade, John; Packer, John

2002-12-01

This paper presents a method of controlling the arterial carbon dioxide tension of patients receiving mechanical ventilation. Controlling of the CO2 tension is achieved by regulating the ventilator initiated breath frequency and also volume per breath.

Improved approach to quantitative cardiac volumetrics using automatic thresholding and manual trimming: a cardiovascular MRI study.

PubMed

Rayarao, Geetha; Biederman, Robert W W; Williams, Ronald B; Yamrozik, June A; Lombardi, Richard; Doyle, Mark

2018-01-01

To establish the clinical validity and accuracy of automatic thresholding and manual trimming (ATMT) by comparing the method with the conventional contouring method for in vivo cardiac volume measurements. CMR was performed on 40 subjects (30 patients and 10 controls) using steady-state free precession cine sequences with slices oriented in the short-axis and acquired contiguously from base to apex. Left ventricular (LV) volumes, end-diastolic volume, end-systolic volume, and stroke volume (SV) were obtained with ATMT and with the conventional contouring method. Additionally, SV was measured independently using CMR phase velocity mapping (PVM) of the aorta for validation. Three methods of calculating SV were compared by applying Bland-Altman analysis. The Bland-Altman standard deviation of variation (SD) and offset bias for LV SV for the three sets of data were: ATMT-PVM (7.65, [Formula: see text]), ATMT-contours (7.85, [Formula: see text]), and contour-PVM (11.01, 4.97), respectively. Equating the observed range to the error contribution of each approach, the error magnitude of ATMT:PVM:contours was in the ratio 1:2.4:2.5. Use of ATMT for measuring ventricular volumes accommodates trabeculae and papillary structures more intuitively than contemporary contouring methods. This results in lower variation when analyzing cardiac structure and function and consequently improved accuracy in assessing chamber volumes.

The Relationship Between Brain Volume and Walking Outcomes in Older Adults With and Without Diabetic Peripheral Neuropathy

PubMed Central

Manor, Brad; Newton, Elizabeth; Abduljalil, Amir; Novak, Vera

2012-01-01

OBJECTIVE Diabetic peripheral neuropathy (DPN) alters walking. Yet, the compensatory role of central locomotor circuits remains unclear. We hypothesized that walking outcomes would be more closely related to regional gray matter volumes in older adults with DPN as compared with nonneuropathic diabetic patients and nondiabetic control subjects. RESEARCH DESIGN AND METHODS Clinically important outcomes of walking (i.e., speed, stride duration variability, and double support time) were measured in 29 patients with DPN (type 2 diabetes with foot-sole somatosensory impairment), 68 diabetic (DM) patients (type 2 diabetes with intact foot-sole sensation), and 89 control subjects. Global and regional gray matter volumes were calculated from 3 Tesla magnetic resonance imaging. RESULTS DPN subjects walked more slowly (P = 0.005) with greater stride duration variability (P < 0.001) and longer double support (P < 0.001) as compared with DM and control subjects. Diabetes was associated with less cerebellar gray matter volume (P < 0.001), but global gray matter volume was similar between groups. DPN subjects with lower gray matter volume globally (P < 0.004) and regionally (i.e., cerebellum, right-hemisphere dorsolateral prefrontal cortex, basal ganglia, P < 0.005) walked more slowly with greater stride duration variability and/or longer double support. Each relationship was stronger in DPN than DM subjects. In control subjects, brain volumes did not relate to walking patterns. CONCLUSIONS Strong relationships between brain volumes and walking outcomes were observed in the DPN group and to a lesser extent the DM group, but not in control subjects. Individuals with DPN may be more dependent upon supraspinal elements of the motor control system to regulate several walking outcomes linked to poor health in elderly adults. PMID:22665216

Fifteen-year results from six cutting methods in second-growth northern hardwoods.

Treesearch

Gayne G. Erdmann; Robert R. Oberg

1973-01-01

Presents and compares stand growth and yield information from three single-tree selection cuts, a crop-tree release treatment, an 8-inch diameter limit cut, and an uncut control. Discusses the influence of stand density on basal area growth, cubic volume growth, and board-foot volume growth.

Determining productivity gains from herbaceous vegetation management with 'age-shift' calculations

Treesearch

David B. South; James H. Miller; Mark O. Kimberley; Curtis L. Vanderschaaf

2006-01-01

Gains in stand volume that result from competition control and fertilization are sometimes reported as 'percentage gains'. Because percentage gains arithmetically decline over time asstand volume increases, plantation managers have difficultyin using percentage gains to project growth and revenues. The 'age-shift' method quantifies the year...

Partial volume correction and image analysis methods for intersubject comparison of FDG-PET studies

NASA Astrophysics Data System (ADS)

Yang, Jun

2000-12-01

Partial volume effect is an artifact mainly due to the limited imaging sensor resolution. It creates bias in the measured activity in small structures and around tissue boundaries. In brain FDG-PET studies, especially for Alzheimer's disease study where there is serious gray matter atrophy, accurate estimate of cerebral metabolic rate of glucose is even more problematic due to large amount of partial volume effect. In this dissertation, we developed a framework enabling inter-subject comparison of partial volume corrected brain FDG-PET studies. The framework is composed of the following image processing steps: (1)MRI segmentation, (2)MR-PET registration, (3)MR based PVE correction, (4)MR 3D inter-subject elastic mapping. Through simulation studies, we showed that the newly developed partial volume correction methods, either pixel based or ROI based, performed better than previous methods. By applying this framework to a real Alzheimer's disease study, we demonstrated that the partial volume corrected glucose rates vary significantly among the control, at risk and disease patient groups and this framework is a promising tool useful for assisting early identification of Alzheimer's patients.

Factors controlling volume errors through 2D gully erosion assessment: guidelines for optimal survey design

NASA Astrophysics Data System (ADS)

Castillo, Carlos; Pérez, Rafael

2017-04-01

The assessment of gully erosion volumes is essential for the quantification of soil losses derived from this relevant degradation process. Traditionally, 2D and 3D approaches has been applied for this purpose (Casalí et al., 2006). Although innovative 3D approaches have recently been proposed for gully volume quantification, a renewed interest can be found in literature regarding the useful information that cross-section analysis still provides in gully erosion research. Moreover, the application of methods based on 2D approaches can be the most cost-effective approach in many situations such as preliminary studies with low accuracy requirements or surveys under time or budget constraints. The main aim of this work is to examine the key factors controlling volume error variability in 2D gully assessment by means of a stochastic experiment involving a Monte Carlo analysis over synthetic gully profiles in order to 1) contribute to a better understanding of the drivers and magnitude of gully erosion 2D-surveys uncertainty and 2) provide guidelines for optimal survey designs. Owing to the stochastic properties of error generation in 2D volume assessment, a statistical approach was followed to generate a large and significant set of gully reach configurations to evaluate quantitatively the influence of the main factors controlling the uncertainty of the volume assessment. For this purpose, a simulation algorithm in Matlab® code was written, involving the following stages: - Generation of synthetic gully area profiles with different degrees of complexity (characterized by the cross-section variability) - Simulation of field measurements characterised by a survey intensity and the precision of the measurement method - Quantification of the volume error uncertainty as a function of the key factors In this communication we will present the relationships between volume error and the studied factors and propose guidelines for 2D field surveys based on the minimal survey densities required to achieve a certain accuracy given the cross-sectional variability of a gully and the measurement method applied. References Casali, J., Loizu, J., Campo, M.A., De Santisteban, L.M., Alvarez-Mozos, J., 2006. Accuracy of methods for field assessment of rill and ephemeral gully erosion. Catena 67, 128-138. doi:10.1016/j.catena.2006.03.005

METHODS FOR OPTIMIZING URBAN WET-WEATHER CONTROL SYSTEM

EPA Science Inventory

To minimize impacts of urban nonpoint source pollution and associated costs of control (storage and treatment) associated with wet-weather flows (WWFs), stormwater runoff volumes and pollutant loads must be reduced. A number of control strategies, so-called “best management pract...

19 CFR 146.93 - Inventory control and recordkeeping system.

Code of Federal Regulations, 2010 CFR

2010-04-01

... (first-in, first-out) method of accounting (see § 191.22(c) of this chapter). The use of this method is... method, measurement (weight or volume), and the price of product consistently (see § 146.92(g) of this...

Control volume based hydrocephalus research; a phantom study

NASA Astrophysics Data System (ADS)

Cohen, Benjamin; Voorhees, Abram; Madsen, Joseph; Wei, Timothy

2009-11-01

Hydrocephalus is a complex spectrum of neurophysiological disorders involving perturbation of the intracranial contents; primarily increased intraventricular cerebrospinal fluid (CSF) volume and intracranial pressure are observed. CSF dynamics are highly coupled to the cerebral blood flows and pressures as well as the mechanical properties of the brain. Hydrocephalus, as such, is a very complex biological problem. We propose integral control volume analysis as a method of tracking these important interactions using mass and momentum conservation principles. As a first step in applying this methodology in humans, an in vitro phantom is used as a simplified model of the intracranial space. The phantom's design consists of a rigid container filled with a compressible gel. Within the gel a hollow spherical cavity represents the ventricular system and a cylindrical passage represents the spinal canal. A computer controlled piston pump supplies sinusoidal volume fluctuations into and out of the flow phantom. MRI is used to measure fluid velocity and volume change as functions of time. Independent pressure measurements and momentum flow rate measurements are used to calibrate the MRI data. These data are used as a framework for future work with live patients and normal individuals. Flow and pressure measurements on the flow phantom will be presented through the control volume framework.

Evaluation of Fractional Regional Ventilation Using 4D-CT and Effects of Breathing Maneuvers on Ventilation

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

Mistry, Nilesh N., E-mail: nmistry@som.umaryland.edu; Diwanji, Tejan; Shi, Xiutao

2013-11-15

Purpose: Current implementations of methods based on Hounsfield units to evaluate regional lung ventilation do not directly incorporate tissue-based mass changes that occur over the respiratory cycle. To overcome this, we developed a 4-dimensional computed tomography (4D-CT)-based technique to evaluate fractional regional ventilation (FRV) that uses an individualized ratio of tidal volume to end-expiratory lung volume for each voxel. We further evaluated the effect of different breathing maneuvers on regional ventilation. The results from this work will help elucidate the relationship between global and regional lung function. Methods and Materials: Eight patients underwent 3 sets of 4D-CT scans during 1more » session using free-breathing, audiovisual guidance, and active breathing control. FRV was estimated using a density-based algorithm with mass correction. Internal validation between global and regional ventilation was performed by use of the imaging data collected during the use of active breathing control. The impact of breathing maneuvers on FRV was evaluated comparing the tidal volume from 3 breathing methods. Results: Internal validation through comparison between the global and regional changes in ventilation revealed a strong linear correlation (slope of 1.01, R{sup 2} of 0.97) between the measured global lung volume and the regional lung volume calculated by use of the “mass corrected” FRV. A linear relationship was established between the tidal volume measured with the automated breathing control system and FRV based on 4D-CT imaging. Consistently larger breathing volumes were observed when coached breathing techniques were used. Conclusions: The technique presented improves density-based evaluation of lung ventilation and establishes a link between global and regional lung ventilation volumes. Furthermore, the results obtained are comparable with those of other techniques of functional evaluation such as spirometry and hyperpolarized-gas magnetic resonance imaging. These results were demonstrated on retrospective analysis of patient data, and further research using prospective data is under way to validate this technique against established clinical tests.« less

MRI Assessment of Superior Temporal Gyrus in Williams Syndrome

PubMed Central

Sampaio, Adriana; Sousa, Nuno; Férnandez, Montse; Vasconcelos, Cristiana; Shenton, Martha E.; Gonçalves, Óscar F.

2009-01-01

Objective To evaluate volumes and asymmetry of superior temporal gyrus (STG) and correlate these measures with a neurocognitive evaluation of verbal performance in Williams syndrome (WS) and in a typically developing age-matched and sex-matched group. Background Despite initial claims of language strength in WS, recent studies suggest delayed language milestones. The STG is implicated in linguistic processing and is a highly lateralized brain region. Method Here, we examined STG volumes and asymmetry of STG in WS patients and in age-matched controls. We also correlated volume of STG with a subset of verbal measures. Magnetic resonance imaging scans were obtained on a GE 1.5-T magnet with 1.5-mm contiguous slices, and were used to measure whole gray matter, white matter, and cerebrospinal fluid volumes, and also STG volume. Results Results revealed significantly reduced intracranial volume in WS patients, compared with controls. Right and left STG were also significantly smaller in WS patients. In addition, compared with normal controls, a lack of normal left >right STG asymmetry was evident in WS. Also of note was the finding that, in contrast to controls, WS patients did not reveal a positive correlation between verbal intelligence quotient and left STG volume, which further suggests a disruption in this region of the brain. Conclusions In conclusion, atypical patterns of asymmetry and reduced STG volume in WS were observed, which may, in part, contribute to some of the linguistic impairments found in this cohort of WS patients. PMID:18797257

A coupling strategy for nonlocal and local diffusion models with mixed volume constraints and boundary conditions

DOE PAGES

D'Elia, Marta; Perego, Mauro; Bochev, Pavel B.; ...

2015-12-21

We develop and analyze an optimization-based method for the coupling of nonlocal and local diffusion problems with mixed volume constraints and boundary conditions. The approach formulates the coupling as a control problem where the states are the solutions of the nonlocal and local equations, the objective is to minimize their mismatch on the overlap of the nonlocal and local domains, and the controls are virtual volume constraints and boundary conditions. When some assumptions on the kernel functions hold, we prove that the resulting optimization problem is well-posed and discuss its implementation using Sandia’s agile software components toolkit. As a result,more » the latter provides the groundwork for the development of engineering analysis tools, while numerical results for nonlocal diffusion in three-dimensions illustrate key properties of the optimization-based coupling method.« less

Reduced Pineal Volume in Alzheimer Disease: A Retrospective Cross-sectional MR Imaging Study.

PubMed

Matsuoka, Teruyuki; Imai, Ayu; Fujimoto, Hiroshi; Kato, Yuka; Shibata, Keisuke; Nakamura, Kaeko; Yokota, Hajime; Yamada, Kei; Narumoto, Jin

2018-01-01

Purpose To evaluate pineal volume in patients with Alzheimer disease (AD), patients with mild cognitive impairment (MCI), and healthy control subjects and to correlate the findings with results of cognitive testing and brain parenchymal volumes. Materials and Methods The ethics committee approved this retrospective study. The participants included 63 patients with AD, 33 patients with MCI, and 24 healthy control subjects. There were 36 men and 84 women, with a mean age (±standard deviation) of 76.7 years ± 7.6. The pineal gland volume and pineal parenchymal volume were measured by using three-dimensional volumetric magnetic resonance imaging (T1-weighted magnetization-prepared rapid gradient-echo sequence; spatial resolution, 0.9 × 0.98 × 0.98 mm). With age and total intracranial volume as covariates, analysis of covariance with the Bonferroni post hoc test was performed to compare the pineal volume among the AD, MCI, and control groups. Multiple regression analyses were used to identify predictor variables associated with pineal volume. Results The mean pineal gland volume in patients with AD (72.3 mm 3 ± 5.4; 95% confidence interval [CI]: 61.5 mm 3 , 83.1 mm 3 ) was significantly smaller than that in control subjects (102.1 mm 3 ± 9.0; 95% CI: 84.4 mm 3 , 119.9 mm 3 ) (P = .019). The mean pineal parenchymal volume in patients with AD (63.8 mm 3 ± 4.2; 95% CI: 55.4 mm 3 , 72.1 mm 3 ) was significantly smaller than that in patients with MCI (81.7 mm 3 ± 5.8; 95% CI: 70.3 mm 3 , 93.1 mm 3 ; P = .044) and control subjects (89.1 mm 3 ± 6.9; 95% CI: 75.4 mm 3 , 102.9 mm 3 ; P = .009). Multiple regression analyses demonstrated that the Mini-Mental State Examination score and total intracranial volume were significant independent predictors of both pineal gland volume and pineal parenchymal volume (P < .001). Conclusion Pineal volume reduction showed correlation with cognitive decline and thus might be useful to predict cognitive decline in patients with AD. © RSNA, 2017.

Waterflood control system for maximizing total oil recovery

DOEpatents

Patzek, Tadeusz Wiktor; Silin, Dimitriy Borisovic; De, Asoke Kumar

2005-06-07

A control system and method for determining optimal fluid injection pressure is based upon a model of a growing hydrofracture due to waterflood injection pressure. This model is used to develop a control system optimizing the injection pressure by using a prescribed injection goal coupled with the historical times, pressures, and volume of injected fluid at a single well. In this control method, the historical data is used to derive two major flow components: the transitional component, where cumulative injection volume is scaled as the square root of time, and a steady-state breakthrough component, which scales linearly with respect to time. These components provide diagnostic information and allow for the prevention of rapid fracture growth and associated massive water break through that is an important part of a successful waterflood, thereby extending the life of both injection and associated production wells in waterflood secondary oil recovery operations.

Waterflood control system for maximizing total oil recovery

DOEpatents

Patzek, Tadeusz Wiktor [Oakland, CA; Silin, Dimitriy Borisovich [Pleasant Hill, CA; De, Asoke Kumar [San Jose, CA

2007-07-24

A control system and method for determining optimal fluid injection pressure is based upon a model of a growing hydrofracture due to waterflood injection pressure. This model is used to develop a control system optimizing the injection pressure by using a prescribed injection goal coupled with the historical times, pressures, and volume of injected fluid at a single well. In this control method, the historical data is used to derive two major flow components: the transitional component, where cumulative injection volume is scaled as the square root of time, and a steady-state breakthrough component, which scales linearly with respect to time. These components provide diagnostic information and allow for the prevention of rapid fracture growth and associated massive water break through that is an important part of a successful waterflood, thereby extending the life of both injection and associated production wells in waterflood secondary oil recovery operations.

40 CFR 60.664 - Test methods and procedures.

Code of Federal Regulations, 2012 CFR

2012-07-01

... (less methane and ethane) reduction efficiency shall be prior to the inlet of the control device and... methane and ethane), dry basis, ppm by volume. %O2d=Concentration of O2, dry basis, percent by volume. (4... emission reduction (R) of TOC (minus methane and ethane) shall be determined using the following equation...

The validity of anthropometric leg muscle volume estimation across a wide spectrum: From able-bodied adults to individuals with a spinal cord injury

PubMed Central

Venturelli, Massimo; Jeong, Eun-Kee; Richardson, Russell S.

2014-01-01

The assessment of muscle volume, and changes over time, have significant clinical and research-related implications. Methods to assess muscle volume vary from simple and inexpensive to complex and expensive. Therefore this study sought to examine the validity of muscle volume estimated simply by anthropometry compared with the more complex proton magnetic resonance imaging (1H-MRI) across a wide spectrum of individuals including those with a spinal cord injury (SCI), a group recognized to exhibit significant muscle atrophy. Accordingly, muscle volume of the thigh and lower leg of eight subjects with a SCI and eight able-bodied subjects (controls) was determined by anthropometry and 1H-MRI. With either method, muscle volumes were significantly lower in the SCI compared with the controls (P < 0.05) and, using pooled data from both groups, anthropometric measurements of muscle volume were strongly correlated to the values assessed by 1H-MRI in both the thigh (r2 = 0.89; P < 0.05) and lower leg (r2 = 0.98; P < 0.05). However, the anthropometric approach systematically overestimated muscle volume compared with 1H-MRI in both the thigh (mean bias = 2407cm3) and the lower (mean bias = 170 cm3) leg. Thus with an appropriate correction for this systemic overestimation, muscle volume estimated from anthropometric measurements is a valid approach and provides acceptable accuracy across a spectrum of adults with normal muscle mass to a SCI and severe muscle atrophy. In practical terms this study provides the formulas that add validity to the already simple and inexpensive anthropometric approach to assess muscle volume in clinical and research settings. PMID:24458749

Development and acceleration of unstructured mesh-based cfd solver

NASA Astrophysics Data System (ADS)

Emelyanov, V.; Karpenko, A.; Volkov, K.

2017-06-01

The study was undertaken as part of a larger effort to establish a common computational fluid dynamics (CFD) code for simulation of internal and external flows and involves some basic validation studies. The governing equations are solved with ¦nite volume code on unstructured meshes. The computational procedure involves reconstruction of the solution in each control volume and extrapolation of the unknowns to find the flow variables on the faces of control volume, solution of Riemann problem for each face of the control volume, and evolution of the time step. The nonlinear CFD solver works in an explicit time-marching fashion, based on a three-step Runge-Kutta stepping procedure. Convergence to a steady state is accelerated by the use of geometric technique and by the application of Jacobi preconditioning for high-speed flows, with a separate low Mach number preconditioning method for use with low-speed flows. The CFD code is implemented on graphics processing units (GPUs). Speedup of solution on GPUs with respect to solution on central processing units (CPU) is compared with the use of different meshes and different methods of distribution of input data into blocks. The results obtained provide promising perspective for designing a GPU-based software framework for applications in CFD.

Systems for Lung Volume Standardization during Static and Dynamic MDCT-based Quantitative Assessment of Pulmonary Structure and Function

PubMed Central

Fuld, Matthew K.; Grout, Randall; Guo, Junfeng; Morgan, John H.; Hoffman, Eric A.

2013-01-01

Rationale and Objectives Multidetector-row Computed Tomography (MDCT) has emerged as a tool for quantitative assessment of parenchymal destruction, air trapping (density metrics) and airway remodeling (metrics relating airway wall and lumen geometry) in chronic obstructive pulmonary disease (COPD) and asthma. Critical to the accuracy and interpretability of these MDCT-derived metrics is the assurance that the lungs are scanned during a breath-hold at a standardized volume. Materials and Methods A computer monitored turbine-based flow meter system was developed to control patient breath-holds and facilitate static imaging at fixed percentages of the vital capacity. Due to calibration challenges with gas density changes during multi-breath xenon-CT an alternative system was required. The design incorporated dual rolling seal pistons. Both systems were tested in a laboratory environment and human subject trials. Results The turbine-based system successfully controlled lung volumes in 32/37 subjects, having a linear relationship for CT measured air volume between repeated scans: for all scans, the mean and confidence interval of the differences (scan1-scan2) was −9 ml (−169, 151); for TLC alone 6 ml (−164, 177); for FRC alone, −23 ml (−172, 126). The dual-piston system successfully controlled lung volume in 31/41 subjects. Study failures related largely to subject non-compliance with verbal instruction and gas leaks around the mouthpiece. Conclusion We demonstrate the successful use of a turbine-based system for static lung volume control and demonstrate its inadequacies for dynamic xenon-CT studies. Implementation of a dual-rolling seal spirometer has been shown to adequately control lung volume for multi-breath wash-in xenon-CT studies. These systems coupled with proper patient coaching provide the tools for the use of CT to quantitate regional lung structure and function. The wash-in xenon-CT method for assessing regional lung function, while not necessarily practical for routine clinical studies, provides for a dynamic protocol against which newly emerging single breath, dual-energy xenon-CT measures can be validated. PMID:22555001

What approach to brain partial volume correction is best for PET/MRI?

NASA Astrophysics Data System (ADS)

Hutton, B. F.; Thomas, B. A.; Erlandsson, K.; Bousse, A.; Reilhac-Laborde, A.; Kazantsev, D.; Pedemonte, S.; Vunckx, K.; Arridge, S. R.; Ourselin, S.

2013-02-01

Many partial volume correction approaches make use of anatomical information, readily available in PET/MRI systems but it is not clear what approach is best. Seven novel approaches to partial volume correction were evaluated, including several post-reconstruction methods and several reconstruction methods that incorporate anatomical information. These were compared with an MRI-independent approach (reblurred van Cittert ) and uncorrected data. Monte Carlo PET data were generated for activity distributions representing both 18F FDG and amyloid tracer uptake. Post-reconstruction methods provided the best recovery with ideal segmentation but were particularly sensitive to mis-registration. Alternative approaches performed better in maintaining lesion contrast (unseen in MRI) with good noise control. These were also relatively insensitive to mis-registration errors. The choice of method will depend on the specific application and reliability of segmentation and registration algorithms.

Predictors of Individual Tumor Local Control After Stereotactic Radiosurgery for Non-Small Cell Lung Cancer Brain Metastases

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

Garsa, Adam A.; Badiyan, Shahed N.; DeWees, Todd

2014-10-01

Purpose: To evaluate local control rates and predictors of individual tumor local control for brain metastases from non-small cell lung cancer (NSCLC) treated with stereotactic radiosurgery (SRS). Methods and Materials: Between June 1998 and May 2011, 401 brain metastases in 228 patients were treated with Gamma Knife single-fraction SRS. Local failure was defined as an increase in lesion size after SRS. Local control was estimated using the Kaplan-Meier method. The Cox proportional hazards model was used for univariate and multivariate analysis. Receiver operating characteristic analysis was used to identify an optimal cutpoint for conformality index relative to local control. Amore » P value <.05 was considered statistically significant. Results: Median age was 60 years (range, 27-84 years). There were 66 cerebellar metastases (16%) and 335 supratentorial metastases (84%). The median prescription dose was 20 Gy (range, 14-24 Gy). Median overall survival from time of SRS was 12.1 months. The estimated local control at 12 months was 74%. On multivariate analysis, cerebellar location (hazard ratio [HR] 1.94, P=.009), larger tumor volume (HR 1.09, P<.001), and lower conformality (HR 0.700, P=.044) were significant independent predictors of local failure. Conformality index cutpoints of 1.4-1.9 were predictive of local control, whereas a cutpoint of 1.75 was the most predictive (P=.001). The adjusted Kaplan-Meier 1-year local control for conformality index ≥1.75 was 84% versus 69% for conformality index <1.75, controlling for tumor volume and location. The 1-year adjusted local control for cerebellar lesions was 60%, compared with 77% for supratentorial lesions, controlling for tumor volume and conformality index. Conclusions: Cerebellar tumor location, lower conformality index, and larger tumor volume were significant independent predictors of local failure after SRS for brain metastases from NSCLC. These results warrant further investigation in a prospective setting.« less

Analysis and Evaluation of German Attainments and Research in the Liquid Rocket Engine Field. Volume 7. Thrust Control

DTIC Science & Technology

1951-01-01

by lowered cost, complexity, and flxed weight of the engine . An evaluation of the effect of throttling on specific impulse, as well as the way in... combustion chamber development. The throttling arrangement and the method of pump control are both closely with the design of the entire engine . As...the use of the rocket engine . For a complete coverage of these subjects, it is recommended that all volumes of this series be consulted

Altered Pituitary Gland Structure and Function in Posttraumatic Stress Disorder

PubMed Central

Bonert, Vivien; Moser, Franklin; Mirocha, James; Melmed, Shlomo

2017-01-01

Objectives: Posttraumatic stress disorder (PTSD) is associated with hypothalamus-pituitary-adrenal (HPA) axis response to stressors, but links to neurophysiological and neuroanatomical changes are unclear. The purpose of this study was to determine whether stress-induced cortisol alters negative feedback on pituitary corticotroph function and pituitary volume. Design: Prospective controlled study in an outpatient clinic. Methods: Subjects with PTSD and matched control subjects underwent pituitary volume measurement on magnetic resonance imaging, with pituitary function assessed by 24-hour urine free cortisol (UFC), 8:00 am cortisol, and adrenocorticotropic hormone (ACTH) levels, and ACTH levels after 2-day dexamethasone/corticotropin-releasing hormone test. Primary outcome was pituitary volume; secondary outcomes were ACTH area under the curve (AUC) and 24-hour UFC. Results: Thirty-nine subjects were screened and 10 subjects with PTSD were matched with 10 healthy control subjects by sex and age. Mean pituitary volume was 729.7 mm3 [standard deviation (SD), 227.3 mm3] in PTSD subjects vs 835.2 mm3 (SD, 302.8 mm3) in control subjects. ACTH AUC was 262.5 pg/mL (SD, 133.3 pg/mL) L in PTSD vs 244.0 pg/mL (SD, 158.3 pg/mL) in control subjects (P = 0.80). In PTSD subjects, UFC levels and pituitary volume inversely correlated with PTSD duration; pituitary volume correlated with ACTH AUC in control subjects (Pearson correlation coefficient, 0.88, P = 0.0009) but not in PTSD subjects. Conclusions: The HPA axis may be downregulated and dysregulated in people with PTSD, as demonstrated by discordant pituitary corticotroph function and pituitary volume vs intact HPA feedback and correlation of pituitary volume with ACTH levels in healthy control subjects. The results suggest a link between pituitary structure and function in PTSD, which may point to endocrine targeted therapeutic approaches. PMID:29264511

Hip Abductor Muscle Volume and Strength Differences Between Women With Chronic Hip Joint Pain and Asymptomatic Controls.

PubMed

Mastenbrook, Matthew J; Commean, Paul K; Hillen, Travis J; Salsich, Gretchen B; Meyer, Gretchen A; Mueller, Michael J; Clohisy, John C; Harris-Hayes, Marcie

2017-12-01

Study Design Secondary analysis, cross-sectional study. Background Chronic hip joint pain (CHJP) can lead to limitations in activity participation, but the musculoskeletal factors associated with the condition are relatively unknown. Understanding the factors associated with CHJP may help develop rehabilitation strategies to improve quality of life of individuals with long-term hip pain. Objectives To compare measures of hip abductor muscle volume and hip abductor muscle strength between women with CHJP and asymptomatic controls. Methods Thirty women, 15 with CHJP and 15 matched asymptomatic controls (age range, 18-40 years), participated in this study. Magnetic resonance imaging was used to determine the volume of the primary hip abductor muscles, consisting of the gluteus medius, gluteus minimus, a small portion of the gluteus maximus, and the tensor fascia latae, within a defined region of interest. Break tests were performed using a handheld dynamometer to assess hip abductor strength. During the strength test, the participant was positioned in sidelying with the involved hip in 15° of abduction. Independent-samples t tests were used to compare muscle volume and strength values between those with CHJP and asymptomatic controls. Results Compared to asymptomatic controls, women with CHJP demonstrated significantly increased gluteal muscle volume (228 ± 40 cm 3 versus 199 ± 29 cm 3 , P = .032), but decreased hip abductor strength (74.6 ± 16.8 Nm versus 93.6 ± 20.2 Nm, P = .009). There were no significant differences in tensor fascia lata muscle volume between the 2 groups (P = .640). Conclusion Women with CHJP appear to have larger gluteal muscle volume, but decreased hip abductor strength, compared to asymptomatic controls. J Orthop Sports Phys Ther 2017;47(12):923-930. Epub 9 Oct 2017. doi:10.2519/jospt.2017.7380.

Reproducible MRI Measurement of Adipose Tissue Volumes in Genetic and Dietary Rodent Obesity Models

PubMed Central

Johnson, David H.; Flask, Chris A.; Ernsberger, Paul R.; Wong, Wilbur C. K.; Wilson, David L.

2010-01-01

Purpose To develop ratio MRI [lipid/(lipid+water)] methods for assessing lipid depots and compare measurement variability to biological differences in lean controls (spontaneously hypertensive rats, SHRs), dietary obese (SHR-DO), and genetic/dietary obese (SHROBs) animals. Materials and Methods Images with and without CHESS water-suppression were processed using a semi-automatic method accounting for relaxometry, chemical shift, receive coil sensitivity, and partial volume. Results Partial volume correction improved results by 10–15%. Over six operators, volume variation was reduced to 1.9 ml from 30.6 ml for single-image-analysis with intensity inhomogeneity. For three acquisitions on the same animal, volume reproducibility was <1%. SHROBs had 6X visceral and 8X subcutaneous adipose tissue than SHRs. SHR-DOs had enlarged visceral depots (3X SHRs). SHROB had significantly more subcutaneous adipose tissue, indicating a strong genetic component to this fat depot. Liver ratios in SHR-DO and SHROB were higher than SHR, indicating elevated fat content. Among SHROBs, evidence suggested a phenotype SHROB* having elevated liver ratios and visceral adipose tissue volumes. Conclusion Effects of diet and genetics on obesity were significantly larger than variations due to image acquisition and analysis, indicating that these methods can be used to assess accumulation/depletion of lipid depots in animal models of obesity. PMID:18821617

Thermodynamic evaluation of transonic compressor rotors using the finite volume approach

NASA Technical Reports Server (NTRS)

Nicholson, S.; Moore, J.

1986-01-01

A method was developed which calculates two-dimensional, transonic, viscous flow in ducts. The finite volume, time marching formulation is used to obtain steady flow solutions of the Reynolds-averaged form of the Navier Stokes equations. The entire calculation is performed in the physical domain. The method is currently limited to the calculation of attached flows. The features of the current method can be summarized as follows. Control volumes are chosen so that smoothing of flow properties, typically required for stability, is now needed. Different time steps are used in the different governing equations to improve the convergence speed of the viscous calculations. A new pressure interpolation scheme is introduced which improves the shock capturing ability of the method. A multi-volume method for pressure changes in the boundary layer allows calculations which use very long and thin control volumes. A special discretization technique is also used to stabilize these calculations. A special formulation of the energy equation is used to provide improved transient behavior of solutions which use the full energy equation. The method is then compared with a wide variety of test cases. The freestream Mach numbers range from 0.075 to 2.8 in the calculations. Transonic viscous flow in a converging diverging nozzle is calculated with the method; the Mach number upstream of the shock is approximately 1.25. The agreement between the calculated and measured shock strength and total pressure losses is good. Essentially incompressible turbulent boundary layer flow in a adverse pressure gradient is calculated and the computed distribution of mean velocity and shear stress are in good agreement with the measurements. At the other end of the Mach number range, a flat plate turbulent boundary layer with a freestream Mach number of 2.8 is calculated using the full energy equation; the computed total temperature distribution and recovery factor agree well with the measurements when a variable Prandtl number is used through the boundary layer.

Induced wettability and surface-volume correlation of composition for bovine bone derived hydroxyapatite particles

NASA Astrophysics Data System (ADS)

Maidaniuc, Andreea; Miculescu, Florin; Voicu, Stefan Ioan; Andronescu, Corina; Miculescu, Marian; Matei, Ecaterina; Mocanu, Aura Catalina; Pencea, Ion; Csaki, Ioana; Machedon-Pisu, Teodor; Ciocan, Lucian Toma

2018-04-01

Hydroxyapatite powders characteristics need to be determined both for quality control purposes and for a proper control of microstructural features of bone reconstruction products. This study combines bulk morphological and compositional analysis methods (XRF, SEM-EDS, FT-IR) with surface-related methods (XPS, contact angle measurements) in order to correlate the characteristics of hydroxyapatite powders derived from bovine bone for its use in medical applications. An experimental approach for correlating the surface and volume composition was designed based on the analysis depth of each spectral method involved in the study. Next, the influences of powder particle size and forming method on the contact angle between water drops and ceramic surface were evaluated for identifying suitable strategies of tuning hydroxyapatite's wettability. The results revealed a preferential arrangement of chemical elements at the surface of hydroxyapatite particles which could induce a favourable material behaviour in terms of sinterability and biological performance.

Abnormal cerebellar morphometry in abstinent adolescent marijuana users

PubMed Central

Medina, Krista Lisdahl; Nagel, Bonnie J.; Tapert, Susan F.

2010-01-01

Background Functional neuroimaging data from adults have, in general, found frontocerebellar dysfunction associated with acute and chronic marijuana (MJ) use (Loeber & Yurgelun-Todd, 1999). One structural neuroimaging study found reduced cerebellar vermis volume in young adult MJ users with a history of heavy polysubstance use (Aasly et al., 1993). The goal of this study was to characterize cerebellar volume in adolescent chronic MJ users following one month of monitored abstinence. Method Participants were MJ users (n=16) and controls (n=16) aged 16-18 years. Extensive exclusionary criteria included history of psychiatric or neurologic disorders. Drug use history, neuropsychological data, and structural brain scans were collected after 28 days of monitored abstinence. Trained research staff defined cerebellar volumes (including three cerebellar vermis lobes and both cerebellar hemispheres) on high-resolution T1-weighted magnetic resonance images. Results Adolescent MJ users demonstrated significantly larger inferior posterior (lobules VIII-X) vermis volume (p<.009) than controls, above and beyond effects of lifetime alcohol and other drug use, gender, and intracranial volume. Larger vermis volumes were associated with poorer executive functioning (p’s<.05). Conclusions Following one month of abstinence, adolescent MJ users had significantly larger posterior cerebellar vermis volumes than non-using controls. These greater volumes are suggested to be pathological based on linkage to poorer executive functioning. Longitudinal studies are needed to examine typical cerebellar development during adolescence and the influence of marijuana use. PMID:20413277

Smaller superior temporal gyrus volume specificity in schizotypal personality disorder

PubMed Central

Goldstein, Kim E.; Hazlett, Erin A.; New, Antonia S.; Haznedar, M. Mehmet; Newmark, Randall E.; Zelmanova, Yuliya; Passarelli, Vincent; Weinstein, Shauna R.; Canfield, Emily L.; Meyerson, David A.; Tang, Cheuk Y.; Buchsbaum, Monte S.; Siever, Larry J.

2009-01-01

Background Superior temporal gyrus (STG/BA22) volume is reduced in schizophrenia and to a milder degree in schizotypal personality disorder (SPD), representing a less severe disorder in the schizophrenia-spectrum. SPD and Borderline personality disorder (BPD) are severe personality disorders characterized by social and cognitive dysfunction. However, while SPD is characterized by social withdrawal/anhedonia, BPD is marked by hyper-reactivity to interpersonal stimuli and hyper-emotionality. This is the first morphometric study to directly compare SPD and BPD patients in temporal volume. Methods We compared three age-gender- and education-matched groups: 27 unmedicated SPD individuals with no BPD traits, 52 unmedicated BPD individuals with no SPD traits, and 45 healthy controls. We examined gray matter volume of frontal and temporal lobe Brodmann areas (BAs), and dorsal/ventral amygdala from 3T magnetic resonance imaging. Results In the STG, an auditory association area reported to be dysfunctional in SPD and BPD, the SPD patients had significantly smaller volume than healthy controls and BPD patients. No group differences were found between BPD patients and controls. Smaller BA22 volume was associated with greater symptom severity in SPD patients. Reduced STG volume may be an important endophenotype for schizophrenia-spectrum disorders. SPD is distinct from BPD in terms of STG volume abnormalities which may reflect different underlying pathophysiological mechanisms and could help discriminate between them. PMID:19473820

Intensity-modulated radiotherapy (IMRT) in pediatric low-grade glioma.

PubMed

Paulino, Arnold C; Mazloom, Ali; Terashima, Keita; Su, Jack; Adesina, Adekunle M; Okcu, M Faith; Teh, Bin S; Chintagumpala, Murali

2013-07-15

The objective of this study was to evaluate local control and patterns of failure in pediatric patients with low-grade glioma (LGG) who received treatment with intensity-modulated radiation therapy (IMRT). In total, 39 children received IMRT after incomplete resection or disease progression. Three methods of target delineation were used. The first was to delineate the gross tumor volume (GTV) and add a 1-cm margin to create the clinical target volume (CTV) (Method 1; n = 19). The second was to add a 0.5-cm margin around the GTV to create the CTV (Method 2; n = 6). The prescribed dose to the GTV was the same as dose to the CTV for both Methods 1 and 2 (median, 50.4 grays [Gy]). The final method was dose painting, in which a GTV was delineated with a second target volume (2TV) created by adding 1 cm to the GTV (Method 3; n = 14). Different doses were prescribed to the GTV (median, 50.4 Gy) and the 2TV (median, 41.4 Gy). The 8-year progression-free and overall survival rates were 78.2% and 93.7%, respectively. Seven failures occurred, all of which were local in the high-dose (≥95%) region of the IMRT field. On multivariate analysis, age ≤5 years at time of IMRT had a detrimental impact on progression-free survival. IMRT provided local control rates comparable to those provided by 2-dimensional and 3-dimensional radiotherapy. Margins ≥1 cm added to the GTV may not be necessary, because excellent local control was achieved by adding a 0.5-cm margin (Method 2) and by dose painting (Method 3). © 2013 American Cancer Society.

Trajectories of Early Brain Volume Development in Fragile X and Autism RH: Trajectory of Brain Volume in Fragile X

PubMed Central

Hazlett, Heather Cody; Poe, Michele D.; Lightbody, Amy A.; Styner, Martin; MacFall, James R.; Reiss, Allan L.; Piven, Joseph

2012-01-01

Objective To examine patterns of early brain growth in young children with fragile X syndrome (FXS) compared to a comparison group (controls) and a group with idiopathic autism. Method The study included 53 boys between 18–42 months of age with FXS, 68 boys with idiopathic autism (ASD), and a comparison group of 50 typically-developing and developmentally-delayed controls. We examined structural brain volumes using magnetic resonance imaging (MRI) across two timepoints between ages 2–3 and 4–5 years and examined total brain volumes and regional (lobar) tissue volumes. Additionally, we studied a selected group of subcortical structures implicated in the behavioral features of FXS (e.g., basal ganglia, hippocampus, amygdala). Results Children with FXS had greater global brain volumes compared to controls, but were not different than children with idiopathic autism, and the rate of brain growth between ages 2 and 5 paralleled that seen in controls. In contrast to the children with idiopathic autism who had generalized cortical lobe enlargement, the children with FXS showed a specific enlargement in temporal lobe white matter, cerebellar gray matter, and caudate nucleus, but significantly smaller amygdala. Conclusions This structural longitudinal MRI study of preschoolers with FXS observed generalized brain overgrowth in FXS compared to controls, evident at age 2 and maintained across ages 4–5. We also find different patterns of brain growth that distinguishes boys with FXS from children with idiopathic autism. PMID:22917205

Volume and Asymmetry Abnormalities of Insula in Antipsychotic-Naive Schizophrenia: A 3-Tesla Magnetic Resonance Imaging Study

PubMed Central

Virupaksha, Harve Shanmugam; Kalmady, Sunil V.; Shivakumar, Venkataram; Arasappa, Rashmi; Venkatasubramanian, Ganesan; Gangadhar, Bangalore N.

2012-01-01

Context: Insula, which is a vital brain region for self-awareness, empathy, and sensory stimuli processing, is critically implicated in schizophrenia pathogenesis. Existing studies on insula volume abnormalities report inconsistent findings potentially due to the evaluation of ‘antipsychotic-treated’ schizophrenia patients as well as suboptimal methodology. Aim: To understand the role of insula in schizophrenia. Materials and Methods: In this first-time 3-T magnetic resonance imaging study, we examined antipsychotic-naive schizophrenic patients (N=30) and age-, sex-, handedness- and education-matched healthy controls (N=28). Positive and negative symptoms were scored with good interrater reliability (intraclass correlation coefficient (ICC)>0.9) by using the scales for negative and positive symptoms. Gray matter volume of insula and its anterior/posterior subregions were measured by using a three-dimensional, interactive, semiautomated software based on the valid method with good interrater reliability (ICC>0.85). Intracranial volume was automatically measured by using the FreeSurfer software. Results: Patients had significantly deficient gray matter volumes of left (F=33.4; P<0.00001) and right (F=11.9; P=0.001) insula after controlling for the effects of age, sex, and intracranial volume. Patients with predominantly negative symptoms had a significantly deficient right posterior insula volume than those with predominantly positive symptoms (F=6.3; P=0.02). Asymmetry index analysis revealed anterior insular asymmetry to be significantly reversed (right>left) in male patients in comparison with male controls (left>right) (t=2.7; P=0.01). Conclusions: Robust insular volume deficits in antipsychotic-naive schizophrenia support intrinsic role for insula in pathogenesis of this disorder. The first-time demonstration of a relationship between right posterior insular deficit and negative symptoms is in tune with the background neurobiological literature. Another novel observation of sex-specific anterior insular asymmetry reversal in patients supports evolutionary postulates of schizophrenia pathogenesis. PMID:23162188

Seagrass metabolism across a productivity gradient using the eddy covariance, Eulerian control volume, and biomass addition techniques

NASA Astrophysics Data System (ADS)

Long, Matthew H.; Berg, Peter; Falter, James L.

2015-05-01

The net ecosystem metabolism of the seagrass Thalassia testudinum was studied across a nutrient and productivity gradient in Florida Bay, Florida, using the Eulerian control volume, eddy covariance, and biomass addition techniques. In situ oxygen fluxes were determined by a triangular Eulerian control volume with sides 250 m long and by eddy covariance instrumentation at its center. The biomass addition technique evaluated the aboveground seagrass productivity through the net biomass added. The spatial and temporal resolutions, accuracies, and applicability of each method were compared. The eddy covariance technique better resolved the short-term flux rates and the productivity gradient across the bay, which was consistent with the long-term measurements from the biomass addition technique. The net primary production rates from the biomass addition technique, which were expected to show greater autotrophy due to the exclusion of sediment metabolism and belowground production, were 71, 53, and 30 mmol carbon m-2 d-1 at 3 sites across the bay. The net ecosystem metabolism was 35, 25, and 11 mmol oxygen m-2 d-1 from the eddy covariance technique and 10, -103, and 14 mmol oxygen m-2 d-1 from the Eulerian control volume across the same sites, respectively. The low-flow conditions in the shallow bays allowed for periodic stratification and long residence times within the Eulerian control volume that likely reduced its precision. Overall, the eddy covariance technique had the highest temporal resolution while producing accurate long-term flux rates that surpassed the capabilities of the biomass addition and Eulerian control volume techniques in these shallow coastal bays.

Nonlinear bioheat transfer models and multi-objective numerical optimization of the cryosurgery operations

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

Kudryashov, Nikolay A.; Shilnikov, Kirill E.

Numerical computation of the three dimensional problem of the freezing interface propagation during the cryosurgery coupled with the multi-objective optimization methods is used in order to improve the efficiency and safety of the cryosurgery operations performing. Prostate cancer treatment and cutaneous cryosurgery are considered. The heat transfer in soft tissue during the thermal exposure to low temperature is described by the Pennes bioheat model and is coupled with an enthalpy method for blurred phase change computations. The finite volume method combined with the control volume approximation of the heat fluxes is applied for the cryosurgery numerical modeling on the tumormore » tissue of a quite arbitrary shape. The flux relaxation approach is used for the stability improvement of the explicit finite difference schemes. The method of the additional heating elements mounting is studied as an approach to control the cellular necrosis front propagation. Whereas the undestucted tumor tissue and destucted healthy tissue volumes are considered as objective functions, the locations of additional heating elements in cutaneous cryosurgery and cryotips in prostate cancer cryotreatment are considered as objective variables in multi-objective problem. The quasi-gradient method is proposed for the searching of the Pareto front segments as the multi-objective optimization problem solutions.« less

Method and apparatus for controlling cross contamination of microfluid channels

DOEpatents

Hasselbrink, Jr., Ernest F.; Rehm, Jason E [Alameda, CA; Paul, Phillip H [Livermore, CA; Arnold, Don W [Livermore, CA

2006-02-07

A method for controlling fluid flow at junctions in microchannel systems. Control of fluid flow is accomplished generally by providing increased resistance to electric-field and pressure-driven flow in the form of regions of reduced effective cross-sectional area within the microchannels and proximate a channel junction. By controlling these flows in the region of a microchannel junction it is possible to eliminate sample dispersion and cross contamination and inject well-defined volumes of fluid from one channel to another.

The effect of ovariectomy on learning and memory and relationship to changes in brain volume and neuronal density.

PubMed

Su, Jian; Sripanidkulchai, Kittisak; Hu, Ying; Wyss, J Michael; Sripanidkulchai, Bungorn

2012-10-01

The loss of sex hormones in postmenopausal women has been suggested to be involved in cognitive degenerative diseases, such as Alzheimer's disease. In the present study, ovariectomized (OVX) and control rats were tested for 4 months in a Morris water maze (MWM) task to track their memory status. Thereafter, postmortem frozen brain sections were analyzed to determine if changes in brain area volumes and neuronal density were related to changes in cognitive ability. A modified artificial-land-mark-based method was used to assure the fidelity of the three dimensions (3D) reconstructed structures. Volumetric areas of the hippocampus, cortex, caudate putamen (cpu), and cerebellum were estimated from the reconstructions, and neuron densities of CA1 and CA3 subregions of the hippocampus were measured in an adjacent second series of Nissl-stained sections. Compared to the control rats, OVX rats displayed memory impairments, beginning in the second month after the ovariectomy (p < .05). Assessments at the end of the study demonstrated that OVX (compared to control) rats displayed reduced brain volume in the hippocampus and neocortex and in the brain as a whole. In contrast, when compared to controls, the volumes of cpu and cerebellum of OVX rats increased slightly. CA3 neuron density of OVX (compared to controls) rats was significantly lower, but the CA1 neuron density was significantly higher. In conclusion, ovariectomy impaired spatial memory and led to morphological changes in cognitive centers of rat brain. The results demonstrate that the 3D reconstructed method is useful for the study of brain morphological abnormality in rats.

Image registration with auto-mapped control volumes

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

Schreibmann, Eduard; Xing Lei

2006-04-15

Many image registration algorithms rely on the use of homologous control points on the two input image sets to be registered. In reality, the interactive identification of the control points on both images is tedious, difficult, and often a source of error. We propose a two-step algorithm to automatically identify homologous regions that are used as a priori information during the image registration procedure. First, a number of small control volumes having distinct anatomical features are identified on the model image in a somewhat arbitrary fashion. Instead of attempting to find their correspondences in the reference image through user interaction,more » in the proposed method, each of the control regions is mapped to the corresponding part of the reference image by using an automated image registration algorithm. A normalized cross-correlation (NCC) function or mutual information was used as the auto-mapping metric and a limited memory Broyden-Fletcher-Goldfarb-Shanno algorithm (L-BFGS) was employed to optimize the function to find the optimal mapping. For rigid registration, the transformation parameters of the system are obtained by averaging that derived from the individual control volumes. In our deformable calculation, the mapped control volumes are treated as the nodes or control points with known positions on the two images. If the number of control volumes is not enough to cover the whole image to be registered, additional nodes are placed on the model image and then located on the reference image in a manner similar to the conventional BSpline deformable calculation. For deformable registration, the established correspondence by the auto-mapped control volumes provides valuable guidance for the registration calculation and greatly reduces the dimensionality of the problem. The performance of the two-step registrations was applied to three rigid registration cases (two PET-CT registrations and a brain MRI-CT registration) and one deformable registration of inhale and exhale phases of a lung 4D CT. Algorithm convergence was confirmed by starting the registration calculations from a large number of initial transformation parameters. An accuracy of {approx}2 mm was achieved for both deformable and rigid registration. The proposed image registration method greatly reduces the complexity involved in the determination of homologous control points and allows us to minimize the subjectivity and uncertainty associated with the current manual interactive approach. Patient studies have indicated that the two-step registration technique is fast, reliable, and provides a valuable tool to facilitate both rigid and nonrigid image registrations.« less

Linear Approximation to Optimal Control Allocation for Rocket Nozzles with Elliptical Constraints

NASA Technical Reports Server (NTRS)

Orr, Jeb S.; Wall, Johnm W.

2011-01-01

In this paper we present a straightforward technique for assessing and realizing the maximum control moment effectiveness for a launch vehicle with multiple constrained rocket nozzles, where elliptical deflection limits in gimbal axes are expressed as an ensemble of independent quadratic constraints. A direct method of determining an approximating ellipsoid that inscribes the set of attainable angular accelerations is derived. In the case of a parameterized linear generalized inverse, the geometry of the attainable set is computationally expensive to obtain but can be approximated to a high degree of accuracy with the proposed method. A linear inverse can then be optimized to maximize the volume of the true attainable set by maximizing the volume of the approximating ellipsoid. The use of a linear inverse does not preclude the use of linear methods for stability analysis and control design, preferred in practice for assessing the stability characteristics of the inertial and servoelastic coupling appearing in large boosters. The present techniques are demonstrated via application to the control allocation scheme for a concept heavy-lift launch vehicle.

Pressurized reactor system and a method of operating the same

DOEpatents

Isaksson, J.M.

1996-06-18

A method and apparatus are provided for operating a pressurized reactor system in order to precisely control the temperature within a pressure vessel in order to minimize condensation of corrosive materials from gases on the surfaces of the pressure vessel or contained circulating fluidized bed reactor, and to prevent the temperature of the components from reaching a detrimentally high level, while at the same time allowing quick heating of the pressure vessel interior volume during start-up. Super-atmospheric pressure gas is introduced from the first conduit into the fluidized bed reactor and heat derived reactions such as combustion and gasification are maintained in the reactor. Gas is exhausted from the reactor and pressure vessel through a second conduit. Gas is circulated from one part of the inside volume to another to control the temperature of the inside volume, such as by passing the gas through an exterior conduit which has a heat exchanger, control valve, blower and compressor associated therewith, or by causing natural convection flow of circulating gas within one or more generally vertically extending gas passages entirely within the pressure vessel (and containing heat exchangers, flow rate control valves, or the like therein). Preferably, inert gas is provided as a circulating gas, and the inert gas may also be used in emergency shut-down situations. In emergency shut-down reaction gas being supplied to the reactor is cut off, while inert gas from the interior gas volume of the pressure vessel is introduced into the reactor. 2 figs.

Pressurized reactor system and a method of operating the same

DOEpatents

Isaksson, Juhani M.

1996-01-01

A method and apparatus are provided for operating a pressurized reactor system in order to precisely control the temperature within a pressure vessel in order to minimize condensation of corrosive materials from gases on the surfaces of the pressure vessel or contained circulating fluidized bed reactor, and to prevent the temperature of the components from reaching a detrimentally high level, while at the same time allowing quick heating of the pressure vessel interior volume during start-up. Superatmospheric pressure gas is introduced from the first conduit into the fluidized bed reactor and heat derived reactions such as combustion and gassification are maintained in the reactor. Gas is exhausted from the reactor and pressure vessel through a second conduit. Gas is circulated from one part of the inside volume to another to control the temperature of the inside volume, such as by passing the gas through an exterior conduit which has a heat exchanger, control valve, blower and compressor associated therewith, or by causing natural convection flow of circulating gas within one or more generally vertically extending gas passages entirely within the pressure vessel (and containing heat exchangers, flow rate control valves, or the like therein). Preferably, inert gas is provided as a circulating gas, and the inert gas may also be used in emergency shut-down situations. In emergency shut-down reaction gas being supplied to the reactor is cut off, while inert gas from the interior gas volume of the pressure vessel is introduced into the reactor.

Microfluidic devices for the controlled manipulation of small volumes

DOEpatents

Ramsey, Michael J; Jacobson, Stephen C

2012-09-18

A method for conducting a broad range of biochemical analyses or manipulations on a series of nano- to subnanoliter reaction volumes and an apparatus for carrying out the same are disclosed. The invention is implemented on a fluidic microchip to provide high serial throughput. In particular, the disclosed device is a microfabricated channel device that can manipulate nanoliter or subnanoliter reaction volumes in a controlled manner to produce results at rates of 1 to 10 Hz per channel. The reaction volumes are manipulated in serial fashion analogous to a digital shift register. The invention has application to such problems as screening molecular or cellular targets using single beads from split-synthesis combinatorial libraries, screening single cells for RNA or protein expression, genetic diagnostic screening at the single cell level, or performing single cell signal transduction studies.

Method and apparatus for electrokinetic transport

NASA Technical Reports Server (NTRS)

James, Patrick Ismail (Inventor); Stejic, George (Inventor)

2012-01-01

Controlled electrokinetic transport of constituents of liquid media can be achieved by connecting at least two volumes containing liquid media with at least one dielectric medium with opposing dielectric surfaces in direct contact with said liquid media, and establishing at least one conduit across said dielectric medium, with a conduit inner surface surrounding a conduit volume and at least a first opening and a second opening opposite to the first opening. The conduit is arranged to connect two volumes containing liquid media and includes a set of at least three electrodes positioned in proximity of the inner conduit surface. A power supply is arranged to deliver energy to the electrodes such that time-varying potentials inside the conduit volume are established, where the superposition of said potentials represents at least one controllable traveling potential well that can travel between the opposing conduit openings.

Microfluidic devices for the controlled manipulation of small volumes

DOEpatents

Ramsey, J Michael [Knoxville, TN; Jacobson, Stephen C [Knoxville, TN

2007-07-03

A method for conducting a broad range of biochemical analyses or manipulations on a series of nano- to subnanoliter reaction volumes and an apparatus for carrying out the same are disclosed. The invention is implemented on a fluidic microchip to provide high serial throughput. In particular, the disclosed device is a microfabricated channel device that can manipulate nanoliter or subnanoliter reaction volumes in a controlled manner to produce results at rates of 1 to 10 Hz per channel. The reaction volumes are manipulated in serial fashion analogous to a digital shift register. The invention has application to such problems as screening molecular or cellular targets using single beads from split-synthesis combinatorial libraries, screening single cells for RNA or protein expression, genetic diagnostic screening at the single cell level, or performing single cell signal transduction studies.

Statewide Intelligent Transportation Systems As-Is Agency Reports For Minnesota, Volume 6, City Of St. Paul

DOT National Transportation Integrated Search

1996-08-01

KEYWORDS: : TRAFFIC SIGNAL CONTROL/REAL-TIME ADAPTIVE CONTROL, ADVANCED TRAFFIC MANAGEMENT SYSTEMS OR ATMS : THIS DOCUMENT PRESENTS THE METHODS, ASSUMPTIONS AND PROCEDURES USED TO COLLECT THE BASELINE INFORMATION. THE DOCUMENTATION OF SYSTEMS ...

Assessing the influence of component processing and donor characteristics on quality of red cell concentrates using quality control data.

PubMed

Jordan, A; Chen, D; Yi, Q-L; Kanias, T; Gladwin, M T; Acker, J P

2016-07-01

Quality control (QC) data collected by blood services are used to monitor production and to ensure compliance with regulatory standards. We demonstrate how analysis of quality control data can be used to highlight the sources of variability within red cell concentrates (RCCs). We merged Canadian Blood Services QC data with manufacturing and donor records for 28 227 RCC between June 2011 and October 2014. Units were categorized based on processing method, bag manufacturer, donor age and donor sex, then assessed based on product characteristics: haemolysis and haemoglobin levels, unit volume, leucocyte count and haematocrit. Buffy-coat method (top/bottom)-processed units exhibited lower haemolysis than units processed using the whole-blood filtration method (top/top). Units from female donors exhibited lower haemolysis than male donations. Processing method influenced unit volume and the ratio of additive solution to residual plasma. Stored red blood cell characteristics are influenced by prestorage processing and donor factors. Understanding the relationship between processing, donors and RCC quality will help blood services to ensure the safety of transfused products. © 2016 International Society of Blood Transfusion.

Double-cross hydrostatic pressure sample injection for chip CE: variable sample plug volume and minimum number of electrodes.

PubMed

Luo, Yong; Wu, Dapeng; Zeng, Shaojiang; Gai, Hongwei; Long, Zhicheng; Shen, Zheng; Dai, Zhongpeng; Qin, Jianhua; Lin, Bingcheng

2006-09-01

A novel sample injection method for chip CE was presented. This injection method uses hydrostatic pressure, generated by emptying the sample waste reservoir, for sample loading and electrokinetic force for dispensing. The injection was performed on a double-cross microchip. One cross, created by the sample and separation channels, is used for formation of a sample plug. Another cross, formed by the sample and controlling channels, is used for plug control. By varying the electric field in the controlling channel, the sample plug volume can be linearly adjusted. Hydrostatic pressure takes advantage of its ease of generation on a microfluidic chip, without any electrode or external pressure pump, thus allowing a sample injection with a minimum number of electrodes. The potential of this injection method was demonstrated by a four-separation-channel chip CE system. In this system, parallel sample separation can be achieved with only two electrodes, which is otherwise impossible with conventional injection methods. Hydrostatic pressure maintains the sample composition during the sample loading, allowing the injection to be free of injection bias.

Dynamic characteristic mechanism of atrial septal defect using real-time three-dimensional echocardiography and evaluation of right ventricular functions.

PubMed

Sharen, Gao-Wa; Zhang, Jun; Qin, Chuan; Lv, Qing

2017-02-01

The dynamic characteristics of the area of the atrial septal defect (ASD) were evaluated using the technique of real-time three-dimensional echocardiography (RT 3DE), the potential factors responsible for the dynamic characteristics of the area of ASD were observed, and the overall and local volume and functions of the patients with ASD were measured. RT 3DE was performed on the 27 normal controls and 28 patients with ASD. Based on the three-dimensional data workstations, the area of ASD was measured at P wave vertex, R wave vertex, T wave starting point, and T wave terminal point and in the T-P section. The right atrial volume in the same time phase of the cardiac cycle and the motion displacement distance of the tricuspid annulus in the corresponding period were measured. The measured value of the area of ASD was analyzed. The changes in the right atrial volume and the motion displacement distance of the tricuspid annulus in the normal control group and the ASD group were compared. The right ventricular ejection fractions in the normal control group and the ASD group were compared using the RT 3DE long-axis eight-plane (LA 8-plane) method. Real-time three-dimensional volume imaging was performed in the normal control group and ASD group (n=30). The right ventricular inflow tract, outflow tract, cardiac apex muscular trabecula dilatation, end-systolic volume, overall dilatation, end-systolic volume, and appropriate local and overall ejection fractions in both two groups were measured with the four-dimensional right ventricular quantitative analysis method (4D RVQ) and compared. The overall right ventricular volume and the ejection fraction measured by the LA 8-plane method and 4D RVQ were subjected to a related analysis. Dynamic changes occurred to the area of ASD in the cardiac cycle. The rules for dynamic changes in the area of ASD and the rules for changes in the right atrial volume in the cardiac cycle were consistent. The maximum value of the changes in the right atrial volume occurred in the end-systolic period when the peak of the curve appeared. The minimum value of the changes occurred in the end-systolic period and was located at the lowest point of the volume variation curve. The area variation curve for ASD and the motion variation curve for the tricuspid annulus in the cardiac cycle were the same. The displacement of the tricuspid annulus exhibited directionality. The measured values of the area of ASD at P wave vertex, R wave vertex, T wave starting point, T wave terminal point and in the T-P section were properly correlated with the right atrial volume (P<0.001). The area of ASD and the motion displacement distance of the tricuspid annulus were negatively correlated (P<0.05). The right atrial volumes in the ASD group in the cardiac cycle in various time phases increased significantly as compared with those in the normal control group (P=0.0001). The motion displacement distance of the tricuspid annulus decreased significantly in the ASD group as compared with that in the normal control group (P=0.043). The right ventricular ejection fraction in the ASD group was lower than that in the normal control group (P=0.032). The ejection fraction of the cardiac apex trabecula of the ASD patients was significantly lower than the ejection fractions of the right ventricular outflow tract and inflow tract and overall ejection fraction. The difference was statistically significant (P=0.005). The right ventricular local and overall dilatation and end-systolic volumes in the ASD group increased significantly as compared with those in the normal control group (P=0.031). The aRVEF and the overall ejection fraction decreased in the ASD group as compared with those in the normal control group (P=0.0005). The dynamic changes in the area of ASD and the motion curves for the right atrial volume and tricuspid annulus have the same dynamic characteristics. RT 3DE can be used to accurately evaluate the local and overall volume and functions of the right ventricle. The local and overall volume loads of the right ventricle in the ASD patients increase significantly as compared with those of the normal people. The right ventricular cardiac apex and the overall systolic function decrease.

Sexual dimorphism in the volume of song control nuclei in European starlings: assessment by a Nissl stain and autoradiography for muscarinic cholinergic receptors.

PubMed

Bernard, D J; Casto, J M; Ball, G F

1993-08-22

Previous studies have found that the volume of several song control nuclei is larger in male songbirds than in female songbirds. The degree of this volumetric sex difference within a given species appears to be systematically related to the degree of the behavioral sex difference. The largest volumetric differences have been reported in species in which the male sings and the female sings little, if at all, and the smallest sex differences in volume have been reported in species in which males and females both sing in nearly equal amounts. We compared the volume of three song control nuclei in male and female European starlings (Sturnus vulgaris), a species in which females are known to sing, though at a much lower rate than males. We investigated the volume of hyperstriatum ventrale, pars caudale, nucleus robustus archistriatalis, and area X of the lobus parolfactorius as defined with the use of a Nissl stain. In addition, we measured the volume of area X as defined by the density of muscarinic cholinergic receptors visualized by in vitro receptor autoradiographic methods. The volumes of all three of the song nuclei, as defined by Nissl staining, are significantly larger in males than in females. For area X, Nissl staining and receptor autoradiography indicate the same significant volumetric sex difference. The three nuclei are approximately one and one half to two times larger in males than in females, a degree of dimorphism that is intermediate to those reported for other species. Previous investigations of sex differences in the avian vocal control system have used only Nissl stains to define nuclear volumes. We demonstrate in this paper that receptor autoradiography can be used to assess dimorphisms in nuclear volume. Broad application of this approach to a number of neurotransmitter receptor systems will better characterize the dimorphisms in the song system, and therefore will provide greater insight into the neuroanatomical and neurochemical control of birdsong.

Recommendations for the Use of Automated Gray Matter Segmentation Tools: Evidence from Huntington’s Disease

PubMed Central

Johnson, Eileanoir B.; Gregory, Sarah; Johnson, Hans J.; Durr, Alexandra; Leavitt, Blair R.; Roos, Raymund A.; Rees, Geraint; Tabrizi, Sarah J.; Scahill, Rachael I.

2017-01-01

The selection of an appropriate segmentation tool is a challenge facing any researcher aiming to measure gray matter (GM) volume. Many tools have been compared, yet there is currently no method that can be recommended above all others; in particular, there is a lack of validation in disease cohorts. This work utilizes a clinical dataset to conduct an extensive comparison of segmentation tools. Our results confirm that all tools have advantages and disadvantages, and we present a series of considerations that may be of use when selecting a GM segmentation method, rather than a ranking of these tools. Seven segmentation tools were compared using 3 T MRI data from 20 controls, 40 premanifest Huntington’s disease (HD), and 40 early HD participants. Segmented volumes underwent detailed visual quality control. Reliability and repeatability of total, cortical, and lobular GM were investigated in repeated baseline scans. The relationship between each tool was also examined. Longitudinal within-group change over 3 years was assessed via generalized least squares regression to determine sensitivity of each tool to disease effects. Visual quality control and raw volumes highlighted large variability between tools, especially in occipital and temporal regions. Most tools showed reliable performance and the volumes were generally correlated. Results for longitudinal within-group change varied between tools, especially within lobular regions. These differences highlight the need for careful selection of segmentation methods in clinical neuroimaging studies. This guide acts as a primer aimed at the novice or non-technical imaging scientist providing recommendations for the selection of cohort-appropriate GM segmentation software. PMID:29066997

Recommendations for the Use of Automated Gray Matter Segmentation Tools: Evidence from Huntington's Disease.

PubMed

Johnson, Eileanoir B; Gregory, Sarah; Johnson, Hans J; Durr, Alexandra; Leavitt, Blair R; Roos, Raymund A; Rees, Geraint; Tabrizi, Sarah J; Scahill, Rachael I

2017-01-01

The selection of an appropriate segmentation tool is a challenge facing any researcher aiming to measure gray matter (GM) volume. Many tools have been compared, yet there is currently no method that can be recommended above all others; in particular, there is a lack of validation in disease cohorts. This work utilizes a clinical dataset to conduct an extensive comparison of segmentation tools. Our results confirm that all tools have advantages and disadvantages, and we present a series of considerations that may be of use when selecting a GM segmentation method, rather than a ranking of these tools. Seven segmentation tools were compared using 3 T MRI data from 20 controls, 40 premanifest Huntington's disease (HD), and 40 early HD participants. Segmented volumes underwent detailed visual quality control. Reliability and repeatability of total, cortical, and lobular GM were investigated in repeated baseline scans. The relationship between each tool was also examined. Longitudinal within-group change over 3 years was assessed via generalized least squares regression to determine sensitivity of each tool to disease effects. Visual quality control and raw volumes highlighted large variability between tools, especially in occipital and temporal regions. Most tools showed reliable performance and the volumes were generally correlated. Results for longitudinal within-group change varied between tools, especially within lobular regions. These differences highlight the need for careful selection of segmentation methods in clinical neuroimaging studies. This guide acts as a primer aimed at the novice or non-technical imaging scientist providing recommendations for the selection of cohort-appropriate GM segmentation software.

Hippocampal volumes in patients exposed to low-dose radiation to the basal brain. A case-control study in long-term survivors from cancer in the head and neck region.

PubMed

Olsson, Erik; Eckerström, Carl; Berg, Gertrud; Borga, Magnus; Ekholm, Sven; Johannsson, Gudmundur; Ribbelin, Susanne; Starck, Göran; Wysocka, Anna; Löfdahl, Elisabet; Malmgren, Helge

2012-11-29

An earlier study from our group of long time survivors of head and neck cancer who had received a low radiation dose to the hypothalamic-pituitary region, with no signs of recurrence or pituitary dysfunction, had their quality of life (QoL) compromised as compared with matched healthy controls. Hippocampal changes have been shown to accompany several psychiatric conditions and the aim of the present study was to test whether the patients' lowered QoL was coupled to a reduction in hippocampal volume. Patients (11 men and 4 women, age 31-65) treated for head and neck cancer 4-10 years earlier and with no sign of recurrence or pituitary dysfunction, and 15 matched controls were included. The estimated radiation doses to the basal brain including the hippocampus (1.5 - 9.3 Gy) had been calculated in the earlier study. The hippocampal volumetry was done on coronal sections from a 1.5 T MRI scanner. Measurements were done by two independent raters, blinded to patients and controls, using a custom method for computer assisted manual segmentation. The volumes were normalized for intracranial volume which was also measured manually. The paired t test and Wilcoxon's signed rank test were used for the main statistical analysis. There was no significant difference with respect to left, right or total hippocampal volume between patients and controls. All mean differences were close to zero, and the two-tailed 95% confidence interval for the difference in total, normalized volume does not include a larger than 8% deficit in the patients. The study gives solid evidence against the hypothesis that the patients' lowered quality of life was due to a major reduction of hippocampal volume.

Substantia Nigra Volume Loss Before Basal Forebrain Degeneration in Early Parkinson Disease

PubMed Central

Ziegler, David A.; Wonderlick, Julien S.; Ashourian, Paymon; Hansen, Leslie A.; Young, Jeremy C.; Murphy, Alex J.; Koppuzha, Cecily K.; Growdon, John H.; Corkin, Suzanne

2017-01-01

Objective To test the hypothesis that degeneration of the substantia nigra pars compacta (SNc) precedes that of the cholinergic basal forebrain (BF) in Parkinson disease (PD) using new multispectral structural magnetic resonance (MR) imaging tools to measure the volumes of the SNc and BF. Design Matched case-control study. Setting The Athinoula A. Martinos Imaging Center at the McGovern Institute for Brain Research, Massachusetts Institute of Technology (MIT), and the Massachusetts General Hospital/MIT Morris Udall Center of Excellence in Parkinson Disease Research. Patients Participants included 29 patients with PD (Hoehn and Yahr [H&Y] stages 1–3) and 27 matched healthy control subjects. Main Outcome Measures We acquired multiecho T1-weighted, multiecho proton density, T2-weighted, and T2-weighted fluid-attenuated inversion recovery (FLAIR) sequences from each participant. For the SNc, we created a weighted mean of the multiple echoes, yielding a single volume with a high ratio of contrast to noise. We visualized the BF using T2-weighted FLAIR images. For each participant, we manually labeled the 2 structures and calculated their volumes. Results Relative to the controls, 13 patients with H&Y stage 1 PD had significantly decreased SNc volumes. Sixteen patients with H&Y stage 2 or 3 PD showed little additional volume loss. In contrast, the BF volume loss occurred later in the disease, with a significant decrease apparent in patients having H&Y stage 2 or 3 PD compared with the controls and the patients having H&Y stage 1 PD. The latter group did not differ significantly from the controls. Conclusion Our results support the proposed neuropathological trajectory in PD and establish novel multispectral methods as MR imaging biomarkers for tracking the degeneration of the SNc and BF. PMID:23183921

Soccer Attenuates the Asymmetry of Rectus Abdominis Muscle Observed in Non-Athletes

PubMed Central

Idoate, Fernando; Calbet, Jose A. L.; Izquierdo, Mikel; Sanchis-Moysi, Joaquin

2011-01-01

Purpose To determine the volume and degree of asymmetry of the rectus abdominis muscle (RA) in professional soccer players. Methods The volume of the RA was determined using magnetic resonance imaging (MRI) in 15 professional male soccer players and 6 non-active male control subjects. Results Soccer players had 26% greater RA volume than controls (P<0.05), due to hypertrophy of both the dominant (28% greater volume, P<0.05) and non-dominant (25% greater volume, P<0.01) sides, after adjusting for age, length of the RA muscle and body mass index (BMI) as covariates. Total volume of the dominant side was similar to the contralateral in soccer players (P = 0.42) and in controls (P = 0.75) (Dominant/non-dominant = 0.99, in both groups). Segmental analysis showed a progressive increase in the degree of side-to-side asymmetry from the first lumbar disc to the pubic symphysis in soccer players (r = 0.80, P<0.05) and in controls (r = 0.75, P<0.05). The slope of the relationship was lower in soccer players, although this trend was not statistically significant (P = 0.14). Conclusions Professional soccer is associated with marked hypertrophy of the rectus abdominis muscle, which achieves a volume that is 26% greater than in non-active controls. Soccer induces the hypertrophy of the non-dominant side in proximal regions and the dominant side in regions closer to pubic symphysis, which attenuates the pattern of asymmetry of rectus abdominis observed in non-active population. It remains to be determined whether the hypertrophy of rectus abdominis in soccer players modifies the risk of injury. PMID:21541351

Larger Gray Matter Volume in the Basal Ganglia of Heavy Cannabis Users Detected by Voxel-Based Morphometry and Subcortical Volumetric Analysis.

PubMed

Moreno-Alcázar, Ana; Gonzalvo, Begoña; Canales-Rodríguez, Erick J; Blanco, Laura; Bachiller, Diana; Romaguera, Anna; Monté-Rubio, Gemma C; Roncero, Carlos; McKenna, Peter J; Pomarol-Clotet, Edith

2018-01-01

Background: Structural imaging studies of cannabis users have found evidence of both cortical and subcortical volume reductions, especially in cannabinoid receptor-rich regions such as the hippocampus and amygdala. However, the findings have not been consistent. In the present study, we examined a sample of adult heavy cannabis users without other substance abuse to determine whether long-term use is associated with brain structural changes, especially in the subcortical regions. Method: We compared the gray matter volume of 14 long-term, heavy cannabis users with non-using controls. To provide robust findings, we conducted two separate studies using two different MRI techniques. Each study used the same sample of cannabis users and a different control group, respectively. Both control groups were independent of each other. First, whole-brain voxel-based morphometry (VBM) was used to compare the cannabis users against 28 matched controls (HC1 group). Second, a volumetric analysis of subcortical regions was performed to assess differences between the cannabis users and a sample of 100 matched controls (HC2 group) obtained from a local database of healthy volunteers. Results: The VBM study revealed that, compared to the control group HC1, the cannabis users did not show cortical differences nor smaller volume in any subcortical structure but showed a cluster ( p < 0.001) of larger GM volume in the basal ganglia, involving the caudate, putamen, pallidum, and nucleus accumbens, bilaterally. The subcortical volumetric analysis revealed that, compared to the control group HC2, the cannabis users showed significantly larger volumes in the putamen ( p = 0.001) and pallidum ( p = 0.0015). Subtle trends, only significant at the uncorrected level, were also found in the caudate ( p = 0.05) and nucleus accumbens ( p = 0.047). Conclusions: This study does not support previous findings of hippocampal and/or amygdala structural changes in long-term, heavy cannabis users. It does, however, provide evidence of basal ganglia volume increases.

Important influence of respiration on human R-R interval power spectra is largely ignored

NASA Technical Reports Server (NTRS)

Brown, T. E.; Beightol, L. A.; Koh, J.; Eckberg, D. L.

1993-01-01

Frequency-domain analyses of R-R intervals are used widely to estimate levels of autonomic neural traffic to the human heart. Because respiration modulates autonomic activity, we determined for nine healthy subjects the influence of breathing frequency and tidal volume on R-R interval power spectra (fast-Fourier transform method). We also surveyed published literature to determine current practices in this burgeoning field of scientific inquiry. Supine subjects breathed at rates of 6, 7.5, 10, 15, 17.1, 20, and 24 breaths/min and with nominal tidal volumes of 1,000 and 1,500 ml. R-R interval power at respiratory and low (0.06-0.14 Hz) frequencies declined significantly as breathing frequency increased. R-R interval power at respiratory frequencies was significantly greater at a tidal volume of 1,500 than 1,000 ml. Neither breathing frequency nor tidal volume influenced average R-R intervals significantly. Our review of studies reporting human R-R interval power spectra showed that 51% of the studies controlled respiratory rate, 11% controlled tidal volume, and 11% controlled both respiratory rate and tidal volume. The major implications of our analyses are that breathing parameters strongly influence low-frequency as well as respiratory frequency R-R interval power spectra and that this influence is largely ignored in published research.

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

PubMed Central

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

2014-01-01

Background Diffusion tensor imaging (DTI) has expanded our knowledge of corticospinal tract (CST) anatomy and development. However, previous developmental DTI studies assessed the CST as a whole, overlooking potential differences in development of its components related to control of the upper and lower extremities. The present cross-sectional study investigated age-related changes, side and gender differences in streamline volume of the leg- and hand-related segments of the CST in children. Subjects and methods DTI data of 31 children (1–14years; mean age: 6±4years; 17 girls) with normal conventional MRI were analyzed. Leg- and hand-related CST streamline volumes were quantified separately, using a recently validated novel tractography approach. CST streamline volumes on both sides were compared between genders and correlated with age. Results Higher absolute streamline volumes were found in the left leg-related CST compared to the right (p=0.001) without a gender effect (p=0.4), whereas no differences were found in the absolute hand-related CST volumes (p>0.4). CST leg-related streamline volumes, normalized to hemispheric white matter volumes, declined with age in the right hemisphere only (R=−.51; p=0.004). Absolute leg-related CST streamline volumes showed similar, but slightly weaker correlations. Hand-related absolute or normalized CST streamline volumes showed no age-related variations on either side. Conclusion These results suggest differential development of CST segments controlling hand vs. leg movements. Asymmetric volume changes in the lower limb motor pathway may be secondary to gradually strengthening left hemispheric dominance and is consistent with previous data suggesting that footedness is a better predictor of hemispheric lateralization than handedness. PMID:25027193

Corpus callosal atrophy and associations with cognitive impairment in Parkinson disease

PubMed Central

Bledsoe, Ian O.; Merkitch, Doug; Dinh, Vy; Bernard, Bryan; Stebbins, Glenn T.

2017-01-01

Objective: To investigate atrophy of the corpus callosum on MRI in Parkinson disease (PD) and its relationship to cognitive impairment. Methods: One hundred patients with PD and 24 healthy control participants underwent clinical and neuropsychological evaluations and structural MRI brain scans. Participants with PD were classified as cognitively normal (PD-NC; n = 28), having mild cognitive impairment (PD-MCI; n = 47), or having dementia (PDD; n = 25) by Movement Disorder Society criteria. Cognitive domain (attention/working memory, executive function, memory, language, visuospatial function) z scores were calculated. With the use of FreeSurfer image processing, volumes for total corpus callosum and its subsections (anterior, midanterior, central, midposterior, posterior) were computed and normalized by total intracranial volume. Callosal volumes were compared between participants with PD and controls and among PD cognitive groups, covarying for age, sex, and PD duration and with multiple comparison corrections. Regression analyses were performed to evaluate relationships between callosal volumes and performance in cognitive domains. Results: Participants with PD had reduced corpus callosum volumes in midanterior and central regions compared to healthy controls. Participants with PDD demonstrated decreased callosal volumes involving multiple subsections spanning anterior to posterior compared to participants with PD-MCI and PD-NC. Regional callosal atrophy predicted cognitive domain performance such that central volumes were associated with the attention/working memory domain; midposterior volumes with executive function, language, and memory domains; and posterior volumes with memory and visuospatial domains. Conclusions: Notable volume loss occurs in the corpus callosum in PD, with specific neuroanatomic distributions in PDD and relationships of regional atrophy to different cognitive domains. Callosal volume loss may contribute to clinical manifestations of PD cognitive impairment. PMID:28235816

Controllable picoliter pipetting using hydrophobic microfluidic valves

NASA Astrophysics Data System (ADS)

Zhang, M.; Huang, J.; Qian, X.; Mi, S.; Wang, X.

2017-06-01

A picoliter pipetting technique using the microfluidic method is presented. Utilizing the hydrophobic self-assembled monolayer films patterned in microchannels as pressure-controlled valves, a small volume of liquid can be separated by a designed channel trap and then ejected from the channel end at a higher pressure. The liquid trap section is composed of a T-shaped channel junction and a hydrophobic patch. The liquid volume can be precisely controlled by varying the distance of the hydrophobic patch from the T-junction. By this means, liquid less than 100 pl can be separated and pipetted. The developed device is potentially useful for sample dispensing in biological, medical, and chemical applications.

Implications of Starvation-Induced Change in Right Dorsal Anterior Cingulate Volume in Anorexia Nervosa

PubMed Central

McCormick, Laurie M.; Keel, Pamela K.; Brumm, Michael C.; Bowers, Wayne; Swayze, Victor; Andersen, Arnold; Andreasen, Nancy

2013-01-01

Objective Converging evidence suggests a role for the anterior cingulate cortex (ACC) in the pathophysiology of anorexia nervosa (AN). This study sought to determine whether ACC volume was affected by starvation in active AN and, if so, whether this had any clinical significance. Method Eighteen patients with active AN and age- and gender-matched normal controls underwent magnetic resonance imaging (MRI). Sixteen patients (89%) with AN had intelligence quotients (IQ) testing at intake, 14 (78%) had repeat MRIs after weight normalization, and 10 (56%) had outcome data at 1-year post-hospitalization. Results Right dorsal ACC volume was significantly reduced in active AN patients versus controls and was correlated with lower performance IQ. While ACC normalization occurred with weight restoration, smaller change in right dorsal ACC volume prospectively predicted relapse after treatment. Conclusion Reduced right dorsal ACC volume during active AN relates to deficits in perceptual organization and conceptual reasoning. The degree of right dorsal ACC normalization during treatment is related to outcome. PMID:18473337

Differences in cognitive ability and hippocampal volume between Alzheimer's disease, amnestic mild cognitive impairment, and healthy control groups, and their correlation.

PubMed

Choi, Mi-Hyun; Kim, Hyung-Sik; Gim, Seon-Young; Kim, Woo-Ram; Mun, Kyung-Ryul; Tack, Gye-Rae; Lee, Bongsoo; Choi, Young Chil; Kim, Hyun-Jun; Hong, Seung Hwa; Lim, Dae-Woon; Chung, Soon-Cheol

2016-05-04

The study investigated differences in cognitive ability and hippocampal volume between groups of patients with Alzheimer's disease (AD) and amnestic mild cognitive impairment (aMCI), and healthy control (HC) subjects, and explored the relationship between cognitive ability and hippocampal volume. Among the sub-tests of Korean version of the Consortium to Establish a Registry for Alzheimer's Disease (CERAD-K), the Boston naming test score decreased in the order HC, aMCI, and AD. The hippocampal volumes of subjects with AD and aMCI were relatively smaller than those of HC individuals. There were strongly positive correlations between hippocampal volume and the scores for the Boston naming test. Discriminant analysis identified the Boston naming test as having the highest level of discrimination among the variables used to differentiate the three groups (89.9%). In conclusion, the Boston naming test accurately differentiated the three groups and was correlated with hippocampal volume. These results will be helpful for choosing an accurate and economically feasible test method that efficiently differentiates the three groups. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Application of Absorbable Hemostatic Materials Observed in Thyroid Operation

NASA Astrophysics Data System (ADS)

Li, Yan-Ming; Liang, Zhen-Zhen; Song, Yan

2016-05-01

To observe the application effects of the absorbable hemostatic materials in thyroid operation. Methods: From May 2014 to January 2015, 100 patients with thyroid surgery in our university affiliated hospital were selected as the research object. Randomly divided into experimental group and control group, 50 cases in each group. Application of absorbable hemostatic hemostatic materials in the experimental group during the operation, the control group using the traditional mechanical methods of hemostasis hemostasis to observe the operation time, bleeding volume, postoperative drainage volume, complications and hospital stay of the two groups. Results: The operation time, bleeding volume, postoperative drainage and hospital stay in the experimental group were significantly lower in the study group than in the control group, and the difference between the two groups was statistically significant (P< 0.05); The satisfaction of patients in the experimental group was significantly higher than that in the control group, the difference was statistically significant in the two groups (P < 0.05); There was no significant difference in the incidence of wound bleeding complications between the study group and the control group (P > 0.05). Conclusion: Absorbable hemostatic materials can effectively shorten the operation time, reduce intraoperative blood loss and postoperative drainage, reduce the length of hospital stay and improve the success rate of surgery and patient satisfaction, which is worthy to be popularized in clinical thyroid surgery.

Datamining approaches for modeling tumor control probability.

PubMed

Naqa, Issam El; Deasy, Joseph O; Mu, Yi; Huang, Ellen; Hope, Andrew J; Lindsay, Patricia E; Apte, Aditya; Alaly, James; Bradley, Jeffrey D

2010-11-01

Tumor control probability (TCP) to radiotherapy is determined by complex interactions between tumor biology, tumor microenvironment, radiation dosimetry, and patient-related variables. The complexity of these heterogeneous variable interactions constitutes a challenge for building predictive models for routine clinical practice. We describe a datamining framework that can unravel the higher order relationships among dosimetric dose-volume prognostic variables, interrogate various radiobiological processes, and generalize to unseen data before when applied prospectively. Several datamining approaches are discussed that include dose-volume metrics, equivalent uniform dose, mechanistic Poisson model, and model building methods using statistical regression and machine learning techniques. Institutional datasets of non-small cell lung cancer (NSCLC) patients are used to demonstrate these methods. The performance of the different methods was evaluated using bivariate Spearman rank correlations (rs). Over-fitting was controlled via resampling methods. Using a dataset of 56 patients with primary NCSLC tumors and 23 candidate variables, we estimated GTV volume and V75 to be the best model parameters for predicting TCP using statistical resampling and a logistic model. Using these variables, the support vector machine (SVM) kernel method provided superior performance for TCP prediction with an rs=0.68 on leave-one-out testing compared to logistic regression (rs=0.4), Poisson-based TCP (rs=0.33), and cell kill equivalent uniform dose model (rs=0.17). The prediction of treatment response can be improved by utilizing datamining approaches, which are able to unravel important non-linear complex interactions among model variables and have the capacity to predict on unseen data for prospective clinical applications.

Surface sampling concentration and reaction probe with controller to adjust sampling position

DOEpatents

Van Berkel, Gary J.; ElNaggar, Mariam S.

2016-07-19

A method of analyzing a chemical composition of a specimen is described. The method can include providing a probe comprising an outer capillary tube and an inner capillary tube disposed co-axially within the outer capillary tube, where the inner and outer capillary tubes define a solvent capillary and a sampling capillary in fluid communication with one another at a distal end of the probe; contacting a target site on a surface of a specimen with a solvent in fluid communication with the probe; maintaining a plug volume proximate a solvent-specimen interface, wherein the plug volume is in fluid communication with the probe; draining plug sampling fluid from the plug volume through the sampling capillary; and analyzing a chemical composition of the plug sampling fluid with an analytical instrument. A system for performing the method is also described.

Determination of plasma volume in anaesthetized piglets using the carbon monoxide (CO) method.

PubMed

Heltne, J K; Farstad, M; Lund, T; Koller, M E; Matre, K; Rynning, S E; Husby, P

2002-07-01

Based on measurements of the circulating red blood cell volume (V(RBC)) in seven anaesthetized piglets using carbon monoxide (CO) as a label, plasma volume (PV) was calculated for each animal. The increase in carboxyhaemoglobin (COHb) concentration following administration of a known amount of CO into a closed circuit re-breathing system was determined by diode-array spectrophotometry. Simultaneously measured haematocrit (HCT) and haemoglobin (Hb) values were used for PV calculation. The PV values were compared with simultaneously measured PVs determined using the Evans blue technique. Mean values (SD) for PV were 1708.6 (287.3)ml and 1738.7 (412.4)ml with the CO method and the Evans blue technique, respectively. Comparison of PVs determined with the two techniques demonstrated good correlation (r = 0.995). The mean difference between PV measurements was -29.9 ml and the limits of agreement (mean difference +/-2SD) were -289.1 ml and 229.3 ml. In conclusion, the CO method can be applied easily under general anaesthesia and controlled ventilation with a simple administration system. The agreement between the compared methods was satisfactory. Plasma volume determined with the CO method is safe, accurate and has no signs of major side effects.

A Second Law Based Unstructured Finite Volume Procedure for Generalized Flow Simulation

NASA Technical Reports Server (NTRS)

Majumdar, Alok

1998-01-01

An unstructured finite volume procedure has been developed for steady and transient thermo-fluid dynamic analysis of fluid systems and components. The procedure is applicable for a flow network consisting of pipes and various fittings where flow is assumed to be one dimensional. It can also be used to simulate flow in a component by modeling a multi-dimensional flow using the same numerical scheme. The flow domain is discretized into a number of interconnected control volumes located arbitrarily in space. The conservation equations for each control volume account for the transport of mass, momentum and entropy from the neighboring control volumes. In addition, they also include the sources of each conserved variable and time dependent terms. The source term of entropy equation contains entropy generation due to heat transfer and fluid friction. Thermodynamic properties are computed from the equation of state of a real fluid. The system of equations is solved by a hybrid numerical method which is a combination of simultaneous Newton-Raphson and successive substitution schemes. The paper also describes the application and verification of the procedure by comparing its predictions with the analytical and numerical solution of several benchmark problems.

Reducing the impact of speed dispersion on subway corridor flow.

PubMed

Qiao, Jing; Sun, Lishan; Liu, Xiaoming; Rong, Jian

2017-11-01

The rapid increase in the volume of subway passengers in Beijing has necessitated higher requirements for the safety and efficiency of subway corridors. Speed dispersion is an important factor that affects safety and efficiency. This paper aims to analyze the management control methods for reducing pedestrian speed dispersion in subways. The characteristics of the speed dispersion of pedestrian flow were analyzed according to field videos. The control measurements which were conducted by placing traffic signs, yellow marking, and guardrail were proposed to alleviate speed dispersion. The results showed that the methods of placing traffic signs, yellow marking, and a guardrail improved safety and efficiency for all four volumes of pedestrian traffic flow, and the best-performing control measurement was guardrails. Furthermore, guardrails' optimal position and design measurements were explored. The research findings provide a rationale for subway managers in optimizing pedestrian traffic flow in subway corridors. Copyright © 2017. Published by Elsevier Ltd.

Controlling sign problems in spin models using tensor renormalization

NASA Astrophysics Data System (ADS)

Denbleyker, Alan; Liu, Yuzhi; Meurice, Y.; Qin, M. P.; Xiang, T.; Xie, Z. Y.; Yu, J. F.; Zou, Haiyuan

2014-01-01

We consider the sign problem for classical spin models at complex β =1/g02 on L ×L lattices. We show that the tensor renormalization group method allows reliable calculations for larger Imβ than the reweighting Monte Carlo method. For the Ising model with complex β we compare our results with the exact Onsager-Kaufman solution at finite volume. The Fisher zeros can be determined precisely with the tensor renormalization group method. We check the convergence of the tensor renormalization group method for the O(2) model on L×L lattices when the number of states Ds increases. We show that the finite size scaling of the calculated Fisher zeros agrees very well with the Kosterlitz-Thouless transition assumption and predict the locations for larger volume. The location of these zeros agree with Monte Carlo reweighting calculation for small volume. The application of the method for the O(2) model with a chemical potential is briefly discussed.

Fracture control methods for space vehicles. Volume 1: Fracture control design methods. [for space shuttle configuration planning

NASA Technical Reports Server (NTRS)

Liu, A. F.

1974-01-01

A systematic approach for applying methods for fracture control in the structural components of space vehicles consists of four major steps. The first step is to define the primary load-carrying structural elements and the type of load, environment, and design stress levels acting upon them. The second step is to identify the potential fracture-critical parts by means of a selection logic flow diagram. The third step is to evaluate the safe-life and fail-safe capabilities of the specified part. The last step in the sequence is to apply the control procedures that will prevent damage to the fracture-critical parts. The fracture control methods discussed include fatigue design and analysis methods, methods for preventing crack-like defects, fracture mechanics analysis methods, and nondestructive evaluation methods. An example problem is presented for evaluation of the safe-crack-growth capability of the space shuttle crew compartment skin structure.

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

Wang Hua; Department of Radiation Oncology, Cancer Hospital of Jiangxi Province, Jiangxi Province; Li Yexiong, E-mail: yexiong@yahoo.com

Purpose: The value of intensity-modulated radiotherapy (IMRT) for early-stage nasal NK/T-cell lymphoma has not been previously reported. The aim of the present study was to assess the dosimetric parameters, toxicity, and treatment outcomes of patients with nasal NK/T-cell lymphoma. Methods and Materials: Between 2003 and 2008, 42 patients with early-stage nasal NK/T-cell lymphoma underwent definitive high-dose and extended involved-field IMRT with or without combination chemotherapy. The median radiation dose to the primary tumor was 50 Gy. The dose-volume histograms of the target volume and critical normal structures were evaluated in all patients. The locoregional control, overall survival, and progression-free survivalmore » were calculated using the Kaplan-Meier method. Results: The average mean dose delivered to the planning target volume was 55.5 Gy. Only 1.3% and 2.5% of the planning target volume received <90% and 95% of the prescribed dose, respectively, indicating excellent planning target volume coverage. The mean dose and average dose to the parotid glands was 15 Gy and 14 Gy, respectively. With a median follow-up time of 27 months, the 2-year locoregional control, overall survival, and progression-free survivalrate was 93%, 78%, and 74%, respectively. No Grade 4 or 5 acute or late toxicity was reported. Conclusions: High-dose and extended involved-field IMRT for patients with early-stage nasal NK/T-cell lymphoma showed favorable locoregional control, overall survival, and progression-free survival, with mild toxicity. The dose constraints of IMRT for the parotid glands can be limited to <20 Gy in these patients.« less

Locoregional Control of Non-Small Cell Lung Cancer in Relation to Automated Early Assessment of Tumor Regression on Cone Beam Computed Tomography

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

Brink, Carsten, E-mail: carsten.brink@rsyd.dk; Laboratory of Radiation Physics, Odense University Hospital; Bernchou, Uffe

2014-07-15

Purpose: Large interindividual variations in volume regression of non-small cell lung cancer (NSCLC) are observable on standard cone beam computed tomography (CBCT) during fractionated radiation therapy. Here, a method for automated assessment of tumor volume regression is presented and its potential use in response adapted personalized radiation therapy is evaluated empirically. Methods and Materials: Automated deformable registration with calculation of the Jacobian determinant was applied to serial CBCT scans in a series of 99 patients with NSCLC. Tumor volume at the end of treatment was estimated on the basis of the first one third and two thirds of the scans.more » The concordance between estimated and actual relative volume at the end of radiation therapy was quantified by Pearson's correlation coefficient. On the basis of the estimated relative volume, the patients were stratified into 2 groups having volume regressions below or above the population median value. Kaplan-Meier plots of locoregional disease-free rate and overall survival in the 2 groups were used to evaluate the predictive value of tumor regression during treatment. Cox proportional hazards model was used to adjust for other clinical characteristics. Results: Automatic measurement of the tumor regression from standard CBCT images was feasible. Pearson's correlation coefficient between manual and automatic measurement was 0.86 in a sample of 9 patients. Most patients experienced tumor volume regression, and this could be quantified early into the treatment course. Interestingly, patients with pronounced volume regression had worse locoregional tumor control and overall survival. This was significant on patient with non-adenocarcinoma histology. Conclusions: Evaluation of routinely acquired CBCT images during radiation therapy provides biological information on the specific tumor. This could potentially form the basis for personalized response adaptive therapy.« less

Entorhinal Cortex Volume in Antipsychotic-naïve Schizophrenia.

PubMed

Jose, Sam P; Sharma, Eesha; Narayanaswamy, Janardhanan C; Rajendran, Vishnurajan; Kalmady, Sunil V; Rao, Naren P; Venkatasubramanian, Ganesan; Gangadhar, Bangalore N

2012-04-01

Entorhinal cortex (ERC), a multimodal sensory relay station for the hippocampus, is critically involved in learning, emotion, and novelty detection. One of the pathogenetic mechanistic bases in schizophrenia is proposed to involve aberrant information processing in the ERC. Several studies have looked at cytoarchitectural and morphometric changes in the ERC, but results have been inconsistent possibly due to the potential confounding effects of antipsychotic treatment. In this study, we have examined the entorhinal cortex volume in antipsychotic-naïve schizophrenia patients (n=40; M:F=22:18) in comparison with age, sex, and handedness, matched (as a group) with healthy subjects (n=42; M:F=25:17) using a valid method. 3-Tesla MR images with 1-mm sections were used and the data was analyzed using the SPSS software. Female schizophrenia patients (1.25±0.22 mL) showed significant volume deficit in the right ERC in comparison with female healthy controls (1.45±0.34 mL) (F=4.9; P=0.03), after controlling for the potential confounding effects of intracranial volume. However, male patients did not differ from male controls. The left ERC volume did not differ between patients and controls. Consistent with the findings of a few earlier studies we found a reduction in the right ERC volume in patients. However, this was limited to women. Contextually, our study finding supports the role for ERC deficit in schizophrenia pathogenesis - perhaps mediated through aberrant novelty detection. Sex-differential observation of ERC volume deficit in schizophrenia needs further studies.

A new Doppler-echo method to quantify regurgitant volume.

PubMed

Wang, S S; Rubenstein, J J; Goldman, M; Sidd, J J

1992-01-01

An in vitro technique using color flow imaging and continuous wave Doppler was developed to measure the initial regurgitant flow jet diameter and velocity integral to yield the parameters for a volume calculation. Jets were produced by volume-controlled injection through tubes of various diameters (1.3, 1.9, 2.8, and 3.5 mm) to deliver volumes from 1 to 7 ml over 100 to 300 msec at pressures from 40 to 200 mm Hg. One hundred forty-five samples were obtained. Flow jet diameter consistently overestimated tube diameter by 2 mm when injected volume was 1.5 to 7 ml and by 1.5 mm when injected volume was less than 1.5 ml. This offset was stable with various transducers (2.5, 3.5, 5.0 MHz) at normal gain setting (just under noise). Therefore, corrected flow jet diameter (FJD) = FJD - 2 mm, and Doppler volume = corrected flow jet area x velocity integral. A range of injectates from 1.1 to 7 ml generated Doppler volume of 1.0 to 8.2 ml. The relation between Doppler volume (DV) and injected volume (IV) was DV = 1.079 IV - 0.22, r2 = 0.945, p less than 0.01. This relation was not altered by tube diameter. Thus a method combining color flow imaging and continuous wave Doppler provides a reliable and accurate measure of in vitro flow volume.

Differences in and correlations between cognitive abilities and brain volumes in healthy control, mild cognitive impairment, and Alzheimer disease groups.

PubMed

Chung, Soon-Cheol; Choi, Mi-Hyun; Kim, Hyung-Sik; Lee, Jung-Chul; Park, Sung-Jun; Jeong, Ul-Ho; Baek, Ji-Hye; Gim, Seon-Young; Choi, Young Chil; Lee, Beob-Yi; Lim, Dae-Woon; Kim, Boseong

2016-05-01

The purpose of this study is to investigate differences in and correlations between cognitive abilities and brain volumes in healthy control (HC), mild cognitive impairment (MCI), and Alzheimer's disease (AD) groups. The Korean Version of the Consortium to Establish a Registry for Alzheimer's Disease (CERAD-K), which is used to diagnose AD, was used to measure the cognitive abilities of the study subjects, and the volumes of typical brain components related to AD diagnosis-cerebrospinal fluid (CSF), gray matter (GM), and white matter (WM)-were acquired. Of the CERAD-K subtests, the Boston Naming Test distinguished significantly among the HC, MCI, and AD groups. GM and WM volumes differed significantly among the three groups. There was a significant positive correlation between Boston Naming Test scores and GM and WM volumes. In conclusion, the Boston Naming Test and GM and WM brain volumes differentiated the three tested groups accurately, and there were strong correlations between Boston Naming Test scores and GM and WM volumes. These results will help to establish a test method that differentiates the three groups accurately and is economically feasible. © 2016 Wiley Periodicals, Inc.

High call volume at poison control centers: identification and implications for communication

PubMed Central

CARAVATI, E. M.; LATIMER, S.; REBLIN, M.; BENNETT, H. K. W.; CUMMINS, M. R.; CROUCH, B. I.; ELLINGTON, L.

2016-01-01

Context High volume surges in health care are uncommon and unpredictable events. Their impact on health system performance and capacity is difficult to study. Objectives To identify time periods that exhibited very busy conditions at a poison control center and to determine whether cases and communication during high volume call periods are different from cases during low volume periods. Methods Call data from a US poison control center over twelve consecutive months was collected via a call logger and an electronic case database (Toxicall®). Variables evaluated for high call volume conditions were: (1) call duration; (2) number of cases; and (3) number of calls per staff member per 30 minute period. Statistical analyses identified peak periods as busier than 99% of all other 30 minute time periods and low volume periods as slower than 70% of all other 30 minute periods. Case and communication characteristics of high volume and low volume calls were compared using logistic regression. Results A total of 65,364 incoming calls occurred over 12 months. One hundred high call volume and 4885 low call volume 30 minute periods were identified. High volume periods were more common between 1500 and 2300 hours and during the winter months. Coded verbal communication data were evaluated for 42 high volume and 296 low volume calls. The mean (standard deviation) call length of these calls during high volume and low volume periods was 3 minutes 27 seconds (1 minute 46 seconds) and 3 minutes 57 seconds (2 minutes 11 seconds), respectively. Regression analyses revealed a trend for fewer overall verbal statements and fewer staff questions during peak periods, but no other significant differences for staff-caller communication behaviors were found. Conclusion Peak activity for poison center call volume can be identified by statistical modeling. Calls during high volume periods were similar to low volume calls. Communication was more concise yet staff was able to maintain a good rapport with callers during busy call periods. This approach allows evaluation of poison exposure call characteristics and communication during high volume periods. PMID:22889059

Face-Name Association Learning and Brain Structural Substrates in Alcoholism

PubMed Central

Pitel, Anne-Lise; Chanraud, Sandra; Rohlfing, Torsten; Pfefferbaum, Adolf; Sullivan, Edith V.

2011-01-01

Background Associative learning is required for face-name association and is impaired in alcoholism, but the cognitive processes and brain structural components underlying this deficit remain unclear. It is also unknown whether prompting alcoholics to implement a deep level of processing during face-name encoding would enhance performance. Methods Abstinent alcoholics and controls performed a levels-of-processing face-name learning task. Participants indicated whether the face was that of an honest person (deep encoding) or that of a man (shallow encoding). Retrieval was examined using an associative (face-name) recognition task and a single-item (face or name only) recognition task. Participants also underwent a 3T structural MRI. Results Compared with controls, alcoholics had poorer associative and single-item recognition, each impaired to the same extent. Level of processing at encoding had little effect on recognition performance but affected reaction time. Correlations with brain volumes were generally modest and based primarily on reaction time in alcoholics, where the deeper the processing at encoding, the more restricted the correlations with brain volumes. In alcoholics, longer control task reaction times correlated modestly with volumes across several anterior to posterior brain regions; shallow encoding correlated with calcarine and striatal volumes; deep encoding correlated with precuneus and parietal volumes; associative recognition RT correlated with cerebellar volumes. In controls, poorer associative recognition with deep encoding correlated significantly with smaller volumes of frontal and striatal structures. Conclusions Despite prompting, alcoholics did not take advantage of encoding memoranda at a deep level to enhance face-name recognition accuracy. Nonetheless, conditions of deeper encoding resulted in faster reaction times and more specific relations with regional brain volumes than did shallow encoding. The normal relation between associative recognition and corticostriatal volumes was not present in alcoholics. Rather, their speeded reaction time occurred at the expense of accuracy and was related most robustly to cerebellar volumes. PMID:22509954

A budget of energy transfer in a sustained vocal folds vibration in glottis

NASA Astrophysics Data System (ADS)

Zhang, Lucy; Yang, Jubiao; Krane, Michael

2016-11-01

A set of force and energy balance equations using the control volume approach is derived based on the first principles of physics for a sustained vocal folds vibration in glottis. The control volume analysis is done for compressible airflow in a moving and deforming control volume in the vicinity of the vocal folds. The interaction between laryngeal airflow and vocal folds are successfully simulated using the modified Immersed Finite Element Method (mIFEM), a fully coupled approach to simulate fluid-structure interactions. Detailed mathematical terms are separated out for deeper physical understanding and utilization of mechanical energy is quantified with the derived equation. The results show that majority of energy input is consumed for driving laryngeal airflow, while a smaller portion is for compensating viscous losses in and sustaining the vibration of the vocal folds. We acknowledge the funding support of NIH 2R01DC005642-10A1.

Application of Control Volume Analysis to Cerebrospinal Fluid Dynamics

NASA Astrophysics Data System (ADS)

Wei, Timothy; Cohen, Benjamin; Anor, Tomer; Madsen, Joseph

2011-11-01

Hydrocephalus is among the most common birth defects and may not be prevented nor cured. Afflicted individuals face serious issues, which at present are too complicated and not well enough understood to treat via systematic therapies. This talk outlines the framework and application of a control volume methodology to clinical Phase Contrast MRI data. Specifically, integral control volume analysis utilizes a fundamental, fluid dynamics methodology to quantify intracranial dynamics within a precise, direct, and physically meaningful framework. A chronically shunted, hydrocephalic patient in need of a revision procedure was used as an in vivo case study. Magnetic resonance velocity measurements within the patient's aqueduct were obtained in four biomedical state and were analyzed using the methods presented in this dissertation. Pressure force estimates were obtained, showing distinct differences in amplitude, phase, and waveform shape for different intracranial states within the same individual. Thoughts on the physiological and diagnostic research and development implications/opportunities will be presented.

International training course on nuclear materials accountability for safeguards purposes

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

Not Available

1980-12-01

The two volumes of this report incorporate all lectures and presentations at the International Training Course on Nuclear Materials Accountability and Control for Safeguards Purposes, held May 27-June 6, 1980, at the Bishop's Lodge near Santa Fe, New Mexico. The course, authorized by the US Nuclear Non-Proliferation Act and sponsored by the US Department of Energy in cooperation with the International Atomic Energy Agency, was developed to provide practical training in the design, implementation, and operation of a National system of nuclear materials accountability and control that satisfies both National and IAEA International safeguards objectives. Volume I, covering the firstmore » week of the course, presents the background, requirements, and general features of material accounting and control in modern safeguard systems. Volume II, covering the second week of the course, provides more detailed information on measurement methods and instruments, practical experience at power reactor and research reactor facilities, and examples of operating state systems of accountability and control.« less

The measurement of peripheral blood volume reactions to tilt test by the electrical impedance technique after exercise in athletes

NASA Astrophysics Data System (ADS)

Melnikov, A. A.; Popov, S. G.; Nikolaev, D. V.; Vikulov, A. D.

2013-04-01

We have investigated the distribution of peripheral blood volumes in different regions of the body in response to the tilt-test in endurance trained athletes after aerobic exercise. Distribution of peripheral blood volumes (ml/beat) simultaneously in six regions of the body (two legs, two hands, abdomen, neck and ECG) was assessed in response to the tilt-test using the impedance method (the impedance change rate (dZ/dT). Before and after exercise session cardiac stroke (CSV) and blood volumes in legs, arms and neck were higher in athletes both in lying and standing positions. Before exercise the increase of heart rate and the decrease of a neck blood volume in response to tilting was lower (p <0.05) but the decrease of leg blood volumes was higher (p<0.001) in athletes. The reactions in arms and abdomen blood volumes were similar. Also, the neck blood volumes as percentage of CSV (%/CSV) did not change in the control but increased in athletes (p <0.05) in response to the tilt test. After (10 min recovery) the aerobic bicycle exercise (mean HR = 156±8 beat/min, duration 30 min) blood volumes in neck and arms in response to the tilting were reduced equally, but abdomen (p<0.05) and leg blood volumes (p <0.001) were lowered more significantly in athletes. The neck blood flow (%/CSV) did not change in athletes but decreased in control (p<0.01), which was offset by higher tachycardia in response to tilt-test in controls after exercise. The data demonstrate greater orthostatic tolerance in athletes both before and after exercise during fatigue which is due to effective distribution of blood flows aimed at maintaining cerebral blood flow.

Taylor bubbles at high viscosity ratios: experiments and numerical simulations

NASA Astrophysics Data System (ADS)

Hewakandamby, Buddhika; Hasan, Abbas; Azzopardi, Barry; Xie, Zhihua; Pain, Chris; Matar, Omar

2015-11-01

The Taylor bubble is a single long bubble which nearly fills the entire cross section of a liquid-filled circular tube, often occurring in gas-liquid slug flows in many industrial applications, particularly oil and gas production. The objective of this study is to investigate the fluid dynamics of three-dimensional Taylor bubble rising in highly viscous silicone oil in a vertical pipe. An adaptive unstructured mesh modelling framework is adopted here which can modify and adapt anisotropic unstructured meshes to better represent the underlying physics of bubble rising and reduce computational effort without sacrificing accuracy. The numerical framework consists of a mixed control volume and finite element formulation, a `volume of fluid'-type method for the interface-capturing based on a compressive control volume advection method, and a force-balanced algorithm for the surface tension implementation. Experimental results for the Taylor bubble shape and rise velocity are presented, together with numerical results for the dynamics of the bubbles. A comparison of the simulation predictions with experimental data available in the literature is also presented to demonstrate the capabilities of our numerical method. EPSRC Programme Grant, MEMPHIS, EP/K0039761/1.

Putaminal volume and diffusion in early familial Creutzfeldt-Jakob disease.

PubMed

Seror, Ilana; Lee, Hedok; Cohen, Oren S; Hoffmann, Chen; Prohovnik, Isak

2010-01-15

The putamen is centrally implicated in the pathophysiology of Creutzfeldt-Jakob Disease (CJD). To our knowledge, its volume has never been measured in this disease. We investigated whether gross putaminal atrophy can be detected by MRI in early stages, when the diffusion is already reduced. Twelve familial CJD patients with the E200K mutation and 22 healthy controls underwent structural and diffusion MRI scans. The putamen was identified in anatomical scans by two methods: manual tracing by a blinded investigator, and automatic parcellation by a computerized segmentation procedure (FSL FIRST). For each method, volume and mean Apparent Diffusion Coefficient (ADC) were calculated. ADC was significantly lower in CJD patients (697+/-64 microm(2)/s vs. 750+/-31 microm(2)/s, p<0.005), as expected, but the volume was not reduced. The computerized FIRST delineation yielded comparable ADC values to the manual method, but computerized volumes were smaller than manual tracing values. We conclude that significant diffusion reduction in the putamen can be detected by delineating the structure manually or with a computerized algorithm. Our findings confirm and extend previous voxel-based and observational studies. Putaminal volume was not reduced in our early-stage patients, thus confirming that diffusion abnormalities precede detectible atrophy in this structure.

The Combination of Micro Diaphragm Pumps and Flow Sensors for Single Stroke Based Liquid Flow Control

PubMed Central

Jenke, Christoph; Pallejà Rubio, Jaume; Kibler, Sebastian; Häfner, Johannes; Richter, Martin; Kutter, Christoph

2017-01-01

With the combination of micropumps and flow sensors, highly accurate and secure closed-loop controlled micro dosing systems for liquids are possible. Implementing a single stroke based control mode with piezoelectrically driven micro diaphragm pumps can provide a solution for dosing of volumes down to nanoliters or variable average flow rates in the range of nL/min to μL/min. However, sensor technologies feature a yet undetermined accuracy for measuring highly pulsatile micropump flow. Two miniaturizable in-line sensor types providing electrical readout—differential pressure based flow sensors and thermal calorimetric flow sensors—are evaluated for their suitability of combining them with mircopumps. Single stroke based calibration of the sensors was carried out with a new method, comparing displacement volumes and sensor flow volumes. Limitations of accuracy and performance for single stroke based flow control are described. Results showed that besides particle robustness of sensors, controlling resistive and capacitive damping are key aspects for setting up reproducible and reliable liquid dosing systems. Depending on the required average flow or defined volume, dosing systems with an accuracy of better than 5% for the differential pressure based sensor and better than 6.5% for the thermal calorimeter were achieved. PMID:28368344

Analysis of Water Volume Changes and Temperature Measurement Location Effect to the Accuracy of RTP Power Calibration

NASA Astrophysics Data System (ADS)

Lanyau, T.; Hamzah, N. S.; Jalal Bayar, A. M.; Karim, J. Abdul; Phongsakorn, P. K.; Suhaimi, K. Mohammad; Hashim, Z.; Razi, H. Md; Fazli, Z. Mohd; Ligam, A. S.; Mustafa, M. K. A.

2018-01-01

Power calibration is one of the important aspect for safe operation of the reactor. In RTP, the calorimetric method has been applied in reactor power calibration. This method involves measurement of water temperature in the RTP tank. Water volume and location of the temperature measurement may play an important role to the accuracy of the measurement. In this study, the analysis of water volume changes and thermocouple location effect to the power calibration accuracy has been done. The changes of the water volume are controlled by the variation of water level in reactor tank. The water level is measured by the ultrasonic measurement device. Temperature measurement has been done by thermocouple placed at three different locations. The accuracy of the temperature trend from various condition of measurement has been determined and discussed in this paper.

Pituitary Volumes Are Reduced in Patients with Somatization Disorder

PubMed Central

Yildirim, Hanefi; Sirlier, Burcu; Kayali, Alperen

2012-01-01

Objective Despite of the suggested physiological relationship between somatoform disorder and disturbances in HPA axis function no volumetric study of pituitary volumes in somatization disorder has been carried out. Therefore, we aimed to use structural MRI to evaluate the pituitary volumes of the patients with somatization disorder. Methods Eighteen female patients with somatization disorder according to DSM-IV and same number of healthy controls were included into the study. All subjects were scanned using a 1.5-T General Electric (GE; Milwaukee, USA) scanner. Pituitary volume measurements were determined by using manuallly tracings according to standard antomical atlases. Results It was found significantly smaller pituitary volumes of the whole group of somatization patients compared to healthy (t=-3.604, p=0.001). ANCOVA predicting pituitary volumes demonstrated a significant main effect of diagnostic group (F=13.530, p<0.001) but TBV (F=1.924, p>0.05) or age (F=1.159, p>0.05). It was determined that there was no significant correlation between smaller pituitary volumes and the duration of illness (r=0.16, p>0.05) in the patient group. Conclusion In conclusion, we suggest that the patients with somatization disorder might have significantly smaller pituitary volumes compared to healthy control subjects. PMID:22993528

29 CFR 1910.1029 - Coke oven emissions.

Code of Federal Regulations, 2014 CFR

2014-07-01

..., including at least one sample during each shift for each battery and each job classification within the... controls to control coke oven emissions during charging operations: (a) One of the following methods of...) Aspiration systems designed and operated to provide sufficient negative pressure and flow volume to...

29 CFR 1910.1029 - Coke oven emissions.

Code of Federal Regulations, 2013 CFR

2013-07-01

..., including at least one sample during each shift for each battery and each job classification within the... controls to control coke oven emissions during charging operations: (a) One of the following methods of...) Aspiration systems designed and operated to provide sufficient negative pressure and flow volume to...

29 CFR 1910.1029 - Coke oven emissions.

Code of Federal Regulations, 2012 CFR

2012-07-01

..., including at least one sample during each shift for each battery and each job classification within the... controls to control coke oven emissions during charging operations: (a) One of the following methods of...) Aspiration systems designed and operated to provide sufficient negative pressure and flow volume to...

Active control of sound transmission through a rectangular panel using point-force actuators and piezoelectric film sensors.

PubMed

Sanada, Akira; Higashiyama, Kouji; Tanaka, Nobuo

2015-01-01

This study deals with the active control of sound transmission through a rectangular panel, based on single input, single output feedforward vibration control using point-force actuators and piezoelectric film sensors. It focuses on the phenomenon in which the sound power transmitted through a finite-sized panel drops significantly at some frequencies just below the resonance frequencies of the panel in the low-frequency range as a result of modal coupling cancellation. In a previous study, it was shown that when point-force actuators are located on nodal lines for the frequency at which this phenomenon occurs, a force equivalent to the incident sound wave can act on the panel. In this study, a practical method for sensing volume velocity using a small number of piezoelectric film strips is investigated. It is found that two quadratically shaped piezoelectric film strips, attached at the same nodal lines as those where the actuators were placed, can sense the volume velocity approximately in the low-frequency range. Results of simulations show that combining the proposed actuation method and the sensing method can achieve a practical control effect at low frequencies over a wide frequency range. Finally, experiments are carried out to demonstrate the validity and feasibility of the proposed method.

Methods of synthesizing hydroxyapatite powders and bulk materials

DOEpatents

Luo, Ping

1999-01-12

Methods are provided for producing non-porous controlled morphology hydroxyapatite granules of less than 8 .mu.m by a spray-drying process. Solid or hollow spheres or doughnuts can be formed by controlling the volume fraction and viscosity of the slurry as well as the spray-drying conditions. Methods of providing for homogenous cellular structure hydroxyapatite granules are also provided. Pores or channels or varying size and number can be formed by varying the temperature at which a hydroxyapatite slurry formed in basic, saturated ammonium hydroxide is spray-dried. Methods of providing non-porous controlled morphology hydroxyapatite granules in ammonium hydroxide are also provided. The hydroxyapatite granules and bulk materials formed by these methods are also provided.

Methods of synthesizing hydroxyapatite powders and bulk materials

DOEpatents

Luo, P.

1999-01-12

Methods are provided for producing non-porous controlled morphology hydroxyapatite granules of less than 8 {micro}m by a spray-drying process. Solid or hollow spheres or doughnuts can be formed by controlling the volume fraction and viscosity of the slurry as well as the spray-drying conditions. Methods of providing for homogeneous cellular structure hydroxyapatite granules are also provided. Pores or channels or varying size and number can be formed by varying the temperature at which a hydroxyapatite slurry formed in basic, saturated ammonium hydroxide is spray-dried. Methods of providing non-porous controlled morphology hydroxyapatite granules in ammonium hydroxide are also provided. The hydroxyapatite granules and bulk materials formed by these methods are also provided. 26 figs.

Calculation of the capnographic index based on expiratory molar mass-volume-curves--a suitable tool to screen for cystic fibrosis lung disease.

PubMed

Fuchs, Susanne I; Junge, Sibylle; Ellemunter, Helmut; Ballmann, Manfred; Gappa, Monika

2013-05-01

Volumetric capnography reflecting the course of CO2-exhalation is used to assess ventilation inhomogeneity. Calculation of the slope of expiratory phase 3 and the capnographic index (KPIv) from expirograms allows quantification of extent and severity of small airway impairment. However, technical limitations have hampered more widespread use of this technique. Using expiratory molar mass-volume-curves sampled with a handheld ultrasonic flow sensor during tidal breathing is a novel approach to extract similar information from expirograms in a simpler manner possibly qualifying as a screening tool for clinical routine. The aim of the present study was to evaluate calculation of the KPIv based on molar mass-volume-curves sampled with an ultrasonic flow sensor in patients with CF and controls by assessing feasibility, reproducibility and comparability with the Lung Clearance Index (LCI) derived from multiple breath washout (MBW) used as the reference method. Measurements were performed in patients with CF and healthy controls during a single test occasion using the EasyOne Pro, MBW Module (ndd Medical Technologies, Switzerland). Capnography and MBW were performed in 87/96 patients with CF and 38/42 controls, with a success rate of 90.6% for capnography. Mean age (range) was 12.1 (4-25) years. Mean (SD) KPIv was 6.94 (3.08) in CF and 5.10 (2.06) in controls (p=0.001). Mean LCI (SD) was 8.0 (1.4) in CF and 6.2 (0.4) in controls (p=<0.001) and correlated significantly with the KPIv (p=<0.001). Calculation of the KPIv based on molar mass-volume-curves is feasible. KPIv is significantly different between patients with CF and controls and correlates with the LCI. However, individual data revealed a relevant overlap between patients and controls requiring further evaluation, before this method can be recommended for clinical use. Copyright © 2012 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

Issues in NASA program and project management

NASA Technical Reports Server (NTRS)

Hoffman, Edward J. (Editor)

1994-01-01

This volume is the eighth in an ongoing series addressing current topics and lessons learned in NASA program and project management. Articles in this volume cover the following topics: (1) power sources for the Galileo and Ulysses Missions; (2) managing requirements; (3) program control of the Tropical Rainfall Measuring Mission; (4) project management method; (5) career development for project managers; and (6) resources for NASA managers.

Corpus Callosum Area and Brain Volume in Autism Spectrum Disorder: Quantitative Analysis of Structural MRI from the ABIDE Database

ERIC Educational Resources Information Center

Kucharsky Hiess, R.; Alter, R.; Sojoudi, S.; Ardekani, B. A.; Kuzniecky, R.; Pardoe, H. R.

2015-01-01

Reduced corpus callosum area and increased brain volume are two commonly reported findings in autism spectrum disorder (ASD). We investigated these two correlates in ASD and healthy controls using T1-weighted MRI scans from the Autism Brain Imaging Data Exchange (ABIDE). Automated methods were used to segment the corpus callosum and intracranial…

Predictive Flow Control to Minimize Convective Time Delays

DTIC Science & Technology

2013-08-19

simulation. The CFO solver used is Cobalt, an unstructured finite-volume code developed for the solution of the compress- ible Navier-Stokes...cell-centered fin ite volume approach applicable to arbitrary cell topologies (e.g, hexahedra, prisms, tetrahedra). The spatial operator uses a Riemann ... solver , least squares gradient calculations using QR factorizati on to provide second order accuracy in space. A point implicit method using

Membranes with artificial free-volume for biofuel production

PubMed Central

Petzetakis, Nikos; Doherty, Cara M.; Thornton, Aaron W.; Chen, X. Chelsea; Cotanda, Pepa; Hill, Anita J.; Balsara, Nitash P.

2015-01-01

Free-volume of polymers governs transport of penetrants through polymeric films. Control over free-volume is thus important for the development of better membranes for a wide variety of applications such as gas separations, pharmaceutical purifications and energy storage. To date, methodologies used to create materials with different amounts of free-volume are based primarily on chemical synthesis of new polymers. Here we report a simple methodology for generating free-volume based on the self-assembly of polyethylene-b-polydimethylsiloxane-b-polyethylene triblock copolymers. We have used this method to fabricate a series of membranes with identical compositions but with different amounts of free-volume. We use the term artificial free-volume to refer to the additional free-volume created by self-assembly. The effect of artificial free-volume on selective transport through the membranes was tested using butanol/water and ethanol/water mixtures due to their importance in biofuel production. We found that the introduction of artificial free-volume improves both alcohol permeability and selectivity. PMID:26104672

Membranes with artificial free-volume for biofuel production

NASA Astrophysics Data System (ADS)

Petzetakis, Nikos; Doherty, Cara M.; Thornton, Aaron W.; Chen, X. Chelsea; Cotanda, Pepa; Hill, Anita J.; Balsara, Nitash P.

2015-06-01

Free-volume of polymers governs transport of penetrants through polymeric films. Control over free-volume is thus important for the development of better membranes for a wide variety of applications such as gas separations, pharmaceutical purifications and energy storage. To date, methodologies used to create materials with different amounts of free-volume are based primarily on chemical synthesis of new polymers. Here we report a simple methodology for generating free-volume based on the self-assembly of polyethylene-b-polydimethylsiloxane-b-polyethylene triblock copolymers. We have used this method to fabricate a series of membranes with identical compositions but with different amounts of free-volume. We use the term artificial free-volume to refer to the additional free-volume created by self-assembly. The effect of artificial free-volume on selective transport through the membranes was tested using butanol/water and ethanol/water mixtures due to their importance in biofuel production. We found that the introduction of artificial free-volume improves both alcohol permeability and selectivity.

Membranes with artificial free-volume for biofuel production

DOE PAGES

Petzetakis, Nikos; Doherty, Cara M.; Thornton, Aaron W.; ...

2015-06-24

Free-volume of polymers governs transport of penetrants through polymeric films. Control over free-volume is thus important for the development of better membranes for a wide variety of applications such as gas separations, pharmaceutical purifications and energy storage. To date, methodologies used to create materials with different amounts of free-volume are based primarily on chemical synthesis of new polymers. Here we report a simple methodology for generating free-volume based on the self-assembly of polyethylene-b-polydimethylsiloxane-b-polyethylene triblock copolymers. Here, we have used this method to fabricate a series of membranes with identical compositions but with different amounts of free-volume. We use the termmore » artificial free-volume to refer to the additional free-volume created by self-assembly. The effect of artificial free-volume on selective transport through the membranes was tested using butanol/water and ethanol/water mixtures due to their importance in biofuel production. Moreover, we found that the introduction of artificial free-volume improves both alcohol permeability and selectivity.« less

Lower Hippocampal Volume Predicts Decrements in Lane Control among Drivers with Amnestic MCI

PubMed Central

Griffith, H Randall; Okonkwo, Ozioma C; Stewart, Christopher C; Stoeckel, Luke E; den Hollander, Jan A; Elgin, Jennifer M; Harrell, Lindy E; Brockington, John C; Clark, David G; Ball, Karlene K; Owsley, Cynthia; Marson, Daniel C; Wadley, Virginia G

2014-01-01

Objectives There are few methods to discern driving risks in patients with early dementia and Mild Cognitive Impairment (MCI). We aimed to determine whether structural MRI of the hippocampus – a biomarker of probable Alzheimer pathology and a measure of disease severity in those affected – is linked to objective ratings of on-road driving performance in older adults with and without amnestic MCI. Methods 49 consensus-diagnosed participants from an Alzheimer's Disease Research Center (15 diagnosed with amnestic MCI and 34 demographically similar controls) underwent structural MRI and on-road driving assessments. Results Mild atrophy of the left hippocampus was associated with less-than-optimal ratings in lane control but not with other discrete driving skills. Decrements in left hippocampal volume conferred higher risk for less-than-optimal lane control ratings in the MCI patients (B = −1.63, SE = .74, Wald = 4.85, P = .028), but not in controls (B = 0.13, SE = .415, Wald = 0.10, P = .752). The odds ratio (OR) and 95% confidence interval (CI) for below optimal lane control in the MCI group was 4.41 (1.18, 16.36), which was attenuated to 3.46 (0.88, 13.60) after accounting for the contribution of left hippocampal volume. Conclusion These findings suggest that there may be a link between hippocampal atrophy and difficulties with lane control in persons with amnestic MCI. Further study appears warranted to better discern patterns of brain atrophy in MCI and AD and whether these could be early markers of clinically meaningful driving risk. PMID:24212246

Research on Volume Measurement System of Weights with Hydrostatic Technique

NASA Astrophysics Data System (ADS)

Wang, Jian; Ren, Xiaoping; Yao, Hong; Cai, Changqing; Zhang, Yue; Zhong, Ruilin; Ding, Jing'an

According to Annex B.7.4 of OIML R111-1, equipment for measuring volume of weights mass ranging from 1 kg to 20 kg including three methods of hydrostatic comparison is described. The equipment consists of a robot arm for transferring weights, a liquid bath, a mass comparator with 26.1 kg of maximum capacity and 1 mg of readability, glass housing, two weight exchangers including in air and in liquid, two weight holders including in air and in liquid, and a controller. The equipment will enable to perform automatically volume measurements.

Aerial applications of ultra-low-volume insecticides to control the vector of Japanese encephalitis in Korea

PubMed Central

Self, L. S.; Ree, H. I.; Lofgren, C. S.; Shim, J. C.; Chow, C. Y.; Shin, H. K.; Kim, K. H.

1973-01-01

As a suitable emergency measure to arrest epidemics of Japanese encephalitis in Korea, the ultra-low-volume method of spraying insecticide to control the mosquito vector Culex tritaeniorhynchus has been tested in 2 successive years over a 16-km 2 area, utilizing a large fixed-wing aircraft. Malathion concentrate applied at 0.36 litres/ha gave insufficient control of the parous (infective) females, and no reduction in total numbers of this species. Fenitrothion concentrate applied at 0.45 litres/ha resulted in a 77-87% reduction in total numbers and an 87-98% reduction in parous females over a 4-day period. PMID:4368385

Improved automatic steam distillation combined with oscillation-type densimetry for determining alcoholic strength in spirits and liqueurs.

PubMed

Lachenmeier, Dirk W; Plato, Leander; Suessmann, Manuela; Di Carmine, Matthew; Krueger, Bjoern; Kukuck, Armin; Kranz, Markus

2015-01-01

The determination of the alcoholic strength in spirits and liqueurs is required to control the labelling of alcoholic beverages. The reference methodology prescribes a distillation step followed by densimetric measurement. The classic distillation using a Vigreux rectifying column and a West condenser is time consuming and error-prone, especially for liqueurs that may have problems with entrainment and charring. For this reason, this methodology suggests the use of an automated steam distillation device as alternative. The novel instrument comprises an increased steam power, a redesigned geometry of the condenser and a larger cooling coil with controllable flow, compared to previously available devices. Method optimization applying D-optimal and central composite designs showed significant influence of sample volume, distillation time and coolant flow, while other investigated parameters such as steam power, receiver volume, or the use of pipettes or flasks for sample measurement did not significantly influence the results. The method validation was conducted using the following settings: steam power 70 %, sample volume 25 mL transferred using pipettes, receiver volume 50 mL, coolant flow 7 L/min, and distillation time as long as possible just below the calibration mark. For four different liqueurs covering the typical range of these products between 15 and 35 % vol, the method showed an adequate precision, with relative standard deviations below 0.4 % (intraday) and below 0.6 % (interday). The absolute standard deviations were between 0.06 % vol and 0.08 % vol (intraday) and between 0.07 % vol and 0.10 % vol (interday). The improved automatic steam distillation devices offer an excellent alternative for sample cleanup of volatiles from complex matrices. A major advantage are the low costs for consumables per analysis (only distilled water is needed). For alcoholic strength determination, the method has become more rugged than before, and there are only few influences that would lead to incomplete distillation. Our validation parameters have shown that the performance of the method corresponds to the data presented for the reference method and we believe that automated steam distillation, can be used for the purpose of labelling control of alcoholic beverages.

Volume 3 - Area Sources and Area Source Method Abstracts

EPA Pesticide Factsheets

Nonpoint (area) source emission reference materials from the EIIP. Provides nonpoint source guidance on planning, emissions estimation, data collection, inventory documentation and reporting, and quality assurance/quality control.

Three-Dimensional High-Order Spectral Finite Volume Method for Unstructured Grids

NASA Technical Reports Server (NTRS)

Liu, Yen; Vinokur, Marcel; Wang, Z. J.; Kwak, Dochan (Technical Monitor)

2002-01-01

Many areas require a very high-order accurate numerical solution of conservation laws for complex shapes. This paper deals with the extension to three dimensions of the Spectral Finite Volume (SV) method for unstructured grids, which was developed to solve such problems. We first summarize the limitations of traditional methods such as finite-difference, and finite-volume for both structured and unstructured grids. We then describe the basic formulation of the spectral finite volume method. What distinguishes the SV method from conventional high-order finite-volume methods for unstructured triangular or tetrahedral grids is the data reconstruction. Instead of using a large stencil of neighboring cells to perform a high-order reconstruction, the stencil is constructed by partitioning each grid cell, called a spectral volume (SV), into 'structured' sub-cells, called control volumes (CVs). One can show that if all the SV cells are partitioned into polygonal or polyhedral CV sub-cells in a geometrically similar manner, the reconstructions for all the SVs become universal, irrespective of their shapes, sizes, orientations, or locations. It follows that the reconstruction is reduced to a weighted sum of unknowns involving just a few simple adds and multiplies, and those weights are universal and can be pre-determined once for all. The method is thus very efficient, accurate, and yet geometrically flexible. The most critical part of the SV method is the partitioning of the SV into CVs. In this paper we present the partitioning of a tetrahedral SV into polyhedral CVs with one free parameter for polynomial reconstructions up to degree of precision five. (Note that the order of accuracy of the method is one order higher than the reconstruction degree of precision.) The free parameter will be determined by minimizing the Lebesgue constant of the reconstruction matrix or similar criteria to obtain optimized partitions. The details of an efficient, parallelizable code to solve three-dimensional problems for any order of accuracy are then presented. Important aspects of the data structure are discussed. Comparisons with the Discontinuous Galerkin (DG) method are made. Numerical examples for wave propagation problems are presented.

Proximal and Overall Gastric Emptying of Solids in Patients with Reduced Gastric Volume Accommodation Compared to Matched Controls

PubMed Central

Camilleri, Michael; Breen, Mary; Ryks, Michael; Burton, Duane

2011-01-01

Background Interventions such as gastric surgery and erythromycin result in displacement of solids to the distal stomach and acceleration of overall and proximal gastric emptying. The effect of non-surgical impairment of gastric accommodation on gastric emptying is unclear. Non-surgical impairment of gastric accommodation is associated with accelerated gastric emptying. Aim To compare measurements of proximal and overall gastric emptying in patients with reduced postprandial gastric volume accommodation with the emptying rates in age- and gender-matched controls with normal postprandial gastric volume accommodation. Methods We evaluated overall and proximal gastric emptying in 9 patients with impaired gastric accommodation and age-equivalent and gender-matched controls. Gastric volumes and emptying were measured using validated SPECT and dual gamma camera scintigraphy respectively. We compared group differences in overall and proximal gastric emptying t1/2 by t test. Results Patients with impaired postprandial gastric volume accommodation had greater fasting gastric volume. The proportion of food emptied from the proximal stomach immediately after meal ingestion was lower and t1/2of proximal gastric emptying correspondingly longer in the group with reduced postprandial gastric accommodation. In contrast, differences were not detected in overall gastric emptying in the two groups, and the ratio of overall to proximal gastric emptying t1/2was greater in the group with impaired volume accommodation. Conclusions Proximal stomach emptying is reduced in patients with impaired postprandial volume accommodation; this difference occurs predominantly during the time of meal ingestion. Compensatory mechanisms that result in normal overall gastric emptying require further elucidation. PMID:21327917

Improvements and new concepts for traffic control in work zones. Volume 4, Speed control in work zones

DOT National Transportation Integrated Search

1985-09-01

Tile objective of the research was to determine or develop effective methods of s1owing traffic to an acceptable speed in work zones. Factors considered in the study included cost, motorist and worker safety, institutional constraints, and probabilit...

Dodecafluoropentane Emulsion Decreases Infarct Volume in a Rabbit Ischemic Stroke Model

PubMed Central

Culp, William C.; Woods, Sean D.; Skinner, Robert D.; Brown, Aliza T.; Lowery, John D.; Johnson, Jennifer L. H.; Unger, Evan C.; Hennings, Leah J.; Borrelli, Michael J.; Roberson, Paula K.

2011-01-01

Purpose To assess the efficacy of dodecafluoropentane emulsion (DDFPe), a nano droplet emulsion with significant oxygen transport potential, in decreasing infarct volume using an insoluble emboli rabbit stroke model. Methods New Zealand White rabbits (n=64; 5.1±0.50 kg) received angiography and embolic spheres in the internal carotid artery occluding branches. Rabbits were randomly assigned to groups in 4-hour and 7-hour studies. Four-hour groups included: control (n=7, embolized without treatment) or DDFPe treatment 30-min before stroke (n=7), or at stroke onset (n=8), 30-min after stroke (n=5), 1-hour after stroke (n=7), 2-hours after stroke (n=5), or 3-hours after stroke (n=6). Seven-hour groups included control (n=6), DDFPe at 1-hour after stroke (n=8), and DDFPe at 6-hours after stroke (n=5). DDFPe dose was 2% w/v (weight/volume) intravenous injection, 0.6 mL/kg, and repeated every 90 minutes as time allowed. Following euthanasia infarct volume was determined using vital stains on brain sections. Results At 4-hours, median percent infarct volume decreased for all DDFPe treatment times (pre-treatment=0.30%, p=0.004; onset=0.20%, p=0.004; 30-min=0.35%, p=0.009, 1-hour=0.30%, p=0.01, 2-hours=0.40%, p=0.009, 3-hours=0.25%, p=0.003) compared with controls (3.20%). At 7-hours, median percent infarct volume decreased with treatment at 1-hour (0.25%, p=0.007) but not for 6-hours (1.4%, p=0.49) compared with controls (2.2%). Conclusions Intravenous DDFPe in an animal model decreases infarct volumes and protects brain tissue from ischemia justifying further investigation. PMID:22079515

Spider phobia is associated with decreased left amygdala volume: a cross-sectional study

PubMed Central

2013-01-01

Background Evidence from animal and human studies imply the amygdala as the most critical structure involved in processing of fear-relevant stimuli. In phobias, the amygdala seems to play a crucial role in the pathogenesis and maintenance of the disorder. However, the neuropathology of specific phobias remains poorly understood. In the present study, we investigated whether patients with spider phobia show altered amygdala volumes as compared to healthy control subjects. Methods Twenty female patients with spider phobia and twenty age-matched healthy female controls underwent magnetic resonance imaging to investigate amygdala volumes. The amygdalae were segmented using an automatic, model-based segmentation tool (FSL FIRST). Differences in amygdala volume were investigated by multivariate analysis of covariance with group as between-subject factor and left and right amygdala as dependent factors. The relation between amygdala volume and clinical features such as symptom severity, disgust sensitivity, trait anxiety and duration of illness was investigated by Spearman correlation analysis. Results Spider phobic patients showed significantly smaller left amygdala volume than healthy controls. No significant difference in right amygdala volume was detected. Furthermore, the diminished amygdala size in patients was related to higher symptom severity, but not to higher disgust sensitivity or trait anxiety and was independent of age. Conclusions In summary, the results reveal a relation between higher symptom severity and smaller left amygdala volume in patients with spider phobia. This relation was independent of other potential confounders such as the disgust sensitivity or trait anxiety. The findings suggest that greater spider phobic fear is associated with smaller left amygdala. However, the smaller left amygdala volume may either stand for a higher vulnerability to develop a phobic disorder or emerge as a consequence of the disorder. PMID:23442196

Reduced Cortical Gray Matter Volume In Male Adolescents With Substance And Conduct Problems

PubMed Central

Dalwani, Manish; Sakai, Joseph T.; Mikulich-Gilbertson, Susan K.; Tanabe, Jody; Raymond, Kristen; McWilliams, Shannon K.; Thompson, Laetitia L.; Banich, Marie T.; Crowley, Thomas J.

2011-01-01

Boys with serious conduct and substance problems (“Antisocial Substance Dependence” (ASD)) repeatedly make impulsive and risky decisions in spite of possible negative consequences. Because prefrontal cortex (PFC) is involved in planning behavior in accord with prior rewards and punishments, structural abnormalities in PFC could contribute to a person's propensity to make risky decisions. Methods We acquired high-resolution structural images of 25 male ASD patients (ages 14–18 years) and 19 controls of similar ages using a 3T MR system. We conducted whole-brain voxel-based morphometric analysis (p<0.05, corrected for multiple comparisons at whole-brain cluster-level) using Statistical Parametric Mapping version-5 and tested group differences in regional gray matter (GM) volume with analyses of covariance, adjusting for total GM volume, age, and IQ; we further adjusted between-group analyses for ADHD and depression. As secondary analyses, we tested for negative associations between GM volume and impulsivity within groups and separately, GM volume and symptom severity within patients using whole-brain regression analyses. Results ASD boys had significantly lower GM volume than controls in left dorsolateral PFC (DLPFC), right lingual gyrus and bilateral cerebellum, and significantly higher GM volume in right precuneus. Left DLPFC GM volume showed negative association with impulsivity within controls and negative association with substance dependence severity within patients. Conclusions ASD boys show reduced GM volumes in several regions including DLPFC, a region highly relevant to impulsivity, disinhibition, and decision-making, and cerebellum, a region important for behavioral regulation, while they showed increased GM in precuneus, a region associated with self-referential and self-centered thinking. PMID:21592680

A quality control method for intensity-modulated radiation therapy planning based on generalized equivalent uniform dose.

PubMed

Pang, Haowen; Sun, Xiaoyang; Yang, Bo; Wu, Jingbo

2018-05-01

To ensure good quality intensity-modulated radiation therapy (IMRT) planning, we proposed the use of a quality control method based on generalized equivalent uniform dose (gEUD) that predicts absorbed radiation doses in organs at risk (OAR). We conducted a retrospective analysis of patients who underwent IMRT for the treatment of cervical carcinoma, nasopharyngeal carcinoma (NPC), or non-small cell lung cancer (NSCLC). IMRT plans were randomly divided into data acquisition and data verification groups. OAR in the data acquisition group for cervical carcinoma and NPC were further classified as sub-organs at risk (sOAR). The normalized volume of sOAR and normalized gEUD (a = 1) were analyzed using multiple linear regression to establish a fitting formula. For NSCLC, the normalized intersection volume of the planning target volume (PTV) and lung, the maximum diameter of the PTV (left-right, anterior-posterior, and superior-inferior), and the normalized gEUD (a = 1) were analyzed using multiple linear regression to establish a fitting formula for the lung gEUD (a = 1). The r-squared and P values indicated that the fitting formula was a good fit. In the data verification group, IMRT plans verified the accuracy of the fitting formula, and compared the gEUD (a = 1) for each OAR between the subjective method and the gEUD-based method. In conclusion, the gEUD-based method can be used effectively for quality control and can reduce the influence of subjective factors on IMRT planning optimization. © 2018 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals, Inc. on behalf of American Association of Physicists in Medicine.

CADDIS Volume 4. Data Analysis: Basic Principles & Issues

EPA Pesticide Factsheets

Use of inferential statistics in causal analysis, introduction to data independence and autocorrelation, methods to identifying and control for confounding variables, references for the Basic Principles section of Data Analysis.

Automatic and manual segmentation of healthy retinas using high-definition optical coherence tomography.

PubMed

Golbaz, Isabelle; Ahlers, Christian; Goesseringer, Nina; Stock, Geraldine; Geitzenauer, Wolfgang; Prünte, Christian; Schmidt-Erfurth, Ursula Margarethe

2011-03-01

This study compared automatic- and manual segmentation modalities in the retina of healthy eyes using high-definition optical coherence tomography (HD-OCT). Twenty retinas in 20 healthy individuals were examined using an HD-OCT system (Carl Zeiss Meditec, Inc.). Three-dimensional imaging was performed with an axial resolution of 6 μm at a maximum scanning speed of 25,000 A-scans/second. Volumes of 6 × 6 × 2 mm were scanned. Scans were analysed using a matlab-based algorithm and a manual segmentation software system (3D-Doctor). The volume values calculated by the two methods were compared. Statistical analysis revealed a high correlation between automatic and manual modes of segmentation. The automatic mode of measuring retinal volume and the corresponding three-dimensional images provided similar results to the manual segmentation procedure. Both methods were able to visualize retinal and subretinal features accurately. This study compared two methods of assessing retinal volume using HD-OCT scans in healthy retinas. Both methods were able to provide realistic volumetric data when applied to raster scan sets. Manual segmentation methods represent an adequate tool with which to control automated processes and to identify clinically relevant structures, whereas automatic procedures will be needed to obtain data in larger patient populations. © 2009 The Authors. Journal compilation © 2009 Acta Ophthalmol.

Efficacy of basal soil injection at different water volumes and landscape settings for Asian longhorn beetle control

Treesearch

Phillip A. Lewis

2007-01-01

The Asian longhorn beetle eradication program currently treats at-risk trees by soil injection with a high volume solution of pesticide placed in concentric rings expanding out from the trunk to the dripline of the tree. Using this method in wooded habitats has previously resulted in no detectable residue in treated trees. Basal soil injection (BSI) uses a high...

Thermodynamic evaluation of transonic compressor rotors using the finite volume approach

NASA Technical Reports Server (NTRS)

Moore, J.; Nicholson, S.; Moore, J. G.

1985-01-01

Research at NASA Lewis Research Center gave the opportunity to incorporate new control volumes in the Denton 3-D finite-volume time marching code. For duct flows, the new control volumes require no transverse smoothing and this allows calculations with large transverse gradients in properties without significant numerical total pressure losses. Possibilities for improving the Denton code to obtain better distributions of properties through shocks were demonstrated. Much better total pressure distributions through shocks are obtained when the interpolated effective pressure, needed to stabilize the solution procedure, is used to calculate the total pressure. This simple change largely eliminates the undershoot in total pressure down-stream of a shock. Overshoots and undershoots in total pressure can then be further reduced by a factor of 10 by adopting the effective density method, rather than the effective pressure method. Use of a Mach number dependent interpolation scheme for pressure then removes the overshoot in static pressure downstream of a shock. The stability of interpolation schemes used for the calculation of effective density is analyzed and a Mach number dependent scheme is developed, combining the advantages of the correct perfect gas equation for subsonic flow with the stability of 2-point and 3-point interpolation schemes for supersonic flow.

Flood replenishment: a new method of processor control.

PubMed

Frank, E D; Gray, J E; Wilken, D A

1980-01-01

In mechanized radiographic film processors that process medium to low volumes of film, roll films, and those that process single-emulsion films from nuclear medicine scans, computed tomography, and ultrasound, it is difficult to maintain the developer solution at a stable processing level. We describe our experience using flood replenishment, which is a method in which developer replenisher containing starter solution is introduced in the processor at timed intervals, independent of the number of films being processed. By this process, a stable level of developer activity is maintained in a processor used to develop a medium to low volume of single-emulsion film.

Facile control of silica nanoparticles using a novel solvent varying method for the fabrication of artificial opal photonic crystals

NASA Astrophysics Data System (ADS)

Gao, Weihong; Rigout, Muriel; Owens, Huw

2016-12-01

In this work, the Stöber process was applied to produce uniform silica nanoparticles (SNPs) in the meso-scale size range. The novel aspect of this work was to control the produced silica particle size by only varying the volume of the solvent ethanol used, whilst fixing the other reaction conditions. Using this one-step Stöber-based solvent varying (SV) method, seven batches of SNPs with target diameters ranging from 70 to 400 nm were repeatedly reproduced, and the size distribution in terms of the polydispersity index (PDI) was well maintained (within 0.1). An exponential equation was used to fit the relationship between the particle diameter and ethanol volume. This equation allows the prediction of the amount of ethanol required in order to produce particles of any target diameter within this size range. In addition, it was found that the reaction was completed in approximately 2 h for all batches regardless of the volume of ethanol. Structurally coloured artificial opal photonic crystals (PCs) were fabricated from the prepared SNPs by self-assembly under gravity sedimentation.

Monitoring and control requirement definition study for Dispersed Storage and Generation (DSG). Volume 2, appendix A: Selected DSG technologies and their general control requirements

NASA Technical Reports Server (NTRS)

1980-01-01

A consistent approach was sought for both hardware and software which will handle the monitoring and control necessary to integrate a number of different DSG technologies into a common distribution dispatch network. It appears that the control of each of the DSG technologies is compatible with a supervisory control method of operation that lends itself to remote control from a distribution dispatch center.

Quantitative measurement for the microstructural parameters of nano-precipitates in Al-Mg-Si-Cu alloys

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

Li, Kai

Size, number density and volume fraction of nano-precipitates are important microstructural parameters controlling the strengthening of materials. In this work a widely accessible, convenient, moderately time efficient method with acceptable accuracy and precision has been provided for measurement of volume fraction of nano-precipitates in crystalline materials. The method is based on the traditional but highly accurate technique of measuring foil thickness via convergent beam electron diffraction. A new equation is proposed and verified with the aid of 3-dimensional atom probe (3DAP) analysis, to compensate for the additional error resulted from the hardly distinguishable contrast of too short incomplete precipitates cutmore » by the foil surface. The method can be performed on a regular foil specimen with a modern LaB{sub 6} or field-emission-gun transmission electron microscope. Precisions around ± 16% have been obtained for precipitate volume fractions of needle-like β″/C and Q precipitates in an aged Al-Mg-Si-Cu alloy. The measured number density is close to that directly obtained using 3DAP analysis by a misfit of 4.5%, and the estimated precision for number density measurement is about ± 11%. The limitations of the method are also discussed. - Highlights: •A facile method for measuring volume fraction of nano-precipitates based on CBED •An equation to compensate for small invisible precipitates, with 3DAP verification •Precisions around ± 16% for volume fraction and ± 11% for number density.« less

Finite Volume Methods: Foundation and Analysis

NASA Technical Reports Server (NTRS)

Barth, Timothy; Ohlberger, Mario

2003-01-01

Finite volume methods are a class of discretization schemes that have proven highly successful in approximating the solution of a wide variety of conservation law systems. They are extensively used in fluid mechanics, porous media flow, meteorology, electromagnetics, models of biological processes, semi-conductor device simulation and many other engineering areas governed by conservative systems that can be written in integral control volume form. This article reviews elements of the foundation and analysis of modern finite volume methods. The primary advantages of these methods are numerical robustness through the obtention of discrete maximum (minimum) principles, applicability on very general unstructured meshes, and the intrinsic local conservation properties of the resulting schemes. Throughout this article, specific attention is given to scalar nonlinear hyperbolic conservation laws and the development of high order accurate schemes for discretizing them. A key tool in the design and analysis of finite volume schemes suitable for non-oscillatory discontinuity capturing is discrete maximum principle analysis. A number of building blocks used in the development of numerical schemes possessing local discrete maximum principles are reviewed in one and several space dimensions, e.g. monotone fluxes, E-fluxes, TVD discretization, non-oscillatory reconstruction, slope limiters, positive coefficient schemes, etc. When available, theoretical results concerning a priori and a posteriori error estimates are given. Further advanced topics are then considered such as high order time integration, discretization of diffusion terms and the extension to systems of nonlinear conservation laws.

Hydrologic risk analysis in the Yangtze River basin through coupling Gaussian mixtures into copulas

NASA Astrophysics Data System (ADS)

Fan, Y. R.; Huang, W. W.; Huang, G. H.; Li, Y. P.; Huang, K.; Li, Z.

2016-02-01

In this study, a bivariate hydrologic risk framework is proposed through coupling Gaussian mixtures into copulas, leading to a coupled GMM-copula method. In the coupled GMM-Copula method, the marginal distributions of flood peak, volume and duration are quantified through Gaussian mixture models and the joint probability distributions of flood peak-volume, peak-duration and volume-duration are established through copulas. The bivariate hydrologic risk is then derived based on the joint return period of flood variable pairs. The proposed method is applied to the risk analysis for the Yichang station on the main stream of the Yangtze River, China. The results indicate that (i) the bivariate risk for flood peak-volume would keep constant for the flood volume less than 1.0 × 105 m3/s day, but present a significant decreasing trend for the flood volume larger than 1.7 × 105 m3/s day; and (ii) the bivariate risk for flood peak-duration would not change significantly for the flood duration less than 8 days, and then decrease significantly as duration value become larger. The probability density functions (pdfs) of the flood volume and duration conditional on flood peak can also be generated through the fitted copulas. The results indicate that the conditional pdfs of flood volume and duration follow bimodal distributions, with the occurrence frequency of the first vertex decreasing and the latter one increasing as the increase of flood peak. The obtained conclusions from the bivariate hydrologic analysis can provide decision support for flood control and mitigation.

Volumetric Magnetic Resonance Imaging Study of Brain and Cerebellum in Children with Cerebral Palsy

PubMed Central

Maciorkowska, Elżbieta; Gościk, Elżbieta

2016-01-01

Introduction. Quantitative magnetic resonance imaging (MRI) studies are rarely used in the diagnosis of patients with cerebral palsy. The aim of present study was to assess the relationships between the volumetric MRI and clinical findings in children with cerebral palsy compared to control subjects. Materials and Methods. Eighty-two children with cerebral palsy and 90 age- and sex-matched healthy controls were collected. Results. The dominant changes identified on MRI scans in children with cerebral palsy were periventricular leukomalacia (42%) and posthemorrhagic hydrocephalus (21%). The total brain and cerebellum volumes in children with cerebral palsy were significantly reduced in comparison to controls. Significant grey matter volume reduction was found in the total brain in children with cerebral palsy compared with the control subjects. Positive correlations between the age of the children of both groups and the grey matter volumes in the total brain were found. Negative relationship between width of third ventricle and speech development was found in the patients. Positive correlations were noted between the ventricles enlargement and motor dysfunction and mental retardation in children with cerebral palsy. Conclusions. By using the voxel-based morphometry, the total brain, cerebellum, and grey matter volumes were significantly reduced in children with cerebral palsy. PMID:27579318

Volumetric Magnetic Resonance Imaging Study of Brain and Cerebellum in Children with Cerebral Palsy.

PubMed

Kułak, Piotr; Maciorkowska, Elżbieta; Gościk, Elżbieta

2016-01-01

Introduction. Quantitative magnetic resonance imaging (MRI) studies are rarely used in the diagnosis of patients with cerebral palsy. The aim of present study was to assess the relationships between the volumetric MRI and clinical findings in children with cerebral palsy compared to control subjects. Materials and Methods. Eighty-two children with cerebral palsy and 90 age- and sex-matched healthy controls were collected. Results. The dominant changes identified on MRI scans in children with cerebral palsy were periventricular leukomalacia (42%) and posthemorrhagic hydrocephalus (21%). The total brain and cerebellum volumes in children with cerebral palsy were significantly reduced in comparison to controls. Significant grey matter volume reduction was found in the total brain in children with cerebral palsy compared with the control subjects. Positive correlations between the age of the children of both groups and the grey matter volumes in the total brain were found. Negative relationship between width of third ventricle and speech development was found in the patients. Positive correlations were noted between the ventricles enlargement and motor dysfunction and mental retardation in children with cerebral palsy. Conclusions. By using the voxel-based morphometry, the total brain, cerebellum, and grey matter volumes were significantly reduced in children with cerebral palsy.

Effect of black tea on enteral feeding tolerance in ICU patients

PubMed Central

Mojdeh, Soheila; Shahin, Samire; Khalili, Gholamreza

2010-01-01

BACKGROUND: Tea consumption has been known mostly as a well-drink after water in the world. Tea drink can affect balance of fluids and renal function. In addition, it can cause loss of many viruses in the stomach and can increase or decrease gastrointestinal movements. This research was done to determine the effect of tea on increasing enteral feeding tolerance in ICU patients in Alzahra Hospital. METHODS: In this clinical trial study, 45 patients were enrolled in two groups, tea consumption group and the standard method of nutrition as control group. Tea gavage was performed two times in the morning; 100 cc tea used for the study group and the same volume of water was used for the control group. Residual volume was measured before gavage. Data collected for one week. Information sheet had two pages; the first page described how to complete the form and the method of tea gavage and the second page was for data collection. Data were analyzed by t-student test, chi-square, and analysis of variance. RESULTS: In two groups, 92% of patients tolerated liquid gavage. Their difference by chi-square test was not significant. Average urine volume after black tea gavage was 783.3 L in the study group and 802.2 L in the control group. ANOVA test showed no significant difference. CONCLUSIONS: Although the difference was not statistically significant between the two groups, but in study group consumption of tea was acceptable by patients. PMID:21589775

[Hybrid 3-D rendering of the thorax and surface-based virtual bronchoscopy in surgical and interventional therapy control].

PubMed

Seemann, M D; Gebicke, K; Luboldt, W; Albes, J M; Vollmar, J; Schäfer, J F; Beinert, T; Englmeier, K H; Bitzer, M; Claussen, C D

2001-07-01

The aim of this study was to demonstrate the possibilities of a hybrid rendering method, the combination of a color-coded surface and volume rendering method, with the feasibility of performing surface-based virtual endoscopy with different representation models in the operative and interventional therapy control of the chest. In 6 consecutive patients with partial lung resection (n = 2) and lung transplantation (n = 4) a thin-section spiral computed tomography of the chest was performed. The tracheobronchial system and the introduced metallic stents were visualized using a color-coded surface rendering method. The remaining thoracic structures were visualized using a volume rendering method. For virtual bronchoscopy, the tracheobronchial system was visualized using a triangle surface model, a shaded-surface model and a transparent shaded-surface model. The hybrid 3D visualization uses the advantages of both the color-coded surface and volume rendering methods and facilitates a clear representation of the tracheobronchial system and the complex topographical relationship of morphological and pathological changes without loss of diagnostic information. Performing virtual bronchoscopy with the transparent shaded-surface model facilitates a reasonable to optimal, simultaneous visualization and assessment of the surface structure of the tracheobronchial system and the surrounding mediastinal structures and lesions. Hybrid rendering relieve the morphological assessment of anatomical and pathological changes without the need for time-consuming detailed analysis and presentation of source images. Performing virtual bronchoscopy with a transparent shaded-surface model offers a promising alternative to flexible fiberoptic bronchoscopy.

23.4% saline decreases brain tissue volume in severe hepatic encephalopathy as assessed by a quantitative computed tomography marker

PubMed Central

Liotta, Eric M; Lizza, Bryan D; Romanova, Anna L; Guth, James C; Berman, Michael D; Carroll, Timothy J; Francis, Brandon; Ganger, Daniel; Ladner, Daniela P; Maas, Matthew B; Naidech, Andrew M

2016-01-01

Objective Cerebral edema is common in severe hepatic encephalopathy and may be life-threatening. Bolus 23.4% hypertonic saline (HTS) improves surveillance neuromonitoring scores, although its mechanism of action is not clearly established. We investigated the hypothesis that bolus HTS decreases cerebral edema in severe hepatic encephalopathy utilizing a quantitative technique to measure brain and CSF volume changes. Design Retrospective analysis of serial computed tomography (CT) scans and clinical data for a case-control series was performed. Setting Intensive care units of a tertiary care hospital. Patients Patients with severe hepatic encephalopathy treated with 23.4% HTS and control patients who did not receive 23.4% HTS. Methods We used clinically obtained CT scans to measure volumes of the ventricles, intracranial CSF, and brain using a previously validated semi-automated technique (Analyze Direct; Overland Park, KS). Volumes before and after 23.4% HTS were compared with Wilcoxon signed-rank test. Associations between total CSF volume, ventricular volume, serum sodium, and Glasgow Coma Scale Scores were assessed using Spearman correlation. Results Eleven patients with 18 administrations of 23.4% HTS met inclusion criteria. Total CSF (median 47.6 [35.1–69.4] to 61.9 [47.7–87.0] mL, p<0.001) and ventricular volumes (median 8.0 [6.9–9.5] to 9.2 [7.8–11.9] mL, p=0.002) increased and Glasgow Coma Scale Scores improved (median 4 [3–6] to 7 [6–9], p=0.008) after 23.4% HTS. In contrast, total CSF and ventricular volumes decreased in untreated control patients. Serum sodium increase was associated with increase in total CSF volume (r=0.83, p<0.001) and change in total CSF volume was associated with ventricular volume change (r=0.86, p<0.001). Conclusions Total CSF and ventricular volumes increased after 23.4% HTS, consistent with a reduction in brain tissue volume. Total CSF and ventricular volume change may be useful quantitative measures to assess cerebral edema in severe hepatic encephalopathy. PMID:26308431

Galerkin Method for Nonlinear Dynamics

NASA Astrophysics Data System (ADS)

Noack, Bernd R.; Schlegel, Michael; Morzynski, Marek; Tadmor, Gilead

A Galerkin method is presented for control-oriented reduced-order models (ROM). This method generalizes linear approaches elaborated by M. Morzyński et al. for the nonlinear Navier-Stokes equation. These ROM are used as plants for control design in the chapters by G. Tadmor et al., S. Siegel, and R. King in this volume. Focus is placed on empirical ROM which compress flow data in the proper orthogonal decomposition (POD). The chapter shall provide a complete description for construction of straight-forward ROM as well as the physical understanding and teste

TEMPEST: A three-dimensional time-dependence computer program for hydrothermal analysis: Volume 1, Numerical methods and input instructions: Revision 2

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

Trent, D.S.; Eyler, L.L.

TEMPEST offers simulation capabilities over a wide range of hydrothermal problems that are definable by input instructions. These capabilities are summarized by categories as follows: modeling capabilities; program control; and I/O control. 10 refs., 22 figs., 2 tabs. (LSP)

Radiobiological Determination of Dose Escalation and Normal Tissue Toxicity in Definitive Chemoradiation Therapy for Esophageal Cancer☆

PubMed Central

Warren, Samantha; Partridge, Mike; Carrington, Rhys; Hurt, Chris; Crosby, Thomas; Hawkins, Maria A.

2014-01-01

Purpose This study investigated the trade-off in tumor coverage and organ-at-risk sparing when applying dose escalation for concurrent chemoradiation therapy (CRT) of mid-esophageal cancer, using radiobiological modeling to estimate local control and normal tissue toxicity. Methods and Materials Twenty-one patients with mid-esophageal cancer were selected from the SCOPE1 database (International Standard Randomised Controlled Trials number 47718479), with a mean planning target volume (PTV) of 327 cm3. A boost volume, PTV2 (GTV + 0.5 cm margin), was created. Radiobiological modeling of tumor control probability (TCP) estimated the dose required for a clinically significant (+20%) increase in local control as 62.5 Gy/25 fractions. A RapidArc (RA) plan with a simultaneously integrated boost (SIB) to PTV2 (RA62.5) was compared to a standard dose plan of 50 Gy/25 fractions (RA50). Dose-volume metrics and estimates of normal tissue complication probability (NTCP) for heart and lungs were compared. Results Clinically acceptable dose escalation was feasible for 16 of 21 patients, with significant gains (>18%) in tumor control from 38.2% (RA50) to 56.3% (RA62.5), and only a small increase in predicted toxicity: median heart NTCP 4.4% (RA50) versus 5.6% (RA62.5) P<.001 and median lung NTCP 6.5% (RA50) versus 7.5% (RA62.5) P<.001. Conclusions Dose escalation to the GTV to improve local control is possible when overlap between PTV and organ-at-risk (<8% heart volume and <2.5% lung volume overlap for this study) generates only negligible increase in lung or heart toxicity. These predictions from radiobiological modeling should be tested in future clinical trials. PMID:25304796

Volume Changes After Stereotactic LINAC Radiotherapy in Vestibular Schwannoma: Control Rate and Growth Patterns

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

Langenberg, Rick van de, E-mail: rickvandelangenberg@hotmail.com; Dohmen, Amy J.C.; Bondt, Bert J. de

2012-10-01

Purpose: The purpose of this study was to evaluate the control rate of vestibular schwannomas (VS) after treatment with linear accelerator (LINAC)-based stereotactic radiosurgery (SRS) or radiotherapy (SRT) by using a validated volumetric measuring tool. Volume-based studies on prognosis after LINAC-based SRS or SRT for VS are reported scarcely. In addition, growth patterns and risk factors predicting treatment failure were analyzed. Materials and Methods: Retrospectively, 37 VS patients treated with LINAC based SRS or SRT were analyzed. Baseline and follow-up magnetic resonance imaging scans were analyzed with volume measurements on contrast enhanced T1-weighted magnetic resonance imaging. Absence of intervention aftermore » radiotherapy was defined as 'no additional intervention group, ' absence of radiological growth was defined as 'radiological control group. ' Significant growth was defined as a volume change of 19.7% or more, as calculated in a previous study. Results: The cumulative 4-year probability of no additional intervention was 96.4% {+-} 0.03; the 4-year radiological control probability was 85.4% {+-} 0.1). The median follow-up was 40 months. Overall, shrinkage was seen in 65%, stable VS in 22%, and growth in 13%. In 54% of all patients, transient swelling was observed. No prognostic factors were found regarding VS growth. Previous treatment and SRS were associated with transient swelling significantly. Conclusions: Good control rates are reported for LINAC based SRS or SRT in VS, in which the lower rate of radiological growth control is attributed to the use of the more sensitive volume measurements. Transient swelling after radiosurgery is a common phenomenon and should not be mistaken for treatment failure. Previous treatment and SRS were significantly associated with transient swelling.« less

Orbito-frontal cortex and thalamus volumes in the patients with obsessive-compulsive disorder before and after cognitive behavioral therapy.

PubMed

Atmaca, Murad; Yildirim, Hanefi; Yilmaz, Seda; Caglar, Neslihan; Mermi, Osman; Korkmaz, Sevda; Akaslan, Unsal; Gurok, M Gurkan; Kekilli, Yasemin; Turkcapar, Hakan

2018-07-01

Background The effect of a variety of treatment modalities including psychopharmacological and cognitive behavioral therapy on the brain volumes and neurochemicals have not been investigated enough in the patients with obsessive-compulsive disorder. Therefore, in the present study, we aimed to investigate the effect of cognitive behavioral therapy on the volumes of the orbito-frontal cortex and thalamus regions which seem to be abnormal in the patients with obsessive-compulsive disorder. We hypothesized that there would be change in the volumes of the orbito-frontal cortex and thalamus. Methods Twelve patients with obsessive-compulsive disorder and same number of healthy controls were included into the study. At the beginning of the study, the volumes of the orbito-frontal cortex and thalamus were compared by using magnetic resonance imaging. In addition, volumes of these regions were measured before and after the cognitive behavioral therapy treatment in the patient group. Results The patients with obsessive-compulsive disorder had greater left and right thalamus volumes and smaller left and right orbito-frontal cortex volumes compared to those of healthy control subjects at the beginning of the study. When we compared baseline volumes of the patients with posttreatment ones, we detected that thalamus volumes significantly decreased throughout the period for both sides and that the orbito-frontal cortex volumes significantly increased throughout the period for only left side. Conclusions In summary, we found that cognitive behavioral therapy might volumetrically affect the key brain regions involved in the neuroanatomy of obsessive-compulsive disorder. However, future studies with larger sample are required.

Structuring and calorie control of bakery products by templating batter with ultra melt-resistant food-grade hydrogel beads.

PubMed

Thompson, Benjamin R; Horozov, Tommy S; Stoyanov, Simeon D; Paunov, Vesselin N

2017-08-01

We report the use of a temperature insensitive, food-grade hydrogel to reduce the caloric density of pancakes that were prepared at temperatures much higher than the boiling point of water. This cheap, facile method utilises a mixed agar-methylcellulose hydrogel, which was blended to produce a slurry of hydrogel microbeads. The pancake batter was mixed with a controlled volume percentage of slurry of hydrogel beads and cooked. From bomb calorimetry experiments, the composites were found to have a reduced caloric density that reflects the volume percentage of hydrogel beads mixed with the batter. Using this procedure, we were able to reduce the caloric density of pancakes by up to 23 ± 3% when the volume percentage of hydrogel beads initially used was 25%. The method is not limited to pancakes and could potentially be applied to various other food products. The structure and morphology of the freeze-dried pancakes and pancake-hydrogel composites were investigated and pores of a similar size to the hydrogel beads were found, confirming that the gel beads maintained their structure during the cooking process. There is scope for further development of this method by the encapsulation of nutritionally beneficial or flavour enhancing ingredients within the hydrogel beads.

Confinement of surface waves at the air-water interface to control aerosol size and dispersity

NASA Astrophysics Data System (ADS)

Nazarzadeh, Elijah; Wilson, Rab; King, Xi; Reboud, Julien; Tassieri, Manlio; Cooper, Jonathan M.

2017-11-01

The precise control over the size and dispersity of droplets, produced within aerosols, is of great interest across many manufacturing, food, cosmetic, and medical industries. Amongst these applications, the delivery of new classes of high value drugs to the lungs has recently attracted significant attention from pharmaceutical companies. This is commonly achieved through the mechanical excitation of surface waves at the air liquid interface of a parent liquid volume. Previous studies have established a correlation between the wavelength on the surface of liquid and the final aerosol size. In this work, we show that the droplet size distribution of aerosols can be controlled by constraining the liquid inside micron-sized cavities and coupling surface acoustic waves into different volumes of liquid inside micro-grids. In particular, we show that by reducing the characteristic physical confinement size (i.e., either the initial liquid volume or the cavities' diameters), higher harmonics of capillary waves are revealed with a consequent reduction of both aerosol mean size and dispersity. In doing so, we provide a new method for the generation and fine control of aerosols' sizes distribution.

Taste Reward Circuitry Related Brain Structures Characterize Ill and Recovered Anorexia Nervosa and Bulimia Nervosa

PubMed Central

Frank, Guido K.; Shott, Megan E.; Hagman, Jennifer O.; Mittal, Vijay A.

2013-01-01

Objective The pathophysiology of the eating disorder anorexia nervosa remains obscure, but structural brain alterations could be functionally important biomarkers. Here we assessed taste pleasantness and reward sensitivity in relation to brain structure, which might be related to food avoidance commonly seen in eating disorders. Method We used structural magnetic resonance brain imaging to study gray and white matter volumes in individuals with restricting type currently ill (n = 19) or recovered-anorexia nervosa (n = 24), bulimia nervosa (n= 19) and healthy control women (n=24). Results All eating disorder groups showed increased gray matter volume of the medial orbitofrontal cortex (gyrus rectus). Manually tracing confirmed larger gyrus rectus volume, and predicted taste pleasantness across all groups. The analyses also indicated other morphological differences between diagnostic categories: Ill and recovered-anorexia nervosa had increased right, while bulimia nervosa had increased left antero-ventral insula gray matter volumes compared to controls. Furthermore, dorsal striatum volumes were reduced in recovered-anorexia and bulimia nervosa, and predicted sensitivity to reward in the eating disorder groups. The eating disorder groups also showed reduced white matter in right temporal and parietal areas when compared to healthy controls. Notably, the results held when controlling for a range of covariates (e.g., age, depression, anxiety, medications). Conclusion Brain structure in medial orbitofrontal cortex, insula and striatum is altered in eating disorders and suggests altered brain circuitry that has been associated with taste pleasantness and reward value. PMID:23680873

Dynamic equilibration of airway smooth muscle contraction during physiological loading.

PubMed

Latourelle, Jeanne; Fabry, Ben; Fredberg, Jeffrey J

2002-02-01

Airway smooth muscle contraction is the central event in acute airway narrowing in asthma. Most studies of isolated muscle have focused on statically equilibrated contractile states that arise from isometric or isotonic contractions. It has recently been established, however, that muscle length is determined by a dynamically equilibrated state of the muscle in which small tidal stretches associated with the ongoing action of breathing act to perturb the binding of myosin to actin. To further investigate this phenomenon, we describe in this report an experimental method for subjecting isolated muscle to a dynamic microenvironment designed to closely approximate that experienced in vivo. Unlike previous methods that used either time-varying length control, force control, or time-invariant auxotonic loads, this method uses transpulmonary pressure as the controlled variable, with both muscle force and muscle length free to adjust as they would in vivo. The method was implemented by using a servo-controlled lever arm to load activated airway smooth muscle strips with transpulmonary pressure fluctuations of increasing amplitude, simulating the action of breathing. The results are not consistent with classical ideas of airway narrowing, which rest on the assumption of a statically equilibrated contractile state; they are consistent, however, with the theory of perturbed equilibria of myosin binding. This experimental method will allow for quantitative experimental evaluation of factors that were previously outside of experimental control, including sensitivity of muscle length to changes of tidal volume, changes of lung volume, shape of the load characteristic, loss of parenchymal support and inflammatory thickening of airway wall compartments.

Ultrahigh-definition dynamic 3D holographic display by active control of volume speckle fields

NASA Astrophysics Data System (ADS)

Yu, Hyeonseung; Lee, Kyeoreh; Park, Jongchan; Park, Yongkeun

2017-01-01

Holographic displays generate realistic 3D images that can be viewed without the need for any visual aids. They operate by generating carefully tailored light fields that replicate how humans see an actual environment. However, the realization of high-performance, dynamic 3D holographic displays has been hindered by the capabilities of present wavefront modulator technology. In particular, spatial light modulators have a small diffraction angle range and limited pixel number limiting the viewing angle and image size of a holographic 3D display. Here, we present an alternative method to generate dynamic 3D images by controlling volume speckle fields significantly enhancing image definition. We use this approach to demonstrate a dynamic display of micrometre-sized optical foci in a volume of 8 mm × 8 mm × 20 mm.

Automatic Extraction of Myocardial Mass and Volume Using Parametric Images from Dynamic Nongated PET.

PubMed

Harms, Hendrik Johannes; Stubkjær Hansson, Nils Henrik; Tolbod, Lars Poulsen; Kim, Won Yong; Jakobsen, Steen; Bouchelouche, Kirsten; Wiggers, Henrik; Frøkiaer, Jørgen; Sörensen, Jens

2016-09-01

Dynamic cardiac PET is used to quantify molecular processes in vivo. However, measurements of left ventricular (LV) mass and volume require electrocardiogram-gated PET data. The aim of this study was to explore the feasibility of measuring LV geometry using nongated dynamic cardiac PET. Thirty-five patients with aortic-valve stenosis and 10 healthy controls underwent a 27-min (11)C-acetate PET/CT scan and cardiac MRI (CMR). The controls were scanned twice to assess repeatability. Parametric images of uptake rate K1 and the blood pool were generated from nongated dynamic data. Using software-based structure recognition, the LV wall was automatically segmented from K1 images to derive functional assessments of LV mass (mLV) and wall thickness. End-systolic and end-diastolic volumes were calculated using blood pool images and applied to obtain stroke volume and LV ejection fraction (LVEF). PET measurements were compared with CMR. High, linear correlations were found for LV mass (r = 0.95), end-systolic volume (r = 0.93), and end-diastolic volume (r = 0.90), and slightly lower correlations were found for stroke volume (r = 0.74), LVEF (r = 0.81), and thickness (r = 0.78). Bland-Altman analyses showed significant differences for mLV and thickness only and an overestimation for LVEF at lower values. Intra- and interobserver correlations were greater than 0.95 for all PET measurements. PET repeatability accuracy in the controls was comparable to CMR. LV mass and volume are accurately and automatically generated from dynamic (11)C-acetate PET without electrocardiogram gating. This method can be incorporated in a standard routine without any additional workload and can, in theory, be extended to other PET tracers. © 2016 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

Subcortical brain structure and suicidal behaviour in major depressive disorder: a meta-analysis from the ENIGMA-MDD working group.

PubMed

Rentería, M E; Schmaal, L; Hibar, D P; Couvy-Duchesne, B; Strike, L T; Mills, N T; de Zubicaray, G I; McMahon, K L; Medland, S E; Gillespie, N A; Hatton, S N; Lagopoulos, J; Veltman, D J; van der Wee, N; van Erp, T G M; Wittfeld, K; Grabe, H J; Block, A; Hegenscheid, K; Völzke, H; Veer, I M; Walter, H; Schnell, K; Schramm, E; Normann, C; Schoepf, D; Konrad, C; Zurowski, B; Godlewska, B R; Cowen, P J; Penninx, B W J H; Jahanshad, N; Thompson, P M; Wright, M J; Martin, N G; Christensen, H; Hickie, I B

2017-05-02

The aetiology of suicidal behaviour is complex, and knowledge about its neurobiological mechanisms is limited. Neuroimaging methods provide a noninvasive approach to explore the neural correlates of suicide vulnerability in vivo. The ENIGMA-MDD Working Group is an international collaboration evaluating neuroimaging and clinical data from thousands of individuals collected by research groups from around the world. Here we present analyses in a subset sample (n=3097) for whom suicidality data were available. Prevalence of suicidal symptoms among major depressive disorder (MDD) cases ranged between 29 and 69% across cohorts. We compared mean subcortical grey matter volumes, lateral ventricle volumes and total intracranial volume (ICV) in MDD patients with suicidal symptoms (N=451) vs healthy controls (N=1996) or MDD patients with no suicidal symptoms (N=650). MDD patients reporting suicidal plans or attempts showed a smaller ICV (P=4.12 × 10 -3 ) or a 2.87% smaller volume compared with controls (Cohen's d=-0.284). In addition, we observed a nonsignificant trend in which MDD cases with suicidal symptoms had smaller subcortical volumes and larger ventricular volumes compared with controls. Finally, no significant differences (P=0.28-0.97) were found between MDD patients with and those without suicidal symptoms for any of the brain volume measures. This is by far the largest neuroimaging meta-analysis of suicidal behaviour in MDD to date. Our results did not replicate previous reports of association between subcortical brain structure and suicidality and highlight the need for collecting better-powered imaging samples and using improved suicidality assessment instruments.

Fluid control structures in microfluidic devices

DOEpatents

Mathies, Richard A.; Grover, William H.; Skelley, Alison; Lagally, Eric; Liu, Chung N.

2008-11-04

Methods and apparatus for implementing microfluidic analysis devices are provided. A monolithic elastomer membrane associated with an integrated pneumatic manifold allows the placement and actuation of a variety of fluid control structures, such as structures for pumping, isolating, mixing, routing, merging, splitting, preparing, and storing volumes of fluid. The fluid control structures can be used to implement a variety of sample introduction, preparation, processing, and storage techniques.

Fluid control structures in microfluidic devices

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

Mathies, Richard A.; Grover, William H.; Skelley, Alison

2017-05-09

Methods and apparatus for implementing microfluidic analysis devices are provided. A monolithic elastomer membrane associated with an integrated pneumatic manifold allows the placement and actuation of a variety of fluid control structures, such as structures for pumping, isolating, mixing, routing, merging, splitting, preparing, and storing volumes of fluid. The fluid control structures can be used to implement a variety of sample introduction, preparation, processing, and storage techniques.

Fluid control structures in microfluidic devices

NASA Technical Reports Server (NTRS)

Skelley, Alison (Inventor); Mathies, Richard A. (Inventor); Lagally, Eric (Inventor); Grover, William H. (Inventor); Liu, Chung N. (Inventor)

2008-01-01

Methods and apparatus for implementing microfluidic analysis devices are provided. A monolithic elastomer membrane associated with an integrated pneumatic manifold allows the placement and actuation of a variety of fluid control structures, such as structures for pumping, isolating, mixing, routing, merging, splitting, preparing, and storing volumes of fluid. The fluid control structures can be used to implement a variety of sample introduction, preparation, processing, and storage techniques.

High-energy surface and volume plasmons in nanopatterned sub-10 nm aluminum nanostructures

DOE PAGES

Hobbs, Richard G.; Manfrinato, Vitor R.; Yang, Yujia; ...

2016-06-13

In this paper, we use electron energy-loss spectroscopy to map the complete plasmonic spectrum of aluminum nanodisks with diameters ranging from 3 to 120 nm fabricated by high-resolution electron-beam lithography. Our nanopatterning approach allows us to produce localized surface plasmon resonances across a wide spectral range spanning 2–8 eV. Electromagnetic simulations using the finite element method support the existence of dipolar, quadrupolar, and hexapolar surface plasmon modes as well as centrosymmetric breathing modes depending on the location of the electron-beam excitation. In addition, we have developed an approach using nanolithography that is capable of meV control over the energy andmore » attosecond control over the lifetime of volume plasmons in these nanodisks. The precise measurement of volume plasmon lifetime may also provide an opportunity to probe and control the DC electrical conductivity of highly confined metallic nanostructures. Lastly, we show the strong influence of the nanodisk boundary in determining both the energy and lifetime of surface plasmons and volume plasmons locally across individual aluminum nanodisks, and we have compared these observations to similar effects produced by scaling the nanodisk diameter.« less

Inter and intra-modal deformable registration: continuous deformations meet efficient optimal linear programming.

PubMed

Glocker, Ben; Paragios, Nikos; Komodakis, Nikos; Tziritas, Georgios; Navab, Nassir

2007-01-01

In this paper we propose a novel non-rigid volume registration based on discrete labeling and linear programming. The proposed framework reformulates registration as a minimal path extraction in a weighted graph. The space of solutions is represented using a set of a labels which are assigned to predefined displacements. The graph topology corresponds to a superimposed regular grid onto the volume. Links between neighborhood control points introduce smoothness, while links between the graph nodes and the labels (end-nodes) measure the cost induced to the objective function through the selection of a particular deformation for a given control point once projected to the entire volume domain, Higher order polynomials are used to express the volume deformation from the ones of the control points. Efficient linear programming that can guarantee the optimal solution up to (a user-defined) bound is considered to recover the optimal registration parameters. Therefore, the method is gradient free, can encode various similarity metrics (simple changes on the graph construction), can guarantee a globally sub-optimal solution and is computational tractable. Experimental validation using simulated data with known deformation, as well as manually segmented data demonstrate the extreme potentials of our approach.

Arterial Pulse Pressure and Its Association With Reduced Stroke Volume During Progressive Central Hypovolemia

DTIC Science & Technology

2006-09-01

NM, Joyner MJ. Influence of increased central venous pressure on baroreflex control of sympathetic activity in humans. Am J Physiol Heart Circ Physiol...Arterial Pulse Pressure and Its Association With Reduced Stroke Volume During Progressive Central Hypovolemia Victor A. Convertino, PhD, William H...reduction of SV and change in MSNA during graded central hypovolemia in humans. Methods: After a 12-minute baseline data collection period, 13 men were

Geometric Variational Methods for Controlled Active Vision

DTIC Science & Technology

2006-08-01

Haker , L. Zhu, and A. Tannenbaum, ``Optimal mass transport for registration and warping’’ Int. Journal Computer Vision, volume 60, 2004, pp. 225-240. G...pp. 119-142. A. Angenent, S. Haker , and A. Tannenbaum, ``Minimizing flows for the Monge-Kantorovich problem,’’ SIAM J. Math. Analysis, volume 35...Shape analysis of structures using spherical wavelets’’ (with S. Haker and D. Nain), Proceeedings of MICCAI, 2005. ``Affine surface evolution for 3D

Estimating removal rates of bacteria from poultry carcasses using two whole-carcass rinse volumes

USDA-ARS?s Scientific Manuscript database

Rinse sampling is a common method for determining the level of microbial contamination on poultry carcasses. One of the advantages of rinse sampling, over other carcass sampling methods, is that the results can be used for both process control applications and to estimate the total microbial level o...

Fracture control methods for space vehicles. Volume 2: Assessment of fracture mechanics technology for space shuttle applications

NASA Technical Reports Server (NTRS)

Ehret, R. M.

1974-01-01

The concepts explored in a state of the art review of those engineering fracture mechanics considered most applicable to the space shuttle vehicle include fracture toughness, precritical flaw growth, failure mechanisms, inspection methods (including proof test logic), and crack growth predictive analysis techniques.

Detention basin alternative outlet design study.

DOT National Transportation Integrated Search

2016-10-01

This study examines the outlets structures CDOT has historically employed to drain water quality treatment detention basins and flood control basins, presents two new methods of metering the water quality capture volume (WQCV), namely 1) the Elliptic...

Randomized clinical trial of ligasure™ versus conventional splenectomy for injured spleen in blunt abdominal trauma.

PubMed

Amirkazem, Vejdan Seyyed; Malihe, Khosravi

2017-02-01

Spleen is the most common organ damaged in cases of blunt abdominal trauma and splenectomy and splenorrhaphy are the main surgical procedures that are used in surgical treatment of such cases. In routine open splenectomy cases, after laparotomy, application of sutures in splenic vasculature is the most widely used procedure to cease the bleeding. This clinical trial evaluates the role and benefits of the Ligasure™ system in traumatic splenectomy without using any suture materials and compares the result with conventional method of splenectomy. After making decision for splenectomy secondary to a blunt abdominal trauma, patients in control group (39) underwent splenectomy using conventional method with silk suture ligation of splenic vasculature. In the interventional group (41) a Ligasure™ vascular sealing system was used for ligating of the splenic vein and artery. The results of operation time, volume of intra-operation bleeding and post-operative complications were compared in both groups. The mean operation times in control and interventional group were 21 and 12 min respectively (p < 0.05). The average volume of bleeding in control group during open splenectomy was 280 cc, but in the interventional group decreased significantly to 80 ml (p < 0.05) using the Ligasure system. Post-operative complications such as bleeding were non-existent in both groups. The application of Ligasure™ in blunt abdominal trauma for splenectomy not only can decrease the operation time but also can decrease the volume of bleeding during operation without any additional increase in post-operative complications. This method is recommendable in traumatic splenic injuries that require splenectomy in order to control the bleeding as opposed to use of traditional silk sutures. Copyright © 2016 IJS Publishing Group Ltd. Published by Elsevier Ltd. All rights reserved.

Methods of obtaining a uniform volume concentration of implanted ions

NASA Astrophysics Data System (ADS)

Reutov, V. F.

1998-05-01

Three simple practical methods of irradiation with high energy particles (>5 MeV/n), providing the conditions of obtaining a uniform volume concentration of the implanted ions in the massive samples are described in the present paper. Realization of the condition of two-sided irradiation of a plane sample during its rotation in the flux of the projectiles is the basis of the first method. The use of free air as a filter with varying absorbent ability due to the movement of the irradiated sample along ion beam brought to the atmosphere is at the basis of the second method of uniform ion alloying. The third method of obtaining a uniform volume concentration of the implanted ions in a massive sample consists of sample irradiation through the absorbent filter in the shape of a foil curved according to the parabolic law moving along its surface. The first method is the most effective for obtaining a great number of the samples, for mechanical tests, for example, the second one - for irradiation in different gaseous media, the third one - for obtaining high concentration of the implanted ions under controlled (regulated) thermal and deformation conditions.

Hippocampal volume change measurement: quantitative assessment of the reproducibility of expert manual outlining and the automated methods FreeSurfer and FIRST.

PubMed

Mulder, Emma R; de Jong, Remko A; Knol, Dirk L; van Schijndel, Ronald A; Cover, Keith S; Visser, Pieter J; Barkhof, Frederik; Vrenken, Hugo

2014-05-15

To measure hippocampal volume change in Alzheimer's disease (AD) or mild cognitive impairment (MCI), expert manual delineation is often used because of its supposed accuracy. It has been suggested that expert outlining yields poorer reproducibility as compared to automated methods, but this has not been investigated. To determine the reproducibilities of expert manual outlining and two common automated methods for measuring hippocampal atrophy rates in healthy aging, MCI and AD. From the Alzheimer's Disease Neuroimaging Initiative (ADNI), 80 subjects were selected: 20 patients with AD, 40 patients with mild cognitive impairment (MCI) and 20 healthy controls (HCs). Left and right hippocampal volume change between baseline and month-12 visit was assessed by using expert manual delineation, and by the automated software packages FreeSurfer (longitudinal processing stream) and FIRST. To assess reproducibility of the measured hippocampal volume change, both back-to-back (BTB) MPRAGE scans available for each visit were analyzed. Hippocampal volume change was expressed in μL, and as a percentage of baseline volume. Reproducibility of the 1-year hippocampal volume change was estimated from the BTB measurements by using linear mixed model to calculate the limits of agreement (LoA) of each method, reflecting its measurement uncertainty. Using the delta method, approximate p-values were calculated for the pairwise comparisons between methods. Statistical analyses were performed both with inclusion and exclusion of visibly incorrect segmentations. Visibly incorrect automated segmentation in either one or both scans of a longitudinal scan pair occurred in 7.5% of the hippocampi for FreeSurfer and in 6.9% of the hippocampi for FIRST. After excluding these failed cases, reproducibility analysis for 1-year percentage volume change yielded LoA of ±7.2% for FreeSurfer, ±9.7% for expert manual delineation, and ±10.0% for FIRST. Methods ranked the same for reproducibility of 1-year μL volume change, with LoA of ±218 μL for FreeSurfer, ±319 μL for expert manual delineation, and ±333 μL for FIRST. Approximate p-values indicated that reproducibility was better for FreeSurfer than for manual or FIRST, and that manual and FIRST did not differ. Inclusion of failed automated segmentations led to worsening of reproducibility of both automated methods for 1-year raw and percentage volume change. Quantitative reproducibility values of 1-year microliter and percentage hippocampal volume change were roughly similar between expert manual outlining, FIRST and FreeSurfer, but FreeSurfer reproducibility was statistically significantly superior to both manual outlining and FIRST after exclusion of failed segmentations. Copyright © 2014 Elsevier Inc. All rights reserved.

Determination of regional lung air volume distribution at mid-tidal breathing from computed tomography: a retrospective study of normal variability and reproducibility

PubMed Central

2014-01-01

Background Determination of regional lung air volume has several clinical applications. This study investigates the use of mid-tidal breathing CT scans to provide regional lung volume data. Methods Low resolution CT scans of the thorax were obtained during tidal breathing in 11 healthy control male subjects, each on two separate occasions. A 3D map of air volume was derived, and total lung volume calculated. The regional distribution of air volume from centre to periphery of the lung was analysed using a radial transform and also using one dimensional profiles in three orthogonal directions. Results The total air volumes for the right and left lungs were 1035 +/− 280 ml and 864 +/− 315 ml, respectively (mean and SD). The corresponding fractional air volume concentrations (FAVC) were 0.680 +/− 0.044 and 0.658 +/− 0.062. All differences between the right and left lung were highly significant (p < 0.0001). The coefficients of variation of repeated measurement of right and left lung air volumes and FAVC were 6.5% and 6.9% and 2.5% and 3.6%, respectively. FAVC correlated significantly with lung space volume (r = 0.78) (p < 0.005). FAVC increased from the centre towards the periphery of the lung. Central to peripheral ratios were significantly higher for the right (0.100 +/− 0.007 SD) than the left (0.089 +/− 0.013 SD) (p < 0.0001). Conclusion A technique for measuring the distribution of air volume in the lung at mid-tidal breathing is described. Mean values and reproducibility are described for healthy male control subjects. Fractional air volume concentration is shown to increase with lung size. PMID:25063729

Diurnal Changes in Volume and Specific Tissue Weight of Crassulacean Acid Metabolism Plants 1

PubMed Central

Chen, Sheng-Shu; Black, Clanton C.

1983-01-01

The diurnal variations in volume and in specific weight were determined for green stems and leaves of Crassulacen acid metabolism (CAM) plants. Volume changes were measured by a water displacement method. Diurnal variations occurred in the volume of green CAM tissues. Their volume increased early in the light period reaching a maximum about mid-day, then the volume decreased to a minimum near midnight. The maximum volume increase each day was about 2.7% of the total volume. Control leaves of C3 and C4 plants exhibited reverse diurnal volume changes of 0.2 to 0.4%. The hypothesis is presented and supported that green CAM tissues should exhibit a diurnal increase in volume due to the increase of internal gas pressure from CO2 and O2 when their stomata are closed. Conversely, the volume should decrease when the gas pressure is decreased. The second hypothesis presented and supported was that the specific weight (milligrams of dry weight per square centimeter of green surface area) of green CAM tissues should increase at night due to the net fixation of CO2. Green CAM tissues increased their specific weight at night in contrast to control C3 and C4 leaves which decreased their specific weight at night. With Kalanchoë daigremontiana leaves, the calculated increase in specific leaf weight at night based on estimates of carbohydrate available for net CO2 fixation was near 6% and the measured increase in specific leaf weight was 6%. Diurnal measurements of CAM tissue water content were neither coincident nor reciprocal with their diurnal patterns of either volume or specific weight changes. PMID:16662833

Definitive Radiotherapy for T1-T2 Squamous Cell Carcinoma of Pyriform Sinus

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

Rabbani, Anna; Amdur, Robert J.; Mancuso, Anthony A.

2008-10-01

Purpose: To report the long-term results after definitive radiotherapy (RT) for T1-T2 pyriform sinus squamous cell carcinoma. Patients and Methods: The data from 123 patients with T1-T2 pyriform sinus squamous cell carcinoma treated with RT with or without neck dissection between November 1964 and June 2003 were analyzed. The median follow-up for all patients was 3.2 years, and the median follow-up for living patients was 10.7 years. Results: The 5-year local control, locoregional control, freedom from distant metastasis, cause-specific survival, and overall survival rate was 85%, 70%, 75%, 61%, and 35%, respectively. The ultimate local control rate, including successful salvagemore » of RT failure, for T1 and T2 cancer patients was 96% and 94%, respectively. The overall local control rate with a functional larynx was 83%. Pretreatment computed tomography tumor volume data were available for 55 patients. The median computed tomography tumor volume was 4.2 cm{sup 3} (range, 0-22.4). Local control was worse for patients with a tumor volume >6.5 cm{sup 3} compared with those with a smaller tumor volume. Of the 123 patients, 16% developed moderate to severe acute (2%), late (9%), or postoperative (5%) complications. Conclusions: Local control with larynx preservation after definitive RT for T1-T2 pyriform sinus squamous cell carcinoma likely results in local control and survival similar to that after total laryngectomy or larynx-conserving surgery. Two-thirds of our living patients retained a functional larynx.« less

The effectiveness of session rating of perceived exertion to monitor resistance training load in acute burns patients.

PubMed

Grisbrook, Tiffany L; Gittings, Paul M; Wood, Fiona M; Edgar, Dale W

2017-02-01

Session-rating of perceived exertion (RPE) is a method frequently utilised in exercise and sports science to quantify training load of an entire aerobic exercise session. It has also been demonstrated that session-RPE is a valid and reliable method to quantify training load during resistance exercise, in healthy and athletic populations. This study aimed to investigate the effectiveness of session-RPE as a method to quantify exercise intensity during resistance training in patients with acute burns. Twenty burns patients (mean age=31.65 (±10.09) years), with a mean TBSA of 16.4% (range=6-40%) were recruited for this study. Patients were randomly allocated to the resistance training (n=10) or control group (n=10). All patients completed a four week resistance training programme. Training load (session-RPE×session duration), resistance training session-volume and pre-exercise pain were recorded for each exercise session. The influence of; age, gender, %TBSA, exercise group (resistance training vs. control), pre-exercise pain, resistance training history and session-volume on training load were analysed using a multilevel mixed-effects linear regression. Session-volume did not influence training load in the final regression model, however training load was significantly greater in the resistance training group, compared with the control group (p<0.001). Pre-exercise pain significantly influenced training load, where increasing pain was associated with a higher session-RPE (p=0.004). Further research is indicated to determine the exact relationship between pain, resistance training history, exercise intensity and session-RPE and training load before it can be used as a method to monitor and prescribe resistance training load in acute burns patients. Copyright © 2016 Elsevier Ltd and ISBI. All rights reserved.

A practical method to calculate the R1 index of waste-to-energy facilities.

PubMed

Viganò, Federico

2018-03-01

According to Directive 98/2008/EC, the operation carried out by an incinerator of Municipal Solid Waste (MSW) is classified either as energy recovery (R1) or as disposal (D10) depending on the result achieved by the application of the R1 formula. In 2011 the DG Environment of the European Commission (EC) issued some non-binding guidelines on the interpretation of such a formula that clarified many aspects related to its application. A point not fully clarified by the EC guidelines is the determination of the energy contained in the treated waste (E W ). For this term of the formula, reference is made to the indirect method for the calculation of boiler thermal efficiency, as defined by the norm EN 12952-15. However, the application of such a norm to an entire year of operation of a Waste-to-Energy (WtE) boiler is not immediate. Therefore, a practical method for the calculation of the E W term has been developed in the framework of a collaboration between the MatER Study Centre and the Lombardy Region (Italy). The method is based on: (i) the identification of the most reliable data available from the Distributed Control System (DCS) of the plant; (ii) the definition of a control volume around the boiler(s) also based on the availability of data; (iii) the closure of the mass balance for such a control volume; (iv) the energy balance of the same control volume that gives, thus, the E W term of the R1 formula. The method has been applied in 2015-2016 to nine plants, generating a number of interesting data reported and discussed in this work, such as R1 index values, Lower Heating Values (LHV) of the treated wastes, main sources of energy losses in WtE boilers, etc. For one case study, discussed in detail in this work, the law of propagation of uncertainties has been applied according to the ISO/IEC Guide 98-3, leading to the assessment of the accuracy of the method, which resulted in ±2.4% with a confidence level of circa 95%. Copyright © 2017 Elsevier Ltd. All rights reserved.

Impact of Volume Management on Volume Overload and Rehospitalization in CAPD Patients.

PubMed

Xu, Yi; Yang, Shen-Min; Wang, Xiao-Hua; Wang, Hai-Fang; Niu, Mei-E; Yang, Yi-Qun; Lu, Guo-Yuan; Pang, Jian-Hong; Wang, Fei; Li, Lin

2018-05-01

Heart failure due to volume overload is a major reason for rehospitalization in continuous ambulatory peritoneal dialysis patients. Strict volume control provides better cardiac functions and blood pressure in this population. Volume management, which is a volume control strategy, may decrease volume overload and related complications. Using a quasi-experimental design, 66 continuous ambulatory peritoneal dialysis patients were randomly assigned to the intervention group ( n = 34) and control group ( n = 32). The patients were followed up for 6 months with scheduled clinic and/or telephone visits; the intervention group adopted volume management strategy, while the control group adopted conventional care. Volume overload and cardiac function were compared between the two groups at the baseline and at 6 months. At Month 6, the intervention group resulted in significant improvement in volume overloaded status, cardiac function, and volume-overload-related rehospitalization. Volume management strategy allows for better control of volume overload and is associated with fewer volume-related readmissions.

The relationship between atrial electromechanical delay and left atrial mechanical function in stroke patients

PubMed Central

Akıl, Mehmet Ata; Akıl, Eşref; Bilik, Mehmet Zihni; Oylumlu, Mustafa; Acet, Halit; Yıldız, Abdülkadir; Akyüz, Abdurrahman; Ertaş, Faruk; Toprak, Nizamettin

2015-01-01

Objective: The aim of this study was to evaluate the relationship between atrial electromechanical delay (EMD) measured with tissue Doppler imaging (TDI) and left atrial (LA) mechanical functions in patients with ischemic stroke and compare them with healthy controls. Methods: Thirty patients with ischemic stroke were enrolled into this cross-sectional, observational study. The control group consisted of 35 age- and gender-matched apparently healthy individuals patients. Acute cerebral infarcts of probable embolic origin were diagnosed via imaging and were confirmed by a neurologist. Echocardiographically, time intervals from the beginning of P wave to beginning of A wave from the lateral and septal mitral and right ventricular tricuspid annuli in TDI were recorded. The differences between these intervals gave the mechanical delays (inter- and intra-atrial). Left atrial (LA) volumes were measured using the biplane area-length method, and LA mechanical function parameters were calculated. Statistical analysis was performed using student’s t-test, chi-squared test, and Pearson’s test. Results: The laboratory and clinical characteristics were similar in the two groups. Increased left atrial EMD (21.36±10.38 ms versus 11.74±6.06 ms, p<0.001), right atrial EMD (13.66±8.62 ms versus 9.66±6.81 ms, p=0.040), and interatrial EMD (35.03±9.95 ms versus 21.40±8.47 ms, p<0.001) were observed in stroke patients as compared to controls. Active LA emptying volume and fraction and passive LA emptying volumes and fraction were similar between controls and stroke patients. Total LA emptying volumes were significantly increased in stroke patients as compared to healthy controls (33.19±11.99 mL/m2 versus 27.48±7.08 mL/m2, p=0.021). Conclusion: According to the results of our study, interatrial electromechanical delay may be a new predictor for ischemic stroke. PMID:25537998

Sex differences in the correlation of emotional control and amygdala volumes in adolescents.

PubMed

Blanton, Rebecca E; Chaplin, Tara M; Sinha, Rajita

2010-10-06

We examined male and female adolescents (8-18 years of age) that were scanned with structural brain MRI and looked for a correlation between volume of the right or the left amygdala and parent-reported ability of emotional control. A sex difference was found in the correlation between emotional control and the corrected volume of the left amygdala (that is the amygdala volume adjusted for total cranial volume). In girls, smaller left amygdala volumes were associated with better emotional control. In boys, larger left amygdala volumes were associated with better emotional control. These findings suggest that healthy girls and boys show a difference in the correlation between parental reports of emotional control and the left amygdala volume.

Generalized Fourier analyses of the advection-diffusion equation - Part I: one-dimensional domains

NASA Astrophysics Data System (ADS)

Christon, Mark A.; Martinez, Mario J.; Voth, Thomas E.

2004-07-01

This paper presents a detailed multi-methods comparison of the spatial errors associated with finite difference, finite element and finite volume semi-discretizations of the scalar advection-diffusion equation. The errors are reported in terms of non-dimensional phase and group speed, discrete diffusivity, artificial diffusivity, and grid-induced anisotropy. It is demonstrated that Fourier analysis provides an automatic process for separating the discrete advective operator into its symmetric and skew-symmetric components and characterizing the spectral behaviour of each operator. For each of the numerical methods considered, asymptotic truncation error and resolution estimates are presented for the limiting cases of pure advection and pure diffusion. It is demonstrated that streamline upwind Petrov-Galerkin and its control-volume finite element analogue, the streamline upwind control-volume method, produce both an artificial diffusivity and a concomitant phase speed adjustment in addition to the usual semi-discrete artifacts observed in the phase speed, group speed and diffusivity. The Galerkin finite element method and its streamline upwind derivatives are shown to exhibit super-convergent behaviour in terms of phase and group speed when a consistent mass matrix is used in the formulation. In contrast, the CVFEM method and its streamline upwind derivatives yield strictly second-order behaviour. In Part II of this paper, we consider two-dimensional semi-discretizations of the advection-diffusion equation and also assess the affects of grid-induced anisotropy observed in the non-dimensional phase speed, and the discrete and artificial diffusivities. Although this work can only be considered a first step in a comprehensive multi-methods analysis and comparison, it serves to identify some of the relative strengths and weaknesses of multiple numerical methods in a common analysis framework. Published in 2004 by John Wiley & Sons, Ltd.

A 3D Freehand Ultrasound System for Multi-view Reconstructions from Sparse 2D Scanning Planes

PubMed Central

2011-01-01

Background A significant limitation of existing 3D ultrasound systems comes from the fact that the majority of them work with fixed acquisition geometries. As a result, the users have very limited control over the geometry of the 2D scanning planes. Methods We present a low-cost and flexible ultrasound imaging system that integrates several image processing components to allow for 3D reconstructions from limited numbers of 2D image planes and multiple acoustic views. Our approach is based on a 3D freehand ultrasound system that allows users to control the 2D acquisition imaging using conventional 2D probes. For reliable performance, we develop new methods for image segmentation and robust multi-view registration. We first present a new hybrid geometric level-set approach that provides reliable segmentation performance with relatively simple initializations and minimum edge leakage. Optimization of the segmentation model parameters and its effect on performance is carefully discussed. Second, using the segmented images, a new coarse to fine automatic multi-view registration method is introduced. The approach uses a 3D Hotelling transform to initialize an optimization search. Then, the fine scale feature-based registration is performed using a robust, non-linear least squares algorithm. The robustness of the multi-view registration system allows for accurate 3D reconstructions from sparse 2D image planes. Results Volume measurements from multi-view 3D reconstructions are found to be consistently and significantly more accurate than measurements from single view reconstructions. The volume error of multi-view reconstruction is measured to be less than 5% of the true volume. We show that volume reconstruction accuracy is a function of the total number of 2D image planes and the number of views for calibrated phantom. In clinical in-vivo cardiac experiments, we show that volume estimates of the left ventricle from multi-view reconstructions are found to be in better agreement with clinical measures than measures from single view reconstructions. Conclusions Multi-view 3D reconstruction from sparse 2D freehand B-mode images leads to more accurate volume quantification compared to single view systems. The flexibility and low-cost of the proposed system allow for fine control of the image acquisition planes for optimal 3D reconstructions from multiple views. PMID:21251284

A comparison of synchronized intermittent mandatory ventilation and pressure-regulated volume control ventilation in elderly patients with acute exacerbations of COPD and respiratory failure

PubMed Central

Chang, Suchi; Shi, Jindong; Fu, Cuiping; Wu, Xu; Li, Shanqun

2016-01-01

Background COPD is the third leading cause of death worldwide. Acute exacerbations of COPD may cause respiratory failure, requiring intensive care unit admission and mechanical ventilation. Intensive care unit patients with acute exacerbations of COPD requiring mechanical ventilation have higher mortality rates than other hospitalized patients. Although mechanical ventilation is the most effective intervention for these conditions, invasive ventilation techniques have yielded variable effects. Objective We evaluated pressure-regulated volume control (PRVC) ventilation treatment efficacy and preventive effects on pulmonary barotrauma in elderly COPD patients with respiratory failure. Patients and methods Thirty-nine intubated patients were divided into experimental and control groups and treated with the PRVC and synchronized intermittent mandatory ventilation – volume control methods, respectively. Vital signs, respiratory mechanics, and arterial blood gas analyses were monitored for 2–4 hours and 48 hours. Results Both groups showed rapidly improved pH, partial pressure of oxygen (PaO2), and PaO2 per fraction of inspired O2 levels and lower partial pressure of carbon dioxide (PaCO2) levels. The pH and PaCO2 levels at 2–4 hours were lower and higher, respectively, in the test group than those in the control group (P<0.05 for both); after 48 hours, blood gas analyses showed no statistical difference in any marker (P>0.05). Vital signs during 2–4 hours and 48 hours of treatment showed no statistical difference in either group (P>0.05). The level of peak inspiratory pressure in the experimental group after mechanical ventilation for 2–4 hours and 48 hours was significantly lower than that in the control group (P<0.05), while other variables were not significantly different between groups (P>0.05). Conclusion Among elderly COPD patients with respiratory failure, application of PRVC resulted in rapid improvement in arterial blood gas analyses while maintaining a low peak inspiratory pressure. PRVC can reduce pulmonary barotrauma risk, making it a safer protective ventilation mode than synchronized intermittent mandatory ventilation – volume control. PMID:27274223

Surface Erosion Control Techniques on Newly Constructed Forest Roads

Treesearch

Johnny M. Grace; John Wilhoit; Robert Rummer; Bryce Stokes

1999-01-01

A newly constructed forest road was treated with three erosion control treatments: wood excelsior erosion mat, native grass species, and exotic grass species. The study evaluates treatment methods on the basis of sediment reduction and runoff volume reduction compared to no treatment. The erosion mat treatment was most effective in mitigating erosion losses with a 98...

Effects of air vessel on water hammer in high-head pumping station

NASA Astrophysics Data System (ADS)

Wang, L.; Wang, F. J.; Zou, Z. C.; Li, X. N.; Zhang, J. C.

2013-12-01

Effects of air vessel on water hammer process in a pumping station with high-head were analyzed by using the characteristics method. The results show that the air vessel volume is the key parameter that determines the protective effect on water hammer pressure. The maximum pressure in the system declines with increasing air vessel volume. For a fixed volume of air vessel, the shape of air vessel and mounting style, such as horizontal or vertical mounting, have little effect on the water hammer. In order to obtain good protection effects, the position of air vessel should be close to the outlet of the pump. Generally, once the volume of air vessel is guaranteed, the water hammer of a entire pipeline is effectively controlled.

Estimating intracranial volume using intracranial area in healthy children and those with childhood status epilepticus

PubMed Central

Piper, Rory J; Yoong, Michael M; Pujar, Suresh; Chin, Richard F

2014-01-01

Background Correcting volumetric measurements of brain structures for intracranial volume (ICV) is important in comparing volumes across subjects with different ICV. The aim of this study was to investigate whether intracranial area (ICA) reliably predicts actual ICV in a healthy pediatric cohort and in children with convulsive status epilepticus (CSE). Methods T1-weighted volumetric MRI was performed on 20 healthy children (control group), 10 with CSE with structurally normal MRI (CSE/MR-), and 12 with CSE with structurally abnormal MRI (CSE/MR+). ICA, using a mid-sagittal slice, and the actual ICV were measured. Results A high Spearman correlation was found between the ICA and ICV measurements in the control (r = 0.96; P < 0.0001), CSE/MR− (r = 0.93; P = 0.0003), and CSE/MR+ (r = 0.94; P < 0.0001) groups. On comparison of predicted and actual ICV, there was no significant difference in the CSE/MR− group (P = 0.77). However, the comparison between predicted and actual ICV was significantly different in the CSE/MR+ (P = 0.001) group. Our Bland–Altman plot showed that the ICA method consistently overestimated ICV in children in the CSE/MR+ group, especially in those with small ICV or widespread structural abnormalities. Conclusions After further validation, ICA measurement may be a reliable alternative to measuring actual ICV when correcting volume measurements for ICV, even in children with localized MRI abnormalities. Caution should be applied when the method is used in children with small ICV and those with multilobar brain pathology. PMID:25365798

Liquid and gaseous oxygen safety review, volume 1

NASA Technical Reports Server (NTRS)

Lapin, A.

1972-01-01

Materials used or contained in liquid and gaseous oxygen systems are analyzed for their compatibility; and areas of possible concern in oxygen systems are outlined. Design criteria, cleaning procedures, and quality control methods are covered in detail.

Design and Control of Chemical Grouting : Volume 3 - Engineering Practice

DOT National Transportation Integrated Search

1983-04-01

Recent improvements in the engineering practice of chemical grouting have provided increased confidence in this method of ground modification. Designers can significantly improve the success of chemical grouting by defining their grouting program obj...

Techniques for optimal crop selection in a controlled ecological life support system

NASA Technical Reports Server (NTRS)

Mccormack, Ann; Finn, Cory; Dunsky, Betsy

1993-01-01

A Controlled Ecological Life Support System (CELSS) utilizes a plant's natural ability to regenerate air and water while being grown as a food source in a closed life support system. Current plant research is directed toward obtaining quantitative empirical data on the regenerative ability of each species of plant and the system volume and power requirements. Two techniques were adapted to optimize crop species selection while at the same time minimizing the system volume and power requirements. Each allows the level of life support supplied by the plants to be selected, as well as other system parameters. The first technique uses decision analysis in the form of a spreadsheet. The second method, which is used as a comparison with and validation of the first, utilizes standard design optimization techniques. Simple models of plant processes are used in the development of these methods.

A Study of Green's Function Methods Applied to Space Radiation Protection

NASA Technical Reports Server (NTRS)

Heinbockel, John H.

2001-01-01

The purpose of this research was to study the propagation of galactic ions through various materials. Galactic light ions result from the break up of heavy ion particles and their propagation through materials is modeled using the one-dimensional Boltzmann equation. When ions enter materials there can occur (i) the interaction of ions with orbital electrons which causes ionization within the material and (ii) ions collide with atoms causing production of secondary particles which penetrate deeper within the material. These processes are modeled by a continuum model. The basic idea is to place a control volume within the material and examine the change in ion flux across this control volume. In this way on can derive the basic equations for the transport of light and heavy ions in matter. Green's function perturbation methods can then be employed to solve the resulting equations using energy dependent nuclear cross sections.

Techniques for optimal crop selection in a controlled ecological life support system

NASA Technical Reports Server (NTRS)

Mccormack, Ann; Finn, Cory; Dunsky, Betsy

1992-01-01

A Controlled Ecological Life Support System (CELSS) utilizes a plant's natural ability to regenerate air and water while being grown as a food source in a closed life support system. Current plant research is directed toward obtaining quantitative empirical data on the regenerative ability of each species of plant and the system volume and power requirements. Two techniques were adapted to optimize crop species selection while at the same time minimizing the system volume and power requirements. Each allows the level of life support supplied by the plants to be selected, as well as other system parameters. The first technique uses decision analysis in the form of a spreadsheet. The second method, which is used as a comparison with and validation of the first, utilizes standard design optimization techniques. Simple models of plant processes are used in the development of these methods.

Heterogeneous asymmetric recombinase polymerase amplification (haRPA) for rapid hygiene control of large-volume water samples.

PubMed

Elsäßer, Dennis; Ho, Johannes; Niessner, Reinhard; Tiehm, Andreas; Seidel, Michael

2018-04-01

Hygiene of drinking water is periodically controlled by cultivation and enumeration of indicator bacteria. Rapid and comprehensive measurements of emerging pathogens are of increasing interest to improve drinking water safety. In this study, the feasibility to detect bacteriophage PhiX174 as a potential indicator for virus contamination in large volumes of water is demonstrated. Three consecutive concentration methods (continuous ultrafiltration, monolithic adsorption filtration, and centrifugal ultrafiltration) were combined to concentrate phages stepwise from 1250 L drinking water into 1 mL. Heterogeneous asymmetric recombinase polymerase amplification (haRPA) is applied as rapid detection method. Field measurements were conducted to test the developed system for hygiene online monitoring under realistic conditions. We could show that this system allows the detection of artificial contaminations of bacteriophage PhiX174 in drinking water pipelines. Copyright © 2018 Elsevier Inc. All rights reserved.

Cytoplasmic removal, enucleation, and cell fusion of mouse oocytes.

PubMed

Kyogoku, Hirohisa; Yoshida, Shuhei; Kitajima, Tomoya S

2018-01-01

Meiotic divisions in females occur in fully grown oocytes that have a large cytoplasmic volume. The intracellular processes that are needed to accomplish meiotic divisions, such as spindle formation, chromosome segregation, and polar body extrusion, are controlled by the concerted actions of nuclear and cytoplasmic factors, which exhibit dynamic quantitative and spatiotemporal changes during meiotic maturation. Thus, distinguishing between meiotic controls that are mediated by cytoplasmic factors and those mediated by nuclear factors helps in the understanding of the mechanisms underlying meiotic divisions. Here, we describe a method to artificially modify the number of nuclei and the volume of the cytoplasm of mouse oocytes through cytoplasmic removal, enucleation, and cell fusion. The oocytes generated by this method are viable and undergo reproducible meiotic divisions exhibiting the effects of altered amounts of cytoplasmic and nuclear factors, which can be analyzed by various assays, such as live imaging microscopy. © 2018 Elsevier Inc. All rights reserved.

Radiotherapy treatment planning: benefits of CT-MR image registration and fusion in tumor volume delineation.

PubMed

Djan, Igor; Petrović, Borislava; Erak, Marko; Nikolić, Ivan; Lucić, Silvija

2013-08-01

Development of imaging techniques, computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET), made great impact on radiotherapy treatment planning by improving the localization of target volumes. Improved localization allows better local control of tumor volumes, but also minimizes geographical misses. Mutual information is obtained by registration and fusion of images achieved manually or automatically. The aim of this study was to validate the CT-MRI image fusion method and compare delineation obtained by CT versus CT-MRI image fusion. The image fusion software (XIO CMS 4.50.0) was applied to delineate 16 patients. The patients were scanned on CT and MRI in the treatment position within an immobilization device before the initial treatment. The gross tumor volume (GTV) and clinical target volume (CTV) were delineated on CT alone and on CT+MRI images consecutively and image fusion was obtained. Image fusion showed that CTV delineated on a CT image study set is mainly inadequate for treatment planning, in comparison with CTV delineated on CT-MRI fused image study set. Fusion of different modalities enables the most accurate target volume delineation. This study shows that registration and image fusion allows precise target localization in terms of GTV and CTV and local disease control.

Evaluation of liver functional reserve by combining D-sorbitol clearance rate and CT measured liver volume

PubMed Central

Li, Yi-Ming; Lv, Fan; Xu, Xin; Ji, Hong; Gao, Wen-Tao; Lei, Tuan-Jie; Ren, Gui-Bing; Bai, Zhi-Lan; Li, Qiang

2003-01-01

AIM: Our research attempted to evaluate the overall functional reserve of cirrhotic liver by combination of hepatic functional blood flow, liver volume, and Child-Pugh’s classification, and to discuss its value of clinical application. METHODS: Ninety two patients with portal hypertension due to hepatic cirrhosis were investigated. All had a history of haematemesis and hematochezia, esophageal and gastric fundus varices, splenomegaly and hypersplenia. A 2-year follow-up was routinely performed and no one was lost. Twenty two healthy volunteers were used as control group. Blood and urine samples were collected 4 times before and after intravenous D-sorbitol infusion. The hepatic clearance (CLH) of D-sorbitol was then calculated according to enzymatic spectrophotometric method while the total blood flow (QTOTAL) and intrahepatic shunt (RINS) were detected by multicolor Doppler ultrasound, and the liver volume was measured by spiral CT. Data were estimated by t-test, variance calculation and chi-squared test. The relationships between all these parameters and different groups were investigated according to Child-Pugh classification and postoperative complications respectively. RESULTS: Steady blood concentration was achieved 120 mins after D-sorbitol intravenous infusion, which was (0.358 ± 0.064) mmol·L-1 in cirrhotic group and (0.189 ± 0.05) mmol·L-1 in control group (P < 0.01). CLH = (812.7 ± 112.4) mL·min-1, QTOTAL = (1280.6 ± 131.4) mL·min-1, and RINS = (36.54 ± 10.65)% in cirrhotic group and CLH = (1248.3 ± 210.5) mL·min-1, QTOTAL = (1362.4 ± 126.9) mL·min-1, and RINS = (8.37 ± 3.32)% in control group (P < 0.01). The liver volume of cirrhotic group was 1057 ± 249 cm3, 851 ± 148 cm3 and 663 ± 77 cm3 in Child A, B and C group respectively with significant difference (P < 0.001). The average volume of cirrhotic liver in Child B, C group was significantly reduced in comparison with that in control group (P < 0.001). The patient, whose liver volume decreased by 40% with the CLH below 600 mL·min-1, would have a higher incidence of postoperative complications. There was no strict correspondent relationship between CLH, liver volume and Child-Pugh’s classification. CONCLUSION: The hepatic clearance of D-sorbitol, CT measured liver volume can be reliably used for the evaluation of hepatic functional blood flow and liver metabolic volume. Combined with the Child-Pugh’s classification, it could be very useful for further understanding the liver functional reserve, therefore help determine reasonable therapeutic plan, choose surgical procedures and operating time. PMID:12970913

A 3D Hermite-based multiscale local active contour method with elliptical shape constraints for segmentation of cardiac MR and CT volumes.

PubMed

Barba-J, Leiner; Escalante-Ramírez, Boris; Vallejo Venegas, Enrique; Arámbula Cosío, Fernando

2018-05-01

Analysis of cardiac images is a fundamental task to diagnose heart problems. Left ventricle (LV) is one of the most important heart structures used for cardiac evaluation. In this work, we propose a novel 3D hierarchical multiscale segmentation method based on a local active contour (AC) model and the Hermite transform (HT) for LV analysis in cardiac magnetic resonance (MR) and computed tomography (CT) volumes in short axis view. Features such as directional edges, texture, and intensities are analyzed using the multiscale HT space. A local AC model is configured using the HT coefficients and geometrical constraints. The endocardial and epicardial boundaries are used for evaluation. Segmentation of the endocardium is controlled using elliptical shape constraints. The final endocardial shape is used to define the geometrical constraints for segmentation of the epicardium. We follow the assumption that epicardial and endocardial shapes are similar in volumes with short axis view. An initialization scheme based on a fuzzy C-means algorithm and mathematical morphology was designed. The algorithm performance was evaluated using cardiac MR and CT volumes in short axis view demonstrating the feasibility of the proposed method.

Physical activity, fitness, and gray matter volume

PubMed Central

Erickson, Kirk I.; Leckie, Regina L.; Weinstein, Andrea M.

2014-01-01

In this review we explore the association between physical activity, cardiorespiratory fitness, and exercise on gray matter volume in older adults. We conclude that higher cardiorespiratory fitness levels are routinely associated with greater gray matter volume in the prefrontal cortex and hippocampus, and less consistently in other regions. We also conclude that physical activity is associated with greater gray matter volume in the same regions that are associated with cardiorespiratory fitness including the prefrontal cortex and hippocampus. Some heterogeneity in the literature may be explained by effect moderation by age, stress, or other factors. Finally, we report promising results from randomized exercise interventions that suggest that the volume of the hippocampus and prefrontal cortex remain pliable and responsive to moderate intensity exercise for 6-months to 1-year. Physical activity appears to be a propitious method for influencing gray matter volume in late adulthood, but additional well-controlled studies are necessary to inform public policies about the potential protective or therapeutic effects of exercise on brain volume. PMID:24952993

Total Quality Management Guide. Volume 2. A Guide to Implementation

DTIC Science & Technology

1990-02-15

Kaoru . Guide to Quality Control. Asian Productivity Organization. 1984. Ishikawa , Kaoru . What is Total Quality Control? The Japanese Way. Englewood...of the new Systems Age. The theories of Deming, Juran, Ishikawa , and other management methods that still predominate are pioneers of Systems Age...Feigenbaum, Armand V. Total Quality Control. New York: McGraw-Hill Book Company. 1983. bnai, Masaaki. Kaizen. New York: Random House. 1986. Ishikawa

Multi-hadron spectroscopy in a large physical volume

NASA Astrophysics Data System (ADS)

Bulava, John; Hörz, Ben; Morningstar, Colin

2018-03-01

We demonstrate the effcacy of the stochastic LapH method to treat all-toall quark propagation on a Nf = 2 + 1 CLS ensemble with large linear spatial extent L = 5:5 fm, allowing us to obtain the benchmark elastic isovector p-wave pion-pion scattering amplitude to good precision already on a relatively small number of gauge configurations. These results hold promise for multi-hadron spectroscopy at close-to-physical pion mass with exponential finite-volume effects under control.

Metabolic Syndrome Is Associated with Atrial Electrical and Mechanical Dysfunction

PubMed Central

Yilmaz, Hale; Özcan, Kazım Serhan; Sayar, Nurten; Kemaloglu, Tugba; Gungor, Baris; Erer, Betul; Yilmaz, Mehmet; Gurkan, Ufuk; Cakmak, Nazmiye; Oz, Dilaver; Calik, Ali Nazmi; Bolca, Osman

2015-01-01

Objective In this study, we aimed to investigate the left atrial (LA) electrical and mechanical functions in patients with metabolic syndrome (MetS). Subjects and Methods The study population consisted of 87 patients with MetS and 67 controls. Intra-atrial and interatrial electromechanical delays (EDs) were measured with tissue Doppler imaging. P-wave dispersion (Pd) was calculated from the 12-lead electrocardiograms. LA volumes were measured echocardiographically by the biplane area-length method. Results Intra-atrial and interatrial EDs and Pd were significantly higher in patients with MetS (10.3 ± 6.3, 21.0 ± 11.5 and 41.7 ± 10.8) than in controls (7.4 ± 5.5, 12.3 ± 10.4 and 29.2 ± 7.4; p = 0.003, p < 0.001 and p < 0.001, respectively). The LA preatrial contraction volume and active emptying volumes were higher in this population, but the LA passive emptying fraction was lower. In the multivariate linear regression analysis, the presence of MetS, LA active emptying volume and left ventricular early diastolic (E) wave velocity/late diastolic (A) wave velocity (E/A) ratios were independent correlates of interatrial ED (p = 0.002, p = 0.001 and p = 0.025, respectively). Conclusions This study showed that intra-atrial and interatrial EDs and Pd were prolonged and LA mechanical functions were impaired in patients with MetS. PMID:25592764

Sector-Based Detection for Hands-Free Speech Enhancement in Cars

NASA Astrophysics Data System (ADS)

Lathoud, Guillaume; Bourgeois, Julien; Freudenberger, Jürgen

2006-12-01

Adaptation control of beamforming interference cancellation techniques is investigated for in-car speech acquisition. Two efficient adaptation control methods are proposed that avoid target cancellation. The "implicit" method varies the step-size continuously, based on the filtered output signal. The "explicit" method decides in a binary manner whether to adapt or not, based on a novel estimate of target and interference energies. It estimates the average delay-sum power within a volume of space, for the same cost as the classical delay-sum. Experiments on real in-car data validate both methods, including a case with[InlineEquation not available: see fulltext.] km/h background road noise.

[Discussion on Quality Evaluation Method of Medical Device During Life-Cycle in Operation Based on the Analytic Hierarchy Process].

PubMed

Zheng, Caixian; Zheng, Kun; Shen, Yunming; Wu, Yunyun

2016-01-01

The content related to the quality during life-cycle in operation of medical device includes daily use, repair volume, preventive maintenance, quality control and adverse event monitoring. In view of this, the article aims at discussion on the quality evaluation method of medical devices during their life cycle in operation based on the Analytic Hierarchy Process (AHP). The presented method is proved to be effective by evaluating patient monitors as example. The method presented in can promote and guide the device quality control work, and it can provide valuable inputs to decisions about purchase of new device.

Alterations in white matter volume and its correlation with neuropsychological scales in patients with Alzheimer's disease: a DARTEL-based voxel-based morphometry study.

PubMed

Moon, Chung-Man; Shin, Il-Seon; Jeong, Gwang-Woo

2017-02-01

Background Non-invasive imaging markers can be used to diagnose Alzheimer's disease (AD) in its early stages, but an optimized quantification analysis to measure the brain integrity has been less studied. Purpose To evaluate white matter volume change and its correlation with neuropsychological scales in patients with AD using a diffeomorphic anatomical registration through exponentiated lie algebra (DARTEL)-based voxel-based morphometry (VBM). Material and Methods The 21 participants comprised 11 patients with AD and 10 age-matched healthy controls. High-resolution magnetic resonance imaging (MRI) data were processed by VBM analysis based on DARTEL algorithm. Results The patients showed significant white matter volume reductions in the posterior limb of the internal capsule, cerebral peduncle of the midbrain, and parahippocampal gyrus compared to healthy controls. In correlation analysis, the parahippocampal volume was positively correlated with the Korean-mini mental state examination score in AD. Conclusion This study provides an evidence for localized white matter volume deficits in conjunction with cognitive dysfunction in AD. These findings would be helpful to understand the neuroanatomical mechanisms in AD and to robust the diagnostic accuracy for AD.

Structural Impairments of Hippocampus in Coal Mine Gas Explosion-Related Posttraumatic Stress Disorder

PubMed Central

Lang, Xu; Li, Huabing; Qin, Wen; Yu, Chunshui

2014-01-01

Investigations on hippocampal and amygdalar volume have revealed inconsistent results in patients with posttraumatic stress disorder (PTSD). Little is known about the structural covariance alterations between the hippocampus and amygdala in PTSD. In this study, we evaluated the alteration in the hippocampal and amygdalar volume and their structural covariance in the coal mine gas explosion related PTSD. High resolution T1-weighted magnetic resonance imaging (MRI) was performed on coal mine gas explosion related PTSD male patients (n = 14) and non-traumatized coalminers without PTSD (n = 25). The voxel-based morphometry (VBM) method was used to test the inter-group differences in hippocampal and amygdalar volume as well as the inter-group differences in structural covariance between the ipsilateral hippocampus and amygdala. PTSD patients exhibited decreased gray matter volume (GMV) in the bilateral hippocampi compared to controls (p<0.05, FDR corrected). GMV covariances between the ipsilateral hippocampus and amygdala were significantly reduced in PTSD patients compared with controls (p<0.05, FDR corrected). The coalminers with gas explosion related PTSD had decreased hippocampal volume and structural covariance with the ipsilateral amygdala, suggesting that the structural impairment of the hippocampus may implicate in the pathophysiology of PTSD. PMID:25000505

Distinct subcortical volume alterations in pediatric and adult OCD

PubMed Central

Boedhoe, Premika S.W.; Schmaal, Lianne; Abe, Yoshinari; Ameis, Stephanie H.; Arnold, Paul D.; Batistuzzo, Marcelo C.; Benedetti, Francesco; Beucke, Jan C.; Bollettini, Irene; Bose, Anushree; Brem, Silvia; Calvo, Anna; Cheng, Yuqi; Cho, Kang Ik K.; Dallaspezia, Sara; Denys, Damiaan; Fitzgerald, Kate D.; Fouche, Jean-Paul; Giménez, Mònica; Gruner, Patricia; Hanna, Gregory L.; Hibar, Derrek P.; Hoexter, Marcelo Q.; Huyser, Chaim; Ikari, Keisuke; Jahanshad, Neda; Kathmann, Norbert; Kaufmann, Christian; Koch, Kathrin; Kwon, Jun Soo; Lazaro, Luisa; Liu, Yanni; Lochner, Christine; Marsh, Rachel; Martínez-Zalacaín, Ignacio; Mataix-Cols, David; Menchón, José M.; Minuzzii, Luciano; Nakamae, Takashi; Nakao, Tomohiro; Narayanaswamy, Janardhanan C.; Piras, Fabrizio; Piras, Federica; Pittenger, Christopher; Reddy, Y.C. Janardhan; Sato, Joao R.; Simpson, H. Blair; Soreni, Noam; Soriano-Mas, Carles; Spalletta, Gianfranco; Stevens, Michael C.; Szeszko, Philip R.; Tolin, David F.; Venkatasubramanian, Ganesan; Walitza, Susanne; Wang, Zhen; van Wingen, Guido A.; Xu, Jian; Xu, Xiufeng; Yun, Je-Yeon; Zhao, Qing; Thompson, Paul M.; Stein, Dan J.; van den Heuvel, Odile A.

2016-01-01

Objective Structural brain imaging studies in Obsessive-Compulsive Disorder (OCD) have produced inconsistent findings. This may be partially due to limited statistical power from relatively small samples and clinical heterogeneity related to variation in disease profile and developmental stage. Methods To address these limitations, we conducted a meta- and mega-analysis of data from OCD sites worldwide. T1 images from 1,830 OCD patients and 1,759 controls were analyzed, using coordinated and standardized processing, to identify subcortical brain volumes that differ in OCD patients and healthy controls. We additionally examined potential modulating effects of clinical characteristics on morphological differences in OCD patients. Results The meta-analysis indicated that adult patients had significantly smaller hippocampal volumes (Cohen’s d=−0.13; p=5.1x10−3, % difference −2.80) and larger pallidum volumes (d=0.16; p=1.6x10−3, % difference 3.16) compared to adult controls. Both effects were stronger in medicated patients compared to controls (d=−0.29; p=2.4x10−5, % difference −4.18 and d=0.29; p=1.2x10−5, % difference 4.38, respectively). Unmedicated pediatric patients had larger thalamic volumes (d=0.38, p=2.1x10−3) compared to pediatric controls. None of these findings were mediated by sample characteristics such as mean age or field strength. Overall the mega-analysis yielded similar results. Conclusion Our study indicates a different pattern of subcortical abnormalities in pediatric versus adult OCD patients. The pallidum and hippocampus seem to be of importance in adult OCD, whereas the thalamus seems to be key in pediatric OCD. This highlights the potential importance of neurodevelopmental alterations in OCD, and suggests that further research on neuroplasticity in OCD may be useful. PMID:27609241

Brain structural correlates of sensory phenomena in patients with obsessive–compulsive disorder

PubMed Central

Subirà, Marta; Sato, João R.; Alonso, Pino; do Rosário, Maria C.; Segalàs, Cinto; Batistuzzo, Marcelo C.; Real, Eva; Lopes, Antonio C.; Cerrillo, Ester; Diniz, Juliana B.; Pujol, Jesús; Assis, Rachel O.; Menchón, José M.; Shavitt, Roseli G.; Busatto, Geraldo F.; Cardoner, Narcís; Miguel, Euripedes C.; Hoexter, Marcelo Q.; Soriano-Mas, Carles

2015-01-01

Background Sensory phenomena (SP) are uncomfortable feelings, including bodily sensations, sense of inner tension, “just-right” perceptions, feelings of incompleteness, or “urge-only” phenomena, which have been described to precede, trigger or accompany repetitive behaviours in individuals with obsessive–compulsive disorder (OCD). Sensory phenomena are also observed in individuals with tic disorders, and previous research suggests that sensorimotor cortex abnormalities underpin the presence of SP in such patients. However, to our knowledge, no studies have assessed the neural correlates of SP in patients with OCD. Methods We assessed the presence of SP using the University of São Paulo Sensory Phenomena Scale in patients with OCD and healthy controls from specialized units in São Paulo, Brazil, and Barcelona, Spain. All participants underwent a structural magnetic resonance examination, and brain images were examined using DARTEL voxel-based morphometry. We evaluated grey matter volume differences between patients with and without SP and healthy controls within the sensorimotor and premotor cortices. Results We included 106 patients with OCD and 87 controls in our study. Patients with SP (67% of the sample) showed grey matter volume increases in the left sensorimotor cortex in comparison to patients without SP and bilateral sensorimotor cortex grey matter volume increases in comparison to controls. No differences were observed between patients without SP and controls. Limitations Most patients were medicated. Participant recruitment and image acquisition were performed in 2 different centres. Conclusion We have identified a structural correlate of SP in patients with OCD involving grey matter volume increases within the sensorimotor cortex; this finding is in agreement with those of tic disorder studies showing that abnormal activity and volume increases within this region are associated with the urges preceding tic onset. PMID:25652753

Bioimpedance, dry weight and blood pressure control: new methods and consequences.

PubMed

Kuhlmann, Martin K; Zhu, Fansan; Seibert, E; Levin, Nathan W

2005-11-01

Chronic overhydration contributes to the development of left ventricular hypertrophy and a high cardiovascular mortality in end-stage renal disease. Assessment of dry weight is highly dependent on clinical assessment. Bioimpedance technology offers the potential to quantify body fluid compartments and to facilitate dry weight prescription. This review covers recent innovative approaches to dry weight assessment using bioimpedance technology. Three different bioimpedance approaches to determine dry weight have been published. The normovolemic/hypervolemic slope method applies whole body multifrequency bioimpedance to assess predialysis total body extracellular fluid volume and compares the extracellular fluid volume/body weight relation at hypervolemia with the standard value in normovolemic individuals. The resistance-reactance graph method uses whole body single frequency bioimpedance for assessment of hydration state and nutritional status from height-adjusted resistance and reactance. The resulting resistance-reactance vector is set in relation to a distribution range in a normovolemic population. An alternative method uses segmental bioimpedance in the form of continuous intradialytic calf bioimpedance to record changes in calf extracellular volume during dialysis. Dry weight by this method is defined as the weight at which calf extracellular volume is not further reduced despite ongoing ultrafiltration. Although promising, none of these methods has gained much popularity, probably due to the difficulties in understanding bioimpedance and the lack of gold standard methods for dry weight determination. Bioimpedance will improve dry weight assessment, but further refinement of the methods as well as large-scale clinical studies to demonstrate the accuracy and the clinical value of objective dry weight determination are needed.

AGARD Flight Test Instrumentation Series. Volume 14. The Analysis of Random Data

DTIC Science & Technology

1981-11-01

obtained at arbitrary times during a number of flights. No constraints have been placed upon the controlling parameters, so that the process is non ...34noisy" environment controlling a non -linear system (the aircraft) using a redundant net of control parameters. when aircraft were flown manually with...structure. Cuse 2. Non -Stationary Measurements. When the 114S value of a random signal varies with parameters which cannot be controlled , then the method

White Matter Hyperintensities and Hypobaric Exposure

PubMed Central

McGuire, Stephen A.; Sherman, Paul M.; Wijtenburg, S. Andrea; Rowland, Laura M.; Grogan, Patrick M.; Sladky, John H.; Robinson, Andrew Y.; Kochunov, Peter V.

2014-01-01

Objective Demonstrate that occupational exposure to nonhypoxic hypobaria is associated with subcortical white matter hyperintensities (WMHs) on fluid-attenuated inversion recovery magnetic resonance imaging (MRI). Methods Eighty-three altitude chamber personnel (PHY), 105 U-2 pilots (U2P), and 148 age- controlled and health-matched doctorate degree controls (DOC) underwent high-resolution MRI. Subcortical WMH burden was quantified as count and volume of subcortical WMH lesions after transformation of images to the Talairach atlas–based stereo-tactic frame. Results Subcortical WMHs were more prevalent in PHY (volume p = 0.011/count p = 0.019) and U2P (volume p<0.001/count p<0.001) when compared to DOC, whereas PHY were not significantly different than U2P. Interpretation This study provides strong evidence that nonhypoxic hypobaric exposure may induce subcortical WMHs in a young, healthy population lacking other risk factors for WMHs and adds this occupational exposure to other environmentally related potential causes of WMHs. PMID:25164539

Survey of instrumentation for environmental monitoring: major update. Volume 3. Radiation

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

Not Available

1979-09-01

This is the third volume of a four-volume (seven-part) series, the culmination of a comprehensive survey of instrumentation for environmental monitoring. Consideration is given to instruments and techniques presently in use and to those developed for other purposes but having possible applications to radiation monitoring. The results of the survey are given as descriptions of the physical and operating characteristics of available instruments, critical comparisons among instrumentation methods, and recommendations of promising methodology and development of new instrumentation. Information is also given regarding the pollutants to be monitored, their characteristics and forms, their sources and pathways, their effects on themore » ecosystem, and the means of controlling them through process and regulatory controls. The discussion is presented under sections entitled radiation sources; instrumentation: by type of radiation or instrument type; and, instrumentation for specific radionuclides. (JGB)« less

Methods to control phase inversions and enhance mass transfer in liquid-liquid dispersions

DOEpatents

Tsouris, Constantinos; Dong, Junhang

2002-01-01

The present invention is directed to the effects of applied electric fields on liquid-liquid dispersions. In general, the present invention is directed to the control of phase inversions in liquid-liquid dispersions. Because of polarization and deformation effects, coalescence of aqueous drops is facilitated by the application of electric fields. As a result, with an increase in the applied voltage, the ambivalence region is narrowed and shifted toward higher volume fractions of the dispersed phase. This permits the invention to be used to ensure that the aqueous phase remains continuous, even at a high volume fraction of the organic phase. Additionally, the volume fraction of the organic phase may be increased without causing phase inversion, and may be used to correct a phase inversion which has already occurred. Finally, the invention may be used to enhance mass transfer rates from one phase to another through the use of phase inversions.

Formulation analysis and computation of an optimization-based local-to-nonlocal coupling method.

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

D'Elia, Marta; Bochev, Pavel Blagoveston

2017-01-01

In this paper, we present an optimization-based coupling method for local and nonlocal continuum models. Our approach couches the coupling of the models into a control problem where the states are the solutions of the nonlocal and local equations, the objective is to minimize their mismatch on the overlap of the local and nonlocal problem domains, and the virtual controls are the nonlocal volume constraint and the local boundary condition. We present the method in the context of Local-to-Nonlocal di usion coupling. Numerical examples illustrate the theoretical properties of the approach.

Pyrolyzed thin film carbon

NASA Technical Reports Server (NTRS)

Harder, Theodore (Inventor); Konishi, Satoshi (Inventor); Miserendino, Scott (Inventor); Tai, Yu-Chong (Inventor); Liger, Matthieu (Inventor)

2010-01-01

A method of making carbon thin films comprises depositing a catalyst on a substrate, depositing a hydrocarbon in contact with the catalyst and pyrolyzing the hydrocarbon. A method of controlling a carbon thin film density comprises etching a cavity into a substrate, depositing a hydrocarbon into the cavity, and pyrolyzing the hydrocarbon while in the cavity to form a carbon thin film. Controlling a carbon thin film density is achieved by changing the volume of the cavity. Methods of making carbon containing patterned structures are also provided. Carbon thin films and carbon containing patterned structures can be used in NEMS, MEMS, liquid chromatography, and sensor devices.

Comparison of surgical conditions in 2 different anesthesia techniques of esmolol-induced controlled hypotension in breast reduction surgery

PubMed Central

Besir, Ahmet; Cekic, Bahanur; Kutanis, Dilek; Akdogan, Ali; Livaoglu, Murat

2017-01-01

Abstract Background: Breast reduction surgery is a common cosmetic surgery with a high incidence of blood loss and transfusion. In this surgery, the reduction of blood loss related to surgical manipulation and the volume of resected tissue is a target. In the present study, we compared the effects of esmolol-induced controlled hypotension on surgical visibility, surgical bleeding, and the duration of surgery in patients anesthetized with propofol/remifentanil (PR) or sevoflurane/remifentanil (SR). Methods: Patients in the American Society of Anesthesiologists I/II risk group undergoing breast reduction surgery were prospectively randomized into PR (n = 25) and SR (n = 25) groups. Controlled hypotension was induced with esmolol in both groups. During the intraoperative period, the heart rate (HR), mean arterial pressure (MAP), operation duration, volume of intraoperative blood loss, volume of blood received through postoperative drains, volume of resected tissues, and surgical area bleeding score were recorded. Results: The duration of operation in the incisional period was shorter in group PR compared to group SR (P = 0.04). The change in HR was lower in incision and hemostasis periods in the group PR compared to the group SR (P < 0.001). Total intraoperative intraoperative bleeding volume and volume of blood received through drains on postoperative postoperative day 1, day 2, and in total were found to be significantly lower in group PR compared to group SR. Surgical visibility scoring was more effective in group PR compared to SR. Conclusion: In the breast reduction surgery performed under esmolol-induced controlled hypotension, the effect of propofol + remifentanil anesthesia on the duration of incisional surgery, surgical visibility, and volume of surgical blood loss was more reliable and effective compared to that of sevoflurane + remifentanil, which seems to be an advantage. PMID:28272228

Subcortical brain structure and suicidal behaviour in major depressive disorder: a meta-analysis from the ENIGMA-MDD working group

PubMed Central

Rentería, M E; Schmaal, L; Hibar, D P; Couvy-Duchesne, B; Strike, L T; Mills, N T; de Zubicaray, G I; McMahon, K L; Medland, S E; Gillespie, N A; Hatton, S N; Lagopoulos, J; Veltman, D J; van der Wee, N; van Erp, T G M; Wittfeld, K; Grabe, H J; Block, A; Hegenscheid, K; Völzke, H; Veer, I M; Walter, H; Schnell, K; Schramm, E; Normann, C; Schoepf, D; Konrad, C; Zurowski, B; Godlewska, B R; Cowen, P J; Penninx, B W J H; Jahanshad, N; Thompson, P M; Wright, M J; Martin, N G; Christensen, H; Hickie, I B

2017-01-01

The aetiology of suicidal behaviour is complex, and knowledge about its neurobiological mechanisms is limited. Neuroimaging methods provide a noninvasive approach to explore the neural correlates of suicide vulnerability in vivo. The ENIGMA-MDD Working Group is an international collaboration evaluating neuroimaging and clinical data from thousands of individuals collected by research groups from around the world. Here we present analyses in a subset sample (n=3097) for whom suicidality data were available. Prevalence of suicidal symptoms among major depressive disorder (MDD) cases ranged between 29 and 69% across cohorts. We compared mean subcortical grey matter volumes, lateral ventricle volumes and total intracranial volume (ICV) in MDD patients with suicidal symptoms (N=451) vs healthy controls (N=1996) or MDD patients with no suicidal symptoms (N=650). MDD patients reporting suicidal plans or attempts showed a smaller ICV (P=4.12 × 10−3) or a 2.87% smaller volume compared with controls (Cohen’s d=−0.284). In addition, we observed a nonsignificant trend in which MDD cases with suicidal symptoms had smaller subcortical volumes and larger ventricular volumes compared with controls. Finally, no significant differences (P=0.28–0.97) were found between MDD patients with and those without suicidal symptoms for any of the brain volume measures. This is by far the largest neuroimaging meta-analysis of suicidal behaviour in MDD to date. Our results did not replicate previous reports of association between subcortical brain structure and suicidality and highlight the need for collecting better-powered imaging samples and using improved suicidality assessment instruments. PMID:28463239

The grey matter correlates of impaired decision-making in multiple sclerosis

PubMed Central

Muhlert, Nils; Sethi, Varun; Cipolotti, Lisa; Haroon, Hamied; Parker, Geoff J M; Yousry, Tarek; Wheeler-Kingshott, Claudia; Miller, David; Ron, Maria; Chard, Declan

2015-01-01

Objective People with multiple sclerosis (MS) have difficulties with decision-making but it is unclear if this is due to changes in impulsivity, risk taking, deliberation or risk adjustment, and how this relates to brain pathology. Methods We assessed these aspects of decision-making in 105 people with MS and 43 healthy controls. We used a novel diffusion MRI method, diffusion orientational complexity (DOC), as an index of grey matter pathology in regions associated with decision-making and also measured grey matter tissue volumes and white matter lesion volumes. Results People with MS showed less adjustment to risk and slower decision-making than controls. Moreover, impaired decision-making correlated with reduced executive function, memory and processing speed. Decision-making impairments were most prevalent in people with secondary progressive MS. They were seen in patients with cognitive impairment and those without cognitive impairment. On diffusion MRI, people with MS showed DOC changes in all regions except the occipital cortex, relative to controls. Risk adjustment correlated with DOC in the hippocampi and deliberation time with DOC in the medial prefrontal, middle frontal gyrus, anterior cingulate and caudate parcellations and with white matter lesion volumes. Conclusions These data clarify the features of decision-making deficits in MS, and provide the first evidence that they relate to grey and white matter abnormalities seen using MRI. PMID:25006208

A comparison between the dimensions of positive transtibial residual limb molds prepared by air pressure casting and weight-bearing casting methods.

PubMed

Hajiaghaei, Behnam; Ebrahimi, Ismail; Kamyab, Mojtaba; Saeedi, Hassan; Jalali, Maryam

2016-01-01

Creating a socket with proper fit is an important factor to ensure the comfort and control of prosthetic devices. Several techniques are commonly used to cast transtibial stumps but their effect on stump shape deformation is not well understood. This study compares the dimensions, circumferences and volumes of the positive casts and also the socket comfort between two casting methods. Our hypothesis was that the casts prepared by air pressure method have less volume and are more comfortable than those prepared by weight bearing method. Fifteen transtibial unilateral amputees participated in the study. Two weight bearing and air pressure casting methods were utilized for their residual limbs. The diameters and circumferences of various areas of the residual limbs and positive casts were compared. The volumes of two types of casts were measured by a volumeter and compared. Visual Analogue Scale (VAS) was used to measure the sockets fit comfort. Circumferences at 10 and 15 cm below the patella on the casts were significantly smaller in air pressure casting method compared to the weight bearing method (p=0.00 and 0.01 respectively). The volume of the cast in air pressure method was lower than that of the weight bearing method (p=0.006). The amputees found the fit of the sockets prepared by air pressure method more comfortable than the weight bearing sockets (p=0.015). The air pressure casting reduced the circumferences of the distal portion of residual limbs which has more soft tissue and because of its snug fit it provided more comfort for amputees, according to the VAS measurements.

Benefit Analysis Using Indirect or Imputed Market Methods. Volumes I-III, (1985-1994)

EPA Pesticide Factsheets

A series of reports were prepared under a grant awarded to the University of Maryland-College Park for the U.S. Environmental Protection Agency focusing on estimating the benefits of water pollution control.

Posttraumatic Stress Disorder and Depression Symptom Severities Are Differentially Associated With Hippocampal Subfield Volume Loss in Combat Veterans.

PubMed

Averill, Christopher L; Satodiya, Ritvij M; Scott, J Cobb; Wrocklage, Kristen M; Schweinsburg, Brian; Averill, Lynnette A; Akiki, Teddy J; Amoroso, Timothy; Southwick, Steven M; Krystal, John H; Abdallah, Chadi G

2017-01-01

Two decades of human neuroimaging research have associated volume reductions in the hippocampus with posttraumatic stress disorder. However, little is known about the distribution of volume loss across hippocampal subfields. Recent advances in neuroimaging methods have made it possible to accurately delineate 10 gray matter hippocampal subfields. Here, we apply a volumetric analysis of hippocampal subfields to data from a group of combat-exposed Veterans. Veterans (total, n = 68, posttraumatic stress disorder, n = 36; combat control, n = 32) completed high-resolution structural magnetic resonance imaging. Based on previously validated methods, hippocampal subfield volume measurements were conducted using FreeSurfer 6.0. The Clinician-Administered PTSD Scale assessed posttraumatic stress disorder symptom severity; Beck Depression Inventory assessed depressive symptom severity. Controlling for age and intracranial volume, partial correlation analysis examined the relationship between hippocampal subfields and symptom severity. Correction for multiple comparisons was performed using false discovery rate. Gender, intelligence, combat severity, comorbid anxiety, alcohol/substance use disorder, and medication status were investigated as potential confounds. In the whole sample, total hippocampal volume negatively correlated with Clinician-Administered PTSD Scale and Beck Depression Inventory scores. Of the 10 hippocampal subfields, Clinician-Administered PTSD Scale symptom severity negatively correlated with the hippocampus-amygdala transition area (HATA). Beck Depression Inventory scores negatively correlated with dentate gyrus, cornu ammonis 4 (CA4), HATA, CA2/3, molecular layer, and CA1. Follow-up analysis limited to the posttraumatic stress disorder group showed a negative correlation between Clinician-Administered PTSD Scale symptom severity and each of HATA, CA2/3, molecular layer, and CA4. This study provides the first evidence relating posttraumatic stress disorder and depression symptoms to abnormalities in the HATA, an anterior hippocampal region highly connected to prefrontal-amygdala circuitry. Notably, dentate gyrus abnormalities were associated with depression severity but not posttraumatic stress disorder symptoms. Future confirmatory studies should determine the extent to which dentate gyrus volume can differentiate between posttraumatic stress disorder- and depression-related pathophysiology.

Efficacy of thigh volume ratios assessed via stereovision body imaging as a predictor of visceral adipose tissue measured by magnetic resonance imaging

PubMed Central

Lee, Jane J; Freeland-Graves, Jeanne H; Pepper, M Reese; Yu, Wurong; Xu, Bugao

2014-01-01

Objectives The research examined the efficacy of regional volumes of thigh ratios assessed by stereovision body imaging (SBI) as a predictor of visceral adipose tissue measured by magnetic resonance imaging (MRI). Body measurements obtained via SBI also were utilized to explore disparities of body size and shape in men and women. Method 121 participants were measured for total/regional body volumes and ratios via SBI and abdominal subcutaneous and visceral adipose tissue areas by MRI. Results Thigh to torso and thigh to abdomen-hip volume ratios were the most reliable parameters to predict the accumulation of visceral adipose tissue depots compared to other body measurements. Thigh volume in relation to torso [odds ratios (OR) 0.44] and abdomen-hip (OR 0.41) volumes were negatively associated with increased risks of greater visceral adipose tissue depots, even after controlling for age, gender, and body mass index (BMI). Irrespective of BMI classification, men exhibited greater total body (80.95L vs. 72.41L), torso (39.26L vs. 34.13L), and abdomen-hip (29.01L vs. 25.85L) volumes than women. Women had higher thigh volumes (4.93L vs. 3.99L) and lower-body volume ratios [thigh to total body (0.07 vs. 0.05), thigh to torso (0.15 vs. 0.11), and thigh to abdomen-hip (0.20 vs. 0.15); p<0.05]. Conclusions The unique parameters of the volumes of thigh in relation to torso and abdomen-hip, by SBI were highly effective in predicting visceral adipose tissue deposition. The SBI provided an efficient method for determining body size and shape in men and women via total and regional body volumes and ratios. PMID:25645428

Monitoring angiogenesis using a human compatible calibration for broadband near-infrared spectroscopy

NASA Astrophysics Data System (ADS)

Yang, Runze; Zhang, Qiong; Wu, Ying; Dunn, Jeff F.

2013-01-01

Angiogenesis is a hallmark of many conditions, including cancer, stroke, vascular disease, diabetes, and high-altitude exposure. We have previously shown that one can study angiogenesis in animal models by using total hemoglobin (tHb) as a marker of cerebral blood volume (CBV), measured using broadband near-infrared spectroscopy (bNIRS). However, the method was not suitable for patients as global anoxia was used for the calibration. Here we determine if angiogenesis could be detected using a calibration method that could be applied to patients. CBV, as a marker of angiogenesis, is quantified in a rat cortex before and after hypoxia acclimation. Rats are acclimated at 370-mmHg pressure for three weeks, while rats in the control group are housed under the same conditions, but under normal pressure. CBV increased in each animal in the acclimation group. The mean CBV (%volume/volume) is 3.49%±0.43% (mean±SD) before acclimation for the experimental group, and 4.76%±0.29% after acclimation. The CBV for the control group is 3.28%±0.75%, and 3.09%±0.48% for the two measurements. This demonstrates that angiogenesis can be monitored noninvasively over time using a bNIRS system with a calibration method that is compatible with human use and less stressful for studies using animals.

"RCL-Pooling Assay": A Simplified Method for the Detection of Replication-Competent Lentiviruses in Vector Batches Using Sequential Pooling.

PubMed

Corre, Guillaume; Dessainte, Michel; Marteau, Jean-Brice; Dalle, Bruno; Fenard, David; Galy, Anne

2016-02-01

Nonreplicative recombinant HIV-1-derived lentiviral vectors (LV) are increasingly used in gene therapy of various genetic diseases, infectious diseases, and cancer. Before they are used in humans, preparations of LV must undergo extensive quality control testing. In particular, testing of LV must demonstrate the absence of replication-competent lentiviruses (RCL) with suitable methods, on representative fractions of vector batches. Current methods based on cell culture are challenging because high titers of vector batches translate into high volumes of cell culture to be tested in RCL assays. As vector batch size and titers are continuously increasing because of the improvement of production and purification methods, it became necessary for us to modify the current RCL assay based on the detection of p24 in cultures of indicator cells. Here, we propose a practical optimization of this method using a pairwise pooling strategy enabling easier testing of higher vector inoculum volumes. These modifications significantly decrease material handling and operator time, leading to a cost-effective method, while maintaining optimal sensibility of the RCL testing. This optimized "RCL-pooling assay" ameliorates the feasibility of the quality control of large-scale batches of clinical-grade LV while maintaining the same sensitivity.

Nanopore sensing at ultra-low concentrations using single-molecule dielectrophoretic trapping

NASA Astrophysics Data System (ADS)

Freedman, Kevin J.; Otto, Lauren M.; Ivanov, Aleksandar P.; Barik, Avijit; Oh, Sang-Hyun; Edel, Joshua B.

2016-01-01

Single-molecule techniques are being developed with the exciting prospect of revolutionizing the healthcare industry by generating vast amounts of genetic and proteomic data. One exceptionally promising route is in the use of nanopore sensors. However, a well-known complexity is that detection and capture is predominantly diffusion limited. This problem is compounded when taking into account the capture volume of a nanopore, typically 108-1010 times smaller than the sample volume. To rectify this disproportionate ratio, we demonstrate a simple, yet powerful, method based on coupling single-molecule dielectrophoretic trapping to nanopore sensing. We show that DNA can be captured from a controllable, but typically much larger, volume and concentrated at the tip of a metallic nanopore. This enables the detection of single molecules at concentrations as low as 5 fM, which is approximately a 103 reduction in the limit of detection compared with existing methods, while still maintaining efficient throughput.

Analysis of volumetric response of pituitary adenomas receiving adjuvant CyberKnife stereotactic radiosurgery with the application of an exponential fitting model.

PubMed

Yu, Yi-Lin; Yang, Yun-Ju; Lin, Chin; Hsieh, Chih-Chuan; Li, Chiao-Zhu; Feng, Shao-Wei; Tang, Chi-Tun; Chung, Tzu-Tsao; Ma, Hsin-I; Chen, Yuan-Hao; Ju, Da-Tong; Hueng, Dueng-Yuan

2017-01-01

Tumor control rates of pituitary adenomas (PAs) receiving adjuvant CyberKnife stereotactic radiosurgery (CK SRS) are high. However, there is currently no uniform way to estimate the time course of the disease. The aim of this study was to analyze the volumetric responses of PAs after CK SRS and investigate the application of an exponential decay model in calculating an accurate time course and estimation of the eventual outcome.A retrospective review of 34 patients with PAs who received adjuvant CK SRS between 2006 and 2013 was performed. Tumor volume was calculated using the planimetric method. The percent change in tumor volume and tumor volume rate of change were compared at median 4-, 10-, 20-, and 36-month intervals. Tumor responses were classified as: progression for >15% volume increase, regression for ≤15% decrease, and stabilization for ±15% of the baseline volume at the time of last follow-up. For each patient, the volumetric change versus time was fitted with an exponential model.The overall tumor control rate was 94.1% in the 36-month (range 18-87 months) follow-up period (mean volume change of -43.3%). Volume regression (mean decrease of -50.5%) was demonstrated in 27 (79%) patients, tumor stabilization (mean change of -3.7%) in 5 (15%) patients, and tumor progression (mean increase of 28.1%) in 2 (6%) patients (P = 0.001). Tumors that eventually regressed or stabilized had a temporary volume increase of 1.07% and 41.5% at 4 months after CK SRS, respectively (P = 0.017). The tumor volume estimated using the exponential fitting equation demonstrated high positive correlation with the actual volume calculated by magnetic resonance imaging (MRI) as tested by Pearson correlation coefficient (0.9).Transient progression of PAs post-CK SRS was seen in 62.5% of the patients receiving CK SRS, and it was not predictive of eventual volume regression or progression. A three-point exponential model is of potential predictive value according to relative distribution. An exponential decay model can be used to calculate the time course of tumors that are ultimately controlled.

Progressive Decrease of Left Heschl Gyrus and Planum Temporale Gray Matter Volume in First-Episode Schizophrenia

PubMed Central

Kasai, Kiyoto; Shenton, Martha E.; Salisbury, Dean F.; Hirayasu, Yoshio; Onitsuka, Toshiaki; Spencer, Magdalena H.; Yurgelun-Todd, Deborah A.; Kikinis, Ron; Jolesz, Ferenc A.; McCarley, Robert W.

2010-01-01

Background The Heschl gyrus and planum temporale have crucial roles in auditory perception and language processing. Our previous investigation using magnetic resonance imaging (MRI) indicated smaller gray matter volumes bilaterally in the Heschl gyrus and in left planum temporale in patients with first-episode schizophrenia but not in patients with first-episode affective psychosis. We sought to determine whether there are progressive decreases in anatomically defined MRI gray matter volumes of the Heschl gyrus and planum temporale in patients with first-episode schizophrenia and also in patients with first-episode affective psychosis. Methods At a private psychiatric hospital, we conducted a prospective high spatial resolution MRI study that included initial scans of 28 patients at their first hospitalization (13 with schizophrenia and 15 with affective psychosis, 13 of whom had a manic psychosis) and 22 healthy control subjects. Follow-up scans occurred, on average, 1.5 years after the initial scan. Results Patients with first-episode schizophrenia showed significant decreases in gray matter volume over time in the left Heschl gyrus (6.9%) and left planum temporale (7.2%) compared with patients with first-episode affective psychosis or control subjects. Conclusions These findings demonstrate a left-biased progressive volume reduction in the Heschl gyrus and planum temporale gray matter in patients with first-episode schizophrenia in contrast to patients with first-episode affective psychosis and control subjects. Schizophrenia but not affective psychosis seems to be characterized by a postonset progression of neocortical gray matter volume loss in the left superior temporal gyrus and thus may not be developmentally fixed. PMID:12912760

Irritable Bowel Syndrome in female patients is associated with alterations in structural brain networks

PubMed Central

Labus, Jennifer; Dinov, Ivo D.; Jiang, Zhiguo; Ashe-McNalley, Cody; Zamanyan, Alen; Shi, Yonggang; Hong, Jui-Yang; Gupta, Arpana; Tillisch, Kirsten; Ebrat, Bahar; Hobel, Sam; Gutman, Boris A.; Joshi, Shantanu; Thompson, Paul M.; Toga, Arthur W.; Mayer, Emeran A.

2014-01-01

Alterations in gray matter (GM) density/ volume and cortical thickness (CT) have been demonstrated in small and heterogeneous samples of subjects with different chronic pain syndromes, including irritable bowel syndrome (IBS). Aggregating across 7 structural neuroimaging studies conducted at UCLA between August 2006 and April 2011, we examined group differences in regional GM volume in 201 predominantly premenopausal female subjects (82 IBS, mean age: 32 ± 10 SD, 119 Healthy Controls [HCs], 30± 10 SD). Applying graph theoretical methods and controlling for total brain volume, global and regional properties of large-scale structural brain networks were compared between IBS and HC groups. Relative to HCs, the IBS group had lower volumes in bilateral superior frontal gyrus, bilateral insula, bilateral amygdala, bilateral hippocampus, bilateral middle orbital frontal gyrus, left cingulate, left gyrus rectus, brainstem, and left putamen. Higher volume was found for the left postcentral gyrus. Group differences were no longer significant for most regions when controlling for Early Trauma Inventory global score with the exception of the right amygdala and the left post central gyrus. No group differences were found for measures of global and local network organization. Compared to HCs, the right cingulate gyrus and right thalamus were identified as significantly more critical for information flow. Regions involved in endogenous pain modulation and central sensory amplification were identified as network hubs in IBS. Overall, evidence for central alterations in IBS was found in the form of regional GM volume differences and altered global and regional properties of brain volumetric networks. PMID:24076048

Longitudinal study of hippocampal volumes in heavy cannabis users

PubMed Central

Koenders, L; Lorenzetti, V; de Haan, L; Suo, C; Vingerhoets, WAM; van den Brink, W; Wiers, RW; Meijer, CJ; Machielsen, MWJ; Goudriaan, AE; Veltman, DJ; Yücel, M; Cousijn, J

2017-01-01

Background: Cannabis exposure, particularly heavy cannabis use, has been associated with neuroanatomical alterations in regions rich with cannabinoid receptors such as the hippocampus in some but not in other (mainly cross-sectional) studies. However, it remains unclear whether continued heavy cannabis use alters hippocampal volume, and whether an earlier age of onset and/or a higher dosage exacerbate these changes. Methods: Twenty heavy cannabis users (mean age 21 years, range 18–24 years) and 23 matched non-cannabis using healthy controls were submitted to a comprehensive psychological assessment and magnetic resonance imaging scan at baseline and at follow-up (average of 39 months post-baseline; standard deviation=2.4). Cannabis users started smoking around 16 years and smoked on average five days per week. A novel aspect of the current study is that hippocampal volume estimates were obtained from manual tracing the hippocampus on T1-weighted anatomical magnetic resonance imaging scans, using a previously validated protocol. Results: Compared to controls, cannabis users did not show hippocampal volume alterations at either baseline or follow-up. Hippocampal volumes increased over time in both cannabis users and controls, following similar trajectories of increase. Cannabis dose and age of onset of cannabis use did not affect hippocampal volumes. Conclusions: Continued heavy cannabis use did not affect hippocampal neuroanatomical changes in early adulthood. This contrasts with prior evidence on alterations in this region in samples of older adult cannabis users. In young adults using cannabis at this level, cannabis use may not be heavy enough to affect hippocampal neuroanatomy. PMID:28741422

Freeze-drying of “pearl milk tea”: A general strategy for controllable synthesis of porous materials

PubMed Central

Zhou, Yingke; Tian, Xiaohui; Wang, Pengcheng; Hu, Min; Du, Guodong

2016-01-01

Porous materials have been widely used in many fields, but the large-scale synthesis of materials with controlled pore sizes, pore volumes, and wall thicknesses remains a considerable challenge. Thus, the controllable synthesis of porous materials is of key general importance. Herein, we demonstrate the “pearl milk tea” freeze-drying method to form porous materials with controllable pore characteristics, which is realized by rapidly freezing the uniformly distributed template-containing precursor solution, followed by freeze-drying and suitable calcination. This general and convenient method has been successfully applied to synthesize various porous phosphate and oxide materials using different templates. The method is promising for the development of tunable porous materials for numerous applications of energy, environment, and catalysis, etc. PMID:27193866

Postural sway and regional cerebellar volume in adults with attention-deficit/hyperactivity disorder

PubMed Central

Hove, Michael J.; Zeffiro, Thomas A.; Biederman, Joseph; Li, Zhi; Schmahmann, Jeremy; Valera, Eve M.

2015-01-01

Objective Motor abnormalities, including impaired balance and increased postural sway, are commonly reported in children with ADHD, but have yet to be investigated in adults with ADHD. Furthermore, although these abnormalities are thought to stem from cerebellar deficits, evidence for an association between the cerebellum and these motor deficits has yet to be provided for either adults or children with ADHD. Method In this study, we measured postural sway in adults with ADHD and controls, examining the relationship between sway and regional cerebellar gray matter volume. Thirty-two ADHD and 28 control participants completed various standing-posture tasks on a Wii balance board. Results Postural sway was significantly higher for the ADHD group compared to the healthy controls. Higher sway was positively associated with regional gray matter volume in the right posterior cerebellum (lobule VIII/IX). Conclusion These findings show that sway abnormalities commonly reported in children with ADHD are also present in adults, and for the first time show a relationship between postural control atypicalities and the cerebellum in this group. Our findings extend the literature on motor abnormalities in ADHD and contribute to our knowledge of their neural substrate. PMID:26106567

DSM-flux: A new technology for reliable Combined Sewer Overflow discharge monitoring with low uncertainties.

PubMed

Maté Marín, Ainhoa; Rivière, Nicolas; Lipeme Kouyi, Gislain

2018-06-01

In the past ten years, governments from the European Union have been encouraged to collect volume and quality data for all the effluent overflows from separated stormwater and combined sewer systems that result in a significant environmental impact on receiving water bodies. Methods to monitor and control these flows require improvements, particularly for complex Combined Sewer Overflow (CSO) structures. The DSM-flux (Device for Stormwater and combined sewer flows Monitoring and the control of pollutant fluxes) is a new pre-designed and pre-calibrated channel that provides appropriate hydraulic conditions suitable for measurement of overflow rates and volumes by means of one water level gauge. In this paper, a stage-discharge relation for the DSM-flux is obtained experimentally and validated for multiple inflow hydraulic configurations. Uncertainties in CSO discharges and volumes are estimated within the Guide to the expression of Uncertainty in Measurement (GUM) framework. Whatever the upstream hydraulic conditions are, relative uncertainties are lower than 15% and 2% for the investigated discharges and volumes, respectively. Copyright © 2018 Elsevier Ltd. All rights reserved.

Systems for lung volume standardization during static and dynamic MDCT-based quantitative assessment of pulmonary structure and function.

PubMed

Fuld, Matthew K; Grout, Randall W; Guo, Junfeng; Morgan, John H; Hoffman, Eric A

2012-08-01

Multidetector-row computed tomography (MDCT) has emerged as a tool for quantitative assessment of parenchymal destruction, air trapping (density metrics), and airway remodeling (metrics relating airway wall and lumen geometry) in chronic obstructive pulmonary disease (COPD) and asthma. Critical to the accuracy and interpretability of these MDCT-derived metrics is the assurance that the lungs are scanned during a breathhold at a standardized volume. A computer monitored turbine-based flow meter system was developed to control patient breathholds and facilitate static imaging at fixed percentages of the vital capacity. Because of calibration challenges with gas density changes during multibreath xenon CT, an alternative system was required. The design incorporated dual rolling seal pistons. Both systems were tested in a laboratory environment and human subject trials. The turbine-based system successfully controlled lung volumes in 32/37 subjects, having a linear relationship for CT measured air volume between repeated scans: for all scans, the mean and confidence interval of the differences (scan1-scan2) was -9 mL (-169, 151); for total lung capacity alone 6 mL (-164, 177); for functional residual capacity alone, -23 mL (-172, 126). The dual-piston system successfully controlled lung volume in 31/41 subjects. Study failures related largely to subject noncompliance with verbal instruction and gas leaks around the mouthpiece. We demonstrate the successful use of a turbine-based system for static lung volume control and demonstrate its inadequacies for dynamic xenon CT studies. Implementation of a dual-rolling seal spirometer has been shown to adequately control lung volume for multibreath wash-in xenon CT studies. These systems coupled with proper patient coaching provide the tools for the use of CT to quantitate regional lung structure and function. The wash-in xenon CT method for assessing regional lung function, although not necessarily practical for routine clinical studies, provides for a dynamic protocol against which newly emerging single breath, dual-energy xenon CT measures can be validated. Copyright © 2012 AUR. Published by Elsevier Inc. All rights reserved.

Re-irradiation stereotactic body radiotherapy for spinal metastases: a multi-institutional outcome analysis.

PubMed

Hashmi, Ahmed; Guckenberger, Matthias; Kersh, Ron; Gerszten, Peter C; Mantel, Frederick; Grills, Inga S; Flickinger, John C; Shin, John H; Fahim, Daniel K; Winey, Brian; Oh, Kevin; John Cho, B C; Létourneau, Daniel; Sheehan, Jason; Sahgal, Arjun

2016-11-01

OBJECTIVE This study is a multi-institutional pooled analysis specific to imaging-based local control of spinal metastases in patients previously treated with conventional external beam radiation therapy (cEBRT) and then treated with re-irradiation stereotactic body radiotherapy (SBRT) to the spine as salvage therapy, the largest such study to date. METHODS The authors reviewed cases involving 215 patients with 247 spinal target volumes treated at 7 institutions. Overall survival was calculated on a patient basis, while local control was calculated based on the spinal target volume treated, both using the Kaplan-Meier method. Local control was defined as imaging-based progression within the SBRT target volume. Equivalent dose in 2-Gy fractions (EQD2) was calculated for the cEBRT and SBRT course using an α/β of 10 for tumor and 2 for both spinal cord and cauda equina. RESULTS The median total dose/number of fractions of the initial cEBRT was 30 Gy/10. The median SBRT total dose and number of fractions were 18 Gy and 1, respectively. Sixty percent of spinal target volumes were treated with single-fraction SBRT (median, 16.6 Gy and EQD2/10 = 36.8 Gy), and 40% with multiple-fraction SBRT (median 24 Gy in 3 fractions, EQD2/10 = 36 Gy). The median time interval from cEBRT to re-irradiation SBRT was 13.5 months, and the median duration of patient follow-up was 8.1 months. Kaplan-Meier estimates of 6- and 12-month overall survival rates were 64% and 48%, respectively; 13% of patients suffered a local failure, and the 6- and 12-month local control rates were 93% and 83%, respectively. Multivariate analysis identified Karnofsky Performance Status (KPS) < 70 as a significant prognostic factor for worse overall survival, and single-fraction SBRT as a significant predictive factor for better local control. There were no cases of radiation myelopathy, and the vertebral compression fracture rate was 4.5%. CONCLUSIONS Re-irradiation spine SBRT is effective in yielding imaging-based local control with a clinically acceptable safety profile. A randomized trial would be required to determine the optimal fractionation.

The Volume-Outcome Relationship in Critical Care

PubMed Central

Wallace, David J.; Yordanov, Youri; Trinquart, Ludovic; Blomkvist, Josefin; Angus, Derek C.; Kahn, Jeremy M.; Ravaud, Philippe; Guidet, Bertrand

2015-01-01

OBJECTIVE: The purpose of this study was to systematically review the research on volume and outcome relationships in critical care. METHODS: From January 1, 2001, to April 30, 2014, MEDLINE and EMBASE were searched for studies assessing the relationship between admission volume and clinical outcomes in critical illness. Bibliographies were reviewed to identify other articles of interest, and experts were contacted about missing or unpublished studies. Of 127 studies reviewed, 46 met inclusion criteria, covering seven clinical conditions. Two investigators independently reviewed each article using a standardized form to abstract information on key study characteristics and results. RESULTS: Overall, 29 of the studies (63%) reported a statistically significant association between higher admission volume and improved outcomes. The magnitude of the association (mortality OR between the lowest vs highest stratum of volume centers), as well as the thresholds used to characterize high volume, varied across clinical conditions. Critically ill patients with cardiovascular (n = 7, OR = 1.49 [1.11-2.00]), respiratory (n = 12, OR = 1.20 [1.04-1.38]), severe sepsis (n = 4, OR = 1.17 [1.03-1.33]), hepato-GI (n = 3, OR = 1.30 [1.08-1.78]), neurologic (n = 3, OR = 1.38 [1.22-1.57]), and postoperative admission diagnoses (n = 3, OR = 2.95 [1.05-8.30]) were more likely to benefit from admission to higher-volume centers compared with lower-volume centers. Studies that controlled for ICU or hospital organizational factors were less likely to find a significant volume-outcome relationship than studies that did not control for these factors. CONCLUSIONS: Critically ill patients generally benefit from care in high-volume centers, with more substantial benefits in selected high-risk conditions. This relationship may in part be mediated by specific ICU and hospital organizational factors. PMID:25927593

High surface area carbon and process for its production

DOEpatents

Romanos, Jimmy; Burress, Jacob; Pfeifer, Peter; Rash, Tyler; Shah, Parag; Suppes, Galen

2016-12-13

Activated carbon materials and methods of producing and using activated carbon materials are provided. In particular, biomass-derived activated carbon materials and processes of producing the activated carbon materials with prespecified surface areas and pore size distributions are provided. Activated carbon materials with preselected high specific surface areas, porosities, sub-nm (<1 nm) pore volumes, and supra-nm (1-5 nm) pore volumes may be achieved by controlling the degree of carbon consumption and metallic potassium intercalation into the carbon lattice during the activation process.

FNAS/advanced protein crystal growth

NASA Technical Reports Server (NTRS)

Rosenberger, Franz

1992-01-01

A scintillation method is presented for determination of the temperature dependence of the solubility, S(T), of proteins in 50-100 micro-l volumes of solution. S(T) data for lysozyme and horse serum albumin were obtained for various combinations of pH and precipitant concentrations. The resulting kinetics and equilibrium information was used for dynamic control, that is the separation of nucleation and growth stages in protein crystallization. Individual lysozyme and horse serum albumin crystals were grown in 15-20 micro-l solution volumes contained in x-ray capillaries.

A characteristic based volume penalization method for general evolution problems applied to compressible viscous flows

NASA Astrophysics Data System (ADS)

Brown-Dymkoski, Eric; Kasimov, Nurlybek; Vasilyev, Oleg V.

2014-04-01

In order to introduce solid obstacles into flows, several different methods are used, including volume penalization methods which prescribe appropriate boundary conditions by applying local forcing to the constitutive equations. One well known method is Brinkman penalization, which models solid obstacles as porous media. While it has been adapted for compressible, incompressible, viscous and inviscid flows, it is limited in the types of boundary conditions that it imposes, as are most volume penalization methods. Typically, approaches are limited to Dirichlet boundary conditions. In this paper, Brinkman penalization is extended for generalized Neumann and Robin boundary conditions by introducing hyperbolic penalization terms with characteristics pointing inward on solid obstacles. This Characteristic-Based Volume Penalization (CBVP) method is a comprehensive approach to conditions on immersed boundaries, providing for homogeneous and inhomogeneous Dirichlet, Neumann, and Robin boundary conditions on hyperbolic and parabolic equations. This CBVP method can be used to impose boundary conditions for both integrated and non-integrated variables in a systematic manner that parallels the prescription of exact boundary conditions. Furthermore, the method does not depend upon a physical model, as with porous media approach for Brinkman penalization, and is therefore flexible for various physical regimes and general evolutionary equations. Here, the method is applied to scalar diffusion and to direct numerical simulation of compressible, viscous flows. With the Navier-Stokes equations, both homogeneous and inhomogeneous Neumann boundary conditions are demonstrated through external flow around an adiabatic and heated cylinder. Theoretical and numerical examination shows that the error from penalized Neumann and Robin boundary conditions can be rigorously controlled through an a priori penalization parameter η. The error on a transient boundary is found to converge as O(η), which is more favorable than the error convergence of the already established Dirichlet boundary condition.

MR Analysis of Regional Brain Volume in Adolescent Idiopathic Scoliosis: Neurological Manifestation of a Systemic Disease

PubMed Central

Liu, Tianming; Chu, Winnie C.W.; Young, Geoffrey; Li, Kaiming; Yeung, Benson H.Y.; Guo, Lei; Man, Gene C.W.; Lam, Wynnie W.M.; Wong, Stephen T.C.; Cheng, Jack C.Y.

2008-01-01

Purpose To investigate whether regional brain volumes in adolescent idiopathic scoliosis (AIS) patients differ from matched control subjects as AIS subjects are reported to have poor performance on combined visual and proprioceptive testing and impaired postural balance in previous studies. Materials and Methods Twenty AIS female patients with typical right-convex thoracic curve (age range,11−18 years; mean, 14.1 years) and 26 female controls (mean age, 14.8 years) underwent three-dimensional magnetization prepared rapid acquisition gradient echo (3D-MPRAGE) MR imaging. Volumes of 99 preselected neuroanatomical regions were compared by statistical parametric mapping and atlas-based hybrid warping. Results Analysis of variance statistics revealed significant mean volumetric differences in 22 brain regions between AIS and controls. Ten regions were larger in AIS including the left frontal gyri and white matter in left frontal, parietal, and temporal regions, corpus callosum and brainstem. Twelve regions were smaller in AIS, including right-sided descending white matter tracts (anterior and posterior limbs of the right internal capsule and the cerebral peduncle) and deep nucleus (caudate), bilateral perirhinal cortices, left hippocampus and amygdala, bilateral precuneus gyri, and left middle and inferior occipital gyri. Conclusion Regional brain volume difference in AIS subjects may help to explain neurological abnormalities in this group. PMID:18302230

Thalamofrontal neurodevelopment in new-onset pediatric idiopathic generalized epilepsy

PubMed Central

Dabbs, K.; Tuchsherer, V.; Sheth, R.D.; Koehn, M.A.; Hermann, B.P.; Seidenberg, M.

2011-01-01

Background: Quantitative MRI techniques have demonstrated thalamocortical abnormalities in idiopathic generalized epilepsy (IGE). However, there are few studies examining IGE early in its course and the neurodevelopmental course of this region is not adequately defined. Objective: We examined the 2-year developmental course of the thalamus and frontal lobes in pediatric new-onset IGE (i.e., within 12 months of diagnosis). Methods: We performed whole-brain MRI in 22 patients with new-onset IGE and 36 age-matched healthy controls. MRI was repeated 24 months after baseline MRI. Quantitative volumetrics were used to examine thalamic and frontal lobe volumes. Results: The IGE group showed significant differences in thalamic volume within 1 year of seizure onset (baseline) and went on to show thalamic volume loss at a significantly faster rate than healthy control children over the 2-year interval. The control group also showed a significantly greater increase in frontal white matter expansion than the IGE group. In contrast, frontal lobe gray matter volume differences were moderate at baseline and persisted over time, indicating similar developmental trajectories with differences early in the disease process that are maintained. Conclusions: Brain tissue abnormalities in thalamic and frontal regions can be identified very early in the course of IGE and an abnormal trajectory of growth continues over a 2-year interval. PMID:21205692

The effect of wall thickness distribution on mechanical reliability and strength in unidirectional porous ceramics.

PubMed

Seuba, Jordi; Deville, Sylvain; Guizard, Christian; Stevenson, Adam J

2016-01-01

Macroporous ceramics exhibit an intrinsic strength variability caused by the random distribution of defects in their structure. However, the precise role of microstructural features, other than pore volume, on reliability is still unknown. Here, we analyze the applicability of the Weibull analysis to unidirectional macroporous yttria-stabilized-zirconia (YSZ) prepared by ice-templating. First, we performed crush tests on samples with controlled microstructural features with the loading direction parallel to the porosity. The compressive strength data were fitted using two different fitting techniques, ordinary least squares and Bayesian Markov Chain Monte Carlo, to evaluate whether Weibull statistics are an adequate descriptor of the strength distribution. The statistical descriptors indicated that the strength data are well described by the Weibull statistical approach, for both fitting methods used. Furthermore, we assess the effect of different microstructural features (volume, size, densification of the walls, and morphology) on Weibull modulus and strength. We found that the key microstructural parameter controlling reliability is wall thickness. In contrast, pore volume is the main parameter controlling the strength. The highest Weibull modulus ([Formula: see text]) and mean strength (198.2 MPa) were obtained for the samples with the smallest and narrowest wall thickness distribution (3.1 [Formula: see text]m) and lower pore volume (54.5%).

The effect of wall thickness distribution on mechanical reliability and strength in unidirectional porous ceramics

NASA Astrophysics Data System (ADS)

Seuba, Jordi; Deville, Sylvain; Guizard, Christian; Stevenson, Adam J.

2016-01-01

Macroporous ceramics exhibit an intrinsic strength variability caused by the random distribution of defects in their structure. However, the precise role of microstructural features, other than pore volume, on reliability is still unknown. Here, we analyze the applicability of the Weibull analysis to unidirectional macroporous yttria-stabilized-zirconia (YSZ) prepared by ice-templating. First, we performed crush tests on samples with controlled microstructural features with the loading direction parallel to the porosity. The compressive strength data were fitted using two different fitting techniques, ordinary least squares and Bayesian Markov Chain Monte Carlo, to evaluate whether Weibull statistics are an adequate descriptor of the strength distribution. The statistical descriptors indicated that the strength data are well described by the Weibull statistical approach, for both fitting methods used. Furthermore, we assess the effect of different microstructural features (volume, size, densification of the walls, and morphology) on Weibull modulus and strength. We found that the key microstructural parameter controlling reliability is wall thickness. In contrast, pore volume is the main parameter controlling the strength. The highest Weibull modulus (?) and mean strength (198.2 MPa) were obtained for the samples with the smallest and narrowest wall thickness distribution (3.1 ?m) and lower pore volume (54.5%).

An Unconditionally Monotone C 2 Quartic Spline Method with Nonoscillation Derivatives

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

Yao, Jin; Nelson, Karl E.

Here, a one-dimensional monotone interpolation method based on interface reconstruction with partial volumes in the slope-space utilizing the Hermite cubic-spline, is proposed. The new method is only quartic, however is C 2 and unconditionally monotone. A set of control points is employed to constrain the curvature of the interpolation function and to eliminate possible nonphysical oscillations in the slope space. An extension of this method in two-dimensions is also discussed.

An Unconditionally Monotone C 2 Quartic Spline Method with Nonoscillation Derivatives

DOE PAGES

Yao, Jin; Nelson, Karl E.

2018-01-24

Here, a one-dimensional monotone interpolation method based on interface reconstruction with partial volumes in the slope-space utilizing the Hermite cubic-spline, is proposed. The new method is only quartic, however is C 2 and unconditionally monotone. A set of control points is employed to constrain the curvature of the interpolation function and to eliminate possible nonphysical oscillations in the slope space. An extension of this method in two-dimensions is also discussed.

76 FR 34700 - Protection of Stratospheric Ozone: Request for Methyl Bromide Critical Use Exemption Applications...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-14

... pest control methods. List how many mills have been fumigated with methyl bromide over the last three... been fumigated with methyl bromide over the last three years, rate, volume and target CT of methyl...

The Mean Platelet Volume in Patients with Retinal Vein Occlusion

PubMed Central

Şahin, Muhammed; Yüksel, Harun; Türkcü, Fatih Mehmet; Çınar, Yasin; Cingü, Abdullah Kürşat; Arı, Şeyhmus; Çaça, İhsan

2013-01-01

Background. The aim of this study was to investigate the mean platelet volume (MPV) of patients with retinal vein occlusion (RVO). Methods. Hundred and ninty-three patients with the diagnosis of RVO and 83 healthy control subjects were included in this retrospective study. Retinal vein occlusion was diagnosed based on clinical examination. All patients and control subjects underwent complete ocular examination. MPV, hematocrit, hemoglobin, and platelet count of the participants were recorded. The data of patients with RVO was compared with the control subjects. Results. Patients with RVO had significantly higher MPV values (8.19 ± 1.22 fL) compared with the control subjects (7.68 ± 1.11 fL) (P = 0.004). No significant difference was found in platelet counts between RVO group and the control group (275.77 ± 70.87 109/L and 261.96 ± 59.40 109/L, resp., P = 0.161), Mean platelet volume was an independent predictor of RVO (odds ratio (OR) = 1.43; 95% confidence interval (CI) = 1.09–1.89; P = 0.011). Conclusion. Our results demonstrated that the MPV values were significantly higher in patients with RVO, suggesting that larger platelets may contribute to the pathogenesis of the RVOs. PMID:23781328

The mean platelet volume in patients with retinal vein occlusion.

PubMed

Sahin, Alparslan; Sahin, Muhammed; Yüksel, Harun; Türkcü, Fatih Mehmet; Cınar, Yasin; Cingü, Abdullah Kürşat; Arı, Seyhmus; Caça, Ihsan

2013-01-01

Background. The aim of this study was to investigate the mean platelet volume (MPV) of patients with retinal vein occlusion (RVO). Methods. Hundred and ninty-three patients with the diagnosis of RVO and 83 healthy control subjects were included in this retrospective study. Retinal vein occlusion was diagnosed based on clinical examination. All patients and control subjects underwent complete ocular examination. MPV, hematocrit, hemoglobin, and platelet count of the participants were recorded. The data of patients with RVO was compared with the control subjects. Results. Patients with RVO had significantly higher MPV values (8.19 ± 1.22 fL) compared with the control subjects (7.68 ± 1.11 fL) (P = 0.004). No significant difference was found in platelet counts between RVO group and the control group (275.77 ± 70.87 10(9)/L and 261.96 ± 59.40 10(9)/L, resp., P = 0.161), Mean platelet volume was an independent predictor of RVO (odds ratio (OR) = 1.43; 95% confidence interval (CI) = 1.09-1.89; P = 0.011). Conclusion. Our results demonstrated that the MPV values were significantly higher in patients with RVO, suggesting that larger platelets may contribute to the pathogenesis of the RVOs.

Method and apparatus for controlling fluid flow

DOEpatents

Miller, J.R.

1980-06-27

A method and apparatus for precisely controlling the rate (and hence amount) of fluid flow are given. The controlled flow rate is finely adjustable, can be extremely small (on the order of microliter-atmospheres per second), can be adjusted to zero (flow stopped), and is stable to better than 1% with time. The dead volume of the valve can be made arbitrarily small, in fact essentially zero. The valve employs no wearing mechanical parts (including springs, stems, or seals). The valve is finely adjustable, has a flow rate dynamic range of many decades, can be made compatible with any fluid, and is suitable for incorporation into an open or closed loop servo-control system.

Method of improving heterogeneous oil reservoir polymer flooding effect by positively-charged gel profile control

NASA Astrophysics Data System (ADS)

Zhao, Ling; Xia, Huifen

2018-01-01

The project of polymer flooding has achieved great success in Daqing oilfield, and the main oil reservoir recovery can be improved by more than 15%. But, for some strong oil reservoir heterogeneity carrying out polymer flooding, polymer solution will be inefficient and invalid loop problem in the high permeability layer, then cause the larger polymer volume, and a significant reduction in the polymer flooding efficiency. Aiming at this problem, it is studied the method that improves heterogeneous oil reservoir polymer flooding effect by positively-charged gel profile control. The research results show that the polymer physical and chemical reaction of positively-charged gel with the residual polymer in high permeability layer can generate three-dimensional network of polymer, plugging high permeable layer, and increase injection pressure gradient, then improve the effect of polymer flooding development. Under the condition of the same dosage, positively-charged gel profile control can improve the polymer flooding recovery factor by 2.3∼3.8 percentage points. Under the condition of the same polymer flooding recovery factor increase value, after positively-charged gel profile control, it can reduce the polymer volume by 50 %. Applying mechanism of positively-charged gel profile control technology is feasible, cost savings, simple construction, and no environmental pollution, therefore has good application prospect.

An update on methods for cryopreservation and thawing of hemopoietic stem cells.

PubMed

Lecchi, Lucilla; Giovanelli, Silvia; Gagliardi, Barbara; Pezzali, Ilaria; Ratti, Ilaria; Marconi, Maurizio

2016-06-01

The aim of this article is to review a number of variables that may affect the cryopreservation of minimally manipulated products containing allogeneic or autologous hemopoietic progenitor cells (HPC) used for transplantation, with particular reference to processing, type and addition of cryoprotectant, cell concentration, volume, freezing procedure, cooling rate, storage, thawing, and quality management. After defining final product's requirements in compliance with norms, laws and regulations, it is crucial to define the critical control points of the process. New approaches of processing were developed in the last few years such as automatic devices for volume reduction and high cell concentration in the frozen product. DMSO at 10% final concentration is still the most used cryoprotectant for HPC cryopreservation. Although controlled rate freezing is the recommended method for HPC cryopreservation, alternative methods may be used. Last generation vapor storage vessels ensure temperature stability better than older tanks. Their use may reduce risks of cross-contamination. Finally we review advantages and disadvantages of thawing procedures that may be carried out in the laboratory or at the patient's bedside. Copyright © 2016 Elsevier Ltd. All rights reserved.

Recommendations for Improving Identification and Quantification in Non-Targeted, GC-MS-Based Metabolomic Profiling of Human Plasma

PubMed Central

Wang, Hanghang; Muehlbauer, Michael J.; O’Neal, Sara K.; Newgard, Christopher B.; Hauser, Elizabeth R.; Shah, Svati H.

2017-01-01

The field of metabolomics as applied to human disease and health is rapidly expanding. In recent efforts of metabolomics research, greater emphasis has been placed on quality control and method validation. In this study, we report an experience with quality control and a practical application of method validation. Specifically, we sought to identify and modify steps in gas chromatography-mass spectrometry (GC-MS)-based, non-targeted metabolomic profiling of human plasma that could influence metabolite identification and quantification. Our experimental design included two studies: (1) a limiting-dilution study, which investigated the effects of dilution on analyte identification and quantification; and (2) a concentration-specific study, which compared the optimal plasma extract volume established in the first study with the volume used in the current institutional protocol. We confirmed that contaminants, concentration, repeatability and intermediate precision are major factors influencing metabolite identification and quantification. In addition, we established methods for improved metabolite identification and quantification, which were summarized to provide recommendations for experimental design of GC-MS-based non-targeted profiling of human plasma. PMID:28841195

Core Engine Noise Control Program. Volume III. Prediction Methods

DTIC Science & Technology

1974-08-01

turbofan engines , and Method (C) is based on an analytical description of viscous wake interaction between adjoining blade rows. Turbine Tone/ Jet ...levels for turbojet , turboshaft and turbofan engines . The turbojet data correlate highest and the turbofan data correlate lowest. Turbine Noise Noise...different engines were examined for combustor, jet and fan noise. Tnree turbojet , two turboshaft and two turbofan

Water vapor mass balance method for determining air infiltration rates in houses

Treesearch

David R. DeWalle; Gordon M. Heisler

1980-01-01

A water vapor mass balance technique that includes the use of common humidity-control equipment can be used to determine average air infiltration rates in buildings. Only measurements of the humidity inside and outside the home, the mass of vapor exchanged by a humidifier/dehumidifier, and the volume of interior air space are needed. This method gives results that...

Chemical Shift MR Imaging Methods for the Quantification of Transcatheter Lipiodol Delivery to the Liver: Preclinical Feasibility Studies in a Rodent Model

PubMed Central

Yin, Xiaoming; Guo, Yang; Li, Weiguo; Huo, Eugene; Zhang, Zhuoli; Nicolai, Jodi; Kleps, Robert A.; Hernando, Diego; Katsaggelos, Aggelos K.; Omary, Reed A.

2012-01-01

Purpose: To demonstrate the feasibility of using chemical shift magnetic resonance (MR) imaging fat-water separation methods for quantitative estimation of transcatheter lipiodol delivery to liver tissues. Materials and Methods: Studies were performed in accordance with institutional Animal Care and Use Committee guidelines. Proton nuclear MR spectroscopy was first performed to identify lipiodol spectral peaks and relative amplitudes. Next, phantoms were constructed with increasing lipiodol-water volume fractions. A multiecho chemical shift–based fat-water separation method was used to quantify lipiodol concentration within each phantom. Six rats served as controls; 18 rats underwent catheterization with digital subtraction angiography guidance for intraportal infusion of a 15%, 30%, or 50% by volume lipiodol-saline mixture. MR imaging measurements were used to quantify lipiodol delivery to each rat liver. Lipiodol concentration maps were reconstructed by using both single-peak and multipeak chemical shift models. Intraclass and Spearman correlation coefficients were calculated for statistical comparison of MR imaging–based lipiodol concentration and volume measurements to reference standards (known lipiodol phantom compositions and the infused lipiodol dose during rat studies). Results: Both single-peak and multipeak measurements were well correlated to phantom lipiodol concentrations (r2 > 0.99). Lipiodol volume measurements were progressively and significantly higher when comparing between animals receiving different doses (P < .05 for each comparison). MR imaging–based lipiodol volume measurements strongly correlated with infused dose (intraclass correlation coefficients > 0.93, P < .001) with both single- and multipeak approaches. Conclusion: Chemical shift MR imaging fat-water separation methods can be used for quantitative measurements of lipiodol delivery to liver tissues. © RSNA, 2012 PMID:22623693

Comparative Analysis of 2-D Versus 3-D Ultrasound Estimation of the Fetal Adrenal Gland Volume and Prediction of Preterm Birth

PubMed Central

Turan, Ozhan M.; Turan, Sifa; Buhimschi, Irina A.; Funai, Edmund F.; Campbell, Katherine H.; Bahtiyar, Ozan M.; Harman, Chris R.; Copel, Joshua A.; Baschat, Ahmet A; Buhimschi, Catalin S.

2013-01-01

Objective We aim to test the hypothesis that 2D fetal AGV measurements offer similar volume estimates as volume calculations based on 3D technique Methods Fetal AGV was estimated by 3D ultrasound (VOCAL) in 93 women with signs/symptoms of preterm labor and 73 controls. Fetal AGV was calculated using an ellipsoid formula derived from 2D measurements of the same blocks (0.523× length × width × depth). Comparisons were performed by intra-class correlation coefficient (ICC), coefficient of repeatability, and Bland-Altman method. The cAGV (AGV/fetal weight) was calculated for both methods and compared for prediction of PTB within 7 days. Results Among 168 volumes, there was a significant correlation between 3D and 2D methods (ICC=0.979[95%CI: 0.971-0.984]). The coefficient of repeatability for the 3D was superior to the 2D method (Intra-observer 3D: 30.8, 2D:57.6; inter-observer 3D: 12.2, 2D: 15.6). Based on 2D calculations, a cAGV≥433mm3/kg, was best for prediction of PTB (sensitivity: 75%(95%CI=59-87); specificity: 89%(95%CI=82-94). Sensitivity and specificity for the 3D cAGV (cut-off ≥420mm3/kg) was 85%(95%CI=70-94) and 95%(95%CI=90-98), respectively. In receiver-operating-curve curve analysis, 3D cAGV was superior to 2D cAGV for prediction of PTB (z=1.99, p=0.047). Conclusion 2D volume estimation of fetal adrenal gland using ellipsoid formula cannot replace 3D AGV calculations for prediction of PTB. PMID:22644825

Extrapolation-Based References Improve Motion and Eddy-Current Correction of High B-Value DWI Data: Application in Parkinson's Disease Dementia.

PubMed

Nilsson, Markus; Szczepankiewicz, Filip; van Westen, Danielle; Hansson, Oskar

2015-01-01

Conventional motion and eddy-current correction, where each diffusion-weighted volume is registered to a non diffusion-weighted reference, suffers from poor accuracy for high b-value data. An alternative approach is to extrapolate reference volumes from low b-value data. We aim to compare the performance of conventional and extrapolation-based correction of diffusional kurtosis imaging (DKI) data, and to demonstrate the impact of the correction approach on group comparison studies. DKI was performed in patients with Parkinson's disease dementia (PDD), and healthy age-matched controls, using b-values of up to 2750 s/mm2. The accuracy of conventional and extrapolation-based correction methods was investigated. Parameters from DTI and DKI were compared between patients and controls in the cingulum and the anterior thalamic projection tract. Conventional correction resulted in systematic registration errors for high b-value data. The extrapolation-based methods did not exhibit such errors, yielding more accurate tractography and up to 50% lower standard deviation in DKI metrics. Statistically significant differences were found between patients and controls when using the extrapolation-based motion correction that were not detected when using the conventional method. We recommend that conventional motion and eddy-current correction should be abandoned for high b-value data in favour of more accurate methods using extrapolation-based references.

Methods for the correction of vascular artifacts in PET O-15 water brain-mapping studies

NASA Astrophysics Data System (ADS)

Chen, Kewei; Reiman, E. M.; Lawson, M.; Yun, Lang-sheng; Bandy, D.; Palant, A.

1996-12-01

While positron emission tomographic (PET) measurements of regional cerebral blood flow (rCBF) can be used to map brain regions that are involved in normal and pathological human behaviors, measurements in the anteromedial temporal lobe can be confounded by the combined effects of radiotracer activity in neighboring arteries and partial-volume averaging. The authors now describe two simple methods to address this vascular artifact. One method utilizes the early frames of a dynamic PET study, while the other method utilizes a coregistered magnetic resonance image (MRI) to characterize the vascular region of interest (VROI). Both methods subsequently assign a common value to each pixel in the VROI for the control (baseline) scan and the activation scan. To study the vascular artifact and to demonstrate the ability of the proposed methods correcting the vascular artifact, four dynamic PET scans were performed in a single subject during the same behavioral state. For each of the four scans, a vascular scan containing vascular activity was computed as the summation of the images acquired 0-60 s after radiotracer administration, and a control scan containing minimal vascular activity was computed as the summation of the images acquired 20-80 s after radiotracer administration. t-score maps calculated from the four pairs of vascular and control scans were used to characterize regional blood flow differences related to vascular activity before and after the application of each vascular artifact correction method. Both methods eliminated the observed differences in vascular activity, as well as the vascular artifact observed in the anteromedial temporal lobes. Using PET data from a study of normal human emotion, these methods permitted the authors to identify rCBF increases in the anteromedial temporal lobe free from the potentially confounding, combined effects of vascular activity and partial-volume averaging.

Optic coherence tomography shows inflammation and degeneration in major depressive disorder patients correlated with disease severity.

PubMed

Kalenderoglu, Aysun; Çelik, Mustafa; Sevgi-Karadag, Ayse; Egilmez, Oguzhan Bekir

2016-11-01

Previous research has consistently detected inflammation in the etiology of depression and neuroimaging studies have demonstrated gray matter abnormalities implying a neurodegenerative process in depression. The aim of this study was to compare ganglion cell layer (GCL), and inner plexiform layer (IPL) volumes and retinal nerve fiber layer (RNFL) thickness between first episode and recurrent major depressive disorder (MDD) patients and controls using optic coherence tomography (OCT) in order to detect findings supporting a degenerative process. Also choroid thicknesses of the same groups were compared to examine effects of inflammation on MDD. This study included 50 recurrent MDD patients, 50 first episode MDD patients and 50 controls. OCT measurements were performed by a spectral OCT device. GCL and IPL volumes and RNFL and choroid thicknesses were measured automatically by the device. GCL and IPL volumes were significantly smaller in recurrent depression patients than first episode patients and in all MDD patients than controls. Also there were significant negative correlations between their volumes and disease severity parameters such as Ham-D and CGI scores, and disease duration. RNFL thicknesses were also lower in recurrent MDD patients than first episode patients and all MDD patients than controls but statistical significance was achieved only for global RNFL and temporal superior RNFL. Mean choroid thickness was higher in MDD patients than controls and in first episode MDD patients than recurrent MDD patients. Cross-sectional design of our study limits conclusions about progressive degeneration during the course of MDD. Lack of a control neuroimaging method like magnetic resonance imaging makes it hard to draw firm conclusions from our results. OCT finding of decreased GCL and IPL volumes supports previous research suggesting degeneration in MDD. OCT may be an important tool to track neurodegeneration in patients with major depression. Considering RNFL to be the latest layer that will be affected during course of degeneration, GCL and IPL volumes appear to be better parameters to follow. In addition, choroid may be an important structure to detect acute attack period and to follow inflammatory process in MDD like in systemic inflammatory diseases. Copyright © 2016 Elsevier B.V. All rights reserved.

A new gas dilution method for measuring body volume.

PubMed Central

Nagao, N; Tamaki, K; Kuchiki, T; Nagao, M

1995-01-01

This study was designed to examine the validity of a new gas dilution method (GD) for measuring human body volume and to compare its accuracy with the results obtained by the underwater weighing method (UW). We measured the volume of plastic bottles and 16 subjects (including two females), aged 18-42 years with each method. For the bottles, the volume measured by hydrostatic weighing was correlated highly (r = 1.000) with that measured by the new gas dilution method. For the subjects, the body volume determined by the two methods was significantly correlated (r = 0.998). However, the subject's volume measured by the gas dilution method was significantly larger than that by underwater weighing method. There was significant correlation (r = 0.806) between GD volume-UW volume and the body mass index (BMI), so that UW volume could be predicted from GD volume and BMI. It can be concluded that the new gas dilution method offers promising possibilities for future research in the population who cannot submerge underwater. PMID:7551760

Disposable Collection Kit for Rapid and Reliable Collection of Saliva

PubMed Central

Yamaguchi, Masaki; Tezuka, Yuki; Takeda, Kazunori; Shetty, Vivek

2015-01-01

Objectives To describe and evaluate disposable saliva collection kit for rapid, reliable, and reproducible collection of saliva samples. Methods The saliva collection kit comprised of a saliva absorbent swab and an extractor unit was used to retrieve whole saliva samples from 10 subjects. The accuracy and precision of the extracted volumes (3, 10, and 30 μl) were compared to similar volumes drawn from control samples obtained by passive drool. Additionally, the impact of kit collection method on subsequent immunoassay results was verified by assessing salivary cortisol levels in the samples and comparing them to controls. Results The recovered volumes for the whole saliva samples were 3.85 ± 0.28, 10.79 ± 0.95, and 31.18 ± 1.72 μl, respectively (CV = 8.76%) and 2.91 ± 0.19, 9.75 ± 0.43, and 29.64 ± 0.91 μl, respectively, (CV = 6.36%) for the controls. There was a close correspondence between the salivary cortisol levels from the saliva samples obtained by the collection kit and the controls (R2 > 0.96). Conclusions The disposable saliva collection kit allows accurate and repeatable collection of fixed amounts of whole saliva and does not interfere with subsequent measurements of salivary cortisol. The simple collection process, lack of elaborate specimen recovery steps, and the short turnaround time (<3 min) should render the kit attractive to test subjects and researchers alike. Am. J. Hum. Biol. 27:720–723, 2015. © 2015 The Authors American Journal of Human Biology Published by Wiley Periodicals, Inc. PMID:25754371

Mapping the Regional Influence of Genetics on Brain Structure Variability - A Tensor-Based Morphometry Study

PubMed Central

Brun, Caroline; Leporé, Natasha; Pennec, Xavier; Lee, Agatha D.; Barysheva, Marina; Madsen, Sarah K.; Avedissian, Christina; Chou, Yi-Yu; de Zubicaray, Greig I.; McMahon, Katie; Wright, Margaret; Toga, Arthur W.; Thompson, Paul M.

2010-01-01

Genetic and environmental factors influence brain structure and function profoundly The search for heritable anatomical features and their influencing genes would be accelerated with detailed 3D maps showing the degree to which brain morphometry is genetically determined. As part of an MRI study that will scan 1150 twins, we applied Tensor-Based Morphometry to compute morphometric differences in 23 pairs of identical twins and 23 pairs of same-sex fraternal twins (mean age: 23.8 ± 1.8 SD years). All 92 twins’ 3D brain MRI scans were nonlinearly registered to a common space using a Riemannian fluid-based warping approach to compute volumetric differences across subjects. A multi-template method was used to improve volume quantification. Vector fields driving each subject’s anatomy onto the common template were analyzed to create maps of local volumetric excesses and deficits relative to the standard template. Using a new structural equation modeling method, we computed the voxelwise proportion of variance in volumes attributable to additive (A) or dominant (D) genetic factors versus shared environmental (C) or unique environmental factors (E). The method was also applied to various anatomical regions of interest (ROIs). As hypothesized, the overall volumes of the brain, basal ganglia, thalamus, and each lobe were under strong genetic control; local white matter volumes were mostly controlled by common environment. After adjusting for individual differences in overall brain scale, genetic influences were still relatively high in the corpus callosum and in early-maturing brain regions such as the occipital lobes, while environmental influences were greater in frontal brain regions which have a more protracted maturational time-course. PMID:19446645

Radiobiological Determination of Dose Escalation and Normal Tissue Toxicity in Definitive Chemoradiation Therapy for Esophageal Cancer

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

Warren, Samantha, E-mail: Samantha.warren@oncology.ox.ac.uk; Partridge, Mike; Carrington, Rhys

2014-10-01

Purpose: This study investigated the trade-off in tumor coverage and organ-at-risk sparing when applying dose escalation for concurrent chemoradiation therapy (CRT) of mid-esophageal cancer, using radiobiological modeling to estimate local control and normal tissue toxicity. Methods and Materials: Twenty-one patients with mid-esophageal cancer were selected from the SCOPE1 database (International Standard Randomised Controlled Trials number 47718479), with a mean planning target volume (PTV) of 327 cm{sup 3}. A boost volume, PTV2 (GTV + 0.5 cm margin), was created. Radiobiological modeling of tumor control probability (TCP) estimated the dose required for a clinically significant (+20%) increase in local control as 62.5more » Gy/25 fractions. A RapidArc (RA) plan with a simultaneously integrated boost (SIB) to PTV2 (RA{sub 62.5}) was compared to a standard dose plan of 50 Gy/25 fractions (RA{sub 50}). Dose-volume metrics and estimates of normal tissue complication probability (NTCP) for heart and lungs were compared. Results: Clinically acceptable dose escalation was feasible for 16 of 21 patients, with significant gains (>18%) in tumor control from 38.2% (RA{sub 50}) to 56.3% (RA{sub 62.5}), and only a small increase in predicted toxicity: median heart NTCP 4.4% (RA{sub 50}) versus 5.6% (RA{sub 62.5}) P<.001 and median lung NTCP 6.5% (RA{sub 50}) versus 7.5% (RA{sub 62.5}) P<.001. Conclusions: Dose escalation to the GTV to improve local control is possible when overlap between PTV and organ-at-risk (<8% heart volume and <2.5% lung volume overlap for this study) generates only negligible increase in lung or heart toxicity. These predictions from radiobiological modeling should be tested in future clinical trials.« less

Cannabis, Cigarettes, and Their Co-Occurring Use: Disentangling Differences in Gray Matter Volume

PubMed Central

Jagannathan, Kanchana; Hager, Nathan; Childress, Anna Rose; Rao, Hengyi; Franklin, Teresa R.

2015-01-01

Background: Structural magnetic resonance imaging techniques are powerful tools for examining the effects of drug use on the brain. The nicotine and cannabis literature has demonstrated differences between nicotine cigarette smokers and cannabis users compared to controls in brain structure; however, less is known about the effects of co-occurring cannabis and tobacco use. Methods: We used voxel-based morphometry to examine gray matter volume differences between four groups: (1) cannabis-dependent individuals who do not smoke tobacco (Cs); (2) cannabis-dependent individuals who smoke tobacco (CTs); (3) cannabis-naïve, nicotine-dependent individuals who smoke tobacco (Ts); and (4) healthy controls (HCs). We also explored associations between gray matter volume and measures of cannabis and tobacco use. Results: A significant group effect was observed in the left putamen, thalamus, right precentral gyrus, and left cerebellum. Compared to HCs, the Cs, CTs, and Ts exhibited larger gray matter volumes in the left putamen. Cs also had larger gray matter volume than HCs in the right precentral gyrus. Cs and CTs exhibited smaller gray matter volume than HCs in the thalamus, and CTs and Ts had smaller left cerebellar gray matter volume than HCs. Conclusions: This study extends previous research that independently examined the effects of cannabis or tobacco use on brain structure by including an examination of co-occurring cannabis and tobacco use, and provides evidence that cannabis and tobacco exposure are associated with alterations in brain regions associated with addiction. PMID:26045474

Reduced anterior insula, enlarged amygdala in alcoholism and associated depleted von Economo neurons

PubMed Central

Senatorov, Vladimir V.; Damadzic, Ruslan; Mann, Claire L.; Schwandt, Melanie L.; George, David T.; Hommer, Daniel W.; Heilig, Markus

2015-01-01

The insula, a structure involved in higher order representation of interoceptive states, has recently been implicated in drug craving and social stress. Here, we performed brain magnetic resonance imaging to measure volumes of the insula and amygdala, a structure with reciprocal insular connections, in 26 alcohol-dependent patients and 24 healthy volunteers (aged 22–56 years, nine females in each group). We used an established morphometry method to quantify total and regional insular volumes. Volumetric measurements of the amygdala were obtained using a model-based segmentation/registration tool. In alcohol-dependent patients, anterior insula volumes were bilaterally reduced compared to healthy volunteers (left by 10%, right by 11%, normalized to total brain volumes). Furthermore, alcohol-dependent patients, compared with healthy volunteers, had bilaterally increased amygdala volumes. The left amygdala was increased by 28% and the right by 29%, normalized to total brain volumes. Post-mortem studies of the anterior insula showed that the reduced anterior insular volume may be associated with a population of von Economo neurons, which were 60% diminished in subjects with a history of alcoholism (n = 6) as compared to subjects without a history of alcoholism (n = 6) (aged 32–56 years, all males). The pattern of neuroanatomical change observed in our alcohol-dependent patients might result in a loss of top-down control of amygdala function, potentially contributing to impaired social cognition as well as an inability to control negatively reinforced alcohol seeking and use. PMID:25367022

Stereological estimation of ovarian oocyte volume, surface area and number: application on mice treated with nandrolone decanoate.

PubMed

Karbalay-Doust, Saied; Noorafshan, Ali

2012-07-05

Changes in the number and size of oocytes can lead to fertilization problems. The present study aimed to evaluate the number, volume, and surface area of oocytes in healthy as well as nandrolone decanoate-treated (ND) mice using stereological methods. Five control mice received vehicle, and five ND-treated mice received ND. Using the 'isotropic Cavalieri' design', the ovary was sectioned. The volume of the ovary (cortex and medulla) was estimated. The oocytes' volume and surface area were estimated using the invariator. The number of the oocytes was estimated using an optical disector. The volumes of the ovary, cortex, and medulla decreased ~50% in the ND-treated mice. The mean number (coefficient of variation) of preantral, antral, and atretic oocytes in the control ovary were 1,690 (0.29), 2,100 (0.52), and 3,900 (0.2), respectively, which decreased ~54%, ~87%, and ~91%, respectively in the ND-treated animals. The mean volume (coefficient of variation) of the preantral, antral, and atretic oocytes were 86,000 (0.27), 110,000 (0.48), and 27,000 (0.33) μm³, respectively. The mean surface area (coefficient of variation) of the three types of oocytes were 9,000 (0.24), 9,900 (0.28), and 4,700 (0.21) μm², respectively. These parameters remained unchanged in the ND-treated mice. ND induces reduction in the number of oocytes, but not in the volume or the surface area.

Humidity sensitive polymers In solution processed adjustable pore-volume Cu(In,Ga)S2 photocathodes for solar hydrogen production

NASA Astrophysics Data System (ADS)

Zhang, Chuan; Luo, Wenjun; Wen, Xin; Guan, Zhongjie; Zou, Zhigang

2017-11-01

P-type Cu(In,Ga)S2 semiconductors are promising candidates to be used as photocathodes for solar water splitting. Porous structures have been widely used to improve the performances of photoelectrodes due to good minority carrier transport. However, a porous photoelectrode has longer transport distance of majority carriers, which limits its performance. Controlling pore volume of a photoelectrode can balance minority and majority carrier transport and improve the performance. Here, a porous Cu(In,Ga)S2 film is prepared by facile spin-coating method. The pore volume of Cu(In,Ga)S2 film is controlled by adjusting relative humidity (RH) of air during spin-coating process. Further studies suggest that polyvinyl acetate (PVAc) in precursor solution is a humidity sensitive polymer and plays a key role to form different pore volume. The 40% RH sample has the best performance due to its optimum pore volume. After further coated with CdS surface passivation layer and Pt electrocatalyst on the surface, a 40% RH Cu(In,Ga)S2 photocathode indicates a photocurrent density of 8.6 mA cm-2 at 0 V RHE, which is one of the highest photocurrents of Cu(In,Ga)S2 photocathodes. This new strategy for adjusting pore volume is also suitable to prepare other solution-processed inorganic materials.

Volume and asymmetry abnormalities of insula in antipsychotic-naive schizophrenia: a 3-tesla magnetic resonance imaging study.

PubMed

Virupaksha, Harve Shanmugam; Kalmady, Sunil V; Shivakumar, Venkataram; Arasappa, Rashmi; Venkatasubramanian, Ganesan; Gangadhar, Bangalore N

2012-04-01

Insula, which is a vital brain region for self-awareness, empathy, and sensory stimuli processing, is critically implicated in schizophrenia pathogenesis. Existing studies on insula volume abnormalities report inconsistent findings potentially due to the evaluation of 'antipsychotic-treated' schizophrenia patients as well as suboptimal methodology. To understand the role of insula in schizophrenia. In this first-time 3-T magnetic resonance imaging study, we examined antipsychotic-naive schizophrenic patients (N=30) and age-, sex-, handedness- and education-matched healthy controls (N=28). Positive and negative symptoms were scored with good interrater reliability (intraclass correlation coefficient (ICC)>0.9) by using the scales for negative and positive symptoms. Gray matter volume of insula and its anterior/posterior subregions were measured by using a three-dimensional, interactive, semiautomated software based on the valid method with good interrater reliability (ICC>0.85). Intracranial volume was automatically measured by using the FreeSurfer software. Patients had significantly deficient gray matter volumes of left (F=33.4; P<0.00001) and right (F=11.9; P=0.001) insula after controlling for the effects of age, sex, and intracranial volume. Patients with predominantly negative symptoms had a significantly deficient right posterior insula volume than those with predominantly positive symptoms (F=6.3; P=0.02). Asymmetry index analysis revealed anterior insular asymmetry to be significantly reversed (right>left) in male patients in comparison with male controls (left>right) (t=2.7; P=0.01). Robust insular volume deficits in antipsychotic-naive schizophrenia support intrinsic role for insula in pathogenesis of this disorder. The first-time demonstration of a relationship between right posterior insular deficit and negative symptoms is in tune with the background neurobiological literature. Another novel observation of sex-specific anterior insular asymmetry reversal in patients supports evolutionary postulates of schizophrenia pathogenesis.

Cumulative Adversity and Smaller Gray Matter Volume in Medial Prefrontal, Anterior Cingulate, and Insula Regions

PubMed Central

Ansell, Emily B.; Rando, Kenneth; Tuit, Keri; Guarnaccia, Joseph; Sinha, Rajita

2012-01-01

Background Cumulative adversity and stress are associated with risk of psychiatric disorders. While basic science studies show repeated and chronic stress effects on prefrontal and limbic neurons, human studies examining cumulative stress and effects on brain morphology are rare. Thus, we assessed whether cumulative adversity is associated with differences in gray matter volume, particularly in regions regulating emotion, self-control, and top-down processing in a community sample. Methods One hundred three healthy community participants, aged 18 to 48 and 68% male, completed interview assessment of cumulative adversity and a structural magnetic resonance imaging protocol. Whole-brain voxel-based-morphometry analysis was performed adjusting for age, gender, and total intracranial volume. Results Cumulative adversity was associated with smaller volume in medial prefrontal cortex (PFC), insular cortex, and subgenual anterior cingulate regions (familywise error corrected, p <.001). Recent stressful life events were associated with smaller volume in two clusters: the medial PFC and the right insula. Life trauma was associated with smaller volume in the medial PFC, anterior cingulate, and subgenual regions. The interaction of greater subjective chronic stress and greater cumulative life events was associated with smaller volume in the orbitofrontal cortex, insula, and anterior and subgenual cingulate regions. Conclusions Current results demonstrate that increasing cumulative exposure to adverse life events is associated with smaller gray matter volume in key prefrontal and limbic regions involved in stress, emotion and reward regulation, and impulse control. These differences found in community participants may serve to mediate vulnerability to depression, addiction, and other stress-related psychopathology. PMID:22218286

Can Land Managers Control Japanese Knotweed? Lessons from Control Tests in Belgium

NASA Astrophysics Data System (ADS)

Delbart, Emmanuel; Mahy, Grégory; Weickmans, Bernard; Henriet, François; Crémer, Sébastien; Pieret, Nora; Vanderhoeven, Sonia; Monty, Arnaud

2012-12-01

Japanese knotweed Fallopia japonica is an extremely abundant invasive plant in Belgium and surrounding countries. To date, no eradication method is available for land managers facing the invasion of this rhizomatous plant. We tested different chemical herbicides with two application methods (spraying and stem injection), as well as mechanical treatments, on knotweed clones throughout southern Belgium. The tested control methods were selected to be potentially usable by managers, e.g., using legally accepted rates for herbicides. Stem volume, height and density reduction were assessed after one or two years, depending on the control method. Labor estimations were made for each control method. No tested control method completely eradicated the clones. Stem injection with glyphosate-based herbicide (3.6 kg ha-1 of acid equivalent glyphosate) caused the most damage, i.e., no sprouting shoots were observed the year following the injection. The following year, though, stunted shoots appeared. Among the mechanical control methods, repeated cuts combined with native tree transplanting most appreciably reduced knotweed development. The most efficient methods we tested could curb knotweed invasion, but are not likely to be effective in eradicating the species. As such, they should be included in a more integrated restoration strategy, together with prevention and public awareness campaigns.

Volume-confined synthesis of ligand-free gold nanoparticles with tailored sizes for enhanced catalytic activity

NASA Astrophysics Data System (ADS)

Shaik, Firdoz; Zhang, Weiqing; Niu, Wenxin; Lu, Xianmao

2014-10-01

Ligand-free Au nanoparticles with controlled sizes are synthesized via a volume-confined method. In this synthesis, mesoporous hollow silica shells (mHSS) are used as nano-containers for the impregnation of HAuCl4 solution before they are separated from the bulk solution. With a simple heating process, the Au precursor confined within the cavity of the isolated hollow shells is converted into ligand-free Au nanoparticles. The size of the Au nanoparticles can be tuned precisely by loading HAuCl4 solution of different concentrations, or by using mHSS with different cavity volumes. The ligand-free Au nanoparticles demonstrate superior catalytic activity than sodium citrate-capped Au nanoparticles.

Practical optimal flight control system design for helicopter aircraft. Volume 1: Technical Report

NASA Technical Reports Server (NTRS)

Hofmann, L. G.; Riedel, S. A.; Mcruer, D.

1980-01-01

A method by which modern and classical theory techniques may be integrated in a synergistic fashion and used in the design of practical flight control systems is presented. A general procedure is developed, and several illustrative examples are included. Emphasis is placed not only on the synthesis of the design, but on the assessment of the results as well.

The Shock and Vibration Digest, Volume 12, Number 9,

DTIC Science & Technology

1980-09-01

include diesel engine noise, process plant noise, and environ- dynamic mechanical properties of viscoelastic mate- mental noise and planning. rials...new numerical methods are presented in- plant noise control, design of facilities for noise in the twelve articles of the mathematics section. control...International Symposium for Innovative the seminar: 31 16 = ,,-,==. ’d-m w .’ " Dynamic Testing of Nuclear Power Plant Struc- ENVIRONMENTAL STRESS

Droplet Sizing Research.

DTIC Science & Technology

1985-04-15

studies, The measurement volume is defined by the intersection aerosol studies, flue gas desulfurization , spray drying, of apertures in front of two...identify by block numberl --A method to measure the size and velocity of individual particles in a flow is discussed. Results are presented for controlled ... controlled m0 monodisperse sprays and compared to flash photographs. Typical errors between predicted and measured sizes are less than 5%. Experimental

Ultra Low Volume Dispersal of Insecticides by Ground Equipment

DTIC Science & Technology

1999-12-01

Chairman) CPT Lewis Boobar, MS, USA (Vice Chairman) Mr. Joseph Deschenes Mr. Sam Jerry Ellis Mr. Felix M. Huertas Dr. James H. Nelson Mr...methods introduced since 1960 in an effort to improve flying insect control. Primary emphasis is placed on ground control techniques; however, aerial...the atomizing head, interior solenoid valve mechanisms, pump assemblies , and exterior portions of the dispersal unit subject to liquid contamination

Arbitrary-Lagrangian-Eulerian Discontinuous Galerkin schemes with a posteriori subcell finite volume limiting on moving unstructured meshes

NASA Astrophysics Data System (ADS)

Boscheri, Walter; Dumbser, Michael

2017-10-01

We present a new family of high order accurate fully discrete one-step Discontinuous Galerkin (DG) finite element schemes on moving unstructured meshes for the solution of nonlinear hyperbolic PDE in multiple space dimensions, which may also include parabolic terms in order to model dissipative transport processes, like molecular viscosity or heat conduction. High order piecewise polynomials of degree N are adopted to represent the discrete solution at each time level and within each spatial control volume of the computational grid, while high order of accuracy in time is achieved by the ADER approach, making use of an element-local space-time Galerkin finite element predictor. A novel nodal solver algorithm based on the HLL flux is derived to compute the velocity for each nodal degree of freedom that describes the current mesh geometry. In our algorithm the spatial mesh configuration can be defined in two different ways: either by an isoparametric approach that generates curved control volumes, or by a piecewise linear decomposition of each spatial control volume into simplex sub-elements. Each technique generates a corresponding number of geometrical degrees of freedom needed to describe the current mesh configuration and which must be considered by the nodal solver for determining the grid velocity. The connection of the old mesh configuration at time tn with the new one at time t n + 1 provides the space-time control volumes on which the governing equations have to be integrated in order to obtain the time evolution of the discrete solution. Our numerical method belongs to the category of so-called direct Arbitrary-Lagrangian-Eulerian (ALE) schemes, where a space-time conservation formulation of the governing PDE system is considered and which already takes into account the new grid geometry (including a possible rezoning step) directly during the computation of the numerical fluxes. We emphasize that our method is a moving mesh method, as opposed to total Lagrangian formulations that are based on a fixed computational grid and which instead evolve the mapping of the reference configuration to the current one. Our new Lagrangian-type DG scheme adopts the novel a posteriori sub-cell finite volume limiter method recently developed in [62] for fixed unstructured grids. In this approach, the validity of the candidate solution produced in each cell by an unlimited ADER-DG scheme is verified against a set of physical and numerical detection criteria, such as the positivity of pressure and density, the absence of floating point errors (NaN) and the satisfaction of a relaxed discrete maximum principle (DMP) in the sense of polynomials. Those cells which do not satisfy all of the above criteria are flagged as troubled cells and are recomputed at the aid of a more robust second order TVD finite volume scheme. To preserve the subcell resolution capability of the original DG scheme, the FV limiter is run on a sub-grid that is 2 N + 1 times finer compared to the mesh of the original unlimited DG scheme. The new subcell averages are then gathered back into a high order DG polynomial by a usual conservative finite volume reconstruction operator. The numerical convergence rates of the new ALE ADER-DG schemes are studied up to fourth order in space and time and several test problems are simulated in order to check the accuracy and the robustness of the proposed numerical method in the context of the Euler and Navier-Stokes equations for compressible gas dynamics, considering both inviscid and viscous fluids. Finally, an application inspired by Inertial Confinement Fusion (ICF) type flows is considered by solving the Euler equations and the PDE of viscous and resistive magnetohydrodynamics (VRMHD).

Body Fat Patterning, Hepatic Fat and Pancreatic Volume of Non-Obese Asian Indians with Type 2 Diabetes in North India: A Case-Control Study

PubMed Central

Misra, Anoop; Anoop, Shajith; Gulati, Seema; Mani, Kalaivani; Bhatt, Surya Prakash; Pandey, Ravindra Mohan

2015-01-01

Objective To evaluate body fat patterning and phenotype including hepatic fat and pancreatic volume of non-obese (BMI: < 25 kg/m2) Asian Indians with type 2 diabetes residing in North India. Methods Non-obese patients with type 2 diabetes (n = 93) and non-obese, normo-glycemic subjects (n = 40) were recruited. BMI, waist & hip circumferences, skinfold thickness at 8 sites, body fat, lean mass and detailed abdominal fat evaluation [total abdominal fat, total subcutaneous fat (superficial, deep, anterior, and posterior), total intra-abdominal fat (intra-peritoneal, retroperitoneal)], liver span, grades of fatty liver and pancreatic volume were compared. Results Waist circumference, subscapular skinfolds and total truncal fat (on DEXA) were higher whereas calf, total peripheral skinfolds and total leg fat (on DEXA) lower in patients. Specifically, the following volumes were higher in cases as compared to controls; total abdominal fat (19.4%), total intra-abdominal fat (49.7%), intra-peritoneal fat (47.7%), retroperitoneal fat (70.7%), pancreatic volume (26.6%), pancreatic volume index (21.3%) and liver span (10.8%). In cases, significant positive correlations were observed for pancreatic volume with BMI, waist and hip circumferences, W-HR, subscapular, abdominal and total truncal skinfolds, truncal, total subcutaneous, total intra-abdominal, intra-peritoneal, retroperitoneal fat depots, liver span and fatty liver. Conclusions In non-obese Asian Indians with type 2 diabetes, subcutaneous and intra-abdominal obesity, including fatty liver, and pancreatic volume were higher and peripheral subcutaneous adiposity was lower than BMI matched non-diabetic subjects. Importantly, increased pancreatic volume in patients was highly correlated with multiple measures of abdominal obesity and liver fat. PMID:26474415

Comparision between Brain Atrophy and Subdural Volume to Predict Chronic Subdural Hematoma: Volumetric CT Imaging Analysis

PubMed Central

Ju, Min-Wook; Kwon, Hyon-Jo; Choi, Seung-Won; Koh, Hyeon-Song; Youm, Jin-Young; Song, Shi-Hun

2015-01-01

Objective Brain atrophy and subdural hygroma were well known factors that enlarge the subdural space, which induced formation of chronic subdural hematoma (CSDH). Thus, we identified the subdural volume that could be used to predict the rate of future CSDH after head trauma using a computed tomography (CT) volumetric analysis. Methods A single institution case-control study was conducted involving 1,186 patients who visited our hospital after head trauma from January 1, 2010 to December 31, 2014. Fifty-one patients with delayed CSDH were identified, and 50 patients with age and sex matched for control. Intracranial volume (ICV), the brain parenchyme, and the subdural space were segmented using CT image-based software. To adjust for variations in head size, volume ratios were assessed as a percentage of ICV [brain volume index (BVI), subdural volume index (SVI)]. The maximum depth of the subdural space on both sides was used to estimate the SVI. Results Before adjusting for cranium size, brain volume tended to be smaller, and subdural space volume was significantly larger in the CSDH group (p=0.138, p=0.021, respectively). The BVI and SVI were significantly different (p=0.003, p=0.001, respectively). SVI [area under the curve (AUC), 77.3%; p=0.008] was a more reliable technique for predicting CSDH than BVI (AUC, 68.1%; p=0.001). Bilateral subdural depth (sum of subdural depth on both sides) increased linearly with SVI (p<0.0001). Conclusion Subdural space volume was significantly larger in CSDH groups. SVI was a more reliable technique for predicting CSDH. Bilateral subdural depth was useful to measure SVI. PMID:27169071

Smaller stress-sensitive hippocampal subfields in women with borderline personality disorder without posttraumatic stress disorder

PubMed Central

Bøen, Erlend; Westlye, Lars T.; Elvsåshagen, Torbjørn; Hummelen, Benjamin; Hol, Per K.; Boye, Birgitte; Andersson, Stein; Karterud, Sigmund; Malt, Ulrik F.

2014-01-01

Background Animal and human studies have suggested that hippocampal subfields are differentially vulnerable to stress, but subfield volume has not been investigated in patients with borderline personality disorder (BPD). Based on the putative role of stressful life events as vulnerability factors for BPD, we hypothesized that patients with BPD would exhibit reduced volumes for the stress-sensitive dentate gyrus (DG) and the cornu ammonis (CA) 3 subfields volumes, and that these volumes would be associated with traumatic childhood experiences. Methods All participants underwent 3 T magnetic resonance imaging. Hippocampal subfield volumes were estimated using an automated and validated segmentation algorithm implemented in FreeSurfer. Age and total subcortical grey matter volume were covariates. We assessed traumatic childhood experiences using the Childhood Trauma Questionnaire (CTQ). Results A total of 18 women with BPD and 21 healthy control women were included in the study. Only 1 patient had comorbid posttraumatic stress disorder (PTSD). The volumes of the left (p = 0.005) and right (p = 0.011) DG-CA4 and left (p = 0.007) and right (p = 0.005) CA2–3 subfields were significantly reduced in patients compared with controls. We also found significant group differences for the left (p = 0.032) and right (p = 0.028) CA1, but not for other hippocampal subfields. No associations were found between CTQ scores and subfield volumes. Limitations The self-reported CTQ might be inferior to more comprehensive assessments of traumatic experiences. The sample size was moderate. Conclusion The volumes of stress-sensitive hippocampal subfields are reduced in women with BPD without PTSD. However, the degree to which childhood trauma is responsible for these changes is unclear. PMID:24309162

Particle tracking approach for transport in three-dimensional discrete fracture networks: Particle tracking in 3-D DFNs

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

Makedonska, Nataliia; Painter, Scott L.; Bui, Quan M.

The discrete fracture network (DFN) model is a method to mimic discrete pathways for fluid flow through a fractured low-permeable rock mass, and may be combined with particle tracking simulations to address solute transport. However, experience has shown that it is challenging to obtain accurate transport results in three-dimensional DFNs because of the high computational burden and difficulty in constructing a high-quality unstructured computational mesh on simulated fractures. We present a new particle tracking capability, which is adapted to control volume (Voronoi polygons) flow solutions on unstructured grids (Delaunay triangulations) on three-dimensional DFNs. The locally mass-conserving finite-volume approach eliminates massmore » balance-related problems during particle tracking. The scalar fluxes calculated for each control volume face by the flow solver are used to reconstruct a Darcy velocity at each control volume centroid. The groundwater velocities can then be continuously interpolated to any point in the domain of interest. The control volumes at fracture intersections are split into four pieces, and the velocity is reconstructed independently on each piece, which results in multiple groundwater velocities at the intersection, one for each fracture on each side of the intersection line. This technique enables detailed particle transport representation through a complex DFN structure. Verified for small DFNs, the new simulation capability enables numerical experiments on advective transport in large DFNs to be performed. As a result, we demonstrate this particle transport approach on a DFN model using parameters similar to those of crystalline rock at a proposed geologic repository for spent nuclear fuel in Forsmark, Sweden.« less

Particle tracking approach for transport in three-dimensional discrete fracture networks: Particle tracking in 3-D DFNs

DOE PAGES

Makedonska, Nataliia; Painter, Scott L.; Bui, Quan M.; ...

2015-09-16

The discrete fracture network (DFN) model is a method to mimic discrete pathways for fluid flow through a fractured low-permeable rock mass, and may be combined with particle tracking simulations to address solute transport. However, experience has shown that it is challenging to obtain accurate transport results in three-dimensional DFNs because of the high computational burden and difficulty in constructing a high-quality unstructured computational mesh on simulated fractures. We present a new particle tracking capability, which is adapted to control volume (Voronoi polygons) flow solutions on unstructured grids (Delaunay triangulations) on three-dimensional DFNs. The locally mass-conserving finite-volume approach eliminates massmore » balance-related problems during particle tracking. The scalar fluxes calculated for each control volume face by the flow solver are used to reconstruct a Darcy velocity at each control volume centroid. The groundwater velocities can then be continuously interpolated to any point in the domain of interest. The control volumes at fracture intersections are split into four pieces, and the velocity is reconstructed independently on each piece, which results in multiple groundwater velocities at the intersection, one for each fracture on each side of the intersection line. This technique enables detailed particle transport representation through a complex DFN structure. Verified for small DFNs, the new simulation capability enables numerical experiments on advective transport in large DFNs to be performed. As a result, we demonstrate this particle transport approach on a DFN model using parameters similar to those of crystalline rock at a proposed geologic repository for spent nuclear fuel in Forsmark, Sweden.« less

Subcortical brain volume differences of participants with ADHD across the lifespan: an ENIGMA collaboration

PubMed Central

Hoogman, Martine; Bralten, Janita; Hibar, Derrek P.; Mennes, Maarten; Zwiers, Marcel P.; Schweren, Lizanne; van Hulzen, Kimm J.E.; Medland, Sarah E.; Shumskaya, Elena; Jahanshad, Neda; de Zeeuw, Patrick; Szekely, Eszter; Sudre, Gustavo; Wolfers, Thomas; Onnink, Alberdingk M.H.; Dammers, Janneke T.; Mostert, Jeanette C.; Vives-Gilabert, Yolanda; Kohls, Gregor; Oberwelland, Eileen; Seitz, Jochen; Schulte-Rüther, Martin; di Bruttopilo, Sara Ambrosino; Doyle, Alysa E.; Høvik, Marie F.; Dramsdahl, Margaretha; Tamm, Leanne; van Erp, Theo G.M.; Dale, Anders; Schork, Andrew; Conzelmann, Annette; Zierhut, Kathrin; Baur, Ramona; McCarthy, Hazel; Yoncheva, Yuliya N.; Cubillo, Ana; Chantiluke, Kaylita; Mehta, Mitul A.; Paloyelis, Yannis; Hohmann, Sarah; Baumeister, Sarah; Bramati, Ivanei; Mattos, Paulo; Tovar-Moll, Fernanda; Douglas, Pamela; Banaschewski, Tobias; Brandeis, Daniel; Kuntsi, Jonna; Asherson, Phil; Rubia, Katya; Kelly, Clare; Di Martino, Adriana; Milham, Michael P.; Castellanos, Francisco X.; Frodl, Thomas; Zentis, Mariam; Lesch, Klaus-Peter; Reif, Andreas; Pauli, Paul; Jernigan, Terry; Haavik, Jan; Plessen, Kerstin J.; Lundervold, Astri J.; Hugdahl, Kenneth; Seidman, Larry J.; Biederman, Joseph; Rommelse, Nanda; Heslenfeld, Dirk J.; Hartman, Catharina; Hoekstra, Pieter J.; Oosterlaan, Jaap; von Polier, Georg; Konrad, Kerstin; Vilarroya, Oscar; Ramos-Quiroga, Josep-Antoni; Soliva, Joan Carles; Durston, Sarah; Buitelaar, Jan K.; Faraone, Stephen V.; Shaw, Philip; Thompson, Paul; Franke, Barbara

2017-01-01

BACKGROUND Neuroimaging studies show structural alterations in several brain regions in children and adults with attention-deficit/hyperactivity disorder (ADHD). Through the formation of the worldwide ENIGMA ADHD Working Group, we addressed weaknesses of prior imaging studies and meta-analyses in sample size and methodological heterogeneity. METHODS Our sample comprised 1713 participants with ADHD and 1529 controls from 23 sites (age range: 4–63 years; 66% males). Individual sites analyzed magnetic resonance imaging brain scans with harmonized protocols. Case-control differences in subcortical structures and intracranial volume (ICV) were assessed through mega-and meta-analysis. FINDINGS The volumes of the accumbens (Cohen’s d=−0.15), amygdala (d=−0.19), caudate (d=−0.11), hippocampus (d=−0.11), putamen (d=−0.14), and ICV (d=−0.10) were found to be smaller in cases relative to controls. Effect sizes were highest in children, case-control differences were not present in adults. Explorative lifespan modeling suggested a delay of maturation and a delay of degeneration. Psychostimulant medication use or presence of comorbid psychiatric disorders did not influence results, nor did symptom scores correlate with brain volume. INTERPRETATION Using the largest data set to date, we extend the brain maturation delay theory for ADHD to include subcortical structures and refute medication effects on brain volume suggested by earlier meta-analyses. We add new knowledge about bilateral amygdala, accumbens, and hippocampus reductions in ADHD, and provide unprecedented precision in effect size estimates. Lifespan analyses suggest that, in the absence of well-powered longitudinal studies, the ENIGMA cross-sectional sample across six decades of life provides a means to generate hypotheses about lifespan trajectories in brain phenotypes. FUNDING National Institutes of Health PMID:28219628

Advanced Unstructured Grid Generation for Complex Aerodynamic Applications

NASA Technical Reports Server (NTRS)

Pirzadeh, Shahyar Z.

2008-01-01

A new approach for distribution of grid points on the surface and in the volume has been developed and implemented in the NASA unstructured grid generation code VGRID. In addition to the point and line sources of prior work, the new approach utilizes surface and volume sources for automatic curvature-based grid sizing and convenient point distribution in the volume. A new exponential growth function produces smoother and more efficient grids and provides superior control over distribution of grid points in the field. All types of sources support anisotropic grid stretching which not only improves the grid economy but also provides more accurate solutions for certain aerodynamic applications. The new approach does not require a three-dimensional background grid as in the previous methods. Instead, it makes use of an efficient bounding-box auxiliary medium for storing grid parameters defined by surface sources. The new approach is less memory-intensive and more efficient computationally. The grids generated with the new method either eliminate the need for adaptive grid refinement for certain class of problems or provide high quality initial grids that would enhance the performance of many adaptation methods.

Advanced Unstructured Grid Generation for Complex Aerodynamic Applications

NASA Technical Reports Server (NTRS)

Pirzadeh, Shahyar

2010-01-01

A new approach for distribution of grid points on the surface and in the volume has been developed. In addition to the point and line sources of prior work, the new approach utilizes surface and volume sources for automatic curvature-based grid sizing and convenient point distribution in the volume. A new exponential growth function produces smoother and more efficient grids and provides superior control over distribution of grid points in the field. All types of sources support anisotropic grid stretching which not only improves the grid economy but also provides more accurate solutions for certain aerodynamic applications. The new approach does not require a three-dimensional background grid as in the previous methods. Instead, it makes use of an efficient bounding-box auxiliary medium for storing grid parameters defined by surface sources. The new approach is less memory-intensive and more efficient computationally. The grids generated with the new method either eliminate the need for adaptive grid refinement for certain class of problems or provide high quality initial grids that would enhance the performance of many adaptation methods.

Lung volumes, ventricular function and pulmonary arterial flow in children operated on for left-sided congenital diaphragmatic hernia: long-term results.

PubMed

Abolmaali, Nasreddin; Koch, Arne; Götzelt, Knut; Hahn, Gabriele; Fitze, Guido; Vogelberg, Christian

2010-07-01

To compare MRI-based functional pulmonary and cardiac measurements in the long-term follow-up of children operated on for left-sided congenital diaphragmatic hernia (CDH) with age- and body size-matched healthy controls. Twelve children who received immediate postnatal surgery for closure of isolated left-sided CDH were included and received basic medical examinations, pulmonary function testing and echocardiography. MRI included measurement of lung volume, ventricular function assessment and velocity-encoded imaging of the pulmonary arteries and was compared with the data for 12 healthy children matched for age and body size. While patients' clinical test results were not suspicious, comparison between the MRI data for patients and those for healthy controls revealed significant differences. In patients, the volumes of the left lungs were increased and the tidal volume was larger on the right side. While the stroke volumes of both ventricles were reduced, heart rate and ejection fraction were increased. Flow, acceleration time and cross-sectional area of the left pulmonary artery were reduced. Functional MRI detected pulmonary and cardiac findings in the late follow-up of CDH children which may be missed by standard clinical methods and might be relevant for decisions regarding late outcome and treatment.

A Simple Graphical Method for Quantification of Disaster Management Surge Capacity Using Computer Simulation and Process-control Tools.

PubMed

Franc, Jeffrey Michael; Ingrassia, Pier Luigi; Verde, Manuela; Colombo, Davide; Della Corte, Francesco

2015-02-01

Surge capacity, or the ability to manage an extraordinary volume of patients, is fundamental for hospital management of mass-casualty incidents. However, quantification of surge capacity is difficult and no universal standard for its measurement has emerged, nor has a standardized statistical method been advocated. As mass-casualty incidents are rare, simulation may represent a viable alternative to measure surge capacity. Hypothesis/Problem The objective of the current study was to develop a statistical method for the quantification of surge capacity using a combination of computer simulation and simple process-control statistical tools. Length-of-stay (LOS) and patient volume (PV) were used as metrics. The use of this method was then demonstrated on a subsequent computer simulation of an emergency department (ED) response to a mass-casualty incident. In the derivation phase, 357 participants in five countries performed 62 computer simulations of an ED response to a mass-casualty incident. Benchmarks for ED response were derived from these simulations, including LOS and PV metrics for triage, bed assignment, physician assessment, and disposition. In the application phase, 13 students of the European Master in Disaster Medicine (EMDM) program completed the same simulation scenario, and the results were compared to the standards obtained in the derivation phase. Patient-volume metrics included number of patients to be triaged, assigned to rooms, assessed by a physician, and disposed. Length-of-stay metrics included median time to triage, room assignment, physician assessment, and disposition. Simple graphical methods were used to compare the application phase group to the derived benchmarks using process-control statistical tools. The group in the application phase failed to meet the indicated standard for LOS from admission to disposition decision. This study demonstrates how simulation software can be used to derive values for objective benchmarks of ED surge capacity using PV and LOS metrics. These objective metrics can then be applied to other simulation groups using simple graphical process-control tools to provide a numeric measure of surge capacity. Repeated use in simulations of actual EDs may represent a potential means of objectively quantifying disaster management surge capacity. It is hoped that the described statistical method, which is simple and reusable, will be useful for investigators in this field to apply to their own research.

Gray Matter Alterations in Adults with Attention-Deficit/Hyperactivity Disorder Identified by Voxel Based Morphometry

PubMed Central

Seidman, Larry J.; Biederman, Joseph; Liang, Lichen; Valera, Eve M.; Monuteaux, Michael C.; Brown, Ariel; Kaiser, Jonathan; Spencer, Thomas; Faraone, Stephen V.; Makris, Nikos

2014-01-01

Background Gray and white matter volume deficits have been reported in many structural magnetic resonance imaging (MRI) studies of children with attention-deficit/hyperactivity disorder (ADHD); however, there is a paucity of structural MRI studies of adults with ADHD. This study used voxel based morphometry and applied an a priori region of interest approach based on our previous work, as well as from well-developed neuroanatomical theories of ADHD. Methods Seventy-four adults with DSM-IV ADHD and 54 healthy control subjects comparable on age, sex, race, handedness, IQ, reading achievement, frequency of learning disabilities, and whole brain volume had an MRI on a 1.5T Siemens scanner. A priori region of interest hypotheses focused on reduced volumes in ADHD in dorsolateral prefrontal cortex, anterior cingulate cortex, caudate, putamen, inferior parietal lobule, and cerebellum. Analyses were carried out by FSL-VBM 1.1. Results Relative to control subjects, ADHD adults had significantly smaller gray matter volumes in parts of six of these regions at p ≤ .01, whereas parts of the dorsolateral prefrontal cortex and inferior parietal lobule were significantly larger in ADHD at this threshold. However, a number of other regions were smaller and larger in ADHD (especially fronto-orbital cortex) at this threshold. Only the caudate remained significantly smaller at the family-wise error rate. Conclusions Adults with ADHD have subtle volume reductions in the caudate and possibly other brain regions involved in attention and executive control supporting frontostriatal models of ADHD. Modest group brain volume differences are discussed in the context of the nature of the samples studied and voxel based morphometry methodology. PMID:21183160

Irritable bowel syndrome in female patients is associated with alterations in structural brain networks.

PubMed

Labus, Jennifer S; Dinov, Ivo D; Jiang, Zhiguo; Ashe-McNalley, Cody; Zamanyan, Alen; Shi, Yonggang; Hong, Jui-Yang; Gupta, Arpana; Tillisch, Kirsten; Ebrat, Bahar; Hobel, Sam; Gutman, Boris A; Joshi, Shantanu; Thompson, Paul M; Toga, Arthur W; Mayer, Emeran A

2014-01-01

Alterations in gray matter (GM) density/volume and cortical thickness (CT) have been demonstrated in small and heterogeneous samples of subjects with differing chronic pain syndromes, including irritable bowel syndrome (IBS). Aggregating across 7 structural neuroimaging studies conducted at University of California, Los Angeles, Los Angeles, CA, USA, between August 2006 and April 2011, we examined group differences in regional GM volume in 201 predominantly premenopausal female subjects (82 IBS, mean age: 32±10 SD, 119 healthy controls [HCs], 30±10 SD). Applying graph theoretical methods and controlling for total brain volume, global and regional properties of large-scale structural brain networks were compared between the group with IBS and the HC group. Relative to HCs, the IBS group had lower volumes in the bilateral superior frontal gyrus, bilateral insula, bilateral amygdala, bilateral hippocampus, bilateral middle orbital frontal gyrus, left cingulate, left gyrus rectus, brainstem, and left putamen. Higher volume was found in the left postcentral gyrus. Group differences were no longer significant for most regions when controlling for the Early Trauma Inventory global score, with the exception of the right amygdala and the left postcentral gyrus. No group differences were found for measures of global and local network organization. Compared to HCs, in patients with IBS, the right cingulate gyrus and right thalamus were identified as being significantly more critical for information flow. Regions involved in endogenous pain modulation and central sensory amplification were identified as network hubs in IBS. Overall, evidence for central alterations in patients with IBS was found in the form of regional GM volume differences and altered global and regional properties of brain volumetric networks. Copyright © 2013 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

Clinical correlations of grey matter reductions in the caudate nucleus of adults with attention deficit hyperactivity disorder

PubMed Central

Montes, Luis Guillermo Almeida; Ricardo-Garcell, Josefina; De La Torre, Lázaro Barajas; Alcántara, Hugo Prado; García, Reyna Beatriz Martínez; Fernández-Bouzas, Antonio; Acosta, David Ávila

2010-01-01

Background Magnetic resonance imaging (MRI) studies have shown decreased caudate volumes in individuals with attention deficit hyperactivity disorder (ADHD). However, most of these studies have been carried out in male children. Very little research has been done in adults, and the results obtained in children are difficult to extrapolate to adults. We sought to compare the volume of the caudate of adults with ADHD with that of healthy controls; we also compared these volumes between men and women. Methods We performed an MRI scan on 20 adults with ADHD (10 men and 10 women) aged 25–35 years and 20 healthy controls matched by age and sex. We used voxel-based morphometry with the DARTEL algorithm for image analyses. We used the specifically designed Friederichsen, Almeida, Serrano, Cortes Test (FASCT) to measure the severity of ADHD; both the self-reported (FASCT-SR) and the observer (FASCT-O) versions were used. Results The statistical parametric map showed a smaller region with low grey matter volume and a smaller concentration of grey matter in this region of the right caudate in ADHD patients than in health controls, both in the entire sample and within each sex. There was a significant correlation between the volume of this region of the caudate with the number of DSM IV-TR criteria, as well as with the total scores and most of the factors of the FASCT-SR and FASCT-O scales. A separate correlation analysis by sex gave similar results. Limitations The study design was cross-sectional. Conclusion The region of the right caudate with low grey matter volume was smaller in adults with ADHD in both sexes and was correlated with ADHD severity. PMID:20569650

Zeolites with Continuously Tuneable Porosity**

PubMed Central

Wheatley, Paul S; Chlubná-Eliášová, Pavla; Greer, Heather; Zhou, Wuzong; Seymour, Valerie R; Dawson, Daniel M; Ashbrook, Sharon E; Pinar, Ana B; McCusker, Lynne B; Opanasenko, Maksym; Čejka, Jiří; Morris, Russell E

2014-01-01

Zeolites are important materials whose utility in industry depends on the nature of their porous structure. Control over microporosity is therefore a vitally important target. Unfortunately, traditional methods for controlling porosity, in particular the use of organic structure-directing agents, are relatively coarse and provide almost no opportunity to tune the porosity as required. Here we show how zeolites with a continuously tuneable surface area and micropore volume over a wide range can be prepared. This means that a particular surface area or micropore volume can be precisely tuned. The range of porosity we can target covers the whole range of useful zeolite porosity: from small pores consisting of 8-rings all the way to extra-large pores consisting of 14-rings. PMID:25284344

Medial prefrontal aberrations in major depressive disorder revealed by cytoarchitectonically informed voxel-based morphometry

PubMed Central

Bludau, Sebastian; Bzdok, Danilo; Gruber, Oliver; Kohn, Nils; Riedl, Valentin; Sorg, Christian; Palomero-Gallagher, Nicola; Müller, Veronika I.; Hoffstaedter, Felix; Amunts, Katrin; Eickhoff, Simon B.

2017-01-01

Objective The heterogeneous human frontal pole has been identified as a node in the dysfunctional network of major depressive disorder. The contribution of the medial (socio-affective) versus lateral (cognitive) frontal pole to major depression pathogenesis is currently unclear. The present study performs morphometric comparison of the microstructurally informed subdivisions of human frontal pole between depressed patients and controls using both uni- and multivariate statistics. Methods Multi-site voxel- and region-based morphometric MRI analysis of 73 depressed patients and 73 matched controls without psychiatric history. Frontal pole volume was first compared between depressed patients and controls by subdivision-wise classical morphometric analysis. In a second approach, frontal pole volume was compared by subdivision-naive multivariate searchlight analysis based on support vector machines. Results Subdivision-wise morphometric analysis found a significantly smaller medial frontal pole in depressed patients with a negative correlation of disease severity and duration. Histologically uninformed multivariate voxel-wise statistics provided converging evidence for structural aberrations specific to the microstructurally defined medial area of the frontal pole in depressed patients. Conclusions Across disparate methods, we demonstrated subregion specificity in the left medial frontal pole volume in depressed patients. Indeed, the frontal pole was shown to structurally and functionally connect to other key regions in major depression pathology like the anterior cingulate cortex and the amygdala via the uncinate fasciculus. Present and previous findings consolidate the left medial portion of the frontal pole as particularly altered in major depression. PMID:26621569

[Comparison of three histometric methods for the comprehension of stimulating effects on the rat thyroid gland].

PubMed

Herrmann, F; Hambsch, K; Wolf, T; Rother, P; Müller, P

1989-01-01

There exist some histometric methods for the morphological quantification of different strongly stimulating effects on the thyroid gland induced by drugs and/or other chemical substances in dependence upon dose and duration of application. But in respect of technical and temporal expense and also diagnostic statement, there are considerable differences between these recording procedures. Therefore we examined the 3 mostly used methods synchronously (i.e. determination of thyroid epithelial cell height, nuclear volume in thyrocytes, and estimation of relative volume parts in the thyroid gland by the point counting method) by investigating the thyroid glands of methylthiouracil-(MTU)-stimulated rats and corresponding controls in order to compare the diagnostic value and temporal expense. The largest temporal expense was required in the nuclear volume determination, the smallest in the point-counting method. On principle, all 3 procedures allow the determination of hypertrophic alterations but only by help of the point-counting method, also hyperplastic changes are recognizable. By nuclear volume determination, we found significant differences between central and peripheral parts of the thyroid gland. Therefore, to avoid the subjective error, it will be necessary to measure a large number of nuclei in many planes of the gland. Also the determination of epithelial cell high reinforces the subjective error because of the heterological structure especially in unstimulated thyroid gland. If the number of counting points is exactly determined and, full of sense, limited, the point-counting method allows a nearly complete measuring of the whole object to be tested within an acceptable investigation time. In this way, the heterological structure of thyroid gland will be regarded, and comparability and reproducibility are guaranteed on an high level.

Proceedings of the 8th Annual Conference on Manual Control

NASA Technical Reports Server (NTRS)

Pew, R. W.

1972-01-01

The volume presents recent developments in the field of manual control theory and applications. The papers give analytical methods as well as examples of the important interplay between man and machine, such as how man controls and stabilizes machine dynamics, and how machines extend man's capability. Included in the broad range of subjects are procedures to evaluate and identify display systems, controllers, manipulators, human operators, aircraft, and non-flying vehicles. Of particular interest is the continuing trend of applying control theory to problems in medicine and psychology, as well as to problems in vehicle control.

Journal of Air Transportation, Volume 12, No. 1

NASA Technical Reports Server (NTRS)

Bowers, Brent D. (Editor); Kabashkin, Igor (Editor)

2007-01-01

Topics discussed include: a) Data Mining Methods Applied to Flight Operations Quality Assurance Data: A Comparison to Standard Statistical Methods; b) Financial Comparisons across Different Business Models in the Canadian Airline Industry; c) Carving a Niche for the "No-Frills" Carrier, Air Arabia, in Oil-Rich Skies; d) Situational Leadership in Air Traffic Control; and e) The Very Light Jet Arrives: Stakeholders and Their Perceptions.

Generating enhanced site topography data to improve permeable pavement performance assessment methods - presentation

EPA Science Inventory

Permeable pavement surfaces are infiltration based stormwater control measures (SCM) commonly applied in parking lots to decrease impervious area and reduce runoff volume. Many are not optimally designed however, as little attention is given to draining a large enough contributin...

Internal jugular and vertebral vein volume flow in patients with clinically isolated syndrome or mild multiple sclerosis and healthy controls: results from a prospective sonographer-blinded study.

PubMed

Chambers, Brian; Chambers, Jayne; Churilov, Leonid; Cameron, Heather; Macdonell, Richard

2014-09-01

We evaluated internal jugular vein and vertebral vein volume flow using ultrasound, in patients with clinically isolated syndrome or mild multiple sclerosis and controls, to determine whether volume flow was different between the two groups. In patients and controls, internal jugular vein volume flow increased from superior to inferior segments, consistent with recruitment from collateral veins. Internal jugular vein and vertebral vein volume flow were greater on the right in supine and sitting positions. Internal jugular vein volume flow was higher in the supine posture. Vertebral vein volume flow was higher in the sitting posture. Regression analyses of cube root transformed volume flow data, adjusted for supine/sitting, right/left and internal jugular vein/vertebral vein, revealed no significant difference in volume flow in patients compared to controls. Our findings further refute the concept of venous obstruction as a causal factor in the pathogenesis of multiple sclerosis. Control volume flow data may provide useful normative reference values. © The Author(s) 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Three-Dimensional High-Order Spectral Volume Method for Solving Maxwell's Equations on Unstructured Grids

NASA Technical Reports Server (NTRS)

Liu, Yen; Vinokur, Marcel; Wang, Z. J.

2004-01-01

A three-dimensional, high-order, conservative, and efficient discontinuous spectral volume (SV) method for the solutions of Maxwell's equations on unstructured grids is presented. The concept of discontinuous 2nd high-order loca1 representations to achieve conservation and high accuracy is utilized in a manner similar to the Discontinuous Galerkin (DG) method, but instead of using a Galerkin finite-element formulation, the SV method is based on a finite-volume approach to attain a simpler formulation. Conventional unstructured finite-volume methods require data reconstruction based on the least-squares formulation using neighboring cell data. Since each unknown employs a different stencil, one must repeat the least-squares inversion for every cell at each time step, or to store the inversion coefficients. In a high-order, three-dimensional computation, the former would involve impractically large CPU time, while for the latter the memory requirement becomes prohibitive. In the SV method, one starts with a relatively coarse grid of triangles or tetrahedra, called spectral volumes (SVs), and partition each SV into a number of structured subcells, called control volumes (CVs), that support a polynomial expansion of a desired degree of precision. The unknowns are cell averages over CVs. If all the SVs are partitioned in a geometrically similar manner, the reconstruction becomes universal as a weighted sum of unknowns, and only a few universal coefficients need to be stored for the surface integrals over CV faces. Since the solution is discontinuous across the SV boundaries, a Riemann solver is thus necessary to maintain conservation. In the paper, multi-parameter and symmetric SV partitions, up to quartic for triangle and cubic for tetrahedron, are first presented. The corresponding weight coefficients for CV face integrals in terms of CV cell averages for each partition are analytically determined. These discretization formulas are then applied to the integral form of the Maxwell equations. All numerical procedures for outer boundary, material interface, zonal interface, and interior SV face are unified with a single characteristic formulation. The load balancing in a massive parallel computing environment is therefore easier to achieve. A parameter is introduced in the Riemann solver to control the strength of the smoothing term. Important aspects of the data structure and its effects to communication and the optimum use of cache memory are discussed. Results will be presented for plane TE and TM waves incident on a perfectly conducting cylinder for up to fifth order of accuracy, and a plane wave incident on a perfectly conducting sphere for up to fourth order of accuracy. Comparisons are made with exact solutions for these cases.

System and method for radiation dose calculation within sub-volumes of a monte carlo based particle transport grid

DOEpatents

Bergstrom, Paul M.; Daly, Thomas P.; Moses, Edward I.; Patterson, Jr., Ralph W.; Schach von Wittenau, Alexis E.; Garrett, Dewey N.; House, Ronald K.; Hartmann-Siantar, Christine L.; Cox, Lawrence J.; Fujino, Donald H.

2000-01-01

A system and method is disclosed for radiation dose calculation within sub-volumes of a particle transport grid. In a first step of the method voxel volumes enclosing a first portion of the target mass are received. A second step in the method defines dosel volumes which enclose a second portion of the target mass and overlap the first portion. A third step in the method calculates common volumes between the dosel volumes and the voxel volumes. A fourth step in the method identifies locations in the target mass of energy deposits. And, a fifth step in the method calculates radiation doses received by the target mass within the dosel volumes. A common volume calculation module inputs voxel volumes enclosing a first portion of the target mass, inputs voxel mass densities corresponding to a density of the target mass within each of the voxel volumes, defines dosel volumes which enclose a second portion of the target mass and overlap the first portion, and calculates common volumes between the dosel volumes and the voxel volumes. A dosel mass module, multiplies the common volumes by corresponding voxel mass densities to obtain incremental dosel masses, and adds the incremental dosel masses corresponding to the dosel volumes to obtain dosel masses. A radiation transport module identifies locations in the target mass of energy deposits. And, a dose calculation module, coupled to the common volume calculation module and the radiation transport module, for calculating radiation doses received by the target mass within the dosel volumes.

Hippocampal MR volumetry

NASA Astrophysics Data System (ADS)

Haller, John W.; Botteron, K.; Brunsden, Barry S.; Sheline, Yvette I.; Walkup, Ronald K.; Black, Kevin J.; Gado, Mokhtar; Vannier, Michael W.

1994-09-01

Goal: To estimate hippocampal volumes from in vivo 3D magnetic resonance (MR) brain images and determine inter-rater and intra- rater repeatability. Objective: The precision and repeatability of hippocampal volume estimates using stereologic measurement methods is sought. Design: Five normal control and five schizophrenic subjects were MR scanned using a MPRAGE protocol. Fixed grid stereologic methods were used to estimate hippocampal volumes on a graphics workstation. The images were preprocessed using histogram analysis to standardize 3D MR image scaling from 16 to 8 bits and image volumes were interpolated to 0.5 mm3 isotropic voxels. The following variables were constant for the repeated stereologic measures: grid size, inter-slice distance (1.5 mm), voxel dimensions (0.5 mm3), number of hippocampi measured (10), total number of measurements per rater (40), and number of raters (5). Two grid sizes were tested to determine the coefficient of error associated with the number of sampled 'hits' (approximately 140 and 280) on the hippocampus. Starting slice and grid position were randomly varied to assure unbiased volume estimates. Raters were blind to subject identity, diagnosis, and side of the brain from which the image volumes were extracted and the order of subject presentation was randomized for each of the raters. Inter- and intra-rater intraclass correlation coefficients (ICC) were determined. Results: The data indicate excellent repeatability of fixed grid stereologic hippocampal volume measures when using an inter-slice distance of 1.5 mm and a 6.25 mm2 grid (inter-rater ICCs equals 0.86 - 0.97, intra- rater ICCs equals 0.85 - 0.97). One major advantage of the current study was the use of 3D MR data which significantly improved visualization of hippocampal boundaries by providing the ability to access simultaneous orthogonal views while counting stereological marks within the hippocampus. Conclusion: Stereological estimates of 3D volumes from 2D MR sections provide an inexpensive, unbiased and efficient way of determining brain structural volumes. The high precision and repeatability demonstrated with stereological MR volumetry suggest that these methods may be efficiently used to measure small volume reductions associated with schizophrenia and other brain disorders.

Living Together in Space: The Design and Operation of the Life Support Systems on the International Space Station. Volume 1

NASA Technical Reports Server (NTRS)

Wieland, P. O.

1998-01-01

The International Space Station (ISS) incorporates elements designed and developed by an international consortium led by the United States (U.S.), and by Russia. For this cooperative effort to succeed, it is crucial that the designs and methods of design of the other partners are understood sufficiently to ensure compatibility. Environmental Control and Life Support (ECLS) is one system in which functions are performed independently on the Russian Segment (RS) and on the U.S./international segments. This document describes, in two volumes, the design and operation of the ECLS Systems (ECLSS) on board the ISS. This current volume, Volume 1, is divided into three chapters. Chapter 1 is a general overview of the ISS, describing the configuration, general requirements, and distribution of systems as related to the ECLSS, and includes discussion of the design philosophies of the partners and methods of verification of equipment. Chapter 2 describes the U.S. ECLSS and technologies in greater detail. Chapter 3 describes the ECLSS in the European Attached Pressurized Module (APM), Japanese Experiment Module (JEM), and Italian Mini-Pressurized Logistics Module (MPLM). Volume II describes the Russian ECLSS and technologies in greater detail. These documents present thorough, yet concise, descriptions of the ISS ECLSS.

Tumor Volume Is a Prognostic Factor in Non-Small-Cell Lung Cancer Treated With Chemoradiotherapy

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

Alexander, Brian M.; Othus, Megan; Caglar, Hale B.

2011-04-01

Purpose: To investigate whether primary tumor and nodal volumes defined on radiotherapy planning scans are correlated with outcome (survival and recurrence) after combined-modality treatment. Methods and Materials: A retrospective review of patients with Stage III non-small-cell lung cancer treated with chemoradiation at Brigham and Women's Hospital/Dana-Farber Cancer Institute from 2000 to 2006 was performed. Tumor and nodal volume measurements, as computed by Eclipse (Varian, Palo Alto, CA), were used as independent variables, along with existing clinical factors, in univariate and multivariate analyses for association with outcomes. Results: For patients treated with definitive chemoradiotherapy, both nodal volume (hazard ratio [HR], 1.09;more » p < 0.01) and tumor volume (HR, 1.03; p < 0.01) were associated with overall survival on multivariate analysis. Both nodal volume (HR, 1.10; p < 0.01) and tumor volume (HR, 1.04; p < 0.01) were also associated with local control but not distant metastases. Conclusions: In addition to traditional surgical staging variables, disease burden, measured by primary tumor and nodal metastases volume, provides information that may be helpful in determining prognosis and identifying groups of patients for which more aggressive local therapy is warranted.« less

Comparison of human septal nuclei MRI measurements using automated segmentation and a new manual protocol based on histology

PubMed Central

Butler, Tracy; Zaborszky, Laszlo; Pirraglia, Elizabeth; Li, Jinyu; Wang, Xiuyuan Hugh; Li, Yi; Tsui, Wai; Talos, Delia; Devinsky, Orrin; Kuchna, Izabela; Nowicki, Krzysztof; French, Jacqueline; Kuzniecky, Rubin; Wegiel, Jerzy; Glodzik, Lidia; Rusinek, Henry; DeLeon, Mony J.; Thesen, Thomas

2014-01-01

Septal nuclei, located in basal forebrain, are strongly connected with hippocampi and important in learning and memory, but have received limited research attention in human MRI studies. While probabilistic maps for estimating septal volume on MRI are now available, they have not been independently validated against manual tracing of MRI, typically considered the gold standard for delineating brain structures. We developed a protocol for manual tracing of the human septal region on MRI based on examination of neuroanatomical specimens. We applied this tracing protocol to T1 MRI scans (n=86) from subjects with temporal epilepsy and healthy controls to measure septal volume. To assess the inter-rater reliability of the protocol, a second tracer used the same protocol on 20 scans that were randomly selected from the 72 healthy controls. In addition to measuring septal volume, maximum septal thickness between the ventricles was measured and recorded. The same scans (n=86) were also analysed using septal probabilistic maps and Dartel toolbox in SPM. Results show that our manual tracing algorithm is reliable, and that septal volume measurements obtained via manual and automated methods correlate significantly with each other (p<001). Both manual and automated methods detected significantly enlarged septal nuclei in patients with temporal lobe epilepsy in accord with a proposed compensatory neuroplastic process related to the strong connections between septal nuclei and hippocampi. Septal thickness, which was simple to measure with excellent inter-rater reliability, correlated well with both manual and automated septal volume, suggesting it could serve as an easy-to-measure surrogate for septal volume in future studies. Our results call attention to the important though understudied human septal region, confirm its enlargement in temporal lobe epilepsy, and provide a reliable new manual delineation protocol that will facilitate continued study of this critical region. PMID:24736183

Comparison of human septal nuclei MRI measurements using automated segmentation and a new manual protocol based on histology.

PubMed

Butler, Tracy; Zaborszky, Laszlo; Pirraglia, Elizabeth; Li, Jinyu; Wang, Xiuyuan Hugh; Li, Yi; Tsui, Wai; Talos, Delia; Devinsky, Orrin; Kuchna, Izabela; Nowicki, Krzysztof; French, Jacqueline; Kuzniecky, Rubin; Wegiel, Jerzy; Glodzik, Lidia; Rusinek, Henry; deLeon, Mony J; Thesen, Thomas

2014-08-15

Septal nuclei, located in basal forebrain, are strongly connected with hippocampi and important in learning and memory, but have received limited research attention in human MRI studies. While probabilistic maps for estimating septal volume on MRI are now available, they have not been independently validated against manual tracing of MRI, typically considered the gold standard for delineating brain structures. We developed a protocol for manual tracing of the human septal region on MRI based on examination of neuroanatomical specimens. We applied this tracing protocol to T1 MRI scans (n=86) from subjects with temporal epilepsy and healthy controls to measure septal volume. To assess the inter-rater reliability of the protocol, a second tracer used the same protocol on 20 scans that were randomly selected from the 72 healthy controls. In addition to measuring septal volume, maximum septal thickness between the ventricles was measured and recorded. The same scans (n=86) were also analyzed using septal probabilistic maps and DARTEL toolbox in SPM. Results show that our manual tracing algorithm is reliable, and that septal volume measurements obtained via manual and automated methods correlate significantly with each other (p<.001). Both manual and automated methods detected significantly enlarged septal nuclei in patients with temporal lobe epilepsy in accord with a proposed compensatory neuroplastic process related to the strong connections between septal nuclei and hippocampi. Septal thickness, which was simple to measure with excellent inter-rater reliability, correlated well with both manual and automated septal volume, suggesting it could serve as an easy-to-measure surrogate for septal volume in future studies. Our results call attention to the important though understudied human septal region, confirm its enlargement in temporal lobe epilepsy, and provide a reliable new manual delineation protocol that will facilitate continued study of this critical region. Copyright © 2014 Elsevier Inc. All rights reserved.

[Structural changes of brain gray matter in male long-term smokers under magnetic resonance imaging].

PubMed

Zhang, Y; Dong, A K; Cheng, J L; Li, Y L; Zhu, C D; Xu, K

2017-12-05

Objective: To evaluate gray matter structure changes in long-term male smokers by voxel-based morphological method. Methods: Fifty long-term smokers and 37 non-smoking healthy volunteers were scanned with Siemens Skyro 3.0T magnetic resonance scanner from August 2014 to August 2016. The subjects underwent routine MRI (excluding intracranial lesions) sequences and 3D-T1 structural sequences (3D-mprage). SPM8 pretreatment based on Matlab was used to analyze the structural data. All of the data were analyzed by SPM8 software. The data were compared between groups with independent sample t test. Spearman correlation analysis was used to analyze the relationship between gray matter volume (GMV) and smoking data of two groups. Results: The gray matter volume of bilateral thalamic, right supramarginal gyrus, left supramarginal gyrus and left putamen of smoking group were (0.55±0.07), (0.40±0.05), (0.48±0.07) and (0.14±0.04) voxels, respectively, and the gray matter volume of the corresponding gyri in control group were (0.61±0.09), (0.43±0.06), (0.54±0.07) and (0.16±0.03) voxels, respectively; and the gray matter volume of smoking group were all lower than those in control group ( t =-3.81, -3.51, -3.86, -2.33, all P <0.05), family wise error (FWE) correction ( P <0.05). The gray matter volume of bilateral thalamus, right supramarginal gyrus and left putamen was negatively correlated with smoking index ( r =-0.368, -0.189, -0.274, all P <0.05), and also negatively correlated with smoking years ( r =-0.391, -0.221, -0.355, all P <0.05), and bilateral thalamus gray matter volume was negatively correlated with daily cigarette smoking ( r =-0.186, P <0.05). Conclusion: The changes of brain structure of smokers mainly occur on reward-related pathways and marginal systems, and related to accumulation of cigarette smoking.

Cardiorespiratory responses to orthostasis and the effects of propranolol

NASA Technical Reports Server (NTRS)

Loeppky, J. A.

1975-01-01

Cardiac output and gas exchange were determined serially using the single-breath method of Kim et al. before, during, and after orthostasis on six subjects after beta-adrenergic blockage and in duplicate controls. In the latter, heart rate increased and pulse pressure dropped immediately on tilting to 60 deg and remained stable while cardiac output and stroke volume declined gradually over 21 min upright. On propranolol, heart rate was 10 bpm lower supine and 20 bpm less at 60 deg but cardiac output was only slightly lower before and following tilt-up. However, after 15 min upright, stroke volume and cardiac output recovered on propranolol exceeding the controls after 21 min without change in heart rate. Returning to supine, heart rate dropped in all tests with a transitory increase in stroke volume, cardiac output and arteriovenous O2 difference. At the same time, apparent O2 uptake increased temporarily, reflecting the return of pooled venous blood to the lungs. Orthostatic tolerance did not appear to be affected by beta-adrenergic blockade.

Rapid Airplane Parametric Input Design(RAPID)

NASA Technical Reports Server (NTRS)

Smith, Robert E.; Bloor, Malcolm I. G.; Wilson, Michael J.; Thomas, Almuttil M.

2004-01-01

An efficient methodology is presented for defining a class of airplane configurations. Inclusive in this definition are surface grids, volume grids, and grid sensitivity. A small set of design parameters and grid control parameters govern the process. The general airplane configuration has wing, fuselage, vertical tail, horizontal tail, and canard components. The wing, tail, and canard components are manifested by solving a fourth-order partial differential equation subject to Dirichlet and Neumann boundary conditions. The design variables are incorporated into the boundary conditions, and the solution is expressed as a Fourier series. The fuselage has circular cross section, and the radius is an algebraic function of four design parameters and an independent computational variable. Volume grids are obtained through an application of the Control Point Form method. Grid sensitivity is obtained by applying the automatic differentiation precompiler ADIFOR to software for the grid generation. The computed surface grids, volume grids, and sensitivity derivatives are suitable for a wide range of Computational Fluid Dynamics simulation and configuration optimizations.

A moving control volume approach to computing hydrodynamic forces and torques on immersed bodies

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

Nangia, Nishant; Johansen, Hans; Patankar, Neelesh A.

Here, we present a moving control volume (CV) approach to computing hydrodynamic forces and torques on complex geometries. The method requires surface and volumetric integrals over a simple and regular Cartesian box that moves with an arbitrary velocity to enclose the body at all times. The moving box is aligned with Cartesian grid faces, which makes the integral evaluation straightforward in an immersed boundary (IB) framework. Discontinuous and noisy derivatives of velocity and pressure at the fluid–structure interface are avoided and far-field (smooth) velo city and pressure information is used. We re-visit the approach to compute hydrodynamic forces and torquesmore » through force/torque balance equations in a Lagrangian frame that some of us took in a prior work (Bhalla et al., 2013 [13]). We prove the equivalence of the two approaches for IB methods, thanks to the use of Peskin's delta functions. Both approaches are able to suppress spurious force oscillations and are in excellent agreement, as expected theoretically. Test cases ranging from Stokes to high Reynolds number regimes are considered. We discuss regridding issues for the moving CV method in an adaptive mesh refinement (AMR) context. The proposed moving CV method is not limited to a specific IB method and can also be used, for example, with embedded boundary methods.« less

A moving control volume approach to computing hydrodynamic forces and torques on immersed bodies

DOE PAGES

Nangia, Nishant; Johansen, Hans; Patankar, Neelesh A.; ...

2017-10-01

Here, we present a moving control volume (CV) approach to computing hydrodynamic forces and torques on complex geometries. The method requires surface and volumetric integrals over a simple and regular Cartesian box that moves with an arbitrary velocity to enclose the body at all times. The moving box is aligned with Cartesian grid faces, which makes the integral evaluation straightforward in an immersed boundary (IB) framework. Discontinuous and noisy derivatives of velocity and pressure at the fluid–structure interface are avoided and far-field (smooth) velo city and pressure information is used. We re-visit the approach to compute hydrodynamic forces and torquesmore » through force/torque balance equations in a Lagrangian frame that some of us took in a prior work (Bhalla et al., 2013 [13]). We prove the equivalence of the two approaches for IB methods, thanks to the use of Peskin's delta functions. Both approaches are able to suppress spurious force oscillations and are in excellent agreement, as expected theoretically. Test cases ranging from Stokes to high Reynolds number regimes are considered. We discuss regridding issues for the moving CV method in an adaptive mesh refinement (AMR) context. The proposed moving CV method is not limited to a specific IB method and can also be used, for example, with embedded boundary methods.« less

Rapid Weight Loss and the Body Fluid Balance and Hemoglobin Mass of Elite Amateur Boxers

PubMed Central

Reljic, Dejan; Hässler, Eike; Jost, Joachim; Friedmann-Bette, Birgit

2013-01-01

Context Dehydration is assumed to be a major adverse effect associated with rapid loss of body mass for competing in a lower weight class in combat sports. However, the effects of such weight cutting on body fluid balance in a real-life setting are unknown. Objective To examine the effects of 5% or greater loss of body mass within a few days before competition on body water, blood volume, and plasma volume in elite amateur boxers. Design Case-control study. Setting Sports medicine laboratory. Patients or Other Participants Seventeen male boxers (age = 19.2 ± 2.9 years, height = 175.1 ± 7.0 cm, mass = 65.6 ± 9.2 kg) were assigned to the weight-loss group (WLG; n = 10) or the control group (CON; n = 7). Intervention(s) The WLG reduced body mass by restricting fluid and food and inducing excessive sweat loss by adhering to individual methods. The CON participated in their usual precompetition training. Main Outcome Measure(s) During an ordinary training period (t-1), 2 days before competition (t-2), and 1 week after competition (t-3), we performed bioelectrical impedance measurements; calculated total body water, intracellular water, and extracellular water; and estimated total hemoglobin mass (tHbmass), blood volume, and plasma volume by the CO-rebreathing method. Results In the WLG, the loss of body mass (5.6% ± 1.7%) led to decreases in total body water (6.0% ± 0.9%), extracellular water (12.4% ± 7.6%), tHbmass (5.3% ± 3.8%), blood volume (7.6% ± 2.1%; P < .001), and plasma volume (8.6% ± 3.9%). The intracellular water did not change (P > .05). At t-3, total body water, extracellular water, and plasma volume had returned to near baseline values, but tHbmass and blood volume still were less than baseline values (P < .05). In CON, we found no changes (P > .05). Conclusions In a real-life setting, the loss of approximately 6% body mass within 5 days induced hypohydration, which became evident by the decreases in body water and plasma volume. The reduction in tHbmass was a surprising observation that needs further investigation. PMID:23672332

NEUTRONIC REACTOR CONTROL

DOEpatents

Metcalf, H.E.

1958-10-14

Methods of controlling reactors are presented. Specifically, a plurality of neutron absorber members are adjustably disposed in the reactor core at different distances from the center thereof. The absorber members extend into the core from opposite faces thereof and are operated by motive means coupled in a manner to simultaneously withdraw at least one of the absorber members while inserting one of the other absorber members. This feature effects fine control of the neutron reproduction ratio by varying the total volume of the reactor effective in developing the neutronic reaction.

Annual Conference on Manual Control (20th) Held in California on June 12 - 14, 1984. Volume 1

DTIC Science & Technology

1984-06-14

and in conjunction with movements of other joints. Much of this data is for atheletic performance . Components of such data can be simulated using JAMM... PERFORMANCE Chairman: Mr. Henry Jex Jewell, W. & Clement, W.F. A method for measuring the effective throughput time delay in simulated displays involving...manual control. 173 Allen, R. W. & DiMarco, R. J. Effects of transport delays on manual control system performance . 185 Sanders, K. E., Anderson, D. C

Two-modality γ detection of blood volume by camera imaging and nonimaging stethoscope for kinetic studies of cardiovascular control in nuclear medicine

NASA Astrophysics Data System (ADS)

Eclancher, Bernard; Chambron, Jacques; Dumitresco, Barbu; Karman, Miklos; Pszota, Agnes; Simon, Atilla; Didon-Poncelet, Anna; Demangeat, Jean

2002-04-01

The quantification of rapid hemodynamic reactions to wide and slow breathing movements has been performed, by two modalities (gamma) -left ventriculography of 99mTc-labeled blood volume, in anterior oblique incidence on standing and even exercising healthy volunteers and cardiac patients. A highly sensitive stethoscope delivered whole (gamma) -counts acquired at 30 msec intervals in a square field of view including the left ventricle, in a one dimensional low resolution imaging mode for beat to beat analysis. A planar 2D (gamma) -camera imaging of the same cardiac area was then performed without cardiac gating for alternate acquisitions during deep inspiration and deep expiration, completed by a 3D MRI assessment of the stethoscope detection field. Young healthy volunteers displayed wide variations of diastolic times and stroke volumes, as a result of enhanced baroreflex control, together with +/- 16% variations of the stethoscope's background blood volume counts. Any of the components of these responses were shifted, abolished or even inverted as a result of either obesity, hypertension, aging or cardiac pathologies. The assessment of breathing control of the cardiovascular system by the beat to beat (gamma) -ventriculography combined with nuclear 2D and 3D MRI imaging is a kinetic method allowing the detection of functional anomalies in still ambulatory patients.

Endocochlear potential generation is associated with intercellular communication in the stria vascularis: structural analysis in the viable dominant spotting mouse mutant.

PubMed

Carlisle, L; Steel, K; Forge, A

1990-11-01

Deafness in the viable dominant spotting mouse mutant is due to a primary defect of the stria vascularis which results in absence of the positive endocochlear potential in scala media. Endocochlear potentials were measured and the structure of stria vascularis of mutants with potentials close to zero was compared with that in normal littermate controls by use of morphometric methods. The stria vascularis was significantly thinner in mutants. Marginal cells were not significantly different from controls in terms of volume density or intramembrane particle density but the network density of tight junctions was significantly reduced in the mutants. A virtual absence of gap junctions between basal cells and marginal or intermediate cells was observed, but intramembrane particle density and junctional complexes between adjacent basal cells were not different from controls. The volume density of basal cells was significantly greater in mutants. Intermediate cells accounted for a significantly smaller volume density of the stria vascularis in mutants and had a lower density of intramembrane particles than controls. Melanocytes were not identified in the stria vascularis of mutants. These results suggest that communication between marginal, intermediate and basal cells might be important to the normal function of the stria vascularis.

SU-E-J-48: Development of An Abdominal Compression Device for Respiratory Correlated Radiation Therapy

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

Kim, T; Kang, S; Kim, D

Purpose: The aim of this study is to develop the abdominal compression device which could control pressure level according to the abdominal respiratory motion and evaluate its feasibility. Methods: In this study, we focused on developing the abdominal compression device which could control pressure level at any point of time so the developed device is possible to use a variety of purpose (gating technique or respiratory training system) while maintaining the merit of the existing commercial device. The compression device (air pad form) was designed to be able to compress the front and side of abdomen and the pressure levelmore » of the abdomen is controlled by air flow. Pressure level of abdomen (air flow) was determined using correlation data between external abdominal motion and respiratory volume signal measured by spirometer. In order to verify the feasibility of the device, it was necessary to confirm the correlation between the abdominal respiratory motion and respiratory volume signal and cooperation with respiratory training system also checked. Results: In the previous study, we could find that the correlation coefficient ratio between diaphragm and respiratory volume signal measured by spirometer was 0.95. In this study, we confirmed the correlation between the respiratory volume signal and the external abdominal motion measured by belt-transducer (correlation coefficient ratio was 0.92) and used the correlated respiratory volume data as an abdominal pressure level. It was possible to control the pressure level with negligible time delay and respiratory volume data based guiding waveforms could be properly inserted into the respiratory training system. Conclusion: Through this feasibility study, we confirmed the correlation between the respiratory volume signal and the external abdominal motion. Also initial assessment of the device and its compatibility with the respiratory training system were verified. Further study on application in respiratory gated therapy and respiratory training system will be investigated. This work was supported by Radiation Technology R and D program (No. 2013M2A2A7043498)and Basic Atomic Energy Research Institute (BAERI)(No. NRF-2009-0078390) through the National Research Foundation of Korea funded by the Ministry of Science, ICT and Future Planning.« less

The DTIC Review. Hybrid and Electronic Vehicles. Volume 4. Number 1, June 1998.

DTIC Science & Technology

1998-06-01

ARGONNE NATIONAL LAB KIRTLAND AFB, NM IL (U) Constant-Thrust Orbit-Raising Transfer Charts. • (U) Dynamics and Controls in Maglev Systems DESCRIPTIVE...method to levitated ( MAGLEV ) ground transportation systems has generate minimum-fuel trajectories between coplanar important consequences for safety...satellite designers to control systems must be considered if MAGLEV systems assess preliminary fuel requirements for constant-thrust are to be economically

Imaging genetics paradigms in depression research: Systematic review and meta-analysis.

PubMed

Pereira, Lícia P; Köhler, Cristiano A; Stubbs, Brendon; Miskowiak, Kamilla W; Morris, Gerwyn; de Freitas, Bárbara P; Thompson, Trevor; Fernandes, Brisa S; Brunoni, André R; Maes, Michael; Pizzagalli, Diego A; Carvalho, André F

2018-05-17

Imaging genetics studies involving participants with major depressive disorder (MDD) have expanded. Nevertheless, findings have been inconsistent. Thus, we conducted a systematic review and meta-analysis of imaging genetics studies that enrolled MDD participants across major databases through June 30th, 2017. Sixty-five studies met eligibility criteria (N = 4034 MDD participants and 3293 controls), and there was substantial between-study variability in the methodological quality of included studies. However, few replicated findings emerged from this literature with only 22 studies providing data for meta-analyses (882 participants with MDD and 616 controls). Total hippocampal volumes did not significantly vary in MDD participants or controls carrying either the BDNF Val66Met 'Met' (386 participants with MDD and 376 controls) or the 5-HTTLPR short 'S' (310 participants with MDD and 230 controls) risk alleles compared to non-carriers. Heterogeneity across studies was explored through meta-regression and subgroup analyses. Gender distribution, the use of medications, segmentation methods used to measure the hippocampus, and age emerged as potential sources of heterogeneity across studies that assessed the association of 5-HTTLPR short 'S' alleles and hippocampal volumes. Our data also suggest that the methodological quality of included studies, publication year, and the inclusion of brain volume as a covariate contributed to the heterogeneity of studies that assessed the association of the BDNF Val66Met 'Met' risk allele and hippocampal volumes. In exploratory voxel-wise meta-analyses, MDD participants carrying the 5-HTTLPR short 'S' allele had white matter microstructural abnormalities predominantly in the corpus callosum, while carriers of the BDNF Val66Met 'Met' allele had larger gray matter volumes and hyperactivation of the right middle frontal gyrus compared to non-carriers. In conclusion, few replicated findings emerged from imaging genetics studies that included participants with MDD. Nevertheless, we explored and identified specific sources of heterogeneity across studies, which could provide insights to enhance the reproducibility of this emerging field. Copyright © 2018 Elsevier Inc. All rights reserved.

Analysis of volumetric response of pituitary adenomas receiving adjuvant CyberKnife stereotactic radiosurgery with the application of an exponential fitting model

PubMed Central

Yu, Yi-Lin; Yang, Yun-Ju; Lin, Chin; Hsieh, Chih-Chuan; Li, Chiao-Zhu; Feng, Shao-Wei; Tang, Chi-Tun; Chung, Tzu-Tsao; Ma, Hsin-I; Chen, Yuan-Hao; Ju, Da-Tong; Hueng, Dueng-Yuan

2017-01-01

Abstract Tumor control rates of pituitary adenomas (PAs) receiving adjuvant CyberKnife stereotactic radiosurgery (CK SRS) are high. However, there is currently no uniform way to estimate the time course of the disease. The aim of this study was to analyze the volumetric responses of PAs after CK SRS and investigate the application of an exponential decay model in calculating an accurate time course and estimation of the eventual outcome. A retrospective review of 34 patients with PAs who received adjuvant CK SRS between 2006 and 2013 was performed. Tumor volume was calculated using the planimetric method. The percent change in tumor volume and tumor volume rate of change were compared at median 4-, 10-, 20-, and 36-month intervals. Tumor responses were classified as: progression for >15% volume increase, regression for ≤15% decrease, and stabilization for ±15% of the baseline volume at the time of last follow-up. For each patient, the volumetric change versus time was fitted with an exponential model. The overall tumor control rate was 94.1% in the 36-month (range 18–87 months) follow-up period (mean volume change of −43.3%). Volume regression (mean decrease of −50.5%) was demonstrated in 27 (79%) patients, tumor stabilization (mean change of −3.7%) in 5 (15%) patients, and tumor progression (mean increase of 28.1%) in 2 (6%) patients (P = 0.001). Tumors that eventually regressed or stabilized had a temporary volume increase of 1.07% and 41.5% at 4 months after CK SRS, respectively (P = 0.017). The tumor volume estimated using the exponential fitting equation demonstrated high positive correlation with the actual volume calculated by magnetic resonance imaging (MRI) as tested by Pearson correlation coefficient (0.9). Transient progression of PAs post-CK SRS was seen in 62.5% of the patients receiving CK SRS, and it was not predictive of eventual volume regression or progression. A three-point exponential model is of potential predictive value according to relative distribution. An exponential decay model can be used to calculate the time course of tumors that are ultimately controlled. PMID:28121913

High-order accurate finite-volume formulations for the pressure gradient force in layered ocean models

NASA Astrophysics Data System (ADS)

Engwirda, Darren; Kelley, Maxwell; Marshall, John

2017-08-01

Discretisation of the horizontal pressure gradient force in layered ocean models is a challenging task, with non-trivial interactions between the thermodynamics of the fluid and the geometry of the layers often leading to numerical difficulties. We present two new finite-volume schemes for the pressure gradient operator designed to address these issues. In each case, the horizontal acceleration is computed as an integration of the contact pressure force that acts along the perimeter of an associated momentum control-volume. A pair of new schemes are developed by exploring different control-volume geometries. Non-linearities in the underlying equation-of-state definitions and thermodynamic profiles are treated using a high-order accurate numerical integration framework, designed to preserve hydrostatic balance in a non-linear manner. Numerical experiments show that the new methods achieve high levels of consistency, maintaining hydrostatic and thermobaric equilibrium in the presence of strongly-sloping layer geometries, non-linear equations-of-state and non-uniform vertical stratification profiles. These results suggest that the new pressure gradient formulations may be appropriate for general circulation models that employ hybrid vertical coordinates and/or terrain-following representations.

40 CFR 63.8232 - What test methods and other procedures must I use to demonstrate initial compliance with the...

Code of Federal Regulations, 2014 CFR

2014-07-01

... sampling volume for each run must be at least 2 hours and 1.70 dry standard cubic meters (dscm). Mercury... final (i.e., the farthest downstream) cooling system when no control devices other than coolers or...

40 CFR 63.8232 - What test methods and other procedures must I use to demonstrate initial compliance with the...

Code of Federal Regulations, 2011 CFR

2011-07-01

... sampling volume for each run must be at least 2 hours and 1.70 dry standard cubic meters (dscm). Mercury... final (i.e., the farthest downstream) cooling system when no control devices other than coolers or...

40 CFR 63.8232 - What test methods and other procedures must I use to demonstrate initial compliance with the...

Code of Federal Regulations, 2012 CFR

2012-07-01

... sampling volume for each run must be at least 2 hours and 1.70 dry standard cubic meters (dscm). Mercury... final (i.e., the farthest downstream) cooling system when no control devices other than coolers or...

40 CFR 63.8232 - What test methods and other procedures must I use to demonstrate initial compliance with the...

Code of Federal Regulations, 2013 CFR

2013-07-01

... sampling volume for each run must be at least 2 hours and 1.70 dry standard cubic meters (dscm). Mercury... final (i.e., the farthest downstream) cooling system when no control devices other than coolers or...

Quality Control for Ambient Sampling of PCDD/PCDF from Open Combustion Sources

EPA Science Inventory

Both long duration (> 6 h) and high temperature (up to 139o C) sampling efforts were conducted using ambient air sampling methods to determine if either high volume throughput or higher than ambient sampling temperatures resulted in loss of target polychlorinated dibenzodioxins/d...

The Influence of DAT1, COMT, and BDNF Genetic Polymorphisms on Total and Subregional Hippocampal Volumes in Early Onset Heavy Cannabis Users

PubMed Central

Batalla, Albert; Lorenzetti, Valentina; Chye, Yann; Yücel, Murat; Soriano-Mas, Carles; Bhattacharyya, Sagnik; Torrens, Marta; Crippa, José A.S.; Martín-Santos, Rocío

2018-01-01

Abstract Introduction: Hippocampal neuroanatomy is affected by genetic variations in dopaminergic candidate genes and environmental insults, such as early onset of chronic cannabis exposure. Here, we examine how hippocampal total and subregional volumes are affected by cannabis use and functional polymorphisms of dopamine-relevant genes, including the catechol-O-methyltransferase (COMT), dopamine transporter (DAT1), and the brain-derived neurotrophic factor (BDNF) genes. Material and Methods: We manually traced total hippocampal volumes and automatically segmented hippocampal subregions using high-resolution MRI images, and performed COMT, DAT1, and BDNF genotyping in 59 male Caucasian young adults aged 18–30 years. These included 30 chronic cannabis users with early-onset (regular use at <16 years) and 29 age-, education-, and intelligence-matched controls. Results: Cannabis use and dopaminergic gene polymorphism had both distinct and interactive effects on the hippocampus. We found emerging alterations of hippocampal total and specific subregional volumes in cannabis users relative to controls (i.e., CA1, CA2/3, and CA4), and associations between cannabis use levels and total and specific subregional volumes. Furthermore, total hippocampal volume and the fissure subregion were affected by cannabis×DAT1 polymorphism (i.e., 9/9R and in 10/10R alleles), reflecting high and low levels of dopamine availability. Conclusion: These findings suggest that cannabis exposure alters the normal relationship between DAT1 polymorphism and the anatomy of total and subregional hippocampal volumes, and that specific hippocampal subregions may be particularly affected. PMID:29404409

The Influence of DAT1, COMT, and BDNF Genetic Polymorphisms on Total and Subregional Hippocampal Volumes in Early Onset Heavy Cannabis Users.

PubMed

Batalla, Albert; Lorenzetti, Valentina; Chye, Yann; Yücel, Murat; Soriano-Mas, Carles; Bhattacharyya, Sagnik; Torrens, Marta; Crippa, José A S; Martín-Santos, Rocío

2018-01-01

Introduction: Hippocampal neuroanatomy is affected by genetic variations in dopaminergic candidate genes and environmental insults, such as early onset of chronic cannabis exposure. Here, we examine how hippocampal total and subregional volumes are affected by cannabis use and functional polymorphisms of dopamine-relevant genes, including the catechol-O-methyltransferase (COMT), dopamine transporter (DAT1), and the brain-derived neurotrophic factor (BDNF) genes. Material and Methods: We manually traced total hippocampal volumes and automatically segmented hippocampal subregions using high-resolution MRI images, and performed COMT, DAT1, and BDNF genotyping in 59 male Caucasian young adults aged 18-30 years. These included 30 chronic cannabis users with early-onset (regular use at <16 years) and 29 age-, education-, and intelligence-matched controls. Results: Cannabis use and dopaminergic gene polymorphism had both distinct and interactive effects on the hippocampus. We found emerging alterations of hippocampal total and specific subregional volumes in cannabis users relative to controls (i.e., CA1, CA2/3, and CA4), and associations between cannabis use levels and total and specific subregional volumes. Furthermore, total hippocampal volume and the fissure subregion were affected by cannabis×DAT1 polymorphism (i.e., 9/9R and in 10/10R alleles), reflecting high and low levels of dopamine availability. Conclusion: These findings suggest that cannabis exposure alters the normal relationship between DAT1 polymorphism and the anatomy of total and subregional hippocampal volumes, and that specific hippocampal subregions may be particularly affected.

Sample Preparation and Extraction in Small Sample Volumes Suitable for Pediatric Clinical Studies: Challenges, Advances, and Experiences of a Bioanalytical HPLC-MS/MS Method Validation Using Enalapril and Enalaprilat

PubMed Central

Burckhardt, Bjoern B.; Laeer, Stephanie

2015-01-01

In USA and Europe, medicines agencies force the development of child-appropriate medications and intend to increase the availability of information on the pediatric use. This asks for bioanalytical methods which are able to deal with small sample volumes as the trial-related blood lost is very restricted in children. Broadly used HPLC-MS/MS, being able to cope with small volumes, is susceptible to matrix effects. The latter restrains the precise drug quantification through, for example, causing signal suppression. Sophisticated sample preparation and purification utilizing solid-phase extraction was applied to reduce and control matrix effects. A scale-up from vacuum manifold to positive pressure manifold was conducted to meet the demands of high-throughput within a clinical setting. Faced challenges, advances, and experiences in solid-phase extraction are exemplarily presented on the basis of the bioanalytical method development and validation of low-volume samples (50 μL serum). Enalapril, enalaprilat, and benazepril served as sample drugs. The applied sample preparation and extraction successfully reduced the absolute and relative matrix effect to comply with international guidelines. Recoveries ranged from 77 to 104% for enalapril and from 93 to 118% for enalaprilat. The bioanalytical method comprising sample extraction by solid-phase extraction was fully validated according to FDA and EMA bioanalytical guidelines and was used in a Phase I study in 24 volunteers. PMID:25873972

Achieving high convection volumes in postdilution online hemodiafiltration: a prospective multicenter study

PubMed Central

Chapdelaine, Isabelle; Nubé, Menso J; Blankestijn, Peter J; Bots, Michiel L; Konings, Constantijn J A M; Kremer Hovinga, Ton K; Molenaar, Femke M; van der Weerd, Neelke C; Grooteman, Muriel P C

2017-01-01

Abstract Background. Available evidence suggests a reduced mortality risk for patients treated with high-volume postdilution hemodiafiltration (HDF) when compared with hemodialysis (HD) patients. As the magnitude of the convection volume depends on treatment-related factors rather than patient-related characteristics, we prospectively investigated whether a high convection volume (defined as ≥22 L/session) is feasible in the majority of patients (>75%). Methods. A multicenter study was performed in adult prevalent dialysis patients. Nonparticipating eligible patients formed the control group. Using a stepwise protocol, treatment time (up to 4 hours), blood flow rate (up to 400 mL/min) and filtration fraction (up to 33%) were optimized as much as possible. The convection volume was determined at the end of this optimization phase and at 4 and 8 weeks thereafter. Results. Baseline characteristics were comparable in participants (n = 86) and controls (n = 58). At the end of the optimization and 8 weeks thereafter, 71/86 (83%) and 66/83 (80%) of the patients achieved high-volume HDF (mean 25.5 ± 3.6 and 26.0 ± 3.4 L/session, respectively). While treatment time remained unaltered, mean blood flow rate increased by 27% and filtration fraction increased by 23%. Patients with <22 L/session had a higher percentage of central venous catheters (CVCs), a shorter treatment time and lower blood flow rate when compared with patients with ≥22 L/session. Conclusions. High-volume HDF is feasible in a clear majority of dialysis patients. Since none of the patients agreed to increase treatment time, these findings indicate that high-volume HDF is feasible just by increasing blood flow rate and filtration fraction. PMID:29225810

Dynamically controlled crystallization method and apparatus and crystals obtained thereby

NASA Technical Reports Server (NTRS)

Arnowitz, Leonard (Inventor); Steinberg, Emanuel (Inventor)

1999-01-01

A method and apparatus for dynamically controlling the crystallization of proteins including a crystallization chamber or chambers for holding a protein in a salt solution, one or more salt solution chambers, two communication passages respectively coupling the crystallization chamber with each of the salt solution chambers, and transfer mechanisms configured to respectively transfer salt solution between each of the salt solution chambers and the crystallization chamber. The transfer mechanisms are interlocked to maintain the volume of salt solution in the crystallization chamber substantially constant. Salt solution of different concentrations is transferred into and out of the crystallization chamber to adjust the salt concentration in the crystallization chamber to achieve precise control of the crystallization process.

Active Control of Fan Noise-Feasibility Study. Volume 2: Canceling Noise Source-Design of an Acoustic Plate Radiator Using Piezoceramic Actuators

NASA Technical Reports Server (NTRS)

Pla, F. G.; Rajiyah, H.

1995-01-01

The feasibility of using acoustic plate radiators powered by piezoceramic thin sheets as canceling sources for active control of aircraft engine fan noise is demonstrated. Analytical and numerical models of actuated beams and plates are developed and validated. An optimization study is performed to identify the optimum combination of design parameters that maximizes the plate volume velocity for a given resonance frequency. Fifteen plates with various plate and actuator sizes, thicknesses, and bonding layers were fabricated and tested using results from the optimization study. A maximum equivalent piston displacement of 0.39 mm was achieved with the optimized plate samples tested with only one actuator powered, corresponding to a plate deflection at the center of over 1 millimeter. This is very close to the deflection required for a full size engine application and represents a 160-fold improvement over previous work. Experimental results further show that performance is limited by the critical stress of the piezoceramic actuator and bonding layer rather than by the maximum moment available from the actuator. Design enhancements are described in detail that will lead to a flight-worthy acoustic plate radiator by minimizing actuator tensile stresses and reducing nonlinear effects. Finally, several adaptive tuning methods designed to increase the bandwidth of acoustic plate radiators are analyzed including passive, active, and semi-active approaches. The back chamber pressurization and volume variation methods are investigated experimentally and shown to be simple and effective ways to obtain substantial control over the resonance frequency of a plate radiator. This study shows that piezoceramic-based plate radiators can be a viable acoustic source for active control of aircraft engine fan noise.

Factors controlling headspace pressure in a manual manometric BMP method can be used to produce a methane output comparable to AMPTS.

PubMed

Himanshu, H; Voelklein, M A; Murphy, J D; Grant, J; O'Kiely, P

2017-08-01

The manual manometric biochemical methane potential (mBMP) test uses the increase in pressure to calculate the gas produced. This gas production may be affected by the headspace volume in the incubation bottle and by the overhead pressure measurement and release (OHPMR) frequency. The biogas and methane yields of cellulose, barley, silage and slurry were compared with three incubation bottle headspace volumes (50, 90 and 180ml; constant 70ml total medium) and four OHPMR frequencies (daily, each third day, weekly and solely at the end of experiment). The methane yields of barley, silage and slurry were compared with those from an automated volumetric method (AMPTS). Headspace volume and OHPMR frequency effects on biogas yield were mediated mainly through headspace pressure, with the latter having a negative effect on the biogas yield measured and relatively little effect on methane yield. Two mBMP treatments produced methane yields equivalent to AMPTS. Copyright © 2017 Elsevier Ltd. All rights reserved.

Nanopore sensing at ultra-low concentrations using single-molecule dielectrophoretic trapping

PubMed Central

Freedman, Kevin J.; Otto, Lauren M.; Ivanov, Aleksandar P.; Barik, Avijit; Oh, Sang-Hyun; Edel, Joshua B.

2016-01-01

Single-molecule techniques are being developed with the exciting prospect of revolutionizing the healthcare industry by generating vast amounts of genetic and proteomic data. One exceptionally promising route is in the use of nanopore sensors. However, a well-known complexity is that detection and capture is predominantly diffusion limited. This problem is compounded when taking into account the capture volume of a nanopore, typically 108–1010 times smaller than the sample volume. To rectify this disproportionate ratio, we demonstrate a simple, yet powerful, method based on coupling single-molecule dielectrophoretic trapping to nanopore sensing. We show that DNA can be captured from a controllable, but typically much larger, volume and concentrated at the tip of a metallic nanopore. This enables the detection of single molecules at concentrations as low as 5 fM, which is approximately a 103 reduction in the limit of detection compared with existing methods, while still maintaining efficient throughput. PMID:26732171

Squeeze strengthening of magnetorheological fluids using mixed mode operation

NASA Astrophysics Data System (ADS)

Becnel, A. C.; Sherman, S. G.; Hu, W.; Wereley, N. M.

2015-05-01

This research details a novel method of increasing the shear yield stress of magnetorheological fluids by combining shear and squeeze modes of operation to manipulate particle chain structures, so-called squeeze strengthening. Using a custom built Searle cell magnetorheometer, which is a model device emulating a rotary magnetorheological energy absorber (MREA), the contribution of squeeze strengthening to the total controllable yield force is experimentally investigated. Using an eccentric rotating inner cylinder, characterization data from large (1 mm) and small (0.25 mm) nominal gap geometries are compared to investigate the squeeze strengthening effect. Details of the experimental setup and method are presented, and a hybrid model is used to explain experimental trends. This study demonstrates that it is feasible, utilizing squeeze strengthening to increase yield stress, to either (1) design a rotary MREA of a given volume to achieve higher energy absorption density (energy absorbed normalized by active fluid volume), or (2) reduce the volume of a given rotary MREA to achieve the same energy absorption density.

Optimization of Adaptive Intraply Hybrid Fiber Composites with Reliability Considerations

NASA Technical Reports Server (NTRS)

Shiao, Michael C.; Chamis, Christos C.

1994-01-01

The reliability with bounded distribution parameters (mean, standard deviation) was maximized and the reliability-based cost was minimized for adaptive intra-ply hybrid fiber composites by using a probabilistic method. The probabilistic method accounts for all naturally occurring uncertainties including those in constituent material properties, fabrication variables, structure geometry, and control-related parameters. Probabilistic sensitivity factors were computed and used in the optimization procedures. For actuated change in the angle of attack of an airfoil-like composite shell structure with an adaptive torque plate, the reliability was maximized to 0.9999 probability, with constraints on the mean and standard deviation of the actuation material volume ratio (percentage of actuation composite material in a ply) and the actuation strain coefficient. The reliability-based cost was minimized for an airfoil-like composite shell structure with an adaptive skin and a mean actuation material volume ratio as the design parameter. At a O.9-mean actuation material volume ratio, the minimum cost was obtained.

Transport jet aircraft noise abatement in foreign countries: Growth, structure, impact. Volume 2: Pacific basin, August 1980

NASA Technical Reports Server (NTRS)

Spencer, F. A.

1980-01-01

Noise control measures at the international airports of Hawaii, New Zealand, Australia, Hong Kong, Japan, and Singapore were studied. Factors in noise control, such as government structure are examined. The increasing power of environmental agencies vis-a-vis aviation departments is noted. The following methods of dealing with aircraft noise are examined by type of control: noise at the source control; noise emmission controls, zoning, building codes, subsidies for relocation, insulation, loss in property values, and for TV, radio and telephone interference; and noise-related landing charges.

Brain Volume Estimation Enhancement by Morphological Image Processing Tools.

PubMed

Zeinali, R; Keshtkar, A; Zamani, A; Gharehaghaji, N

2017-12-01

Volume estimation of brain is important for many neurological applications. It is necessary in measuring brain growth and changes in brain in normal/abnormal patients. Thus, accurate brain volume measurement is very important. Magnetic resonance imaging (MRI) is the method of choice for volume quantification due to excellent levels of image resolution and between-tissue contrast. Stereology method is a good method for estimating volume but it requires to segment enough MRI slices and have a good resolution. In this study, it is desired to enhance stereology method for volume estimation of brain using less MRI slices with less resolution. In this study, a program for calculating volume using stereology method has been introduced. After morphologic method, dilation was applied and the stereology method enhanced. For the evaluation of this method, we used T1-wighted MR images from digital phantom in BrainWeb which had ground truth. The volume of 20 normal brain extracted from BrainWeb, was calculated. The volumes of white matter, gray matter and cerebrospinal fluid with given dimension were estimated correctly. Volume calculation from Stereology method in different cases was made. In three cases, Root Mean Square Error (RMSE) was measured. Case I with T=5, d=5, Case II with T=10, D=10 and Case III with T=20, d=20 (T=slice thickness, d=resolution as stereology parameters). By comparing these results of two methods, it is obvious that RMSE values for our proposed method are smaller than Stereology method. Using morphological operation, dilation allows to enhance the estimation volume method, Stereology. In the case with less MRI slices and less test points, this method works much better compared to Stereology method.

Preparation method and quality control of multigamma volume sources with different matrices.

PubMed

Listkowska, A; Lech, E; Saganowski, P; Tymiński, Z; Dziel, T; Cacko, D; Ziemek, T; Kołakowska, E; Broda, R

2018-04-01

The aim of the work was to develop new radioactive standard sources based on epoxy resins. The optimal proportions of the components and the homogeneity of the matrices were determined. The activity of multigamma sources prepared in Marinelli beakers was determined with reference to the National Standard of Radionuclides Activity in Poland. The difference of radionuclides activity values determined using calibrated gamma spectrometer and the activity of standard solutions used are in most cases significantly lower than measurement uncertainty limits. Sources production method and quality control procedure have been developed. Copyright © 2017 Elsevier Ltd. All rights reserved.

Hemodynamic alterations in chronically conscious unrestrained diabetic rats

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

Carbonell, L.F.; Salmon, M.G.; Garcia-Estan, J.

1987-05-01

Important cardiovascular dysfunctions have been described in streptozotocin (STZ)-diabetic rats. To determine the influence of these changes on the hemodynamic state and whether insulin treatment can avoid them, different hemodynamic parameters, obtained by the thermodilution method, were studied in STZ-induced (65 mg/kg) diabetic male Wistar rats, as well as in age-control, weight-control, and insulin-treated diabetic ones. Plasma volume was measured by dilution of radioiodinated (/sup 125/I) human serum albumin. All rats were examined in the conscious, unrestrained state 12 wk after induction of diabetes or acidified saline (pH 4.5) injection. At 12 wk of diabetic state most important findings weremore » normotension, high blood volume, bradycardia, increase in stroke volume, cardiac output, and cardiosomatic ratio, and decrease in total peripheral resistance and cardiac contractility and relaxation (dP/dt/sub max/ and dP/dt/sub min/ of left ventricular pressure curves). The insulin-treated diabetic rats did not show any hemodynamic differences when compared with the control animals. These results suggest that important hemodynamic alterations are present in the chronic diabetic states, possibly conditioning congestive heart failure. These alterations can be prevented by insulin treatment.« less

Grey matter correlates of autistic traits in women with anorexia nervosa

PubMed Central

Davidovic, Monika; Karjalainen, Louise; Starck, Göran; Olausson, Håkan; Wentz, Elisabet

2018-01-01

Background Patients with anorexia nervosa exhibit higher levels of behaviours typically associated with autism-spectrum disorder (ASD), but the neural basis is unclear. We sought to determine whether elevated autistic traits in women with anorexia nervosa may be reflected in cortical morphology. Methods We used voxel-based morphometry (VBM) to examine regional grey matter volumes in high-resolution MRI structural brain scans in women with anorexia nervosa and matched healthy controls. The Autism-spectrum Quotient (AQ) scale was used to assess autistic traits. Results Women with anorexia nervosa (n = 25) had higher AQ scores and lower bilateral superior temporal sulcus (STS) grey matter volumes than the control group (n = 25). The AQ scores correlated negatively with average left STS grey matter volume in women with anorexia nervosa. Limitations We did not control for cognitive ability and examined only women with ongoing anorexia nervosa. Conclusion Elevated autistic traits in women with anorexia nervosa are associated with morphometric alterations of brain areas linked to social cognition. This finding provides neurobiological support for the behavioural link between anorexia nervosa and ASD and emphasizes the importance of recognizing autistic traits in preventing and treating anorexia nervosa. PMID:29481315

Grid Generation Techniques Utilizing the Volume Grid Manipulator

NASA Technical Reports Server (NTRS)

Alter, Stephen J.

1998-01-01

This paper presents grid generation techniques available in the Volume Grid Manipulation (VGM) code. The VGM code is designed to manipulate existing line, surface and volume grids to improve the quality of the data. It embodies an easy to read rich language of commands that enables such alterations as topology changes, grid adaption and smoothing. Additionally, the VGM code can be used to construct simplified straight lines, splines, and conic sections which are common curves used in the generation and manipulation of points, lines, surfaces and volumes (i.e., grid data). These simple geometric curves are essential in the construction of domain discretizations for computational fluid dynamic simulations. By comparison to previously established methods of generating these curves interactively, the VGM code provides control of slope continuity and grid point-to-point stretchings as well as quick changes in the controlling parameters. The VGM code offers the capability to couple the generation of these geometries with an extensive manipulation methodology in a scripting language. The scripting language allows parametric studies of a vehicle geometry to be efficiently performed to evaluate favorable trends in the design process. As examples of the powerful capabilities of the VGM code, a wake flow field domain will be appended to an existing X33 Venturestar volume grid; negative volumes resulting from grid expansions to enable flow field capture on a simple geometry, will be corrected; and geometrical changes to a vehicle component of the X33 Venturestar will be shown.

Does Stroke Volume Increase During an Incremental Exercise? A Systematic Review

PubMed Central

Vieira, Stella S.; Lemes, Brunno; de T. C. de Carvalho, Paulo; N. de Lima, Rafael; S. Bocalini, Danilo; A. S. Junior, José; Arsa, Gisela; A. Casarin, Cezar; L. Andrade, Erinaldo; J. Serra, Andrey

2016-01-01

Introduction: Cardiac output increases during incremental-load exercise to meet metabolic skeletal muscle demand. This response requires a fast adjustment in heart rate and stroke volume. The heart rate is well known to increase linearly with exercise load; however, data for stroke volume during incremental-load exercise are unclear. Our objectives were to (a) review studies that have investigated stroke volume on incremental load exercise and (b) summarize the findings for stroke volume, primarily at maximal-exercise load. Methods: A comprehensive review of the Cochrane Library’s, Embase, Medline, SportDiscus, PubMed, and Web of Sci-ence databases was carried out for the years 1985 to the present. The search was performed between February and June 2014 to find studies evaluating changes in stroke volume during incremental-load exercise. Controlled and uncontrolled trials were evaluated for a quality score. Results: The stroke volume data in maximal-exercise load are inconsistent. There is evidence to hypothesis that stroke volume increases during maximal-exercise load, but other lines of evidence indicate that stroke volume reaches a plateau under these circumstances, or even decreases. Conclusion: The stroke volume are unclear, include contradictory evidence. Additional studies with standardized reporting for subjects (e.g., age, gender, physical fitness, and body position), exercise test protocols, and left ventricular function are required to clarify the characteristics of stroke volume during incremental maximal-exercise load. PMID:27347221

Control theory based airfoil design using the Euler equations

NASA Technical Reports Server (NTRS)

Jameson, Antony; Reuther, James

1994-01-01

This paper describes the implementation of optimization techniques based on control theory for airfoil design. In our previous work it was shown that control theory could be employed to devise effective optimization procedures for two-dimensional profiles by using the potential flow equation with either a conformal mapping or a general coordinate system. The goal of our present work is to extend the development to treat the Euler equations in two-dimensions by procedures that can readily be generalized to treat complex shapes in three-dimensions. Therefore, we have developed methods which can address airfoil design through either an analytic mapping or an arbitrary grid perturbation method applied to a finite volume discretization of the Euler equations. Here the control law serves to provide computationally inexpensive gradient information to a standard numerical optimization method. Results are presented for both the inverse problem and drag minimization problem.

Extraction and LOD control of colored interval volumes

NASA Astrophysics Data System (ADS)

Miyamura, Hiroko N.; Takeshima, Yuriko; Fujishiro, Issei; Saito, Takafumi

2005-03-01

Interval volume serves as a generalized isosurface and represents a three-dimensional subvolume for which the associated scalar filed values lie within a user-specified closed interval. In general, it is not an easy task for novices to specify the scalar field interval corresponding to their ROIs. In order to extract interval volumes from which desirable geometric features can be mined effectively, we propose a suggestive technique which extracts interval volumes automatically based on the global examination of the field contrast structure. Also proposed here is a simplification scheme for decimating resultant triangle patches to realize efficient transmission and rendition of large-scale interval volumes. Color distributions as well as geometric features are taken into account to select best edges to be collapsed. In addition, when a user wants to selectively display and analyze the original dataset, the simplified dataset is restructured to the original quality. Several simulated and acquired datasets are used to demonstrate the effectiveness of the present methods.

Can mean platelet volume and mean platelet volume/platelet count ratio be used as a diagnostic marker for sepsis and systemic inflammatory response syndrome?

PubMed Central

Ates, Selma; Oksuz, Hafıze; Dogu, Bırsen; Bozkus, Fulsen; Ucmak, Hasan; Yanıt, Fadime

2015-01-01

Objectives: To determine whether the mean platelet volume (MPV) and MPV/platelet (PLT) values can be used in the study of sepsis and systemic inflammatory response syndrome (SIRS). Methods: In this retrospective case-controlled study, 69 sepsis, 69 SIRS patients, and 72 control group who were treated in the years 2012-2013 were reviewed, and both the MPV and MPV/PLT rates were evaluated in all groups at Kahramanmaras Sutcu Imam University Intensive Care Unit, Kahramanmaras, Turkey. Results: Statistically significant difference was found between sepsis, SIRS, and control groups when comparing the MPV and MPV/PLT ratio (p<0.05), and no significant difference was found between sepsis and SIRS groups in terms of MPV and MPV/PLT ratio (p>0.05). Mean platelet volume values for sepsis and control groups was 10.07/8.731 femtoliter (fL) (p=0.000), and 9.45/8.731 fL (p=0.000) for SIRS and control groups. In the group of sepsis patients, the MPV was found to be at cut-off 8.915, sensitivity 71%, and specificity 63.9%. In the group of patients with SIRS, MPV was found to be at cut-off 8.85, sensitivity 69.6%, and specificity 62.5%. For the MPV/PLT values, the specificity and sensitivity were found to be insignificant. Conclusion: This study shows that although there was no significant reduction in the PLT values between the sepsis and SIRS patients, the MPV and MPV/PLT ratio values were found to have significant differences. However, the specificity and sensitivity of the values were not reliable standard to be used as a test. PMID:26446329

Non-invasive detection and monitoring of experimental hydrocephalus with distortion product otoacoustic emissions.

PubMed

Ezerarslan, Hande; Beriat, Güçlü Kaan; Nurhat, Raziye Handan; Kazancı, Burak; Çelikkan, Ferda Topal; Sabuncuoğlu, Bizden; Sabuncuoğlu, Hakan

2016-08-01

We aimed to find out the effects of short term and long term hydrocephalus and intracranial ventricular volume changes on cochlear functions by using distortion product otoacoustic emission (DPOAE) in experimental hydrocephalus rat models for the first time in literature. This study was performed with 48 healthy, adult (8 weeks old), Sprague-Dawley rats which weighed between 200 and 240g. Six groups were formed in this study: short term control, short term sham, short term hydrocephalus, long term control, long term sham and long term hydrocephalus groups. Each group contained eight rats. Short term period was 4 weeks and long term period was 8 weeks after the study started. At the end of these periods, DPOAE measurements were performed and then rats were sacrificed to determine ventricular volumes. DPOAE values at all frequencies were significantly decreased in the short term hydrocephalus group when compared to the short term control and short term sham groups. DPOAE values at all frequencies were significantly decreased in the long term hydrocephalus group when compared to the long term control and long term sham groups. Besides, long term sham group which had higher ventricular volumes than long term control group also had lower DPOAE measurements. Significant associations were present between DPOAE measurements and ventricular volumes in hydrocephalus models. The functional disturbances in cochlear functions due to hydrocephalus have been demonstrated with DPOAE measurements in this study. DPOAE measurements may be thought as an easily applicable non-invasive method in detection and follow-up of patients with hydrocephalus. Our findings should be supported with clinical studies in humans. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Design of an essentially non-oscillatory reconstruction procedure in finite-element type meshes

NASA Technical Reports Server (NTRS)

Abgrall, Remi

1992-01-01

An essentially non oscillatory reconstruction for functions defined on finite element type meshes is designed. Two related problems are studied: the interpolation of possibly unsmooth multivariate functions on arbitary meshes and the reconstruction of a function from its averages in the control volumes surrounding the nodes of the mesh. Concerning the first problem, the behavior of the highest coefficients of two polynomial interpolations of a function that may admit discontinuities of locally regular curves is studied: the Lagrange interpolation and an approximation such that the mean of the polynomial on any control volume is equal to that of the function to be approximated. This enables the best stencil for the approximation to be chosen. The choice of the smallest possible number of stencils is addressed. Concerning the reconstruction problem, two methods were studied: one based on an adaptation of the so called reconstruction via deconvolution method to irregular meshes and one that lies on the approximation on the mean as defined above. The first method is conservative up to a quadrature formula and the second one is exactly conservative. The two methods have the expected order of accuracy, but the second one is much less expensive than the first one. Some numerical examples are given which demonstrate the efficiency of the reconstruction.

Comparison of MRI-assessed body fat content between lean women with polycystic ovary syndrome (PCOS) and matched controls: less visceral fat with PCOS.

PubMed

Dolfing, Jacoba G; Stassen, Chrit M; van Haard, Paul M M; Wolffenbuttel, Bruce H R; Schweitzer, Dave H

2011-06-01

BACKGROUND Polycystic ovary syndrome (PCOS) is a heterogeneous disorder. However, PCOS has a strong resemblance to the metabolic syndrome, including preponderance of visceral fat deposition. The aim of this study is to compare fat distribution between lean women with PCOS and controls matched for body composition but with regular menstrual cycles and proven fertility. METHODS In this prospective cross-sectional study in a fertility outpatient clinic, 10 Caucasian women with PCOS and 10 controls, all with a BMI between 19 and 25 kg/m(2), were included. Fasting glucose, insulin and C-peptide concentrations, homeostasis model assessment (HOMA), hormonal levels and bioelectrical impedance analysis (BIA) variables were assessed and fat content and ovarian volume determinations were obtained with magnetic resonance imaging (MRI). Multiple axial cross-sections were calculated. RESULTS The age of the PCOS and control groups were [mean (SD)] 28.2 years (2.6) versus 33.7 years (2.3) P < 0.0001, respectively, and both groups were matched for BMI: 21.6 kg/m(2) (1.1) versus 21.8 kg/m(2) (2.1) (ns), fasting glucose, insulin, C-peptide, HOMA-insulin resistance (IR) levels and BIA parameters. PCOS cases had higher ovarian volumes and less visceral fat compared with controls. CONCLUSIONS Lean women with PCOS have higher MRI-determined ovarian volumes and less visceral fat content when compared with control women.

Reduction of peritoneal carcinomatosis by intraperitoneal administration of phospholipids in rats

PubMed Central

Otto, Jens; Jansen, Petra Lynen; Lucas, Stefan; Schumpelick, Volker; Jansen, Marc

2007-01-01

Background Intraperitoneal tumor cell attachment after resection of gastrointestinal cancer may lead to a developing of peritoneal carcinosis. Intraabdominal application of phospholipids shows a significant decrease of adhesion formation even in case of rising tumor cell concentration. Methods In experiment A 2*106 colonic tumor cells (DHD/K12/Trb) were injected intraperitonely in female BD-IX-rats. A total of 30 rats were divided into three groups with treatments of phospholipids at 6% or 9% and the control group. In experiment B a total of 100 rats were divided into ten groups with treatments of phospholipids at 9% and the control group. A rising concentration of tumor cells (10,000, 50,000, 100,000, 250,000 and 500,000) were injected intraperitonely in female BD-IX-rats of the different groups. After 30 days, the extent of peritoneal carcinosis was determined by measuring the tumor volume, the area of attachment and the Peritoneal Cancer Index (PCI). Results In experiment A, we found a significant reduction (control group: tumor volume: 12.0 ± 4.9 ml; area of tumor adhesion: 2434.4 ± 766 mm2; PCI 28.5 ± 10.0) of peritoneal dissemination according to all evaluation methods after treatment with phospholipids 6% (tumor volume: 5.2 ± 2.2 ml; area of tumor adhesion: 1106.8 ± 689 mm2; PCI 19.0 ± 5.0) and phospholipids 9% (tumor volume: 4.0 ± 3.5 ml; area of tumor adhesion: 362.7 ± 339 mm2; PCI 13.8 ± 5.1). In experiment B we found a significant reduction of tumor volume in all different groups of rising tumor cell concentration compared to the control. As detected by the area of attachment we found a significant reduction in the subgroups 1*104, 25*104 and 50*104. The reduction in the other subgroups shows no significance. The PCI could be reduced significantly in all subgroups apart from 5*104. Conclusion In this animal study intraperitoneal application of phospholipids resulted in reduction of the extent of peritoneal carcinomatosis after intraperitoneal administration of free tumor cells. This effect was exceptionally noticed when the amount of intraperitoneal tumor cells was limited. Consequently, intraperitoneal administration of phospholipids might be effective in reducing peritoneal carcinomatosis after surgery of gastrointestinal tumors in humans. PMID:17584925

Hippocampus and amygdala volumes in patients with vaginismus.

PubMed

Atmaca, Murad; Baykara, Sema; Ozer, Omer; Korkmaz, Sevda; Akaslan, Unsal; Yildirim, Hanefi

2016-06-22

To compare hippocampus and amygdala volumes of patients with vaginismus with those of healthy control subjects. Magnetic resonance imaging was performed on ten patients with vaginismus and ten control subjects matched for age and gender. Volumes of the hippocampus and amygdala were blindly measured. We found that the mean right amygdala volume of patients with vaginismus were smaller than that of the healthy controls. With regard to hippocampus volumes, the mean left and right hippocampus volumes were smaller than those of the healthy controls. Our present findings suggest that there have been hippocampus and amygdala structural abnormalities in patients with vaginismus. These changes provide the notion that vaginismus may be a fear-related condition.

Three-dimensional MRI perfusion maps: a step beyond volumetric analysis in mental disorders

PubMed Central

Fabene, Paolo F; Farace, Paolo; Brambilla, Paolo; Andreone, Nicola; Cerini, Roberto; Pelizza, Luisa; Versace, Amelia; Rambaldelli, Gianluca; Birbaumer, Niels; Tansella, Michele; Sbarbati, Andrea

2007-01-01

A new type of magnetic resonance imaging analysis, based on fusion of three-dimensional reconstructions of time-to-peak parametric maps and high-resolution T1-weighted images, is proposed in order to evaluate the perfusion of selected volumes of interest. Because in recent years a wealth of data have suggested the crucial involvement of vascular alterations in mental diseases, we tested our new method on a restricted sample of schizophrenic patients and matched healthy controls. The perfusion of the whole brain was compared with that of the caudate nucleus by means of intrasubject analysis. As expected, owing to the encephalic vascular pattern, a significantly lower time-to-peak was observed in the caudate nucleus than in the whole brain in all healthy controls, indicating that the suggested method has enough sensitivity to detect subtle perfusion changes even in small volumes of interest. Interestingly, a less uniform pattern was observed in the schizophrenic patients. The latter finding needs to be replicated in an adequate number of subjects. In summary, the three-dimensional analysis method we propose has been shown to be a feasible tool for revealing subtle vascular changes both in normal subjects and in pathological conditions. PMID:17229290

WaferOptics® mass volume production and reliability

NASA Astrophysics Data System (ADS)

Wolterink, E.; Demeyer, K.

2010-05-01

The Anteryon WaferOptics® Technology platform contains imaging optics designs, materials, metrologies and combined with wafer level based Semicon & MEMS production methods. WaferOptics® first required complete new system engineering. This system closes the loop between application requirement specifications, Anteryon product specification, Monte Carlo Analysis, process windows, process controls and supply reject criteria. Regarding the Anteryon product Integrated Lens Stack (ILS), new design rules, test methods and control systems were assessed, implemented, validated and customer released for mass production. This includes novel reflowable materials, mastering process, replication, bonding, dicing, assembly, metrology, reliability programs and quality assurance systems. Many of Design of Experiments were performed to assess correlations between optical performance parameters and machine settings of all process steps. Lens metrologies such as FFL, BFL, and MTF were adapted for wafer level production and wafer mapping was introduced for yield management. Test methods for screening and validating suitable optical materials were designed. Critical failure modes such as delamination and popcorning were assessed and modeled with FEM. Anteryon successfully managed to integrate the different technologies starting from single prototypes to high yield mass volume production These parallel efforts resulted in a steep yield increase from 30% to over 90% in a 8 months period.

A new methodological approach to assess cardiac work by pressure-volume and stress-length relations in patients with aortic valve stenosis and dilated cardiomyopathy.

PubMed

Alter, P; Rupp, H; Rominger, M B; Klose, K J; Maisch, B

2008-01-01

In experimental animals, cardiac work is derived from pressure-volume area and analyzed further using stress-length relations. Lack of methods for determining accurately myocardial mass has until now prevented the use of stress-length relations in patients. We hypothesized, therefore, that not only pressure-volume loops but also stress-length diagrams can be derived from cardiac volume and cardiac mass as assessed by cardiac magnetic resonance imaging (CMR) and invasively measured pressure. Left ventricular (LV) volume and myocardial mass were assessed in seven patients with aortic valve stenosis (AS), eight with dilated cardiomyopathy (DCM), and eight controls using electrocardiogram (ECG)-gated CMR. LV pressure was measured invasively. Pressure-volume curves were calculated based on ECG triggering. Stroke work was assessed as area within the pressure-volume loop. LV wall stress was calculated using a thick-wall sphere model. Similarly, stress-length loops were calculated to quantify stress-length-based work. Taking the LV geometry into account, the normalization with regard to ventricular circumference resulted in "myocardial work." Patients with AS (valve area 0.73+/-0.18 cm(2)) exhibited an increased LV myocardial mass when compared with controls (P<0.05). LV wall stress was increased in DCM but not in AS. Stroke work of AS was unchanged when compared with controls (0.539+/-0.272 vs 0.621+/-0.138 Nm, not significant), whereas DCM exhibited a significant depression (0.367+/-0.157 Nm, P<0.05). Myocardial work was significantly reduced in both AS and DCM when compared with controls (129.8+/-69.6, 200.6+/-80.1, 332.2+/-89.6 Nm/m(2), P<0.05), also after normalization (7.40+/-5.07, 6.27+/-3.20, 14.6+/-4.07 Nm/m(2), P<0.001). It is feasible to obtain LV pressure-volume and stress-length diagrams in patients based on the present novel methodological approach of using CMR and invasive pressure measurement. Myocardial work was reduced in patients with DCM and noteworthy also in AS, while stroke work was reduced in DCM only. Most likely, deterioration of myocardial work is crucial for the prognosis. It is suggested to include these basic physiological procedures in the clinical assessment of the pump function of the heart.

Aseptic minimum volume vitrification technique for porcine parthenogenetically activated blastocyst.

PubMed

Lin, Lin; Yu, Yutao; Zhang, Xiuqing; Yang, Huanming; Bolund, Lars; Callesen, Henrik; Vajta, Gábor

2011-01-01

Minimum volume vitrification may provide extremely high cooling and warming rates if the sample and the surrounding medium contacts directly with the respective liquid nitrogen and warming medium. However, this direct contact may result in microbial contamination. In this work, an earlier aseptic technique was applied for minimum volume vitrification. After equilibration, samples were loaded on a plastic film, immersed rapidly into factory derived, filter-sterilized liquid nitrogen, and sealed into sterile, pre-cooled straws. At warming, the straw was cut, the filmstrip was immersed into a 39 degree C warming medium, and the sample was stepwise rehydrated. Cryosurvival rates of porcine blastocysts produced by parthenogenetical activation did not differ from control, vitrified blastocysts with Cryotop. This approach can be used for minimum volume vitrification methods and may be suitable to overcome the biological dangers and legal restrictions that hamper the application of open vitrification techniques.

Spray Characterization of Ultra-Low-Volume Sprayers Typically Used in Vector Control

DTIC Science & Technology

2009-01-01

Standard test method for determining liquid drop size characteristics in a spray using optical nonimaging light-scattering instruments. An- nual book of...cloud was directed through the optical path of the laser varied between sprayers, depending on the width of the spray 1 Mention of a trademark

Statistical control in hydrologic forecasting.

Treesearch

H.G. Wilm

1950-01-01

With rapidly growing development and uses of water, a correspondingly great demand has developed for advance estimates of the volumes or rates of flow which are supplied by streams. Therefore much attention is being devoted to hydrologic forecasting, and numerous methods have been tested in efforts to make increasingly reliable estimates of future supplies.

76 FR 70833 - National Emission Standards for Hazardous Air Pollutant Emissions for Primary Lead Processing

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-15

... Classification System. \\2\\ Maximum Achievable Control Technology. Table 2 is not intended to be exhaustive, but..., methods, systems, or techniques that reduce the volume of or eliminate HAP emissions through process changes, substitution of materials, or other modifications; enclose systems or processes to eliminate...

Evaluating the Accuracy of Common Runoff Estimation Methods for New Impervious Hot-Mix Asphalt

EPA Science Inventory

Accurately predicting runoff volume from impervious surfaces for water quality design events (e.g., 25.4 mm) is important for sizing green infrastructure stormwater control measures to meet water quality and infiltration design targets. The objective of this research was to quan...

Method for applying group selection in central Appalachian hardwoods

Treesearch

Gary W. Miller; Thomas M. Schuler; H. Clay Smith

1995-01-01

Public concern over the adverse visual impact of clearcutting has heightened interest in developing and testing alternative regeneration practices for central Appalachian hardwoods. Group selection can meet aesthetic goals while providing suitable light conditions to reproduce shade-intolerant species. Volume control and residual stand density are used to regulate...

Transient flow thrust prediction for an ejector propulsion concept

NASA Technical Reports Server (NTRS)

Drummond, Colin K.

1989-01-01

A method for predicting transient thrust augmenting ejector characteristics is introduced. The analysis blends classic self-similar turbulent jet descriptions with a mixing region control volume analysis to predict transient effects in a new way. Details of the theoretical foundation, the solution algorithm, and sample calculations are given.

Combination of microscopic model and VoF-multiphase approach for numerical simulation of nodular cast iron solidification

NASA Astrophysics Data System (ADS)

Subasic, E.; Huang, C.; Jakumeit, J.; Hediger, F.

2015-06-01

The ongoing increase in the size and capacity of state-of-the-art wind power plants is highlighting the need to reduce the weight of critical components, such as hubs, main shaft bearing housings, gear box housings and support bases. These components are manufactured as nodular iron castings (spheroid graphite iron, or SGI). A weight reduction of up to 20% is achievable by optimizing the geometry to minimize volume, thus enabling significant downsizing of wind power plants. One method for enhancing quality control in the production of thick-walled SGI castings, and thus reducing tolerances and, consequently, enabling castings of smaller volume is via a casting simulation of mould filling and solidification based on a combination of microscopic model and VoF-multiphase approach. Coupled fluid flow with heat transport and phase transformation kinetics during solidification is described by partial differential equations and solved using the finite volume method. The flow of multiple phases is described using a volume of fluid approach. Mass conservation equations are solved separately for both liquid and solid phases. At the micro-level, the diffusion-controlled growth model for grey iron eutectic grains by Wetterfall et al. is combined with a growth model for white iron eutectic grains. The micro-solidification model is coupled with macro-transport equations via source terms in the energy and continuity equations. As a first step the methodology was applied to a simple geometry to investigate the impact of mould-filling on the grey-to-white transition prediction in nodular cast iron.

Simulating effects of brain atrophy in longitudinal PET imaging with an anthropomorphic brain phantom

NASA Astrophysics Data System (ADS)

Jonasson, L. S.; Axelsson, J.; Riklund, K.; Boraxbekk, C. J.

2017-07-01

In longitudinal positron emission tomography (PET), the presence of volumetric changes over time can lead to an overestimation or underestimation of the true changes in the quantified PET signal due to the partial volume effect (PVE) introduced by the limited spatial resolution of existing PET cameras and reconstruction algorithms. Here, a 3D-printed anthropomorphic brain phantom with attachable striata in three sizes was designed to enable controlled volumetric changes. Using a method to eliminate the non-radioactive plastic wall, and manipulating BP levels by adding different number of events from list-mode acquisitions, we investigated the artificial volume dependence of BP due to PVE, and potential bias arising from varying BP. Comparing multiple reconstruction algorithms we found that a high-resolution ordered-subsets maximization algorithm with spatially variant point-spread function resolution modeling provided the most accurate data. For striatum, the BP changed by 0.08% for every 1% volume change, but for smaller volumes such as the posterior caudate the artificial change in BP was as high as 0.7% per 1% volume change. A simple gross correction for striatal volume is unsatisfactory, as the amplitude of the PVE on the BP differs depending on where in the striatum the change occurred. Therefore, to correctly interpret age-related longitudinal changes in the BP, we must account for volumetric changes also within a structure, rather than across the whole volume. The present 3D-printing technology, combined with the wall removal method, can be implemented to gain knowledge about the predictable bias introduced by the PVE differences in uptake regions of varying shape.

Evaluation of Intersection Traffic Control Measures through Simulation

NASA Astrophysics Data System (ADS)

Asaithambi, Gowri; Sivanandan, R.

2015-12-01

Modeling traffic flow is stochastic in nature due to randomness in variables such as vehicle arrivals and speeds. Due to this and due to complex vehicular interactions and their manoeuvres, it is extremely difficult to model the traffic flow through analytical methods. To study this type of complex traffic system and vehicle interactions, simulation is considered as an effective tool. Application of homogeneous traffic models to heterogeneous traffic may not be able to capture the complex manoeuvres and interactions in such flows. Hence, a microscopic simulation model for heterogeneous traffic is developed using object oriented concepts. This simulation model acts as a tool for evaluating various control measures at signalized intersections. The present study focuses on the evaluation of Right Turn Lane (RTL) and Channelised Left Turn Lane (CLTL). A sensitivity analysis was performed to evaluate RTL and CLTL by varying the approach volumes, turn proportions and turn lane lengths. RTL is found to be advantageous only up to certain approach volumes and right-turn proportions, beyond which it is counter-productive. CLTL is found to be advantageous for lower approach volumes for all turn proportions, signifying the benefits of CLTL. It is counter-productive for higher approach volume and lower turn proportions. This study pinpoints the break-even points for various scenarios. The developed simulation model can be used as an appropriate intersection lane control tool for enhancing the efficiency of flow at intersections. This model can also be employed for scenario analysis and can be valuable to field traffic engineers in implementing vehicle-type based and lane-based traffic control measures.

SU-E-T-287: Dose Verification On the Variation of Target Volume and Organ at Risk in Preradiation Chemotherapy IMRT for Nasopharyngeal Cancer

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

Zhang, X; Kong, L; Wang, J

2015-06-15

Purpose: To quantify the target volume and organ at risk of nasopharyngeal carcinoma (NPC) patients with preradiation chemotherapy based on CT scanned during intensity-modulated radiotherapy (IMRT), and recalculate the dose distribution. Methods: Seven patients with NPC and preradiation chemotherapy, treated with IMRT (35 to 37 fractions) were reviewed. Repeat CT scanning was required to all of the patients during the radiotherapy, and the number of repeat CTs varies from 2 to 6. The plan CT and repeat CT were generated by different CT scanner. To ensure crespectively on the same IMPT plan. The real dose distribution was calculated by deformablemore » registration and weighted method in Raystation (v 4.5.1). The fraction of each dose is based on radiotherapy record. The volumetric and dose differences among these images were calculated for nascIpharyngeal tumor and retro-pharyngeal lymph nodes (GTV-NX), neck lymph nodes(GTV-ND), and parotid glands. Results: The volume variation in GTV-NX from CT1 to CT2 was 1.15±3.79%, and in GTV-LN −0.23±4.93%. The volume variation in left parotid from CT1 to CT2 was −6.79±11.91%, and in right parotid −3.92±8.80%. In patient 2, the left parotid volume were decreased remarkably, as a Result, the V30 and V40 of it were increased as well. Conclusion: The target volume of patients with NPC varied lightly during IMRT. It shows that preradiation chemotherapy can control the target volume variation and perform a good dose repeatability. Also, the decreasing volume of parotid in some patient might increase the dose of it, which might course potential complications.« less

Towards and FVE-FAC Method for Determining Thermocapillary Effects on Weld Pool Shape

NASA Technical Reports Server (NTRS)

Canright, David; Henson, Van Emden

1996-01-01

Several practical materials processes, e.g., welding, float-zone purification, and Czochralski crystal growth, involve a pool of molten metal with a free surface, with strong temperature gradients along the surface. In some cases, the resulting thermocapillary flow is vigorous enough to convect heat toward the edges of the pool, increasing the driving force in a sort of positive feedback. In this work we examine this mechanism and its effect on the solid-liquid interface through a model problem: a half space of pure substance with concentrated axisymmetric surface heating, where surface tension is strong enough to keep the liquid free surface flat. The numerical method proposed for this problem utilizes a finite volume element (FVE) discretization in cylindrical coordinates. Because of the axisymmetric nature of the model problem, the control volumes used are torroidal prisms, formed by taking a polygonal cross-section in the (r, z) plane and sweeping it completely around the z-axis. Conservation of energy (in the solid), and conservation of energy, momentum, and mass (in the liquid) are enforced globally by integrating these quantities and enforcing conservation over each control volume. Judicious application of the Divergence Theorem and Stokes' Theorem, combined with a Crank-Nicolson time-stepping scheme leads to an implicit algebraic system to be solved at each time step. It is known that near the boundary of the pool, that is, near the solid-liquid interface, the full conduction-convection solution will require extremely fine length scales to resolve the physical behavior of the system. Furthermore, this boundary moves as a function of time. Accordingly, we develop the foundation of an adaptive refinement scheme based on the principles of Fast Adaptive Composite Grid methods (FAC). Implementation of the method and numerical results will appear in a later report.

Ammonia Volatilization Losses from Paddy Fields under Controlled Irrigation with Different Drainage Treatments

PubMed Central

He, Yupu; Yang, Shihong; Wang, Yijiang

2014-01-01

The effect of controlled drainage (CD) on ammonia volatilization (AV) losses from paddy fields under controlled irrigation (CI) was investigated by managing water table control levels using a lysimeter. Three drainage treatments were implemented, namely, controlled water table depth 1 (CWT1), controlled water table depth 2 (CWT2), and controlled water table depth 3 (CWT3). As the water table control levels increased, irrigation water volumes in the CI paddy fields decreased. AV losses from paddy fields reduced due to the increases in water table control levels. Seasonal AV losses from CWT1, CWT2, and CWT3 were 59.8, 56.7, and 53.0 kg N ha−1, respectively. AV losses from CWT3 were 13.1% and 8.4% lower than those from CWT1 and CWT2, respectively. A significant difference in the seasonal AV losses was confirmed between CWT1 and CWT3. Less weekly AV losses followed by TF and PF were also observed as the water table control levels increased. The application of CD by increasing water table control levels to a suitable level could effectively reduce irrigation water volumes and AV losses from CI paddy fields. The combination of CI and CD may be a feasible water management method of reducing AV losses from paddy fields. PMID:24741349

Ammonia volatilization losses from paddy fields under controlled irrigation with different drainage treatments.

PubMed

He, Yupu; Yang, Shihong; Xu, Junzeng; Wang, Yijiang; Peng, Shizhang

2014-01-01

The effect of controlled drainage (CD) on ammonia volatilization (AV) losses from paddy fields under controlled irrigation (CI) was investigated by managing water table control levels using a lysimeter. Three drainage treatments were implemented, namely, controlled water table depth 1 (CWT1), controlled water table depth 2 (CWT2), and controlled water table depth 3 (CWT3). As the water table control levels increased, irrigation water volumes in the CI paddy fields decreased. AV losses from paddy fields reduced due to the increases in water table control levels. Seasonal AV losses from CWT1, CWT2, and CWT3 were 59.8, 56.7, and 53.0 kg N ha(-1), respectively. AV losses from CWT3 were 13.1% and 8.4% lower than those from CWT1 and CWT2, respectively. A significant difference in the seasonal AV losses was confirmed between CWT1 and CWT3. Less weekly AV losses followed by TF and PF were also observed as the water table control levels increased. The application of CD by increasing water table control levels to a suitable level could effectively reduce irrigation water volumes and AV losses from CI paddy fields. The combination of CI and CD may be a feasible water management method of reducing AV losses from paddy fields.

Use of recycled chunk rubber asphalt concrete (CRAC) on low volume roads and use of recycled crumb rubber modifier in asphalt pavements. Final report, June 1993-June 1995

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

Hossain, M.; Funk, L.P.; Sadeq, M.A.

1995-06-01

The major objective of this project was to formulate a Chunk Rubber Asphalt Concrete (CRAC) mix for use on low volume roads. CRAC is a rubber modified asphalt concrete product produced by the `dry process` where rubber chunks of 1/2 inch size are used as aggregate in a cold mix with a type C fly ash. The second objective of this project was to develop guidelines concerning the use of rubber modified asphalt concrete hot mix to include: (1) Design methods for use of asphalt-rubber mix for new construction and overlay, (2) Mix design method for asphalt-rubber, and (3) Testmore » method for determining the amount of rubber in an asphalt-rubber concrete for quality control purposes.« less

Altered Volume, Morphology and Composition of the Pancreas in Type 2 Diabetes

PubMed Central

Macauley, Mavin; Percival, Katie; Thelwall, Peter E.; Hollingsworth, Kieren G.; Taylor, Roy

2015-01-01

Objective Although impairment in pancreatic insulin secretion is known to precede the clinical diagnosis of type 2 diabetes by up to a decade, fasting blood glucose concentration only rises abnormally once the impairment reaches a critical threshold. Despite its centrality to the pathogenesis of type 2 diabetes, the pancreas is the least studied organ due to its inaccessible anatomical position. Previous ultrasound and CT studies have suggested a possible decrease in pancreatic volume in type 2 diabetes. However, ultrasound techniques are relatively insensitive while CT uses ionizing radiation, making these modalities unsuitable for precise, longitudinal studies designed to explore the underlying mechanisms of type 2 diabetes. Hence there is a need to develop a non-invasive, safe and precise method to quantitate pancreas volume. Methods We developed and applied magnetic resonance imaging at 3.0T to obtain balanced turbo field echo (BTFE) structural images of the pancreas, together with 3-point Dixon images to quantify pancreatic triglyceride content. Pancreas volume, morphology and triglyceride content was quantified in a group of 41 subjects with well-controlled type 2 diabetes (HbA1c ≤ 7.6%) taking only metformin (duration of T2DM 5.7±0.7years), and a control group of 14 normal glucose tolerance subjects matched for age, weight and sex. Results The mean pancreatic volume was found to be 33% less in type 2 diabetes than in normal glucose tolerant subjects (55.5±2.8 vs. 82.6±4.8cm3; p<0.0001). Pancreas volume was positively correlated with HOMA-β in the type 2 diabetes subjects (r = 0.31; p = 0.03) and controls (r = 0.46; p = 0.05) considered separately; and in the whole population studied (r = 0.37; p = 0.003). In type 2 diabetes, the pancreas was typically involuted with a serrated border. Pancreatic triglyceride content was 23% greater (5.4±0.3 vs. 4.4±0.4%; p = 0.02) in the type 2 diabetes group. Conclusion This study describes for the first time gross abnormalities of the pancreas in early type 2 diabetes and quantifies the decrease in pancreas size, the irregular morphology and increase in fat content. PMID:25950180

A 3D freehand ultrasound system for multi-view reconstructions from sparse 2D scanning planes.

PubMed

Yu, Honggang; Pattichis, Marios S; Agurto, Carla; Beth Goens, M

2011-01-20

A significant limitation of existing 3D ultrasound systems comes from the fact that the majority of them work with fixed acquisition geometries. As a result, the users have very limited control over the geometry of the 2D scanning planes. We present a low-cost and flexible ultrasound imaging system that integrates several image processing components to allow for 3D reconstructions from limited numbers of 2D image planes and multiple acoustic views. Our approach is based on a 3D freehand ultrasound system that allows users to control the 2D acquisition imaging using conventional 2D probes.For reliable performance, we develop new methods for image segmentation and robust multi-view registration. We first present a new hybrid geometric level-set approach that provides reliable segmentation performance with relatively simple initializations and minimum edge leakage. Optimization of the segmentation model parameters and its effect on performance is carefully discussed. Second, using the segmented images, a new coarse to fine automatic multi-view registration method is introduced. The approach uses a 3D Hotelling transform to initialize an optimization search. Then, the fine scale feature-based registration is performed using a robust, non-linear least squares algorithm. The robustness of the multi-view registration system allows for accurate 3D reconstructions from sparse 2D image planes. Volume measurements from multi-view 3D reconstructions are found to be consistently and significantly more accurate than measurements from single view reconstructions. The volume error of multi-view reconstruction is measured to be less than 5% of the true volume. We show that volume reconstruction accuracy is a function of the total number of 2D image planes and the number of views for calibrated phantom. In clinical in-vivo cardiac experiments, we show that volume estimates of the left ventricle from multi-view reconstructions are found to be in better agreement with clinical measures than measures from single view reconstructions. Multi-view 3D reconstruction from sparse 2D freehand B-mode images leads to more accurate volume quantification compared to single view systems. The flexibility and low-cost of the proposed system allow for fine control of the image acquisition planes for optimal 3D reconstructions from multiple views.

A mature Bosch CO2 reduction technology. [for long-duration space missions

NASA Technical Reports Server (NTRS)

King, C. D.; Holmes, R. F.

1976-01-01

The reduction of CO2 is one of the steps in closing the oxygen loop for long-duration manned space missions. Several units utilizing the Bosch process, which catalytically reduces CO2 with hydrogen, have been built and operated during the past decade. Each contributed substantial information affecting subsequent designs. Early challenges were primarily concerned with carbon control, materials durability, and reliability of reaction initiation. These were followed by concern about power consumption, expendable weight, volume, and process rate control. Suitable materials and techniques for carbon containment and process reliability have been demonstrated. Power requirements have been reduced by almost an order of magnitude. Methods for significant reductions in expendable weight and volume have been developed. The technology is at a state of maturity directly applicable to designs for space missions.

The Impact of Tumor Size on Outcomes After Stereotactic Body Radiation Therapy for Medically Inoperable Early-Stage Non-Small Cell Lung Cancer

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

Allibhai, Zishan; Taremi, Mojgan; Bezjak, Andrea

2013-12-01

Purpose: Stereotactic body radiation therapy for medically inoperable early-stage non-small cell lung cancer (NSCLC) offers excellent control rates. Most published series deal mainly with small (usually <4 cm), peripheral, solitary tumors. Larger tumors are associated with poorer outcomes (ie, lower control rates, higher toxicity) when treated with conventional RT. It is unclear whether SBRT is sufficiently potent to control these larger tumors. We therefore evaluated and examined the influence of tumor size on treatment outcomes after SBRT. Methods and Materials: Between October 2004 and October 2010, 185 medically inoperable patients with early (T1-T2N0M0) NSCLC were treated on a prospective researchmore » ethics board-approved single-institution protocol. Prescription doses were risk-adapted based on tumor size and location. Follow-up included prospective assessment of toxicity (as per Common Terminology Criteria for Adverse Events, version 3.0) and serial computed tomography scans. Patterns of failure, toxicity, and survival outcomes were calculated using Kaplan-Meier method, and the significance of tumor size (diameter, volume) with respect to patient, treatment, and tumor factors was tested. Results: Median follow-up was 15.2 months. Tumor size was not associated with local failure but was associated with regional failure (P=.011) and distant failure (P=.021). Poorer overall survival (P=.001), disease-free survival (P=.001), and cause-specific survival (P=.005) were also significantly associated with tumor size (with tumor volume more significant than diameter). Gross tumor volume and planning target volume were significantly associated with grade 2 or worse radiation pneumonitis. However, overall rates of grade ≥3 pneumonitis were low and not significantly affected by tumor or target size. Conclusions: Currently employed stereotactic body radiation therapy dose regimens can provide safe effective local therapy even for larger solitary NSCLC tumors (up to 5.7 cm in tumor diameter or 100 cm{sup 3} in tumor volume) but are associated with more nonlocal failures as well as poorer survival. These observations suggest these patients may benefit from more extensive staging or consideration of adjuvant therapy.« less

Effect of Electroacupuncture on Visceral and Hepatic Fat in Women with Abdominal Obesity: A Randomized Controlled Study Based on Magnetic Resonance Imaging.

PubMed

Lei, Hong; Chen, Xiao; Liu, Shuyun; Chen, Zhenyan

2017-04-01

Visceral adipose tissue (VAT) and hepatic fat deposition are the most important risk factors for women's health. Acupuncture, including electroacupuncture (EA), is used to treat obesity throughout the world. The effect of EA is evaluated mainly by body mass index (BMI) and waist circumference (WC). Few studies have assessed its effect in reducing VAT volume and hepatic fat fraction (HFF) based on an exact measurement method such as magnetic resonance imaging (MRI). This study aimed to resolve this issue. Thirty subjects were randomly divided into two groups. The control group (n = 15) did not receive any intervention and maintained a normal diet and their usual exercise habits. The treatment group (n = 15) received EA three times a week for 3 months. BMI and WC were measured using different devices. VAT and HFF were measured by MRI and calculated by related software before and after the intervention. A marked difference was evident in group that received EA treatment in the following tests. The differences in BMI (U = 21.00, p < 0.001), WC (U = 40.50, p = 0.002), VAT volume (U = 13.00, p < 0.001), and mean HFF (U = 0.00, p < 0.001) before and after the intervention in the treatment group were distinct and significant compared with those of the control group. Three months later, the treatment group showed a lower BMI (W = 91.00, p = 0.001), WC (t = 4.755, p < 0.001), VAT volume (t = 5.164, p < 0.001), and mean HFF (W = 120.00, p = 0.001) compared with pretreatment levels. Compared with the control group, the treatment group showed a lower VAT volume (t = 60.00, p = 0.029) after 3 months of treatment. After 3 months, the control group showed higher mean HFF (t = -2.900, p = 0.012) and VAT volume (W = 11.50, p = 0.006) compared with their initial levels. Based on MRI evaluation, this randomized controlled study proved that EA treatment reduces BMI and WC as well as VAT volume and HFF in women with abdominal obesity.

Reinforcement of acrylic resins for provisional fixed restorations. Part III: effects of addition of titania and zirconia mixtures on some mechanical and physical properties.

PubMed

Panyayong, W; Oshida, Y; Andres, C J; Barco, T M; Brown, D T; Hovijitra, S

2002-01-01

Acrylic resins have been used in many different applications in dentistry, especially in the fabrication of provisional fixed partial dentures. Ideally, a provisional crown and bridge material should be easy to handle and should protect teeth against physical, chemical, and thermal injuries. Some of the problems associated with this use are related to the material's poor mechanical properties. It has been demonstrated that acrylic resin can be strengthened through the addition of structural component of different size distributed in the acrylic matrix, thus forming a composite structure. The purpose of this study was to investigate the addition effects of mixtures of titania (titanium dioxide, TiO(2)) powder and zirconia (zirconium dioxide, ZrO(2)) powder being incorporated with pre-polymerized beads mixed in monomer liquid, on some mechanical and physical properties of PMMA resin. The pre-polymerized powder poly(methyl methacrylate) resin was admixed with titania and zirconia powder. A mixing ratio was controlled by volume % of 0, 1.0, 2.0, and 3.0 (samples with 0 v/o served as control groups). For using mixture of titania and zirconia, total amount of the mixture was controlled by volume % of 1.0, 2.0, and 3.0, in which titania and zirconia were mixed at the ratio 1 :1, 1 :2 and 2 :1. Prior to mechanical tests, all rectangular-shaped samples (25 mm x 2 mm x 5 mm) were stored in 37 degrees C distilled water for 7 days after polishing all six sides of samples. Samples were then subjected to the three-point bending flexion test to evaluate the bending strength as well as the modulus of elasticity. Weight gain and exothermic reaction survey were investigated as well. All data were collected and analyzed with one-way analysis of variance (ANOVA) and Sidak method (p=0.05). It was found that the addition of particles generally decreased the water absorbed by the composite system. Only 1 percent by volume concentration of 1 :1 ratio and 2 percent by volume concentration of 1 :2 and 2 :1 ratios had significantly higher strength than control group. There was significantly higher toughness (in terms of energy-to-break) for 1 percent by volume concentration of 1 :1 ratio and 2 percent by volume concentration of 2 :1 ratio than control group. There was no significant difference between control group and all percent by volume combinations in modulus of elasticity. In addition, there was no significant variations of exothermic reaction.

Numerical simulation of immiscible viscous fingering using adaptive unstructured meshes

NASA Astrophysics Data System (ADS)

Adam, A.; Salinas, P.; Percival, J. R.; Pavlidis, D.; Pain, C.; Muggeridge, A. H.; Jackson, M.

2015-12-01

Displacement of one fluid by another in porous media occurs in various settings including hydrocarbon recovery, CO2 storage and water purification. When the invading fluid is of lower viscosity than the resident fluid, the displacement front is subject to a Saffman-Taylor instability and is unstable to transverse perturbations. These instabilities can grow, leading to fingering of the invading fluid. Numerical simulation of viscous fingering is challenging. The physics is controlled by a complex interplay of viscous and diffusive forces and it is necessary to ensure physical diffusion dominates numerical diffusion to obtain converged solutions. This typically requires the use of high mesh resolution and high order numerical methods. This is computationally expensive. We demonstrate here the use of a novel control volume - finite element (CVFE) method along with dynamic unstructured mesh adaptivity to simulate viscous fingering with higher accuracy and lower computational cost than conventional methods. Our CVFE method employs a discontinuous representation for both pressure and velocity, allowing the use of smaller control volumes (CVs). This yields higher resolution of the saturation field which is represented CV-wise. Moreover, dynamic mesh adaptivity allows high mesh resolution to be employed where it is required to resolve the fingers and lower resolution elsewhere. We use our results to re-examine the existing criteria that have been proposed to govern the onset of instability.Mesh adaptivity requires the mapping of data from one mesh to another. Conventional methods such as consistent interpolation do not readily generalise to discontinuous fields and are non-conservative. We further contribute a general framework for interpolation of CV fields by Galerkin projection. The method is conservative, higher order and yields improved results, particularly with higher order or discontinuous elements where existing approaches are often excessively diffusive.

A double-blind, randomized, placebo-controlled trial of itopride (100 and 200 mg three times daily) on gastric motor and sensory function in healthy volunteers.

PubMed

Choung, R S; Talley, N J; Peterson, J; Camilleri, M; Burton, D; Harmsen, W S; Zinsmeister, A R

2007-03-01

Itopride, a dopamine D2 antagonist and acetylcholinesterase inhibitor, significantly improved symptoms in patients with functional dyspepsia in one phase II randomized trial. However, the mechanisms by which itopride may improve symptoms are unknown. We aimed to compare the effects of two doses of itopride and placebo on gastric volumes, gastric emptying, small bowel transit and satiation in female and male healthy volunteers. Randomized, double-blind, placebo-controlled study evaluated gastric function before and after 7 days of itopride 100 mg (n = 16) or 200 mg (n = 15) or placebo (n = 15) t.i.d. Validated methods were used to study gastric accommodation (single photon emission computed tomography), gastric emptying and orocecal transit and satiation postnutrient challenge. The three arms were comparable with regard to age, gender and body mass index. There were no statistically significant effects of itopride on gastric emptying, orocecal transit, fasting gastric volume, maximum tolerated volume or aggregate symptom score with nutrient drink challenge. Postprandial (PP) change in gastric volume differed in the three groups (P = 0.019): 625[+/-28 (SEM)], 555(+/-26) and 512(+/-33) in placebo, itopride 100 and 200 mg groups, respectively. In healthy subjects, itopride reduced total PP gastric volume without accelerating gastric emptying or significantly altering gastric motor and sensory function in healthy individuals.

A chemical risk ranking and scoring method for the selection of harmful substances to be specially controlled in occupational environments.

PubMed

Shin, Saemi; Moon, Hyung-Il; Lee, Kwon Seob; Hong, Mun Ki; Byeon, Sang-Hoon

2014-11-20

This study aimed to devise a method for prioritizing hazardous chemicals for further regulatory action. To accomplish this objective, we chose appropriate indicators and algorithms. Nine indicators from the Globally Harmonized System of Classification and Labeling of Chemicals were used to identify categories to which the authors assigned numerical scores. Exposure indicators included handling volume, distribution, and exposure level. To test the method devised by this study, sixty-two harmful substances controlled by the Occupational Safety and Health Act in Korea, including acrylamide, acrylonitrile, and styrene were ranked using this proposed method. The correlation coefficients between total score and each indicator ranged from 0.160 to 0.641, and those between total score and hazard indicators ranged from 0.603 to 0.641. The latter were higher than the correlation coefficients between total score and exposure indicators, which ranged from 0.160 to 0.421. Correlations between individual indicators were low (-0.240 to 0.376), except for those between handling volume and distribution (0.613), suggesting that each indicator was not strongly correlated. The low correlations between each indicator mean that the indicators and independent and were well chosen for prioritizing harmful chemicals. This method proposed by this study can improve the cost efficiency of chemical management as utilized in occupational regulatory systems.

A moving control volume method for smooth computation of hydrodynamic forces and torques on immersed bodies

NASA Astrophysics Data System (ADS)

Nangia, Nishant; Patankar, Neelesh A.; Bhalla, Amneet P. S.

2017-11-01

Fictitious domain methods for simulating fluid-structure interaction (FSI) have been gaining popularity in the past few decades because of their robustness in handling arbitrarily moving bodies. Often the transient net hydrodynamic forces and torques on the body are desired quantities for these types of simulations. In past studies using immersed boundary (IB) methods, force measurements are contaminated with spurious oscillations due to evaluation of possibly discontinuous spatial velocity of pressure gradients within or on the surface of the body. Based on an application of the Reynolds transport theorem, we present a moving control volume (CV) approach to computing the net forces and torques on a moving body immersed in a fluid. The approach is shown to be accurate for a wide array of FSI problems, including flow past stationary and moving objects, Stokes flow, and high Reynolds number free-swimming. The approach only requires far-field (smooth) velocity and pressure information, thereby suppressing spurious force oscillations and eliminating the need for any filtering. The proposed moving CV method is not limited to a specific IB method and is straightforward to implement within an existing parallel FSI simulation software. This work is supported by NSF (Award Numbers SI2-SSI-1450374, SI2-SSI-1450327, and DGE-1324585), the US Department of Energy, Office of Science, ASCR (Award Number DE-AC02-05CH11231), and NIH (Award Number HL117163).

A comparison of five partial volume correction methods for Tau and Amyloid PET imaging with [18F]THK5351 and [11C]PIB.

PubMed

Shidahara, Miho; Thomas, Benjamin A; Okamura, Nobuyuki; Ibaraki, Masanobu; Matsubara, Keisuke; Oyama, Senri; Ishikawa, Yoichi; Watanuki, Shoichi; Iwata, Ren; Furumoto, Shozo; Tashiro, Manabu; Yanai, Kazuhiko; Gonda, Kohsuke; Watabe, Hiroshi

2017-08-01

To suppress partial volume effect (PVE) in brain PET, there have been many algorithms proposed. However, each methodology has different property due to its assumption and algorithms. Our aim of this study was to investigate the difference among partial volume correction (PVC) method for tau and amyloid PET study. We investigated two of the most commonly used PVC methods, Müller-Gärtner (MG) and geometric transfer matrix (GTM) and also other three methods for clinical tau and amyloid PET imaging. One healthy control (HC) and one Alzheimer's disease (AD) PET studies of both [ 18 F]THK5351 and [ 11 C]PIB were performed using a Eminence STARGATE scanner (Shimadzu Inc., Kyoto, Japan). All PET images were corrected for PVE by MG, GTM, Labbé (LABBE), Regional voxel-based (RBV), and Iterative Yang (IY) methods, with segmented or parcellated anatomical information processed by FreeSurfer, derived from individual MR images. PVC results of 5 algorithms were compared with the uncorrected data. In regions of high uptake of [ 18 F]THK5351 and [ 11 C]PIB, different PVCs demonstrated different SUVRs. The degree of difference between PVE uncorrected and corrected depends on not only PVC algorithm but also type of tracer and subject condition. Presented PVC methods are straight-forward to implement but the corrected images require careful interpretation as different methods result in different levels of recovery.

Automotive Stirling Engine Mod 1 Design Review, volume 2

NASA Technical Reports Server (NTRS)

1982-01-01

The auxiliaries and the control system for the ASE MOD I: (1) provide the required fuel and air flows for a well controlled combustion process, generating heat to the Stirling cycle; (2) provide a driver acceptable method for controlling the power output of the engine; (3) provide adequate lubrication and cooling water circulation; (4) generate the electric energy required for engine and vehicle operation; (5) provide a driver acceptable method for starting, stopping and monitoring the engine; and (6) provide a guard system, that protects the engine at component or system malfunction. The control principles and the way the different components and sub-systems interact are described as well as the different auxiliaries, the air fuel system, the power control systems and the electronics. The arrangement and location of auxiliaries and other major components are also examined.

10 CFR Appendix A1 to Subpart B of... - Uniform Test Method for Measuring the Energy Consumption of Electric Refrigerators and Electric...

Code of Federal Regulations, 2010 CFR

2010-01-01

... freezer compartment volume as defined in HRF-1-1979, in cubic feet. 1.3“Anti-sweat heater” means a device... operating characteristics. 1.7“Standard cycle” means the cycle type in which the anti-sweat heater control... unit under test. Defrost controls are to be operative and the anti-sweat heater switch is to be “on...

The Effect of Pressure-Controlled Ventilation and Volume-Controlled Ventilation in Prone Position on Pulmonary Mechanics and Inflammatory Markers.

PubMed

Şenay, Hasan; Sıvacı, Remziye; Kokulu, Serdar; Koca, Buğra; Bakı, Elif Doğan; Ela, Yüksel

2016-08-01

The aim of this present study is to compare the effect of pressure-controlled ventilation and volume-controlled ventilation on pulmonary mechanics and inflammatory markers in prone position. The study included 41 patients undergoing to vertebrae surgery. The patients were randomized into two groups: Group 1 received volume-controlled ventilation, while group 2 received pressure-controlled ventilation. The demographic data, pulmonary mechanics, the inflammatory marker levels just after the induction of anesthetics, at the 6th and 12th hours, and gas analysis from arterial blood samples taken at the beginning and the 30th minute were recorded. The inflammatory marker levels increased in both groups, without any significant difference among groups. Peak inspiratory pressure level was higher in the volume-controlled ventilation group. This study revealed that there is no difference regarding inflammatory marker levels between volume- and pressure-controlled ventilation.

Scan-based volume animation driven by locally adaptive articulated registrations.

PubMed

Rhee, Taehyun; Lewis, J P; Neumann, Ulrich; Nayak, Krishna S

2011-03-01

This paper describes a complete system to create anatomically accurate example-based volume deformation and animation of articulated body regions, starting from multiple in vivo volume scans of a specific individual. In order to solve the correspondence problem across volume scans, a template volume is registered to each sample. The wide range of pose variations is first approximated by volume blend deformation (VBD), providing proper initialization of the articulated subject in different poses. A novel registration method is presented to efficiently reduce the computation cost while avoiding strong local minima inherent in complex articulated body volume registration. The algorithm highly constrains the degrees of freedom and search space involved in the nonlinear optimization, using hierarchical volume structures and locally constrained deformation based on the biharmonic clamped spline. Our registration step establishes a correspondence across scans, allowing a data-driven deformation approach in the volume domain. The results provide an occlusion-free person-specific 3D human body model, asymptotically accurate inner tissue deformations, and realistic volume animation of articulated movements driven by standard joint control estimated from the actual skeleton. Our approach also addresses the practical issues arising in using scans from living subjects. The robustness of our algorithms is tested by their applications on the hand, probably the most complex articulated region in the body, and the knee, a frequent subject area for medical imaging due to injuries. © 2011 IEEE

Peripheral telomere length and hippocampal volume in adolescents with major depressive disorder.

PubMed

Henje Blom, E; Han, L K M; Connolly, C G; Ho, T C; Lin, J; LeWinn, K Z; Simmons, A N; Sacchet, M D; Mobayed, N; Luna, M E; Paulus, M; Epel, E S; Blackburn, E H; Wolkowitz, O M; Yang, T T

2015-11-10

Several studies have reported that adults with major depressive disorder have shorter telomere length and reduced hippocampal volumes. Moreover, studies of adult populations without major depressive disorder suggest a relationship between peripheral telomere length and hippocampal volume. However, the relationship of these findings in adolescents with major depressive disorder has yet to be explored. We examined whether adolescent major depressive disorder is associated with altered peripheral telomere length and hippocampal volume, and whether these measures relate to one another. In 54 unmedicated adolescents (13-18 years) with major depressive disorder and 63 well-matched healthy controls, telomere length was assessed from saliva using quantitative polymerase chain reaction methods, and bilateral hippocampal volumes were measured with magnetic resonance imaging. After adjusting for age and sex (and total brain volume in the hippocampal analysis), adolescents with major depressive disorder exhibited significantly shorter telomere length and significantly smaller right, but not left hippocampal volume. When corrected for age, sex, diagnostic group and total brain volume, telomere length was not significantly associated with left or right hippocampal volume, suggesting that these cellular and neural processes may be mechanistically distinct during adolescence. Our findings suggest that shortening of telomere length and reduction of hippocampal volume are already present in early-onset major depressive disorder and thus unlikely to be only a result of accumulated years of exposure to major depressive disorder.

Pancreatic Cysts in Autosomal Dominant Polycystic Kidney Disease: Prevalence and Association with PKD2 Gene Mutations.

PubMed

Kim, Jin Ah; Blumenfeld, Jon D; Chhabra, Shalini; Dutruel, Silvina P; Thimmappa, Nanda Deepa; Bobb, Warren O; Donahue, Stephanie; Rennert, Hanna E; Tan, Adrian Y; Giambrone, Ashley E; Prince, Martin R

2016-09-01

Purpose To define the magnetic resonance (MR) imaging prevalence of pancreatic cysts in a cohort of patients with autosomal dominant polycystic kidney disease (ADPKD) compared with a control group without ADPKD that was matched for age, sex, and renal function. Materials and Methods In this HIPAA-compliant, institutional review board-approved study, all patients with ADPKD provided informed consent; for control subjects, informed consent was waived. Patients with ADPKD (n = 110) with mutations identified in PKD1 or PKD2 and control subjects without ADPKD or known pancreatic disease (n = 110) who were matched for age, sex, estimated glomerular filtration rate, and date of MR imaging examination were evaluated for pancreatic cysts by using axial and coronal single-shot fast spin-echo T2-weighted images obtained at 1.5 T. Total kidney volume and liver volume were measured. Univariate and multivariable logistic regression analyses were conducted to evaluate potential associations between collected variables and presence of pancreatic cysts among patients with ADPKD. The number, size, location, and imaging characteristics of the cysts were recorded. Results Patients with ADPKD were significantly more likely than control subjects to have at least one pancreatic cyst (40 of 110 patients [36%] vs 25 of 110 control subjects [23%]; P = .027). In a univariate analysis, pancreatic cysts were more prevalent in patients with ADPKD with mutations in PKD2 than in PKD1 (21 of 34 patients [62%] vs 19 of 76 patients [25%]; P = .0002). In a multivariable logistic regression model, PKD2 mutation locus was significantly associated with the presence of pancreatic cysts (P = .0004) and with liver volume (P = .038). Patients with ADPKD and a pancreatic cyst were 5.9 times more likely to have a PKD2 mutation than a PKD1 mutation after adjusting for age, race, sex, estimated glomerular filtration rate, liver volume, and total kidney volume. Conclusion Pancreatic cysts were more prevalent in patients with ADPKD with PKD2 mutation than in control subjects or patients with PKD1 mutation. (©) RSNA, 2016 Online supplemental material is available for this article.

Structural changes of the corpus callosum in tinnitus

PubMed Central

Diesch, Eugen; Schummer, Verena; Kramer, Martin; Rupp, Andre

2012-01-01

Objectives: In tinnitus, several brain regions seem to be structurally altered, including the medial partition of Heschl's gyrus (mHG), the site of the primary auditory cortex. The mHG is smaller in tinnitus patients than in healthy controls. The corpus callosum (CC) is the main interhemispheric commissure of the brain connecting the auditory areas of the left and the right hemisphere. Here, we investigate whether tinnitus status is associated with CC volume. Methods: The midsagittal cross-sectional area of the CC was examined in tinnitus patients and healthy controls in which an examination of the mHG had been carried out earlier. The CC was extracted and segmented into subregions which were defined according to the most common CC morphometry schemes introduced by Witelson (1989) and Hofer and Frahm (2006). Results: For both CC segmentation schemes, the CC posterior midbody was smaller in male patients than in male healthy controls and the isthmus, the anterior midbody, and the genou were larger in female patients than in female controls. With CC size normalized relative to mHG volume, the normalized CC splenium was larger in male patients than male controls and the normalized CC splenium, the isthmus and the genou were larger in female patients than female controls. Normalized CC segment size expresses callosal interconnectivity relative to auditory cortex volume. Conclusion: It may be argued that the predominant function of the CC is excitatory. The stronger callosal interconnectivity in tinnitus patients, compared to healthy controls, may facilitate the emergence and maintenance of a positive feedback loop between tinnitus generators located in the two hemispheres. PMID:22470322

Demographic confounders in volumetric MRI analysis: is the posterior fossa really small in the adult Chiari 1 malformation?

PubMed

Roller, Lauren A; Bruce, Beau B; Saindane, Amit M

2015-04-01

Measurement of posterior fossa volume has been proposed to have diagnostic utility and physiologic significance in the Chiari malformation type 1. This study evaluated the effects of demographics on posterior fossa volume and total intracranial volume in adult control subjects, adult patients with Chiari malformation type 1, and adult patients with idiopathic intracranial hypertension, who may share some imaging features of patients with Chiari malformation type 1. Twenty-eight patients with Chiari malformation type 1, 21 patients with idiopathic intracranial hypertension, and 113 control subjects underwent brain MRI including contrast-enhanced 3D gradient-recalled echo (GRE) T1-weighted imaging. Linear measurements of the posterior fossa and intracranial space were obtained. Manual segmentation of the posterior fossa and intracranial space was performed to yield posterior fossa volume and total intracranial volume. Age, sex, race, and body mass index (weight in kilograms divided by the square of height in meters; BMI) were controlled for when comparing cohorts. Three of the 12 linear measurements significantly predicted total intracranial volume (accounting for 74% of variance), and four predicted posterior fossa volume (54% of variance). Age, race, sex, and BMI each statistically significantly influenced posterior fossa volume and total intracranial volume. No statistically significant differences in posterior fossa volume, total intracranial volume, or ratio of posterior fossa volume to total intracranial volume were seen between the Chiari malformation type 1 group and control group after controlling for demographics. Patients with idiopathic intracranial hypertension were more likely than control subjects to have smaller posterior fossa volumes (odds ratio [OR]=1.81; p=0.01) and larger total intracranial volumes (OR=1.24; p=0.06). Linear measurements of the posterior fossa are not strong predictors of posterior fossa volume. Age, race, sex, and BMI have statistically significant effects on intracranial measurements that must be considered, particularly with respect to posterior fossa volume in Chiari malformation type 1. Even when these demographic variables are appropriately accounted for, other similarly presenting diseases may show small posterior fossa volumes.

Iliopsoas and Gluteal Muscles Are Asymmetric in Tennis Players but Not in Soccer Players

PubMed Central

Sanchis-Moysi, Joaquin; Idoate, Fernando; Izquierdo, Mikel; Calbet, Jose A. L.; Dorado, Cecilia

2011-01-01

Purpose To determine the volume and degree of asymmetry of iliopsoas (IL) and gluteal muscles (GL) in tennis and soccer players. Methods IL and GL volumes were determined using magnetic resonance imaging (MRI) in male professional tennis (TP) and soccer players (SP), and in non-active control subjects (CG) (n = 8, 15 and 6, respectively). Results The dominant and non-dominant IL were hypertrophied in TP (24 and 36%, respectively, P<0.05) and SP (32 and 35%, respectively, P<0.05). In TP the asymmetric hypertrophy of IL (13% greater volume in the non-dominant than in the dominant IL, P<0.01) reversed the side-to-side relationship observed in CG (4% greater volume in the dominant than in the contralateral IL, P<0.01), whilst soccer players had similar volumes in both sides (P = 0.87). The degree of side-to-side asymmetry decreased linearly from the first lumbar disc to the pubic symphysis in TP (r = −0.97, P<0.001), SP (r = −0.85, P<0.01) and CG (r = −0.76, P<0.05). The slope of the relationship was lower in SP due to a greater hypertrophy of the proximal segments of the dominant IL. Soccer and CG had similar GL volumes in both sides (P = 0.11 and P = 0.19, for the dominant and contralateral GL, respectively). GL was asymmetrically hypertrophied in TP. The non-dominant GL volume was 20% greater in TP than in CG (P<0.05), whilst TP and CG had similar dominant GL volumes (P = 0.14). Conclusions Tennis elicits an asymmetric hypertrophy of IL and reverses the normal dominant-to-non-dominant balance observed in non-active controls, while soccer is associated to a symmetric hypertrophy of IL. Gluteal muscles are asymmetrically hypertrophied in TP, while SP display a similar size to that observed in controls. It remains to be determined whether the different patterns of IL and GL hypertrophy may influence the risk of injury. PMID:21829539

Larger men have larger prostates: Detection bias in epidemiologic studies of obesity and prostate cancer risk

PubMed Central

Rundle, Andrew; Wang, Yun; Sadasivan, Sudha; Chitale, Dhananjay A.; Gupta, Nilesh S.; Tang, Deliang; Rybicki, Benjamin A.

2017-01-01

BACKGROUND Obesity is associated with risk of aggressive prostate cancer (PCa), but not with over-all PCa risk. However, obese men have larger prostates which may lower biopsy accuracy and cause a systematic bias towards the null in epidemiologic studies of over-all risk. METHODS Within a cohort of 6,692 men followed-up after a biopsy or transurethral resection of the prostate (TURP) with benign findings, a nested case-control study was conducted of 495 prostate cancer cases and controls matched on age, race, follow-up duration, biopsy versus TURP and procedure date. Data on body mass index and prostate volume at the time of the initial procedure were abstracted from medical records. RESULTS Prior to consideration of differences in prostate volume, overweight (OR = 1.41; 95% CI 1.01, 1.97) and obese status (OR = 1.59; 95% CI 1.09, 2.33) at the time of the original benign biopsy or TURP were associated with PCa incidence during follow-up. Prostate volume did not significantly moderate the association between body-size and PCa, however it did act as an inverse confounder; adjustment for prostate volume increased the effect size for overweight by 22% (adjusted OR = 1.52; 95% CI 1.08, 2.14) and for obese status by 23% (adjusted OR = 1.77; 95% CI 1.20, 2.62). Larger prostate volume at the time of the original benign biopsy or TURP was inversely associated with PCa incidence during follow-up (OR = 0.92 per 10 cc difference in volume; 95% CI 0.88, 0.97). In analyses that stratified case-control pairs by tumor aggressiveness of the case, prostate volume acted as an inverse confounder in analyses of non-aggressive PCa but not in analyses of aggressive PCa. CONCLUSIONS In studies of obesity and PCa, differences in prostate volume cause a bias towards the null, particularly in analyses of non-aggressive PCa. A pervasive underestimation of the association between obesity and overall PCa risk may exist in the literature. PMID:28349547

[Method of detection of residual tissues in recurrent operations on the thyroid gland].

PubMed

Gostimskiĭ, A V; Romanchishen, A F; Zaĭtseva, I V; Kuznetsova, Iu V

2014-01-01

A search of residual tissues is complicated in recurrent operations on the thyroid gland. The Saint-Petersburg Centre of Surgery of the Endocrine System and Oncology developed the method of detection of residual tissues of the thyroid gland with the aim of preoperative chromothyroidolymphography under control of ultrasound. The method consisted of US performance during 15-20 minutes before the operation and an introduction of 1% sterile water solution of methylene blue in revealed residual tissues of the thyroid gland. The volume of injected coloring agent was 0.5-2 ml in the residual tissue volume smaller than 9 cm3 and 2-3 ml injected in case of more than 9 cm3. The residual tissues of the thyroid gland accurately visualized during the following operation. Described method gives the possibility to detect all regions of residual tissues which should be removed and at the same time it shortens a revision and surgery trauma.

Development of Methodology and Technology for Identifying and Quantifying Emission Products from Open Burning and Open Detonation Thermal Treatment Methods. Field Test Series A, B, and C. Volume 2, Part B. Quality Assurance and Quality Control. Appendices

DTIC Science & Technology

1992-01-01

the uncertainty. The above method can give an estimate of the precision of the * analysis. However, determining the accuracy can not be done as...speciation has been determined from analyzing model samples as well as comparison with other methods and combinations of other methods with this method . 3...laboratory. The output of the sensor is characterized over its working range and an appropriate response factor determined by linear regression of the

Quantification of sweat gland volume and innervation in neuropathy: Correlation with thermoregulatory sweat testing.

PubMed

Loavenbruck, Adam; Wendelschaefer-Crabbe, Gwen; Sandroni, Paola; Kennedy, William R

2014-10-01

No study has correlated thermoregulatory sweat testing (TST) with histopathologic study of sweat glands (SGs) and SG nerve fibers (SGNFs). We studied 10 neuropathy patients in whom anhidrosis was found by TST and 10 matched controls. Skin biopsies were taken from both anhidrotic and sweating skin and immunohistochemical staining was done for nerves and basement membrane. For each biopsy, total tissue volume, total SG volume, and total SGNF length were measured. SGNF length per biopsy volume, SG volume per biopsy volume (SG%), and SGNF length per SG volume were calculated. SGNF length per biopsy volume was reduced in anhidrotic site biopsies of patients compared with controls. SG% was decreased and SGNF length per SG volume increased in patients compared with controls. The results suggest a concomitant loss of SG volume and SGNF length in neuropathy, with greater loss of SGNFs in anhidrotic skin, possibly exceeding collateral reinnervation. Copyright © 2014 Wiley Periodicals, Inc.

Water quality management library. 2. edition

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

Eckenfelder, W.W.; Malina, J.F.; Patterson, J.W.

1998-12-31

A series of ten books offered in conjunction with Water Quality International, the Biennial Conference and Exposition of the International Association on Water Pollution Research and Control (IAWPRC). Volume 1, Activated Sludge Process, Design and Control, 2nd edition, 1998: Volume 2, Upgrading Wastewater Treatment Plants, 2nd edition, 1998: Volume 3, Toxicity Reduction, 2nd edition, 1998: Volume 4, Municipal Sewage Sludge Management, 2nd edition, 1998: Volume 5, Design and Retrofit of Wastewater Treatment Plants for Biological Nutrient Removal, 1st edition, 1992: Volume 6, Dynamics and Control of the Activated Sludge Process, 2nd edition, 1998: Volume 7: Design of Anaerobic Processes formore » the Treatment of Industrial and Municipal Wastes, 1st edition, 1992: Volume 8, Groundwater Remediation, 1st edition, 1992: Volume 9, Nonpoint Pollution and Urban Stormwater Management, 1st edition, 1995: Volume 10, Wastewater Reclamation and Reuse, 1st edition, 1998.« less

High-pressure-assisted synthesis of high-volume ZnGeP2 polycrystalline

NASA Astrophysics Data System (ADS)

Huang, Changbao; Wu, Haixin; Xiao, Ruichun; Chen, Shijing; Ma, Jiaren

2018-06-01

The pnictide and chalcogenide semiconductors are promising materials for the applications in the field of photoelectric. High-purity and high-volume polycrystalline required in the real-world applications is hard to be synthesized due to the high vapor pressure of phosphorus and sulfur components at high temperature. A new high-pressure-resisted method was used to investigate the synthesis of the nonlinear-optical semiconductor ZnGeP2. The high-purity ZnGeP2 polycrystalline material of approximately 500 g was synthesized in one run, which enables the preparation of nominally stoichiometric material. Since increasing internal pressure resistance of quartz crucible and reducing the reaction space, the high-pressure-resisted method can be used to rapidly synthesize other pnictide and chalcogenide semiconductors and control the components ratio.

Data acquisition and processing system and method for investigating sub-surface features of a rock formation

DOEpatents

Vu, Cung Khac; Nihei, Kurt; Johnson, Paul A; Guyer, Robert; Ten Cate, James A; Le Bas, Pierre-Yves; Larmat, Carene S

2015-01-27

A system and a method includes generating a first signal at a first frequency; and a second signal at a second frequency. Respective sources are positioned within the borehole and controllable such that the signals intersect in an intersection volume outside the borehole. A receiver detects a difference signal returning to the borehole generated by a non-linear mixing process within the intersection volume, and records the detected signal and stores the detected signal in a storage device and records measurement parameters including a position of the first acoustic source, a position of the second acoustic source, a position of the receiver, elevation angle and azimuth angle of the first acoustic signal and elevation angle and azimuth angle of the second acoustic signal.

Five methods of breast volume measurement: a comparative study of measurements of specimen volume in 30 mastectomy cases.

PubMed

Kayar, Ragip; Civelek, Serdar; Cobanoglu, Murat; Gungor, Osman; Catal, Hidayet; Emiroglu, Mustafa

2011-03-27

To compare breast volume measurement techniques in terms of accuracy, convenience, and cost. Breast volumes of 30 patients who were scheduled to undergo total mastectomy surgery were measured preoperatively by using five different methods (mammography, anatomic [anthropometric], thermoplastic casting, the Archimedes procedure, and the Grossman-Roudner device). Specimen volume after total mastectomy was measured in each patient with the water displacement method (Archimedes). The results were compared statistically with the values obtained by the five different methods. The mean mastectomy specimen volume was 623.5 (range 150-1490) mL. The breast volume values were established to be 615.7 mL (r = 0.997) with the mammographic method, 645.4 mL (r = 0.975) with the anthropometric method, 565.8 mL (r = 0.934) with the Grossman-Roudner device, 583.2 mL (r = 0.989) with the Archimedes procedure, and 544.7 mL (r = 0.94) with the casting technique. Examination of r values revealed that the most accurate method was mammography for all volume ranges, followed by the Archimedes method. The present study demonstrated that the most accurate method of breast volume measurement is mammography, followed by the Archimedes method. However, when patient comfort, ease of application, and cost were taken into consideration, the Grossman-Roudner device and anatomic measurement were relatively less expensive, and easier methods with an acceptable degree of accuracy.

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

Patel, Pretesh R., E-mail: patel073@mc.duke.edu; Yoo, Sua; Broadwater, Gloria

Purpose: To assess the impact of increasing experience with intensity-modulated radiation therapy (IMRT) after extrapleural pneumonectomy (EPP) for malignant pleural mesothelioma (MPM). Methods and Materials: The records of all patients who received IMRT following EPP at Duke University Medical Center between 2005 and 2010 were reviewed. Target volumes included the preoperative extent of the pleural space, chest wall incisions, involved nodal stations, and a boost to close/positive surgical margins if applicable. Patients were typically treated with 9-11 beams with gantry angles, collimator rotations, and beam apertures manually fixed to avoid the contalateral lung and to optimize target coverage. Toxicity wasmore » graded retrospectively using National Cancer Institute common toxicity criteria version 4.0. Target coverage and contralateral lung irradiation were evaluated over time by using linear regression. Local control, disease-free survival, and overall survival rates were estimated using the Kaplan-Meier method. Results: Thirty patients received IMRT following EPP; 21 patients also received systemic chemotherapy. Median follow-up was 15 months. The median dose prescribed to the entire ipsilateral hemithorax was 45 Gy (range, 40-50.4 Gy) with a boost of 8-25 Gy in 9 patients. Median survival was 23.2 months. Two-year local control, disease-free survival, and overall survival rates were 47%, 34%, and 50%, respectively. Increasing experience planning MPM cases was associated with improved coverage of planning target volumes (P=.04). Similarly, mean lung dose (P<.01) and lung V5 (volume receiving 5 Gy or more; P<.01) values decreased with increasing experience. Lung toxicity developed after IMRT in 4 (13%) patients at a median of 2.2 months after RT (three grade 3-4 and one grade 5). Lung toxicity developed in 4 of the initial 15 patients vs none of the last 15 patients treated. Conclusions: With increasing experience, target volume coverage improved and dose to the contralateral lung decreased. Rates of pulmonary toxicity were relatively low. However, both local and distant control rates remained suboptimal.« less

Environmental Validation of Legionella Control in a VHA Facility Water System.

PubMed

Jinadatha, Chetan; Stock, Eileen M; Miller, Steve E; McCoy, William F

2018-03-01

OBJECTIVES We conducted this study to determine what sample volume, concentration, and limit of detection (LOD) are adequate for environmental validation of Legionella control. We also sought to determine whether time required to obtain culture results can be reduced compared to spread-plate culture method. We also assessed whether polymerase chain reaction (PCR) and in-field total heterotrophic aerobic bacteria (THAB) counts are reliable indicators of Legionella in water samples from buildings. DESIGN Comparative Legionella screening and diagnostics study for environmental validation of a healthcare building water system. SETTING Veterans Health Administration (VHA) facility water system in central Texas. METHODS We analyzed 50 water samples (26 hot, 24 cold) from 40 sinks and 10 showers using spread-plate cultures (International Standards Organization [ISO] 11731) on samples shipped overnight to the analytical lab. In-field, on-site cultures were obtained using the PVT (Phigenics Validation Test) culture dipslide-format sampler. A PCR assay for genus-level Legionella was performed on every sample. RESULTS No practical differences regardless of sample volume filtered were observed. Larger sample volumes yielded more detections of Legionella. No statistically significant differences at the 1 colony-forming unit (CFU)/mL or 10 CFU/mL LOD were observed. Approximately 75% less time was required when cultures were started in the field. The PCR results provided an early warning, which was confirmed by spread-plate cultures. The THAB results did not correlate with Legionella status. CONCLUSIONS For environmental validation at this facility, we confirmed that (1) 100 mL sample volumes were adequate, (2) 10× concentrations were adequate, (3) 10 CFU/mL LOD was adequate, (4) in-field cultures reliably reduced time to get results by 75%, (5) PCR provided a reliable early warning, and (6) THAB was not predictive of Legionella results. Infect Control Hosp Epidemiol 2018;39:259-266.

Liposuction: Anaesthesia challenges

PubMed Central

Sood, Jayashree; Jayaraman, Lakshmi; Sethi, Nitin

2011-01-01

Liposuction is one of the most popular treatment modalities in aesthetic surgery with certain unique anaesthetic considerations. Liposuction is often performed as an office procedure. There are four main types of liposuction techniques based on the volume of infiltration or wetting solution injected, viz dry, wet, superwet, and tumescent technique. The tumescent technique is one of the most common liposuction techniques in which large volumes of dilute local anaesthetic (wetting solution) are injected into the fat to facilitate anaesthesia and decrease blood loss. The amount of lignocaine injected may be very large, approximately 35-55 mg/kg, raising concerns regarding local anaesthetic toxicity. Liposuction can be of two types according to the volume of solution aspirated: High volume (>4,000 ml aspirated) or low volume (<4,000 ml aspirated). While small volume liposuction may be done under local/monitored anaesthesia care, large-volume liposuction requires general anaesthesia. As a large volume of wetting solution is injected into the subcutaneous tissue, the intraoperative fluid management has to be carefully titrated along with haemodynamic monitoring and temperature control. Assessment of blood loss is difficult, as it is mixed with the aspirated fat. Since most obese patients opt for liposuction as a quick method to lose weight, all concerns related to obesity need to be addressed in a preoperative evaluation. PMID:21808392

A Novel Method to Compute Breathing Volumes via Motion Capture Systems: Design and Experimental Trials.

PubMed

Massaroni, Carlo; Cassetta, Eugenio; Silvestri, Sergio

2017-10-01

Respiratory assessment can be carried out by using motion capture systems. A geometrical model is mandatory in order to compute the breathing volume as a function of time from the markers' trajectories. This study describes a novel model to compute volume changes and calculate respiratory parameters by using a motion capture system. The novel method, ie, prism-based method, computes the volume enclosed within the chest by defining 82 prisms from the 89 markers attached to the subject chest. Volumes computed with this method are compared to spirometry volumes and to volumes computed by a conventional method based on the tetrahedron's decomposition of the chest wall and integrated in a commercial motion capture system. Eight healthy volunteers were enrolled and 30 seconds of quiet breathing data collected from each of them. Results show a better agreement between volumes computed by the prism-based method and the spirometry (discrepancy of 2.23%, R 2  = .94) compared to the agreement between volumes computed by the conventional method and the spirometry (discrepancy of 3.56%, R 2  = .92). The proposed method also showed better performances in the calculation of respiratory parameters. Our findings open up prospects for the further use of the new method in the breathing assessment via motion capture systems.

CT-based Diagnosis of Diffuse Coronary Artery Disease on the Basis of Scaling Power Laws

PubMed Central

Huo, Yunlong; Wischgoll, Thomas; Choy, Jenny Susana; Sola, Srikanth; Navia, Jose L.; Teague, Shawn D.; Bhatt, Deepak L.

2013-01-01

Purpose: To provide proof of concept for a diagnostic method to assess diffuse coronary artery disease (CAD) on the basis of coronary computed tomography (CT) angiography. Materials and Methods: The study was approved by the Cleveland Clinic Institutional Review Board, and all subjects gave informed consent. Morphometric data from the epicardial coronary artery tree, determined with CT angiography in 120 subjects (89 patients with metabolic syndrome and 31 age- and sex-matched control subjects) were analyzed on the basis of the scaling power law. Results obtained in patients with metabolic syndrome and control subjects were compared statistically. Results: The mean lumen cross-sectional area (ie, lumen cross-sectional area averaged over each vessel of an epicardial coronary artery tree) and sum of intravascular volume in patients with metabolic syndrome (0.039 cm2 ± 0.015 [standard deviation] and 2.71 cm3 ± 1.75, respectively) were significantly less than those in control subjects (0.054 cm2± 0.015 and 3.29 cm3± 1.77, respectively; P < .05). The length-volume power law showed coefficients of 27.0 cm−4/3 ± 9.0 (R2 = 0.91 ± 0.08) for patients with metabolic syndrome and 19.9 cm−4/3 ± 4.3 (R2 = 0.92 ± 0.07) for control subjects (P < .05). The probability frequency shows that more than 65% of patients with metabolic syndrome had a coefficient of 23 or more for the length-volume scaling power law, whereas approximately 90% of the control subjects had a coefficient of less than 23. Conclusion: The retrospective scaling analysis provides a quantitative rationale for diagnosis of diffuse CAD. © RSNA, 2013 Supplemental material: http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.13122181/-/DC1 PMID:23616633

A Comparison of Height-Accumulation and Volume-Equation Methods for Estimating Tree and Stand Volumes

Treesearch

R.B. Ferguson; V. Clark Baldwin

1995-01-01

Estimating tree and stand volume in mature plantations is time consuming, involving much manpower and equipment; however, several sampling and volume-prediction techniques are available. This study showed that a well-constructed, volume-equation method yields estimates comparable to those of the often more time-consuming, height-accumulation method, even though the...

Nanofluid MHD natural convection through a porous complex shaped cavity considering thermal radiation

NASA Astrophysics Data System (ADS)

Sheikholeslami, M.; Li, Zhixiong; Shamlooei, M.

2018-06-01

Control volume based finite element method (CVFEM) is applied to simulate H2O based nanofluid radiative and convective heat transfer inside a porous medium. Non-Darcy model is employed for porous media. Influences of Hartmann number, nanofluid volume fraction, radiation parameter, Darcy number, number of undulations and Rayleigh number on nanofluid behavior were demonstrated. Thermal conductivity of nanofluid is estimated by means of previous experimental correlation. Results show that Nusselt number enhances with augment of permeability of porous media. Effect of Hartmann number on rate of heat transfer is opposite of radiation parameter.

Brain Morphometry using MRI in Schizophrenia Patients

NASA Astrophysics Data System (ADS)

Abanshina, I.; Pirogov, Yu.; Kupriyanov, D.; Orlova, V.

2010-01-01

Schizophrenia has been the focus of intense neuroimaging research. Although its fundamental pathobiology remains elusive, neuroimaging studies provide evidence of abnormalities of cerebral structure and function in patients with schizophrenia. We used morphometry as a quantitative method for estimation of volume of brain structures. Seventy eight right-handed subjects aged 18-45 years were exposed to MRI-examination. Patients were divided into 3 groups: patients with schizophrenia, their relatives and healthy controls. The volumes of interested structures (caudate nucleus, putamen, ventricles, frontal and temporal lobe) were measured using T2-weighted MR-images. Correlations between structural differences and functional deficit were evaluated.

Application effect of sterile normal saline ice for post-partum hemorrhage at the time of cesarean delivery: A retrospective review.

PubMed

Cheng, Wenjing; Wang, Qiushi; Zhang, Zhenyu

2016-10-01

Post-partum hemorrhage (PPH) is a common complication of cesarean sections (CS) and affects maternal and newborn health. We used a new method to control bleeding and compared its efficacy with conventional methods. Eighty-six women who experienced PPH with volume of bleeding over 1000 mL in CS between January 2008 and January 2012 were chosen as samples. Thirty-three underwent the new method in which normal saline ice blocks are placed in the uterus, and 53 underwent the conventional method. We evaluated blood loss, volume of transfusion and complications. Patients who were treated with ice blocks had better hemostatic efficacy than those who underwent the conventional method (1450 ± 251.9 mL vs 1800 ± 278.9 mL; P < 0.001); they also had less blood transfusion (806.1 ± 242.3 mL vs 1222.6 ± 308.0 mL; P < 0.001), lower rate of hysterectomy and infection (3.03% vs 5.66%; P = 0.971; 0% vs 7.55%; P = 0.276), and shorter duration of hospital stay (5.3 ± 0.5 days vs 7.6 ± 3.0 days; P < 0.001). PPH in CS can be treated with peeled sterile normal saline ice blocks, a simple and reliable method for stopping bleeding. Nonetheless, there needs to be a large randomized control trial for confirmation. © 2016 Japan Society of Obstetrics and Gynecology.

Reduced anterior insula, enlarged amygdala in alcoholism and associated depleted von Economo neurons.

PubMed

Senatorov, Vladimir V; Damadzic, Ruslan; Mann, Claire L; Schwandt, Melanie L; George, David T; Hommer, Daniel W; Heilig, Markus; Momenan, Reza

2015-01-01

The insula, a structure involved in higher order representation of interoceptive states, has recently been implicated in drug craving and social stress. Here, we performed brain magnetic resonance imaging to measure volumes of the insula and amygdala, a structure with reciprocal insular connections, in 26 alcohol-dependent patients and 24 healthy volunteers (aged 22-56 years, nine females in each group). We used an established morphometry method to quantify total and regional insular volumes. Volumetric measurements of the amygdala were obtained using a model-based segmentation/registration tool. In alcohol-dependent patients, anterior insula volumes were bilaterally reduced compared to healthy volunteers (left by 10%, right by 11%, normalized to total brain volumes). Furthermore, alcohol-dependent patients, compared with healthy volunteers, had bilaterally increased amygdala volumes. The left amygdala was increased by 28% and the right by 29%, normalized to total brain volumes. Post-mortem studies of the anterior insula showed that the reduced anterior insular volume may be associated with a population of von Economo neurons, which were 60% diminished in subjects with a history of alcoholism (n = 6) as compared to subjects without a history of alcoholism (n = 6) (aged 32-56 years, all males). The pattern of neuroanatomical change observed in our alcohol-dependent patients might result in a loss of top-down control of amygdala function, potentially contributing to impaired social cognition as well as an inability to control negatively reinforced alcohol seeking and use. Published by Oxford University Press on behalf of the Guarantors of Brain 2014. This work is written by US Government employees and is in the public domain in the US.

Anatomical pulmonary magnetic resonance imaging segmentation for regional structure-function measurements of asthma

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

Guo, F.; Graduate Program in Biomedical Engineering, University of Western Ontario, London, Ontario N6A 5B9; Svenningsen, S.

Purpose: Pulmonary magnetic-resonance-imaging (MRI) and x-ray computed-tomography have provided strong evidence of spatially and temporally persistent lung structure-function abnormalities in asthmatics. This has generated a shift in their understanding of lung disease and supports the use of imaging biomarkers as intermediate endpoints of asthma severity and control. In particular, pulmonary {sup 1}H MRI can be used to provide quantitative lung structure-function measurements longitudinally and in response to treatment. However, to translate such biomarkers of asthma, robust methods are required to segment the lung from pulmonary {sup 1}H MRI. Therefore, their objective was to develop a pulmonary {sup 1}H MRI segmentationmore » algorithm to provide regional measurements with the precision and speed required to support clinical studies. Methods: The authors developed a method to segment the left and right lung from {sup 1}H MRI acquired in 20 asthmatics including five well-controlled and 15 severe poorly controlled participants who provided written informed consent to a study protocol approved by Health Canada. Same-day spirometry and plethysmography measurements of lung function and volume were acquired as well as {sup 1}H MRI using a whole-body radiofrequency coil and fast spoiled gradient-recalled echo sequence at a fixed lung volume (functional residual capacity + 1 l). We incorporated the left-to-right lung volume proportion prior based on the Potts model and derived a volume-proportion preserved Potts model, which was approximated through convex relaxation and further represented by a dual volume-proportion preserved max-flow model. The max-flow model led to a linear problem with convex and linear equality constraints that implicitly encoded the proportion prior. To implement the algorithm, {sup 1}H MRI was resampled into ∼3 × 3 × 3 mm{sup 3} isotropic voxel space. Two observers placed seeds on each lung and on the background of 20 pulmonary {sup 1}H MR images in a randomized dataset, on five occasions, five consecutive days in a row. Segmentation accuracy was evaluated using the Dice-similarity-coefficient (DSC) of the segmented thoracic cavity with comparison to five-rounds of manual segmentation by an expert observer. The authors also evaluated the root-mean-squared-error (RMSE) of the Euclidean distance between lung surfaces, the absolute, and percent volume error. Reproducibility was measured using the coefficient of variation (CoV) and intraclass correlation coefficient (ICC) for two observers who repeated segmentation measurements five-times. Results: For five well-controlled asthmatics, forced expiratory volume in 1 s (FEV{sub 1})/forced vital capacity (FVC) was 83% ± 7% and FEV{sub 1} was 86 ± 9%{sub pred}. For 15 severe, poorly controlled asthmatics, FEV{sub 1}/FV C = 66% ± 17% and FEV{sub 1} = 72 ± 27%{sub pred}. The DSC for algorithm and manual segmentation was 91% ± 3%, 92% ± 2% and 91% ± 2% for the left, right, and whole lung, respectively. RMSE was 4.0 ± 1.0 mm for each of the left, right, and whole lung. The absolute (percent) volume errors were 0.1 l (∼6%) for each of right and left lung and ∼0.2 l (∼6%) for whole lung. Intra- and inter-CoV (ICC) were <0.5% (>0.91%) for DSC and <4.5% (>0.93%) for RMSE. While segmentation required 10 s including ∼6 s for user interaction, the smallest detectable difference was 0.24 l for algorithm measurements which was similar to manual measurements. Conclusions: This lung segmentation approach provided the necessary and sufficient precision and accuracy required for research and clinical studies.« less

[Effects of simulated weightlessness on pressure-volume relationships of femoral vein of New Zealand Rabbits].

PubMed

Yue, Yong; Yao, Yong-jie; Xie, Xiao-ping; Wang, Bing; Zhu, Qing-sheng; Wu, Xing-yu

2002-12-01

Objective. To observe the changes of pressure-volume relationships of rabbit femoral veins and their structural changes caused by simulated weightlessness. Method. Head-Down Tilt (HDT) -20 degrees rabbit model was used to simulate weightlessness. Twenty four healthy male New Zealand Rabbits were randomly divided into 21 d HDT group,10 d HDT group and control group, (8 in each group). Pressure-volume (P-V) relationship of rabbits femoral veins was measured and the microstructure of the veins was observed. Result. The femoral vein P-V relationship curves of HDT groups showed a larger volume change ratio than that of control group. This change was that 21 d HDT group was even more obvious than that of HDT-10 d group. B1 and B2 in quadratic equations of 21 d HDT group were significantly higher than the values of both 10 d HDT group and control group during expansion (inflow) and collapse (outflow) (P<0.01). The result of histological examination showed that the contents and structure of femoral vein wall of HDT-rabbits changed significantly. Endothelial cells of femoral vein became short and columnar or cubic, some of which fell off. Smooth muscle layer became thinner. Conclusion. Femoral venous compliance increased after weightlessness-simulation and the femoral venous compliance in 21 d-HDT rabbits increased more obviously than that in 10 d-HDT rabbits. The structure of femoral vein wall had changed obviously.

Cardiac size of high-volume resistance trained female athletes: shaping the body but not the heart.

PubMed

Venckunas, T; Simonavicius, J; Marcinkeviciene, J E

2016-03-01

Introduction Exercise training, besides many health benefits, may result in cardiac remodelling which is dependent on the type and amount of exercise performed. It is not clear, however, whether significant adaptation in cardiac structure is possible in females undergoing resistance type of exercise training. Rigorous high volume training of most muscle groups emphasising resistance exercises are being undertaken by athletes of some aesthetic sports such as female fitness (light bodybuilding). The impact of this type of training on cardiac adaptation has not been investigated until now. The aim of the current study was to disclose the effect of high volume resistance training on cardiac structure and function. Methods 11 top-level female fitness athletes and 20 sedentary age-matched controls were recruited to undergo two-dimensional echocardiography. Results Cardiac structure did not differ between elite female fitness athletes and controls (p > 0.05), and fitness athletes had a tendency for a smaller (p = 0.07) left ventricular (LV) mass indexed to lean body mass. Doppler diastolic function index (E/A ratio) and LV ejection fraction were similar between the groups (p > 0.05). Conclusions Elite female fitness athletes have normal cardiac size and function that do not differ from matched sedentary controls. Consequently, as high volume resistance training has no easily observable effect on adaptation of cardiac structure, when cardiac hypertrophy is present in young resistance-trained lean female, other reasons such as inherited cardiac disease are to be considered carefully.

47 CFR 68.6 - Telephones with volume control.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 47 Telecommunication 3 2011-10-01 2011-10-01 false Telephones with volume control. 68.6 Section 68.6 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES (CONTINUED) CONNECTION OF TERMINAL EQUIPMENT TO THE TELEPHONE NETWORK General § 68.6 Telephones with volume control. As...

47 CFR 68.6 - Telephones with volume control.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 3 2010-10-01 2010-10-01 false Telephones with volume control. 68.6 Section 68.6 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES (CONTINUED) CONNECTION OF TERMINAL EQUIPMENT TO THE TELEPHONE NETWORK General § 68.6 Telephones with volume control. As...

Pituitary volumes are changed in patients with conversion disorder.

PubMed

Atmaca, Murad; Baykara, Sema; Mermi, Osman; Yildirim, Hanefi; Akaslan, Unsal

2016-03-01

Our study group previously measured pituitary volumes and found a relationship between somatoform disoders and pituitary volumes. Therefore, in conversion disorder, another somatoform disorder, we hypothesized that pituitary gland volumes would be reduced. Twenty female patients and healthy controls were recruited to the present investigation. The volumes of the pituitary gland were determined by using a 1.5 Tesla magnetic resonance scanner. We found that the pituitary gland volumes of the patients with conversion disorder were significantly smaller than those of healthy control subjects. In the patients with conversion disorder but not in the healthy control group, a significant negative correlation between the duration of illness and pituitary gland volume was determined. In summary, in the present study, we suggest that the patients with conversion disorder have smaller pituitary volumes compared to those of healthy control subjects. Further studies should confirm our data and ascertain whether volumetric alterations determined in the patients with conversion disorder can be changed with treatment or if they change over time.

Cardiovascular response to lower body negative pressure stimulation before, during, and after space flight

NASA Technical Reports Server (NTRS)

Baisch, F.; Beck, L.; Blomqvist, G.; Wolfram, G.; Drescher, J.; Rome, J. L.; Drummer, C.

2000-01-01

BACKGROUND: It is well known that space travel cause post-flight orthostatic hypotension and it was assumed that autonomic cardiovascular control deteriorates in space. Lower body negative pressure (LBNP) was used to assess autonomic function of the cardiovascular system. METHODS: LBNP tests were performed on six crew-members before and on the first days post-flight in a series of three space missions. Additionally, two of the subjects performed LBNP tests in-flight. LBNP mimics fluid distribution of upright posture in a gravity independent way. It causes an artificial sequestration of blood, reduces preload, and filtrates plasma into the lower part of the body. Fluid distribution was assessed by bioelectrical impedance and anthropometric measurements. RESULTS: Heart rate, blood pressure, and total peripheral resistance increased significantly during LBNP experiments in-flight. The decrease in stroke volume, the increased pooling of blood, and the increased filtration of plasma into the lower limbs during LBNP indicated that a plasma volume reduction and a deficit of the interstitial volume of lower limbs rather than a change in cardiovascular control was responsible for the in-flight response. Post-flight LBNP showed no signs of cardiovascular deterioration. The still more pronounced haemodynamic changes during LBNP reflected the expected behaviour of cardiovascular control faced with less intravascular volume. In-flight, the status of an intra-and extravascular fluid deficit increases sympathetic activity, the release of vasoactive substances and consequently blood pressure. Post-flight, blood pressure decreases significantly below pre-flight values after restoration of volume deficits. CONCLUSION: We conclude that the cardiovascular changes in-flight are a consequence of a fluid deficit rather than a consequence of changes in autonomic signal processing.

Left atrial asynchrony and mechanical function in patients with mitral stenosis before and immediately after percutaneous balloon mitral valvuloplasty: a real time three-dimensional echocardiography study.

PubMed

Deng, Yan; Guo, Sheng-lan; Su, Hong-yue; Wang, Qian; Tan, Zhen; Wu, Ji; Zhang, Di

2015-02-01

This study evaluated the feasibility of assessing left atrium (LA) function and asynchrony in patients with rheumatic mitral stenosis (MS) before and immediately after percutaneous balloon mitral valvuloplasty (PBMV) by real time three-dimensional echocardiography (RT3DE). Thirty patients with rheumatic MS who underwent PBMV and 30 controls were enrolled. RT3DE was used to measure LA volume and function, the standard deviation of time to the minimal systolic volume divided into 16 segments, 12 segments, or 6 segments (Tmsv 16-SD, Tmsv 12-SD, Tmsv 6-SD), and the maximum differences (Tmsv 16-Dif, 12-Dif, 6-Dif) in RT3DE derived values in MS patients before and 2 days after PBMV were obtained and compared with those of normal controls. The associations between the LA asynchrony and heart volume, function, mitral valve area (MVA), maximum mitral valve gradient (MVGmax ), mean mitral valve gradient (MVGmean), and mean LA pressure (MLAP) were investigated. Left atrium asynchrony indexes were significantly larger, and LA function parameters were significantly lower in the MS group than in the controls (P < 0.05 for all). Of all the LA asynchrony indexes, LA Tmsv16-SD was most significantly correlated with the LA volume and function parameters, MVGmax , MVGmean , and MLAP (P < 0.05 for all). LA asynchrony indexes and LA volume significantly deceased, and LA function significantly increased post-PBMV (P < 0.05). Real time three-dimensional echocardiography is a reliable and reproducible method to quantify LA function and asynchrony. RT3DE revealed a significant, early improvement in LA function and asynchrony in MS patients after PBMV. © 2014, Wiley Periodicals, Inc.

Vortex-ring mixing as a measure of diastolic function of the human heart: Phantom validation and initial observations in healthy volunteers and patients with heart failure.

PubMed

Töger, Johannes; Kanski, Mikael; Arvidsson, Per M; Carlsson, Marcus; Kovács, Sándor J; Borgquist, Rasmus; Revstedt, Johan; Söderlind, Gustaf; Arheden, Håkan; Heiberg, Einar

2016-06-01

To present and validate a new method for 4D flow quantification of vortex-ring mixing during early, rapid filling of the left ventricle (LV) as a potential index of diastolic dysfunction and heart failure. 4D flow mixing measurements were validated using planar laser-induced fluorescence (PLIF) in a phantom setup. Controls (n = 23) and heart failure patients (n = 23) were studied using 4D flow at 1.5T (26 subjects) or 3T (20 subjects) to determine vortex volume (VV) and inflowing volume (VVinflow ). The volume mixed into the vortex-ring was quantified as VVmix-in = VV-VVinflow . The mixing ratio was defined as MXR = VVmix-in /VV. Furthermore, we quantified the fraction of the end-systolic volume (ESV) mixed into the vortex-ring (VVmix-in /ESV) and the fraction of the LV volume at diastasis (DV) occupied by the vortex-ring (VV/DV). PLIF validation of MXR showed fair agreement (R(2) = 0.45, mean ± SD 1 ± 6%). MXR was higher in patients compared to controls (28 ± 11% vs. 16 ± 10%, P < 0.001), while VVmix-in /ESV and VV/DV were lower in patients (10 ± 6% vs. 18 ± 12%, P < 0.01 and 25 ± 8% vs. 50 ± 6%, P < 0.0001). Vortex-ring mixing can be quantified using 4D flow. The differences in mixing parameters observed between controls and patients motivate further investigation as indices of diastolic dysfunction. J. Magn. Reson. Imaging 2016;43:1386-1397. © 2015 Wiley Periodicals, Inc.

Abnormal hippocampal shape in offenders with psychopathy.

PubMed

Boccardi, Marina; Ganzola, Rossana; Rossi, Roberta; Sabattoli, Francesca; Laakso, Mikko P; Repo-Tiihonen, Eila; Vaurio, Olli; Könönen, Mervi; Aronen, Hannu J; Thompson, Paul M; Frisoni, Giovanni B; Tiihonen, Jari

2010-03-01

Posterior hippocampal volumes correlate negatively with the severity of psychopathy, but local morphological features are unknown. The aim of this study was to investigate hippocampal morphology in habitually violent offenders having psychopathy. Manual tracings of hippocampi from magnetic resonance images of 26 offenders (age: 32.5 +/- 8.4), with different degrees of psychopathy (12 high, 14 medium psychopathy based on the Psychopathy Checklist Revised), and 25 healthy controls (age: 34.6 +/- 10.8) were used for statistical modelling of local changes with a surface-based radial distance mapping method. Both offenders and controls had similar hippocampal volume and asymmetry ratios. Local analysis showed that the high psychopathy group had a significant depression along the longitudinal hippocampal axis, on both the dorsal and ventral aspects, when compared with the healthy controls and the medium psychopathy group. The opposite comparison revealed abnormal enlargement of the lateral borders in both the right and left hippocampi of both high and medium psychopathy groups versus controls, throughout CA1, CA2-3 and the subicular regions. These enlargement and reduction effects survived statistical correction for multiple comparisons in the main contrast (26 offenders vs. 25 controls) and in most subgroup comparisons. A statistical check excluded a possible confounding effect from amphetamine and polysubstance abuse. These results indicate that habitually violent offenders exhibit a specific abnormal hippocampal morphology, in the absence of total gray matter volume changes, that may relate to different autonomic modulation and abnormal fear-conditioning. 2009 Wiley-Liss, Inc.

Management control and status reports documentation standard and Data Item Descriptions (DID). Volume of the information system life-cycle and documentation standards, volume 5

NASA Technical Reports Server (NTRS)

Callender, E. David; Steinbacher, Jody

1989-01-01

This is the fifth of five volumes on Information System Life-Cycle and Documentation Standards. This volume provides a well organized, easily used standard for management control and status reports used in monitoring and controlling the management, development, and assurance of informations systems and software, hardware, and operational procedures components, and related processes.

Voxel-based morphometry analysis reveals frontal brain differences in participants with ADHD and their unaffected siblings

PubMed Central

Bralten, Janita; Greven, Corina U.; Franke, Barbara; Mennes, Maarten; Zwiers, Marcel P.; Rommelse, Nanda N.J.; Hartman, Catharina; van der Meer, Dennis; O’Dwyer, Laurence; Oosterlaan, Jaap; Hoekstra, Pieter J.; Heslenfeld, Dirk; Arias-Vasquez, Alejandro; Buitelaar, Jan K.

2016-01-01

Background Data on structural brain alterations in patients with attention-deficit/hyperactivity disorder (ADHD) have been inconsistent. Both ADHD and brain volumes have a strong genetic loading, but whether brain alterations in patients with ADHD are familial has been underexplored. We aimed to detect structural brain alterations in adolescents and young adults with ADHD compared with healthy controls. We examined whether these alterations were also found in their unaffected siblings, using a uniquely large sample. Methods We performed voxel-based morphometry analyses on MRI scans of patients with ADHD, their unaffected siblings and typically developing controls. We identified brain areas that differed between participants with ADHD and controls and investigated whether these areas were different in unaffected siblings. Influences of medication use, age, sex and IQ were considered. Results Our sample included 307 patients with ADHD, 169 unaffected siblings and 196 typically developing controls (mean age 17.2 [range 8–30] yr). Compared with controls, participants with ADHD had significantly smaller grey matter volume in 5 clusters located in the precentral gyrus, medial and orbitofrontal cortex, and (para)cingulate cortices. Unaffected siblings showed intermediate volumes significantly different from controls in 4 of these clusters (all except the precentral gyrus). Medication use, age, sex and IQ did not have an undue influence on the results. Limitations Our sample was heterogeneous, most participants with ADHD were taking medication, and the comparison was cross-sectional. Conclusion Brain areas involved in decision making, motivation, cognitive control and motor functioning were smaller in participants with ADHD than in controls. Investigation of unaffected siblings indicated familiality of 4 of the structural brain differences, supporting their potential in molecular genetic analyses in ADHD research. PMID:26679925

Methodology for Software Reliability Prediction. Volume 2.

DTIC Science & Technology

1987-11-01

The overall acquisition ,z program shall include the resources, schedule, management, structure , and controls necessary to ensure that specified AD...Independent Verification/Validation - Programming Team Structure - Educational Level of Team Members - Experience Level of Team Members * Methods Used...Prediction or Estimation Parameter Supported: Software - Characteristics 3. Objectives: Structured programming studies and Government Ur.’.. procurement

40 CFR 60.614 - Test methods and procedures.

Code of Federal Regulations, 2012 CFR

2012-07-01

... or TOC (less methane and ethane) reduction efficiency shall be prior to the inlet of the control... TOC (minus methane and ethane), dry basis, ppm by volume. %O2d=Concentration of O2, dry basis, percent.... (ii) The emission reduction (R) of TOC (minus methane and ethane) shall be determined using the...

CrossTalk: The Journal of Defense Software Engineering. Volume 25, Number 1, January/February 2012

DTIC Science & Technology

2012-02-01

Equipment Certification – RTCA/DO-178B,” Washington, D.C., 1992. 5. Ishikawa , Kaoru (Translator: J. H. Loftus), Introduction to Quality Control, Tokyo...cause analysis process is performed. This method uses fishbone or Ishikawa diagrams [5], where possible causes for the outliers are listed, followed by

ROUTING DEMAND CHANGES TO USERS ON THE WM LATERAL CANAL WITH SACMAN

USDA-ARS?s Scientific Manuscript database

Most canals have either long travel times or insufficient in-canal storage to operate on-demand. Thus, most flow changes must be routed through the canal. Volume compensation has been proposed as a method for easily applying feedforward control to irrigation canals. SacMan (Software for Automated Ca...

Reduced Amygdalar Gray Matter Volume in Familial Pediatric Bipolar Disorder

ERIC Educational Resources Information Center

Chang, Kiki; Karchemskiy, Asya; Barnea-Goraly, Naama; Garrett, Amy; Simeonova, Diana Iorgova; Reiss, Allan

2005-01-01

Objective: Subcortical limbic structures have been proposed to be involved in the pathophysiology of adult and pediatric bipolar disorder (BD). We sought to study morphometric characteristics of these structures in pediatric subjects with familial BD compared with healthy controls. Method: Twenty children and adolescents with BD I (mean age = 14.6…

Showercap Mindmap: A Spatial Activity for Learning Physiology Terminology and Location

ERIC Educational Resources Information Center

Vanags, Thea; Budimlic, Mira; Herbert, Elissa; Montgomery, Melena M.; Vickers, Tracy

2012-01-01

Students struggle with the volume and complexity of physiology terminology. We compared first-year undergraduate psychology students' learning of physiological terms using two teaching methods: one verbal (control group; n = 16) and one spatial and multisensory (experimental group; n = 19). The experimental group used clear plastic shower caps to…

Corpus Callosum Volume and Neurocognition in Autism

ERIC Educational Resources Information Center

Keary, Christopher J.; Minshew, Nancy J.; Bansal, Rahul; Goradia, Dhruman; Fedorov, Serguei; Keshavan, Matcheri S.; Hardan, Antonio Y.

2009-01-01

The corpus callosum has recently been considered as an index of interhemispheric connectivity. This study applied a novel volumetric method to examine the size of the corpus callosum in 32 individuals with autism and 34 age-, gender- and IQ-matched controls and to investigate the relationship between this structure and cognitive measures linked to…

Direct volume estimation without segmentation

NASA Astrophysics Data System (ADS)

Zhen, X.; Wang, Z.; Islam, A.; Bhaduri, M.; Chan, I.; Li, S.

2015-03-01

Volume estimation plays an important role in clinical diagnosis. For example, cardiac ventricular volumes including left ventricle (LV) and right ventricle (RV) are important clinical indicators of cardiac functions. Accurate and automatic estimation of the ventricular volumes is essential to the assessment of cardiac functions and diagnosis of heart diseases. Conventional methods are dependent on an intermediate segmentation step which is obtained either manually or automatically. However, manual segmentation is extremely time-consuming, subjective and highly non-reproducible; automatic segmentation is still challenging, computationally expensive, and completely unsolved for the RV. Towards accurate and efficient direct volume estimation, our group has been researching on learning based methods without segmentation by leveraging state-of-the-art machine learning techniques. Our direct estimation methods remove the accessional step of segmentation and can naturally deal with various volume estimation tasks. Moreover, they are extremely flexible to be used for volume estimation of either joint bi-ventricles (LV and RV) or individual LV/RV. We comparatively study the performance of direct methods on cardiac ventricular volume estimation by comparing with segmentation based methods. Experimental results show that direct estimation methods provide more accurate estimation of cardiac ventricular volumes than segmentation based methods. This indicates that direct estimation methods not only provide a convenient and mature clinical tool for cardiac volume estimation but also enables diagnosis of cardiac diseases to be conducted in a more efficient and reliable way.

Bubble measuring instrument and method

NASA Technical Reports Server (NTRS)

Magari, Patrick J. (Inventor); Kline-Schoder, Robert (Inventor)

2003-01-01

Method and apparatus are provided for a non-invasive bubble measuring instrument operable for detecting, distinguishing, and counting gaseous embolisms such as bubbles over a selectable range of bubble sizes of interest. A selected measurement volume in which bubbles may be detected is insonified by two distinct frequencies from a pump transducer and an image transducer, respectively. The image transducer frequency is much higher than the pump transducer frequency. The relatively low-frequency pump signal is used to excite bubbles to resonate at a frequency related to their diameter. The image transducer is operated in a pulse-echo mode at a controllable repetition rate that transmits bursts of high-frequency ultrasonic signal to the measurement volume in which bubbles may be detected and then receives the echo. From the echo or received signal, a beat signal related to the repetition rate may be extracted and used to indicate the presence or absence of a resonant bubble. In a preferred embodiment, software control maintains the beat signal at a preselected frequency while varying the pump transducer frequency to excite bubbles of different diameters to resonate depending on the range of bubble diameters selected for investigation.

Open-atmosphere sustenance of highly volatile attoliter-size droplets on surfaces.

PubMed

Galliker, Patrick; Schneider, Julian; Rüthemann, Lukas; Poulikakos, Dimos

2013-08-13

The controlled formation and handling of minute liquid volumes on surfaces is essential to the success of microfluidics in biology, chemistry, and materials applications. Even though current methods have demonstrated their potential in a variety of experimental assays, there remain significant difficulties concerning breadth of applicability, standardization, throughput, and economics. Here we introduce a unique microfluidic paradigm in which microscopic volatile droplets are formed, sustained, and manipulated in size and content at any desired spot on unpatterned substrates. Their sustainability is warranted by continuous replacement of the rapidly vaporizing sessile fluid through controlled equivalent volume deposition of smaller discrete liquid entities by an electrohydrodynamic nanodripping process. Using nanoparticle inks we show that the concentration of solutes in so-stabilized droplets can be linearly increased at isochoric conditions and user-defined rates. An intriguing insensitivity of the droplet shape toward surface heterogeneities ensures robustness and experimental reproducibility, even when handling attoliter quantities. The unique capabilities and technical simplicity of the presented method introduce a high degree of flexibility and make it pertinent to a diverse range of applications.

Open-atmosphere sustenance of highly volatile attoliter-size droplets on surfaces

PubMed Central

Galliker, Patrick; Schneider, Julian; Rüthemann, Lukas; Poulikakos, Dimos

2013-01-01

The controlled formation and handling of minute liquid volumes on surfaces is essential to the success of microfluidics in biology, chemistry, and materials applications. Even though current methods have demonstrated their potential in a variety of experimental assays, there remain significant difficulties concerning breadth of applicability, standardization, throughput, and economics. Here we introduce a unique microfluidic paradigm in which microscopic volatile droplets are formed, sustained, and manipulated in size and content at any desired spot on unpatterned substrates. Their sustainability is warranted by continuous replacement of the rapidly vaporizing sessile fluid through controlled equivalent volume deposition of smaller discrete liquid entities by an electrohydrodynamic nanodripping process. Using nanoparticle inks we show that the concentration of solutes in so-stabilized droplets can be linearly increased at isochoric conditions and user-defined rates. An intriguing insensitivity of the droplet shape toward surface heterogeneities ensures robustness and experimental reproducibility, even when handling attoliter quantities. The unique capabilities and technical simplicity of the presented method introduce a high degree of flexibility and make it pertinent to a diverse range of applications. PMID:23898173

Bubble Measuring Instrument and Method

NASA Technical Reports Server (NTRS)

Kline-Schoder, Robert (Inventor); Magari, Patrick J. (Inventor)

2002-01-01

Method and apparatus are provided for a non-invasive bubble measuring instrument operable for detecting, distinguishing, and counting gaseous embolisms such as bubbles over a selectable range of bubble sizes of interest. A selected measurement volume in which bubbles may be detected is insonified by two distinct frequencies from a pump transducer and an image transducer. respectively. The image transducer frequency is much higher than the pump transducer frequency. The relatively low-frequency pump signal is used to excite bubbles to resonate at a frequency related to their diameter. The image transducer is operated in a pulse-echo mode at a controllable repetition rate that transmits bursts of high-frequency ultrasonic signal to the measurement volume in which bubbles may be detected and then receives the echo. From the echo or received signal, a beat signal related to the repetition rate may be extracted and used to indicate the presence or absence of a resonant bubble. In a preferred embodiment, software control maintains the beat signal at a preselected frequency while varying the pump transducer frequency to excite bubbles of different diameters to resonate depending on the range of bubble diameters selected for investigation.

Aircraft drag prediction and reduction. Addendum 1: Computational drag analyses and minimization; mission impossible?

NASA Technical Reports Server (NTRS)

Slooff, J. W.

1986-01-01

The Special Course on Aircraft Drag Prediction was sponsored by the AGARD Fluid Dynamics Panel and the von Karman Institute and presented at the von Karman Institute, Rhode-Saint-Genese, Belgium, on 20 to 23 May 1985 and at the NASA Langley Research Center, Hampton, Virginia, USA, 5 to 6 August 1985. The course began with a general review of drag reduction technology. Then the possibility of reduction of skin friction through control of laminar flow and through modification of the structure of the turbulence in the boundary layer were discussed. Methods for predicting and reducing the drag of external stores, of nacelles, of fuselage protuberances, and of fuselage afterbodies were then presented followed by discussion of transonic drag rise. The prediction of viscous and wave drag by a method matching inviscid flow calculations and boundary layer integral calculations, and the reduction of transonic drag through boundary layer control are also discussed. This volume comprises Paper No. 9 Computational Drag Analyses and Minimization: Mission Impossible, which was not included in AGARD Report 723 (main volume).

Optimal back-extrapolation method for estimating plasma volume in humans using the indocyanine green dilution method.

PubMed

Polidori, David; Rowley, Clarence

2014-07-22

The indocyanine green dilution method is one of the methods available to estimate plasma volume, although some researchers have questioned the accuracy of this method. We developed a new, physiologically based mathematical model of indocyanine green kinetics that more accurately represents indocyanine green kinetics during the first few minutes postinjection than what is assumed when using the traditional mono-exponential back-extrapolation method. The mathematical model is used to develop an optimal back-extrapolation method for estimating plasma volume based on simulated indocyanine green kinetics obtained from the physiological model. Results from a clinical study using the indocyanine green dilution method in 36 subjects with type 2 diabetes indicate that the estimated plasma volumes are considerably lower when using the traditional back-extrapolation method than when using the proposed back-extrapolation method (mean (standard deviation) plasma volume = 26.8 (5.4) mL/kg for the traditional method vs 35.1 (7.0) mL/kg for the proposed method). The results obtained using the proposed method are more consistent with previously reported plasma volume values. Based on the more physiological representation of indocyanine green kinetics and greater consistency with previously reported plasma volume values, the new back-extrapolation method is proposed for use when estimating plasma volume using the indocyanine green dilution method.

Effect of streptozotocin-induced diabetes on left ventricular function in adult rats: an in vivo Pinhole Gated SPECT study

PubMed Central

Cosyns, Bernard; Droogmans, Steven; Weytjens, Caroline; Lahoutte, Tony; Van Camp, Guy; Schoors, Danny; Franken, Philippe R

2007-01-01

Background Recent studies have suggested that diabetes mellitus (DM) may cause left ventricular (LV) dysfunction directly resulting in increased susceptibility to heart failure. Using pinhole collimators and advances in data processing, gated SPECT was recently adapted to image the rat heart. The present study was aimed to assess this new imaging technique for quantifying LV function and remodeling from the Streptozotocin (STZ) rat model compared to controls. Methods Twenty one rats were randomly assigned to control or diabetic group. Six months after the induction of diabetes by STZ, Pinhole 99 m Tc-sestamibi gated SPECT was performed for determining rat LV volumes and function. Post-mortem histopathologic analysis was performed to evaluate the determinant of LV remodeling in this model. Results After six months, the normalized to body weight LV End-systolic volume was significantly different in diabetic rats compared to controls (0.46 ± 0.02 vs 0.33 ± 0.03 μL/g; p = 0.01). The normalized LV End-diastolic volume was also different in both groups (1.51 ± 0.03 vs 0.88 ± 0.05 μL/g; p = 0.001) and the normalized stroke volume was significantly higher in STZ-rats (1.05 ± 0.02 vs 0.54 ± 0.06 μL/g; p = 0.001). The muscular fibers were thinner at histology in the diabetic rats (0.44 ± 0.07 vs 0.32 ± 0.06 AU; p = 0.01). Conclusion Pinhole 99 m Tc-sestamibi gated SPECT can successfully be applied for the evaluation of cardiac function and remodeling in STZ-induced diabetic rats. In this model, LV volumes were significantly changed compared to a control population, leading to a LV dysfunction. These findings were consistent with the histopathological abnormalities. Finally, these data further suggest the presence of diabetes cardiomyopathy. PMID:17937784

Multi-modal neuroimaging in premanifest and early Huntington's disease: 18 month longitudinal data from the IMAGE-HD study.

PubMed

Domínguez D, Juan F; Egan, Gary F; Gray, Marcus A; Poudel, Govinda R; Churchyard, Andrew; Chua, Phyllis; Stout, Julie C; Georgiou-Karistianis, Nellie

2013-01-01

IMAGE-HD is an Australian based multi-modal longitudinal magnetic resonance imaging (MRI) study in premanifest and early symptomatic Huntington's disease (pre-HD and symp-HD, respectively). In this investigation we sought to determine the sensitivity of imaging methods to detect macrostructural (volume) and microstructural (diffusivity) longitudinal change in HD. We used a 3T MRI scanner to acquire T1 and diffusion weighted images at baseline and 18 months in 31 pre-HD, 31 symp-HD and 29 controls. Volume was measured across the whole brain, and volume and diffusion measures were ascertained for caudate and putamen. We observed a range of significant volumetric and, for the first time, diffusion changes over 18 months in both pre-HD and symp-HD, relative to controls, detectable at the brain-wide level (volume change in grey and white matter) and in caudate and putamen (volume and diffusivity change). Importantly, longitudinal volume change in the caudate was the only measure that discriminated between groups across all stages of disease: far from diagnosis (>15 years), close to diagnosis (<15 years) and after diagnosis. Of the two diffusion metrics (mean diffusivity, MD; fractional anisotropy, FA), only longitudinal FA change was sensitive to group differences, but only after diagnosis. These findings further confirm caudate atrophy as one of the most sensitive and early biomarkers of neurodegeneration in HD. They also highlight that different tissue properties have varying schedules in their ability to discriminate between groups along disease progression and may therefore inform biomarker selection for future therapeutic interventions.

Analysis of the Substantia Innominata Volume in Patients with Parkinson’s Disease with Dementia, Dementia with Lewy Bodies, and Alzheimer’s Disease

PubMed Central

Kim, Hee Jin; Lee, Ji Eun; Shin, Soo Jeong; Sohn, Young Ho; Lee, Phil Hyu

2011-01-01

Background and Purpose The substantia innominata (SI) contains the nucleus basalis of Meynert, which is the major source of cholinergic input to the cerebral cortex. We hypothesized that degeneration of the SI and its relationship to general cognitive performance differs in amyloidopathy and synucleinopathy. Methods We used magnetic resonance imaging (MRI)-based volumetric analysis to evaluate the SI volume in patients with amnestic mild cognitive impairment (aMCI), Alzheimer’s disease (AD), Parkinson’s disease-mild cognitive impairment (PD-MCI), PD with dementia (PDD), dementia with Lewy bodies (DLB), and healthy elderly controls. The correlation between SI volume and general cognitive performance, measured using the Korean version of the Mini-Mental State Examination (K-MMSE), was examined. Results Compared to control subjects, the mean normalized SI volume was significantly decreased in all of the other groups. The normalized SI volume did not differ between the subjects with PDD and DLB, whereas it was significantly smaller in subjects with PDD (p = 0.029) and DLB (p = 0.011) compared with AD. In subjects with PD-related cognitive impairment (PD-MCI, PDD, or DLB), there was a significant positive correlation between the SI volume and K-MMSE score (r = 0.366, p < 0.001), whereas no correlation was seen in subjects with AD-related cognitive impairment (aMCI or AD). Conclusions Our data suggest that the SI loss is greater in synucleinopathy-related dementia (PDD or DLB) than in AD and that the contribution of the SI to cognitive performance is greater in synucleinopathy than in amyloidopathy. PMID:24868398

Four-chamber heart modeling and automatic segmentation for 3-D cardiac CT volumes using marginal space learning and steerable features.

PubMed

Zheng, Yefeng; Barbu, Adrian; Georgescu, Bogdan; Scheuering, Michael; Comaniciu, Dorin

2008-11-01

We propose an automatic four-chamber heart segmentation system for the quantitative functional analysis of the heart from cardiac computed tomography (CT) volumes. Two topics are discussed: heart modeling and automatic model fitting to an unseen volume. Heart modeling is a nontrivial task since the heart is a complex nonrigid organ. The model must be anatomically accurate, allow manual editing, and provide sufficient information to guide automatic detection and segmentation. Unlike previous work, we explicitly represent important landmarks (such as the valves and the ventricular septum cusps) among the control points of the model. The control points can be detected reliably to guide the automatic model fitting process. Using this model, we develop an efficient and robust approach for automatic heart chamber segmentation in 3-D CT volumes. We formulate the segmentation as a two-step learning problem: anatomical structure localization and boundary delineation. In both steps, we exploit the recent advances in learning discriminative models. A novel algorithm, marginal space learning (MSL), is introduced to solve the 9-D similarity transformation search problem for localizing the heart chambers. After determining the pose of the heart chambers, we estimate the 3-D shape through learning-based boundary delineation. The proposed method has been extensively tested on the largest dataset (with 323 volumes from 137 patients) ever reported in the literature. To the best of our knowledge, our system is the fastest with a speed of 4.0 s per volume (on a dual-core 3.2-GHz processor) for the automatic segmentation of all four chambers.

A voxel-based morphometry study of anosmic patients

PubMed Central

Peng, P; Xiao, W; Si, L F; Wang, J F; Wang, S K; Zhai, R Y; Wei, Y X

2013-01-01

Objective: The aim of our study was to compare volume change in grey matter (GM) and white matter (WM) in a group of subjects with anosmia and a healthy control group. We tried to find a regular pattern of atrophy within and between GM and WM and to determine whether any particular areas are more sensitive to olfactory injury. Methods: There were 19 anosmic patients and 20 age- and sex-matched control subjects. We acquired MR images on a 3-T scanner and performed voxel-based morphometry using the VBM8 toolbox and SPM8 in a MATLAB® (MathWorks®, Natick, MA) environment. Results: Patients with anosmia showed a significant decrease in GM volume, mainly in the anterior cingulate cortex, middle temporal gyrus, superior temporal gyrus, fusiform gyrus, supramarginal gyrus, superior frontal gyrus, middle frontal gyrus, middle occipital gyrus, anterior insular cortex and cerebellum. In addition, we observed volume decreases in smaller areas such as the piriform cortex, the inferior temporal gyrus, the precuneus and the subcallosal gyrus. All WM areas with atrophy were near those GM areas that experienced volume loss. There was more volume atrophy in GM areas corresponding to WM areas with more volume loss. Atrophy increased with disease duration. Conclusion: There is simultaneous atrophy in GM and WM, and the degree of atrophy is greater with longer disease duration. Different GM and WM areas have different sensitivities to olfactory injury. Advances in knowledge: This study examines the atrophy pattern in and between GM and WM—a subject that has not been widely researched previously. PMID:24133057

Dose escalation to high-risk sub-volumes based on non-invasive imaging of hypoxia and glycolytic activity in canine solid tumors: a feasibility study

PubMed Central

2013-01-01

Introduction Glycolytic activity and hypoxia are associated with poor prognosis and radiation resistance. Including both the tumor uptake of 2-deoxy-2-[18 F]-fluorodeoxyglucose (FDG) and the proposed hypoxia tracer copper(II)diacetyl-bis(N4)-methylsemithio-carbazone (Cu-ATSM) in targeted therapy planning may therefore lead to improved tumor control. In this study we analyzed the overlap between sub-volumes of FDG and hypoxia assessed by the uptake of 64Cu-ATSM in canine solid tumors, and evaluated the possibilities for dose redistribution within the gross tumor volume (GTV). Materials and methods Positron emission tomography/computed tomography (PET/CT) scans of five spontaneous canine solid tumors were included. FDG-PET/CT was obtained at day 1, 64Cu-ATSM at day 2 and 3 (3 and 24 h pi.). GTV was delineated and CT images were co-registered. Sub-volumes for 3 h and 24 h 64Cu-ATSM (Cu3 and Cu24) were defined by a threshold based method. FDG sub-volumes were delineated at 40% (FDG40) and 50% (FDG50) of SUVmax. The size of sub-volumes, intersection and biological target volume (BTV) were measured in a treatment planning software. By varying the average dose prescription to the tumor from 66 to 85 Gy, the possible dose boost (D B ) was calculated for the three scenarios that the optimal target for the boost was one, the union or the intersection of the FDG and 64Cu-ATSM sub-volumes. Results The potential boost volumes represented a fairly large fraction of the total GTV: Cu3 49.8% (26.8-72.5%), Cu24 28.1% (2.4-54.3%), FDG40 45.2% (10.1-75.2%), and FDG50 32.5% (2.6-68.1%). A BTV including the union (∪) of Cu3 and FDG would involve boosting to a larger fraction of the GTV, in the case of Cu3∪FDG40 63.5% (51.8-83.8) and Cu3∪FDG50 48.1% (43.7-80.8). The union allowed only a very limited D B whereas the intersection allowed a substantial dose escalation. Conclusions FDG and 64Cu-ATSM sub-volumes were only partly overlapping, suggesting that the tracers offer complementing information on tumor physiology. Targeting the combined PET positive volume (BTV) for dose escalation within the GTV results in a limited D B . This suggests a more refined dose redistribution based on a weighted combination of the PET tracers in order to obtain an improved tumor control. PMID:24199939

Machine intelligence and autonomy for aerospace systems

NASA Technical Reports Server (NTRS)

Heer, Ewald (Editor); Lum, Henry (Editor)

1988-01-01

The present volume discusses progress toward intelligent robot systems in aerospace applications, NASA Space Program automation and robotics efforts, the supervisory control of telerobotics in space, machine intelligence and crew/vehicle interfaces, expert-system terms and building tools, and knowledge-acquisition for autonomous systems. Also discussed are methods for validation of knowledge-based systems, a design methodology for knowledge-based management systems, knowledge-based simulation for aerospace systems, knowledge-based diagnosis, planning and scheduling methods in AI, the treatment of uncertainty in AI, vision-sensing techniques in aerospace applications, image-understanding techniques, tactile sensing for robots, distributed sensor integration, and the control of articulated and deformable space structures.

A program for calculating load coefficient matrices utilizing the force summation method, L218 (LOADS). Volume 2: Supplemental system design and maintenance document

NASA Technical Reports Server (NTRS)

Anderson, L. R.; Miller, R. D.

1979-01-01

The LOADS computer program L218 which calculates dynamic load coefficient matrices utilizing the force summation method is described. The load equations are derived for a flight vehicle in straight and level flight and excited by gusts and/or control motions. In addition, sensor equations are calculated for use with an active control system. The load coefficient matrices are calculated for the following types of loads: (1) translational and rotational accelerations, velocities, and displacements; (2) panel aerodynamic forces; (3) net panel forces; and (4) shears, bending moments, and torsions.

Digital Correction of Motion Artifacts in Microscopy Image Sequences Collected from Living Animals Using Rigid and Non-Rigid Registration

PubMed Central

Lorenz, Kevin S.; Salama, Paul; Dunn, Kenneth W.; Delp, Edward J.

2013-01-01

Digital image analysis is a fundamental component of quantitative microscopy. However, intravital microscopy presents many challenges for digital image analysis. In general, microscopy volumes are inherently anisotropic, suffer from decreasing contrast with tissue depth, lack object edge detail, and characteristically have low signal levels. Intravital microscopy introduces the additional problem of motion artifacts, resulting from respiratory motion and heartbeat from specimens imaged in vivo. This paper describes an image registration technique for use with sequences of intravital microscopy images collected in time-series or in 3D volumes. Our registration method involves both rigid and non-rigid components. The rigid registration component corrects global image translations, while the non-rigid component manipulates a uniform grid of control points defined by B-splines. Each control point is optimized by minimizing a cost function consisting of two parts: a term to define image similarity, and a term to ensure deformation grid smoothness. Experimental results indicate that this approach is promising based on the analysis of several image volumes collected from the kidney, lung, and salivary gland of living rodents. PMID:22092443

Neuromelanin imaging and midbrain volumetry in progressive supranuclear palsy and Parkinson's disease.

PubMed

Taniguchi, Daisuke; Hatano, Taku; Kamagata, Koji; Okuzumi, Ayami; Oji, Yutaka; Mori, Akio; Hori, Masaaki; Aoki, Shigeki; Hattori, Nobutaka

2018-05-14

Background Nigral degeneration patterns differ between PSP and PD. However, the relationship between nigral degeneration and midbrain atrophy in PSP remains unclear. Objective We analyzed differences and relationships between nigral degeneration and midbrain atrophy in PSP and PD. Methods Neuromelanin-sensitive MRI and midbrain volumetry were performed in 11 PSP patients, 24 PD patients, and 10 controls to measure the neuromelanin-sensitive SNpc area and midbrain volume. Results The neuromelanin-sensitive SNpc area and midbrain volume were significantly smaller in PSP patients compared with PD patients and controls. Motor deficits were inversely correlated with neuromelanin-sensitive SNpc area in PD, but not PSP patients. There was no significant correlation between neuromelanin-sensitive SNpc area and midbrain volume in either disease group. Midbrain volumetry discriminated PSP from PD. Diagnostic accuracy was improved when neuromelanin-sensitive MRI analysis was added. Conclusions Neuromelanin-sensitive MRI and midbrain volumetry may reflect the clinical and pathological characteristics of PSP and PD. Combining neuromelanin-sensitive MRI and midbrain volumetry may be useful for differentiating PSP from PD. © 2018 International Parkinson and Movement Disorder Society. © 2018 International Parkinson and Movement Disorder Society.

Challenges in Development of Sperm Repositories for Biomedical Fishes: Quality Control in Small-Bodied Species.

PubMed

Torres, Leticia; Liu, Yue; Guitreau, Amy; Yang, Huiping; Tiersch, Terrence R

2017-12-01

Quality control (QC) is essential for reproducible and efficient functioning of germplasm repositories. However, many biomedical fish models present significant QC challenges due to small body sizes (<5 cm) and miniscule sperm volumes (<5 μL). Using minimal volumes of sperm, we used Zebrafish to evaluate common QC endpoints as surrogates for fertilization success along sequential steps of cryopreservation. First, concentrations of calibration bead suspensions were evaluated with a Makler ® counting chamber by using different sample volumes and mixing methods. For sperm analysis, samples were initially diluted at a 1:30 ratio with Hanks' balanced salt solution (HBSS). Motility was evaluated by using different ratios of sperm and activation medium, and membrane integrity was analyzed with flow cytometry at different concentrations. Concentration and sperm motility could be confidently estimated by using volumes as small as 1 μL, whereas membrane integrity required a minimum of 2 μL (at 1 × 10 6 cells/mL). Thus, <5 μL of sperm suspension (after dilution to 30-150 μL with HBSS) was required to evaluate sperm quality by using three endpoints. Sperm quality assessment using a combination of complementary endpoints enhances QC efforts during cryopreservation, increasing reliability and reproducibility, and reducing waste of time and resources.