MPCV Exercise Operational Volume Analysis

NASA Technical Reports Server (NTRS)

Godfrey, A.; Humphreys, B.; Funk, J.; Perusek, G.; Lewandowski, B. E.

2017-01-01

In order to minimize the loss of bone and muscle mass during spaceflight, the Multi-purpose Crew Vehicle (MPCV) will include an exercise device and enough free space within the cabin for astronauts to use the device effectively. The NASA Digital Astronaut Project (DAP) has been tasked with using computational modeling to aid in determining whether or not the available operational volume is sufficient for in-flight exercise.Motion capture data was acquired using a 12-camera Smart DX system (BTS Bioengineering, Brooklyn, NY), while exercisers performed 9 resistive exercises without volume restrictions in a 1g environment. Data were collected from two male subjects, one being in the 99th percentile of height and the other in the 50th percentile of height, using between 25 and 60 motion capture markers. Motion capture data was also recorded as a third subject, also near the 50th percentile in height, performed aerobic rowing during a parabolic flight. A motion capture system and algorithms developed previously and presented at last years HRP-IWS were utilized to collect and process the data from the parabolic flight [1]. These motions were applied to a scaled version of a biomechanical model within the biomechanical modeling software OpenSim [2], and the volume sweeps of the motions were visually assessed against an imported CAD model of the operational volume. Further numerical analysis was performed using Matlab (Mathworks, Natick, MA) and the OpenSim API. This analysis determined the location of every marker in space over the duration of the exercise motion, and the distance of each marker to the nearest surface of the volume. Containment of the exercise motions within the operational volume was determined on a per-exercise and per-subject basis. The orientation of the exerciser and the angle of the footplate were two important factors upon which containment was dependent. Regions where the exercise motion exceeds the bounds of the operational volume have been identified by determining which markers from the motion capture exceed the operational volume and by how much. A credibility assessment of this analysis was performed in accordance with NASA-STD-7009 prior to delivery to the MPCV program.

Basic as well as detailed neurosonograms can be performed by offline analysis of three-dimensional fetal brain volumes.

PubMed

Bornstein, E; Monteagudo, A; Santos, R; Strock, I; Tsymbal, T; Lenchner, E; Timor-Tritsch, I E

2010-07-01

To evaluate the feasibility and the processing time of offline analysis of three-dimensional (3D) brain volumes to perform a basic, as well as a detailed, targeted, fetal neurosonogram. 3D fetal brain volumes were obtained in 103 consecutive healthy fetuses that underwent routine anatomical survey at 20-23 postmenstrual weeks. Transabdominal gray-scale and power Doppler volumes of the fetal brain were acquired by one of three experienced sonographers (an average of seven volumes per fetus). Acquisition was first attempted in the sagittal and coronal planes. When the fetal position did not enable easy and rapid access to these planes, axial acquisition at the level of the biparietal diameter was performed. Offline analysis of each volume was performed by two of the authors in a blinded manner. A systematic technique of 'volume manipulation' was used to identify a list of 25 brain dimensions/structures comprising a complete basic evaluation, intracranial biometry and a detailed targeted fetal neurosonogram. The feasibility and reproducibility of obtaining diagnostic-quality images of the different structures was evaluated, and processing times were recorded, by the two examiners. Diagnostic-quality visualization was feasible in all of the 25 structures, with an excellent visualization rate (85-100%) reported in 18 structures, a good visualization rate (69-97%) reported in five structures and a low visualization rate (38-54%) reported in two structures, by the two examiners. An average of 4.3 and 5.4 volumes were used to complete the examination by the two examiners, with a mean processing time of 7.2 and 8.8 minutes, respectively. The overall agreement rate for diagnostic visualization of the different brain structures between the two examiners was 89.9%, with a kappa coefficient of 0.5 (P < 0.001). In experienced hands, offline analysis of 3D brain volumes is a reproducible modality that can identify all structures necessary to complete both a basic and a detailed second-trimester fetal neurosonogram. Copyright 2010 ISUOG. Published by John Wiley & Sons, Ltd.

Cerebellar contribution to motor and cognitive performance in multiple sclerosis: An MRI sub-regional volumetric analysis.

PubMed

D'Ambrosio, Alessandro; Pagani, Elisabetta; Riccitelli, Gianna C; Colombo, Bruno; Rodegher, Mariaemma; Falini, Andrea; Comi, Giancarlo; Filippi, Massimo; Rocca, Maria A

2017-08-01

To investigate the role of cerebellar sub-regions on motor and cognitive performance in multiple sclerosis (MS) patients. Whole and sub-regional cerebellar volumes, brain volumes, T2 hyperintense lesion volumes (LV), and motor performance scores were obtained from 95 relapse-onset MS patients and 32 healthy controls (HC). MS patients also underwent an evaluation of working memory and processing speed functions. Cerebellar anterior and posterior lobes were segmented using the Spatially Unbiased Infratentorial Toolbox (SUIT) from Statistical Parametric Mapping (SPM12). Multivariate linear regression models assessed the relationship between magnetic resonance imaging (MRI) measures and motor/cognitive scores. Compared to HC, only secondary progressive multiple sclerosis (SPMS) patients had lower cerebellar volumes (total and posterior cerebellum). In MS patients, lower anterior cerebellar volume and brain T2 LV predicted worse motor performance, whereas lower posterior cerebellar volume and brain T2 LV predicted poor cognitive performance. Global measures of brain volume and infratentorial T2 LV were not selected by the final multivariate models. Cerebellar volumetric abnormalities are likely to play an important contribution to explain motor and cognitive performance in MS patients. Consistently with functional mapping studies, cerebellar posterior-inferior volume accounted for variance in cognitive measures, whereas anterior cerebellar volume accounted for variance in motor performance, supporting the assessment of cerebellar damage at sub-regional level.

Impact of Depression, Fatigue, and Global Measure of Cortical Volume on Cognitive Impairment in Multiple Sclerosis

PubMed Central

De Cola, Maria Cristina; D'Aleo, Giangaetano; Sessa, Edoardo; Marino, Silvia

2015-01-01

Objective. To investigate the influence of demographic and clinical variables, such as depression, fatigue, and quantitative MRI marker on cognitive performances in a sample of patients affected by multiple sclerosis (MS). Methods. 60 MS patients (52 relapsing remitting and 8 primary progressive) underwent neuropsychological assessments using Rao's Brief Repeatable Battery of Neuropsychological Tests (BRB-N), the Beck Depression Inventory-second edition (BDI-II), and the Fatigue Severity Scale (FSS). We performed magnetic resonance imaging to all subjects using a 3 T scanner and obtained tissue-specific volumes (normalized brain volume and cortical brain volume). We used Student's t-test to compare depressed and nondepressed MS patients. Finally, we performed a multivariate regression analysis in order to assess possible predictors of patients' cognitive outcome among demographic and clinical variables. Results. 27.12% of the sample (16/59) was cognitively impaired, especially in tasks requiring attention and information processing speed. From between group comparison, we find that depressed patients had worse performances on BRB-N score, greater disability and disease duration, and brain volume decrease. According to multiple regression analysis, the BDI-II score was a significant predictor for most of the neuropsychological tests. Conclusions. Our findings suggest that the presence of depressive symptoms is an important determinant of cognitive performance in MS patients. PMID:25861633

Orbit Transfer Vehicle (OTV) engine, phase A study. Volume 2: Study

NASA Technical Reports Server (NTRS)

Mellish, J. A.

1979-01-01

The hydrogen oxygen engine used in the orbiter transfer vehicle is described. The engine design is analyzed and minimum engine performance and man rating requirements are discussed. Reliability and safety analysis test results are presented and payload, risk and cost, and engine installation parameters are defined. Engine tests were performed including performance analysis, structural analysis, thermal analysis, turbomachinery analysis, controls analysis, and cycle analysis.

Space Shuttle Main Engine structural analysis and data reduction/evaluation. Volume 5: Main Injector LOX Inlet analysis

NASA Technical Reports Server (NTRS)

Violett, Rebeca S.

1989-01-01

The analysis performed on the Main Injector LOX Inlet Assembly located on the Space Shuttle Main Engine is summarized. An ANSYS finite element model of the inlet assemably was built and executed. Static stress analysis was also performed.

A Study of Job Demands and Curriculum Development in Agricultural Training Related to the Muskegon County Wastewater Management System. Final Report. Volume II. Task Analysis Results.

ERIC Educational Resources Information Center

Fisher, Harold S.; And Others

This is the second volume of a four-volume report of a research project designed to (1) identify job needs for agricultural occupations which will result from the Muskegon County Wastewater Management System and perform a task analysis on each occupation, (2) develop instructional modules and determine their place in either high school or 2-year…

Individual Global Navigation Satellite Systems in the Space Service Volume

NASA Technical Reports Server (NTRS)

Force, Dale A.

2015-01-01

Besides providing position, navigation, and timing (PNT) to terrestrial users, GPS is currently used to provide for precision orbit determination, precise time synchronization, real-time spacecraft navigation, and three-axis control of Earth orbiting satellites. With additional Global Navigation Satellite Systems (GNSS) coming into service (GLONASS, Beidou, and Galileo), it will be possible to provide these services by using other GNSS constellations. The paper, "GPS in the Space Service Volume," presented at the ION GNSS 19th International Technical Meeting in 2006 (Ref. 1), defined the Space Service Volume, and analyzed the performance of GPS out to 70,000 km. This paper will report a similar analysis of the performance of each of the additional GNSS and compare them with GPS alone. The Space Service Volume, defined as the volume between 3,000 km altitude and geosynchronous altitude, as compared with the Terrestrial Service Volume between the surface and 3,000 km. In the Terrestrial Service Volume, GNSS performance will be similar to performance on the Earth's surface. The GPS system has established signal requirements for the Space Service Volume. A separate paper presented at the conference covers the use of multiple GNSS in the Space Service Volume.

Cerebellum and cognition in multiple sclerosis: the fall status matters.

PubMed

Kalron, Alon; Allali, Gilles; Achiron, Anat

2018-04-01

Cerebellar volume has been linked with cognitive performances in MS; however, the association in terms of fall status has never been compared. Therefore, the objective of the current study was to compare cognitive performance with cerebellar volume between MS fallers and non-fallers. The cross-sectional study included 140 PwMS (96 women). MRI volumetric analysis was based on the FreeSurfer image analysis suite. Volumes of the cerebellar gray and white matter were identified as the region of interest. Cognitive function included scores obtained from a computerized cognitive battery of tests. The sample was divided into fallers and non-fallers. MS fallers demonstrated a lower global cognitive performance and reduced gray and white matter cerebellar volumes compared to non-fallers. A significant association was found between total gray and white matter cerebellar volume and visual spatial subdomain (P value = 0.044 and 0.032, respectively) in the non-fallers group. The association remained significant after controlling for the total cranial volume and neurological disability (P value = 0.026 and 0.047, respectively). A relationship was found between the visual spatial score and the left gray matter cerebellum volume; R 2  = 0.44, P value = 0.021. We believe that a unique relationship exists between the cerebellum structure and cognitive processing according to fall history in PwMS and should be considered when investigating the association between brain functioning and cognitive performances in MS.

A Study of Job Demands and Curriculum Development in Agricultural Training Related to the Muskegon County Wastewater Management System. Final Report. Volume III. Student Terminal Performance Objectives and Instructional Modules.

ERIC Educational Resources Information Center

Fisher, Harold S.; And Others

This is the third volume of a four-volume report of a research project designed to (1) identify job needs for agricultural occupations which will result from the Muskegon County Wastewater Management System and perform a task analysis on each occupation, (2) develop instructional modules and determine their place in either high school or 2-year…

Identifying factors that predict the choice and success rate of radial artery catheterisation in contemporary real world cardiology practice: a sub-analysis of the PREVAIL study data.

PubMed

Pristipino, Christian; Roncella, Adriana; Trani, Carlo; Nazzaro, Marco S; Berni, Andrea; Di Sciascio, Germano; Sciahbasi, Alessandro; Musarò, Salvatore Donato; Mazzarotto, Pietro; Gioffrè, Gaetano; Speciale, Giulio

2010-06-01

To assess: the reasons behind an operator choosing to perform radial artery catheterisation (RAC) as against femoral arterial catheterisation, and to explore why RAC may fail in the real world. A pre-determined analysis of PREVAIL study database was performed. Relevant data were collected in a prospective, observational survey of 1,052 consecutive patients undergoing invasive cardiovascular procedures at nine Italian hospitals over a one month observation period. By multivariate analysis, the independent predictors of RAC choice were having the procedure performed: (1) at a high procedural volume centre; and (2) by an operator who performs a high volume of radial procedures; clinical variables played no statistically significant role. RAC failure was predicted independently by (1) a lower operator propensity to use RAC; and (2) the presence of obstructive peripheral artery disease. A 10-fold lower rate of RAC failure was observed among operators who perform RAC for > 85% of their personal caseload than among those who use RAC < 25% of the time (3.8% vs. 33.0%, respectively); by receiver operator characteristic (ROC) analysis, no threshold value for operator RAC volume predicted RAC failure. A routine RAC in all-comers is superior to a selective strategy in terms of feasibility and success rate.

Digital 3D Microstructure Analysis of Concrete using X-Ray Micro Computed Tomography SkyScan 1173: A Preliminary Study

NASA Astrophysics Data System (ADS)

Latief, F. D. E.; Mohammad, I. H.; Rarasati, A. D.

2017-11-01

Digital imaging of a concrete sample using high resolution tomographic imaging by means of X-Ray Micro Computed Tomography (μ-CT) has been conducted to assess the characteristic of the sample’s structure. A standard procedure of image acquisition, reconstruction, image processing of the method using a particular scanning device i.e., the Bruker SkyScan 1173 High Energy Micro-CT are elaborated. A qualitative and a quantitative analysis were briefly performed on the sample to deliver some basic ideas of the capability of the system and the bundled software package. Calculation of total VOI volume, object volume, percent of object volume, total VOI surface, object surface, object surface/volume ratio, object surface density, structure thickness, structure separation, total porosity were conducted and analysed. This paper should serve as a brief description of how the device can produce the preferred image quality as well as the ability of the bundled software packages to help in performing qualitative and quantitative analysis.

The Centralization of Total Joint Arthroplasty in New York State An Analysis of 168,247 Cases.

PubMed

Adrados, Murillo; Theobald, Jason; Hutzler, Lorraine; Bosco, Joseph

2016-11-01

We identified 168,247 total hip and total knee arthroplasties performed in New York State between 2010 and 2012 to examine the evidence for increased geographical and institutional centralization of these procedures. We measured the increased growth of high volume institutions as compared to lower volume hospitals in New York State. We found a high proportion of total arthroplasties already performed in the dozen biggest hospitals in New York back in 2010 and a significant higher growth of these high volume, "centers of excellence," hospitals when compared to low volume hospitals.

An Analysis of Organizational Behavior Management Research in Terms of the Three-Contingency Model of Performance Management

ERIC Educational Resources Information Center

Weatherly, Nicholas L.; Malott, Richard W.

2008-01-01

The three-contingency model of performance management (Malott, 1992, 1993, 1999) was used to analyze interventions in the "Journal of Organizational Behavior Management (JOBM)" from the years 1990 through 2005 (Volume 11[1]-Volume 25[4]). The current article extends previous reviews (Malott, Shimamune, & Malott, 1992; Otto & Malott, 2004) by…

Reduction of Costs for Pelvic Exenteration Performed by High Volume Surgeons: Analysis of the Maryland Health Service Cost Review Commission Database.

PubMed

Althumairi, Azah A; Canner, Joseph K; Gorin, Michael A; Fang, Sandy H; Gearhart, Susan L; Wick, Elizabeth C; Safar, Bashar; Bivalacqua, Trinity J; Efron, Jonathan E

2016-01-01

High volume hospitals (HVHs) and high volume surgeons (HVSs) have better outcomes after complex procedures, but the association between surgeon and hospital volumes and patient outcomes is not completely understood. Our aim was to evaluate the impact of surgeon and hospital volumes, and their interaction, on postoperative outcomes and costs in patients undergoing pelvic exenteration (PE) in the state of Maryland. A review of the Maryland Health Services Cost Review Commission database between 2000 and 2011 was performed. Patients were compared for demographics and clinical variables. The differences in length of hospital stay , length of intensive care unit (ICU) stay, operating room (OR) cost, and total cost were compared for surgeon volume and hospital volume controlling for all other factors. Surgery performed by HVS at HVH had the shortest ICU stay and lowest OR cost. When PE was performed by a low volume surgeon at an HVH, the OR cost and total cost were the highest and increased by $2,683 (P < 0.0001) and $16,076 (P < 0.0001), respectively. OR costs reduced when surgery was performed by an HVS at an HVH ($-1632, P = 0.008). PE performed by HVS at HVH is significantly associated with lower OR costs and ICU stay. We feel this is indicative of lower complication rates and higher quality care.

Solar cell array design handbook, volume 1

NASA Technical Reports Server (NTRS)

Rauschenbach, H. S.

1976-01-01

Twelve chapters discuss the following: historical developments, the environment and its effects, solar cells, solar cell filters and covers, solar cell and other electrical interconnections, blocking and shunt diodes, substrates and deployment mechanisms, material properties, design synthesis and optimization, design analysis, procurement, production and cost aspects, evaluation and test, orbital performance, and illustrative design examples. A comprehensive index permits rapid locating of desired topics. The handbook consists of two volumes: Volume 1 is of an expository nature while Volume 2 contains detailed design data in an appendix-like fashion. Volume 2 includes solar cell performance data, applicable unit conversion factors and physical constants, and mechanical, electrical, thermal optical, magnetic, and outgassing material properties. Extensive references are provided.

Airport Landside. Volume I. Planning Guide.

DOT National Transportation Integrated Search

1982-01-01

This volume describes a methodology for performing airport landside planning by applying the Airport Landside Simulation Model (ALSIM) developed by TSC. For this analysis, the airport landside is defined as extending from the airport boundary to the ...

Public Interest in Breast Augmentation: Analysis and Implications of Google Trends Data.

PubMed

Wilson, Stelios C; Daar, David A; Sinno, Sammy; Levine, Steven M

2018-06-01

Breast augmentation is the most common aesthetic surgery performed in the United States (US) annually. Analysis of Google Trends (GT) data may give plastic surgeons useful information regarding worldwide, national, and regional interest for breast augmentation and other commonly performed aesthetic surgeries. Data were collected using GT for breast augmentation and associated search terms from January 2004 to May 2017. Case volume was obtained from the American Society of Plastic Surgeons (ASPS) annual reports for the calendar year 2005-2016. Trend analysis showed that total search term volume for breast augmentation and breast implants gradually decreased worldwide and in the US over the study period while the search term boob job slowly increased. Univariate linear regression demonstrated a statistically significant positive correlation between average annual Google search volume of "breast augmentation" and the annual volume of breast augmentations performed in the US according to ASPS data (R 2  = 0.44, p = 0.018). There was no significant correlation between national volume of breast augmentations performed and search volume using the terms "breast implants" or "boob job" over time (p = 0.84 and p = 0.07, respectively). In addition, there appears to be country specific variation in interest based on time of year and peaks in interest following specific policies. To our knowledge, this is the first and only analysis of GT data in the plastic surgery literature to date. To that end, this study highlights this large and potentially powerful data set for plastic surgeons both in the US and around the world. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Underground Test Area Subproject Phase I Data Analysis Task. Volume VIII - Risk Assessment Documentation Package

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

None

Volume VIII of the documentation for the Phase I Data Analysis Task performed in support of the current Regional Flow Model, Transport Model, and Risk Assessment for the Nevada Test Site Underground Test Area Subproject contains the risk assessment documentation. Because of the size and complexity of the model area, a considerable quantity of data was collected and analyzed in support of the modeling efforts. The data analysis task was consequently broken into eight subtasks, and descriptions of each subtask's activities are contained in one of the eight volumes that comprise the Phase I Data Analysis Documentation.

Underground Test Area Subproject Phase I Data Analysis Task. Volume VII - Tritium Transport Model Documentation Package

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

None

Volume VII of the documentation for the Phase I Data Analysis Task performed in support of the current Regional Flow Model, Transport Model, and Risk Assessment for the Nevada Test Site Underground Test Area Subproject contains the tritium transport model documentation. Because of the size and complexity of the model area, a considerable quantity of data was collected and analyzed in support of the modeling efforts. The data analysis task was consequently broken into eight subtasks, and descriptions of each subtask's activities are contained in one of the eight volumes that comprise the Phase I Data Analysis Documentation.

Cognitive correlates of white matter lesion load and brain atrophy

PubMed Central

Dong, Chuanhui; Nabizadeh, Nooshin; Caunca, Michelle; Cheung, Ying Kuen; Rundek, Tatjana; Elkind, Mitchell S.V.; DeCarli, Charles; Sacco, Ralph L.; Stern, Yaakov

2015-01-01

Objective: We investigated white matter lesion load and global and regional brain volumes in relation to domain-specific cognitive performance in the stroke-free Northern Manhattan Study (NOMAS) population. Methods: We quantified white matter hyperintensity volume (WMHV), total cerebral volume (TCV), and total lateral ventricular (TLV) volume, as well as hippocampal and cortical gray matter (GM) lobar volumes in a subgroup. We used general linear models to examine MRI markers in relation to domain-specific cognitive performance, adjusting for key covariates. Results: MRI and cognitive data were available for 1,163 participants (mean age 70 ± 9 years; 60% women; 66% Hispanic, 17% black, 15% white). Across the entire sample, those with greater WMHV had worse processing speed. Those with larger TLV volume did worse on episodic memory, processing speed, and semantic memory tasks, and TCV did not explain domain-specific variability in cognitive performance independent of other measures. Age was an effect modifier, and stratified analysis showed that TCV and WMHV explained variability in some domains above age 70. Smaller hippocampal volume was associated with worse performance across domains, even after adjusting for APOE ε4 and vascular risk factors, whereas smaller frontal lobe volumes were only associated with worse executive function. Conclusions: In this racially/ethnically diverse, community-based sample, white matter lesion load was inversely associated with cognitive performance, independent of brain atrophy. Lateral ventricular, hippocampal, and lobar GM volumes explained domain-specific variability in cognitive performance. PMID:26156514

Eliminating the blood-flow confounding effect in intravoxel incoherent motion (IVIM) using the non-negative least square analysis in liver.

PubMed

Gambarota, Giulio; Hitti, Eric; Leporq, Benjamin; Saint-Jalmes, Hervé; Beuf, Olivier

2017-01-01

Tissue perfusion measurements using intravoxel incoherent motion (IVIM) diffusion-MRI are of interest for investigations of liver pathologies. A confounding factor in the perfusion quantification is the partial volume between liver tissue and large blood vessels. The aim of this study was to assess and correct for this partial volume effect in the estimation of the perfusion fraction. MRI experiments were performed at 3 Tesla with a diffusion-MRI sequence at 12 b-values. Diffusion signal decays in liver were analyzed using the non-negative least square (NNLS) method and the biexponential fitting approach. In some voxels, the NNLS analysis yielded a very fast-decaying component that was assigned to partial volume with the blood flowing in large vessels. Partial volume correction was performed by biexponential curve fitting, where the first data point (b = 0 s/mm 2 ) was eliminated in voxels with a very fast-decaying component. Biexponential fitting with partial volume correction yielded parametric maps with perfusion fraction values smaller than biexponential fitting without partial volume correction. The results of the current study indicate that the NNLS analysis in combination with biexponential curve fitting allows to correct for partial volume effects originating from blood flow in IVIM perfusion fraction measurements. Magn Reson Med 77:310-317, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Preoperative prognostic value of dynamic contrast-enhanced MRI-derived contrast transfer coefficient and plasma volume in patients with cerebral gliomas.

PubMed

Nguyen, T B; Cron, G O; Mercier, J F; Foottit, C; Torres, C H; Chakraborty, S; Woulfe, J; Jansen, G H; Caudrelier, J M; Sinclair, J; Hogan, M J; Thornhill, R E; Cameron, I G

2015-01-01

The prognostic value of dynamic contrast-enhanced MR imaging-derived plasma volume obtained in tumor and the contrast transfer coefficient has not been well-established in patients with gliomas. We determined whether plasma volume and contrast transfer coefficient in tumor correlated with survival in patients with gliomas in addition to other factors such as age, type of surgery, preoperative Karnofsky score, contrast enhancement, and histopathologic grade. This prospective study included 46 patients with a new pathologically confirmed diagnosis of glioma. The contrast transfer coefficient and plasma volume obtained in tumor maps were calculated directly from the signal-intensity curve without T1 measurements, and values were obtained from multiple small ROIs placed within tumors. Survival curve analysis was performed by dichotomizing patients into groups of high and low contrast transfer coefficient and plasma volume. Univariate analysis was performed by using dynamic contrast-enhanced parameters and clinical factors. Factors that were significant on univariate analysis were entered into multivariate analysis. For all patients with gliomas, survival was worse for groups of patients with high contrast transfer coefficient and plasma volume obtained in tumor (P < .05). In subgroups of high- and low-grade gliomas, survival was worse for groups of patients with high contrast transfer coefficient and plasma volume obtained in tumor (P < .05). Univariate analysis showed that factors associated with lower survival were age older than 50 years, low Karnofsky score, biopsy-only versus resection, marked contrast enhancement versus no/mild enhancement, high contrast transfer coefficient, and high plasma volume obtained in tumor (P < .05). In multivariate analysis, a low Karnofsky score, biopsy versus resection in combination with marked contrast enhancement, and a high contrast transfer coefficient were associated with lower survival rates (P < .05). In patients with glioma, those with a high contrast transfer coefficient have lower survival than those with low parameters. © 2015 by American Journal of Neuroradiology.

Driver performance measurement and analysis system (DPMAS). Volume 1, Description and operations manual

DOT National Transportation Integrated Search

1976-08-01

A prototype driver performance measurement and analysis system (DPMAS) has been developed for the National Highway Traffic Safety Administration (NHTSA). This system includes a completely instrumented 1974 Chevrolet Impala capable of digitally record...

Prone positioning reduces mortality from acute respiratory distress syndrome in the low tidal volume era: a meta-analysis

PubMed Central

Shaefi, Shahzad; Montesi, Sydney B.; Devlin, Amy; Loring, Stephen H.; Talmor, Daniel; Malhotra, Atul

2014-01-01

Purpose Prone positioning for ARDS has been performed for decades without definitive evidence of clinical benefit. A recent multicenter trial demonstrated for the first time significantly reduced mortality with prone positioning. This meta-analysis was performed to integrate these findings with existing literature and test whether differences in tidal volume explain conflicting results among randomized trials. Methods Studies were identified using MEDLINE, EMBASE, Cochrane Register of Controlled Trials, LILACS, and citation review. Included were randomized trials evaluating the effect on mortality of prone versus supine positioning during conventional ventilation for ARDS. The primary outcome was risk ratio of death at 60 days meta-analyzed using random effects models. Analysis stratified by high (>8 ml/kg predicted body weight) or low (≤8 ml/kg PBW) mean baseline tidal volume was planned a priori. Results Seven trials were identified including 2,119 patients, of whom 1,088 received prone positioning. Overall, prone positioning was not significantly associated with the risk ratio of death (RR 0.83; 95 % CI 0.68–1.02; p = 0.073; I2 = 64 %). When stratified by high or low tidal volume, prone positioning was associated with a significant decrease in RR of death only among studies with low baseline tidal volume (RR 0.66; 95 % CI 0.50–0.86; p = 0.002; I2 = 25 %). Stratification by tidal volume explained over half the between-study heterogeneity observed in the unstratified analysis. Conclusions Prone positioning is associated with significantly reduced mortality from ARDS in the low tidal volume era. Substantial heterogeneity across studies can be explained by differences in tidal volume. PMID:24435203

Twenty-fifth water reactor safety information meeting: Proceedings. Volume 2: Human reliability analysis and human performance evaluation; Technical issues related to rulemakings; Risk-informed, performance-based initiatives; High burn-up fuel research

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

Monteleone, S.

1998-03-01

This three-volume report contains papers presented at the conference. The papers are printed in the order of their presentation in each session and describe progress and results of programs in nuclear safety research conducted in this country and abroad. Foreign participation in the meeting included papers presented by researchers from France, Japan, Norway, and Russia. The titles of the papers and the names of the authors have been updated and may differ from those that appeared in the final program of the meeting. This volume contains the following: (1) human reliability analysis and human performance evaluation; (2) technical issues relatedmore » to rulemakings; (3) risk-informed, performance-based initiatives; and (4) high burn-up fuel research. Selected papers have been indexed separately for inclusion in the Energy Science and Technology Database.« less

Volumetrically-Derived Global Navigation Satellite System Performance Assessment from the Earths Surface through the Terrestrial Service Volume and the Space Service Volume

NASA Technical Reports Server (NTRS)

Welch, Bryan W.

2016-01-01

NASA is participating in the International Committee on Global Navigation Satellite Systems (GNSS) (ICG)'s efforts towards demonstrating the benefits to the space user from the Earth's surface through the Terrestrial Service Volume (TSV) to the edge of the Space Service Volume (SSV), when a multi-GNSS solution space approach is utilized. The ICG Working Group: Enhancement of GNSS Performance, New Services and Capabilities has started a three phase analysis initiative as an outcome of recommendations at the ICG-10 meeting, in preparation for the ICG-11 meeting. The first phase of that increasing complexity and fidelity analysis initiative was recently expanded to compare nadir-facing and zenith-facing user hemispherical antenna coverage with omnidirectional antenna coverage at different distances of 8,000 km altitude and 36,000 km altitude. This report summarizes the performance using these antenna coverage techniques at distances ranging from 100 km altitude to 36,000 km to be all encompassing, as well as the volumetrically-derived system availability metrics.

Break-even analysis revisited: the need to adjust for profitability, the collection rate and autonomous income.

PubMed

Broyles, R W; Narine, L; Khaliq, A

2003-08-01

This paper modifies traditional break-even analysis and develops a model that reflects the influence of variation in payer mix, the collection rate, profitability and autonomous income on the desired volume alternative. The augmented model indicates that a failure to adjust for uncollectibles and the net surplus results in a systematic understatement of the desired volume alternative. Conversely, a failure to adjust for autonomous income derived from the operation of cafeterias, gift shops or an organization's investment in marketable securities produces an overstatement of the desired volume. In addition, this paper uses Microsoft Excel to develop a spreadsheet that constructs a pro forma income statement, expressed in terms of the contribution margin. The spreadsheet also relies on the percentage of sales or revenue approach to prepare a balance sheet from which indicators of fiscal performance are calculated. Hence, the analysis enables the organization to perform a sensitivity analysis of potential changes in the desired volume, the operating margin, the current ratio, the debt: equity ratio and the amount of cash derived from operations that are associated with expected variation in payer mix, the collection rate, grouped by payer, the net surplus and autonomous income.

Theoretical and experimental analysis of a multiphase screw pump, handling gas-liquid mixtures with very high gas volume fractions

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

Raebiger, K.; Faculty of Advanced Technology, University of Glamorgan, Pontypridd, Wales; Maksoud, T.M.A.

In the investigation of the pumping behaviour of multiphase screw pumps, handling gas-liquid mixtures with very high gas volume fractions, theoretical and experimental analyses were performed. A new theoretical screw pump model was developed, which calculates the time-dependent conditions inside the several chambers of a screw pump as well as the exchange of mass and energy between these chambers. By means of the performed experimental analysis, the screw pump model was verified, especially at very high gas volume fractions from 90% to 99%. The experiments, which were conducted with the reference fluids water and air, can be divided mainly intomore » the determination of the steady state pumping behaviour on the one hand and into the analysis of selected transient operating conditions on the other hand, whereas the visualisation of the leakage flows through the circumferential gaps was rounded off the experimental analysis. (author)« less

Associations between regional brain volumes at term-equivalent age and development at 2 years of age in preterm children.

PubMed

Lind, Annika; Parkkola, Riitta; Lehtonen, Liisa; Munck, Petriina; Maunu, Jonna; Lapinleimu, Helena; Haataja, Leena

2011-08-01

Altered brain volumes and associations between volumes and developmental outcomes have been reported in prematurely born children. To assess which regional brain volumes are different in very low birth weight (VLBW) children without neurodevelopmental impairments ([NDI] cerebral palsy, hearing loss, blindness and significantly delayed cognitive performance) compared with VLBW children with NDI, and to evaluate the association between regional brain volumes at term-equivalent age and cognitive development and neurological performance at a corrected age of 2 years. The study group consisted of a regional cohort of 164 VLBW children, divided into one group of children without NDI (n = 148) and one group of children with NDI (n = 16). Brain (MRI) was performed at term-equivalent age, from which brain volumes were manually analysed. Cognitive development was assessed with the Bayley Scales of Infant Development II (BSID-II), and neurological performance with the Hammersmith Infant Neurological Examination at the corrected age of 2 years. The volumes of total brain tissue, cerebrum, frontal lobes, basal ganglia and thalami, and cerebellum were significantly smaller, and the volume of the ventricles significantly larger, in the children with NDI than in those without NDI. Even in children without NDI, a smaller cerebellar volume was significantly correlated with poor neurological performance at 2 years of corrected age. Volumetric analysis at brain MRI can provide an additional parameter for early prediction of outcome in VLBW children.

MOD-5A wind turbine generator program design report: Volume 1: Executive Summary

NASA Technical Reports Server (NTRS)

1984-01-01

The design, development and analysis of the 7.3 MW MOD-5A wind turbine generator covering work performed between July 1980 and June 1984 is discussed. The report is divided into four volumes: Volume 1 summarizes the entire MOD-5A program, Volume 2 discusses the conceptual and preliminary design phases, Volume 3 describes the final design of the MOD-5A, and Volume 4 contains the drawings and specifications developed for the final design. Volume 1, the Executive Summary, summarizes all phases of the MOD-5A program. The performance and cost of energy generated by the MOD-5A are presented. Each subsystem - the rotor, drivetrain, nacelle, tower and foundation, power generation, and control and instrumentation subsystems - is described briefly. The early phases of the MOD-5A program, during which the design was analyzed and optimized, and new technologies and materials were developed, are discussed. Manufacturing, quality assurance, and safety plans are presented. The volume concludes with an index of volumes 2 and 3.

An analysis of malar fat volume in two age groups: implications for craniofacial surgery.

PubMed

Corey, Christina L; Popelka, Gerald R; Barrera, Jose E; Most, Sam P

2012-12-01

Objective To evaluate how malar fat pad (MFP) volumes vary with age, after controlling for gender and body mass index (BMI). Study Design A prospective case-control study evaluating volume of the MFP in women of two age groups. Methods Soft tissue dimensions were measured in eight subjects using magnetic resonance imaging. A multiplanar localizing sequence, followed in sagittal and coronal orientations using a turbo spin echo sequence, was performed to define the MFP. Volumetric calculations were then performed using a 3D image analysis application (Dextroscope, Volume Interactions, Republic of Singapore) to circumscribe areas, orient dimensions, and calculate volumes of the MFP. Results These data reveal no significant difference in the mean (standard deviation) right MFP (p = 0.50), left MFP (p = 0.41), or total MFP (p = 0.45) volumes when comparing the two age groups. In addition, these data indicate that there was no correlation between age and total MFP volume (Pearson correlation coefficient 0.27). Moreover, there was no correlation between age and the ratio of total volume/BMI (Pearson correlation coefficient -0.18). Conclusions Although the sample size of this study was small, these data indicate that ptosis of midfacial fat is more important than volume loss in midfacial aging. These data would suggest repositioning as the primary modality for craniofacial reconstruction.

Evolutionary space platform concept study. Volume 2, part B: Manned space platform concepts

NASA Technical Reports Server (NTRS)

1982-01-01

Logical, cost-effective steps in the evolution of manned space platforms are investigated and assessed. Tasks included the analysis of requirements for a manned space platform, identifying alternative concepts, performing system analysis and definition of the concepts, comparing the concepts and performing programmatic analysis for a reference concept.

The Impact of Hospital Size on CMS Hospital Profiling.

PubMed

Sosunov, Eugene A; Egorova, Natalia N; Lin, Hung-Mo; McCardle, Ken; Sharma, Vansh; Gelijns, Annetine C; Moskowitz, Alan J

2016-04-01

The Centers for Medicare & Medicaid Services (CMS) profile hospitals using a set of 30-day risk-standardized mortality and readmission rates as a basis for public reporting. These measures are affected by hospital patient volume, raising concerns about uniformity of standards applied to providers with different volumes. To quantitatively determine whether CMS uniformly profile hospitals that have equal performance levels but different volumes. Retrospective analysis of patient-level and hospital-level data using hierarchical logistic regression models with hospital random effects. Simulation of samples including a subset of hospitals with different volumes but equal poor performance (hospital effects=+3 SD in random-effect logistic model). A total of 1,085,568 Medicare fee-for-service patients undergoing 1,494,993 heart failure admissions in 4930 hospitals between July 1, 2005 and June 30, 2008. CMS methodology was used to determine the rank and proportion (by volume) of hospitals reported to perform "Worse than US National Rate." Percent of hospitals performing "Worse than US National Rate" was ∼40 times higher in the largest (fifth quintile by volume) compared with the smallest hospitals (first quintile). A similar gradient was seen in a cohort of 100 hospitals with simulated equal poor performance (0%, 0%, 5%, 20%, and 85% in quintiles 1 to 5) effectively leaving 78% of poor performers undetected. Our results illustrate the disparity of impact that the current CMS method of hospital profiling has on hospitals with higher volumes, translating into lower thresholds for detection and reporting of poor performance.

Evaluation of Diesel Engine Performance with Intake and Exhaust System Throttling : Volume 2. Appendix 1.

DOT National Transportation Integrated Search

1975-11-01

The appendix to the preceding volume presents the data for the subject diesel engine noise study, including an engine sound power level analysis and sound spectrums showing the effect of intake and exhaust restrictions.

A modeling technique for STOVL ejector and volume dynamics

NASA Technical Reports Server (NTRS)

Drummond, C. K.; Barankiewicz, W. S.

1990-01-01

New models for thrust augmenting ejector performance prediction and feeder duct dynamic analysis are presented and applied to a proposed Short Take Off and Vertical Landing (STOVL) aircraft configuration. Central to the analysis is the nontraditional treatment of the time-dependent volume integrals in the otherwise conventional control-volume approach. In the case of the thrust augmenting ejector, the analysis required a new relationship for transfer of kinetic energy from the primary flow to the secondary flow. Extraction of the required empirical corrections from current steady-state experimental data is discussed; a possible approach for modeling insight through Computational Fluid Dynamics (CFD) is presented.

Heat Transfer Characteristics of Fan Coil Unit (FCU) Under The Effect of Chilled Water Volume Flowrate

NASA Astrophysics Data System (ADS)

Wijaya Sunu, Putu; Anakottapary, Daud Simon; Mulawarman, A. A. N. B.; Cipta Santosa, I. D. M.; Putu Sastra Negara, I.

2018-01-01

In this paper, the volume flowrate of chilled water in the water chiller simulation apparatus was optimized using experimental studied. The experimental analysis was performed on the fan coil unit (FCU) of the system. The chilled water flows in tube side and the air as a hot fluid flows throughout the tube and fin of FCU. The thermal performance and analysis of the heat transfer is examined using various chilled water flowrate e.g. 11, 12, 13, 14, 15 lpm. The effect of the flowrate to the important parameter such as LMTD temperature, heat absorb used for investigate the heat transfer characteristics. The result showed that the heat transfer characteristics has been increased with the increased of chilled water volume flowrate.

Performance Analysis and Design Synthesis (PADS) computer program. Volume 2: Program description, part 2

NASA Technical Reports Server (NTRS)

1972-01-01

The QL module of the Performance Analysis and Design Synthesis (PADS) computer program is described. Execution of this module is initiated when and if subroutine PADSI calls subroutine GROPE. Subroutine GROPE controls the high level logical flow of the QL module. The purpose of the module is to determine a trajectory that satisfies the necessary variational conditions for optimal performance. The module achieves this by solving a nonlinear multi-point boundary value problem. The numerical method employed is described. It is an iterative technique that converges quadratically when it does converge. The three basic steps of the module are: (1) initialization, (2) iteration, and (3) culmination. For Volume 1 see N73-13199.

Geometric convex cone volume analysis

NASA Astrophysics Data System (ADS)

Li, Hsiao-Chi; Chang, Chein-I.

2016-05-01

Convexity is a major concept used to design and develop endmember finding algorithms (EFAs). For abundance unconstrained techniques, Pixel Purity Index (PPI) and Automatic Target Generation Process (ATGP) which use Orthogonal Projection (OP) as a criterion, are commonly used method. For abundance partially constrained techniques, Convex Cone Analysis is generally preferred which makes use of convex cones to impose Abundance Non-negativity Constraint (ANC). For abundance fully constrained N-FINDR and Simplex Growing Algorithm (SGA) are most popular methods which use simplex volume as a criterion to impose ANC and Abundance Sum-to-one Constraint (ASC). This paper analyze an issue encountered in volume calculation with a hyperplane introduced to illustrate an idea of bounded convex cone. Geometric Convex Cone Volume Analysis (GCCVA) projects the boundary vectors of a convex cone orthogonally on a hyperplane to reduce the effect of background signatures and a geometric volume approach is applied to address the issue arose from calculating volume and further improve the performance of convex cone-based EFAs.

Surgical volume-to-outcome relationship and monitoring of technical performance in pediatric cardiac surgery.

PubMed

Kalfa, David; Chai, Paul; Bacha, Emile

2014-08-01

A significant inverse relationship of surgical institutional and surgeon volumes to outcome has been demonstrated in many high-stakes surgical specialties. By and large, the same results were found in pediatric cardiac surgery, for which a more thorough analysis has shown that this relationship depends on case complexity and type of surgical procedures. Lower-volume programs tend to underperform larger-volume programs as case complexity increases. High-volume pediatric cardiac surgeons also tend to have better results than low-volume surgeons, especially at the more complex end of the surgery spectrum (e.g., the Norwood procedure). Nevertheless, this trend for lower mortality rates at larger centers is not universal. All larger programs do not perform better than all smaller programs. Moreover, surgical volume seems to account for only a small proportion of the overall between-center variation in outcome. Intraoperative technical performance is one of the most important parts, if not the most important part, of the therapeutic process and a critical component of postoperative outcome. Thus, the use of center-specific, risk-adjusted outcome as a tool for quality assessment together with monitoring of technical performance using a specific score may be more reliable than relying on volume alone. However, the relationship between surgical volume and outcome in pediatric cardiac surgery is strong enough that it ought to support adapted and well-balanced health care strategies that take advantage of the positive influence that higher center and surgeon volumes have on outcome.

Right-\\0xADturn traffic volume adjustment in traffic signal warrant analysis : final report.

DOT National Transportation Integrated Search

2016-05-06

This report was based on the research project, Right-Turn Traffic Volume Adjustment in : Traffic Signal Warrants, sponsored by the Nevada Department of Transportation (NDOT) : and SOLARIS. Right-turn traffic does not affect intersection performance i...

Right-­turn traffic volume adjustment in traffic signal warrant analysis : final report.

DOT National Transportation Integrated Search

2016-05-06

This report was based on the research project, Right-Turn Traffic Volume Adjustment in Traffic Signal Warrants, sponsored by the Nevada Department of Transportation (NDOT) and SOLARIS. Right-turn traffic does not affect intersection performance in th...

Validity of automated measurement of left ventricular ejection fraction and volume using the Philips EPIQ system.

PubMed

Hovnanians, Ninel; Win, Theresa; Makkiya, Mohammed; Zheng, Qi; Taub, Cynthia

2017-11-01

To assess the efficiency and reproducibility of automated measurements of left ventricular (LV) volumes and LV ejection fraction (LVEF) in comparison to manually traced biplane Simpson's method. This is a single-center prospective study. Apical four- and two-chamber views were acquired in patients in sinus rhythm. Two operators independently measured LV volumes and LVEF using biplane Simpson's method. In addition, the image analysis software a2DQ on the Philips EPIQ system was applied to automatically assess the LV volumes and LVEF. Time spent on each analysis, using both methods, was documented. Concordance of echocardiographic measures was evaluated using intraclass correlation (ICC) and Bland-Altman analysis. Manual tracing and automated measurement of LV volumes and LVEF were performed in 184 patients with a mean age of 67.3 ± 17.3 years and BMI 28.0 ± 6.8 kg/m 2 . ICC and Bland-Altman analysis showed good agreements between manual and automated methods measuring LVEF, end-systolic, and end-diastolic volumes. The average analysis time was significantly less using the automated method than manual tracing (116 vs 217 seconds/patient, P < .0001). Automated measurement using the novel image analysis software a2DQ on the Philips EPIQ system produced accurate, efficient, and reproducible assessment of LV volumes and LVEF compared with manual measurement. © 2017, Wiley Periodicals, Inc.

Design of an optimum computer vision-based automatic abalone (Haliotis discus hannai) grading algorithm.

PubMed

Lee, Donggil; Lee, Kyounghoon; Kim, Seonghun; Yang, Yongsu

2015-04-01

An automatic abalone grading algorithm that estimates abalone weights on the basis of computer vision using 2D images is developed and tested. The algorithm overcomes the problems experienced by conventional abalone grading methods that utilize manual sorting and mechanical automatic grading. To design an optimal algorithm, a regression formula and R(2) value were investigated by performing a regression analysis for each of total length, body width, thickness, view area, and actual volume against abalone weights. The R(2) value between the actual volume and abalone weight was 0.999, showing a relatively high correlation. As a result, to easily estimate the actual volumes of abalones based on computer vision, the volumes were calculated under the assumption that abalone shapes are half-oblate ellipsoids, and a regression formula was derived to estimate the volumes of abalones through linear regression analysis between the calculated and actual volumes. The final automatic abalone grading algorithm is designed using the abalone volume estimation regression formula derived from test results, and the actual volumes and abalone weights regression formula. In the range of abalones weighting from 16.51 to 128.01 g, the results of evaluation of the performance of algorithm via cross-validation indicate root mean square and worst-case prediction errors of are 2.8 and ±8 g, respectively. © 2015 Institute of Food Technologists®

Early Change in Stroke Size Performs Best in Predicting Response to Therapy.

PubMed

Simpkins, Alexis Nétis; Dias, Christian; Norato, Gina; Kim, Eunhee; Leigh, Richard

2017-01-01

Reliable imaging biomarkers of response to therapy in acute stroke are needed. The final infarct volume and percent of early reperfusion have been used for this purpose. Early fluctuation in stroke size is a recognized phenomenon, but its utility as a biomarker for response to therapy has not been established. This study examined the clinical relevance of early change in stroke volume and compared it with the final infarct volume and percent of early reperfusion in identifying early neurologic improvement (ENI). Acute stroke patients, enrolled between 2013 and 2014 with serial magnetic resonance imaging (MRI) scans (pretreatment baseline, 2 h post, and 24 h post), who received thrombolysis were included in the analysis. Early change in stroke volume, infarct volume at 24 h on diffusion, and percent of early reperfusion were calculated from the baseline and 2 h MRI scans were compared. ENI was defined as ≥4 point decrease in National Institutes of Health Stroke Scales within 24 h. Logistic regression models and receiver operator characteristics analysis were used to compare the efficacy of 3 imaging biomarkers. Serial MRIs of 58 acute stroke patients were analyzed. Early change in stroke volume was significantly associated with ENI by logistic regression analysis (OR 0.93, p = 0.048) and remained significant after controlling for stroke size and severity (OR 0.90, p = 0.032). Thus, for every 1 mL increase in stroke volume, there was a 10% decrease in the odds of ENI, while for every 1 mL decrease in stroke volume, there was a 10% increase in the odds of ENI. Neither infarct volume at 24 h nor percent of early reperfusion were significantly associated with ENI by logistic regression. Receiver-operator characteristic analysis identified early change in stroke volume as the only biomarker of the 3 that performed significantly different than chance (p = 0.03). Early fluctuations in stroke size may represent a more reliable biomarker for response to therapy than the more traditional measures of final infarct volume and percent of early reperfusion. © 2017 S. Karger AG, Basel.

A study on risk factors and diagnostic efficiency of posthepatectomy liver failure in the nonobstructive jaundice.

PubMed

Wang, He; Lu, Shi-Chun; He, Lei; Dong, Jia-Hong

2018-02-01

Liver failure remains as the most common complication and cause of death after hepatectomy, and continues to be a challenge for doctors.t test and χ test were used for single factor analysis of data-related variables, then results were introduced into the model to undergo the multiple factors logistic regression analysis. Pearson correlation analysis was performed for related postoperative indexes, and a diagnostic evaluation was performed using the receiver operating characteristic (ROC) of postoperative indexes.Differences in age, body mass index (BMI), portal vein hypertension, bile duct cancer, total bilirubin, alkaline phosphatase (ALP), gamma-glutamyl transpeptidase (GGT), operation time, cumulative portal vein occlusion time, intraoperative blood volume, residual liver volume (RLV)/entire live rvolume, ascites volume at postoperative day (POD)3, supplemental albumin amount at POD3, hospitalization time after operation, and the prothrombin activity (PTA) were statistically significant. Furthermore, there were significant differences in total bilirubin and the supplemental albumin amount at POD3. ROC analysis of the average PTA, albumin amounts, ascites volume at POD3, and their combined diagnosis were performed, which had diagnostic value for postoperative liver failure (area under the curve (AUC): 0.895, AUC: 0.798, AUC: 0.775, and AUC: 0.903).Preoperative total bilirubin level and the supplemental albumin amount at POD3 were independent risk factors. PTA can be used as the index of postoperative liver failure, and the combined diagnosis of the indexes can improve the early prediction of postoperative liver failure.

Space Shuttle Main Engine structural analysis and data reduction/evaluation. Volume 3B: High pressure fuel turbo-pump preburner pump bearing assembly analysis

NASA Technical Reports Server (NTRS)

Power, Gloria B.; Violett, Rebeca S.

1989-01-01

The analysis performed on the High Pressure Oxidizer Turbopump (HPOTP) preburner pump bearing assembly located on the Space Shuttle Main Engine (SSME) is summarized. An ANSYS finite element model for the inlet assembly was built and executed. Thermal and static analyses were performed.

Serial 3-dimensional computed tomography and a novel method of volumetric analysis for the evaluation of the osteo-odonto-keratoprosthesis.

PubMed

Sipkova, Zuzana; Lam, Fook Chang; Francis, Ian; Herold, Jim; Liu, Christopher

2013-04-01

To assess the use of serial computed tomography (CT) in the detection of osteo-odonto-lamina resorption in osteo-odonto-keratoprosthesis (OOKP) and to investigate the use of new volumetric software, Advanced Lung Analysis software (3D-ALA; GE Healthcare), for detecting changes in OOKP laminar volume. A retrospective assessment of the radiological databases and hospital records was performed for 22 OOKP patients treated at the National OOKP referral center in Brighton, United Kingdom. Three-dimensional surface reconstructions of the OOKP laminae were performed using stored CT data. For the 2-dimensional linear analysis, the linear dimensions of the reconstructed laminae were measured, compared with original measurements taken at the time of surgery, and then assigned a CT grade based on a predetermined resorption grading scale. The volumetric analysis involved calculating the laminar volumes using 3D-ALA. The effectiveness of 2-dimensional linear analysis, volumetric analysis, and clinical examination in detecting laminar resorption was compared. The mean change in laminar volume between the first and second scans was -6.67% (range, +10.13% to -24.86%). CT grades assigned to patients based on laminar dimension measurements remained the same, despite significant changes in laminar volumes. Clinical examination failed to identify 60% of patients who were found to have resorption on volumetric analysis. Currently, the detection of laminar resorption relies on clinical examination and the measurement of laminar dimensions on the 2- and 3-dimensional radiological images. Laminar volume measurement is a useful new addition to the armamentarium. It provides an objective tool that allows for a precise and reproducible assessment of laminar resorption.

Risk adjustment for case mix and the effect of surgeon volume on morbidity.

PubMed

Maas, Matthew B; Jaff, Michael R; Rordorf, Guy A

2013-06-01

Retrospective studies of large administrative databases have shown higher mortality for procedures performed by low-volume surgeons, but the adequacy of risk adjustment in those studies is in doubt. To determine whether the relationship between surgeon volume and outcomes is an artifact of case mix using a prospective sample of carotid endarterectomy cases. Observational cohort study from January 1, 2008, through December 31, 2010, with preoperative, immediate postoperative, and 30-day postoperative assessments acquired by independent monitors. Urban, tertiary academic medical center. All 841 patients who underwent carotid endarterectomy performed by a vascular surgeon or cerebrovascular neurosurgeon at the institution. Carotid endarterectomy without another concurrent surgery. Stroke, death, and other surgical complications occurring within 30 days of surgery along with other case data. A low-volume surgeon performed 40 or fewer cases per year. Variables used in a comparison administrative database study, as well as variables identified by our univariate analysis, were used for adjusted analyses to assess for an association between low-volume surgeons and the rate of stroke and death as well as other complications. RESULTS The rate of stroke and death was 6.9% for low-volume surgeons and 2.0% for high-volume surgeons (P = .001). Complications were similarly higher (13.4% vs 7.2%, P = .008). Low-volume surgeons performed more nonelective cases. Low-volume surgeons were significantly associated with stroke and death in the unadjusted analysis as well as after adjustment with variables used in the administrative database study (odds ratio, 3.61; 95% CI, 1.70-7.67, and odds ratio, 3.68; 95% CI, 1.72-7.89, respectively). However, adjusting for the significant disparity of American Society of Anesthesiologists Physical Status classification in case mix eliminated the effect of surgeon volume on the rate of stroke and death (odds ratio, 1.65; 95% CI, 0.59-4.64) and other complications. Variables selected for risk adjustment in studies using administrative databases appear to be inadequate to control for case mix bias between low-volume and high-volume surgeons. Risk adjustment should empirically analyze for case mix imbalances between surgeons to identify meaningful risk modifiers in clinical practice such as the American Society of Anesthesiologists Physical Status classification. A true relationship between surgeon volume and outcomes remains uncertain, and caution is advised in developing policies based on these findings.

The effect of surgeon and hospital volume on shoulder arthroplasty perioperative quality metrics.

PubMed

Singh, Anshu; Yian, Edward H; Dillon, Mark T; Takayanagi, Miwa; Burke, Mary F; Navarro, Ronald A

2014-08-01

There has been a significant increase in both the incidence of shoulder arthroplasty and the number of surgeons performing these procedures. Literature regarding the relationship between surgeon or hospital volume and the performance of modern shoulder arthroplasty is limited. This study examines the effect of surgeon or hospital shoulder arthroplasty volume on perioperative metrics related to shoulder hemiarthroplasty, total shoulder arthroplasty, and reverse shoulder arthroplasty. Blood loss, length of stay, and operative time were the main endpoints analyzed. Prospective data were analyzed from a multicenter shoulder arthroplasty registry; 1176 primary shoulder arthroplasty cases were analyzed. Correlation and analysis of covariance were used to examine the association between surgeon and hospital volume and perioperative metrics adjusting for age, sex, and body mass index. Surgeon volume is inversely correlated with length of stay for hemiarthroplasty and total shoulder arthroplasty and with blood loss and operative time for all 3 procedures. Hospital volume is inversely correlated with length of stay for hemiarthroplasty, with blood loss for total and reverse shoulder arthroplasty, and with operative time for all 3 procedures. High-volume surgeons performed shoulder arthroplasty 30 to 50 minutes faster than low-volume surgeons did. Higher surgeon and hospital case volumes led to improved perioperative metrics with all shoulder arthroplasty procedures, including reverse total shoulder arthroplasty, which has not been previously described in the literature. Surgeon volume had a larger effect on metrics than hospital volume did. This study supports the concept that complex shoulder procedures are, on average, performed more efficiently by higher volume surgeons in higher volume centers. Copyright © 2014 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Mosby, Inc. All rights reserved.

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.

Use of bioimpedance vector analysis in critically ill and cardiorenal patients.

PubMed

Peacock, W Frank

2010-01-01

Prospective outcome prediction and volume status assessment are difficult tasks in the acute care environment. Rapidly available, non-invasive, bioimpedance vector analysis (BIVA) may offer objective measures to improve clinical decision-making and predict outcomes. Performed by the placement of bipolar electrodes at the wrist and ankle, data is graphically displayed such that short-term morality risk and volume status can be accurately quantified. BIVA is able to provide indices of general cellular health, which has significant prognostic implications, as well as total body volume. Knowledge of these parameters can provide insight as to the short-term prognosis, as well as the presenting volume status. 2010 S. Karger AG, Basel.

Simplex volume analysis for finding endmembers in hyperspectral imagery

NASA Astrophysics Data System (ADS)

Li, Hsiao-Chi; Song, Meiping; Chang, Chein-I.

2015-05-01

Using maximal simplex volume as an optimal criterion for finding endmembers is a common approach and has been widely studied in the literature. Interestingly, very little work has been reported on how simplex volume is calculated. It turns out that the issue of calculating simplex volume is much more complicated and involved than what we may think. This paper investigates this issue from two different aspects, geometric structure and eigen-analysis. The geometric structure is derived from its simplex structure whose volume can be calculated by multiplying its base with its height. On the other hand, eigen-analysis takes advantage of the Cayley-Menger determinant to calculate the simplex volume. The major issue of this approach is that when the matrix is ill-rank where determinant is desired. To deal with this problem two methods are generally considered. One is to perform data dimensionality reduction to make the matrix to be of full rank. The drawback of this method is that the original volume has been shrunk and the found volume of a dimensionality-reduced simplex is not the real original simplex volume. Another is to use singular value decomposition (SVD) to find singular values for calculating simplex volume. The dilemma of this method is its instability in numerical calculations. This paper explores all of these three methods in simplex volume calculation. Experimental results show that geometric structure-based method yields the most reliable simplex volume.

Statistical representative elementary volumes of porous media determined using greyscale analysis of 3D tomograms

NASA Astrophysics Data System (ADS)

Bruns, S.; Stipp, S. L. S.; Sørensen, H. O.

2017-09-01

Digital rock physics carries the dogmatic concept of having to segment volume images for quantitative analysis but segmentation rejects huge amounts of signal information. Information that is essential for the analysis of difficult and marginally resolved samples, such as materials with very small features, is lost during segmentation. In X-ray nanotomography reconstructions of Hod chalk we observed partial volume voxels with an abundance that limits segmentation based analysis. Therefore, we investigated the suitability of greyscale analysis for establishing statistical representative elementary volumes (sREV) for the important petrophysical parameters of this type of chalk, namely porosity, specific surface area and diffusive tortuosity, by using volume images without segmenting the datasets. Instead, grey level intensities were transformed to a voxel level porosity estimate using a Gaussian mixture model. A simple model assumption was made that allowed formulating a two point correlation function for surface area estimates using Bayes' theory. The same assumption enables random walk simulations in the presence of severe partial volume effects. The established sREVs illustrate that in compacted chalk, these simulations cannot be performed in binary representations without increasing the resolution of the imaging system to a point where the spatial restrictions of the represented sample volume render the precision of the measurement unacceptable. We illustrate this by analyzing the origins of variance in the quantitative analysis of volume images, i.e. resolution dependence and intersample and intrasample variance. Although we cannot make any claims on the accuracy of the approach, eliminating the segmentation step from the analysis enables comparative studies with higher precision and repeatability.

Accuracy of Screening Mammography Interpretation by Characteristics of Radiologists

PubMed Central

Barlow, William E.; Chi, Chen; Carney, Patricia A.; Taplin, Stephen H.; D’Orsi, Carl; Cutter, Gary; Hendrick, R. Edward; Elmore, Joann G.

2011-01-01

Background Radiologists differ in their ability to interpret screening mammograms accurately. We investigated the relationship of radiologist characteristics to actual performance from 1996 to 2001. Methods Screening mammograms (n = 469 512) interpreted by 124 radiologists were linked to cancer outcome data. The radiologists completed a survey that included questions on demographics, malpractice concerns, years of experience interpreting mammograms, and the number of mammograms read annually. We used receiver operating characteristics (ROC) analysis to analyze variables associated with sensitivity, specificity, and the combination of the two, adjusting for patient variables that affect performance. All P values are two-sided. Results Within 1 year of the mammogram, 2402 breast cancers were identified. Relative to low annual interpretive volume (≤1000 mammograms), greater interpretive volume was associated with higher sensitivity (P = .001; odds ratio [OR] for moderate volume [1001–2000] = 1.68, 95% CI = 1.18 to 2.39; OR for high volume [>2000] = 1.89, 95% CI = 1.36 to 2.63). Specificity decreased with volume (OR for 1001–2000 = 0.65, 95% CI = 0.52 to 0.83; OR for more than 2000 = 0.76, 95% CI = 0.60 to 0.96), compared with 1000 or less (P = .002). Greater number of years of experience interpreting mammograms was associated with lower sensitivity (P = .001), but higher specificity (P = .003). ROC analysis using the ordinal BI-RADS interpretation showed an association between accuracy and both previous mammographic history (P = .012) and breast density (P<.001). No association was observed between accuracy and years interpreting mammograms (P = .34) or mammography volume (P = .94), after adjusting for variables that affect the threshold for calling a mammogram positive. Conclusions We found no evidence that greater volume or experience at interpreting mammograms is associated with better performance. However, they may affect sensitivity and specificity, possibly by determining the threshold for calling a mammogram positive. Increasing volume requirements is unlikely to improve overall mammography performance. PMID:15601640

Intrasystem Electromagnetic Compatibility Analysis Program. Volume 1. User’s Manual Engineering Section

DTIC Science & Technology

1974-12-01

AD-A008 526 INTRASYSTEM ELECTROMAGNETIC COMPATI- BILITY ANALYSIS PROGRAM. VOLUME I. USER’S MANUAL ENGINEERING SECTION J. L. Bogdanor , et al McDonnell...e) 8 CONTRACT OR GRANT NUMBERfs) J.L. Bogdanor F30602-72-C-0277 R.A. Pearlman M.D. Siegel PERFORMING ORGANIZATION NAME AND ADDRESS I0 PROGRAM ELEMENT...June 1968. 14. J. L. Bogdanor , M. D. Siegel, G. L. Weinstock, "Intra-Vehicle Electromagnetic Compatibility Analysis," AFAL-TR-71-155, July 1971. 15

Three-Dimensional Topographic Surface Changes in Response to Compartmental Volumization of the Medial Cheek: Defining a Malar Augmentation Zone.

PubMed

Stern, Carrie S; Schreiber, Jillian E; Surek, Chris C; Garfein, Evan S; Jelks, Elizabeth B; Jelks, Glenn W; Tepper, Oren M

2016-05-01

Given the widespread use of facial fillers and recent identification of distinct facial fat compartments, a better understanding of three-dimensional surface changes in response to volume augmentation is needed. Advances in three-dimensional imaging technology now afford an opportunity to elucidate these morphologic changes for the first time. A cadaver study was undertaken in which volumization of the deep medial cheek compartment was performed at intervals up to 4 cc (n = 4). Three-dimensional photographs were taken after each injection to analyze the topographic surface changes, which the authors define as the "augmentation zone." Perimeter, diameter, and projection were studied. The arcus marginalis of the inferior orbit consistently represented a fixed boundary of the augmentation zone, and additional cadavers underwent similar volumization following surgical release of this portion of the arcus marginalis (n = 4). Repeated three-dimensional computer analysis was performed comparing the augmentation zone with and without arcus marginalis release. Volumization of the deep medial cheek led to unique topographic changes of the malar region defined by distinct boundaries. Interestingly, the cephalic border of the augmentation zone was consistently noted to be at the level of the arcus marginalis in all specimens. When surgical release of the arcus marginalis was performed, the cephalic border of the augmentation zone was no longer restricted. Using advances in three-dimensional photography and computer analysis, the authors demonstrate characteristic surface anatomy changes in response to volume augmentation of facial compartments. This novel concept of the augmentation zone can be applied to volumization of other distinct facial regions. Therapeutic, V.

Space tug economic analysis study. Volume 2: Tug concepts analysis. Part 1: Overall approach and data generation

NASA Technical Reports Server (NTRS)

1972-01-01

An economic analysis of space tug operations is presented. The subjects discussed are: (1) data base for orbit injection stages, (2) data base for reusable space tug, (3) performance equations, (4) data integration and interpretation, (5) tug performance and mission model accomodation, (6) total program cost, (7) payload analysis, (8) computer software, and (9) comparison of tug concepts.

Effects of VR system fidelity on analyzing isosurface visualization of volume datasets.

PubMed

Laha, Bireswar; Bowman, Doug A; Socha, John J

2014-04-01

Volume visualization is an important technique for analyzing datasets from a variety of different scientific domains. Volume data analysis is inherently difficult because volumes are three-dimensional, dense, and unfamiliar, requiring scientists to precisely control the viewpoint and to make precise spatial judgments. Researchers have proposed that more immersive (higher fidelity) VR systems might improve task performance with volume datasets, and significant results tied to different components of display fidelity have been reported. However, more information is needed to generalize these results to different task types, domains, and rendering styles. We visualized isosurfaces extracted from synchrotron microscopic computed tomography (SR-μCT) scans of beetles, in a CAVE-like display. We ran a controlled experiment evaluating the effects of three components of system fidelity (field of regard, stereoscopy, and head tracking) on a variety of abstract task categories that are applicable to various scientific domains, and also compared our results with those from our prior experiment using 3D texture-based rendering. We report many significant findings. For example, for search and spatial judgment tasks with isosurface visualization, a stereoscopic display provides better performance, but for tasks with 3D texture-based rendering, displays with higher field of regard were more effective, independent of the levels of the other display components. We also found that systems with high field of regard and head tracking improve performance in spatial judgment tasks. Our results extend existing knowledge and produce new guidelines for designing VR systems to improve the effectiveness of volume data analysis.

Risk factors for radiation pneumonitis after stereotactic radiation therapy for lung tumours: clinical usefulness of the planning target volume to total lung volume ratio.

PubMed

Ueyama, Tomoko; Arimura, Takeshi; Takumi, Koji; Nakamura, Fumihiko; Higashi, Ryutaro; Ito, Soichiro; Fukukura, Yoshihiko; Umanodan, Tomokazu; Nakajo, Masanori; Koriyama, Chihaya; Yoshiura, Takashi

2018-06-01

To identify risk factors for symptomatic radiation pneumonitis (RP) after stereotactic radiation therapy (SRT) for lung tumours. We retrospectively evaluated 68 lung tumours in 63 patients treated with SRT between 2011 and 2015. RP was graded according to the National Cancer Institute-Common Terminology Criteria for Adverse Events version 4.0. SRT was delivered at 7.0-12.0 Gy per each fraction, once daily, to a total of 48-64 Gy (median, 50 Gy). Univariate analysis was performed to assess patient- and treatment-related factors, including age, sex, smoking index (SI), pulmonary function, tumour location, serum Krebs von den Lungen-6 value (KL-6), dose-volume metrics (V5, V10, V20, V30, V40 and VS5), homogeneity index of the planning target volume (PTV), PTV dose, mean lung dose (MLD), contralateral MLD and V2, PTV volume, lung volume and the PTV/lung volume ratio (PTV/Lung). Performance of PTV/Lung in predicting symptomatic RP was also analysed using receiver operating characteristic (ROC) analysis. The median follow-up period was 21 months. 10 of 63 patients (15.9%) developed symptomatic RP after SRT. On univariate analysis, V10, V20, PTV volume and PTV/Lung were significantly associated with occurrence of RP  ≥Grade 2. ROC curves indicated that symptomatic RP could be predicted using PTV/Lung [area under curve (AUC): 0.88, confidence interval (CI: 0.78-0.95), cut-off value: 1.09, sensitivity: 90.0% and specificity: 72.4%]. PTV/Lung is a good predictor of symptomatic RP after SRT. Advances in knowledge: The cases with high PTV/Lung should be carefully monitored with caution for the occurrence of RP after SRT.

Space tug economic analysis study. Volume 2: Tug concepts analysis. Appendix: Tug design and performance data base

NASA Technical Reports Server (NTRS)

1972-01-01

The tug design and performance data base for the economic analysis of space tug operation are presented. A compendium of the detailed design and performance information from the data base is developed. The design data are parametric across a range of reusable space tug sizes. The performance curves are generated for selected point designs of expendable orbit injection stages and reusable tugs. Data are presented in the form of graphs for various modes of operation.

On the suitability of the copula types for the joint modelling of flood peaks and volumes along the Danube River

NASA Astrophysics Data System (ADS)

Kohnová, Silvia; Papaioannou, George; Bacigál, Tomáš; Szolgay, Ján; Hlavčová, Kamila; Loukas, Athanasios; Výleta, Roman

2017-04-01

Flood frequency analysis is often performed as a univariate analysis of flood peaks using a suitable theoretical probability distribution of the annual maximum flood peaks or peak over threshold values. However, also other flood attributes, such as flood volume and duration, are often necessary for the design of hydrotechnical structures and projects. In this study, the suitability of various copula families for a bivariate analysis of peak discharges and flood volumes has been tested on the streamflow data from gauging stations along the whole Danube River. Kendall's rank correlation coefficient (tau) quantifies the dependence between flood peak discharge and flood volume settings. The methodology is tested on two different data samples: 1) annual maximum flood (AMF) peaks with corresponding flood volumes, which is a typical choice for engineering studies and 2). annual maximum flood (AMF) peaks combined with annual maximum flow volumes of fixed durations at 5, 10, 15, 20, 25, 30 and 60 days, which can be regarded as a regime analysis of the dependence between the extremes of both variables in a given year. The bivariate modelling of the peak discharge - flood volume couples is achieved with the use of the the following copulas: Ali-Mikhail-Haq (AMH), Clayton, Frank, Joe, Gumbel, HuslerReiss, Galambos, Tawn, Normal, Plackett and FGM, respectively. Scatterplots of the observed and simulated peak discharge - flood volume pairs and goodness-of-fit tests have been used to assess the overall applicability of the copulas as well as observing any changes in suitable models along the Danube River. The results indicate that, almost all of the considered Archimedean class copulas (e.g. Frank, Clayton and Ali-Mikhail-Haq) perform better than the other copula families selected for this study, and that for the second data samples mostly the upper-tail-flat copulas were suitable.

Relation of perioperative deaths to hospital volume among patients undergoing pancreatic resection for malignancy.

PubMed Central

Lieberman, M D; Kilburn, H; Lindsey, M; Brennan, M F

1995-01-01

OBJECTIVE: The authors examined the effect of hospital and surgeon volume on perioperative mortality rates after pancreatic resection for the treatment of pancreatic cancer. METHODS: Discharge abstracts from 1972 patients who had undergone pancreaticoduodenectomy or total pancreatectomy for malignancy in New York State between 1984 and 1991 were obtained from the Statewide Planning and Research Cooperative System. Logistic regression analysis was used to determine the relationship between hospital and surgeon experience to perioperative outcome. RESULTS: More than 75% of patients underwent resection at minimal-volume (fewer than 10 cases) or low-volume (10-50 cases) centers (defined as hospitals in which a minimal number of resections were performed in a given year), and these hospitals represented 98% of the institutions treating peripancreatic cancer. The two high-volume hospitals (more than 81 cases) demonstrated a significantly lower perioperative mortality rate (4.0%) compared with the minimal- (21.8%) and low-volume (12.3%) hospitals (p < 0.001). The perioperative mortality rate was 15.5% for low-volume (fewer than 9 cases) surgeons (defined as surgeons who had performed a minimal number of resections in any hospital in a given year) (n = 687) compared with 4.7% for high-volume (more than 41 cases) pancreatic surgeons (n = 4) (p < 0.001). Logistic regression analysis demonstrated that perioperative death is significantly (p < 0.05) related to hospital volume, but the surgeon's experience is not significantly related to perioperative deaths when hospital volume is controlled. CONCLUSIONS: These data support a defined minimum hospital experience for elective pancreatectomy for malignancy to minimize perioperative deaths. PMID:7487211

Pushing quantitation limits in micro UHPLC-MS/MS analysis of steroid hormones by sample dilution using high volume injection.

PubMed

Márta, Zoltán; Bobály, Balázs; Fekete, Jenő; Magda, Balázs; Imre, Tímea; Mészáros, Katalin Viola; Szabó, Pál Tamás

2016-09-10

Ultratrace analysis of sample components requires excellent analytical performance in terms of limits of quantitation (LoQ). Micro UHPLC coupling with sensitive tandem mass spectrometry provides state of the art solutions for such analytical problems. Decreased column volume in micro LC limits the injectable sample volume. However, if analyte concentration is extremely low, it might be necessary to inject high sample volumes. This is particularly critical for strong sample solvents and weakly retained analytes, which are often the case when preparing biological samples (protein precipitation, sample extraction, etc.). In that case, high injection volumes may cause band broadening, peak distortion or even elution in dead volume. In this study, we evaluated possibilities of high volume injection onto microbore RP-LC columns, when sample solvent is diluted. The presented micro RP-LC-MS/MS method was optimized for the analysis of steroid hormones from human plasma after protein precipitation with organic solvents. A proper sample dilution procedure helps to increase the injection volume without compromising peak shapes. Finally, due to increased injection volume, the limit of quantitation can be decreased by a factor of 2-5, depending on the analytes and the experimental conditions. Copyright © 2016 Elsevier B.V. All rights reserved.

Geometrical-Based Navigation System Performance Assessment in the Space Service Volume Using a Multiglobal Navigation Satellite System Methodology

NASA Technical Reports Server (NTRS)

Welch, Bryan W.

2016-01-01

NASA is participating in the International Committee on Global Navigation Satellite Systems (GNSS) (ICG)'s efforts towards demonstrating the benefits to the space user in the Space Service Volume (SSV) when a multi-GNSS solution space approach is utilized. The ICG Working Group: Enhancement of GNSS Performance, New Services and Capabilities has started a three phase analysis initiative as an outcome of recommendations at the ICG-10 meeting, in preparation for the ICG-11 meeting. The first phase of that increasing complexity and fidelity analysis initiative is based on a pure geometrically-derived access technique. The first phase of analysis has been completed, and the results are documented in this paper.

Tracking and data relay satellite system configuration and tradeoff study, part 1. Volume 3: Telecommunications service system

NASA Technical Reports Server (NTRS)

1972-01-01

The results of the telecommunications subsystem analysis are presented. The relay system requirements and constraints, interference analysis, frequency selection, modulation and coding analysis, and the performance analysis of the relay system are included.

An economic analysis of robotically assisted hysterectomy.

PubMed

Wright, Jason D; Ananth, Cande V; Tergas, Ana I; Herzog, Thomas J; Burke, William M; Lewin, Sharyn N; Lu, Yu-Shiang; Neugut, Alfred I; Hershman, Dawn L

2014-05-01

To perform an econometric analysis to examine the influence of procedure volume, variation in hospital accounting methodology, and use of various analytic methodologies on cost of robotically assisted hysterectomy for benign gynecologic disease and endometrial cancer. A national sample was used to identify women who underwent laparoscopic or robotically assisted hysterectomy for benign indications or endometrial cancer from 2006 to 2012. Surgeon and hospital volume were classified as the number of procedures performed before the index surgery. Total costs as well as fixed and variable costs were modeled using multivariable quantile regression methodology. A total of 180,230 women, including 169,324 women who underwent minimally invasive hysterectomy for benign indications and 10,906 patients whose hysterectomy was performed for endometrial cancer, were identified. The unadjusted median cost of robotically assisted hysterectomy for benign indications was $8,152 (interquartile range [IQR] $6,011-10,932) compared with $6,535 (IQR $5,127-8,357) for laparoscopic hysterectomy (P<.001). The cost differential decreased with increasing surgeon and hospital volume. The unadjusted median cost of robotically assisted hysterectomy for endometrial cancer was $9,691 (IQR $7,591-12,428) compared with $8,237 (IQR $6,400-10,807) for laparoscopic hysterectomy (P<.001). The cost differential decreased with increasing hospital volume from $2,471 for the first 5 to 15 cases to $924 for more than 50 cases. Based on surgeon volume, robotically assisted hysterectomy for endometrial cancer was $1,761 more expensive than laparoscopy for those who had performed fewer than five cases; the differential declined to $688 for more than 50 procedures compared with laparoscopic hysterectomy. The cost of robotic gynecologic surgery decreases with increased procedure volume. However, in all of the scenarios modeled, robotically assisted hysterectomy remained substantially more costly than laparoscopic hysterectomy.

Cerebellar Volume in Children With Attention-Deficit Hyperactivity Disorder (ADHD).

PubMed

Wyciszkiewicz, Aleksandra; Pawlak, Mikolaj A; Krawiec, Krzysztof

2017-02-01

Attention Deficit Hyperactivity Disorder (ADHD) is associated with altered cerebellar volume and cerebellum is associated with cognitive performance. However there are mixed results regarding the cerebellar volume in young patients with ADHD. To clarify the size and direction of this effect, we conducted the analysis on the large public database of brain images. The aim of this study was to confirm that cerebellar volume in ADHD is smaller than in control subjects in currently the largest publicly available cohort of ADHD subjects.We applied cross-sectional case control study design by comparing 286 ADHD patients (61 female) with age and gender matched control subjects. Volumetric measurements of cerebellum were obtained using automated segmentation with FreeSurfer 5.1. Statistical analysis was performed in R-CRAN statistical environment. Patients with ADHD had significantly smaller total cerebellar volumes (134.5±17.11cm 3 vs.138.90±15.32 cm 3 ). The effect was present in both females and males (males 136.9±14.37 cm 3 vs. 141.20±14.75 cm 3 ; females 125.7±12.34 cm 3 vs. 131.20±15.03 cm 3 ). Age was positively and significantly associated with the cerebellar volumes. These results indicate either delayed or disrupted cerebellar development possibly contributing to ADHD pathophysiology.

Comparing Volume Loss in Neuroanatomical Regions of Emotion versus Regions of Cognition in Healthy Aging.

PubMed

Pressman, Peter S; Noniyeva, Yuliana; Bott, Nick; Dutt, Shubir; Sturm, Virginia; Miller, Bruce L; Kramer, Joel H

2016-01-01

Many emotional functions are relatively preserved in aging despite declines in several cognitive domains and physical health. High levels of happiness exist even among centenarians. To address the hypothesis of whether preservation of emotional function in healthy aging may relate to different rates of age-related volume loss across brain structures, we performed two volumetric analyses on structural magnetic resonance neuroimaging of a group of healthy aging research participants using Freesurfer version 5.1. Volumes selected as supporting cognition included bilateral midfrontal and lateral frontal gyri, lateral parietal and temporal cortex, and medial temporal lobes. Volumes supporting emotion included bilateral amygdala, rostral anterior cingulate, insula, orbitofrontal cortex, and nucleus accumbens. A cross-sectional analysis was performed using structural MRI scans from 258 subjects. We found no difference in proportional change between groups. A longitudinal mixed effects model was used to compare regional changes over time in a subset of 84 subjects. Again, there was no difference in proportional change over time. While our results suggest that aging does not collectively target cognitive brain regions more than emotional regions, subgroup analysis suggests relative preservation of the anterior cingulate cortex, with greater volume loss in the nucleus accumbens. Implications of these relative rates of age-related volume loss in healthy aging are discussed and merit further research.

Geotechnical Field Data and Analysis Report, July 1991--June 1992. Volume 1

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

Not Available

1993-09-01

The Geotechnical Field Data and Analysis Report documents the geotechnical data from the underground excavations at the Waste Isolation Pilot Plant (WIPP) located near Carlsbad, New Mexico. The data are used to characterize conditions, confirm design assumptions, and understand and predict the performance of the underground excavations during operations. The data are obtained as part of a routine monitoring program and do not include data from tests performed by Sandia National Laboratories (SNL), the Scientific Advisor to the project, in support of performance assessment studies. The purpose of the geomechanical monitoring program is to provide in situ data to supportmore » continuing assessments of the design for the underground facilities. Specifically, the program provides: Early detection of conditions that could compromise operational safety; evaluation of room closure to ensure retrievability of waste; guidance for design modifications and remedial actions; and data for interpreting the actual behavior of underground openings, in comparison with established design criteria. This Geotechnical Field Data and Analysis Report covers the period July 1, 1991 to June 30, 1992. Volume 1 provides an interpretation of the field data while Volume 2 describes and presents the data itself.« less

Delivery of Essential Medicines to Primary Care Institutions and its Association with Procurement Volume and Price: A Case Study in Hubei Province, China.

PubMed

Tang, Yuqing; Liu, Chaojie; Zhang, Xinping

2017-02-01

The low availability of essential medicines is a worldwide issue of concern. In 2009, China introduced a National Essential Medicines List (NEML), with NEML medicines being purchased in bulk at contracted prices established by tenders conducted at the provincial level. The availability of essential medicines in the public sector largely relies on commercial supply chains. The objectives of this paper were to analyze the delivery performance of essential medicines under NEML provincial procurement arrangements, and to determine whether the procurement volume and price of medicines are associated with the delivery performance of suppliers. We reviewed 9390 recorded orders of 1099 essential medicines in Hubei province from August 2011 to April 2012. The reliability of medicine delivery in-full and on-time (DIFOT) was considered the performance indicator, and we used Spearman correlation analyses to explore whether there were any associations between DIFOT and procurement price and volume. Quantile regressions were performed to determine such associations. The DIFOT had positive correlations with procurement price and volume. The Spearman rank correlation coefficients between price and DIFOT were 0.114, 0.34 and 0.25 for medicines with low one-third, middle one-third and high one-third procurement volumes, respectively. The quantile regression analysis revealed a positive association between price and DIFOT across all quantiles of DIFOT, and although significant positive associations between volume and DIFOT were only found at the 25th percentile of DIFOT, volume showed significant interactions with price for both the 25th and 50th percentiles of DIFOT. Higher procurement price is associated with better delivery performance of essential medicines; however, it is important to link procurement price with procurement volume. Increasing procurement volume may alleviate the negative effect of low price on delivery performance. Variation in volumes of repeated orders imposes uncertainties and may jeopardize the delivery of essential medicines.

Collaborative Multidisciplinary Sciences for Analysis and Design of Aerospace Vehicles. Volume 1

DTIC Science & Technology

2017-05-01

AEROSPACE VEHICLES Volume 1 5a. CONTRACT NUMBER FA8650-09-2-3938 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 62201F 6. AUTHOR(S) Raymond M...S) AND ADDRESS(ES) 8. PERFORMING ORGANIZATION REPORT NUMBERDesign and Analysis Branch (AFRL/RQVC) Aerospace Vehicles Division Air Force Research...Laboratory, Aerospace Systems Directorate Wright-Patterson Air Force Base, OH 45433-7542 Air Force Materiel Command, United States Air Force Virginia

Lower-volume muscle-damaging exercise protects against high-volume muscle-damaging exercise and the detrimental effects on endurance performance.

PubMed

Burt, Dean; Lamb, Kevin; Nicholas, Ceri; Twist, Craig

2015-07-01

This study examined whether lower-volume exercise-induced muscle damage (EIMD) performed 2 weeks before high-volume muscle-damaging exercise protects against its detrimental effect on running performance. Sixteen male participants were randomly assigned to a lower-volume (five sets of ten squats, n = 8) or high-volume (ten sets of ten squats, n = 8) EIMD group and completed baseline measurements for muscle soreness, knee extensor torque, creatine kinase (CK), a 5-min fixed-intensity running bout and a 3-km running time-trial. Measurements were repeated 24 and 48 h after EIMD, and the running time-trial after 48 h. Two weeks later, both groups repeated the baseline measurements, ten sets of ten squats and the same follow-up testing (Bout 2). Data analysis revealed increases in muscle soreness and CK and decreases in knee extensor torque 24-48 h after the initial bouts of EIMD. Increases in oxygen uptake [Formula: see text], minute ventilation [Formula: see text] and rating of perceived exertion were observed during fixed-intensity running 24-48 h after EIMD Bout 1. Likewise, time increased and speed and [Formula: see text] decreased during a 3-km running time-trial 48 h after EIMD. Symptoms of EIMD, responses during fixed-intensity and running time-trial were attenuated in the days after the repeated bout of high-volume EIMD performed 2 weeks after the initial bout. This study demonstrates that the protective effect of lower-volume EIMD on subsequent high-volume EIMD is transferable to endurance running. Furthermore, time-trial performance was found to be preserved after a repeated bout of EIMD.

Nonlinear bivariate dependency of price-volume relationships in agricultural commodity futures markets: A perspective from Multifractal Detrended Cross-Correlation Analysis

NASA Astrophysics Data System (ADS)

He, Ling-Yun; Chen, Shu-Peng

2011-01-01

Nonlinear dependency between characteristic financial and commodity market quantities (variables) is crucially important, especially between trading volume and market price. Studies on nonlinear dependency between price and volume can provide practical insights into market trading characteristics, as well as the theoretical understanding of market dynamics. Actually, nonlinear dependency and its underlying dynamical mechanisms between price and volume can help researchers and technical analysts in understanding the market dynamics by integrating the market variables, instead of investigating them in the current literature. Therefore, for investigating nonlinear dependency of price-volume relationships in agricultural commodity futures markets in China and the US, we perform a new statistical test to detect cross-correlations and apply a new methodology called Multifractal Detrended Cross-Correlation Analysis (MF-DCCA), which is an efficient algorithm to analyze two spatially or temporally correlated time series. We discuss theoretically the relationship between the bivariate cross-correlation exponent and the generalized Hurst exponents for time series of respective variables. We also perform an empirical study and find that there exists a power-law cross-correlation between them, and that multifractal features are significant in all the analyzed agricultural commodity futures markets.

Senior Dance Experience, Cognitive Performance, and Brain Volume in Older Women.

PubMed

Niemann, Claudia; Godde, Ben; Voelcker-Rehage, Claudia

2016-01-01

Physical activity is positively related to cognitive functioning and brain volume in older adults. Interestingly, different types of physical activity vary in their effects on cognition and on the brain. For example, dancing has become an interesting topic in aging research, as it is a popular leisure activity among older adults, involving cardiovascular and motor fitness dimensions that can be positively related to cognition. However, studies on brain structure are missing. In this study, we tested the association of long-term senior dance experience with cognitive performance and gray matter brain volume in older women aged 65 to 82 years. We compared nonprofessional senior dancers ( n = 28) with nonsedentary control group participants without any dancing experience ( n = 29), who were similar in age, education, IQ score, lifestyle and health factors, and fitness level. Differences neither in the four tested cognitive domains (executive control, perceptual speed, episodic memory, and long-term memory) nor in brain volume (VBM whole-brain analysis, region-of-interest analysis of the hippocampus) were observed. Results indicate that moderate dancing activity (1-2 times per week, on average) has no additional effects on gray matter volume and cognitive functioning when a certain lifestyle or physical activity and fitness level are reached.

Thalamic volume and related visual recognition are associated with freezing of gait in non-demented patients with Parkinson's disease.

PubMed

Sunwoo, Mun Kyung; Cho, Kyoo H; Hong, Jin Yong; Lee, Ji E; Sohn, Young H; Lee, Phil Hyu

2013-12-01

The pathophysiology of freezing of gait (FOG) in non-demented Parkinson's disease (PD) patients remains poorly understood. Recent studies have suggested that neurochemical alterations in the cholinergic systems play a role in the development of FOG. Here, we evaluated the association between subcortical cholinergic structures and FOG in patients with non-demented PD. We recruited 46 non-demented patients with PD, categorized into PD with (n = 16) and without FOG (n = 30) groups. We performed neuropsychological test, region-of-interest-based volumetric analysis of the substantia innominata (SI) and automatic analysis of subcortical brain structures using a computerized segmentation procedure. The comprehensive neuropsychological assessment showed that PD patients with FOG had lower cognitive performance in the frontal executive and visual-related functions compared with those without freezing of gait. The normalized SI volume did not differ significantly between the two groups (1.65 ± 0.18 vs. 1.68 ± 0.31). The automatic analysis of subcortical structures revealed that the thalamic volumes were significantly reduced in PD patients with FOG compared with those without FOG after adjusting for age, sex, disease duration, the Unified PD Rating Scale scores and total intracranial volume (left: 6.71 vs. 7.16 cm3, p = 0.029, right: 6.47 vs. 6.91 cm3, p = 0.026). Multiple linear regression analysis revealed that thalamic volume showed significant positive correlations with visual recognition memory (left: β = 0.441, p = 0.037, right: β = 0.498, p = 0.04). These data suggest that thalamic volume and related visual recognition, rather than the cortical cholinergic system arising from the SI, may be a major contributor to the development of freezing of gait in non-demented patients with PD. Copyright © 2013. Published by Elsevier Ltd.

White matter volume loss in amyotrophic lateral sclerosis: A meta-analysis of voxel-based morphometry studies.

PubMed

Chen, Guangxiang; Zhou, Baiwan; Zhu, Hongyan; Kuang, Weihong; Bi, Feng; Ai, Hua; Gu, Zhongwei; Huang, Xiaoqi; Lui, Su; Gong, Qiyong

2018-04-20

Structural neuroimaging studies of white matter (WM) volume in amyotrophic lateral sclerosis (ALS) using voxel-based morphometry (VBM) have yielded inconsistent findings. This study aimed to perform a quantitative voxel-based meta-analysis using effect-size signed differential mapping (ES-SDM) to establish a statistical consensus between published studies for WM volume alterations in ALS. The pooled meta-analysis revealed significant WM volume losses in the bilateral supplementary motor areas (SMAs), bilateral precentral gyri (PGs), left middle cerebellar peduncle and right cerebellum in patients with ALS, involving the corticospinal tract (CST), interhemispheric fibers, subcortical arcuate fibers, projection fibers to the striatum and cortico-ponto-cerebellar tract. The meta-regression showed that the ALS functional rating scale-revised (ALSFRS-R) was positively correlated with decreased WM volume in the bilateral SMAs, whereas illness duration was negatively correlated with WM volume reduction in the right SMA. This study provides a thorough profile of WM volume loss in ALS and robust evidence that ALS is a multisystem neurodegenerative disease that involves a variety of subcortical WM tracts extending beyond motor cortex involvement. Copyright © 2018 Elsevier Inc. All rights reserved.

Applications of advanced V/STOL aircraft concepts to civil utility missions. Volume 2: Appendices

NASA Technical Reports Server (NTRS)

1977-01-01

The linear performance definition curves for the lift fan aircraft, tilt rotor aircraft, and advanced helicopter are given. The computer program written to perform the mission analysis for this study is also documented, and examples of its use are shown. Methods used to derive the performance coefficients for use in the mission analysis of the lift fan aircraft are described.

Bronchoscopic Lung Volume Reduction with Endobronchial Valves in Low-FEV1 Patients.

PubMed

Darwiche, Kaid; Karpf-Wissel, Rüdiger; Eisenmann, Stephan; Aigner, Clemens; Welter, Stefan; Zarogoulidis, Paul; Hohenforst-Schmidt, Wolfgang; Freitag, Lutz; Oezkan, Filiz

2016-01-01

Bronchoscopic lung volume reduction (BLVR) with valves has been shown to improve lung function, exercise capacity, and quality of life in patients with emphysema, but only few patients with forced expiratory volume in 1 s (FEV1) ≤20% predicted have been included in former studies. Although the procedure can be performed safely, pneumothorax is a frequent complication, which can be critical for these very severely diseased patients. The aim of the study was to assess the safety of BLVR in patients with a very advanced stage of emphysema, as indicated by FEV1 ≤20% predicted. Patients in whom BLVR was performed between January 2013 and August 2015 were included in this analysis if their baseline predicted FEV1 was ≤20%. BLVR, performed only if collateral ventilation was absent, achieved complete occlusion of the target lobe. All patients were closely monitored and were not discharged before the fourth day after BLVR. Twenty patients with FEV1 ≤20% predicted were included in the analysis. Lung volume reduction was achieved in 65% of the cases. Pneumothorax occurred in 4 cases (20%). No patient died. Lung function and exercise tolerance improved after 1 and 3 months, respectively. BLVR with valves can be safely performed in patients with FEV1 ≤20% predicted when close postprocedural monitoring is provided. Improvement in lung function and exercise capacity can be achieved. © 2016 S. Karger AG, Basel.

MR volumetric analysis of the course of nephroblastomatosis under chemotherapy in childhood.

PubMed

Günther, Patrick; Tröger, Jochen; Graf, Norbert; Waag, Karl Ludwig; Schenk, Jens-Peter

2004-08-01

Nephroblastomatosis is a paediatric renal disease that may undergo malignant transformation. When neoadjuvant chemotherapy is indicated for nephroblastomatosis or bilateral Wilms' tumours, exact volumetric analysis using high-speed data processing and visualization may aid in determining tumour response. Using 3D-volume-rendering software, the 0.5-T MRI data of a 2-year-old girl with bilateral nephroblastomatosis was analysed. Exact volume determination of foci of nephroblastomatosis was performed by automatic and manual segmentation, and the relation to normal renal parenchyma was determined over a 12-month period. At the first visit, 80% (460/547 ml) of the extremely enlarged right kidney was due to nephroblastomatosis. Total tumour volume within the right kidney decreased to 74 ml under chemotherapy. Volume analysis of the two emerging right-sided masses after treatment correctly suggested Wilms' tumour. Three-dimensional rendering of the growing masses aided the surgeon in nephron-sparing surgery during tumour resection.

Knowledge-based reconstruction for measurement of right ventricular volumes on cardiovascular magnetic resonance images in a mixed population.

PubMed

Pieterman, Elise D; Budde, Ricardo P J; Robbers-Visser, Daniëlle; van Domburg, Ron T; Helbing, Willem A

2017-09-01

Follow-up of right ventricular performance is important for patients with congenital heart disease. Cardiac magnetic resonance imaging is optimal for this purpose. However, observer-dependency of manual analysis of right ventricular volumes limit its use. Knowledge-based reconstruction is a new semiautomatic analysis tool that uses a database including knowledge of right ventricular shape in various congenital heart diseases. We evaluated whether knowledge-based reconstruction is a good alternative for conventional analysis. To assess the inter- and intra-observer variability and agreement of knowledge-based versus conventional analysis of magnetic resonance right ventricular volumes, analysis was done by two observers in a mixed group of 22 patients with congenital heart disease affecting right ventricular loading conditions (dextro-transposition of the great arteries and right ventricle to pulmonary artery conduit) and a group of 17 healthy children. We used Bland-Altman analysis and coefficient of variation. Comparison between the conventional method and the knowledge-based method showed a systematically higher volume for the latter group. We found an overestimation for end-diastolic volume (bias -40 ± 24 mL, r = .956), end-systolic volume (bias -34 ± 24 mL, r = .943), stroke volume (bias -6 ± 17 mL, r = .735) and an underestimation of ejection fraction (bias 7 ± 7%, r = .671) by knowledge-based reconstruction. The intra-observer variability of knowledge-based reconstruction varied with a coefficient of variation of 9% for end-diastolic volume and 22% for stroke volume. The same trend was noted for inter-observer variability. A systematic difference (overestimation) was noted for right ventricular size as assessed with knowledge-based reconstruction compared with conventional methods for analysis. Observer variability for the new method was comparable to what has been reported for the right ventricle in children and congenital heart disease with conventional analysis. © 2017 Wiley Periodicals, Inc.

Novel analysis of 4DCT imaging quantifies progressive increases in anatomic dead space during mechanical ventilation in mice.

PubMed

Kim, Elizabeth H; Preissner, Melissa; Carnibella, Richard P; Samarage, Chaminda R; Bennett, Ellen; Diniz, Marcio A; Fouras, Andreas; Zosky, Graeme R; Jones, Heather D

2017-09-01

Increased dead space is an important prognostic marker in early acute respiratory distress syndrome (ARDS) that correlates with mortality. The cause of increased dead space in ARDS has largely been attributed to increased alveolar dead space due to ventilation/perfusion mismatching and shunt. We sought to determine whether anatomic dead space also increases in response to mechanical ventilation. Mice received intratracheal lipopolysaccharide (LPS) or saline and mechanical ventilation (MV). Four-dimensional computed tomography (4DCT) scans were performed at onset of MV and after 5 h of MV. Detailed measurements of airway volumes and lung tidal volumes were performed using image analysis software. The forced oscillation technique was used to obtain measures of airway resistance, tissue damping, and tissue elastance. The ratio of airway volumes to total tidal volume increased significantly in response to 5 h of mechanical ventilation, regardless of LPS exposure, and airways demonstrated significant variation in volumes over the respiratory cycle. These findings were associated with an increase in tissue elastance (decreased lung compliance) but without changes in tidal volumes. Airway volumes increased over time with exposure to mechanical ventilation without a concomitant increase in tidal volumes. These findings suggest that anatomic dead space fraction increases progressively with exposure to positive pressure ventilation and may represent a pathological process. NEW & NOTEWORTHY We demonstrate that anatomic dead space ventilation increases significantly over time in mice in response to mechanical ventilation. The novel functional lung-imaging techniques applied here yield sensitive measures of airway volumes that may have wide applications. Copyright © 2017 the American Physiological Society.

Insulation commonality assessment (phase 1). Volume 2: Section 7.0 through 16.0. [evaluation of materials used for spacecraft thermal insulation

NASA Technical Reports Server (NTRS)

1973-01-01

The heat transfer characteristics of various materials used for the thermal insulation of spacecraft are discussed. Techniques for conducting thermal performance analysis, structural performance analysis, and dynamic analysis are described. Processes for producing and finishing the materials are explained. The methods for determining reliability, system safety, materials tests, and design effectiveness are explained.

A systematic review of the impact of center volume in dialysis.

PubMed

Pieper, Dawid; Mathes, Tim; Marshall, Mark Roger

2015-12-22

A significant relationship exists between the volume of surgical procedures that a given center performs and subsequent outcomes. It seems plausible that such a volume-outcome relationship is also present in dialysis. MEDLINE and EMBASE were searched in November 2014 for non-experimental studies evaluating the association between center volume and patient outcomes [mortality, morbidity, peritonitis, switch to hemodialysis (HD) or any other treatment], without language restrictions or other limits. Selection of relevant studies, data extraction and critical appraisal were performed by two independent reviewers. We did not perform meta-analysis due to clinical and methodological heterogeneity (e.g. different volume categories). 16 studies met out inclusion criteria. Most studies were performed in the US. The study quality ranged from fair to good. Only few items were judged to have a high risk of bias, while many items were judged to have an unclear risk of bias due to insufficient reporting. All 10 studies that analyzed peritoneal dialysis (PD) technique survival by modeling switch to HD or any other treatment as an outcome showed a statistical significant effect. The relative effect measures ranged from 0.25 to 0.94 (median 0.73) in favor of high volume centers. All nine studies indicated a lower mortality for PD in high volume centers, but only study was statistical significant. This systematic review supports a volume-outcome relationship in peritoneal dialysis with respect to switch to HD or any other treatment. An effect on mortality is probably present in HD. Further research is needed to identify and understand the associations of center volume that are causally related to patient benefit.

Emergency department imaging: are weather and calendar factors associated with imaging volume?

PubMed

Burns, K; Chernyak, V; Scheinfeld, M H

2016-12-01

To identify weather and calendar factors that would enable prediction of daily emergency department (ED) imaging volume to aid appropriate scheduling of imaging resources for efficient ED function. Daily ED triage and imaging volumes for radiography, computed tomography (CT), and ultrasound were obtained from hospital databases for the period between January 2011 and December 2013 at a large tertiary urban hospital with a Level II trauma centre. These data were tabulated alongside daily weather conditions (temperature, wind and precipitation), day of week, season, and holidays. Multivariate analysis was performed. Pearson correlations were used to measure the association between number of imaging studies performed and ED triage volume. For every additional 50 triaged patients, the odds of having high (imaging volume ≥90th percentile) radiography, CT, and ultrasound volume increased by 4.3 times (p<0.001), 1.5 times (p=0.02), and 1.4 times (p=0.02), respectively. Tuesday was an independent predictor of high radiography volume (odds ratio=2.8) and Monday was an independent predictor of high CT volume (odds ratio=3.0). Weekday status was an independent factor increasing the odds of a high US volume compared to Saturday (odds ratios ranging from 5.6-9.8). Weather factors and other calendar variables were not independent predictors of high imaging volume. Using Pearson correlations, ED triage volume correlated with number of radiographs, CT, and ultrasound examinations with r=0.73, 0.37, and 0.41, respectively (p<0.0001). As ED triage volume was found to be the only factor associated with imaging volume for all techniques, analysis of predictors of ED triage volumes at a particular healthcare facility would be useful to determine imaging needs. Although calendar and weather factors were found to be minor or non-significant independent predictors of ED imaging utilisation, these may be important in influencing the actual number of ED triages. Copyright © 2016 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

Thermal imager for dismounted infantry

NASA Astrophysics Data System (ADS)

Bigwood, Christopher R.; Eccles, Lee; Jones, Arwyn O.; Jones, Berwyn; Meakin, David L.; Rickard, Steve; Robinson, Rob

2004-12-01

Thermal Imager for Dismounted Infantry (TIDI), is a UK MOD / Thales Optics Ltd. joint funded technology demonstrator programme and is part of the overall programme managed by QinetiQ. The aim of this programme is to evaluate and demonstrate a cost effective route to equipping the infantry soldier with a small, lightweight, rugged, short range, weapon mounted thermal imaging sight; intended for mass deployment. TIDI is an unusual programme in that the requirement was not rigidly defined in terms of a detailed specification. Instead, the requirement was expressed in terms of the question 'What weapon sight performance can be achieved for a volume production cost of 5000 Euro?' This requirement was subject to the constraints that the sight mass should be less than 500 g and the volume should be less than 500 ml. To address the requirements of this programme, Thales Optics Ltd. have performed a detailed trade-off analysis considering alternative uncooled LWIR sensor formats and technologies. The effect of using alternative sensors on the sight cost, mass, volume, power and performance has been compared. A design study has been performed concentrating on simplification of the optics, mechanics and electronics to minimise the overall sight complexity. Based on this analysis, a demonstrator sight has been designed that is cost effective and suitable for volume manufacture, whilst still offering useful performance to the user. Six technical demonstrator units based on this design have been manufactured and evaluated. This paper will give an overview of the work completed to date on the TIDI program, including a description of the demonstrator hardware and its performance.

International Spine Radiosurgery Consortium Consensus Guidelines for Target Volume Definition in Spinal Stereotactic Radiosurgery

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

Cox, Brett W., E-mail: coxb@mskcc.org; Spratt, Daniel E.; Lovelock, Michael

2012-08-01

Purpose: Spinal stereotactic radiosurgery (SRS) is increasingly used to manage spinal metastases. However, target volume definition varies considerably and no consensus target volume guidelines exist. This study proposes consensus target volume definitions using common scenarios in metastatic spine radiosurgery. Methods and Materials: Seven radiation oncologists and 3 neurological surgeons with spinal radiosurgery expertise independently contoured target and critical normal structures for 10 cases representing common scenarios in metastatic spine radiosurgery. Each set of volumes was imported into the Computational Environment for Radiotherapy Research. Quantitative analysis was performed using an expectation maximization algorithm for Simultaneous Truth and Performance Level Estimation (STAPLE)more » with kappa statistics calculating agreement between physicians. Optimized confidence level consensus contours were identified using histogram agreement analysis and characterized to create target volume definition guidelines. Results: Mean STAPLE agreement sensitivity and specificity was 0.76 (range, 0.67-0.84) and 0.97 (range, 0.94-0.99), respectively, for gross tumor volume (GTV) and 0.79 (range, 0.66-0.91) and 0.96 (range, 0.92-0.98), respectively, for clinical target volume (CTV). Mean kappa agreement was 0.65 (range, 0.54-0.79) for GTV and 0.64 (range, 0.54-0.82) for CTV (P<.01 for GTV and CTV in all cases). STAPLE histogram agreement analysis identified optimal consensus contours (80% confidence limit). Consensus recommendations include that the CTV should include abnormal marrow signal suspicious for microscopic invasion and an adjacent normal bony expansion to account for subclinical tumor spread in the marrow space. No epidural CTV expansion is recommended without epidural disease, and circumferential CTVs encircling the cord should be used only when the vertebral body, bilateral pedicles/lamina, and spinous process are all involved or there is extensive metastatic disease along the circumference of the epidural space. Conclusions: This report provides consensus guidelines for target volume definition for spinal metastases receiving upfront SRS in common clinical situations.« less

A Study of Job Demands and Curriculum Development in Agricultural Training Related to the Muskegon County Wastewater Management System. Final Report. Volume IV. Career Awareness Information.

ERIC Educational Resources Information Center

Fisher, Harold S.; And Others

This is the final volume of a four-volume report of a research project designed to (1) identify job needs for agricultural occupations which will result from the Muskegon County Wastewater Management System and perform a task analysis on each occupation, (2) develop instructional modules and determine their place in either high school or 2-year…

Comparing surgical trays with redundant instruments with trays with reduced instruments: a cost analysis

PubMed Central

John-Baptiste, A.; Sowerby, L.J.; Chin, C.J.; Martin, J.; Rotenberg, B.W.

2016-01-01

Background: When prearranged standard surgical trays contain instruments that are repeatedly unused, the redundancy can result in unnecessary health care costs. Our objective was to estimate potential savings by performing an economic evaluation comparing the cost of surgical trays with redundant instruments with surgical trays with reduced instruments ("reduced trays"). Methods: We performed a cost-analysis from the hospital perspective over a 1-year period. Using a mathematical model, we compared the direct costs of trays containing redundant instruments to reduced trays for 5 otolaryngology procedures. We incorporated data from several sources including local hospital data on surgical volume, the number of instruments on redundant and reduced trays, wages of personnel and time required to pack instruments. From the literature, we incorporated instrument depreciation costs and the time required to decontaminate an instrument. We performed 1-way sensitivity analyses on all variables, including surgical volume. Costs were estimated in 2013 Canadian dollars. Results: The cost of redundant trays was $21 806 and the cost of reduced trays was $8803, for a 1-year cost saving of $13 003. In sensitivity analyses, cost savings ranged from $3262 to $21 395, based on the surgical volume at the institution. Variation in surgical volume resulted in a wider range of estimates, with a minimum of $3253 for low-volume to a maximum of $52 012 for high-volume institutions. Interpretation: Our study suggests moderate savings may be achieved by reducing surgical tray redundancy and, if applied to other surgical specialties, may result in savings to Canadian health care systems. PMID:27975045

Comparing surgical trays with redundant instruments with trays with reduced instruments: a cost analysis.

PubMed

John-Baptiste, A; Sowerby, L J; Chin, C J; Martin, J; Rotenberg, B W

2016-01-01

When prearranged standard surgical trays contain instruments that are repeatedly unused, the redundancy can result in unnecessary health care costs. Our objective was to estimate potential savings by performing an economic evaluation comparing the cost of surgical trays with redundant instruments with surgical trays with reduced instruments ("reduced trays"). We performed a cost-analysis from the hospital perspective over a 1-year period. Using a mathematical model, we compared the direct costs of trays containing redundant instruments to reduced trays for 5 otolaryngology procedures. We incorporated data from several sources including local hospital data on surgical volume, the number of instruments on redundant and reduced trays, wages of personnel and time required to pack instruments. From the literature, we incorporated instrument depreciation costs and the time required to decontaminate an instrument. We performed 1-way sensitivity analyses on all variables, including surgical volume. Costs were estimated in 2013 Canadian dollars. The cost of redundant trays was $21 806 and the cost of reduced trays was $8803, for a 1-year cost saving of $13 003. In sensitivity analyses, cost savings ranged from $3262 to $21 395, based on the surgical volume at the institution. Variation in surgical volume resulted in a wider range of estimates, with a minimum of $3253 for low-volume to a maximum of $52 012 for high-volume institutions. Our study suggests moderate savings may be achieved by reducing surgical tray redundancy and, if applied to other surgical specialties, may result in savings to Canadian health care systems.

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

Distinct Subcortical Volume Alterations in Pediatric and Adult OCD: A Worldwide Meta- and Mega-Analysis.

PubMed

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; Hu, Hao; 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; Minuzzi, 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

2017-01-01

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 illness profile and developmental stage. To address these limitations, the authors conducted meta- and mega-analyses of data from OCD sites worldwide. T 1 images from 1,830 OCD patients and 1,759 control subjects were analyzed, using coordinated and standardized processing, to identify subcortical brain volumes that differ between OCD patients and healthy subjects. The authors performed a meta-analysis on the mean of the left and right hemisphere measures of each subcortical structure, and they performed a mega-analysis by pooling these volumetric measurements from each site. The authors additionally examined potential modulating effects of clinical characteristics on morphological differences in OCD patients. The meta-analysis indicated that adult patients had significantly smaller hippocampal volumes (Cohen's d=-0.13; % difference=-2.80) and larger pallidum volumes (d=0.16; % difference=3.16) compared with adult controls. Both effects were stronger in medicated patients compared with controls (d=-0.29, % difference=-4.18, and d=0.29, % difference=4.38, respectively). Unmedicated pediatric patients had significantly larger thalamic volumes (d=0.38, % difference=3.08) compared with pediatric controls. None of these findings were mediated by sample characteristics, such as mean age or scanning field strength. The mega-analysis yielded similar results. The results indicate different patterns of subcortical abnormalities in pediatric and 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. These findings highlight the potential importance of neurodevelopmental alterations in OCD and suggest that further research on neuroplasticity in OCD may be useful.

Signal Strength-Based Global Navigation Satellite System Performance Assessment in the Space Service Volume

NASA Technical Reports Server (NTRS)

Welch, Bryan W.

2016-01-01

NASA is participating in the International Committee on Global Navigation Satellite Systems (GNSS) (ICG)'s efforts towards demonstrating the benefits to the space user in the Space Service Volume (SSV) when a multi-GNSS solution space approach is utilized. The ICG Working Group: Enhancement of GNSS Performance, New Services and Capabilities has started a three phase analysis initiative as an outcome of recommendations at the ICG-10 meeting, in preparation for the ICG-11 meeting. The second phase of that increasing complexity and fidelity analysis initiative is based on augmenting the Phase 1 pure geometrical approach with signal strength-based limitations to determine if access is valid. The second phase of analysis has been completed, and the results are documented in this paper.

The effects of load history and design variables on performance limit states of circular bridge columns - volume 3 : analysis methods.

DOT National Transportation Integrated Search

2015-01-01

This report is the third of three volumes and presents the numerical portion of the research project on the impacts of loading history on : the behavior of reinforced concrete bridge columns. Two independent finite element methods were utilized to ac...

Reliability of Volumetry and Perimetry to Assess Knee Volume.

PubMed

Nunes, Guilherme S; Yamashitafuji, Igor; Wageck, Bruna; Teixeira, Guilherme Garcia; Karloh, Manuela; de Noronha, Marcos

2016-08-24

The treatment of edema after a knee injury is usually 1 of the main objectives during rehabilitation. To assess the success of treatment, 2 methods are commonly used in clinical practice: volumetry and perimetry. To investigate the intra- and interassessor reliability of volumetry and perimetry to assess knee volume. Cross-sectional. Laboratory. 45 healthy participants (26 women) with mean age of 22.4 ± 2.8 y. Knee volume was assessed by 3 assessors (A, B, and C) with 3 methods (lower-limb volumetry [LLV], knee volumetry [KV], and knee perimetry [KP]). Assessor A was the most-experienced assessor, and assessor C, the least experienced. LLV and KV were performed with participants in the orthostatic position, while KP was performed with participants in supine. For the interassessor analysis, the ICC2,1 was high (.82) for KV and very high for LLV (.99) and KP (.99). For the intra-assessor analysis, ICC2,1 ranged from moderate to high for KV (.69-.83) and was very high for LLV (.99) and KP (.97-.99). KV, LLV, and KP are reliable methods, both intra- and interassessor, to measure knee volume.

[Liver volume, intrahepatic fat and body weight in the course of a lifestyle interventional study: Analysis with quantitative MR-based methods].

PubMed

Bongers, M N; Stefan, N; Fritsche, A; Häring, H-U; Nikolaou, K; Schick, F; Machann, J

2015-04-01

The aim of this study was to investigate potential associations between changes in liver volume, the amount of intrahepatic lipids (IHL) and body weight during lifestyle interventions. In a prospective study 150 patients with an increased risk for developing type 2 diabetes mellitus were included who followed a caloric restriction diet for 6 months. In the retrospective analysis 18 women and 9 men (age range 22-71 years) with an average body mass index (BMI) of 32 kg/m(2) were enrolled. The liver volume was determined at the beginning and after 6 months by three-dimensional magnetic resonance imaging (3D-MRI, echo gradient, opposed-phase) and IHLs were quantified by volume-selective MR spectroscopy in single voxel stimulated echo acquisition mode (STEAM). Univariable and multivariable correlation analyses between changes of liver volume (Δliver volume), intrahepatic lipids (ΔIHL) and body weight (ΔBW) were performed. Univariable correlation analysis in the whole study cohort showed associations between ΔIHL and ΔBW (r = 0.69; p < 0.0001), ΔIHL and Δliver volume (r = 0.66; p = 0.0002) as well as ΔBW and Δliver volume (r = 0.5; p = 0.0073). Multivariable correlation analysis revealed that changes of liver volume are primarily determined by changes in IHL independent of changes in body weight (β = 0.0272; 95% CI: 0.0155-0.034; p < 0.0001). Changes of liver volume during lifestyle interventions are independent of changes of body weight primarily determined by changes of IHL. These results show the reversibility of augmented liver volume in steatosis if it is possible to reduce IHLs during lifestyle interventions.

A New Volumetric Radiologic Method to Assess Indirect Decompression After Extreme Lateral Interbody Fusion Using High-Resolution Intraoperative Computed Tomography.

PubMed

Navarro-Ramirez, Rodrigo; Berlin, Connor; Lang, Gernot; Hussain, Ibrahim; Janssen, Insa; Sloan, Stephen; Askin, Gulce; Avila, Mauricio J; Zubkov, Micaella; Härtl, Roger

2018-01-01

Two-dimensional radiographic methods have been proposed to evaluate the radiographic outcome after indirect decompression through extreme lateral interbody fusion (XLIF). However, the assessment of neural decompression in a single plane may underestimate the effect of indirect decompression on central canal and foraminal volumes. The present study aimed to assess the reliability and consistency of a novel 3-dimensional radiographic method that assesses neural decompression by volumetric analysis using a new generation of intraoperative fan-beam computed tomography scanner in patients undergoing XLIF. Prospectively collected data from 7 patients (9 levels) undergoing XLIF was retrospectively analyzed. Three independent, blind raters using imaging analysis software performed volumetric measurements pre- and postoperatively to determine central canal and foraminal volumes. Intrarater and Interrater reliability tests were performed to assess the reliability of this novel volumetric method. The interrater reliability between the three raters ranged from 0.800 to 0.952, P < 0.0001. The test-retest analysis on a randomly selected subset of three patients showed good to excellent internal reliability (range of 0.78-1.00) for all 3 raters. There was a significant increase in mean volume ≈20% for right foramen, left foramen, and central canal volumes postoperatively (P = 0.0472; P = 0.0066; P = 0.0003, respectively). Here we demonstrate a new volumetric analysis technique that is feasible, reliable, and reproducible amongst independent raters for central canal and foraminal volumes in the lumbar spine using an intraoperative computed tomography scanner. Copyright © 2017. Published by Elsevier Inc.

Morphologic changes in the mesolimbic pathway in Parkinson's disease motor subtypes.

PubMed

Nyberg, Eric M; Tanabe, Jody; Honce, Justin M; Krmpotich, Theodore; Shelton, Erika; Hedeman, Jessica; Berman, Brian D

2015-05-01

Parkinson's disease (PD) is a common neurodegenerative disorder associated with gray matter atrophy. Cortical atrophy patterns may further help distinguish between PD motor subtypes. Comparable differences in subcortical volumes have not been found. Twenty-one cognitively intact and treated PD patients, including 12 tremor dominant (TD) subtype, Nine postural instability gait dominant (PIGD) subtype, and 20 matched healthy control subjects underwent 3.0 T high-resolution structural MRI scanning. Subcortical volumetric analysis was performed using FreeSurfer and shape analysis was performed with FIRST to assess for differences between PD patients and controls and between PD subtypes. No significant differences in subcortical volumes were found between motor PD subtypes, but comparing grouped PD patients with controls revealed a significant increase in hippocampal volume in PD patients (p = 0.03). A significant shape difference was detected in the right nucleus accumbens (NAcc) between PD and controls and between motor subtypes. Shape differences were driven by positive deviations in the TD subtype. Correlation analysis revealed a trend between hippocampal volume and decreasing MDS-UPDRS (p = 0.06). While no significant differences in subcortical volumes between PD motor subtypes were found, increased hippocampal volumes were observed in PD patients compared to controls. Right NAcc shape differences in PD patients were driven by changes in the TD subtype. These unexpected findings may be related to the effects of chronic dopaminergic replacement on the mesolimbic pathway. Further studies are needed to replicate and determine the clinical significance of such morphologic changes. Copyright © 2015 Elsevier Ltd. All rights reserved.

Real-time fMRI processing with physiological noise correction - Comparison with off-line analysis.

PubMed

Misaki, Masaya; Barzigar, Nafise; Zotev, Vadim; Phillips, Raquel; Cheng, Samuel; Bodurka, Jerzy

2015-12-30

While applications of real-time functional magnetic resonance imaging (rtfMRI) are growing rapidly, there are still limitations in real-time data processing compared to off-line analysis. We developed a proof-of-concept real-time fMRI processing (rtfMRIp) system utilizing a personal computer (PC) with a dedicated graphic processing unit (GPU) to demonstrate that it is now possible to perform intensive whole-brain fMRI data processing in real-time. The rtfMRIp performs slice-timing correction, motion correction, spatial smoothing, signal scaling, and general linear model (GLM) analysis with multiple noise regressors including physiological noise modeled with cardiac (RETROICOR) and respiration volume per time (RVT). The whole-brain data analysis with more than 100,000voxels and more than 250volumes is completed in less than 300ms, much faster than the time required to acquire the fMRI volume. Real-time processing implementation cannot be identical to off-line analysis when time-course information is used, such as in slice-timing correction, signal scaling, and GLM. We verified that reduced slice-timing correction for real-time analysis had comparable output with off-line analysis. The real-time GLM analysis, however, showed over-fitting when the number of sampled volumes was small. Our system implemented real-time RETROICOR and RVT physiological noise corrections for the first time and it is capable of processing these steps on all available data at a given time, without need for recursive algorithms. Comprehensive data processing in rtfMRI is possible with a PC, while the number of samples should be considered in real-time GLM. Copyright © 2015 Elsevier B.V. All rights reserved.

Mean platelet volume (MPV) predicts middle distance running performance.

PubMed

Lippi, Giuseppe; Salvagno, Gian Luca; Danese, Elisa; Skafidas, Spyros; Tarperi, Cantor; Guidi, Gian Cesare; Schena, Federico

2014-01-01

Running economy and performance in middle distance running depend on several physiological factors, which include anthropometric variables, functional characteristics, training volume and intensity. Since little information is available about hematological predictors of middle distance running time, we investigated whether some hematological parameters may be associated with middle distance running performance in a large sample of recreational runners. The study population consisted in 43 amateur runners (15 females, 28 males; median age 47 years), who successfully concluded a 21.1 km half-marathon at 75-85% of their maximal aerobic power (VO2max). Whole blood was collected 10 min before the run started and immediately thereafter, and hematological testing was completed within 2 hours after sample collection. The values of lymphocytes and eosinophils exhibited a significant decrease compared to pre-run values, whereas those of mean corpuscular volume (MCV), platelets, mean platelet volume (MPV), white blood cells (WBCs), neutrophils and monocytes were significantly increased after the run. In univariate analysis, significant associations with running time were found for pre-run values of hematocrit, hemoglobin, mean corpuscular hemoglobin (MCH), red blood cell distribution width (RDW), MPV, reticulocyte hemoglobin concentration (RetCHR), and post-run values of MCH, RDW, MPV, monocytes and RetCHR. In multivariate analysis, in which running time was entered as dependent variable whereas age, sex, blood lactate, body mass index, VO2max, mean training regimen and the hematological parameters significantly associated with running performance in univariate analysis were entered as independent variables, only MPV values before and after the trial remained significantly associated with running time. After adjustment for platelet count, the MPV value before the run (p = 0.042), but not thereafter (p = 0.247), remained significantly associated with running performance. The significant association between baseline MPV and running time suggest that hyperactive platelets may exert some pleiotropic effects on endurance performance.

Performance Analysis and Design Synthesis (PADS) computer program. Volume 2: Program description, part 1

NASA Technical Reports Server (NTRS)

1972-01-01

The Performance Analysis and Design Synthesis (PADS) computer program has a two-fold purpose. It can size launch vehicles in conjunction with calculus-of-variations optimal trajectories and can also be used as a general-purpose branched trajectory optimization program. In the former use, it has the Space Shuttle Synthesis Program as well as a simplified stage weight module for optimally sizing manned recoverable launch vehicles. For trajectory optimization alone or with sizing, PADS has two trajectory modules. The first trajectory module uses the method of steepest descent; the second employs the method of quasilinearization, which requires a starting solution from the first trajectory module. For Volume 1 see N73-13199.

Magnetite-doped polydimethylsiloxane (PDMS) for phosphopeptide enrichment.

PubMed

Sandison, Mairi E; Jensen, K Tveen; Gesellchen, F; Cooper, J M; Pitt, A R

2014-10-07

Reversible phosphorylation plays a key role in numerous biological processes. Mass spectrometry-based approaches are commonly used to analyze protein phosphorylation, but such analysis is challenging, largely due to the low phosphorylation stoichiometry. Hence, a number of phosphopeptide enrichment strategies have been developed, including metal oxide affinity chromatography (MOAC). Here, we describe a new material for performing MOAC that employs a magnetite-doped polydimethylsiloxane (PDMS), that is suitable for the creation of microwell array and microfluidic systems to enable low volume, high throughput analysis. Incubation time and sample loading were explored and optimized and demonstrate that the embedded magnetite is able to enrich phosphopeptides. This substrate-based approach is rapid, straightforward and suitable for simultaneously performing multiple, low volume enrichments.

Treatment Planning and Volumetric Response Assessment for Yttrium-90 Radioembolization: Semiautomated Determination of Liver Volume and Volume of Tumor Necrosis in Patients with Hepatic Malignancy

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

Monsky, Wayne L., E-mail: wayne.monsky@ucdmc.ucdavis.edu; Garza, Armando S.; Kim, Isaac

Purpose: The primary purpose of this study was to demonstrate intraobserver/interobserver reproducibility for novel semiautomated measurements of hepatic volume used for Yttrium-90 dose calculations as well as whole-liver and necrotic-liver (hypodense/nonenhancing) tumor volume after radioembolization. The secondary aim was to provide initial comparisons of tumor volumetric measurements with linear measurements, as defined by Response Evaluation Criteria in Solid Tumors criteria, and survival outcomes. Methods: Between 2006 and 2009, 23 consecutive radioembolization procedures were performed for 14 cases of hepatocellular carcinoma and 9 cases of hepatic metastases. Baseline and follow-up computed tomography obtained 1 month after treatment were retrospectively analyzed. Threemore » observers measured liver, whole-tumor, and tumor-necrosis volumes twice using semiautomated software. Results: Good intraobserver/interobserver reproducibility was demonstrated (intraclass correlation [ICC] > 0.9) for tumor and liver volumes. Semiautomated measurements of liver volumes were statistically similar to those obtained with manual tracing (ICC = 0.868), but they required significantly less time to perform (p < 0.0001, ICC = 0.088). There was a positive association between change in linear tumor measurements and whole-tumor volume (p < 0.0001). However, linear measurements did not correlate with volume of necrosis (p > 0.05). Dose, change in tumor diameters, tumor volume, and necrotic volume did not correlate with survival (p > 0.05 in all instances). However, Kaplan-Meier curves suggest that a >10% increase in necrotic volume correlated with survival (p = 0.0472). Conclusion: Semiautomated volumetric analysis of liver, whole-tumor, and tumor-necrosis volume can be performed with good intraobserver/interobserver reproducibility. In this small retrospective study, measurements of tumor necrosis were suggested to correlate with survival.« less

Architectural and Behavioral Systems Design Methodology and Analysis for Optimal Habitation in a Volume-Limited Spacecraft for Long Duration Flights

NASA Technical Reports Server (NTRS)

Kennedy, Kriss J.; Lewis, Ruthan; Toups, Larry; Howard, Robert; Whitmire, Alexandra; Smitherman, David; Howe, Scott

2016-01-01

As our human spaceflight missions change as we reach towards Mars, the risk of an adverse behavioral outcome increases, and requirements for crew health, safety, and performance, and the internal architecture, will need to change to accommodate unprecedented mission demands. Evidence shows that architectural arrangement and habitability elements impact behavior. Net habitable volume is the volume available to the crew after accounting for elements that decrease the functional volume of the spacecraft. Determination of minimum acceptable net habitable volume and associated architectural design elements, as mission duration and environment varies, is key to enabling, maintaining, andor enhancing human performance and psychological and behavioral health. Current NASA efforts to derive minimum acceptable net habitable volumes and study the interaction of covariates and stressors, such as sensory stimulation, communication, autonomy, and privacy, and application to internal architecture design layouts, attributes, and use of advanced accommodations will be presented. Furthermore, implications of crew adaptation to available volume as they transfer from Earth accommodations, to deep space travel, to planetary surface habitats, and return, will be discussed.

Space Shuttle Main Engine structural analysis and data reduction/evaluation. Volume 3A: High pressure oxidizer turbo-pump preburner pump housing stress analysis report

NASA Technical Reports Server (NTRS)

Shannon, Robert V., Jr.

1989-01-01

The model generation and structural analysis performed for the High Pressure Oxidizer Turbopump (HPOTP) preburner pump volute housing located on the main pump end of the HPOTP in the space shuttle main engine are summarized. An ANSYS finite element model of the volute housing was built and executed. A static structural analysis was performed on the Engineering Analysis and Data System (EADS) Cray-XMP supercomputer

Hospital esophagectomy volume and postoperative length of stay: A systematic review and meta-analysis.

PubMed

Giwa, Femi; Salami, Aitua; Abioye, Ajibola I

2018-01-01

Much attention in the volume-outcomes literature has focused on the empirical impact of surgical caseload on outcomes. However, relevant studies on the association between surgical volume and variables that potentially contribute to healthcare costs are limited. The objective of this study was to systematically elucidate a contemporary analysis of the empirical relationship between hospital esophagectomy volume and postoperative length of stay, a cost-related outcome. OvidSP, PubMed, EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL), ISI Web of Science and OpenGrey were searched for relevant articles published from 2000 to 2016. High hospital esophagectomy volume was associated with reduced postoperative length of stay (mean: 3 days; 95%CI: 2.8, 3.2) and risk of prolonged length of stay (RR: 0.80, 95%CI: 0.74, 0.87) in a dose-response fashion. Complex surgeries performed at high surgical volume centers may be associated with overall decrease in postoperative length of stay, a cost-related outcome. Copyright © 2017 Elsevier Inc. All rights reserved.

Impact Assessment and Forecasts of Information and Telecommunications Technologies Applied to Education and Training: Volume II--Main Report and Issues Analyses. Analysis for the Orientation of the Work of Sector Actors in the Framework of DELTA.

ERIC Educational Resources Information Center

Commission of the European Communities, Brussels (Belgium).

This report, the second volume in a three volume set, summarizes the results of a study performed by the DELTA (Developing European Learning through Technological Advance) unit in parallel with the projects underway in the research and development Exploratory Action. The report identifies the key issues, associated requirements and options, and…

Impact of donor- and collection-related variables on product quality in ex utero cord blood banking.

PubMed

Askari, Sabeen; Miller, John; Chrysler, Gayl; McCullough, Jeffrey

2005-02-01

Optimizing product quality is a current focus in cord blood banking. This study evaluates the role of selected donor- and collection-related variables. Retrospective review was performed of cord blood units (CBUs) collected ex utero between February 1, 2000, and February 28, 2002. Preprocessing volume and total nucleated cell (TNC) counts and postprocessing CD34 cell counts were used as product quality indicators. Of 2084 CBUs, volume determinations and TNC counts were performed on 1628 and CD34+ counts on 1124 CBUs. Mean volume and TNC and CD34+ counts were 85.2 mL, 118.9 x 10(7), and 5.2 x 10(6), respectively. In univariate analysis, placental weight of greater than 500 g and meconium in amniotic fluid correlated with better volume and TNC and CD34+ counts. Greater than 40 weeks' gestation predicted enhanced volume and TNC count. Cesarean section, two- versus one-person collection, and not greater than 5 minutes between placental delivery and collection produced superior volume. Increased TNC count was also seen in Caucasian women, primigravidae, female newborns, and collection duration of more than 5 minutes. A time between delivery of newborn and placenta of not greater than 10 minutes predicted better volume and CD34+ count. By regression analysis, collection within not greater than 5 minutes of placental delivery produced superior volume and TNC count. Donor selection and collection technique modifications may improve product quality. TNC count appears to be more affected by different variables than CD34+ count.

Impact of surgeon volume on the morbidity and costs of radical cystectomy in the USA: a contemporary population-based analysis.

PubMed

Leow, Jeffrey J; Reese, Stephen; Trinh, Quoc-Dien; Bellmunt, Joaquim; Chung, Benjamin I; Kibel, Adam S; Chang, Steven L

2015-05-01

To evaluate the relationship between surgeon volume of radical cystectomy (RC) and postoperative morbidity, and to assess the economic burden of bladder cancer in the USA. We captured all patients who underwent RC (International Classification of Diseases, ninth revision, code 57.71) between 2003 and 2010, using a nationwide hospital discharge database. Patient, hospital and surgical characteristics were evaluated. The annual volume of RCs performed by the surgeons was divided into quintiles. Multivariable regression models were developed, adjusting for clustering and survey weighting, to evaluate the outcomes, including 90-day major complications (Clavien grade III-V) and direct patient costs. We adjusted for clustering and weighting to achieve a nationally representative analysis. The weighted cohort included 49,792 patients who underwent RC, with an overall 90-day major complication rate of 16.2%. Compared with surgeons performing one RC annually, surgeons performing ≥7 RCs each year had 45% lower odds of major complications (odds ratio [OR] 0.55; P < 0.001) and lower costs by $1690 (P = 0.02). Results were consistent when we analysed surgeon volume as a continuous variable and when we examined the surgeons with the highest volumes (≥28 cases annually), which showed markedly lower odds of major complications compared with the surgeons with the lowest volumes (OR 0.45, 95% CI 0.31-0.67; P < 0.001). Compared with patients who did not have any complications, those who had a major complication were associated with significantly higher 90-day median direct hospital costs ($43,965 vs $24,341; P < 0.001). We showed that there was an inverse relationship between surgeon volume and the development of postoperative 90-day major complication rates as well as direct hospital costs. Centralisation of RC to surgeons with higher volumes may reduce the development of postoperative major complications, thereby decreasing the burden of bladder cancer on the healthcare system. © 2014 The Authors. BJU International © 2014 BJU International.

Baseline Description and Analysis of the Operations Related to Warehouse Controlled Documents at the Navy Publications and Forms Center, Philadelphia, Pennsylvania. Volume I. Phase I.

DTIC Science & Technology

1980-03-06

performing the present NPFC tasks. Potential automation technologies may include order processing mechanization, demand printing from micrographic or...effort and documented in this volume included the following: a. Functional description of the order processing activities as they currently operate. b...covered under each analysis area. i It is obvious from the exhibit that the functional description of order processing operations was to include COG I

Space shuttle/food system study. Volume 2, appendix E: Alternate flight systems analysis

NASA Technical Reports Server (NTRS)

1974-01-01

The functional requirements of stowage, preparation, serving, consumption, and cleanup were applied to each of the five food mixes selected for study in terms of the overall design of the space shuttle food system. The analysis led to a definition of performance requirements for each food mix, along with a definition of equipment to meet those requirements. Weight and volume data for all five systems, in terms of food and packaging, support equipment, and galley installation penalties, are presented.

Fluid Vessel Quantity using Non-Invasive PZT Technology Flight Volume Measurements Under Zero G Analysis

NASA Technical Reports Server (NTRS)

Garofalo, Anthony A.

2013-01-01

The purpose of the project is to perform analysis of data using the Systems Engineering Educational Discovery (SEED) program data from 2011 and 2012 Fluid Vessel Quantity using Non-Invasive PZT Technology flight volume measurements under Zero G conditions (parabolic Plane flight data). Also experimental planning and lab work for future sub-orbital experiments to use the NASA PZT technology for fluid volume measurement. Along with conducting data analysis of flight data, I also did a variety of other tasks. I provided the lab with detailed technical drawings, experimented with 3d printers, made changes to the liquid nitrogen skid schematics, and learned how to weld. I also programmed microcontrollers to interact with various sensors and helped with other things going on around the lab.

Fluid Vessel Quantity Using Non-invasive PZT Technology Flight Volume Measurements Under Zero G Analysis

NASA Technical Reports Server (NTRS)

Garofalo, Anthony A

2013-01-01

The purpose of the project is to perform analysis of data using the Systems Engineering Educational Discovery (SEED) program data from 2011 and 2012 Fluid Vessel Quantity using Non-Invasive PZT Technology flight volume measurements under Zero G conditions (parabolic Plane flight data). Also experimental planning and lab work for future sub-orbital experiments to use the NASA PZT technology for fluid volume measurement. Along with conducting data analysis of flight data, I also did a variety of other tasks. I provided the lab with detailed technical drawings, experimented with 3d printers, made changes to the liquid nitrogen skid schematics, and learned how to weld. I also programmed microcontrollers to interact with various sensors and helped with other things going on around the lab.

Surgical volume and conversion rate in laparoscopic hysterectomy: does volume matter? A multicenter retrospective cohort study.

PubMed

Keurentjes, José H M; Briët, Justine M; de Bock, Geertruida H; Mourits, Marian J E

2018-02-01

A multicenter, retrospective, cohort study was conducted in the Netherlands. The aim was to evaluate whether surgical volume of laparoscopic hysterectomies (LHs) performed by proven skilled gynecologists had an impact on the conversion rate from laparoscopy to laparotomy. In 14 hospitals, all LHs performed by 19 proven skilled gynecologists between 2007 and 2010 were included in the analysis. Surgical volume, conversion rate and type of conversion (reactive or strategic) were retrospectively assessed. To estimate the impact of surgical volume on the conversion rate, logistic regressions were performed. These regressions were adjusted for patient's age, Body Mass Index (BMI), ASA classification, previous abdominal surgery and the indication (malignant versus benign) for the LH. During the study period, 19 proven skilled gynecologists performed a total of 1051 LHs. Forty percent of the gynecologists performed over 20 LHs per year (median 17.3, range 5.4-49.5). Conversion to laparotomy occurred in 5.0% of all LHs (53 of 1051); 38 (3.6%) were strategic and 15 (1.4%) were reactive conversions. Performing over 20 LHs per year was significantly associated with a lower overall conversion rate (OR adjusted 0.43, 95% CI 0.24-0.77), a lower strategic conversion rate (OR adjusted 0.32, 95% CI 0.16-0.65), but not with a lower reactive conversion rate (OR adjusted 0.96, 95% CI 0.33-2.79). A higher annual surgical volume of LHs by proven skilled gynecologists is inversely related to the conversion rate to laparotomy, and results in a lower strategic conversion rate.

Impact of case volume on outcome and performance of targeted temperature management in out-of-hospital cardiac arrest survivors.

PubMed

Lee, Seung Joon; Jeung, Kyung Woon; Lee, Byung Kook; Min, Yong Il; Park, Kyu Nam; Suh, Gil Joon; Kim, Kyung Su; Kang, Gu Hyun

2015-01-01

This study aimed to determine the effect of case volume on targeted temperature management (TTM) performance, incidence of adverse events, and neurologic outcome in comatose out-of-hospital cardiac arrest (OHCA) survivors treated with TTM. We used a Web-based, multicenter registry (Korean Hypothermia Network registry), to which 24 hospitals throughout the Republic of Korea participated to study adult (≥18 years) comatose out-of-hospital cardiac arrest patients treated with TTM between 2007 and 2012. The primary outcome was neurologic outcome at hospital discharge. The secondary outcomes were inhospital mortality, TTM performance, and adverse events. We extracted propensity-matched cohorts to control for bias. Multivariate logistic regression analysis was performed to assess independent risk factors for neurologic outcome. A total of 901 patients were included in this study; 544 (60.4%) survived to hospital discharge, and 248 (27.5%) were discharged with good neurologic outcome. The high-volume hospitals initiated TTM significantly earlier and had lower rates of hyperglycemia, bleeding, hypotension, and rebound hyperthermia. However, neurologic outcome and inhospital mortality were comparable between high-volume (27.7% and 44.6%, respectively) and low-volume hospitals (21.1% and 40.5%) in the propensity-matched cohorts. The adjusted odds ratio for the high-volume hospitals compared with low-volume hospitals was 1.506 (95% confidence interval, 0.875-2.592) for poor neurologic outcome. Higher TTM case volume was significantly associated with early initiation of TTM and lower incidence of adverse events. However, case volume had no association with neurologic outcome and inhospital mortality. Copyright © 2014 Elsevier Inc. All rights reserved.

Magnetic resonance imaging volume of the angular gyri predicts financial skill deficits in people with amnestic mild cognitive impairment.

PubMed

Griffith, H Randall; Stewart, Christopher C; Stoeckel, Luke E; Okonkwo, Ozioma C; den Hollander, Jan A; Martin, Roy C; Belue, Katherine; Copeland, Jacquelynn N; Harrell, Lindy E; Brockington, John C; Clark, David G; Marson, Daniel C

2010-02-01

To better understand how brain atrophy in amnestic mild cognitive impairment (MCI) as measured using magnetic resonance imaging (MRI) volumetrics could affect instrumental activities of daily living (IADLs) such as financial abilities. Controlled, matched-sample, cross-sectional analysis regressing MRI volumetrics with financial performance measures. University medical and research center. Thirty-eight people with MCI and 28 older adult controls. MRI volumetric measurement of the hippocampi, angular gyri, precunei, and medial frontal lobes. Participants also completed neuropsychological tests and the Financial Capacity Instrument (FCI). Correlations were performed between FCI scores and MRI volumes in the group with MCI. People with MCI performed significantly below controls on the FCI and had significantly smaller hippocampi. Among people with MCI, performance on the FCI was moderately correlated with angular gyri and precunei volumes. Regression models demonstrated that angular gyrus volumes were predictive of FCI scores. Tests of mediation showed that measures of arithmetic and possibly attention partially mediated the relationship between angular gyrus volume and FCI score. Impaired financial abilities in amnestic MCI correspond with volume of the angular gyri as mediated by arithmetic knowledge. The findings suggest that early neuropathology within the lateral parietal region in MCI leads to a breakdown of cognitive abilities that affect everyday financial skills. The findings have implications for diagnosis and clinical care of people with MCI and AD.

Quantitative CT: technique dependence of volume estimation on pulmonary nodules

NASA Astrophysics Data System (ADS)

Chen, Baiyu; Barnhart, Huiman; Richard, Samuel; Colsher, James; Amurao, Maxwell; Samei, Ehsan

2012-03-01

Current estimation of lung nodule size typically relies on uni- or bi-dimensional techniques. While new three-dimensional volume estimation techniques using MDCT have improved size estimation of nodules with irregular shapes, the effect of acquisition and reconstruction parameters on accuracy (bias) and precision (variance) of the new techniques has not been fully investigated. To characterize the volume estimation performance dependence on these parameters, an anthropomorphic chest phantom containing synthetic nodules was scanned and reconstructed with protocols across various acquisition and reconstruction parameters. Nodule volumes were estimated by a clinical lung analysis software package, LungVCAR. Precision and accuracy of the volume assessment were calculated across the nodules and compared between protocols via a generalized estimating equation analysis. Results showed that the precision and accuracy of nodule volume quantifications were dependent on slice thickness, with different dependences for different nodule characteristics. Other parameters including kVp, pitch, and reconstruction kernel had lower impact. Determining these technique dependences enables better volume quantification via protocol optimization and highlights the importance of consistent imaging parameters in sequential examinations.

The Effect of Instruction on the Acquisition of Conservation of Volume.

ERIC Educational Resources Information Center

Butts, David P.; Howe, Ann C.

Tested was the hypothesis that science instruction based on task analysis will lead to the acquisition of the ability to perform certain Piaget volume tasks which have been characterized as requiring formal operations for their solutions. A Test on Formal Operations and a Learning Hierarchies Test were given to fourth- and sixth-grade students in…

Senior Dance Experience, Cognitive Performance, and Brain Volume in Older Women

PubMed Central

Niemann, Claudia; Godde, Ben

2016-01-01

Physical activity is positively related to cognitive functioning and brain volume in older adults. Interestingly, different types of physical activity vary in their effects on cognition and on the brain. For example, dancing has become an interesting topic in aging research, as it is a popular leisure activity among older adults, involving cardiovascular and motor fitness dimensions that can be positively related to cognition. However, studies on brain structure are missing. In this study, we tested the association of long-term senior dance experience with cognitive performance and gray matter brain volume in older women aged 65 to 82 years. We compared nonprofessional senior dancers (n = 28) with nonsedentary control group participants without any dancing experience (n = 29), who were similar in age, education, IQ score, lifestyle and health factors, and fitness level. Differences neither in the four tested cognitive domains (executive control, perceptual speed, episodic memory, and long-term memory) nor in brain volume (VBM whole-brain analysis, region-of-interest analysis of the hippocampus) were observed. Results indicate that moderate dancing activity (1-2 times per week, on average) has no additional effects on gray matter volume and cognitive functioning when a certain lifestyle or physical activity and fitness level are reached. PMID:27738528

The volume threshold of 300 versus 100 ml/day for chest tube removal after pulmonary lobectomy: a meta-analysis.

PubMed

Zhang, Tian-Xiang; Zhang, Ye; Liu, Zhi-Dong; Zhou, Shi-Jie; Xu, Shao-Fa

2018-05-07

In this meta-analysis, we conducted a pooled analysis of clinical studies comparing the efficacy of a volume threshold of 300 ml/day before removing a chest tube (CT) versus 100 ml/day after a lobectomy. According to the recommendations of the Cochrane Collaboration, we established a rigorous study protocol. We performed a systematic electronic search of PubMed, Embase, Cochrane Library, Web of Science databases, CNKI, the Wanfang database, CBMdisc and Google Scholar to identify articles to include in our meta-analysis. A literature search was performed using relevant keywords. A meta-analysis was performed using RevMan© software. Five studies, published between 2014 and 2015, including 615 patients (314 patients who had the CT removed when daily drainage was <300 ml and 301 patients who had the CT removed when daily drainage was <100 ml) met the selection criteria. From the available data, the patients using the volume threshold of 300 ml/day had a significantly decreased duration of drainage [MD = -44.07; 95% confidence interval (CI) -64.45 to -23.68; P < 0.0001] and hospital stay after operation (MD = -2.25; 95% CI -3.52 to -0.97; P = 0.0006) compared with patients using a volume threshold of 100 ml/day after a pulmonary lobectomy. However, no significant differences were observed in postoperative complications, such as pleural fluid reaccumulation [Odds ratio (OR) = 1.73; 95% CI = 0.74-4.07; P = 0.21] and atelectasis (OR = 0.97; 95% CI = 0.52-1.81; P = 0.93). Thoracentesis rates after removing the CT also showed no significant difference (OR = 1.53; 95% CI 0.55-4.22; P = 0.41). Our results showed that a higher volume threshold, up to 300 ml/day, is effective in reducing hospitalization times and duration of drainage in patients who undergo a lobectomy. Moreover, the volume threshold of 300 ml/day does not increase the occurrence of postoperative atelectasis, pleural fluid reaccumulation and thoracentesis rates. However, this review is limited by the methodological quality of the included trials, and additional studies according to the recommendations of Cochrane Library are appreciated.

Airport Surface Traffic Control Concept Formulation Study : Volume II. Operations Analysis of O'Hare Airport - Part 1

DOT National Transportation Integrated Search

1975-07-01

The report describes the approach followed and the analysis techniques employed in the performance of the operations analysis of the current ASTC system for the baseline airport, O'Hare International Airport, Chicago, Illinois. It also describes the ...

A PROPOSED CHEMICAL INFORMATION AND DATA SYSTEM. VOLUME I.

DTIC Science & Technology

CHEMICAL COMPOUNDS, *DATA PROCESSING, *INFORMATION RETRIEVAL, * CHEMICAL ANALYSIS, INPUT OUTPUT DEVICES, COMPUTER PROGRAMMING, CLASSIFICATION...CONFIGURATIONS, DATA STORAGE SYSTEMS, ATOMS, MOLECULES, PERFORMANCE( ENGINEERING ), MAINTENANCE, SUBJECT INDEXING, MAGNETIC TAPE, AUTOMATIC, MILITARY REQUIREMENTS, TYPEWRITERS, OPTICS, TOPOLOGY, STATISTICAL ANALYSIS, FLOW CHARTING.

Detection of traffic incidents using nonlinear time series analysis

NASA Astrophysics Data System (ADS)

Fragkou, A. D.; Karakasidis, T. E.; Nathanail, E.

2018-06-01

In this study, we present results of the application of nonlinear time series analysis on traffic data for incident detection. More specifically, we analyze daily volume records of Attica Tollway (Greece) collected from sensors located at various locations. The analysis was performed using the Recurrence Plot (RP) and Recurrence Quantification Analysis (RQA) method of the volume data of the lane closest to the median. The results show that it is possible to identify, through the abrupt change of the dynamics of the system revealed by RPs and RQA, the occurrence of incidents on the freeway and differentiate from recurrent traffic congestion. The proposed methodology could be of interest for big data traffic analysis.

Probabilistic Structural Analysis Methods for select space propulsion system components (PSAM). Volume 2: Literature surveys of critical Space Shuttle main engine components

NASA Technical Reports Server (NTRS)

Rajagopal, K. R.

1992-01-01

The technical effort and computer code development is summarized. Several formulations for Probabilistic Finite Element Analysis (PFEA) are described with emphasis on the selected formulation. The strategies being implemented in the first-version computer code to perform linear, elastic PFEA is described. The results of a series of select Space Shuttle Main Engine (SSME) component surveys are presented. These results identify the critical components and provide the information necessary for probabilistic structural analysis. Volume 2 is a summary of critical SSME components.

Intranasal volume increases with age: Computed tomography volumetric analysis in adults.

PubMed

Loftus, Patricia A; Wise, Sarah K; Nieto, Daniel; Panella, Nicholas; Aiken, Ashley; DelGaudio, John M

2016-10-01

It is theorized that intranasal cavity volumes change throughout the aging process, possibly secondary to hormonal changes and atrophy of the sinonasal mucosa. Our objective is to compare intranasal volumes from different age groups to test the hypothesis that intranasal cavity volume increases with age. Case series. An analysis of computed tomography (CT) scans performed for reasons other than sinonasal complaints. Intranasal volumes of three groups (age 20-30 years, 40-50 years, and 70 years and above) were calculated using Vitrea software. The total intranasal volume was measured from the nasal vestibule anteriorly, the nasopharynx posteriorly, the olfactory cleft superiorly, and the nasal floor inferiorly. The total volume included the sum of the right and left sides. Sixty-two CT scans were analyzed. There was a progressive, relatively linear, increase in intranasal volume with increasing age: 20 to 30 years = 15.73 mL, 40 to 50 years = 17.30 mL, and 70 years and above = 18.38 mL. Mean intranasal volume for males was 19.07 mL, and for females was 15.23 mL. Analysis of variance demonstrated significant group differences in mean intranasal volume for age (P = .003) and gender (P < .001), with moderate-to-large effect size of 0.206 and 0.289 (partial η(2) ), respectively. Post hoc testing revealed a significant difference between the 20 to 30-year and >70-year age groups (P = .006). There was no significant difference in intranasal volume dependent upon body mass index. Intranasal volume increases with age and is larger in males. Specific etiologies responsible for increased intranasal cavity volume with age are actively being evaluated. 4 Laryngoscope, 126:2212-2215, 2016. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.

Brain volume reduction after whole-brain radiotherapy: quantification and prognostic relevance.

PubMed

Hoffmann, Christian; Distel, Luitpold; Knippen, Stefan; Gryc, Thomas; Schmidt, Manuel Alexander; Fietkau, Rainer; Putz, Florian

2018-01-22

Recent studies have questioned the value of adding whole-brain radiotherapy (WBRT) to stereotactic radiosurgery (SRS) for brain metastasis treatment. Neurotoxicity, including radiation-induced brain volume reduction, could be one reason why not all patients benefit from the addition of WBRT. In this study, we quantified brain volume reduction after WBRT and assessed its prognostic significance. Brain volumes of 91 patients with cerebral metastases were measured during a 150-day period after commencing WBRT and were compared with their pretreatment volumes. The average daily relative change in brain volume of each patient, referred to as the "brain volume reduction rate," was calculated. Univariate and multivariate Cox regression analyses were performed to assess the prognostic significance of the brain volume reduction rate, as well as of 3 treatment-related and 9 pretreatment factors. A one-way analysis of variance was used to compare the brain volume reduction rate across recursive partitioning analysis (RPA) classes. On multivariate Cox regression analysis, the brain volume reduction rate was a significant predictor of overall survival after WBRT (P < 0.001), as well as the number of brain metastases (P = 0.002) and age (P = 0.008). Patients with a relatively favorable prognosis (RPA classes 1 and 2) experienced significantly less brain volume decrease after WBRT than patients with a poor prognosis (RPA class 3) (P = 0.001). There was no significant correlation between delivered radiation dose and brain volume reduction rate (P = 0.147). In this retrospective study, a smaller decrease in brain volume after WBRT was an independent predictor of longer overall survival. © The Author(s) 2017. Published by Oxford University Press on behalf of the Society for Neuro-Oncology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com

Age accounts for racial differences in ischemic stroke volume in a population-based study.

PubMed

Zakaria, Tarek; Lindsell, Christopher J; Kleindorfer, Dawn; Alwell, Kathleen; Moomaw, Charles J; Woo, Daniel; Szaflarski, Jerzy P; Khoury, Jane; Miller, Rosie; Broderick, Joseph P; Kissela, Brett

2008-01-01

The stroke volume among black ischemic stroke patients in phase I of the population-based Greater Cincinnati/Northern Kentucky Stroke Study (GCNKSS) was smaller than reported among acute stroke studies, with a median stroke volume of 2.5 cm. However, it is not known if stroke volume was similar between black and white patients within the same study population. Phase II of the GCNKSS identified all ischemic strokes between July 1993 and June 1994. The stroke volume was estimated by study physicians using the modified ellipsoid method. Analysis of stroke volume by race, sex and age was performed for strokes with a measurable lesion of >or=0.5 cm(3). Among verified cases of ischemic stroke, 334 patients were eligible for this analysis. There were 191 whites (57%) and 143 blacks (43%). The mean age was 69.4 years. The median stroke volume for all patients was 8.8 cm(3) (range 0.5-540), with a mean of 36.4 cm(3). Stroke volume was not different between men and women, and it tended to increase with age. Although stroke volume was significantly higher among whites, age was a confounding factor. Subsequent analysis of stroke volume stratified by age showed no difference between blacks and whites in any age group. Our data show that most ischemic stroke lesions, regardless of the race, are of small size, and this may be an important reason for the low percentage of strokes treated currently with tissue-type plasminogen activator. The association of age with stroke volume requires further study. Copyright 2008 S. Karger AG, Basel.

Volumetric analysis of pelvic hematomas after blunt trauma using semi-automated seeded region growing segmentation: a method validation study.

PubMed

Dreizin, David; Bodanapally, Uttam K; Neerchal, Nagaraj; Tirada, Nikki; Patlas, Michael; Herskovits, Edward

2016-11-01

Manually segmented traumatic pelvic hematoma volumes are strongly predictive of active bleeding at conventional angiography, but the method is time intensive, limiting its clinical applicability. We compared volumetric analysis using semi-automated region growing segmentation to manual segmentation and diameter-based size estimates in patients with pelvic hematomas after blunt pelvic trauma. A 14-patient cohort was selected in an anonymous randomized fashion from a dataset of patients with pelvic binders at MDCT, collected retrospectively as part of a HIPAA-compliant IRB-approved study from January 2008 to December 2013. To evaluate intermethod differences, one reader (R1) performed three volume measurements using the manual technique and three volume measurements using the semi-automated technique. To evaluate interobserver differences for semi-automated segmentation, a second reader (R2) performed three semi-automated measurements. One-way analysis of variance was used to compare differences in mean volumes. Time effort was also compared. Correlation between the two methods as well as two shorthand appraisals (greatest diameter, and the ABC/2 method for estimating ellipsoid volumes) was assessed with Spearman's rho (r). Intraobserver variability was lower for semi-automated compared to manual segmentation, with standard deviations ranging between ±5-32 mL and ±17-84 mL, respectively (p = 0.0003). There was no significant difference in mean volumes between the two readers' semi-automated measurements (p = 0.83); however, means were lower for the semi-automated compared with the manual technique (manual: mean and SD 309.6 ± 139 mL; R1 semi-auto: 229.6 ± 88.2 mL, p = 0.004; R2 semi-auto: 243.79 ± 99.7 mL, p = 0.021). Despite differences in means, the correlation between the two methods was very strong and highly significant (r = 0.91, p < 0.001). Correlations with diameter-based methods were only moderate and nonsignificant. Mean semi-automated segmentation time effort was 2 min and 6 s and 2 min and 35 s for R1 and R2, respectively, vs. 22 min and 8 s for manual segmentation. Semi-automated pelvic hematoma volumes correlate strongly with manually segmented volumes. Since semi-automated segmentation can be performed reliably and efficiently, volumetric analysis of traumatic pelvic hematomas is potentially valuable at the point-of-care.

Three-Dimensional Analysis of Long-Term Midface Volume Change After Vertical Vector Deep-Plane Rhytidectomy.

PubMed

Jacono, Andrew A; Malone, Melanie H; Talei, Benjamin

2015-07-01

Facial aging is a complicated process that includes volume loss and soft tissue descent. This study provides quantitative 3-dimensional (3D) data on the long-term effect of vertical vector deep-plane rhytidectomy on restoring volume to the midface. To determine if primary vertical vector deep-plane rhytidectomy resulted in long-term volume change in the midface. We performed a prospective study on patients undergoing primary vertical vector deep-plane rhytidectomy to quantitate 3D volume changes in the midface. Quantitative analysis of volume changes was made using the Vectra 3D imaging software (Canfield Scientific, Inc, Fairfield, New Jersey) at a minimum follow-up of 1 year. Forty-three patients (86 hemifaces) were analyzed. The average volume gained in each hemi-midface after vertical vector deep-plane rhytidectomy was 3.2 mL. Vertical vector deep-plane rhytidectomy provides significant long-term augmentation of volume in the midface. These quantitative data demonstrate that some midface volume loss is related to gravitational descent of the cheek fat compartments and that vertical vector deep-plane rhytidectomy may obviate the need for other volumization procedures such as autologous fat grafting in selected cases. 4 Therapeutic. © 2015 The American Society for Aesthetic Plastic Surgery, Inc. Reprints and permission: journals.permissions@oup.com.

Impact Assessment and Forecasts of Information and Telecommunications Technologies Applied to Education and Training: Volume III--Annex & Glossary. Analysis of Key Issues for the Orientation of the Work of Sector Actors in the Framework of DELTA.

ERIC Educational Resources Information Center

Commission of the European Communities, Brussels (Belgium).

This annex to the main report, the third volume in a three volume set, is based on a study performed by the DELTA (Developing European Learning through Technological Advance) unit in parallel with the projects underway in the research and development Exploratory Action. It provides an assessment of the world situation in flexible and distance…

Development of a hip joint model for finite volume simulations.

PubMed

Cardiff, P; Karač, A; FitzPatrick, D; Ivanković, A

2014-01-01

This paper establishes a procedure for numerical analysis of a hip joint using the finite volume method. Patient-specific hip joint geometry is segmented directly from computed tomography and magnetic resonance imaging datasets and the resulting bone surfaces are processed into a form suitable for volume meshing. A high resolution continuum tetrahedral mesh has been generated, where a sandwich model approach is adopted; the bones are represented as a stiffer cortical shells surrounding more flexible cancellous cores. Cartilage is included as a uniform thickness extruded layer and the effect of layer thickness is investigated. To realistically position the bones, gait analysis has been performed giving the 3D positions of the bones for the full gait cycle. Three phases of the gait cycle are examined using a finite volume based custom structural contact solver implemented in open-source software OpenFOAM.

Quantitative coronary plaque analysis predicts high-risk plaque morphology on coronary computed tomography angiography: results from the ROMICAT II trial.

PubMed

Liu, Ting; Maurovich-Horvat, Pál; Mayrhofer, Thomas; Puchner, Stefan B; Lu, Michael T; Ghemigian, Khristine; Kitslaar, Pieter H; Broersen, Alexander; Pursnani, Amit; Hoffmann, Udo; Ferencik, Maros

2018-02-01

Semi-automated software can provide quantitative assessment of atherosclerotic plaques on coronary CT angiography (CTA). The relationship between established qualitative high-risk plaque features and quantitative plaque measurements has not been studied. We analyzed the association between quantitative plaque measurements and qualitative high-risk plaque features on coronary CTA. We included 260 patients with plaque who underwent coronary CTA in the Rule Out Myocardial Infarction/Ischemia Using Computer Assisted Tomography (ROMICAT) II trial. Quantitative plaque assessment and qualitative plaque characterization were performed on a per coronary segment basis. Quantitative coronary plaque measurements included plaque volume, plaque burden, remodeling index, and diameter stenosis. In qualitative analysis, high-risk plaque was present if positive remodeling, low CT attenuation plaque, napkin-ring sign or spotty calcium were detected. Univariable and multivariable logistic regression analyses were performed to assess the association between quantitative and qualitative high-risk plaque assessment. Among 888 segments with coronary plaque, high-risk plaque was present in 391 (44.0%) segments by qualitative analysis. In quantitative analysis, segments with high-risk plaque had higher total plaque volume, low CT attenuation plaque volume, plaque burden and remodeling index. Quantitatively assessed low CT attenuation plaque volume (odds ratio 1.12 per 1 mm 3 , 95% CI 1.04-1.21), positive remodeling (odds ratio 1.25 per 0.1, 95% CI 1.10-1.41) and plaque burden (odds ratio 1.53 per 0.1, 95% CI 1.08-2.16) were associated with high-risk plaque. Quantitative coronary plaque characteristics (low CT attenuation plaque volume, positive remodeling and plaque burden) measured by semi-automated software correlated with qualitative assessment of high-risk plaque features.

Accurate computer-aided quantification of left ventricular parameters: experience in 1555 cardiac magnetic resonance studies from the Framingham Heart Study.

PubMed

Hautvast, Gilion L T F; Salton, Carol J; Chuang, Michael L; Breeuwer, Marcel; O'Donnell, Christopher J; Manning, Warren J

2012-05-01

Quantitative analysis of short-axis functional cardiac magnetic resonance images can be performed using automatic contour detection methods. The resulting myocardial contours must be reviewed and possibly corrected, which can be time-consuming, particularly when performed across all cardiac phases. We quantified the impact of manual contour corrections on both analysis time and quantitative measurements obtained from left ventricular short-axis cine images acquired from 1555 participants of the Framingham Heart Study Offspring cohort using computer-aided contour detection methods. The total analysis time for a single case was 7.6 ± 1.7 min for an average of 221 ± 36 myocardial contours per participant. This included 4.8 ± 1.6 min for manual contour correction of 2% of all automatically detected endocardial contours and 8% of all automatically detected epicardial contours. However, the impact of these corrections on global left ventricular parameters was limited, introducing differences of 0.4 ± 4.1 mL for end-diastolic volume, -0.3 ± 2.9 mL for end-systolic volume, 0.7 ± 3.1 mL for stroke volume, and 0.3 ± 1.8% for ejection fraction. We conclude that left ventricular functional parameters can be obtained under 5 min from short-axis functional cardiac magnetic resonance images using automatic contour detection methods. Manual correction more than doubles analysis time, with minimal impact on left ventricular volumes and ejection fraction. Copyright © 2011 Wiley Periodicals, Inc.

Telemedicine in the management of chronic pain: a cost analysis study.

PubMed

Pronovost, Antoine; Peng, Philip; Kern, Ralph

2009-08-01

Telemedicine provides patients with easy and remote access to consultant expertise irrespective of geographic location. In a randomized controlled trial, this study has applied a rigorous costing methodology to the use of telemedicine in chronic pain management. We performed a randomized two-period crossover trial comparing in-person (IP) consultation with telemedicine (TM) consultation in the management of chronic pain. Over an 18-month period, 26 patients each completed two diaries capturing their direct and indirect travel costs, daily pain scores, and satisfaction with physician consultation. Costing models were developed to account for direct, indirect, fixed, and variable costs in order to perform break-even analyses. Sensitivity analysis was performed over a broad range of assumptions. Direct patient costs were significantly lower in the TM group than in the IP group, with median cost and interquartile range 133 dollars (28-377) vs 443 dollars (292-1075), respectively (P = 0.001). More patients were highly satisfied with the TM consultation than with the IP consultation (56 and 24%, respectively; P < 0.05). Break-even annual patient volume was estimated at 57 patients. A two-way sensitivity analysis controlling for annual patient volume and round-trip distance indicated that TM remains cost-effective at volumes >50 patients/year or at round-trip distances >200 km. Telemedicine is cost-effective over a broad range of assumptions, including annual patient volumes, travel distance, fuel costs, amortization, and discount rates. This study provides data from a real-world setting to determine relevant thresholds and targets for establishing a TM program for patients who are undergoing chronic pain therapy.

Feasibility study: Atmospheric general circulation experiment, volume 2

NASA Technical Reports Server (NTRS)

Homsey, R. J. (Editor)

1981-01-01

The feasibility analysis of the atmospheric general circulation experiment (AGCE) are documented. The analysis performed in each technical area, the rationale and substantiation for the design approaches selected for the hardware, and the design details for the baseline AGCE are presented.

Airport Surface Traffic Control Concept Formulation Study : Volume 1. Executive Summary.

DOT National Transportation Integrated Search

1975-07-01

The report describes the approach followed and the analysis techniques employed in the performance of the operations analysis of the current ASTC system for the baseline airport, O'Hare International Airport, Chicago, Illinois. It also describes the ...

Evaluation of Toluene Adsorption Performance of Mortar Adhesives Using Porous Carbon Material as Adsorbent.

PubMed

Wi, Seunghwan; Chang, Seong Jin; Jeong, Su-Gwang; Lee, Jongki; Kim, Taeyeon; Park, Kyung-Won; Lee, Dong Ryeol; Kim, Sumin

2017-07-26

Porous carbon materials are advantageous in adsorbing pollutants due to their wide range of specific surface areas, pore diameter, and pore volume. Among the porous carbon materials in the current study, expanded graphite, xGnP, xGnP C-300, xGnP C-500, and xGnP C-750 were prepared as adsorbent materials. Brunauer-Emmett-Teller (BET) analysis was conducted to select the adsorbent material through the analysis of the specific surface area, pore size, and pore volume of the prepared porous carbon materials. Morphological analysis using SEM was also performed. The xGnP C-500 as adsorbent material was applied to a mortar adhesive that is widely used in the installation of interior building materials. The toluene adsorption performances of the specimens were evaluated using 20 L small chamber. Furthermore, the performance of the mortar adhesive, as indicated by the shear bond strength, length change rate, and water retention rate, was analyzed according to the required test method specified in the Korean standards. It was confirmed that for the mortar adhesives prepared using the xGnP C-500 as adsorbent material, the toluene adsorption performance was excellent and satisfied the required physical properties.

Automotive Gas Turbine Power System-Performance Analysis Code

NASA Technical Reports Server (NTRS)

Juhasz, Albert J.

1997-01-01

An open cycle gas turbine numerical modelling code suitable for thermodynamic performance analysis (i.e. thermal efficiency, specific fuel consumption, cycle state points, working fluid flowrates etc.) of automotive and aircraft powerplant applications has been generated at the NASA Lewis Research Center's Power Technology Division. The use this code can be made available to automotive gas turbine preliminary design efforts, either in its present version, or, assuming that resources can be obtained to incorporate empirical models for component weight and packaging volume, in later version that includes the weight-volume estimator feature. The paper contains a brief discussion of the capabilities of the presently operational version of the code, including a listing of input and output parameters and actual sample output listings.

Design and testing a high fuel volume fraction, externally finned, thermionic emitter.

NASA Technical Reports Server (NTRS)

Peelgren, M. L.; Ernst, D. M.

1971-01-01

A prototypical, high fuel volume fraction, thermionic emitter body was designed and tested. The emitter body is all tungsten, with a 1.40-cm ID, a 3.23-cm OD, and eight full-length axial fins. The emitter thickness is 0.15 cm while the fins and outer clad are 0.075 cm thick. Different methods of fabrication were used in making the test samples. Stress analysis was performed with a three-dimensional elastic code. Thermal testing of the samples, duplicating calculated radial temperature gradients, heatup and cooldown rates, and emitter body temperatures in operation, was performed with no structural failures noted (six heatup and cooldown cycles per sample). Further emitter analysis and testing is planned.

Age estimation by assessment of pulp chamber volume: a Bayesian network for the evaluation of dental evidence.

PubMed

Sironi, Emanuele; Taroni, Franco; Baldinotti, Claudio; Nardi, Cosimo; Norelli, Gian-Aristide; Gallidabino, Matteo; Pinchi, Vilma

2017-11-14

The present study aimed to investigate the performance of a Bayesian method in the evaluation of dental age-related evidence collected by means of a geometrical approximation procedure of the pulp chamber volume. Measurement of this volume was based on three-dimensional cone beam computed tomography images. The Bayesian method was applied by means of a probabilistic graphical model, namely a Bayesian network. Performance of that method was investigated in terms of accuracy and bias of the decisional outcomes. Influence of an informed elicitation of the prior belief of chronological age was also studied by means of a sensitivity analysis. Outcomes in terms of accuracy were adequate with standard requirements for forensic adult age estimation. Findings also indicated that the Bayesian method does not show a particular tendency towards under- or overestimation of the age variable. Outcomes of the sensitivity analysis showed that results on estimation are improved with a ration elicitation of the prior probabilities of age.

Performance of an underwater acoustic volume array using time-reversal focusing.

PubMed

Root, Joseph A; Rogers, Peter H

2002-11-01

Time reversal permits acoustic focusing and beam forming in inhomogeneous and/or high-scattering environments. A volumetric array geometry can suppress back lobes and can fit a large, powerful array of elements into small spaces, like the free-water spaces on submarines. This research investigates applying the time-reversal method to an underwater acoustic volume array. The experiments evaluate the focusing performance of a 27-element volume array when different scattering structures are present within the volume of the array. The array is arranged in a 3x3x3 cubic matrix configuration with 18.75-cm vertical and horizontal element spacing. The system utilizes second-derivative Gaussian pulses to focus on a point 30 cm from the array. Results include a comparison between time-reversal focusing and standard focusing, an evaluation of the volume array's ability to suppress back lobes, and an analysis of how different scattering environments affect focal region size. Potential underwater applications for a volume array using time reversal include acoustic imaging, naval mine hunting, sonar, and underwater communications.

Performance of an underwater acoustic volume array using time-reversal focusing

NASA Astrophysics Data System (ADS)

Root, Joseph A.; Rogers, Peter H.

2002-11-01

Time reversal permits acoustic focusing and beam forming in inhomogeneous and/or high-scattering environments. A volumetric array geometry can suppress back lobes and can fit a large, powerful array of elements into small spaces, like the free-water spaces on submarines. This research investigates applying the time-reversal method to an underwater acoustic volume array. The experiments evaluate the focusing performance of a 27-element volume array when different scattering structures are present within the volume of the array. The array is arranged in a 3 x3 x3 cubic matrix configuration with 18.75-cm vertical and horizontal element spacing. The system utilizes second-derivative Gaussian pulses to focus on a point 30 cm from the array. Results include a comparison between time-reversal focusing and standard focusing, an evaluation of the volume array's ability to suppress back lobes, and an analysis of how different scattering environments affect focal region size. Potential underwater applications for a volume array using time reversal include acoustic imaging, naval mine hunting, sonar, and underwater communications. copyright 2002 Acoustical Society of America.

Computer program to perform cost and weight analysis of transport aircraft. Volume 2: Technical volume

NASA Technical Reports Server (NTRS)

1973-01-01

An improved method for estimating aircraft weight and cost using a unique and fundamental approach was developed. The results of this study were integrated into a comprehensive digital computer program, which is intended for use at the preliminary design stage of aircraft development. The program provides a means of computing absolute values for weight and cost, and enables the user to perform trade studies with a sensitivity to detail design and overall structural arrangement. Both batch and interactive graphics modes of program operation are available.

Mod-5A wind turbine generator program design report. Volume 3: Final design and system description, book 1

NASA Technical Reports Server (NTRS)

1984-01-01

The design, development and analysis of the 7.3 MW MOD-5A wind turbine generator is documented. Volume 3, book 1 describes the performance and characteristics of the MOD-5A wind turbine generator in its final configuration. Each subsystem - the rotor, drivetrain, nacelle, tower and foundation is described in detail.

Equivalence of Fluctuation Splitting and Finite Volume for One-Dimensional Gas Dynamics

NASA Technical Reports Server (NTRS)

Wood, William A.

1997-01-01

The equivalence of the discretized equations resulting from both fluctuation splitting and finite volume schemes is demonstrated in one dimension. Scalar equations are considered for advection, diffusion, and combined advection/diffusion. Analysis of systems is performed for the Euler and Navier-Stokes equations of gas dynamics. Non-uniform mesh-point distributions are included in the analyses.

Effect of wheat flour characteristics on sponge cake quality.

PubMed

Moiraghi, Malena; de la Hera, Esther; Pérez, Gabriela T; Gómez, Manuel

2013-02-01

To select the flour parameters that relate strongly to cake-making performance, in this study the relationship between sponge cake quality, solvent retention capacity (SRC) profile and flour physicochemical characteristics was investigated using 38 soft wheat samples of different origins. Particle size average, protein, damaged starch, water-soluble pentosans, total pentosans, SRC and pasting properties were analysed. Sponge cake volume and crumb texture were measured to evaluate cake quality. Cluster analysis was applied to assess differences in flour quality parameters among wheat lines based on the SRC profile. Cluster 1 showed significantly higher sponge cake volume and crumb softness, finer particle size and lower SRC sucrose, SRC carbonate, SRC water, damaged starch and protein content. Particle size, damaged starch, protein, thickening capacity and SRC parameters correlated negatively with sponge cake volume, while total pentosans and pasting temperature showed the opposite effect. The negative correlations between cake volume and SRC parameters along with the cluster analysis results indicated that flours with smaller particle size, lower absorption capacity and higher pasting temperature had better cake-making performance. Some simple analyses, such as SRC, particle size distribution and pasting properties, may help to choose flours suitable for cake making. Copyright © 2012 Society of Chemical Industry.

Systematic review and meta-analysis of colon cleansing preparations in patients with inflammatory bowel disease

PubMed Central

Restellini, Sophie; Kherad, Omar; Bessissow, Talat; Ménard, Charles; Martel, Myriam; Taheri Tanjani, Maryam; Lakatos, Peter L; Barkun, Alan N

2017-01-01

AIM To performed a systematic review and meta-analysis to determine any possible differences in terms of effectiveness, safety and tolerability between existing colon-cleansing products in patients with inflammatory bowel disease. METHODS Systematic searches were performed (January 1980-September 2016) using MEDLINE, EMBASE, Scopus, CENTRAL and ISI Web of knowledge for randomized trials assessing preparations with or without adjuvants, given in split and non-split dosing, and in high (> 3 L) or low-volume (2 L or less) regimens. Bowel cleansing quality was the primary outcome. Secondary outcomes included patient willingness-to-repeat the procedure and side effects/complications. RESULTS Out of 439 citations, 4 trials fulfilled our inclusion criteria (n = 449 patients). One trial assessed the impact of adding simethicone to polyethylene glycol (PEG) 4 L with no effect on bowel cleansing quality, but a better tolerance. Another trial compared senna to castor oil, again without any differences in term of bowel cleansing. Two trials compared the efficacy of PEG high-volume vs PEG low-volume associated to an adjuvant in split-dose regimens: PEG low-dose efficacy was not different to PEG high-dose; OR = 0.84 (0.37-1.92). A higher proportion of patients were willing to repeat low-volume preparations vs high-volume; OR = 5.11 (1.31-20.0). CONCLUSION In inflammatory bowel disease population, PEG low-volume regimen seems not inferior to PEG high-volume to clean the colon, and yields improved willingness-to-repeat. Further additional research is urgently required to compare contemporary products in this population. PMID:28932092

Systematic review and meta-analysis of colon cleansing preparations in patients with inflammatory bowel disease.

PubMed

Restellini, Sophie; Kherad, Omar; Bessissow, Talat; Ménard, Charles; Martel, Myriam; Taheri Tanjani, Maryam; Lakatos, Peter L; Barkun, Alan N

2017-08-28

To performed a systematic review and meta-analysis to determine any possible differences in terms of effectiveness, safety and tolerability between existing colon-cleansing products in patients with inflammatory bowel disease. Systematic searches were performed (January 1980-September 2016) using MEDLINE, EMBASE, Scopus, CENTRAL and ISI Web of knowledge for randomized trials assessing preparations with or without adjuvants, given in split and non-split dosing, and in high (> 3 L) or low-volume (2 L or less) regimens. Bowel cleansing quality was the primary outcome. Secondary outcomes included patient willingness-to-repeat the procedure and side effects/complications. Out of 439 citations, 4 trials fulfilled our inclusion criteria ( n = 449 patients). One trial assessed the impact of adding simethicone to polyethylene glycol (PEG) 4 L with no effect on bowel cleansing quality, but a better tolerance. Another trial compared senna to castor oil, again without any differences in term of bowel cleansing. Two trials compared the efficacy of PEG high-volume vs PEG low-volume associated to an adjuvant in split-dose regimens: PEG low-dose efficacy was not different to PEG high-dose; OR = 0.84 (0.37-1.92). A higher proportion of patients were willing to repeat low-volume preparations vs high-volume; OR = 5.11 (1.31-20.0). In inflammatory bowel disease population, PEG low-volume regimen seems not inferior to PEG high-volume to clean the colon, and yields improved willingness-to-repeat. Further additional research is urgently required to compare contemporary products in this population.

Basal Forebrain Atrophy Contributes to Allocentric Navigation Impairment in Alzheimer’s Disease Patients

PubMed Central

Kerbler, Georg M.; Nedelska, Zuzana; Fripp, Jurgen; Laczó, Jan; Vyhnalek, Martin; Lisý, Jiří; Hamlin, Adam S.; Rose, Stephen; Hort, Jakub; Coulson, Elizabeth J.

2015-01-01

The basal forebrain degenerates in Alzheimer’s disease (AD) and this process is believed to contribute to the cognitive decline observed in AD patients. Impairment in spatial navigation is an early feature of the disease but whether basal forebrain dysfunction in AD is responsible for the impaired navigation skills of AD patients is not known. Our objective was to investigate the relationship between basal forebrain volume and performance in real space as well as computer-based navigation paradigms in an elderly cohort comprising cognitively normal controls, subjects with amnestic mild cognitive impairment and those with AD. We also tested whether basal forebrain volume could predict the participants’ ability to perform allocentric- vs. egocentric-based navigation tasks. The basal forebrain volume was calculated from 1.5 T magnetic resonance imaging (MRI) scans, and navigation skills were assessed using the human analog of the Morris water maze employing allocentric, egocentric, and mixed allo/egocentric real space as well as computerized tests. When considering the entire sample, we found that basal forebrain volume correlated with spatial accuracy in allocentric (cued) and mixed allo/egocentric navigation tasks but not the egocentric (uncued) task, demonstrating an important role of the basal forebrain in mediating cue-based spatial navigation capacity. Regression analysis revealed that, although hippocampal volume reflected navigation performance across the entire sample, basal forebrain volume contributed to mixed allo/egocentric navigation performance in the AD group, whereas hippocampal volume did not. This suggests that atrophy of the basal forebrain contributes to aspects of navigation impairment in AD that are independent of hippocampal atrophy. PMID:26441643

Performance of an Anaerobic Baffled Reactor (ABR) in treatment of cassava wastewater

PubMed Central

Ferraz, Fernanda M.; Bruni, Aline T.; Del Bianchi, Vanildo L.

2009-01-01

The performance of an anaerobic baffled reactor (ABR) was evaluated in the treatment of cassava wastewater, a pollutant residue. An ABR divided in four equal volume compartments (total volume 4L) and operated at 35ºC was used in cassava wastewater treatment. Feed tank chemical oxygen demand (COD) was varied from 2000 to 7000 mg L-1 and it was evaluated the most appropriated hydraulic retention time (HRT) for the best performance on COD removal. The ABR was evaluated by analysis of COD (colorimetric method), pH, turbidity, total and volatile solids, alkalinity and acidity. Principal component analysis (PCA) was carried to better understand data obtained. The system showed buffering ability as acidity decreased along compartments while alkalinity and pH values were increased. There was particulate material retention and COD removal varied from 83 to 92% for HRT of 3.5 days. PMID:24031316

Combined Global Navigation Satellite Systems in the Space Service Volume

NASA Technical Reports Server (NTRS)

Force, Dale A.; Miller, James J.

2015-01-01

Besides providing position, navigation, and timing (PNT) services to traditional terrestrial and airborne users, GPS is also being increasingly used as a tool to enable precision orbit determination, precise time synchronization, real-time spacecraft navigation, and three-axis attitude control of Earth orbiting satellites. With additional Global Navigation Satellite System (GNSS) constellations being replenished and coming into service (GLONASS, Beidou, and Galileo), it will become possible to benefit from greater signal availability and robustness by using evolving multi-constellation receivers. The paper, "GPS in the Space Service Volume," presented at the ION GNSS 19th International Technical Meeting in 2006 (Ref. 1), defined the Space Service Volume, and analyzed the performance of GPS out to seventy thousand kilometers. This paper will report a similar analysis of the signal coverage of GPS in the space domain; however, the analyses will also consider signal coverage from each of the additional GNSS constellations noted earlier to specifically demonstrate the expected benefits to be derived from using GPS in conjunction with other foreign systems. The Space Service Volume is formally defined as the volume of space between three thousand kilometers altitude and geosynchronous altitude circa 36,000 km, as compared with the Terrestrial Service Volume between 3,000 km and the surface of the Earth. In the Terrestrial Service Volume, GNSS performance is the same as on or near the Earth's surface due to satellite vehicle availability and geometry similarities. The core GPS system has thereby established signal requirements for the Space Service Volume as part of technical Capability Development Documentation (CDD) that specifies system performance. Besides the technical discussion, we also present diplomatic efforts to extend the GPS Space Service Volume concept to other PNT service providers in an effort to assure that all space users will benefit from the enhanced interoperability of GNSS services in the space domain. A separate paper presented at the conference covers the individual GNSS performance parameters for respective Space Service Volumes.

Linear systems analysis program, L224(QR). Volume 2: Supplemental system design and maintenance document

NASA Technical Reports Server (NTRS)

Heidergott, K. W.

1979-01-01

The computer program known as QR is described. Classical control systems analysis and synthesis (root locus, time response, and frequency response) can be performed using this program. Programming details of the QR program are presented.

Urine monitoring system failure analysis and operational verification test report

NASA Technical Reports Server (NTRS)

Glanfield, E. J.

1978-01-01

Failure analysis and testing of a prototype urine monitoring system (UMS) are reported. System performance was characterized by a regression formula developed from volume measurement test data. When the volume measurement test data. When the volume measurement data was imputted to the formula, the standard error of the estimate calculated using the regression formula was found to be within 1.524% of the mean of the mass of the input. System repeatability was found to be somewhat dependent upon the residual volume of the system and the evaporation of fluid from the separator. The evaporation rate was determined to be approximately 1cc/minute. The residual volume in the UMS was determined by measuring the concentration of LiCl in the flush water. Observed results indicated residual levels in the range of 9-10ml, however, results obtained during the flushing efficiency test indicated a residual level of approximately 20ml. It is recommended that the phase separator pumpout time be extended or the design modified to minimize the residual level.

Free volume study on the miscibility of PEEK/PEI blend using positron annihilation and dynamic mechanical thermal analysis

NASA Astrophysics Data System (ADS)

Ramani, R.; Alam, S.

2015-06-01

High performance polymer blend of poly(ether ether ketone) (PEEK) and poly(ether imide) (PEI) was examined for their free volume behaviour using positron annihilation lifetime spectroscopy and dynamic mechanical thermal analysis methods. The fractional free volume obtained from PALS shows a negative deviation from linear additivity rule implying good miscibility between PEEK and PEI. The dynamic modulus and loss tangent were obtained for the blends at three different frequencies 1, 10 and 100 Hz at temperatures close to and above their glass transition temperature. Applying Time-Temperature-Superposition (TTS) principle to the DMTA results, master curves were obtained at a reference temperature To and the WLF coefficients c01 and c02 were evaluated. Both the methods give similar results for the dependence of fractional free volume on PEI content in this blend. The results reveal that free volume plays an important role in determining the visco-elastic properties in miscible polymer blends.

Cardiologist service volume, percutaneous coronary intervention and hospital level in relation to medical costs and mortality in patients with acute myocardial infarction: a nationwide study.

PubMed

Liu, C-Y; Lin, Y-N; Lin, C-L; Chang, Y-J; Hsu, Y-H; Tsai, W-C; Kao, C-H

2014-07-01

We explore whether cardiologist service volume, hospital level and percutaneous coronary intervention (PCI) are associated with medical costs and acute myocardial infarction (AMI) mortality. From the 1997-2010 Taiwan National Health Insurance Research Database of the National Health Research Institute, we identified AMI patients and performed multiple regression analyses to explore the relationships among the different hospital levels and treatment factors. We identified 2942 patients with AMI in medical centers and 4325 patients with AMI in regional hospitals. Cardiologist service volume, performing PCI and medical costs per patient were higher in medical centers than in regional hospitals (P < 0.0001). However, the two hospital levels did not differ significantly in in-hospital mortality (P = 0.1557). Post hoc analysis showed significant differences in in-hospital mortality rate and in medical costs among the eight groups subdivided on the basis of hospital level, cardiologist service volume, and whether PCI was performed (P < 0.001 and P = 0.001, respectively). These results highlight the importance of encouraging hospitals to develop PCI capability and increase their cardiologist service volume after taking medical costs into account. Transferring AMI patients to hospitals with higher cardiologist service volume and PCI performed can also be very important. © The Author 2014. Published by Oxford University Press on behalf of the Association of Physicians. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Exergy analysis of hybrid nanofluids with optimum concentration in a plate heat exchanger

NASA Astrophysics Data System (ADS)

Kumar, Vikas; Tiwari, Arun Kumar; Ghosh, Subrata Kumar

2018-06-01

This paper highlights an investigation on the comparative analyses of exergetic performance with optimum volume concentration of hybrid nanofluids in a plate heat exchanger (PHE). Different types of hybrid nanofluids (Al2O3 + MWCNT/water, TiO2 + MWCNT/water, ZnO + MWCNT/water, and CeO2 + MWCNT/water) as coolant have been tested. Proportion of 0.75% of nanofluid has been found to be the optimum volume concentration. The requisite thermal and physical properties of the hybrid nanofluids were measured at 35 °C. Various exergetic performance parameters have been examined for comparing different hybrid nanofluids. The highest reduction in exergy loss of CeO2 + MWCNT/water hybrid nanofluid has been obtained at a concentration of about 24.75%. Entropy generation decreased with the increase in volume concentration. The results established that CeO2 + MWCNT/water hybrid nanofluid can be a promising coolant for exergetic performances in a PHE.

Develop Advanced Nonlinear Signal Analysis Topographical Mapping System

NASA Technical Reports Server (NTRS)

Jong, Jen-Yi

1997-01-01

During the development of the SSME, a hierarchy of advanced signal analysis techniques for mechanical signature analysis has been developed by NASA and AI Signal Research Inc. (ASRI) to improve the safety and reliability for Space Shuttle operations. These techniques can process and identify intelligent information hidden in a measured signal which is often unidentifiable using conventional signal analysis methods. Currently, due to the highly interactive processing requirements and the volume of dynamic data involved, detailed diagnostic analysis is being performed manually which requires immense man-hours with extensive human interface. To overcome this manual process, NASA implemented this program to develop an Advanced nonlinear signal Analysis Topographical Mapping System (ATMS) to provide automatic/unsupervised engine diagnostic capabilities. The ATMS will utilize a rule-based Clips expert system to supervise a hierarchy of diagnostic signature analysis techniques in the Advanced Signal Analysis Library (ASAL). ASAL will perform automatic signal processing, archiving, and anomaly detection/identification tasks in order to provide an intelligent and fully automated engine diagnostic capability. The ATMS has been successfully developed under this contract. In summary, the program objectives to design, develop, test and conduct performance evaluation for an automated engine diagnostic system have been successfully achieved. Software implementation of the entire ATMS system on MSFC's OISPS computer has been completed. The significance of the ATMS developed under this program is attributed to the fully automated coherence analysis capability for anomaly detection and identification which can greatly enhance the power and reliability of engine diagnostic evaluation. The results have demonstrated that ATMS can significantly save time and man-hours in performing engine test/flight data analysis and performance evaluation of large volumes of dynamic test data.

The relationship between nocturnal polyuria and the distribution of body fluid: assessment by bioelectric impedance analysis.

PubMed

Torimoto, Kazumasa; Hirayama, Akihide; Samma, Shoji; Yoshida, Katsunori; Fujimoto, Kiyohide; Hirao, Yoshihiko

2009-01-01

Increased nocturnal urinary volume is closely associated with nocturia. We investigated the relationship between nocturnal polyuria and the variation of body fluid distribution during the daytime using bioelectric impedance analysis. A total of 34 men older than 60 years were enrolled in this study. A frequency volume chart was recorded. Nocturnal polyuria was defined as a nocturnal urine volume per 24-hour production of greater than 0.35 (the nocturnal polyuria index). Bioelectric impedance analysis was performed 4 times daily at 8 and 11 a.m., and 5 and 9 p.m. using an InBody S20 body composition analyzer (BioSpace, Seoul, Korea). A significant difference was found in mean +/- SEM 24-hour urine production per fat-free mass between the groups with and without nocturnal polyuria (17.8 +/- 1.4 vs 7.7 +/- 0.9 ml/kg). The increase in fluid in the legs compared with the volume at 8 a.m. was significantly larger at 5 p.m., while there was no difference in the arms or trunk. Nocturnal urine volume significantly correlated with the difference in fluid volume in the legs (r = 0.527, p = 0.0019) and extracellular fluid volume (r = 0.3844, p = 0.0248) between the volumes at 8 a.m. and 9 p.m. Overproduction of urine per fat-free mass leads to nocturnal polyuria. Extracellular fluid accumulates as edema in the legs during the day in patients with nocturnal polyuria. The volume of accumulated extracellular fluid correlates with nocturnal urine volume. We suggest that leg edema is the source of nocturnal urine volume and decreasing edema may cure nocturnal polyuria.

PuMA: the Porous Microstructure Analysis software

NASA Astrophysics Data System (ADS)

Ferguson, Joseph C.; Panerai, Francesco; Borner, Arnaud; Mansour, Nagi N.

2018-01-01

The Porous Microstructure Analysis (PuMA) software has been developed in order to compute effective material properties and perform material response simulations on digitized microstructures of porous media. PuMA is able to import digital three-dimensional images obtained from X-ray microtomography or to generate artificial microstructures. PuMA also provides a module for interactive 3D visualizations. Version 2.1 includes modules to compute porosity, volume fractions, and surface area. Two finite difference Laplace solvers have been implemented to compute the continuum tortuosity factor, effective thermal conductivity, and effective electrical conductivity. A random method has been developed to compute tortuosity factors from the continuum to rarefied regimes. Representative elementary volume analysis can be performed on each property. The software also includes a time-dependent, particle-based model for the oxidation of fibrous materials. PuMA was developed for Linux operating systems and is available as a NASA software under a US & Foreign release.

Survival in pediatric lung transplantation: The effect of center volume and expertise.

PubMed

Khan, Muhammad S; Zhang, Wei; Taylor, Rachel A; Dean McKenzie, E; Mallory, George B; Schecter, Marc G; Morales, David L S; Heinle, Jeffrey S; Adachi, Iki

2015-08-01

Institutional operative volume has been shown to impact outcomes of various procedures including lung transplantation (LTx). We sought to determine whether this holds true with pediatric LTx by comparing outcomes of adult centers (with larger overall volume) to those of pediatric centers (with smaller volume but more pediatric-specific experience). A retrospective analysis of the Organ Procurement and Transplant Network data was performed. Centers were categorized as either adult (LTx volume predominantly in adult patients), high-volume pediatric (HVP, ≥4 LTxs/year), or low-volume pediatric (LVP, <4 LTxs/year). Outcomes were compared in "younger children" (<12 years) and "older children and adolescents" (12 to 17 years). In total, 1,046 pediatric LTxs were performed between 1987 and 2012 at 62 centers (adult 51 [82%], HVP 3 [5%], LVP 8 [13%]). Although adult centers had larger overall LTx volume, their pediatric experiences were severely limited (median 1/year). In younger children, HVP centers were significantly better than LVP centers for patient survival (half-life: 7.3 vs 2.9 years, p = 0.002). Similarly, in older children and adolescents, HVP centers were significantly better than adult centers for patient survival (half-life: 4.6 vs 2.5 years, p = 0.001). Of note, even LVP centers tended to have longer patient survival than adult centers (p = 0.064). Multivariable analysis identified adult centers as an independent risk factor for graft failure (hazard ratio: 1.5, p < 0.001) as with LVP (hazard ratio: 1.3, p = 0.0078). Despite larger overall clinical volume, outcomes among pediatric LTx recipients in adult centers are not superior to those of pediatric centers. Not only center volume but pediatric-specific experience has an impact on outcomes in pediatric LTx. Copyright © 2015 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.

Non-invasive volumetric analysis of asymptomatic hands using a 3-D scanner

PubMed Central

Shinkai, Hiroki; Yamamoto, Michiro; Tatebe, Masahiro; Iwatsuki, Katsuyuki; Kurimoto, Shigeru; Hirata, Hitoshi

2017-01-01

Hand swelling is one of the symptoms often seen in practice, but none of the available morphometric methods can quickly and efficiently quantify hand volume in an objective manner, and the current gold-standard volume measurement requires immersion in water, which can be difficult to use. Therefore, we aimed to analyze the accuracy of using 3-dimensional (3-D) scanning to measure hand volume. First, we compared the hand volume calculated using the 3-D scanner to that calculated from the conventional method among 109 volunteers to determine the reliability of 3-D measurements. We defined the beginning of the hand as the distal wrist crease, and 3-D forms of the hands were captured by the 3-D scanning system. Second, 238 volunteers (87 men, 151 women) with no disease or history of hand surgery underwent 3-D scanning. Data collected included age, height, weight, and shoe size. The wrist circumference (WC) and the distance between distal wrist crease and tip of middle finger (DDT) were measured. Statistical analyses were performed using linear regression to investigate the relationship between the hand volume and these parameters. In the first study, a significantly strong positive correlation was observed [R = 0.98] between the hand volume calculated via 3-D scanning and that calculated via the conventional method. In the second study, no significant differences between the volumes, WC or DDT of right and left hands were found. The correlations of hand volume with weight, WC, and DDT were strong. We created a formula to predict the hand volume using these parameters; these variables explained approximately 80% of the predicted volume. We confirmed that the new 3-D scanning method, which is performed without touching the hand and can record the form of the hand, yields an accurate volumetric analysis of an asymptomatic hand. PMID:28796816

Prognostic Factors for Hormone Sensitive Metastatic Prostate Cancer: Impact of Disease Volume

PubMed

Alhanafy, Alshimaa Mahmoud; Zanaty, Fouad; Ibrahem, Reda; Omar, Suzan

2018-04-27

Background and Aim: The optimal management of metastatic hormone-sensitive prostate cancer has been controversial in recent years with introduction of upfront chemohormonal treatment based on results of several Western studies. This changing landscape has renewed interest in the concept “disease volume”, the focus of the present study is the Egyptian patients. Methods: Patients with hormone sensitive metastatic prostate cancer presenting at Menoufia University Hospital, Egypt, during the period from June 2013 to May 2016, were enrolled. All received hormonal treatment. Radiologic images were evaluated and patients were stratified according to their disease volume into high or low, other clinical and pathological data that could affect survival also being collected and analyzed. Results: A total of 128 patients were included, with a median age of 70 years (53.9% ≥70). About 46% had co-morbidities, 62% having high volume disease. During the median follow up period of 28 months about half of the patients progressed and one third received chemotherapy. On univariate analysis, disease volume, performance status (PS), prostate specific antigen level (PSA) and presence of pain at presentation were identified as factors influencing overall survival. Multivariate analysis revealed the independent predictor factors for survival to be PS, PSA and disease volume. The median overall survival with 27 months was high volume versus 49 with low volume disease (hazard ratio 2.1; 95% CI 1.2 - 4.4; P=0.02). Median progression free survival was 19 months in the high volume, as compared with 48 months in the low volume disease patients (hazard ratio, 2.44; 95% CI, 1.42 – 7.4; P=0.009). Conclusions: Disease volume is a reliable predictor of survival which should be incorporated with other important factors as; patient performance status and comorbidities in treatment decision-making. Creative Commons Attribution License

New Directions in Library and Information Science Education. Final Report. Volume 2.10: Information Analysis Center Professional Competencies.

ERIC Educational Resources Information Center

Griffiths, Jose-Marie; And Others

This document contains validated activities and competencies needed by information professionals working in an information analysis center. The activities and competencies are organized according to the functions which information professionals in such centers perform: acquisitions; indexing/abstracting; reference; information analysis research;…

High Speed Cylindrical Roller Bearing Analysis, SKF Computer Program CYBEAN. Volume 1: Analysis

NASA Technical Reports Server (NTRS)

Kleckner, R. J.; Pirvics, J.

1978-01-01

The CYBEAN (CYlindrical BEaring ANalysis) program was created to detail radially loaded, aligned and misaligned Cylindrical roller bearing performance under a variety of operating conditions. The models and associated mathematics used within CYBEAN are described. The user is referred to the material for formulation assumptions and algorithm detail.

Left ventricular volume analysis as a basic tool to describe cardiac function.

PubMed

Kerkhof, Peter L M; Kuznetsova, Tatiana; Ali, Rania; Handly, Neal

2018-03-01

The heart is often regarded as a compression pump. Therefore, determination of pressure and volume is essential for cardiac function analysis. Traditionally, ventricular performance was described in terms of the Starling curve, i.e., output related to input. This view is based on two variables (namely, stroke volume and end-diastolic volume), often studied in the isolated (i.e., denervated) heart, and has dominated the interpretation of cardiac mechanics over the last century. The ratio of the prevailing coordinates within that paradigm is termed ejection fraction (EF), which is the popular metric routinely used in the clinic. Here we present an insightful alternative approach while describing volume regulation by relating end-systolic volume (ESV) to end-diastolic volume. This route obviates the undesired use of metrics derived from differences or ratios, as employed in previous models. We illustrate basic principles concerning ventricular volume regulation by data obtained from intact animal experiments and collected in healthy humans. Special attention is given to sex-specific differences. The method can be applied to the dynamics of a single heart and to an ensemble of individuals. Group analysis allows for stratification regarding sex, age, medication, and additional clinically relevant covariates. A straightforward procedure derives the relationship between EF and ESV and describes myocardial oxygen consumption in terms of ESV. This representation enhances insight and reduces the impact of the metric EF, in favor of the end-systolic elastance concept advanced 4 decades ago.

Fuzzy hidden Markov chains segmentation for volume determination and quantitation in PET.

PubMed

Hatt, M; Lamare, F; Boussion, N; Turzo, A; Collet, C; Salzenstein, F; Roux, C; Jarritt, P; Carson, K; Cheze-Le Rest, C; Visvikis, D

2007-06-21

Accurate volume of interest (VOI) estimation in PET is crucial in different oncology applications such as response to therapy evaluation and radiotherapy treatment planning. The objective of our study was to evaluate the performance of the proposed algorithm for automatic lesion volume delineation; namely the fuzzy hidden Markov chains (FHMC), with that of current state of the art in clinical practice threshold based techniques. As the classical hidden Markov chain (HMC) algorithm, FHMC takes into account noise, voxel intensity and spatial correlation, in order to classify a voxel as background or functional VOI. However the novelty of the fuzzy model consists of the inclusion of an estimation of imprecision, which should subsequently lead to a better modelling of the 'fuzzy' nature of the object of interest boundaries in emission tomography data. The performance of the algorithms has been assessed on both simulated and acquired datasets of the IEC phantom, covering a large range of spherical lesion sizes (from 10 to 37 mm), contrast ratios (4:1 and 8:1) and image noise levels. Both lesion activity recovery and VOI determination tasks were assessed in reconstructed images using two different voxel sizes (8 mm3 and 64 mm3). In order to account for both the functional volume location and its size, the concept of % classification errors was introduced in the evaluation of volume segmentation using the simulated datasets. Results reveal that FHMC performs substantially better than the threshold based methodology for functional volume determination or activity concentration recovery considering a contrast ratio of 4:1 and lesion sizes of <28 mm. Furthermore differences between classification and volume estimation errors evaluated were smaller for the segmented volumes provided by the FHMC algorithm. Finally, the performance of the automatic algorithms was less susceptible to image noise levels in comparison to the threshold based techniques. The analysis of both simulated and acquired datasets led to similar results and conclusions as far as the performance of segmentation algorithms under evaluation is concerned.

The impact of BMI on sperm parameters and the metabolite changes of seminal plasma concomitantly.

PubMed

Guo, Dan; Wu, Wei; Tang, Qiuqin; Qiao, Shanlei; Chen, Yiqiu; Chen, Minjian; Teng, Mengying; Lu, Chuncheng; Ding, Hongjuan; Xia, Yankai; Hu, Lingqing; Chen, Daozhen; Sha, Jiahao; Wang, Xinru

2017-07-25

The development of male infertility increased rapidly worldwide, which coinciding with the epidemic of obesity. However, the impact of weight abnormalities on sperm quality is still contestable. To assess the correlation between BMI and sperm parameters, we searched relevant articles in PubMed, Embase, Web of science, and Wanfang database published until June 2015 without language restriction. Otherwise, we also recruited some participants who attended fertility clinic as well as some general populations in this report. We performed a systematic review and meta-analysis about BMI and sperm parameters containing total sperm count, concentration, semen volume and sperm motility (overall and progressive). Metabolomic analysis of seminal plasma was performed to explore the mechanism from a new perspective. This study found standardized weighted mean differences (SMD) in sperm parameters (total sperm count, sperm concentration, and semen volume) of abnormal weight groups decreased to different degree compared to normal weight. Dose-response analysis found SMD of sperm count, sperm concentration and semen volume respectively fell 2.4%, 1.3% and 2.0% compared with normal weight for every 5-unit increase in BMI. Metabolomic analysis of seminal plasma showed that spermidine and spermine were likely to play a vital role in the spermatogenesis progress. This systematic review with meta-analysis has confirmed there was a relationship between BMI and sperm quality, suggesting obesity may be a detrimental factor of male infertility.

Accuracy of surgical wound drainage measurements: an analysis and comparison.

PubMed

Yue, Brian; Nizzero, Danielle; Zhang, Chunxiao; van Zyl, Natasha; Ting, Jeannette

2015-05-01

Surgical drain tube readings can influence the clinical management of the post-operative patient. The accuracy of these readings has not been documented in the current literature and this experimental study aims to address this paucity. Aliquots (10, 25, 40 and 90 mL) of black tea solution prepared to mimic haemoserous fluid were injected into UnoVac, RedoVac and Jackson-Pratt drain tubes. Nursing and medical staff from a tertiary hospital were asked to estimate drain volumes by direct observation; analysis of variance was performed on the results and significance level was set at 0.05. Doctors and nurses are equally accurate in estimating drain tube volumes. Jackson-Pratt systems were found to be the most accurate for intermediate volumes of 25 and 40 mL. For extreme of volumes (both high and low), all drainage systems were inaccurate. This study suggests that for intermediate volumes (25 and 40 mL), Jackson-Pratt is the drainage system of choice. The accuracy of volume measurement is diminished at the extremes of drain volumes; emptying of drainage systems is recommended to avoid overfilling of drainage systems. © 2014 Royal Australasian College of Surgeons.

Eleven fetal echocardiographic planes using 4-dimensional ultrasound with spatio-temporal image correlation (STIC): a logical approach to fetal heart volume analysis.

PubMed

Jantarasaengaram, Surasak; Vairojanavong, Kittipong

2010-09-15

Theoretically, a cross-sectional image of any cardiac planes can be obtained from a STIC fetal heart volume dataset. We described a method to display 11 fetal echocardiographic planes from STIC volumes. Fetal heart volume datasets were acquired by transverse acquisition from 200 normal fetuses at 15 to 40 weeks of gestation. Analysis of the volume datasets using the described technique to display 11 echocardiographic planes in the multiplanar display mode were performed offline. Volume datasets from 18 fetuses were excluded due to poor image resolution. The mean visualization rates for all echocardiographic planes at 15-17, 18-22, 23-27, 28-32 and 33-40 weeks of gestation fetuses were 85.6% (range 45.2-96.8%, N = 31), 92.9% (range 64.0-100%, N = 64), 93.4% (range 51.4-100%, N = 37), 88.7%(range 54.5-100%, N = 33) and 81.8% (range 23.5-100%, N = 17) respectively. Overall, the applied technique can favorably display the pertinent echocardiographic planes. Description of the presented method provides a logical approach to explore the fetal heart volumes.

Simple method for the generation of multiple homogeneous field volumes inside the bore of superconducting magnets.

PubMed

Chou, Ching-Yu; Ferrage, Fabien; Aubert, Guy; Sakellariou, Dimitris

2015-07-17

Standard Magnetic Resonance magnets produce a single homogeneous field volume, where the analysis is performed. Nonetheless, several modern applications could benefit from the generation of multiple homogeneous field volumes along the axis and inside the bore of the magnet. In this communication, we propose a straightforward method using a combination of ring structures of permanent magnets in order to cancel the gradient of the stray field in a series of distinct volumes. These concepts were demonstrated numerically on an experimentally measured magnetic field profile. We discuss advantages and limitations of our method and present the key steps required for an experimental validation.

Constant pressure mode extended simple gradient liquid chromatography system for micro and nanocolumns.

PubMed

Šesták, Jozef; Kahle, Vladislav

2014-07-11

Performing gradient liquid chromatography at constant pressure instead of constant flow rate has serious potential for shortening the analysis time and increasing the productivity of HPLC instruments that use gradient methods. However, in the constant pressure mode the decreasing column permeability during a long period of time negatively affects the repeatability of retention time. Thus a volume-based approach, in which the detector signal is plotted as a function of retention volume, must be taken into consideration. Traditional HPLC equipment, however, requires quite complex hardware and software modifications in order to work at constant pressure and in the volume-based mode. In this short communication, a low cost and easily feasible pressure-controlled extension of the previously described simple gradient liquid chromatography platform is proposed. A test mixture of four nitro esters was separated by 10-60% (v/v) acetone/water gradient and a high repeatability of retention volumes at 20MPa (RSD less than 0.45%) was realized. Separations were also performed at different values of pressure (20, 25, and 31MPa), and only small variations of the retention volumes (up to 0.8%) were observed. In this particular case, the gain in the analysis speed of 7% compared to the constant flow mode was realized at a constant pressure. Copyright © 2014 Elsevier B.V. All rights reserved.

Nondestructive microimaging during preclinical pin-on-plate testing of novel materials for arthroplasty.

PubMed

Teeter, Matthew G; Langohr, G Daniel G; Medley, John B; Holdsworth, David W

2014-02-01

The purpose of this study was to determine the ability of micro-computed tomography to quantify wear in preclinical pin-on-plate testing of materials for use in joint arthroplasty. Wear testing of CoCr pins articulating against six polyetheretherketone plates was performed using a pin-on-plate apparatus over 2 million cycles. Change in volume due to wear was quantified with gravimetric analysis and with micro-computed tomography, and the volumes were compared. Separately, the volume of polyetheretherketone pin-on-plate specimens that had been soaking in fluid for 52 weeks was quantified with both gravimetric analysis and micro-computed tomography, and repeated after drying. The volume change with micro-computed tomography was compared to the mass change with gravimetric analysis. The mean wear volume measured was 8.02 ± 6.38 mm(3) with gravimetric analysis and 6.76 ± 5.38 mm(3) with micro-computed tomography (p = 0.06). Micro-computed tomography volume measurements did not show a statistically significant change with drying for either the plates (p = 0.60) or the pins (p = 0.09), yet drying had a significant effect on the gravimetric mass measurements for both the plates (p = 0.03) and the pins (p = 0.04). Micro-computed tomography provided accurate measurements of wear in polyetheretherketone pin-on-plate test specimens, and no statistically significant change was caused by fluid uptake. Micro-computed tomography quantifies wear depth and wear volume, mapped to the specific location of damage on the specimen, and is also capable of examining subsurface density as well as cracking. Its noncontact, nondestructive nature makes it ideal for preclinical testing of materials, in which further additional analysis techniques may be utilized.

A CFD Analysis of Hydrogen Leakage During On-Pad Purge in the ORION/ARES I Shared Volume

NASA Technical Reports Server (NTRS)

Ajmani, Kumud; Edwards, Daryl A.

2011-01-01

A common open volume is created by the stacking of the Orion vehicle onto the Ares I Upper Stage. Called the Shared Volume, both vehicles contribute to its gas, fluid, and thermal environment. One of these environments is related to hazardous hydrogen gas. While both vehicles use inert purge gas to mitigate any hazardous gas buildup, there are concerns that hydrogen gas may still accumulate and that the Ares I Hazardous Gas Detection System will not be sufficient for monitoring the integrated volume. This Computational Fluid Dynamics (CFD) analysis has been performed to examine these topics. Results of the analysis conclude that the Ares I Hazardous Gas Detection System will be able to sample the vent effluent containing the highest hydrogen concentrations. A second conclusion is that hydrogen does not accumulate under the Orion Service Module (SM) avionics ring as diffusion and purge flow mixing sufficiently dilute the hydrogen to safe concentrations. Finally the hydrogen concentrations within the Orion SM engine nozzle may slightly exceed the 1 percent volume fraction when the entire worse case maximum full leak is directed vertically into the engine nozzle.

Breast surgery techniques: preoperative bracketing wire localization by surgeons.

PubMed

Burkholder, Hans C; Witherspoon, Laura E; Burns, R Phillip; Horn, Jeffrey S; Biderman, Michael D

2007-06-01

With the development of expertise in image guidance for breast surgery, many surgeons now perform preoperative wire localization themselves. Use of a single wire versus multiple wires to bracket a radiographic breast abnormality has previously been described, although benefits of this technique based on clinical outcomes such as margin status, tissue volume removed, and re-excision rates have not been established. This study is a retrospective analysis of wire-localized breast biopsies performed by 14 surgeons over 29 months; stereotactic and ultrasound guidance were used. During this time, 489 wire localizations were done, of which 159 used multiple wires. Two hundred eleven of these biopsies were done for malignant disease, 86 using multiple wires. After controlling for tumor node metastases stage, single and multiple wire placements were compared using endpoints of margin status, need for re-excision, and total volume of tissue removed. Neither margin status nor re-excision was related to the number of wires placed. However, the number of wires placed was significantly related to the total volume of tissue removed. Use of more than one localizing wire was associated with greater volume of tissue removal (measured in centimeters cubed) in benign disease (46 vs 25, P < 0.001), equivalent volumes in stage 0 disease (73 vs 67), less volume in stage 1 disease (113 vs 164), and less volume in stages 2 through 4 (158 vs 207, P = 0.03). Outcomes based on surgeon case volume during the study period demonstrated that low- (1-40), medium- (41-80), and high-volume (>80) surgeons did not differ in the type or stage of breast pathology treated. Surgeons with high case volumes were more likely to place multiple localizing wires (P < 0.001) and were more likely to do a breast-conserving procedure if re-excision was performed (P < 0.018). Surgeons with low case volumes were more likely to perform a re-excision (P < 0.025). Surgeon experience has a positive impact on quality outcome measures such as performance of a definitive procedure at the time of initial surgery and use of breast-conserving procedures at the time of re-excision. Multiple wire localization can be used to significantly reduce the volume of breast tissue removed in malignant disease without sacrificing margin status or increasing the need for future re-excision.

Procedure for analysis and design of weaving sections : volume 2, users guide.

DOT National Transportation Integrated Search

1983-12-01

This research was performed to complete and advance the status of recently developed procedures for analysis and design of weaving sections (known as the Leisch method and-initially published in the 1979 issue of ITE Journal). The objective was to en...

CALS Baseline Architecture Analysis of Weapons System. Technical Information: Army, Draft. Volume 8

DOT National Transportation Integrated Search

1989-09-01

This effort was performed to provide a common framework for analysis and planning of CALS initiatives across the military services, leading eventually to the development of a common DoD-wide architecture for CALS. This study addresses Army technical ...

Time history solution program, L225 (TEV126). Volume 1: Engineering and usage

NASA Technical Reports Server (NTRS)

Kroll, R. I.; Tornallyay, A.; Clemmons, R. E.

1979-01-01

Volume 1 of a two volume document is presented. The usage of the convolution program L225 (TEV 126) is described. The program calculates the time response of a linear system by convoluting the impulsive response function with the time-dependent excitation function. The convolution is performed as a multiplication in the frequency domain. Fast Fourier transform techniques are used to transform the product back into the time domain to obtain response time histories. A brief description of the analysis used is presented.

Impact Assessment and Forecasts of Information and Telecommunications Technologies Applied to Education and Training. R&D in Information and Communication Based Learning Technology. Analysis of Key Issues for the Orientation of the Work of Sector Actors in the Framework of DELTA. Volume I--Executive Summary.

ERIC Educational Resources Information Center

Commission of the European Communities, Brussels (Belgium).

This report, the first volume in a three volume set, summarizes the results of a study performed by the DELTA (Developing European Learning through Technological Advance) Unit in parallel with the projects underway in the research and development Exploratory Action. The report identifies the key issues, associated requirements and options, and…

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.

System analysis of a piston steam engine employing the uniflow principle, a study in optimized performance

NASA Technical Reports Server (NTRS)

Peoples, J. A.

1975-01-01

Results are reported which were obtained from a mathematical model of a generalized piston steam engine configuration employing the uniflow principal. The model accounted for the effects of clearance volume, compression work, and release volume. A simple solution is presented which characterizes optimum performance of the steam engine, based on miles per gallon. Development of the mathematical model is presented. The relationship between efficiency and miles per gallon is developed. An approach to steam car analysis and design is presented which has purpose rather than lucky hopefulness. A practical engine design is proposed which correlates to the definition of the type engine used. This engine integrates several system components into the engine structure. All conclusions relate to the classical Rankine Cycle.

Small-Volume Injections: Evaluation of Volume Administration Deviation From Intended Injection Volumes.

PubMed

Muffly, Matthew K; Chen, Michael I; Claure, Rebecca E; Drover, David R; Efron, Bradley; Fitch, William L; Hammer, Gregory B

2017-10-01

In the perioperative period, anesthesiologists and postanesthesia care unit (PACU) nurses routinely prepare and administer small-volume IV injections, yet the accuracy of delivered medication volumes in this setting has not been described. In this ex vivo study, we sought to characterize the degree to which small-volume injections (≤0.5 mL) deviated from the intended injection volumes among a group of pediatric anesthesiologists and pediatric postanesthesia care unit (PACU) nurses. We hypothesized that as the intended injection volumes decreased, the deviation from those intended injection volumes would increase. Ten attending pediatric anesthesiologists and 10 pediatric PACU nurses each performed a series of 10 injections into a simulated patient IV setup. Practitioners used separate 1-mL tuberculin syringes with removable 18-gauge needles (Becton-Dickinson & Company, Franklin Lakes, NJ) to aspirate 5 different volumes (0.025, 0.05, 0.1, 0.25, and 0.5 mL) of 0.25 mM Lucifer Yellow (LY) fluorescent dye constituted in saline (Sigma Aldrich, St. Louis, MO) from a rubber-stoppered vial. Each participant then injected the specified volume of LY fluorescent dye via a 3-way stopcock into IV tubing with free-flowing 0.9% sodium chloride (10 mL/min). The injected volume of LY fluorescent dye and 0.9% sodium chloride then drained into a collection vial for laboratory analysis. Microplate fluorescence wavelength detection (Infinite M1000; Tecan, Mannedorf, Switzerland) was used to measure the fluorescence of the collected fluid. Administered injection volumes were calculated based on the fluorescence of the collected fluid using a calibration curve of known LY volumes and associated fluorescence.To determine whether deviation of the administered volumes from the intended injection volumes increased at lower injection volumes, we compared the proportional injection volume error (loge [administered volume/intended volume]) for each of the 5 injection volumes using a linear regression model. Analysis of variance was used to determine whether the absolute log proportional error differed by the intended injection volume. Interindividual and intraindividual deviation from the intended injection volume was also characterized. As the intended injection volumes decreased, the absolute log proportional injection volume error increased (analysis of variance, P < .0018). The exploratory analysis revealed no significant difference in the standard deviations of the log proportional errors for injection volumes between physicians and pediatric PACU nurses; however, the difference in absolute bias was significantly higher for nurses with a 2-sided significance of P = .03. Clinically significant dose variation occurs when injecting volumes ≤0.5 mL. Administering small volumes of medications may result in unintended medication administration errors.

Focal Gray Matter Plasticity as a Function of Long Duration Head-down Tilt Bed Rest

NASA Technical Reports Server (NTRS)

Koppelmans, V.; DeDios, Y. E.; Wood, S. J.; Reuter-Lorenz, P. A.; Kofman, I.; Bloomberg, J. J.; Mulavara, A. P.; Koppelmans, V.

2014-01-01

Long duration spaceflight (i.e., > or = 22 days) has been associated with changes in sensorimotor systems, resulting in difficulties that astronauts experience with posture control, locomotion, and manual control. The microgravity environment is an important causal factor for spaceflight induced sensorimotor changes. Whether these sensorimotor changes may be related to structural and functional brain changes is yet unknown. However, experimental studies revealed changes in the gray matter (GM) of the brain after simulated microgravity. Thus, it is possible that spaceflight may affect brain structure and thereby cognitive functioning and motor behavior. Long duration head-down tilt bed rest has been suggested as an exclusionary analog to study microgravity effects on the sensorimotor system. Bed rest mimics microgravity in body unloading and bodily fluid shifts. In consideration of the health and performance of crewmembers both in- and post-flight, we are conducting a prospective longitudinal 70-day bed rest study as an analog to investigate the effects of microgravity on the brain. VBM analysis revealed a progressive decrease from pre- to in- bed rest in GM volume in bilateral areas including the frontal medial cortex, the insular cortex and the caudate. Over the same time period, there was a progressive increase in GM volume in the cerebellum, occipital-, and parietal cortex, including the precuneus. The majority of these changes did not fully recover during the post-bed rest period. Analysis of lobular GM volumes obtained with BRAINS showed significantly increased volume from pre-bed rest to in-bed rest in GM of the parietal lobe and the third ventricle. Temporal GM volume at 70 days in bed rest was smaller than that at the first pre-bed rest measurement. Trend analysis showed significant positive linear and negative quadratic relationships between parietal GM and time, a positive linear relationship between third ventricle volume and time, and a negative linear relationship between cerebellar GM volume and time. FM performance improved from pre-bed rest session 1 to session 2. From the second pre-bed rest measure to the last-day-in-bed rest, there was a significant decrease in performance that only partially recovered post-bed rest. No significant association was observed between changes in brain volume and changes in functional mobility. Extended bed rest, which is an analog for microgravity, can result in local volumetric GM increase and decrease and adversely affect functional mobility. These changes in brain structure and performance were not related in this sample. Whether the effects of bed rest dissipate at longer times post-bed rest, and if they are associated with behavior are important questions that warrant further research including more subjects and longer follow-up times.

Fukushima Daiichi Unit 1 Uncertainty Analysis-Exploration of Core Melt Progression Uncertain Parameters-Volume II.

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

Denman, Matthew R.; Brooks, Dusty Marie

Sandia National Laboratories (SNL) has conducted an uncertainty analysi s (UA) on the Fukushima Daiichi unit (1F1) accident progression wit h the MELCOR code. Volume I of the 1F1 UA discusses the physical modeling details and time history results of the UA. Volume II of the 1F1 UA discusses the statistical viewpoint. The model used was developed for a previous accident reconstruction investigation jointly sponsored by the US Department of Energy (DOE) and Nuclear Regulatory Commission (NRC). The goal of this work was to perform a focused evaluation of uncertainty in core damage progression behavior and its effect on keymore » figures - of - merit (e.g., hydrogen production, fraction of intact fuel, vessel lower head failure) and in doing so assess the applicability of traditional sensitivity analysis techniques .« less

Space station tracking requirements feasibility study, volume 2

NASA Technical Reports Server (NTRS)

Udalov, Sergei; Dodds, James

1988-01-01

The objective of this feasibility study is to determine analytically the accuracies of various sensors being considered as candidates for Space Station use. Specifically, the studies were performed whether or not the candidate sensors are capable of providing the required accuracy, or if alternate sensor approaches should be investigated. Other topics related to operation in the Space Station environment were considered as directed by NASA-JSC. The following topics are addressed: (1) Space Station GPS; (2) Space Station Radar; (3) Docking Sensors; (4) Space Station Link Analysis; (5) Antenna Switching, Power Control, and AGC Functions for Multiple Access; (6) Multichannel Modems; (7) FTS/EVA Emergency Shutdown; (8) Space Station Information Systems Coding; (9) Wanderer Study; and (10) Optical Communications System Analysis. Brief overviews of the abovementioned topics are given. Wherever applicable, the appropriate appendices provide detailed technical analysis. The report is presented in two volumes. This is Volume 2, containing Appendices K through U.

Space station tracking requirements feasibility study, volume 1

NASA Technical Reports Server (NTRS)

Udalov, Sergei; Dodds, James

1988-01-01

The objective of this feasibility study is to determine analytically the accuracies of various sensors being considered as candidates for Space Station use. Specifically, the studies were performed whether or not the candidate sensors are capable of providing the required accuracy, or if alternate sensor approaches be investigated. Other topics related to operation in the Space Station environment were considered as directed by NASA-JCS. The following topics are addressed: (1) Space Station GPS; (2) Space Station Radar; (3) Docking Sensors; (4) Space Station Link Analysis; (5) Antenna Switching, Power Control, and AGC Functions for Multiple Access; (6) Multichannel Modems; (7) FTS/EVA Emergency Shutdown; (8) Space Station Information Systems Coding; (9) Wanderer Study; and (10) Optical Communications System Analysis. Brief overviews of the abovementioned topics are given. Wherever applicable, the appropriate appendices provide detailed technical analysis. The report is presented in two volumes. This is Volume 1, containing the main body and Appendices A through J.

The Geomorphic Road Analysis and Inventory Package (GRAIP) Volume 2: Office Procedures

Treesearch

Richard M. Cissel; Thomas A. Black; Kimberly A. T. Schreuders; Ajay Prasad; Charles H. Luce; David G. Tarboton; Nathan A. Nelson

2012-01-01

An important first step in managing forest roads for improved water quality and aquatic habitat is the performance of an inventory. The Geomorphic Roads Analysis and Inventory Package (GRAIP) was developed as a tool for making a comprehensive inventory and analysis of the effects of forest roads on watersheds. This manual describes the data analysis and process of a...

Prognostic value of adrenal gland volume after cardiac arrest: Association of CT-scan evaluation with shock and mortality.

PubMed

Mongardon, Nicolas; Savary, Guillaume; Geri, Guillaume; El Bejjani, Marie-Rose; Silvera, Stéphane; Dumas, Florence; Charpentier, Julien; Pène, Frédéric; Mira, Jean-Paul; Cariou, Alain

2018-05-28

Adrenal gland volume is associated with survival in septic shock. As sepsis and post-cardiac arrest syndrome share many pathophysiological features, we assessed the association between adrenal gland volume measured by computerized tomography (CT)-scan and post-cardiac arrest shock and intensive care unit (ICU) mortality, in a large cohort of out-of-hospital cardiac arrest (OHCA) patients. We also investigated the association between adrenal hormonal function and both adrenal gland volume and outcomes. Prospective analysis of CT-scan performed at hospital admission in patients admitted after OHCA (2007-2012). A pair of blinded radiologist calculated manually adrenal gland volume. In a subgroup of patients, plasma cortisol was measured at admission and 60 min after a cosyntropin test. Factors associated with post-cardiac arrest shock and ICU mortality were identified using multivariate logistic regression. Among 775 patients admitted during this period after OHCA, 138 patients were included: 72 patients (52.2%) developed a post-cardiac arrest shock, and 98 patients (71.1%) died. In univariate analysis, adrenal gland volume was not different between patients with and without post-cardiac arrest shock: 10.6 and 11.3 cm 3 , respectively (p = 0.9) and between patients discharged alive or dead: 10.2 and 11.8 cm 3 , respectively (p = 0.4). Multivariate analysis confirmed that total adrenal gland volume was associated neither with post-cardiac arrest shock nor mortality. Neither baseline cortisol level nor delta between baseline and after cosyntropin test cortisol levels were associated with adrenal volume, post-cardiac arrest shock onset or mortality. After OHCA, adrenal gland volume is not associated with post-cardiac arrest shock onset or ICU mortality. Adrenal gland volume does not predict adrenal gland hormonal response. Copyright © 2018 Elsevier B.V. All rights reserved.

Comparison of three-dimensional analysis and stereological techniques for quantifying lithium-ion battery electrode microstructures.

PubMed

Taiwo, Oluwadamilola O; Finegan, Donal P; Eastwood, David S; Fife, Julie L; Brown, Leon D; Darr, Jawwad A; Lee, Peter D; Brett, Daniel J L; Shearing, Paul R

2016-09-01

Lithium-ion battery performance is intrinsically linked to electrode microstructure. Quantitative measurement of key structural parameters of lithium-ion battery electrode microstructures will enable optimization as well as motivate systematic numerical studies for the improvement of battery performance. With the rapid development of 3-D imaging techniques, quantitative assessment of 3-D microstructures from 2-D image sections by stereological methods appears outmoded; however, in spite of the proliferation of tomographic imaging techniques, it remains significantly easier to obtain two-dimensional (2-D) data sets. In this study, stereological prediction and three-dimensional (3-D) analysis techniques for quantitative assessment of key geometric parameters for characterizing battery electrode microstructures are examined and compared. Lithium-ion battery electrodes were imaged using synchrotron-based X-ray tomographic microscopy. For each electrode sample investigated, stereological analysis was performed on reconstructed 2-D image sections generated from tomographic imaging, whereas direct 3-D analysis was performed on reconstructed image volumes. The analysis showed that geometric parameter estimation using 2-D image sections is bound to be associated with ambiguity and that volume-based 3-D characterization of nonconvex, irregular and interconnected particles can be used to more accurately quantify spatially-dependent parameters, such as tortuosity and pore-phase connectivity. © 2016 The Authors. Journal of Microscopy published by John Wiley & Sons Ltd on behalf of Royal Microscopical Society.

Association between surgeon volume and hospitalisation costs for patients with oral cancer: a nationwide population base study in Taiwan.

PubMed

Lee, C-C; Ho, H-C; Jack, Lee C-C; Su, Y-C; Lee, M-S; Hung, S-K; Chou, Pesus

2010-02-01

Oral cancer leads to a considerable use of and expenditure on health care. Wide resection of the tumour and reconstruction with a pedicle flap/free flap is widely used. This study was conducted to explore the relationship between hospitalisation costs and surgeon case volume when this operation was performed. A population-based study. This study uses data for the years 2005-2006 obtained from the National Health Insurance Research Database published in the Taiwanese National Health Research Institute. From this population-based data, the authors selected a total of 2663 oral cancer patients who underwent tumour resection and reconstruction. Case volume relationships were based on the following criteria; low-, medium-, high-, very high-volume surgeons were defined by or= 56 resections with reconstruction, respectively. Hierarchical linear regression analysis was subsequently performed to explore the relationship between surgeon case volume and the cost and length of hospitalisation. The mean hospitalisation cost among the 2663 patients was US$ 9528 (all costs are given in US dollars). After adjusting for physician, hospital, and patient characteristics in a hierarchical linear regression model, the cost per patient for low-volume surgeons was found to be US$ 741 (P = 0.012) higher than that for medium-volume surgeons, US$ 1546 (P < 0.001) higher than that for high-volume surgeons, and US$ 1820 (P < 0.001) higher than that for very-high-volume surgeons. After adjustment for physician, hospital, and patient characteristics, the hierarchical linear regression model revealed that the mean length of stay per patient for low-volume surgeons was the highest (P < 0.001). After adjustment for physician, hospital, and patient characteristics, low-volume surgeons performing wide excision with reconstructive surgery in oral cancer patients incurred significantly higher costs and longer hospital stays per patient than did other surgeons. Treatment strategies adopted by high- and very-high-volume surgeons should be analysed further and utilised more widely.

Ku-band antenna acquisition and tracking performance study, volume 4

NASA Technical Reports Server (NTRS)

Huang, T. C.; Lindsey, W. C.

1977-01-01

The results pertaining to the tradeoff analysis and performance of the Ku-band shuttle antenna pointing and signal acquisition system are presented. The square, hexagonal and spiral antenna trajectories were investigated assuming the TDRS postulated uncertainty region and a flexible statistical model for the location of the TDRS within the uncertainty volume. The scanning trajectories, shuttle/TDRS signal parameters and dynamics, and three signal acquisition algorithms were integrated into a hardware simulation. The hardware simulation is quite flexible in that it allows for the evaluation of signal acquisition performance for an arbitrary (programmable) antenna pattern, a large range of C/N sub O's, various TDRS/shuttle a priori uncertainty distributions, and three distinct signal search algorithms.

Adhesive blood microsampling systems for steroid measurement via LC-MS/MS in the rat.

PubMed

Heussner, Kirsten; Rauh, Manfred; Cordasic, Nada; Menendez-Castro, Carlos; Huebner, Hanna; Ruebner, Matthias; Schmidt, Marius; Hartner, Andrea; Rascher, Wolfgang; Fahlbusch, Fabian B

2017-04-01

Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS) allows for the direct analysis of multiple hormones in a single probe with minimal sample volume. Rodent-based animal studies strongly rely on microsampling, such as the dry blood spot (DBS) method. However, DBS suffers the drawback of hematocrit-dependence (non-volumetric). Hence, novel volumetric microsampling techniques were introduced recently, allowing sampling of fixed accurate volumes. We compared these methods for steroid analysis in the rat to improve inter-system comparability. We analyzed steroid levels in blood using the absorptive microsampling devices Whatman® 903 Protein Saver Cards, Noviplex™ Plasma Prep Cards and the Mitra™ Microsampling device and compared the obtained results to the respective EDTA plasma levels. Quantitative steroid analysis was performed via LC-MS/MS. For the determination of the plasma volume factor for each steroid, their levels in pooled blood samples from each human adults and rats (18weeks) were compared and the transferability of these factors was evaluated in a new set of juvenile (21days) and adult (18weeks) rats. Hematocrit was determined concomitantly. Using these approaches, we were unable to apply one single volume factor for each steroid. Instead, plasma volume factors had to be adjusted for the recovery rate of each steroid and device individually. The tested microsampling systems did not allow the use of one single volume factor for adult and juvenile rats based on an unexpectedly strong hematocrit-dependency and other steroid specific (pre-analytic) factors. Our study provides correction factors for LC-MS/MS steroid analysis of volumetric and non-volumetric microsampling systems in comparison to plasma. It argues for thorough analysis of chromatographic effects before the use of novel volumetric systems for steroid analysis. Copyright © 2017 Elsevier Inc. All rights reserved.

Cervical Vertebral Body's Volume as a New Parameter for Predicting the Skeletal Maturation Stages.

PubMed

Choi, Youn-Kyung; Kim, Jinmi; Yamaguchi, Tetsutaro; Maki, Koutaro; Ko, Ching-Chang; Kim, Yong-Il

2016-01-01

This study aimed to determine the correlation between the volumetric parameters derived from the images of the second, third, and fourth cervical vertebrae by using cone beam computed tomography with skeletal maturation stages and to propose a new formula for predicting skeletal maturation by using regression analysis. We obtained the estimation of skeletal maturation levels from hand-wrist radiographs and volume parameters derived from the second, third, and fourth cervical vertebrae bodies from 102 Japanese patients (54 women and 48 men, 5-18 years of age). We performed Pearson's correlation coefficient analysis and simple regression analysis. All volume parameters derived from the second, third, and fourth cervical vertebrae exhibited statistically significant correlations (P < 0.05). The simple regression model with the greatest R-square indicated the fourth-cervical-vertebra volume as an independent variable with a variance inflation factor less than ten. The explanation power was 81.76%. Volumetric parameters of cervical vertebrae using cone beam computed tomography are useful in regression models. The derived regression model has the potential for clinical application as it enables a simple and quantitative analysis to evaluate skeletal maturation level.

Cervical Vertebral Body's Volume as a New Parameter for Predicting the Skeletal Maturation Stages

PubMed Central

Choi, Youn-Kyung; Kim, Jinmi; Maki, Koutaro; Ko, Ching-Chang

2016-01-01

This study aimed to determine the correlation between the volumetric parameters derived from the images of the second, third, and fourth cervical vertebrae by using cone beam computed tomography with skeletal maturation stages and to propose a new formula for predicting skeletal maturation by using regression analysis. We obtained the estimation of skeletal maturation levels from hand-wrist radiographs and volume parameters derived from the second, third, and fourth cervical vertebrae bodies from 102 Japanese patients (54 women and 48 men, 5–18 years of age). We performed Pearson's correlation coefficient analysis and simple regression analysis. All volume parameters derived from the second, third, and fourth cervical vertebrae exhibited statistically significant correlations (P < 0.05). The simple regression model with the greatest R-square indicated the fourth-cervical-vertebra volume as an independent variable with a variance inflation factor less than ten. The explanation power was 81.76%. Volumetric parameters of cervical vertebrae using cone beam computed tomography are useful in regression models. The derived regression model has the potential for clinical application as it enables a simple and quantitative analysis to evaluate skeletal maturation level. PMID:27340668

OTEC modular experiment cold water pipe concept evaluation. Volume III. Appendices

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

Not Available

1979-04-01

The Cold Water Pipe System Design Study was undertaken to evaluate the diverse CWP concepts, recommend the most viable alternatives for a 1984 deployment of the 10 to 40 MWe MEP, and carry out preliminary designs of three concepts. The concept evaluation phase reported involved a systems analysis of design alternatives in the broad categories of rigid walled (with hinges), compliant walled, stockade and bottom mounted buoyant. Quantitative evaluations were made of concept performance, availability, deployment schedule, technical feasibility and cost. CWP concepts were analyzed to determine if they met or could be made to meet established system requirements andmore » could be deployed by 1984. Fabrication, construction and installation plans were developed for successful concepts, and costs were determined in a WBS format. Evaluations were performed on the basis of technical and cost risk. This volume includes the following appendices: (A) materials and associated design criteria; (B) summary of results of dynamic flow and transportation analysis; (C) CWP sizing analysis; (D) CWP thermal performance; and (E) investigation of the APL/ABAM CWP design. (WHK)« less

Assessment of the relationship between renal volume and renal function after minimally-invasive partial nephrectomy: the role of computed tomography and nuclear renal scan.

PubMed

Bertolo, Riccardo; Fiori, Cristian; Piramide, Federico; Amparore, Daniele; Barrera, Monica; Sardo, Diego; Veltri, Andrea; Porpiglia, Francesco

2018-05-14

To evaluate the correlation between the loss of renal function as assessed by Tc99MAG-3 renal scan and the loss of renal volume as calculated by volumetric assessment on CT-scan in patients who underwent minimally-invasive partial nephrectomy (PN). PN prospectively-maintained database was retrospectively queried for patients who underwent minimally-invasive PN (2012-2017) for renal mass

Volumetric analysis of cerebrospinal fluid and brain parenchyma in a patient with hydranencephaly and macrocephaly--case report.

PubMed

Radoš, Milan; Klarica, Marijan; Mučić-Pucić, Branka; Nikić, Ines; Raguž, Marina; Galkowski, Valentina; Mandić, Dora; Orešković, Darko

2014-08-28

The aim of this study was to perform for the first time the intracranial volumetric analysis of cerebrospinal fluid (CSF) and brain parenchyma in the supratentorial and infratentorial space in a 30-year-old female patient with hydranencephaly and macrocephaly. A head scan performed using a 3T magnetic resonance was followed by manual segmentation of the brain parenchyma and CSF on T2 coronal brain sections. The volume of CSF and brain parenchyma was measured separately for the supratentorial and infratentorial space. The total volume of the intracranial space was 3645.5 cm3. In the supratentorial space, the volume of CSF was 3375.2 cm3 and the volume of brain parenchyma was 80.3 cm3. In the infratentorial space, the volume of CSF was 101.3 cm3 and the volume of the brain parenchyma was 88.7 cm3. In the supratentorial space, there was severe malacia of almost all brain parenchyma with no visible remnants of the choroid plexuses. Infratentorial structures of the brainstem and cerebellum were hypoplastic but completely developed. Since our patient had no choroid plexuses in the supratentorial space and no obstruction between dural sinuses and CSF, development of hydrocephalus and macrocephaly cannot be explained by the classic hypothesis of CSF physiology with secretion, unidirectional circulation, and absorption as its basic postulates. However, the origin and turnover of the enormous amount of intracranial CSF volume, at least 10-fold larger than normal, and the mechanisms of macroencephaly development could be elucidated by the new hypothesis of CSF physiology recently published by our research team.

Mod-5A wind turbine generator program design report. Volume 3: Final design and system description, book 2

NASA Technical Reports Server (NTRS)

1984-01-01

The design, development and analysis of the 7.3MW MOD-5A wind turbine generator is documented. The report is divided into four volumes: Volume 1 summarizes the entire MOD-5A program, Volume 2 discusses the conceptual and preliminary design phases, Volume 3 describes the final design of the MOD-5A, and Volume 4 contains the drawings and specifications developed for the final design. Volume 3, book 2 describes the performance and characteristics of the MOD-5A wind turbine generator in its final configuration. The subsystem for power generation, control, and instrumentation subsystems is described in detail. The manufacturing and construction plans, and the preparation of a potential site on Oahu, Hawaii, are documented. The quality assurance and safety plan, and analyses of failure modes and effects, and reliability, availability and maintainability are presented.

Computer Program (HEVSIM) for Heavy Duty Vehicle Fuel Economy and Performance Simulation. Volume I: Description and Analysis

DOT National Transportation Integrated Search

1981-09-01

This report presents a description of a vehicle simulation program, which can determine the fuel economy and performance of a specified motor vehicle over a defined route as it executes a given driving schedule. Vehicle input accommodated by HEVSIM i...

Climatological Study to Determine the Impact of Icing on the Low Level Windshear Alert System. Volume I. Analysis.

DOT National Transportation Integrated Search

1989-09-01

The climatological study was performed to determine the impact of icing on the performance of Low Level Windshear Alert System (LLWAS). : This report presents the icing statistical profile in the form of data tables and histograms of 106 LLWAS sites....

Transportation safety data and analysis : Volume 2, Calibration of the highway safety manual and development of new safety performance functions.

DOT National Transportation Integrated Search

2011-03-01

This report documents the calibration of the Highway Safety Manual (HSM) safety performance function (SPF) : for rural two-lane two-way roadway segments in Utah and the development of new models using negative : binomial and hierarchical Bayesian mod...

A computer program (VEHSIM) for vehicle fuel economy and performance simulation (automobiles and light trucks). Volume 1. Description and analysis

DOT National Transportation Integrated Search

1981-01-01

This report presents an updated description of a vehicle simulation program, VEHSIM, which can determine the fuel economy and performance of a specified vehicle over a defined route as it executes a given driving schedule. Vehicle input accommodated ...

A computer program (HEVSIM) for heavy duty vehicle fuel economy and performance simulation : Volume 1: Description and Analysis

DOT National Transportation Integrated Search

1981-09-01

This report presents a description of a vehicle simulation program, which can determine the fuel economy and performance of a specified motor vehicle over a defined route as it executes a given driving schedule. Vehicle input accommodated by HEVSIM i...

Sensitivity of Spaceborne and Ground Radar Comparison Results to Data Analysis Methods and Constraints

NASA Technical Reports Server (NTRS)

Morris, Kenneth R.; Schwaller, Mathew

2011-01-01

With the availability of active weather radar observations from space from the Precipitation Radar (PR) on board the Tropical Rainfall Measuring Mission (TR.MM) satellite, numerous studies have been performed comparing PR reflectivity and derived rain rates to similar observations from ground-based weather radars (GR). These studies have used a variety of algorithms to compute matching PR and GR volumes for comparison. Most studies have used a fixed 3-dimensional Cartesian grid centered on the ground radar, onto which the PR and GR data are interpolated using a proprietary approach and/or commonly available GR analysis software (e.g., SPRINT, REORDER). Other studies have focused on the intersection of the PR and GR viewing geometries either explicitly or using a hybrid of the fixed grid and PR/GR common fields of view. For the Dual-Frequency Precipitation Radar (DPR) of the upcoming Global Precipitation Measurement (GPM) mission, a prototype DPR/GR comparison algorithm based on similar TRMM PR data has been developed that defines the common volumes in terms of the geometric intersection of PR and GR rays, where smoothing of the PR and GR data are minimized and no interpolation is performed. The PR and GR volume-averaged reflectivity values of each sample volume are accompanied by descriptive metadata, for attributes including the variability and maximum of the reflectivity within the sample volume, and the fraction of range gates in the sample average having reflectivity values above an adjustable detection threshold (typically taken to be 18 dBZ for the PR). Sample volumes are further characterized by rain type (Stratiform or Convective), proximity to the melting layer, underlying surface (land/water/mixed), and the time difference between the PR and GR observations. The mean reflectivity differences between the PR and GR can differ between data sets produced by the different analysis methods; and for the GPM prototype, by the type of constraints and categorization applied to the data. In this paper, we will show results comparing the 3-D gridded analysis "black box" approach to the GPM prototype volume-matching approach, using matching TRMM PR and WSR-88D ground radar data. The affects of applying data constraints and data categorizations on the volume-matched data to the results will be shown, and explanations of the differences in terms of data and analysis algorithm characteristics will be presented. Implications of the differences to the determination of PR/DPR calibration differences and use of ground radar data to evaluate the PR and DPR attenuation correction algorithms will be discussed.

Analysis of flexible aircraft longitudinal dynamics and handling qualities. Volume 2: Data

NASA Technical Reports Server (NTRS)

Waszak, M. R.; Schmidt, D. K.

1985-01-01

Two analysis methods are applied to a family of flexible aircraft in order to investigate how and when structural (especially dynamic aeroelastic) effects affect the dynamic characteristics of aircraft. The first type of analysis is an open loop modal analysis technique. This method considers the effect of modal residue magnitudes on determining vehicle handling qualities. The second method is a pilot in the loop analysis procedure that considers several closed loop system characteristics. Both analyses indicated that dynamic aeroelastic effects caused a degradation in vehicle tracking performance, based on the evaluation of some simulation results. Volume 2 consists of the presentation of the state variable models of the flexible aircraft configurations used in the analysis applications mode shape plots for the structural modes, numerical results from the modal analysis frequency response plots from the pilot in the loop analysis and a listing of the modal analysis computer program.

Evaluation of Toluene Adsorption Performance of Mortar Adhesives Using Porous Carbon Material as Adsorbent

PubMed Central

Chang, Seong Jin; Jeong, Su-Gwang; Lee, Jongki; Kim, Taeyeon; Park, Kyung-Won; Lee, Dong Ryeol; Kim, Sumin

2017-01-01

Porous carbon materials are advantageous in adsorbing pollutants due to their wide range of specific surface areas, pore diameter, and pore volume. Among the porous carbon materials in the current study, expanded graphite, xGnP, xGnP C-300, xGnP C-500, and xGnP C-750 were prepared as adsorbent materials. Brunauer–Emmett–Teller (BET) analysis was conducted to select the adsorbent material through the analysis of the specific surface area, pore size, and pore volume of the prepared porous carbon materials. Morphological analysis using SEM was also performed. The xGnP C-500 as adsorbent material was applied to a mortar adhesive that is widely used in the installation of interior building materials. The toluene adsorption performances of the specimens were evaluated using 20 L small chamber. Furthermore, the performance of the mortar adhesive, as indicated by the shear bond strength, length change rate, and water retention rate, was analyzed according to the required test method specified in the Korean standards. It was confirmed that for the mortar adhesives prepared using the xGnP C-500 as adsorbent material, the toluene adsorption performance was excellent and satisfied the required physical properties. PMID:28773214

Numerical simulations of loop quantum Bianchi-I spacetimes

NASA Astrophysics Data System (ADS)

Diener, Peter; Joe, Anton; Megevand, Miguel; Singh, Parampreet

2017-05-01

Due to the numerical complexities of studying evolution in an anisotropic quantum spacetime, in comparison to the isotropic models, the physics of loop quantized anisotropic models has remained largely unexplored. In particular, robustness of bounce and the validity of effective dynamics have so far not been established. Our analysis fills these gaps for the case of vacuum Bianchi-I spacetime. To efficiently solve the quantum Hamiltonian constraint we perform an implementation of the Cactus framework which is conventionally used for applications in numerical relativity. Using high performance computing, numerical simulations for a large number of initial states with a wide variety of fluctuations are performed. Big bang singularity is found to be replaced by anisotropic bounces for all the cases. We find that for initial states which are sharply peaked at the late times in the classical regime and bounce at a mean volume much greater than the Planck volume, effective dynamics is an excellent approximation to the underlying quantum dynamics. Departures of the effective dynamics from the quantum evolution appear for the states probing deep Planck volumes. A detailed analysis of the behavior of this departure reveals a non-monotonic and subtle dependence on fluctuations of the initial states. We find that effective dynamics in almost all of the cases underestimates the volume and hence overestimates the curvature at the bounce, a result in synergy with earlier findings in the isotropic case. The expansion and shear scalars are found to be bounded throughout the evolution.

Space Shuttle Main Engine structural analysis and data reduction/evaluation. Volume 4: High pressure fuel turbo-pump inlet housing analysis

NASA Technical Reports Server (NTRS)

Pool, Kirby V.

1989-01-01

The analysis performed on the Space Shuttle Main Engine (SSME) High Pressure Fuel Turbopump (HPFTP) inlet housings is summarized. Three DIAL finite element models were build to aid in assessing the structural life of the welds and fillets at the vanes. Complete results are given.

Space shuttle navigation analysis. Volume 2: Baseline system navigation

NASA Technical Reports Server (NTRS)

Jones, H. L.; Luders, G.; Matchett, G. A.; Rains, R. G.

1980-01-01

Studies related to the baseline navigation system for the orbiter are presented. The baseline navigation system studies include a covariance analysis of the Inertial Measurement Unit calibration and alignment procedures, postflight IMU error recovery for the approach and landing phases, on-orbit calibration of IMU instrument biases, and a covariance analysis of entry and prelaunch navigation system performance.

Gray Matter Features of Reading Disability: A Combined Meta-Analytic and Direct Analysis Approach1234

PubMed Central

Berninger, Virginia W.; Gebregziabher, Mulugeta; Tsu, Loretta

2016-01-01

Abstract Meta-analysis of voxel-based morphometry dyslexia studies and direct analysis of 293 reading disability and control cases from six different research sites were performed to characterize defining gray matter features of reading disability. These analyses demonstrated consistently lower gray matter volume in left posterior superior temporal sulcus/middle temporal gyrus regions and left orbitofrontal gyrus/pars orbitalis regions. Gray matter volume within both of these regions significantly predicted individual variation in reading comprehension after correcting for multiple comparisons. These regional gray matter differences were observed across published studies and in the multisite dataset after controlling for potential age and gender effects, and despite increased anatomical variance in the reading disability group, but were not significant after controlling for total gray matter volume. Thus, the orbitofrontal and posterior superior temporal sulcus gray matter findings are relatively reliable effects that appear to be dependent on cases with low total gray matter volume. The results are considered in the context of genetics studies linking orbitofrontal and superior temporal sulcus regions to alleles that confer risk for reading disability. PMID:26835509

Shortened Mean Transit Time in CT Perfusion With Singular Value Decomposition Analysis in Acute Cerebral Infarction: Quantitative Evaluation and Comparison With Various CT Perfusion Parameters.

PubMed

Murayama, Kazuhiro; Katada, Kazuhiro; Hayakawa, Motoharu; Toyama, Hiroshi

We aimed to clarify the cause of shortened mean transit time (MTT) in acute ischemic cerebrovascular disease and examined its relationship with reperfusion. Twenty-three patients with acute ischemic cerebrovascular disease underwent whole-brain computed tomography perfusion (CTP). The maximum MTT (MTTmax), minimum MTT (MTTmin), ratio of maximum and minimum MTT (MTTmin/max), and minimum cerebral blood volume (CBV) (CBVmin) were measured by automatic region of interest analysis. Diffusion weighted image was performed to calculate infarction volume. We compared these CTP parameters between reperfusion and nonreperfusion groups and calculated correlation coefficients between the infarction core volume and CTP parameters. Significant differences were observed between reperfusion and nonreperfusion groups (MTTmin/max: P = 0.014; CBVmin ratio: P = 0.038). Regression analysis of CTP and high-intensity volume on diffusion weighted image showed negative correlation (CBVmin ratio: r = -0.41; MTTmin/max: r = -0.30; MTTmin ratio: r = -0.27). A region of shortened MTT indicated obstructed blood flow, which was attributed to the singular value decomposition method error.

Advanced Transportation System Studies Technical Area 2 (TA-2) Heavy Lift Launch Vehicle Development Contract. Volume 2; Technical Results

NASA Technical Reports Server (NTRS)

1995-01-01

The purpose of the Advanced Transportation System Studies (ATSS) Technical Area 2 (TA-2) Heavy Lift Launch Vehicle Development contract was to provide advanced launch vehicle concept definition and analysis to assist NASA in the identification of future launch vehicle requirements. Contracted analysis activities included vehicle sizing and performance analysis, subsystem concept definition, propulsion subsystem definition (foreign and domestic), ground operations and facilities analysis, and life cycle cost estimation. This document is Volume 2 of the final report for the contract. It provides documentation of selected technical results from various TA-2 analysis activities, including a detailed narrative description of the SSTO concept assessment results, a user's guide for the associated SSTO sizing tools, an SSTO turnaround assessment report, an executive summary of the ground operations assessments performed during the first year of the contract, a configuration-independent vehicle health management system requirements report, a copy of all major TA-2 contract presentations, a copy of the FLO launch vehicle final report, and references to Pratt & Whitney's TA-2 sponsored final reports regarding the identification of Russian main propulsion technologies.

Grid orthogonality effects on predicted turbine midspan heat transfer and performance

NASA Technical Reports Server (NTRS)

Boyle, R. J.; Ameri, A. A.

1995-01-01

The effect of five different C type grid geometries on the predicted heat transfer and aerodynamic performance of a turbine stator is examined. Predictions were obtained using two flow analysis codes. One was a finite difference analysis, and the other was a finite volume analysis. Differences among the grids in terms of heat transfer and overall performance were small. The most significant difference among the five grids occurred in the prediction of pitchwise variation in total pressure. There was consistency between results obtained with each of the flow analysis codes when the same grid was used. A grid generating procedure in which the viscous grid is embedded within an inviscid type grid resulted in the best overall performance.

MRT letter: Guided filtering of image focus volume for 3D shape recovery of microscopic objects.

PubMed

Mahmood, Muhammad Tariq

2014-12-01

In this letter, a shape from focus (SFF) method is proposed that utilizes the guided image filtering to enhance the image focus volume efficiently. First, image focus volume is computed using a conventional focus measure. Then each layer of image focus volume is filtered using guided filtering. In this work, the all-in-focus image, which can be obtained from the initial focus volume, is used as guidance image. Finally, improved depth map is obtained from the filtered image focus volume by maximizing the focus measure along the optical axis. The proposed SFF method is efficient and provides better depth maps. The improved performance is highlighted by conducting several experiments using image sequences of simulated and real microscopic objects. The comparative analysis demonstrates the effectiveness of the proposed SFF method. © 2014 Wiley Periodicals, Inc.

Economic analysis of the future growth of cosmetic surgery procedures.

PubMed

Liu, Tom S; Miller, Timothy A

2008-06-01

The economic growth of cosmetic surgical and nonsurgical procedures has been tremendous. Between 1992 and 2005, annual U.S. cosmetic surgery volume increased by 725 percent, with over $10 billion spent in 2005. It is unknown whether this growth will continue for the next decade and, if so, what impact it will it have on the plastic surgeon workforce. The authors analyzed annual U.S. cosmetic surgery procedure volume reported by the American Society of Plastic Surgeons (ASPS) National Clearinghouse of Plastic Surgery Statistics between 1992 and 2005. Reconstructive plastic surgery volume was not included in the analysis. The authors analyzed the ability of economic and noneconomic variables to predict annual cosmetic surgery volume. The authors also used growth rate analyses to construct models with which to predict the future growth of cosmetic surgery. None of the economic and noneconomic variables were a significant predictor of annual cosmetic surgery volume. Instead, based on current compound annual growth rates, the authors predict that total cosmetic surgery volume (surgical and nonsurgical) will exceed 55 million annual procedures by 2015. ASPS members are projected to perform 299 surgical and 2165 nonsurgical annual procedures. Non-ASPS members are projected to perform 39 surgical and 1448 nonsurgical annual procedures. If current growth rates continue into the next decade, the future demand in cosmetic surgery will be driven largely by nonsurgical procedures. The growth of surgical procedures will be met by ASPS members. However, meeting the projected growth in nonsurgical procedures could be a potential challenge and a potential area for increased competition.

Which echocardiographic parameter is a better marker of volume status in hemodialysis patients?

PubMed

Sabaghian, Tahereh; Hajibaratali, Bahareh; Samavat, Shiva

2016-11-01

Bio-impedance analysis (BIA) is a preferred method for estimating the volume status. However, it cannot be utilized in daily practice. Since the assessment of the volume status is important and challenging for hemodialysis (HD) patients, the aim of study was to determine the volume status in chronic HD patients using echocardiographic parameters and assess its correlation with BIA. In this cross-sectional analysis, echocardiography and BIA were performed on 30 chronic HD patients 30 min before and 30 min after dialysis. All the cases of dialysis were performed in the middle of the week. This study also assessed the correlation between echocardiographic parameters and BIA parameters. There were significant differences between ECW, TBW, and TBW% (TBW/W) before and after HD. Significant differences were observed between echocardiographic parameters of IVCD, IVCDi min , IVCDi max before and after the HD. LVEDD, LVESD, LA area, mitral valve inflow, E/E', and IVRT, were improved after dialysis, too. There was a significant correlation between IVCDi min as an index of volume status, ECW% and TBW% before HD and IVCDi min change after dialysis had a significant correlation with %ECW change after dialysis. Comparison between hypertensive and non-hypertensive groups indicated IVCDi min was significantly lower in non-hypertensive group after dialysis. Our results showed a correlation between IVCDi min and BIA parameters before HD. So, it seems that IVCDi min can be a good parameter for determining the volume status of HD patients. However, further studies, with larger sample size and with a prospective study design, are required to confirm these results.

Localized hippocampus measures are associated with Alzheimer pathology and cognition independent of total hippocampal volume.

PubMed

Carmichael, Owen; Xie, Jing; Fletcher, Evan; Singh, Baljeet; DeCarli, Charles

2012-06-01

Hippocampal injury in the Alzheimer's disease (AD) pathological process is region-specific and magnetic resonance imaging (MRI)-based measures of localized hippocampus (HP) atrophy are known to detect region-specific changes associated with clinical AD, but it is unclear whether these measures provide information that is independent of that already provided by measures of total HP volume. Therefore, this study assessed the strength of association between localized HP atrophy measures and AD-related measures including cerebrospinal fluid (CSF) amyloid beta and tau concentrations, and cognitive performance, in statistical models that also included total HP volume as a covariate. A computational technique termed localized components analysis (LoCA) was used to identify 7 independent patterns of HP atrophy among 390 semiautomatically delineated HP from baseline magnetic resonance imaging of participants in the Alzheimer's Disease Neuroimaging Initiative (ADNI). Among cognitively normal participants, multiple measures of localized HP atrophy were significantly associated with CSF amyloid concentration, while total HP volume was not. In addition, among all participants, localized HP atrophy measures and total HP volume were both independently and additively associated with CSF tau concentration, performance on numerous neuropsychological tests, and discrimination between normal, mild cognitive impairment (MCI), and AD clinical diagnostic groups. Together, these results suggest that regional measures of hippocampal atrophy provided by localized components analysis may be more sensitive than total HP volume to the effects of AD pathology burden among cognitively normal individuals and may provide information about HP regions whose deficits may have especially profound cognitive consequences throughout the AD clinical course. Copyright © 2012 Elsevier Inc. All rights reserved.

The combination of ovarian volume and outline has better diagnostic accuracy than prostate-specific antigen (PSA) concentrations in women with polycystic ovarian syndrome (PCOs).

PubMed

Bili, Eleni; Bili, Authors Eleni; Dampala, Kaliopi; Iakovou, Ioannis; Tsolakidis, Dimitrios; Giannakou, Anastasia; Tarlatzis, Basil C

2014-08-01

The aim of this study was to determine the performance of prostate specific antigen (PSA) and ultrasound parameters, such as ovarian volume and outline, in the diagnosis of polycystic ovary syndrome (PCOS). This prospective, observational, case-controlled study included 43 women with PCOS, and 40 controls. Between day 3 and 5 of the menstrual cycle, fasting serum samples were collected and transvaginal ultrasound was performed. The diagnostic performance of each parameter [total PSA (tPSA), total-to-free PSA ratio (tPSA:fPSA), ovarian volume, ovarian outline] was estimated by means of receiver operating characteristic (ROC) analysis, along with area under the curve (AUC), threshold, sensitivity, specificity as well as positive (+) and negative (-) likelihood ratios (LRs). Multivariate logistical regression models, using ovarian volume and ovarian outline, were constructed. The tPSA and tPSA:fPSA ratio resulted in AUC of 0.74 and 0.70, respectively, with moderate specificity/sensitivity and insufficient LR+/- values. In the multivariate logistic regression model, the combination of ovarian volume and outline had a sensitivity of 97.7% and a specificity of 97.5% in the diagnosis of PCOS, with +LR and -LR values of 39.1 and 0.02, respectively. In women with PCOS, tPSA and tPSA:fPSA ratio have similar diagnostic performance. The use of a multivariate logistic regression model, incorporating ovarian volume and outline, offers very good diagnostic accuracy in distinguishing women with PCOS patients from controls. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Overuse of surgery in patients with pancreatic cancer. A nationwide analysis in Italy

PubMed Central

Balzano, Gianpaolo; Capretti, Giovanni; Callea, Giuditta; Cantù, Elena; Carle, Flavia; Pezzilli, Raffaele

2016-01-01

Background According to current guidelines, pancreatic cancer patients should be strictly selected for surgery, either palliative or resective. Methods Population-based study, including all patients undergoing surgery for pancreatic cancer in Italy between 2010 and 2012. Hospitals were divided into five volume groups (quintiles), to search for differences among volume categories. Results There were 544 hospitals performing 10 936 pancreatic cancer operations. The probability of undergoing palliative/explorative surgery was inversely related to volume, being 24.4% in very high-volume hospitals and 62.5% in very low-volume centres (adjusted OR 5.175). Contrarily, the resection rate in patients without metastases decreased from 86.9% to 46.1% (adjusted OR 7.429). As for resections, the mortality of non-resective surgery was inversely related to volume (p < 0.001). Surprisingly, mortality of non-resective surgery was higher than that for resections (8.2% vs. 6.7%; p < 0.01). Approximately 9% of all resections were performed on patients with distant metastases, irrespective of hospital volume group. The excess cost for the National Health System from surgery overuse was estimated at 12.5 million euro. Discussion. Discrepancies between guidelines on pancreatic cancer treatment and surgical practice were observed. An overuse of surgery was detected, with serious clinical and economic consequences. PMID:27154812

Longitudinal 3.0T MRI analysis of changes in lymph node volume and apparent diffusion coefficient in an experimental animal model of metastatic and hyperplastic lymph nodes.

PubMed

Klerkx, Wenche M; Geldof, Albert A; Heintz, A Peter; van Diest, Paul J; Visser, Fredy; Mali, Willem P; Veldhuis, Wouter B

2011-05-01

To perform a longitudinal analysis of changes in lymph node volume and apparent diffusion coefficient (ADC) in healthy, metastatic, and hyperplastic lymph nodes. Three groups of four female Copenhagen rats were studied. Metastasis was induced by injecting cells with a high metastatic potential in their left hind footpad. Reactive nodes were induced by injecting Complete Freund Adjuvant (CFA). Imaging was performed at baseline and at 2, 5, 8, 11, and 14 days after tumor cell injection. Finally, lymph nodes were examined histopathologically. The model was highly efficient in inducing lymphadenopathy: subcutaneous cell or CFA inoculation resulted in ipsilateral metastatic or reactive popliteal lymph nodes in all rats. Metastatic nodal volumes increased exponentially from 5-7 mm(3) at baseline to 25 mm(3) at day 14, while the control node remained 5 mm(3). The hyperplastic nodes showed a rapid volume increase reaching a plateau at day 6. The ADC of metastatic nodes significantly decreased (range 13%-32%), but this decrease was also seen in reactive nodes. Metastatic and hyperplastic lymph nodes differed in terms of enlargement patterns and ADC changes. Enlarged reactive or malignant nodes could not be differentiated based on their ADC values. Copyright © 2011 Wiley-Liss, Inc.

Importance of nasal clipping in screening investigations of flow volume curve.

PubMed

Yanev, I

1992-01-01

Comparative analysis of some basic lung indices obtained from a screening investigation of the flow volume curve by using two techniques, with a nose clip and without a nose clip, was made on a cohort of 86 workers in a factory shop for the production of bearings. We found no statistically significant differences between the indices obtained by the two techniques. Our study showed that the FVC and FEV1 obtained in workers without using nose clips were equal to or better than those obtained using nose clips in 60% of the workers. The reproducibility of the two methods was similar. The analysis of the data has shown that the flow volume curve investigation gives better results when performed without a nose clip, especially in industrial conditions.

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

Sewell, Christopher Meyer

This is a set of slides from a guest lecture for a class at the University of Texas, El Paso on visualization and data analysis for high-performance computing. The topics covered are the following: trends in high-performance computing; scientific visualization, such as OpenGL, ray tracing and volume rendering, VTK, and ParaView; data science at scale, such as in-situ visualization, image databases, distributed memory parallelism, shared memory parallelism, VTK-m, "big data", and then an analysis example.

An automated system for chromosome analysis. Volume 1: Goals, system design, and performance

NASA Technical Reports Server (NTRS)

Castleman, K. R.; Melnyk, J. H.

1975-01-01

The design, construction, and testing of a complete system to produce karyotypes and chromosome measurement data from human blood samples, and a basis for statistical analysis of quantitative chromosome measurement data is described. The prototype was assembled, tested, and evaluated on clinical material and thoroughly documented.

Procedure for analysis and design of weaving sections : volume 1, research findings and development of techniques for application.

DOT National Transportation Integrated Search

1983-12-01

This research was performed to complete and advance the status of recently developed : procedures for analysis and design of weaving sections (known as the Leisch method and-initially published in the 1979 issue of ITE Journal). The objective was to ...

Back-calculation of layer parameters for LTPP test sections, volume II : layered elastic analysis for flexible and rigid pavements.

DOT National Transportation Integrated Search

2000-09-01

The Long Term Pavement Performance (LTPP) program has been collecting profile and : International Roughness Index (IRI) information from more than 2,062 test sections since 1989 : using K.J. Law 690DNC optical sensor Profilometers. Analysis of the IR...

DOD/NASA system impact analysis (study 2.1). Volume 2: Study results

NASA Technical Reports Server (NTRS)

1973-01-01

Results of the tug turnaround cost study and the space transportation system (STS) abort modes and effects study are presented for DOD/NASA system impact analysis. Cost estimates are given for tug turnabout; and vehicle description, abort assessment, and abort performance capability are given for the STS.

Thyroid disorders in patients treated with radiotherapy for head-and-neck cancer: A retrospective analysis of seventy-three patients

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

Alterio, Daniela; Jereczek-Fossa, Barbara Alicja; University of Milan, Milan

2007-01-01

Purpose: To evaluate the incidence of thyroid disorders and dose distribution to the thyroid in patients treated with radiotherapy for head-and-neck carcinomas. Methods and Materials: A retrospective evaluation of data from 73 patients treated for head-and-neck cancers in our department was performed. Thyroid function was evaluated mainly by the measurement of thyrotropin (thyroid stimulating hormone [TSH]). A retrospective analysis of treatment plans was performed for 57 patients. Percentages of thyroid glandular volume absorbing 10, 30, and 50 Gy (V10, V30, and V50 respectively) were considered for statistical analysis. Results: A majority of patients (61%) had a normal thyroid function whereasmore » 19 patients (26%) had hypothyroidism. Mean thyroid volume was 30.39 cc. Point 3 (located at isthmus) absorbed lower doses compared with other points (p < 0.0001). Median values of V10, V30, and V50 were 92% (range, 57-100%), 75% (range, 28.5-100%), and 35% (range, 3-83%) respectively. Gender was associated with toxicity (presence of any kind of thyroid disorders) (p < 0.05), with females displaying higher levels of TSHr (relative TSH = patient's value/maximum value of the laboratory range) (p = 0.0005) and smaller thyroid volume (p 0.0012) compared with male population. TSHr values were associated with thyroid volume, and the presence of midline shielding block in the anterior field was associated with relative free thyroxine (FT4r = patient's value/maximum value of the laboratory range) values. Conclusions: Gender and thyroid volume seem to play an important role in the occurrence of thyroid toxicity, but further studies on dose-effect relationship for radiotherapy-induced thyroid toxicity are needed.« less

Program Helps To Determine Chemical-Reaction Mechanisms

NASA Technical Reports Server (NTRS)

Bittker, D. A.; Radhakrishnan, K.

1995-01-01

General Chemical Kinetics and Sensitivity Analysis (LSENS) computer code developed for use in solving complex, homogeneous, gas-phase, chemical-kinetics problems. Provides for efficient and accurate chemical-kinetics computations and provides for sensitivity analysis for variety of problems, including problems involving honisothermal conditions. Incorporates mathematical models for static system, steady one-dimensional inviscid flow, reaction behind incident shock wave (with boundary-layer correction), and perfectly stirred reactor. Computations of equilibrium properties performed for following assigned states: enthalpy and pressure, temperature and pressure, internal energy and volume, and temperature and volume. Written in FORTRAN 77 with exception of NAMELIST extensions used for input.

The effects of contrast media volume on acute kidney injury after transcatheter aortic valve replacement: a systematic review and meta-analysis.

PubMed

Thongprayoon, Charat; Cheungpasitporn, Wisit; Podboy, Alexander J; Gillaspie, Erin A; Greason, Kevin L; Kashani, Kianoush B

2016-11-01

The goal of this systematic review was to assess the effects of contrast media volume on transcatheter aortic valve replacement-related acute kidney injury. A literature search was performed using Medline, EMbase, the Cochrane Database of Systematic Reviews, and clinicaltrials.gov from the inception of these databases through December 2015. Studies that reported relative risk, odds ratio, or hazard ratio comparing the risks of acute kidney injury following transcatheter aortic valve replacement in patients who received high contrast media volume were included. Pooled risk ratio (RR) and 95% confidence intervals (95% CI) were calculated using a random-effect, generic inverse variance method. Four cohort studies composed of 891 patients were included in the analyses to assess the risk of acute kidney injury after transcatheter aortic valve replacement in patients who received high contrast media volume. The pooled RR of acute kidney injury after transcatheter aortic valve replacement in patients who received a large volume of contrast media was 1.41 (95% CI, 0.87 to 2.28) compared with low contrast media volume. The meta-analysis was limited to studies using standard acute kidney injury definitions, and the pooled RR of acute kidney injury in patients who received high contrast media volume is 1.12 (95% CI, 0.78 to 1.62). Our meta-analysis shows no significant association between contrast media volume and risk of acute kidney injury after transcatheter aortic valve replacement. © 2016 Chinese Cochrane Center, West China Hospital of Sichuan University and John Wiley & Sons Australia, Ltd.

Bone Histology of Two Cases with Osteomalacia Related to Low-dose Adefovir

PubMed Central

Hiramatsu, Rikako; Ubara, Yoshifumi; Sawa, Naoki; Hasegawa, Eiko; Kawada, Masahiro; Imafuku, Aya; Sumida, Keiichi; Hoshino, Junichi; Takaichi, Kenmei

2016-01-01

We performed a bone histomorphometric analysis in two patients demonstrating Fanconi syndrome with hypophosphatemia, adefovir-related bone disease and chronic hepatitis B infection. Both patients had osteomalacia, but showed two different histological patterns. The osteoid volume of the patient without risedronate increased with [(osteoid volume/ bone volume)×100=18.6%]. However, the osteoid volume of the patient receiving risedronate without vitamin D analogue showed a greater increase of 53.8%. In both patients bone pain and hypophosphatemia subsided soon after the discontinuation of adefovir and the administration of phosphate derivative. These findings show that bisphosphonate may worsen this disease when this drug is administered without a vitamin D analogue. PMID:27746441

Flat-plate solar array project. Volume 5: Process development

NASA Technical Reports Server (NTRS)

Gallagher, B.; Alexander, P.; Burger, D.

1986-01-01

The goal of the Process Development Area, as part of the Flat-Plate Solar Array (FSA) Project, was to develop and demonstrate solar cell fabrication and module assembly process technologies required to meet the cost, lifetime, production capacity, and performance goals of the FSA Project. R&D efforts expended by Government, Industry, and Universities in developing processes capable of meeting the projects goals during volume production conditions are summarized. The cost goals allocated for processing were demonstrated by small volume quantities that were extrapolated by cost analysis to large volume production. To provide proper focus and coverage of the process development effort, four separate technology sections are discussed: surface preparation, junction formation, metallization, and module assembly.

Simple method for the generation of multiple homogeneous field volumes inside the bore of superconducting magnets

PubMed Central

Chou, Ching-Yu; Ferrage, Fabien; Aubert, Guy; Sakellariou, Dimitris

2015-01-01

Standard Magnetic Resonance magnets produce a single homogeneous field volume, where the analysis is performed. Nonetheless, several modern applications could benefit from the generation of multiple homogeneous field volumes along the axis and inside the bore of the magnet. In this communication, we propose a straightforward method using a combination of ring structures of permanent magnets in order to cancel the gradient of the stray field in a series of distinct volumes. These concepts were demonstrated numerically on an experimentally measured magnetic field profile. We discuss advantages and limitations of our method and present the key steps required for an experimental validation. PMID:26182891

Bone Histology of Two Cases with Osteomalacia Related to Low-dose Adefovir.

PubMed

Hiramatsu, Rikako; Ubara, Yoshifumi; Sawa, Naoki; Hasegawa, Eiko; Kawada, Masahiro; Imafuku, Aya; Sumida, Keiichi; Hoshino, Junichi; Takaichi, Kenmei

We performed a bone histomorphometric analysis in two patients demonstrating Fanconi syndrome with hypophosphatemia, adefovir-related bone disease and chronic hepatitis B infection. Both patients had osteomalacia, but showed two different histological patterns. The osteoid volume of the patient without risedronate increased with [(osteoid volume/ bone volume)×100=18.6%]. However, the osteoid volume of the patient receiving risedronate without vitamin D analogue showed a greater increase of 53.8%. In both patients bone pain and hypophosphatemia subsided soon after the discontinuation of adefovir and the administration of phosphate derivative. These findings show that bisphosphonate may worsen this disease when this drug is administered without a vitamin D analogue.

Comparative study of standard space and real space analysis of quantitative MR brain data.

PubMed

Aribisala, Benjamin S; He, Jiabao; Blamire, Andrew M

2011-06-01

To compare the robustness of region of interest (ROI) analysis of magnetic resonance imaging (MRI) brain data in real space with analysis in standard space and to test the hypothesis that standard space image analysis introduces more partial volume effect errors compared to analysis of the same dataset in real space. Twenty healthy adults with no history or evidence of neurological diseases were recruited; high-resolution T(1)-weighted, quantitative T(1), and B(0) field-map measurements were collected. Algorithms were implemented to perform analysis in real and standard space and used to apply a simple standard ROI template to quantitative T(1) datasets. Regional relaxation values and histograms for both gray and white matter tissues classes were then extracted and compared. Regional mean T(1) values for both gray and white matter were significantly lower using real space compared to standard space analysis. Additionally, regional T(1) histograms were more compact in real space, with smaller right-sided tails indicating lower partial volume errors compared to standard space analysis. Standard space analysis of quantitative MRI brain data introduces more partial volume effect errors biasing the analysis of quantitative data compared to analysis of the same dataset in real space. Copyright © 2011 Wiley-Liss, Inc.

Paying for volume: British Columbia's experiment with funding hospitals based on activity.

PubMed

Sutherland, Jason M; Liu, Guiping; Crump, R Trafford; Law, Michael

2016-11-01

For decades, Canadian hospitals have been funded using global budgets, a lump sum for providing care irrespective of the volume or mix of patients. In 2010, British Columbia (BC) introduced a controversial, but limited, form of activity-based funding (ABF) for hospitals. This study uses a quasi-experimental design to evaluate the impact of the introduction of ABF funding in the province. Our analysis used the population of patient-level acute hospitalization and day surgery discharge summaries from BC's acute hospitals from April 1, 2008 to March 31, 2013. Our outcome measures focused on both the intended and unintended impacts of ABF including the volume of cases, the efficiency of care, and the quality of care delivered. Our analysis used interrupted time series analysis. There was an increase in the volume of inpatient surgical activity associated with the implementation of ABF. The volume of medical cases dropped, and medical patients' lengths of stays increased. There were no changes in measures of quality. Hospitals' measurable responses to ABF policies on a number of key performance measures were mixed. Though BC's experiment with ABF was not associated with increases in hospital volumes for all types of care, the experience provides key lessons that small magnitude and short-term reforms are unlikely to change hospitals' behaviors quickly. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Surgeon specialization and operative mortality in United States: retrospective analysis

PubMed Central

Dalton, Maurice; Cutler, David M; Birkmeyer, John D; Chandra, Amitabh

2016-01-01

Objective To measure the association between a surgeon’s degree of specialization in a specific procedure and patient mortality. Design Retrospective analysis of Medicare data. Setting US patients aged 66 or older enrolled in traditional fee for service Medicare. Participants 25 152 US surgeons who performed one of eight procedures (carotid endarterectomy, coronary artery bypass grafting, valve replacement, abdominal aortic aneurysm repair, lung resection, cystectomy, pancreatic resection, or esophagectomy) on 695 987 patients in 2008-13. Main outcome measure Relative risk reduction in risk adjusted and volume adjusted 30 day operative mortality between surgeons in the bottom quarter and top quarter of surgeon specialization (defined as the number of times the surgeon performed the specific procedure divided by his/her total operative volume across all procedures). Results For all four cardiovascular procedures and two out of four cancer resections, a surgeon’s degree of specialization was a significant predictor of operative mortality independent of the number of times he or she performed that procedure: carotid endarterectomy (relative risk reduction between bottom and top quarter of surgeons 28%, 95% confidence interval 0% to 48%); coronary artery bypass grafting (15%, 4% to 25%); valve replacement (46%, 37% to 53%); abdominal aortic aneurysm repair (42%, 29% to 53%); lung resection (28%, 5% to 46%); and cystectomy (41%, 8% to 63%). In five procedures (carotid endarterectomy, valve replacement, lung resection, cystectomy, and esophagectomy), the relative risk reduction from surgeon specialization was greater than that from surgeon volume for that specific procedure. Furthermore, surgeon specialization accounted for 9% (coronary artery bypass grafting) to 100% (cystectomy) of the relative risk reduction otherwise attributable to volume in that specific procedure. Conclusion For several common procedures, surgeon specialization was an important predictor of operative mortality independent of volume in that specific procedure. When selecting a surgeon, patients, referring physicians, and administrators assigning operative workload may want to consider a surgeon’s procedure specific volume as well as the degree to which a surgeon specializes in that procedure. PMID:27444190

Volumetric analysis of chronic maxillary atelectasis.

PubMed

Lin, Giant C; Sedaghat, Ahmad R; Bleier, Benjamin S; Holbrook, Eric H; Busaba, Nicolas Y; Yoon, Michael K; Gray, Stacey T

2015-01-01

The relationship between orbit and maxillary sinus volumes in patients with chronic maxillary atelectasis (CMA), commonly known as silent sinus syndrome if enophthalmos is present, is poorly understood. A retrospective review of 22 patients who underwent endoscopic sinus surgery (ESS) for CMA from 2005 to 2013 was performed. Computed tomography (CT) images were analyzed using OsiriX 5.8.2 software for volumetric analysis of the orbit and maxillary sinus at presentation and after surgical treatment with ESS. Pretreatment mean orbit volumes on the diseased side (DS) and the contralateral side (CS) were 29.22 and 26.50 mL, respectively (p < 0.001); mean sinus volumes on the DS and CS were 8.51 and 17.20 mL, respectively (p < 0.001); and pretreatment mean midorbit heights (MOHs) on the DS and CS were 3.39 cm and 3.07 cm, respectively (p < 0.001). The percent decrease in sinus volume on the DS compared to that on the CS did not correlate significantly with the percent orbit-volume increase. Enophthalmos was present in nine (41%) patients, and diplopia was present in three (14%) patients. The measured degree of increased orbit volume and decreased sinus volume secondary to CMA did not significantly predict the presence of enophthalmos at presentation. Seven patients underwent sinus CT more than 6 months after ESS. In these patients, orbit volume on the DS decreased from 29.67 to 27.52 mL (p = 0.005), and sinus volume on the DS increased from 9.78 to 11.84 mL (p = 0.08). Volumetric analysis is a powerful and novel method for objectively demonstrating the degree of orbit expansion and maxillary sinus contraction seen with CMA. Spontaneous maxillary sinus expansion and a decrease in orbit volume can occur after ESS, but post-ESS volumes do not return to the normal volume of the CS.

Sediment Transportation Induced by Deep-Seated Landslides in a Debris Flow Basin in Taiwan

NASA Astrophysics Data System (ADS)

Lin, Meei Ling; Chen, Te Wei; Chen, Yong Sheng; Sin Jhuang, Han

2016-04-01

Typhoon Morakot brought huge amount of rainfall to the southern Taiwan in 2009 and caused severe landslides and debris flow hazard. After Typhoon Morakot, it was found that the volume of sediment transported by the debris flow and its effects on the affected area were much more significant compared to previous case history, which may due to the huge amount of rainfall causing significant deep-seated landslides in the basin. In this study, the effects and tendency of the sediment transportation in a river basin following deep-seated landslides caused by typhoon Morakot were evaluated. We used LiDAR, DEM, and aerial photo to identify characteristics of deep-seated landslides in a debris flow river basin, KSDF079 in Liuoguey District, Kaohsiung City, Taiwan. Eight deep-seated landslides were identified in the basin. To estimate the potential landslide volume associated with the deep-seated landslides, the stability analysis was conducted to locate the critical sliding surface, and the potential landside volume was estimated based on the estimation equation proposed by the International Geotechnical Societies' UNESCO Working Party on World Landslide Inventory (WP/WLI, 1990). The total potential landslide volume of the eight deep-seated landslides in KSDF079 basin was about 28,906,856 m3. Topographic analysis was performed by using DEM before and LiDAR derived DEM after typhoon Morakot to calculate the landslide volume transported. The result of erosion volume and deposition volume lead to a run out volume of 5,832,433 m3. The results appeared to consist well with the field condition and aerial photo. Comparing the potential landslide volume and run out volume of eight deep-seated landslides, it was found that the remaining potential landslide volume was about 80%. Field investigation and topographic analysis of the KSDF079 debris flow revealed that a significant amount of sediment deposition remained in the river channel ranging from the middle to the downstream section of the channel, and the channel has been widen. Such large proportion of landslide volume remained in the basin on deep-seated landslide scars and debris flow river channel would likely to cause further debris transportation in the future events. The stability analysis used in this study provided a feasible method and satisfactory results for estimating sediment volume transportation associated with the deep-seated landslides in the study area. Combination of the stability analysis results and the topographic analysis provided estimation of sediment transportation caused by the deep-seated landslides, and trend variation of further sediment transport of the basin, which could provide vital information for hazard mitigation. Keyword: deep-seated landslide, sediment transport, DEM, LiDAR, stability analysis

Dispersion of a Nanoliter Bolus in Microfluidic Co-Flow.

PubMed

Conway, A J; Saadi, W M; Sinatra, F L; Kowalski, G; Larson, D; Fiering, J

2014-03-01

Microfluidic systems enable reactions and assays on the scale of nanoliters. However, at this scale nonuniformities in sample delivery become significant. To determine the fundamental minimum sample volume required for a particular device, a detailed understanding of mass transport is required. Co-flowing laminar streams are widely used in many devices, but typically only in the steady-state. Because establishing the co-flow steady-state consumes excess sample volume and time, there is a benefit to operating devices in the transient state, which predominates as the volume of the co-flow reactor decreases. Analysis of the co-flow transient has been neglected thus far. In this work we describe the fabrication of a pneumatically controlled microfluidic injector constructed to inject a discrete 50nL bolus into one side of a two-stream co-flow reactor. Using dye for image analysis, injections were performed at a range of flow rates from 0.5-10μL/min, and for comparison we collected the co-flow steady-state data for this range. The results of the image analysis were also compared against theory and simulations for device validation. For evaluation, we established a metric that indicates how well the mass distribution in the bolus injection approximates steady-state co-flow. Using such analysis, transient-state injections can approximate steady-state conditions within predefined errors, allowing straight forward measurements to be performed with reduced reagent consumption.

Automatic Perceptual Color Map Generation for Realistic Volume Visualization

PubMed Central

Silverstein, Jonathan C.; Parsad, Nigel M.; Tsirline, Victor

2008-01-01

Advances in computed tomography imaging technology and inexpensive high performance computer graphics hardware are making high-resolution, full color (24-bit) volume visualizations commonplace. However, many of the color maps used in volume rendering provide questionable value in knowledge representation and are non-perceptual thus biasing data analysis or even obscuring information. These drawbacks, coupled with our need for realistic anatomical volume rendering for teaching and surgical planning, has motivated us to explore the auto-generation of color maps that combine natural colorization with the perceptual discriminating capacity of grayscale. As evidenced by the examples shown that have been created by the algorithm described, the merging of perceptually accurate and realistically colorized virtual anatomy appears to insightfully interpret and impartially enhance volume rendered patient data. PMID:18430609

In vivo MRS and MRSI: Performance analysis, measurement considerations and evaluation of metabolite concentration images

NASA Astrophysics Data System (ADS)

Vikhoff-Baaz, Barbro

2000-10-01

The doctoral thesis concerns development, evaluation and performance of quality assessment methods for volume- selection methods in 31P and 1H MR spectroscopy (MRS). It also contains different aspects of the measurement procedure for 1H MR spectroscopic imaging (MRSI) with application on the human brain, image reconstruction of the MRSI images and evaluation methods for lateralization of temporal lobe epilepsy (TLE). Two complementary two-compartment phantoms and evaluation methods for quality assessment of 31P MRS in small-bore MR systems were presented. The first phantom consisted of an inner cube inside a sphere phantom where measurements with and without volume selection where compared for various VOI sizes. The multi-centre showed that the evaluated parameters provide useful information of the performance of volume-selective MRS at the MR system. The second phantom consisted of two compartments divided by a very thin wall and was found useful for measurements of the appearance and position of the VOI profile in specific gradient directions. The second part concerned 1H MRS and MRSI of whole-body MR systems. Different factors that may degrade or complicate the measurement procedure like for MRSI were evaluated, e.g. the volume selection performance, contamination, susceptibility and motion. Two interpolation methods for reconstruction of MRSI images were compared. Measurements and computer simulations showed that Fourier interpolation correctly visualizes the information inherent in the data set, while the results were dependent on the position of the object relative the original matrix using Cubic spline interpolation. Application of spatial filtering may improve the image representation of the data. Finally, 1H MRSI was performed on healthy volunteers and patients with temporal lobe epilepsy (TLE). Metabolite concentration images were used for lateralization of TLE, where the signal intensity in the two hemispheres were compared. Visual analysis of the metabolite concentration images can, with high accuracy, be used for lateralization in routine examinations. Analysis from measurements with region-of-interests (ROI) in different locations gives quantitative information about the degree of signal loss and the spatial distribution.

SCALE: A modular code system for performing standardized computer analyses for licensing evaluation. Functional modules F1--F8 -- Volume 2, Part 1, Revision 4

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

Greene, N.M.; Petrie, L.M.; Westfall, R.M.

SCALE--a modular code system for Standardized Computer Analyses Licensing Evaluation--has been developed by Oak Ridge National Laboratory at the request of the US Nuclear Regulatory Commission. The SCALE system utilizes well-established computer codes and methods within standard analysis sequences that (1) allow an input format designed for the occasional user and/or novice, (2) automate the data processing and coupling between modules, and (3) provide accurate and reliable results. System development has been directed at problem-dependent cross-section processing and analysis of criticality safety, shielding, heat transfer, and depletion/decay problems. Since the initial release of SCALE in 1980, the code system hasmore » been heavily used for evaluation of nuclear fuel facility and package designs. This revision documents Version 4.2 of the system. The manual is divided into three volumes: Volume 1--for the control module documentation; Volume 2--for functional module documentation; and Volume 3--for documentation of the data libraries and subroutine libraries.« less

Determination of Normal Distribution of Distended Colon Volumes to Guide Performance of Colonic Imaging With Fluid Distention.

PubMed

Zheng, Karen S; Small, William C; Mittal, Pardeep K; Cai, Qingpo; Kang, Jian; Moreno, Courtney C

2016-01-01

The purpose was to determine the normal distribution of distended colon volumes as a guide for rectal contrast material administration protocols. All computed tomography colonography studies performed at Emory University Hospital, Atlanta, Georgia, between January 2009 and January 2015, were reviewed retrospectively. In total, 85 subjects were included in the analysis (64% [54 of 85] female and 36% [31 of 85] male). Mean patient age was 65 years (range: 42-86y). Distended colon volumes were determined from colon length and transaxial diameter measurements made using a 3-dimensional workstation. Age, sex, race, height, weight, and body mass index were recorded. The normal distributions of distended colon volumes and lengths were determined. Correlations between colonic volume and colonic length, and demographic variables were assessed. Mean colon volume was 2.1L (range: 0.7-4.4L). Nearly, 17% of patients had a distended colonic volume of >3L. Mean colon length was 197cm (range: 118-285cm). A weak negative correlation was found between age and colonic volume (r = -0.221; P = 0.04). A weak positive correlation was found between body mass index and colonic length (r = 0.368; P = 0.007). Otherwise, no significant correlations were found for distended colonic volume or length and demographic variables. In conclusion, an average of approximately 2L of contrast material may be necessary to achieve full colonic opacification. This volume is larger than previously reported volumes (0.8-1.5L) for rectal contrast material administration protocols. Copyright © 2015 Mosby, Inc. All rights reserved.

Decision-making performance in Parkinson's disease correlates with lateral orbitofrontal volume.

PubMed

Kobayakawa, Mutsutaka; Tsuruya, Natsuko; Kawamura, Mitsuru

2017-01-15

Patients with Parkinson's disease (PD) exhibit poor decision-making, and the underlying neural correlates are unclear. We used voxel-based morphometry with Diffeomorphic Anatomical Registration through Exponentiated Lie algebra to examine this issue. The decision-making abilities of 20 patients with PD and 37 healthy controls (HCs) were measured with a computerized Iowa Gambling Task (IGT). We assessed the local gray matter volumes of the patients and HCs and their correlations with decision-making performance, disease duration, disease severity, and anti-Parkinsonism medication dose. Compared with the HCs, the patients with PD exhibited poor IGT performances. The gray matter volumes in the medial orbitofrontal cortex, left inferior temporal cortex, and right middle frontal gyrus were decreased in the patients. Results in the regression analysis showed that lateral orbitofrontal volume correlated with performance in the IGT in PD. Regions that correlated with disease duration, severity, and medication dose did not overlap with orbitofrontal regions. Our results indicate that the lateral and medial orbitofrontal cortex are related to decision-making in PD patients. Since the medial orbitofrontal cortex is shown to be involved in monitoring reward, reward monitoring seems to be impaired as a whole in PD patients. Meanwhile, the lateral region is related to evaluation of punishment, which is considered to have an influence on individual differences in decision-making performance in PD patients. Copyright © 2016 Elsevier B.V. All rights reserved.

A High-Performance Liquid Chromatography-Based Screening Method for the Analysis of Atrazine, Alachlor, and Ten of Their Transformation Products

USGS Publications Warehouse

Schroyer, B.R.; Capel, P.D.

1996-01-01

A high-performance liquid Chromatography (HPLC) method is presented for the for the fast, quantitative analysis of the target analytes in water and in low organic-carbon, sandy soils that are known to be contaminated with the parent herbicides. Speed and ease of sample preparation was prioritized above minimizing detection limits. Soil samples were extracted using 80:20 methanol:water (volume:volume). Water samples (50 ??L) were injected directly into the HPLC without prior preparation. Method quantification limits for soil samples (10 g dry weight) and water samples ranged from 20 to 110 ng/g and from 20 to 110 ??g/L for atrazine and its transformation products and from 80 to 320 ng/g and from 80 to 320 ??g/L for alachlor and its transformation products, respectively.

A semi-automatic method for left ventricle volume estimate: an in vivo validation study

NASA Technical Reports Server (NTRS)

Corsi, C.; Lamberti, C.; Sarti, A.; Saracino, G.; Shiota, T.; Thomas, J. D.

2001-01-01

This study aims to the validation of the left ventricular (LV) volume estimates obtained by processing volumetric data utilizing a segmentation model based on level set technique. The validation has been performed by comparing real-time volumetric echo data (RT3DE) and magnetic resonance (MRI) data. A validation protocol has been defined. The validation protocol was applied to twenty-four estimates (range 61-467 ml) obtained from normal and pathologic subjects, which underwent both RT3DE and MRI. A statistical analysis was performed on each estimate and on clinical parameters as stroke volume (SV) and ejection fraction (EF). Assuming MRI estimates (x) as a reference, an excellent correlation was found with volume measured by utilizing the segmentation procedure (y) (y=0.89x + 13.78, r=0.98). The mean error on SV was 8 ml and the mean error on EF was 2%. This study demonstrated that the segmentation technique is reliably applicable on human hearts in clinical practice.

Implementing DBS methodology for the determination of Compound A in monkey blood: GLP method validation and investigation of the impact of blood spreading on performance.

PubMed

Fan, Leimin; Lee, Jacob; Hall, Jeffrey; Tolentino, Edward J; Wu, Huaiqin; El-Shourbagy, Tawakol

2011-06-01

This article describes validation work for analysis of an Abbott investigational drug (Compound A) in monkey whole blood with dried blood spots (DBS). The impact of DBS spotting volume on analyte concentration was investigated. The quantitation range was between 30.5 and 10,200 ng/ml. Accuracy and precision of quality controls, linearity of calibration curves, matrix effect, selectivity, dilution, recovery and multiple stabilities were evaluated in the validation, and all demonstrated acceptable results. Incurred sample reanalysis was performed with 57 out of 58 samples having a percentage difference (versus the mean value) less than 20%. A linear relationship between the spotting volume and the spot area was drawn. The influence of spotting volume on concentration was discussed. All validation results met good laboratory practice acceptance requirements. Radial spreading of blood on DBS cards can be a factor in DBS concentrations at smaller spotting volumes.

Quantitative analysis of the renal aging in rats. Stereological study.

PubMed

Melchioretto, Eduardo Felippe; Zeni, Marcelo; Veronez, Djanira Aparecida da Luz; Martins, Eduardo Lopes; Fraga, Rogério de

2016-05-01

To evaluate the renal function and the renal histological alterations through the stereology and morphometrics in rats submitted to the natural process of aging. Seventy two Wistar rats, divided in six groups. Each group was sacrificed in a different age: 3, 6, 9, 12, 18 and 24 months. It was performed right nephrectomy, stereological and morphometric analysis of the renal tissue (renal volume and weight, density of volume (Vv[glom]) and numerical density (Nv[glom]) of the renal glomeruli and average glomerular volume (Vol[glom])) and also it was evaluated the renal function for the dosage of serum creatinine and urea. There was significant decrease of the renal function in the oldest rats. The renal volume presented gradual increase during the development of the rats with the biggest values registered in the group of animals at 12 months of age and significant progressive decrease in older animals. Vv[glom] presented statistically significant gradual reduction between the groups and the Nv[glom] also decreased significantly. The renal function proved to be inferior in senile rats when compared to the young rats. The morphometric and stereological analysis evidenced renal atrophy, gradual reduction of the volume density and numerical density of the renal glomeruli associated to the aging process.

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

PubMed

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

2016-12-01

Multitasking refers to the ability to organize assorted tasks efficiently in a short period of time, which plays an important role in daily life. However, the structural neural correlates of multitasking performance remain unclear. The present study aimed at exploring the brain regions associated with multitasking performance using global correlation analysis. Twenty-six healthy participants first underwent structural brain scans and then performed the modified Six Element Test, which required participants to attempt six subtasks in 10 min while obeying a specific rule. Voxel-based morphometry of the whole brain was used to detect the structural correlates of multitasking ability. Grey matter volume of the anterior cingulate cortex (ACC) was positively correlated with the overall performance and time monitoring in multitasking. In addition, white matter volume of the anterior thalamic radiation (ATR) was also positively correlated with time monitoring during multitasking. Other related brain regions associated with multitasking included the superior frontal gyrus, the inferior occipital gyrus, the lingual gyrus, and the inferior longitudinal fasciculus. No significant correlation was found between grey matter volume of the prefrontal cortex (Brodmann Area 10) and multitasking performance. Using a global correlation analysis to examine various aspects of multitasking performance, this study provided new insights into the structural neural correlates of multitasking ability. In particular, the ACC was identified as an important brain region that played both a general and a specific time-monitoring role in multitasking, extending the role of the ACC from lesioned populations to healthy populations. The present findings also support the view that the ATR may influence multitasking performance by affecting time-monitoring abilities. © 2016 The Institute of Psychology, Chinese Academy of Sciences and John Wiley & Sons Australia, Ltd.

Scalable Performance Measurement and Analysis

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

Gamblin, Todd

2009-01-01

Concurrency levels in large-scale, distributed-memory supercomputers are rising exponentially. Modern machines may contain 100,000 or more microprocessor cores, and the largest of these, IBM's Blue Gene/L, contains over 200,000 cores. Future systems are expected to support millions of concurrent tasks. In this dissertation, we focus on efficient techniques for measuring and analyzing the performance of applications running on very large parallel machines. Tuning the performance of large-scale applications can be a subtle and time-consuming task because application developers must measure and interpret data from many independent processes. While the volume of the raw data scales linearly with the number ofmore » tasks in the running system, the number of tasks is growing exponentially, and data for even small systems quickly becomes unmanageable. Transporting performance data from so many processes over a network can perturb application performance and make measurements inaccurate, and storing such data would require a prohibitive amount of space. Moreover, even if it were stored, analyzing the data would be extremely time-consuming. In this dissertation, we present novel methods for reducing performance data volume. The first draws on multi-scale wavelet techniques from signal processing to compress systemwide, time-varying load-balance data. The second uses statistical sampling to select a small subset of running processes to generate low-volume traces. A third approach combines sampling and wavelet compression to stratify performance data adaptively at run-time and to reduce further the cost of sampled tracing. We have integrated these approaches into Libra, a toolset for scalable load-balance analysis. We present Libra and show how it can be used to analyze data from large scientific applications scalably.« less

Department of Defense Fiscal Year (FY) 2005 Budget Estimates. Research, Development, Test and Evaluation, Defense-Wide. Volume 1 - Defense Advanced Research Projects Agency

DTIC Science & Technology

2004-02-01

UNCLASSIFIED − Conducted experiments to determine the usability of general-purpose anomaly detection algorithms to monitor a large, complex military...reaction and detection modules to perform tailored analysis sequences to monitor environmental conditions, health hazards and physiological states...scalability of lab proven anomaly detection techniques for intrusion detection in real world high volume environments. Narrative Title FY 2003

Performance analysis of CCSDS path service

NASA Technical Reports Server (NTRS)

Johnson, Marjory J.

1989-01-01

A communications service, called Path Service, is currently being developed by the Consultative Committee for Space Data Systems (CCSDS) to provide a mechanism for the efficient transmission of telemetry data from space to ground for complex space missions of the future. This is an important service, due to the large volumes of telemetry data that will be generated during these missions. A preliminary analysis of performance of Path Service is presented with respect to protocol-processing requirements and channel utilization.

A Review of Models of Cost and Training Effectiveness Analysis (CTEA). Volume 1. Training Effectiveness Analysis

DTIC Science & Technology

1987-10-01

19 treated in interaction with each other and the hardware and software design. The authors point out some of the inadequacies in HP technologies and...life cycle costs recognition performance on secondary tasks effort/efficiency number of wins ( gaming tasks) number of instructors needed amount of...student interacts with this material in real time via a terminal and display system. The computer performs many functions, such as diagnose student

MDCT quantification is the dominant parameter in decision–making regarding chest tube drainage for stable patients with traumatic pneumothorax

PubMed Central

Cai, Wenli; Lee, June-Goo; Fikry, Karim; Yoshida, Hiroyuki; Novelline, Robert; de Moya, Marc

2013-01-01

It is commonly believed that the size of a pneumothorax is an important determinant of treatment decision, in particular regarding whether chest tube drainage (CTD) is required. However, the volumetric quantification of pneumothoraces has not routinely been performed in clinics. In this paper, we introduced an automated computer-aided volumetry (CAV) scheme for quantification of volume of pneumothoraces in chest multi-detect CT (MDCT) images. Moreover, we investigated the impact of accurate volume of pneumothoraces in the improvement of the performance in decision-making regarding CTD in the management of traumatic pneumothoraces. For this purpose, an occurrence frequency map was calculated for quantitative analysis of the importance of each clinical parameter in the decision-making regarding CTD by a computer simulation of decision-making using a genetic algorithm (GA) and a support vector machine (SVM). A total of 14 clinical parameters, including volume of pneumothorax calculated by our CAV scheme, was collected as parameters available for decision-making. The results showed that volume was the dominant parameter in decision-making regarding CTD, with an occurrence frequency value of 1.00. The results also indicated that the inclusion of volume provided the best performance that was statistically significant compared to the other tests in which volume was excluded from the clinical parameters. This study provides the scientific evidence for the application of CAV scheme in MDCT volumetric quantification of pneumothoraces in the management of clinically stable chest trauma patients with traumatic pneumothorax. PMID:22560899

Brain structure correlates of component reading processes: implications for reading disability.

PubMed

Phinney, Erin; Pennington, Bruce F; Olson, Richard; Filley, Christopher M; Filipek, Pauline A

2007-08-01

Brain structures implicated in developmental dyslexia (reading disability - RD) vary greatly across structural magnetic resonance imaging (MRI) studies due to methodological differences regarding the definition of RD and the exact measurements of a specific brain structure. The current study attempts to resolve some of those methodological concerns by examining brain volume as it relates to components of proposed RD subtypes. We performed individual regression analyses on total cerebral volume, neocortical volume, subcortical volume, 9 neo-cortical structures and 2 sub-cortical structures. These analyses used three dimensions of reading, phonemic ability (PA), orthographic ability, and rapid naming (RN) ability, while accounting for total cerebral volume, age, and performance IQ (PIQ). Primary analyses included membership to a group (poor reader vs. good reader) in the analysis. The result was a significant interaction between PA and reading ability as it predicts total cerebral volume. Analyses revealed that poor readers lacked a relationship between PA and brain size, but that good readers had a significant positive relationship. This pattern of interaction was not present for the other two reading component factors. These findings bring into question the general belief that individuals with RD are at the low end of a reading ability distribution and do not have a unique disorder. Additional analyses revealed only a few significant relationships between brain size and task performance, most notably a positive correlation between orthographic ability and the angular gyrus (AG), as well as a negative correlation between RN ability and the parietal operculum (PO).

Pancreatic mucinous cystic neoplasm size using CT volumetry, spherical and ellipsoid formulas: validation study.

PubMed

Chalian, Hamid; Seyal, Adeel Rahim; Rezai, Pedram; Töre, Hüseyin Gürkan; Miller, Frank H; Bentrem, David J; Yaghmai, Vahid

2014-01-10

The accuracy for determining pancreatic cyst volume with commonly used spherical and ellipsoid methods is unknown. The role of CT volumetry in volumetric assessment of pancreatic cysts needs to be explored. To compare volumes of the pancreatic cysts by CT volumetry, spherical and ellipsoid methods and determine their accuracy by correlating with actual volume as determined by EUS-guided aspiration. Setting This is a retrospective analysis performed at a tertiary care center. Patients Seventy-eight pathologically proven pancreatic cysts evaluated with CT and endoscopic ultrasound (EUS) were included. Design The volume of fourteen cysts that had been fully aspirated by EUS was compared to CT volumetry and the routinely used methods (ellipsoid and spherical volume). Two independent observers measured all cysts using commercially available software to evaluate inter-observer reproducibility for CT volumetry. The volume of pancreatic cysts as determined by various methods was compared using repeated measures analysis of variance. Bland-Altman plot and intraclass correlation coefficient were used to determine mean difference and correlation between observers and methods. The error was calculated as the percentage of the difference between the CT estimated volumes and the aspirated volume divided by the aspirated one. CT volumetry was comparable to aspirated volume (P=0.396) with very high intraclass correlation (r=0.891, P<0.001) and small mean difference (0.22 mL) and error (8.1%). Mean difference with aspirated volume and error were larger for ellipsoid (0.89 mL, 30.4%; P=0.024) and spherical (1.73 mL, 55.5%; P=0.004) volumes than CT volumetry. There was excellent inter-observer correlation in volumetry of the entire cohort (r=0.997, P<0.001). CT volumetry is accurate and reproducible. Ellipsoid and spherical volume overestimate the true volume of pancreatic cysts.

Independent Orbiter Assessment (IOA): Assessment of the extravehicular mobility unit, volume 2

NASA Technical Reports Server (NTRS)

Raffaelli, Gary G.

1988-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA effort performed an independent analysis of the Extravehicular Mobility Unit (EMU) hardware and system, generating draft failure modes criticalities and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The IOA results were then compared to the most recent proposed Post 51-L NASA FMEA/CIL baseline. A resolution of each discrepancy from the comparison was provided through additional analysis as required. This report documents the results of that comparison for the Orbiter EMU hardware. Volume 2 continues the presentation of IOA analysis worksheets and contains the potential critical items list and NASA FMEA to IOA worksheet cross references and recommendations.

ABC Analysis for Inventory Management: Bridging the Gap between Research and Classroom

ERIC Educational Resources Information Center

Ravinder, Handanhal; Misra, Ram B.

2014-01-01

ABC analysis is a well-established categorization technique based on the Pareto Principle for determining which items should get priority in the management of a company's inventory. In discussing this topic, today's operations management and supply chain textbooks focus on dollar volume as the sole criterion for performing the categorization. The…

New Directions in Library and Information Science Education. Final Report. Volume 2.11: Information Service Company Professional Competencies.

ERIC Educational Resources Information Center

Griffiths, Jose-Marie; And Others

This document contains validated activities and competencies needed by information professionals working in an information service company. The activities and competencies are organized according to the functions which information professionals in such companies perform: project management; reference/analysis of secondary data; research, analysis,…

Evaluation of Military Field-Water Quality. Volume 8. Performance of Mobile Water-Purification Unit (MWPU) and Pretreatment Components of the 600-GPH Reverse Osmosis Water Purification Unit (ROWPU), and Consideration of Reverse Osmosis (RO) Bypass, Potable-Water Disinfection, and Water-Quality Analysis Techniques

DTIC Science & Technology

1990-05-01

Health Risks in Potential Theaters of Operation for U.S. Military Forces. The nine volumes of this study contain a comprehensive assessment of the chemical...module. The percentage of total free chlorine ( hypochlorous acid , HOCl) plus hypochlorlte ion (OClN), measured by the Model 453 membrane sensor, varies...between the performances of the 600-Sph Reverse Osmosis Water Purification Unit (ROWPU) operated in the bypass node and ’the Mobile Water Purification

Fractional watt Vuillemier cryogenic refrigerator program engineering notebook. Volume 2: Stress analysis

NASA Technical Reports Server (NTRS)

Miller, W. S.

1974-01-01

A structural analysis performed on the 1/4-watt cryogenic refrigerator. The analysis covered the complete assembly except for the cooling jacket and mounting brackets. Maximum stresses, margin of safety, and natural frequencies were calculated for structurally loaded refrigerator components shown in assembly drawings. The stress analysis indicates that the design is satisfactory for the specified vibration environment, and the proof, burst, and normal operating loads.

CrossTalk: The Journal of Defense Software Engineering. Volume 19, Number 12, December 2006

DTIC Science & Technology

2006-12-01

Feature-Oriented Domain Analysis ( FODA ) FODA is a domain analysis and engineer- ing method that focuses on developing reusable assets [9]. By examining...Eliciting Security Requirements This article describes an approach for doing trade-off analysis among requirements elicitation methods. by Dr. Nancy R...high-level requirements are addressed and met in the requirements work products. 3. Unclear requirements Mitigation Perform requirements analysis and

The Shock and Vibration Digest. Volume 14, Number 12

DTIC Science & Technology

1982-12-01

to evaluate the uses of statistical energy analysis for determining sound transmission performance. Coupling loss factors were mea- sured and compared...measurements for the artificial (Also see No. 2623) cracks in mild-steel test pieces. 82-2676 Ihprovement of the Method of Statistical Energy Analysis for...eters, using a large number of free-response time histories In the application of the statistical energy analysis theory simultaneously in one analysis

Improving the performance of air-conditioning systems in an ASEAN (Association of South East Asian Nations) climate

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

Busch, J.F.; Warren, M.L.

1988-09-01

This paper describes an analysis of air conditioning performance under hot and humid tropical climate conditions appropriate to the Association of South East Asian Nations (ASEAN) countries. This region, with over 280 million people, has one of the fastest economic and energy consumption growth rates in the world. The work reported here is aimed at estimating the conservation potential derived from good design and control of air conditioning systems in commercial buildings. To test the performance of different air conditioning system types and control options, whole building energy performance was simulated using DOE-2. The 5100 m/sup 2/ (50,000 ft/sup 2/)more » prototype office building module was previously used in earlier commercial building energy standards analysis for Malaysia and Singapore. In general, the weather pattern for ASEAN countries is uniform, with hot and humid air masses known as ''monsoons'' dictating the weather patterns. Since a concentration of cities occurs near the tip of the Malay peninsula, hourly temperature, humidity, and wind speed data for Kuala Lumpur was used for the analysis. Because of the absence of heating loads in ASEAN regions, we have limited air conditioning configurations to two pipe fan coil, constant volume, variable air volume, powered induction, and ceiling bypass configurations. Control strategies were varied to determine the conservation potential in both energy use and peak electric power demands. Sensitivities including fan control, pre-cooling and night ventilation, supply air temperature control, zone temperature set point, ventilation and infiltration, daylighting and internal gains, and system sizing were examined and compared with a base case which was a variable air volume system with no reheat or economizer. Comfort issues, such as over-cooling and space humidity, were also examined.« less

Supercomputing '91; Proceedings of the 4th Annual Conference on High Performance Computing, Albuquerque, NM, Nov. 18-22, 1991

NASA Technical Reports Server (NTRS)

1991-01-01

Various papers on supercomputing are presented. The general topics addressed include: program analysis/data dependence, memory access, distributed memory code generation, numerical algorithms, supercomputer benchmarks, latency tolerance, parallel programming, applications, processor design, networks, performance tools, mapping and scheduling, characterization affecting performance, parallelism packaging, computing climate change, combinatorial algorithms, hardware and software performance issues, system issues. (No individual items are abstracted in this volume)

Independent Orbiter Assessment (IOA): Analysis of the Electrical Power Distribution and Control Subsystem, Volume 2

NASA Technical Reports Server (NTRS)

Schmeckpeper, K. R.

1987-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA approach features a top-down analysis of the hardware to determine failure modes, criticality, and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. This report documents the independent analysis results corresponding to the Orbiter Electrical Power Distribution and Control (EPD and C) hardware. The EPD and C hardware performs the functions of distributing, sensing, and controlling 28 volt DC power and of inverting, distributing, sensing, and controlling 117 volt 400 Hz AC power to all Orbiter subsystems from the three fuel cells in the Electrical Power Generation (EPG) subsystem. Volume 2 continues the presentation of IOA analysis worksheets and contains the potential critical items list.

A Human Factors Evaluation of a Methodology for Pressurized Crew Module Acceptability for Zero-Gravity Ingress of Spacecraft

NASA Technical Reports Server (NTRS)

Sanchez, Merri J.

2000-01-01

This project aimed to develop a methodology for evaluating performance and acceptability characteristics of the pressurized crew module volume suitability for zero-gravity (g) ingress of a spacecraft and to evaluate the operational acceptability of the NASA crew return vehicle (CRV) for zero-g ingress of astronaut crew, volume for crew tasks, and general crew module and seat layout. No standard or methodology has been established for evaluating volume acceptability in human spaceflight vehicles. Volume affects astronauts'ability to ingress and egress the vehicle, and to maneuver in and perform critical operational tasks inside the vehicle. Much research has been conducted on aircraft ingress, egress, and rescue in order to establish military and civil aircraft standards. However, due to the extremely limited number of human-rated spacecraft, this topic has been un-addressed. The NASA CRV was used for this study. The prototype vehicle can return a 7-member crew from the International Space Station in an emergency. The vehicle's internal arrangement must be designed to facilitate rapid zero-g ingress, zero-g maneuverability, ease of one-g egress and rescue, and ease of operational tasks in multiple acceleration environments. A full-scale crew module mockup was built and outfitted with representative adjustable seats, crew equipment, and a volumetrically equivalent hatch. Human factors testing was conducted in three acceleration environments using ground-based facilities and the KC-135 aircraft. Performance and acceptability measurements were collected. Data analysis was conducted using analysis of variance and nonparametric techniques.

Frequency spectrum analysis of finger photoplethysmographic waveform variability during haemodialysis.

PubMed

Javed, Faizan; Middleton, Paul M; Malouf, Philip; Chan, Gregory S H; Savkin, Andrey V; Lovell, Nigel H; Steel, Elizabeth; Mackie, James

2010-09-01

This study investigates the peripheral circulatory and autonomic response to volume withdrawal in haemodialysis based on spectral analysis of photoplethysmographic waveform variability (PPGV). Frequency spectrum analysis was performed on the baseline and pulse amplitude variabilities of the finger infrared photoplethysmographic (PPG) waveform and on heart rate variability extracted from the ECG signal collected from 18 kidney failure patients undergoing haemodialysis. Spectral powers were calculated from the low frequency (LF, 0.04-0.145 Hz) and high frequency (HF, 0.145-0.45 Hz) bands. In eight stable fluid overloaded patients (fluid removal of >2 L) not on alpha blockers, progressive reduction in relative blood volume during haemodialysis resulted in significant increase in LF and HF powers of PPG baseline and amplitude variability (P < 0.01), when expressed in mean-scaled units. The augmentation of LF powers in PPGV during haemodialysis may indicate the recovery and possibly further enhancement of peripheral sympathetic vascular modulation subsequent to volume unloading, whilst the increase in respiratory HF power in PPGV is most likely a sign of preload reduction. Spectral analysis of finger PPGV may provide valuable information on the autonomic vascular response to blood volume reduction in haemodialysis, and can be potentially utilized as a non-invasive tool for assessing peripheral circulatory control during routine dialysis procedure.

CT coronary angiography: impact of adapted statistical iterative reconstruction (ASIR) on coronary stenosis and plaque composition analysis.

PubMed

Fuchs, Tobias A; Fiechter, Michael; Gebhard, Cathérine; Stehli, Julia; Ghadri, Jelena R; Kazakauskaite, Egle; Herzog, Bernhard A; Husmann, Lars; Gaemperli, Oliver; Kaufmann, Philipp A

2013-03-01

To assess the impact of adaptive statistical iterative reconstruction (ASIR) on coronary plaque volume and composition analysis as well as on stenosis quantification in high definition coronary computed tomography angiography (CCTA). We included 50 plaques in 29 consecutive patients who were referred for the assessment of known or suspected coronary artery disease (CAD) with contrast-enhanced CCTA on a 64-slice high definition CT scanner (Discovery HD 750, GE Healthcare). CCTA scans were reconstructed with standard filtered back projection (FBP) with no ASIR (0 %) or with increasing contributions of ASIR, i.e. 20, 40, 60, 80 and 100 % (no FBP). Plaque analysis (volume, components and stenosis degree) was performed using a previously validated automated software. Mean values for minimal diameter and minimal area as well as degree of stenosis did not change significantly using different ASIR reconstructions. There was virtually no impact of reconstruction algorithms on mean plaque volume or plaque composition (e.g. soft, intermediate and calcified component). However, with increasing ASIR contribution, the percentage of plaque volume component between 401 and 500 HU decreased significantly (p < 0.05). Modern image reconstruction algorithms such as ASIR, which has been developed for noise reduction in latest high resolution CCTA scans, can be used reliably without interfering with the plaque analysis and stenosis severity assessment.

Multi-Modal Glioblastoma Segmentation: Man versus Machine

PubMed Central

Pica, Alessia; Schucht, Philippe; Beck, Jürgen; Verma, Rajeev Kumar; Slotboom, Johannes; Reyes, Mauricio; Wiest, Roland

2014-01-01

Background and Purpose Reproducible segmentation of brain tumors on magnetic resonance images is an important clinical need. This study was designed to evaluate the reliability of a novel fully automated segmentation tool for brain tumor image analysis in comparison to manually defined tumor segmentations. Methods We prospectively evaluated preoperative MR Images from 25 glioblastoma patients. Two independent expert raters performed manual segmentations. Automatic segmentations were performed using the Brain Tumor Image Analysis software (BraTumIA). In order to study the different tumor compartments, the complete tumor volume TV (enhancing part plus non-enhancing part plus necrotic core of the tumor), the TV+ (TV plus edema) and the contrast enhancing tumor volume CETV were identified. We quantified the overlap between manual and automated segmentation by calculation of diameter measurements as well as the Dice coefficients, the positive predictive values, sensitivity, relative volume error and absolute volume error. Results Comparison of automated versus manual extraction of 2-dimensional diameter measurements showed no significant difference (p = 0.29). Comparison of automated versus manual segmentation of volumetric segmentations showed significant differences for TV+ and TV (p<0.05) but no significant differences for CETV (p>0.05) with regard to the Dice overlap coefficients. Spearman's rank correlation coefficients (ρ) of TV+, TV and CETV showed highly significant correlations between automatic and manual segmentations. Tumor localization did not influence the accuracy of segmentation. Conclusions In summary, we demonstrated that BraTumIA supports radiologists and clinicians by providing accurate measures of cross-sectional diameter-based tumor extensions. The automated volume measurements were comparable to manual tumor delineation for CETV tumor volumes, and outperformed inter-rater variability for overlap and sensitivity. PMID:24804720

Enabling High-performance Interactive Geoscience Data Analysis Through Data Placement and Movement Optimization

NASA Astrophysics Data System (ADS)

Zhu, F.; Yu, H.; Rilee, M. L.; Kuo, K. S.; Yu, L.; Pan, Y.; Jiang, H.

2017-12-01

Since the establishment of data archive centers and the standardization of file formats, scientists are required to search metadata catalogs for data needed and download the data files to their local machines to carry out data analysis. This approach has facilitated data discovery and access for decades, but it inevitably leads to data transfer from data archive centers to scientists' computers through low-bandwidth Internet connections. Data transfer becomes a major performance bottleneck in such an approach. Combined with generally constrained local compute/storage resources, they limit the extent of scientists' studies and deprive them of timely outcomes. Thus, this conventional approach is not scalable with respect to both the volume and variety of geoscience data. A much more viable solution is to couple analysis and storage systems to minimize data transfer. In our study, we compare loosely coupled approaches (exemplified by Spark and Hadoop) and tightly coupled approaches (exemplified by parallel distributed database management systems, e.g., SciDB). In particular, we investigate the optimization of data placement and movement to effectively tackle the variety challenge, and boost the popularization of parallelization to address the volume challenge. Our goal is to enable high-performance interactive analysis for a good portion of geoscience data analysis exercise. We show that tightly coupled approaches can concentrate data traffic between local storage systems and compute units, and thereby optimizing bandwidth utilization to achieve a better throughput. Based on our observations, we develop a geoscience data analysis system that tightly couples analysis engines with storages, which has direct access to the detailed map of data partition locations. Through an innovation data partitioning and distribution scheme, our system has demonstrated scalable and interactive performance in real-world geoscience data analysis applications.

Intravoxel Incoherent Motion–derived Histogram Metrics for Assessment of Response after Combined Chemotherapy and Radiation Therapy in Rectal Cancer: Initial Experience and Comparison between Single-Section and Volumetric Analyses

PubMed Central

Vargas, Hebert Alberto; Lakhman, Yulia; Sudre, Romain; Do, Richard K. G.; Bibeau, Frederic; Azria, David; Assenat, Eric; Molinari, Nicolas; Pierredon, Marie-Ange; Rouanet, Philippe; Guiu, Boris

2016-01-01

Purpose To determine the diagnostic performance of intravoxel incoherent motion (IVIM) parameters and apparent diffusion coefficient (ADC) to assess response to combined chemotherapy and radiation therapy (CRT) in patients with rectal cancer by using histogram analysis derived from whole-tumor volumes and single-section regions of interest (ROIs). Materials and Methods The institutional review board approved this retrospective study of 31 patients with rectal cancer who underwent magnetic resonance (MR) imaging before and after CRT, including diffusion-weighted imaging with 34 b values prior to surgery. Patient consent was not required. ADC, perfusion-related diffusion fraction (f), slow diffusion coefficient (D), and fast diffusion coefficient (D*) were calculated on MR images acquired before and after CRT by using biexponential fitting. ADC and IVIM histogram metrics and median values were obtained by using whole-tumor volume and single-section ROI analyses. All ADC and IVIM parameters obtained before and after CRT were compared with histopathologic findings by using t tests with Holm-Sidak correction. Receiver operating characteristic curves were generated to evaluate the diagnostic performance of IVIM parameters derived from whole-tumor volume and single-section ROIs for prediction of histopathologic response. Results Extreme values aside, results of histogram analysis of ADC and IVIM were equivalent to median values for tumor response assessment (P > .06). Prior to CRT, none of the median ADC and IVIM diffusion metrics correlated with subsequent tumor response (P > .36). Median D and ADC values derived from either whole-volume or single-section analysis increased significantly after CRT (P ≤ .01) and were significantly higher in good versus poor responders (P ≤ .02). Median IVIM f and D* values did not significantly change after CRT and were not associated with tumor response to CRT (P > .36). Interobserver agreement was excellent for whole-tumor volume analysis (range, 0.91–0.95) but was only moderate for single-section ROI analysis (range, 0.50–0.63). Conclusion Median D and ADC values obtained after CRT were useful for discrimination between good and poor responders. Histogram metrics did not add to the median values for assessment of tumor response. Volumetric analysis demonstrated better interobserver reproducibility when compared with single-section ROI analysis. © RSNA, 2016 Online supplemental material is available for this article. PMID:26919562

Comparison of echocardiographic and pressure-volume loop indices of systolic function in patients with single ventricle physiology: a preliminary report.

PubMed

Butts, Ryan J; Chowdhury, Shahryar M; Buckley, Jason; Hlavacek, Anthony M; Hsia, Tain Yen; Khambadkone, Sachin; Baker, G Hamilton

2015-01-01

Differences in ventricular geometry and physiology of patients with single ventricle anatomy complicate the application of traditional, noninvasive measurements of systolic function. We compared noninvasive measures of ventricular systolic function in single ventricle patients with invasive measures to evaluate their validity in this population. A secondary analysis of patients with single ventricle physiology enrolled in the multi-institutional research project, "multi-scale modeling of single ventricle hearts," was performed. Pressure-volume loops (PVLs) were recorded using microconductance catheters. Transthoracic echocardiogram and cardiac magnetic resonance imaging were performed on the same day. PVL indices of systolic function including end-systolic elastance (Ees), maximal rate of pressure increase (dP/dTmax), and stroke work indexed to end-diastolic volume (SW/EDV) were compared with noninvasive measures, including echocardiographic myocardial performance index (MPI), rate of pressure rise (AV valve dP/dT), isovolumic acceleration, longitudinal shortening fraction (longSF), and fractional area change (FAC). Fifteen patients had PVLs available for analysis. Eleven had a dominant right ventricle, three were status poststage 1 repair, five had superior cavopulmonary anastomosis, and seven had a total cavopulmonary anastomosis. FAC correlated with Ees (r = 0.69, P < .01), SW/EDV (r = 0.64, P = .01), and dP/dTmax (r = 0.59, P = .03). LongSF correlated with dP/dTmax (r = 0.61, P = .02) MPI, AV valve dP/dT, and isovolumic acceleration did not correlate with pressure-volume loop indices of systolic function. Obtaining PVLs via microconductance catheters can reliably be performed in the single ventricle population and serve as a method to validate echocardiographic indices in this high-risk population. Of the echocardiographic variables, FAC showed the best correlation with PVL indices. Future studies controlling for stage of palliation should be performed to further validate echocardiographic measures of systolic function in this patient population. © 2014 Wiley Periodicals, Inc.

On 3-D inelastic analysis methods for hot section components. Volume 1: Special finite element models

NASA Technical Reports Server (NTRS)

Nakazawa, S.

1988-01-01

This annual status report presents the results of work performed during the fourth year of the 3-D Inelastic Analysis Methods for Hot Section Components program (NASA Contract NAS3-23697). The objective of the program is to produce a series of new computer codes permitting more accurate and efficient 3-D analysis of selected hot section components, i.e., combustor liners, turbine blades and turbine vanes. The computer codes embody a progression of math models and are streamlined to take advantage of geometrical features, loading conditions, and forms of material response that distinguish each group of selected components. Volume 1 of this report discusses the special finite element models developed during the fourth year of the contract.

[Modeling and analysis of volume conduction based on field-circuit coupling].

PubMed

Tang, Zhide; Liu, Hailong; Xie, Xiaohui; Chen, Xiufa; Hou, Deming

2012-08-01

Numerical simulations of volume conduction can be used to analyze the process of energy transfer and explore the effects of some physical factors on energy transfer efficiency. We analyzed the 3D quasi-static electric field by the finite element method, and developed A 3D coupled field-circuit model of volume conduction basing on the coupling between the circuit and the electric field. The model includes a circuit simulation of the volume conduction to provide direct theoretical guidance for energy transfer optimization design. A field-circuit coupling model with circular cylinder electrodes was established on the platform of the software FEM3.5. Based on this, the effects of electrode cross section area, electrode distance and circuit parameters on the performance of volume conduction system were obtained, which provided a basis for optimized design of energy transfer efficiency.

Normal brain tissue volumes after long-term recovery in anorexia and bulimia nervosa.

PubMed

Wagner, Angela; Greer, Phil; Bailer, Ursula F; Frank, Guido K; Henry, Shannan E; Putnam, Karen; Meltzer, Carolyn C; Ziolko, Scott K; Hoge, Jessica; McConaha, Claire; Kaye, Walter H

2006-02-01

Individuals who are ill with anorexia (AN) and bulimia nervosa (BN) often have increased cerebrospinal fluid (CSF) volumes and decreased total gray and white matter volumes. It is unclear whether such disturbances persist after recovery from an eating disorder. Magnetic resonance imaging was performed on 40 women who were long-term recovered (>1 year no binging, purging, or restricting behaviors, normal weight, and menstrual cycles, not on medication) from restricting or binge/purging type AN or BN and 31 healthy control women (CW). Voxel-based morphometry (VBM) was used for data analysis. Recovered AN and BN subgroups were similar to CW in terms of cerebrospinal fluid (CSF) volume as well as total or regional gray or white matter volume. These findings suggest that structural brain abnormalities are reversible in individuals with eating disorders after long-term recovery.

The prediction of radiofrequency ablation zone volume using vascular indices of 3-dimensional volumetric colour Doppler ultrasound in an in vitro blood-perfused bovine liver model

PubMed Central

Lanctot, Anthony C; McCarter, Martin D; Roberts, Katherine M; Glueck, Deborah H; Dodd, Gerald D

2017-01-01

Objective: To determine the most reliable predictor of radiofrequency (RF) ablation zone volume among three-dimensional (3D) volumetric colour Doppler vascular indices in an in vitro blood-perfused bovine liver model. Methods: 3D colour Doppler volume data of the local hepatic parenchyma were acquired from 37 areas of 13 bovine livers connected to an in vitro oxygenated blood perfusion system. Doppler vascular indices of vascularization index (VI), flow index (FI) and vascularization flow index (VFI) were obtained from the volume data using 3D volume analysis software. 37 RF ablations were performed at the same locations where the ultrasound data were obtained from. The relationship of these vascular indices and the ablation zone volumes measured from gross specimens were analyzed using a general linear mixed model fit with random effect for liver and backward stepwise regression analysis. Results: FI was significantly associated with ablation zone volumes measured on gross specimens (p = 0.0047), but explained little of the variance (Rβ2 = 0.21). Ablation zone volume decreased by 0.23 cm3 (95% confidence interval: −0.38, −0.08) for every 1 increase in FI. Neither VI nor VFI was significantly associated with ablation zone volumes (p > 0.05). Conclusion: Although FI was associated with ablation zone volumes, it could not sufficiently explain their variability, limiting its clinical applicability. VI, FI and VFI are not clinically useful in the prediction of RF ablation zone volume in the liver. Advances in knowledge: Despite a significant association of FI with ablation zone volumes, VI, FI and VFI cannot be used for their prediction. Different Doppler vascular indices need to be investigated for clinical use. PMID:27925468

Extra-hippocampal subcortical limbic involvement predicts episodic recall performance in multiple sclerosis.

PubMed

Dineen, Robert A; Bradshaw, Christopher M; Constantinescu, Cris S; Auer, Dorothee P

2012-01-01

Episodic memory impairment is a common but poorly-understood phenomenon in multiple sclerosis (MS). We aim to establish the relative contributions of reduced integrity of components of the extended hippocampal-diencephalic system to memory performance in MS patients using quantitative neuroimaging. 34 patients with relapsing-remitting MS and 24 healthy age-matched controls underwent 3 T MRI including diffusion tensor imaging and 3-D T1-weighted volume acquisition. Manual fornix regions-of-interest were used to derive fornix fractional anisotropy (FA). Normalized hippocampal, mammillary body and thalamic volumes were derived by manual segmentation. MS subjects underwent visual recall, verbal recall, verbal recognition and verbal fluency assessment. Significant differences between MS patients and controls were found for fornix FA (0.38 vs. 0.46, means adjusted for age and fornix volume, P<.0005) and mammillary body volumes (age-adjusted means 0.114 ml vs. 0.126 ml, P<.023). Multivariate regression analysis identified fornix FA and mammillary bodies as predictor of visual recall (R(2) = .31, P = .003, P = .006), and thalamic volume as predictive of verbal recall (R(2) = .37, P<.0005). No limbic measures predicted verbal recognition or verbal fluency. These findings indicate that structural and ultrastructural alterations in subcortical limbic components beyond the hippocampus predict performance of episodic recall in MS patients with mild memory dysfunction.

A Solar Volumetric Receiver: Influence of Absorbing Cells Configuration on Device Thermal Performance

NASA Astrophysics Data System (ADS)

Yilbas, B. S.; Shuja, S. Z.

2017-01-01

Thermal performance of a solar volumetric receiver incorporating the different cell geometric configurations is investigated. Triangular, hexagonal, and rectangular absorbing cells are incorporated in the analysis. The fluid volume fraction, which is the ratio of the volume of the working fluid over the total volume of solar volumetric receiver, is introduced to assess the effect of cell size on the heat transfer rates in the receiver. In this case, reducing the fluid volume fraction corresponds to increasing cell size in the receiver. SiC is considered as the cell material, and air is used as the working fluid in the receiver. The Lambert's Beer law is incorporated to account for the solar absorption in the receiver. A finite element method is used to solve the governing equation of flow and heat transfer. It is found that the fluid volume fraction has significant effect on the flow field in the solar volumetric receiver, which also modifies thermal field in the working fluid. The triangular absorbing cell gives rise to improved effectiveness of the receiver and then follows the hexagonal and rectangular cells. The second law efficiency of the receiver remains high when hexagonal cells are used. This occurs for the fluid volume fraction ratio of 0.5.

Sequential Blood Filtration for Extracorporeal Circulation: Initial Results from a Proof-of-Concept Prototype.

PubMed

Herbst, Daniel P

2014-09-01

Micropore filters are used during extracorporeal circulation to prevent gaseous and solid particles from entering the patient's systemic circulation. Although these devices improve patient safety, limitations in current designs have prompted the development of a new concept in micropore filtration. A prototype of the new design was made using 40-μm filter screens and compared against four commercially available filters for performance in pressure loss and gross air handling. Pre- and postfilter bubble counts for 5- and 10-mL bolus injections in an ex vivo test circuit were recorded using a Doppler ultrasound bubble counter. Statistical analysis of results for bubble volume reduction between test filters was performed with one-way repeated-measures analysis of variance using Bonferroni post hoc tests. Changes in filter performance with changes in microbubble load were also assessed with dependent t tests using the 5- and 10-mL bolus injections as the paired sample for each filter. Significance was set at p < .05. All filters in the test group were comparable in pressure loss performance, showing a range of 26-33 mmHg at a flow rate of 6 L/min. In gross air-handling studies, the prototype showed improved bubble volume reduction, reaching statistical significance with three of the four commercial filters. All test filters showed decreased performance in bubble volume reduction when the microbubble load was increased. Findings from this research support the underpinning theories of a sequential arterial-line filter design and suggest that improvements in microbubble filtration may be possible using this technique.

Sequential Blood Filtration for Extracorporeal Circulation: Initial Results from a Proof-of-Concept Prototype

PubMed Central

Herbst, Daniel P.

2014-01-01

Abstract: Micropore filters are used during extracorporeal circulation to prevent gaseous and solid particles from entering the patient’s systemic circulation. Although these devices improve patient safety, limitations in current designs have prompted the development of a new concept in micropore filtration. A prototype of the new design was made using 40-μm filter screens and compared against four commercially available filters for performance in pressure loss and gross air handling. Pre- and postfilter bubble counts for 5- and 10-mL bolus injections in an ex vivo test circuit were recorded using a Doppler ultrasound bubble counter. Statistical analysis of results for bubble volume reduction between test filters was performed with one-way repeated-measures analysis of variance using Bonferroni post hoc tests. Changes in filter performance with changes in microbubble load were also assessed with dependent t tests using the 5- and 10-mL bolus injections as the paired sample for each filter. Significance was set at p < .05. All filters in the test group were comparable in pressure loss performance, showing a range of 26–33 mmHg at a flow rate of 6 L/min. In gross air-handling studies, the prototype showed improved bubble volume reduction, reaching statistical significance with three of the four commercial filters. All test filters showed decreased performance in bubble volume reduction when the microbubble load was increased. Findings from this research support the underpinning theories of a sequential arterial-line filter design and suggest that improvements in microbubble filtration may be possible using this technique. PMID:26357790

Development and Evaluation of a Semi-automated Segmentation Tool and a Modified Ellipsoid Formula for Volumetric Analysis of the Kidney in Non-contrast T2-Weighted MR Images.

PubMed

Seuss, Hannes; Janka, Rolf; Prümmer, Marcus; Cavallaro, Alexander; Hammon, Rebecca; Theis, Ragnar; Sandmair, Martin; Amann, Kerstin; Bäuerle, Tobias; Uder, Michael; Hammon, Matthias

2017-04-01

Volumetric analysis of the kidney parenchyma provides additional information for the detection and monitoring of various renal diseases. Therefore the purposes of the study were to develop and evaluate a semi-automated segmentation tool and a modified ellipsoid formula for volumetric analysis of the kidney in non-contrast T2-weighted magnetic resonance (MR)-images. Three readers performed semi-automated segmentation of the total kidney volume (TKV) in axial, non-contrast-enhanced T2-weighted MR-images of 24 healthy volunteers (48 kidneys) twice. A semi-automated threshold-based segmentation tool was developed to segment the kidney parenchyma. Furthermore, the three readers measured renal dimensions (length, width, depth) and applied different formulas to calculate the TKV. Manual segmentation served as a reference volume. Volumes of the different methods were compared and time required was recorded. There was no significant difference between the semi-automatically and manually segmented TKV (p = 0.31). The difference in mean volumes was 0.3 ml (95% confidence interval (CI), -10.1 to 10.7 ml). Semi-automated segmentation was significantly faster than manual segmentation, with a mean difference = 188 s (220 vs. 408 s); p < 0.05. Volumes did not differ significantly comparing the results of different readers. Calculation of TKV with a modified ellipsoid formula (ellipsoid volume × 0.85) did not differ significantly from the reference volume; however, the mean error was three times higher (difference of mean volumes -0.1 ml; CI -31.1 to 30.9 ml; p = 0.95). Applying the modified ellipsoid formula was the fastest way to get an estimation of the renal volume (41 s). Semi-automated segmentation and volumetric analysis of the kidney in native T2-weighted MR data delivers accurate and reproducible results and was significantly faster than manual segmentation. Applying a modified ellipsoid formula quickly provides an accurate kidney volume.

Space station data system analysis/architecture study. Task 2: Options development, DR-5. Volume 3: Programmatic options

NASA Technical Reports Server (NTRS)

1985-01-01

Task 2 in the Space Station Data System (SSDS) Analysis/Architecture Study is the development of an information base that will support the conduct of trade studies and provide sufficient data to make design/programmatic decisions. This volume identifies the preferred options in the programmatic category and characterizes these options with respect to performance attributes, constraints, costs, and risks. The programmatic category includes methods used to administrate/manage the development, operation and maintenance of the SSDS. The specific areas discussed include standardization/commonality; systems management; and systems development, including hardware procurement, software development and system integration, test and verification.

Pros and cons of practice-owned and office-based ambulatory surgery centers.

PubMed

Bert, J M

2000-01-01

A detailed feasibility analysis is imperative to ensure the success of a practice-owned ASC. Analysis of the payer mix and the market relating to surgical volume that can be performed at the ASC is imperative. If overbuilding, overequipping, and overstaffing are avoided and the group has adequate volume that can be managed at the ASC, the facility should be a success. Building a practice-owned ASC without an accurate and detailed financial feasibility and payer study can place the endeavor at risk. A well-planned, economically constructed and properly managed ASC will result in an efficient and successful ancillary service for the orthopedic group practice.

A detailed analysis of the erythropoietic control system in the human, squirrel, monkey, rat and mouse

NASA Technical Reports Server (NTRS)

Nordheim, A. W.

1985-01-01

The erythropoiesis modeling performed in support of the Body Fluid and Blood Volume Regulation tasks is described. The mathematical formulation of the species independent model, the solutions to the steady state and dynamic versions of the model, and the individual species specific models for the human, squirrel monkey, rat and mouse are outlined. A detailed sensitivity analysis of the species independent model response to parameter changes and how those responses change from species to species is presented. The species to species response to a series of simulated stresses directly related to blood volume regulation during space flight is analyzed.

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

Wang Shulian; Liao Zhongxing; Vaporciyan, Ara A.

Purpose: To assess the association of clinical and especially dosimetric factors with the incidence of postoperative pulmonary complications among esophageal cancer patients treated with concurrent chemoradiation therapy followed by surgery. Method and Materials: Data from 110 esophageal cancer patients treated between January 1998 and December 2003 were analyzed retrospectively. All patients received concurrent chemoradiotherapy followed by surgery; 72 patients also received irinotecan-based induction chemotherapy. Concurrent chemotherapy was 5-fluorouracil-based and in 97 cases included taxanes. Radiotherapy was delivered to a total dose of 41.4-50.4 Gy at 1.8-2.0 Gy per fraction with a three-dimensional conformal technique. Surgery (three-field, Ivor-Lewis, or transhiatal esophagectomy)more » was performed 27-123 days (median, 45 days) after completion of radiotherapy. The following dosimetric parameters were generated from the dose-volume histogram (DVH) for total lung: lung volume, mean dose to lung, relative and absolute volumes of lung receiving more than a threshold dose (relative V{sub dose} and absolute V{sub dose}), and absolute volume of lung receiving less than a threshold dose (volume spared, or VS{sub dose}). Occurrence of postoperative pulmonary complications, defined as pneumonia or acute respiratory distress syndrome (ARDS) within 30 days after surgery, was the endpoint for all analyses. Fisher's exact test was used to investigate the relationship between categorical factors and incidence of postoperative pulmonary complications. Logistic analysis was used to analyze the relationship between continuous factors (e.g., V{sub dose} or VS{sub dose}) and complication rate. Logistic regression with forward stepwise inclusion of factors was used to perform multivariate analysis of those factors having univariate significance (p < 0.05). The Mann-Whitney test was used to compare length of hospital stay in patients with and without lung complications and to compare lung volumes, VS5 values, and absolute and relative V5 values in male vs. female patients. Pearson correlation analysis was used to determine correlations between dosimetric factors. Results: Eighteen (16.4%) of the 110 patients developed postoperative pulmonary complications. Two of these died of progressive pneumonia. Hospitalizations were significantly longer for patients with postoperative pulmonary complications than for those without (median, 15 days vs. 11 days, p = 0.003). On univariate analysis, female gender (p = 0.017), higher mean lung dose (p = 0.036), higher relative volume of lung receiving {>=}5 Gy (V5) (p = 0.023), and smaller volumes of lung spared from doses {>=}5-35 Gy (VS5-VS35) (p < 0.05) were all significantly associated with an increased incidence of postoperative pulmonary complications. No other clinical factors were significantly associated with the incidence of postoperative pulmonary complications in this cohort. On multivariate analysis, the volume of lung spared from doses {>=}5 Gy (VS5) was the only significant independent factor associated with postoperative pulmonary complications (p = 0.005). Conclusions: Dosimetric factors but not clinical factors were found to be strongly associated with the incidence of postoperative pulmonary complications in this cohort of esophageal cancer patients treated with concurrent chemoradiation plus surgery. The volume of the lung spared from doses of {>=}5 Gy was the only independent dosimetric factor in multivariate analysis. This suggests that ensuring an adequate volume of lung unexposed to radiation might reduce the incidence of postoperative pulmonary complications.« less

Investigation of clinical and dosimetric factors associated with postoperative pulmonary complications in esophageal cancer patients treated with concurrent chemoradiotherapy followed by surgery.

PubMed

Wang, Shu-lian; Liao, Zhongxing; Vaporciyan, Ara A; Tucker, Susan L; Liu, Helen; Wei, Xiong; Swisher, Stephen; Ajani, Jaffer A; Cox, James D; Komaki, Ritsuko

2006-03-01

To assess the association of clinical and especially dosimetric factors with the incidence of postoperative pulmonary complications among esophageal cancer patients treated with concurrent chemoradiation therapy followed by surgery. Data from 110 esophageal cancer patients treated between January 1998 and December 2003 were analyzed retrospectively. All patients received concurrent chemoradiotherapy followed by surgery; 72 patients also received irinotecan-based induction chemotherapy. Concurrent chemotherapy was 5-fluorouracil-based and in 97 cases included taxanes. Radiotherapy was delivered to a total dose of 41.4-50.4 Gy at 1.8-2.0 Gy per fraction with a three-dimensional conformal technique. Surgery (three-field, Ivor-Lewis, or transhiatal esophagectomy) was performed 27-123 days (median, 45 days) after completion of radiotherapy. The following dosimetric parameters were generated from the dose-volume histogram (DVH) for total lung: lung volume, mean dose to lung, relative and absolute volumes of lung receiving more than a threshold dose (relative V(dose) and absolute V(dose)), and absolute volume of lung receiving less than a threshold dose (volume spared, or VS(dose)). Occurrence of postoperative pulmonary complications, defined as pneumonia or acute respiratory distress syndrome (ARDS) within 30 days after surgery, was the endpoint for all analyses. Fisher's exact test was used to investigate the relationship between categorical factors and incidence of postoperative pulmonary complications. Logistic analysis was used to analyze the relationship between continuous factors (e.g., V(dose) or VS(dose)) and complication rate. Logistic regression with forward stepwise inclusion of factors was used to perform multivariate analysis of those factors having univariate significance (p < 0.05). The Mann-Whitney test was used to compare length of hospital stay in patients with and without lung complications and to compare lung volumes, VS5 values, and absolute and relative V5 values in male vs. female patients. Pearson correlation analysis was used to determine correlations between dosimetric factors. Eighteen (16.4%) of the 110 patients developed postoperative pulmonary complications. Two of these died of progressive pneumonia. Hospitalizations were significantly longer for patients with postoperative pulmonary complications than for those without (median, 15 days vs. 11 days, p = 0.003). On univariate analysis, female gender (p = 0.017), higher mean lung dose (p = 0.036), higher relative volume of lung receiving > or = 5 Gy (V5) (p = 0.023), and smaller volumes of lung spared from doses > or = 5-35 Gy (VS5-VS35) (p < 0.05) were all significantly associated with an increased incidence of postoperative pulmonary complications. No other clinical factors were significantly associated with the incidence of postoperative pulmonary complications in this cohort. On multivariate analysis, the volume of lung spared from doses > or = 5 Gy (VS5) was the only significant independent factor associated with postoperative pulmonary complications (p = 0.005). Dosimetric factors but not clinical factors were found to be strongly associated with the incidence of postoperative pulmonary complications in this cohort of esophageal cancer patients treated with concurrent chemoradiation plus surgery. The volume of the lung spared from doses of > or = 5 Gy was the only independent dosimetric factor in multivariate analysis. This suggests that ensuring an adequate volume of lung unexposed to radiation might reduce the incidence of postoperative pulmonary complications.

Earthscape, a Multi-Purpose Interactive 3d Globe Viewer for Hybrid Data Visualization and Analysis

NASA Astrophysics Data System (ADS)

Sarthou, A.; Mas, S.; Jacquin, M.; Moreno, N.; Salamon, A.

2015-08-01

The hybrid visualization and interaction tool EarthScape is presented here. The software is able to display simultaneously LiDAR point clouds, draped videos with moving footprint, volume scientific data (using volume rendering, isosurface and slice plane), raster data such as still satellite images, vector data and 3D models such as buildings or vehicles. The application runs on touch screen devices such as tablets. The software is based on open source libraries, such as OpenSceneGraph, osgEarth and OpenCV, and shader programming is used to implement volume rendering of scientific data. The next goal of EarthScape is to perform data analysis using ENVI Services Engine, a cloud data analysis solution. EarthScape is also designed to be a client of Jagwire which provides multisource geo-referenced video fluxes. When all these components will be included, EarthScape will be a multi-purpose platform that will provide at the same time data analysis, hybrid visualization and complex interactions. The software is available on demand for free at france@exelisvis.com.

Effects of complex aural stimuli on mental performance.

PubMed

Vij, Mohit; Aghazadeh, Fereydoun; Ray, Thomas G; Hatipkarasulu, Selen

2003-06-01

The objective of this study is to investigate the effect of complex aural stimuli on mental performance. A series of experiments were designed to obtain data for two different analyses. The first analysis is a "Stimulus" versus "No-stimulus" comparison for each of the four dependent variables, i.e. quantitative ability, reasoning ability, spatial ability and memory of an individual, by comparing the control treatment with the rest of the treatments. The second set of analysis is a multi-variant analysis of variance for component level main effects and interactions. The two component factors are tempo of the complex aural stimuli and sound volume level, each administered at three discrete levels for all four dependent variables. Ten experiments were conducted on eleven subjects. It was found that complex aural stimuli influence the quantitative and spatial aspect of the mind, while the reasoning ability was unaffected by the stimuli. Although memory showed a trend to be worse with the presence of complex aural stimuli, the effect was statistically insignificant. Variation in tempo and sound volume level of an aural stimulus did not significantly affect the mental performance of an individual. The results of these experiments can be effectively used in designing work environments.

The Geomorphic Road Analysis and Inventory Package (GRAIP) Volume 1: Data Collection Method

Treesearch

Thomas A. Black; Richard M. Cissel; Charles H. Luce

2012-01-01

An important first step in managing forest roads for improved water quality and aquatic habitat is the performance of an inventory. The Geomorphic Roads Analysis and Inventory Package (GRAIP) was developed as a tool for making a comprehensive inventory and analysis of the effects of forest roads on watersheds. This manual describes the data collection and process of a...

Study of solid rocket motor for space shuttle booster, volume 2, book 3, appendix A

NASA Technical Reports Server (NTRS)

1972-01-01

A systems requirements analysis for the solid propellant rocket engine to be used with the space shuttle was conducted. The systems analysis was developed to define the physical and functional requirements for the systems and subsystems. The operations analysis was performed to identify the requirements of the various launch operations, mission operations, ground operations, and logistic and flight support concepts.

Hand surgery volume and the US economy: is there a statistical correlation?

PubMed

Gordon, Chad R; Pryor, Landon; Afifi, Ahmed M; Gatherwright, James R; Evans, Peter J; Hendrickson, Mark; Bernard, Steven; Zins, James E

2010-11-01

To the best of our knowledge, there have been no previous studies evaluating the correlation of the US economy and hand surgery volume. Therefore, in light of the current recession, our objective was to study our institution's hand surgery volume over the last 17 years in relation to the nation's economy. A retrospective analysis of our institution's hand surgery volume, as represented by our most common procedure (ie, carpal tunnel release), was performed between January 1992 and October 2008. Liposuction and breast augmentation volumes were chosen to serve as cosmetic plastic surgery comparison groups. Pearson correlation statistics were used to estimate the relationship between the surgical volume and the US economy, as represented by the 3 market indices (Dow Jones, NASDAQ, and S&P500). A combined total of 7884 hand surgery carpal tunnel release (open or endoscopic) patients were identified. There were 1927 (24%) and 5957 (76%) patients within the departments of plastic and orthopedic surgery, respectively. In the plastic surgery department, there was a strong negative (ie, inverse relationship) correlation between hand surgery volume and the economy (P < 0.001). In converse, the orthopedic department's hand surgery volume demonstrated a positive (ie, parallel) correlation (P < 0.001). The volumes of liposuction and breast augmentation also showed a positive correlation (P < 0.001). To our knowledge, we have demonstrated for the first time an inverse (ie, negative) correlation between hand surgery volumes performed by plastic surgeons in relation to the US economy, as represented by the 3 major market indices. In contrast, orthopedic hand surgery volume and cosmetic surgery show a parallel (ie, positive) correlation. This data suggests that plastic surgeons are increasing their cosmetic surgery-to-reconstructive/hand surgery ratio during strong economic times and vice versa during times of economic slowdown.

Ninety-day mortality after resection for lung cancer is nearly double 30-day mortality.

PubMed

Pezzi, Christopher M; Mallin, Katherine; Mendez, Andres Samayoa; Greer Gay, Emmelle; Putnam, Joe B

2014-11-01

To evaluate 30-day and 90-day mortality after major pulmonary resection for lung cancer including the relationship to hospital volume. Major lung resections from 2007 to 2011 were identified in the National Cancer Data Base. Mortality was compared according to annual volume and demographic and clinical covariates using univariate and multivariable analyses, and included information on comorbidity. Statistical significance (P<.05) and 95% confidence intervals were assessed. There were 124,418 major pulmonary resections identified in 1233 facilities. The 30-day mortality rate was 2.8%. The 90-day mortality rate was 5.4%. Hospital volume was significantly associated with 30-day mortality, with a mortality rate of 3.7% for volumes less than 10, and 1.7% for volumes of 90 or more. Other variables significantly associated with 30-day mortality include older age, male sex, higher stage, pneumonectomy, a previous primary cancer, and multiple comorbidities. Similar results were found for 90-day mortality rates. In the multivariate analysis, hospital volume remained significant with adjusted odds ratios of 2.1 (95% confidence interval [CI], 1.7-2.6) for 30-day mortality and 1.3 (95% CI, 1.1-1.6) for conditional 90-day mortality for the hospitals with the lowest volume (<10) compared with those with the highest volume (>90). Hospitals with a volume less than 30 had an adjusted odds ratio for 30-day mortality of 1.3 (95% CI, 1.2-1.5) compared with those with a volume greater than 30. Mortality at 30 and 90 days and hospital volume should be monitored by institutions performing major pulmonary resection and benchmarked against hospitals performing at least 30 resections per year. Copyright © 2014 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.

Optical Automatic Car Identification (OACI) : Volume 1. Advanced System Specification.

DOT National Transportation Integrated Search

1978-12-01

A performance specification is provided in this report for an Optical Automatic Car Identification (OACI) scanner system which features 6% improved readability over existing industry scanner systems. It also includes the analysis and rationale which ...

Analysis and estimation of service life of corrosion prevention materials using diffusion, resistivity and accelerated curing for new bridge structures : volume 1 : corrosion prevention materials (monitoring and forensic examination).

DOT National Transportation Integrated Search

2013-12-01

This investigation compiles the results describing the performance of: a) reinforced concrete specimens cast with : 0.37 water to cementitious (w/cm) and binary blends of high performance concrete; the specimens have been : exposed to seawater wet/dr...

Automation system for measurement of gamma-ray spectra of induced activity for multi-element high volume neutron activation analysis at the reactor IBR-2 of Frank Laboratory of Neutron Physics at the joint institute for nuclear research

NASA Astrophysics Data System (ADS)

Pavlov, S. S.; Dmitriev, A. Yu.; Chepurchenko, I. A.; Frontasyeva, M. V.

2014-11-01

The automation system for measurement of induced activity of gamma-ray spectra for multi-element high volume neutron activation analysis (NAA) was designed, developed and implemented at the reactor IBR-2 at the Frank Laboratory of Neutron Physics. The system consists of three devices of automatic sample changers for three Canberra HPGe detector-based gamma spectrometry systems. Each sample changer consists of two-axis of linear positioning module M202A by DriveSet company and disk with 45 slots for containers with samples. Control of automatic sample changer is performed by the Xemo S360U controller by Systec company. Positioning accuracy can reach 0.1 mm. Special software performs automatic changing of samples and measurement of gamma spectra at constant interaction with the NAA database.

Study on fluid-structure interaction in liquid oxygen feeding pipe systems using finite volume method

NASA Astrophysics Data System (ADS)

Wei, Xin; Sun, Bing

2011-10-01

The fluid-structure interaction may occur in space launch vehicles, which would lead to bad performance of vehicles, damage equipments on vehicles, or even affect astronauts' health. In this paper, analysis on dynamic behavior of liquid oxygen (LOX) feeding pipe system in a large scale launch vehicle is performed, with the effect of fluid-structure interaction (FSI) taken into consideration. The pipe system is simplified as a planar FSI model with Poisson coupling and junction coupling. Numerical tests on pipes between the tank and the pump are solved by the finite volume method. Results show that restrictions weaken the interaction between axial and lateral vibrations. The reasonable results regarding frequencies and modes indicate that the FSI affects substantially the dynamic analysis, and thus highlight the usefulness of the proposed model. This study would provide a reference to the pipe test, as well as facilitate further studies on oscillation suppression.

A structural model of age, grey matter volumes, education, and personality traits.

PubMed

Kitamura, Soichiro; Yasuno, Fumihiko; Yamamoto, Akihide; Kazui, Hiroaki; Kudo, Takashi; Matsuoka, Kiwamu; Kiuchi, Kuniaki; Kosaka, Jun; Nagatsuka, Kazuyuki; Iida, Hidehiro; Kishimoto, Toshifumi

2016-01-01

When the relationship between ageing and changes in personality traits is considered, it is important to know how they are influenced by biological and environmental factors. The present study examined the relationships between various factors associated with the effect of ageing on personality traits, including structural changes of the brain and environmental factors such as education. We recruited 41 healthy subjects. We administered the NEO Five-Factor Inventory to assess personality factors. Magnetic resonance imaging was performed, and regional grey matter (GM) volumes were obtained. We identified associations in the correlation analysis of age, cerebral GM volume, years of education, and the personality trait of openness. Path analysis was used to estimate the relationships among these factors. The path analysis model of age, GM volume, years of education, and the personality trait of openness revealed that age has an indirect negative association with openness through GM volume and years of education. Ageing was related to a decrease in GM volume, which was in turn related to a decrease in the openness score. Older subjects generally had fewer years of education, which was related to a lower openness score. Maintaining openness against the effects of ageing is desirable, and our results imply that interventions against age-related cerebral atrophy and the promotion of opportunities for higher education may contribute to the development and stability of a healthy personality during the adult life course. © 2015 The Authors. Psychogeriatrics © 2015 Japanese Psychogeriatric Society.

DOT/NASA comparative assessment of Brayton engines for guideway vehicles and busses. Volume 2: Analysis and results

NASA Technical Reports Server (NTRS)

1975-01-01

Gas turbine engines were assessed for application to hear duty transportation. A summary of the assumptions, applications, and methods of analysis is included along with a discussion of the approach taken, the technical program flow chart, and weighting criteria used for performance evaluation. The various engines are compared on the bases of weight, performance, emissions and noise, technology status, and growth potential. The results of the engine screening phase and the conceptual design phase are presented.

BDNF is Associated With Age-Related Decline in Hippocampal Volume

PubMed Central

Erickson, Kirk I.; Prakash, Ruchika Shaurya; Voss, Michelle W.; Chaddock, Laura; Heo, Susie; McLaren, Molly; Pence, Brandt D.; Martin, Stephen A.; Vieira, Victoria J.; Woods, Jeffrey A.; Kramer, Arthur F.

2010-01-01

Hippocampal volume shrinks in late adulthood, but the neuromolecular factors that trigger hippocampal decay in aging humans remains a matter of speculation. In rodents, brain derived neurotrophic factor (BDNF) promotes the growth and proliferation of cells in the hippocampus and is important in long-term potentiation and memory formation. In humans, circulating levels of BDNF decline with advancing age and a genetic polymorphism for BDNF has been related to gray matter volume loss in old age. In this study, we tested whether age-related reductions in serum levels of BDNF would be related to shrinkage of the hippocampus and memory deficits in older adults. Hippocampal volume was acquired by automated segmentation of magnetic resonance images in 142 older adults without dementia. The caudate nucleus was also segmented and examined in relation to levels of serum BDNF. Spatial memory was tested using a paradigm in which memory load was parametrically increased. We found that increasing age was associated with smaller hippocampal volumes, reduced levels of serum BDNF, and poorer memory performance. Lower levels of BDNF were associated with smaller hippocampi and poorer memory, even when controlling for the variation related to age. In an exploratory mediation analysis, hippocampal volume mediated the age-related decline in spatial memory and BDNF mediated the age-related decline in hippocampal volume. Caudate nucleus volume was unrelated to BDNF levels or spatial memory performance. Our results identify serum BDNF as a significant factor related to hippocampal shrinkage and memory decline in late adulthood. PMID:20392958

The evolution of self-control

PubMed Central

MacLean, Evan L.; Hare, Brian; Nunn, Charles L.; Addessi, Elsa; Amici, Federica; Anderson, Rindy C.; Aureli, Filippo; Baker, Joseph M.; Bania, Amanda E.; Barnard, Allison M.; Boogert, Neeltje J.; Brannon, Elizabeth M.; Bray, Emily E.; Bray, Joel; Brent, Lauren J. N.; Burkart, Judith M.; Call, Josep; Cantlon, Jessica F.; Cheke, Lucy G.; Clayton, Nicola S.; Delgado, Mikel M.; DiVincenti, Louis J.; Fujita, Kazuo; Herrmann, Esther; Hiramatsu, Chihiro; Jacobs, Lucia F.; Jordan, Kerry E.; Laude, Jennifer R.; Leimgruber, Kristin L.; Messer, Emily J. E.; de A. Moura, Antonio C.; Ostojić, Ljerka; Picard, Alejandra; Platt, Michael L.; Plotnik, Joshua M.; Range, Friederike; Reader, Simon M.; Reddy, Rachna B.; Sandel, Aaron A.; Santos, Laurie R.; Schumann, Katrin; Seed, Amanda M.; Sewall, Kendra B.; Shaw, Rachael C.; Slocombe, Katie E.; Su, Yanjie; Takimoto, Ayaka; Tan, Jingzhi; Tao, Ruoting; van Schaik, Carel P.; Virányi, Zsófia; Visalberghi, Elisabetta; Wade, Jordan C.; Watanabe, Arii; Widness, Jane; Young, Julie K.; Zentall, Thomas R.; Zhao, Yini

2014-01-01

Cognition presents evolutionary research with one of its greatest challenges. Cognitive evolution has been explained at the proximate level by shifts in absolute and relative brain volume and at the ultimate level by differences in social and dietary complexity. However, no study has integrated the experimental and phylogenetic approach at the scale required to rigorously test these explanations. Instead, previous research has largely relied on various measures of brain size as proxies for cognitive abilities. We experimentally evaluated these major evolutionary explanations by quantitatively comparing the cognitive performance of 567 individuals representing 36 species on two problem-solving tasks measuring self-control. Phylogenetic analysis revealed that absolute brain volume best predicted performance across species and accounted for considerably more variance than brain volume controlling for body mass. This result corroborates recent advances in evolutionary neurobiology and illustrates the cognitive consequences of cortical reorganization through increases in brain volume. Within primates, dietary breadth but not social group size was a strong predictor of species differences in self-control. Our results implicate robust evolutionary relationships between dietary breadth, absolute brain volume, and self-control. These findings provide a significant first step toward quantifying the primate cognitive phenome and explaining the process of cognitive evolution. PMID:24753565

Surgical outcomes for low-volume vs high-volume surgeons in gynecology surgery: a systematic review and meta-analysis.

PubMed

Mowat, Alex; Maher, Christopher; Ballard, Emma

2016-07-01

The aim of this study was to determine the impact of gynecological surgeon volumes on patient outcomes. Eligible studies were selected through an electronic literature search from database inception up until September 2015 and references in published studies. Search terms included surgical volume, surgeon volume, low-volume or high-volume, and gynecology or hysterectomy or sling or pelvic floor repair or continence procedure. The literature search was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We defined a low-volume surgeon (LVS) as one performing the procedure once a month or less, and studies were excluded if their definition of LVS was > ±33% of our definition. Primary outcomes were total complications, intraoperative complications, and postoperative complications. All outcome data for individual studies were entered into systematic review software. When 2 or more studies evaluated a designated outcome, a meta-analysis of the entered data was undertaken as per the Cochrane database methodology. Data analysis was entered into a software product, which generated a summary of findings table that included structured and qualified grading (very low to high) of the quality for the evidence of the individual outcomes and provided a measure of effect. Fourteen peer-reviewed studies with 741,760 patients were included in the systematic review. For gynecology the LVS group had an increased rate of total complications (odds ratio [OR], 1.3, 95% confidence interval [CI], 1.2-1.5), intraoperative complications (OR, 1.6, 95% CI, 1.2-2.1), and postoperative complications (OR, 1.4 95% CI, 1.3-1.4). In gynecological oncology, the LVS group had higher mortality (OR, 1.9, 95% CI, 1.3-2.6). In the urogynecology group, a single study reported that the LVS group had a higher rate of any complication (risk ratio [RR], 1.4, 95% CI, -1.2-1.6). Another single study found that LVS had higher rates of reoperation for mesh complications after midurethral sling procedures (RR, 1.4, 95% CI, 1.2-1.5). The evidence is of moderate to very low quality. Gynecologists performing procedures approximately once a month or less were found to have higher rates of adverse outcomes in gynecology, gynecological oncology, and urogynecology, with higher mortality in gynecological oncology. Crown Copyright © 2016. Published by Elsevier Inc. All rights reserved.

System cost performance analysis (study 2.3). Volume 1: Executive summary. [unmanned automated payload programs and program planning

NASA Technical Reports Server (NTRS)

Campbell, B. H.

1974-01-01

A study is described which was initiated to identify and quantify the interrelationships between and within the performance, safety, cost, and schedule parameters for unmanned, automated payload programs. The result of the investigation was a systems cost/performance model which was implemented as a digital computer program and could be used to perform initial program planning, cost/performance tradeoffs, and sensitivity analyses for mission model and advanced payload studies. Program objectives and results are described briefly.

Back to the future: estimating pre-injury brain volume in patients with traumatic brain injury.

PubMed

Ross, David E; Ochs, Alfred L; D Zannoni, Megan; Seabaugh, Jan M

2014-11-15

A recent meta-analysis by Hedman et al. allows for accurate estimation of brain volume changes throughout the life span. Additionally, Tate et al. showed that intracranial volume at a later point in life can be used to estimate reliably brain volume at an earlier point in life. These advancements were combined to create a model which allowed the estimation of brain volume just prior to injury in a group of patients with mild or moderate traumatic brain injury (TBI). This volume estimation model was used in combination with actual measurements of brain volume to test hypotheses about progressive brain volume changes in the patients. Twenty six patients with mild or moderate TBI were compared to 20 normal control subjects. NeuroQuant® was used to measure brain MRI volume. Brain volume after the injury (from MRI scans performed at t1 and t2) was compared to brain volume just before the injury (volume estimation at t0) using longitudinal designs. Groups were compared with respect to volume changes in whole brain parenchyma (WBP) and its 3 major subdivisions: cortical gray matter (GM), cerebral white matter (CWM) and subcortical nuclei+infratentorial regions (SCN+IFT). Using the normal control data, the volume estimation model was tested by comparing measured brain volume to estimated brain volume; reliability ranged from good to excellent. During the initial phase after injury (t0-t1), the TBI patients had abnormally rapid atrophy of WBP and CWM, and abnormally rapid enlargement of SCN+IFT. Rates of volume change during t0-t1 correlated with cross-sectional measures of volume change at t1, supporting the internal reliability of the volume estimation model. A logistic regression analysis using the volume change data produced a function which perfectly predicted group membership (TBI patients vs. normal control subjects). During the first few months after injury, patients with mild or moderate TBI have rapid atrophy of WBP and CWM, and rapid enlargement of SCN+IFT. The magnitude and pattern of the changes in volume may allow for the eventual development of diagnostic tools based on the volume estimation approach. Copyright © 2014 Elsevier Inc. All rights reserved.

An Ultra-Sensitive Method for the Analysis of Perfluorinated ...

EPA Pesticide Factsheets

In epidemiological research, it has become increasingly important to assess subjects' exposure to different classes of chemicals in multiple environmental media. It is a common practice to aliquot limited volumes of samples into smaller quantities for specific trace level chemical analysis. A novel method was developed for the determination of 14 perfluorinated alkyl acids (PFAAs) in small volumes (10 mL) of drinking water using off-line solid phase extraction (SPE) pre-treatment followed by on-line pre-concentration on WAX column before analysis on column-switching high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS). In general, large volumes (100 - 1000 mL) have been used for the analysis of PFAAs in drinking water. The current method requires approximately 10 mL of drinking water concentrated by using an SPE cartridge and eluted with methanol. A large volume injection of the extract was introduced on to a column-switching HPLC-MS/MS using a mix-mode SPE column for the trace level analysis of PFAAs in water. The recoveries for most of the analytes in the fortified laboratory blanks ranged from 73±14% to 128±5%. The lowest concentration minimum reporting levels (LCMRL) for the 14 PFAAs ranged from 0.59 to 3.4 ng/L. The optimized method was applied to a pilot-scale analysis of a subset of drinking water samples from an epidemiological study. These samples were collected directly from the taps in the households of Ohio and Nor

Learning process for performing and analyzing 3D/4D transperineal ultrasound imaging and interobserver reliability study.

PubMed

Siafarikas, F; Staer-Jensen, J; Braekken, I H; Bø, K; Engh, M Ellström

2013-03-01

To evaluate the learning process for acquiring three- and four-dimensional (3D/4D) transperineal ultrasound volumes of the levator hiatus (LH) dimensions at rest, during pelvic floor muscle (PFM) contraction and on Valsalva maneuver, and for analyzing the ultrasound volumes, as well as to perform an interobserver reliability study between two independent ultrasound examiners. This was a prospective study including 22 women. We monitored the learning process of an inexperienced examiner (IE) performing 3D/4D transperineal ultrasonography and analyzing the volumes. The examination included acquiring volumes during three PFM contractions and three Valsalva maneuvers. LH dimensions were determined in the axial plane. The learning process was documented by estimating agreement between the IE and an experienced examiner (E) using the intraclass correlation coefficient. Agreement was calculated in blocks of 10 ultrasound examinations and analyzed volumes. After the learning process was complete the interobserver reliability for the technique was calculated between these two independent examiners. For offline analysis of the first 10 ultrasound volumes obtained by E, good to very good agreement between E and IE was achieved for all LH measurements except for the left and right levator-urethra gap and pubic arc. For the next 10 analyzed volumes, agreement improved for all LH measurements. Volumes that had been obtained by IE and E were then re-evaluated by IE, and good to very good agreement was found for all LH measurements indicating consistency in volume acquisition. The interobserver reliability study showed excellent ICC values (ICC, 0.81-0.97) for all LH measurements except the pubic arc (ICC = 0.67). 3D/4D transperineal ultrasound is a reliable technique that can be learned in a short period of time. Copyright © 2012 ISUOG. Published by John Wiley & Sons, Ltd.

A 20-year period of orthotopic liver transplantation activity in a single center: a time series analysis performed using the R Statistical Software.

PubMed

Santori, G; Andorno, E; Morelli, N; Casaccia, M; Bottino, G; Di Domenico, S; Valente, U

2009-05-01

In many Western countries a "minimum volume rule" policy has been adopted as a quality measure for complex surgical procedures. In Italy, the National Transplant Centre set the minimum number of orthotopic liver transplantation (OLT) procedures/y at 25/center. OLT procedures performed in a single center for a reasonably large period may be treated as a time series to evaluate trend, seasonal cycles, and nonsystematic fluctuations. Between January 1, 1987 and December 31, 2006, we performed 563 cadaveric donor OLTs to adult recipients. During 2007, there were another 28 procedures. The greatest numbers of OLTs/y were performed in 2001 (n = 51), 2005 (n = 50), and 2004 (n = 49). A time series analysis performed using R Statistical Software (Foundation for Statistical Computing, Vienna, Austria), a free software environment for statistical computing and graphics, showed an incremental trend after exponential smoothing as well as after seasonal decomposition. The predicted OLT/mo for 2007 calculated with the Holt-Winters exponential smoothing applied to the previous period 1987-2006 helped to identify the months where there was a major difference between predicted and performed procedures. The time series approach may be helpful to establish a minimum volume/y at a single-center level.

The reciprocal iso-inhibition volume concept: A procedure for the evaluation in effect-directed analysis with thin-layer chromatography - using the thin-layer chromatography-luminescent bacteria assay as an example.

PubMed

Schulz, Wolfgang; Weiss, Stefan C; Weber, Walter H; Winzenbacher, Rudi

2017-10-13

In effect-directed analysis (EDA) with high-performance thin-layer chromatography (HPTLC), the effect is often detected using images. Thus, an approach to create inhibition chromatograms from these images was developed using the example of the HPTLC- bioluminescence inhibition test. A comparison between the cuvette test and the HPTLC test shows that the test on the plate is significantly more sensitive. To describe the strength of the effect, the EC 50 value is determined from the dose-response relationship. However, the inhibiting compounds are generally unknown and thus their concentrations are also unknown. Therefore, instead of the concentration, the known application volumes are used. This enables the calculation of the application volume necessary to achieve 50% inhibition. Since the volume is inversely proportional to the concentration, the reciprocal value of the calculated volume is indicated and is referred to as the reciprocal iso-inhibition volume (RIV). Using this RIV-concept, it is now possible to compare inhibition bands within and between plates. The entire evaluation is described by the means of two samples from a contaminated site using the bioluminescence inhibition. Copyright © 2017 Elsevier B.V. All rights reserved.

[A voxel-based morphometric analysis of brain gray matter in online game addicts].

PubMed

Weng, Chuan-bo; Qian, Ruo-bing; Fu, Xian-ming; Lin, Bin; Ji, Xue-bing; Niu, Chao-shi; Wang, Ye-han

2012-12-04

To explore the possible brain mechanism of online game addiction (OGA) in terms of brain morphology through voxel-based morphometric (VBM) analysis. Seventeen subjects with OGA and 17 age- and gender-matched healthy controls (HC group) were recruited from Department of Psychology at our hospital during February-December 2011. The internet addiction scale (IAS) was used to measure the degree of OGA tendency. Magnetic resonance imaging (MRI) scans were performed to acquire 3-dimensional T1-weighted images. And FSL 4.1 software was employed to confirm regional gray matter volume changes. For the regions where OGA subjects showed significantly different gray matter volumes from the controls, the gray matter volumes of these areas were extracted, averaged and regressed against the scores of IAS. The OGA group had lower gray matter volume in left orbitofrontal cortex (OFC), left medial prefrontal cortex (mPFC), bilateral insula (INS), left posterior cingulate cortex (PCC) and left supplementary motor area (SMA). Gray matter volumes of left OFC and bilateral INS showed a negative correlation with the scores of IAS (r = -0.65, r = -0.78, P < 0.05). Gray matter volume changes are present in online game addicts and they may be correlated with the occurrence and maintenance of OGA.

NPAC-Nozzle Performance Analysis Code

NASA Technical Reports Server (NTRS)

Barnhart, Paul J.

1997-01-01

A simple and accurate nozzle performance analysis methodology has been developed. The geometry modeling requirements are minimal and very flexible, thus allowing rapid design evaluations. The solution techniques accurately couple: continuity, momentum, energy, state, and other relations which permit fast and accurate calculations of nozzle gross thrust. The control volume and internal flow analyses are capable of accounting for the effects of: over/under expansion, flow divergence, wall friction, heat transfer, and mass addition/loss across surfaces. The results from the nozzle performance methodology are shown to be in excellent agreement with experimental data for a variety of nozzle designs over a range of operating conditions.

Study 2.5 final report. DORCA computer program. Volume 5: Analysis report

NASA Technical Reports Server (NTRS)

Campbell, N.

1972-01-01

A modification of the Dynamic Operational Requirements and Cost Analysis Program to perform traffic analyses of the automated satellite program is described. Inherent in the analyses of the automated satellite program was the assumption that a number of vehicles were available to perform any or all of the missions within the satellite program. The objective of the modification was to select a vehicle or group of vehicles for performing all of the missions at the lowest possible cost. A vehicle selection routine and the capability to simulate ground based vehicle operational modes were incorporated into the program.

NSEG: A segmented mission analysis program for low and high speed aircraft. Volume 2: Program users manual

NASA Technical Reports Server (NTRS)

Hague, D. S.; Rozendaal, H. L.

1977-01-01

A rapid mission analysis code based on the use of approximate flight path equations of motion is described. Equation form varies with the segment type, for example, accelerations, climbs, cruises, descents, and decelerations. Realistic and detailed vehicle characteristics are specified in tabular form. In addition to its mission performance calculation capabilities, the code also contains extensive flight envelop performance mapping capabilities. Approximate take off and landing analyses can be performed. At high speeds, centrifugal lift effects are taken into account. Extensive turbojet and ramjet engine scaling procedures are incorporated in the code.

The performances of standard and ResMed masks during bag-valve-mask ventilation.

PubMed

Lee, Hyoung Youn; Jeung, Kyung Woon; Lee, Byung Kook; Lee, Seung Joon; Jung, Yong Hun; Lee, Geo Sung; Min, Yong Il; Heo, Tag

2013-01-01

A tight mask seal is frequently difficult to obtain and maintain during single-rescuer bag-valve-mask (BVM) ventilation. The ResMed mask (Bella Vista, NSW, Australia) is a continuous-positive-airway-pressure mask (CM) designed for noninvasive ventilation. In this study, we compared the ventilation performances of a standard mask (SM) and a ResMed CM using a simulation manikin in an out-of-hospital single-rescuer BVM ventilation scenario. Thirty emergency medical technicians (EMTs) performed two 2-minute attempts to ventilate a simulation manikin using BVM ventilation, alternatively, with the SM or the ResMed CM in a randomized order. Ventilation parameters including tidal volume and peak airway pressure were measured using computer analysis software connected to the simulation manikin. Successful volume delivery was defined as delivery of 440-540 mL of tidal volume in accord with present cardiopulmonary resuscitation guidelines. BVM ventilation using the ResMed CM produced higher mean (± standard deviation) tidal volumes (452 ± 50 mL vs. 394 ± 113 mL, p = 0.014) and had a higher proportion of successful volume deliveries (65.3% vs. 26.7%, p < 0.001) than that using the SM. Peak airway pressure was higher in BVM ventilation using the ResMed CM (p = 0.035). Stomach insufflation did not occur during either method. Twenty-nine of the participants (96.7%) preferred BVM ventilation using the ResMed CM. BVM ventilations using ResMed CM resulted in a significantly higher proportion of successful volume deliveries meeting the currently recommended range of tidal volume. Clinical studies are needed to determine the value of the ResMed CM for BVM ventilation.

Structural Arrangement Trade Study. Volume 1: Reusable Hydrogen Composite Tank System (RHCTS) and Graphite Composite Primary Structures (GCPS). Executive summary

NASA Astrophysics Data System (ADS)

1995-03-01

This volume is the first of a three volume set that discusses the structural arrangement trade study plan that will identify the most suitable configuration for an SSTO winged vehicle capable of delivering 25,000 lbs to a 220 nm circular orbit at 51.6 deg inclination. The Reusable Hydrogen Composite Tank System (RHCTS), and Graphite Composite Primary Structures most suitable for intertank, wing and thrust structures are identified. This executive summary presents the trade study process, the selection process, requirements used, analysis performed and data generated. Conclusions and recommendations are also presented.

Satellite Power Systems (SPS) concept definition study, exhibit C. Volume 2, part 1: System engineering

NASA Technical Reports Server (NTRS)

Hanley, G. M.

1979-01-01

Volume 2, Part 1, of a seven volume report is presented. Part 1 encompasses Satellite Power Systems (SPS) systems engineering aspects and is divided into three sections. The first section presents descriptions of the various candidate concepts considered and conclusions and recommendations for a preferred concept. The second section presents a summary of results of the various trade studies and analysis conducted during the course of the study. The third section describes the Photovoltaic Satellite Based Satellite Power System (SPS) Point Design as it was defined through studies performed during the period January 1977 through March 1979.

Structural Arrangement Trade Study. Volume 1: Reusable Hydrogen Composite Tank System (RHCTS) and Graphite Composite Primary Structures (GCPS). Executive summary

NASA Technical Reports Server (NTRS)

1995-01-01

This volume is the first of a three volume set that discusses the structural arrangement trade study plan that will identify the most suitable configuration for an SSTO winged vehicle capable of delivering 25,000 lbs to a 220 nm circular orbit at 51.6 deg inclination. The Reusable Hydrogen Composite Tank System (RHCTS), and Graphite Composite Primary Structures most suitable for intertank, wing and thrust structures are identified. This executive summary presents the trade study process, the selection process, requirements used, analysis performed and data generated. Conclusions and recommendations are also presented.

An air-pressure-free elastomeric valve for integrated nucleic acid analysis by capillary electrophoresis

NASA Astrophysics Data System (ADS)

Jung, Wooseok; Barrett, Matthew; Brooks, Carla; Rivera, Andrew; Birdsell, Dawn N.; Wagner, David M.; Zenhausern, Frederic

2015-12-01

We present a new elastomeric valve for integrated nucleic acid analysis by capillary electrophoresis. The valve functions include metering to capture a designated volume of biological sample into a polymerase chain reaction (PCR) chamber, sealing to preserve the sample during PCR cycling, and transfer of the PCR-products and on-chip formamide post-processing for the analysis of DNA fragments by capillary gel electrophoresis. This new valve differs from prior art polydimethylsiloxane (PDMS) valves in that the valve is not actuated externally by air-pressure or vacuum so that it simplifies a DNA analysis system by eliminating the need for an air-pressure or vacuum source, and off-cartridge solenoid valves, control circuit boards and software. Instead, the new valve is actuated by a thermal cycling peltier assembly integrated within the hardware instrument that tightly comes in contact with a microfluidic cartridge for thermal activation during PCR, so that it spontaneously closes the valve without an additional actuator system. The valve has bumps in the designated locations so that it has a self-alignment that does not require precise alignment of a valve actuator. Moreover, the thickness of the new valve is around 600 μm with an additional bump height of 400 μm so that it is easy to handle and very feasible to fabricate by injection molding compared to other PDMS valves whose thicknesses are around 30-100 μm. The new valve provided over 95% of metering performance in filling the fixed volume of the PCR chamber, preserved over 97% of the sample volume during PCR, and showed very comparable capillary electrophoresis peak heights to the benchtop assay tube controls with very consistent transfer volume of the PCR-product and on-chip formamide. The new valve can perform a core function for integrated nucleic acid analysis by capillary electrophoresis.

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

PubMed

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

2015-10-01

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

First experiences with model based iterative reconstructions influence on quantitative plaque volume and intensity measurements in coronary computed tomography angiography.

PubMed

Precht, H; Kitslaar, P H; Broersen, A; Gerke, O; Dijkstra, J; Thygesen, J; Egstrup, K; Lambrechtsen, J

2017-02-01

Investigate the influence of adaptive statistical iterative reconstruction (ASIR) and the model-based IR (Veo) reconstruction algorithm in coronary computed tomography angiography (CCTA) images on quantitative measurements in coronary arteries for plaque volumes and intensities. Three patients had three independent dose reduced CCTA performed and reconstructed with 30% ASIR (CTDI vol at 6.7 mGy), 60% ASIR (CTDI vol 4.3 mGy) and Veo (CTDI vol at 1.9 mGy). Coronary plaque analysis was performed for each measured CCTA volumes, plaque burden and intensities. Plaque volume and plaque burden show a decreasing tendency from ASIR to Veo as median volume for ASIR is 314 mm 3 and 337 mm 3 -252 mm 3 for Veo and plaque burden is 42% and 44% for ASIR to 39% for Veo. The lumen and vessel volume decrease slightly from 30% ASIR to 60% ASIR with 498 mm 3 -391 mm 3 for lumen volume and vessel volume from 939 mm 3 to 830 mm 3 . The intensities did not change overall between the different reconstructions for either lumen or plaque. We found a tendency of decreasing plaque volumes and plaque burden but no change in intensities with the use of low dose Veo CCTA (1.9 mGy) compared to dose reduced ASIR CCTA (6.7 mGy & 4.3 mGy), although more studies are warranted. Copyright © 2016 The College of Radiographers. Published by Elsevier Ltd. All rights reserved.

The in vivo performance of a novel thermal accelerant agent used for augmentation of microwave energy delivery within biologic tissues during image-guided thermal ablation: a porcine study.

PubMed

Park, William Keun Chan; Maxwell, Aaron Wilhelm Palmer; Frank, Victoria Elizabeth; Primmer, Michael Patrick; Paul, Jarod Brian; Collins, Scott Andrew; Lombardo, Kara Anne; Lu, Shaolei; Borjeson, Tiffany Marie; Baird, Grayson Luderman; Dupuy, Damian Edward

2018-02-01

To investigate the effects of a novel caesium-based thermal accelerant (TA) agent on ablation zone volumes following in vivo microwave ablation of porcine liver and skeletal muscle, and to correlate the effects of TA with target organ perfusion. This prospective study was performed following institutional animal care and use committee approval. Microwave ablation was performed in liver and resting skeletal muscle in eight Sus scrofa domesticus swine following administration of TA at concentrations of 0 mg/mL (control), 100 mg/mL and 250 mg/mL. Treated tissues were explanted and stained with triphenyltetrazolium chloride (TTC) for quantification of ablation zone volumes, which were compared between TA and control conditions. Hematoxylin and eosin (H&E) staining was also performed for histologic analysis. General mixed modelling with a log-normal distribution was used for all quantitative comparisons (p = 0.05). A total of 28 ablations were performed in the liver and 18 in the skeletal muscle. The use of TA significantly increased ablation zone volumes in a dose-dependent manner in both the porcine muscle and liver (p < 0.01). Both the absolute mean ablation zone volume and percentage increase in ablation zone volume were greater in the resting skeletal muscle than in the liver. In one swine, a qualitative mitigation of heat sink effects was observed by TTC and H&E staining. Non-lethal polymorphic ventricular tachycardia was identified in one swine, treated with intravenous amiodarone. The use of a novel TA agent significantly increased mean ablation zone volumes following microwave ablation using a porcine model. The relationship between TA administration and ablation size was dose-dependent and inversely proportional to the degree of target organ perfusion, and a qualitative reduction in heat-sink effects was observed.

Accuracy evaluation of Fourier series analysis and singular spectrum analysis for predicting the volume of motorcycle sales in Indonesia

NASA Astrophysics Data System (ADS)

Sasmita, Yoga; Darmawan, Gumgum

2017-08-01

This research aims to evaluate the performance of forecasting by Fourier Series Analysis (FSA) and Singular Spectrum Analysis (SSA) which are more explorative and not requiring parametric assumption. Those methods are applied to predicting the volume of motorcycle sales in Indonesia from January 2005 to December 2016 (monthly). Both models are suitable for seasonal and trend component data. Technically, FSA defines time domain as the result of trend and seasonal component in different frequencies which is difficult to identify in the time domain analysis. With the hidden period is 2,918 ≈ 3 and significant model order is 3, FSA model is used to predict testing data. Meanwhile, SSA has two main processes, decomposition and reconstruction. SSA decomposes the time series data into different components. The reconstruction process starts with grouping the decomposition result based on similarity period of each component in trajectory matrix. With the optimum of window length (L = 53) and grouping effect (r = 4), SSA predicting testing data. Forecasting accuracy evaluation is done based on Mean Absolute Percentage Error (MAPE), Mean Absolute Error (MAE) and Root Mean Square Error (RMSE). The result shows that in the next 12 month, SSA has MAPE = 13.54 percent, MAE = 61,168.43 and RMSE = 75,244.92 and FSA has MAPE = 28.19 percent, MAE = 119,718.43 and RMSE = 142,511.17. Therefore, to predict volume of motorcycle sales in the next period should use SSA method which has better performance based on its accuracy.

Experiments and analysis concerning the use of external burning to reduce aerospace vehicle transonic drag. Ph.D. Thesis - Maryland Univ., 1991

NASA Technical Reports Server (NTRS)

Trefny, Charles J.

1992-01-01

The external combustion of hydrogen to reduce transonic drag was investigated. A control volume analysis is developed and indicates that the specific impulse performance of external burning is competitive with other forms of airbreathing propulsion and depends on the fuel-air ratio, freestream Mach number, and the severity of the base drag. A method is presented for sizing fuel injectors for a desired fuel-air ratio in the unconfined stream. A two-dimensional Euler analysis is also presented which indicates that the total axial force generated by external burning depends on the total amount of energy input and is independent of the transverse and streamwise distribution of heat addition. Good agreement between the Euler and control volume analysis is demonstrated. Features of the inviscid external burning flowfield are discussed. Most notably, a strong compression forms at the sonic line within the burning stream which may induce separation of the plume and prevent realization of the full performance potential. An experimental program was conducted in a Mach 1.26 free-jet to demonstrate drag reduction on a simple expansion ramp geometry, and verify hydrogen-air stability limits at external burning conditions. Stable combustion appears feasible to Mach number of between 1.4 and 2 depending on the vehicle flight trajectory. Drag reduction is demonstrated on the expansion ramp at Mach 1.26; however, force levels showed little dependence on fuel pressure or altitude in contrast to control volume analysis predictions. Various facility interference mechanisms and scaling issues were studied and are discussed.

Traumatic Spinal Injury: Global Epidemiology and Worldwide Volume.

PubMed

Kumar, Ramesh; Lim, Jaims; Mekary, Rania A; Rattani, Abbas; Dewan, Michael C; Sharif, Salman Y; Osorio-Fonseca, Enrique; Park, Kee B

2018-05-01

Traumatic spinal injury (TSI) results from injury to bony, ligamentous, and/or neurologic structures of the spinal column and can cause significant morbidity and mortality. The global burden of TSI is poorly understood, so we performed a systematic review and meta-analysis to estimate the global volume of TSI. We performed a systematic review through PubMed, Embase, and Cochrane Databases on TSI studies reported from 2000 to 2016. Collected data were used to perform a meta-analysis to estimate the annual incidence of TSI across World Health Organization regions and World Bank income groups using random-effect models. Incorporating global population figures, the annual worldwide volume of TSI was estimated. A total of 102 studies were included in the systematic review and 19 studies in the meta-analysis. The overall global incidence of TSI was 10.5 cases per 100,000 persons, resulting in an estimated 768,473 [95% confidence interval, 597,213-939,732] new cases of TSI annually worldwide. The incidence of TSI was higher in low- and middle-income countries (8.72 per 100,000 persons) compared with high-income countries (13.69 per 100,000 persons). Road traffic accidents, followed by falls, were the most common mechanism of TSI worldwide. Overall, 48.8% of patients with TSI required surgery. TSI is a major source of morbidity and mortality throughout the world. Largely preventable mechanisms, including road traffic accidents and falls, are the main causes of TSI globally. Further investigation is needed to delineate local and regional TSI incidences and causes, especially in low- and middle-income countries. Copyright © 2018 Elsevier Inc. All rights reserved.

Liver volume measurement: reason of the difference between in vivo CT-volumetry and intraoperative ex vivo determination and how to cope it.

PubMed

Niehues, Stefan M; Unger, J K; Malinowski, M; Neymeyer, J; Hamm, B; Stockmann, M

2010-08-20

Volumetric assessment of the liver regularly yields discrepant results between pre- and intraoperatively determined volumes. Nevertheless, the main factor responsible for this discrepancy remains still unclear. The aim of this study was to systematically determine the difference between in vivo CT-volumetry and ex vivo volumetry in a pig animal model. Eleven pigs were studied. Liver density assessment, CT-volumetry and water displacement volumetry was performed after surgical removal of the complete liver. Known possible errors of volume determination like resection or segmentation borders were eliminated in this model. Regression analysis was performed and differences between CT-volumetry and water displacement determined. Median liver density was 1.07g/ml. Regression analysis showed a high correlation of r(2) = 0.985 between CT-volumetry and water displacement. CT-volumetry was found to be 13% higher than water displacement volumetry (p<0.0001). In this study the only relevant factor leading to the difference between in vivo CT-volumetry and ex vivo water displacement volumetry seems to be blood perfusion of the liver. The systematic difference of 13 percent has to be taken in account when dealing with those measures.

Probabilistic boundary element method

NASA Technical Reports Server (NTRS)

Cruse, T. A.; Raveendra, S. T.

1989-01-01

The purpose of the Probabilistic Structural Analysis Method (PSAM) project is to develop structural analysis capabilities for the design analysis of advanced space propulsion system hardware. The boundary element method (BEM) is used as the basis of the Probabilistic Advanced Analysis Methods (PADAM) which is discussed. The probabilistic BEM code (PBEM) is used to obtain the structural response and sensitivity results to a set of random variables. As such, PBEM performs analogous to other structural analysis codes such as finite elements in the PSAM system. For linear problems, unlike the finite element method (FEM), the BEM governing equations are written at the boundary of the body only, thus, the method eliminates the need to model the volume of the body. However, for general body force problems, a direct condensation of the governing equations to the boundary of the body is not possible and therefore volume modeling is generally required.

[The heterogeneity of blood flow on magnetic resonance imaging: a biomarker for grading cerebral astrocytomas].

PubMed

Revert Ventura, A J; Sanz Requena, R; Martí-Bonmatí, L; Pallardó, Y; Jornet, J; Gaspar, C

2014-01-01

To study whether the histograms of quantitative parameters of perfusion in MRI obtained from tumor volume and peritumor volume make it possible to grade astrocytomas in vivo. We included 61 patients with histological diagnoses of grade II, III, or IV astrocytomas who underwent T2*-weighted perfusion MRI after intravenous contrast agent injection. We manually selected the tumor volume and peritumor volume and quantified the following perfusion parameters on a voxel-by-voxel basis: blood volume (BV), blood flow (BF), mean transit time (TTM), transfer constant (K(trans)), washout coefficient, interstitial volume, and vascular volume. For each volume, we obtained the corresponding histogram with its mean, standard deviation, and kurtosis (using the standard deviation and kurtosis as measures of heterogeneity) and we compared the differences in each parameter between different grades of tumor. We also calculated the mean and standard deviation of the highest 10% of values. Finally, we performed a multiparametric discriminant analysis to improve the classification. For tumor volume, we found statistically significant differences among the three grades of tumor for the means and standard deviations of BV, BF, and K(trans), both for the entire distribution and for the highest 10% of values. For the peritumor volume, we found no significant differences for any parameters. The discriminant analysis improved the classification slightly. The quantification of the volume parameters of the entire region of the tumor with BV, BF, and K(trans) is useful for grading astrocytomas. The heterogeneity represented by the standard deviation of BF is the most reliable diagnostic parameter for distinguishing between low grade and high grade lesions. Copyright © 2011 SERAM. Published by Elsevier Espana. All rights reserved.

Association between provider volume and healthcare expenditures of patients with oral cancer in Taiwan: a population-based study.

PubMed

Chen, Li-Fu; Ho, Hsu-Chueh; Su, Yu-Chieh; Lee, Moon-Sing; Hung, Shih-Kai; Chou, Pesus; Lee, Ching-Chieh J; Lin, Li-Chu; Lee, Ching-Chih

2013-01-01

Oral cancer requires considerable utilization of healthcare services. Wide resection of the tumor and reconstruction with free flap are widely used. Due to high recurrence rate, close follow-up is mandatory. This study was conducted to explore the relationship between the healthcare expenditure of oncological surgery and one-year follow up and provider volume. From the National Health Insurance Research Database published by the Taiwanese National Health Research Institute, the authors selected a total of 1300 oral cancer patients who underwent tumor resection and free flap reconstruction in 2008. Hierarchical linear regression analysis was subsequently performed to explore the relationship between provider volume and expenditures of oncological surgery and one-year follow-up period. Emergency department (ED) visits and 30-day readmission rates were also analyzed. The mean expenditure for oncological surgery was $11080±4645 (all costs are given in U.S. dollars) and $10129±9248 for one-year follow up. For oncological surgery expenditure, oral cancer patients treated by low-volume surgeons had an additional $845 than those in high-volume surgeons in mixed model. For one-year follow-up expenditure, patients in low-volume hospitals had an additional $3439 than those in high-volume hospitals; patient in low-volume surgeons and medium-volume surgeons incurred an additional expenditure of $2065 and $1811 than those in high-volume surgeons. Oral cancer patients treated in low-volume hospitals incurred higher risk of 30-day readmission rate (odds ratio, 6.6; 95% confidence interval, 1.6-27). After adjusting for physician, hospital, and patient characteristics, low-volume provider performing wide excision with reconstructive surgery in oral cancer patients incurred significantly higher expenditure for oncological surgery and one-year healthcare per patient than did others with higher volumes. Treatment strategies adapted by high-volume providers should be further analyzed.

Impact of robotic technique and surgical volume on the cost of radical prostatectomy.

PubMed

Hyams, Elias S; Mullins, Jeffrey K; Pierorazio, Phillip M; Partin, Alan W; Allaf, Mohamad E; Matlaga, Brian R

2013-03-01

Our present understanding of the effect of robotic surgery and surgical volume on the cost of radical prostatectomy (RP) is limited. Given the increasing pressures placed on healthcare resource utilization, such determinations of healthcare value are becoming increasingly important. Therefore, we performed a study to define the effect of robotic technology and surgical volume on the cost of RP. The state of Maryland mandates that all acute-care hospitals report encounter-level and hospital discharge data to the Health Service Cost Review Commission (HSCRC). The HSCRC was queried for men undergoing RP between 2008 and 2011 (the period during which robot-assisted laparoscopic radical prostatectomy [RALRP] was coded separately). High-volume hospitals were defined as >60 cases per year, and high-volume surgeons were defined as >40 cases per year. Multivariate regression analysis was performed to evaluate whether robotic technique and high surgical volume impacted the cost of RP. There were 1499 patients who underwent RALRP and 2565 who underwent radical retropubic prostatectomy (RRP) during the study period. The total cost for RALRP was higher than for RRP ($14,000 vs 10,100; P<0.001) based primarily on operating room charges and supply charges. Multivariate regression demonstrated that RALRP was associated with a significantly higher cost (β coeff 4.1; P<0.001), even within high-volume hospitals (β coeff 3.3; P<0.001). High-volume surgeons and high-volume hospitals, however, were associated with a significantly lower cost for RP overall. High surgeon volume was associated with lower cost for RALRP and RRP, while high institutional volume was associated with lower cost for RALRP only. High surgical volume was associated with lower cost of RP. Even at high surgical volume, however, the cost of RALRP still exceeded that of RRP. As robotic surgery has come to dominate the healthcare marketplace, strategies to increase the role of high-volume providers may be needed to improve the cost-effectiveness of prostate cancer surgical therapy.

Energy and Exergy Analysis of a Diesel Engine Fuelled with Diesel and Simarouba Biodiesel Blends

NASA Astrophysics Data System (ADS)

Panigrahi, Nabnit; Mohanty, Mahendra Kumar; Mishra, Sruti Ranjan; Mohanty, Ramesh Chandra

2018-02-01

This article intends to determine the available work and various losses of a diesel engine fuelled with diesel and SB20 (20 % Simarouba biodiesel by volume blended with 80 % diesel by volume). The energy and exergy analysis were carried out by using first law and second law of thermodynamics respectively. The experiments were carried out on a 3.5 kW compression ignition engine. The analysis was conducted on per mole of fuel basis. The energy analysis indicates that about 37.23 and 37.79 % of input energy is converted into the capacity to do work for diesel and SB20 respectively. The exergetic efficiency was 34.8 and 35 % for diesel and Simarouba respectively. Comparative study indicates that the energetic and exergetic performance of SB20 resembles with that of diesel fuel.

Noninvasive Assessment of Advanced Fibrosis Based on Hepatic Volume in Patients with Nonalcoholic Fatty Liver Disease.

PubMed

Hayashi, Tatsuya; Saitoh, Satoshi; Fukuzawa, Kei; Tsuji, Yoshinori; Takahashi, Junji; Kawamura, Yusuke; Akuta, Norio; Kobayashi, Masahiro; Ikeda, Kenji; Fujii, Takeshi; Miyati, Tosiaki; Kumada, Hiromitsu

2017-09-15

Noninvasive liver fibrosis evaluation was performed in patients with nonalcoholic fatty liver disease (NAFLD). We used a quantitative method based on the hepatic volume acquired from gadoxetate disodium-enhanced (Gd-EOB-DTPA-enhanced) magnetic resonance imaging (MRI) for diagnosing advanced fibrosis in patients with NAFLD. A total of 130 patients who were diagnosed with NAFLD and underwent Gd-EOB-DTPA-enhanced MRI were retrospectively included. Histological data were available for 118 patients. Hepatic volumetric parameters, including the left hepatic lobe to right hepatic lobe volume ratio (L/R ratio), were measured. The usefulness of the L/R ratio for diagnosing fibrosis ≥F3-4 and F4 was assessed using the area under the receiver operating characteristic (AUROC) curve. Multiple regression analysis was performed to identify variables (age, body mass index, serum fibrosis markers, and histological features) that were associated with the L/R ratio. The L/R ratio demonstrated good performance in differentiating advanced fibrosis (AUROC, 0.80; 95% confidence interval, 0.72 to 0.88) from cirrhosis (AUROC, 0.87; 95% confidence interval, 0.75 to 0.99). Multiple regression analysis showed that only fibrosis was significantly associated with the L/R ratio (coefficient, 0.121; p<0.0001). The L/R ratio, which is not influenced by pathological parameters other than fibrosis, is useful for diagnosing cirrhosis in patients with NAFLD.

Radiotherapy volume delineation using dynamic [18F]-FDG PET/CT imaging in patients with oropharyngeal cancer: a pilot study.

PubMed

Silvoniemi, Antti; Din, Mueez U; Suilamo, Sami; Shepherd, Tony; Minn, Heikki

2016-11-01

Delineation of gross tumour volume in 3D is a critical step in the radiotherapy (RT) treatment planning for oropharyngeal cancer (OPC). Static [ 18 F]-FDG PET/CT imaging has been suggested as a method to improve the reproducibility of tumour delineation, but it suffers from low specificity. We undertook this pilot study in which dynamic features in time-activity curves (TACs) of [ 18 F]-FDG PET/CT images were applied to help the discrimination of tumour from inflammation and adjacent normal tissue. Five patients with OPC underwent dynamic [ 18 F]-FDG PET/CT imaging in treatment position. Voxel-by-voxel analysis was performed to evaluate seven dynamic features developed with the knowledge of differences in glucose metabolism in different tissue types and visual inspection of TACs. The Gaussian mixture model and K-means algorithms were used to evaluate the performance of the dynamic features in discriminating tumour voxels compared to the performance of standardized uptake values obtained from static imaging. Some dynamic features showed a trend towards discrimination of different metabolic areas but lack of consistency means that clinical application is not recommended based on these results alone. Impact of inflammatory tissue remains a problem for volume delineation in RT of OPC, but a simple dynamic imaging protocol proved practicable and enabled simple data analysis techniques that show promise for complementing the information in static uptake values.

A Quantitative Analysis of the Relationship between Medicare Payment and Service Volume for Glaucoma Procedures from 2005 through 2009.

PubMed

Gong, Dan; Jun, Lin; Tsai, James C

2015-05-01

To calculate the association between Medicare payment and service volume for 6 commonly performed glaucoma procedures. Retrospective, longitudinal database study. A 100% dataset of all glaucoma procedures performed on Medicare Part B beneficiaries within the United States from 2005 to 2009. Fixed-effects regression model using Medicare Part B carrier data for all 50 states and the District of Columbia, controlling for time-invariant carrier-specific characteristics, national trends in glaucoma service volume, Medicare beneficiary population, number of ophthalmologists, and income per capita. Payment-volume elasticities, defined as the percent change in service volume per 1% change in Medicare payment, for laser trabeculoplasty (Current Procedural Terminology [CPT] code 65855), trabeculectomy without previous surgery (CPT code 66170), trabeculectomy with previous surgery (CPT code 66172), aqueous shunt to reservoir (CPT code 66180), laser iridotomy (CPT code 66761), and scleral reinforcement with graft (CPT code 67255). The payment-volume elasticity was nonsignificant for 4 of 6 procedures studied: laser trabeculoplasty (elasticity, -0.27; 95% confidence interval [CI], -1.31 to 0.77; P = 0.61), trabeculectomy without previous surgery (elasticity, -0.42; 95% CI, -0.85 to 0.01; P = 0.053), trabeculectomy with previous surgery (elasticity, -0.28; 95% CI, -0.83 to 0.28; P = 0.32), and aqueous shunt to reservoir (elasticity, -0.47; 95% CI, -3.32 to 2.37; P = 0.74). Two procedures yielded significant associations between Medicare payment and service volume. For laser iridotomy, the payment-volume elasticity was -1.06 (95% CI, -1.39 to -0.72; P < 0.001): for every 1% decrease in CPT code 66761 payment, laser iridotomy service volume increased by 1.06%. For scleral reinforcement with graft, the payment-volume elasticity was -2.92 (95% CI, -5.72 to -0.12; P = 0.041): for every 1% decrease in CPT code 67255 payment, scleral reinforcement with graft service volume increased by 2.92%. This study calculated the association between Medicare payment and service volume for 6 commonly performed glaucoma procedures and found varying magnitudes of payment-volume elasticities, suggesting that the volume response to changes in Medicare payments, if present, is not uniform across all Medicare procedures. Copyright © 2015 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

175.4 The Relationship of Aging and Inflammatory Biomarkers to Gray Matter Volume and Episodic Memory Performance in Schizophrenia: Evidence of Pathological Accelerated Aging

PubMed Central

Gama, Clarissa

2017-01-01

Abstract Background: Schizophrenia (SZ) is associated with increased somatic morbidity and mortality, in addition to cognitive impairments similar to those seen in normal aging, which may suggest that pathological accelerated aging occurs in SZ. Therefore, we aim to evaluate the relationships of age, telomere length (TL) and CCL11 (aging and inflammatory biomarkers), and gray matter volumes (GM) to episodic memory performance in individuals with SZ compared to healthy controls (HC). Methods: 112 participants (48 SZ and 64 HC) underwent clinical and memory assessments, structural MRI, and had their peripheral blood drawn for biomarkers analysis. Comparisons of group means and correlations were performed. Results: Participants with SZ had decreased TL and GM residual volume, increased CCL11, and worse memory performance compared to HC. In SZ, shorter TL was related to increased CCL11, and they were both related to reduced GM residual volume, all of which were related to worse memory performance. Older age was only associated with reduced GM, but longer duration of illness was related with all the aforementioned variables. Younger age of disease onset was related with increased CCL11 levels and worse memory performance. In HC, there were no significant correlations except for between memory and GM. Conclusion: Our results are consistent with accelerated aging in SZ. These results may indicate that it is not age itself, but the impact of the disease associated with a pathological accelerated aging that leads to impaired outcomes in SZ. Akira Sawa, johns Hopkins University, Johns Hopkins Hospital and Medical Institutions

A Study of ATLAS Grid Performance for Distributed Analysis

NASA Astrophysics Data System (ADS)

Panitkin, Sergey; Fine, Valery; Wenaus, Torre

2012-12-01

In the past two years the ATLAS Collaboration at the LHC has collected a large volume of data and published a number of ground breaking papers. The Grid-based ATLAS distributed computing infrastructure played a crucial role in enabling timely analysis of the data. We will present a study of the performance and usage of the ATLAS Grid as platform for physics analysis in 2011. This includes studies of general properties as well as timing properties of user jobs (wait time, run time, etc). These studies are based on mining of data archived by the PanDA workload management system.

Design analysis and computer-aided performance evaluation of shuttle orbiter electrical power system. Volume 1: Summary

NASA Technical Reports Server (NTRS)

1974-01-01

Studies were conducted to develop appropriate space shuttle electrical power distribution and control (EPDC) subsystem simulation models and to apply the computer simulations to systems analysis of the EPDC. A previously developed software program (SYSTID) was adapted for this purpose. The following objectives were attained: (1) significant enhancement of the SYSTID time domain simulation software, (2) generation of functionally useful shuttle EPDC element models, and (3) illustrative simulation results in the analysis of EPDC performance, under the conditions of fault, current pulse injection due to lightning, and circuit protection sizing and reaction times.

Lung ventilation strategies for acute respiratory distress syndrome: a systematic review and network meta-analysis

PubMed Central

Wang, Changsong; Wang, Xiaoyang; Chi, Chunjie; Guo, Libo; Guo, Lei; Zhao, Nana; Wang, Weiwei; Pi, Xin; Sun, Bo; Lian, Ailing; Shi, Jinghui; Li, Enyou

2016-01-01

To identify the best lung ventilation strategy for acute respiratory distress syndrome (ARDS), we performed a network meta-analysis. The Cochrane Central Register of Controlled Trials, EMBASE, MEDLINE, CINAHL, and the Web of Science were searched, and 36 eligible articles were included. Compared with higher tidal volumes with FiO2-guided lower positive end-expiratory pressure [PEEP], the hazard ratios (HRs) for mortality were 0.624 (95% confidence interval (CI) 0.419–0.98) for lower tidal volumes with FiO2-guided lower PEEP and prone positioning and 0.572 (0.34–0.968) for pressure-controlled ventilation with FiO2-guided lower PEEP. Lower tidal volumes with FiO2-guided higher PEEP and prone positioning had the greatest potential to reduce mortality, and the possibility of receiving the first ranking was 61.6%. Permissive hypercapnia, recruitment maneuver, and low airway pressures were most likely to be the worst in terms of all-cause mortality. Compared with higher tidal volumes with FiO2-guided lower PEEP, pressure-controlled ventilation with FiO2-guided lower PEEP and lower tidal volumes with FiO2-guided lower PEEP and prone positioning ventilation are associated with lower mortality in ARDS patients. Lower tidal volumes with FiO2-guided higher PEEP and prone positioning ventilation and lower tidal volumes with pressure-volume (P–V) static curve-guided individual PEEP are potential optimal strategies for ARDS patients. PMID:26955891

[Experience of a Break-Even Point Analysis for Make-or-Buy Decision.].

PubMed

Kim, Yunhee

2006-12-01

Cost containment through continuous quality improvement of medical service is required in an age of a keen competition of the medical market. Laboratory managers should examine the matters on make-or-buy decision periodically. On this occasion, a break-even point analysis can be useful as an analyzing tool. In this study, cost accounting and break-even point (BEP) analysis were performed in case that the immunoassay items showing a recent increase in order volume were to be in-house made. Fixed and variable costs were calculated in case that alpha fetoprotein (AFP), carcinoembryonic antigen (CEA), prostate-specific antigen (PSA), ferritin, free thyroxine (fT4), triiodothyronine (T3), thyroid-stimulating hormone (TSH), CA 125, CA 19-9, and hepatitis B envelope antibody (HBeAb) were to be tested with Abbott AxSYM instrument. Break-even volume was calculated as fixed cost per year divided by purchasing cost per test minus variable cost per test and BEP ratio as total purchasing costs at break-even volume divided by total purchasing costs at actual annual volume. The average fixed cost per year of AFP, CEA, PSA, ferritin, fT4, T3, TSH, CA 125, CA 19-9, and HBeAb was 8,279,187 won and average variable cost per test, 3,786 won. Average break-even volume was 1,599 and average BEP ratio was 852%. Average BEP ratio without including quality costs such as calibration and quality control was 74%. Because the quality assurance of clinical tests cannot be waived, outsourcing all of 10 items was more adequate than in-house make at the present volume in financial aspect. BEP analysis was useful as a financial tool for make-or-buy decision, the common matter which laboratory managers meet with.

Development and proof-of-concept of three-dimensional lung histology volumes

NASA Astrophysics Data System (ADS)

Mathew, Lindsay; Alabousi, Mostafa; Wheatley, Andrew; Aladl, Usaf; Slipetz, Deborah; Hogg, James C.; Fenster, Aaron; Parraga, Grace

2012-03-01

Most medical imaging is inherently three-dimensional (3D) but for validation of pathological findings, histopathology is commonly used and typically histopathology images are acquired as twodimensional slices with quantitative analysis performed in a single dimension. Histopathology is invasive, labour-intensive, and the analysis cannot be performed in real time, yet it remains the gold standard for the pathological diagnosis and validation of clinical or radiological diagnoses of disease. A major goal worldwide is to improve medical imaging resolution, sensitivity and specificity to better guide therapy and biopsy and to one day delay or replace biopsy. A key limitation however is the lack of tools to directly compare 3D macroscopic imaging acquired in patients with histopathology findings, typically provided in a single dimension (1D) or in two dimensions (2D). To directly address this, we developed methods for 2D histology slice visualization/registration to generate 3D volumes and quantified tissue components in the 3D volume for direct comparison to volumetric micro-CT and clinical CT. We used the elastase-instilled mouse emphysema lung model to evaluate our methods with murine lungs sectioned (5 μm thickness/10 μm gap) and digitized with 2μm in-plane resolution. 3D volumes were generated for wildtype and elastase mouse lung sections after semi-automated registration of all tissue slices. The 1D mean linear intercept (Lm) for wildtype (WT) (47.1 μm +/- 9.8 μm) and elastase mouse lung (64.5 μm +/- 14.0 μm) was significantly different (p<.001). We also generated 3D measurements based on tissue and airspace morphometry from the 3D volumes and all of these were significantly different (p<.0001) when comparing elastase and WT mouse lung. The ratio of the airspace-to-lung volume for the entire lung volume was also significantly and strongly correlated with Lm.

Analysis of Hydraulic Servo Equations for WRDRF Prototype Control System : Volume I

DOT National Transportation Integrated Search

1971-10-01

A set of dynamic performance equations derived by Wylie Labs., Huntsville, Alabama, were independently rederived and checked. These equations describe the perfromance of the prototype electro hydraulic servo actuator system selected by Wylie as repre...

Cyclic fatigue analysis of rocket thrust chambers. Volume 1: OFHC copper chamber low cycle fatigue

NASA Technical Reports Server (NTRS)

Miller, R. W.

1974-01-01

A three-dimensional finite element elasto-plastic strain analysis was performed for the throat section of a regeneratively cooled rocket combustion chamber. The analysis employed the RETSCP finite element computer program. The analysis included thermal and pressure loads, and the effects of temperature dependent material properties, to determine the strain range corresponding to the chamber operating cycle. The analysis was performed for chamber configuration and operating conditions corresponding to a hydrogen-oxygen combustion chamber which was fatigue tested to failure. The computed strain range at typical chamber operating conditions was used in conjunction with oxygen-free, high-conductivity (OHFC) copper isothermal fatigue test data to predict chamber low-cycle fatigue life.

Functional Data Analysis in NTCP Modeling: A New Method to Explore the Radiation Dose-Volume Effects

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

Benadjaoud, Mohamed Amine, E-mail: mohamedamine.benadjaoud@gustaveroussy.fr; Université Paris sud, Le Kremlin-Bicêtre; Institut Gustave Roussy, Villejuif

2014-11-01

Purpose/Objective(s): To describe a novel method to explore radiation dose-volume effects. Functional data analysis is used to investigate the information contained in differential dose-volume histograms. The method is applied to the normal tissue complication probability modeling of rectal bleeding (RB) for patients irradiated in the prostatic bed by 3-dimensional conformal radiation therapy. Methods and Materials: Kernel density estimation was used to estimate the individual probability density functions from each of the 141 rectum differential dose-volume histograms. Functional principal component analysis was performed on the estimated probability density functions to explore the variation modes in the dose distribution. The functional principalmore » components were then tested for association with RB using logistic regression adapted to functional covariates (FLR). For comparison, 3 other normal tissue complication probability models were considered: the Lyman-Kutcher-Burman model, logistic model based on standard dosimetric parameters (LM), and logistic model based on multivariate principal component analysis (PCA). Results: The incidence rate of grade ≥2 RB was 14%. V{sub 65Gy} was the most predictive factor for the LM (P=.058). The best fit for the Lyman-Kutcher-Burman model was obtained with n=0.12, m = 0.17, and TD50 = 72.6 Gy. In PCA and FLR, the components that describe the interdependence between the relative volumes exposed at intermediate and high doses were the most correlated to the complication. The FLR parameter function leads to a better understanding of the volume effect by including the treatment specificity in the delivered mechanistic information. For RB grade ≥2, patients with advanced age are significantly at risk (odds ratio, 1.123; 95% confidence interval, 1.03-1.22), and the fits of the LM, PCA, and functional principal component analysis models are significantly improved by including this clinical factor. Conclusion: Functional data analysis provides an attractive method for flexibly estimating the dose-volume effect for normal tissues in external radiation therapy.« less

MDCT quantification is the dominant parameter in decision-making regarding chest tube drainage for stable patients with traumatic pneumothorax.

PubMed

Cai, Wenli; Lee, June-Goo; Fikry, Karim; Yoshida, Hiroyuki; Novelline, Robert; de Moya, Marc

2012-07-01

It is commonly believed that the size of a pneumothorax is an important determinant of treatment decision, in particular regarding whether chest tube drainage (CTD) is required. However, the volumetric quantification of pneumothoraces has not routinely been performed in clinics. In this paper, we introduced an automated computer-aided volumetry (CAV) scheme for quantification of volume of pneumothoraces in chest multi-detect CT (MDCT) images. Moreover, we investigated the impact of accurate volume of pneumothoraces in the improvement of the performance in decision-making regarding CTD in the management of traumatic pneumothoraces. For this purpose, an occurrence frequency map was calculated for quantitative analysis of the importance of each clinical parameter in the decision-making regarding CTD by a computer simulation of decision-making using a genetic algorithm (GA) and a support vector machine (SVM). A total of 14 clinical parameters, including volume of pneumothorax calculated by our CAV scheme, was collected as parameters available for decision-making. The results showed that volume was the dominant parameter in decision-making regarding CTD, with an occurrence frequency value of 1.00. The results also indicated that the inclusion of volume provided the best performance that was statistically significant compared to the other tests in which volume was excluded from the clinical parameters. This study provides the scientific evidence for the application of CAV scheme in MDCT volumetric quantification of pneumothoraces in the management of clinically stable chest trauma patients with traumatic pneumothorax. Copyright © 2012 Elsevier Ltd. All rights reserved.

A decade of changes in brain volume and cognition.

PubMed

Aljondi, Rowa; Szoeke, Cassandra; Steward, Chris; Yates, Paul; Desmond, Patricia

2018-05-09

Brain atrophy can occur several decades prior to onset of cognitive impairments. However, few longitudinal studies have examined the relationship between brain volume changes and cognition over a long follow-up period in healthy elderly women. In the present study we investigate the relationship between whole brain and hippocampal atrophy rates and longitudinal changes in cognition, including verbal episodic memory and executive function, in older women. We also examine whether baseline brain volume predicts subsequent changes in cognitive performance over a 10-year period. A total of 60 individuals from the population-based Women's Healthy Ageing Project with a mean age at baseline of 59 years underwent 3T MRI. Of these, 40 women completed follow-up cognitive assessments, 23 of whom had follow-up MRI scans. Linear regression analysis was used to examine the relationship between brain atrophy and changes in verbal episodic memory and executive function over a 10-year period. The results show that baseline measurements of frontal and temporal grey matter volumes predict changes in verbal episodic memory performance, whereas hippocampal volume at baseline is associated with changes in executive function performance over a 10-year period of follow-ups. In addition, higher whole brain and hippocampal atrophy rates are correlated with a decline in verbal episodic memory. These findings indicate that in addition to atrophy rate, smaller regional grey matter volumes even 10 years prior is associated with increased rates of cognitive decline. This study suggests useful neuroimaging biomarkers for the prediction of cognitive decline in healthy elderly women.

Nanopipettes: probes for local sample analysis.

PubMed

Saha-Shah, Anumita; Weber, Anna E; Karty, Jonathan A; Ray, Steven J; Hieftje, Gary M; Baker, Lane A

2015-06-01

Nanopipettes (pipettes with diameters <1 μm) were explored as pressure-driven fluid manipulation tools for sampling nanoliter volumes of fluids. The fundamental behavior of fluids confined in the narrow channels of the nanopipette shank was studied to optimize sampling volume and probe geometry. This method was utilized to collect nanoliter volumes (<10 nL) of sample from single Allium cepa cells and live Drosophila melanogaster first instar larvae. Matrix assisted laser desorption/ionization-mass spectrometry (MALDI-MS) was utilized to characterize the collected sample. The use of nanopipettes for surface sampling of mouse brain tissue sections was also explored. Lipid analyses were performed on mouse brain tissues with spatial resolution of sampling as small as 50 μm. Nanopipettes were shown to be a versatile tool that will find further application in studies of sample heterogeneity and population analysis for a wide range of samples.

Confined detection volume of fluorescence correlation spectroscopy by bare fiber probes.

PubMed

Lu, Guowei; Lei, Franck H; Angiboust, Jean-François; Manfait, Michel

2010-04-01

A fiber-tip-based near-field fluorescence correlation spectroscopy (FCS) has been developed for confining the detection volume to sub-diffraction-limited dimensions. This near-field FCS is based on near-field illumination by coupling a scanning near-field optical microscope (SNOM) to a conventional confocal FCS. Single-molecule FCS analysis at 100 nM Rhodamine 6G has been achieved by using bare chemically etched, tapered fiber tips. The detection volume under control of the SNOM system has been reduced over one order of magnitude compared to that of the conventional confocal FCS. Related factors influencing the near-field FCS performance are investigated and discussed in detail. In this proof-of-principle study, the preliminary experimental results suggest that the fiber-tip-based near-field FCS might be a good alternative to realize localized analysis at the single-molecule level.

Associations of Early Kidney Disease With Brain Magnetic Resonance Imaging and Cognitive Function in African Americans With Type 2 Diabetes Mellitus.

PubMed

Freedman, Barry I; Sink, Kaycee M; Hugenschmidt, Christina E; Hughes, Timothy M; Williamson, Jeff D; Whitlow, Christopher T; Palmer, Nicholette D; Miller, Michael E; Lovato, Laura C; Xu, Jianzhao; Smith, S Carrie; Launer, Lenore J; Barzilay, Joshua I; Cohen, Robert M; Sullivan, Mark D; Bryan, R Nick; Wagner, Benjamin C; Bowden, Donald W; Maldjian, Joseph A; Divers, Jasmin

2017-11-01

Relationships between early kidney disease, neurocognitive function, and brain anatomy are poorly defined in African Americans with type 2 diabetes mellitus (T2DM). Cross-sectional associations were assessed between cerebral anatomy and cognitive performance with estimated glomerular filtration rate (eGFR) and urine albumin-creatinine ratio (UACR) in African Americans with T2DM. African Americans with cognitive testing and cerebral magnetic resonance imaging (MRI) in the African American-Diabetes Heart Study Memory in Diabetes (AA-DHS MIND; n=512; 480 with MRI) and Action to Control Cardiovascular Risk in Diabetes (ACCORD) MIND (n=484; 104 with MRI) studies. eGFR (CKD-EPI creatinine equation), spot UACR. MRI-based cerebral white matter volume (WMV), gray matter volume (GMV), and white matter lesion volume; cognitive performance (Mini-Mental State Examination, Digit Symbol Coding, Stroop Test, and Rey Auditory Verbal Learning Test). Multivariable models adjusted for age, sex, body mass index, scanner, intracranial volume, education, diabetes duration, hemoglobin A 1c concentration, low-density lipoprotein cholesterol concentration, smoking, hypertension, and cardiovascular disease were used to test for associations between kidney phenotypes and the brain in each study; a meta-analysis was performed. Mean participant age was 60.1±7.9 (SD) years; diabetes duration, 12.1±7.7 years; hemoglobin A 1c concentration, 8.3%±1.7%; eGFR, 88.7±21.6mL/min/1.73m 2 ; and UACR, 119.2±336.4mg/g. In the fully adjusted meta-analysis, higher GMV associated with lower UACR (P<0.05), with a trend toward association with higher eGFR. Higher white matter lesion volume was associated with higher UACR (P<0.05) and lower eGFR (P<0.001). WMV was not associated with either kidney parameter. Higher UACR was associated with lower Digit Symbol Coding performance (P<0.001) and a trend toward association with higher Stroop interference; eGFR was not associated with cognitive tests. Cross-sectional; single UACR measurement. In African Americans with T2DM, mildly high UACR and mildly low eGFR were associated with smaller GMV and increased white matter lesion volume. UACR was associated with poorer processing speed and working memory. Copyright © 2017 National Kidney Foundation, Inc. All rights reserved.

Correlation of Electrolyte Volume and Electrochemical Performance in Lithium-Ion Pouch Cells with Graphite Anodes and NMC532 Cathodes

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

An, Seong Jin; Li, Jianlin; Mohanty, Debasish

2017-01-01

The work herein reports on studies aimed at exploring the correlation between electrolyte volume and electrochemical performance of full cell, pouch-cells consisting of graphite/ Li 1.02Ni 0.50Mn 0.29Co 0.19O 2 (NMC-532) as the electrodes and 1.2 M LiPF6 in ethylene carbonate:ethylmethyl carbonate (EC:EMC) as the electrolyte. It is demonstrated that a minimum electrolyte volume factor of 1.9 times the total pore volume of cell components (cathode, anode, and separator) is needed for long-term cyclability and low impedance. Less electrolyte results in an increase of the measured ohmic resistances. Increased resistance ratios for charge transfer and passivation layers at cathode, relativemore » to initial values, were 1.5–2.0 after 100 cycles. At the cathode, the resistance from charge transfer was 2–3 times higher than for passivation layers. Differential voltage analysis showed that anodes were less delithiated after discharging as the cells were cycled.« less

Correlation of Electrolyte Volume and Electrochemical Performance in Lithium-Ion Pouch Cells with Graphite Anodes and NMC532 Cathodes

DOE PAGES

An, Seong Jin; Li, Jianlin; Mohanty, Debasish; ...

2017-04-07

The work herein reports on studies aimed at exploring the correlation between electrolyte volume and electrochemical performance of full cell, pouch-cells consisting of graphite/ Li 1.02Ni 0.50Mn 0.29Co 0.19O 2 (NMC-532) as the electrodes and 1.2 M LiPF 6 in ethylene carbonate:ethylmethyl carbonate (EC:EMC) as the electrolyte. In addition, it is demonstrated that a minimum electrolyte volume factor of 1.9 times the total pore volume of cell components (cathode, anode, and separator) is needed for long-term cyclability and low impedance. Less electrolyte results in an increase of the measured Ohmic resistances. Increased resistance ratios for charge transfer and passivation layersmore » at cathode, relative to initial values, were 1.5 2.0 after 100 cycles. At the cathode, the resistance from charge transfer was 2-3 times higher than for passivation layers. Lastly, differential voltage analysis showed that anodes were less delithiated after discharging as the cells were cycled.« less

Physical activity volume in relation to risk of atrial fibrillation. A non-linear meta-regression analysis.

PubMed

Ricci, Cristian; Gervasi, Federico; Gaeta, Maddalena; Smuts, Cornelius M; Schutte, Aletta E; Leitzmann, Michael F

2018-05-01

Background Light physical activity is known to reduce atrial fibrillation risk, whereas moderate to vigorous physical activity may result in an increased risk. However, the question of what volume of physical activity can be considered beneficial remains poorly understood. The scope of the present work was to examine the relation between physical activity volume and atrial fibrillation risk. Design A comprehensive systematic review was performed following the PRISMA guidelines. Methods A non-linear meta-regression considering the amount of energy spent in physical activity was carried out. The first derivative of the non-linear relation between physical activity and atrial fibrillation risk was evaluated to determine the volume of physical activity that carried the minimum atrial fibrillation risk. Results The dose-response analysis of the relation between physical activity and atrial fibrillation risk showed that physical activity at volumes of 5-20 metabolic equivalents per week (MET-h/week) was associated with significant reduction in atrial fibrillation risk (relative risk for 19 MET-h/week = 0.92 (0.87, 0.98). By comparison, physical activity volumes exceeding 20 MET-h/week were unrelated to atrial fibrillation risk (relative risk for 21 MET-h/week = 0.95 (0.88, 1.02). Conclusion These data show a J-shaped relation between physical activity volume and atrial fibrillation risk. Physical activity at volumes of up to 20 MET-h/week is associated with reduced atrial fibrillation risk, whereas volumes exceeding 20 MET-h/week show no relation with risk.

On the utility of 3D hand cursors to explore medical volume datasets with a touchless interface.

PubMed

Lopes, Daniel Simões; Parreira, Pedro Duarte de Figueiredo; Paulo, Soraia Figueiredo; Nunes, Vitor; Rego, Paulo Amaral; Neves, Manuel Cassiano; Rodrigues, Pedro Silva; Jorge, Joaquim Armando

2017-08-01

Analyzing medical volume datasets requires interactive visualization so that users can extract anatomo-physiological information in real-time. Conventional volume rendering systems rely on 2D input devices, such as mice and keyboards, which are known to hamper 3D analysis as users often struggle to obtain the desired orientation that is only achieved after several attempts. In this paper, we address which 3D analysis tools are better performed with 3D hand cursors operating on a touchless interface comparatively to a 2D input devices running on a conventional WIMP interface. The main goals of this paper are to explore the capabilities of (simple) hand gestures to facilitate sterile manipulation of 3D medical data on a touchless interface, without resorting on wearables, and to evaluate the surgical feasibility of the proposed interface next to senior surgeons (N=5) and interns (N=2). To this end, we developed a touchless interface controlled via hand gestures and body postures to rapidly rotate and position medical volume images in three-dimensions, where each hand acts as an interactive 3D cursor. User studies were conducted with laypeople, while informal evaluation sessions were carried with senior surgeons, radiologists and professional biomedical engineers. Results demonstrate its usability as the proposed touchless interface improves spatial awareness and a more fluent interaction with the 3D volume than with traditional 2D input devices, as it requires lesser number of attempts to achieve the desired orientation by avoiding the composition of several cumulative rotations, which is typically necessary in WIMP interfaces. However, tasks requiring precision such as clipping plane visualization and tagging are best performed with mouse-based systems due to noise, incorrect gestures detection and problems in skeleton tracking that need to be addressed before tests in real medical environments might be performed. Copyright © 2017 Elsevier Inc. All rights reserved.

Regular Topologies for Gigabit Wide-Area Networks. Volume 1

NASA Technical Reports Server (NTRS)

Shacham, Nachum; Denny, Barbara A.; Lee, Diane S.; Khan, Irfan H.; Lee, Danny Y. C.; McKenney, Paul

1994-01-01

In general terms, this project aimed at the analysis and design of techniques for very high-speed networking. The formal objectives of the project were to: (1) Identify switch and network technologies for wide-area networks that interconnect a large number of users and can provide individual data paths at gigabit/s rates; (2) Quantitatively evaluate and compare existing and proposed architectures and protocols, identify their strength and growth potentials, and ascertain the compatibility of competing technologies; and (3) Propose new approaches to existing architectures and protocols, and identify opportunities for research to overcome deficiencies and enhance performance. The project was organized into two parts: 1. The design, analysis, and specification of techniques and protocols for very-high-speed network environments. In this part, SRI has focused on several key high-speed networking areas, including Forward Error Control (FEC) for high-speed networks in which data distortion is the result of packet loss, and the distribution of broadband, real-time traffic in multiple user sessions. 2. Congestion Avoidance Testbed Experiment (CATE). This part of the project was done within the framework of the DARTnet experimental T1 national network. The aim of the work was to advance the state of the art in benchmarking DARTnet's performance and traffic control by developing support tools for network experimentation, by designing benchmarks that allow various algorithms to be meaningfully compared, and by investigating new queueing techniques that better satisfy the needs of best-effort and reserved-resource traffic. This document is the final technical report describing the results obtained by SRI under this project. The report consists of three volumes: Volume 1 contains a technical description of the network techniques developed by SRI in the areas of FEC and multicast of real-time traffic. Volume 2 describes the work performed under CATE. Volume 3 contains the source code of all software developed under CATE.

How the dispersion of magnesium oxide nanoparticles effects on the viscosity of water-ethylene glycol mixture: Experimental evaluation and correlation development

NASA Astrophysics Data System (ADS)

Afrand, Masoud; Abedini, Ehsan; Teimouri, Hamid

2017-03-01

In this paper, the effect of dispersion of magnesium oxide nanoparticles on viscosity of a mixture of water and ethylene glycol (50-50% vol.) was examined experimentally. Experiments were performed for various nanofluid samples at different temperatures and shear rates. Measurements revealed that the nanofluid samples with volume fractions of less than 1.5% had Newtonian behavior, while the sample with volume fraction of 3% showed non-Newtonian behavior. Results showed that the viscosity of nanofluids enhanced with increasing nanoparticles volume fraction and decreasing temperature. Results of sensitivity analysis revealed that the viscosity sensitivity of nanofluid samples to temperature at higher volume fractions is more than that of at lower volume fractions. Finally, because of the inability of the existing model to predict the viscosity of MgO/EG-water nanofluid, an experimental correlation has been proposed for predicting the viscosity of the nanofluid.

Heat transfer analysis of radiator using graphene oxide nanofluids

NASA Astrophysics Data System (ADS)

Rao Ponangi, Babu; Sumanth, S.; Krishna, V.; Seetharam, T. R.; Seetharamu, K. N.

2018-04-01

As the technology is developing day by day, there is a requirement for enhancement in performance of automobile radiator to have a better performance of the IC Engine and fuel effectiveness. One of the major and recent approach to upgrade the performance of a radiator is that nanoparticles must be suspended in the general coolant (Ethylene Glycol – Water) which form nanofluids. Present work has been carried out by suspending graphene oxide nanoparticles in 50:50 Ethylene Glycol and RO-Water as base fluid. Experimentation is carried out by using three volume concentrations of the nanofluid (0.02%, 0.03% and 0.04%) and at different volumetric flow rates ranging from 3 to 6 LPM. Effect of volume concentration, inlet temperature and flow rate on Effectiveness, pressure drop and friction factor has been studied experimentally. Effectiveness versus NTU curves are plotted for further design calculations. The results show that the nanofluids will enhance the performance of an automobile radiator when compared with base fluid. Results also shows a maximum of 56.45% and 41.47% improvement in effectiveness for 0.03% volume concentration and 5 LPM flow rate at 40°C and 50°C inlet temperatures respectively.

Study of cavitating inducer instabilities

NASA Technical Reports Server (NTRS)

Young, W. E.; Murphy, R.; Reddecliff, J. M.

1972-01-01

An analytic and experimental investigation into the causes and mechanisms of cavitating inducer instabilities was conducted. Hydrofoil cascade tests were performed, during which cavity sizes were measured. The measured data were used, along with inducer data and potential flow predictions, to refine an analysis for the prediction of inducer blade suction surface cavitation cavity volume. Cavity volume predictions were incorporated into a linearized system model, and instability predictions for an inducer water test loop were generated. Inducer tests were conducted and instability predictions correlated favorably with measured instability data.

Ada (Trade Name) Foundation Technology. Volume 4. Software Requirements for WIS (WWMCCS (World Wide Military Command and Control System) Information System) Text Processing Prototypes

DTIC Science & Technology

1986-12-01

graphics : The package allows a character set which can be defined by users giving the picture for a character by designating its pixels. Such characters...type lonts and gsei-oriented "help" messages tailored to the operations being performed and user expertise In general, critical design issues...other volumes include command language, software design , description and analysis tools, database management system operating systems; planning and

[Stereological analysis of rat bone tissue after a flight on the Kosmos-1129 biosatellite].

PubMed

Prokhonchukov, A A; Peschanskiĭ, V S

1982-01-01

Stereological measurements of volume fractions of 53 samples of compact and spongy structures of bones of 15 rats were carried out. The measurements were performed on cortical lamellae, trabecules and lacunae, channels of osteons and matrices of femoral, tibial and fibular bones of rats. Postflight no significant changes were seen in the above parameters as compared to the vivarium controls. During readaptation to I g a slight increase in the volume fraction of spongy bones was noted.

Design improvement of permanent magnet flux switching motor with dual rotor structure

NASA Astrophysics Data System (ADS)

Soomro, H. A.; Sulaiman, E.; Kumar, R.; Rahim, N. S.

2017-08-01

This paper presents design enhancement to reduce permanent magnet (PM) volume for 7S-6P-7S dual rotor permanent magnet flux-switching machines (DRPMFSM) for electric vehicle application. In recent years, Permanent magnet flux switching (PMFS) motor and a new member of brushless permanent magnet machine are prominently used for the electric vehicle. Though, more volume of Rare-Earth Permanent Magnet (REPM) is used to increase the cost and weight of these motors. Thus, to overcome the issue, new configuration of 7S-6P- 7S dual rotor permanent magnet flux-switching machine (DRPMFSM) has been proposed and investigated in this paper. Initially proposed 7S-6P-7S DRPMFSM has been optimized using “deterministic optimization” to reduce the volume of PM and to attain optimum performances. In addition, the performances of initial and optimized DRPMFSM have been compared such that back-emf, cogging torque, average torque, torque and power vs speed performances, losses and efficiency have been analysed by 2D-finite element analysis (FEA) using the JMAG- Designer software ver. 14.1. Consequently, the final design 7S-6P-7S DRPMFSM has achieved the efficiency of 83.91% at reduced PM volume than initial design to confirm the better efficient motor for HEVs applications.

The influence of cellulose nanocrystal additions on the performance of cement paste

Treesearch

Yizheng Cao; Pablo Zavaterri; Jeff Youngblood; Robert Moon; Jason Weiss

2015-01-01

The influence of cellulose nanocrystals (CNCs) addition on the performance of cement paste was investigated. Our mechanical tests show an increase in the flexural strength of approximately 30% with only 0.2% volume of CNCs with respect to cement. Isothermal calorimetry (IC) and thermogravimetric analysis (TGA) show that the degree of hydration (DOH) of the cement paste...

SRM Internal Flow Test and Computational Fluid Dynamic Analysis. Volume 1; Major Task Summaries

NASA Technical Reports Server (NTRS)

Whitesides, R. Harold; Dill, Richard A.; Purinton, David C.

1995-01-01

During the four year period of performance for NASA contract, NASB-39095, ERC has performed a wide variety of tasks to support the design and continued development of new and existing solid rocket motors and the resolution of operational problems associated with existing solid rocket motor's at NASA MSFC. This report summarizes the support provided to NASA MSFC during the contractual period of performance. The report is divided into three main sections. The first section presents summaries for the major tasks performed. These tasks are grouped into three major categories: full scale motor analysis, subscale motor analysis and cold flow analysis. The second section includes summaries describing the computational fluid dynamics (CFD) tasks performed. The third section, the appendices of the report, presents detailed descriptions of the analysis efforts as well as published papers, memoranda and final reports associated with specific tasks. These appendices are referenced in the summaries. The subsection numbers for the three sections correspond to the same topics for direct cross referencing.

Computer program for design and performance analysis of navigation-aid power systems. Program documentation. Volume 1: Software requirements document

NASA Technical Reports Server (NTRS)

Goltz, G.; Kaiser, L. M.; Weiner, H.

1977-01-01

A computer program has been developed for designing and analyzing the performance of solar array/battery power systems for the U.S. Coast Guard Navigational Aids. This program is called the Design Synthesis/Performance Analysis (DSPA) Computer Program. The basic function of the Design Synthesis portion of the DSPA program is to evaluate functional and economic criteria to provide specifications for viable solar array/battery power systems. The basic function of the Performance Analysis portion of the DSPA program is to simulate the operation of solar array/battery power systems under specific loads and environmental conditions. This document establishes the software requirements for the DSPA computer program, discusses the processing that occurs within the program, and defines the necessary interfaces for operation.

Surgeon specialization and operative mortality in United States: retrospective analysis.

PubMed

Sahni, Nikhil R; Dalton, Maurice; Cutler, David M; Birkmeyer, John D; Chandra, Amitabh

2016-07-21

 To measure the association between a surgeon's degree of specialization in a specific procedure and patient mortality.  Retrospective analysis of Medicare data.  US patients aged 66 or older enrolled in traditional fee for service Medicare.  25 152 US surgeons who performed one of eight procedures (carotid endarterectomy, coronary artery bypass grafting, valve replacement, abdominal aortic aneurysm repair, lung resection, cystectomy, pancreatic resection, or esophagectomy) on 695 987 patients in 2008-13.  Relative risk reduction in risk adjusted and volume adjusted 30 day operative mortality between surgeons in the bottom quarter and top quarter of surgeon specialization (defined as the number of times the surgeon performed the specific procedure divided by his/her total operative volume across all procedures).  For all four cardiovascular procedures and two out of four cancer resections, a surgeon's degree of specialization was a significant predictor of operative mortality independent of the number of times he or she performed that procedure: carotid endarterectomy (relative risk reduction between bottom and top quarter of surgeons 28%, 95% confidence interval 0% to 48%); coronary artery bypass grafting (15%, 4% to 25%); valve replacement (46%, 37% to 53%); abdominal aortic aneurysm repair (42%, 29% to 53%); lung resection (28%, 5% to 46%); and cystectomy (41%, 8% to 63%). In five procedures (carotid endarterectomy, valve replacement, lung resection, cystectomy, and esophagectomy), the relative risk reduction from surgeon specialization was greater than that from surgeon volume for that specific procedure. Furthermore, surgeon specialization accounted for 9% (coronary artery bypass grafting) to 100% (cystectomy) of the relative risk reduction otherwise attributable to volume in that specific procedure.  For several common procedures, surgeon specialization was an important predictor of operative mortality independent of volume in that specific procedure. When selecting a surgeon, patients, referring physicians, and administrators assigning operative workload may want to consider a surgeon's procedure specific volume as well as the degree to which a surgeon specializes in that procedure. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Zero-mode clad waveguides for performing spectroscopy with confined effective observation volumes

DOEpatents

Levene, Michael J.; Korlach, Jonas; Turner, Stephen W.; Craighead, Harold G.; Webb, Watt W.

2005-07-12

The present invention is directed to a method and an apparatus for analysis of an analyte. The method involves providing a zero-mode waveguide which includes a cladding surrounding a core where the cladding is configured to preclude propagation of electromagnetic energy of a frequency less than a cutoff frequency longitudinally through the core of the zero-mode waveguide. The analyte is positioned in the core of the zero-mode waveguide and is then subjected, in the core of the zero-mode waveguide, to activating electromagnetic radiation of a frequency less than the cut-off frequency under conditions effective to permit analysis of the analyte in an effective observation volume which is more compact than if the analysis were carried out in the absence of the zero-mode waveguide.

Waveguides for performing spectroscopy with confined effective observation volumes

DOEpatents

Levene, Michael J.; Korlach, Jonas; Turner, Stephen W.; Craighead, Harold G.; Webb, Watt W.

2006-03-14

The present invention is directed to a method and an apparatus for analysis of an analyte. The method involves providing a zero-mode waveguide which includes a cladding surrounding a core where the cladding is configured to preclude propagation of electromagnetic energy of a frequency less than a cutoff frequency longitudinally through the core of the zero-mode waveguide. The analyte is positioned in the core of the zero-mode waveguide and is then subjected, in the core of the zero-mode waveguide, to activating electromagnetic radiation of a frequency less than the cut-off frequency under conditions effective to permit analysis of the analyte in an effective observation volume which is more compact than if the analysis were carried out in the absence of the zero-mode waveguide.

Predictive Utility of Marketed Volumetric Software Tools in Subjects at Risk for Alzheimer's: Do Regions Outside the Hippocampus Matter?

PubMed Central

Tanpitukpongse, Teerath P.; Mazurowski, Maciej A.; Ikhena, John; Petrella, Jeffrey R.

2016-01-01

Background and Purpose To assess prognostic efficacy of individual versus combined regional volumetrics in two commercially-available brain volumetric software packages for predicting conversion of patients with mild cognitive impairment to Alzheimer's disease. Materials and Methods Data was obtained through the Alzheimer's Disease Neuroimaging Initiative. 192 subjects (mean age 74.8 years, 39% female) diagnosed with mild cognitive impairment at baseline were studied. All had T1WI MRI sequences at baseline and 3-year clinical follow-up. Analysis was performed with NeuroQuant® and Neuroreader™. Receiver operating characteristic curves assessing the prognostic efficacy of each software package were generated using a univariable approach employing individual regional brain volumes, as well as two multivariable approaches (multiple regression and random forest), combining multiple volumes. Results On univariable analysis of 11 NeuroQuant® and 11 Neuroreader™ regional volumes, hippocampal volume had the highest area under the curve for both software packages (0.69 NeuroQuant®, 0.68 Neuroreader™), and was not significantly different (p > 0.05) between packages. Multivariable analysis did not increase the area under the curve for either package (0.63 logistic regression, 0.60 random forest NeuroQuant®; 0.65 logistic regression, 0.62 random forest Neuroreader™). Conclusion Of the multiple regional volume measures available in FDA-cleared brain volumetric software packages, hippocampal volume remains the best single predictor of conversion of mild cognitive impairment to Alzheimer's disease at 3-year follow-up. Combining volumetrics did not add additional prognostic efficacy. Therefore, future prognostic studies in MCI, combining such tools with demographic and other biomarker measures, are justified in using hippocampal volume as the only volumetric biomarker. PMID:28057634

Analysis of microdialysate monoamines, including noradrenaline, dopamine and serotonin, using capillary ultra-high performance liquid chromatography and electrochemical detection.

PubMed

Ferry, Barbara; Gifu, Elena-Patricia; Sandu, Ioana; Denoroy, Luc; Parrot, Sandrine

2014-03-01

Electrochemical methods are very often used to detect catecholamine and indolamine neurotransmitters separated by conventional reverse-phase high performance liquid chromatography (HPLC). The present paper presents the development of a chromatographic method to detect monoamines present in low-volume brain dialysis samples using a capillary column filled with sub-2μm particles. Several parameters (repeatability, linearity, accuracy, limit of detection) for this new ultrahigh performance liquid chromatography (UHPLC) method with electrochemical detection were examined after optimization of the analytical conditions. Noradrenaline, adrenaline, serotonin, dopamine and its metabolite 3-methoxytyramine were separated in 1μL of injected sample volume; they were detected above concentrations of 0.5-1nmol/L, with 2.1-9.5% accuracy and intra-assay repeatability equal to or less than 6%. The final method was applied to very low volume dialysates from rat brain containing monoamine traces. The study demonstrates that capillary UHPLC with electrochemical detection is suitable for monitoring dialysate monoamines collected at high sampling rate. Copyright © 2014 Elsevier B.V. All rights reserved.

Optimization design and performance analysis of a miniature stirling engine

NASA Astrophysics Data System (ADS)

You, Zhanping; Yang, Bo; Pan, Lisheng; Hao, Changsheng

2017-10-01

Under given operation conditions, a stirling engine of 2 kW is designed which takes hydrogen as working medium. Through establishment of adiabatic model, the ways are achieved about performance improving. The ways are raising the temperature of hot terminal, lowering the temperature of cold end, increasing the average cycle pressure, speeding up the speed, phase angle being 90°, stroke volume ratio approximating to 1 and increasing the performance of regenerator.

A medical software system for volumetric analysis of cerebral pathologies in magnetic resonance imaging (MRI) data.

PubMed

Egger, Jan; Kappus, Christoph; Freisleben, Bernd; Nimsky, Christopher

2012-08-01

In this contribution, a medical software system for volumetric analysis of different cerebral pathologies in magnetic resonance imaging (MRI) data is presented. The software system is based on a semi-automatic segmentation algorithm and helps to overcome the time-consuming process of volume determination during monitoring of a patient. After imaging, the parameter settings-including a seed point-are set up in the system and an automatic segmentation is performed by a novel graph-based approach. Manually reviewing the result leads to reseeding, adding seed points or an automatic surface mesh generation. The mesh is saved for monitoring the patient and for comparisons with follow-up scans. Based on the mesh, the system performs a voxelization and volume calculation, which leads to diagnosis and therefore further treatment decisions. The overall system has been tested with different cerebral pathologies-glioblastoma multiforme, pituitary adenomas and cerebral aneurysms- and evaluated against manual expert segmentations using the Dice Similarity Coefficient (DSC). Additionally, intra-physician segmentations have been performed to provide a quality measure for the presented system.

3-dimensional computed tomographic analysis of the pharynx in adult patients with unrepaired isolated cleft palate.

PubMed

Xu, Yi; Zhao, Shufan; Shi, Jiayu; Wang, Yan; Shi, Bing; Zheng, Qian; Lo, Lun-Jou

2013-08-01

This study investigated 3D differences of the pharynx in adult patients with unrepaired isolated cleft palate (ICP) versus normal adults using cone-beam computed tomography (CBCT). CBCT data of 32 adult patients with nonsyndromic unrepaired ICP and 30 normal controls were acquired. Image processing and analyses were performed using Mimics (Materialise NV, Leuven, Belgium). Linear, planar, and volumetric measurements and comparisons were performed between patients with ICP and controls. Interobserver and intraobserver reliabilities of 3D pharyngeal analysis were determined by the Pearson correlation coefficient. Statistical analyses comparing patients with ICP to normal adults were performed using independent-samples t test, with the significance threshold set at P = .05. Interobserver and intraobserver reliabilities were high. Pearson correlation coefficients ranged from 0.992 to 0.999 for interobserver measurements and from 0.994 to 0.999 for intraobserver measurements. Anterior height (P = .000), total depth (P = .003), and floor length (P = .034) of the bony nasopharynx; posteroanterior diameter of the pharyngeal airway at the palatal plane (P = .000); cross-sectional area of the pharyngeal airway at the palatal plane (P = .000); total volume (P = .031); volume above the palatal plane (P = .024); and the volume between the palatal plane and the plane of the most anterior point on the inferior margin of the outline of the body of the second cervical vertebra (P = .022) were larger in patients with ICP. This imaging study showed an enlarged nasopharynx in the sagittal plane and increased nasopharyngeal airway volume at the palatal plane in patients with ICP. Crown Copyright © 2013. Published by Elsevier Inc. All rights reserved.

Analysis of Radio Frequency Surveillance Systems for Air Traffic Control : Volume 1. Text.

DOT National Transportation Integrated Search

1976-02-01

Performance criteria that afford quantitative evaluation of a variety of current and proposed configurations of the Air Traffic Control Radar Beacon System (ATCRBS) are described in detail. Two analytic system models are developed to allow applicatio...

Collision avoidance system cost-benefit analysis : volume I - technical manual

DOT National Transportation Integrated Search

1981-09-01

Collision-avoidance systems under development in the U.S.A., Japan and Germany were evaluated. The performance evaluation showed that the signal processing and the control law of a system were the key parameters that decided the system's capability, ...

10 CFR 74.45 - Measurements and measurement control.

Code of Federal Regulations, 2013 CFR

2013-01-01

... measurements, obtaining samples, and performing laboratory analyses for element concentration and isotope... of random error behavior. On a predetermined schedule, the program shall include, as appropriate: (i) Replicate analyses of individual samples; (ii) Analysis of replicate process samples; (iii) Replicate volume...

10 CFR 74.45 - Measurements and measurement control.

Code of Federal Regulations, 2014 CFR

2014-01-01

... measurements, obtaining samples, and performing laboratory analyses for element concentration and isotope... of random error behavior. On a predetermined schedule, the program shall include, as appropriate: (i) Replicate analyses of individual samples; (ii) Analysis of replicate process samples; (iii) Replicate volume...

10 CFR 74.45 - Measurements and measurement control.

Code of Federal Regulations, 2012 CFR

2012-01-01

... measurements, obtaining samples, and performing laboratory analyses for element concentration and isotope... of random error behavior. On a predetermined schedule, the program shall include, as appropriate: (i) Replicate analyses of individual samples; (ii) Analysis of replicate process samples; (iii) Replicate volume...

Improving visit cycle time using patient flow analysis in a high-volume inner-city hospital-based ambulatory clinic serving minority New Yorkers.

PubMed

Dhar, Sanjay; Michel, Raquel; Kanna, Balavenkatesh

2011-01-01

Patient waiting time and waiting room congestion are quality indicators that are related to efficiency of ambulatory care systems and patient satisfaction. Our main purpose was to test a program to decrease patient visit cycle time, while maintaining high-quality healthcare in a high-volume inner-city hospital-based clinic in New York City. Use of patient flow analysis and the creation of patient care teams proved useful in identifying areas for improvement, target, and measure effectiveness of interventions. The end result is reduced visit cycle time, improved provider team performance, and sustained patient care outcomes. © 2010 National Association for Healthcare Quality.

Breast cancer screening in Italy: evaluating key performance indicators for time trends and activity volumes.

PubMed

Giordano, Livia; Castagno, Roberta; Giorgi, Daniela; Piccinelli, Cristiano; Ventura, Leonardo; Segnan, Nereo; Zappa, Marco

2015-01-01

Together with the National centre for screening monitoring (ONS), GISMa supports annual collection of data on national breast screening activities. Aggregated data on implementation and performance are gathered through a standardized form to calculate process and impact indicators. Analyzed data belong to 153 local programmes in the period 2006-2011 (2006-2012 for participation rate only). During the whole period, Italian crude participation rate exceeded GISMa's acceptable standard (50%), even though a higher participation in northern and central Italy compared to southern Italy and Islands was observed. Time trend analysis of diagnostic indicators confirmed in 2011 an adequate quality of breast screening performance, especially at subsequent screening. Recall rate at initial screening did not reach the acceptable standard (<7%) and rose slightly over the period. On the contrary, a good performance was achieved at subsequent screening. The same trend was followed by the overall detection rate and positive predictive value. They both showed a progressive reduction (from 6.2‰ in 2006 to 4.5‰ in 2011 for DR and from 8.0% in 2006 to 5.2% in 2011 for PPV, respectively) at initial screening and a good, stable trend at subsequent screening. Activity volume analysis shows that in programmes with greater activity (test/year ≥10,000) RR at both initial and subsequent screening has a better performance. This is also true for DR and PPV where programmes with high volumes of activity do better, especially when compared with those that interpret fewer than 5,000 mammograms per year. In spite of a few limits, these results are reassuring, and they reward the efforts made by screening professionals. It is therefore important to continue to monitor screening indicators and suggest, test, and evaluate new strategies for continuous improvement.

Comparison between the Prebolus T1 Measurement and the Fixed T1 Value in Dynamic Contrast-Enhanced MR Imaging for the Differentiation of True Progression from Pseudoprogression in Glioblastoma Treated with Concurrent Radiation Therapy and Temozolomide Chemotherapy.

PubMed

Nam, J G; Kang, K M; Choi, S H; Lim, W H; Yoo, R-E; Kim, J-H; Yun, T J; Sohn, C-H

2017-12-01

Glioblastoma is the most common primary brain malignancy and differentiation of true progression from pseudoprogression is clinically important. Our purpose was to compare the diagnostic performance of dynamic contrast-enhanced pharmacokinetic parameters using the fixed T1 and measured T1 on differentiating true from pseudoprogression of glioblastoma after chemoradiation with temozolomide. This retrospective study included 37 patients with histopathologically confirmed glioblastoma with new enhancing lesions after temozolomide chemoradiation defined as true progression ( n = 15) or pseudoprogression ( n = 22). Dynamic contrast-enhanced pharmacokinetic parameters, including the volume transfer constant, the rate transfer constant, the blood plasma volume per unit volume, and the extravascular extracellular space per unit volume, were calculated by using both the fixed T1 of 1000 ms and measured T1 by using the multiple flip-angle method. Intra- and interobserver reproducibility was assessed by using the intraclass correlation coefficient. Dynamic contrast-enhanced pharmacokinetic parameters were compared between the 2 groups by using univariate and multivariate analysis. The diagnostic performance was evaluated by receiver operating characteristic analysis and leave-one-out cross validation. The intraclass correlation coefficients of all the parameters from both T1 values were fair to excellent (0.689-0.999). The volume transfer constant and rate transfer constant from the fixed T1 were significantly higher in patients with true progression ( P = .048 and .010, respectively). Multivariate analysis revealed that the rate transfer constant from the fixed T1 was the only independent variable (OR, 1.77 × 10 5 ) and showed substantial diagnostic power on receiver operating characteristic analysis (area under the curve, 0.752; P = .002). The sensitivity and specificity on leave-one-out cross validation were 73.3% (11/15) and 59.1% (13/20), respectively. The dynamic contrast-enhanced parameter of rate transfer constant from the fixed T1 acted as a preferable marker to differentiate true progression from pseudoprogression. © 2017 by American Journal of Neuroradiology.

A study of space station needs, attributes, and architectural options, volume 2, technical. Book 2: Mission implementation concepts

NASA Technical Reports Server (NTRS)

1983-01-01

Space station systems characteristics and architecture are described. A manned space station operational analysis is performed to determine crew size, crew task complexity and time tables, and crew equipment to support the definition of systems and subsystems concepts. This analysis is used to select and evaluate the architectural options for development.

Micro-CT and nano-CT analysis of filling quality of three different endodontic sealers.

PubMed

Huang, Yan; Celikten, Berkan; de Faria Vasconcelos, Karla; Ferreira Pinheiro Nicolielo, Laura; Lippiatt, Nicholas; Buyuksungur, Arda; Jacobs, Reinhilde; Orhan, Kaan

2017-12-01

To investigate voids in different root canal sealers using micro-CT and nano-CT, and to explore the feasibility of using nano-CT for quantitative analysis of sealer filling quality. 30 extracted mandibular central incisors were randomly assigned into three groups according to the applied root canal sealers (Total BC Sealer, Sure Seal Root, AH Plus) by the single cone technique. Subsequently, micro-CT and nano-CT were performed to analyse the incidence rate of voids, void fraction, void volume and their distribution in each sample. Micro-CT evaluation showed no significant difference among sealers for the incidence rate of voids or void fraction in the whole filling materials (p > 0.05), whereas a significant difference was found between AH Plus and the other two sealers using nano-CT (p < 0.05). All three sealers presented less void volume in the apical third; however, higher void volumes were observed in the apical and coronal thirds in AH Plus using micro-CT (p < 0.05), while nano-CT results displayed higher void volume in AH Plus among all the sealers and regions (p < 0.05). Bioactive sealers showed higher root filling rate, lower incidence rate of voids, void fraction and void volume than AH Plus under nano-CT analysis, when round root canals were treated by the single cone technique. The disparate results suggest that the higher resolution of nano-CT have a greater ability of distinguishing internal porosity, and therefore suggesting the potential use of nano-CT in quantitative analysis of filling quality of sealers.

Risk factors for neovascular glaucoma after carbon ion radiotherapy of choroidal melanoma using dose-volume histogram analysis

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

Hirasawa, Naoki; Tsuji, Hiroshi; Ishikawa, Hitoshi

2007-02-01

Purpose: To determine the risk factors for neovascular glaucoma (NVG) after carbon ion radiotherapy (C-ion RT) of choroidal melanoma. Methods and Materials: A total of 55 patients with choroidal melanoma were treated between 2001 and 2005 with C-ion RT based on computed tomography treatment planning. All patients had a tumor of large size or one located close to the optic disk. Univariate and multivariate analyses were performed to identify the risk factors of NVG for the following parameters; gender, age, dose-volumes of the iris-ciliary body and the wall of eyeball, and irradiation of the optic disk (ODI). Results: Neovascular glaucomamore » occurred in 23 patients and the 3-year cumulative NVG rate was 42.6 {+-} 6.8% (standard error), but enucleation from NVG was performed in only three eyes. Multivariate analysis revealed that the significant risk factors for NVG were V50{sub IC} (volume irradiated {>=}50 GyE to iris-ciliary body) (p = 0.002) and ODI (p = 0.036). The 3-year NVG rate for patients with V50{sub IC} {>=}0.127 mL and those with V50{sub IC} <0.127 mL were 71.4 {+-} 8.5% and 11.5 {+-} 6.3%, respectively. The corresponding rate for the patients with and without ODI were 62.9 {+-} 10.4% and 28.4 {+-} 8.0%, respectively. Conclusion: Dose-volume histogram analysis with computed tomography indicated that V50{sub IC} and ODI were independent risk factors for NVG. An irradiation system that can reduce the dose to both the anterior segment and the optic disk might be worth adopting to investigate whether or not incidence of NVG can be decreased with it.« less

Evaluation of the Risk of Grade 3 Oral and Pharyngeal Dysphagia Using Atlas-Based Method and Multivariate Analyses of Individual Patient Dose Distributions

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

Otter, Sophie; Schick, Ulrike; Gulliford, Sarah

Purpose: The study aimed to apply the atlas of complication incidence (ACI) method to patients receiving radical treatment for head and neck squamous cell carcinomas (HNSCC), to generate constraints based on dose-volume histograms (DVHs), and to identify clinical and dosimetric parameters that predict the risk of grade 3 oral mucositis (g3OM) and pharyngeal dysphagia (g3PD). Methods and Materials: Oral and pharyngeal mucosal DVHs were generated for 253 patients who received radiation (RT) or chemoradiation (CRT). They were used to produce ACI for g3OM and g3PD. Multivariate analysis (MVA) of the effect of dosimetry, clinical, and patient-related variables was performed usingmore » logistic regression and bootstrapping. Receiver operating curve (ROC) analysis was also performed, and the Youden index was used to find volume constraints that discriminated between volumes that predicted for toxicity. Results: We derived statistically significant dose-volume constraints for g3OM over the range v28 to v70. Only 3 statistically significant constraints were derived for g3PD v67, v68, and v69. On MVA, mean dose to the oral mucosa predicted for g3OM and concomitant chemotherapy and mean dose to the inferior constrictor (IC) predicted for g3PD. Conclusions: We have used the ACI method to evaluate incidences of g3OM and g3PD and ROC analysis to generate constraints to predict g3OM and g3PD derived from entire individual patient DVHs. On MVA, the strongest predictors were radiation dose (for g3OM) and concomitant chemotherapy (for g3PD).« less

Early effects of a high-caloric diet and physical exercise on brain volumetry and behavior: a combined MRI and histology study in mice.

PubMed

Sack, Markus; Lenz, Jenny N; Jakovcevski, Mira; Biedermann, Sarah V; Falfán-Melgoza, Claudia; Deussing, Jan; Bielohuby, Maximilian; Bidlingmaier, Martin; Pfister, Frederik; Stalla, Günter K; Sartorius, Alexander; Gass, Peter; Weber-Fahr, Wolfgang; Fuss, Johannes; Auer, Matthias K

2017-10-01

Excessive intake of high-caloric diets as well as subsequent development of obesity and diabetes mellitus may exert a wide range of unfavorable effects on the central nervous system (CNS) in the long-term. The potentially harmful effects of such diets were suggested to be mitigated by physical exercise. Here, we conducted a study investigating early effects of a cafeteria-diet on gray and white brain matter volume by means of voxel-based morphometry (VBM) and region-of-interest (ROI) analysis. Half of the mice performed voluntary wheel running to study if regular physical exercise prevents unfavorable effects of a cafeteria-diet. In addition, histological analyses for myelination and neurogenesis were performed. As expected, wheel running resulted in a significant increase of gray matter volume in the CA1-3 areas, the dentate gyrus and stratum granulosum of the hippocampus in the VBM analysis, while a positive effect of the cafeteria-diet was shown for the whole hippocampal CA1-3 area only in the ROI analysis, indicating a regional volume effect. It was earlier found that hippocampal neurogenesis may be related to volume increases after exercise. Interestingly, while running resulted in a significant increase in neurogenesis assessed by doublecortin (DCX)-labeling, this was not true for cafeteria diet. This indicates different underlying mechanisms for gray matter increase. Moreover, animals receiving cafeteria diet only showed mild deficits in long-term memory assessed by the puzzle-box paradigm, while executive functioning and short term memory were not affected. Our data therefore highlight that high caloric diet impacts on the brain and behavior. Physical exercise seems not to interact with these mechanisms.

Effect of Neutral-pH, Low–Glucose Degradation Product Peritoneal Dialysis Solutions on Residual Renal Function, Urine Volume, and Ultrafiltration: A Systematic Review and Meta-Analysis

PubMed Central

Yohanna, Seychelle; Alkatheeri, Ali M.A.; Brimble, Scott K.; McCormick, Brendan; Iansavitchous, Arthur; Blake, Peter G.

2015-01-01

Background and objectives Neutral-pH, low–glucose degradation products solutions were developed in an attempt to lessen the adverse effects of conventional peritoneal dialysis solutions. A systematic review was performed evaluating the effect of these solutions on residual renal function, urine volume, peritoneal ultrafiltration, and peritoneal small-solute transport (dialysate to plasma creatinine ratio) over time. Design, setting, participants, & measurements Multiple electronic databases were searched from January of 1995 to January of 2013. Randomized trials reporting on any of four prespecified outcomes were selected by consensus among multiple reviewers. Results Eleven trials of 643 patients were included. Trials were generally of poor quality. The meta-analysis was performed using a random effects model. The use of neutral-pH, low-glucose degradation products solutions resulted in better preserved residual renal function at various study durations, including >1 year (combined analysis: 11 studies; 643 patients; standardized mean difference =0.17 ml/min; 95% confidence interval, 0.01 to 0.32), and greater urine volumes (eight studies; 598 patients; mean difference =128 ml/d; 95% confidence interval, 58 to 198). There was no significant difference in peritoneal ultrafiltration (seven studies; 571 patients; mean difference =−110; 95% confidence interval, −312 to 91) or dialysate to plasma creatinine ratio (six studies; 432 patients; mean difference =0.03; 95% confidence interval, 0.00 to 0.06). Conclusions The use of neutral-pH, low–glucose degradation products solutions results in better preservation of residual renal function and greater urine volumes. The effect on residual renal function occurred early and persisted beyond 12 months. Additional studies are required to evaluate the use of neutral-pH, low–glucose degradation products solutions on hard clinical outcomes. PMID:26048890

Spatial and temporal skin blood volume and saturation estimation using a multispectral snapshot imaging camera

NASA Astrophysics Data System (ADS)

Ewerlöf, Maria; Larsson, Marcus; Salerud, E. Göran

2017-02-01

Hyperspectral imaging (HSI) can estimate the spatial distribution of skin blood oxygenation, using visible to near-infrared light. HSI oximeters often use a liquid-crystal tunable filter, an acousto-optic tunable filter or mechanically adjustable filter wheels, which has too long response/switching times to monitor tissue hemodynamics. This work aims to evaluate a multispectral snapshot imaging system to estimate skin blood volume and oxygen saturation with high temporal and spatial resolution. We use a snapshot imager, the xiSpec camera (MQ022HG-IM-SM4X4-VIS, XIMEA), having 16 wavelength-specific Fabry-Perot filters overlaid on the custom CMOS-chip. The spectral distribution of the bands is however substantially overlapping, which needs to be taken into account for an accurate analysis. An inverse Monte Carlo analysis is performed using a two-layered skin tissue model, defined by epidermal thickness, haemoglobin concentration and oxygen saturation, melanin concentration and spectrally dependent reduced-scattering coefficient, all parameters relevant for human skin. The analysis takes into account the spectral detector response of the xiSpec camera. At each spatial location in the field-of-view, we compare the simulated output to the detected diffusively backscattered spectra to find the best fit. The imager is evaluated for spatial and temporal variations during arterial and venous occlusion protocols applied to the forearm. Estimated blood volume changes and oxygenation maps at 512x272 pixels show values that are comparable to reference measurements performed in contact with the skin tissue. We conclude that the snapshot xiSpec camera, paired with an inverse Monte Carlo algorithm, permits us to use this sensor for spatial and temporal measurement of varying physiological parameters, such as skin tissue blood volume and oxygenation.

Sex dependence of brain size and shape in bipolar disorder: an exploratory study.

PubMed

Mackay, Clare E; Roddick, Elina; Barrick, Thomas R; Lloyd, Adrian J; Roberts, Neil; Crow, Tim J; Young, Allan H; Ferrier, I Nicol

2010-05-01

Anomalies of asymmetry and sex differences in brain structure have frequently been described in schizophrenic illnesses but have seldom been explored in bipolar disorder. We measured volumes of the left and right frontal, temporal, parietal, and occipital lobes and computed the magnitude of brain torque (i.e., rightward frontal and leftward occipital asymmetry) for 49 patients with bipolar disorder and 47 healthy controls and performed an exploratory analysis of sex differences in patients and controls. Patients had significantly greater cerebrospinal fluid volume than controls, but no difference in total brain volume. There were no main effects of diagnosis in gray matter lobe volume or brain torque, but when analyses were performed separately for male and female subjects, significant sex-by-diagnosis interactions were found in the volume of the left frontal, left temporal, right parietal, and right occipital lobes, such that male patients with bipolar disorder tend toward larger, more symmetric brains than male controls, whereas female patients tend toward smaller, more asymmetric brains than female controls. The lateralised nature of these interactions was such that the normal sex difference in volume was significantly accentuated, whilst the normal sex difference in asymmetry tended to be diminished in patients with bipolar disorder. We conclude that bipolar disorder in part reflects an interaction between brain growth and sex along the anterior-posterior axis of the human brain.

Use of a turbine in a breath-by-breath computer-based respiratory measurement system.

PubMed

Venkateswaran, R S; Gallagher, R R

1997-01-01

The Computer-Based Respiratory Measurement System (CBRMS) is capable of analyzing individual breaths to monitor the kinetics of oxygen uptake, carbon dioxide production, tidal volumes, pulmonary ventilation, and other respiratory parameters during rest, exercise, and recovery. Respiratory gas volumes are measured by a calibrated turbine transducer while the respiratory gas concentrations are measured by a calibrated, fast-responding medical gas analyzer. To improve accuracy of the results, the inspiratory volumes and gas concentrations are measured and not assumed to be equal to expiratory volumes or ambient concentrations respectively. The respiratory gas volumes and concentration signals are digitized and stored in arrays. The gas volumes are converted to flow signals by software differentiation. These digitized data arrays are stored as files in a personal computer. Time alignment of the flow and gas concentration signals is performed at each breath for maximum accuracy in analysis. For system verification, data were obtained under resting conditions and under constant load exercises at 50 W, 100 W, and 150 W. These workloads were performed by a healthy, male subject on a bicycle ergometer. A strong correlation existed between the CBRMS steady-state results and the standard end-expirate bag collection technique. Thus, there is reason to believe that the CBRMS is capable of calculating respiratory transient responses accurately, a significant contribution to an understanding of total respiratory system function.

Effects of international football matches on ambulance call profiles and volumes during the 2006 World Cup.

PubMed

Deakin, Charles D; Thompson, Fizz; Gibson, Caroline; Green, Mark

2007-06-01

Prompt ambulance attendance is aimed at improving patient care. With finite resources struggling to meet performance targets, unforeseen demand precludes the ability to tailor resources to cope with increased call volumes, and can have a marked detrimental effect on performance and hence patient care. The effects of the 2006 World Cup football matches on call volumes and profiles were analysed to understand how public events can influence demands on the ambulance service. All emergency calls to the Hampshire Ambulance Service NHS Trust (currently the Hampshire Division of South Central Ambulance Service, Winchester, UK) during the first weekend of the 2006 World Cup football matches were analysed by call volume and classification of call (call type). On the day of the first football match, call volume was over 50% higher than that on a typical Saturday, with distinct peaks before and after the inaugural match. Call profile analysis showed increases in alcohol-related emergencies, including collapse, unconsciousness, assault and road traffic accidents. The increase in assaults was particularly marked at the end of each match and increased again into the late evening. A detailed mapping of call volumes and profiles during the World Cup football shows a significant increase in overall emergency calls, mostly alcohol related. Mapping of limited resources to these patterns will allow improved responses to emergency calls.

Effects of international football matches on ambulance call profiles and volumes during the 2006 World Cup

PubMed Central

Deakin, Charles D; Thompson, Fizz; Gibson, Caroline; Green, Mark

2007-01-01

Background Prompt ambulance attendance is aimed at improving patient care. With finite resources struggling to meet performance targets, unforeseen demand precludes the ability to tailor resources to cope with increased call volumes, and can have a marked detrimental effect on performance and hence patient care. The effects of the 2006 World Cup football matches on call volumes and profiles were analysed to understand how public events can influence demands on the ambulance service. Methods All emergency calls to the Hampshire Ambulance Service NHS Trust (currently the Hampshire Division of South Central Ambulance Service, Winchester, UK) during the first weekend of the 2006 World Cup football matches were analysed by call volume and classification of call (call type). Results On the day of the first football match, call volume was over 50% higher than that on a typical Saturday, with distinct peaks before and after the inaugural match. Call profile analysis showed increases in alcohol‐related emergencies, including collapse, unconsciousness, assault and road traffic accidents. The increase in assaults was particularly marked at the end of each match and increased again into the late evening. Conclusion A detailed mapping of call volumes and profiles during the World Cup football shows a significant increase in overall emergency calls, mostly alcohol related. Mapping of limited resources to these patterns will allow improved responses to emergency calls. PMID:17513536

Matrix-array 3-dimensional echocardiographic assessment of volumes, mass, and ejection fraction in young pediatric patients with a functional single ventricle: a comparison study with cardiac magnetic resonance.

PubMed

Soriano, Brian D; Hoch, Martin; Ithuralde, Alejandro; Geva, Tal; Powell, Andrew J; Kussman, Barry D; Graham, Dionne A; Tworetzky, Wayne; Marx, Gerald R

2008-04-08

Quantitative assessment of ventricular volumes and mass in pediatric patients with single-ventricle physiology would aid clinical management, but it is difficult to obtain with 2-dimensional echocardiography. The purpose of the present study was to compare matrix-array 3-dimensional echocardiography (3DE) measurements of single-ventricle volumes, mass, and ejection fraction with those measured by cardiac magnetic resonance (CMR) in young patients. Twenty-nine patients (median age, 7 months) with a functional single ventricle undergoing CMR under general anesthesia were prospectively enrolled. The 3DE images were acquired at the conclusion of the CMR. Twenty-seven of 29 3DE data sets (93%) were optimal for 3DE assessment. Two blinded and independent observers performed 3DE measurements of volume, mass, and ejection fraction. The 3DE end-diastolic volume correlated well (r=0.96) but was smaller than CMR by 9% (P<0.01), and 3DE ejection fraction was smaller than CMR by 11% (P<0.01). There was no significant difference in measurements of end-systolic volume and mass. The 3DE interobserver differences for mass and volumes were not significant except for ejection fraction (8% difference; P<0.05). Intraobserver differences were not significant. In young pediatric patients with a functional single ventricle, matrix-array 3DE measurements of mass and volumes compare well with those obtained by CMR. 3DE will provide an important modality for the serial analysis of ventricular size and performance in young patients with functional single ventricles.

A Nationwide Analysis of Cost Variation for Autologous Free Flap Breast Reconstruction.

PubMed

Billig, Jessica I; Lu, Yiwen; Momoh, Adeyiza O; Chung, Kevin C

2017-11-01

Cost variation among hospitals has been demonstrated for surgical procedures. Uncovering these differences has helped guide measures taken to reduce health care spending. To date, the fiscal consequence of hospital variation for autologous free flap breast reconstruction is unknown. To investigate factors that influence cost variation for autologous free flap breast reconstruction. A secondary cross-sectional analysis was performed using the Healthcare Cost and Utilization Project National Inpatient Sample database from 2008 to 2010. The dates of analysis were September 2016 to February 2017. The setting was a stratified sample of all US community hospitals. Participants were female patients who were diagnosed as having breast cancer or were at high risk for breast cancer and underwent autologous free flap breast reconstruction. Variables of interest included demographic data, hospital characteristics, length of stay, complications (surgical and systemic), and inpatient cost. The study used univariate and generalized linear mixed models to examine associations between patient and hospital characteristics and cost. A total of 3302 patients were included in the study, with a median age of 50 years (interquartile range, 44-57 years). The mean cost for autologous free flap breast reconstruction was $22 677 (interquartile range, $14 907-$33 391). Flap reconstructions performed at high-volume hospitals were significantly more costly than those performed at low-volume hospitals ($24 360 vs $18 918, P < .001). Logistic regression demonstrated that hospital volume correlated with increased cost (Exp[β], 1.06; 95% CI, 1.02-1.11; P = .003). Fewer surgical complications (16.4% [169 of 1029] vs 23.7% [278 of 1174], P < .001) and systemic complications (24.2% [249 of 1029] vs 31.2% [366 of 1174], P < .001) were experienced in high-volume hospitals compared with low-volume hospitals. Flap procedures performed in the West were the most expensive ($28 289), with a greater odds of increased expenditure (Exp[β], 1.53; 95% CI, 1.46-1.61; P < .001) compared with the Northeast. A significant difference in length of stay was found between the West and Northeast (odds ratio, 1.25; 95% CI, 1.17-1.33). There is significant cost variation among patients undergoing autologous free flap breast reconstruction. Experience, as measured by a hospital's volume, provides quality health care with fewer complications but is more costly. Longer length of stay contributed to regional cost variation and may be a target for decreasing expenditure, without compromising care. In the era of bundled health care payment, strategies should be implemented to eliminate cost variation to condense spending while still providing quality care.

Neuroanatomical correlates of intelligence in healthy young adults: the role of basal ganglia volume.

PubMed

Rhein, Cosima; Mühle, Christiane; Richter-Schmidinger, Tanja; Alexopoulos, Panagiotis; Doerfler, Arnd; Kornhuber, Johannes

2014-01-01

In neuropsychiatric diseases with basal ganglia involvement, higher cognitive functions are often impaired. In this exploratory study, we examined healthy young adults to gain detailed insight into the relationship between basal ganglia volume and cognitive abilities under non-pathological conditions. We investigated 137 healthy adults that were between the ages of 21 and 35 years with similar educational backgrounds. Magnetic resonance imaging (MRI) was performed, and volumes of basal ganglia nuclei in both hemispheres were calculated using FreeSurfer software. The cognitive assessment consisted of verbal, numeric and figural aspects of intelligence for either the fluid or the crystallised intelligence factor using the intelligence test Intelligenz-Struktur-Test (I-S-T 2000 R). Our data revealed significant correlations of the caudate nucleus and pallidum volumes with figural and numeric aspects of intelligence, but not with verbal intelligence. Interestingly, figural intelligence associations were dependent on sex and intelligence factor; in females, the pallidum volumes were correlated with crystallised figural intelligence (r = 0.372, p = 0.01), whereas in males, the caudate volumes were correlated with fluid figural intelligence (r = 0.507, p = 0.01). Numeric intelligence was correlated with right-lateralised caudate nucleus volumes for both females and males, but only for crystallised intelligence (r = 0.306, p = 0.04 and r = 0.459, p = 0.04, respectively). The associations were not mediated by prefrontal cortical subfield volumes when controlling with partial correlation analyses. The findings of our exploratory analysis indicate that figural and numeric intelligence aspects, but not verbal aspects, are strongly associated with basal ganglia volumes. Unlike numeric intelligence, the type of figural intelligence appears to be related to distinct basal ganglia nuclei in a sex-specific manner. Subcortical brain structures thus may contribute substantially to cognitive performance.

Variations in inpatient pediatric anesthesia in California from 2000 to 2009: a caseload and geographic analysis.

PubMed

Mudumbai, Seshadri C; Honkanen, Anita; Chan, Jia; Schmitt, Susan; Saynina, Olga; Hackel, Alvin; Gregory, George; Phibbs, Ciaran S; Wise, Paul H

2014-12-01

Regional referral systems are considered important for children hospitalized for surgery, but there is little information on existing systems. To examine geographic variations in anesthetic caseloads in California for surgical inpatients ≤6 years and to evaluate the feasibility of regionalizing anesthetic care. We reviewed California's unmasked patient discharge database between 2000 and 2009 to determine surgical procedures, dates, and inpatient anesthetic caseloads. Hospitals were classified as urban or rural and were further stratified as low, intermediate, high, and very high volume. We reviewed 257,541 anesthetic cases from 402 hospitals. Seventeen California Children's Services (CCS) hospitals conducted about two-thirds of all inpatient anesthetics; 385 non-CCS hospitals accounted for the rest. Urban hospitals comprised 82% of low- and intermediate-volume centers (n = 297) and 100% of the high- and very high-volume centers (n = 41). Ninety percent (n = 361) of hospitals performed <100 cases annually. Although potentially lower risk procedures such as appendectomies were the most frequent in urban low- and intermediate-volume hospitals, fairly complex neurosurgical and general surgeries were also performed. The median distance from urban lower-volume hospitals to the nearest high- or very high-volume center was 12 miles. Up to 98% (n = 40,316) of inpatient anesthetics at low- or intermediate-volume centers could have been transferred to higher-volume centers within 25 miles of smaller centers. Many urban California hospitals maintained low annual inpatient anesthetic caseloads for children ≤6 years while conducting potentially more complex procedures. Further efforts are necessary to define the scope of pediatric anesthetic care at urban low- and intermediate-volume hospitals in California. © 2014 John Wiley & Sons Ltd.

Orbital transfer vehicle concept definition and system analysis study. Volume 2: OTV concept definition and evaluation. Book 1: Mission and system requirements

NASA Technical Reports Server (NTRS)

Kofal, Allen E.

1987-01-01

The mission and system requirements for the concept definition and system analysis of the Orbital Transfer Vehicle (OTV) are established. The requirements set forth constitute the single authority for the selection, evaluation, and optimization of the technical performance and design of the OTV. This requirements document forms the basis for the Ground and Space Based OTV concept definition analyses and establishes the physical, functional, performance and design relationships to STS, Space Station, Orbital Maneuvering Vehicle (OMV), and payloads.

Performance Analysis and Design Synthesis (PADS) computer program. Volume 3: User manual

NASA Technical Reports Server (NTRS)

1972-01-01

The two-fold purpose of the Performance Analysis and Design Synthesis (PADS) computer program is discussed. The program can size launch vehicles in conjunction with calculus-of-variations optimal trajectories and can also be used as a general purpose branched trajectory optimization program. For trajectory optimization alone or with sizing, PADS has two trajectory modules. The first trajectory module uses the method of steepest descent. The second module uses the method of quasi-linearization, which requires a starting solution from the first trajectory module.

NSEG, a segmented mission analysis program for low and high speed aircraft. Volume 1: Theoretical development

NASA Technical Reports Server (NTRS)

Hague, D. S.; Rozendaal, H. L.

1977-01-01

A rapid mission analysis code based on the use of approximate flight path equations of motion is presented. Equation form varies with the segment type, for example, accelerations, climbs, cruises, descents, and decelerations. Realistic and detailed characteristics were specified in tabular form. The code also contains extensive flight envelope performance mapping capabilities. Approximate take off and landing analyses were performed. At high speeds, centrifugal lift effects were accounted for. Extensive turbojet and ramjet engine scaling procedures were incorporated in the code.

Volumetric analysis of maxillary sinuses of Zulu and European crania by helical, multislice computed tomography.

PubMed

Fernandes, C L

2004-11-01

The volumes of the maxillary sinuses are of interest to surgeons operating endoscopically as variation in maxillary sinus volume may mean variation in anatomical landmarks. Other surgical disciplines, such as dentistry, maxillo-facial surgery and plastic surgery, may benefit from this information. To compare the maxillary sinus volumes of dried crania from cadavers of European and Zulu descent, with respect to ethnic group and gender. Helical, multislice computed tomography (CT) was performed using 1-mm coronal slices. The area for each slice was obtained by tracing the outline of each slice. The CT machine calculated a volume by totalling the slices for each sinus. Ethnic and gender variations were found in the different groups. It was found that European crania had significantly larger antral volumes than Zulu crania and men had larger volumes than women. Race and gender interaction was also assessed, as was maxillary sinus side. A variation in maxillary sinus volume between different ethnic groups and genders exists, and surgeons operating in this region should be aware of this.

Cost drivers and resource allocation in military health care systems.

PubMed

Fulton, Larry; Lasdon, Leon S; McDaniel, Reuben R

2007-03-01

This study illustrates the feasibility of incorporating technical efficiency considerations in the funding of military hospitals and identifies the primary drivers for hospital costs. Secondary data collected for 24 U.S.-based Army hospitals and medical centers for the years 2001 to 2003 are the basis for this analysis. Technical efficiency was measured by using data envelopment analysis; subsequently, efficiency estimates were included in logarithmic-linear cost models that specified cost as a function of volume, complexity, efficiency, time, and facility type. These logarithmic-linear models were compared against stochastic frontier analysis models. A parsimonious, three-variable, logarithmic-linear model composed of volume, complexity, and efficiency variables exhibited a strong linear relationship with observed costs (R(2) = 0.98). This model also proved reliable in forecasting (R(2) = 0.96). Based on our analysis, as much as $120 million might be reallocated to improve the United States-based Army hospital performance evaluated in this study.

Quantitative analysis of titanium-induced artifacts and correlated factors during micro-CT scanning.

PubMed

Li, Jun Yuan; Pow, Edmond Ho Nang; Zheng, Li Wu; Ma, Li; Kwong, Dora Lai Wan; Cheung, Lim Kwong

2014-04-01

To investigate the impact of cover screw, resin embedment, and implant angulation on artifact of microcomputed tomography (micro-CT) scanning for implant. A total of twelve implants were randomly divided into 4 groups: (i) implant only; (ii) implant with cover screw; (iii) implant with resin embedment; and (iv) implants with cover screw and resin embedment. Implants angulation at 0°, 45°, and 90° were scanned by micro-CT. Images were assessed, and the ratio of artifact volume to total volume (AV/TV) was calculated. A multiple regression analysis in stepwise model was used to determine the significance of different factors. One-way ANOVA was performed to identify which combination of factors could minimize the artifact. In the regression analysis, implant angulation was identified as the best predictor for artifact among the factors (P < 0.001). Resin embedment also had significant effect on artifact volume (P = 0.028), while cover screw had not (P > 0.05). Non-embedded implants with the axis parallel to X-ray source of micro-CT produced minimal artifact. Implant angulation and resin embedment affected the artifact volume of micro-CT scanning for implant, while cover screw did not. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Image analysis and mathematical modelling for the supervision of the dough fermentation process

NASA Astrophysics Data System (ADS)

Zettel, Viktoria; Paquet-Durand, Olivier; Hecker, Florian; Hitzmann, Bernd

2016-10-01

The fermentation (proof) process of dough is one of the quality-determining steps in the production of baking goods. Beside the fluffiness, whose fundaments are built during fermentation, the flavour of the final product is influenced very much during this production stage. However, until now no on-line measurement system is available, which can supervise this important process step. In this investigation the potential of an image analysis system is evaluated, that enables the determination of the volume of fermented dough pieces. The camera is moving around the fermenting pieces and collects images from the objects by means of different angles (360° range). Using image analysis algorithms the volume increase of individual dough pieces is determined. Based on a detailed mathematical description of the volume increase, which based on the Bernoulli equation, carbon dioxide production rate of yeast cells and the diffusion processes of carbon dioxide, the fermentation process is supervised. Important process parameters, like the carbon dioxide production rate of the yeast cells and the dough viscosity can be estimated just after 300 s of proofing. The mean percentage error for forecasting the further evolution of the relative volume of the dough pieces is just 2.3 %. Therefore, a forecast of the further evolution can be performed and used for fault detection.

Gamut Volume Index: a color preference metric based on meta-analysis and optimized colour samples.

PubMed

Liu, Qiang; Huang, Zheng; Xiao, Kaida; Pointer, Michael R; Westland, Stephen; Luo, M Ronnier

2017-07-10

A novel metric named Gamut Volume Index (GVI) is proposed for evaluating the colour preference of lighting. This metric is based on the absolute gamut volume of optimized colour samples. The optimal colour set of the proposed metric was obtained by optimizing the weighted average correlation between the metric predictions and the subjective ratings for 8 psychophysical studies. The performance of 20 typical colour metrics was also investigated, which included colour difference based metrics, gamut based metrics, memory based metrics as well as combined metrics. It was found that the proposed GVI outperformed the existing counterparts, especially for the conditions where correlated colour temperatures differed.

Precise measurement of instantaneous volume of eccrine sweat gland in mental sweating by optical coherence tomography

NASA Astrophysics Data System (ADS)

Sugawa, Yoshihiko; Fukuda, Akihiro; Ohmi, Masato

2015-03-01

We have demonstrated dynamic analysis of the physiological function of eccrine sweat glands underneath skin surface by optical coherence tomography (OCT). We propose a method for extraction of the target eccrine sweat gland by use of the connected component extraction process and the adaptive threshold method, where the en-face OCT images are constructed by the SS-OCT. Furthermore, we demonstrate precise measurement of instantaneous volume of the sweat gland in response to the external stimulus. The dynamic change of instantaneous volume of eccrine sweat gland in mental sweating is performed by this method during the period of 300 sec with the frame intervals of 3.23 sec.

Journal of Naval Science. Volume 2, Number 1

DTIC Science & Technology

1976-01-01

has defined a probability distribution function which fits this type of data and forms the basis for statistical analysis of test results (see...Conditions to Assess the Performance of Fire-Resistant Fluids’. Wear, 28 (1974) 29. J.N.S., Vol. 2, No. 1 APPENDIX A Analysis of Fatigue Test Data...used to produce the impulse response and the equipment required for the analysis is relatively simple. The methods that must be used to produce

Collision avoidance system cost-benefit analysis : volume III - appendices F-M

DOT National Transportation Integrated Search

1981-09-01

Collision-avoidance systems under development in the U.S.A., Japan and Germany were evaluated. The performance evaluation showed that the signal processing and the control law of a system were the key parameters that decided the system's capability, ...

Collision avoidance system cost-benefit analysis : volume II - appendices A-E

DOT National Transportation Integrated Search

1981-09-01

Collision-avoidance systems under development in the U.S.A., Japan and Germany were evaluated. The performance evaluation showed that the signal processing and the control law of a system were the key parameters that decided the system's capability, ...

Evaluation of Subsurface Engineered Barriers at Waste Sites Volumes 1 and 2

EPA Pesticide Factsheets

This report provides the U.S. Environmental Protection Agency’s (EPA) waste programs with a national retrospective analysis of barrier field performance, as well as information that useful in developing guidance on the use and evaluation of barrier systems

Synthesis and analysis of precise spaceborne laser ranging systems, volume 2. [Spacelab payload

NASA Technical Reports Server (NTRS)

Paddon, E. A.

1978-01-01

The performance capabilities of specific shuttle-based laser ranging systems were evaluated, and interface and support requirements were determined. The preliminary design of a shuttle-borne laser ranging experiment developed as part of the Spacelab program is discussed.

An analysis of radio frequency surveillance systems for air traffic control volume II: appendixes

DOT National Transportation Integrated Search

1976-02-01

Performance criteria that afford quantitative evaluation of a variety of current and proposed configurations of the Air Traffic Control Radar Beacon System (ATCRBS) are described in detail. Two analytic system models are developed to allow applicatio...

Modular space station phase B extension preliminary system design. Volume 3: Experiment analyses

NASA Technical Reports Server (NTRS)

Wengrow, G. L.; Lillenas, A. N.

1972-01-01

Experiment analysis tasks performed during program definition study are described. Experiment accommodation and scheduling, and defining and implementing the laboratory evolution are discussed. The general purpose laboratory requirements and concepts are defined, and supplemental studies are reported.

Temporal and geographical external validation study and extension of the Mayo Clinic prediction model to predict eGFR in the younger population of Swiss ADPKD patients.

PubMed

Girardat-Rotar, Laura; Braun, Julia; Puhan, Milo A; Abraham, Alison G; Serra, Andreas L

2017-07-17

Prediction models in autosomal dominant polycystic kidney disease (ADPKD) are useful in clinical settings to identify patients with greater risk of a rapid disease progression in whom a treatment may have more benefits than harms. Mayo Clinic investigators developed a risk prediction tool for ADPKD patients using a single kidney value. Our aim was to perform an independent geographical and temporal external validation as well as evaluate the potential for improving the predictive performance by including additional information on total kidney volume. We used data from the on-going Swiss ADPKD study from 2006 to 2016. The main analysis included a sample size of 214 patients with Typical ADPKD (Class 1). We evaluated the Mayo Clinic model performance calibration and discrimination in our external sample and assessed whether predictive performance could be improved through the addition of subsequent kidney volume measurements beyond the baseline assessment. The calibration of both versions of the Mayo Clinic prediction model using continuous Height adjusted total kidney volume (HtTKV) and using risk subclasses was good, with R 2 of 78% and 70%, respectively. Accuracy was also good with 91.5% and 88.7% of the predicted within 30% of the observed, respectively. Additional information regarding kidney volume did not substantially improve the model performance. The Mayo Clinic prediction models are generalizable to other clinical settings and provide an accurate tool based on available predictors to identify patients at high risk for rapid disease progression.

Apollo/Skylab suit program management systems study. Volume 2: Cost analysis

NASA Technical Reports Server (NTRS)

1974-01-01

The business management methods employed in the performance of the Apollo-Skylab Suit Program are studied. The data accumulated over the span of the contract as well as the methods used to accumulate the data are examined. Management methods associated with the monitoring and control of resources applied towards the performance of the contract are also studied and recommended upon. The primary objective is the compilation, analysis, and presentation of historical cost performance criteria. Cost data are depicted for all phases of the Apollo-Skylab program in common, meaningful terms, whereby the data may be applicable to future suit program planning efforts.

Birdcage volume coils and magnetic resonance imaging: a simple experiment for students.

PubMed

Vincent, Dwight E; Wang, Tianhao; Magyar, Thalia A K; Jacob, Peni I; Buist, Richard; Martin, Melanie

2017-01-01

This article explains some simple experiments that can be used in undergraduate or graduate physics or biomedical engineering laboratory classes to learn how birdcage volume radiofrequency (RF) coils and magnetic resonance imaging (MRI) work. For a clear picture, and to do any quantitative MRI analysis, acquiring images with a high signal-to-noise ratio (SNR) is required. With a given MRI system at a given field strength, the only means to change the SNR using hardware is to change the RF coil used to collect the image. RF coils can be designed in many different ways including birdcage volume RF coil designs. The choice of RF coil to give the best SNR for any MRI study is based on the sample being imaged. The data collected in the simple experiments show that the SNR varies as inverse diameter for the birdcage volume RF coils used in these experiments. The experiments were easily performed by a high school student, an undergraduate student, and a graduate student, in less than 3 h, the time typically allotted for a university laboratory course. The article describes experiments that students in undergraduate or graduate laboratories can perform to observe how birdcage volume RF coils influence MRI measurements. It is designed for students interested in pursuing careers in the imaging field.

Automated segmentation and dose-volume analysis with DICOMautomaton

NASA Astrophysics Data System (ADS)

Clark, H.; Thomas, S.; Moiseenko, V.; Lee, R.; Gill, B.; Duzenli, C.; Wu, J.

2014-03-01

Purpose: Exploration of historical data for regional organ dose sensitivity is limited by the effort needed to (sub-)segment large numbers of contours. A system has been developed which can rapidly perform autonomous contour sub-segmentation and generic dose-volume computations, substantially reducing the effort required for exploratory analyses. Methods: A contour-centric approach is taken which enables lossless, reversible segmentation and dramatically reduces computation time compared with voxel-centric approaches. Segmentation can be specified on a per-contour, per-organ, or per-patient basis, and can be performed along either an embedded plane or in terms of the contour's bounds (e.g., split organ into fractional-volume/dose pieces along any 3D unit vector). More complex segmentation techniques are available. Anonymized data from 60 head-and-neck cancer patients were used to compare dose-volume computations with Varian's EclipseTM (Varian Medical Systems, Inc.). Results: Mean doses and Dose-volume-histograms computed agree strongly with Varian's EclipseTM. Contours which have been segmented can be injected back into patient data permanently and in a Digital Imaging and Communication in Medicine (DICOM)-conforming manner. Lossless segmentation persists across such injection, and remains fully reversible. Conclusions: DICOMautomaton allows researchers to rapidly, accurately, and autonomously segment large amounts of data into intricate structures suitable for analyses of regional organ dose sensitivity.

Predictability and Market Efficiency in Agricultural Futures Markets: a Perspective from Price-Volume Correlation Based on Wavelet Coherency Analysis

NASA Astrophysics Data System (ADS)

He, Ling-Yun; Wen, Xing-Chun

2015-12-01

In this paper, we use a time-frequency domain technique, namely, wavelet squared coherency, to examine the associations between the trading volumes of three agricultural futures and three different forms of these futures' daily closing prices, i.e. prices, returns and volatilities, over the past several years. These agricultural futures markets are selected from China as a typical case of the emerging countries, and from the US as a representative of the developed economies. We investigate correlations and lead-lag relationships between the trading volumes and the prices to detect the predictability and efficiency of these futures markets. The results suggest that the information contained in the trading volumes of the three agricultural futures markets in China can be applied to predict the prices or returns, while that in US has extremely weak predictive power for prices or returns. We also conduct the wavelet analysis on the relationships between the volumes and returns or volatilities to examine the existence of the two "stylized facts" proposed by Karpoff [J. M. Karpoff, The relation between price changes and trading volume: A survey, J. Financ. Quant. Anal.22(1) (1987) 109-126]. Different markets in the two countries perform differently in reproducing the two stylized facts. As the wavelet tools can decode nonlinear regularities and hidden patterns behind price-volume relationship in time-frequency space, different from the conventional econometric framework, this paper offers a new perspective into the market predictability and efficiency.

Surgeon volume for percutaneous nephrolithotomy is associated with medical costs and length of hospital stay: a nationwide population-based study in Taiwan.

PubMed

Huang, Wei-Yi; Wu, Shiao-Chi; Chen, Yu-Fen; Lan, Chung-Fu; Hsieh, Ju-Ton; Huang, Kuo-How

2014-08-01

To investigate the factors associated with outcomes and medical costs for percutaneous nephrolithotomy (PCNL). The present study uses a subset of the National Health Insurance Research Database (NHIRD), known as the Longitudinal Health Insurance Database 2005 (LHID 2005), which contains the data of all medical benefit claims from 1997 to 2010 for a subset of 1 million enrollees randomly drawn from the population of 22.72 million persons who were enrolled in 2005. The claims data for all subjects with a diagnosis of urolithiasis who underwent PCNL were analyzed. Hospital and surgeon case volume were classified by quartile. The correlations of all patient, surgeon, and hospital variables with the outcomes and medical costs of PCNL were analyzed by generalized estimating equations. A total of 995 subjects received PCNL. In univariate analysis, PCNL performed by high-volume surgeons (≥12) cost 26% less ($2684 vs $1986) and resulted in a 34.3% shorter hospital stay (6.5 vs 9.9 days) compared with low-volume surgeons (≤3). In multivariate analysis, surgeon volume was a significant predictor for medical cost, length of stay, and intensive care unit transfer but not complications and mortality. Surgeon volume was associated with lower medical costs and shorter length of stay after PCNL. Surgeon volume, however, was not an independent predictor of complications and mortality. Our findings have important implications for urologists and policymakers with regard to the cost and effectiveness of PCNL.

Influence of Adaptive Statistical Iterative Reconstruction on coronary plaque analysis in coronary computed tomography angiography.

PubMed

Precht, Helle; Kitslaar, Pieter H; Broersen, Alexander; Dijkstra, Jouke; Gerke, Oke; Thygesen, Jesper; Egstrup, Kenneth; Lambrechtsen, Jess

The purpose of this study was to study the effect of iterative reconstruction (IR) software on quantitative plaque measurements in coronary computed tomography angiography (CCTA). Thirty patients with a three clinical risk factors for coronary artery disease (CAD) had one CCTA performed. Images were reconstructed using FBP, 30% and 60% adaptive statistical IR (ASIR). Coronary plaque analysis was performed as per patient and per vessel (LM, LAD, CX and RCA) measurements. Lumen and vessel volumes and plaque burden measurements were based on automatic detected contours in each reconstruction. Lumen and plaque intensity measurements and HU based plaque characterization were based on corrected contours copied to each reconstruction. No significant changes between FBP and 30% ASIR were found except for lumen- (-2.53 HU) and plaque intensities (-1.28 HU). Between FBP and 60% ASIR the change in total volume showed an increase of 0.94%, 4.36% and 2.01% for lumen, plaque and vessel, respectively. The change in total plaque burden between FBP and 60% ASIR was 0.76%. Lumen and plaque intensities decreased between FBP and 60% ASIR with -9.90 HU and -1.97 HU, respectively. The total plaque component volume changes were all small with a maximum change of -1.13% of necrotic core between FBP and 60% ASIR. Quantitative plaque measurements only showed modest differences between FBP and the 60% ASIR level. Differences were increased lumen-, vessel- and plaque volumes, decreased lumen- and plaque intensities and a small percentage change in the individual plaque component volumes. Copyright © 2016 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.

Implementation of Coupled Skin Temperature Analysis and Bias Correction in a Global Atmospheric Data Assimilation System

NASA Technical Reports Server (NTRS)

Radakovich, Jon; Bosilovich, M.; Chern, Jiun-dar; daSilva, Arlindo

2004-01-01

The NASA/NCAR Finite Volume GCM (fvGCM) with the NCAR CLM (Community Land Model) version 2.0 was integrated into the NASA/GMAO Finite Volume Data Assimilation System (fvDAS). A new method was developed for coupled skin temperature assimilation and bias correction where the analysis increment and bias correction term is passed into the CLM2 and considered a forcing term in the solution to the energy balance. For our purposes, the fvDAS CLM2 was run at 1 deg. x 1.25 deg. horizontal resolution with 55 vertical levels. We assimilate the ISCCP-DX (30 km resolution) surface temperature product. The atmospheric analysis was performed 6-hourly, while the skin temperature analysis was performed 3-hourly. The bias correction term, which was updated at the analysis times, was added to the skin temperature tendency equation at every timestep. In this presentation, we focus on the validation of the surface energy budget at the in situ reference sites for the Coordinated Enhanced Observation Period (CEOP). We will concentrate on sites that include independent skin temperature measurements and complete energy budget observations for the month of July 2001. In addition, MODIS skin temperature will be used for validation. Several assimilations were conducted and preliminary results will be presented.

Recombinant Tissue Plasminogen Activator Induces Neurological Side Effects Independent on Thrombolysis in Mechanical Animal Models of Focal Cerebral Infarction: A Systematic Review and Meta-Analysis.

PubMed

Dong, Mei-Xue; Hu, Qing-Chuan; Shen, Peng; Pan, Jun-Xi; Wei, You-Dong; Liu, Yi-Yun; Ren, Yi-Fei; Liang, Zi-Hong; Wang, Hai-Yang; Zhao, Li-Bo; Xie, Peng

2016-01-01

Recombinant tissue plasminogen activator (rtPA) is the only effective drug approved by US FDA to treat ischemic stroke, and it contains pleiotropic effects besides thrombolysis. We performed a meta-analysis to clarify effect of tissue plasminogen activator (tPA) on cerebral infarction besides its thrombolysis property in mechanical animal stroke. Relevant studies were identified by two reviewers after searching online databases, including Pubmed, Embase, and ScienceDirect, from 1979 to 2016. We identified 6, 65, 17, 12, 16, 12 and 13 comparisons reporting effect of endogenous tPA on infarction volume and effects of rtPA on infarction volume, blood-brain barrier, brain edema, intracerebral hemorrhage, neurological function and mortality rate in all 47 included studies. Standardized mean differences for continuous measures and risk ratio for dichotomous measures were calculated to assess the effects of endogenous tPA and rtPA on cerebral infarction in animals. The quality of included studies was assessed using the Stroke Therapy Academic Industry Roundtable score. Subgroup analysis, meta-regression and sensitivity analysis were performed to explore sources of heterogeneity. Funnel plot, Trim and Fill method and Egger's test were obtained to detect publication bias. We found that both endogenous tPA and rtPA had not enlarged infarction volume, or deteriorated neurological function. However, rtPA would disrupt blood-brain barrier, aggravate brain edema, induce intracerebral hemorrhage and increase mortality rate. This meta-analysis reveals rtPA can lead to neurological side effects besides thrombolysis in mechanical animal stroke, which may account for clinical exacerbation for stroke patients that do not achieve vascular recanalization with rtPA.

Recombinant Tissue Plasminogen Activator Induces Neurological Side Effects Independent on Thrombolysis in Mechanical Animal Models of Focal Cerebral Infarction: A Systematic Review and Meta-Analysis

PubMed Central

Wei, You-Dong; Liu, Yi-Yun; Ren, Yi-Fei; Liang, Zi-Hong; Wang, Hai-Yang; Zhao, Li-Bo; Xie, Peng

2016-01-01

Background and Purpose Recombinant tissue plasminogen activator (rtPA) is the only effective drug approved by US FDA to treat ischemic stroke, and it contains pleiotropic effects besides thrombolysis. We performed a meta-analysis to clarify effect of tissue plasminogen activator (tPA) on cerebral infarction besides its thrombolysis property in mechanical animal stroke. Methods Relevant studies were identified by two reviewers after searching online databases, including Pubmed, Embase, and ScienceDirect, from 1979 to 2016. We identified 6, 65, 17, 12, 16, 12 and 13 comparisons reporting effect of endogenous tPA on infarction volume and effects of rtPA on infarction volume, blood-brain barrier, brain edema, intracerebral hemorrhage, neurological function and mortality rate in all 47 included studies. Standardized mean differences for continuous measures and risk ratio for dichotomous measures were calculated to assess the effects of endogenous tPA and rtPA on cerebral infarction in animals. The quality of included studies was assessed using the Stroke Therapy Academic Industry Roundtable score. Subgroup analysis, meta-regression and sensitivity analysis were performed to explore sources of heterogeneity. Funnel plot, Trim and Fill method and Egger’s test were obtained to detect publication bias. Results We found that both endogenous tPA and rtPA had not enlarged infarction volume, or deteriorated neurological function. However, rtPA would disrupt blood-brain barrier, aggravate brain edema, induce intracerebral hemorrhage and increase mortality rate. Conclusions This meta-analysis reveals rtPA can lead to neurological side effects besides thrombolysis in mechanical animal stroke, which may account for clinical exacerbation for stroke patients that do not achieve vascular recanalization with rtPA. PMID:27387385

Determination of volume-time curves for the right ventricle and its outflow tract for functional analyses.

PubMed

Gabbert, Dominik D; Entenmann, Andreas; Jerosch-Herold, Michael; Frettlöh, Felicitas; Hart, Christopher; Voges, Inga; Pham, Minh; Andrade, Ana; Pardun, Eileen; Wegner, P; Hansen, Traudel; Kramer, Hans-Heiner; Rickers, Carsten

2013-12-01

The determination of right ventricular volumes and function is of increasing interest for the postoperative care of patients with congenital heart defects. The presentation of volumetry data in terms of volume-time curves allows a comprehensive functional assessment. By using manual contour tracing, the generation of volume-time curves is exceedingly time-consuming. This study describes a fast and precise method for determining volume-time curves for the right ventricle and for the right ventricular outflow tract. The method applies contour detection and includes a feature for identifying the right ventricular outflow tract volume. The segregation of the outflow tract is performed by four-dimensional curved smooth boundary surfaces defined by prespecified anatomical landmarks. The comparison with manual contour tracing demonstrates that the method is accurate and improves the precision of the measurement. Compared to manual contour tracing the bias is <0.1% ± 4.1% (right ventricle) and -2.6% ± 20.0% (right ventricular outflow tract). The standard deviations of inter- and intraobserver variabilities for determining the volume of the right ventricular outflow tract are reduced to less than half the values of manual contour tracing. The time consumption per patient is reduced from 341 ± 80 min (right ventricle) and 56 ± 11 min (right ventricular outflow tract) using manual contour tracing to 46 ± 9 min for a combined analysis of right ventricle and right ventricular outflow tract. The analysis of volume-time curves for the right ventricle and its outflow tract discloses new evaluation methods in clinical routine and science. Copyright © 2013 Wiley Periodicals, Inc.

Digital processing of mesoscale analysis and space sensor data

NASA Technical Reports Server (NTRS)

Hickey, J. S.; Karitani, S.

1985-01-01

The mesoscale analysis and space sensor (MASS) data management and analysis system on the research computer system is presented. The MASS data base management and analysis system was implemented on the research computer system which provides a wide range of capabilities for processing and displaying large volumes of conventional and satellite derived meteorological data. The research computer system consists of three primary computers (HP-1000F, Harris/6, and Perkin-Elmer 3250), each of which performs a specific function according to its unique capabilities. The overall tasks performed concerning the software, data base management and display capabilities of the research computer system in terms of providing a very effective interactive research tool for the digital processing of mesoscale analysis and space sensor data is described.

Manufacture of low carbon astroloy turbine disk shapes by hot isostatic pressing. Volume 2, project 1

NASA Technical Reports Server (NTRS)

Eng, R. D.; Evans, D. J.

1979-01-01

The performance of a hot isotatic pressed disk installed in an experimental engine and exposed to realistic operating conditions in a 150-hour engine test and a 1000 cycle endurance test is documented. Post test analysis, based on visual, fluorescent penetrant and dimensional inspection, revealed no defects in the disk and indicated that the disk performed satisfactorily.

Follow Through Pupil Achievement Characteristics in Philadelphia Quasi-Longitudinal Data 1975-1976 and 1976-1977. Report #7870. Appendices Volume.

ERIC Educational Resources Information Center

McNamara, Thomas

Quasi-longitudinal data on student achievement, drawn from a computerized file on about 50,000 children, essentially consist of cross-sectional performance data analyzed in terms of length of program exposure while allowing for analysis of post-program performance on the basis of program exposure. The data are also analyzed according to the major…

Development of Instructor Support Feature Guidelines. Volume 1.

DTIC Science & Technology

1986-05-01

dated) Flight Objectives Pamphlet (8/84) TAC Syllabus (8/84) Gradesheet B-52 Training Program WST Coursebook (not dated) Console Familiarization Course...Wordstar Lesson Plans (1984) Gradesheets Instructor Handbook (3/82) KC-135 Pilot WST Coursebook (1/84) Navigator WST Coursebook (1/84) 2 T-37 Instrument...time aircrew performance measurement and instructor feedback, and post-mission data retrieval and analysis. Various levels of statistical performance

Proceedings of the tenth annual DOE low-level waste management conference: Session 2: Site performance assessment

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

Not Available

1988-12-01

This document contains twelve papers on various aspects of low-level radioactive waste management. Topics of this volume include: performance assessment methodology; remedial action alternatives; site selection and site characterization procedures; intruder scenarios; sensitivity analysis procedures; mathematical models for mixed waste environmental transport; and risk assessment methodology. Individual papers were processed separately for the database. (TEM)

New High-Performance Droplet Freezing Assay (HP-DFA) for the Analysis of Ice Nuclei with Complex Composition

NASA Astrophysics Data System (ADS)

Kunert, Anna Theresa; Scheel, Jan Frederik; Helleis, Frank; Klimach, Thomas; Pöschl, Ulrich; Fröhlich-Nowoisky, Janine

2016-04-01

Freezing of water above homogeneous freezing is catalyzed by ice nucleation active (INA) particles called ice nuclei (IN), which can be of various inorganic or biological origin. The freezing temperatures reach up to -1 °C for some biological samples and are dependent on the chemical composition of the IN. The standard method to analyze IN in solution is the droplet freezing assay (DFA) established by Gabor Vali in 1970. Several modifications and improvements were already made within the last decades, but they are still limited by either small droplet numbers, large droplet volumes or inadequate separation of the single droplets resulting in mutual interferences and therefore improper measurements. The probability that miscellaneous IN are concentrated together in one droplet increases with the volume of the droplet, which can be described by the Poisson distribution. At a given concentration, the partition of a droplet into several smaller droplets leads to finely dispersed IN resulting in better statistics and therefore in a better resolution of the nucleation spectrum. We designed a new customized high-performance droplet freezing assay (HP-DFA), which represents an upgrade of the previously existing DFAs in terms of temperature range and statistics. The necessity of observing freezing events at temperatures lower than homogeneous freezing due to freezing point depression, requires high-performance thermostats combined with an optimal insulation. Furthermore, we developed a cooling setup, which allows both huge and tiny temperature changes within a very short period of time. Besides that, the new DFA provides the analysis of more than 750 droplets per run with a small droplet volume of 5 μL. This enables a fast and more precise analysis of biological samples with complex IN composition as well as better statistics for every sample at the same time.

Practical determination of aortic valve calcium volume score on contrast-enhanced computed tomography prior to transcatheter aortic valve replacement and impact on paravalvular regurgitation: Elucidating optimal threshold cutoffs.

PubMed

Bettinger, Nicolas; Khalique, Omar K; Krepp, Joseph M; Hamid, Nadira B; Bae, David J; Pulerwitz, Todd C; Liao, Ming; Hahn, Rebecca T; Vahl, Torsten P; Nazif, Tamim M; George, Isaac; Leon, Martin B; Einstein, Andrew J; Kodali, Susheel K

The threshold for the optimal computed tomography (CT) number in Hounsfield Units (HU) to quantify aortic valvular calcium on contrast-enhanced scans has not been standardized. Our aim was to find the most accurate threshold to predict paravalvular regurgitation (PVR) after transcatheter aortic valve replacement (TAVR). 104 patients who underwent TAVR with the CoreValve prosthesis were studied retrospectively. Luminal attenuation (LA) in HU was measured at the level of the aortic annulus. Calcium volume score for the aortic valvular complex was measured using 6 threshold cutoffs (650 HU, 850 HU, LA × 1.25, LA × 1.5, LA+50, LA+100). Receiver-operating characteristic (ROC) analysis was performed to assess the predictive value for > mild PVR (n = 16). Multivariable analysis was performed to determine the accuracy to predict > mild PVR after adjustment for depth and perimeter oversizing. ROC analysis showed lower area under the curve (AUC) values for fixed threshold cutoffs (650 or 850 HU) compared to thresholds relative to LA. The LA+100 threshold had the highest AUC (0.81), and AUC was higher than all studied protocols, other than the LA x 1.25 and LA + 50 protocols, where the difference approached statistical significance (p = 0.05, and 0.068, respectively). Multivariable analysis showed calcium volume determined by the LAx1.25, LAx1.5, LA+50, and LA+ 100 HU protocols to independently predict PVR. Calcium volume scoring thresholds which are relative to LA are more predictive of PVR post-TAVR than those which use fixed cutoffs. A threshold of LA+100 HU had the highest predictive value. Copyright © 2017 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.

Comparison of IMRT versus 3D-CRT in the treatment of esophagus cancer: A systematic review and meta-analysis.

PubMed

Xu, Dandan; Li, Guowen; Li, Hongfei; Jia, Fei

2017-08-01

Esophageal cancer (EC) is a common cancer with high mortality because of its rapid progression and poor prognosis. Radiotherapy is one of the most effective treatments for EC. Three-dimensional conformal radiotherapy (3D-CRT) and intensity-modulated radiotherapy (IMRT) are 2 recently developed radiotherapy techniques. IMRT is believed to be more effective than 3D-CRT in target coverage, dose homogeneity, and reducing toxicity to normal organs. However, these advantages have not been demonstrated in the treatment of EC. This meta-analysis was performed to compare IMRT and 3D-CRT in the treatment of EC in terms of dose-volume histograms and outcomes including survival and toxicity. A literature search was performed in PubMed, Embase, and the Cochrane library databases from their inceptions to Dec 30, 2016. Two authors independently assessed the included studies and extracted data. The average percent irradiated volumes of adjacent noncancerous organs were calculated and compared between IMRT and 3D-CRT. The odds ratio of overall survival (OS), and radiation pneumonitis and radiation esophagitis was also evaluated. Totally 7 studies were included. Of them, 5 studies (80 patients) were included in the dosimetric comparison, 3 studies (871 patients) were included in the OS analysis, and 2 studies (205 patients) were included in the irradiation toxicity analysis. For lung in patients receiving doses ≥20 Gy and heart in patients receiving dose = 50 Gy, the average irradiated volumes of IMRT were less than those from 3D-CRT. IMRT resulted in a higher OS than 3D-CRT. However, no significant difference was observed in the incidence of radiation pneumonitis and radiation esophagitis between 2 radiotherapy techniques. Our data suggest that IMRT-delivered high radiation dose produces significantly less average percent volumes of irradiated lung and heart than 3D-CRT. IMRT is superior to 3D-CRT in the OS of EC while shows no benefit on radiation toxicity.

F-16 Task Analysis Criterion-Referenced Objective and Objectives Hierarchy Report. Volume 4

DTIC Science & Technology

1981-03-01

Initiation cues: Engine flameout Systems presenting cues: Aircraft fuel, engine STANDARD: Authority: TACR 60-2 Performance precision: TD in first 1/3 of...task: None Initiation cues: On short final Systems preventing cues: N/A STANDARD: Authority: 60-2 Performance precision: +/- .5 AOA; TD zone 150-1000...precision: +/- .05 AOA; TD Zone 150-1000 Computational accuracy: N/A ... . . ... . ... e e m I TASK NO.: 1.9.4 BEHAVIOR: Perform short field landing

A time series analysis performed on a 25-year period of kidney transplantation activity in a single center.

PubMed

Santori, G; Fontana, I; Bertocchi, M; Gasloli, G; Valente, U

2010-05-01

Following the example of many Western countries, where a "minimum volume rule" policy has been adopted as a quality parameter for complex surgical procedures, the Italian National Transplant Centre set the minimum number of kidney transplantation procedures/y at 30/center. The number of procedures performed in a single center over a large period may be treated as a time series to evaluate trends, seasonal cycles, and nonsystematic fluctuations. Between January 1, 1983, and December 31, 2007, we performed 1376 procedures in adult or pediatric recipients from living or cadaveric donors. The greatest numbers of cases/y were performed in 1998 (n = 86) followed by 2004 (n = 82), 1996 (n = 75), and 2003 (n = 73). A time series analysis performed using R Statistical Software (Foundation for Statistical Computing, Vienna, Austria), a free software environment for statistical computing and graphics, showed a whole incremental trend after exponential smoothing as well as after seasonal decomposition. However, starting from 2005, we observed a decreased trend in the series. The number of kidney transplants expected to be performed for 2008 by using the Holt-Winters exponential smoothing applied to the period 1983 to 2007 suggested 58 procedures, while in that year there were 52. The time series approach may be helpful to establish a minimum volume/y at a single-center level. Copyright (c) 2010 Elsevier Inc. All rights reserved.

A Macro Analysis of DoD Logistics Systems. Volume 3. A Framework for Policy-Level Logistics Management

DTIC Science & Technology

1978-12-01

prioritization. 5 (We have chosen to use a variation of Saaty’s method in our hierarchical analysis, discussed in chapter 5, but for a purpose different ...the word "framework" to refer to an abstract structure for think- ing through policy-tieel management problems. This structure raises method - ological...readiness and logistics system performance, and we relied heavily on "structural" and trend analysis. By structural analysis, we meant a formal method for

Agreement and reliability of pelvic floor measurements during contraction using three-dimensional pelvic floor ultrasound and virtual reality.

PubMed

Speksnijder, L; Rousian, M; Steegers, E A P; Van Der Spek, P J; Koning, A H J; Steensma, A B

2012-07-01

Virtual reality is a novel method of visualizing ultrasound data with the perception of depth and offers possibilities for measuring non-planar structures. The levator ani hiatus has both convex and concave aspects. The aim of this study was to compare levator ani hiatus volume measurements obtained with conventional three-dimensional (3D) ultrasound and with a virtual reality measurement technique and to establish their reliability and agreement. 100 symptomatic patients visiting a tertiary pelvic floor clinic with a normal intact levator ani muscle diagnosed on translabial ultrasound were selected. Datasets were analyzed using a rendered volume with a slice thickness of 1.5 cm at the level of minimal hiatal dimensions during contraction. The levator area (in cm(2)) was measured and multiplied by 1.5 to get the levator ani hiatus volume in conventional 3D ultrasound (in cm(3)). Levator ani hiatus volume measurements were then measured semi-automatically in virtual reality (cm(3) ) using a segmentation algorithm. An intra- and interobserver analysis of reliability and agreement was performed in 20 randomly chosen patients. The mean difference between levator ani hiatus volume measurements performed using conventional 3D ultrasound and virtual reality was 0.10 (95% CI, - 0.15 to 0.35) cm(3). The intraclass correlation coefficient (ICC) comparing conventional 3D ultrasound with virtual reality measurements was > 0.96. Intra- and interobserver ICCs for conventional 3D ultrasound measurements were > 0.94 and for virtual reality measurements were > 0.97, indicating good reliability for both. Levator ani hiatus volume measurements performed using virtual reality were reliable and the results were similar to those obtained with conventional 3D ultrasonography. Copyright © 2012 ISUOG. Published by John Wiley & Sons, Ltd.

SU-E-J-83: CBCT Based Rectum and Bladder Dose Tracking in the Prostate Radiotherapy

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

Chen, Z; Wang, J; Yang, Z

2015-06-15

Purpose: The aim of this study is to monitor the volume changes of bladder and rectum and evaluate the dosimetric changes of bladder and rectum using daily cone-beam CT for prostate radiotherapy. Methods: The data of this study were obtained from 12 patients, totally 222 CBCTs. All the volume of the bladder and the rectum on the CBCT were normalized to the bladder and the rectum on their own original CT to monitory the volume changes. To evaluate dose delivered to the OARs, volumes that receive 70Gy (V70Gy), 60Gy, 50Gy, 40Gy and 30Gy are calculated for the bladder and themore » rectum, V20Gy and V10Gy for rectum additionally. And the deviation of the mean dose to the bladder and the rectum are also chosen as the evaluation parameter. Linear regression analysis was performed to identify the mean dose change of the volume change using SPSS 19. Results: The results show that the variances of the normalize volume of the bladder and the rectum are 0.15–0.58 and 0.13–0.50. The variances of V70Gy, V60Gy, V50Gy, V40Gy and V30Gy of bladder are bigger than rectum for 11 patients. The linear regression analysis indicated a negative correlation between the volume and the mean dose of the bladder (p < 0.05). A 10% increase in bladder volume will cause 5.1% (±4.3%) reduction in mean dose. Conclusion: The bladder volume change is more significant than that for rectum for the prostate cancer patient. The volume changes of rectum are not significant except air gap in the rectum. Bladder volume varies will cause significant dose change. The bladder volume monitoring before fractional treatment delivery would be crucial for accuracy dose delivery.« less

Comparing diffuse optical tomography and functional magnetic resonance imaging signals during a cognitive task: pilot study

PubMed Central

Hernández-Martin, Estefania; Marcano, Francisco; Casanova, Oscar; Modroño, Cristian; Plata-Bello, Julio; González-Mora, Jose Luis

2017-01-01

Abstract. Diffuse optical tomography (DOT) measures concentration changes in both oxy- and deoxyhemoglobin providing three-dimensional images of local brain activations. A pilot study, which compares both DOT and functional magnetic resonance imaging (fMRI) volumes through t-maps given by canonical statistical parametric mapping (SPM) processing for both data modalities, is presented. The DOT series were processed using a method that is based on a Bayesian filter application on raw DOT data to remove physiological changes and minimum description length application index to select a number of singular values, which reduce the data dimensionality during image reconstruction and adaptation of DOT volume series to normalized standard space. Therefore, statistical analysis is performed with canonical SPM software in the same way as fMRI analysis is done, accepting DOT volumes as if they were fMRI volumes. The results show the reproducibility and ruggedness of the method to process DOT series on group analysis using cognitive paradigms on the prefrontal cortex. Difficulties such as the fact that scalp–brain distances vary between subjects or cerebral activations are difficult to reproduce due to strategies used by the subjects to solve arithmetic problems are considered. T-images given by fMRI and DOT volume series analyzed in SPM show that at the functional level, both DOT and fMRI measures detect the same areas, although DOT provides complementary information to fMRI signals about cerebral activity. PMID:28386575

Bilateral Thalamocortical Abnormalities in Focal Cortical Dysplasia.

PubMed

Rezayev, Arthur; Feldman, Henry A; Levman, Jacob; Takahashi, Emi

2018-05-05

Focal cortical dysplasia (FCD), a congenital malformation of the neocortex and one of the most common causes of medication resistant epilepsy in pediatric populations, can be studied noninvasively by diffusion tensor imaging (DTI). The present study aimed to quantify changes in the thalamus and thalamocortical pathways with respect to fractional anisotropy (FA), apparent diffusion coefficient (ADC), volume, and other common measures. The study quantified data collected from pediatric patients with a prior diagnosis of FCD; 75 patients (35 females, 10.1 ± 6.5 years) for analysis of thalamic volume and 68 patients (32 females, 10.2 ± 6.4 years) for DTI analysis. DTI scans were taken at 3 Tesla MRI scanners (30 diffusion gradient directions; b= 1000 s/mm 2 and 5 non diffusion-weighted measurements). DTI tractography was performed using the FACT algorithm with an angle threshold of 45 degrees. Manually delineated ROIs were used to compare the hemisphere containing the dysplasia to the contralateral hemisphere and controls. A significant decrease in the volume of the FCD hemisphere thalamus was detected as compared to the contralateral hemisphere. In comparison to controls, there was an observed reduction in tract volume, length, count, FA of thalami, and FA of thalamocortical pathways in FCD patients. FCD patients had higher odds of exhibiting high ADC in both the thalamus and thalamocortical pathways. The data implied a widespread reduction in structural connectivity of the thalamocortical network. MRI analysis suggests a potential influence of FCD on thalamic volume. Copyright © 2018. Published by Elsevier B.V.

Intra- and interobserver agreement for fetal cerebral measurements in 3D-ultrasonography.

PubMed

Albers, Maria E W A; Buisman, Erato T I A; Kahn, René S; Franx, Arie; Onland-Moret, N Charlotte; de Heus, Roel

2018-04-10

The aim of this study is to evaluate intra- and interobserver agreement for measurement of intracranial, cerebellar, and thalamic volume with the Virtual Organ Computer-aided AnaLysis (VOCAL) technique in three-dimensional ultrasound images, in comparison to two-dimensional measurements of these brain structures. Three-dimensional ultrasound images of the brains of 80 fetuses at 20-24 weeks' gestational age were obtained from YOUth, a Dutch prospective cohort study. Two observers performed offline measurement of the occipitofrontal diameter, intracranial volume, transcerebellar diameter, cerebellar volume, and thalamic width, area, and volume, independently. VOCAL was used for calculation of the volumes. The two-way random, single measures intraclass correlation coefficient (ICC) was used for analysis of agreement and Bland-Altman plots were configured. Intra- and interobserver agreement was almost perfect for occipitofrontal diameter (intra ICC 0.88, 95% CI 0.82-0.92; inter ICC 0.91, 95% CI 0.85-0.94), intracranial volume (intra ICC 0.96, 95% CI 0.91-0.98; inter ICC 0.97, 95% CI 0.96-0.98) and transcerebellar diameter (intra ICC 0.91, 95% CI 0.86-0.94; inter ICC 0.86, 95% CI 0.78-0.910). For cerebellar volume, the intraobserver agreement was almost perfect (0.85, 95% CI 0.76-0.90), whereas the interobserver agreement was substantial (0.75, 95% CI 0.44-0.88). Agreement was only moderate for thalamic measurements. Bland-Altman plots for the volume measurements are normally distributed with acceptable mean differences and 95% limits of agreement. The intra- and interobserver agreement of the measurement of intracranial and cerebellar volume with VOCAL was almost perfect. These measurements are therefore reliable, and can be used to investigate fetal brain development. Thalamic measurements are not reliable enough. © 2018 Wiley Periodicals, Inc.

Preoperative Renal Volume: A Surrogate Measure for Radical Nephrectomy-Induced Chronic Kidney Disease.

PubMed

Wu, Fiona Mei Wen; Tay, Melissa Hui Wen; Tai, Bee Choo; Chen, Zhaojin; Tan, Lincoln; Goh, Benjamin Yen Seow; Raman, Lata; Tiong, Ho Yee

2015-12-01

Surgically induced chronic kidney disease (CKD) has been found to have less impact on survival as well as function when compared to medical causes for CKD. The aim of this study is to evaluate whether preoperative remaining kidney volume correlates with renal function after nephrectomy, which represents an individual's renal reserve before surgically induced CKD. A retrospective review of 75 consecutive patients (29.3% females) who underwent radical nephrectomy (RN) (2000-2010) was performed. Normal side kidney parenchyma, excluding renal vessels and central sinus fat, was manually outlined in each transverse slice of CT image and multiplied by slice thickness to calculate volume. Estimated glomerular filtration rate (eGFR) was determined using the Modification of Diet in Renal Disease equation. CKD is defined as eGFR < 60 mL/min/1.73 m(2). Mean preoperative normal kidney parenchymal volume (mean age 55 [SD 13] years) is 150.7 (SD 36.4) mL. Over median follow-up of 36 months postsurgery, progression to CKD occurred in 42.6% (n = 32) of patients. On multivariable analysis, preoperative eGFR and preoperative renal volume <144 mL are independent predictors for postoperative CKD. On Kaplan-Meier analysis, median time to reach CKD postnephrectomy is 12.7 (range 0.03-43.66) months for renal volume <144 mL but not achieved if renal volume is >144 mL. Normal kidney parenchymal volume and preoperative eGFR are independent predictive factors for postoperative CKD after RN and may represent renal reserve for both surgically and medically induced CKD, respectively. Preoperative remaining kidney volume may be an adjunct representation of renal reserve postsurgery and predict later renal function decline due to perioperative loss of nephrons.

Association of Deep Gray Matter Damage With Cortical and Spinal Cord Degeneration in Primary Progressive Multiple Sclerosis.

PubMed

Ruggieri, Serena; Petracca, Maria; Miller, Aaron; Krieger, Stephen; Ghassemi, Rezwan; Bencosme, Yadira; Riley, Claire; Howard, Jonathan; Lublin, Fred; Inglese, Matilde

2015-12-01

The investigation of cortical gray matter (GM), deep GM nuclei, and spinal cord damage in patients with primary progressive multiple sclerosis (PP-MS) provides insights into the neurodegenerative process responsible for clinical progression of MS. To investigate the association of magnetic resonance imaging measures of cortical, deep GM, and spinal cord damage and their effect on clinical disability. Cross-sectional analysis of 26 patients with PP-MS (mean age, 50.9 years; range, 31-65 years; including 14 women) and 20 healthy control participants (mean age, 51.1 years; range, 34-63 years; including 11 women) enrolled at a single US institution. Clinical disability was measured with the Expanded Disability Status Scale, 9-Hole Peg Test, and 25-Foot Walking Test. We collected data from January 1, 2012, through December 31, 2013. Data analysis was performed from January 21 to April 10, 2015. Cortical lesion burden, brain and deep GM volumes, spinal cord area and volume, and scores on the Expanded Disability Status Scale (score range, 0 to 10; higher scores indicate greater disability), 9-Hole Peg Test (measured in seconds; longer performance time indicates greater disability), and 25-Foot Walking Test (test covers 7.5 m; measured in seconds; longer performance time indicates greater disability). The 26 patients with PP-MS showed significantly smaller mean (SD) brain and spinal cord volumes than the 20 control group patients (normalized brain volume, 1377.81 [65.48] vs 1434.06 [53.67] cm3 [P = .003]; normalized white matter volume, 650.61 [46.38] vs 676.75 [37.02] cm3 [P = .045]; normalized gray matter volume, 727.20 [40.74] vs 757.31 [38.95] cm3 [P = .02]; normalized neocortical volume, 567.88 [85.55] vs 645.00 [42.84] cm3 [P = .001]; normalized spinal cord volume for C2-C5, 72.71 [7.89] vs 82.70 [7.83] mm3 [P < .001]; and normalized spinal cord volume for C2-C3, 64.86 [7.78] vs 72.26 [7.79] mm3 [P =.002]). The amount of damage in deep GM structures, especially with respect to the thalamus, was correlated with the number and volume of cortical lesions (mean [SD] thalamus volume, 8.89 [1.10] cm3; cortical lesion number, 12.6 [11.7]; cortical lesion volume, 0.65 [0.58] cm3; r = -0.52; P < .01). Thalamic atrophy also showed an association with cortical lesion count in the frontal cortex (mean [SD] thalamus volume, 8.89 [1.1] cm3; cortical lesion count in the frontal lobe, 5.0 [5.7]; r = -0.60; P < .01). No association was identified between magnetic resonance imaging measures of the brain and spinal cord damage. In this study, the neurodegenerative process occurring in PP-MS appeared to spread across connected structures in the brain while proceeding independently in the spinal cord. These results support the relevance of anatomical connectivity for the propagation of MS damage in the PP phenotype.

Deep learning approach for the detection and quantification of intraretinal cystoid fluid in multivendor optical coherence tomography.

PubMed

Venhuizen, Freerk G; van Ginneken, Bram; Liefers, Bart; van Asten, Freekje; Schreur, Vivian; Fauser, Sascha; Hoyng, Carel; Theelen, Thomas; Sánchez, Clara I

2018-04-01

We developed a deep learning algorithm for the automatic segmentation and quantification of intraretinal cystoid fluid (IRC) in spectral domain optical coherence tomography (SD-OCT) volumes independent of the device used for acquisition. A cascade of neural networks was introduced to include prior information on the retinal anatomy, boosting performance significantly. The proposed algorithm approached human performance reaching an overall Dice coefficient of 0.754 ± 0.136 and an intraclass correlation coefficient of 0.936, for the task of IRC segmentation and quantification, respectively. The proposed method allows for fast quantitative IRC volume measurements that can be used to improve patient care, reduce costs, and allow fast and reliable analysis in large population studies.

Deep learning approach for the detection and quantification of intraretinal cystoid fluid in multivendor optical coherence tomography

PubMed Central

Venhuizen, Freerk G.; van Ginneken, Bram; Liefers, Bart; van Asten, Freekje; Schreur, Vivian; Fauser, Sascha; Hoyng, Carel; Theelen, Thomas; Sánchez, Clara I.

2018-01-01

We developed a deep learning algorithm for the automatic segmentation and quantification of intraretinal cystoid fluid (IRC) in spectral domain optical coherence tomography (SD-OCT) volumes independent of the device used for acquisition. A cascade of neural networks was introduced to include prior information on the retinal anatomy, boosting performance significantly. The proposed algorithm approached human performance reaching an overall Dice coefficient of 0.754 ± 0.136 and an intraclass correlation coefficient of 0.936, for the task of IRC segmentation and quantification, respectively. The proposed method allows for fast quantitative IRC volume measurements that can be used to improve patient care, reduce costs, and allow fast and reliable analysis in large population studies. PMID:29675301

Correlation of Apollo oxygen tank thermodynamic performance predictions

NASA Technical Reports Server (NTRS)

Patterson, H. W.

1971-01-01

Parameters necessary to analyze the stratified performance of the Apollo oxygen tanks include g levels, tank elasticity, flow rates and pressurized volumes. Methods for estimating g levels and flow rates from flight plans prior to flight, and from quidance and system data for use in the post flight analysis are described. Equilibrium thermodynamic equations are developed for the effects of tank elasticity and pressurized volumes on the tank pressure response and their relative magnitudes are discussed. Correlations of tank pressures and heater temperatures from flight data with the results of a stratification model are shown. Heater temperatures were also estimated with empirical heat transfer agreement with flight data when fluid properties were averaged rather than evaluated at the mean film temperature.

COMMIX-PPC: A three-dimensional transient multicomponent computer program for analyzing performance of power plant condensers. Volume 1, Equations and numerics

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

Chien, T.H.; Domanus, H.M.; Sha, W.T.

1993-02-01

The COMMIX-PPC computer pregrain is an extended and improved version of earlier COMMIX codes and is specifically designed for evaluating the thermal performance of power plant condensers. The COMMIX codes are general-purpose computer programs for the analysis of fluid flow and heat transfer in complex Industrial systems. In COMMIX-PPC, two major features have been added to previously published COMMIX codes. One feature is the incorporation of one-dimensional equations of conservation of mass, momentum, and energy on the tube stile and the proper accounting for the thermal interaction between shell and tube side through the porous-medium approach. The other added featuremore » is the extension of the three-dimensional conservation equations for shell-side flow to treat the flow of a multicomponent medium. COMMIX-PPC is designed to perform steady-state and transient. Three-dimensional analysis of fluid flow with heat transfer tn a power plant condenser. However, the code is designed in a generalized fashion so that, with some modification, it can be used to analyze processes in any heat exchanger or other single-phase engineering applications. Volume I (Equations and Numerics) of this report describes in detail the basic equations, formulation, solution procedures, and models for a phenomena. Volume II (User`s Guide and Manual) contains the input instruction, flow charts, sample problems, and descriptions of available options and boundary conditions.« less

Breast Volume Measurement by Recycling the Data Obtained From 2 Routine Modalities, Mammography and Magnetic Resonance Imaging.

PubMed

Itsukage, Shizu; Sowa, Yoshihiro; Goto, Mariko; Taguchi, Tetsuya; Numajiri, Toshiaki

2017-01-01

Objective: Preoperative prediction of breast volume is important in the planning of breast reconstructive surgery. In this study, we prospectively estimated the accuracy of measurement of breast volume using data from 2 routine modalities, mammography and magnetic resonance imaging, by comparison with volumes of mastectomy specimens. Methods: The subjects were 22 patients (24 breasts) who were scheduled to undergo total mastectomy for breast cancer. Preoperatively, magnetic resonance imaging volume measurement was performed using a medical imaging system and the mammographic volume was calculated using a previously proposed formula. Volumes of mastectomy specimens were measured intraoperatively using a method based on Archimedes' principle and Newton's third law. Results: The average breast volumes measured on magnetic resonance imaging and mammography were 318.47 ± 199.4 mL and 325.26 ± 217.36 mL, respectively. The correlation coefficients with mastectomy specimen volumes were 0.982 for magnetic resonance imaging and 0.911 for mammography. Conclusions: Breast volume measurement using magnetic resonance imaging was highly accurate but requires data analysis software. In contrast, breast volume measurement with mammography requires only a simple formula and is sufficiently accurate, although the accuracy was lower than that obtained with magnetic resonance imaging. These results indicate that mammography could be an alternative modality for breast volume measurement as a substitute for magnetic resonance imaging.

Breast Volume Measurement by Recycling the Data Obtained From 2 Routine Modalities, Mammography and Magnetic Resonance Imaging

PubMed Central

Itsukage, Shizu; Goto, Mariko; Taguchi, Tetsuya; Numajiri, Toshiaki

2017-01-01

Objective: Preoperative prediction of breast volume is important in the planning of breast reconstructive surgery. In this study, we prospectively estimated the accuracy of measurement of breast volume using data from 2 routine modalities, mammography and magnetic resonance imaging, by comparison with volumes of mastectomy specimens. Methods: The subjects were 22 patients (24 breasts) who were scheduled to undergo total mastectomy for breast cancer. Preoperatively, magnetic resonance imaging volume measurement was performed using a medical imaging system and the mammographic volume was calculated using a previously proposed formula. Volumes of mastectomy specimens were measured intraoperatively using a method based on Archimedes’ principle and Newton's third law. Results: The average breast volumes measured on magnetic resonance imaging and mammography were 318.47 ± 199.4 mL and 325.26 ± 217.36 mL, respectively. The correlation coefficients with mastectomy specimen volumes were 0.982 for magnetic resonance imaging and 0.911 for mammography. Conclusions: Breast volume measurement using magnetic resonance imaging was highly accurate but requires data analysis software. In contrast, breast volume measurement with mammography requires only a simple formula and is sufficiently accurate, although the accuracy was lower than that obtained with magnetic resonance imaging. These results indicate that mammography could be an alternative modality for breast volume measurement as a substitute for magnetic resonance imaging. PMID:29308107

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

Using Solid State Disk Array as a Cache for LHC ATLAS Data Analysis

NASA Astrophysics Data System (ADS)

Yang, W.; Hanushevsky, A. B.; Mount, R. P.; Atlas Collaboration

2014-06-01

User data analysis in high energy physics presents a challenge to spinning-disk based storage systems. The analysis is data intense, yet reads are small, sparse and cover a large volume of data files. It is also unpredictable due to users' response to storage performance. We describe here a system with an array of Solid State Disk as a non-conventional, standalone file level cache in front of the spinning disk storage to help improve the performance of LHC ATLAS user analysis at SLAC. The system uses several days of data access records to make caching decisions. It can also use information from other sources such as a work-flow management system. We evaluate the performance of the system both in terms of caching and its impact on user analysis jobs. The system currently uses Xrootd technology, but the technique can be applied to any storage system.

Spatial and temporal single-cell volume estimation by a fluorescence imaging technique with application to astrocytes in primary culture

NASA Astrophysics Data System (ADS)

Khatibi, Siamak; Allansson, Louise; Gustavsson, Tomas; Blomstrand, Fredrik; Hansson, Elisabeth; Olsson, Torsten

1999-05-01

Cell volume changes are often associated with important physiological and pathological processes in the cell. These changes may be the means by which the cell interacts with its surrounding. Astroglial cells change their volume and shape under several circumstances that affect the central nervous system. Following an incidence of brain damage, such as a stroke or a traumatic brain injury, one of the first events seen is swelling of the astroglial cells. In order to study this and other similar phenomena, it is desirable to develop technical instrumentation and analysis methods capable of detecting and characterizing dynamic cell shape changes in a quantitative and robust way. We have developed a technique to monitor and to quantify the spatial and temporal volume changes in a single cell in primary culture. The technique is based on two- and three-dimensional fluorescence imaging. The temporal information is obtained from a sequence of microscope images, which are analyzed in real time. The spatial data is collected in a sequence of images from the microscope, which is automatically focused up and down through the specimen. The analysis of spatial data is performed off-line and consists of photobleaching compensation, focus restoration, filtering, segmentation and spatial volume estimation.

Blood-threshold CMR volume analysis of functional univentricular heart.

PubMed

Secchi, Francesco; Alì, Marco; Petrini, Marcello; Pluchinotta, Francesca Romana; Cozzi, Andrea; Carminati, Mario; Sardanelli, Francesco

2018-05-01

To validate a blood-threshold (BT) segmentation software for cardiac magnetic resonance (CMR) cine images in patients with functional univentricular heart (FUH). We evaluated retrospectively 44 FUH patients aged 25 ± 8 years (mean ± standard deviation). For each patient, the epicardial contour of the single ventricle was manually segmented on cine images by two readers and an automated BT algorithm was independently applied to calculate end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV), ejection fraction (EF), and cardiac mass (CM). Aortic flow analysis (AFA) was performed on through-plane images to obtain forward volumes and used as a benchmark. Reproducibility was tested in a subgroup of 24 randomly selected patients. Wilcoxon, Spearman, and Bland-Altman statistics were used. No significant difference was found between SV (median 57.7 ml; interquartile range 47.9-75.6) and aortic forward flow (57.4 ml; 48.9-80.4) (p = 0.123), with a high correlation (r = 0.789, p < 0.001). Intra-reader reproducibility was 86% for SV segmentation, and 96% for AFA. Inter-reader reproducibility was 85 and 96%, respectively. The BT segmentation provided an accurate and reproducible assessment of heart function in FUH patients.

The association between hospital volume and processes, outcomes, and costs of care for congestive heart failure

PubMed Central

Joynt, Karen E.; Orav, E. John; Jha, Ashish K.

2012-01-01

Background Congestive Heart Failure (CHF) is common and costly, and despite pharmacologic and technical advances, outcomes remain suboptimal. Objective To examine whether hospitals that have more experience caring for patients with CHF provide better, more efficient care. Design We used national Medicare claims data from 2006–2007 to examine the relationship between hospitals’ case volume and quality, outcomes, and costs for patients with CHF. Setting 4,095 U.S. hospitals Patients Medicare fee-for-service patients with a primary discharge diagnosis of CHF Measurements Hospital Quality Alliance (HQA) CHF process measures, 30-day risk-adjusted mortality rates, 30-day risk-adjusted readmission rates, and costs per discharge. Results Hospitals in the lowest volume group had lower performance on HQA measures than medium- or high-volume hospitals (80.2% versus 87.0% versus 89.1%, p<0.001). Within the low volume group, being admitted to a hospital with a higher case volume was associated with lower mortality, lower readmission, and higher costs. For example, in the lowest volume group of hospitals, an increase of 10 cases of CHF was associated with 1% lower odds of mortality, 1% lower odds of readmissions and $22 higher costs per case. We found similar though smaller relationships between case volume and both mortality and costs in the medium and high-volume hospital cohorts. Limitations Our analysis was limited to Medicare patients 65 years of age or older; risk adjustment was performed using administrative data. Conclusions Experience with managing CHF, as measured by an institution’s volume, is associated with higher quality of care and better outcomes for patients, but at a higher cost. Understanding which practices employed by high-volume institutions account for these advantages can help improve quality of care and clinical outcomes for all CHF patients. PMID:21242366

Impaired decision-making and brain shrinkage in alcoholism.

PubMed

Le Berre, A-P; Rauchs, G; La Joie, R; Mézenge, F; Boudehent, C; Vabret, F; Segobin, S; Viader, F; Allain, P; Eustache, F; Pitel, A-L; Beaunieux, H

2014-03-01

Alcohol-dependent individuals usually favor instant gratification of alcohol use and ignore its long-term negative consequences, reflecting impaired decision-making. According to the somatic marker hypothesis, decision-making abilities are subtended by an extended brain network. As chronic alcohol consumption is known to be associated with brain shrinkage in this network, the present study investigated relationships between brain shrinkage and decision-making impairments in alcohol-dependent individuals early in abstinence using voxel-based morphometry. Thirty patients performed the Iowa Gambling Task and underwent a magnetic resonance imaging investigation (1.5T). Decision-making performances and brain data were compared with those of age-matched healthy controls. In the alcoholic group, a multiple regression analysis was conducted with two predictors (gray matter [GM] volume and decision-making measure) and two covariates (number of withdrawals and duration of alcoholism). Compared with controls, alcoholics had impaired decision-making and widespread reduced gray matter volume, especially in regions involved in decision-making. The regression analysis revealed links between high GM volume in the ventromedial prefrontal cortex, dorsal anterior cingulate cortex and right hippocampal formation, and high decision-making scores (P<0.001, uncorrected). Decision-making deficits in alcoholism may result from impairment of both emotional and cognitive networks. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

A method of minimum volume simplex analysis constrained unmixing for hyperspectral image

NASA Astrophysics Data System (ADS)

Zou, Jinlin; Lan, Jinhui; Zeng, Yiliang; Wu, Hongtao

2017-07-01

The signal recorded by a low resolution hyperspectral remote sensor from a given pixel, letting alone the effects of the complex terrain, is a mixture of substances. To improve the accuracy of classification and sub-pixel object detection, hyperspectral unmixing(HU) is a frontier-line in remote sensing area. Unmixing algorithm based on geometric has become popular since the hyperspectral image possesses abundant spectral information and the mixed model is easy to understand. However, most of the algorithms are based on pure pixel assumption, and since the non-linear mixed model is complex, it is hard to obtain the optimal endmembers especially under a highly mixed spectral data. To provide a simple but accurate method, we propose a minimum volume simplex analysis constrained (MVSAC) unmixing algorithm. The proposed approach combines the algebraic constraints that are inherent to the convex minimum volume with abundance soft constraint. While considering abundance fraction, we can obtain the pure endmember set and abundance fraction correspondingly, and the final unmixing result is closer to reality and has better accuracy. We illustrate the performance of the proposed algorithm in unmixing simulated data and real hyperspectral data, and the result indicates that the proposed method can obtain the distinct signatures correctly without redundant endmember and yields much better performance than the pure pixel based algorithm.

Solar power satellite system definition study. Volume 5, phase 1: Executive summary

NASA Technical Reports Server (NTRS)

1979-01-01

An analysis of the solar power satellite system is presented. Performance, cost, and operational characteristics are assessed. The photovoltaic system is described and investigated. Alternative construction concepts are discussed. The structural bay configuration is presented along with the antenna structure options.

IVHS Countermeasures For Rear-End Collisions, Task 1 Volume V: 1985 Nass Case Analysis, Interim Report

DOT National Transportation Integrated Search

1994-02-01

THE ATTACHED REPORT IS FROM THE NHTSA SPONSORED PROGRAM, "IVHS COUNTERMEASURES FOR REAR-END COLLISIONS," CONTRACT #DTNH22-93-C-07326. THE PROGRAM'S PRIMARY OBJECTIVE IS TO DEVELOP PRACTICAL PERFORMANCE GUIDELINES OR SPECIFICATIONS FOR REAR-END COLLIS...

DYNALIST II : A Computer Program for Stability and Dynamic Response Analysis of Rail Vehicle Systems : Volume 4. Revised User's Manual.

DOT National Transportation Integrated Search

1976-07-01

The Federal Railroad Administration (FRA) is sponsoring research, development, and demonstration programs to provide improved safety, performance, speed, reliability, and maintainability of rail transportation systems at reduced life-cycle costs. A m...

Critical determinants of combined sprint and endurance performance: an integrative analysis from muscle fiber to the human body.

PubMed

van der Zwaard, Stephan; van der Laarse, Willem J; Weide, Guido; Bloemers, Frank W; Hofmijster, Mathijs J; Levels, Koen; Noordhof, Dionne A; de Koning, Jos J; de Ruiter, Cornelis J; Jaspers, Richard T

2018-04-01

Optimizing physical performance is a major goal in current physiology. However, basic understanding of combining high sprint and endurance performance is currently lacking. This study identifies critical determinants of combined sprint and endurance performance using multiple regression analyses of physiologic determinants at different biologic levels. Cyclists, including 6 international sprint, 8 team pursuit, and 14 road cyclists, completed a Wingate test and 15-km time trial to obtain sprint and endurance performance results, respectively. Performance was normalized to lean body mass 2/3 to eliminate the influence of body size. Performance determinants were obtained from whole-body oxygen consumption, blood sampling, knee-extensor maximal force, muscle oxygenation, whole-muscle morphology, and muscle fiber histochemistry of musculus vastus lateralis. Normalized sprint performance was explained by percentage of fast-type fibers and muscle volume ( R 2 = 0.65; P < 0.001) and normalized endurance performance by performance oxygen consumption ( V̇o 2 ), mean corpuscular hemoglobin concentration, and muscle oxygenation ( R 2 = 0.92; P < 0.001). Combined sprint and endurance performance was explained by gross efficiency, performance V̇o 2 , and likely by muscle volume and fascicle length ( P = 0.056; P = 0.059). High performance V̇o 2 related to a high oxidative capacity, high capillarization × myoglobin, and small physiologic cross-sectional area ( R 2 = 0.67; P < 0.001). Results suggest that fascicle length and capillarization are important targets for training to optimize sprint and endurance performance simultaneously.-Van der Zwaard, S., van der Laarse, W. J., Weide, G., Bloemers, F. W., Hofmijster, M. J., Levels, K., Noordhof, D. A., de Koning, J. J., de Ruiter, C. J., Jaspers, R. T. Critical determinants of combined sprint and endurance performance: an integrative analysis from muscle fiber to the human body.

[An analysis of cost and profit of a nursing unit using performance-based costing: case of a general surgical ward in a general hospital].

PubMed

Lim, Ji Young

2008-02-01

The aim of this study was to analyze net income of a surgical nursing ward in a general hospital. Data collection and analysis was conducted using a performance-based costing and activity-based costing method. Direct nursing activities in the surgical ward were 68, indirect nursing activities were 10. The total cost volume of the surgical ward was calculated at won 119,913,334.5. The cost volume of the allocated medical department was won 91,588,200.3, and the ward consumed cost was won 28,325,134.2. The revenue of the surgical nursing ward was won 33,269,925.0. The expense of a surgical nursing ward was 28,325,134.2. Therefore, the net income of a surgical nursing ward was won 4,944,790.8. We suggest that to develop a more refined nursing cost calculation model, a standard nursing cost calculation system needs to be developed.

An inkjet vision measurement technique for high-frequency jetting

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

Kwon, Kye-Si, E-mail: kskwon@sch.ac.kr; Jang, Min-Hyuck; Park, Ha Yeong

2014-06-15

Inkjet technology has been used as manufacturing a tool for printed electronics. To increase the productivity, the jetting frequency needs to be increased. When using high-frequency jetting, the printed pattern quality could be non-uniform since the jetting performance characteristics including the jetting speed and droplet volume could vary significantly with increases in jet frequency. Therefore, high-frequency jetting behavior must be evaluated properly for improvement. However, it is difficult to measure high-frequency jetting behavior using previous vision analysis methods, because subsequent droplets are close or even merged. In this paper, we present vision measurement techniques to evaluate the drop formation ofmore » high-frequency jetting. The proposed method is based on tracking target droplets such that subsequent droplets can be excluded in the image analysis by focusing on the target droplet. Finally, a frequency sweeping method for jetting speed and droplet volume is presented to understand the overall jetting frequency effects on jetting performance.« less

Space Station Systems Analysis Study. Volume 1: Executive summary, part 1 and 2

NASA Technical Reports Server (NTRS)

1977-01-01

The elements of space station programs required to support an operational base theme, a space laboratory theme, and advanced missions relatable to public needs/national interests are defined. Missions satisfying the foregoing requirements are identified, program scenarios/options are established. System options are evaluated for a selected number of program options. Subsystem analysis and programmatic comparisons are performed for selected primary concepts.

Correlation between orbital volume, body mass index, and eyeball position in healthy East asians.

PubMed

Yoo, Jun Ho; Lee, Young Hen; Lee, Hwa; Kim, Jung Wan; Chang, Minwook; Park, Minsoo; Baek, Sehyun

2013-05-01

The objectives of this study were measure the orbital volume of healthy Koreans and analyze the differences between orbital tissue volume with respect to age and sex and to assess any correlation between body mass index (BMI), eyeball position, and orbital volume. We retrospectively evaluated the scan results of patients who had undergone orbital computed tomography scans between November 2010 and November 2011. We assessed the scan results of 184 orbits in 92 adults who had no pathology of the orbit. The individuals were classified into 3 groups with respect to age. Orbital volume, effective orbital volume (defined as the difference between orbital and eyeball volume), extraocular muscle volume, orbital fat volume, and transverse globe protrusion were recorded and analyzed. The records of the subjects were reviewed retrospectively, and BMI was calculated. A correlation analysis was performed to investigate the correlation between BMI, eyeball position, and orbital volume. Orbital tissue volume, with the exception of orbital fat volume, was larger in men compared with women. In both sexes, orbital fat volume increased with increasing age, whereas the other volumes decreased. Orbital tissue volumes increased with increasing BMI, but transverse globe protrusion was not significantly related to BMI. In addition, orbital volume and effective orbital volume were positively correlated with transverse globe protrusion. These results provide basic information about the effects of age, sex, and BMI on orbital volume and eyeball position in healthy Koreans. Furthermore, these results will be helpful in the diagnosis of orbital diseases and in planning orbital surgeries.

Evaluation of pharyngeal space and its correlation with mandible and hyoid bone in patients with different skeletal classes and facial types.

PubMed

Nejaim, Yuri; Aps, Johan K M; Groppo, Francisco Carlos; Haiter Neto, Francisco

2018-06-01

The purpose of this article was to evaluate the pharyngeal space volume, and the size and shape of the mandible and the hyoid bone, as well as their relationships, in patients with different facial types and skeletal classes. Furthermore, we estimated the volume of the pharyngeal space with a formula using only linear measurements. A total of 161 i-CAT Next Generation (Imaging Sciences International, Hatfield, Pa) cone-beam computed tomography images (80 men, 81 women; ages, 21-58 years; mean age, 27 years) were retrospectively studied. Skeletal class and facial type were determined for each patient from multiplanar reconstructions using the NemoCeph software (Nemotec, Madrid, Spain). Linear and angular measurements were performed using 3D imaging software (version 3.4.3; Carestream Health, Rochester, NY), and volumetric analysis of the pharyngeal space was carried out with ITK-SNAP (version 2.4.0; Cognitica, Philadelphia, Pa) segmentation software. For the statistics, analysis of variance and the Tukey test with a significance level of 0.05, Pearson correlation, and linear regression were used. The pharyngeal space volume, when correlated with mandible and hyoid bone linear and angular measurements, showed significant correlations with skeletal class or facial type. The linear regression performed to estimate the volume of the pharyngeal space showed an R of 0.92 and an adjusted R 2 of 0.8362. There were significant correlations between pharyngeal space volume, and the mandible and hyoid bone measurements, suggesting that the stomatognathic system should be evaluated in an integral and nonindividualized way. Furthermore, it was possible to develop a linear regression model, resulting in a useful formula for estimating the volume of the pharyngeal space. Copyright © 2018 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

Decision support system in an international-voice-services business company

NASA Astrophysics Data System (ADS)

Hadianti, R.; Uttunggadewa, S.; Syamsuddin, M.; Soewono, E.

2017-01-01

We consider a problem facing by an international telecommunication services company in maximizing its profit. From voice services by controlling cost and business partnership. The competitiveness in this industry is very high, so that any efficiency from controlling cost and business partnership can help the company to survive in the very high competitiveness situation. The company trades voice traffic with a large number of business partners. There are four trading schemes that can be chosen by this company, namely, flat rate, class tiering, volume commitment, and revenue capped. Each scheme has a specific characteristic on the rate and volume deal, where the last three schemes are regarded as strategic schemes to be offered to business partner to ensure incoming traffic volume for both parties. This company and each business partner need to choose an optimal agreement in a certain period of time that can maximize the company’s profit. In this agreement, both parties agree to use a certain trading scheme, rate and rate/volume/revenue deal. A decision support system is then needed in order to give a comprehensive information to the sales officers to deal with the business partners. This paper discusses the mathematical model of the optimal decision for incoming traffic volume control, which is a part of the analysis needed to build the decision support system. The mathematical model is built by first performing data analysis to see how elastic the incoming traffic volume is. As the level of elasticity is obtained, we then derive a mathematical modelling that can simulate the impact of any decision on trading to the revenue of the company. The optimal decision can be obtained from these simulations results. To evaluate the performance of the proposed method we implement our decision model to the historical data. A software tool incorporating our methodology is currently in construction.

Gamma Knife Radiosurgery for Treatment of Cerebral Metastases From Non-Small-Cell Lung Cancer

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

Motta, Micaela, E-mail: motta.micaela@hsr.it; Vecchio, Antonella del; Attuati, Luca

2011-11-15

Purpose: To evaluate clinical and physico-dosimetric variables affecting clinical outcome of patients treated with Gamma Knife radiosurgery (GKRS) for brain metastases from non-small cell lung cancer (NSCLC). Methods and Materials: Between 2001 and 2006, 373 patients (298 men and 75 women, median age 65 years) with brain metastases from NSCLC underwent GKRS. All of them had KPS {>=} 60%, eight or fewer brain metastases, confirmed histopathological diagnosis and recent work-up (<3 months). Thirty-five patients belonged to recursive partitioning analysis (RPA) Class I, 307 patients were in RPA Class II, 7 patients were in RPA Class III. Median tumor volume wasmore » 3.6 cm{sup 3}. Median marginal dose was 22.5 Gy at 50% isodose.; median 10 Gy and 12 Gy isodose volumes were 30.8 cm{sup 3} and 15.8 cm{sup 3}, respectively. Follow-up with MRI was performed every 3 months. Overall survival data were collected from internal database, telephone interviews, and identifying registries. Results: Mean follow-up after GKRS was 51 months (range, 6 to 96 months); mean overall survival was 14.2 months. Of 373 patients, 29 were alive at time of writing, 104 had died of cerebral progression, and 176 had died of systemic progression. In 64 cases it was not possible to ascertain the cause. Univariate and multivariate analysis were adjusted for the following: RPA class, surgery, WBRT, age, gender, number of lesions, median tumor volume, median peripheral dose, and 10 Gy and 12 Gy volumes. Identified RPA class and overall tumor volume >5 cc were the only two covariates independently predictive of overall survival in patients who died of cerebral progression. Conclusions: Global volume of brain disease should be the main parameter to consider for performing GKRS, which is a first-line therapy for patient in good general condition and controlled systemic disease.« less

Characterization and optimization of low cost microfluidic thread based electroanalytical device for micro flow injection analysis.

PubMed

Agustini, Deonir; Bergamini, Márcio F; Marcolino-Junior, Luiz Humberto

2017-01-25

The micro flow injection analysis (μFIA) is a powerful technique that uses the principles of traditional flow analysis in a microfluidic device and brings a number of improvements related to the consumption of reagents and samples, speed of analysis and portability. However, the complexity and cost of manufacturing processes, difficulty in integrating micropumps and the limited performance of systems employing passive pumps are challenges that must be overcome. Here, we present the characterization and optimization of a low cost device based on cotton threads as microfluidic channel to perform μFIA based on passive pumps with good analytical performance in a simple, easy and inexpensive way. The transport of solutions is made through cotton threads by capillary force facilitated by gravity. After studying and optimizing several features related to the device, were obtained a flow rate of 2.2 ± 0.1 μL s -1 , an analytical frequency of 208 injections per hour, a sample injection volume of 2.0 μL and a waste volume of approximately 40 μL per analysis. For chronoamperometric determination of naproxen, a detection limit of 0.29 μmol L -1 was reached, with a relative standard deviation (RSD) of 1.69% between injections and a RSD of 3.79% with five different devices. Thus, based on the performance presented by proposed microfluidic device, it is possible to overcome some limitations of the μFIA systems based on passive pumps and allow expansion in the use of this technique. Copyright © 2016 Elsevier B.V. All rights reserved.

Whole-lesion apparent diffusion coefficient histogram analysis: significance in T and N staging of gastric cancers.

PubMed

Liu, Song; Zhang, Yujuan; Chen, Ling; Guan, Wenxian; Guan, Yue; Ge, Yun; He, Jian; Zhou, Zhengyang

2017-10-02

Whole-lesion apparent diffusion coefficient (ADC) histogram analysis has been introduced and proved effective in assessment of multiple tumors. However, the application of whole-volume ADC histogram analysis in gastrointestinal tumors has just started and never been reported in T and N staging of gastric cancers. Eighty patients with pathologically confirmed gastric carcinomas underwent diffusion weighted (DW) magnetic resonance imaging before surgery prospectively. Whole-lesion ADC histogram analysis was performed by two radiologists independently. The differences of ADC histogram parameters among different T and N stages were compared with independent-samples Kruskal-Wallis test. Receiver operating characteristic (ROC) analysis was performed to evaluate the performance of ADC histogram parameters in differentiating particular T or N stages of gastric cancers. There were significant differences of all the ADC histogram parameters for gastric cancers at different T (except ADC min and ADC max ) and N (except ADC max ) stages. Most ADC histogram parameters differed significantly between T1 vs T3, T1 vs T4, T2 vs T4, N0 vs N1, N0 vs N3, and some parameters (ADC 5% , ADC 10% , ADC min ) differed significantly between N0 vs N2, N2 vs N3 (all P < 0.05). Most parameters except ADC max performed well in differentiating different T and N stages of gastric cancers. Especially for identifying patients with and without lymph node metastasis, the ADC 10% yielded the largest area under the ROC curve of 0.794 (95% confidence interval, 0.677-0.911). All the parameters except ADC max showed excellent inter-observer agreement with intra-class correlation coefficients higher than 0.800. Whole-volume ADC histogram parameters held great potential in differentiating different T and N stages of gastric cancers preoperatively.

Evaluation of pollutant loads from stormwater BMPs to receiving water using load frequency curves with uncertainty analysis.

PubMed

Park, Daeryong; Roesner, Larry A

2012-12-15

This study examined pollutant loads released to receiving water from a typical urban watershed in the Los Angeles (LA) Basin of California by applying a best management practice (BMP) performance model that includes uncertainty. This BMP performance model uses the k-C model and incorporates uncertainty analysis and the first-order second-moment (FOSM) method to assess the effectiveness of BMPs for removing stormwater pollutants. Uncertainties were considered for the influent event mean concentration (EMC) and the aerial removal rate constant of the k-C model. The storage treatment overflow and runoff model (STORM) was used to simulate the flow volume from watershed, the bypass flow volume and the flow volume that passes through the BMP. Detention basins and total suspended solids (TSS) were chosen as representatives of stormwater BMP and pollutant, respectively. This paper applies load frequency curves (LFCs), which replace the exceedance percentage with an exceedance frequency as an alternative to load duration curves (LDCs), to evaluate the effectiveness of BMPs. An evaluation method based on uncertainty analysis is suggested because it applies a water quality standard exceedance based on frequency and magnitude. As a result, the incorporation of uncertainty in the estimates of pollutant loads can assist stormwater managers in determining the degree of total daily maximum load (TMDL) compliance that could be expected from a given BMP in a watershed. Copyright © 2012 Elsevier Ltd. All rights reserved.

Microbleeds versus macrobleeds: evidence for distinct entities.

PubMed

Greenberg, Steven M; Nandigam, R N Kaveer; Delgado, Pilar; Betensky, Rebecca A; Rosand, Jonathan; Viswanathan, Anand; Frosch, Matthew P; Smith, Eric E

2009-07-01

Small, asymptomatic microbleeds commonly accompany larger symptomatic macrobleeds. It is unclear whether microbleeds and macrobleeds represent arbitrary categories within a single continuum versus truly distinct events with separate pathophysiologies. We performed 2 complementary retrospective analyses. In a radiographic analysis, we measured and plotted the volumes of all hemorrhagic lesions detected by gradient-echo MRI among 46 consecutive patients with symptomatic primary lobar intracerebral hemorrhage diagnosed as probable or possible cerebral amyloid angiopathy. In a second neuropathologic analysis, we performed blinded qualitative and quantitative examinations of amyloid-positive vessel segments in 6 autopsied subjects whose MRI scans demonstrated particularly high microbleed counts (>50 microbleeds on MRI, n=3) or low microbleed counts (<3 microbleeds, n=3). Plotted on a logarithmic scale, the volumes of 163 hemorrhagic lesions identified on scans from the 46 subjects fell in a distinctly bimodal distribution with mean volumes for the 2 modes of 0.009 cm(3) and 27.5 cm(3). The optimal cut point for separating the 2 peaks (determined by receiver operating characteristics) corresponded to a lesion diameter of 0.57 cm. On neuropathologic analysis, the high microbleed-count autopsied subjects showed significantly thicker amyloid-positive vessel walls than the low microbleed-count subjects (proportional wall thickness 0.53+/-0.01 versus 0.37+/-0.01; P<0.0001; n=333 vessel segments analyzed). These findings suggest that cerebral amyloid angiopathy-associated microbleeds and macrobleeds comprise distinct entities. Increased vessel wall thickness may predispose to formation of microbleeds relative to macrobleeds.

Microbleeds versus Macrobleeds: Evidence for Distinct Entities

PubMed Central

Greenberg, SM; Nandigam, RNK; Delgado, P; Betensky, RA; Rosand, J; Viswanathan, A; Frosch, MP; Smith, EE

2009-01-01

Background and Purpose Small, asymptomatic microbleeds commonly accompany larger symptomatic macrobleeds. It is unclear whether microbleeds and macrobleeds represent arbitrary categories within a single continuum versus truly distinct events with separate pathophysiologies. Methods We performed two complementary retrospective analyses. In a radiographic analysis, we measured and plotted the volumes of all hemorrhagic lesions detected by gradient-echo MRI among 46 consecutive patients with symptomatic primary lobar intracerebral hemorrhage diagnosed as probable or possible cerebral amyloid angiopathy (CAA). In a second neuropathologic analysis, we performed blinded qualitative and quantitative examinations of amyloid-positive vessel segments in 6 autopsied subjects whose MRI scans demonstrated particularly high microbleed counts (>50 microbleeds on MRI, n=3) or low microbleed counts (<3 microbleeds, n=3). Results Plotted on a logarithmic scale, the volumes of 163 hemorrhagic lesions identified on scans from the 46 subjects fell in a distinctly bimodal distribution with mean volumes for the two modes of 0.009 cm3 and 27.5 cm3. The optimal cut-point for separating the two peaks (determined by receiver operating characteristics) corresponded to a lesion diameter of 0.57 cm. On neuropathologic analysis, the high microbleed-count autopsied subjects showed significantly thicker amyloid-positive vessel walls than the low microbleed-count subjects (proportional wall thickness 0.53±0.01 versus 0.37±0.01, p<.0001, n=333 vessel segments analyzed). Conclusions These findings suggest that CAA-associated microbleeds and macrobleeds comprise distinct entities. Increased vessel wall thickness may predispose to formation of microbleeds relative to macrobleeds. PMID:19443797

Inter- and intra-observer variation in soft-tissue sarcoma target definition.

PubMed

Roberge, D; Skamene, T; Turcotte, R E; Powell, T; Saran, N; Freeman, C

2011-08-01

To evaluate inter- and intra-observer variability in gross tumor volume definition for adult limb/trunk soft tissue sarcomas. Imaging studies of 15 patients previously treated with preoperative radiation were used in this study. Five physicians (radiation oncologists, orthopedic surgeons and a musculoskeletal radiologist) were asked to contour each of the 15 tumors on T1-weighted, gadolinium-enhanced magnetic resonance images. These contours were drawn twice by each physician. The volume and center of mass coordinates for each gross tumor volume were extracted and a Boolean analysis was performed to measure the degree of volume overlap. The median standard deviation in gross tumor volumes across observers was 6.1% of the average volume (range: 1.8%-24.9%). There was remarkably little variation in the 3D position of the gross tumor volume center of mass. For the 15 patients, the standard deviation of the 3D distance between centers of mass ranged from 0.06 mm to 1.7 mm (median 0.1mm). Boolean analysis demonstrated that 53% to 90% of the gross tumor volume was common to all observers (median overlap: 79%). The standard deviation in gross tumor volumes on repeat contouring was 4.8% (range: 0.1-14.4%) with a standard deviation change in the position of the center of mass of 0.4mm (range: 0mm-2.6mm) and a median overlap of 93% (range: 73%-98%). Although significant inter-observer differences were seen in gross tumor volume definition of adult soft-tissue sarcoma, the center of mass of these volumes was remarkably consistent. Variations in volume definition did not correlate with tumor size. Radiation oncologists should not hesitate to review their contours with a colleague (surgeon, radiologist or fellow radiation oncologist) to ensure that they are not outliers in sarcoma gross tumor volume definition. Protocols should take into account variations in volume definition when considering tighter clinical target volumes. Copyright © 2011 Société française de radiothérapie oncologique (SFRO). Published by Elsevier SAS. All rights reserved.

Outcomes of PCI in Relation to Procedural Characteristics and Operator Volumes in the United States.

PubMed

Fanaroff, Alexander C; Zakroysky, Pearl; Dai, David; Wojdyla, Daniel; Sherwood, Matthew W; Roe, Matthew T; Wang, Tracy Y; Peterson, Eric D; Gurm, Hitinder S; Cohen, Mauricio G; Messenger, John C; Rao, Sunil V

2017-06-20

Professional guidelines have reduced the recommended minimum number to an average of 50 percutaneous coronary intervention (PCI) procedures performed annually by each operator. Operator volume patterns and associated outcomes since this change are unknown. The authors describe herein PCI operator procedure volumes; characteristics of low-, intermediate-, and high-volume operators; and the relationship between operator volume and clinical outcomes in a large, contemporary, nationwide sample. Using data from the National Cardiovascular Data Registry collected between July 1, 2009, and March 31, 2015, we examined operator annual PCI volume. We divided operators into low- (<50 PCIs per year), intermediate- (50 to 100 PCIs per year), and high- (>100 PCIs per year) volume groups, and determined the adjusted association between annual PCI volume and in-hospital outcomes, including mortality. The median annual number of procedures performed per operator was 59; 44% of operators performed <50 PCI procedures per year. Low-volume operators more frequently performed emergency and primary PCI procedures and practiced at hospitals with lower annual PCI volumes. Unadjusted in-hospital mortality was 1.86% for low-volume operators, 1.73% for intermediate-volume operators, and 1.48% for high-volume operators. The adjusted risk of in-hospital mortality was higher for PCI procedures performed by low- and intermediate-volume operators compared with those performed by high-volume operators (adjusted odds ratio: 1.16 for low versus high; adjusted odds ratio: 1.05 for intermediate vs. high volume) as was the risk for new dialysis post PCI. No volume relationship was observed for post-PCI bleeding. Many PCI operators in the United States are performing fewer than the recommended number of PCI procedures annually. Although absolute risk differences are small and may be partially explained by unmeasured differences in case mix between operators, there remains an inverse relationship between PCI operator volume and in-hospital mortality that persisted in risk-adjusted analyses. Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Apparent volume dependence of 1/f noise in thin film structures: role of contacts.

PubMed

Barone, C; Pagano, S; Méchin, L; Routoure, J-M; Orgiani, P; Maritato, L

2008-05-01

The experimental investigation of low-frequency noise properties in new materials is very useful for the understanding of the involved physical transport mechanisms. In this paper it is shown that, when contact noise is present, the experimental values of the normalized Hooge parameter show a fictitious linear dependence on the volume of the analyzed samples. Experimental data on noise measurements of La0.7Sr0.3MnO3 thin films are reported to demonstrate the validity of the analysis performed.

Evaluation of Military Field-Water Quality. Volume 7. Performance Evaluation of the 600-GPH Reverse Osmosis Water Purification Unit (ROWPU): reverse Osmosis (RO) Components

DTIC Science & Technology

1986-02-01

Data-for ASsessingHealthRISKS In Potential Theaters ~ of Operation forU,5. Mil-itary._orces. Jf-jr cLAss t:cAToN 9; r-.$ ’AGg UNCLASSIFIED Volume 7...Bypass, Potable-Water Disinfection,_ and Water-Quality Analysis Techniques; and Vol. 9, Data for Assessing Health Risks in Potential Theaters of Operation ...cleaning the RO elements, with objectives of improving solute rejection and reducing operating pressure. The most common method is to flush citric acid

Parameter study of dual-mode space nuclear fission solid core power and propulsion systems, NUROC3A. AMS report No. 1239c

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

Smith, W.W.; Layton, J.P.

1976-09-13

The three-volume report describes a dual-mode nuclear space power and propulsion system concept that employs an advanced solid-core nuclear fission reactor coupled via heat pipes to one of several electric power conversion systems. The NUROC3A systems analysis code was designed to provide the user with performance characteristics of the dual-mode system. Volume 3 describes utilization of the NUROC3A code to produce a detailed parameter study of the system.

(131)I-MIBG therapy for malignant paraganglioma and phaeochromocytoma: systematic review and meta-analysis.

PubMed

van Hulsteijn, L T; Niemeijer, N D; Dekkers, O M; Corssmit, E P M

2014-04-01

(131)I-MIBG therapy can be used for palliative treatment of malignant paraganglioma and phaeochromocytoma. The main objective of this study was to perform a systematic review and meta-analysis assessing the effect of (131)I-MIBG therapy on tumour volume in patients with malignant paraganglioma/phaeochromocytoma. A literature search was performed in December 2012 to identify potentially relevant studies. Main outcomes were the pooled proportions of complete response, partial response and stable disease after radionuclide therapy. A meta-analysis was performed with an exact likelihood approach using a logistic regression with a random effect at the study level. Pooled proportions with 95% confidence intervals (CI) were reported. Seventeen studies concerning a total of 243 patients with malignant paraganglioma/phaeochromocytoma were treated with (131)I-MIBG therapy. The mean follow-up ranged from 24 to 62 months. A meta-analysis of the effect of (131)I-MIBG therapy on tumour volume showed pooled proportions of complete response, partial response and stable disease of, respectively, 0·03 (95% CI: 0·06-0·15), 0·27 (95% CI: 0·19-0·37) and 0·52 (95% CI: 0·41-0·62) and for hormonal response 0·11 (95% CI: 0·05-0·22), 0·40 (95% CI: 0·28-0·53) and 0·21 (95% CI: 0·10-0·40), respectively. Separate analyses resulted in better results in hormonal response for patients with paraganglioma than for patients with phaeochromocytoma. Data on the effects of (131)I-MIBG therapy on malignant paraganglioma/phaeochromocytoma suggest that stable disease concerning tumour volume and a partial hormonal response can be achieved in over 50% and 40% of patients, respectively, treated with (131)I-MIBG therapy. It cannot be ruled out that stable disease reflects not only the effect of MIBG therapy, but also (partly) the natural course of the disease. © 2013 John Wiley & Sons Ltd.

Labyrinth Seal Analysis. Volume 3. Analytical and Experimental Development of a Design Model for Labyrinth Seals

DTIC Science & Technology

1986-01-01

the information that has been determined experimentally. The Labyrinth Seal Analysis program was, therefore, directed to the develop - ment of an...labyrinth seal performance, the program included the development of an improved empirical design model to pro- j. .,’ vide the calculation of the flow... program . * Phase I was directed to the analytical development of both an *analysis* model and an improvwd empirical *design" model. Supporting rig tests

Preliminary Problem Definition Study of 48 Munitions-Related Chemicals. Volume II. Propellant-Related Chemicals

DTIC Science & Technology

1978-04-01

34analysis of sediment and biota samples from Radford AAP aquatic toxicity studies if the literature evaluation reveals the need for more information... Sampling and analysis at Radford be performed to determine the quantity of the compound entering the New River Best Available Co. -7- V - A literature...chemical properties of this compound if they can not be obtained from the manufacturer - Sampling and analysis of sediment and biota at Radford AAP to

Associated factors of radiation pneumonitis induced by precise radiotherapy in 186 elderly patients with esophageal cancer.

PubMed

Cui, Zhen; Tian, Ye; He, Bin; Li, Hongwei; Li, Duojie; Liu, Jingjing; Cai, Hanfei; Lou, Jianjun; Jiang, Hao; Shen, Xueming; Peng, Kaigui

2015-01-01

Radiation pneumonitis is one of the most severe complications of esophageal cancer. To explore the factors correlated to radiation pneumonitis induced by precise radiotherapy for elderly patients with esophageal cancer. The retrospective analysis was used to collect clinical data from 186 elderly patients with esophageal cancer. The incidence of radiation pneumonitis was observed, followed by statistical analysis through ANVON or multiple regression analysis. 27 in 186 cases of esophageal cancer suffered from radiation pneumonitis, with incidence of 14.52%. The single factor analysis showed that, Karnofsky performance status (KPS) score, chronic obstructive pulmonary disease, concurrent chemoradiotherapy, gross tumor volume (GTV) dose, lung V20, mean lung dose (MLD) and planning target volume (PTV) were associated with radiation pneumonitis. The logistic regression analysis indicated that, concurrent chemoradiotherapy, GTV dose, lung V20 and PTV were the independent factors of radiation pneumonitis. The concurrent chemoradiotherapy, GTV dose, lung V20, MLD and PTV are the major risk factors of radiation pneumonitis for elderly patients with esophageal cancer.

Design and Optimization of Composite Gyroscope Momentum Wheel Rings

NASA Technical Reports Server (NTRS)

Bednarcyk, Brett A.; Arnold, Steven M.

2007-01-01

Stress analysis and preliminary design/optimization procedures are presented for gyroscope momentum wheel rings composed of metallic, metal matrix composite, and polymer matrix composite materials. The design of these components involves simultaneously minimizing both true part volume and mass, while maximizing angular momentum. The stress analysis results are combined with an anisotropic failure criterion to formulate a new sizing procedure that provides considerable insight into the design of gyroscope momentum wheel ring components. Results compare the performance of two optimized metallic designs, an optimized SiC/Ti composite design, and an optimized graphite/epoxy composite design. The graphite/epoxy design appears to be far superior to the competitors considered unless a much greater premium is placed on volume efficiency compared to mass efficiency.

The Impact of Surgeon Volume on Perioperative Outcomes in Hysterectomy

PubMed Central

Vree, Florentien E. M.; Cohen, Sarah L.; Chavan, Niraj

2014-01-01

Background and Objectives: To estimate the effect of surgeon volume on key perioperative outcomes after all modes of hysterectomy. Methods: We performed a review of 1914 hysterectomies performed at a large, academic tertiary-care hospital. Women who underwent abdominal, laparoscopic, vaginal, or robotic hysterectomy for benign non-obstetric indications in 2006, 2009, and 2010 were included. Results: Gynecologic surgeons were categorized according their average annual hysterectomy case volume: low volume (<11 cases per year), intermediate volume (11–50 cases per year), and high-volume (>51 cases per year). Taking all modes of hysterectomy together, surgeries performed by high-volume surgeons required a shorter operative time (155.11 minutes vs 199.19–203.35 minutes, P < .001) and resulted in less estimated blood loss compared with low- and intermediate-volume surgeons (161.09 mL vs 205.58–237.96 mL, P < .001). The 3 surgical volume groups did not differ from each other significantly in the conversion to laparotomy, readmission rate, or incidence of intraoperative or postoperative complications. These findings were maintained when subgroup analyses were performed by type of hysterectomy, with few exceptions. In the subgroup of vaginal hysterectomies by intermediate-volume surgeons, there were slightly more postoperative complications. There were fewer intraoperative complications in laparoscopic/robotic hysterectomies performed by high-volume surgeons, though not statistically significant. Conclusions: Hysterectomies performed by high-volume surgeons at our institution during the 3-year study period were associated with shorter operative times and less estimated blood loss. PMID:24960479

Evaluation of Aspergillus PCR protocols for testing serum specimens.

PubMed

White, P Lewis; Mengoli, Carlo; Bretagne, Stéphane; Cuenca-Estrella, Manuel; Finnstrom, Niklas; Klingspor, Lena; Melchers, Willem J G; McCulloch, Elaine; Barnes, Rosemary A; Donnelly, J Peter; Loeffler, Juergen

2011-11-01

A panel of human serum samples spiked with various amounts of Aspergillus fumigatus genomic DNA was distributed to 23 centers within the European Aspergillus PCR Initiative to determine analytical performance of PCR. Information regarding specific methodological components and PCR performance was requested. The information provided was made anonymous, and meta-regression analysis was performed to determine any procedural factors that significantly altered PCR performance. Ninety-seven percent of protocols were able to detect a threshold of 10 genomes/ml on at least one occasion, with 83% of protocols reproducibly detecting this concentration. Sensitivity and specificity were 86.1% and 93.6%, respectively. Positive associations between sensitivity and the use of larger sample volumes, an internal control PCR, and PCR targeting the internal transcribed spacer (ITS) region were shown. Negative associations between sensitivity and the use of larger elution volumes (≥100 μl) and PCR targeting the mitochondrial genes were demonstrated. Most Aspergillus PCR protocols used to test serum generate satisfactory analytical performance. Testing serum requires less standardization, and the specific recommendations shown in this article will only improve performance.

Evaluation of Aspergillus PCR Protocols for Testing Serum Specimens▿†

PubMed Central

White, P. Lewis; Mengoli, Carlo; Bretagne, Stéphane; Cuenca-Estrella, Manuel; Finnstrom, Niklas; Klingspor, Lena; Melchers, Willem J. G.; McCulloch, Elaine; Barnes, Rosemary A.; Donnelly, J. Peter; Loeffler, Juergen

2011-01-01

A panel of human serum samples spiked with various amounts of Aspergillus fumigatus genomic DNA was distributed to 23 centers within the European Aspergillus PCR Initiative to determine analytical performance of PCR. Information regarding specific methodological components and PCR performance was requested. The information provided was made anonymous, and meta-regression analysis was performed to determine any procedural factors that significantly altered PCR performance. Ninety-seven percent of protocols were able to detect a threshold of 10 genomes/ml on at least one occasion, with 83% of protocols reproducibly detecting this concentration. Sensitivity and specificity were 86.1% and 93.6%, respectively. Positive associations between sensitivity and the use of larger sample volumes, an internal control PCR, and PCR targeting the internal transcribed spacer (ITS) region were shown. Negative associations between sensitivity and the use of larger elution volumes (≥100 μl) and PCR targeting the mitochondrial genes were demonstrated. Most Aspergillus PCR protocols used to test serum generate satisfactory analytical performance. Testing serum requires less standardization, and the specific recommendations shown in this article will only improve performance. PMID:21940479

Birth weight and neonatal adiposity prediction using fractional limb volume obtained with 3D ultrasound.

PubMed

O'Connor, Clare; O'Higgins, Amy; Doolan, Anne; Segurado, Ricardo; Stuart, Bernard; Turner, Michael J; Kennelly, Máireád M

2014-01-01

The objective of this investigation was to study fetal thigh volume throughout gestation and explore its correlation with birth weight and neonatal body composition. This novel technique may improve birth weight prediction and lead to improved detection rates for fetal growth restriction. Fractional thigh volume (TVol) using 3D ultrasound, fetal biometry and soft tissue thickness were studied longitudinally in 42 mother-infant pairs. The percentages of neonatal body fat, fat mass and fat-free mass were determined using air displacement plethysmography. Correlation and linear regression analyses were performed. Linear regression analysis showed an association between TVol and birth weight. TVol at 33 weeks was also associated with neonatal fat-free mass. There was no correlation between TVol and neonatal fat mass. Abdominal circumference, estimated fetal weight (EFW) and EFW centile showed consistent correlations with birth weight. Thigh volume demonstrated an additional independent contribution to birth weight prediction when added to the EFW centile from the 38-week scan (p = 0.03). Fractional TVol performed at 33 weeks gestation is correlated with birth weight and neonatal lean body mass. This screening test may highlight those at risk of fetal growth restriction or macrosomia.

Analytical description of the modern steam automobile

NASA Technical Reports Server (NTRS)

Peoples, J. A.

1974-01-01

The sensitivity of operating conditions upon performance of the modern steam automobile is discussed. The word modern has been used in the title to indicate that emphasis is upon miles per gallon rather than theoretical thermal efficiency. This has been accomplished by combining classical power analysis with the ideal Pressure-Volume diagram. Several parameters are derived which characterize performance capability of the modern steam car. The report illustrates that performance is dictated by the characteristics of the working medium, and the supply temperature. Performance is nearly independent of pressures above 800 psia. Analysis techniques were developed specifically for reciprocating steam engines suitable for automotive application. Specific performance charts have been constructed on the basis of water as a working medium. The conclusions and data interpretation are therefore limited within this scope.

A Highly Miniaturized Inertial Grade Gyroscope for Space Applications

NASA Technical Reports Server (NTRS)

Wiberg, D. V.; Challoner, A. D.; Shcheglov, K.; Hayworth, K.; Bae, S.; Yee, K.; Blaes, B.; DAgostino, S.; Stock, T.

2001-01-01

The evolution of inertial grade gyroscopes for space applications represents well over 50 years of technology development and an investment of hundreds of millions of dollars. The workhorse product which represents the current state-of-the art for commercially available high performance devices is the Litton-Hemishperical Resonator Gyro (HRG) Inertial Measurement Unit (IMU). This product has a performance figure of merit of 0.003 deg/hr bias drift, a volume of 567 cubic inches, weighs 19 pounds, draws about 30 watts and costs over $1 million each. Clearly devices of this magnitude are not conducive to the minimized mass, volume, power, and cost constraints of outer planet missions. An approach to breaking these potential barriers is the use of Microelectromechanical Systems (MEMS) based inertial devices. Although substantially reduced in size, mass power and cost, this approach has produced devices in the tactical performance range of greater than 1 deg/hour bias drift. This level of performance satisfies the preponderance of high market volume requirements such as automotive and tactical munitions but does not meet the limited market quantity requirements for the high precision space based market. Because of the very limited size of the space based market, there is little economic incentive for commercial fabricators of tactical grade devices to address the necessary performance improvements. The Jet Propulsion Laboratory (JPL) in conjunction with Boeing Space Systems (BSS) is addressing this void to satisfy our mutual requirements in this area. The project objective to is to achieve 0.01 deg/hr performance in an IMU which is less than 10 cubic inches in volume, weighs less than 0.5 pounds, draws less than 1 watt and is available in volume production for less than $2500. Reductions of this magnitude will be mission enabling capabilities for a variety of anticipated outer planet mission attributes such as autonomous control and docking, formation flying and robotic outposts. The improved performance will be realized using improved relative precision fabrication, enhanced vibratory drive and sense designs, and statistical data analysis.