Application of the Low-dose One-stop-shop Cardiac CT Protocol with Third-generation Dual-source CT.

PubMed

Lin, Lu; Wang, Yining; Yi, Yan; Cao, Jian; Kong, Lingyan; Qian, Hao; Zhang, Hongzhi; Wu, Wei; Wang, Yun; Jin, Zhengyu

2017-02-20

Objective To evaluate the feasibility of a low-dose one-stop-shop cardiac CT imaging protocol with third-generation dual-source CT (DSCT). Methods Totally 23 coronary artery disease (CAD) patients were prospectively enrolled between March to September in 2016. All patients underwent an ATP stress dynamic myocardial perfusion imaging (MPI) (data acquired prospectively ECG-triggered during end systole by table shuttle mode in 32 seconds) at 70 kV combined with prospectively ECG-triggered high-pitch coronary artery angiography (CCTA) on a third-generation DSCT system. Myocardial blood flow (MBF) was quantified and compared between perfusion normal and abnormal myocardial segments based on AHA-17-segment model. CCTA images were evaluated qualitatively based on SCCT-18-segment model and the effective dose(ED) was calculated. In patients with subsequent catheter coronary angiography (CCA) as reference,the diagnosis performance of MPI (for per-vessel ≥50% and ≥70% stenosis) and CCTA (for≥50% stenosis) were assessed. Results Of 23 patients who had completed the examination of ATP stress MPI plus CCTA,12 patients received follow-up CCA. At ATP stress MPI,77 segments (19.7%) in 13 patients (56.5%) had perfusion abnormalities. The MBF values of hypo-perfused myocardial segments decreased significantly compared with normal segments [(93±22)ml/(100 ml·min) vs. (147±27)ml/(100 ml·min);t=15.978,P=0.000]. At CCTA,93.9% (308/328) of the coronary segments had diagnostic image quality. With CCA as the reference standard,the per-vessel and per-segment sensitivity,specificity,and accuracy of CCTA for stenosis≥50% were 94.1%,93.5%,and 93.7% and 90.9%,97.8%,and 96.8%,and the per-vessel sensitivity,specificity and accuracy of ATP stress MPI for stenosis≥50% and ≥70% were 68.7%,100%,and 89.5% and 91.7%,100%,and 97.9%. The total ED of MPI and CCTA was (3.9±1.3) mSv [MPI:(3.5±1.2) mSv,CCTA:(0.3±0.1) mSv]. Conclusion The third-generation DSCT stress dynamic MPI at 70 kV combined with prospectively ECG-triggered high-pitch CCTA is a feasible and reliable tool for clinical diagnosis,with remarkably reduced radiation dose.

Usefulness of myocardial parametric imaging to evaluate myocardial viability in experimental and in clinical studies

PubMed Central

Korosoglou, G; Hansen, A; Bekeredjian, R; Filusch, A; Hardt, S; Wolf, D; Schellberg, D; Katus, H A; Kuecherer, H

2006-01-01

Objective To evaluate whether myocardial parametric imaging (MPI) is superior to visual assessment for the evaluation of myocardial viability. Methods and results Myocardial contrast echocardiography (MCE) was assessed in 11 pigs before, during, and after left anterior descending coronary artery occlusion and in 32 patients with ischaemic heart disease by using intravenous SonoVue administration. In experimental studies perfusion defect area assessment by MPI was compared with visually guided perfusion defect planimetry. Histological assessment of necrotic tissue was the standard reference. In clinical studies viability was assessed on a segmental level by (1) visual analysis of myocardial opacification; (2) quantitative estimation of myocardial blood flow in regions of interest; and (3) MPI. Functional recovery between three and six months after revascularisation was the standard reference. In experimental studies, compared with visually guided perfusion defect planimetry, planimetric assessment of infarct size by MPI correlated more significantly with histology (r2  =  0.92 versus r2  =  0.56) and had a lower intraobserver variability (4% v 15%, p < 0.05). In clinical studies, MPI had higher specificity (66% v 43%, p < 0.05) than visual MCE and good accuracy (81%) for viability detection. It was less time consuming (3.4 (1.6) v 9.2 (2.4) minutes per image, p < 0.05) than quantitative blood flow estimation by regions of interest and increased the agreement between observers interpreting myocardial perfusion (κ  =  0.87 v κ  =  0.75, p < 0.05). Conclusion MPI is useful for the evaluation of myocardial viability both in animals and in patients. It is less time consuming than quantification analysis by regions of interest and less observer dependent than visual analysis. Thus, strategies incorporating this technique may be valuable for the evaluation of myocardial viability in clinical routine. PMID:15939722

Coming of spring in Europe and on Day Night Year Globe

NASA Astrophysics Data System (ADS)

Marković-Topalović, Tatjana; Božić, Mirjana; Stojićević, Goran

2014-05-01

Day and night cycles, change of seasons, secular variations of climate on Earth are phenomena that depend on insolation of the Earth, its internal rotation and the orientation of its axis with respect to the Sun. For teaching about these phenomena, we have been using, since 2011, the outdoor globe that has the same orientation in space as the Earth. We call it Day Night Year Globe (DING). It was erected in the Center for advanced education of teachers in Šabac, Serbia [1]. Such globes were also erected in the Weizmann Institute in Israel, near the Max Valier Observatory in Italy, in the courtyard of the Tre University in Rome, in the Science Park in Zurich. During 2010 and 2011, the High Medical School took part and coordinated the realization of the Greenwave project [2] in the Šabac region. Twenty-two teachers, in seven primary schools, inspired and instructed their students to observe how exactly spring arrives and moves across Europe. Their task was to measure on daily basis: wind speed, temperature and rain precipitation. They also recorded sightings of species (barn swallow and frog spawns), common to all European countries, and of local species, which act as early indicators of the arrival of spring. The scientific contribution of the Šabac team consisted of correlating these observations and observations of changes of illumination on DING. During one sunny day, students observe the mapping of Earth's daily rotation onto DING. By observing the circle of illumination, day by day, students see how the inclination of this circle changes during the year. At the spring equinox the circle of illumination lies along the meridian. Our idea was that participants in other country could incorporate observations on DING, or a hands-on globe with two-rotation axes, properly oriented. We tried to induce interest for this idea to the authors and leaders of the Greenwave project. In Milanković's theory of the climate change of Earth, the orientation of Earth's axis with respect to the Sun is an essential parameter. Because of that, DING may be useful [3] in teaching an introduction to Milanković's theory.In his Mathematical theory of thermic phenomena caused by solar radiations (1920) and in Canon (1941), Milanković concisely explained astronomical mechanisms behind the climate change on Earth during last 600000 years. Secular variations of parameters of Earth's motion and impact of these variations on insolation of Earth have caused the secular changes of climate on Earth, resulting in the series of ice ages with interglacial periods. If we would live long enough, we could follow the DING changes that are consequences of secular variations of Earth's parameters. But during our short lives we can only make thought observations, i.e. we could imagine how these changes on DING would be. References 1. T. M. Topalović and M. Božić,Physics Education,46 (2011) 365. 2.http://greenwave-europe.eu/ 3. M. Božić, M. Popović, L. Vu\\vsković, S. Popović, J. Popović, T. M. Topalović, Day Night Year Globe, submitted to Science &Education

Optoelectronic Device Integration in Silicon (OpSIS)

DTIC Science & Technology

2015-10-26

silicon-on-insulator," Opt. Express 22, 17872-17879 (2014) Y. Yang, C. Galland, Y. Liu, K. Tan , R. Ding, Q. Li, K. Bergman, T. Baehr-Jones, M...Ding, Ran; Liu, Yang; Ayazi, Ali; Pinguet, Thierry; Harris, Nicholas C; Streshinsky, Matt; Lee, Poshen; Zhang, Yi; Lim, Andy Eu-Jin; “Ultralow drive...Ding, Ran; Harris, Nicholas C; Baehr-Jones, Tom; Hochberg, Michael; “Broadband on-chip optical non-reciprocity using phase modulators” Optics express

MSAProbs-MPI: parallel multiple sequence aligner for distributed-memory systems.

PubMed

González-Domínguez, Jorge; Liu, Yongchao; Touriño, Juan; Schmidt, Bertil

2016-12-15

MSAProbs is a state-of-the-art protein multiple sequence alignment tool based on hidden Markov models. It can achieve high alignment accuracy at the expense of relatively long runtimes for large-scale input datasets. In this work we present MSAProbs-MPI, a distributed-memory parallel version of the multithreaded MSAProbs tool that is able to reduce runtimes by exploiting the compute capabilities of common multicore CPU clusters. Our performance evaluation on a cluster with 32 nodes (each containing two Intel Haswell processors) shows reductions in execution time of over one order of magnitude for typical input datasets. Furthermore, MSAProbs-MPI using eight nodes is faster than the GPU-accelerated QuickProbs running on a Tesla K20. Another strong point is that MSAProbs-MPI can deal with large datasets for which MSAProbs and QuickProbs might fail due to time and memory constraints, respectively. Source code in C ++ and MPI running on Linux systems as well as a reference manual are available at http://msaprobs.sourceforge.net CONTACT: jgonzalezd@udc.esSupplementary information: Supplementary data are available at Bioinformatics online. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

The Evaluation of Physical Stillness with Wearable Chest and Arm Accelerometer during Chan Ding Practice.

PubMed

Chang, Kang-Ming; Chun, Yu-Teng; Chen, Sih-Huei; Lu, Luo; Su, Hsiao-Ting Jannis; Liang, Hung-Meng; Santhosh, Jayasree; Ching, Congo Tak-Shing; Liu, Shing-Hong

2016-07-20

Chan Ding training is beneficial to health and emotional wellbeing. More and more people have taken up this practice over the past few years. A major training method of Chan Ding is to focus on the ten Mailuns, i.e., energy points, and to maintain physical stillness. In this article, wireless wearable accelerometers were used to detect physical stillness, and the created physical stillness index (PSI) was also shown. Ninety college students participated in this study. Primarily, accelerometers used on the arms and chest were examined. The results showed that the PSI values on the arms were higher than that of the chest, when participants moved their bodies in three different ways, left-right, anterior-posterior, and hand, movements with natural breathing. Then, they were divided into three groups to practice Chan Ding for approximately thirty minutes. Participants without any Chan Ding experience were in Group I. Participants with one year of Chan Ding experience were in Group II, and participants with over three year of experience were in Group III. The Chinese Happiness Inventory (CHI) was also conducted. Results showed that the PSI of the three groups measured during 20-30 min were 0.123 ± 0.155, 0.012 ± 0.013, and 0.001 ± 0.0003, respectively (p < 0.001 ***). The averaged CHI scores of the three groups were 10.13, 17.17, and 25.53, respectively (p < 0.001 ***). Correlation coefficients between PSI and CHI of the three groups were -0.440, -0.369, and -0.537, respectively (p < 0.01 **). PSI value and the wearable accelerometer that are presently available on the market could be used to evaluate the quality of the physical stillness of the participants during Chan Ding practice.

The Evaluation of Physical Stillness with Wearable Chest and Arm Accelerometer during Chan Ding Practice

PubMed Central

Chang, Kang-Ming; Chun, Yu-Teng; Chen, Sih-Huei; Lu, Luo; Su, Hsiao-Ting Jannis; Liang, Hung-Meng; Santhosh, Jayasree; Ching, Congo Tak-Shing; Liu, Shing-Hong

2016-01-01

Chan Ding training is beneficial to health and emotional wellbeing. More and more people have taken up this practice over the past few years. A major training method of Chan Ding is to focus on the ten Mailuns, i.e., energy points, and to maintain physical stillness. In this article, wireless wearable accelerometers were used to detect physical stillness, and the created physical stillness index (PSI) was also shown. Ninety college students participated in this study. Primarily, accelerometers used on the arms and chest were examined. The results showed that the PSI values on the arms were higher than that of the chest, when participants moved their bodies in three different ways, left-right, anterior-posterior, and hand, movements with natural breathing. Then, they were divided into three groups to practice Chan Ding for approximately thirty minutes. Participants without any Chan Ding experience were in Group I. Participants with one year of Chan Ding experience were in Group II, and participants with over three year of experience were in Group III. The Chinese Happiness Inventory (CHI) was also conducted. Results showed that the PSI of the three groups measured during 20–30 min were 0.123 ± 0.155, 0.012 ± 0.013, and 0.001 ± 0.0003, respectively (p < 0.001 ***). The averaged CHI scores of the three groups were 10.13, 17.17, and 25.53, respectively (p < 0.001 ***). Correlation coefficients between PSI and CHI of the three groups were −0.440, −0.369, and −0.537, respectively (p < 0.01 **). PSI value and the wearable accelerometer that are presently available on the market could be used to evaluate the quality of the physical stillness of the participants during Chan Ding practice. PMID:27447641

A systems approach for the development of a sustainable community--the application of the sensitivity model (SM).

PubMed

Chan, Shih-Liang; Huang, Shu-Li

2004-09-01

Corresponding to the concept of 'Think globally, act locally and plan regionally' of sustainable development, this paper discusses the approach of planning a sustainable community in terms of systems thinking. We apply a systems tool, the sensitivity model (SM), to build a model of the development of the community of Ping-Ding, located adjacent to the Yang-Ming-Shan National Park, Taiwan. The major issue in the development of Ping-Ding is the conflict between environmental conservation and the development of a local tourism industry. With the involvement of local residents, planners, and interest groups, a system model of 26 variables was defined to identify characteristics of Ping-Ding through pattern recognition. Two scenarios concerning the sustainable development of Ping-Ding are simulated with interlinked feedbacks from variables. The results of the analysis indicate that the development of Ping-Ding would be better served by the planning of agriculture and the tourism industry. The advantages and shortfalls of applying SM in the current planning environment of Taiwan are also discussed to conclude this paper.

Development of km23-Based Diagnostics and Therapeutics

DTIC Science & Technology

2004-05-01

Publishers, Cancer Treatment and Research Book Series. Chap . 15, 315-327, 2004. Abstracts: Jin Q, MD, Ding W, MD, PhD, Staub CM, Gao G, MD, Mulder KM, PhD...Kluwer Academic Publishers, Cancer Treatment and Research Book Series. Chap . 15, 315-327, 2004. Ilangovan U, Ding W, Zuniga J, Wilson, CL, Hinck AP...Academic Publishers, Cancer Treatment and Research Book Series. Chap . 15, 315-327, 2004. 2. Manuscript Submitted: Jin Q. Ding W, Staub CM, Gao G, Tang Q

Large Eddy Simulation of stratified flows over structures

NASA Astrophysics Data System (ADS)

Fuka, V.; Brechler, J.

2013-04-01

We tested the ability of the LES model CLMM (Charles University Large-Eddy Microscale Model) to model the stratified flow around three dimensional hills. We compared the quantities, as the height of the dividing streamline, recirculation zone length or length of the lee waves with experiments by Hunt and Snyder[3] and numerical computations by Ding, Calhoun and Street[5]. The results mostly agreed with the references, but some important differences are present.

Normal Databases for the Relative Quantification of Myocardial Perfusion

PubMed Central

Rubeaux, Mathieu; Xu, Yuan; Germano, Guido; Berman, Daniel S.; Slomka, Piotr J.

2016-01-01

Purpose of review Myocardial perfusion imaging (MPI) with SPECT is performed clinically worldwide to detect and monitor coronary artery disease (CAD). MPI allows an objective quantification of myocardial perfusion at stress and rest. This established technique relies on normal databases to compare patient scans against reference normal limits. In this review, we aim to introduce the process of MPI quantification with normal databases and describe the associated perfusion quantitative measures that are used. Recent findings New equipment and new software reconstruction algorithms have been introduced which require the development of new normal limits. The appearance and regional count variations of normal MPI scan may differ between these new scanners and standard Anger cameras. Therefore, these new systems may require the determination of new normal limits to achieve optimal accuracy in relative myocardial perfusion quantification. Accurate diagnostic and prognostic results rivaling those obtained by expert readers can be obtained by this widely used technique. Summary Throughout this review, we emphasize the importance of the different normal databases and the need for specific databases relative to distinct imaging procedures. use of appropriate normal limits allows optimal quantification of MPI by taking into account subtle image differences due to the hardware and software used, and the population studied. PMID:28138354

Glauber gluons and multiple parton interactions

NASA Astrophysics Data System (ADS)

Gaunt, Jonathan R.

2014-07-01

We show that for hadronic transverse energy E T in hadron-hadron collisions, the classic Collins-Soper-Sterman (CSS) argument for the cancellation of Glauber gluons breaks down at the level of two Glauber gluons exchanged between the spectators. Through an argument that relates the diagrams with these Glauber gluons to events containing additional soft scatterings, we suggest that this failure of the CSS cancellation actually corresponds to a failure of the `standard' factorisation formula with hard, soft and collinear functions to describe E T at leading power. This is because the observable receives a leading power contribution from multiple parton interaction (or spectator-spectator Glauber) processes. We also suggest that the same argument can be used to show that a whole class of observables, which we refer to as MPI sensitive observables, do not obey the standard factorisation at leading power. MPI sensitive observables are observables whose distributions in hadron-hadron collisions are disrupted strongly by the presence of multiple parton interactions (MPI) in the event. Examples of further MPI sensitive observables include the beam thrust B {/a, b +} and transverse thrust.

Feasibility of SPECT myocardial perfusion imaging in the super-obese using a multi-head semiconductor camera with attenuation correction.

PubMed

DeCicco, Anthony E; Sokil, Alexis B; Marhefka, Gregary D; Reist, Kirk; Hansen, Christopher L

2015-04-01

Obesity is not only associated with an increased risk of coronary artery disease, but also decreases the accuracy of many diagnostic modalities pertinent to this disease. Advances in myocardial perfusion imaging (MPI) have mitigated somewhat the effects of obesity, although the feasibility of MPI in the super-obese (defined as a BMI > 50) is currently untested. We undertook this study to assess the practicality of MPI in the super-obese using a multi-headed solid-state gamma camera with attenuation correction. We retrospectively identified consecutive super-obese patients referred for MPI at our institution. The images were interpreted by 3 blinded, experienced readers and graded for quality and diagnosis, and subjectively evaluated the contribution of attenuation correction. Clinical follow-up was obtained from review of medical records. 72 consecutive super-obese patients were included. Their BMI ranged from 50 to 67 (55.7 ± 5.1). Stress image quality was considered good or excellent in 45 (63%), satisfactory in 24 (33%), poor in 3 (4%), and uninterpretable in 0 patients. Rest images were considered good or excellent in 34 (49%), satisfactory in 23 (33%), poor in 13 (19%), and uninterpretable in 0 patients. Attenuation correction changed the interpretation in 34 (47%) of studies. MPI is feasible and provides acceptable image quality for super-obese patients, although it may be camera and protocol dependent.

Biochemical characterization and immunolocalization studies of a Capsicum chinense Jacq. protein fraction containing DING proteins and anti-microbial activity.

PubMed

Brito-Argáez, Ligia; Tamayo-Sansores, José A; Madera-Piña, Dianeli; García-Villalobos, Francisco J; Moo-Puc, Rosa E; Kú-González, Ángela; Villanueva, Marco A; Islas-Flores, Ignacio

2016-12-01

The DING protein family consists of proteins of great biological importance due to their ability to inhibit carcinogenic cell growth. A DING peptide with Mr ∼7.57 kDa and pI ∼5.06 was detected in G10P1.7.57, a protein fraction from Capsicum chinense Jacq. seeds. Amino acid sequencing of the peptide produced three smaller peptides showing identity to the DING protein family. G10P1.7.57 displayed a phosphatase activity capable of dephosphorylating different phosphorylated substrates and inhibited the growth of Saccharomyces cerevisiae cells. Western immunoblotting with a custom-made polyclonal antibody raised against a sequence (ITYMSPDYAAPTLAGLDDATK), derived from the ∼7.57 kDa polypeptide, immunodetected an ∼ 39 kDa polypeptide in G10P1.7.57. Purification by electroelution followed by amino acid sequencing of the ∼39 kDa polypeptide yielded seven new peptide sequences and an additional one identical to that of the initially identified peptide. Western immunoblotting of soluble proteins from C. chinense seeds and leaves revealed the presence of the ∼39 kDa polypeptide at all developmental stages, with increased accumulation when the organs reached maturity. Immunolocalization using Dabsyl chloride- or Alexa fluor 488-conjugated antibodies revealed a specific fluorescent signal in the cell cytoplasm at all developmental stages, giving support to the idea that the ∼39 kDa polypeptide is a soluble DING protein. Thus, we have identified and characterized a protein fraction with a DING protein from C. chinense. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

The Research of the Parallel Computing Development from the Angle of Cloud Computing

NASA Astrophysics Data System (ADS)

Peng, Zhensheng; Gong, Qingge; Duan, Yanyu; Wang, Yun

2017-10-01

Cloud computing is the development of parallel computing, distributed computing and grid computing. The development of cloud computing makes parallel computing come into people’s lives. Firstly, this paper expounds the concept of cloud computing and introduces two several traditional parallel programming model. Secondly, it analyzes and studies the principles, advantages and disadvantages of OpenMP, MPI and Map Reduce respectively. Finally, it takes MPI, OpenMP models compared to Map Reduce from the angle of cloud computing. The results of this paper are intended to provide a reference for the development of parallel computing.

Diagnostic yield and accuracy of coronary CT angiography after abnormal nuclear myocardial perfusion imaging.

PubMed

Meinel, Felix G; Schoepf, U Joseph; Townsend, Jacob C; Flowers, Brian A; Geyer, Lucas L; Ebersberger, Ullrich; Krazinski, Aleksander W; Kunz, Wolfgang G; Thierfelder, Kolja M; Baker, Deborah W; Khan, Ashan M; Fernandes, Valerian L; O'Brien, Terrence X

2018-06-15

We aimed to determine the diagnostic yield and accuracy of coronary CT angiography (CCTA) in patients referred for invasive coronary angiography (ICA) based on clinical concern for coronary artery disease (CAD) and an abnormal nuclear stress myocardial perfusion imaging (MPI) study. We enrolled 100 patients (84 male, mean age 59.6 ± 8.9 years) with an abnormal MPI study and subsequent referral for ICA. Each patient underwent CCTA prior to ICA. We analyzed the prevalence of potentially obstructive CAD (≥50% stenosis) on CCTA and calculated the diagnostic accuracy of ≥50% stenosis on CCTA for the detection of clinically significant CAD on ICA (defined as any ≥70% stenosis or ≥50% left main stenosis). On CCTA, 54 patients had at least one ≥50% stenosis. With ICA, 45 patients demonstrated clinically significant CAD. A positive CCTA had 100% sensitivity and 84% specificity with a 100% negative predictive value and 83% positive predictive value for clinically significant CAD on a per patient basis in MPI positive symptomatic patients. In conclusion, almost half (48%) of patients with suspected CAD and an abnormal MPI study demonstrate no obstructive CAD on CCTA.

An MPI + $X$ implementation of contact global search using Kokkos

DOE PAGES

Hansen, Glen A.; Xavier, Patrick G.; Mish, Sam P.; ...

2015-10-05

This paper describes an approach that seeks to parallelize the spatial search associated with computational contact mechanics. In contact mechanics, the purpose of the spatial search is to find “nearest neighbors,” which is the prelude to an imprinting search that resolves the interactions between the external surfaces of contacting bodies. In particular, we are interested in the contact global search portion of the spatial search associated with this operation on domain-decomposition-based meshes. Specifically, we describe an implementation that combines standard domain-decomposition-based MPI-parallel spatial search with thread-level parallelism (MPI-X) available on advanced computer architectures (those with GPU coprocessors). Our goal ismore » to demonstrate the efficacy of the MPI-X paradigm in the overall contact search. Standard MPI-parallel implementations typically use a domain decomposition of the external surfaces of bodies within the domain in an attempt to efficiently distribute computational work. This decomposition may or may not be the same as the volume decomposition associated with the host physics. The parallel contact global search phase is then employed to find and distribute surface entities (nodes and faces) that are needed to compute contact constraints between entities owned by different MPI ranks without further inter-rank communication. Key steps of the contact global search include computing bounding boxes, building surface entity (node and face) search trees and finding and distributing entities required to complete on-rank (local) spatial searches. To enable source-code portability and performance across a variety of different computer architectures, we implemented the algorithm using the Kokkos hardware abstraction library. While we targeted development towards machines with a GPU accelerator per MPI rank, we also report performance results for OpenMP with a conventional multi-core compute node per rank. Results here demonstrate a 47 % decrease in the time spent within the global search algorithm, comparing the reference ACME algorithm with the GPU implementation, on an 18M face problem using four MPI ranks. As a result, while further work remains to maximize performance on the GPU, this result illustrates the potential of the proposed implementation.« less

Binocular combination of phase and contrast explained by a gain-control and gain-enhancement model

PubMed Central

Ding, Jian; Klein, Stanley A.; Levi, Dennis M.

2013-01-01

We investigated suprathreshold binocular combination, measuring both the perceived phase and perceived contrast of a cyclopean sine wave. We used a paradigm adapted from Ding and Sperling (2006, 2007) to measure the perceived phase by indicating the apparent location (phase) of the dark trough in the horizontal cyclopean sine wave relative to a black horizontal reference line, and we used the same stimuli to measure perceived contrast by matching the binocular combined contrast to a standard contrast presented to one eye. We found that under normal viewing conditions (high contrast and long stimulus duration), perceived contrast is constant, independent of the interocular contrast ratio and the interocular phase difference, while the perceived phase shifts smoothly from one eye to the other eye depending on the contrast ratios. However, at low contrasts and short stimulus durations, binocular combination is more linear and contrast summation is phase-dependent. To account for phase-dependent contrast summation, we incorporated a fusion remapping mechanism into our model, using disparity energy to shift the monocular phases towards the cyclopean phase in order to align the two eyes' images through motor/sensory fusion. The Ding-Sperling model with motor/sensory fusion mechanism gives a reasonable account of the phase dependence of binocular contrast combination and can account for either the perceived phase or the perceived contrast of a cyclopean sine wave separately; however it requires different model parameters for the two. However, when fit to both phase and contrast data simultaneously, the Ding-Sperling model fails. Incorporating interocular gain enhancement into the model results in a significant improvement in fitting both phase and contrast data simultaneously, successfully accounting for both linear summation at low contrast energy and strong nonlinearity at high contrast energy. PMID:23397038

Calibration free beam hardening correction for cardiac CT perfusion imaging

NASA Astrophysics Data System (ADS)

Levi, Jacob; Fahmi, Rachid; Eck, Brendan L.; Fares, Anas; Wu, Hao; Vembar, Mani; Dhanantwari, Amar; Bezerra, Hiram G.; Wilson, David L.

2016-03-01

Myocardial perfusion imaging using CT (MPI-CT) and coronary CTA have the potential to make CT an ideal noninvasive gate-keeper for invasive coronary angiography. However, beam hardening artifacts (BHA) prevent accurate blood flow calculation in MPI-CT. BH Correction (BHC) methods require either energy-sensitive CT, not widely available, or typically a calibration-based method. We developed a calibration-free, automatic BHC (ABHC) method suitable for MPI-CT. The algorithm works with any BHC method and iteratively determines model parameters using proposed BHA-specific cost function. In this work, we use the polynomial BHC extended to three materials. The image is segmented into soft tissue, bone, and iodine images, based on mean HU and temporal enhancement. Forward projections of bone and iodine images are obtained, and in each iteration polynomial correction is applied. Corrections are then back projected and combined to obtain the current iteration's BHC image. This process is iterated until cost is minimized. We evaluate the algorithm on simulated and physical phantom images and on preclinical MPI-CT data. The scans were obtained on a prototype spectral detector CT (SDCT) scanner (Philips Healthcare). Mono-energetic reconstructed images were used as the reference. In the simulated phantom, BH streak artifacts were reduced from 12+/-2HU to 1+/-1HU and cupping was reduced by 81%. Similarly, in physical phantom, BH streak artifacts were reduced from 48+/-6HU to 1+/-5HU and cupping was reduced by 86%. In preclinical MPI-CT images, BHA was reduced from 28+/-6 HU to less than 4+/-4HU at peak enhancement. Results suggest that the algorithm can be used to reduce BHA in conventional CT and improve MPI-CT accuracy.

A technician carefully checks the thermal tiles on the underside of Space Shuttle Endeavour for nicks and dings following its landing at Edwards Air Force Base

NASA Image and Video Library

2008-12-02

A United Space Alliance technician carefully checks the thermal tiles on the underside of Space Shuttle Endeavour for nicks and dings following its landing at Edwards Air Force Base to conclude mission STS-126.

Kac determinant and singular vector of the level N representation of Ding-Iohara-Miki algebra

NASA Astrophysics Data System (ADS)

Ohkubo, Yusuke

2018-05-01

In this paper, we obtain the formula for the Kac determinant of the algebra arising from the level N representation of the Ding-Iohara-Miki algebra. It is also discovered that its singular vectors correspond to generalized Macdonald functions (the q-deformed version of the AFLT basis).

An Examination of Target Tracking in the Antisubmarine Warfare Systems Evaluation Tool (ASSET)

DTIC Science & Technology

1991-09-01

fnCorC- Ingi Ing?)))) WX CY) Calt) (dlat2 Ccosl.±sp lat2 C) (if 0- C. diet dIng? 0.0001) (proqa (if (- flag 0) (proqa (if f- ding 0) (proqa (if (c latl...x Y)) (if (or C brg 90) Cbzg 2101) fsetq rnq C- cat? dIng)) Csetq tag (abs C/ diet Cco&Lisp brgC C C Csetq rng tC 60.1077 rng)) (list rag brgC C;let...Xdus i .X KetO : 0 yea 0 0 vi : .- (-2ln(md(I ))) cod 2rad(l ( i +Xd ye n .- (-2.n(rd(I)))n 2- rnd(I ) +Ydis n ,Vet V .xp -aA 4A,- - .k .H- it .- vx

Monitoring intrahepatic cholestasis of pregnancy using the fetal myocardial performance index: a cohort study.

PubMed

Henry, A; Welsh, A W

2015-11-01

To investigate use of the fetal myocardial performance index (MPI) in assessing intrahepatic cholestasis of pregnancy (ICP). This was a cohort study including cross-sectional and longitudinal data from 31 women with ICP recruited from June 2012 to March 2014. Fetal left, right and delta MPI (LMPI, RMPI and DMPI), and routine measures of fetal growth and wellbeing, were obtained at each ultrasound examination. Results were evaluated with respect to gestational age (GA)-adjusted reference intervals, level of maternal serum bile acid (SBA) and fetal outcome. Lower SBA (≥ 7.5 and < 40 μmol/L) and high SBA (≥ 40 μmol/L) subgroups of cases were defined for the analysis. A total of 51 ultrasound examinations were performed in 33 fetuses. The mean LMPI, and means of its isovolumetric relaxation time (IRT) and isovolumetric contraction time (ICT) components were significantly higher in all subgroups of cases of ICP relative to the normal reference mean. Considering only the first examination in each case of ICP, IRT was significantly more prolonged in the high SBA group (n = 10) in comparison to the lower SBA group (n = 23) (52.7 ± 8.0 ms vs 47.3 ± 4.8 ms, P = 0.02), and both IRT (r = 0.538, P = 0.001) and LMPI (r = 0.367, P = 0.036) were significantly correlated with SBA concentration. The proportion of high SBA cases with LMPI, RMPI or DMPI > 2 SD above the GA-adjusted reference mean was not significantly greater than for the lower SBA group. On analysis of all data from those cases with more than one examination, no significant correlation was found between SBA concentration and any of the MPI variables. LMPI values increase above the population GA-adjusted mean in cases of ICP, particularly amongst women with higher SBA. A significant correlation between IRT and LMPI at initial examination and increasing SBA concentration was found. A future multicenter prospective study may clarify the prognostic utility of MPI in ICP. Copyright © 2014 ISUOG. Published by John Wiley & Sons Ltd.

Comparison of Gated SPECT Myocardial Perfusion Imaging with Echocardiography for the Measurement of Left Ventricular Volumes and Ejection Fraction in Patients With Severe Heart Failure

PubMed Central

Shojaeifard, Maryam; Ghaedian, Tahereh; Yaghoobi, Nahid; Malek, Hadi; Firoozabadi, Hasan; Bitarafan-Rajabi, Ahmad; Haghjoo, Majid; Amin, Ahmad; Azizian, Nasrin; Rastgou, Feridoon

2015-01-01

Background: Gated single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) is known as a feasible tool for the measurement of left ventricular ejection fraction (EF) and volumes, which are of great importance in the management and follow-up of patients with coronary artery diseases. However, considering the technical shortcomings of SPECT in the presence of perfusion defect, the accuracy of this method in heart failure patients is still controversial. Objectives: The aim of the present study was to compare the results from gated SPECT MPI with those from echocardiography in heart failure patients to compare echocardiographically-derived left ventricular dimension and function data to those from gated SPECT MPI in heart failure patients. Patients and Methods: Forty-one patients with severely reduced left ventricular systolic function (EF ≤ 35%) who were referred for gated SPECT MPI were prospectively enrolled. Quantification of EF, end-diastolic volume (EDV), and end-systolic volume (ESV) was performed by using quantitative gated spect (QGS) (QGS, version 0.4, May 2009) and emory cardiac toolbox (ECTb) (ECTb, revision 1.0, copyright 2007) software packages. EF, EDV, and ESV were also measured with two-dimensional echocardiography within 3 days after MPI. Results: A good correlation was found between echocardiographically-derived EF, EDV, and ESV and the values derived using QGS (r = 0.67, r = 0.78, and r = 0.80 for EF, EDV, and ESV, respectively; P < 0.001) and ECTb (r = 0.68, 0.79, and r = 0.80 for EF, EDV, and ESV, respectively; P < 0.001). However, Bland-Altman plots indicated significantly different mean values for EF, 11.4 and 20.9 using QGS and ECTb, respectively, as compared with echocardiography. ECTb-derived EDV was also significantly higher than the EDV measured with echocardiography and QGS. The highest correlation between echocardiography and gated SPECT MPI was found for mean values of ESV different. Conclusions: Gated SPECT MPI has a good correlation with echocardiography for the measurement of left ventricular EF, EDV, and ESV in patients with severe heart failure. However, the absolute values of these functional parameters from echocardiography and gated SPECT MPI measured with different software packages should not be used interchangeably. PMID:26889455

Rationale and design of the dual-energy computed tomography for ischemia determination compared to "gold standard" non-invasive and invasive techniques (DECIDE-Gold): A multicenter international efficacy diagnostic study of rest-stress dual-energy computed tomography angiography with perfusion.

PubMed

Truong, Quynh A; Knaapen, Paul; Pontone, Gianluca; Andreini, Daniele; Leipsic, Jonathon; Carrascosa, Patricia; Lu, Bin; Branch, Kelley; Raman, Subha; Bloom, Stephen; Min, James K

2015-10-01

Dual-energy CT (DECT) has potential to improve myocardial perfusion for physiologic assessment of coronary artery disease (CAD). Diagnostic performance of rest-stress DECT perfusion (DECTP) is unknown. DECIDE-Gold is a prospective multicenter study to evaluate the accuracy of DECT to detect hemodynamic (HD) significant CAD, as compared to fractional flow reserve (FFR) as a reference standard. Eligible participants are subjects with symptoms of CAD referred for invasive coronary angiography (ICA). Participants will undergo DECTP, which will be performed by pharmacological stress, and participants will subsequently proceed to ICA and FFR. HD-significant CAD will be defined as FFR ≤ 0.80. In those undergoing myocardial stress imaging (MPI) by positron emission tomography (PET), single photon emission computed tomography (SPECT) or cardiac magnetic resonance (CMR) imaging, ischemia will be graded by % ischemic myocardium. Blinded core laboratory interpretation will be performed for CCTA, DECTP, MPI, ICA, and FFR. Primary endpoint is accuracy of DECTP to detect ≥1 HD-significant stenosis at the subject level when compared to FFR. Secondary and tertiary endpoints are accuracies of combinations of DECTP at the subject and vessel levels compared to FFR and MPI. DECIDE-Gold will determine the performance of DECTP for diagnosing ischemia.

OpenMPI and ExxonMobil Topics

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

Hjelm, Nathan Thomas; Pritchard, Howard Porter

These are a series of slides for a presentation for ExxonMobil's visit to Los Alamos National Laboratory. Topics covered are: Open MPI - The Release Story, MPI-3 RMA in Open MPI, MPI dynamic process management and Open MPI, and new options with CLE 6. Open MPI RMA features are: since v2.0.0 full support for the MPI-3.1 specification, support for non-contiguous datatypes, support for direct use of the RDMA capabilities of high performance networks (Cray Gemini/Aries, Infiniband), starting in v2.1.0 will have support for using network atomic operations for MPI_Fetch_and_op and MPI_Compare_and_swap, tested with MPI_THREAD_MULTIPLE.

Downstream resource utilization following hybrid cardiac imaging with an integrated cadmium-zinc-telluride/64-slice CT device.

PubMed

Fiechter, Michael; Ghadri, Jelena R; Wolfrum, Mathias; Kuest, Silke M; Pazhenkottil, Aju P; Nkoulou, Rene N; Herzog, Bernhard A; Gebhard, Cathérine; Fuchs, Tobias A; Gaemperli, Oliver; Kaufmann, Philipp A

2012-03-01

Low yield of invasive coronary angiography and unnecessary coronary interventions have been identified as key cost drivers in cardiology for evaluation of coronary artery disease (CAD). This has fuelled the search for noninvasive techniques providing comprehensive functional and anatomical information on coronary lesions. We have evaluated the impact of implementation of a novel hybrid cadmium-zinc-telluride (CZT)/64-slice CT camera into the daily clinical routine on downstream resource utilization. Sixty-two patients with known or suspected CAD were referred for same-day single-session hybrid evaluation with CZT myocardial perfusion imaging (MPI) and coronary CT angiography (CCTA). Hybrid MPI/CCTA images from the integrated CZT/CT camera served for decision-making towards conservative versus invasive management. Based on the hybrid images patients were classified into those with and those without matched findings. Matched findings were defined as the combination of MPI defect with a stenosis by CCTA in the coronary artery subtending the respective territory. All patients with normal MPI and CCTA as well as those with isolated MPI or CCTA finding or combined but unmatched findings were categorized as "no match". All 23 patients with a matched finding underwent invasive coronary angiography and 21 (91%) were revascularized. Of the 39 patients with no match, 5 (13%, p < 0.001 vs matched) underwent catheterization and 3 (8%, p < 0.001 vs matched) were revascularized. Cardiac hybrid imaging in CAD evaluation has a profound impact on patient management and may contribute to optimal downstream resource utilization.

HerDing: herb recommendation system to treat diseases using genes and chemicals

PubMed Central

Choi, Wonjun; Choi, Chan-Hun; Kim, Young Ran; Kim, Seon-Jong; Na, Chang-Su; Lee, Hyunju

2016-01-01

In recent years, herbs have been researched for new drug candidates because they have a long empirical history of treating diseases and are relatively free from side effects. Studies to scientifically prove the medical efficacy of herbs for target diseases often spend a considerable amount of time and effort in choosing candidate herbs and in performing experiments to measure changes of marker genes when treating herbs. A computational approach to recommend herbs for treating diseases might be helpful to promote efficiency in the early stage of such studies. Although several databases related to traditional Chinese medicine have been already developed, there is no specialized Web tool yet recommending herbs to treat diseases based on disease-related genes. Therefore, we developed a novel search engine, HerDing, focused on retrieving candidate herb-related information with user search terms (a list of genes, a disease name, a chemical name or an herb name). HerDing was built by integrating public databases and by applying a text-mining method. The HerDing website is free and open to all users, and there is no login requirement. Database URL: http://combio.gist.ac.kr/herding PMID:26980517

HerDing: herb recommendation system to treat diseases using genes and chemicals.

PubMed

Choi, Wonjun; Choi, Chan-Hun; Kim, Young Ran; Kim, Seon-Jong; Na, Chang-Su; Lee, Hyunju

2016-01-01

In recent years, herbs have been researched for new drug candidates because they have a long empirical history of treating diseases and are relatively free from side effects. Studies to scientifically prove the medical efficacy of herbs for target diseases often spend a considerable amount of time and effort in choosing candidate herbs and in performing experiments to measure changes of marker genes when treating herbs. A computational approach to recommend herbs for treating diseases might be helpful to promote efficiency in the early stage of such studies. Although several databases related to traditional Chinese medicine have been already developed, there is no specialized Web tool yet recommending herbs to treat diseases based on disease-related genes. Therefore, we developed a novel search engine, HerDing, focused on retrieving candidate herb-related information with user search terms (a list of genes, a disease name, a chemical name or an herb name). HerDing was built by integrating public databases and by applying a text-mining method. The HerDing website is free and open to all users, and there is no login requirement. Database URL: http://combio.gist.ac.kr/herding. © The Author(s) 2016. Published by Oxford University Press.

Evaluation of a Method Using Three Genomic Guided Escherichia coli Markers for Phylogenetic Typing of E. coli Isolates of Various Genetic Backgrounds

PubMed Central

Hamamoto, Kouta; Ueda, Shuhei; Yamamoto, Yoshimasa

2015-01-01

Genotyping and characterization of bacterial isolates are essential steps in the identification and control of antibiotic-resistant bacterial infections. Recently, one novel genotyping method using three genomic guided Escherichia coli markers (GIG-EM), dinG, tonB, and dipeptide permease (DPP), was reported. Because GIG-EM has not been fully evaluated using clinical isolates, we assessed this typing method with 72 E. coli collection of reference (ECOR) environmental E. coli reference strains and 63 E. coli isolates of various genetic backgrounds. In this study, we designated 768 bp of dinG, 745 bp of tonB, and 655 bp of DPP target sequences for use in the typing method. Concatenations of the processed marker sequences were used to draw GIG-EM phylogenetic trees. E. coli isolates with identical sequence types as identified by the conventional multilocus sequence typing (MLST) method were localized to the same branch of the GIG-EM phylogenetic tree. Sixteen clinical E. coli isolates were utilized as test isolates without prior characterization by conventional MLST and phylogenetic grouping before GIG-EM typing. Of these, 14 clinical isolates were assigned to a branch including only isolates of a pandemic clone, E. coli B2-ST131-O25b, and these results were confirmed by conventional typing methods. Our results suggested that the GIG-EM typing method and its application to phylogenetic trees might be useful tools for the molecular characterization and determination of the genetic relationships among E. coli isolates. PMID:25809972

Evaluation of a Method Using Three Genomic Guided Escherichia coli Markers for Phylogenetic Typing of E. coli Isolates of Various Genetic Backgrounds.

PubMed

Hamamoto, Kouta; Ueda, Shuhei; Yamamoto, Yoshimasa; Hirai, Itaru

2015-06-01

Genotyping and characterization of bacterial isolates are essential steps in the identification and control of antibiotic-resistant bacterial infections. Recently, one novel genotyping method using three genomic guided Escherichia coli markers (GIG-EM), dinG, tonB, and dipeptide permease (DPP), was reported. Because GIG-EM has not been fully evaluated using clinical isolates, we assessed this typing method with 72 E. coli collection of reference (ECOR) environmental E. coli reference strains and 63 E. coli isolates of various genetic backgrounds. In this study, we designated 768 bp of dinG, 745 bp of tonB, and 655 bp of DPP target sequences for use in the typing method. Concatenations of the processed marker sequences were used to draw GIG-EM phylogenetic trees. E. coli isolates with identical sequence types as identified by the conventional multilocus sequence typing (MLST) method were localized to the same branch of the GIG-EM phylogenetic tree. Sixteen clinical E. coli isolates were utilized as test isolates without prior characterization by conventional MLST and phylogenetic grouping before GIG-EM typing. Of these, 14 clinical isolates were assigned to a branch including only isolates of a pandemic clone, E. coli B2-ST131-O25b, and these results were confirmed by conventional typing methods. Our results suggested that the GIG-EM typing method and its application to phylogenetic trees might be useful tools for the molecular characterization and determination of the genetic relationships among E. coli isolates. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

GHEP-ISFG collaborative simulated exercise for DVI/MPI: Lessons learned about large-scale profile database comparisons.

PubMed

Vullo, Carlos M; Romero, Magdalena; Catelli, Laura; Šakić, Mustafa; Saragoni, Victor G; Jimenez Pleguezuelos, María Jose; Romanini, Carola; Anjos Porto, Maria João; Puente Prieto, Jorge; Bofarull Castro, Alicia; Hernandez, Alexis; Farfán, María José; Prieto, Victoria; Alvarez, David; Penacino, Gustavo; Zabalza, Santiago; Hernández Bolaños, Alejandro; Miguel Manterola, Irati; Prieto, Lourdes; Parsons, Thomas

2016-03-01

The GHEP-ISFG Working Group has recognized the importance of assisting DNA laboratories to gain expertise in handling DVI or missing persons identification (MPI) projects which involve the need for large-scale genetic profile comparisons. Eleven laboratories participated in a DNA matching exercise to identify victims from a hypothetical conflict with 193 missing persons. The post mortem database was comprised of 87 skeletal remain profiles from a secondary mass grave displaying a minimal number of 58 individuals with evidence of commingling. The reference database was represented by 286 family reference profiles with diverse pedigrees. The goal of the exercise was to correctly discover re-associations and family matches. The results of direct matching for commingled remains re-associations were correct and fully concordant among all laboratories. However, the kinship analysis for missing persons identifications showed variable results among the participants. There was a group of laboratories with correct, concordant results but nearly half of the others showed discrepant results exhibiting likelihood ratio differences of several degrees of magnitude in some cases. Three main errors were detected: (a) some laboratories did not use the complete reference family genetic data to report the match with the remains, (b) the identity and/or non-identity hypotheses were sometimes wrongly expressed in the likelihood ratio calculations, and (c) many laboratories did not properly evaluate the prior odds for the event. The results suggest that large-scale profile comparisons for DVI or MPI is a challenge for forensic genetics laboratories and the statistical treatment of DNA matching and the Bayesian framework should be better standardized among laboratories. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

KENNEDY SPACE CENTER, FLA. - In the Vehicle Assembly Building, Jim Landy, NDE specialist, performs flash thermography on flight crew lockers. He is screening the lockers for hidden damage underneath dings and dents that might occur during handling.

NASA Image and Video Library

2003-09-04

KENNEDY SPACE CENTER, FLA. - In the Vehicle Assembly Building, Jim Landy, NDE specialist, performs flash thermography on flight crew lockers. He is screening the lockers for hidden damage underneath dings and dents that might occur during handling.

KENNEDY SPACE CENTER, FLA. - In the Vehicle Assembly Building, Jim Landy, NDE specialist, examines flight crew lockers using flash thermography. He is screening the lockers for hidden damage underneath dings and dents that might occur during handling.

NASA Image and Video Library

2003-09-04

KENNEDY SPACE CENTER, FLA. - In the Vehicle Assembly Building, Jim Landy, NDE specialist, examines flight crew lockers using flash thermography. He is screening the lockers for hidden damage underneath dings and dents that might occur during handling.

76 FR 47144 - In the Matter of: Jianwei Ding, 51 Bukit Batok Crescent, #0828 Unity Centre, Singapore 658077...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-04

... the China Academy of Space Technology (``CAST''), participated in a scheme whereby he directed... instructions and informed Ding that he ``had to make up the story [when] I call for [a] rate quote.'' On or... kilograms of Toray M40 material to New Bluesky Technology Co. Ltd. in Hong Kong. These exports were destined...

Comparison of conventional and cadmium-zinc-telluride single-photon emission computed tomography for analysis of thallium-201 myocardial perfusion imaging: an exploratory study in normal databases for different ethnicities.

PubMed

Ishihara, Masaru; Onoguchi, Masahisa; Taniguchi, Yasuyo; Shibutani, Takayuki

2017-12-01

The aim of this study was to clarify the differences in thallium-201-chloride (thallium-201) myocardial perfusion imaging (MPI) scans evaluated by conventional anger-type single-photon emission computed tomography (conventional SPECT) versus cadmium-zinc-telluride SPECT (CZT SPECT) imaging in normal databases for different ethnic groups. MPI scans from 81 consecutive Japanese patients were examined using conventional SPECT and CZT SPECT and analyzed with the pre-installed quantitative perfusion SPECT (QPS) software. We compared the summed stress score (SSS), summed rest score (SRS), and summed difference score (SDS) for the two SPECT devices. For a normal MPI reference, we usually use Japanese databases for MPI created by the Japanese Society of Nuclear Medicine, which can be used with conventional SPECT but not with CZT SPECT. In this study, we used new Japanese normal databases constructed in our institution to compare conventional and CZT SPECT. Compared with conventional SPECT, CZT SPECT showed lower SSS (p < 0.001), SRS (p = 0.001), and SDS (p = 0.189) using the pre-installed SPECT database. In contrast, CZT SPECT showed no significant difference from conventional SPECT in QPS analysis using the normal databases from our institution. Myocardial perfusion analyses by CZT SPECT should be evaluated using normal databases based on the ethnic group being evaluated.

Comment on "Acoustical observation of bubble oscillations induced by bubble popping"

NASA Astrophysics Data System (ADS)

Blanc, É.; Ollivier, F.; Antkowiak, A.; Wunenburger, R.

2015-03-01

We have reproduced the experiment of acoustic monitoring of spontaneous popping of single soap bubbles standing in air reported by Ding et al. [2aa Phys. Rev. E 75, 041601 (2007), 10.1103/PhysRevE.75.041601]. By using a single microphone and two different signal acquisition systems recording in parallel the signal at the microphone output, among them the system used by Ding et al., we have experimentally evidenced that the acoustic precursors of bubble popping events detected by Ding et al. actually result from an acausal artifact of the signal processing performed by their acquisition system which lies outside of its prescribed working frequency range. No acoustic precursor of popping could be evidenced with the microphone used in these experiments, whose sensitivity is 1 V Pa-1 and frequency range is 500 Hz-100 kHz.

Assessment of left ventricular mechanical dyssynchrony by phase analysis of gated-SPECT myocardial perfusion imaging and tissue Doppler imaging: comparison between QGS and ECTb software packages.

PubMed

Rastgou, Fereydoon; Shojaeifard, Maryam; Amin, Ahmad; Ghaedian, Tahereh; Firoozabadi, Hasan; Malek, Hadi; Yaghoobi, Nahid; Bitarafan-Rajabi, Ahmad; Haghjoo, Majid; Amouzadeh, Hedieh; Barati, Hossein

2014-12-01

Recently, the phase analysis of gated single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) has become feasible via several software packages for the evaluation of left ventricular mechanical dyssynchrony. We compared two quantitative software packages, quantitative gated SPECT (QGS) and Emory cardiac toolbox (ECTb), with tissue Doppler imaging (TDI) as the conventional method for the evaluation of left ventricular mechanical dyssynchrony. Thirty-one patients with severe heart failure (ejection fraction ≤35%) and regular heart rhythm, who referred for gated-SPECT MPI, were enrolled. TDI was performed within 3 days after MPI. Dyssynchrony parameters derived from gated-SPECT MPI were analyzed by QGS and ECTb and were compared with the Yu index and septal-lateral wall delay measured by TDI. QGS and ECTb showed a good correlation for assessment of phase histogram bandwidth (PHB) and phase standard deviation (PSD) (r = 0.664 and r = 0.731, P < .001, respectively). However, the mean value of PHB and PSD by ECTb was significantly higher than that of QGS. No significant correlation was found between ECTb and QGS and the Yu index. Nevertheless, PHB, PSD, and entropy derived from QGS revealed a significant (r = 0.424, r = 0.478, r = 0.543, respectively; P < .02) correlation with septal-lateral wall delay. Despite a good correlation between QGS and ECTb software packages, different normal cut-off values of PSD and PHB should be defined for each software package. There was only a modest correlation between phase analysis of gated-SPECT MPI and TDI data, especially in the population of heart failure patients with both narrow and wide QRS complex.

KENNEDY SPACE CENTER, FLA. - In the Vehicle Assembly Building, Jim Landy, NDE specialist, sets up a flight crew lockers for flash thermography. He is screening the lockers for hidden damage underneath dings and dents that might occur during handling.

NASA Image and Video Library

2003-09-04

KENNEDY SPACE CENTER, FLA. - In the Vehicle Assembly Building, Jim Landy, NDE specialist, sets up a flight crew lockers for flash thermography. He is screening the lockers for hidden damage underneath dings and dents that might occur during handling.

3D Gaussian Beam Modeling

DTIC Science & Technology

2011-09-01

optimized building blocks such as a parallelized tri-diagonal linear solver (used in the “implicit finite differences ” and split-step Pade PE models...and Ding Lee. “A finite - difference treatment of interface conditions for the parabolic wave equation: The horizontal interface.” The Journal of the...Acoustical Society of America, 71(4):855, 1982. 3. Ding Lee and Suzanne T. McDaniel. “A finite - difference treatment of interface conditions for

Study of the Neurophysiology of Central Fatigue

DTIC Science & Technology

2014-11-05

AGENCY NAME(S) AND ADDRESS (ES) U.S. Army Research Office P.O. Box 12211 Research Triangle Park, NC 27709-2211 cognitive, fatigue, fatigability...Fatigability in Parkinson Disease. Movement Disorders 2012;27:e6. 4. Wang C, Ding M, Kluger BM. High-density EEG study of cue-evoked preparatory...258. 3. Kluger B, Wang C, Proemsey J, Ding M. Neuronal Correlates of Executive Dysfunction and Fatigability in Parkinson Disease. Movement Disorders

Processing MPI Datatypes Outside MPI

NASA Astrophysics Data System (ADS)

Ross, Robert; Latham, Robert; Gropp, William; Lusk, Ewing; Thakur, Rajeev

The MPI datatype functionality provides a powerful tool for describing structured memory and file regions in parallel applications, enabling noncontiguous data to be operated on by MPI communication and I/O routines. However, no facilities are provided by the MPI standard to allow users to efficiently manipulate MPI datatypes in their own codes.

DAMAGE MODELING OF INJECTION-MOLDED SHORT- AND LONG-FIBER THERMOPLASTICS

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

Nguyen, Ba Nghiep; Kunc, Vlastimil; Bapanapalli, Satish K.

2009-10-30

This article applies the recent anisotropic rotary diffusion – reduced strain closure (ARD-RSC) model for predicting fiber orientation and a new damage model for injection-molded long-fiber thermoplastics (LFTs) to analyze progressive damage leading to total failure of injection-molded long-glass-fiber/polypropylene (PP) specimens. The ARD-RSC model was implemented in a research version of the Autodesk Moldflow Plastics Insight (MPI) processing code, and it has been used to simulate injection-molding of a long-glass-fiber/PP plaque. The damage model combines micromechanical modeling with a continuum damage mechanics description to predict the nonlinear behavior due to plasticity coupled with damage in LFTs. This model has beenmore » implemented in the ABAQUS finite element code via user-subroutines and has been used in the damage analyses of tensile specimens removed from the injection-molded long-glass-fiber/PP plaques. Experimental characterization and mechanical testing were performed to provide input data to support and validate both process modeling and damage analyses. The predictions are in agreement with the experimental results.« less

X-space MPI: magnetic nanoparticles for safe medical imaging.

PubMed

Goodwill, Patrick William; Saritas, Emine Ulku; Croft, Laura Rose; Kim, Tyson N; Krishnan, Kannan M; Schaffer, David V; Conolly, Steven M

2012-07-24

One quarter of all iodinated contrast X-ray clinical imaging studies are now performed on Chronic Kidney Disease (CKD) patients. Unfortunately, the iodine contrast agent used in X-ray is often toxic to CKD patients' weak kidneys, leading to significant morbidity and mortality. Hence, we are pioneering a new medical imaging method, called Magnetic Particle Imaging (MPI), to replace X-ray and CT iodinated angiography, especially for CKD patients. MPI uses magnetic nanoparticle contrast agents that are much safer than iodine for CKD patients. MPI already offers superb contrast and extraordinary sensitivity. The iron oxide nanoparticle tracers required for MPI are also used in MRI, and some are already approved for human use, but the contrast agents are far more effective at illuminating blood vessels when used in the MPI modality. We have recently developed a systems theoretic framework for MPI called x-space MPI, which has already dramatically improved the speed and robustness of MPI image reconstruction. X-space MPI has allowed us to optimize the hardware for fi ve MPI scanners. Moreover, x-space MPI provides a powerful framework for optimizing the size and magnetic properties of the iron oxide nanoparticle tracers used in MPI. Currently MPI nanoparticles have diameters in the 10-20 nanometer range, enabling millimeter-scale resolution in small animals. X-space MPI theory predicts that larger nanoparticles could enable up to 250 micrometer resolution imaging, which would represent a major breakthrough in safe imaging for CKD patients.

Simple, efficient allocation of modelling runs on heterogeneous clusters with MPI

USGS Publications Warehouse

Donato, David I.

2017-01-01

In scientific modelling and computation, the choice of an appropriate method for allocating tasks for parallel processing depends on the computational setting and on the nature of the computation. The allocation of independent but similar computational tasks, such as modelling runs or Monte Carlo trials, among the nodes of a heterogeneous computational cluster is a special case that has not been specifically evaluated previously. A simulation study shows that a method of on-demand (that is, worker-initiated) pulling from a bag of tasks in this case leads to reliably short makespans for computational jobs despite heterogeneity both within and between cluster nodes. A simple reference implementation in the C programming language with the Message Passing Interface (MPI) is provided.

Randomized, single-blind, factorial design study of the interaction of food and time on intestinal activity in 99mTc-tetrofosmin stress myocardial perfusion scintigraphy.

PubMed

Lyngholm, Ann Marie; Pedersen, Begitte H; Petersen, Lars J

2008-09-01

Intestinal activity at the inferior myocardial wall represents an issue for assessment of myocardial perfusion imaging (MPI) with 99mTc-labelled tracers. The aim of this study was to investigate the effect of time and food on upper abdominal activity in 99mTc-tetrofosmin MPI. The study population consisted of 152 consecutive patients referred for routine MPI. All patients underwent 2-day stress-rest 99mTc-tetrofosmin single-photon emission computed tomography MPI. Before stress testing, patients were randomized in a factorial design to four different regimens. Group A: early scan (image acquisition initiated within 15 min after injection of the tracer) and no food; group B: early scan and food (two pieces of white bread with butter and a minimum of 450 ml of water); group C: late scan (image acquisition 30-60 min after injection of the tracer) and no food; and group D: late and scan with food. Patients underwent standard bicycle exercise or pharmacological stress test. The degree of upper abdominal activity was evaluated by trained observers blinded to the randomization code. The primary endpoint was the proportion of accepted scans in the intention-to-treat population in stress MPI. The results showed statistical significant impact on both time and food on upper abdominal activity. The primary endpoint showed that the acceptance rate improved from 55% in group A to 100% success rate in group D. An early scan reduced the acceptance rate by 30% versus a late scan [hazard ratio 0.70, 95% confidence interval 0.58-0.84; P<0.0001], whereas the addition of food improved the success rate versus no food by 27% (hazard ratio 1.27, 95% confidence interval 1.07-1.51; P=0.006). No significant interaction between food and time was observed. An analysis of accepted scans according to the actual scan time and food consumption confirmed the findings of the intention-to-treat analysis. In addition, similar findings were seen in 116 of 152 patients with a rest MPI (success rate of 53% in group A vs. 96% in group D). A combination of solid food and water administered after injection of the tracer and delayed image acquisition led to significant and clinically relevant decrease of interfering upper abdominal activity in 99mTc-tetrofosmin MPI.

Enabling communication concurrency through flexible MPI endpoints

DOE PAGES

Dinan, James; Grant, Ryan E.; Balaji, Pavan; ...

2014-09-23

MPI defines a one-to-one relationship between MPI processes and ranks. This model captures many use cases effectively; however, it also limits communication concurrency and interoperability between MPI and programming models that utilize threads. Our paper describes the MPI endpoints extension, which relaxes the longstanding one-to-one relationship between MPI processes and ranks. Using endpoints, an MPI implementation can map separate communication contexts to threads, allowing them to drive communication independently. Also, endpoints enable threads to be addressable in MPI operations, enhancing interoperability between MPI and other programming models. Furthermore, these characteristics are illustrated through several examples and an empirical study thatmore » contrasts current multithreaded communication performance with the need for high degrees of communication concurrency to achieve peak communication performance.« less

Enabling communication concurrency through flexible MPI endpoints

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

Dinan, James; Grant, Ryan E.; Balaji, Pavan

MPI defines a one-to-one relationship between MPI processes and ranks. This model captures many use cases effectively; however, it also limits communication concurrency and interoperability between MPI and programming models that utilize threads. Our paper describes the MPI endpoints extension, which relaxes the longstanding one-to-one relationship between MPI processes and ranks. Using endpoints, an MPI implementation can map separate communication contexts to threads, allowing them to drive communication independently. Also, endpoints enable threads to be addressable in MPI operations, enhancing interoperability between MPI and other programming models. Furthermore, these characteristics are illustrated through several examples and an empirical study thatmore » contrasts current multithreaded communication performance with the need for high degrees of communication concurrency to achieve peak communication performance.« less

Enabling communication concurrency through flexible MPI endpoints

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

Dinan, James; Grant, Ryan E.; Balaji, Pavan

MPI defines a one-to-one relationship between MPI processes and ranks. This model captures many use cases effectively; however, it also limits communication concurrency and interoperability between MPI and programming models that utilize threads. This paper describes the MPI endpoints extension, which relaxes the longstanding one-to-one relationship between MPI processes and ranks. Using endpoints, an MPI implementation can map separate communication contexts to threads, allowing them to drive communication independently. Endpoints also enable threads to be addressable in MPI operations, enhancing interoperability between MPI and other programming models. These characteristics are illustrated through several examples and an empirical study that contrastsmore » current multithreaded communication performance with the need for high degrees of communication concurrency to achieve peak communication performance.« less

Multicenter evaluation of stress-first myocardial perfusion image triage by nuclear technologists and automated quantification.

PubMed

Chaudhry, Waseem; Hussain, Nasir; Ahlberg, Alan W; Croft, Lori B; Fernandez, Antonio B; Parker, Mathew W; Swales, Heather H; Slomka, Piotr J; Henzlova, Milena J; Duvall, W Lane

2017-06-01

A stress-first myocardial perfusion imaging (MPI) protocol saves time, is cost effective, and decreases radiation exposure. A limitation of this protocol is the requirement for physician review of the stress images to determine the need for rest images. This hurdle could be eliminated if an experienced technologist and/or automated computer quantification could make this determination. Images from consecutive patients who were undergoing a stress-first MPI with attenuation correction at two tertiary care medical centers were prospectively reviewed independently by a technologist and cardiologist blinded to clinical and stress test data. Their decision on the need for rest imaging along with automated computer quantification of perfusion results was compared with the clinical reference standard of an assessment of perfusion images by a board-certified nuclear cardiologist that included clinical and stress test data. A total of 250 patients (mean age 61 years and 55% female) who underwent a stress-first MPI were studied. According to the clinical reference standard, 42 (16.8%) and 208 (83.2%) stress-first images were interpreted as "needing" and "not needing" rest images, respectively. The technologists correctly classified 229 (91.6%) stress-first images as either "needing" (n = 28) or "not needing" (n = 201) rest images. Their sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were 66.7%, 96.6%, 80.0%, and 93.5%, respectively. An automated stress TPD score ≥1.2 was associated with optimal sensitivity and specificity and correctly classified 179 (71.6%) stress-first images as either "needing" (n = 31) or "not needing" (n = 148) rest images. Its sensitivity, specificity, PPV, and NPV were 73.8%, 71.2%, 34.1%, and 93.1%, respectively. In a model whereby the computer or technologist could correct for the other's incorrect classification, 242 (96.8%) stress-first images were correctly classified. The composite sensitivity, specificity, PPV, and NPV were 83.3%, 99.5%, 97.2%, and 96.7%, respectively. Technologists and automated quantification software had a high degree of agreement with the clinical reference standard for determining the need for rest images in a stress-first imaging protocol. Utilizing an experienced technologist and automated systems to screen stress-first images could expand the use of stress-first MPI to sites where the cardiologist is not immediately available for interpretation.

Analysis of pain behavior profiles and functional disability in outpatient physical therapy clinics.

PubMed

Hankin, H A; Spencer, T; Kegerreis, S; Worrell, T; Rice, J M

2001-02-01

Descriptive, ex post facto. To determine the proportion of physical therapy outpatients with pain who exhibit various pain behavior profiles, and to determine whether there are differences in functional disability across the profiles. Physical therapists treat many patients who have chronic pain. Research suggests that early identification and multidisciplinary treatment are effective and economical for these patients. The Multidimensional Pain Inventory (MPI) and the Pain Disability Index (PDI) are potential screening tools that could be used in physical therapy clinics to determine which patients should be referred for multidisciplinary treatment. MPI and PDI data were gathered on 57 physical therapy outpatients (mean age 44.3 +/- 14.5 years, 22 men and 35 women) with pain of 3 or more months duration. ANOVA was used to analyze differences in mean PDI scores across the MPI profiles. Of all patients, 42.1% fit the Adaptive Coper profile, 29.8% fit the Interpersonally Distressed profile, and 28.1% fit the Dysfunctional profile. There were significant differences in PDI scores among profile groups. Post hoc analysis showed that the PDI scores of the Adaptive Coper and Interpersonally Distressed groups were different from the Dysfunctional group, but that there was no difference between the Adaptive Coper and Interpersonally Distressed groups. Many patients in outpatient physical therapy settings exhibit behavioral, affective, and cognitive characteristics associated with chronic pain. Thirty-three patients (57.9%) had MPI profiles (interpersonally distressed and dysfunctional) that suggest they might benefit from multidisciplinary treatment.

Safety of regadenoson in patients with severe chronic obstructive pulmonary disease.

PubMed

Salgado-Garcia, C; Jimenez-Heffernan, A; Ramos-Font, C; Lopez-Martin, J; Sanchez-de-Mora, E; Aroui, T; Lopez-Aguilar, R; Rivera-de-Los-Santos, F; Ruiz-Frutos, C

2016-01-01

To assess the safety of regadenoson, a selective agonist of A2A adenosine receptors, combined with low-level exercise in subjects with severe chronic obstructive pulmonary disease (COPD), referred for myocardial perfusion imaging (MPI). We studied prospectively 12 male patients with severe COPD. Stress was 4min of low-level exercise with bolus injection of regadenoson (0.4mg) at 1.5min, followed by (99m)Tc-MPI agent injection. Demographics, medical history, lung medications, adverse events, oxygen saturation (SatO2), MPI findings for coronary artery disease (CAD), and changes in systolic blood pressure (SBP), and heart rate (HR) were registered. The observed adverse event profile of regadenoson was similar to that of patients with mild-moderate COPD. There was no clinical exacerbation of COPD. Adverse events were self-limiting: dyspnea (33.3%), fatigue (25.0%), chest pain, headache (16.7%, respectively), and gastrointestinal discomfort, dry mouth, flushing, feeling hot and dizziness (8.3%, respectively). 25.0% of patients did not report any symptoms. We observed significant increases in SBP and HR from baseline (142.6mmHg±22.3 vs 152.5mmHg±18.5, and 80 b.p.m.±18 vs 105 b.p.m.±22, respectively; p<0.05). Regadenoson combined with low-level exercise is safe and well tolerated in stable patients with severe COPD undergoing MPI. Copyright © 2016 Elsevier España, S.L.U. y SEMNIM. All rights reserved.

Gas Control and Thermal Modeling Methods for Pressed Pellet and Fast Rise Thin-Film Thermal Batteries

DTIC Science & Technology

2015-09-01

Thin-Film Thermal Batteries by Frank C Krieger and Michael S Ding Approved for public release; distribution unlimited...Laboratory Gas Control and Thermal Modeling Methods for Pressed Pellet and Fast Rise Thin-Film Thermal Batteries by Frank C Krieger and Michael S...Batteries 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Frank C Krieger and Michael S Ding 5d. PROJECT NUMBER

Myocardial perfusion imaging in patients with a recent, normal exercise test.

PubMed

Bovin, Ann; Klausen, Ib C; Petersen, Lars J

2013-03-26

To investigate the added value of myocardial perfusion scintigraphy imaging (MPI) in consecutive patients with suspected coronary artery disease (CAD) and a recent, normal exercise electrocardiography (ECG). This study was a retrospective analysis of consecutive patients referred for MPI during a 2-year period from 2006-2007 at one clinic. All eligible patients were suspected of suffering from CAD, and had performed a satisfactory bicycle exercise test (i.e., peak heart rate > 85% of the expected, age-predicted maximum) within 6 mo of referral, their exercise ECG was had no signs of ischemia, there was no exercise-limiting angina, and no cardiac events occurred between the exercise test and referral. The patients subsequently underwent a standard 2-d, stress-rest exercise MPI. Ischemia was defined based on visual scoring supported by quantitative segmental analysis (i.e., sum of stress score > 3). The results of cardiac catheterization were analyzed, and clinical follow up was performed by review of electronic medical files. A total of 56 patients fulfilled the eligibility criteria. Most patients had a low or intermediate ATPIII pre-test risk of CAD (6 patients had a high pre-test risk). The referral exercise test showed a mean Duke score of 5 (range: 2 to 11), which translated to a low post-exercise risk in 66% and intermediate risk in 34%. A total of seven patients were reported with ischemia by MPI. Three of these patients had high ATPIII pre-test risk scores. Six of these seven patients underwent cardiac catheterization, which showed significant stenosis in one patient with a high pre-test risk of CAD, and indeterminate lesions in three patients (two of whom had high pre-test risk scores). With MPI as a gate keeper for catheterization, no significant, epicardial stenosis was observed in any of the 50 patients (0%, 95% confidence interval 0.0 to 7.1) with low to intermediate pre-test risk of CAD and a negative exercise test. No cardiac events occurred in any patients within a median follow up period of > 1200 d. The added diagnostic value of MPI in patients with low or intermediate risk of CAD and a recent, normal exercise test is marginal.

An MPI-1 Compliant Thread-Based Implementation

NASA Astrophysics Data System (ADS)

Díaz Martín, J. C.; Rico Gallego, J. A.; Álvarez Llorente, J. M.; Perogil Duque, J. F.

This work presents AzequiaMPI, the first full compliant implementation of the MPI-1 standard where the MPI node is a thread. Performance comparisons with MPICH2-Nemesis show that thread-based implementations exploit adequately the multicore architectures under oversubscription, what could make MPI competitive with OpenMP-like solutions.

An implementation and evaluation of the MPI 3.0 one-sided communication interface

DOE PAGES

Dinan, James S.; Balaji, Pavan; Buntinas, Darius T.; ...

2016-01-09

The Q1 Message Passing Interface (MPI) 3.0 standard includes a significant revision to MPI’s remote memory access (RMA) interface, which provides support for one-sided communication. MPI-3 RMA is expected to greatly enhance the usability and performance ofMPI RMA.We present the first complete implementation of MPI-3 RMA and document implementation techniques and performance optimization opportunities enabled by the new interface. Our implementation targets messaging-based networks and is publicly available in the latest release of the MPICH MPI implementation. Here using this implementation, we explore the performance impact of new MPI-3 functionality and semantics. Results indicate that the MPI-3 RMA interface providesmore » significant advantages over the MPI-2 interface by enabling increased communication concurrency through relaxed semantics in the interface and additional routines that provide new window types, synchronization modes, and atomic operations.« less

An implementation and evaluation of the MPI 3.0 one-sided communication interface

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

Dinan, James S.; Balaji, Pavan; Buntinas, Darius T.

The Q1 Message Passing Interface (MPI) 3.0 standard includes a significant revision to MPI’s remote memory access (RMA) interface, which provides support for one-sided communication. MPI-3 RMA is expected to greatly enhance the usability and performance ofMPI RMA.We present the first complete implementation of MPI-3 RMA and document implementation techniques and performance optimization opportunities enabled by the new interface. Our implementation targets messaging-based networks and is publicly available in the latest release of the MPICH MPI implementation. Here using this implementation, we explore the performance impact of new MPI-3 functionality and semantics. Results indicate that the MPI-3 RMA interface providesmore » significant advantages over the MPI-2 interface by enabling increased communication concurrency through relaxed semantics in the interface and additional routines that provide new window types, synchronization modes, and atomic operations.« less

78 FR 40954 - Airworthiness Directives; Various Restricted Category Helicopters

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-09

.... This AD requires a magnetic particle inspection (MPI) of the fittings for a crack, and if there is a..., energy, or federalism impacts that resulted from adopting this AD. The most helpful comments reference a..., whichever comes first, to magnetic particle inspect for a crack in the fitting. As these helicopters are...

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

Grant, Ryan E.; Barrett, Brian W.; Pedretti, Kevin

The Portals reference implementation is based on the Portals 4.X API, published by Sandia National Laboratories as a freely available public document. It is designed to be an implementation of the Portals Networking Application Programming Interface and is used by several other upper layer protocols like SHMEM, GASNet and MPI. It is implemented over existing networks, specifically Ethernet and InfiniBand networks. This implementation provides Portals networks functionality and serves as a software emulation of Portals compliant networking hardware. It can be used to develop software using the Portals API prior to the debut of Portals networking hardware, such as Bull’smore » BXI interconnect, as well as a substitute for portals hardware on development platforms that do not have Portals compliant hardware. The reference implementation provides new capabilities beyond that of a typical network, namely the ability to have messages matched in hardware in a way compatible with upper layer software such as MPI or SHMEM. It also offers methods of offloading network operations via triggered operations, which can be used to create offloaded collective operations. Specific details on the Portals API can be found at http://portals4.org.« less

Psychomotor Vigilance Performance Predicted by Epworth Sleepiness Scale Scores in an Operational Setting with the United States Navy

DTIC Science & Technology

2015-01-01

using the Motionlogger Watch [Ambulatory Monitoring Inc (AMI), Ardsley, NY, USA] using the zero-crossing mode. Analysis of the actigraphic recordings... rhythmicity (Dinges et al., 1997; Doran et al., 2001; Durmer and Dinges, 2005; Jewett et al., 1999; Wyatt et al., 1997). The PVT has only minor learning...subset of data selected for this analysis was an 11-day period from 4 December to 14 December 2012. Actigraphic record- ings were used to determine

[Traditional Chinese medicine inheritance system analysis of professor Ding Yuanqing in treating tic disorder medication based on experience].

PubMed

Sun, Lu-yan; Li, Qing-peng; Zhao, Li-li; Ding, Yuan-qing

2015-08-01

In recent years, the incidence of tic disorders has increased, and it is not uncommon for the patients to treat the disease. The pathogenesis and pathogenesis of Western medicine are not yet clear, the clinical commonly used western medicine has many adverse reactions, traditional Chinese medicine (TCM) research is increasingly valued. Based on the software of TCM inheritance assistant system, this paper discusses Ding Yuanqing's experience in treating tic disorder with Professor. Collect yuan Qing Ding professor in treating tic disorder of medical records by association rules Apriori algorithm, complex system entropy clustering without supervision and data mining method, carries on the analysis to the selected 800 prescriptions, to determine the frequency of use of prescription drugs, the association rules between the drug and digging out the 12 core combination and the first six new prescription, medication transferred to the liver and extinguish wind, cooling blood and relieving convulsion, Qingxin soothe the nerves, with the card cut, flexible application, strict compatibility.

Visualization on the Day Night Year Globe

NASA Astrophysics Data System (ADS)

Božić, Mirjana; Vušković, Leposava; Popović, Svetozar; Popović, Jelena; Marković-Topalović, Tatjana

2016-11-01

The story about a properly oriented outdoor globe in the hands and minds of Eratosthenes, Jefferson, Milanković and science educators is presented. Having the same orientation in space as the Earth, the Day Night Year Globe (DING) shows in real time the pattern of illumination of the Earth’s surface and its diurnal and seasonal variations. It is an ideal object for the visualization of knowledge and increase in knowledge about: the form of the Earth, Earth’s rotation, Earth’s revolution around the Sun, the length of seasons, solstices, equinoxes, the longitude problem, the distribution of the Sun’s radiation over the Earth, the impact of this radiation on Earth’s climate, and how to use it efficiently. By attaching a movable vane to the poles, or adding pins around the equator to read time, DING becomes a spherical/globe-shaped sundial. So, the DING is simultaneously useful for teaching physics, geophysics, astronomy, use of solar energy and promoting an inquiry-based learning environment for students and the public.

MPI Runtime Error Detection with MUST: Advances in Deadlock Detection

DOE PAGES

Hilbrich, Tobias; Protze, Joachim; Schulz, Martin; ...

2013-01-01

The widely used Message Passing Interface (MPI) is complex and rich. As a result, application developers require automated tools to avoid and to detect MPI programming errors. We present the Marmot Umpire Scalable Tool (MUST) that detects such errors with significantly increased scalability. We present improvements to our graph-based deadlock detection approach for MPI, which cover future MPI extensions. Our enhancements also check complex MPI constructs that no previous graph-based detection approach handled correctly. Finally, we present optimizations for the processing of MPI operations that reduce runtime deadlock detection overheads. Existing approaches often require ( p ) analysis time permore » MPI operation, for p processes. We empirically observe that our improvements lead to sub-linear or better analysis time per operation for a wide range of real world applications.« less

Prognostic value of stress myocardial perfusion positron emission tomography: results from a multicenter observational registry.

PubMed

Dorbala, Sharmila; Di Carli, Marcelo F; Beanlands, Rob S; Merhige, Michael E; Williams, Brent A; Veledar, Emir; Chow, Benjamin J W; Min, James K; Pencina, Michael J; Berman, Daniel S; Shaw, Leslee J

2013-01-15

The primary objective of this multicenter registry was to study the prognostic value of positron emission tomography (PET) myocardial perfusion imaging (MPI) and the improved classification of risk in a large cohort of patients with suspected or known coronary artery disease (CAD). Limited prognostic data are available for MPI with PET. A total of 7,061 patients from 4 centers underwent a clinically indicated rest/stress rubidium-82 PET MPI, with a median follow-up of 2.2 years. The primary outcome of this study was cardiac death (n = 169), and the secondary outcome was all-cause death (n = 570). Net reclassification improvement (NRI) and integrated discrimination analyses were performed. Risk-adjusted hazard of cardiac death increased with each 10% myocardium abnormal with mildly, moderately, or severely abnormal stress PET (hazard ratio [HR]: 2.3 [95% CI: 1.4 to 3.8; p = 0.001], HR: 4.2 [95% CI: 2.3 to 7.5; p < 0.001], and HR: 4.9 [95% CI: 2.5 to 9.6; p < 0.0001], respectively [normal MPI: referent]). Addition of percent myocardium ischemic and percent myocardium scarred to clinical information (age, female sex, body mass index, history of hypertension, diabetes, dyslipidemia, smoking, angina, beta-blocker use, prior revascularization, and resting heart rate) improved the model performance (C-statistic 0.805 [95% CI: 0.772 to 0.838] to 0.839 [95% CI: 0.809 to 0.869]) and risk reclassification for cardiac death (NRI 0.116 [95% CI: 0.021 to 0.210]), with smaller improvements in risk assessment for all-cause death. In patients with known or suspected CAD, the extent and severity of ischemia and scar on PET MPI provided powerful and incremental risk estimates of cardiac death and all-cause death compared with traditional coronary risk factors. Copyright © 2013 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Characterization of a Polymer Composite Section of Foreign Armor

DTIC Science & Technology

2000-03-01

Core Sample 8 6. ESEM From Owens - Corning S-2 Glass Reference 10 7. ESEM From Owens-Coming E Glass Reference 11 8. ESEM From Known Russian S...light element energy dispersive spectrometer. Samples of domestic Owens - Corning E and S-2 glass fibers were first analyzed for reference purposes...for comparison to the unknown Russian armor fiber. The two domestic reference fibers were Owens - Corning E and S-2 glass. Their spectra are shown in

mpiGraph

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

Moody, Adam

2007-05-22

MpiGraph consists of an MPI application called mpiGraph written in C to measure message bandwidth and an associated crunch_mpiGraph script written in Perl to process the application output into an HTMO report. The mpiGraph application is designed to inspect the health and scalability of a high-performance interconnect while under heavy load. This is useful to detect hardware and software problems in a system, such as slow nodes, links, switches, or contention in switch routing. It is also useful to characterize how interconnect performance changes with different settings or how one interconnect type compares to another.

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

Fang, Aiman; Laguna, Ignacio; Sato, Kento

Future high-performance computing systems may face frequent failures with their rapid increase in scale and complexity. Resilience to faults has become a major challenge for large-scale applications running on supercomputers, which demands fault tolerance support for prevalent MPI applications. Among failure scenarios, process failures are one of the most severe issues as they usually lead to termination of applications. However, the widely used MPI implementations do not provide mechanisms for fault tolerance. We propose FTA-MPI (Fault Tolerance Assistant MPI), a programming model that provides support for failure detection, failure notification and recovery. Specifically, FTA-MPI exploits a try/catch model that enablesmore » failure localization and transparent recovery of process failures in MPI applications. We demonstrate FTA-MPI with synthetic applications and a molecular dynamics code CoMD, and show that FTA-MPI provides high programmability for users and enables convenient and flexible recovery of process failures.« less

Multicenter evaluation of stress-first myocardial perfusion image triage by nuclear technologists and automated quantification

PubMed Central

Chaudhry, Waseem; Hussain, Nasir; Ahlberg, Alan W.; Croft, Lori B.; Fernandez, Antonio B.; Parker, Mathew W.; Swales, Heather H.; Slomka, Piotr J.; Henzlova, Milena J.; Duvall, W. Lane

2016-01-01

Background A stress-first myocardial perfusion imaging (MPI) protocol saves time, is cost effective, and decreases radiation exposure. A limitation of this protocol is the requirement for physician review of the stress images to determine the need for rest images. This hurdle could be eliminated if an experienced technologist and/or automated computer quantification could make this determination. Methods Images from consecutive patients who were undergoing a stress-first MPI with attenuation correction at two tertiary care medical centers were prospectively reviewed independently by a technologist and cardiologist blinded to clinical and stress test data. Their decision on the need for rest imaging along with automated computer quantification of perfusion results was compared with the clinical reference standard of an assessment of perfusion images by a board-certified nuclear cardiologist that included clinical and stress test data. Results A total of 250 patients (mean age 61 years and 55% female) who underwent a stress-first MPI were studied. According to the clinical reference standard, 42 (16.8%) and 208 (83.2%) stress-first images were interpreted as “needing” and “not needing” rest images, respectively. The technologists correctly classified 229 (91.6%) stress-first images as either “needing” (n = 28) or “not needing” (n = 201) rest images. Their sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were 66.7%, 96.6%, 80.0%, and 93.5%, respectively. An automated stress TPD score ≥1.2 was associated with optimal sensitivity and specificity and correctly classified 179 (71.6%) stress-first images as either “needing” (n = 31) or “not needing” (n = 148) rest images. Its sensitivity, specificity, PPV, and NPV were 73.8%, 71.2%, 34.1%, and 93.1%, respectively. In a model whereby the computer or technologist could correct for the other's incorrect classification, 242 (96.8%) stress-first images were correctly classified. The composite sensitivity, specificity, PPV, and NPV were 83.3%, 99.5%, 97.2%, and 96.7%, respectively. Conclusion Technologists and automated quantification software had a high degree of agreement with the clinical reference standard for determining the need for rest images in a stress-first imaging protocol. Utilizing an experienced technologist and automated systems to screen stress-first images could expand the use of stress-first MPI to sites where the cardiologist is not immediately available for interpretation. PMID:26566774

How Are Academic Age, Productivity and Collaboration Related to Citing Behavior of Researchers?

PubMed Central

Milojević, Staša

2012-01-01

References are an essential component of research articles and therefore of scientific communication. In this study we investigate referencing (citing) behavior in five diverse fields (astronomy, mathematics, robotics, ecology and economics) based on 213,756 core journal articles. At the macro level we find: (a) a steady increase in the number of references per article over the period studied (50 years), which in some fields is due to a higher rate of usage, while in others reflects longer articles and (b) an increase in all fields in the fraction of older, foundational references since the 1980s, with no obvious change in citing patterns associated with the introduction of the Internet. At the meso level we explore current (2006–2010) referencing behavior of different categories of authors (21,562 total) within each field, based on their academic age, productivity and collaborative practices. Contrary to some previous findings and expectations we find that senior researchers use references at the same rate as their junior colleagues, with similar rates of re-citation (use of same references in multiple papers). High Modified Price Index (MPI, which measures the speed of the research front more accurately than the traditional Price Index) of senior authors indicates that their research has the similar cutting-edge aspect as that of their younger colleagues. In all fields both the productive researchers and especially those who collaborate more use a significantly lower fraction of foundational references and have much higher MPI and lower re-citation rates, i.e., they are the ones pushing the research front regardless of researcher age. This paper introduces improved bibliometric methods to measure the speed of the research front, disambiguate lead authors in co-authored papers and decouple measures of productivity and collaboration. PMID:23145111

Reuse of refinery's tertiary-treated wastewater in cooling towers: microbiological monitoring.

PubMed

Dos Santos, Vera Lúcia; Veiga, Andréa Azevedo; Mendonça, Rafael Silva; Alves, Andrea Lima; Pagnin, Sérgio; Santiago, Vânia M J

2015-02-01

The study was planned to quantify the distribution of bacteria between bulk water and biofilm formed on different materials in an industrial scale cooling tower system of an oil refinery operating with clarified and chlorinated freshwater (CCW) or chlorinated tertiary effluent (TRW) as makeup water. The sessile and planktonic heterotrophic bacteria and Pseudomonas aeruginosa densities were significantly higher in the cooling tower supplied with clarified and chlorinated freshwater (CTCW) (p < 0.05). In the two towers, the biofilm density was higher on the surface of glass slides and stainless steel coupons than on the surface of carbon steel coupons. The average corrosion rates of carbon steel coupons (0.4-0.8 millimeters per year (mpy)) and densities of sessile (12-1.47 × 10(3) colony-forming unit (CFU) cm(-1)) and planktonic (0-2.36 × 10(3) CFU mL(-1)) microbiota remained below of the maximum values of reference used by water treatment companies as indicative of efficient microbial control. These data indicate that the strategies of the water treatment station (WTS) (free chlorine) and industrial wastewater treatment station (IWTS) followed by reverse electrodialysis system (RES) (free chlorine plus chloramine) were effective for the microbiological control of the two makeup water sources.

FLY MPI-2: a parallel tree code for LSS

NASA Astrophysics Data System (ADS)

Becciani, U.; Comparato, M.; Antonuccio-Delogu, V.

2006-04-01

New version program summaryProgram title: FLY 3.1 Catalogue identifier: ADSC_v2_0 Licensing provisions: yes Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADSC_v2_0 Program obtainable from: CPC Program Library, Queen's University of Belfast, N. Ireland No. of lines in distributed program, including test data, etc.: 158 172 No. of bytes in distributed program, including test data, etc.: 4 719 953 Distribution format: tar.gz Programming language: Fortran 90, C Computer: Beowulf cluster, PC, MPP systems Operating system: Linux, Aix RAM: 100M words Catalogue identifier of previous version: ADSC_v1_0 Journal reference of previous version: Comput. Phys. Comm. 155 (2003) 159 Does the new version supersede the previous version?: yes Nature of problem: FLY is a parallel collisionless N-body code for the calculation of the gravitational force Solution method: FLY is based on the hierarchical oct-tree domain decomposition introduced by Barnes and Hut (1986) Reasons for the new version: The new version of FLY is implemented by using the MPI-2 standard: the distributed version 3.1 was developed by using the MPICH2 library on a PC Linux cluster. Today the FLY performance allows us to consider the FLY code among the most powerful parallel codes for tree N-body simulations. Another important new feature regards the availability of an interface with hydrodynamical Paramesh based codes. Simulations must follow a box large enough to accurately represent the power spectrum of fluctuations on very large scales so that we may hope to compare them meaningfully with real data. The number of particles then sets the mass resolution of the simulation, which we would like to make as fine as possible. The idea to build an interface between two codes, that have different and complementary cosmological tasks, allows us to execute complex cosmological simulations with FLY, specialized for DM evolution, and a code specialized for hydrodynamical components that uses a Paramesh block structure. Summary of revisions: The parallel communication schema was totally changed. The new version adopts the MPICH2 library. Now FLY can be executed on all Unix systems having an MPI-2 standard library. The main data structure, is declared in a module procedure of FLY (fly_h.F90 routine). FLY creates the MPI Window object for one-sided communication for all the shared arrays, with a call like the following: CALL MPI_WIN_CREATE(POS, SIZE, REAL8, MPI_INFO_NULL, MPI_COMM_WORLD, WIN_POS, IERR) the following main window objects are created: win_pos, win_vel, win_acc: particles positions velocities and accelerations, win_pos_cell, win_mass_cell, win_quad, win_subp, win_grouping: cells positions, masses, quadrupole momenta, tree structure and grouping cells. Other windows are created for dynamic load balance and global counters. Restrictions: The program uses the leapfrog integrator schema, but could be changed by the user. Unusual features: FLY uses the MPI-2 standard: the MPICH2 library on Linux systems was adopted. To run this version of FLY the working directory must be shared among all the processors that execute FLY. Additional comments: Full documentation for the program is included in the distribution in the form of a README file, a User Guide and a Reference manuscript. Running time: IBM Linux Cluster 1350, 512 nodes with 2 processors for each node and 2 GB RAM for each processor, at Cineca, was adopted to make performance tests. Processor type: Intel Xeon Pentium IV 3.0 GHz and 512 KB cache (128 nodes have Nocona processors). Internal Network: Myricom LAN Card "C" Version and "D" Version. Operating System: Linux SuSE SLES 8. The code was compiled using the mpif90 compiler version 8.1 and with basic optimization options in order to have performances that could be useful compared with other generic clusters Processors

Characterizing MPI matching via trace-based simulation

DOE PAGES

Ferreira, Kurt Brian; Levy, Scott Larson Nicoll; Pedretti, Kevin; ...

2017-01-01

With the increased scale expected on future leadership-class systems, detailed information about the resource usage and performance of MPI message matching provides important insights into how to maintain application performance on next-generation systems. However, obtaining MPI message matching performance data is often not possible without significant effort. A common approach is to instrument an MPI implementation to collect relevant statistics. While this approach can provide important data, collecting matching data at runtime perturbs the application's execution, including its matching performance, and is highly dependent on the MPI library's matchlist implementation. In this paper, we introduce a trace-based simulation approach tomore » obtain detailed MPI message matching performance data for MPI applications without perturbing their execution. Using a number of key parallel workloads, we demonstrate that this simulator approach can rapidly and accurately characterize matching behavior. Specifically, we use our simulator to collect several important statistics about the operation of the MPI posted and unexpected queues. For example, we present data about search lengths and the duration that messages spend in the queues waiting to be matched. Here, data gathered using this simulation-based approach have significant potential to aid hardware designers in determining resource allocation for MPI matching functions and provide application and middleware developers with insight into the scalability issues associated with MPI message matching.« less

41. VIEW NORTH OF UPPER LEVEL OF CRUSHER ADDITION. DINGS ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

41. VIEW NORTH OF UPPER LEVEL OF CRUSHER ADDITION. DINGS MAGNETIC PULLEY AT CENTER. ALSO SHOWS 100-TON CRUSHED UNOXIDIZED ORE BIN (RIGHT), PULLEY FORM 18 INCH BELT CONVEYOR CRUSHED OXIDIZED ORE BIN FEED AND STEPHENSADAMSON 25 TON/HR BUCKET ELEVATOR (UPPER CENTER). THE UPPER PORTION OF THE SAMPLING ELEVATOR IS ABOVE THE MAGNETIC PULLEY (CENTER LEFT) WITH THE ROUTE OF THE 16 INCH BELT CONVEYOR FINES FEED TO CRUSHED OXIDIZED ORE BIN TO ITS LEFT. - Bald Mountain Gold Mill, Nevada Gulch at head of False Bottom Creek, Lead, Lawrence County, SD

Estimation of infarct size using transthoracic Doppler echocardiographic measurement of coronary flow reserve in infarct related and reference coronary artery.

PubMed

Giga, Vojislav; Dobric, Milan; Beleslin, Branko; Sobic-Saranovic, Dragana; Tesic, Milorad; Djordjevic-Dikic, Ana; Stepanovic, Jelena; Nedeljkovic, Ivana; Artiko, Vera; Obradovic, Vladimir; Seferovic, Petar M; Ostojic, Miodrag

2013-09-20

Patients in chronic phase of myocardial infarction (MI) have decreased coronary flow reserve (CFR) in infarct related artery (IRA) that is proportional to the extent of microvascular/myocardial damage. We proposed a novel model for the assessment of microvascular damage and infarct size using Doppler echocardiography evaluation of CFRs of the IRA (LAD) and reference artery (RCA). Our study included 34 consecutive patients (28 men, mean age 50 ± 11 years) with first anterior STEMI and single vessel disease successfully treated with primary PCI. All patients underwent SPECT MPI for the assessment of infarct size (expressed as a percentage of myocardium with fixed perfusion abnormalities) and CFR evaluation of LAD and RCA. CFR derived percentage of microvascular damage (CFR PMD) was calculated as: CFR PMD=(CFR RCA-CFR LAD)/(CFR RCA-1)×100 (%). CFR PMD correlated significantly with all parameters evaluating the severity of myocardial damage including: peak CK activity (r=0.632, p<0.001), WMSI (r=0.857, p<0.001), ejection fraction (r=-0.820, p<0.001), left ventricular end diastolic (r=0.757, p<0.001) and end systolic volume (r=0.794, p<0.001). Most importantly, CFR PMD (22 ± 17%) correlated significantly with infarct size by SPECT MPI (21 ± 17%) (r=0.874, p<0.001). CFR PMD derived from the proposed model was significantly related to echocardiographic and enzymatic parameters of infarct size, as well as to myocardial damage assessed by SPECT MPI in patients with successfully reperfused first anterior STEMI. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Detection and Correction of Silent Data Corruption for Large-Scale High-Performance Computing

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

Fiala, David J; Mueller, Frank; Engelmann, Christian

Faults have become the norm rather than the exception for high-end computing on clusters with 10s/100s of thousands of cores. Exacerbating this situation, some of these faults remain undetected, manifesting themselves as silent errors that corrupt memory while applications continue to operate and report incorrect results. This paper studies the potential for redundancy to both detect and correct soft errors in MPI message-passing applications. Our study investigates the challenges inherent to detecting soft errors within MPI application while providing transparent MPI redundancy. By assuming a model wherein corruption in application data manifests itself by producing differing MPI message data betweenmore » replicas, we study the best suited protocols for detecting and correcting MPI data that is the result of corruption. To experimentally validate our proposed detection and correction protocols, we introduce RedMPI, an MPI library which resides in the MPI profiling layer. RedMPI is capable of both online detection and correction of soft errors that occur in MPI applications without requiring any modifications to the application source by utilizing either double or triple redundancy. Our results indicate that our most efficient consistency protocol can successfully protect applications experiencing even high rates of silent data corruption with runtime overheads between 0% and 30% as compared to unprotected applications without redundancy. Using our fault injector within RedMPI, we observe that even a single soft error can have profound effects on running applications, causing a cascading pattern of corruption in most cases causes that spreads to all other processes. RedMPI's protection has been shown to successfully mitigate the effects of soft errors while allowing applications to complete with correct results even in the face of errors.« less

Influence of stability of polymer surfactant on oil displacement mechanism

NASA Astrophysics Data System (ADS)

Liu, Li; Li, Chengliang; Pi, Yanming; Wu, Di; He, Ying; Geng, Liang

2018-02-01

At present, most of the oilfields of China have entered the late stage of high water-cut development, and three oil recovery technique has become the leading technology for improving oil recovery. With the improvement of three oil recovery techniques, the polymer surfactant flooding technology has been widely promoted in oil fields in recent years. But in the actual field experiment, it has been found that the polymer surfactant has chromatographic separation at the extraction end, which indicates that the property of the polymer surfactant has changed during the displacement process. At present, there was few literature about how the stability of polymer surfactant affects the oil displacement mechanism. This paper used HuaDing-I polymer surfactant to conduct a micro photolithography glass flooding experiment, and then compared the oil displacement law of polymer surfactant before and after static setting. Finally, the influence law of stability of polymer surfactant on the oil displacement mechanism is obtained by comprehensive analysis.

Using WEED to simulate the global wetland distribution in a ESM

NASA Astrophysics Data System (ADS)

Stacke, Tobias; Hagemann, Stefan

2016-04-01

Lakes and wetlands are an important land surface feature. In terms of hydrology, they regulate river discharge, mitigate flood events and constitute a significant surface water storage. Considering physical processes, they link the surface water and energy balances by altering the separation of incoming energy into sensible and latent heat fluxes. Finally, they impact biogeochemical processes and may act as carbon sinks or sources. Most global hydrology and climate models regard wetland extent and properties as constant in time. However, to study interactions between wetlands and different states of climate, it is necessary to implement surface water bodies (thereafter referred to as wetlands) with dynamical behavior into these models. Besides an improved representation of geophysical feedbacks between wetlands, land surface and atmosphere, a dynamical wetland scheme could also provide estimates of soil wetness as input for biogeochemical models, which are used to compute methane production in wetlands. Recently, a model for the representation of wetland extent dynamics (WEED) was developed as part of the hydrology model (MPI-HM) of the Max-Planck-Institute for Meteorology (MPI-M). The WEED scheme computes wetland extent in agreement with the range of observations for the high northern latitudes. It simulates a realistic seasonal cycle which shows sensitivity to northern snow-melt as well as rainy seasons in the tropics. Furthermore, flood peaks in river discharge are mitigated. However, the WEED scheme overestimates wetland extent in the Tropics which might be related to the MPI-HM's simplified potential evapotranspiration computation. In order to overcome this limitation, the WEED scheme is implemented into the MPI-M's land surface model JSBACH. Thus, not only its effect on water fluxes can be investigated but also its impact on the energy cycle, which is not included in the MPI-HM. Furthermore, it will be possible to analyze the physical effects of wetlands in a coupled land-atmosphere simulation. First simulations with JSBACH-WEED show results similar to the MPI-HM simulations. As the next step, the scheme is modified to account for energy cycle relevant issues such as the dynamical alteration of surface albedo as well as the allocation of appropriate thermal properties to the wetlands. In our presentation, we will give an overview on the functionality of the WEED scheme and the effect of wetlands in coupled land-atmosphere simulations.

Implementing the PM Programming Language using MPI and OpenMP - a New Tool for Programming Geophysical Models on Parallel Systems

NASA Astrophysics Data System (ADS)

Bellerby, Tim

2015-04-01

PM (Parallel Models) is a new parallel programming language specifically designed for writing environmental and geophysical models. The language is intended to enable implementers to concentrate on the science behind the model rather than the details of running on parallel hardware. At the same time PM leaves the programmer in control - all parallelisation is explicit and the parallel structure of any given program may be deduced directly from the code. This paper describes a PM implementation based on the Message Passing Interface (MPI) and Open Multi-Processing (OpenMP) standards, looking at issues involved with translating the PM parallelisation model to MPI/OpenMP protocols and considering performance in terms of the competing factors of finer-grained parallelisation and increased communication overhead. In order to maximise portability, the implementation stays within the MPI 1.3 standard as much as possible, with MPI-2 MPI-IO file handling the only significant exception. Moreover, it does not assume a thread-safe implementation of MPI. PM adopts a two-tier abstract representation of parallel hardware. A PM processor is a conceptual unit capable of efficiently executing a set of language tasks, with a complete parallel system consisting of an abstract N-dimensional array of such processors. PM processors may map to single cores executing tasks using cooperative multi-tasking, to multiple cores or even to separate processing nodes, efficiently sharing tasks using algorithms such as work stealing. While tasks may move between hardware elements within a PM processor, they may not move between processors without specific programmer intervention. Tasks are assigned to processors using a nested parallelism approach, building on ideas from Reyes et al. (2009). The main program owns all available processors. When the program enters a parallel statement then either processors are divided out among the newly generated tasks (number of new tasks < number of processors) or tasks are divided out among the available processors (number of tasks > number of processors). Nested parallel statements may further subdivide the processor set owned by a given task. Tasks or processors are distributed evenly by default, but uneven distributions are possible under programmer control. It is also possible to explicitly enable child tasks to migrate within the processor set owned by their parent task, reducing load unbalancing at the potential cost of increased inter-processor message traffic. PM incorporates some programming structures from the earlier MIST language presented at a previous EGU General Assembly, while adopting a significantly different underlying parallelisation model and type system. PM code is available at www.pm-lang.org under an unrestrictive MIT license. Reference Ruymán Reyes, Antonio J. Dorta, Francisco Almeida, Francisco de Sande, 2009. Automatic Hybrid MPI+OpenMP Code Generation with llc, Recent Advances in Parallel Virtual Machine and Message Passing Interface, Lecture Notes in Computer Science Volume 5759, 185-195

Towards quantitative magnetic particle imaging: A comparison with magnetic particle spectroscopy

NASA Astrophysics Data System (ADS)

Paysen, Hendrik; Wells, James; Kosch, Olaf; Steinhoff, Uwe; Trahms, Lutz; Schaeffter, Tobias; Wiekhorst, Frank

2018-05-01

Magnetic Particle Imaging (MPI) is a quantitative imaging modality with promising features for several biomedical applications. Here, we study quantitatively the raw data obtained during MPI measurements. We present a method for the calibration of the MPI scanner output using measurements from a magnetic particle spectrometer (MPS) to yield data in units of magnetic moments. The calibration technique is validated in a simplified MPI mode with a 1D excitation field. Using the calibrated results from MPS and MPI, we determine and compare the detection limits for each system. The detection limits were found to be 5.10-12 Am2 for MPS and 3.6.10-10 Am2 for MPI. Finally, the quantitative information contained in a standard MPI measurement with a 3D excitation is analyzed and compared to the previous results, showing a decrease in signal amplitudes of the odd harmonics related to the case of 1D excitation. We propose physical explanations for all acquired results; and discuss the possible benefits for the improvement of MPI technology.

Performance Analysis of Scientific and Engineering Applications Using MPInside and TAU

NASA Technical Reports Server (NTRS)

Saini, Subhash; Mehrotra, Piyush; Taylor, Kenichi Jun Haeng; Shende, Sameer Suresh; Biswas, Rupak

2010-01-01

In this paper, we present performance analysis of two NASA applications using performance tools like Tuning and Analysis Utilities (TAU) and SGI MPInside. MITgcmUV and OVERFLOW are two production-quality applications used extensively by scientists and engineers at NASA. MITgcmUV is a global ocean simulation model, developed by the Estimating the Circulation and Climate of the Ocean (ECCO) Consortium, for solving the fluid equations of motion using the hydrostatic approximation. OVERFLOW is a general-purpose Navier-Stokes solver for computational fluid dynamics (CFD) problems. Using these tools, we analyze the MPI functions (MPI_Sendrecv, MPI_Bcast, MPI_Reduce, MPI_Allreduce, MPI_Barrier, etc.) with respect to message size of each rank, time consumed by each function, and how ranks communicate. MPI communication is further analyzed by studying the performance of MPI functions used in these two applications as a function of message size and number of cores. Finally, we present the compute time, communication time, and I/O time as a function of the number of cores.

Application of Corrosion- and Fire-Resistant Coating Systems on Buildings 227 and 299 at Rock Island Arsenal

DTIC Science & Technology

2009-08-01

event of a fire. The mesh prevents cracking to the steel substrate, which would reduce the insulating properties of the char. The procedure is as...Top Coats: MPI #9, Exterior Alkyd Enamel , Gloss, MPI Gloss Level 6 (i.e., a semi-gloss) • System 2: o Primer: MPI #23, Surface Tolerant Metal...Metal Primer X X MPI Paint #9 Exterior Alkyd Enamel , Gloss X MPI Paint #94 Exterior Alkyd

Influence of proton-pump inhibitors on stomach wall uptake of 99mTc-tetrofosmin in cadmium-zinc-telluride SPECT myocardial perfusion imaging.

PubMed

Mouden, Mohamed; Rijkee, Karlijn S; Schreuder, Nanno; Timmer, Jorik R; Jager, Pieter L

2015-02-01

Proton-pump inhibitors (PPIs) induce potentially interfering stomach wall activity in single-photon emission computed tomography myocardial perfusion imaging (SPECT-MPI) with technetium-99m ((99m)Tc)-sestamibi. However, no data are available for (99m)Tc-tetrofosmin. We assessed the influence of prolonged (>2 weeks) PPI use on the stomach wall uptake of (99m)Tc-tetrofosmin in patients referred for stress MPI with a cadmium-zinc-telluride-based SPECT camera and its relation with dyspepsia symptoms. Consecutive patients (n=127) underwent a 1-day adenosine stress-first SPECT-MPI with (99m)Tc-tetrofosmin, of whom 54 (43%) patients had been on PPIs for more than 2 weeks. Stomach wall activity was identified on stress SPECT using computed tomographic attenuation maps and was scored using a four-point grading scale into clinically relevant (scores 2 or 3) or nonrelevant (scores 0 or 1).Patients on PPIs had stomach wall uptake more frequently as compared with patients not using PPIs (22 vs. 7%, P=0.017). Dyspepsia was similar in both groups. Prolonged use of PPIs is associated with stomach wall uptake of (99m)Tc-tetrofosmin in stress cadmium-zinc-telluride-SPECT images. Gastric symptoms were not associated with stomach wall uptake.

Integrating MPI and deduplication engines: a software architecture roadmap.

PubMed

Baksi, Dibyendu

2009-03-01

The objective of this paper is to clarify the major concepts related to architecture and design of patient identity management software systems so that an implementor looking to solve a specific integration problem in the context of a Master Patient Index (MPI) and a deduplication engine can address the relevant issues. The ideas presented are illustrated in the context of a reference use case from Integrating the Health Enterprise Patient Identifier Cross-referencing (IHE PIX) profile. Sound software engineering principles using the latest design paradigm of model driven architecture (MDA) are applied to define different views of the architecture. The main contribution of the paper is a clear software architecture roadmap for implementors of patient identity management systems. Conceptual design in terms of static and dynamic views of the interfaces is provided as an example of platform independent model. This makes the roadmap applicable to any specific solutions of MPI, deduplication library or software platform. Stakeholders in need of integration of MPIs and deduplication engines can evaluate vendor specific solutions and software platform technologies in terms of fundamental concepts and can make informed decisions that preserve investment. This also allows freedom from vendor lock-in and the ability to kick-start integration efforts based on a solid architecture.

MPI-Defrost: Extension of Defrost to MPI-based Cluster Environment

NASA Astrophysics Data System (ADS)

Amin, Mustafa A.; Easther, Richard; Finkel, Hal

2011-06-01

MPI-Defrost extends Frolov’s Defrost to an MPI-based cluster environment. This version has been restricted to a single field. Restoring two-field support should be straightforward, but will require some code changes. Some output options may also not be fully supported under MPI. This code was produced to support our own work, and has been made available for the benefit of anyone interested in either oscillon simulations or an MPI capable version of Defrost, and it is provided on an "as-is" basis. Andrei Frolov is the primary developer of Defrost and we thank him for placing his work under the GPL (GNU Public License), and thus allowing us to distribute this modified version.

Impact of the implementation of MPI point-to-point communications on the performance of two general sparse solvers

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

Amestoy, Patrick R.; Duff, Iain S.; L'Excellent, Jean-Yves

2001-10-10

We examine the mechanics of the send and receive mechanism of MPI and in particular how we can implement message passing in a robust way so that our performance is not significantly affected by changes to the MPI system. This leads us to using the Isend/Irecv protocol which will entail sometimes significant algorithmic changes. We discuss this within the context of two different algorithms for sparse Gaussian elimination that we have parallelized. One is a multifrontal solver called MUMPS, the other is a supernodal solver called SuperLU. Both algorithms are difficult to parallelize on distributed memory machines. Our initial strategiesmore » were based on simple MPI point-to-point communication primitives. With such approaches, the parallel performance of both codes are very sensitive to the MPI implementation, the way MPI internal buffers are used in particular. We then modified our codes to use more sophisticated nonblocking versions of MPI communication. This significantly improved the performance robustness (independent of the MPI buffering mechanism) and scalability, but at the cost of increased code complexity.« less

On the Suitability of MPI as a PGAS Runtime

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

Daily, Jeffrey A.; Vishnu, Abhinav; Palmer, Bruce J.

2014-12-18

Partitioned Global Address Space (PGAS) models are emerging as a popular alternative to MPI models for designing scalable applications. At the same time, MPI remains a ubiquitous communication subsystem due to its standardization, high performance, and availability on leading platforms. In this paper, we explore the suitability of using MPI as a scalable PGAS communication subsystem. We focus on the Remote Memory Access (RMA) communication in PGAS models which typically includes {\\em get, put,} and {\\em atomic memory operations}. We perform an in-depth exploration of design alternatives based on MPI. These alternatives include using a semantically-matching interface such as MPI-RMA,more » as well as not-so-intuitive interfaces such as MPI two-sided with a combination of multi-threading and dynamic process management. With an in-depth exploration of these alternatives and their shortcomings, we propose a novel design which is facilitated by the data-centric view in PGAS models. This design leverages a combination of highly tuned MPI two-sided semantics and an automatic, user-transparent split of MPI communicators to provide asynchronous progress. We implement the asynchronous progress ranks approach and other approaches within the Communication Runtime for Exascale which is a communication subsystem for Global Arrays. Our performance evaluation spans pure communication benchmarks, graph community detection and sparse matrix-vector multiplication kernels, and a computational chemistry application. The utility of our proposed PR-based approach is demonstrated by a 2.17x speed-up on 1008 processors over the other MPI-based designs.« less

Magnetic Particle Imaging for Real-Time Perfusion Imaging in Acute Stroke.

PubMed

Ludewig, Peter; Gdaniec, Nadine; Sedlacik, Jan; Forkert, Nils D; Szwargulski, Patryk; Graeser, Matthias; Adam, Gerhard; Kaul, Michael G; Krishnan, Kannan M; Ferguson, R Matthew; Khandhar, Amit P; Walczak, Piotr; Fiehler, Jens; Thomalla, Götz; Gerloff, Christian; Knopp, Tobias; Magnus, Tim

2017-10-24

The fast and accurate assessment of cerebral perfusion is fundamental for the diagnosis and successful treatment of stroke patients. Magnetic particle imaging (MPI) is a new radiation-free tomographic imaging method with a superior temporal resolution, compared to other conventional imaging methods. In addition, MPI scanners can be built as prehospital mobile devices, which require less complex infrastructure than computed tomography (CT) and magnetic resonance imaging (MRI). With these advantages, MPI could accelerate the stroke diagnosis and treatment, thereby improving outcomes. Our objective was to investigate the capabilities of MPI to detect perfusion deficits in a murine model of ischemic stroke. Cerebral ischemia was induced by inserting of a microfilament in the internal carotid artery in C57BL/6 mice, thereby blocking the blood flow into the medial cerebral artery. After the injection of a contrast agent (superparamagnetic iron oxide nanoparticles) specifically tailored for MPI, cerebral perfusion and vascular anatomy were assessed by the MPI scanner within seconds. To validate and compare our MPI data, we performed perfusion imaging with a small animal MRI scanner. MPI detected the perfusion deficits in the ischemic brain, which were comparable to those with MRI but in real-time. For the first time, we showed that MPI could be used as a diagnostic tool for relevant diseases in vivo, such as an ischemic stroke. Due to its shorter image acquisition times and increased temporal resolution compared to that of MRI or CT, we expect that MPI offers the potential to improve stroke imaging and treatment.

Magnetic Particle / Magnetic Resonance Imaging: In-Vitro MPI-Guided Real Time Catheter Tracking and 4D Angioplasty Using a Road Map and Blood Pool Tracer Approach.

PubMed

Salamon, Johannes; Hofmann, Martin; Jung, Caroline; Kaul, Michael Gerhard; Werner, Franziska; Them, Kolja; Reimer, Rudolph; Nielsen, Peter; Vom Scheidt, Annika; Adam, Gerhard; Knopp, Tobias; Ittrich, Harald

2016-01-01

In-vitro evaluation of the feasibility of 4D real time tracking of endovascular devices and stenosis treatment with a magnetic particle imaging (MPI) / magnetic resonance imaging (MRI) road map approach and an MPI-guided approach using a blood pool tracer. A guide wire and angioplasty-catheter were labeled with a thin layer of magnetic lacquer. For real time MPI a custom made software framework was developed. A stenotic vessel phantom filled with saline or superparamagnetic iron oxide nanoparticles (MM4) was equipped with bimodal fiducial markers for co-registration in preclinical 7T MRI and MPI. In-vitro angioplasty was performed inflating the balloon with saline or MM4. MPI data were acquired using a field of view of 37.3×37.3×18.6 mm3 and a frame rate of 46 volumes/sec. Analysis of the magnetic lacquer-marks on the devices were performed with electron microscopy, atomic absorption spectrometry and micro-computed tomography. Magnetic marks allowed for MPI/MRI guidance of interventional devices. Bimodal fiducial markers enable MPI/MRI image fusion for MRI based roadmapping. MRI roadmapping and the blood pool tracer approach facilitate MPI real time monitoring of in-vitro angioplasty. Successful angioplasty was verified with MPI and MRI. Magnetic marks consist of micrometer sized ferromagnetic plates mainly composed of iron and iron oxide. 4D real time MP imaging, tracking and guiding of endovascular instruments and in-vitro angioplasty is feasible. In addition to an approach that requires a blood pool tracer, MRI based roadmapping might emerge as a promising tool for radiation free 4D MPI-guided interventions.

MPI as high temporal resolution imaging technique for in vivo bolus tracking of Ferucarbotran in mouse model

NASA Astrophysics Data System (ADS)

Jung, C.; Salamon, J.; Hofmann, M.; Kaul, M. G.; Adam, G.; Ittrich, H.; Knopp, T.

2016-03-01

Purpose: The goal of this study was to achieve a real time 3D visualisation of the murine cardiovascular system by intravenously injected superparamagnetic nanoparticles using Magnetic particle imaging (MPI). Material and Methods: MPI scans of FVB mice were performed using a 3D imaging sequence (1T/m gradient strength, 10mT drive-field strength). A dynamic scan with a temporal resolution of 21.5ms per 3D volume acquisition was performed. 50μl ferucarbotran (Resovist®, Bayer Healthcare AG) were injected into the tail vein after baseline MPI measurements. As MPI delivers no anatomic information, MRI scans at a 7T ClinScan (Bruker) were performed using a T2-weighted 2D TSE sequence. The reconstruction of the MPI data was performed on the MPI console (ParaVision 6.0/MPI, Bruker). Image fusion was done using additional image processing software (Imalytics, Philips). The dynamic information was extracted using custom software developed in the Julia programming environment. Results: The combined MRI-MPI measurements were carried out successfully. MPI data clearly demonstrated the passage of the SPIO tracer through the inferior vena cava, the heart and finally the liver. By co-registration with MRI the anatomical regions were identified. Due to the volume frame rate of about 46 volumes per second a signal modulation with the frequency of the heart beat was detectable and a heart beat of 520 beats per minute (bpm) has been assumed. Moreover, the blood flow velocity of approximately 5cm/s in the vena cava has been estimated. Conclusions: The high temporal resolution of MPI allows real-time imaging and bolus tracking of intravenous injected nanoparticles and offers a real time tool to assess blood flow velocity.

Children's judgements of social withdrawal behaviours.

PubMed

Watling, Dawn

2015-06-01

Ding et al. (Brit. J. Dev. Psychol., 2015; 33, 159-173) demonstrated that Chinese children discriminate between the three subtypes of social withdrawal: Shyness, unsociability, and social avoidance. This commentary on the Ding et al.'s paper highlights the need to further explore the following: (1) children's understanding of the implications of being shy, unsociable, or socially avoidant, including assessing these which we know are associated with outcomes for socially withdrawn children; (2) what additional subtypes might exist naturally within the Chinese culture; and (3) consider the implications of social withdrawal on children's developing social skills. © 2015 The British Psychological Society.

Optimizing Blocking and Nonblocking Reduction Operations for Multicore Systems: Hierarchical Design and Implementation

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

Gorentla Venkata, Manjunath; Shamis, Pavel; Graham, Richard L

2013-01-01

Many scientific simulations, using the Message Passing Interface (MPI) programming model, are sensitive to the performance and scalability of reduction collective operations such as MPI Allreduce and MPI Reduce. These operations are the most widely used abstractions to perform mathematical operations over all processes that are part of the simulation. In this work, we propose a hierarchical design to implement the reduction operations on multicore systems. This design aims to improve the efficiency of reductions by 1) tailoring the algorithms and customizing the implementations for various communication mechanisms in the system 2) providing the ability to configure the depth ofmore » hierarchy to match the system architecture, and 3) providing the ability to independently progress each of this hierarchy. Using this design, we implement MPI Allreduce and MPI Reduce operations (and its nonblocking variants MPI Iallreduce and MPI Ireduce) for all message sizes, and evaluate on multiple architectures including InfiniBand and Cray XT5. We leverage and enhance our existing infrastructure, Cheetah, which is a framework for implementing hierarchical collective operations to implement these reductions. The experimental results show that the Cheetah reduction operations outperform the production-grade MPI implementations such as Open MPI default, Cray MPI, and MVAPICH2, demonstrating its efficiency, flexibility and portability. On Infini- Band systems, with a microbenchmark, a 512-process Cheetah nonblocking Allreduce and Reduce achieves a speedup of 23x and 10x, respectively, compared to the default Open MPI reductions. The blocking variants of the reduction operations also show similar performance benefits. A 512-process nonblocking Cheetah Allreduce achieves a speedup of 3x, compared to the default MVAPICH2 Allreduce implementation. On a Cray XT5 system, a 6144-process Cheetah Allreduce outperforms the Cray MPI by 145%. The evaluation with an application kernel, Conjugate Gradient solver, shows that the Cheetah reductions speeds up total time to solution by 195%, demonstrating the potential benefits for scientific simulations.« less

Google Test MPI Listener

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

Oxberry, Geoffrey

Google Test MPI Listener is a plugin for the Google Test c++ unit testing library that organizes test output of software that uses both the MPI parallel programming model and Google Test. Typically, such output is ordered arbitrarily and disorganized, making difficult the process of interpreting test output. This plug organizes output in MPI rank order, enabling easy interpretation of test results.

Final report: Compiled MPI. Cost-Effective Exascale Application Development

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

Gropp, William Douglas

2015-12-21

This is the final report on Compiled MPI: Cost-Effective Exascale Application Development, and summarizes the results under this project. The project investigated runtime enviroments that improve the performance of MPI (Message-Passing Interface) programs; work at Illinois in the last period of this project looked at optimizing data access optimizations expressed with MPI datatypes.

SBML-PET-MPI: a parallel parameter estimation tool for Systems Biology Markup Language based models.

PubMed

Zi, Zhike

2011-04-01

Parameter estimation is crucial for the modeling and dynamic analysis of biological systems. However, implementing parameter estimation is time consuming and computationally demanding. Here, we introduced a parallel parameter estimation tool for Systems Biology Markup Language (SBML)-based models (SBML-PET-MPI). SBML-PET-MPI allows the user to perform parameter estimation and parameter uncertainty analysis by collectively fitting multiple experimental datasets. The tool is developed and parallelized using the message passing interface (MPI) protocol, which provides good scalability with the number of processors. SBML-PET-MPI is freely available for non-commercial use at http://www.bioss.uni-freiburg.de/cms/sbml-pet-mpi.html or http://sites.google.com/site/sbmlpetmpi/.

Use of carbonated water in reduction of adjacent gastric activity in 456 consecutive technetium-99m myocardial perfusion imaging studies.

PubMed

Thomas, Dustin M; Lee, Joshua S; Charmforoush, Anthony; Rubal, Bernard J; Rosenblatt, Stephen A; Butler, Joshua T; Clemenshaw, Michael; Cheezum, Michael K; Slim, Ahmad M

2015-12-01

Small, observational trials have suggested a reduction in adjacent gastric activity with ingestion of soda water in myocardial perfusion imaging (MPI). We report our findings prior to and after implementation of soda water in 467 consecutive MPI studies. Consecutive MPI studies performed at a high-volume facility referred for vasodilator (VD) or exercise treadmill testing (ETT) were retrospectively reviewed before and after implementation of the soda water protocol. Patients undergoing the soda water protocol received 100 ml of soda water administered 30 min prior to image acquisition and after stress. Studies were performed using a same day rest/stress protocol. Incidence of adjacent gastric activity, diaphragmatic attenuation, stress and rest perfusion defects, and major adverse cardiovascular events (MACE) outcomes defined as death, myocardial infarction, stroke, reevaluation for chest pain, and late revascularization (>90 days from MPI) were abstracted using International Classification of Diseases, Ninth Revision (ICD-9) search. Two hundred and eighteen studies were performed prior to implementation of the soda water protocol and 249 studies were performed with the use of soda water. Baseline demographic data were equal between the groups with the exception of more patients undergoing VD stress receiving soda water (p < 0.001). Soda water was not associated with a decreased incidence of adjacent gastric activity with stress (54.7% versus 61.9% with no soda water, p = 0.129) or rest (68.6% versus 69.5% with no soda water, p = 0.919) imaging. Less adjacent gastric activity was observed with patients undergoing ETT who received soda water (42.5% versus 56.9% with no soda water, p = 0.031), but no difference was observed between the groups with VD stress (69.0% versus 68.1% with no soda water, p = 1.000). The use of soda water prior to technetium-99m MPI was associated with lower rates of adjacent gastric activity only in patients undergoing ETT stress but not rest or VD stress. This differs from previously published data. © The Author(s), 2015.

Psychometric evaluation of the Spanish version of the MPI-SCI.

PubMed

Soler, M D; Cruz-Almeida, Y; Saurí, J; Widerström-Noga, E G

2013-07-01

Postal surveys. To confirm the factor structure of the Spanish version of the MPI-SCI (MPI-SCI-S, Multidimensional Pain Inventory in the SCI population) and to test its internal consistency and construct validity in a Spanish population. Guttmann Institute, Barcelona, Spain. The MPI-SCI-S along with Spanish measures of pain intensity (Numerical Rating Scale), pain interference (Brief Pain Inventory), functional independence (Functional Independence Measure), depression (Beck Depression Inventory), locus of control (Multidimensional health Locus of Control), support (Functional Social Support Questionnaire (Duke-UNC)), psychological well-being (Psychological Global Well-Being Index) and demographic/injury characteristics were assessed in persons with spinal cord injury (SCI) and chronic pain (n=126). Confirmatory factor analysis suggested an adequate factor structure for the MPI-SCI-S. The internal consistency of the MPI-SCI-S subscales ranged from acceptable (r=0.66, Life Control) to excellent (r=0.94, Life Interference). All MPI-SCI-S subscales showed adequate construct validity, with the exception of the Negative and Solicitous Responses subscales. The Spanish version of the MPI-SCI is adequate for evaluating chronic pain impact following SCI in a Spanish-speaking population. Future studies should include additional measures of pain-related support in the Spanish-speaking SCI population.

Relaxation in x-space magnetic particle imaging.

PubMed

Croft, Laura R; Goodwill, Patrick W; Conolly, Steven M

2012-12-01

Magnetic particle imaging (MPI) is a new imaging modality that noninvasively images the spatial distribution of superparamagnetic iron oxide nanoparticles (SPIOs). MPI has demonstrated high contrast and zero attenuation with depth, and MPI promises superior safety compared to current angiography methods, X-ray, computed tomography, and magnetic resonance imaging angiography. Nanoparticle relaxation can delay the SPIO magnetization, and in this work we investigate the open problem of the role relaxation plays in MPI scanning and its effect on the image. We begin by amending the x-space theory of MPI to include nanoparticle relaxation effects. We then validate the amended theory with experiments from a Berkeley x-space relaxometer and a Berkeley x-space projection MPI scanner. Our theory and experimental data indicate that relaxation reduces SNR and asymmetrically blurs the image in the scanning direction. While relaxation effects can have deleterious effects on the MPI scan, we show theoretically and experimentally that x-space reconstruction remains robust in the presence of relaxation. Furthermore, the role of relaxation in x-space theory provides guidance as we develop methods to minimize relaxation-induced blurring. This will be an important future area of research for the MPI community.

False-positive defects on exercise 99mTc-sestamibi SPECT imaging, but not on dipyridamole 99mTc-sestamibi SPECT imaging, in a patient with right bundle branch block (RBBB).

PubMed

Javadi, Hamid; Jallalat, Sara; Semnani, Shahriar; Mogharrabi, Mehdi; Nabipour, Iraj; Abbaszadeh, Moloud; Assadi, Majid

2013-01-01

False-positive findings with myocardial perfusion imaging (MPI) have frequently been identified in the presence of left bundle branch block (LBBB) and tend to lower the accuracy of MPI in individuals with normal coronary angiographs. Pharmacologic stress is recognized as the preferred method for MPI in patients with LBBB. In contrast, very few studies have evaluated the effect of right bundle branch block (RBBB) on MPI, and there is no consensus regarding the selection of pharmacologic versus exercise stress during MPI for the RBBB patient. In this study, we present a 45-year-old man with RBBB, who has a normal coronary artery angiography, but who showed abnormal myocardial perfusion with exercise MPI, and normal perfusion on dipyridamole MPI. The aim of the study is to stimulate awareness that the stress method selected for patients with RBBB can potentially interfere with the accuracy of the data.

Collective Framework and Performance Optimizations to Open MPI for Cray XT Platforms

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

Ladd, Joshua S; Gorentla Venkata, Manjunath; Shamis, Pavel

2011-01-01

The performance and scalability of collective operations plays a key role in the performance and scalability of many scientific applications. Within the Open MPI code base we have developed a general purpose hierarchical collective operations framework called Cheetah, and applied it at large scale on the Oak Ridge Leadership Computing Facility's Jaguar (OLCF) platform, obtaining better performance and scalability than the native MPI implementation. This paper discuss Cheetah's design and implementation, and optimizations to the framework for Cray XT 5 platforms. Our results show that the Cheetah's Broadcast and Barrier perform better than the native MPI implementation. For medium data,more » the Cheetah's Broadcast outperforms the native MPI implementation by 93% for 49,152 processes problem size. For small and large data, it out performs the native MPI implementation by 10% and 9%, respectively, at 24,576 processes problem size. The Cheetah's Barrier performs 10% better than the native MPI implementation for 12,288 processes problem size.« less

MPI_XSTAR: MPI-based parallelization of XSTAR program

NASA Astrophysics Data System (ADS)

Danehkar, A.

2017-12-01

MPI_XSTAR parallelizes execution of multiple XSTAR runs using Message Passing Interface (MPI). XSTAR (ascl:9910.008), part of the HEASARC's HEAsoft (ascl:1408.004) package, calculates the physical conditions and emission spectra of ionized gases. MPI_XSTAR invokes XSTINITABLE from HEASoft to generate a job list of XSTAR commands for given physical parameters. The job list is used to make directories in ascending order, where each individual XSTAR is spawned on each processor and outputs are saved. HEASoft's XSTAR2TABLE program is invoked upon the contents of each directory in order to produce table model FITS files for spectroscopy analysis tools.

Mycobacterium tuberculosis Infection and Innate Responses in a New Model of Lung Alveolar Macrophages.

PubMed

Woo, Minjeong; Wood, Connor; Kwon, Doyoon; Park, Kyu-Ho Paul; Fejer, György; Delorme, Vincent

2018-01-01

Lung alveolar macrophages (AMs) are in the first line of immune defense against respiratory pathogens and play key roles in the pathogenesis of Mycobacterium tuberculosis ( Mtb ) in humans. Nevertheless, AMs are available only in limited amounts for in vitro studies, which hamper the detailed molecular understanding of host- Mtb interactions in these macrophages. The recent establishment of the self-renewing and primary Max Planck Institute (MPI) cells, functionally very close to lung AMs, opens unique opportunities for in vitro studies of host-pathogen interactions in respiratory diseases. Here, we investigated the suitability of MPI cells as a host cell system for Mtb infection. Bacterial, cellular, and innate immune features of MPI cells infected with Mtb were characterized. Live bacteria were readily internalized and efficiently replicated in MPI cells, similarly to primary murine macrophages and other cell lines. MPI cells were also suitable for the determination of anti-tuberculosis (TB) drug activity. The primary innate immune response of MPI cells to live Mtb showed significantly higher and earlier induction of the pro-inflammatory cytokines TNFα, interleukin 6 (IL-6), IL-1α, and IL-1β, as compared to stimulation with heat-killed (HK) bacteria. MPI cells previously showed a lack of induction of the anti-inflammatory cytokine IL-10 to a wide range of stimuli, including HK Mtb . By contrast, we show here that live Mtb is able to induce significant amounts of IL-10 in MPI cells. Autophagy experiments using light chain 3B immunostaining, as well as LysoTracker labeling of acidic vacuoles, demonstrated that MPI cells efficiently control killed Mtb by elimination through phagolysosomes. MPI cells were also able to accumulate lipid droplets in their cytoplasm following exposure to lipoproteins. Collectively, this study establishes the MPI cells as a relevant, versatile host cell model for TB research, allowing a deeper understanding of AMs functions in this pathology.

Mathematical analysis of the 1D model and reconstruction schemes for magnetic particle imaging

NASA Astrophysics Data System (ADS)

Erb, W.; Weinmann, A.; Ahlborg, M.; Brandt, C.; Bringout, G.; Buzug, T. M.; Frikel, J.; Kaethner, C.; Knopp, T.; März, T.; Möddel, M.; Storath, M.; Weber, A.

2018-05-01

Magnetic particle imaging (MPI) is a promising new in vivo medical imaging modality in which distributions of super-paramagnetic nanoparticles are tracked based on their response in an applied magnetic field. In this paper we provide a mathematical analysis of the modeled MPI operator in the univariate situation. We provide a Hilbert space setup, in which the MPI operator is decomposed into simple building blocks and in which these building blocks are analyzed with respect to their mathematical properties. In turn, we obtain an analysis of the MPI forward operator and, in particular, of its ill-posedness properties. We further get that the singular values of the MPI core operator decrease exponentially. We complement our analytic results by some numerical studies which, in particular, suggest a rapid decay of the singular values of the MPI operator.

Value of automatic patient motion detection and correction in myocardial perfusion imaging using a CZT-based SPECT camera.

PubMed

van Dijk, Joris D; van Dalen, Jorn A; Mouden, Mohamed; Ottervanger, Jan Paul; Knollema, Siert; Slump, Cornelis H; Jager, Pieter L

2018-04-01

Correction of motion has become feasible on cadmium-zinc-telluride (CZT)-based SPECT cameras during myocardial perfusion imaging (MPI). Our aim was to quantify the motion and to determine the value of automatic correction using commercially available software. We retrospectively included 83 consecutive patients who underwent stress-rest MPI CZT-SPECT and invasive fractional flow reserve (FFR) measurement. Eight-minute stress acquisitions were reformatted into 1.0- and 20-second bins to detect respiratory motion (RM) and patient motion (PM), respectively. RM and PM were quantified and scans were automatically corrected. Total perfusion deficit (TPD) and SPECT interpretation-normal, equivocal, or abnormal-were compared between the noncorrected and corrected scans. Scans with a changed SPECT interpretation were compared with FFR, the reference standard. Average RM was 2.5 ± 0.4 mm and maximal PM was 4.5 ± 1.3 mm. RM correction influenced the diagnostic outcomes in two patients based on TPD changes ≥7% and in nine patients based on changed visual interpretation. In only four of these patients, the changed SPECT interpretation corresponded with FFR measurements. Correction for PM did not influence the diagnostic outcomes. Respiratory motion and patient motion were small. Motion correction did not appear to improve the diagnostic outcome and, hence, the added value seems limited in MPI using CZT-based SPECT cameras.

Temperature dependence in magnetic particle imaging

NASA Astrophysics Data System (ADS)

Wells, James; Paysen, Hendrik; Kosch, Olaf; Trahms, Lutz; Wiekhorst, Frank

2018-05-01

Experimental results are presented demonstrating how temperature can influence the dynamics of magnetic nanoparticles (MNPs) in liquid suspension, when exposed to alternating magnetic fields in the kilohertz frequency range. The measurements used to probe the nanoparticle systems are directly linked to both the emerging biomedical technique of magnetic particle imaging (MPI), and to the recently proposed concept of remote nanoscale thermometry using MNPs under AC field excitation. Here, we report measurements on three common types of MNPs, two of which are currently leading candidates for use as tracers in MPI. Using highly-sensitive magnetic particle spectroscopy (MPS), we demonstrate significant and divergent thermal dependences in several key measures used in the evaluation of MNP dynamics for use in MPI and other applications. The temperature range studied was between 296 and 318 Kelvin, making our findings of particular importance for MPI and other biomedical technologies. Furthermore, we report the detection of the same temperature dependences in measurements conducted using the detection coils within an operational preclinical MPI scanner. This clearly shows the importance of considering temperature during MPI development, and the potential for temperature-resolved MPI using this system. We propose possible physical explanations for the differences in the behaviors observed between the different particle types, and discuss our results in terms of the opportunities and concerns they raise for MPI and other MNP based technologies.

Enhancing Application Performance Using Mini-Apps: Comparison of Hybrid Parallel Programming Paradigms

NASA Technical Reports Server (NTRS)

Lawson, Gary; Poteat, Michael; Sosonkina, Masha; Baurle, Robert; Hammond, Dana

2016-01-01

In this work, several mini-apps have been created to enhance a real-world application performance, namely the VULCAN code for complex flow analysis developed at the NASA Langley Research Center. These mini-apps explore hybrid parallel programming paradigms with Message Passing Interface (MPI) for distributed memory access and either Shared MPI (SMPI) or OpenMP for shared memory accesses. Performance testing shows that MPI+SMPI yields the best execution performance, while requiring the largest number of code changes. A maximum speedup of 23X was measured for MPI+SMPI, but only 10X was measured for MPI+OpenMP.

Effect of central hypothyroidism on Doppler-derived myocardial performance index.

PubMed

Doin, Fabio Luiz Casanova; Borges, Mariana da Rosa; Campos, Orlando; de Camargo Carvalho, Antonio Carlos; de Paola, Angelo Amato Vincenzo; Paiva, Marcelo Goulart; Abucham, Julio; Moises, Valdir Ambrosio

2004-06-01

Myocardial performance index (MPI) has been used to assess global ventricular function in different types of cardiac disease. Thyroid hormones influence cardiac performance directly and indirectly by changes in peripheral circulation. The aim of this study was to evaluate the possible effect of central hypothyroidism (CH) on MPI. The study included 28 control subjects and 7 patients with CH without cardiac disease. MPI was defined as the sum of isovolumetric contraction time (ICT) and isovolumetric relaxation time divided by ejection time. Patients were submitted to hormonal therapy with thyroxin and the study was repeated after 35 to 42 days. MPI was significantly higher in patients with CH (0.54 +/- 0.08) than in control subjects (0.40 +/- 0.05) (P =.002). The increase in MPI was caused by the prolongation of ICT without a significant variation of isovolumetric relaxation time and ejection time. After hormonal therapy there was a significant reduction of MPI (0.54 +/- 0.08 vs 0.42 +/- 0.07; P =.028) and ICT. MPI was increased in patients with untreated CH. The increase was related to prolongation of ICT and reverted by hormonal therapy.

Budget impact of applying appropriateness criteria for myocardial perfusion scintigraphy: The perspective of a developing country.

PubMed

Dos Santos, Mauro Augusto; Santos, Marisa Silva; Tura, Bernardo Rangel; Félix, Renata; Brito, Adriana Soares X; De Lorenzo, Andrea

2016-10-01

Myocardial perfusion imaging is widely used for the risk stratification of coronary artery disease. In view of its cost, besides radiation issues, judicious evaluation of the appropriateness of its indications is essential to prevent an unnecessary economic burden on the health system. We evaluated, at a tertiary-care, public Brazilian hospital, the appropriateness of myocardial perfusion scintigraphy indications, and estimated the budget impact of applying appropriateness criteria. An observational, cross-sectional study of 190 patients with suspected or known coronary artery disease referred for myocardial perfusion imaging was conducted. The appropriateness of myocardial perfusion imaging indications was evaluated with the Appropriate Use Criteria for Cardiac Radionuclide Imaging published in 2009. Budget impact analysis was performed with a deterministic model. The prevalence of appropriate requests was 78%; of inappropriate indications, 12%; and of uncertain indications, 10%. Budget impact analysis showed that the use of appropriateness criteria, applied to the population referred to myocardial perfusion scintigraphy within 1 year, could generate savings of $ 64,252.04 dollars. The 12% inappropriate requests for myocardial perfusion scintigraphy at a tertiary-care hospital suggest that a reappraisal of MPI indications is needed. Budget impact analysis estimated resource savings of 18.6% with the establishment of appropriateness criteria for MPI.

Determination of trichloroethylene by using self-referenced SERS and gold-core/silver-shell nanoparticles.

PubMed

Yu, Zhao; Smith, Michael E; Zhang, Jinnan; Zhou, Yan; Zhang, Peng

2018-06-18

A surface-enhanced Raman scattering (SERS) method has been developed to determine the concentration of trichloroethylene (TCE) in environmental water. Au-core/Ag-shell nanoparticles containing 4-mercaptophenylboronic acid (4-MPBA) between the core and shell are used as the SERS substrate. 4-MPBA serves as an internal reference with a Raman shift at 534 cm -1 . TCE reacts with 4-mercaptopyridine (4-MPy) in a so-called Fujiwara reaction. With the presence of TCE in water, the consumption of 4-MPy results in a change in the intensity of its Raman signal at 1220 cm -1 . The ratio of the Raman shift at 1220 cm -1 and 534 cm -1 decreases linearly in the 0.2 to 1.0 μM TCE concentration range, and the detection limit of TCE is as low as 8 ppb (60 nM). The method has been successfully applied to the determination of TCE in spiked lake water. Graphical abstract Gold-core/silver-shell nanoparticles with internal reference embedded have been fabracated to improve the quantitative measurement of SERS. These nanoparticles as SERS substrates, are used to indirectly quantify the concentration of trichloroethylene (a typical halogenated organic compound) by the consumption of 4-mercaptopyridine through the Fujiwara reaction.

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

Sayan Ghosh, Jeff Hammond

OpenSHMEM is a community effort to unifyt and standardize the SHMEM programming model. MPI (Message Passing Interface) is a well-known community standard for parallel programming using distributed memory. The most recen t release of MPI, version 3.0, was designed in part to support programming models like SHMEM.OSHMPI is an implementation of the OpenSHMEM standard using MPI-3 for the Linux operating system. It is the first implementation of SHMEM over MPI one-sided communication and has the potential to be widely adopted due to the portability and widely availability of Linux and MPI-3. OSHMPI has been tested on a variety of systemsmore » and implementations of MPI-3, includingInfiniBand clusters using MVAPICH2 and SGI shared-memory supercomputers using MPICH. Current support is limited to Linux but may be extended to Apple OSX if there is sufficient interest. The code is opensource via https://github.com/jeffhammond/oshmpi« less

The Assessment and Potential Implications of the Myocardial Performance Index Post Exercise in an at Risk Population.

PubMed

Ruisi, Michael; Levine, Michael; Finkielstein, Dennis

2013-12-01

The myocardial performance index (MPI) first described by Chuwa Tei in 1995 is a relatively new echocardiographic variable used for assessment of overall cardiac function. Previous studies have demonstrated the MPI to be a sum representation of both left ventricular systolic and diastolic function with prognostic value in patients with coronary artery disease as well as symptomatic heart failure. Ninety patients with either established coronary artery disease (CAD) or CAD risk factors underwent routine treadmill exercise stress testing with two-dimensional Doppler echocardiography using the standard Bruce protocol. Both resting and stress MPI values were measured for all 90 of the patients. Using a normal MPI cut off of ≤ 0.47, the prevalence of an abnormal resting MPI in our 90 subjects was 72/90 or 80% and the prevalence of an abnormal stress MPI in our 90 subjects was 48/90 or 53.33%. The average MPI observed in the resting portion of the stress test for the cohort was: 0.636 with a standard deviation of 0.182. The average MPI in the stress portion of the stress test for the cohort was 0.530 with a standard deviation of 0.250. The P value with the use of a one-tailed dependent T test was calculated to be < 0.05. We postulate that these findings reflect that the MPI (Tei) index assessed during exercise may be a sensitive indicator of occult coronary disease in an at risk group independent of wall motion assessment.

Modified personal interviews: resurrecting reliable personal interviews for admissions?

PubMed

Hanson, Mark D; Kulasegaram, Kulamakan Mahan; Woods, Nicole N; Fechtig, Lindsey; Anderson, Geoff

2012-10-01

Traditional admissions personal interviews provide flexible faculty-student interactions but are plagued by low inter-interview reliability. Axelson and Kreiter (2009) retrospectively showed that multiple independent sampling (MIS) may improve reliability of personal interviews; thus, the authors incorporated MIS into the admissions process for medical students applying to the University of Toronto's Leadership Education and Development Program (LEAD). They examined the reliability and resource demands of this modified personal interview (MPI) format. In 2010-2011, LEAD candidates submitted written applications, which were used to screen for participation in the MPI process. Selected candidates completed four brief (10-12 minutes) independent MPIs each with a different interviewer. The authors blueprinted MPI questions to (i.e., aligned them with) leadership attributes, and interviewers assessed candidates' eligibility on a five-point Likert-type scale. The authors analyzed inter-interview reliability using the generalizability theory. Sixteen candidates submitted applications; 10 proceeded to the MPI stage. Reliability of the written application components was 0.75. The MPI process had overall inter-interview reliability of 0.79. Correlation between the written application and MPI scores was 0.49. A decision study showed acceptable reliability of 0.74 with only three MPIs scored using one global rating. Furthermore, a traditional admissions interview format would take 66% more time than the MPI format. The MPI format, used during the LEAD admissions process, achieved high reliability with minimal faculty resources. The MPI format's reliability and effective resource use were possible through MIS and employment of expert interviewers. MPIs may be useful for other admissions tasks.

Design analysis of an MPI human functional brain scanner

PubMed Central

Mason, Erica E.; Cooley, Clarissa Z.; Cauley, Stephen F.; Griswold, Mark A.; Conolly, Steven M.; Wald, Lawrence L.

2017-01-01

MPI’s high sensitivity makes it a promising modality for imaging brain function. Functional contrast is proposed based on blood SPION concentration changes due to Cerebral Blood Volume (CBV) increases during activation, a mechanism utilized in fMRI studies. MPI offers the potential for a direct and more sensitive measure of SPION concentration, and thus CBV, than fMRI. As such, fMPI could surpass fMRI in sensitivity, enhancing the scientific and clinical value of functional imaging. As human-sized MPI systems have not been attempted, we assess the technical challenges of scaling MPI from rodent to human brain. We use a full-system MPI simulator to test arbitrary hardware designs and encoding practices, and we examine tradeoffs imposed by constraints that arise when scaling to human size as well as safety constraints (PNS and central nervous system stimulation) not considered in animal scanners, thereby estimating spatial resolutions and sensitivities achievable with current technology. Using a projection FFL MPI system, we examine coil hardware options and their implications for sensitivity and spatial resolution. We estimate that an fMPI brain scanner is feasible, although with reduced sensitivity (20×) and spatial resolution (5×) compared to existing rodent systems. Nonetheless, it retains sufficient sensitivity and spatial resolution to make it an attractive future instrument for studying the human brain; additional technical innovations can result in further improvements. PMID:28752130

Feasibility of using auto Mod-MPI system, a novel technique for automated measurement of fetal modified myocardial performance index.

PubMed

Lee, M-Y; Won, H-S; Jeon, E-J; Yoon, H C; Choi, J Y; Hong, S J; Kim, M-J

2014-06-01

To evaluate the reproducibility of measurement of the fetal left modified myocardial performance index (Mod-MPI) determined using a novel automated system. This was a prospective study of 116 ultrasound examinations from 110 normal singleton pregnancies at 12 + 1 to 37 + 1 weeks' gestation. Two experienced operators each measured the left Mod-MPI twice manually and twice automatically using the Auto Mod-MPI system. Intra- and interoperator reproducibility were assessed using intraclass correlation coefficients (ICCs) and the manual and automated measurements obtained by the more experienced operator were compared using Bland-Altman plots and ICCs. Both operators successfully measured the left Mod-MPI in all cases using the Auto Mod-MPI system. For both operators, intraoperator reproducibility was higher when performing automated measurements (ICC = 0.967 and 0.962 for Operators 1 and 2, respectively) than when performing manual measurements (ICC = 0.857 and 0.856 for Operators 1 and 2, respectively). Interoperator agreement was also better for automated than for manual measurements (ICC = 0.930 vs 0.723, respectively). There was good agreement between the automated and manual values measured by the more experienced operator. The Auto Mod-MPI system is a reliable technique for measuring fetal left Mod-MPI and demonstrates excellent reproducibility. Copyright © 2013 ISUOG. Published by John Wiley & Sons Ltd.

Effect of caffeine on SPECT myocardial perfusion imaging during regadenoson pharmacologic stress: rationale and design of a prospective, randomized, multicenter study.

PubMed

Tejani, Furqan H; Thompson, Randall C; Iskandrian, Ami E; McNutt, Bruce E; Franks, Billy

2011-02-01

Caffeine attenuates the coronary hyperemic response to adenosine by competitive A₂(A) receptor blockade. This study aims to determine whether oral caffeine administration compromises diagnostic accuracy in patients undergoing vasodilator stress myocardial perfusion imaging (MPI) with regadenoson, a selective adenosine A(2A) agonist. This multicenter, randomized, double-blind, placebo-controlled, parallel-group study includes patients with suspected coronary artery disease who regularly consume caffeine. Each participant undergoes three SPECT MPI studies: a rest study on day 1 (MPI-1); a regadenoson stress study on day 3 (MPI-2), and a regadenoson stress study on day 5 with double-blind administration of oral caffeine 200 or 400 mg or placebo capsules (MPI-3; n = 90 per arm). Only participants with ≥ 1 reversible defect on the second MPI study undergo the subsequent stress MPI test. The primary endpoint is the difference in the number of reversible defects on the two stress tests using a 17-segment model. Pharmacokinetic/pharmacodynamic analyses will evaluate the effect of caffeine on the regadenoson exposure-response relationship. Safety will also be assessed. The results of this study will show whether the consumption of caffeine equivalent to 2-4 cups of coffee prior to an MPI study with regadenoson affects the diagnostic validity of stress testing (ClinicalTrials.gov number, NCT00826280).

Doppler-derived myocardial performance index in patients with impaired left ventricular relaxation and preserved systolic function.

PubMed

Fernandes, José Maria G; Rivera, Ivan Romero; de Oliveira Romão, Benício; Mendonça, Maria Alayde; Vasconcelos, Miriam Lira Castro; Carvalho, Antônio Carlos; Campos, Orlando; De Paola, Angelo Amato V; Moisés, Valdir A

2009-09-01

The Doppler-derived myocardial performance index (MPI) has been used in the evaluation of left ventricular (LV) function in several diseases. In patients with isolated diastolic dysfunction, the diagnostic utility of this index remains unclear. The aim of this study was to determine the diagnostic utility of MPI in patients with systemic hypertension, impaired LV relaxation, and normal ejection fraction. Thirty hypertensive patients with impaired LV relaxation were compared to 30 control subjects. MPI and its components, isovolumetric relaxation time (IRT), isovolumetric contraction time (ICT), and the ejection time (ET), were measured from LV outflow and mitral inflow Doppler velocity profiles. MPI was higher in patients than in control subjects (0.45 +/- 0.13 vs 0.37 +/- 0.07 P < 0.0029). The increase in MPI was due to the prolongation of IRT without significant change of ICT and ET. MPI cutoff value of > or =0.40 identified impaired LV relaxation with a sensitivity of 63% and specificity of 70% while an IRT >94 ms had a sensitivity of 67% and specificity of 80%. Multivariate analysis identified relative wall thickness, mitral early filling wave velocity (E), and systolic myocardial velocity (Sm) as independent predictors of MPI in patients with hypertension. MPI was increase in patients with hypertension, diastolic dysfunction, and normal ejection fraction but was not superior to IRT to detect impaired LV relaxation.

Adenosine triphosphate stress myocardial perfusion imaging for risk stratification of patients aged 70 years and older with suspected coronary artery disease.

PubMed

Yao, Zhiming; Zhu, Hui; Li, Wenchan; Chen, Congxia; Wang, Hua; Shi, Lei; Zhang, Wenjie

2017-04-01

We investigated the cardiac risk stratification value of adenosine triphosphate stress myocardial perfusion imaging (ATP-MPI) in patients aged 70 years and older with suspected coronary artery disease (CAD). We identified a series of 415 consecutive patients aged 70 years and older with suspected CAD, who had undergone ATP-MPI with 99m Tc-MIBI. The presence of a fixed and/or reversible perfusion defect was considered as an abnormal MPI. Follow-up was available in 399 patients (96.1%) over 3.45 ± 1.71 years after excluding 16 patients who underwent early coronary revascularization <60 days after MPI. The major adverse cardiac events (MACE), including cardiac death, nonfatal infarction, and late coronary revascularization, were recorded. One hundred twenty-five (31.3%) patients had abnormal MPI and the remaining had normal MPI. A multivariable analysis using Cox regression demonstrated that abnormal MPI was independently associated with MACE (hazard ratio 19.50 and 95% confidence interval 5.91-64.31, P value .000). The patients with SSS > 8 had significantly higher cumulative MACE rate than patients with SSS ≤ 8 had (37.8% vs 5.2%, respectively, P < .001). The Kaplan-Meier cumulative MACE-free survival in patients with abnormal MPI (57.0%) was significantly lower than that in patients with normal MPI (89.6%), P < .0001. Among patients with SSS > 8, the Kaplan-Meier cumulative MACE-free survival were 36.9% in patients ≥80 years old and 49.5% in patients 70-79 years old, respectively, P < .05. However, among patients with SSS ≤ 8, there was no difference between the Kaplan-Meier cumulative MACE-free survivals of these two age groups. ATP-MPI data are useful for the prediction of major adverse cardiac events in patients aged 70 years and older with suspected CAD.

Generalized Knizhnik-Zamolodchikov equation for Ding-Iohara-Miki algebra

NASA Astrophysics Data System (ADS)

Awata, Hidetoshi; Kanno, Hiroaki; Mironov, Andrei; Morozov, Alexei; Morozov, Andrey; Ohkubo, Yusuke; Zenkevich, Yegor

2017-07-01

We derive the generalization of the Knizhnik-Zamolodchikov equation (KZE) associated with the Ding-Iohara-Miki algebra Uq ,t(gl^ ^ 1) . We demonstrate that certain refined topological string amplitudes satisfy these equations and find that the braiding transformations are performed by the R matrix of Uq ,t(gl^ ^ 1) . The resulting system is the uplifting of the u^1 Wess-Zumino-Witten model. The solutions to the (q ,t ) KZE are identified with the (spectral dual of) building blocks of the Nekrasov partition function for five-dimensional linear quiver gauge theories. We also construct an elliptic version of the KZE and discuss its modular and monodromy properties, the latter being related to a dual version of the KZE.

Magnetic particle testing of turbine blades mounted on the turbine rotor shaft

NASA Astrophysics Data System (ADS)

Imbert, Clement; Rampersad, Krishna

1992-07-01

An outline is presented of the general technique of magnetic particle inspection (MPI) of turbine blades mounted on the turbine rotor shaft with specific reference to the placement of the magnetizing coils. In particular, this study reports on the use of MPI in the examination of martensitic stainless steel turbine blades in power plants in Trinidad and Tobago in order to establish procedures for the detection of discontinuities. The techniques described are applicable to ferromagnetic turbine blades in general. The two practical techniques mentioned are the method of placing a preformed coil over a number of blades in one row and the method of wrapping the coil around the rotor shaft across an entire row of blades. Of the two methods, the former is preferred to the latter one, because there is greater uniformity of magnetic flux induced and lower current required to induce adequate flux density with the preformed coil. However, both methods provide satisfactory magnetic flux, and either can be used.

Acceleration of Semiempirical QM/MM Methods through Message Passage Interface (MPI), Hybrid MPI/Open Multiprocessing, and Self-Consistent Field Accelerator Implementations.

PubMed

Ojeda-May, Pedro; Nam, Kwangho

2017-08-08

The strategy and implementation of scalable and efficient semiempirical (SE) QM/MM methods in CHARMM are described. The serial version of the code was first profiled to identify routines that required parallelization. Afterward, the code was parallelized and accelerated with three approaches. The first approach was the parallelization of the entire QM/MM routines, including the Fock matrix diagonalization routines, using the CHARMM message passage interface (MPI) machinery. In the second approach, two different self-consistent field (SCF) energy convergence accelerators were implemented using density and Fock matrices as targets for their extrapolations in the SCF procedure. In the third approach, the entire QM/MM and MM energy routines were accelerated by implementing the hybrid MPI/open multiprocessing (OpenMP) model in which both the task- and loop-level parallelization strategies were adopted to balance loads between different OpenMP threads. The present implementation was tested on two solvated enzyme systems (including <100 QM atoms) and an S N 2 symmetric reaction in water. The MPI version exceeded existing SE QM methods in CHARMM, which include the SCC-DFTB and SQUANTUM methods, by at least 4-fold. The use of SCF convergence accelerators further accelerated the code by ∼12-35% depending on the size of the QM region and the number of CPU cores used. Although the MPI version displayed good scalability, the performance was diminished for large numbers of MPI processes due to the overhead associated with MPI communications between nodes. This issue was partially overcome by the hybrid MPI/OpenMP approach which displayed a better scalability for a larger number of CPU cores (up to 64 CPUs in the tested systems).

Magnetic Particle Imaging (MPI) for NMR and MRI researchers

NASA Astrophysics Data System (ADS)

Saritas, Emine U.; Goodwill, Patrick W.; Croft, Laura R.; Konkle, Justin J.; Lu, Kuan; Zheng, Bo; Conolly, Steven M.

2013-04-01

Magnetic Particle Imaging (MPI) is a new tracer imaging modality that is gaining significant interest from NMR and MRI researchers. While the physics of MPI differ substantially from MRI, it employs hardware and imaging concepts that are familiar to MRI researchers, such as magnetic excitation and detection, pulse sequences, and relaxation effects. Furthermore, MPI employs the same superparamagnetic iron oxide (SPIO) contrast agents that are sometimes used for MR angiography and are often used for MRI cell tracking studies. These SPIOs are much safer for humans than iodine or gadolinium, especially for Chronic Kidney Disease (CKD) patients. The weak kidneys of CKD patients cannot safely excrete iodine or gadolinium, leading to increased morbidity and mortality after iodinated X-ray or CT angiograms, or after gadolinium-MRA studies. Iron oxides, on the other hand, are processed in the liver, and have been shown to be safe even for CKD patients. Unlike the “black blood” contrast generated by SPIOs in MRI due to increased T2∗ dephasing, SPIOs in MPI generate positive, “bright blood” contrast. With this ideal contrast, even prototype MPI scanners can already achieve fast, high-sensitivity, and high-contrast angiograms with millimeter-scale resolutions in phantoms and in animals. Moreover, MPI shows great potential for an exciting array of applications, including stem cell tracking in vivo, first-pass contrast studies to diagnose or stage cancer, and inflammation imaging in vivo. So far, only a handful of prototype small-animal MPI scanners have been constructed worldwide. Hence, MPI is open to great advances, especially in hardware, pulse sequence, and nanoparticle improvements, with the potential to revolutionize the biomedical imaging field.

Performance comparison analysis library communication cluster system using merge sort

NASA Astrophysics Data System (ADS)

Wulandari, D. A. R.; Ramadhan, M. E.

2018-04-01

Begins by using a single processor, to increase the speed of computing time, the use of multi-processor was introduced. The second paradigm is known as parallel computing, example cluster. The cluster must have the communication potocol for processing, one of it is message passing Interface (MPI). MPI have many library, both of them OPENMPI and MPICH2. Performance of the cluster machine depend on suitable between performance characters of library communication and characters of the problem so this study aims to analyze the comparative performances libraries in handling parallel computing process. The case study in this research are MPICH2 and OpenMPI. This case research execute sorting’s problem to know the performance of cluster system. The sorting problem use mergesort method. The research method is by implementing OpenMPI and MPICH2 on a Linux-based cluster by using five computer virtual then analyze the performance of the system by different scenario tests and three parameters for to know the performance of MPICH2 and OpenMPI. These performances are execution time, speedup and efficiency. The results of this study showed that the addition of each data size makes OpenMPI and MPICH2 have an average speed-up and efficiency tend to increase but at a large data size decreases. increased data size doesn’t necessarily increased speed up and efficiency but only execution time example in 100000 data size. OpenMPI has a execution time greater than MPICH2 example in 1000 data size average execution time with MPICH2 is 0,009721 and OpenMPI is 0,003895 OpenMPI can customize communication needs.

Cardiovascular mortality prediction in veterans with arm exercise vs pharmacologic myocardial perfusion imaging.

PubMed

Martin, Wade H; Xian, Hong; Chandiramani, Pooja; Bainter, Emily; Klein, Andrew J P

2015-08-01

No data exist comparing outcome prediction from arm exercise vs pharmacologic myocardial perfusion imaging (MPI) stress test variables in patients unable to perform treadmill exercise. In this retrospective study, 2,173 consecutive lower extremity disabled veterans aged 65.4 ± 11.0years (mean ± SD) underwent either pharmacologic MPI (1730 patients) or arm exercise stress tests (443 patients) with MPI (n = 253) or electrocardiography alone (n = 190) between 1997 and 2002. Cox multivariate regression models and reclassification analysis by integrated discrimination improvement (IDI) were used to characterize stress test and MPI predictors of cardiovascular mortality at ≥10-year follow-up after inclusion of significant demographic, clinical, and other variables. Cardiovascular death occurred in 561 pharmacologic MPI and 102 arm exercise participants. Multivariate-adjusted cardiovascular mortality was predicted by arm exercise resting metabolic equivalents (hazard ratio [HR] 0.52, 95% CI 0.39-0.69, P < .001), 1-minute heart rate recovery (HR 0.61, 95% CI 0.44-0.86, P < .001), and pharmacologic and arm exercise delta (peak-rest) heart rate (both P < .001). Only an abnormal arm exercise MPI prognosticated cardiovascular death by multivariate Cox analysis (HR 1.98, 95% CI 1.04-3.77, P < .05). Arm exercise MPI defect number, type, and size provided IDI over covariates for prediction of cardiovascular mortality (IDI = 0.074-0.097). Only pharmacologic defect size prognosticated cardiovascular mortality (IDI = 0.022). Arm exercise capacity, heart rate recovery, and pharmacologic and arm exercise heart rate responses are robust predictors of cardiovascular mortality. Arm exercise MPI results are equivalent and possibly superior to pharmacologic MPI for cardiovascular mortality prediction in patients unable to perform treadmill exercise. Published by Elsevier Inc.

Negative predictive value and potential cost savings of acute nuclear myocardial perfusion imaging in low risk patients with suspected acute coronary syndrome: A prospective single blinded study

PubMed Central

Forberg, Jakob L; Hilmersson, Catarina E; Carlsson, Marcus; Arheden, Håkan; Björk, Jonas; Hjalte, Krister; Ekelund, Ulf

2009-01-01

Background Previous studies from the USA have shown that acute nuclear myocardial perfusion imaging (MPI) in low risk emergency department (ED) patients with suspected acute coronary syndrome (ACS) can be of clinical value. The aim of this study was to evaluate the utility and hospital economics of acute MPI in Swedish ED patients with suspected ACS. Methods We included 40 patients (mean age 55 ± 2 years, 50% women) who were admitted from the ED at Lund University Hospital for chest pain suspicious of ACS, and who had a normal or non-ischemic ECG and no previous myocardial infarction. All patients underwent MPI from the ED, and the results were analyzed only after patient discharge. The current diagnostic practice of admitting the included patients for observation and further evaluation was compared to a theoretical "MPI strategy", where patients with a normal MPI test would have been discharged home from the ED. Results Twenty-seven patients had normal MPI results, and none of them had ACS. MPI thus had a negative predictive value for ACS of 100%. With the MPI strategy, 2/3 of the patients would thus have been discharged from the ED, resulting in a reduction of total hospital cost by some 270 EUR and of bed occupancy by 0.8 days per investigated patient. Conclusion Our findings in a Swedish ED support the results of larger American trials that acute MPI has the potential to safely reduce the number of admissions and decrease overall costs for low-risk ED patients with suspected ACS. PMID:19545365

Development and Initial Validation of the Multicultural Personality Inventory (MPI).

PubMed

Ponterotto, Joseph G; Fietzer, Alexander W; Fingerhut, Esther C; Woerner, Scott; Stack, Lauren; Magaldi-Dopman, Danielle; Rust, Jonathan; Nakao, Gen; Tsai, Yu-Ting; Black, Natasha; Alba, Renaldo; Desai, Miraj; Frazier, Chantel; LaRue, Alyse; Liao, Pei-Wen

2014-01-01

Two studies summarize the development and initial validation of the Multicultural Personality Inventory (MPI). In Study 1, the 115-item prototype MPI was administered to 415 university students where exploratory factor analysis resulted in a 70-item, 7-factor model. In Study 2, the 70-item MPI and theoretically related companion instruments were administered to a multisite sample of 576 university students. Confirmatory factory analysis found the 7-factor structure to be a relatively good fit to the data (Comparative Fit Index =.954; root mean square error of approximation =.057), and MPI factors predicted variance in criterion variables above and beyond the variance accounted for by broad personality traits (i.e., Big Five). Study limitations and directions for further validation research are specified.

NDL-v2.0: A new version of the numerical differentiation library for parallel architectures

NASA Astrophysics Data System (ADS)

Hadjidoukas, P. E.; Angelikopoulos, P.; Voglis, C.; Papageorgiou, D. G.; Lagaris, I. E.

2014-07-01

We present a new version of the numerical differentiation library (NDL) used for the numerical estimation of first and second order partial derivatives of a function by finite differencing. In this version we have restructured the serial implementation of the code so as to achieve optimal task-based parallelization. The pure shared-memory parallelization of the library has been based on the lightweight OpenMP tasking model allowing for the full extraction of the available parallelism and efficient scheduling of multiple concurrent library calls. On multicore clusters, parallelism is exploited by means of TORC, an MPI-based multi-threaded tasking library. The new MPI implementation of NDL provides optimal performance in terms of function calls and, furthermore, supports asynchronous execution of multiple library calls within legacy MPI programs. In addition, a Python interface has been implemented for all cases, exporting the functionality of our library to sequential Python codes. Catalog identifier: AEDG_v2_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEDG_v2_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 63036 No. of bytes in distributed program, including test data, etc.: 801872 Distribution format: tar.gz Programming language: ANSI Fortran-77, ANSI C, Python. Computer: Distributed systems (clusters), shared memory systems. Operating system: Linux, Unix. Has the code been vectorized or parallelized?: Yes. RAM: The library uses O(N) internal storage, N being the dimension of the problem. It can use up to O(N2) internal storage for Hessian calculations, if a task throttling factor has not been set by the user. Classification: 4.9, 4.14, 6.5. Catalog identifier of previous version: AEDG_v1_0 Journal reference of previous version: Comput. Phys. Comm. 180(2009)1404 Does the new version supersede the previous version?: Yes Nature of problem: The numerical estimation of derivatives at several accuracy levels is a common requirement in many computational tasks, such as optimization, solution of nonlinear systems, and sensitivity analysis. For a large number of scientific and engineering applications, the underlying functions correspond to simulation codes for which analytical estimation of derivatives is difficult or almost impossible. A parallel implementation that exploits systems with multiple CPUs is very important for large scale and computationally expensive problems. Solution method: Finite differencing is used with a carefully chosen step that minimizes the sum of the truncation and round-off errors. The parallel versions employ both OpenMP and MPI libraries. Reasons for new version: The updated version was motivated by our endeavors to extend a parallel Bayesian uncertainty quantification framework [1], by incorporating higher order derivative information as in most state-of-the-art stochastic simulation methods such as Stochastic Newton MCMC [2] and Riemannian Manifold Hamiltonian MC [3]. The function evaluations are simulations with significant time-to-solution, which also varies with the input parameters such as in [1, 4]. The runtime of the N-body-type of problem changes considerably with the introduction of a longer cut-off between the bodies. In the first version of the library, the OpenMP-parallel subroutines spawn a new team of threads and distribute the function evaluations with a PARALLEL DO directive. This limits the functionality of the library as multiple concurrent calls require nested parallelism support from the OpenMP environment. Therefore, either their function evaluations will be serialized or processor oversubscription is likely to occur due to the increased number of OpenMP threads. In addition, the Hessian calculations include two explicit parallel regions that compute first the diagonal and then the off-diagonal elements of the array. Due to the barrier between the two regions, the parallelism of the calculations is not fully exploited. These issues have been addressed in the new version by first restructuring the serial code and then running the function evaluations in parallel using OpenMP tasks. Although the MPI-parallel implementation of the first version is capable of fully exploiting the task parallelism of the PNDL routines, it does not utilize the caching mechanism of the serial code and, therefore, performs some redundant function evaluations in the Hessian and Jacobian calculations. This can lead to: (a) higher execution times if the number of available processors is lower than the total number of tasks, and (b) significant energy consumption due to wasted processor cycles. Overcoming these drawbacks, which become critical as the time of a single function evaluation increases, was the primary goal of this new version. Due to the code restructure, the MPI-parallel implementation (and the OpenMP-parallel in accordance) avoids redundant calls, providing optimal performance in terms of the number of function evaluations. Another limitation of the library was that the library subroutines were collective and synchronous calls. In the new version, each MPI process can issue any number of subroutines for asynchronous execution. We introduce two library calls that provide global and local task synchronizations, similarly to the BARRIER and TASKWAIT directives of OpenMP. The new MPI-implementation is based on TORC, a new tasking library for multicore clusters [5-7]. TORC improves the portability of the software, as it relies exclusively on the POSIX-Threads and MPI programming interfaces. It allows MPI processes to utilize multiple worker threads, offering a hybrid programming and execution environment similar to MPI+OpenMP, in a completely transparent way. Finally, to further improve the usability of our software, a Python interface has been implemented on top of both the OpenMP and MPI versions of the library. This allows sequential Python codes to exploit shared and distributed memory systems. Summary of revisions: The revised code improves the performance of both parallel (OpenMP and MPI) implementations. The functionality and the user-interface of the MPI-parallel version have been extended to support the asynchronous execution of multiple PNDL calls, issued by one or multiple MPI processes. A new underlying tasking library increases portability and allows MPI processes to have multiple worker threads. For both implementations, an interface to the Python programming language has been added. Restrictions: The library uses only double precision arithmetic. The MPI implementation assumes the homogeneity of the execution environment provided by the operating system. Specifically, the processes of a single MPI application must have identical address space and a user function resides at the same virtual address. In addition, address space layout randomization should not be used for the application. Unusual features: The software takes into account bound constraints, in the sense that only feasible points are used to evaluate the derivatives, and given the level of the desired accuracy, the proper formula is automatically employed. Running time: Running time depends on the function's complexity. The test run took 23 ms for the serial distribution, 25 ms for the OpenMP with 2 threads, 53 ms and 1.01 s for the MPI parallel distribution using 2 threads and 2 processes respectively and yield-time for idle workers equal to 10 ms. References: [1] P. Angelikopoulos, C. Paradimitriou, P. Koumoutsakos, Bayesian uncertainty quantification and propagation in molecular dynamics simulations: a high performance computing framework, J. Chem. Phys 137 (14). [2] H.P. Flath, L.C. Wilcox, V. Akcelik, J. Hill, B. van Bloemen Waanders, O. Ghattas, Fast algorithms for Bayesian uncertainty quantification in large-scale linear inverse problems based on low-rank partial Hessian approximations, SIAM J. Sci. Comput. 33 (1) (2011) 407-432. [3] M. Girolami, B. Calderhead, Riemann manifold Langevin and Hamiltonian Monte Carlo methods, J. R. Stat. Soc. Ser. B (Stat. Methodol.) 73 (2) (2011) 123-214. [4] P. Angelikopoulos, C. Paradimitriou, P. Koumoutsakos, Data driven, predictive molecular dynamics for nanoscale flow simulations under uncertainty, J. Phys. Chem. B 117 (47) (2013) 14808-14816. [5] P.E. Hadjidoukas, E. Lappas, V.V. Dimakopoulos, A runtime library for platform-independent task parallelism, in: PDP, IEEE, 2012, pp. 229-236. [6] C. Voglis, P.E. Hadjidoukas, D.G. Papageorgiou, I. Lagaris, A parallel hybrid optimization algorithm for fitting interatomic potentials, Appl. Soft Comput. 13 (12) (2013) 4481-4492. [7] P.E. Hadjidoukas, C. Voglis, V.V. Dimakopoulos, I. Lagaris, D.G. Papageorgiou, Supporting adaptive and irregular parallelism for non-linear numerical optimization, Appl. Math. Comput. 231 (2014) 544-559.

CLOMP v1.5

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

Gyllenhaal, J.

CLOMP is the C version of the Livermore OpenMP benchmark developed to measure OpenMP overheads and other performance impacts due to threading. For simplicity, it does not use MPI by default but it is expected to be run on the resources a threaded MPI task would use (e.g., a portion of a shared memory compute node). Compiling with -DWITH_MPI allows packing one or more nodes with CLOMP tasks and having CLOMP report OpenMP performance for the slowest MPI task. On current systems, the strong scaling performance results for 4, 8, or 16 threads are of the most interest. Suggested weakmore » scaling inputs are provided for evaluating future systems. Since MPI is often used to place at least one MPI task per coherence or NUMA domain, it is recommended to focus OpenMP runtime measurements on a subset of node hardware where it is most possible to have low OpenMP overheads (e.g., within one coherence domain or NUMA domain).« less

How to use MPI communication in highly parallel climate simulations more easily and more efficiently.

NASA Astrophysics Data System (ADS)

Behrens, Jörg; Hanke, Moritz; Jahns, Thomas

2014-05-01

In this talk we present a way to facilitate efficient use of MPI communication for developers of climate models. Exploitation of the performance potential of today's highly parallel supercomputers with real world simulations is a complex task. This is partly caused by the low level nature of the MPI communication library which is the dominant communication tool at least for inter-node communication. In order to manage the complexity of the task, climate simulations with non-trivial communication patterns often use an internal abstraction layer above MPI without exploiting the benefits of communication aggregation or MPI-datatypes. The solution for the complexity and performance problem we propose is the communication library YAXT. This library is built on top of MPI and takes high level descriptions of arbitrary domain decompositions and automatically derives an efficient collective data exchange. Several exchanges can be aggregated in order to reduce latency costs. Examples are given which demonstrate the simplicity and the performance gains for selected climate applications.

Murine Polyomavirus Virus-Like Particles Carrying Full-Length Human PSA Protect BALB/c Mice from Outgrowth of a PSA Expressing Tumor

PubMed Central

Eriksson, Mathilda; Andreasson, Kalle; Weidmann, Joachim; Lundberg, Kajsa; Tegerstedt, Karin

2011-01-01

Virus-like particles (VLPs) consist of capsid proteins from viruses and have been shown to be usable as carriers of protein and peptide antigens for immune therapy. In this study, we have produced and assayed murine polyomavirus (MPyV) VLPs carrying the entire human Prostate Specific Antigen (PSA) (PSA-MPyVLPs) for their potential use for immune therapy in a mouse model system. BALB/c mice immunized with PSA-MPyVLPs were only marginally protected against outgrowth of a PSA-expressing tumor. To improve protection, PSA-MPyVLPs were co-injected with adjuvant CpG, either alone or loaded onto murine dendritic cells (DCs). Immunization with PSA-MPyVLPs loaded onto DCs in the presence of CpG was shown to efficiently protect mice from tumor outgrowth. In addition, cellular and humoral immune responses after immunization were examined. PSA-specific CD4+ and CD8+ cells were demonstrated, but no PSA-specific IgG antibodies. Vaccination with DCs loaded with PSA-MPyVLPs induced an eight-fold lower titre of anti-VLP antibodies than vaccination with PSA-MPyVLPs alone. In conclusion, immunization of BALB/c mice with PSA-MPyVLPs, loaded onto DCs and co-injected with CpG, induces an efficient PSA-specific tumor protective immune response, including both CD4+ and CD8+ cells with a low induction of anti-VLP antibodies. PMID:21858228

Usefulness of the comprehensive geriatric assessment in older patients with upper gastrointestinal bleeding: a two-year follow-up study.

PubMed

Pilotto, Alberto; Ferrucci, Luigi; Scarcelli, Carlo; Niro, Valeria; Di Mario, Francesco; Seripa, Davide; Andriulli, Angelo; Leandro, Gioacchino; Franceschi, Marilisa

2007-01-01

The potential usefulness of standardized comprehensive geriatric assessment (CGA) in evaluating treatment and follow-up of older patients with upper gastrointestinal bleeding is unknown. To evaluate the usefulness of the CGA as a 2-year mortality multidimensional prognostic index (MPI) in older patients hospitalized for upper gastrointestinal bleeding. Patients aged > or =65 years consecutively hospitalized for acute upper gastrointestinal bleeding were included. Diagnosis of bleeding was based on clinical and endoscopic features. All patients underwent a CGA that included six standardized scales, i.e., Activities of Daily Living (ADL), Instrumental Activities of Daily Living (IADL), Short Portable Mental Status Questionnaire (SPMSQ), Mini Nutritional Assessment (MNA), Exton-Smith Score (ESS) and Comorbity Index Rating Scale (CIRS), as well as information on medication history and cohabitation, for a total of 63 items. A MPI was calculated from the integrated total scores and expressed as MPI 1 = low risk, MPI 2 = moderate risk, and MPI 3 = severe risk. The predictive value of the MPI for mortality over a 24-month follow-up was calculated. 36 elderly patients (M 16/F 20, mean age 82.8 +/- 7.9 years, range 70-101 years) were included in the study. A significant difference in mean age was observed between males and females (M 80.1 +/- 4.8 vs. F 84.9 +/- 9.3 years; p < 0.05). The causes of upper gastrointestinal bleeding were duodenal ulcer in 38.8%, gastric ulcer in 22.2%, and erosive gastritis in 16.6% of the patients, while 16.6% had gastrointestinal bleeding from unknown origin. The overall 2-year mortality rate was 30.5%. 18 patients (50%) were classified as having a low-risk MPI (mean value 0.18 +/- 0.09), 12 (33.3%) as having a moderate-risk MPI (mean value 0.48 +/- 0.08) and 6 (16.6%) as having a severe-risk MPI (mean value 0.83 +/- 0.06). Higher MPI grades were significantly associated with higher mortality (grade 1 = 12.5%, grade 2 = 41.6%, grade 3 = 83.3%; p = 0.001). Adjusting for age and sex, the prognostic efficacy of MPI for mortality was confirmed and highly significant (odds ratio 10.47, 95% CI 2.04-53.6). CGA is a useful tool for calculating a MPI that significantly predicts the risk of 2-year mortality in older patients with upper gastrointestinal bleeding. Copyright 2007 S. Karger AG, Basel.

Singapore Students' Performance on Australian and Singapore Assessment Items

ERIC Educational Resources Information Center

Ho, Siew Yin; Lowrie, Tom

2012-01-01

This study describes Singapore students' (N = 607) performance on a recently developed Mathematics Processing Instrument (MPI). The MPI comprised tasks sourced from Australia's NAPLAN and Singapore's PSLE. In addition, the MPI had a corresponding question which encouraged students to describe how they solved the respective tasks. In particular,…

Magnetic particle imaging for radiation-free, sensitive and high-contrast vascular imaging and cell tracking.

PubMed

Zhou, Xinyi Y; Tay, Zhi Wei; Chandrasekharan, Prashant; Yu, Elaine Y; Hensley, Daniel W; Orendorff, Ryan; Jeffris, Kenneth E; Mai, David; Zheng, Bo; Goodwill, Patrick W; Conolly, Steven M

2018-05-10

Magnetic particle imaging (MPI) is an emerging ionizing radiation-free biomedical tracer imaging technique that directly images the intense magnetization of superparamagnetic iron oxide nanoparticles (SPIOs). MPI offers ideal image contrast because MPI shows zero signal from background tissues. Moreover, there is zero attenuation of the signal with depth in tissue, allowing for imaging deep inside the body quantitatively at any location. Recent work has demonstrated the potential of MPI for robust, sensitive vascular imaging and cell tracking with high contrast and dose-limited sensitivity comparable to nuclear medicine. To foster future applications in MPI, this new biomedical imaging field is welcoming researchers with expertise in imaging physics, magnetic nanoparticle synthesis and functionalization, nanoscale physics, and small animal imaging applications. Copyright © 2018 Elsevier Ltd. All rights reserved.

MPI_XSTAR: MPI-based Parallelization of the XSTAR Photoionization Program

NASA Astrophysics Data System (ADS)

Danehkar, Ashkbiz; Nowak, Michael A.; Lee, Julia C.; Smith, Randall K.

2018-02-01

We describe a program for the parallel implementation of multiple runs of XSTAR, a photoionization code that is used to predict the physical properties of an ionized gas from its emission and/or absorption lines. The parallelization program, called MPI_XSTAR, has been developed and implemented in the C++ language by using the Message Passing Interface (MPI) protocol, a conventional standard of parallel computing. We have benchmarked parallel multiprocessing executions of XSTAR, using MPI_XSTAR, against a serial execution of XSTAR, in terms of the parallelization speedup and the computing resource efficiency. Our experience indicates that the parallel execution runs significantly faster than the serial execution, however, the efficiency in terms of the computing resource usage decreases with increasing the number of processors used in the parallel computing.

Magnetic particle imaging: advancements and perspectives for real-time in vivo monitoring and image-guided therapy

NASA Astrophysics Data System (ADS)

Pablico-Lansigan, Michele H.; Situ, Shu F.; Samia, Anna Cristina S.

2013-05-01

Magnetic particle imaging (MPI) is an emerging biomedical imaging technology that allows the direct quantitative mapping of the spatial distribution of superparamagnetic iron oxide nanoparticles. MPI's increased sensitivity and short image acquisition times foster the creation of tomographic images with high temporal and spatial resolution. The contrast and sensitivity of MPI is envisioned to transcend those of other medical imaging modalities presently used, such as magnetic resonance imaging (MRI), X-ray scans, ultrasound, computed tomography (CT), positron emission tomography (PET) and single photon emission computed tomography (SPECT). In this review, we present an overview of the recent advances in the rapidly developing field of MPI. We begin with a basic introduction of the fundamentals of MPI, followed by some highlights over the past decade of the evolution of strategies and approaches used to improve this new imaging technique. We also examine the optimization of iron oxide nanoparticle tracers used for imaging, underscoring the importance of size homogeneity and surface engineering. Finally, we present some future research directions for MPI, emphasizing the novel and exciting opportunities that it offers as an important tool for real-time in vivo monitoring. All these opportunities and capabilities that MPI presents are now seen as potential breakthrough innovations in timely disease diagnosis, implant monitoring, and image-guided therapeutics.

Determination of the optimal atrioventricular interval in sick sinus syndrome during DDD pacing.

PubMed

Kato, Masaya; Dote, Keigo; Sasaki, Shota; Goto, Kenji; Takemoto, Hiroaki; Habara, Seiji; Hasegawa, Daiji; Matsuda, Osamu

2005-09-01

Although the AAI pacing mode has been shown to be electromechanically superior to the DDD pacing mode in sick sinus syndrome (SSS), there is evidence suggesting that during AAI pacing the presence of natural ventricular activation pattern is not enough for hemodynamic benefit to occur. Myocardial performance index (MPI) is a simply measurable Doppler-derived index of combined systolic and diastolic myocardial performance. The aim of this study was to investigate whether AAI pacing mode is electromechanically superior to the DDD mode in patients with SSS by using Doppler-derived MPI. Thirty-nine SSS patients with dual-chamber pacing devices were evaluated by using Doppler echocardiography in AAI mode and DDD mode. The optimal atrioventricular (AV) interval in DDD mode was determined and atrial stimulus-R interval was measured in AAI mode. The ratio of the atrial stimulus-R interval to the optimal AV interval was defined as relative AV interval (rAVI) and the ratio of MPI in AAI mode to that in DDD mode was defined as relative MPI (rMPI). The rMPI was significantly correlated with atrial stimulus-R interval and rAVI (r = 0.57, P = 0.0002, and r = 0.67, P < 0.0001, respectively). A cutoff point of 1.73 for rAVI provided optimum sensitivity and specificity for rMPI >1 based on the receiver operator curves. Even though the intrinsic AV conduction is moderately prolonged, some SSS patients with dual-chamber pacing devices benefit from the ventricular pacing with optimal AV interval. MPI is useful to determine the optimal pacing mode in acute experiment.

Plant Vascular Biology 2010

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

Ding, Biao

This grant supported the Second International Conference on Plant Vascular Biology (PVB 2010) held July 24-28, 2010 on the campus of Ohio State University, Columbus, Ohio. Biao Ding (Ohio State University; OSU) and David Hannapel (Iowa State University; ISU) served as co-chairs of this conference. Biao Ding served as the local organizer. PVB is defined broadly here to include studies on the biogenesis, structure and function of transport systems in plants, under conditions of normal plant growth and development as well as of plant interactions with pathogens. The transport systems cover broadly the xylem, phloem, plasmodesmata and vascular cell membranes.more » The PVB concept has emerged in recent years to emphasize the integrative nature of the transport systems and approaches to investigate them.« less

An MPI-CUDA approach for hypersonic flows with detailed state-to-state air kinetics using a GPU cluster

NASA Astrophysics Data System (ADS)

Bonelli, Francesco; Tuttafesta, Michele; Colonna, Gianpiero; Cutrone, Luigi; Pascazio, Giuseppe

2017-10-01

This paper describes the most advanced results obtained in the context of fluid dynamic simulations of high-enthalpy flows using detailed state-to-state air kinetics. Thermochemical non-equilibrium, typical of supersonic and hypersonic flows, was modeled by using both the accurate state-to-state approach and the multi-temperature model proposed by Park. The accuracy of the two thermochemical non-equilibrium models was assessed by comparing the results with experimental findings, showing better predictions provided by the state-to-state approach. To overcome the huge computational cost of the state-to-state model, a multiple-nodes GPU implementation, based on an MPI-CUDA approach, was employed and a comprehensive code performance analysis is presented. Both the pure MPI-CPU and the MPI-CUDA implementations exhibit excellent scalability performance. GPUs outperform CPUs computing especially when the state-to-state approach is employed, showing speed-ups, of the single GPU with respect to the single-core CPU, larger than 100 in both the case of one MPI process and multiple MPI process.

Iron Oxide Nanoparticle-Micelles (ION-Micelles) for Sensitive (Molecular) Magnetic Particle Imaging and Magnetic Resonance Imaging

PubMed Central

Starmans, Lucas W. E.; Burdinski, Dirk; Haex, Nicole P. M.; Moonen, Rik P. M.; Strijkers, Gustav J.; Nicolay, Klaas; Grüll, Holger

2013-01-01

Background Iron oxide nanoparticles (IONs) are a promising nanoplatform for contrast-enhanced MRI. Recently, magnetic particle imaging (MPI) was introduced as a new imaging modality, which is able to directly visualize magnetic particles and could serve as a more sensitive and quantitative alternative to MRI. However, MPI requires magnetic particles with specific magnetic properties for optimal use. Current commercially available iron oxide formulations perform suboptimal in MPI, which is triggering research into optimized synthesis strategies. Most synthesis procedures aim at size control of iron oxide nanoparticles rather than control over the magnetic properties. In this study, we report on the synthesis, characterization and application of a novel ION platform for sensitive MPI and MRI. Methods and Results IONs were synthesized using a thermal-decomposition method and subsequently phase-transferred by encapsulation into lipidic micelles (ION-Micelles). Next, the material and magnetic properties of the ION-Micelles were analyzed. Most notably, vibrating sample magnetometry measurements showed that the effective magnetic core size of the IONs is 16 nm. In addition, magnetic particle spectrometry (MPS) measurements were performed. MPS is essentially zero-dimensional MPI and therefore allows to probe the potential of iron oxide formulations for MPI. ION-Micelles induced up to 200 times higher signal in MPS measurements than commercially available iron oxide formulations (Endorem, Resovist and Sinerem) and thus likely allow for significantly more sensitive MPI. In addition, the potential of the ION-Micelle platform for molecular MPI and MRI was showcased by MPS and MRI measurements of fibrin-binding peptide functionalized ION-Micelles (FibPep-ION-Micelles) bound to blood clots. Conclusions The presented data underlines the potential of the ION-Micelle nanoplatform for sensitive (molecular) MPI and warrants further investigation of the FibPep-ION-Micelle platform for in vivo, non-invasive imaging of fibrin in preclinical disease models of thrombus-related pathologies and atherosclerosis. PMID:23437371

Iron oxide nanoparticle-micelles (ION-micelles) for sensitive (molecular) magnetic particle imaging and magnetic resonance imaging.

PubMed

Starmans, Lucas W E; Burdinski, Dirk; Haex, Nicole P M; Moonen, Rik P M; Strijkers, Gustav J; Nicolay, Klaas; Grüll, Holger

2013-01-01

Iron oxide nanoparticles (IONs) are a promising nanoplatform for contrast-enhanced MRI. Recently, magnetic particle imaging (MPI) was introduced as a new imaging modality, which is able to directly visualize magnetic particles and could serve as a more sensitive and quantitative alternative to MRI. However, MPI requires magnetic particles with specific magnetic properties for optimal use. Current commercially available iron oxide formulations perform suboptimal in MPI, which is triggering research into optimized synthesis strategies. Most synthesis procedures aim at size control of iron oxide nanoparticles rather than control over the magnetic properties. In this study, we report on the synthesis, characterization and application of a novel ION platform for sensitive MPI and MRI. IONs were synthesized using a thermal-decomposition method and subsequently phase-transferred by encapsulation into lipidic micelles (ION-Micelles). Next, the material and magnetic properties of the ION-Micelles were analyzed. Most notably, vibrating sample magnetometry measurements showed that the effective magnetic core size of the IONs is 16 nm. In addition, magnetic particle spectrometry (MPS) measurements were performed. MPS is essentially zero-dimensional MPI and therefore allows to probe the potential of iron oxide formulations for MPI. ION-Micelles induced up to 200 times higher signal in MPS measurements than commercially available iron oxide formulations (Endorem, Resovist and Sinerem) and thus likely allow for significantly more sensitive MPI. In addition, the potential of the ION-Micelle platform for molecular MPI and MRI was showcased by MPS and MRI measurements of fibrin-binding peptide functionalized ION-Micelles (FibPep-ION-Micelles) bound to blood clots. The presented data underlines the potential of the ION-Micelle nanoplatform for sensitive (molecular) MPI and warrants further investigation of the FibPep-ION-Micelle platform for in vivo, non-invasive imaging of fibrin in preclinical disease models of thrombus-related pathologies and atherosclerosis.

''Towards a High-Performance and Robust Implementation of MPI-IO on Top of GPFS''

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

Prost, J.P.; Tremann, R.; Blackwore, R.

2000-01-11

MPI-IO/GPFS is a prototype implementation of the I/O chapter of the Message Passing Interface (MPI) 2 standard. It uses the IBM General Parallel File System (GPFS), with prototyped extensions, as the underlying file system. this paper describes the features of this prototype which support its high performance and robustness. The use of hints at the file system level and at the MPI-IO level allows tailoring the use of the file system to the application needs. Error handling in collective operations provides robust error reporting and deadlock prevention in case of returning errors.

A novel artificial neural network method for biomedical prediction based on matrix pseudo-inversion.

PubMed

Cai, Binghuang; Jiang, Xia

2014-04-01

Biomedical prediction based on clinical and genome-wide data has become increasingly important in disease diagnosis and classification. To solve the prediction problem in an effective manner for the improvement of clinical care, we develop a novel Artificial Neural Network (ANN) method based on Matrix Pseudo-Inversion (MPI) for use in biomedical applications. The MPI-ANN is constructed as a three-layer (i.e., input, hidden, and output layers) feed-forward neural network, and the weights connecting the hidden and output layers are directly determined based on MPI without a lengthy learning iteration. The LASSO (Least Absolute Shrinkage and Selection Operator) method is also presented for comparative purposes. Single Nucleotide Polymorphism (SNP) simulated data and real breast cancer data are employed to validate the performance of the MPI-ANN method via 5-fold cross validation. Experimental results demonstrate the efficacy of the developed MPI-ANN for disease classification and prediction, in view of the significantly superior accuracy (i.e., the rate of correct predictions), as compared with LASSO. The results based on the real breast cancer data also show that the MPI-ANN has better performance than other machine learning methods (including support vector machine (SVM), logistic regression (LR), and an iterative ANN). In addition, experiments demonstrate that our MPI-ANN could be used for bio-marker selection as well. Copyright © 2013 Elsevier Inc. All rights reserved.

Gender differences in the diagnostic accuracy of SPECT myocardial perfusion imaging: a bivariate meta-analysis.

PubMed

Iskandar, Aline; Limone, Brendan; Parker, Matthew W; Perugini, Andrew; Kim, Hyejin; Jones, Charles; Calamari, Brian; Coleman, Craig I; Heller, Gary V

2013-02-01

It remains controversial whether the diagnostic accuracy of single-photon emission computed tomography myocardial perfusion imaging (SPECT MPI) is different in men as compared to women. We performed a meta-analysis to investigate gender differences of SPECT MPI for the diagnosis of CAD (≥50% stenosis). Two investigators independently performed a systematic review of the MEDLINE and EMBASE databases from inception through January 2012 for English-language studies determining the diagnostic accuracy of SPECT MPI. We included prospective studies that compared SPECT MPI with conventional coronary angiography which provided sufficient data to calculate gender-specific true and false positives and negatives. Data from studies evaluating <20 patients of one gender were excluded. Bivariate meta-analysis was used to create summary receiver operating curves. Twenty-six studies met inclusion criteria, representing 1,148 women and 1,142 men. Bivariate meta-analysis yielded a mean sensitivity and specificity of 84.2% (95% confidence interval [CI] 78.7%-88.6%) and 78.7% (CI 70.0%-85.3%) for SPECT MPI in women and 89.1% (CI 84.0%-92.7%) and 71.2% (CI 60.8%-79.8%) for SPECT MPI in men. There was no significant difference in the sensitivity (P = .15) or specificity (P = .23) between male and female subjects. In a bivariate meta-analysis of the available literature, the diagnostic accuracy of SPECT MPI is similar for both men and women.

Direct comparison of rest and adenosine stress myocardial perfusion CT with rest and stress SPECT

PubMed Central

Okada, David R.; Ghoshhajra, Brian B.; Blankstein, Ron; Rocha-Filho, Jose A.; Shturman, Leonid D.; Rogers, Ian S.; Bezerra, Hiram G.; Sarwar, Ammar; Gewirtz, Henry; Hoffmann, Udo; Mamuya, Wilfred S.; Brady, Thomas J.; Cury, Ricardo C.

2010-01-01

Introduction We have recently described a technique for assessing myocardial perfusion using adenosine-mediated stress imaging (CTP) with dual source computed tomography. SPECT myocardial perfusion imaging (SPECT-MPI) is a widely utilized and extensively validated method for assessing myocardial perfusion. The aim of this study was to determine the level of agreement between CTP and SPECT-MPI at rest and under stress on a per-segment, per-vessel, and per-patient basis. Methods Forty-seven consecutive patients underwent CTP and SPECT-MPI. Perfusion images were interpreted using the 17 segment AHA model and were scored on a 0 (normal) to 3 (abnormal) scale. Summed rest and stress scores were calculated for each vascular territory and patient by adding corresponding segmental scores. Results On a per-segment basis (n = 799), CTP and SPECT-MPI demonstrated excellent correlation: Goodman-Kruskall γ = .59 (P < .0001) for stress and .75 (P < .0001) for rest. On a per-vessel basis (n = 141), CTP and SPECT-MPI summed scores demonstrated good correlation: Pearson r = .56 (P < .0001) for stress and .66 (P < .0001) for rest. On a per-patient basis (n = 47), CTP and SPECT-MPI demonstrated good correlation: Pearson r = .60 (P < .0001) for stress and .76 (P < .0001) for rest. Conclusions CTP compares favorably with SPECT-MPI for detection, extent, and severity of myocardial perfusion defects at rest and stress. PMID:19936863

Ag2O:SiO2:V2O5 Glass System:. a Novel Reference Electrode for SO2 Gas Sensor

NASA Astrophysics Data System (ADS)

Singh, K.; Lad, A.; Bhoga, S. S.

2002-12-01

Ag2O:SiO2:V2O5 glass system with 0.5≤ y ≥ 0.66 for fixed n = 9 is synthesized, structurally and electrically characterized with a view to have high glass transition temperature (Tg ≈ 500°C) which can be used as solid reference electrode in electrochemical SOx gas sensor application. 10Ag2O:40SiO2:50V2O5 glass having Tg ≈ 502°C exhibits maximum bulk and electronic conductivity 3.67*10-3 and 4.47*10-2 S/cm, respectively at 450°C. The increase in conductivity is understood to be due to a mixed former effect. A few galvanic SOx sensors fabricated utilizing optimized glass as reference and Ag+ conducting solid electrolyte responds to change in PSOx according to 2 electron cell reaction.

Association of Antidementia Drugs and Mortality in Community-Dwelling Frail Older Patients With Dementia: The Role of Mortality Risk Assessment.

PubMed

Pilotto, Alberto; Polidori, Maria Cristina; Veronese, Nicola; Panza, Francesco; Arboretti Giancristofaro, Rosa; Pilotto, Andrea; Daragjati, Julia; Carrozzo, Eleonora; Prete, Camilla; Gallina, Pietro; Padovani, Alessandro; Maggi, Stefania

2018-02-01

To evaluate whether treatment with antidementia drugs is associated with reduced mortality in older patients with different mortality risk at baseline. Retrospective. Community-dwelling. A total of 6818 older people who underwent a Standardized Multidimensional Assessment Schedule for Adults and Aged Persons (SVaMA) evaluation to determine accessibility to homecare services or nursing home admission from 2005 to 2013 in the Padova Health District, Italy were included. Mortality risk at baseline was calculated by the Multidimensional Prognostic Index (MPI), based on information collected with the SVaMA. Participants were categorized to have mild (MPI-SVaMA-1), moderate (MPI-SVaMA-2), and high (MPI-SVaMA-3) mortality risk. Propensity score-adjusted hazard ratios (HR) of 2-year mortality were calculated according to antidementia drug treatment. Patients treated with antidementia drugs had a significant lower risk of death than untreated patients (HR 0.82; 95% confidence interval [CI] 0.73-0.92 and 0.56; 95% CI 0.49-0.65 for patients treated less than 2 years and more than 2 years treatment, respectively). After dividing patients according to their MPI-SVaMA grade, antidementia treatment was significantly associated with reduced mortality in the MPI-SVaMA-1 mild (HR 0.71; 95% CI 0.54-0.92) and MPI-SVaMA-2 moderate risk (HR 0.61; 95% CI 0.40-0.91, matched sample), but not in the MPI-SVaMA-3 high risk of death. This large community-dwelling patient study suggests that antidementia drugs might contribute to increased survival in older adults with dementia with lower mortality risk. Copyright © 2017 AMDA – The Society for Post-Acute and Long-Term Care Medicine. Published by Elsevier Inc. All rights reserved.

Cardiovascular outcomes after pharmacologic stress myocardial perfusion imaging.

PubMed

Lee, Douglas S; Husain, Mansoor; Wang, Xuesong; Austin, Peter C; Iwanochko, Robert M

2016-04-01

While pharmacologic stress single photon emission computed tomography myocardial perfusion imaging (SPECT-MPI) is used for noninvasive evaluation of patients who are unable to perform treadmill exercise, its impact on net reclassification improvement (NRI) of prognosis is unknown. We evaluated the prognostic value of pharmacologic stress MPI for prediction of cardiovascular death or non-fatal myocardial infarction (MI) within 1 year at a single-center, university-based laboratory. We examined continuous and categorical NRI of pharmacologic SPECT-MPI for prediction of outcomes beyond clinical factors alone. Six thousand two hundred forty patients (median age 66 years [IQR 56-74], 3466 men) were studied and followed for 5963 person-years. SPECT-MPI variables associated with increased risk of cardiovascular death or non-fatal MI included summed stress score, stress ST-shift, and post-stress resting left ventricular ejection fraction ≤50%. Compared to a clinical model which included age, sex, cardiovascular disease, risk factors, and medications, model χ(2) (210.5 vs. 281.9, P < .001) and c-statistic (0.74 vs. 0.78, P < .001) were significantly increased by addition of SPECT-MPI predictors (summed stress score, stress ST-shift and stress resting left ventricular ejection fraction). SPECT-MPI predictors increased continuous NRI by 49.4% (P < .001), reclassifying 66.5% of patients as lower risk and 32.8% as higher risk of cardiovascular death or non-fatal MI. Addition of MPI predictors to clinical factors using risk categories, defined as <1%, 1% to 3%, and >3% annualized risk of cardiovascular death or non-fatal MI, yielded a 15.0% improvement in NRI (95% CI 7.6%-27.6%, P < .001). Pharmacologic stress MPI substantially improved net reclassification of cardiovascular death or MI risk beyond that afforded by clinical factors. Copyright © 2016 Elsevier Inc. All rights reserved.

Relation of Coronary Flow Reserve to Other Findings on Positron Emission Tomography Myocardial Perfusion Imaging and Left Heart Catheterization in Patients With End-stage Renal Disease Being Evaluated for Kidney Transplant.

PubMed

Paz, Yehuda; Morgenstern, Rachelle; Weinberg, Richard; Chiles, Mariana; Bhatti, Navdeep; Ali, Ziad; Mohan, Sumit; Bokhari, Sabahat

2017-12-01

Cardiovascular disease is the leading cause of death in patients with end-stage renal disease (ESRD) and often goes undetected. Abnormal coronary flow reserve (CFR), which predicts increased risk of cardiac death, may be present in patients with ESRD without other evidence of coronary artery disease (CAD). We prospectively studied 131 patients who had rest and dipyridamole pharmacologic stress N 13 -ammonia positron emission tomography myocardial perfusion imaging (PET MPI) for kidney transplant evaluation. Thirty-four patients also had left heart catheterization. Abnormal PET MPI was defined as qualitative ischemia or infarct, stress electrocardiogram ischemia, or transient ischemic dilation. CFR was calculated as the ratio of stress to rest coronary blood flow. Global CFR < 2 was defined as abnormal. Of 131 patients who had PET MPI (66% male, 55.6 ± 12.1 years), 30% (39 of 131) had abnormal PET MPI and 59% (77 of 131) had abnormal CFR. In a subset of 34 patients who had left heart catheterization (66% male, 61.0 ± 12.1 years), 68% (23 of 34) had abnormal CFR on PET MPI, and 68% (23 of 34) had ≥70% obstruction on left heart catheterization. Abnormal CFR was not significantly associated with abnormal PET MPI (p = 0.13) or obstructive CAD on left heart catheterization (p = 0.26). In conclusion, in the first prospective study of PET MPI in patients with ESRD, abnormal CFR is highly prevalent and is independent of abnormal findings on PET MPI or obstructive CAD on left heart catheterization. Copyright © 2017 Elsevier Inc. All rights reserved.

Dobutamine stress myocardial perfusion imaging: 8-year outcomes in patients with diabetes mellitus.

PubMed

Boiten, Hendrik J; van Domburg, Ron T; Valkema, Roelf; Zijlstra, Felix; Schinkel, Arend F L

2016-08-01

Many studies have examined the prognostic value of myocardial perfusion imaging (MPI) using single-photon emission computed tomography (SPECT) for the prediction of short- to medium-term outcomes. However, the long-term prognostic value of MPI in patients with diabetes mellitus remains unclear. Therefore, this study assessed the long-term prognostic value of MPI in a high-risk cohort of patients with diabetes mellitus. A high-risk cohort of 207 patients with diabetes mellitus who were unable to undergo exercise testing underwent dobutamine stress MPI. Follow-up was successful in 206 patients; 12 patients were excluded due to early revascularization. The current data are based on the remaining 194 patients. Follow-up end points were all-cause mortality, cardiac mortality, and nonfatal myocardial infarction. The Kaplan-Meier survival curves were constructed, and univariable and multivariable analyses were performed to identify predictors of long-term outcome. During a mean follow-up of 8.1 ± 5.9 years, 134 (69%) patients died of which 68 (35%) died due to cardiac causes. Nonfatal myocardial infarction occurred in 24 patients (12%), and late (>60 days) coronary revascularization was performed in 61 (13%) patients. Survival analysis showed that MPI provided optimal risk stratification up to 4 years after testing. After that period, the outcome was comparable in patients with normal and abnormal MPI. Multivariable analyses showed that MPI provided incremental prognostic value up to 4 years after testing. In high-risk patients with diabetes mellitus, dobutamine MPI provides incremental prognostic information in addition to clinical data for a 4-year period after testing. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.

The Comprehensive Geriatric Assessment and the multidimensional approach. A new look at the older patient with gastroenterological disorders.

PubMed

Pilotto, Alberto; Addante, Filomena; D'Onofrio, Grazia; Sancarlo, Daniele; Ferrucci, Luigi

2009-01-01

The Comprehensive Geriatric Assessment (CGA) is a multidimensional, usually interdisciplinary, diagnostic process intended to determine an elderly person's medical, psychosocial, and functional capacity and problems with the objective of developing an overall plan for treatment and short- and long-term follow-up. The potential usefulness of the CGA in evaluating treatment and follow-up of older patients with gastroenterological disorders is unknown. In the paper we reported the efficacy of a Multidimensional-Prognostic Index (MPI), calculated from information collected by a standardized CGA, in predicting mortality risk in older patients hospitalized with upper gastrointestinal bleeding and liver cirrhosis. Patients underwent a CGA that included six standardized scales, i.e. Activities of Daily Living (ADL), Instrumental Activities of Daily Living (IADL), Short-Portable Mental Status Questionnaire (SPMSQ), Mini-Nutritional Assessment (MNA), Exton-Smith Score (ESS) and Comorbity Index Rating Scale (CIRS), as well as information on medication history and cohabitation, for a total of 63 items. The MPI was calculated from the integrated total scores and expressed as MPI 1=low risk, MPI 2=moderate risk and MPI 3=severe risk of mortality. Higher MPI values were significantly associated with higher short- and long-term mortality in older patients with both upper gastrointestinal bleeding and liver cirrhosis. A close agreement was found between the estimated mortality by MPI and the observed mortality. Moreover, MPI seems to have a greater discriminatory power than organ-specific prognostic indices such as Rockall and Blatchford scores (in upper gastrointestinal bleeding patients) and Child-Plugh score (in liver cirrhosis patients). All these findings support the concept that a multidimensional approach may be appropriate for the evaluation of older patients with gastroenterological disorders, like it has been reported for patients with other pathological conditions.

Myocardial perfusion imaging with PET

PubMed Central

Nakazato, Ryo; Berman, Daniel S; Alexanderson, Erick; Slomka, Piotr

2013-01-01

PET-myocardial perfusion imaging (MPI) allows accurate measurement of myocardial perfusion, absolute myocardial blood flow and function at stress and rest in a single study session performed in approximately 30 min. Various PET tracers are available for MPI, and rubidium-82 or nitrogen-13-ammonia is most commonly used. In addition, a new fluorine-18-based PET-MPI tracer is currently being evaluated. Relative quantification of PET perfusion images shows very high diagnostic accuracy for detection of obstructive coronary artery disease. Dynamic myocardial blood flow analysis has demonstrated additional prognostic value beyond relative perfusion imaging. Patient radiation dose can be reduced and image quality can be improved with latest advances in PET/CT equipment. Simultaneous assessment of both anatomy and perfusion by hybrid PET/CT can result in improved diagnostic accuracy. Compared with SPECT-MPI, PET-MPI provides higher diagnostic accuracy, using lower radiation doses during a shorter examination time period for the detection of coronary artery disease. PMID:23671459

How Formal Dynamic Verification Tools Facilitate Novel Concurrency Visualizations

NASA Astrophysics Data System (ADS)

Aananthakrishnan, Sriram; Delisi, Michael; Vakkalanka, Sarvani; Vo, Anh; Gopalakrishnan, Ganesh; Kirby, Robert M.; Thakur, Rajeev

With the exploding scale of concurrency, presenting valuable pieces of information collected by formal verification tools intuitively and graphically can greatly enhance concurrent system debugging. Traditional MPI program debuggers present trace views of MPI program executions. Such views are redundant, often containing equivalent traces that permute independent MPI calls. In our ISP formal dynamic verifier for MPI programs, we present a collection of alternate views made possible by the use of formal dynamic verification. Some of ISP’s views help pinpoint errors, some facilitate discerning errors by eliminating redundancy, while others help understand the program better by displaying concurrent even orderings that must be respected by all MPI implementations, in the form of completes-before graphs. In this paper, we describe ISP’s graphical user interface (GUI) capabilities in all these areas which are currently supported by a portable Java based GUI, a Microsoft Visual Studio GUI, and an Eclipse based GUI whose development is in progress.

Multiphoton imaging with high peak power VECSELs

NASA Astrophysics Data System (ADS)

Mirkhanov, Shamil; Quarterman, Adrian H.; Swift, Samuel; Praveen, Bavishna B.; Smyth, Conor J. C.; Wilcox, Keith G.

2016-03-01

Multiphoton imaging (MMPI) has become one of thee key non-invasive light microscopy techniques. This technique allows deep tissue imaging with high resolution and less photo-damage than conventional confocal microscopy. MPI is type of laser-scanning microscopy that employs localized nonlinear excitation, so that fluorescence is excited only with is scanned focal volume. For many years, Ti: sapphire femtosecond lasers have been the leading light sources for MPI applications. However, recent developments in laser sources and new types of fluorophores indicate that longer wavelength excitation could be a good alternative for these applications. Mode-locked VECSEELs have the potential to be low cost, compact light sources for MPI systems, with the additional advantage of broad wavelength coverage through use of different semiconductor material systems. Here, we use a femtosecond fibber laser to investigate the effect average power and repetition rate has on MPI image quality, to allow us to optimize our mode-locked VVECSELs for MPI.

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

Murase, Kenya, E-mail: murase@sahs.med.osaka-u.ac.jp; Song, Ruixiao; Hiratsuka, Samu

We investigated the feasibility of visualizing blood coagulation using a system for magnetic particle imaging (MPI). A magnetic field-free line is generated using two opposing neodymium magnets and transverse images are reconstructed from the third-harmonic signals received by a gradiometer coil, using the maximum likelihood-expectation maximization algorithm. Our MPI system was used to image the blood coagulation induced by adding CaCl{sub 2} to whole sheep blood mixed with magnetic nanoparticles (MNPs). The “MPI value” was defined as the pixel value of the transverse image reconstructed from the third-harmonic signals. MPI values were significantly smaller for coagulated blood samples than thosemore » without coagulation. We confirmed the rationale of these results by calculating the third-harmonic signals for the measured viscosities of samples, with an assumption that the magnetization and particle size distribution of MNPs obey the Langevin equation and log-normal distribution, respectively. We concluded that MPI can be useful for visualizing blood coagulation.« less

Memory Compression Techniques for Network Address Management in MPI

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

Guo, Yanfei; Archer, Charles J.; Blocksome, Michael

MPI allows applications to treat processes as a logical collection of integer ranks for each MPI communicator, while internally translating these logical ranks into actual network addresses. In current MPI implementations the management and lookup of such network addresses use memory sizes that are proportional to the number of processes in each communicator. In this paper, we propose a new mechanism, called AV-Rankmap, for managing such translation. AV-Rankmap takes advantage of logical patterns in rank-address mapping that most applications naturally tend to have, and it exploits the fact that some parts of network address structures are naturally more performance criticalmore » than others. It uses this information to compress the memory used for network address management. We demonstrate that AV-Rankmap can achieve performance similar to or better than that of other MPI implementations while using significantly less memory.« less

Facilitating Co-Design for Extreme-Scale Systems Through Lightweight Simulation

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

Engelmann, Christian; Lauer, Frank

This work focuses on tools for investigating algorithm performance at extreme scale with millions of concurrent threads and for evaluating the impact of future architecture choices to facilitate the co-design of high-performance computing (HPC) architectures and applications. The approach focuses on lightweight simulation of extreme-scale HPC systems with the needed amount of accuracy. The prototype presented in this paper is able to provide this capability using a parallel discrete event simulation (PDES), such that a Message Passing Interface (MPI) application can be executed at extreme scale, and its performance properties can be evaluated. The results of an initial prototype aremore » encouraging as a simple 'hello world' MPI program could be scaled up to 1,048,576 virtual MPI processes on a four-node cluster, and the performance properties of two MPI programs could be evaluated at up to 16,384 virtual MPI processes on the same system.« less

Evaluating and extending user-level fault tolerance in MPI applications

DOE PAGES

Laguna, Ignacio; Richards, David F.; Gamblin, Todd; ...

2016-01-11

The user-level failure mitigation (ULFM) interface has been proposed to provide fault-tolerant semantics in the Message Passing Interface (MPI). Previous work presented performance evaluations of ULFM; yet questions related to its programability and applicability, especially to non-trivial, bulk synchronous applications, remain unanswered. In this article, we present our experiences on using ULFM in a case study with a large, highly scalable, bulk synchronous molecular dynamics application to shed light on the advantages and difficulties of this interface to program fault-tolerant MPI applications. We found that, although ULFM is suitable for master–worker applications, it provides few benefits for more common bulkmore » synchronous MPI applications. Furthermore, to address these limitations, we introduce a new, simpler fault-tolerant interface for complex, bulk synchronous MPI programs with better applicability and support than ULFM for application-level recovery mechanisms, such as global rollback.« less

Accelerating Climate Simulations Through Hybrid Computing

NASA Technical Reports Server (NTRS)

Zhou, Shujia; Sinno, Scott; Cruz, Carlos; Purcell, Mark

2009-01-01

Unconventional multi-core processors (e.g., IBM Cell B/E and NYIDIDA GPU) have emerged as accelerators in climate simulation. However, climate models typically run on parallel computers with conventional processors (e.g., Intel and AMD) using MPI. Connecting accelerators to this architecture efficiently and easily becomes a critical issue. When using MPI for connection, we identified two challenges: (1) identical MPI implementation is required in both systems, and; (2) existing MPI code must be modified to accommodate the accelerators. In response, we have extended and deployed IBM Dynamic Application Virtualization (DAV) in a hybrid computing prototype system (one blade with two Intel quad-core processors, two IBM QS22 Cell blades, connected with Infiniband), allowing for seamlessly offloading compute-intensive functions to remote, heterogeneous accelerators in a scalable, load-balanced manner. Currently, a climate solar radiation model running with multiple MPI processes has been offloaded to multiple Cell blades with approx.10% network overhead.

A Convex Formulation for Magnetic Particle Imaging X-Space Reconstruction.

PubMed

Konkle, Justin J; Goodwill, Patrick W; Hensley, Daniel W; Orendorff, Ryan D; Lustig, Michael; Conolly, Steven M

2015-01-01

Magnetic Particle Imaging (mpi) is an emerging imaging modality with exceptional promise for clinical applications in rapid angiography, cell therapy tracking, cancer imaging, and inflammation imaging. Recent publications have demonstrated quantitative mpi across rat sized fields of view with x-space reconstruction methods. Critical to any medical imaging technology is the reliability and accuracy of image reconstruction. Because the average value of the mpi signal is lost during direct-feedthrough signal filtering, mpi reconstruction algorithms must recover this zero-frequency value. Prior x-space mpi recovery techniques were limited to 1d approaches which could introduce artifacts when reconstructing a 3d image. In this paper, we formulate x-space reconstruction as a 3d convex optimization problem and apply robust a priori knowledge of image smoothness and non-negativity to reduce non-physical banding and haze artifacts. We conclude with a discussion of the powerful extensibility of the presented formulation for future applications.

Tracking short-term biodistribution and long-term clearance of SPIO tracers in magnetic particle imaging

NASA Astrophysics Data System (ADS)

Keselman, Paul; Yu, Elaine Y.; Zhou, Xinyi Y.; Goodwill, Patrick W.; Chandrasekharan, Prashant; Ferguson, R. Matthew; Khandhar, Amit P.; Kemp, Scott J.; Krishnan, Kannan M.; Zheng, Bo; Conolly, Steven M.

2017-05-01

Magnetic particle imaging (MPI) is an emerging tracer-based medical imaging modality that images non-radioactive, kidney-safe superparamagnetic iron oxide (SPIO) tracers. MPI offers quantitative, high-contrast and high-SNR images, so MPI has exceptional promise for applications such as cell tracking, angiography, brain perfusion, cancer detection, traumatic brain injury and pulmonary imaging. In assessing MPI’s utility for applications mentioned above, it is important to be able to assess tracer short-term biodistribution as well as long-term clearance from the body. Here, we describe the biodistribution and clearance for two commonly used tracers in MPI: Ferucarbotran (Meito Sangyo Co., Japan) and LS-oo8 (LodeSpin Labs, Seattle, WA). We successfully demonstrate that 3D MPI is able to quantitatively assess short-term biodistribution, as well as long-term tracking and clearance of these tracers in vivo.

Using Modules with MPICH-G2 (and "Loose Ends")

NASA Technical Reports Server (NTRS)

Chang, Johnny; Thigpen, William W. (Technical Monitor)

2002-01-01

A new approach to running complex, distributed MPI jobs using the MPICH-G2 library is described. This approach allows the user to switch between different versions of compilers, system libraries, MPI libraries, etc. via the "module" command. The key idea is a departure from the prescribed "(jobtype=mpi)" approach to running distributed MPI jobs. The new method requires the user to provide a script that will be run as the "executable" with the "(jobtype=single)" RSL attribute. The major advantage of the proposed method is to enable users to decide in their own script what modules, environment, etc. they would like to have in running their job.

A Log-Scaling Fault Tolerant Agreement Algorithm for a Fault Tolerant MPI

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

Hursey, Joshua J; Naughton, III, Thomas J; Vallee, Geoffroy R

The lack of fault tolerance is becoming a limiting factor for application scalability in HPC systems. The MPI does not provide standardized fault tolerance interfaces and semantics. The MPI Forum's Fault Tolerance Working Group is proposing a collective fault tolerant agreement algorithm for the next MPI standard. Such algorithms play a central role in many fault tolerant applications. This paper combines a log-scaling two-phase commit agreement algorithm with a reduction operation to provide the necessary functionality for the new collective without any additional messages. Error handling mechanisms are described that preserve the fault tolerance properties while maintaining overall scalability.

New Trends in Radionuclide Myocardial Perfusion Imaging

PubMed Central

Hung, Guang-Uei; Wang, Yuh-Feng; Su, Hung-Yi; Hsieh, Te-Chun; Ko, Chi-Lun; Yen, Ruoh-Fang

2016-01-01

Radionuclide myocardial perfusion imaging (MPI) with single photon emission computed tomography (SPECT) has been widely used clinically as one of the major functional imaging modalities for patients with coronary artery disease (CAD) for decades. Ample evidence has supported the use of MPI as a useful and important tool in the diagnosis, risk stratification and treatment planning for CAD. Although popular in the United States, MPI has become the most frequently used imaging modality among all nuclear medicine tests in Taiwan. However, it should be acknowledged that MPI SPECT does have its limitations. These include false-positive results due to certain artifacts, false-negative due to balanced ischemia, complexity and adverse reaction arising from current pharmacological stressors, time consuming nature of the imaging procedure, no blood flow quantitation and relatively high radiation exposure. The purpose of this article was to review the recent trends in nuclear cardiology, including the utilization of positron emission tomography (PET) for MPI, new stressor, new SPECT camera with higher resolution and higher sensitivity, dynamic SPECT protocol for blood flow quantitation, new software of phase analysis for evaluation of LV dyssynchrony, and measures utilized for reducing radiation exposure of MPI. PMID:27122946

Relaxation-based viscosity mapping for magnetic particle imaging.

PubMed

Utkur, M; Muslu, Y; Saritas, E U

2017-05-07

Magnetic particle imaging (MPI) has been shown to provide remarkable contrast for imaging applications such as angiography, stem cell tracking, and cancer imaging. Recently, there is growing interest in the functional imaging capabilities of MPI, where 'color MPI' techniques have explored separating different nanoparticles, which could potentially be used to distinguish nanoparticles in different states or environments. Viscosity mapping is a promising functional imaging application for MPI, as increased viscosity levels in vivo have been associated with numerous diseases such as hypertension, atherosclerosis, and cancer. In this work, we propose a viscosity mapping technique for MPI through the estimation of the relaxation time constant of the nanoparticles. Importantly, the proposed time constant estimation scheme does not require any prior information regarding the nanoparticles. We validate this method with extensive experiments in an in-house magnetic particle spectroscopy (MPS) setup at four different frequencies (between 250 Hz and 10.8 kHz) and at three different field strengths (between 5 mT and 15 mT) for viscosities ranging between 0.89 mPa · s-15.33 mPa · s. Our results demonstrate the viscosity mapping ability of MPI in the biologically relevant viscosity range.

Development of training modules for magnetic particle inspection

NASA Astrophysics Data System (ADS)

Kosaka, Daigo; Eisenmann, David J.; Enyart, Darrel; Nakagawa, Norio; Lo, Chester; Orman, David

2015-03-01

Magnetic particle inspection (MPI) is a nondestructive evaluation technique used with ferromagnetic materials. Although the application of this method may appear straightforward, MPI combines the complicated nature of electromagnetics, metallurgical material effects, fluid-particle motion dynamics, and physiological human factors into a single inspection. To fully appreciate industry specifications such as ASTM E-1444, users should develop a basic understanding of the many factors that are involved in MPI. We have developed a series of MPI training modules that are aimed at addressing this requirement. The modules not only offer qualitative explanations, but also show quantitative explanations in terms of measurement and numerical simulation data in many instances. There are five modules in all. Module ♯1 shows characteristics of waveforms and magnetizing methods. This allows MPI practitioners to make optimum choice of waveform and magnetizing method. Module ♯2 explains how material properties relate to the magnetic characteristics. Module ♯3 shows the strength of the excitation field or the flux leakage from a crack and how it compares to the detectability of a crack by MPI. Module ♯4 shows how specimen status may influence defect detection. Module ♯5 shows the effects of particle properties on defect detection.

KSC-99pp0514

NASA Image and Video Library

1999-05-12

At Launch Pad 39B, the top of the external tank (ET) mated to Space Shuttle Discovery is dotted with nearly a dozen visible dings from recent hail storms. Workers are investigating the damage and potential problems for launch posed by ice forming in the holes, which may number as many as 150 over the entire tank. The average size of the dings is one-half inch in diameter and one-tenth inch deep. The external tank contains the liquid hydrogen fuel and liquid oxygen oxidizer and supplies them under pressure to the three space shuttle main engines in the orbiter during liftoff and ascent. The ET thermal protection system consists of sprayed-on foam insulation. The Shuttle Discovery is targeted for launch of mission STS-96 on May 20 at 9:32 a.m

Mannose phosphate isomerase regulates fibroblast growth factor receptor family signaling and glioma radiosensitivity.

PubMed

Cazet, Aurélie; Charest, Jonathan; Bennett, Daniel C; Sambrooks, Cecilia Lopez; Contessa, Joseph N

2014-01-01

Asparagine-linked glycosylation is an endoplasmic reticulum co- and post-translational modification that enables the transit and function of receptor tyrosine kinase (RTK) glycoproteins. To gain insight into the regulatory role of glycosylation enzymes on RTK function, we investigated shRNA and siRNA knockdown of mannose phosphate isomerase (MPI), an enzyme required for mature glycan precursor biosynthesis. Loss of MPI activity reduced phosphorylation of FGFR family receptors in U-251 and SKMG-3 malignant glioma cell lines and also resulted in significant decreases in FRS2, Akt, and MAPK signaling. However, MPI knockdown did not affect ligand-induced activation or signaling of EGFR or MET RTKs, suggesting that FGFRs are more susceptible to MPI inhibition. The reductions in FGFR signaling were not caused by loss of FGF ligands or receptors, but instead were caused by interference with receptor dimerization. Investigations into the cellular consequences of MPI knockdown showed that cellular programs driven by FGFR signaling, and integral to the clinical progression of malignant glioma, were impaired. In addition to a blockade of cellular migration, MPI knockdown also significantly reduced glioma cell clonogenic survival following ionizing radiation. Therefore our results suggest that targeted inhibition of enzymes required for cell surface receptor glycosylation can be manipulated to produce discrete and limited consequences for critical client glycoproteins expressed by tumor cells. Furthermore, this work identifies MPI as a potential enzymatic target for disrupting cell surface receptor-dependent survival signaling and as a novel approach for therapeutic radiosensitization.

ParDRe: faster parallel duplicated reads removal tool for sequencing studies.

PubMed

González-Domínguez, Jorge; Schmidt, Bertil

2016-05-15

Current next generation sequencing technologies often generate duplicated or near-duplicated reads that (depending on the application scenario) do not provide any interesting biological information but can increase memory requirements and computational time of downstream analysis. In this work we present ParDRe, a de novo parallel tool to remove duplicated and near-duplicated reads through the clustering of Single-End or Paired-End sequences from fasta or fastq files. It uses a novel bitwise approach to compare the suffixes of DNA strings and employs hybrid MPI/multithreading to reduce runtime on multicore systems. We show that ParDRe is up to 27.29 times faster than Fulcrum (a representative state-of-the-art tool) on a platform with two 8-core Sandy-Bridge processors. Source code in C ++ and MPI running on Linux systems as well as a reference manual are available at https://sourceforge.net/projects/pardre/ jgonzalezd@udc.es. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Eddy current-shielded x-space relaxometer for sensitive magnetic nanoparticle characterization

PubMed Central

Bauer, L. M.; Hensley, D. W.; Zheng, B.; Tay, Z. W.; Goodwill, P. W.; Griswold, M. A.; Conolly, S. M.

2016-01-01

The development of magnetic particle imaging (MPI) has created a need for optimized magnetic nanoparticles. Magnetic particle relaxometry is an excellent tool for characterizing potential tracers for MPI. In this paper, we describe the design and construction of a high-throughput tabletop relaxometer that is able to make sensitive measurements of MPI tracers without the need for a dedicated shield room. PMID:27250472

Eddy current-shielded x-space relaxometer for sensitive magnetic nanoparticle characterization.

PubMed

Bauer, L M; Hensley, D W; Zheng, B; Tay, Z W; Goodwill, P W; Griswold, M A; Conolly, S M

2016-05-01

The development of magnetic particle imaging (MPI) has created a need for optimized magnetic nanoparticles. Magnetic particle relaxometry is an excellent tool for characterizing potential tracers for MPI. In this paper, we describe the design and construction of a high-throughput tabletop relaxometer that is able to make sensitive measurements of MPI tracers without the need for a dedicated shield room.

[Peritonitis in diverticulitis: the Bern concept].

PubMed

Seiler, C A; Brügger, L; Maurer, C A; Renzulli, P; Büchler, M W

1998-01-01

The colon is the most frequent origine for a diffuse peritonitis and diverticular perforation is again the most common source of a spontaneous secondary peritonitis. This paper first focuses on the treatment of peritonitis and secondly on the strategies of source control in peritonitis with special emphasis on the tactics (primary anastomosis vs. Hartmann procedure with colostomy) for surgical source control. Prospective analysis of 404 patients suffering from peritonitis (11/93-2/98), treated with an uniform treatment concept including early operation, source control and extensive intraoperative lavage (20 to 30 liters) as a standard procedure. Other treatment measures were added in special indications "on demand" only. Peritonitis was graded with the Mannheim Peritonitis Index (MPI). Tactics of source control in peritonitis due to diverticulitis were performed according to "general condition" respectively the MPI of the patient. The 404 patients averaged a MPI of 19 (0-35) in "local" peritonitis and a MPI of 26 (11-43) in "diffuse" peritonitis. The colon as a source of peritonitis resulted in MPI of 16 (0-33) in the case of "local" respectively 27 (11-43) in "diffuse" peritonitis. From 181 patients suffering from diverticulitis 144 needed an operation and in 78 (54%) peritonitis was present. Fourty-six percent (36) of the patients suffered from "local", 54% (42) from "diffuse" peritonitis. Resection with primary anastomosis was performed in 26% (20/78) whereas in 74% (58/78) of the patients a Hartmann procedure with colostomy was performed. The correlating MPI was 16 (0-28) vs. 23 (16-27) respectively. The analysis of complications and mortality based on the MPI showed a decent discrimination potential for primary anastomosis vs Hartmann procedure: morbidity 35% vs. 41%; reoperation 5% vs. 5%; mortality 0% vs. 14%. In case of peritonitis due to diverticulitis the treatment of peritonitis comes first. Thanks to advances in intensive care and improved anti-inflammatory care, a more conservative surgical concept nowadays is accepted. In the case of diverticulitis the MPI is helpful to choose between primary anastomosis vs. Hartmann procedure with colostomy as source control. The MPI includes the "general condition" of the patient into the tactical decision how to attain source control.

Electrolytic cell with reference electrode

DOEpatents

Kessie, Robert W.

1989-01-01

A reference electrode device is provided for a high temperature electrolytic cell used to electrolytically recover uranium from spent reactor fuel dissolved in an anode pool, the device having a glass tube to enclose the electrode and electrolyte and serve as a conductive membrane with the cell electrolyte, and an outer metal tube about the glass tube to serve as a shield and basket for any glass sections broken by handling of the tube to prevent their contact with the anode pool, the metal tube having perforations to provide access between the bulk of the cell electrolyte and glass membrane.

Reference electrode for electrolytic cell

DOEpatents

Kessie, R.W.

1988-07-28

A reference electrode device is provided for a high temperature electrolytic cell used to electrolytically recover uranium from spent reactor fuel dissolved in an anode pool, the device having a glass tube to enclose the electrode and electrolyte and serve as a conductive membrane with the cell electrolyte, and an outer metal tube about the glass tube to serve as a shield and basket for any glass sections broken by handling of the tube to prevent their contact with the anode pool, the metal tube having perforations to provide access between the bulk of the cell electrolyte and glass membrane. 4 figs.

Basin-Scale Assessment of the Land Surface Water Budget in the National Centers for Environmental Prediction Operational and Research NLDAS-2 Systems

NASA Technical Reports Server (NTRS)

Xia, Youlong; Cosgrove, Brian A.; Mitchell, Kenneth E.; Peters-Lidard, Christa D.; Ek, Michael B.; Brewer, Michael; Mocko, David; Kumar, Sujay V.; Wei, Helin; Meng, Jesse;

Improved field free line magnetic particle imaging using saddle coils.

PubMed

Erbe, Marlitt; Sattel, Timo F; Buzug, Thorsten M

2013-12-01

Magnetic particle imaging (MPI) is a novel tracer-based imaging method detecting the distribution of superparamagnetic iron oxide (SPIO) nanoparticles in vivo in three dimensions and in real time. Conventionally, MPI uses the signal emitted by SPIO tracer material located at a field free point (FFP). To increase the sensitivity of MPI, however, an alternative encoding scheme collecting the particle signal along a field free line (FFL) was proposed. To provide the magnetic fields needed for line imaging in MPI, a very efficient scanner setup regarding electrical power consumption is needed. At the same time, the scanner needs to provide a high magnetic field homogeneity along the FFL as well as parallel to its alignment to prevent the appearance of artifacts, using efficient radon-based reconstruction methods arising for a line encoding scheme. This work presents a dynamic FFL scanner setup for MPI that outperforms all previously presented setups in electrical power consumption as well as magnetic field quality.

MPI implementation of PHOENICS: A general purpose computational fluid dynamics code

NASA Astrophysics Data System (ADS)

Simunovic, S.; Zacharia, T.; Baltas, N.; Spalding, D. B.

1995-03-01

PHOENICS is a suite of computational analysis programs that are used for simulation of fluid flow, heat transfer, and dynamical reaction processes. The parallel version of the solver EARTH for the Computational Fluid Dynamics (CFD) program PHOENICS has been implemented using Message Passing Interface (MPI) standard. Implementation of MPI version of PHOENICS makes this computational tool portable to a wide range of parallel machines and enables the use of high performance computing for large scale computational simulations. MPI libraries are available on several parallel architectures making the program usable across different architectures as well as on heterogeneous computer networks. The Intel Paragon NX and MPI versions of the program have been developed and tested on massively parallel supercomputers Intel Paragon XP/S 5, XP/S 35, and Kendall Square Research, and on the multiprocessor SGI Onyx computer at Oak Ridge National Laboratory. The preliminary testing results of the developed program have shown scalable performance for reasonably sized computational domains.

MPI implementation of PHOENICS: A general purpose computational fluid dynamics code

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

Simunovic, S.; Zacharia, T.; Baltas, N.

1995-04-01

PHOENICS is a suite of computational analysis programs that are used for simulation of fluid flow, heat transfer, and dynamical reaction processes. The parallel version of the solver EARTH for the Computational Fluid Dynamics (CFD) program PHOENICS has been implemented using Message Passing Interface (MPI) standard. Implementation of MPI version of PHOENICS makes this computational tool portable to a wide range of parallel machines and enables the use of high performance computing for large scale computational simulations. MPI libraries are available on several parallel architectures making the program usable across different architectures as well as on heterogeneous computer networks. Themore » Intel Paragon NX and MPI versions of the program have been developed and tested on massively parallel supercomputers Intel Paragon XP/S 5, XP/S 35, and Kendall Square Research, and on the multiprocessor SGI Onyx computer at Oak Ridge National Laboratory. The preliminary testing results of the developed program have shown scalable performance for reasonably sized computational domains.« less

Enhancing Application Performance Using Mini-Apps: Comparison of Hybrid Parallel Programming Paradigms

NASA Technical Reports Server (NTRS)

Lawson, Gary; Sosonkina, Masha; Baurle, Robert; Hammond, Dana

2017-01-01

In many fields, real-world applications for High Performance Computing have already been developed. For these applications to stay up-to-date, new parallel strategies must be explored to yield the best performance; however, restructuring or modifying a real-world application may be daunting depending on the size of the code. In this case, a mini-app may be employed to quickly explore such options without modifying the entire code. In this work, several mini-apps have been created to enhance a real-world application performance, namely the VULCAN code for complex flow analysis developed at the NASA Langley Research Center. These mini-apps explore hybrid parallel programming paradigms with Message Passing Interface (MPI) for distributed memory access and either Shared MPI (SMPI) or OpenMP for shared memory accesses. Performance testing shows that MPI+SMPI yields the best execution performance, while requiring the largest number of code changes. A maximum speedup of 23 was measured for MPI+SMPI, but only 11 was measured for MPI+OpenMP.

Performance of OVERFLOW-D Applications based on Hybrid and MPI Paradigms on IBM Power4 System

NASA Technical Reports Server (NTRS)

Djomehri, M. Jahed; Biegel, Bryan (Technical Monitor)

2002-01-01

This report briefly discusses our preliminary performance experiments with parallel versions of OVERFLOW-D applications. These applications are based on MPI and hybrid paradigms on the IBM Power4 system here at the NAS Division. This work is part of an effort to determine the suitability of the system and its parallel libraries (MPI/OpenMP) for specific scientific computing objectives.

: A Scalable and Transparent System for Simulating MPI Programs

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

Perumalla, Kalyan S

2010-01-01

is a scalable, transparent system for experimenting with the execution of parallel programs on simulated computing platforms. The level of simulated detail can be varied for application behavior as well as for machine characteristics. Unique features of are repeatability of execution, scalability to millions of simulated (virtual) MPI ranks, scalability to hundreds of thousands of host (real) MPI ranks, portability of the system to a variety of host supercomputing platforms, and the ability to experiment with scientific applications whose source-code is available. The set of source-code interfaces supported by is being expanded to support a wider set of applications, andmore » MPI-based scientific computing benchmarks are being ported. In proof-of-concept experiments, has been successfully exercised to spawn and sustain very large-scale executions of an MPI test program given in source code form. Low slowdowns are observed, due to its use of purely discrete event style of execution, and due to the scalability and efficiency of the underlying parallel discrete event simulation engine, sik. In the largest runs, has been executed on up to 216,000 cores of a Cray XT5 supercomputer, successfully simulating over 27 million virtual MPI ranks, each virtual rank containing its own thread context, and all ranks fully synchronized by virtual time.« less

Assessment of Fetal Myocardial Performance Index in Women with Placenta Previa.

PubMed

Zhang, Na; Sun, Lijuan; Zhang, Lina; Li, Zhen; Han, Jijing; Wu, Qingqing

2017-12-15

BACKGROUND This study investigated whether fetuses of placenta previa pregnancies have cardiac dysfunction by use of a modified myocardial performance index (Mod-MPI). MATERIAL AND METHODS A prospective cross-sectional study was conducted including 178 fetuses at 28-40 weeks of gestation. Eighty-nine fetuses of mothers with placenta previa and without pregnancy complications were recruited (placenta previa group) and matched with 89 fetuses of mothers with normal pregnancies (control group). Fetal cardiac function parameters and perinatal outcomes as well as the Mod-MPI were compared between the 2 groups. RESULTS The median Mod-MPI was significantly increased in fetuses of mothers with placenta previa compared with controls (0.47±0.05 vs. 0.45±0.05; P<0.01). Among fetuses of mothers with or without placenta previa, the Mod-MPI was significantly higher in the incomplete placenta previa group compared with the complete placenta previa group and control group (P<0.01). An increased Mod-MPI in placenta previa pregnancies was independently associated with fetal cord pH <7.2 (odds ratio, 4.8; 95% confidence interval, 0.98-23.54; P=0.003). CONCLUSIONS There is impairment of fetal cardiac function in pregnancies with placenta previa. An increased MPI was independently associated with adverse perinatal outcomes to some extent in the placenta previa pregnancies.

[Three-dimensional finite element modeling and biomechanical simulation for evaluating and improving postoperative internal instrumentation of neck-thoracic vertebral tumor en bloc resection].

PubMed

Qinghua, Zhao; Jipeng, Li; Yongxing, Zhang; He, Liang; Xuepeng, Wang; Peng, Yan; Xiaofeng, Wu

2015-04-07

To employ three-dimensional finite element modeling and biomechanical simulation for evaluating the stability and stress conduction of two postoperative internal fixed modeling-multilevel posterior instrumentation ( MPI) and MPI with anterior instrumentation (MPAI) with neck-thoracic vertebral tumor en bloc resection. Mimics software and computed tomography (CT) images were used to establish the three-dimensional (3D) model of vertebrae C5-T2 and simulated the C7 en bloc vertebral resection for MPI and MPAI modeling. Then the statistics and images were transmitted into the ANSYS finite element system and 20N distribution load (simulating body weight) and applied 1 N · m torque on neutral point for simulating vertebral displacement and stress conduction and distribution of motion mode, i. e. flexion, extension, bending and rotating. With a better stability, the displacement of two adjacent vertebral bodies of MPI and MPAI modeling was less than that of complete vertebral modeling. No significant differences existed between each other. But as for stress shielding effect reduction, MPI was slightly better than MPAI. From biomechanical point of view, two internal instrumentations with neck-thoracic tumor en bloc resection may achieve an excellent stability with no significant differences. But with better stress conduction, MPI is more advantageous in postoperative reconstruction.

Quantitative Magnetic Particle Imaging Monitors the Transplantation, Biodistribution, and Clearance of Stem Cells In Vivo

PubMed Central

Zheng, Bo; von See, Marc P.; Yu, Elaine; Gunel, Beliz; Lu, Kuan; Vazin, Tandis; Schaffer, David V.; Goodwill, Patrick W.; Conolly, Steven M.

2016-01-01

Stem cell therapies have enormous potential for treating many debilitating diseases, including heart failure, stroke and traumatic brain injury. For maximal efficacy, these therapies require targeted cell delivery to specific tissues followed by successful cell engraftment. However, targeted delivery remains an open challenge. As one example, it is common for intravenous deliveries of mesenchymal stem cells (MSCs) to become entrapped in lung microvasculature instead of the target tissue. Hence, a robust, quantitative imaging method would be essential for developing efficacious cell therapies. Here we show that Magnetic Particle Imaging (MPI), a novel technique that directly images iron-oxide nanoparticle-tagged cells, can longitudinally monitor and quantify MSC administration in vivo. MPI offers near-ideal image contrast, depth penetration, and robustness; these properties make MPI both ultra-sensitive and linearly quantitative. Here, we imaged, for the first time, the dynamic trafficking of intravenous MSC administrations using MPI. Our results indicate that labeled MSC injections are immediately entrapped in lung tissue and then clear to the liver within one day, whereas standard iron oxide particle (Resovist) injections are immediately taken up by liver and spleen. Longitudinal MPI-CT imaging also indicated a clearance half-life of MSC iron oxide labels in the liver at 4.6 days. Finally, our ex vivo MPI biodistribution measurements of iron in liver, spleen, heart, and lungs after injection showed excellent agreement (R2 = 0.943) with measurements from induction coupled plasma spectrometry. These results demonstrate that MPI offers strong utility for noninvasively imaging and quantifying the systemic distribution of cell therapies and other therapeutic agents. PMID:26909106

Costs and clinical outcomes for non-invasive versus invasive diagnostic approaches to patients with suspected in-stent restenosis.

PubMed

Min, James K; Hasegawa, James T; Machacz, Susanne F; O'Day, Ken

2016-02-01

This study compared costs and clinical outcomes of invasive versus non-invasive diagnostic evaluations for patients with suspected in-stent restenosis (ISR) after percutaneous coronary intervention. We developed a decision model to compare 2 year diagnosis-related costs for patients who presented with suspected ISR and were evaluated by: (1) invasive coronary angiography (ICA); (2) non-invasive stress testing strategy of myocardial perfusion imaging (MPI) with referral to ICA based on MPI; (3) coronary CT angiography-based testing strategy with referral to ICA based on CCTA. Costs were modeled from the payer's perspective using 2014 Medicare rates. 56 % of patients underwent follow-up diagnostic testing over 2 years. Compared to ICA, MPI (98.6 %) and CCTA (98.1 %) exhibited lower rates of correct diagnoses. Non-invasive strategies were associated with reduced referrals to ICA and costs compared to an ICA-based strategy, with diagnostic costs lower for CCTA than MPI. Overall 2-year costs were highest for ICA for both metallic as well as BVS stents ($1656 and $1656, respectively) when compared to MPI ($1444 and $1411) and CCTA. CCTA costs differed based upon stent size and type, and were highest for metallic stents >3.0 mm followed by metallic stents <3.0 mm, BVS < 3.0 mm and BVS > 3.0 mm ($1466 vs. $1242 vs. $855 vs. $490, respectively). MPI for suspected ISR results in lower costs and rates of complications than invasive strategies using ICA while maintaining high diagnostic performance. Depending upon stent size and type, CCTA results in lower costs than MPI.

Discovery Orbiter Major Modifications

NASA Image and Video Library

2003-08-27

In the Vehicle Assembly Building, Jim Landy, NDE specialist, sets up a flight crew lockers for flash thermography. He is screening the lockers for hidden damage underneath dings and dents that might occur during handling.

Multiple Testing, Cumulative Radiation Dose, and Clinical Indications in Patients Undergoing Myocardial Perfusion Imaging

PubMed Central

Einstein, Andrew J.; Weiner, Shepard D.; Bernheim, Adam; Kulon, Michal; Bokhari, Sabahat; Johnson, Lynne L.; Moses, Jeffrey W.; Balter, Stephen

2013-01-01

Context Myocardial perfusion imaging (MPI) is the single medical test with the highest radiation burden to the US population. While many patients undergoing MPI receive repeat MPI testing, or additional procedures involving ionizing radiation, no data are available characterizing their total longitudinal radiation burden and relating radiation burden with reasons for testing. Objective To characterize procedure counts, cumulative estimated effective doses of radiation, and clinical indications, for patients undergoing MPI. Design, Setting, Patients Retrospective cohort study evaluating, for 1097 consecutive patients undergoing index MPI during the first 100 days of 2006 at Columbia University Medical Center, all preceding medical imaging procedures involving ionizing radiation undergone beginning October 1988, and all subsequent procedures through June 2008, at that center. Main Outcome Measures Cumulative estimated effective dose of radiation, number of procedures involving radiation, and indications for testing. Results Patients underwent a median (interquartile range, mean) of 15 (6–32, 23.9) procedures involving radiation exposure; 4 (2–8, 6.5) were high-dose (≥3 mSv, i.e. one year's background radiation), including 1 (1–2, 1.8) MPI studies per patient. 31% of patients received cumulative estimated effective dose from all medical sources >100mSv. Multiple MPIs were performed in 39% of patients, for whom cumulative estimated effective dose was 121 (81–189, 149) mSv. Men and whites had higher cumulative estimated effective doses, and there was a trend towards men being more likely to undergo multiple MPIs than women (40.8% vs. 36.6%, Odds ratio 1.29, 95% confidence interval 0.98–1.69). Over 80% of initial and 90% of repeat MPI exams were performed in patients with known cardiac disease or symptoms consistent with it. Conclusion In this institution, multiple testing with MPI was very common, and in many patients associated with very high cumulative estimated doses of radiation. PMID:21078807

The geochemistry of Seine River Basin particulate matter: Distribution of an integrated metal pollution index

USGS Publications Warehouse

Meybeck, Michel; Horowitz, A.J.; Grosbois, C.

2004-01-01

Spatial analysis (1994-2001) and temporal trends (1980-2000) for particulate-associated metals at key stations in the Seine River Basin have been determined using a new metal pollution index (MPI). The MPI is based on the concentrations of Cd, Cu, Hg, Pb and Zn, normalized to calculated background levels estimated for each particulate matter samples for four fractions (clays and other aluminosilicates, carbonates, organic matter, and quartz). Background levels ascribed to each fraction were determined from a specific set of samples collected from relatively pristine areas in the upper Seine basin and validated on prehistoric samples. The unitless MPI is designed to vary between 0 for pristine samples to 100 for the ones extremely impacted by human activities and to assess the trends of general metal contamination and its mapping. Throughout the Seine basin, MPI currently range from 1 to 40, but values exceeding 100 have been found in periurban streams and the Eure tributary. Based on the MPI spatial distribution, the Seine River Basin displays a wide range of anthropogenic impacts linked to variations in population density, stream order, wastewater discharges and industrial activities. Correlations between the MPI and other trace elements indicate that anthropogenic impacts also strongly affect the concentrations of Ag, Sb, and P, marginally affect the concentrations of Ba, Ni, and Cr, and appear to have little effect on the concentrations of Li, Be, V, Co, and the major elements. Temporal MPI trends can also be reconstituted from past regulatory surveys. In the early 1980s, MPI were 2-5 times higher than nowadays at most locations, particularly downstream of Greater Paris where it reached levels as high as 250 (now 40), a value characteristic of present Paris urban sewage. The exceptional contamination of the Seine basin is gradually improving over the last 20 years but remains very high. ?? 2004 Elsevier B.V. All rights reserved.

Predictors and Diagnostic Significance of the Adenosine Related Side Effects on Myocardial Perfusion SPECT/CT Imaging

PubMed Central

Yıldırım Poyraz, Nilüfer; Özdemir, Elif; Poyraz, Barış Mustafa; Kandemir, Zuhal; Keskin, Mutlay; Türkölmez, Şeyda

2014-01-01

Objective: The aim of this study was to investigate the relationship between patient characteristics and adenosine-related side-effects during stress myocard perfusion imaging (MPI). The effect of presence of adenosine-related side-effects on the diagnostic value of MPI with integrated SPECT/CT system for coronary artery disease (CAD), was also assessed in this study. Methods: Total of 281 patients (109 M, 172 F; mean age:62.6±10) who underwent standard adenosine stress protocol for MPI, were included in this study. All symptoms during adenosine infusion were scored according to the severity and duration. For the estimation of diagnostic value of adenosine MPI with integrated SPECT/CT system, coronary angiography (CAG) or clinical follow-up were used as gold standard. Results: Total of 173 patients (61.6%) experienced adenosine-related side-effects (group 1); flushing, dyspnea, and chest pain were the most common. Other 108 patients completed pharmacologic stress (PS) test without any side-effects (group 2). Test tolerability were similar in the patients with cardiovascular or airway disease to others, however dyspnea were observed significantly more common in patients with mild airway disease. Body mass index (BMI) ≥30 kg/m2 and age ≤45 years were independent predictors of side-effects. The diagnostic value of MPI was similar in both groups. Sensitivity of adenosine MPI SPECT/CT was calculated to be 86%, specificity was 94% and diagnostic accuracy was 92% for diagnosis of CAD. Conclusion: Adenosine MPI is a feasible and well tolerated method in patients who are not suitable for exercise stress test as well as patients with cardiopulmonary disease. However age ≤45 years and BMI ≥30 kg/m2 are the positive predictors of adenosine-related side-effects, the diagnostic value of adenosine MPI SPECT/CT is not affected by the presence of adenosine related side-effects. PMID:25541932

What Multilevel Parallel Programs do when you are not Watching: A Performance Analysis Case Study Comparing MPI/OpenMP, MLP, and Nested OpenMP

NASA Technical Reports Server (NTRS)

Jost, Gabriele; Labarta, Jesus; Gimenez, Judit

2004-01-01

With the current trend in parallel computer architectures towards clusters of shared memory symmetric multi-processors, parallel programming techniques have evolved that support parallelism beyond a single level. When comparing the performance of applications based on different programming paradigms, it is important to differentiate between the influence of the programming model itself and other factors, such as implementation specific behavior of the operating system (OS) or architectural issues. Rewriting-a large scientific application in order to employ a new programming paradigms is usually a time consuming and error prone task. Before embarking on such an endeavor it is important to determine that there is really a gain that would not be possible with the current implementation. A detailed performance analysis is crucial to clarify these issues. The multilevel programming paradigms considered in this study are hybrid MPI/OpenMP, MLP, and nested OpenMP. The hybrid MPI/OpenMP approach is based on using MPI [7] for the coarse grained parallelization and OpenMP [9] for fine grained loop level parallelism. The MPI programming paradigm assumes a private address space for each process. Data is transferred by explicitly exchanging messages via calls to the MPI library. This model was originally designed for distributed memory architectures but is also suitable for shared memory systems. The second paradigm under consideration is MLP which was developed by Taft. The approach is similar to MPi/OpenMP, using a mix of coarse grain process level parallelization and loop level OpenMP parallelization. As it is the case with MPI, a private address space is assumed for each process. The MLP approach was developed for ccNUMA architectures and explicitly takes advantage of the availability of shared memory. A shared memory arena which is accessible by all processes is required. Communication is done by reading from and writing to the shared memory.

Slump with Success

ERIC Educational Resources Information Center

White, Heather

2008-01-01

Glass slumping is one of those projects that gives students a feeling of success and accomplishment. Glass slumping looks difficult to produce, and it often leaves others wondering how it is created. Slumping glass can provide dramatic results. Slumping refers to glass that, when heated, softens and conforms to the shape of a mold. Elementary…

KSC-03PD-2548

NASA Technical Reports Server (NTRS)

2003-01-01

KENNEDY SPACE CENTER, FLA. In the Vehicle Assembly Building, Jim Landy, NDE specialist, performs flash thermography on flight crew lockers. He is screening the lockers for hidden damage underneath dings and dents that might occur during handling.

KSC-03PD-2549

NASA Technical Reports Server (NTRS)

2003-01-01

KENNEDY SPACE CENTER, FLA. In the Vehicle Assembly Building, Jim Landy, NDE specialist, examines flight crew lockers using flash thermography. He is screening the lockers for hidden damage underneath dings and dents that might occur during handling.

Reflection states in Ding-Iohara-Miki algebra and brane-web for D-type quiver

NASA Astrophysics Data System (ADS)

Bourgine, J.-E.; Fukuda, M.; Matsuo, Y.; Zhu, R.-D.

2017-12-01

Reflection states are introduced in the vertical and horizontal modules of the Ding-Iohara-Miki (DIM) algebra (quantum toroidal gl_1 ). Webs of DIM representations are in correspondence with ( p, q)-web diagrams of type IIB string theory, under the identification of the algebraic intertwiner of Awata, Feigin and Shiraishi with the refined topological vertex. Extending the correspondence to the vertical reflection states, it is possible to engineer the N=1 quiver gauge theory of D-type (with unitary gauge groups). In this way, the Nekrasov instanton partition function is reproduced from the evaluation of expectation values of intertwiners. This computation leads to the identification of the vertical reflection state with the orientifold plane of string theory. We also provide a translation of this construction in the Iqbal-Kozcaz-Vafa refined topological vertex formalism.

Chronic traumatic encephalopathy: the dangers of getting "dinged"

PubMed Central

2012-01-01

Chronic traumatic encephalopathy (CTE) is a form of neurodegeneration that results from repetitive brain trauma. Not surprisingly, CTE has been linked to participation in contact sports such as boxing, hockey and American football. In American football getting "dinged" equates to moments of dizziness, confusion, or grogginess that can follow a blow to the head. There are approximately 100,000 to 300,000 concussive episodes occurring in the game of American football alone each year. It is believed that repetitive brain trauma, with or possibly without symptomatic concussion, sets off a cascade of events that result in neurodegenerative changes highlighted by accumulations of hyperphosphorylated tau and neuronal TAR DNA-binding protein-43 (TDP-43). Symptoms of CTE may begin years or decades later and include a progressive decline of memory, as well as depression, poor impulse control, suicidal behavior, and, eventually, dementia similar to Alzheimer's disease. In some individuals, CTE is also associated with motor neuron disease similar to amyotrophic lateral sclerosis. Given the millions of athletes participating in contact sports that involve repetitive brain trauma, CTE represents an important public health issue. In this review, we discuss recent advances in understanding the etiology of CTE. It is now known that those instances of mild concussion or "dings" that we may have previously not noticed could very well be causing progressive neurodegenerative damage to a player's brain. In the future, focused and intensive study of the risk factors could potentially uncover methods to prevent and treat this disease. PMID:23984220

An evaluation of MPI message rate on hybrid-core processors

DOE PAGES

Barrett, Brian W.; Brightwell, Ron; Grant, Ryan; ...

2014-11-01

Power and energy concerns are motivating chip manufacturers to consider future hybrid-core processor designs that may combine a small number of traditional cores optimized for single-thread performance with a large number of simpler cores optimized for throughput performance. This trend is likely to impact the way in which compute resources for network protocol processing functions are allocated and managed. In particular, the performance of MPI match processing is critical to achieving high message throughput. In this paper, we analyze the ability of simple and more complex cores to perform MPI matching operations for various scenarios in order to gain insightmore » into how MPI implementations for future hybrid-core processors should be designed.« less

MPI investigation for 40G NRZ link with low-RL cable assemblies

NASA Astrophysics Data System (ADS)

Satake, Toshiaki; Berdinskikh, Tatiana; Thongdaeng, Rutsuda; Faysanyo, Pitak; Gurreri, Michael

2017-01-01

Bit Error Ratio (BER) dependence on received power was studied for 40Gb/s NRZ short optical fiber transmission, including a series of four low return loss (RL 21dB) and low insertion loss (IL 0.1dB) connections. The calculated power penalty (PP) was 0.15dB for BER 10-11. Although the fiber length was within DFB laser's coherent length of 100m and the multi path interference (MPI) value was 34.3dB, no PP of BER was observed. There was no PP due to low MPI probably because the polarization of the signal pulses were not aligned for optical interference, indicating that NRZ systems have a high resistance to MPI.

Exploiting Efficient Transpacking for One-Sided Communication and MPI-IO

NASA Astrophysics Data System (ADS)

Mir, Faisal Ghias; Träff, Jesper Larsson

Based on a construction of socalled input-output datatypes that define a mapping between non-consecutive input and output buffers, we outline an efficient method for copying of structured data. We term this operation transpacking, and show how transpacking can be applied for the MPI implementation of one-sided communication and MPI-IO. For one-sided communication via shared-memory, we demonstrate the expected performance improvements by up to a factor of two. For individual MPI-IO, the time to read or write from file dominates the overall time, but even here efficient transpacking can in some scenarios reduce file I/O time considerably. The reported results have been achieved on a single NEC SX-8 vector node.

Membrane reference electrode

DOEpatents

Redey, L.; Bloom, I.D.

1988-01-21

A reference electrode utilizes a small thin, flat membrane of a highly conductive glass placed on a small diameter insulator tube having a reference material inside in contact with an internal voltage lead. When the sensor is placed in a non-aqueous ionic electrolytic solution, the concentration difference across the glass membrane generates a low voltage signal in precise relationship to the concentration of the species to be measured, with high spatial resolution. 2 figs.

Microbeam Characterization of Corning Archeological Reference Glasses: New Additions to the Smithsonian Microbeam Standard Collection

PubMed Central

Vicenzi, Edward P.; Eggins, Stephen; Logan, Amelia; Wysoczanski, Richard

2002-01-01

An initial study of the minor element, trace element, and impurities in Corning archeological references glasses have been performed using three microbeam techniques: electron probe microanalysis (EPMA), laser ablation ICP-mass spectrometry (LA ICP-MS), and secondary ion mass spectrometry (SIMS). The EPMA results suggest a significant level of heterogeneity for a number of metals. Conversely, higher precision and a larger sampling volume analysis by LA ICP-MS indicates a high degree of chemical uniformity within all glasses, typically <2 % relative (1 σ). SIMS data reveal that small but measurable quantities of volatile impurities are present in the glasses, including H at roughly the 0.0001 mass fraction level. These glasses show promise for use as secondary standards for minor and trace element analyses of insulating materials such as synthetic ceramics, minerals, and silicate glasses. PMID:27446764

Compiled MPI: Cost-Effective Exascale Applications Development

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

Bronevetsky, G; Quinlan, D; Lumsdaine, A

2012-04-10

The complexity of petascale and exascale machines makes it increasingly difficult to develop applications that can take advantage of them. Future systems are expected to feature billion-way parallelism, complex heterogeneous compute nodes and poor availability of memory (Peter Kogge, 2008). This new challenge for application development is motivating a significant amount of research and development on new programming models and runtime systems designed to simplify large-scale application development. Unfortunately, DoE has significant multi-decadal investment in a large family of mission-critical scientific applications. Scaling these applications to exascale machines will require a significant investment that will dwarf the costs of hardwaremore » procurement. A key reason for the difficulty in transitioning today's applications to exascale hardware is their reliance on explicit programming techniques, such as the Message Passing Interface (MPI) programming model to enable parallelism. MPI provides a portable and high performance message-passing system that enables scalable performance on a wide variety of platforms. However, it also forces developers to lock the details of parallelization together with application logic, making it very difficult to adapt the application to significant changes in the underlying system. Further, MPI's explicit interface makes it difficult to separate the application's synchronization and communication structure, reducing the amount of support that can be provided by compiler and run-time tools. This is in contrast to the recent research on more implicit parallel programming models such as Chapel, OpenMP and OpenCL, which promise to provide significantly more flexibility at the cost of reimplementing significant portions of the application. We are developing CoMPI, a novel compiler-driven approach to enable existing MPI applications to scale to exascale systems with minimal modifications that can be made incrementally over the application's lifetime. It includes: (1) New set of source code annotations, inserted either manually or automatically, that will clarify the application's use of MPI to the compiler infrastructure, enabling greater accuracy where needed; (2) A compiler transformation framework that leverages these annotations to transform the original MPI source code to improve its performance and scalability; (3) Novel MPI runtime implementation techniques that will provide a rich set of functionality extensions to be used by applications that have been transformed by our compiler; and (4) A novel compiler analysis that leverages simple user annotations to automatically extract the application's communication structure and synthesize most complex code annotations.« less

Myocardial performance index in female rats with myocardial infarction: relationship with ventricular function parameters by Doppler echocardiography.

PubMed

Cury, Alexandre Ferreira; Bonilha, Andre; Saraiva, Roberto; Campos, Orlando; Carvalho, Antonio Carlos C; De Paola, Angelo Amato V; Fischer, Claudio; Tucci, Paulo Ferreira; Moises, Valdir Ambrosio

2005-05-01

The aim of the study was to analyze the myocardial performance index (MPI), its relationship with the standard variables of systolic and diastolic functions, and the influence of time intervals in an experimental model of female rats with myocardial infarction (MI). Forty-one Wistar female rats were submitted to surgery to induce MI. Six weeks later, Doppler echocardiography was performed to assess infarct size (IS,%), fractional area change (FAC,%), ejection fraction biplane Simpson (EF), E/A ratio of mitral inflow, MPI and its time intervals: isovolumetric contraction (IVCT, ms) and relaxation (IVRT, ms) times, and ejection time (ET, ms); MPI = IVCT + IVRT/ET. EF and FAC were progressively lower in rats with small, medium and large-size MI ( P < .001). E/A ratio was higher only in rats with large-size MI (6.25 +/- 2.69; P < .001). MPI was not different between control rats and small-size MI (0.37 +/- 0.03 vs 0.34 +/- 0.06, P = .87), but different between large and medium-size MI (0.69 +/- 0.08 vs 0.47 +/- 0.07; P < .001) and between these two compared to small-size MI. MPI correlated with IS (r = 0.85; P < .001), EF (r = -0.86; P < .001), FAC (r = -0.77; P < .001) and E/A ratio (r = 0.77; P < .001, non-linear). IVCT was longer in large size MI compared to medium-size MI (31.87 +/- 7.99 vs 15.92 +/- 5.88; P < .001) and correlated with IS (r = 0.85; P < .001) and MPI (r = 0.92; P < .001). ET was shorter only in large-size MI (81.07 +/- 7.23; P < .001), and correlated with IS (r = -0.70; P < .001) and MPI (r = -0.85; P < .001). IVRT was shorter only in large-size compared to medium-size MI (24.40 +/- 5.38 vs 29.69 +/- 5.92; P < .037), had borderline correlation with MPI (r = 0.34; P = .0534) and no correlation with IS (r = 0.26; p = 0.144). The MPI increased with IS, correlated inversely with systolic function parameters and had a non-linear relationship with diastolic function. These changes were due to the increase of IVCT and a decrease of ET, without significant influence of IVRT.

A Case for Application Oblivious Energy-Efficient MPI Runtime

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

Venkatesh, Akshay; Vishnu, Abhinav; Hamidouche, Khaled

Power has become the major impediment in designing large scale high-end systems. Message Passing Interface (MPI) is the {\\em de facto} communication interface used as the back-end for designing applications, programming models and runtime for these systems. Slack --- the time spent by an MPI process in a single MPI call --- provides a potential for energy and power savings, if an appropriate power reduction technique such as core-idling/Dynamic Voltage and Frequency Scaling (DVFS) can be applied without perturbing application's execution time. Existing techniques that exploit slack for power savings assume that application behavior repeats across iterations/executions. However, an increasingmore » use of adaptive, data-dependent workloads combined with system factors (OS noise, congestion) makes this assumption invalid. This paper proposes and implements Energy Aware MPI (EAM) --- an application-oblivious energy-efficient MPI runtime. EAM uses a combination of communication models of common MPI primitives (point-to-point, collective, progress, blocking/non-blocking) and an online observation of slack for maximizing energy efficiency. Each power lever incurs time overhead, which must be amortized over slack to minimize degradation. When predicted communication time exceeds a lever overhead, the lever is used {\\em as soon as possible} --- to maximize energy efficiency. When mis-prediction occurs, the lever(s) are used automatically at specific intervals for amortization. We implement EAM using MVAPICH2 and evaluate it on ten applications using up to 4096 processes. Our performance evaluation on an InfiniBand cluster indicates that EAM can reduce energy consumption by 5--41\\% in comparison to the default approach, with negligible (less than 4\\% in all cases) performance loss.« less

Rapeseed and milk protein exhibit a similar overall nutritional value but marked difference in postprandial regional nitrogen utilization in rats

PubMed Central

2011-01-01

Background Rapeseed is an emerging and promising source of dietary protein for human nutrition and health. We previously found that rapeseed protein displayed atypical nutritional properties in humans, characterized by low bioavailability and a high postprandial biological value. The objective of the present study was to investigate the metabolic fate of rapeseed protein isolate (RPI) and its effect on protein fractional synthesis rates (FSR) in various tissues when compared to a milk protein isolate (MPI). Methods Rats (n = 48) were given a RPI or MPI meal, either for the first time or after 2-week adaptation to a MPI or RPI-based diet. They were divided in two groups for measuring the fed-state tissue FSR 2 h after the meal (using a flooding dose of 13C-valine) and the dietary N postprandial distribution at 5 h (using 15N-labeled meals). Results RPI and MPI led to similar FSR and dietary nitrogen (N) losses (ileal and deamination losses of 4% and 12% of the meal, respectively). By contrast, the dietary N incorporation was significantly higher in the intestinal mucosa and liver (+36% and +16%, respectively) and lower in skin (-24%) after RPI than MPI. Conclusions Although RPI and MPI led to the same overall level of postprandial dietary N retention in rats (in line with our findings in humans), this global response conceals marked qualitative differences at the tissue level regarding dietary N accretion. The fact that FSR did not however differed between groups suggest a differential modulation of proteolysis after RPI or MPI ingestion, or other mechanisms that warrant further study. PMID:21787407

Synthesis and characterization of methyl pyrazolone functionalized magnetic chitosan composite for visible light photocatalytic degradation of methylene blue.

PubMed

Abdelwahab, N A; Morsy, E M H

2018-03-01

TiO 2 /Fe 3 O 4 , TiO 2 /Fe 3 O 4 /chitosan and Methylpyrazolone functionalized TiO 2 /Fe 3 O 4 /chitosan (MPyTMChi) were successfully prepared. The chemical structure of the prepared materials was confirmed by FT-IR spectra, XRD, SEM and TEM. BET surface area increased from 2.4 to 3.1m 2 /g, E g decreased from 2.58 to 2.25eV and more quenching of PL emission spectra was observed upon functionalization of TMChi by MPy. Moreover, high Ti and oxygen percentages were detected by EDX. Magnetization value (M s ) reached 21 emu.g -1 for MPyTMChi. MPyTMChi showed enhanced photocatalytic degradation rate of methylene blue (MB) dye under visibe light irradiation (99.8% after 40min) as compared with that for TiO 2 /Fe 3 O 4 (96.7% after 100min) and TMChi (98.9% after 60min), respectively. It was regarded that the photocatalytic degradation of MB dye on MPyTMChi follows apparent pseudo-first-order according to the Langmuir-Hinshelwood (L-H) model and k app value was 0.089min -1 . Active species trapping experiment revealed that h + and O 2 - played the main role in the photodegradation of MB dye while OH quenching did not greatly affect photodegradation rate. Additionally, MPyTMChi can be efficiently reused for six repetitive cycles. MPyTMChi showed higher antimicrobial activity against gram-positive, gram- negative bacterial and fungal strains while large inhibition zone was observed for gram-positive bacteria. Copyright © 2017 Elsevier B.V. All rights reserved.

Myocardial Perfusion Pattern for Stratification of Ischemic Mitral Regurgitation Response to Percutaneous Coronary Intervention

PubMed Central

Goyal, Parag; Kim, Jiwon; Feher, Attila; Ma, Claudia L.; Gurevich, Sergey; Veal, David R.; Szulc, Massimiliano; Wong, Franklin J.; Ratcliffe, Mark B.; Levine, Robert A.; Devereux, Richard B.; Weinsaft, Jonathan W.

2015-01-01

Objective Ischemic mitral regurgitation (MR) is common, but its response to percutaneous coronary intervention (PCI) is poorly understood. This study tested utility of myocardial perfusion imaging (MPI) for stratification of MR response to PCI. Methods MPI and echo were performed among patients undergoing PCI. MPI was used to assess stress/rest myocardial perfusion. MR was assessed via echo (performed pre- and post-PCI). Results 317 patients with abnormal myocardial perfusion on MPI underwent echo 25±39 days prior to PCI. MR was present in 52%, among whom 24% had advanced (≥moderate) MR. MR was associated with LV chamber dilation on MPI and echo (both p<0.001). Magnitude of global LV perfusion deficits increased in relation to MR severity (p<0.01). Perfusion differences were greatest for global summed rest scores, which were 1.6-fold higher among patients with advanced MR vs. those with mild MR (p=0.004), and 2.4-fold higher vs. those without MR (p<0.001). In multivariate analysis, advanced MR was associated with fixed perfusion defect size on MPI (OR 1.16 per segment [CI 1.002–1.34], p=0.046) independent of LV volume (OR 1.10 per 10ml [CI 1.04–1.17], p=0.002). Follow-up via echo (1.0±0.6 years) demonstrated MR to decrease (≥1 grade) in 31% of patients, and increase in 12%. Patients with increased MR after PCI had more severe inferior perfusion defects on baseline MPI (p=0.028), whereas defects in other distributions and LV volumes were similar (p=NS). Conclusions Extent and distribution of SPECT-evidenced myocardial perfusion defects impacts MR response to revascularization. Increased magnitude of inferior fixed perfusion defects predicts post-PCI progression of MR. PMID:26049923

Cationic ionene as an n-dopant agent of poly(3,4-ethylenedioxythiophene).

PubMed

Saborío, Maricruz G; Bertran, Oscar; Lanzalaco, Sonia; Häring, Marleen; Díaz Díaz, David; Estrany, Francesc; Alemán, Carlos

2018-04-18

We report the reduction of poly(3,4-ethylenedioxythiophene) (PEDOT) films with a cationic 1,4-diazabicyclo[2.2.2]octane-based ionene bearing N,N'-(meta-phenylene)dibenzamide linkages (mPI). Our main goal is to obtain n-doped PEDOT using a polymeric dopant agent rather than small conventional tetramethylammonium (TMA), as is usual. This has been achieved using a three-step process, which has been individually optimized: (1) preparation of p-doped (oxidized) PEDOT at a constant potential of +1.40 V in acetonitrile with LiClO4 as the electrolyte; (2) dedoping of oxidized PEDOT using a fixed potential of -1.30 V in water; and (3) redoping of dedoped PEDOT applying a reduction potential of -1.10 V in water with mPI. The resulting films display the globular appearance typically observed for PEDOT, with mPI being structured in separated phases forming nanospheres or ultrathin sheets. This organization, which has been supported by atomistic molecular dynamics simulations, resembles the nanosegregated phase distribution observed for PEDOT p-doped with poly(styrenesulfonate). Furthermore, the doping level achieved using mPI as the doping agent is comparable to that achieved using TMA, even though ionene provides distinctive properties to the conducting polymer. For example, films redoped with mPI exhibit much more hydrophilicity than the oxidized ones, whereas films redoped with TMA are hydrophobic. Similarly, films redoped with mPI exhibit the highest thermal stability, while those redoped with TMA show thermal stability that is intermediate between those of the latter and the dedoped PEDOT. Overall, the incorporation of an mPI polycation as the n-dopant into PEDOT has important advantages for modulating the properties of this emblematic conducting polymer.

Relationship Between Coronary Contrast-Flow Quantitative Flow Ratio and Myocardial Ischemia Assessed by SPECT MPI.

PubMed

Smit, Jeff M; Koning, Gerhard; van Rosendael, Alexander R; Dibbets-Schneider, Petra; Mertens, Bart J; Jukema, J Wouter; Delgado, Victoria; Reiber, Johan H C; Bax, Jeroen J; Scholte, Arthur J

2017-10-01

A new method has been developed to calculate fractional flow reserve (FFR) from invasive coronary angiography, the so-called "contrast-flow quantitative flow ratio (cQFR)". Recently, cQFR was compared to invasive FFR in intermediate coronary lesions showing an overall diagnostic accuracy of 85%. The purpose of this study was to investigate the relationship between cQFR and myocardial ischemia assessed by single-photon emission computed tomography myocardial perfusion imaging (SPECT MPI). Patients who underwent SPECT MPI and coronary angiography within 3 months were included. The cQFR computation was performed offline, using dedicated software. The cQFR computation was based on 3-dimensional quantitative coronary angiography (QCA) and computational fluid dynamics. The standard 17-segment model was used to determine the vascular territories. Myocardial ischemia was defined as a summed difference score ≥2 in a vascular territory. A cQFR of ≤0.80 was considered abnormal. Two hundred and twenty-four coronary arteries were analysed in 85 patients. Overall accuracy of cQFR to detect ischemia on SPECT MPI was 90%. In multivariable analysis, cQFR was independently associated with ischemia on SPECT MPI (OR per 0.01 decrease of cQFR: 1.10; 95% CI 1.04-1.18, p = 0.002), whereas clinical and QCA parameters were not. Furthermore, cQFR showed incremental value for the detection of ischemia compared to clinical and QCA parameters (global chi square 48.7 to 62.6; p <0.001). A good relationship between cQFR and SPECT MPI was found. cQFR was independently associated with ischemia on SPECT MPI and showed incremental value to detect ischemia compared to clinical and QCA parameters.

Accelerating free breathing myocardial perfusion MRI using multi coil radial k - t SLR

NASA Astrophysics Data System (ADS)

Goud Lingala, Sajan; DiBella, Edward; Adluru, Ganesh; McGann, Christopher; Jacob, Mathews

2013-10-01

The clinical utility of myocardial perfusion MR imaging (MPI) is often restricted by the inability of current acquisition schemes to simultaneously achieve high spatio-temporal resolution, good volume coverage, and high signal to noise ratio. Moreover, many subjects often find it difficult to hold their breath for sufficiently long durations making it difficult to obtain reliable MPI data. Accelerated acquisition of free breathing MPI data can overcome some of these challenges. Recently, an algorithm termed as k - t SLR has been proposed to accelerate dynamic MRI by exploiting sparsity and low rank properties of dynamic MRI data. The main focus of this paper is to further improve k - t SLR and demonstrate its utility in considerably accelerating free breathing MPI. We extend its previous implementation to account for multi-coil radial MPI acquisitions. We perform k - t sampling experiments to compare different radial trajectories and determine the best sampling pattern. We also introduce a novel augmented Lagrangian framework to considerably improve the algorithm’s convergence rate. The proposed algorithm is validated using free breathing rest and stress radial perfusion data sets from two normal subjects and one patient with ischemia. k - t SLR was observed to provide faithful reconstructions at high acceleration levels with minimal artifacts compared to existing MPI acceleration schemes such as spatio-temporal constrained reconstruction and k - t SPARSE/SENSE.

Practical Formal Verification of MPI and Thread Programs

NASA Astrophysics Data System (ADS)

Gopalakrishnan, Ganesh; Kirby, Robert M.

Large-scale simulation codes in science and engineering are written using the Message Passing Interface (MPI). Shared memory threads are widely used directly, or to implement higher level programming abstractions. Traditional debugging methods for MPI or thread programs are incapable of providing useful formal guarantees about coverage. They get bogged down in the sheer number of interleavings (schedules), often missing shallow bugs. In this tutorial we will introduce two practical formal verification tools: ISP (for MPI C programs) and Inspect (for Pthread C programs). Unlike other formal verification tools, ISP and Inspect run directly on user source codes (much like a debugger). They pursue only the relevant set of process interleavings, using our own customized Dynamic Partial Order Reduction algorithms. For a given test harness, DPOR allows these tools to guarantee the absence of deadlocks, instrumented MPI object leaks and communication races (using ISP), and shared memory races (using Inspect). ISP and Inspect have been used to verify large pieces of code: in excess of 10,000 lines of MPI/C for ISP in under 5 seconds, and about 5,000 lines of Pthread/C code in a few hours (and much faster with the use of a cluster or by exploiting special cases such as symmetry) for Inspect. We will also demonstrate the Microsoft Visual Studio and Eclipse Parallel Tools Platform integrations of ISP (these will be available on the LiveCD).

Safety and efficacy of Regadenoson in myocardial perfusion imaging (MPI) stress tests: A review

NASA Astrophysics Data System (ADS)

Ahmed, Ambereen

2018-02-01

Myocardial perfusion imaging (MPI) tests are often used to help diagnose coronary heart disease (CAD). The tests usually involve applying stress, such as hard physical exercise together with administration of vasodilators, to the patients. To date, many of these tests use non-selective A2A adenosine receptor agonists which, however, can be associated with highly undesirable and life-threatening side effects such as chest pain, dyspnea, severe bronchoconstriction and atrioventricular conduction anomalies. Regadenoson is a relatively new, highly selective A2A adenosine receptor agonist, suitable for use in MPI tests which exhibits far fewer adverse side effects and, unlike others testing agents, can be used without the necessity of excessive concomitant exercise. Also, the dose of regadenoson required is not dependent upon patient weight or renal impairment, and it can be rapidly administered by i.v. Injection. Regadenoson use in MPI testing thus has the potential as a simplified, relatively safe, time-saving and cost-effective method for helping diagnose CAD. The present study was designed to review several articles on the safety, efficacy, and suitability of regadenoson in MPI testing for CAD. Overall, the combined studies demonstrated that use of regadenoson in conjunction with low-level exercise in MPI is a highly efficient and relatively safe test for CAD, especially for more severe health-compromised patients.

Geometry planning and image registration in magnetic particle imaging using bimodal fiducial markers

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

Werner, F., E-mail: f.werner@uke.de; Hofmann, M.; Them, K.

Purpose: Magnetic particle imaging (MPI) is a quantitative imaging modality that allows the distribution of superparamagnetic nanoparticles to be visualized. Compared to other imaging techniques like x-ray radiography, computed tomography (CT), and magnetic resonance imaging (MRI), MPI only provides a signal from the administered tracer, but no additional morphological information, which complicates geometry planning and the interpretation of MP images. The purpose of the authors’ study was to develop bimodal fiducial markers that can be visualized by MPI and MRI in order to create MP–MR fusion images. Methods: A certain arrangement of three bimodal fiducial markers was developed and usedmore » in a combined MRI/MPI phantom and also during in vivo experiments in order to investigate its suitability for geometry planning and image fusion. An algorithm for automated marker extraction in both MR and MP images and rigid registration was established. Results: The developed bimodal fiducial markers can be visualized by MRI and MPI and allow for geometry planning as well as automated registration and fusion of MR–MP images. Conclusions: To date, exact positioning of the object to be imaged within the field of view (FOV) and the assignment of reconstructed MPI signals to corresponding morphological regions has been difficult. The developed bimodal fiducial markers and the automated image registration algorithm help to overcome these difficulties.« less

Assessment of Fetal Myocardial Performance Index in Women with Placenta Previa

PubMed Central

Zhang, Na; Sun, Lijuan; Zhang, Lina; Li, Zhen; Han, Jijing; Wu, Qingqing

2017-01-01

Background This study investigated whether fetuses of placenta previa pregnancies have cardiac dysfunction by use of a modified myocardial performance index (Mod-MPI). Material/Methods A prospective cross-sectional study was conducted including 178 fetuses at 28–40 weeks of gestation. Eighty-nine fetuses of mothers with placenta previa and without pregnancy complications were recruited (placenta previa group) and matched with 89 fetuses of mothers with normal pregnancies (control group). Fetal cardiac function parameters and perinatal outcomes as well as the Mod-MPI were compared between the 2 groups. Results The median Mod-MPI was significantly increased in fetuses of mothers with placenta previa compared with controls (0.47±0.05 vs. 0.45±0.05; P<0.01). Among fetuses of mothers with or without placenta previa, the Mod-MPI was significantly higher in the incomplete placenta previa group compared with the complete placenta previa group and control group (P<0.01). An increased Mod-MPI in placenta previa pregnancies was independently associated with fetal cord pH <7.2 (odds ratio, 4.8; 95% confidence interval, 0.98–23.54; P=0.003). Conclusions There is impairment of fetal cardiac function in pregnancies with placenta previa. An increased MPI was independently associated with adverse perinatal outcomes to some extent in the placenta previa pregnancies. PMID:29242496

Accelerating free breathing myocardial perfusion MRI using multi coil radial k-t SLR

PubMed Central

Lingala, Sajan Goud; DiBella, Edward; Adluru, Ganesh; McGann, Christopher; Jacob, Mathews

2013-01-01

The clinical utility of myocardial perfusion MR imaging (MPI) is often restricted by the inability of current acquisition schemes to simultaneously achieve high spatio-temporal resolution, good volume coverage, and high signal to noise ratio. Moreover, many subjects often find it difficult to hold their breath for sufficiently long durations making it difficult to obtain reliable MPI data. Accelerated acquisition of free breathing MPI data can overcome some of these challenges. Recently, an algorithm termed as k − t SLR has been proposed to accelerate dynamic MRI by exploiting sparsity and low rank properties of dynamic MRI data. The main focus of this paper is to further improve k − t SLR and demonstrate its utility in considerably accelerating free breathing MPI. We extend its previous implementation to account for multi-coil radial MPI acquisitions. We perform k − t sampling experiments to compare different radial trajectories and determine the best sampling pattern. We also introduce a novel augmented Lagrangian framework to considerably improve the algorithm's convergence rate. The proposed algorithm is validated using free breathing rest and stress radial perfusion data sets from two normal subjects and one patient with ischemia. k − t SLR was observed to provide faithful reconstructions at high acceleration levels with minimal artifacts compared to existing MPI acceleration schemes such as spatio-temporal constrained reconstruction (STCR) and k − t SPARSE/SENSE. PMID:24077063

KSC-03PD-2464

NASA Technical Reports Server (NTRS)

2003-01-01

KENNEDY SPACE CENTER, FLA. In the Vehicle Assembly Building, Jim Landy, NDE specialist, sets up a flight crew lockers for flash thermography. He is screening the lockers for hidden damage underneath dings and dents that might occur during handling.

KSC-03PD-2550

NASA Technical Reports Server (NTRS)

2003-01-01

KENNEDY SPACE CENTER, FLA. In the Vehicle Assembly Building, Jim Landy, NDE specialist, sets up a flight crew lockers for flash thermography. He is screening the lockers for hidden damage underneath dings and dents that might occur during handling.

Substrate dependent structure of adsorbed aryl isocyanides studied by sum frequency generation (SFG) spectroscopy.

PubMed

Ito, Mikio; Noguchi, Hidenori; Ikeda, Katsuyoshi; Uosaki, Kohei

2010-04-07

Effects of metal substrate on the bonding nature of isocyanide group of two aryl isocyanides, 1,4-phenylene diisocyanide (PDI) and 4-methylphenyl isocyanide (MPI), and tilt angle of MPI were examined by measuring sum frequency generation (SFG) spectra of the self-assembled monolayers (SAMs) of these molecules on Au, Pt, Ag, and Pd surfaces. The SFG peaks due to "metal bonded" and "free"-NC groups were resolved by comparing the SFG spectra of PDI with IR spectra obtained by DFT calculations and previous results of vibrational spectroscopy. Based on the peak positions of the "metal bonded"-NC, it is clarified that while PDI and MPI were adsorbed at top sites on Au, Ag, and Pt surfaces, they adsorbed at bridge sites on the Pd surface. The tilt angles of MPI were determined from the intensity ratio between the SFG peaks of C-H symmetric and asymmetric stretching vibrational modes of the CH(3) group. The tilt angles of the MPI SAMs were in the order of Pt < Pd < Ag < Au, reflecting the bonding nature between the -NC group and the substrate atoms.

First in vivo magnetic particle imaging of lung perfusion in rats

NASA Astrophysics Data System (ADS)

Zhou, Xinyi Y.; Jeffris, Kenneth E.; Yu, Elaine Y.; Zheng, Bo; Goodwill, Patrick W.; Nahid, Payam; Conolly, Steven M.

2017-05-01

Pulmonary embolism (PE), along with the closely related condition of deep vein thrombosis, affect an estimated 600 000 patients in the US per year. Untreated, PE carries a mortality rate of 30%. Because many patients experience mild or non-specific symptoms, imaging studies are necessary for definitive diagnosis of PE. Iodinated CT pulmonary angiography is recommended for most patients, while nuclear medicine-based ventilation/perfusion (V/Q) scans are reserved for patients in whom the use of iodine is contraindicated. Magnetic particle imaging (MPI) is an emerging tracer imaging modality with high image contrast (no tissue background signal) and sensitivity to superparamagnetic iron oxide (SPIO) tracer. Importantly, unlike CT or nuclear medicine, MPI uses no ionizing radiation. Further, MPI is not derived from magnetic resonance imaging (MRI); MPI directly images SPIO tracers via their strong electronic magnetization, enabling deep imaging of anatomy including within the lungs, which is very challenging with MRI. Here, the first high-contrast in vivo MPI lung perfusion images of rats are shown using a novel lung perfusion agent, MAA-SPIOs.

Model-based phase-shifting interferometer

NASA Astrophysics Data System (ADS)

Liu, Dong; Zhang, Lei; Shi, Tu; Yang, Yongying; Chong, Shiyao; Miao, Liang; Huang, Wei; Shen, Yibing; Bai, Jian

2015-10-01

A model-based phase-shifting interferometer (MPI) is developed, in which a novel calculation technique is proposed instead of the traditional complicated system structure, to achieve versatile, high precision and quantitative surface tests. In the MPI, the partial null lens (PNL) is employed to implement the non-null test. With some alternative PNLs, similar as the transmission spheres in ZYGO interferometers, the MPI provides a flexible test for general spherical and aspherical surfaces. Based on modern computer modeling technique, a reverse iterative optimizing construction (ROR) method is employed for the retrace error correction of non-null test, as well as figure error reconstruction. A self-compiled ray-tracing program is set up for the accurate system modeling and reverse ray tracing. The surface figure error then can be easily extracted from the wavefront data in forms of Zernike polynomials by the ROR method. Experiments of the spherical and aspherical tests are presented to validate the flexibility and accuracy. The test results are compared with those of Zygo interferometer (null tests), which demonstrates the high accuracy of the MPI. With such accuracy and flexibility, the MPI would possess large potential in modern optical shop testing.

PVM Wrapper

NASA Technical Reports Server (NTRS)

Katz, Daniel

2004-01-01

PVM Wrapper is a software library that makes it possible for code that utilizes the Parallel Virtual Machine (PVM) software library to run using the message-passing interface (MPI) software library, without needing to rewrite the entire code. PVM and MPI are the two most common software libraries used for applications that involve passing of messages among parallel computers. Since about 1996, MPI has been the de facto standard. Codes written when PVM was popular often feature patterns of {"initsend," "pack," "send"} and {"receive," "unpack"} calls. In many cases, these calls are not contiguous and one set of calls may even exist over multiple subroutines. These characteristics make it difficult to obtain equivalent functionality via a single MPI "send" call. Because PVM Wrapper is written to run with MPI- 1.2, some PVM functions are not permitted and must be replaced - a task that requires some programming expertise. The "pvm_spawn" and "pvm_parent" function calls are not replaced, but a programmer can use "mpirun" and knowledge of the ranks of parent and child tasks with supplied macroinstructions to enable execution of codes that use "pvm_spawn" and "pvm_parent."

Message Passing and Shared Address Space Parallelism on an SMP Cluster

NASA Technical Reports Server (NTRS)

Shan, Hongzhang; Singh, Jaswinder P.; Oliker, Leonid; Biswas, Rupak; Biegel, Bryan (Technical Monitor)

2002-01-01

Currently, message passing (MP) and shared address space (SAS) are the two leading parallel programming paradigms. MP has been standardized with MPI, and is the more common and mature approach; however, code development can be extremely difficult, especially for irregularly structured computations. SAS offers substantial ease of programming, but may suffer from performance limitations due to poor spatial locality and high protocol overhead. In this paper, we compare the performance of and the programming effort required for six applications under both programming models on a 32-processor PC-SMP cluster, a platform that is becoming increasingly attractive for high-end scientific computing. Our application suite consists of codes that typically do not exhibit scalable performance under shared-memory programming due to their high communication-to-computation ratios and/or complex communication patterns. Results indicate that SAS can achieve about half the parallel efficiency of MPI for most of our applications, while being competitive for the others. A hybrid MPI+SAS strategy shows only a small performance advantage over pure MPI in some cases. Finally, improved implementations of two MPI collective operations on PC-SMP clusters are presented.

Progression of HPV infection to detectable cervical lesions or clearance in adult women: Analysis of the control arm of the VIVIANE study.

PubMed

Skinner, S Rachel; Wheeler, Cosette M; Romanowski, Barbara; Castellsagué, Xavier; Lazcano-Ponce, Eduardo; Del Rosario-Raymundo, M Rowena; Vallejos, Carlos; Minkina, Galina; Pereira Da Silva, Daniel; McNeil, Shelly; Prilepskaya, Vera; Gogotadze, Irina; Money, Deborah; Garland, Suzanne M; Romanenko, Viktor; Harper, Diane M; Levin, Myron J; Chatterjee, Archana; Geeraerts, Brecht; Struyf, Frank; Dubin, Gary; Bozonnat, Marie-Cécile; Rosillon, Dominique; Baril, Laurence

2016-05-15

The control arm of the phase III VIVIANE (Human PapillomaVIrus: Vaccine Immunogenicity ANd Efficacy; NCT00294047) study in women >25 years was studied to assess risk of progression from cervical HPV infection to detectable cervical intraepithelial neoplasia (CIN). The risk of detecting CIN associated with the same HPV type as the reference infection was analysed using Kaplan-Meier and multivariable Cox models. Infections were categorised depending upon persistence as 6-month persistent infection (6MPI) or infection of any duration. The 4-year interim analysis included 2,838 women, of whom 1,073 (37.8%) experienced 2,615 infections of any duration and 708 (24.9%) experienced 1,130 6MPIs. Infection with oncogenic HPV types significantly increased the risk of detecting CIN grade 2 or greater (CIN2+) versus non-oncogenic types. For 6MPI, the highest risk was associated with HPV-33 (hazard ratio [HR]: 31.9 [8.3-122.2, p < 0.0001]). The next highest risk was with HPV-16 (21.1 [6.3-70.0], p < 0.0001). Similar findings were seen for infections of any duration. Significant risk was also observed for HPV-18, HPV-31, and HPV-45. Concomitant HPV infection or CIN grade 1 or greater associated with a different oncogenic HPV type increased risk. Most women (79.3%) with an HPV infection at baseline cleared detectable infections of any duration, and 69.9% cleared a 6MPI. The risk of progression of HPV infection to CIN2+ in women >25 years in this study was similar to that in women 15-25 years in PATRICIA. © 2015 The Authors and GlaxoSmithKline. International Journal of Cancer published by John Wiley & Sons Ltd on behalf of UICC.

Progression of HPV infection to detectable cervical lesions or clearance in adult women: Analysis of the control arm of the VIVIANE study

PubMed Central

Wheeler, Cosette M.; Romanowski, Barbara; Castellsagué, Xavier; Lazcano‐Ponce, Eduardo; Rowena Del Rosario‐Raymundo, M.; Vallejos, Carlos; Minkina, Galina; Pereira Da Silva, Daniel; McNeil, Shelly; Prilepskaya, Vera; Gogotadze, Irina; Money, Deborah; Garland, Suzanne M.; Romanenko, Viktor; Harper, Diane M.; Levin, Myron J.; Chatterjee, Archana; Geeraerts, Brecht; Struyf, Frank; Dubin, Gary; Bozonnat, Marie‐Cécile; Rosillon, Dominique; Baril, Laurence

2016-01-01

The control arm of the phase III VIVIANE (Human PapillomaVIrus: Vaccine Immunogenicity ANd Efficacy; NCT00294047) study in women >25 years was studied to assess risk of progression from cervical HPV infection to detectable cervical intraepithelial neoplasia (CIN). The risk of detecting CIN associated with the same HPV type as the reference infection was analysed using Kaplan–Meier and multivariable Cox models. Infections were categorised depending upon persistence as 6‐month persistent infection (6MPI) or infection of any duration. The 4‐year interim analysis included 2,838 women, of whom 1,073 (37.8%) experienced 2,615 infections of any duration and 708 (24.9%) experienced 1,130 6MPIs. Infection with oncogenic HPV types significantly increased the risk of detecting CIN grade 2 or greater (CIN2+) versus non‐oncogenic types. For 6MPI, the highest risk was associated with HPV‐33 (hazard ratio [HR]: 31.9 [8.3–122.2, p < 0.0001]). The next highest risk was with HPV‐16 (21.1 [6.3–70.0], p < 0.0001). Similar findings were seen for infections of any duration. Significant risk was also observed for HPV‐18, HPV‐31, and HPV‐45. Concomitant HPV infection or CIN grade 1 or greater associated with a different oncogenic HPV type increased risk. Most women (79.3%) with an HPV infection at baseline cleared detectable infections of any duration, and 69.9% cleared a 6MPI. The risk of progression of HPV infection to CIN2+ in women >25 years in this study was similar to that in women 15–25 years in PATRICIA. PMID:26685704

A study of patients with spinal disease using Maudsley Personality Inventory.

PubMed

Kasai, Yuichi; Takegami, Kenji; Uchida, Atsumasa

2004-02-01

We administered the Maudsley Personality Inventory (MPI) preoperatively to 303 patients with spinal diseases about to undergo surgery. Patients younger than 20 years, patients previously treated in the Department of Psychiatry, and patients with poor postoperative results were excluded. Patients with N-scores (neuroticism scale) of 39 points or greater or L-scores (lie scale) of 26 points or greater were regarded as "abnormal." Based on clinical definitions we identified 24 "problem patients" during the course and categorized them as "Unsatisfied," "Indecisive," "Doctor shoppers," or "Distrustful." Preoperative MPI categorized 26 patients as abnormal; 22 patients categorized as abnormal became problem patients ( p<0.001). MPI sensitivity and specificity was 84.6% and 99.3%, respectively. Preoperative MPI to patients with spinal disease was found to be useful in detecting problem patients.

Ytterbium-doped glass-ceramics for optical refrigeration.

PubMed

Filho, Elton Soares de Lima; Krishnaiah, Kummara Venkata; Ledemi, Yannick; Yu, Ye-Jin; Messaddeq, Younes; Nemova, Galina; Kashyap, Raman

2015-02-23

We report for the first time the characterization of glass-ceramics for optical refrigeration. Ytterbium-doped nanocrystallites were grown in an oxyfluoride glass matrix of composition 2YbF(3):30SiO(2)-15Al(2)O(3)-25CdF(2)-22PbF(2)-4YF(3), forming bulk glass-ceramics at three different crystalisation levels. The samples are compared with a corresponding uncrystalised (glass) sample, as well as a Yb:YAG sample which has presented optical cooling. The measured X-ray diffraction spectra, and thermal capacities of the samples are reported. We also report for the first time the use of Yb:YAG as a reference for absolute photometric quantum efficiency measurement, and use the same setup to characterize the glass and glass-ceramic samples. The cooling figure-of-merit was measured by optical calorimetry using a fiber Bragg grating and found to depend on the level of crystallization of the sample, and that samples with nanocrystallites result in higher quantum efficiency and lower background absorption than the pure-glass sample. In addition to laser-induced cooling, the glass-ceramics have the potential to serve as a reference for quantum efficiency measurements.

A new basaltic glass microanalytical reference material for multiple techniques

USGS Publications Warehouse

Wilson, Steve; Koenig, Alan; Lowers, Heather

2012-01-01

The U.S. Geological Survey (USGS) has been producing reference materials since the 1950s. Over 50 materials have been developed to cover bulk rock, sediment, and soils for the geological community. These materials are used globally in geochemistry, environmental, and analytical laboratories that perform bulk chemistry and/or microanalysis for instrument calibration and quality assurance testing. To answer the growing demand for higher spatial resolution and sensitivity, there is a need to create a new generation of microanalytical reference materials suitable for a variety of techniques, such as scanning electron microscopy/X-ray spectrometry (SEM/EDS), electron probe microanalysis (EPMA), laser ablation inductively coupled mass spectrometry (LA-ICP-MS), and secondary ion mass spectrometry (SIMS). As such, the microanalytical reference material (MRM) needs to be stable under the beam, be homogeneous at scales of better than 10–25 micrometers for the major to ultra-trace element level, and contain all of the analytes (elements or isotopes) of interest. Previous development of basaltic glasses intended for LA-ICP-MS has resulted in a synthetic basaltic matrix series of glasses (USGS GS-series) and a natural basalt series of glasses (BCR-1G, BHVO-2G, and NKT-1G). These materials have been useful for the LA-ICP-MS community but were not originally intended for use by the electron or ion beam community. A material developed from start to finish with intended use in multiple microanalytical instruments would be useful for inter-laboratory and inter-instrument platform comparisons. This article summarizes the experiments undertaken to produce a basalt glass reference material suitable for distribution as a multiple-technique round robin material. The goal of the analytical work presented here is to demonstrate that the elemental homogeneity of the new glass is acceptable for its use as a reference material. Because the round robin exercise is still underway, only nominal compositional ranges for each element are given in the article.

Specification of Fenix MPI Fault Tolerance library version 1.0.1

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

Gamble, Marc; Van Der Wijngaart, Rob; Teranishi, Keita

This document provides a specification of Fenix, a software library compatible with the Message Passing Interface (MPI) to support fault recovery without application shutdown. The library consists of two modules. The first, termed process recovery , restores an application to a consistent state after it has suffered a loss of one or more MPI processes (ranks). The second specifies functions the user can invoke to store application data in Fenix managed redundant storage, and to retrieve it from that storage after process recovery.

Simultaneous monitoring technique for ASE and MPI noises in distributed Raman Amplified Systems.

PubMed

Choi, H Y; Jun, S B; Shin, S K; Chung, Y C

2007-07-09

We develop a new technique for simultaneously monitoring the amplified spontaneous emission (ASE) and multi-path interference (MPI) noises in distributed Raman amplified (DRA) systems. This technique utilizes the facts that the degree-of polarization (DOP) of the MPI noise is 1/9, while the ASE noise is unpolarized. The results show that the proposed technique can accurately monitor both of these noises regardless of the bit rates, modulation formats, and optical signal-to-noise ratio (OSNR) levels of the signals.

An Ldrims Instrument for Portable Rb-Sr Dating with Accuracy of Better than ±150 MA for the MARS-2020 Rover

NASA Astrophysics Data System (ADS)

Anderson, F. Scott; Whitaker, Tom; Hamilton, Victoria; Nowicki, Keith

2013-04-01

Using a laser desorption resonance ionization mass spectrometer (LDRIMS), we can now demonstrate repeatable dates with portable hardware that could be carried on MER- or MSL-sized rovers. This is important because NASA is developing science requirements for a Mars 2020 rover mission based on MSL hardware, and for Mars, the National Research Council Decadal Survey (NRC DS) specifically supports: "...long-term development of instruments ... focusing on the most important future in situ measurements... [including] ... in situ geochronology experiments". The LDRIMS instrument can produce these science measurements today, and in so doing, triage samples for Mars Sample Return. The LDRIMS technique can be miniaturized and avoids the mass interference issues requiring unwieldy chemical separation for traditional geochronology techniques. With LDRIMS sample is placed in a time-of-flight (TOF) mass spectrometer and surface atoms, molecules, and ions are desorbed with a 213 nm laser. Ions are suppressed by an electric field and the plume of expanding particles is present for many μs, during which it is first illuminated with laser light tuned to ionize only Sr, and then 1-3 μs later, for Rb. This eliminates isobars for Rb and Sr, insures that the measured atoms come from the same ablation event, and hence target materials, and reduces the total number of measurements required. The LDRIMS system has demonstrated a sensitivity of 300 parts-per-trillion, and isotope ratio precisions of ±0.3 to ±0.1% in 3000-5000 ablations of one spot on a sample in 3-5 minutes. The bench top prototype has been tested on the Boulder Creek Granite (BCG) from Elephant Butte, Colorado, comprised primarily of a gneissic quartz monzonite and granodiorite. Whole rock Rb-Sr TIMS measurements of the BCG, and our own preliminary micro-drill TIMS measurements of individual minerals, are consistent with an age of 1700±40 Ma. To obtain a LDRIMS date using the BCG sample, we measured hundreds of spots with a ~300 μm spacing, producing microscopic pits ~75 μm wide by ~0.5 μm deep. We also acquire interleaved measurements of a glass calibration standard, MPI-DING-T1-G. Four repeat measurement runs were carried out over 6 months; the results have an average of 1.766 Ma±0.147 Ga for an MSWD=1, and for an MSWD=2, the average precision improves to ±0.105 Ga; both measurements have a precision and accuracy better than that called for by NASA (< ±200 Ma). A second-generation portable version of the instrument has been built, with an approximate volume of 0.25 m^3. We are now working on developing a "flight like" instrument, with a volume of approximately 0.03 m^3.

Automated simultaneous measurement of the δ(13) C and δ(2) H values of methane and the δ(13) C and δ(18) O values of carbon dioxide in flask air samples using a new multi cryo-trap/gas chromatography/isotope ratio mass spectrometry system.

PubMed

Brand, Willi A; Rothe, Michael; Sperlich, Peter; Strube, Martin; Wendeberg, Magnus

2016-07-15

The isotopic composition of greenhouse gases helps to constrain global budgets and to study sink and source processes. We present a new system for high-precision stable isotope measurements of carbon, hydrogen and oxygen in atmospheric methane and carbon dioxide. The design is intended for analyzing flask air samples from existing sampling programs without the need for extra sample air for methane analysis. CO2 and CH4 isotopes are measured simultaneously using two isotope ratio mass spectrometers, one for the analysis of δ(13) C and δ(18) O values and the second one for δ(2) H values. The inlet carousel delivers air from 16 sample positions (glass flasks 1-5 L and high-pressure cylinders). Three 10-port valves take aliquots from the sample stream. CH4 from 100-mL air aliquots is preconcentrated in 0.8-mL sample loops using a new cryo-trap system. A precisely calibrated working reference air is used in parallel with the sample according to the Principle of Identical Treatment. It takes about 36 hours for a fully calibrated analysis of a complete carousel including extractions of four working reference and one quality control reference air. Long-term precision values, as obtained from the quality control reference gas since 2012, account for 0.04 ‰ (δ(13) C values of CO2 ), 0.07 ‰ (δ(18) O values of CO2 ), 0.11 ‰ (δ(13) C values of CH4 ) and 1.0 ‰ (δ(2) H values of CH4 ). Within a single day, the system exhibits a typical methane δ(13) C standard deviation (1σ) of 0.06 ‰ for 10 repeated measurements. The system has been in routine operation at the MPI-BGC since 2012. Consistency of the data and compatibility with results from other laboratories at a high precision level are of utmost importance. A high sample throughput and reliability of operation are important achievements of the presented system to cope with the large number of air samples to be analyzed. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Parallel hyperbolic PDE simulation on clusters: Cell versus GPU

NASA Astrophysics Data System (ADS)

Rostrup, Scott; De Sterck, Hans

2010-12-01

Increasingly, high-performance computing is looking towards data-parallel computational devices to enhance computational performance. Two technologies that have received significant attention are IBM's Cell Processor and NVIDIA's CUDA programming model for graphics processing unit (GPU) computing. In this paper we investigate the acceleration of parallel hyperbolic partial differential equation simulation on structured grids with explicit time integration on clusters with Cell and GPU backends. The message passing interface (MPI) is used for communication between nodes at the coarsest level of parallelism. Optimizations of the simulation code at the several finer levels of parallelism that the data-parallel devices provide are described in terms of data layout, data flow and data-parallel instructions. Optimized Cell and GPU performance are compared with reference code performance on a single x86 central processing unit (CPU) core in single and double precision. We further compare the CPU, Cell and GPU platforms on a chip-to-chip basis, and compare performance on single cluster nodes with two CPUs, two Cell processors or two GPUs in a shared memory configuration (without MPI). We finally compare performance on clusters with 32 CPUs, 32 Cell processors, and 32 GPUs using MPI. Our GPU cluster results use NVIDIA Tesla GPUs with GT200 architecture, but some preliminary results on recently introduced NVIDIA GPUs with the next-generation Fermi architecture are also included. This paper provides computational scientists and engineers who are considering porting their codes to accelerator environments with insight into how structured grid based explicit algorithms can be optimized for clusters with Cell and GPU accelerators. It also provides insight into the speed-up that may be gained on current and future accelerator architectures for this class of applications. Program summaryProgram title: SWsolver Catalogue identifier: AEGY_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEGY_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: GPL v3 No. of lines in distributed program, including test data, etc.: 59 168 No. of bytes in distributed program, including test data, etc.: 453 409 Distribution format: tar.gz Programming language: C, CUDA Computer: Parallel Computing Clusters. Individual compute nodes may consist of x86 CPU, Cell processor, or x86 CPU with attached NVIDIA GPU accelerator. Operating system: Linux Has the code been vectorised or parallelized?: Yes. Tested on 1-128 x86 CPU cores, 1-32 Cell Processors, and 1-32 NVIDIA GPUs. RAM: Tested on Problems requiring up to 4 GB per compute node. Classification: 12 External routines: MPI, CUDA, IBM Cell SDK Nature of problem: MPI-parallel simulation of Shallow Water equations using high-resolution 2D hyperbolic equation solver on regular Cartesian grids for x86 CPU, Cell Processor, and NVIDIA GPU using CUDA. Solution method: SWsolver provides 3 implementations of a high-resolution 2D Shallow Water equation solver on regular Cartesian grids, for CPU, Cell Processor, and NVIDIA GPU. Each implementation uses MPI to divide work across a parallel computing cluster. Additional comments: Sub-program numdiff is used for the test run.

In vitro and in vivo comparison of a tailored magnetic particle imaging blood pool tracer with Resovist.

PubMed

Kaul, Michael Gerhard; Mummert, Tobias; Jung, Caroline; Salamon, Johannes; Khandhar, Amit P; Ferguson, R Matthew; Kemp, Scott J; Ittrich, Harald; Krishnan, Kannan M; Adam, Gerhard; Knopp, Tobias

2017-05-07

Optimizing tracers for individual imaging techniques is an active field of research. The purpose of this study was to perform in vitro and in vivo magnetic particle imaging (MPI) measurements using a new monodisperse and size-optimized tracer, LS-008, and to compare it with the performance of Resovist, the standard MPI tracer. Magnetic particle spectroscopy (MPS) and in vitro MPI measurements were performed in concerns of concentration and amount of tracer in a phantom. In vivo studies were carried out in healthy FVB mice. The first group (n  =  3) received 60 µl LS-008 (87 mM) and the second (n  =  3) diluted Resovist of the same concentration and volume. Tracer injections were performed with a syringe pump during a dynamic MPI scan. For anatomic referencing MRI was applied beforehand of the MPI measurements. Summing up MPS examinations and in vitro MPI experiments, LS-008 showed better sensitivity and spatial resolution than Resovist. In vivo both tracers can visualize the propagation of the bolus through the inferior vena cava. MPI with LS-008 did show less temporal fluctuation artifacts and the pulsation of blood due to respiratory and cardiac cycle was detectable. With LS-008 the aorta was distinguishable from the caval vein while with Resovist this failed. A liver vessel and a vessel structure leading cranially could only be observed with LS-008 and not with Resovist. Beside these structural advantages both tracers showed very different blood half-life. For LS-008 we found 88 min. Resovist did show a fast liver accumulation and a half-life of 13 min. Only with LS-008 the perfusion fraction in liver and kidney was measureable. MPI for angiography can be significantly improved by applying more effective tracers. LS-008 shows a clear improvement concerning the delineation while resolving a larger number of vessels in comparison to Resovist. Therefore, in aspects of quality and quantity LS-008 is clearly favorable for angiographic and perfusion studies.

Differences in pain, function and coping in Multidimensional Pain Inventory subgroups of chronic back pain: a one-group pretest-posttest study.

PubMed

Verra, Martin L; Angst, Felix; Staal, J Bart; Brioschi, Roberto; Lehmann, Susanne; Aeschlimann, André; de Bie, Rob A

2011-06-30

Patients with non-specific back pain are not a homogeneous group but heterogeneous with regard to their bio-psycho-social impairments. This study examined a sample of 173 highly disabled patients with chronic back pain to find out how the three subgroups based on the Multidimensional Pain Inventory (MPI) differed in their response to an inpatient pain management program. Subgroup classification was conducted by cluster analysis using MPI subscale scores at entry into the program. At program entry and at discharge after four weeks, participants completed the MPI, the MOS Short Form-36 (SF-36), the Hospital Anxiety and Depression Scale (HADS), and the Coping Strategies Questionnaire (CSQ). Pairwise analyses of the score changes of the mentioned outcomes of the three MPI subgroups were performed using the Mann-Whitney-U-test for significance. Cluster analysis identified three MPI subgroups in this highly disabled sample: a dysfunctional, interpersonally distressed and an adaptive copers subgroup. The dysfunctional subgroup (29% of the sample) showed the highest level of depression in SF-36 mental health (33.4 ± 13.9), the interpersonally distressed subgroup (35% of the sample) a modest level of depression (46.8 ± 20.4), and the adaptive copers subgroup (32% of the sample) the lowest level of depression (57.8 ± 19.1). Significant differences in pain reduction and improvement of mental health and coping were observed across the three MPI subgroups, i.e. the effect sizes for MPI pain reduction were: 0.84 (0.44-1.24) for the dysfunctional subgroup, 1.22 (0.86-1.58) for the adaptive copers subgroup, and 0.53 (0.24-0.81) for the interpersonally distressed subgroup (p = 0.006 for pairwise comparison). Significant score changes between subgroups concerning activities and physical functioning could not be identified. MPI subgroup classification showed significant differences in score changes for pain, mental health and coping. These findings underscore the importance of assessing individual differences to understand how patients adjust to chronic back pain.

Coinfection with Enterohepatic Helicobacter Species Can Ameliorate or Promote Helicobacter pylori-Induced Gastric Pathology in C57BL/6 Mice ▿

PubMed Central

Ge, Zhongming; Feng, Yan; Muthupalani, Sureshkumar; Eurell, Laura Lemke; Taylor, Nancy S.; Whary, Mark T.; Fox, James G.

2011-01-01

To investigate how different enterohepatic Helicobacter species (EHS) influence Helicobacter pylori gastric pathology, C57BL/6 mice were infected with Helicobacter hepaticus or Helicobacter muridarum, followed by H. pylori infection 2 weeks later. Compared to H. pylori-infected mice, mice infected with H. muridarum and H. pylori (HmHp mice) developed significantly lower histopathologic activity index (HAI) scores (P < 0.0001) at 6 and 11 months postinoculation (MPI). However, mice infected with H. hepaticus and H. pylori (HhHp mice) developed more severe gastric pathology at 6 MPI (P = 0.01), with a HAI at 11 MPI (P = 0.8) similar to that of H. pylori-infected mice. H. muridarum-mediated attenuation of gastritis in coinfected mice was associated with significant downregulation of proinflammatory Th1 (interlukin-1beta [Il-1β], gamma interferon [Ifn-γ], and tumor necrosis factor-alpha [Tnf-α]) cytokines at both time points and Th17 (Il-17A) cytokine mRNA levels at 6 MPI in murine stomachs compared to those of H. pylori-infected mice (P < 0.01). Coinfection with H. hepaticus also suppressed H. pylori-induced elevation of gastric Th1 cytokines Ifn-γ and Tnf-α (P < 0.0001) but increased Th17 cytokine mRNA levels (P = 0.028) at 6 MPI. Furthermore, mRNA levels of Il-17A were positively correlated with the severity of helicobacter-induced gastric pathology (HhHp>H. pylori>HmHp) (at 6 MPI, r2 = 0.92, P < 0.0001; at 11 MPI, r2 = 0.82, P < 0.002). Despite disparate effects on gastritis, colonization levels of gastric H. pylori were increased in HhHp mice (at 6 MPI) and HmHp mice (at both time points) compared to those in mono-H. pylori-infected mice. These data suggest that despite consistent downregulation of Th1 responses, EHS coinfection either attenuated or promoted the severity of H. pylori-induced gastric pathology in C57BL/6 mice. This modulation was related to the variable effects of EHS on gastric interleukin 17 (IL-17) responses to H. pylori infection. PMID:21788386

In vitro and in vivo comparison of a tailored magnetic particle imaging blood pool tracer with Resovist

NASA Astrophysics Data System (ADS)

Kaul, Michael Gerhard; Mummert, Tobias; Jung, Caroline; Salamon, Johannes; Khandhar, Amit P.; Ferguson, R. Matthew; Kemp, Scott J.; Ittrich, Harald; Krishnan, Kannan M.; Adam, Gerhard; Knopp, Tobias

2017-05-01

Optimizing tracers for individual imaging techniques is an active field of research. The purpose of this study was to perform in vitro and in vivo magnetic particle imaging (MPI) measurements using a new monodisperse and size-optimized tracer, LS-008, and to compare it with the performance of Resovist, the standard MPI tracer. Magnetic particle spectroscopy (MPS) and in vitro MPI measurements were performed in concerns of concentration and amount of tracer in a phantom. In vivo studies were carried out in healthy FVB mice. The first group (n  =  3) received 60 µl LS-008 (87 mM) and the second (n  =  3) diluted Resovist of the same concentration and volume. Tracer injections were performed with a syringe pump during a dynamic MPI scan. For anatomic referencing MRI was applied beforehand of the MPI measurements. Summing up MPS examinations and in vitro MPI experiments, LS-008 showed better sensitivity and spatial resolution than Resovist. In vivo both tracers can visualize the propagation of the bolus through the inferior vena cava. MPI with LS-008 did show less temporal fluctuation artifacts and the pulsation of blood due to respiratory and cardiac cycle was detectable. With LS-008 the aorta was distinguishable from the caval vein while with Resovist this failed. A liver vessel and a vessel structure leading cranially could only be observed with LS-008 and not with Resovist. Beside these structural advantages both tracers showed very different blood half-life. For LS-008 we found 88 min. Resovist did show a fast liver accumulation and a half-life of 13 min. Only with LS-008 the perfusion fraction in liver and kidney was measureable. MPI for angiography can be significantly improved by applying more effective tracers. LS-008 shows a clear improvement concerning the delineation while resolving a larger number of vessels in comparison to Resovist. Therefore, in aspects of quality and quantity LS-008 is clearly favorable for angiographic and perfusion studies.

Glass Ceiling in Academic Administration in Turkey: 1990s versus 2000s

ERIC Educational Resources Information Center

Gunluk-Senesen, Gulay

2009-01-01

This paper assesses the glass ceiling for academics in the Turkish universities with reference to top administration positions: rectors and deans. Glass ceiling indicators show that the glass ceiling thickened from the 1990s to late 2000s. The findings are discussed against the background of the transformation in the Turkish universities in the…

Extension of the AMBER molecular dynamics software to Intel's Many Integrated Core (MIC) architecture

NASA Astrophysics Data System (ADS)

Needham, Perri J.; Bhuiyan, Ashraf; Walker, Ross C.

2016-04-01

We present an implementation of explicit solvent particle mesh Ewald (PME) classical molecular dynamics (MD) within the PMEMD molecular dynamics engine, that forms part of the AMBER v14 MD software package, that makes use of Intel Xeon Phi coprocessors by offloading portions of the PME direct summation and neighbor list build to the coprocessor. We refer to this implementation as pmemd MIC offload and in this paper present the technical details of the algorithm, including basic models for MPI and OpenMP configuration, and analyze the resultant performance. The algorithm provides the best performance improvement for large systems (>400,000 atoms), achieving a ∼35% performance improvement for satellite tobacco mosaic virus (1,067,095 atoms) when 2 Intel E5-2697 v2 processors (2 ×12 cores, 30M cache, 2.7 GHz) are coupled to an Intel Xeon Phi coprocessor (Model 7120P-1.238/1.333 GHz, 61 cores). The implementation utilizes a two-fold decomposition strategy: spatial decomposition using an MPI library and thread-based decomposition using OpenMP. We also present compiler optimization settings that improve the performance on Intel Xeon processors, while retaining simulation accuracy.

Automatic Thread-Level Parallelization in the Chombo AMR Library

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

Christen, Matthias; Keen, Noel; Ligocki, Terry

2011-05-26

The increasing on-chip parallelism has some substantial implications for HPC applications. Currently, hybrid programming models (typically MPI+OpenMP) are employed for mapping software to the hardware in order to leverage the hardware?s architectural features. In this paper, we present an approach that automatically introduces thread level parallelism into Chombo, a parallel adaptive mesh refinement framework for finite difference type PDE solvers. In Chombo, core algorithms are specified in the ChomboFortran, a macro language extension to F77 that is part of the Chombo framework. This domain-specific language forms an already used target language for an automatic migration of the large number ofmore » existing algorithms into a hybrid MPI+OpenMP implementation. It also provides access to the auto-tuning methodology that enables tuning certain aspects of an algorithm to hardware characteristics. Performance measurements are presented for a few of the most relevant kernels with respect to a specific application benchmark using this technique as well as benchmark results for the entire application. The kernel benchmarks show that, using auto-tuning, up to a factor of 11 in performance was gained with 4 threads with respect to the serial reference implementation.« less

Mach-Zehnder Fourier transform spectrometer for astronomical spectroscopy at submillimeter wavelengths

NASA Astrophysics Data System (ADS)

Naylor, David A.; Gom, Bradley G.; Schofield, Ian; Tompkins, Gregory; Davis, Gary R.

2003-02-01

Astronomical spectroscopy at submillimeter wavelengths holds much promise for fields as diverse as the study of planetary atmospheres, molecular clouds and extragalactic sources. Fourier transform spectrometers (FTS) represent an important class of spectrometers well suited to observations that require broad spectral coverage at intermediate spectral resolution. In this paper we present the design and performance of a novel FTS, which has been developed for use at the James Clerk Maxwell Telescope (JCMT). The design uses two broadband intensity beamsplitters in a Mach-Zehnder configuration, which provide access to all four interferometer ports while maintaining a high and uniform efficiency over a broad spectral range. Since the interferometer processes both polarizations it is twice as efficient as the Martin-Puplett interferometer (MPI). As with the MPI, the spatial separation of the two input ports allows a reference blackbody to be viewed at all times in one port, while continually viewing the astronomical source in the other. Furthermore, by minimizing the size of the optical beam at the beamsplitter, the design is well suited to imaging Fourier transform spectroscopy (IFTS) as evidenced by its selection for the SPIRE instrument on Herschel.

What does fault tolerant Deep Learning need from MPI?

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

Amatya, Vinay C.; Vishnu, Abhinav; Siegel, Charles M.

Deep Learning (DL) algorithms have become the {\\em de facto} Machine Learning (ML) algorithm for large scale data analysis. DL algorithms are computationally expensive -- even distributed DL implementations which use MPI require days of training (model learning) time on commonly studied datasets. Long running DL applications become susceptible to faults -- requiring development of a fault tolerant system infrastructure, in addition to fault tolerant DL algorithms. This raises an important question: {\\em What is needed from MPI for designing fault tolerant DL implementations?} In this paper, we address this problem for permanent faults. We motivate the need for amore » fault tolerant MPI specification by an in-depth consideration of recent innovations in DL algorithms and their properties, which drive the need for specific fault tolerance features. We present an in-depth discussion on the suitability of different parallelism types (model, data and hybrid); a need (or lack thereof) for check-pointing of any critical data structures; and most importantly, consideration for several fault tolerance proposals (user-level fault mitigation (ULFM), Reinit) in MPI and their applicability to fault tolerant DL implementations. We leverage a distributed memory implementation of Caffe, currently available under the Machine Learning Toolkit for Extreme Scale (MaTEx). We implement our approaches by extending MaTEx-Caffe for using ULFM-based implementation. Our evaluation using the ImageNet dataset and AlexNet neural network topology demonstrates the effectiveness of the proposed fault tolerant DL implementation using OpenMPI based ULFM.« less

Task-parallel message passing interface implementation of Autodock4 for docking of very large databases of compounds using high-performance super-computers.

PubMed

Collignon, Barbara; Schulz, Roland; Smith, Jeremy C; Baudry, Jerome

2011-04-30

A message passing interface (MPI)-based implementation (Autodock4.lga.MPI) of the grid-based docking program Autodock4 has been developed to allow simultaneous and independent docking of multiple compounds on up to thousands of central processing units (CPUs) using the Lamarkian genetic algorithm. The MPI version reads a single binary file containing precalculated grids that represent the protein-ligand interactions, i.e., van der Waals, electrostatic, and desolvation potentials, and needs only two input parameter files for the entire docking run. In comparison, the serial version of Autodock4 reads ASCII grid files and requires one parameter file per compound. The modifications performed result in significantly reduced input/output activity compared with the serial version. Autodock4.lga.MPI scales up to 8192 CPUs with a maximal overhead of 16.3%, of which two thirds is due to input/output operations and one third originates from MPI operations. The optimal docking strategy, which minimizes docking CPU time without lowering the quality of the database enrichments, comprises the docking of ligands preordered from the most to the least flexible and the assignment of the number of energy evaluations as a function of the number of rotatable bounds. In 24 h, on 8192 high-performance computing CPUs, the present MPI version would allow docking to a rigid protein of about 300K small flexible compounds or 11 million rigid compounds.

78 FR 60834 - Initiation of Antidumping and Countervailing Duty Administrative Reviews and Request for...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-02

.... Shanghai Colour Nail Co., Ltd. Shanghai Curvet Hardware Products Co., Ltd. Shanghai Ding Ying Printing... of initiation of the review, will determine, consistent with FAG Italia v. United States, 291 F.3d...

78 FR 72630 - Initiation of Antidumping and Countervailing Duty Administrative Reviews and Request for...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-03

... Ding Ying Printing & Dyeing Co. Ltd..... Shanghai Guoxing Metal Products Co. Ltd Shanghai Jianhai... of initiation of the review, will determine, consistent with FAG Italia v. United States, 291 F.3d...

Practical automated glass selection and the design of apochromats with large field of view.

PubMed

Siew, Ronian

2016-11-10

This paper presents an automated approach to the selection of optical glasses for the design of an apochromatic lens with large field of view, based on a design originally provided by Yang et al. [Appl. Opt.55, 5977 (2016)APOPAI0003-693510.1364/AO.55.005977]. Following from this reference's preliminary optimized structure, it is shown that the effort of glass selection is significantly reduced by using the global optimization feature in the Zemax optical design program. The glass selection process is very fast, complete within minutes, and the key lies in automating the substitution of glasses found from the global search without the need to simultaneously optimize any other lens parameter during the glass search. The result is an alternate optimized version of the lens from the above reference possessing zero axial secondary color within the visible spectrum and a large field of view. Supplementary material is provided in the form of Zemax and text files, before and after final optimization.

Myocardial Performance Index for Patients with Overt and Subclinical Hypothyroidism.

PubMed

Karabulut, Aziz; Doğan, Abdullah; Tuzcu, Alpaslan Kemal

2017-05-25

BACKGROUND Hypothyroid has several effects on the cardiovascular system. Global myocardial performance index (MPI) is used in assessment of both left ventricular (LV) systolic and diastolic function. We compared MPI in hypothyroidism patients vs. normal control subjects. MATERIAL AND METHODS Eighty-two hypothyroid patients were divided into 2 groups: a subclinical hypothyroid (SH) group (n=50), and an overt hypothyroid (OH) group (n=32). The healthy control group (CG) constituted of 37 patients. TSH, FT3, and FT4, anti-TPO, anti-TG, insulin, lipid values, and fasting glucose levels were studied. All patients underwent an echocardiographic examination. Myocardial performance indexes were assessed and standard echocardiographic examinations were investigated. RESULTS MPI averages in OH, SH, and control groups were 0.53±0.06, 0.51±0.05, and 0.44±0.75 mm, respectively. MPI was increased in the OH and SH groups in comparison to CG (p<0.001, p<0.001, respectively). CONCLUSIONS MPI value was significantly higher in hypothyroid patients in comparison to the control group, showing that regression in global left ventricular functions is an important echocardiographic finding. Future studies are required to determine the effects of this finding on long-term cardiovascular outcomes.

Relaxation-based viscosity mapping for magnetic particle imaging

NASA Astrophysics Data System (ADS)

Utkur, M.; Muslu, Y.; Saritas, E. U.

2017-05-01

Magnetic particle imaging (MPI) has been shown to provide remarkable contrast for imaging applications such as angiography, stem cell tracking, and cancer imaging. Recently, there is growing interest in the functional imaging capabilities of MPI, where ‘color MPI’ techniques have explored separating different nanoparticles, which could potentially be used to distinguish nanoparticles in different states or environments. Viscosity mapping is a promising functional imaging application for MPI, as increased viscosity levels in vivo have been associated with numerous diseases such as hypertension, atherosclerosis, and cancer. In this work, we propose a viscosity mapping technique for MPI through the estimation of the relaxation time constant of the nanoparticles. Importantly, the proposed time constant estimation scheme does not require any prior information regarding the nanoparticles. We validate this method with extensive experiments in an in-house magnetic particle spectroscopy (MPS) setup at four different frequencies (between 250 Hz and 10.8 kHz) and at three different field strengths (between 5 mT and 15 mT) for viscosities ranging between 0.89 mPa · s-15.33 mPa · s. Our results demonstrate the viscosity mapping ability of MPI in the biologically relevant viscosity range.

32 CFR 637.2 - Use of MPI and DAC Detectives/Investigators.

Code of Federal Regulations, 2010 CFR

2010-07-01

.../investigators may be employed in joint MPI/USACIDC drug suppression teams; however, the conduct of such... and DAC detectives/investigators may also be utilized to make controlled buys of suspected controlled...

76 FR 18865 - Airworthiness Directives; Bell Helicopter Textron, Inc. Model 212 Helicopters

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-06

... also requires performing a magnetic particle inspection (MPI) on fittings with certain serial numbers... expanding the applicability to require performing a magnetic particle inspection (MPI) for a crack on the...

MPI-IO: A Parallel File I/O Interface for MPI Version 0.3

NASA Technical Reports Server (NTRS)

Corbett, Peter; Feitelson, Dror; Hsu, Yarsun; Prost, Jean-Pierre; Snir, Marc; Fineberg, Sam; Nitzberg, Bill; Traversat, Bernard; Wong, Parkson

1995-01-01

Thanks to MPI [9], writing portable message passing parallel programs is almost a reality. One of the remaining problems is file I/0. Although parallel file systems support similar interfaces, the lack of a standard makes developing a truly portable program impossible. Further, the closest thing to a standard, the UNIX file interface, is ill-suited to parallel computing. Working together, IBM Research and NASA Ames have drafted MPI-I0, a proposal to address the portable parallel I/0 problem. In a nutshell, this proposal is based on the idea that I/0 can be modeled as message passing: writing to a file is like sending a message, and reading from a file is like receiving a message. MPI-IO intends to leverage the relatively wide acceptance of the MPI interface in order to create a similar I/0 interface. The above approach can be materialized in different ways. The current proposal represents the result of extensive discussions (and arguments), but is by no means finished. Many changes can be expected as additional participants join the effort to define an interface for portable I/0. This document is organized as follows. The remainder of this section includes a discussion of some issues that have shaped the style of the interface. Section 2 presents an overview of MPI-IO as it is currently defined. It specifies what the interface currently supports and states what would need to be added to the current proposal to make the interface more complete and robust. The next seven sections contain the interface definition itself. Section 3 presents definitions and conventions. Section 4 contains functions for file control, most notably open. Section 5 includes functions for independent I/O, both blocking and nonblocking. Section 6 includes functions for collective I/O, both blocking and nonblocking. Section 7 presents functions to support system-maintained file pointers, and shared file pointers. Section 8 presents constructors that can be used to define useful filetypes (the role of filetypes is explained in Section 2 below). Section 9 presents how the error handling mechanism of MPI is supported by the MPI-IO interface. All this is followed by a set of appendices, which contain information about issues that have not been totally resolved yet, and about design considerations. The reader can find there the motivation behind some of our design choices. More information on this would definitely be welcome and will be included in a further release of this document. The first appendix contains a description of MPI-I0's 'hints' structure which is used when opening a file. Appendix B is a discussion of various issues in the support for file pointers. Appendix C explains what we mean in talking about atomic access. Appendix D provides detailed examples of filetype constructors, and Appendix E contains a collection of arguments for and against various design decisions.

Use of bio-informatics assessment schema (BIAS) to improve diagnosis and prognosis of myocardial perfusion data: results from the NHLBI-sponsored women's ischemia syndrome evaluation (WISE).

PubMed

Doyle, Mark; Pohost, Gerald M; Bairey Merz, C Noel; Shaw, Leslee J; Sopko, George; Rogers, William J; Sharaf, Barry L; Pepine, Carl J; Thompson, Diane V; Rayarao, Geetha; Tauxe, Lindsey; Kelsey, Sheryl F; Biederman, Robert W W

2016-10-01

We introduce an algorithmic approach to optimize diagnostic and prognostic value of gated cardiac single photon emission computed tomography (SPECT) and magnetic resonance (MR) myocardial perfusion imaging (MPI) modalities in women with suspected myocardial ischemia. The novel approach: bio-informatics assessment schema (BIAS) forms a mathematical model utilizing MPI data and cardiac metrics generated by one modality to predict the MPI status of another modality. The model identifies cardiac features that either enhance or mask the image-based evidence of ischemia. For each patient, the BIAS model value is used to set an appropriate threshold for the detection of ischemia. Women (n=130), with symptoms and signs of suspected myocardial ischemia, underwent MPI assessment for regional perfusion defects using two different modalities: gated SPECT and MR. To determine perfusion status, MR data were evaluated qualitatively (MRI QL ) and semi-quantitatively (MRI SQ ) while SPECT data were evaluated using conventional clinical criteria. Evaluators were masked to results of the alternate modality. These MPI status readings were designated "original". Two regression models designated "BIAS" models were generated to model MPI status obtained with one modality (e.g., MRI) compared with a second modality (e.g., SPECT), but importantly, the BIAS models did not include the primary Original MPI reading of the predicting modality. Instead, the BIAS models included auxiliary measurements like left ventricular chamber volumes and myocardial wall thickness. For each modality, the BIAS model was used to set a progressive threshold for interpretation of MPI status. Women were then followed for 38±14 months for the development of a first major adverse cardiovascular event [MACE: CV death, nonfatal myocardial infarction (MI) or hospitalization for heart failure]. Original and BIAS-augmented perfusion status were compared in their ability to detect coronary artery disease (CAD) and for prediction of MACE. Adverse events occurred in 14 (11%) women and CAD was present in 13 (10%). There was a positive correlation of maximum coronary artery stenosis and BIAS score for MRI and SPECT (P<0.001). Receiver operator characteristic (ROC) analysis was conducted and showed an increase in the area under the curve of the BIAS-augmented MPI interpretation of MACE vs . the original for MRI SQ (0.78 vs . 0.54), MRI QL (0.78 vs . 0.64), SPECT (0.82 vs . 0.63) and the average of the three readings (0.80±0.02 vs . 0.60±0.05, P<0.05). Increasing values of the BIAS score generated by both MRI and SPECT corresponded to the increasing prevalence of CAD and MACE. The BIAS-augmented detection of ischemia better predicted MACE compared with the Original reading for the MPI data for both MRI and SPECT.

Use of bio-informatics assessment schema (BIAS) to improve diagnosis and prognosis of myocardial perfusion data: results from the NHLBI-sponsored women’s ischemia syndrome evaluation (WISE)

PubMed Central

Pohost, Gerald M.; Bairey Merz, C. Noel; Shaw, Leslee J.; Sopko, George; Rogers, William J.; Sharaf, Barry L.; Pepine, Carl J.; Thompson, Diane V.; Rayarao, Geetha; Tauxe, Lindsey; Kelsey, Sheryl F.; Biederman, Robert W. W.

2016-01-01

Background We introduce an algorithmic approach to optimize diagnostic and prognostic value of gated cardiac single photon emission computed tomography (SPECT) and magnetic resonance (MR) myocardial perfusion imaging (MPI) modalities in women with suspected myocardial ischemia. The novel approach: bio-informatics assessment schema (BIAS) forms a mathematical model utilizing MPI data and cardiac metrics generated by one modality to predict the MPI status of another modality. The model identifies cardiac features that either enhance or mask the image-based evidence of ischemia. For each patient, the BIAS model value is used to set an appropriate threshold for the detection of ischemia. Methods Women (n=130), with symptoms and signs of suspected myocardial ischemia, underwent MPI assessment for regional perfusion defects using two different modalities: gated SPECT and MR. To determine perfusion status, MR data were evaluated qualitatively (MRIQL) and semi-quantitatively (MRISQ) while SPECT data were evaluated using conventional clinical criteria. Evaluators were masked to results of the alternate modality. These MPI status readings were designated “original”. Two regression models designated “BIAS” models were generated to model MPI status obtained with one modality (e.g., MRI) compared with a second modality (e.g., SPECT), but importantly, the BIAS models did not include the primary Original MPI reading of the predicting modality. Instead, the BIAS models included auxiliary measurements like left ventricular chamber volumes and myocardial wall thickness. For each modality, the BIAS model was used to set a progressive threshold for interpretation of MPI status. Women were then followed for 38±14 months for the development of a first major adverse cardiovascular event [MACE: CV death, nonfatal myocardial infarction (MI) or hospitalization for heart failure]. Original and BIAS-augmented perfusion status were compared in their ability to detect coronary artery disease (CAD) and for prediction of MACE. Results Adverse events occurred in 14 (11%) women and CAD was present in 13 (10%). There was a positive correlation of maximum coronary artery stenosis and BIAS score for MRI and SPECT (P<0.001). Receiver operator characteristic (ROC) analysis was conducted and showed an increase in the area under the curve of the BIAS-augmented MPI interpretation of MACE vs. the original for MRISQ (0.78 vs. 0.54), MRIQL (0.78 vs. 0.64), SPECT (0.82 vs. 0.63) and the average of the three readings (0.80±0.02 vs. 0.60±0.05, P<0.05). Conclusions Increasing values of the BIAS score generated by both MRI and SPECT corresponded to the increasing prevalence of CAD and MACE. The BIAS-augmented detection of ischemia better predicted MACE compared with the Original reading for the MPI data for both MRI and SPECT. PMID:27747165

Temporal Trends in the Prevalence, Severity, and Localization of Myocardial Ischemia and Necrosis at Myocardial Perfusion Imaging After Myocardial Infarction.

PubMed

Nudi, Francesco; Schillaci, Orazio; Di Belardino, Natale; Versaci, Francesco; Tomai, Fabrizio; Pinto, Annamaria; Neri, Giandomenico; Procaccini, Enrica; Nudi, Alessandro; Frati, Giacomo; Biondi-Zoccai, Giuseppe

2017-10-15

The definition, presentation, and management of myocardial infarction (MI) have changed substantially in the last decade. Whether these changes have impacted on the presence, severity, and localization of necrosis at myocardial perfusion imaging (MPI) has not been appraised to date. Subjects undergoing MPI and reporting a history of clinical MI were shortlisted. We focused on the presence, severity, and localization of necrosis at MPI with a retrospective single-center analysis. A total of 10,476 patients were included, distinguishing 5 groups according to the period in which myocardial perfusion scintigraphy had been performed (2004 to 2005, 2006 to 2007, 2008 to 2009, 2010 to 2011, 2012 to 2013). Trend analysis showed over time a significant worsening in baseline features (e.g., age, diabetes mellitus, and Q waves at electrocardiogram), whereas medical therapy and revascularization were offered with increasing frequency. Over the years, there was also a lower prevalence of normal MPI (from 16.8% to 13.6%) and ischemic MPI (from 35.6% to 32.8%), and a higher prevalence of ischemic and necrotic MPI (from 12.0% to 12.7%) or solely necrotic MPI (from 35.7% to 40.9%, p <0.001). Yet the prevalence of severe ischemia decreased over time from 11.4% to 2.0%, with a similar trend for moderate ischemia (from 15.9% to 11.8%, p <0.001). Similarly sobering results were wound for the prevalence of severe necrosis (from 19.8% to 8.2%) and moderate necrosis (from 8.5% to 7.8%, p = 0.028). These trends were largely confirmed at regional level and after propensity score matching. In conclusion, the outlook of stable patients with previous MI has substantially improved in the last decade, with a decrease in the severity of residual myocardial ischemia and necrosis, despite an apparent worsening in baseline features. Copyright © 2017 Elsevier Inc. All rights reserved.

In vivo liver visualizations with magnetic particle imaging based on the calibration measurement approach

NASA Astrophysics Data System (ADS)

Dieckhoff, J.; Kaul, M. G.; Mummert, T.; Jung, C.; Salamon, J.; Adam, G.; Knopp, T.; Ludwig, F.; Balceris, C.; Ittrich, H.

2017-05-01

Magnetic particle imaging (MPI) facilitates the rapid determination of 3D in vivo magnetic nanoparticle distributions. In this work, liver MPI following intravenous injections of ferucarbotran (Resovist®) was studied. The image reconstruction was based on a calibration measurement, the so called system function. The application of an enhanced system function sample reflecting the particle mobility and aggregation status of ferucarbotran resulted in significantly improved image reconstructions. The finding was supported by characterizations of different ferucarbotran compositions with the magnetorelaxometry and magnetic particle spectroscopy technique. For instance, similar results were obtained between ferucarbotran embedded in freeze-dried mannitol sugar and liver tissue harvested after a ferucarbotran injection. In addition, the combination of multiple shifted measurement patches for a joint reconstruction of the MPI data enlarged the field of view and increased the covering of liver MPI on magnetic resonance images noticeably.

In vivo liver visualizations with magnetic particle imaging based on the calibration measurement approach.

PubMed

Dieckhoff, J; Kaul, M G; Mummert, T; Jung, C; Salamon, J; Adam, G; Knopp, T; Ludwig, F; Balceris, C; Ittrich, H

2017-05-07

Magnetic particle imaging (MPI) facilitates the rapid determination of 3D in vivo magnetic nanoparticle distributions. In this work, liver MPI following intravenous injections of ferucarbotran (Resovist ® ) was studied. The image reconstruction was based on a calibration measurement, the so called system function. The application of an enhanced system function sample reflecting the particle mobility and aggregation status of ferucarbotran resulted in significantly improved image reconstructions. The finding was supported by characterizations of different ferucarbotran compositions with the magnetorelaxometry and magnetic particle spectroscopy technique. For instance, similar results were obtained between ferucarbotran embedded in freeze-dried mannitol sugar and liver tissue harvested after a ferucarbotran injection. In addition, the combination of multiple shifted measurement patches for a joint reconstruction of the MPI data enlarged the field of view and increased the covering of liver MPI on magnetic resonance images noticeably.

Toxoplasma gondii strain-dependent effects on mouse behaviour.

PubMed

Kannan, Geetha; Moldovan, Krisztina; Xiao, Jian-Chun; Yolken, Robert H; Jones-Brando, Lorraine; Pletnikov, Mikhail V

2010-06-01

Toxoplasma gondii reportedly manipulates rodent behaviour to increase transmission to its definitive feline host. We compared the effects of mouse infection by two Type II strains of T. gondii, Prugniaud (PRU) and ME49, on attraction to cat odour, locomotor activity, anxiety, sensorimotor gating, and spatial working and recognition memory 2 months post-infection (mpi). Attraction to cat odour was reassessed 7 mpi. At 2 mpi, mice infected with either strain exhibited significantly more attraction to cat odour than uninfected animals did, but only PRU-infected mice exhibited this behaviour 7 mpi. PRU-infected mice had significantly greater body weights and hyperactivity, while ME49-infected mice exhibited impaired spatial working memory. No differences in parasite antibody titres were seen between PRU- and ME49-infected mice. The present data suggest the effect of T. gondii infection on mouse behaviour is parasite strain-dependent.

Conflict Detection Algorithm to Minimize Locking for MPI-IO Atomicity

NASA Astrophysics Data System (ADS)

Sehrish, Saba; Wang, Jun; Thakur, Rajeev

Many scientific applications require high-performance concurrent I/O accesses to a file by multiple processes. Those applications rely indirectly on atomic I/O capabilities in order to perform updates to structured datasets, such as those stored in HDF5 format files. Current support for atomicity in MPI-IO is provided by locking around the operations, imposing lock overhead in all situations, even though in many cases these operations are non-overlapping in the file. We propose to isolate non-overlapping accesses from overlapping ones in independent I/O cases, allowing the non-overlapping ones to proceed without imposing lock overhead. To enable this, we have implemented an efficient conflict detection algorithm in MPI-IO using MPI file views and datatypes. We show that our conflict detection scheme incurs minimal overhead on I/O operations, making it an effective mechanism for avoiding locks when they are not needed.

Architecture and method for a burst buffer using flash technology

DOEpatents

Tzelnic, Percy; Faibish, Sorin; Gupta, Uday K.; Bent, John; Grider, Gary Alan; Chen, Hsing-bung

2016-03-15

A parallel supercomputing cluster includes compute nodes interconnected in a mesh of data links for executing an MPI job, and solid-state storage nodes each linked to a respective group of the compute nodes for receiving checkpoint data from the respective compute nodes, and magnetic disk storage linked to each of the solid-state storage nodes for asynchronous migration of the checkpoint data from the solid-state storage nodes to the magnetic disk storage. Each solid-state storage node presents a file system interface to the MPI job, and multiple MPI processes of the MPI job write the checkpoint data to a shared file in the solid-state storage in a strided fashion, and the solid-state storage node asynchronously migrates the checkpoint data from the shared file in the solid-state storage to the magnetic disk storage and writes the checkpoint data to the magnetic disk storage in a sequential fashion.

Radiological analysis of plutonium glass batches with natural/enriched boron

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

Rainisch, R.

2000-06-22

The disposition of surplus plutonium inventories by the US Department of Energy (DOE) includes the immobilization of certain plutonium materials in a borosilicate glass matrix, also referred to as vitrification. This paper addresses source terms of plutonium masses immobilized in a borosilicate glass matrix where the glass components include both natural boron and enriched boron. The calculated source terms pertain to neutron and gamma source strength (particles per second), and source spectrum changes. The calculated source terms corresponding to natural boron and enriched boron are compared to determine the benefits (decrease in radiation source terms) for to the use ofmore » enriched boron. The analysis of plutonium glass source terms shows that a large component of the neutron source terms is due to (a, n) reactions. The Americium-241 and plutonium present in the glass emit alpha particles (a). These alpha particles interact with low-Z nuclides like B-11, B-10, and O-17 in the glass to produce neutrons. The low-Z nuclides are referred to as target particles. The reference glass contains 9.4 wt percent B{sub 2}O{sub 3}. Boron-11 was found to strongly support the (a, n) reactions in the glass matrix. B-11 has a natural abundance of over 80 percent. The (a, n) reaction rates for B-10 are lower than for B-11 and the analysis shows that the plutonium glass neutron source terms can be reduced by artificially enriching natural boron with B-10. The natural abundance of B-10 is 19.9 percent. Boron enriched to 96-wt percent B-10 or above can be obtained commercially. Since lower source terms imply lower dose rates to radiation workers handling the plutonium glass materials, it is important to know the achievable decrease in source terms as a result of boron enrichment. Plutonium materials are normally handled in glove boxes with shielded glass windows and the work entails both extremity and whole-body exposures. Lowering the source terms of the plutonium batches will make the handling of these materials less difficult and will reduce radiation exposure to operating workers.« less

Additive value of 3T cardiovascular magnetic resonance coronary angiography for detecting coronary artery disease.

PubMed

Zhang, Lijun; Song, Xiantao; Dong, Li; Li, Jianan; Dou, Ruiyu; Fan, Zhanming; An, Jing; Li, Debiao

2018-04-30

The purpose of the work was to evaluate the incremental diagnostic value of free-breathing, contrast-enhanced, whole-heart, 3 T cardiovascular magnetic resonance coronary angiography (CE-MRCA) to stress/rest myocardial perfusion imaging (MPI) and late gadolinium enhancement (LGE) imaging for detecting coronary artery disease (CAD). Fifty-one patients with suspected CAD underwent a comprehensive cardiovascular magnetic resonance (CMR) examination (CE-MRCA, MPI, and LGE). The additive diagnostic value of MRCA to MPI and LGE was evaluated using invasive x-ray coronary angiography (XA) as the standard for defining functionally significant CAD (≥ 50% stenosis in vessels > 2 mm in diameter). 90.2% (46/51) patients (54.0 ± 11.5 years; 71.7% men) completed CE-MRCA successfully. On per-patient basis, compared to MPI/LGE alone or MPI alone, the addition of MRCA resulted in higher sensitivity (100% vs. 76.5%, p < 0.01), no change in specificity (58.3% vs. 66.7%, p = 0.6), and higher accuracy (89.1% vs 73.9%, p < 0.01) for CAD detection (prevalence = 73.9%). Compared to LGE alone, the addition of CE-MRCA resulted in higher sensitivity (97.1% vs. 41.2%, p < 0.01), inferior specificity (83.3% vs. 91.7%, p = 0.02), and higher diagnostic accuracy (93.5% vs. 54.3%, p < 0.01). The inclusion of successful free-breathing, whole-heart, 3 T CE-MRCA significantly improved the sensitivity and diagnostic accuracy as compared to MPI and LGE alone for CAD detection.

46 CFR 160.048-1 - Incorporation by reference.

Code of Federal Regulations, 2010 CFR

2010-10-01

...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Specification for a Buoyant Cushion, Fibrous Glass § 160.048-1... documents: (1) Military specification: MIL-B-2766—Batt, Fibrous Glass, Lifesaving Equipment. (2) Federal... issue in effect on the date kapok or fibrous glass buoyant cushions are manufactured, form a part of...

Radiopaque Strontium Fluoroapatite Glass-Ceramics.

PubMed

Höland, Wolfram; Schweiger, Marcel; Dittmer, Marc; Ritzberger, Christian

2015-01-01

The controlled precipitation of strontium fluoroapatite crystals was studied in four base glass compositions derived from the SiO2-Al2O3-Y2O3-SrO-Na2O-K2O/Rb2O/Cs2O-P2O5-F system. The crystal phase formation of these glasses and the main properties of the glass-ceramics, such as thermal and optical properties and radiopacity were compared with a fifth, a reference glass-ceramic. The reference glass-ceramic was characterized as Ca-fluoroapatite glass-ceramic. The four strontium fluoroapatite glass-ceramics showed the following crystal phases: (a) Sr5(PO4)3F - leucite, KAlSi2O6, (b) Sr5(PO4)3F - leucite, KAlSi2O6, and nano-sized NaSrPO4, (c) Sr5(PO4)3F - pollucite, CsAlSi2O6, and nano-sized NaSrPO4, and (d) Sr5(PO4)3F - Rb-leucite, RbAlSi2O6, and nano-sized NaSrPO4. The proof of crystal phase formation was possible by X-ray diffraction. The microstructures, which were studied using scanning electron microscopy, demonstrated a uniform distribution of the crystals in the glass matrix. The Sr-fluoroapatites were precipitated based on an internal crystallization process, and the crystals demonstrated a needle-like morphology. The study of the crystal growth of needle-like Sr-fluoroapatites gave a clear evidence of an Ostwald ripening mechanism. The formation of leucite, pollucite, and Rb-leucite was based on a surface crystallization mechanism. Therefore, a twofold crystallization mechanism was successfully applied to develop these types of glass-ceramics. The main focus of this study was the controlled development of glass-ceramics exhibiting high radiopacity in comparison to the reference glass-ceramic. This goal could be achieved with all four glass-ceramics with the preferred development of the Sr-fluoroapatite - pollucite-type glass-ceramic. In addition to this main development, it was possible to control the thermal properties. Especially the Rb-leucite containing glass-ceramic showed the highest coefficient of thermal expansion (CTE). These glass-ceramics allow optical properties, especially the translucency and color, to be tailored to the needs of biomaterials for dental applications. The authors conclude that it is possible to use twofold crystallization processes to develop glass-ceramic biomaterials featuring different properties, such as specific radiopacity values, CTEs, and optical characteristics.

Radiopaque Strontium Fluoroapatite Glass-Ceramics

PubMed Central

Höland, Wolfram; Schweiger, Marcel; Dittmer, Marc; Ritzberger, Christian

2015-01-01

The controlled precipitation of strontium fluoroapatite crystals was studied in four base glass compositions derived from the SiO2–Al2O3–Y2O3–SrO–Na2O–K2O/Rb2O/Cs2O–P2O5–F system. The crystal phase formation of these glasses and the main properties of the glass-ceramics, such as thermal and optical properties and radiopacity were compared with a fifth, a reference glass-ceramic. The reference glass-ceramic was characterized as Ca-fluoroapatite glass-ceramic. The four strontium fluoroapatite glass-ceramics showed the following crystal phases: (a) Sr5(PO4)3F – leucite, KAlSi2O6, (b) Sr5(PO4)3F – leucite, KAlSi2O6, and nano-sized NaSrPO4, (c) Sr5(PO4)3F – pollucite, CsAlSi2O6, and nano-sized NaSrPO4, and (d) Sr5(PO4)3F – Rb-leucite, RbAlSi2O6, and nano-sized NaSrPO4. The proof of crystal phase formation was possible by X-ray diffraction. The microstructures, which were studied using scanning electron microscopy, demonstrated a uniform distribution of the crystals in the glass matrix. The Sr-fluoroapatites were precipitated based on an internal crystallization process, and the crystals demonstrated a needle-like morphology. The study of the crystal growth of needle-like Sr-fluoroapatites gave a clear evidence of an Ostwald ripening mechanism. The formation of leucite, pollucite, and Rb-leucite was based on a surface crystallization mechanism. Therefore, a twofold crystallization mechanism was successfully applied to develop these types of glass-ceramics. The main focus of this study was the controlled development of glass-ceramics exhibiting high radiopacity in comparison to the reference glass-ceramic. This goal could be achieved with all four glass-ceramics with the preferred development of the Sr-fluoroapatite – pollucite-type glass-ceramic. In addition to this main development, it was possible to control the thermal properties. Especially the Rb-leucite containing glass-ceramic showed the highest coefficient of thermal expansion (CTE). These glass-ceramics allow optical properties, especially the translucency and color, to be tailored to the needs of biomaterials for dental applications. The authors conclude that it is possible to use twofold crystallization processes to develop glass-ceramic biomaterials featuring different properties, such as specific radiopacity values, CTEs, and optical characteristics. PMID:26528470

77 FR 44677 - RG Steel Sparrows Point LLC, Formerly Known as Severstal Sparrows Point LLC, a Subsidiary of RG...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-30

... Leased Workers From Echelon Service Company, Sun Associated Industries, Inc., MPI Consultants LLC...-site leased workers from Echelon Service Company, Sun Associated Industries, Inc., MPI Consultants LLC...

Analysis and optimization of gyrokinetic toroidal simulations on homogenous and heterogenous platforms

DOE PAGES

Ibrahim, Khaled Z.; Madduri, Kamesh; Williams, Samuel; ...

2013-07-18

The Gyrokinetic Toroidal Code (GTC) uses the particle-in-cell method to efficiently simulate plasma microturbulence. This paper presents novel analysis and optimization techniques to enhance the performance of GTC on large-scale machines. We introduce cell access analysis to better manage locality vs. synchronization tradeoffs on CPU and GPU-based architectures. Finally, our optimized hybrid parallel implementation of GTC uses MPI, OpenMP, and NVIDIA CUDA, achieves up to a 2× speedup over the reference Fortran version on multiple parallel systems, and scales efficiently to tens of thousands of cores.

SAMPLING DEVICE FOR pH MEASUREMENT IN PROCESS STREAMS

DOEpatents

Michelson, C.E.; Carson, W.N. Jr.

1958-11-01

A pH cell is presented for monitoring the hydrogen ion concentration of a fluid in a process stream. The cell is made of glass with a side entry arm just above a reservoir in which the ends of a glass electrode and a reference electrode are situated. The glass electrode contains the usual internal solution which is connected to a lead. The reference electrode is formed of saturated calomel having a salt bridge in its bottom portion fabricated of a porous glass to insure low electrolyte flow. A flush tube leads into the cell through which buffer and flush solutions are introduced. A ground wire twists about both electrode ends to insure constant electrical grounding of the sample. The electrode leads are electrically connected to a pH meter of aay standard type.

Evaluation of new geological reference materials for uranium-series measurements: Chinese Geological Standard Glasses (CGSG) and macusanite obsidian.

PubMed

Denton, J S; Murrell, M T; Goldstein, S J; Nunn, A J; Amato, R S; Hinrichs, K A

2013-10-15

Recent advances in high-resolution, rapid, in situ microanalytical techniques present numerous opportunities for the analytical community, provided accurately characterized reference materials are available. Here, we present multicollector thermal ionization mass spectrometry (MC-TIMS) and multicollector inductively coupled plasma mass spectrometry (MC-ICP-MS) uranium and thorium concentration and isotopic data obtained by isotope dilution for a suite of newly available Chinese Geological Standard Glasses (CGSG) designed for microanalysis. These glasses exhibit a range of compositions including basalt, syenite, andesite, and a soil. Uranium concentrations for these glasses range from ∼2 to 14 μg g(-1), Th/U weight ratios range from ∼4 to 6, (234)U/(238)U activity ratios range from 0.93 to 1.02, and (230)Th/(238)U activity ratios range from 0.98 to 1.12. Uranium and thorium concentration and isotopic data are also presented for a rhyolitic obsidian from Macusani, SE Peru (macusanite). This glass can also be used as a rhyolitic reference material, has a very low Th/U weight ratio (around 0.077), and is approximately in (238)U-(234)U-(230)Th secular equilibrium. The U-Th concentration data agree with but are significantly more precise than those previously measured. U-Th concentration and isotopic data agree within estimated errors for the two measurement techniques, providing validation of the two methods. The large (238)U-(234)U-(230)Th disequilibria for some of the glasses, along with the wide range in their chemical compositions and Th/U ratios should provide useful reference points for the U-series analytical community.

JPRS Report, China.

DTIC Science & Technology

1993-06-03

2691]; the chief of staff was Liao Zhongfu [1675 0112 4569]; and the Political Depart- ment director was Ding Guoyu [ 0002 0948 6877]. The commander...shashousjian [4499 0427 3010 2087 9505 ]. Direct observation of the Gulf War shows that America’s conventional deterrence was in overall performance

42. VIEW OF SYMONS 3 BY 6 FEET VIBRATING SCREEN ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

42. VIEW OF SYMONS 3 BY 6 FEET VIBRATING SCREEN FROM NORTHWEST. SCREEN IS BELOW AND FED BY DINGS MAGNETIC PULLEY - DRIVE GEAR VISIBLE. - Bald Mountain Gold Mill, Nevada Gulch at head of False Bottom Creek, Lead, Lawrence County, SD

1. VIEW OF DAM 332, LOOKING TO THE SOUTHWEST ALONG ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

1. VIEW OF DAM 332, LOOKING TO THE SOUTHWEST ALONG THE CREST FROM THE RIGHT ABUTMENT, SHOWING CONCRETE MONUMENT SURVIVING FROM CCC CAMP DING - J. Clark Salyer National Wildlife Refuge, Dam 332, Along Lower Souris River, Kramer, Bottineau County, ND

Performance Evaluation of Supercomputers using HPCC and IMB Benchmarks

NASA Technical Reports Server (NTRS)

Saini, Subhash; Ciotti, Robert; Gunney, Brian T. N.; Spelce, Thomas E.; Koniges, Alice; Dossa, Don; Adamidis, Panagiotis; Rabenseifner, Rolf; Tiyyagura, Sunil R.; Mueller, Matthias;

High-Performance Design Patterns for Modern Fortran

DOE PAGES

Haveraaen, Magne; Morris, Karla; Rouson, Damian; ...

2015-01-01

This paper presents ideas for using coordinate-free numerics in modern Fortran to achieve code flexibility in the partial differential equation (PDE) domain. We also show how Fortran, over the last few decades, has changed to become a language well-suited for state-of-the-art software development. Fortran’s new coarray distributed data structure, the language’s class mechanism, and its side-effect-free, pure procedure capability provide the scaffolding on which we implement HPC software. These features empower compilers to organize parallel computations with efficient communication. We present some programming patterns that support asynchronous evaluation of expressions comprised of parallel operations on distributed data. We implemented thesemore » patterns using coarrays and the message passing interface (MPI). We compared the codes’ complexity and performance. The MPI code is much more complex and depends on external libraries. The MPI code on Cray hardware using the Cray compiler is 1.5–2 times faster than the coarray code on the same hardware. The Intel compiler implements coarrays atop Intel’s MPI library with the result apparently being 2–2.5 times slower than manually coded MPI despite exhibiting nearly linear scaling efficiency. As compilers mature and further improvements to coarrays comes in Fortran 2015, we expect this performance gap to narrow.« less

Accelerating k-NN Algorithm with Hybrid MPI and OpenSHMEM

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

Lin, Jian; Hamidouche, Khaled; Zheng, Jie

2015-08-05

Machine Learning algorithms are benefiting from the continuous improvement of programming models, including MPI, MapReduce and PGAS. k-Nearest Neighbors (k-NN) algorithm is a widely used machine learning algorithm, applied to supervised learning tasks such as classification. Several parallel implementations of k-NN have been proposed in the literature and practice. However, on high-performance computing systems with high-speed interconnects, it is important to further accelerate existing designs of the k-NN algorithm through taking advantage of scalable programming models. To improve the performance of k-NN on large-scale environment with InfiniBand network, this paper proposes several alternative hybrid MPI+OpenSHMEM designs and performs a systemicmore » evaluation and analysis on typical workloads. The hybrid designs leverage the one-sided memory access to better overlap communication with computation than the existing pure MPI design, and propose better schemes for efficient buffer management. The implementation based on k-NN program from MaTEx with MVAPICH2-X (Unified MPI+PGAS Communication Runtime over InfiniBand) shows up to 9.0% time reduction for training KDD Cup 2010 workload over 512 cores, and 27.6% time reduction for small workload with balanced communication and computation. Experiments of running with varied number of cores show that our design can maintain good scalability.« less

Effects of variation in chain length on ternary polymer electrolyte - Ionic liquid mixture - A molecular dynamics simulation study

NASA Astrophysics Data System (ADS)

Raju, S. G.; Hariharan, Krishnan S.; Park, Da-Hye; Kang, HyoRang; Kolake, Subramanya Mayya

2015-10-01

Molecular dynamics (MD) simulations of ternary polymer electrolyte - ionic liquid mixtures are conducted using an all-atom model. N-alkyl-N-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide ([CnMPy][TFSI], n = 1, 3, 6, 9) and polyethylene oxide (PEO) are used. Microscopic structure, energetics and dynamics of ionic liquid (IL) in these ternary mixtures are studied. Properties of these four pure IL are also calculated and compared to that in ternary mixtures. Interaction between pyrrolidinium cation and TFSI is stronger and there is larger propensity of ion-pair formation in ternary mixtures. Unlike the case in imidazolium IL, near neighbor structural correlation between TFSI reduces with increase in chain length on cation in both pure IL and ternary mixtures. Using spatial density maps, regions where PEO and TFSI interact with pyrrolidinium cation are identified. Oxygens of PEO are above and below the pyrrolidinium ring and away from the bulky alkyl groups whereas TFSI is present close to nitrogen atom of CnMPy. In pure IL, diffusion coefficient (D) of C3MPy is larger than of TFSI but D of C9MPy and C6MPy are larger than that of TFSI. The reasons for alkyl chain dependent phenomena are explored.

Sensors for monitoring waste glass quality and method of using the same

DOEpatents

Bickford, Dennis F.

1994-01-01

A set of three electrical probes for monitoring alkali and oxygen activity of a glass melt. On-line, real time measurements of the potential difference among the probes when they are placed in electrical contact with the melt yield the activity information and can be used to adjust the composition of the melt in order to produce higher quality glass. The first two probes each has a reference gas and a reference electrolyte and a pair of wires in electrical connection with each other in the reference gas but having one of the wires extending further into the reference electrolyte. The reference gases both include a known concentration of oxygen. The third electrode has a pair of wires extending through an otherwise solid body to join electrically just past the body but having one of the wires extend past this junction. Measuring the potential difference between wires of the first and second probes provides the alkali activity; measurement of the potential difference between wires of the second and third probes provides the oxygen activity of the melt.

Sensors for monitoring waste glass quality and method of using the same

DOEpatents

Bickford, D.F.

1994-03-15

A set of three electrical probes is described for monitoring alkali and oxygen activity of a glass melt. On-line, real time measurements of the potential difference among the probes when they are placed in electrical contact with the melt yield the activity information and can be used to adjust the composition of the melt in order to produce higher quality glass. The first two probes each has a reference gas and a reference electrolyte and a pair of wires in electrical connection with each other in the reference gas but having one of the wires extending further into the reference electrolyte. The reference gases both include a known concentration of oxygen. The third electrode has a pair of wires extending through an otherwise solid body to join electrically just past the body but having one of the wires extend past this junction. Measuring the potential difference between wires of the first and second probes provides the alkali activity; measurement of the potential difference between wires of the second and third probes provides the oxygen activity of the melt. 1 figure.

Noise spatial nonuniformity and the impact of statistical image reconstruction in CT myocardial perfusion imaging.

PubMed

Lauzier, Pascal Theriault; Tang, Jie; Speidel, Michael A; Chen, Guang-Hong

2012-07-01

To achieve high temporal resolution in CT myocardial perfusion imaging (MPI), images are often reconstructed using filtered backprojection (FBP) algorithms from data acquired within a short-scan angular range. However, the variation in the central angle from one time frame to the next in gated short scans has been shown to create detrimental partial scan artifacts when performing quantitative MPI measurements. This study has two main purposes. (1) To demonstrate the existence of a distinct detrimental effect in short-scan FBP, i.e., the introduction of a nonuniform spatial image noise distribution; this nonuniformity can lead to unexpectedly high image noise and streaking artifacts, which may affect CT MPI quantification. (2) To demonstrate that statistical image reconstruction (SIR) algorithms can be a potential solution to address the nonuniform spatial noise distribution problem and can also lead to radiation dose reduction in the context of CT MPI. Projection datasets from a numerically simulated perfusion phantom and an in vivo animal myocardial perfusion CT scan were used in this study. In the numerical phantom, multiple realizations of Poisson noise were added to projection data at each time frame to investigate the spatial distribution of noise. Images from all datasets were reconstructed using both FBP and SIR reconstruction algorithms. To quantify the spatial distribution of noise, the mean and standard deviation were measured in several regions of interest (ROIs) and analyzed across time frames. In the in vivo study, two low-dose scans at tube currents of 25 and 50 mA were reconstructed using FBP and SIR. Quantitative perfusion metrics, namely, the normalized upslope (NUS), myocardial blood volume (MBV), and first moment transit time (FMT), were measured for two ROIs and compared to reference values obtained from a high-dose scan performed at 500 mA. Images reconstructed using FBP showed a highly nonuniform spatial distribution of noise. This spatial nonuniformity led to large fluctuations in the temporal direction. In the numerical phantom study, the level of noise was shown to vary by as much as 87% within a given image, and as much as 110% between different time frames for a ROI far from isocenter. The spatially nonuniform noise pattern was shown to correlate with the source trajectory and the object structure. In contrast, images reconstructed using SIR showed a highly uniform spatial distribution of noise, leading to smaller unexpected noise fluctuations in the temporal direction when a short scan angular range was used. In the numerical phantom study, the noise varied by less than 37% within a given image, and by less than 20% between different time frames. Also, the noise standard deviation in SIR images was on average half of that of FBP images. In the in vivo studies, the deviation observed between quantitative perfusion metrics measured from low-dose scans and high-dose scans was mitigated when SIR was used instead of FBP to reconstruct images. (1) Images reconstructed using FBP suffered from nonuniform spatial noise levels. This nonuniformity is another manifestation of the detrimental effects caused by short-scan reconstruction in CT MPI. (2) Images reconstructed using SIR had a much lower and more uniform noise level and thus can be used as a potential solution to address the FBP nonuniformity. (3) Given the improvement in the accuracy of the perfusion metrics when using SIR, it may be desirable to use a statistical reconstruction framework to perform low-dose dynamic CT MPI.

Noise spatial nonuniformity and the impact of statistical image reconstruction in CT myocardial perfusion imaging

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

Lauzier, Pascal Theriault; Tang Jie; Speidel, Michael A.

Purpose: To achieve high temporal resolution in CT myocardial perfusion imaging (MPI), images are often reconstructed using filtered backprojection (FBP) algorithms from data acquired within a short-scan angular range. However, the variation in the central angle from one time frame to the next in gated short scans has been shown to create detrimental partial scan artifacts when performing quantitative MPI measurements. This study has two main purposes. (1) To demonstrate the existence of a distinct detrimental effect in short-scan FBP, i.e., the introduction of a nonuniform spatial image noise distribution; this nonuniformity can lead to unexpectedly high image noise andmore » streaking artifacts, which may affect CT MPI quantification. (2) To demonstrate that statistical image reconstruction (SIR) algorithms can be a potential solution to address the nonuniform spatial noise distribution problem and can also lead to radiation dose reduction in the context of CT MPI. Methods: Projection datasets from a numerically simulated perfusion phantom and an in vivo animal myocardial perfusion CT scan were used in this study. In the numerical phantom, multiple realizations of Poisson noise were added to projection data at each time frame to investigate the spatial distribution of noise. Images from all datasets were reconstructed using both FBP and SIR reconstruction algorithms. To quantify the spatial distribution of noise, the mean and standard deviation were measured in several regions of interest (ROIs) and analyzed across time frames. In the in vivo study, two low-dose scans at tube currents of 25 and 50 mA were reconstructed using FBP and SIR. Quantitative perfusion metrics, namely, the normalized upslope (NUS), myocardial blood volume (MBV), and first moment transit time (FMT), were measured for two ROIs and compared to reference values obtained from a high-dose scan performed at 500 mA. Results: Images reconstructed using FBP showed a highly nonuniform spatial distribution of noise. This spatial nonuniformity led to large fluctuations in the temporal direction. In the numerical phantom study, the level of noise was shown to vary by as much as 87% within a given image, and as much as 110% between different time frames for a ROI far from isocenter. The spatially nonuniform noise pattern was shown to correlate with the source trajectory and the object structure. In contrast, images reconstructed using SIR showed a highly uniform spatial distribution of noise, leading to smaller unexpected noise fluctuations in the temporal direction when a short scan angular range was used. In the numerical phantom study, the noise varied by less than 37% within a given image, and by less than 20% between different time frames. Also, the noise standard deviation in SIR images was on average half of that of FBP images. In the in vivo studies, the deviation observed between quantitative perfusion metrics measured from low-dose scans and high-dose scans was mitigated when SIR was used instead of FBP to reconstruct images. Conclusions: (1) Images reconstructed using FBP suffered from nonuniform spatial noise levels. This nonuniformity is another manifestation of the detrimental effects caused by short-scan reconstruction in CT MPI. (2) Images reconstructed using SIR had a much lower and more uniform noise level and thus can be used as a potential solution to address the FBP nonuniformity. (3) Given the improvement in the accuracy of the perfusion metrics when using SIR, it may be desirable to use a statistical reconstruction framework to perform low-dose dynamic CT MPI.« less

Noise spatial nonuniformity and the impact of statistical image reconstruction in CT myocardial perfusion imaging

PubMed Central

Lauzier, Pascal Thériault; Tang, Jie; Speidel, Michael A.; Chen, Guang-Hong

2012-01-01

Purpose: To achieve high temporal resolution in CT myocardial perfusion imaging (MPI), images are often reconstructed using filtered backprojection (FBP) algorithms from data acquired within a short-scan angular range. However, the variation in the central angle from one time frame to the next in gated short scans has been shown to create detrimental partial scan artifacts when performing quantitative MPI measurements. This study has two main purposes. (1) To demonstrate the existence of a distinct detrimental effect in short-scan FBP, i.e., the introduction of a nonuniform spatial image noise distribution; this nonuniformity can lead to unexpectedly high image noise and streaking artifacts, which may affect CT MPI quantification. (2) To demonstrate that statistical image reconstruction (SIR) algorithms can be a potential solution to address the nonuniform spatial noise distribution problem and can also lead to radiation dose reduction in the context of CT MPI. Methods: Projection datasets from a numerically simulated perfusion phantom and an in vivo animal myocardial perfusion CT scan were used in this study. In the numerical phantom, multiple realizations of Poisson noise were added to projection data at each time frame to investigate the spatial distribution of noise. Images from all datasets were reconstructed using both FBP and SIR reconstruction algorithms. To quantify the spatial distribution of noise, the mean and standard deviation were measured in several regions of interest (ROIs) and analyzed across time frames. In the in vivo study, two low-dose scans at tube currents of 25 and 50 mA were reconstructed using FBP and SIR. Quantitative perfusion metrics, namely, the normalized upslope (NUS), myocardial blood volume (MBV), and first moment transit time (FMT), were measured for two ROIs and compared to reference values obtained from a high-dose scan performed at 500 mA. Results: Images reconstructed using FBP showed a highly nonuniform spatial distribution of noise. This spatial nonuniformity led to large fluctuations in the temporal direction. In the numerical phantom study, the level of noise was shown to vary by as much as 87% within a given image, and as much as 110% between different time frames for a ROI far from isocenter. The spatially nonuniform noise pattern was shown to correlate with the source trajectory and the object structure. In contrast, images reconstructed using SIR showed a highly uniform spatial distribution of noise, leading to smaller unexpected noise fluctuations in the temporal direction when a short scan angular range was used. In the numerical phantom study, the noise varied by less than 37% within a given image, and by less than 20% between different time frames. Also, the noise standard deviation in SIR images was on average half of that of FBP images. In the in vivo studies, the deviation observed between quantitative perfusion metrics measured from low-dose scans and high-dose scans was mitigated when SIR was used instead of FBP to reconstruct images. Conclusions: (1) Images reconstructed using FBP suffered from nonuniform spatial noise levels. This nonuniformity is another manifestation of the detrimental effects caused by short-scan reconstruction in CT MPI. (2) Images reconstructed using SIR had a much lower and more uniform noise level and thus can be used as a potential solution to address the FBP nonuniformity. (3) Given the improvement in the accuracy of the perfusion metrics when using SIR, it may be desirable to use a statistical reconstruction framework to perform low-dose dynamic CT MPI. PMID:22830741

DAILY INPATIENT GLYCEMIC SURVEY (DINGS): A PROCESS TO REMOTELY IDENTIFY AND ASSIST IN THE MANAGEMENT OF HOSPITALIZED PATIENTS WITH DIABETES AND HYPERGLYCEMIA.

PubMed

Mendez, Carlos E; Ata, Ashar; Rourke, Joanne M; Stain, Steven C; Umpierrez, Guillermo

2015-08-01

Hyperglycemia, hypoglycemia, and glycemic variability have been associated with increased morbidity, mortality, and overall costs of care in hospitalized patients. At the Stratton VA Medical Center in Albany, New York, a process aimed to improve inpatient glycemic control by remotely assisting primary care teams in the management of hyperglycemia and diabetes was designed. An electronic query comprised of hospitalized patients with glucose values <70 mg/dL or >350 mg/dL is generated daily. Electronic medical records (EMRs) are individually reviewed by diabetes specialist providers, and management recommendations are sent to primary care teams when applicable. Glucose data was retrospectively examined before and after the establishment of the daily inpatient glycemic survey (DINGS) process, and rates of hyperglycemia and hypoglycemia were compared. Patient-day mean glucose slightly but significantly decreased from 177.6 ± 64.4 to 173.2 ± 59.4 mg/dL (P<.001). The percentage of patient-days with any value >350 mg/dL also decreased from 9.69 to 7.36% (P<.001), while the percentage of patient-days with mean glucose values in the range of 90 to 180 mg/dL increased from 58.1 to 61.4% (P<.001). Glycemic variability, assessed by the SD of glucose, significantly decreased from 53.9 to 49.8 mg/dL (P<.001). Moreover, rates of hypoglycemia (<70 mg/dL) decreased significantly by 41% (P<.001). Quality metrics of inpatient glycemic control improved significantly after the establishment of the DINGS process within our facility. Prospective controlled studies are needed to confirm a causal association.

Bio-Based Nanocomposites: An Alternative to Traditional Composites

ERIC Educational Resources Information Center

Tate, Jitendra S.; Akinola, Adekunle T.; Kabakov, Dmitri

2009-01-01

Polymer matrix composites (PMC), often referred to as fiber reinforced plastics (FRP), consist of fiber reinforcement (E-glass, S2-glass, aramid, carbon, or natural fibers) and polymer matrix/resin (polyester, vinyl ester, polyurethane, phenolic, and epoxies). Eglass/ polyester and E-glass/vinyl ester composites are extensively used in the marine,…

OpenGeoSys-GEMS: Hybrid parallelization of a reactive transport code with MPI and threads

NASA Astrophysics Data System (ADS)

Kosakowski, G.; Kulik, D. A.; Shao, H.

2012-04-01

OpenGeoSys-GEMS is a generic purpose reactive transport code based on the operator splitting approach. The code couples the Finite-Element groundwater flow and multi-species transport modules of the OpenGeoSys (OGS) project (http://www.ufz.de/index.php?en=18345) with the GEM-Selektor research package to model thermodynamic equilibrium of aquatic (geo)chemical systems utilizing the Gibbs Energy Minimization approach (http://gems.web.psi.ch/). The combination of OGS and the GEM-Selektor kernel (GEMS3K) is highly flexible due to the object-oriented modular code structures and the well defined (memory based) data exchange modules. Like other reactive transport codes, the practical applicability of OGS-GEMS is often hampered by the long calculation time and large memory requirements. • For realistic geochemical systems which might include dozens of mineral phases and several (non-ideal) solid solutions the time needed to solve the chemical system with GEMS3K may increase exceptionally. • The codes are coupled in a sequential non-iterative loop. In order to keep the accuracy, the time step size is restricted. In combination with a fine spatial discretization the time step size may become very small which increases calculation times drastically even for small 1D problems. • The current version of OGS is not optimized for memory use and the MPI version of OGS does not distribute data between nodes. Even for moderately small 2D problems the number of MPI processes that fit into memory of up-to-date workstations or HPC hardware is limited. One strategy to overcome the above mentioned restrictions of OGS-GEMS is to parallelize the coupled code. For OGS a parallelized version already exists. It is based on a domain decomposition method implemented with MPI and provides a parallel solver for fluid and mass transport processes. In the coupled code, after solving fluid flow and solute transport, geochemical calculations are done in form of a central loop over all finite element nodes with calls to GEMS3K and consecutive calculations of changed material parameters. In a first step the existing MPI implementation was utilized to parallelize this loop. Calculations were split between the MPI processes and afterwards data was synchronized by using MPI communication routines. Furthermore, multi-threaded calculation of the loop was implemented with help of the boost thread library (http://www.boost.org). This implementation provides a flexible environment to distribute calculations between several threads. For each MPI process at least one and up to several dozens of worker threads are spawned. These threads do not replicate the complete OGS-GEM data structure and use only a limited amount of memory. Calculation of the central geochemical loop is shared between all threads. Synchronization between the threads is done by barrier commands. The overall number of local threads times MPI processes should match the number of available computing nodes. The combination of multi-threading and MPI provides an effective and flexible environment to speed up OGS-GEMS calculations while limiting the required memory use. Test calculations on different hardware show that for certain types of applications tremendous speedups are possible.

Fenix, A Fault Tolerant Programming Framework for MPI Applications

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

Gamel, Marc; Teranihi, Keita; Valenzuela, Eric

2016-10-05

Fenix provides APIs to allow the users to add fault tolerance capability to MPI-based parallel programs in a transparent manner. Fenix-enabled programs can run through process failures during program execution using a pool of spare processes accommodated by Fenix.

Description of Defense Waste Processing Facility reference waste form and canister. Revision 1

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

Baxter, R.G.

1983-08-01

The Defense Waste Processing Facility (DWPF) will be located at the Savannah River Plant in Aiken, SC, and is scheduled for construction authorization during FY-1984. The reference waste form is borosilicate glass containing approx. 28 wt % sludge oxides, with the balance glass frit. Borosilicate glass was chosen because of its high resistance to leaching by water, its relatively high solubility for nuclides found in the sludge, and its reasonably low melting temperature. The glass frit contains about 58% SiO/sub 2/ and 15% B/sub 2/O/sub 3/. Leachabilities of SRP waste glasses are expected to approach 10/sup -8/ g/m/sup 2/-day basedmore » upon 1000-day tests using glasses containing SRP radioactive waste. Tests were performed under a wide variety of conditions simulating repository environments. The canister is filled with 3260 lb of glass which occupies about 85% of the free canister volume. The filled canister will generate approx. 470 watts when filled with oxides from 5-year-old sludge and 15-year-old supernate from the sludge and supernate processes. The radionuclide content of the canister is about 177,000 ci, with a radiation level of 5500 rem/h at canister surface contact. The reference canister is fabricated of standard 24-in.-OD, Schedule 20, 304L stainless steel pipe with a dished bottom, domed head, and a combined lifting and welding flange on the head neck. The overall canister length is 9 ft 10 in. with a 3/8-in. wall thickness. The 3-m canister length was selected to reduce equipment cell height in the DWPF to a practical size. The canister diameter was selected as an optimum size from glass quality considerations, a logical size for repository handling and to ensure that a filled canister with its double containment shipping cask could be accommodated on a legal-weight truck. The overall dimensions and weight appear to be compatible with preliminary assessments of repository requirements. 10 references.« less

Impact of age on the selection of nuclear cardiology stress protocols: The INCAPS (IAEA nuclear cardiology protocols) study.

PubMed

Al-Mallah, Mouaz H; Pascual, Thomas N B; Mercuri, Mathew; Vitola, João V; Karthikeyan, Ganesan; Better, Nathan; Dondi, Maurizio; Paez, Diana; Einstein, Andrew J

2018-05-15

There is growing concern about radiation exposure from nuclear myocardial perfusion imaging (MPI), particularly among younger patients who are more prone to develop untoward effects of ionizing radiation, and hence US and European professional society guidelines recommend age as a consideration in weighing radiation risk from MPI. We aimed to determine how patient radiation doses from MPI vary across age groups in a large contemporary international cohort. Data were collected as part of a global cross-sectional study of centers performing MPI coordinated by the International Atomic Energy Agency (IAEA). Sites provided information on each MPI study completed during a single week in March-April 2013. We compared across age groups laboratory adherence to pre-specified radiation-related best practices, radiation effective dose (ED; a whole-body measure reflecting the amount of radiation to each organ and its relative sensitivity to radiation's deleterious effects), and the proportion of patients with ED ≤ 9 mSv, a target level specified in guidelines. Among 7911 patients undergoing MPI in 308 laboratories in 65 countries, mean ED was 10.0 ± 4.5 mSv with slightly higher exposure among younger age groups (trend p value < 0.001). There was no difference in the proportion of patients with ED ≤ 9 mSv across age groups, or in adherence to best practices based on the median age of patients in a laboratory. In contemporary nuclear cardiology practice, the age of the patient appears not to impact protocol selection and radiation dose, contrary to professional society guidelines. Copyright © 2018. Published by Elsevier B.V.

Does Classification of Chronic Musculoskeletal Disorder Patients Into Psychosocial Subgroups Predict Differential Treatment Responsiveness and 1-Year Outcomes After a Functional Restoration Program?

PubMed

Asih, Sali; Mayer, Tom G; Williams, Mark; Choi, Yun Hee; Gatchel, Robert J

2015-12-01

The objectives of this study: (1) to assess whether Multidimensional Pain Inventory (MPI) profiles predicted differential responses to a functional restoration program (FRP) in chronic disabling occupational musculoskeletal disorder (CDOMD) patients; (2) to examine whether coping style improves following FRP; and (3) to determine whether discharge MPI profiles predict discharge psychosocial and 1-year socioeconomic outcomes. Consecutive CDOMD patients (N=716) were classified into Adaptive Coper (AC, n=209), Interpersonally Distressed (ID, n=154), Dysfunctional (DYS, n=310), and Anomalous (n=43) using the MPI, and reclassified at discharge. Profiles were compared on psychosocial measures and 1-year socioeconomic outcomes. An intent-to-treat sample analyzed the effect of drop-outs on treatment responsiveness. The MPI classification significantly predicted program completion (P=0.001), although the intent-to-treat analyses found no significant effects of drop-out on treatment responsiveness. There was a significant increase in the number of patients who became AC or Anomalous at FRP discharge and a decrease in those who were ID or DYS. Patients who changed or remained as DYS at FRP discharge reported the highest levels of pain, disability, and depression. No significant interaction effect was found between MPI group and time for pain intensity or disability. All groups improved on psychosocial measures at discharge. DYS patients had decreased work retention and a greater health care utilization at 1 year. An FRP was clinically effective for CDOMD patients regardless of initial MPI profiles. The FRP modified profiles, with patients changing from negative to positive profiles. Discharge DYS were more likely to have poor 1-year outcomes. Those classified as Anomalous had a good prognosis for functional recovery similar to ACs.

The effect of patient anxiety and depression on motion during myocardial perfusion SPECT imaging.

PubMed

Lyra, Vassiliki; Kallergi, Maria; Rizos, Emmanouil; Lamprakopoulos, Georgios; Chatziioannou, Sofia N

2016-08-22

Patient motion during myocardial perfusion SPECT imaging (MPI) may be triggered by a patient's physical and/or psychological discomfort. The aim of this study was to investigate the impact of state anxiety (patient's reaction to exam-related stress), trait anxiety (patient's personality characteristic) and depression on patient motion during MPI. All patients that underwent MPI in our department in a six-month period were prospectively enrolled. One hundred eighty-three patients (45 females; 138 males) filled in the State-Trait Anxiety Inventory (STAI) and the Beck Depression Inventory (BDI), along with a short questionnaire regarding their age, height and weight, level of education in years, occupation, and marital status. Cardiovascular and other co-morbidity factors were also evaluated. Through inspection of raw data on cinematic display, the presence or absence of patient motion was registered and classified into mild, moderate and severe, for both phases involved in image acquisition. The correlation of patient motion in the stress and delay phases of MPI and each of the other variables was investigated and the corresponding Pearson's coefficients of association were calculated. The anxiety-motion (r = 0.43, P < 0.0001) and depression-motion (r = 0.32, P < 0.0001) correlation results were moderately strong and statistically significant for the female but not the male patients. All the other variables did not demonstrate any association with motion in MPI, except a weak correlation between age and motion in females (r = 0.23, P < 0.001). The relationship between anxiety-motion and depression-motion identified in female patients represents the first supporting evidence of psychological discomfort as predisposing factor for patient motion during MPI.

Theoretical predictions for spatially-focused heating of magnetic nanoparticles guided by magnetic particle imaging field gradients

NASA Astrophysics Data System (ADS)

Dhavalikar, Rohan; Rinaldi, Carlos

2016-12-01

Magnetic nanoparticles in alternating magnetic fields (AMFs) transfer some of the field's energy to their surroundings in the form of heat, a property that has attracted significant attention for use in cancer treatment through hyperthermia and in developing magnetic drug carriers that can be actuated to release their cargo externally using magnetic fields. To date, most work in this field has focused on the use of AMFs that actuate heat release by nanoparticles over large regions, without the ability to select specific nanoparticle-loaded regions for heating while leaving other nanoparticle-loaded regions unaffected. In parallel, magnetic particle imaging (MPI) has emerged as a promising approach to image the distribution of magnetic nanoparticle tracers in vivo, with sub-millimeter spatial resolution. The underlying principle in MPI is the application of a selection magnetic field gradient, which defines a small region of low bias field, superimposed with an AMF (of lower frequency and amplitude than those normally used to actuate heating by the nanoparticles) to obtain a signal which is proportional to the concentration of particles in the region of low bias field. Here we extend previous models for estimating the energy dissipation rates of magnetic nanoparticles in uniform AMFs to provide theoretical predictions of how the selection magnetic field gradient used in MPI can be used to selectively actuate heating by magnetic nanoparticles in the low bias field region of the selection magnetic field gradient. Theoretical predictions are given for the spatial decay in energy dissipation rate under magnetic field gradients representative of those that can be achieved with current MPI technology. These results underscore the potential of combining MPI and higher amplitude/frequency actuation AMFs to achieve selective magnetic fluid hyperthermia (MFH) guided by MPI.

Stress-induced ST-segment deviation in relation to the presence and severity of coronary artery disease in patients with normal myocardial perfusion imaging.

PubMed

Weinsaft, Jonathan W; Manoushagian, Shant J; Patel, Taral; Shakoor, Aqsa; Kim, Robert J; Mirchandani, Sunil; Lin, Fay; Wong, Franklin J; Szulc, Massimiliano; Okin, Peter M; Kligfield, Paul D; Min, James K

2009-01-01

To assess the utility of stress electrocardiography (ECG) for identifying the presence and severity of obstructive coronary artery disease (CAD) defined by coronary computed tomographic angiography (CCTA) among patients with normal nuclear myocardial perfusion imaging (MPI). The study population comprised 119 consecutive patients with normal MPI who also underwent CCTA (interval 3.5+/-3.8 months). Stress ECG was performed at the time of MPI. CCTA and MPI were interpreted using established scoring systems, and CCTA was used to define the presence and extent of CAD, which was quantified by a coronary artery jeopardy score. Within this population, 28 patients (24%) had obstructive CAD identified by CCTA. The most common CAD pattern was single-vessel CAD (61%), although proximal vessel involvement was present in 46% of patients. Patients with CAD were nearly three times more likely to have positive standard test responses (1 mm ST-segment deviation) than patients with patent coronary arteries (36 vs. 13%, P=0.007). In multivariate analysis, a positive ST-segment test response was an independent marker for CAD (odds ratio: 2.02, confidence interval: 1.09-3.78, P=0.03) even after adjustment for a composite of clinical cardiac risk factors (odds ratio: 1.85, confidence interval: 1.05-3.23, P=0.03). Despite uniformly normal MPI, mean coronary jeopardy score was three-fold higher among patients with positive compared to those with negative ST-segment response to exercise or dobutamine stress (1.9+/-2.7 vs. 0.5+/-1.4, P=0.03). Stress-induced ST-segment deviation is an independent marker for obstructive CAD among patients with normal MPI. A positive stress ECG identifies patients with a greater anatomic extent of CAD as quantified by coronary jeopardy score.

Effects of medially posted insoles on foot and lower limb mechanics across walking and running in overpronating men.

PubMed

Kosonen, Jukka; Kulmala, Juha-Pekka; Müller, Erich; Avela, Janne

2017-03-21

Anti-pronation orthoses, like medially posted insoles (MPI), have traditionally been used to treat various of lower limb problems. Yet, we know surprisingly little about their effects on overall foot motion and lower limb mechanics across walking and running, which represent highly different loading conditions. To address this issue, multi-segment foot and lower limb mechanics was examined among 11 overpronating men with normal (NORM) and MPI insoles during walking (self-selected speed 1.70±0.19m/s vs 1.72±0.20m/s, respectively) and running (4.04±0.17m/s vs 4.10±0.13m/s, respectively). The kinematic results showed that MPI reduced the peak forefoot eversion movement in respect to both hindfoot and tibia across walking and running when compared to NORM (p<0.05-0.01). No differences were found in hindfoot eversion between conditions. The kinetic results showed no insole effects in walking, but during running MPI shifted center of pressure medially under the foot (p<0.01) leading to an increase in frontal plane moments at the hip (p<0.05) and knee (p<0.05) joints and a reduction at the ankle joint (p<0.05). These findings indicate that MPI primarily controlled the forefoot motion across walking and running. While kinetic response to MPI was more pronounced in running than walking, kinematic effects were essentially similar across both modes. This suggests that despite higher loads placed upon lower limb during running, there is no need to have a stiffer insoles to achieve similar reduction in the forefoot motion than in walking. Copyright © 2017 Elsevier Ltd. All rights reserved.

Magnetic particle imaging for in vivo blood flow velocity measurements in mice

NASA Astrophysics Data System (ADS)

Kaul, Michael G.; Salamon, Johannes; Knopp, Tobias; Ittrich, Harald; Adam, Gerhard; Weller, Horst; Jung, Caroline

2018-03-01

Magnetic particle imaging (MPI) is a new imaging technology. It is a potential candidate to be used for angiographic purposes, to study perfusion and cell migration. The aim of this work was to measure velocities of the flowing blood in the inferior vena cava of mice, using MPI, and to evaluate it in comparison with magnetic resonance imaging (MRI). A phantom mimicking the flow within the inferior vena cava with velocities of up to 21 cm s‑1 was used for the evaluation of the applied analysis techniques. Time–density and distance–density analyses for bolus tracking were performed to calculate flow velocities. These findings were compared with the calibrated velocities set by a flow pump, and it can be concluded that velocities of up to 21 cm s‑1 can be measured by MPI. A time–density analysis using an arrival time estimation algorithm showed the best agreement with the preset velocities. In vivo measurements were performed in healthy FVB mice (n  =  10). MRI experiments were performed using phase contrast (PC) for velocity mapping. For MPI measurements, a standardized injection of a superparamagnetic iron oxide tracer was applied. In vivo MPI data were evaluated by a time–density analysis and compared to PC MRI. A Bland–Altman analysis revealed good agreement between the in vivo velocities acquired by MRI of 4.0  ±  1.5 cm s‑1 and those measured by MPI of 4.8  ±  1.1 cm s‑1. Magnetic particle imaging is a new tool with which to measure and quantify flow velocities. It is fast, radiation-free, and produces 3D images. It therefore offers the potential for vascular imaging.

Development of Modeling and Simulation for Magnetic Particle Inspection Using Finite Elements

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

Lee, Jun-Youl

2003-01-01

Magnetic particle inspection (MPI) is a widely used nondestructive inspection method for aerospace applications essentially limited to experiment-based approaches. The analysis of MPI characteristics that affect sensitivity and reliability contributes not only reductions in inspection design cost and time but also improvement of analysis of experimental data. Magnetic particles are easily attracted toward a high magnetic field gradient. Selection of a magnetic field source, which produces a magnetic field gradient large enough to detect a defect in a test sample or component, is an important factor in magnetic particle inspection. In this work a finite element method (FEM) has beenmore » employed for numerical calculation of the MPI simulation technique. The FEM method is known to be suitable for complicated geometries such as defects in samples. This thesis describes the research that is aimed at providing a quantitative scientific basis for magnetic particle inspection. A new FEM solver for MPI simulation has been developed in this research for not only nonlinear reversible permeability materials but also irreversible hysteresis materials that are described by the Jiles-Atherton model. The material is assumed to have isotropic ferromagnetic properties in this research (i.e., the magnetic properties of the material are identical in all directions in a single crystal). In the research, with a direct current field mode, an MPI situation has been simulated to measure the estimated volume of magnetic particles around defect sites before and after removing any external current fields. Currently, this new MPI simulation package is limited to solving problems with the single current source from either a solenoid or an axial directional current rod.« less

Thermodynamic model of natural, medieval and nuclear waste glass durability

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

Jantzen, C.M.; Plodinec, M.J.

1983-01-01

A thermodynamic model of glass durability based on hydration of structural units has been applied to natural glass, medieval window glasses, and glasses containing nuclear waste. The relative durability predicted from the calculated thermodynamics correlates directly with the experimentally observed release of structural silicon in the leaching solution in short-term laboratory tests. By choosing natural glasses and ancient glasses whose long-term performance is known, and which bracket the durability of waste glasses, the long-term stability of nuclear waste glasses can be interpolated among these materials. The current Savannah River defense waste glass formulation is as durable as natural basalt frommore » the Hanford Reservation (10/sup 6/ years old). The thermodynamic hydration energy is shown to be related to the bond energetics of the glass. 69 references, 2 figures, 1 table.« less

KSC-99pp0537

NASA Image and Video Library

1999-05-16

KENNEDY SPACE CENTER, FLA. -- Inside High Bay 1 of the Vehicle Assembly Building (VAB) John Blue, with United Space Alliance, and Jorge Rivera, with NASA, look at the dings in the foam insulation on the external tank of Space Shuttle Discovery. About 150 dings were caused by hail during recent storms. The Shuttle was rolled back from Pad 39B to the VAB for repairs because access to all of the damaged areas was not possible at the pad. The work is expected to take two to three days, allowing Discovery to roll back to the pad as early as May 20 for launch of mission STS-96, the 94th launch in the Space Shuttle Program. Liftoff will occur no earlier than May 27. STS-96 is a logistics and resupply mission for the International Space Station, carrying such payloads as a Russian crane, the Strela; a U.S.-built crane; the Spacehab Oceaneering Space System Box (SHOSS), a logistics items carrier; and STARSHINE, a student-shared experiment

Applications of the similarity relations in radiative transfer to remote sensing implementation and flux simulation

NASA Astrophysics Data System (ADS)

Yang, P.; Ding, J.; Tang, G.; King, M. D.; Platnick, S. E.; Meyer, K.; Mlawer, E. J.

2017-12-01

Van de Hulst (1974) showed several quasi-invariant quantities in radiative transfer concerning multiple scattering. Recently, we illustrated that the aforesaid quasi-invariant quantities are useful in remote sensing of ice cloud properties from spaceborne radiometric observations (Ding et al. 2017). Specifically, the overall performance of an ice cloud optical property model can be estimated without carrying out detailed retrieval implementation. In this presentation, we will review the radiative transfer similarity relations and some recent results including the study by Ding et al. (2017). Furthermore, we will illustrate an application of the similarity relations to improvement of broadband radiative flux computation. For example, the Rapid Radiative Transfer Model (RRTM, Mlawer et al, 1999) does not consider multiple scattering in the longwave spectral regime (RRTMG-LW) ("G" indicates a version suitable for GCM applications). We show that the similarity relations can be used to effectively improve the accuracy of RRTMG-LW without increasing computational effort.

Resource-Efficient, Hierarchical Auto-Tuning of a Hybrid Lattice Boltzmann Computation on the Cray XT4

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

Computational Research Division, Lawrence Berkeley National Laboratory; NERSC, Lawrence Berkeley National Laboratory; Computer Science Department, University of California, Berkeley

2009-05-04

We apply auto-tuning to a hybrid MPI-pthreads lattice Boltzmann computation running on the Cray XT4 at National Energy Research Scientific Computing Center (NERSC). Previous work showed that multicore-specific auto-tuning can improve the performance of lattice Boltzmann magnetohydrodynamics (LBMHD) by a factor of 4x when running on dual- and quad-core Opteron dual-socket SMPs. We extend these studies to the distributed memory arena via a hybrid MPI/pthreads implementation. In addition to conventional auto-tuning at the local SMP node, we tune at the message-passing level to determine the optimal aspect ratio as well as the correct balance between MPI tasks and threads permore » MPI task. Our study presents a detailed performance analysis when moving along an isocurve of constant hardware usage: fixed total memory, total cores, and total nodes. Overall, our work points to approaches for improving intra- and inter-node efficiency on large-scale multicore systems for demanding scientific applications.« less

Accelerating list management for MPI.

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

Hemmert, K. Scott; Rodrigues, Arun F.; Underwood, Keith Douglas

2005-07-01

The latency and throughput of MPI messages are critically important to a range of parallel scientific applications. In many modern networks, both of these performance characteristics are largely driven by the performance of a processor on the network interface. Because of the semantics of MPI, this embedded processor is forced to traverse a linked list of posted receives each time a message is received. As this list grows long, the latency of message reception grows and the throughput of MPI messages decreases. This paper presents a novel hardware feature to handle list management functions on a network interface. By movingmore » functions such as list insertion, list traversal, and list deletion to the hardware unit, latencies are decreased by up to 20% in the zero length queue case with dramatic improvements in the presence of long queues. Similarly, the throughput is increased by up to 10% in the zero length queue case and by nearly 100% in the presence queues of 30 messages.« less

Parallel Fortran-MPI software for numerical inversion of the Laplace transform and its application to oscillatory water levels in groundwater environments

USGS Publications Warehouse

Zhan, X.

2005-01-01

A parallel Fortran-MPI (Message Passing Interface) software for numerical inversion of the Laplace transform based on a Fourier series method is developed to meet the need of solving intensive computational problems involving oscillatory water level's response to hydraulic tests in a groundwater environment. The software is a parallel version of ACM (The Association for Computing Machinery) Transactions on Mathematical Software (TOMS) Algorithm 796. Running 38 test examples indicated that implementation of MPI techniques with distributed memory architecture speedups the processing and improves the efficiency. Applications to oscillatory water levels in a well during aquifer tests are presented to illustrate how this package can be applied to solve complicated environmental problems involved in differential and integral equations. The package is free and is easy to use for people with little or no previous experience in using MPI but who wish to get off to a quick start in parallel computing. ?? 2004 Elsevier Ltd. All rights reserved.

Porting the AVS/Express scientific visualization software to Cray XT4.

PubMed

Leaver, George W; Turner, Martin J; Perrin, James S; Mummery, Paul M; Withers, Philip J

2011-08-28

Remote scientific visualization, where rendering services are provided by larger scale systems than are available on the desktop, is becoming increasingly important as dataset sizes increase beyond the capabilities of desktop workstations. Uptake of such services relies on access to suitable visualization applications and the ability to view the resulting visualization in a convenient form. We consider five rules from the e-Science community to meet these goals with the porting of a commercial visualization package to a large-scale system. The application uses message-passing interface (MPI) to distribute data among data processing and rendering processes. The use of MPI in such an interactive application is not compatible with restrictions imposed by the Cray system being considered. We present details, and performance analysis, of a new MPI proxy method that allows the application to run within the Cray environment yet still support MPI communication required by the application. Example use cases from materials science are considered.

An examination of the psychometric structure of the Multidimensional Pain Inventory in temporomandibular disorder patients: a confirmatory factor analysis

PubMed Central

Andreu, Yolanda; Galdon, Maria J; Durá, Estrella; Ferrando, Maite; Pascual, Juan; Turk, Dennis C; Jiménez, Yolanda; Poveda, Rafael

2006-01-01

Background This paper seeks to analyse the psychometric and structural properties of the Multidimensional Pain Inventory (MPI) in a sample of temporomandibular disorder patients. Methods The internal consistency of the scales was obtained. Confirmatory Factor Analysis was carried out to test the MPI structure section by section in a sample of 114 temporomandibular disorder patients. Results Nearly all scales obtained good reliability indexes. The original structure could not be totally confirmed. However, with a few adjustments we obtained a satisfactory structural model of the MPI which was slightly different from the original: certain items and the Self control scale were eliminated; in two cases, two original scales were grouped in one factor, Solicitous and Distracting responses on the one hand, and Social activities and Away from home activities, on the other. Conclusion The MPI has been demonstrated to be a reliable tool for the assessment of pain in temporomandibular disorder patients. Some divergences to be taken into account have been clarified. PMID:17169143

Projection x-space magnetic particle imaging.

PubMed

Goodwill, Patrick W; Konkle, Justin J; Zheng, Bo; Saritas, Emine U; Conolly, Steven M

2012-05-01

Projection magnetic particle imaging (MPI) can improve imaging speed by over 100-fold over traditional 3-D MPI. In this work, we derive the 2-D x-space signal equation, 2-D image equation, and introduce the concept of signal fading and resolution loss for a projection MPI imager. We then describe the design and construction of an x-space projection MPI scanner with a field gradient of 2.35 T/m across a 10 cm magnet free bore. The system has an expected resolution of 3.5 × 8.0 mm using Resovist tracer, and an experimental resolution of 3.8 × 8.4 mm resolution. The system images 2.5 cm × 5.0 cm partial field-of views (FOVs) at 10 frames/s, and acquires a full field-of-view of 10 cm × 5.0 cm in 4 s. We conclude by imaging a resolution phantom, a complex "Cal" phantom, mice injected with Resovist tracer, and experimentally confirm the theoretically predicted x-space spatial resolution.

Finite magnetic relaxation in x-space magnetic particle imaging: Comparison of measurements and ferrohydrodynamic models.

PubMed

Dhavalikar, R; Hensley, D; Maldonado-Camargo, L; Croft, L R; Ceron, S; Goodwill, P W; Conolly, S M; Rinaldi, C

2016-08-03

Magnetic Particle Imaging (MPI) is an emerging tomographic imaging technology that detects magnetic nanoparticle tracers by exploiting their non-linear magnetization properties. In order to predict the behavior of nanoparticles in an imager, it is possible to use a non-imaging MPI relaxometer or spectrometer to characterize the behavior of nanoparticles in a controlled setting. In this paper we explore the use of ferrohydrodynamic magnetization equations for predicting the response of particles in an MPI relaxometer. These include a magnetization equation developed by Shliomis (Sh) which has a constant relaxation time and a magnetization equation which uses a field-dependent relaxation time developed by Martsenyuk, Raikher and Shliomis (MRSh). We compare the predictions from these models with measurements and with the predictions based on the Langevin function that assumes instantaneous magnetization response of the nanoparticles. The results show good qualitative and quantitative agreement between the ferrohydrodynamic models and the measurements without the use of fitting parameters and provide further evidence of the potential of ferrohydrodynamic modeling in MPI.

The clinical implications of myocardial perfusion abnormalities in patients with esophageal or lung cancer after chemoradiation therapy.

PubMed

Gayed, Isis; Gohar, Salman; Liao, Zhongxing; McAleer, Mary; Bassett, Roland; Yusuf, Syed Wamique

2009-06-01

This study aims to identify the clinical implications of myocardial perfusion defects after chemoradiation therapy (CRT) in patients with esophageal and lung cancer. We retrospectively compared myocardial perfusion imaging (MPI) results before and after CRT in 16 patients with esophageal cancer and 24 patients with lung cancer. New MPI defects in the radiation therapy (RT) fields were considered related to RT. Follow-up to evaluate for cardiac complications and their relation with the results of MPI was performed. Statistical analysis identified predictors of cardiac morbidities. Eleven females and twenty nine males at a mean age of 66.7 years were included. Five patients (31%) with esophageal cancer and seven patients (29%) with lung cancer developed myocardial ischemia in the RT field at mean intervals of 7.0 and 8.4 months after RT. The patients were followed-up for mean intervals of 15 and 23 months in the esophageal and lung cancer groups, respectively. Seven patients in each of the esophageal (44%) and lung (29%) cancer patients (P = 0.5) developed cardiac complications of which one patient with esophageal cancer died of complete heart block. Six out of the fourteen patients (43%) with cardiac complication had new ischemia on MPI after CRT of which only one developed angina. The remaining eight patients with cardiac complications had normal MPI results. MPI result was not a statistically significant predictor of future cardiac complications after CRT. A history of congestive heart failure (CHF) (P = 0.003) or arrhythmia (P = 0.003) is a significant predictor of cardiac morbidity after CRT in univariate analysis but marginal predictors when multivariate analysis was performed (P = 0.06 and 0.06 for CHF and arrhythmia, respectively). Cardiac complications after CRT are more common in esophageal than lung cancer patients but the difference is not statistically significant. MPI abnormalities are frequently seen after CRT but are not predictive of future cardiac complications. A history of arrhythmia or CHF is significantly associated with cardiac complications after CRT.

ParBiBit: Parallel tool for binary biclustering on modern distributed-memory systems

PubMed Central

Expósito, Roberto R.

2018-01-01

Biclustering techniques are gaining attention in the analysis of large-scale datasets as they identify two-dimensional submatrices where both rows and columns are correlated. In this work we present ParBiBit, a parallel tool to accelerate the search of interesting biclusters on binary datasets, which are very popular on different fields such as genetics, marketing or text mining. It is based on the state-of-the-art sequential Java tool BiBit, which has been proved accurate by several studies, especially on scenarios that result on many large biclusters. ParBiBit uses the same methodology as BiBit (grouping the binary information into patterns) and provides the same results. Nevertheless, our tool significantly improves performance thanks to an efficient implementation based on C++11 that includes support for threads and MPI processes in order to exploit the compute capabilities of modern distributed-memory systems, which provide several multicore CPU nodes interconnected through a network. Our performance evaluation with 18 representative input datasets on two different eight-node systems shows that our tool is significantly faster than the original BiBit. Source code in C++ and MPI running on Linux systems as well as a reference manual are available at https://sourceforge.net/projects/parbibit/. PMID:29608567

ParBiBit: Parallel tool for binary biclustering on modern distributed-memory systems.

PubMed

González-Domínguez, Jorge; Expósito, Roberto R

2018-01-01

Biclustering techniques are gaining attention in the analysis of large-scale datasets as they identify two-dimensional submatrices where both rows and columns are correlated. In this work we present ParBiBit, a parallel tool to accelerate the search of interesting biclusters on binary datasets, which are very popular on different fields such as genetics, marketing or text mining. It is based on the state-of-the-art sequential Java tool BiBit, which has been proved accurate by several studies, especially on scenarios that result on many large biclusters. ParBiBit uses the same methodology as BiBit (grouping the binary information into patterns) and provides the same results. Nevertheless, our tool significantly improves performance thanks to an efficient implementation based on C++11 that includes support for threads and MPI processes in order to exploit the compute capabilities of modern distributed-memory systems, which provide several multicore CPU nodes interconnected through a network. Our performance evaluation with 18 representative input datasets on two different eight-node systems shows that our tool is significantly faster than the original BiBit. Source code in C++ and MPI running on Linux systems as well as a reference manual are available at https://sourceforge.net/projects/parbibit/.

Multiple Parton Interactions in p$$bar{p}$$ Collisions in D0 Experiment at the Tevatron Collider (in Russian)

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

Golovanov, Georgy

The thesis is devoted to the study of processes with multiple parton interactions (MPI) in a ppbar collision collected by D0 detector at the Fermilab Tevatron collider at sqrt(s) = 1.96 TeV. The study includes measurements of MPI event fraction and effective cross section, a process-independent parameter related to the effective interaction region inside the nucleon. The measurements are done using events with a photon and three hadronic jets in the final state. The measured effective cross section is used to estimate background from MPI for WH production at the Tevatron energy

A Generator-Produced Gallium-68 Radiopharmaceutical for PET Imaging of Myocardial Perfusion

PubMed Central

Sharma, Vijay; Sivapackiam, Jothilingam; Harpstrite, Scott E.; Prior, Julie L.; Gu, Hannah; Rath, Nigam P.; Piwnica-Worms, David

2014-01-01

Lipophilic cationic technetium-99m-complexes are widely used for myocardial perfusion imaging (MPI). However, inherent uncertainties in the supply chain of molybdenum-99, the parent isotope required for manufacturing 99Mo/99mTc generators, intensifies the need for discovery of novel MPI agents incorporating alternative radionuclides. Recently, germanium/gallium (Ge/Ga) generators capable of producing high quality 68Ga, an isotope with excellent emission characteristics for clinical PET imaging, have emerged. Herein, we report a novel 68Ga-complex identified through mechanism-based cell screening that holds promise as a generator-produced radiopharmaceutical for PET MPI. PMID:25353349

Glass Doesn't Flow and Doesn't Crystallize and It Isn't a Liquid.

ERIC Educational Resources Information Center

Hawkes, Stephen J.

2000-01-01

Illustrates that, contrary to some assertions made in the popular press, scientific literature, and introductory textbooks, glass does not flow in historic time. Contends that glass is a rigid solid with a lower degree of molecular order than a crystal but with greater molecular order than a liquid. (Contains 27 references.) (WRM)

Underrepresentation of Females in the Superintendency in Minnesota

ERIC Educational Resources Information Center

Wyland, Catherine

2016-01-01

Public school district leadership is dominated by males while teaching is dominated by females (Blount, 1998; Glass, Björk, & Brunner, 2000; Grogan, 1996). Some may not recognize this as a problem while others might refer to this underrepresentation as a glass ceiling, a sticky floor, a concrete wall, or a glass cliff. In any case, the…

Cardiovascular outcomes of a positive nuclear stress test but negative coronary angiography in a multiethnic male predominant cohort.

PubMed

Addison, Daniel; Singh, Vinita; Okyere-Asante, K; Okafor, Henry

2014-01-01

Patients presenting with chest pain and evidence of functional ischemia by myocardial perfusion imaging (MPI), but lacking commensurate angiographic disease pose a diagnostic and therapeutic dilemma. They are often dismissed as having 'false-positive MPI'. Moreover, a majority of the available long-term outcome data for it has been derived from homogenous female populations. In this study, we sought to evaluate the long-term outcomes of this presentation in a multiethnic male-predominant cohort. We retrospectively identified 47 patients who presented to our institution between 2002 and 2005 with chest pain and evidence of ischemia on MPI, but with no significant angiographic disease on subsequent cardiac catheterization (cases). The occurrence of adverse cardiovascular outcomes (chest pain, congestive heart failure, acute myocardial infarction and stroke) post-index coronary angiogram was tracked. Similar data was collected for 37 patients who also presented with chest pain, but normal MPI over the same period (controls). Overall average follow-up was over 22 months. Fifty-three percent (26/47) of the cases had one or more of the adverse outcomes as compared with 22% (8/37) of controls (P < 0.01). Of these, 13 (50.0%) and 3 (37.5%) were males, respectively. Ischemia on MPI is predictive of long-term adverse cardiovascular outcomes despite normal ('false-negative') coronary angiography. This appears to be gender-neutral.

Multilevel Parallelization of AutoDock 4.2.

PubMed

Norgan, Andrew P; Coffman, Paul K; Kocher, Jean-Pierre A; Katzmann, David J; Sosa, Carlos P

2011-04-28

Virtual (computational) screening is an increasingly important tool for drug discovery. AutoDock is a popular open-source application for performing molecular docking, the prediction of ligand-receptor interactions. AutoDock is a serial application, though several previous efforts have parallelized various aspects of the program. In this paper, we report on a multi-level parallelization of AutoDock 4.2 (mpAD4). Using MPI and OpenMP, AutoDock 4.2 was parallelized for use on MPI-enabled systems and to multithread the execution of individual docking jobs. In addition, code was implemented to reduce input/output (I/O) traffic by reusing grid maps at each node from docking to docking. Performance of mpAD4 was examined on two multiprocessor computers. Using MPI with OpenMP multithreading, mpAD4 scales with near linearity on the multiprocessor systems tested. In situations where I/O is limiting, reuse of grid maps reduces both system I/O and overall screening time. Multithreading of AutoDock's Lamarkian Genetic Algorithm with OpenMP increases the speed of execution of individual docking jobs, and when combined with MPI parallelization can significantly reduce the execution time of virtual screens. This work is significant in that mpAD4 speeds the execution of certain molecular docking workloads and allows the user to optimize the degree of system-level (MPI) and node-level (OpenMP) parallelization to best fit both workloads and computational resources.

Hybrid cloud and cluster computing paradigms for life science applications

PubMed Central

2010-01-01

Background Clouds and MapReduce have shown themselves to be a broadly useful approach to scientific computing especially for parallel data intensive applications. However they have limited applicability to some areas such as data mining because MapReduce has poor performance on problems with an iterative structure present in the linear algebra that underlies much data analysis. Such problems can be run efficiently on clusters using MPI leading to a hybrid cloud and cluster environment. This motivates the design and implementation of an open source Iterative MapReduce system Twister. Results Comparisons of Amazon, Azure, and traditional Linux and Windows environments on common applications have shown encouraging performance and usability comparisons in several important non iterative cases. These are linked to MPI applications for final stages of the data analysis. Further we have released the open source Twister Iterative MapReduce and benchmarked it against basic MapReduce (Hadoop) and MPI in information retrieval and life sciences applications. Conclusions The hybrid cloud (MapReduce) and cluster (MPI) approach offers an attractive production environment while Twister promises a uniform programming environment for many Life Sciences applications. Methods We used commercial clouds Amazon and Azure and the NSF resource FutureGrid to perform detailed comparisons and evaluations of different approaches to data intensive computing. Several applications were developed in MPI, MapReduce and Twister in these different environments. PMID:21210982

Hybrid cloud and cluster computing paradigms for life science applications.

PubMed

Qiu, Judy; Ekanayake, Jaliya; Gunarathne, Thilina; Choi, Jong Youl; Bae, Seung-Hee; Li, Hui; Zhang, Bingjing; Wu, Tak-Lon; Ruan, Yang; Ekanayake, Saliya; Hughes, Adam; Fox, Geoffrey

2010-12-21

Clouds and MapReduce have shown themselves to be a broadly useful approach to scientific computing especially for parallel data intensive applications. However they have limited applicability to some areas such as data mining because MapReduce has poor performance on problems with an iterative structure present in the linear algebra that underlies much data analysis. Such problems can be run efficiently on clusters using MPI leading to a hybrid cloud and cluster environment. This motivates the design and implementation of an open source Iterative MapReduce system Twister. Comparisons of Amazon, Azure, and traditional Linux and Windows environments on common applications have shown encouraging performance and usability comparisons in several important non iterative cases. These are linked to MPI applications for final stages of the data analysis. Further we have released the open source Twister Iterative MapReduce and benchmarked it against basic MapReduce (Hadoop) and MPI in information retrieval and life sciences applications. The hybrid cloud (MapReduce) and cluster (MPI) approach offers an attractive production environment while Twister promises a uniform programming environment for many Life Sciences applications. We used commercial clouds Amazon and Azure and the NSF resource FutureGrid to perform detailed comparisons and evaluations of different approaches to data intensive computing. Several applications were developed in MPI, MapReduce and Twister in these different environments.

Advances in PET myocardial perfusion imaging: F-18 labeled tracers.

PubMed

Rischpler, Christoph; Park, Min-Jae; Fung, George S K; Javadi, Mehrbod; Tsui, Benjamin M W; Higuchi, Takahiro

2012-01-01

Coronary artery disease and its related cardiac disorders represent the most common cause of death in the USA and Western world. Despite advancements in treatment and accompanying improvements in outcome with current diagnostic and therapeutic modalities, it is the correct assignment of these diagnostic techniques and treatment options which are crucial. From a diagnostic standpoint, SPECT myocardial perfusion imaging (MPI) using traditional radiotracers like thallium-201 chloride, Tc-99m sestamibi or Tc-99m tetrofosmin is the most utilized imaging technique. However, PET MPI using N-13 ammonia, rubidium-82 chloride or O-15 water is increasing in availability and usage as a result of the growing number of medical centers with new-generation PET/CT systems taking advantage of the superior imaging properties of PET over SPECT. The routine clinical use of PET MPI is still limited, in part because of the short half-life of conventional PET MPI tracers. The disadvantages of these conventional PET tracers include expensive onsite production and inconvenient on-scanner tracer administration making them unsuitable for physical exercise stress imaging. Recently, two F-18 labeled radiotracers with longer radioactive half-lives than conventional PET imaging agents have been introduced. These are flurpiridaz F 18 (formerly known as F-18 BMS747158-02) and F-18 fluorobenzyltriphenylphosphonium. These longer half-life F-18 labeled perfusion tracers can overcome the production and protocol limitations of currently used radiotracers for PET MPI.

Cloning, expression, purification, crystallization and preliminary X-ray crystallographic analysis of the mannose 6-phosphate isomerase from Salmonella typhimurium

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

Gowda, Giri; Sagurthi, Someswar Rao; Savithri, H. S.

2008-02-01

The cloning, expression, purification, crystallization and preliminary X-ray crystallographic studies of mannose 6-phosphate isomerase from S. typhimurium are reported. Mannose 6-phosphate isomerase (MPI; EC 5.3.1.8) catalyzes the reversible isomerization of d-mannose 6-phosphate (M6P) and d-fructose 6-phosphate (F6P). In the eukaryotes and prokaryotes investigated to date, the enzyme has been reported to play a crucial role in d-mannose metabolism and supply of the activated mannose donor guanosine diphosphate d-mannose (GDP-d-mannose). In the present study, MPI was cloned from Salmonella typhimurium, overexpressed in Escherichia coli and purified using Ni–NTA affinity column chromatography. Purified MPI crystallized in space group P2{sub 1}2{sub 1}2{sub 1},more » with unit-cell parameters a = 36.03, b = 92.2, c = 111.01 Å. A data set extending to 1.66 Å resolution was collected with 98.8% completeness using an image-plate detector system mounted on a rotating-anode X-ray generator. The asymmetric unit of the crystal cell was compatible with the presence of a monomer of MPI. A preliminary structure solution of the enzyme has been obtained by molecular replacement using Candida albicans MPI as the phasing model and the program Phaser. Further refinement and model building are in progress.« less

Dietary mung bean protein reduces high-fat diet-induced weight gain by modulating host bile acid metabolism in a gut microbiota-dependent manner.

PubMed

Nakatani, Akiho; Li, Xuan; Miyamoto, Junki; Igarashi, Miki; Watanabe, Hitoshi; Sutou, Asuka; Watanabe, Keita; Motoyama, Takayasu; Tachibana, Nobuhiko; Kohno, Mitsutaka; Inoue, Hiroshi; Kimura, Ikuo

2018-07-02

The 8-globulin-rich mung bean protein (MPI) suppresses hepatic lipogenesis in rodent models and reduces fasting plasma glucose and insulin levels in obese adults. However, its effects on mitigating high fat diet (HFD)-induced obesity and the mechanism underlying these effects remain to be elucidated. Herein, we examined the metabolic phenotype, intestinal bile acid (BA) pool, and gut microbiota of conventionally raised (CONV-R) male C57BL/6 mice and germ-free (GF) mice that were randomized to receive either regular HFD or HFD containing mung bean protein isolate (MPI) instead of the dairy protein present in regular HFD. MPI intake significantly reduced HFD-induced weight gain and adipose tissue accumulation, and attenuated hepatic steatosis. Enhancement in the secretion of intestinal glucagon-like peptide-1 (GLP-1) and an enlarged cecal and fecal BA pool of dramatically elevated secondary/primary BA ratio were observed in mice that had consumed MPI. These effects were abolished in GF mice, indicating that the effects were dependent upon the presence of the microbiota. As revealed by 16S rRNA gene sequence analysis, MPI intake also elicited dramatic changes in the gut microbiome, such as an expansion of taxa belonging to the phylum Bacteroidetes along with a reduced abundance of the Firmicutes. Copyright © 2018 Elsevier Inc. All rights reserved.

Differential Changes in Myocardial Performance Index and Its Time Intervals in Donors and Recipients of Twin-to-Twin Transfusion Syndrome before and after Laser Therapy.

PubMed

Ortiz, Javier U; Torres, Ximena; Eixarch, Elisenda; Bennasar, Mar; Cruz-Lemini, Monica; Gómez, Olga; Lobmaier, Silvia M; Martínez, Josep M; Gratacós, Eduard; Crispi, Fatima

2018-01-19

To evaluate left myocardial performance index (MPI) and time intervals in fetuses with twin-to-twin transfusion syndrome (TTTS) before and after laser surgery. Fifty-one fetal pairs with TTTS and 47 uncomplicated monochorionic twin pairs were included. Left ventricular isovolumetric contraction time (ICT), ejection time (ET), and isovolumetric relaxation time (IRT) were measured using conventional Doppler. Recipients showed prolonged ICT (46 ± 12 vs. 31 ± 8 vs. 30 ± 5 ms; p < 0.001) and IRT (51 ± 9 vs. 43 ± 8 vs. 43 ± 5 ms; p < 0.001) and higher MPI (0.57 ± 0.12 vs. 0.47 ± 0.09 vs. 0.44 ± 0.05; p < 0.001) than donors and controls. Donors showed shorter ET than recipients and controls (157 ± 12 vs. 169 ± 10 vs. 168 ± 10 ms; p < 0.001) and higher MPI than controls (0.47 ± 0.09 vs. 0.44 ± 0.05; p = 0.006). Preoperative MPI changes were observed in all TTTS stages. Time intervals partially improved after surgery. Donor and recipient twins had higher MPI due to different changes in the time intervals, possibly reflecting the state of hypovolemia in the donor and hypervolemia and pressure overload in the recipient. © 2018 S. Karger AG, Basel.

Workshop on Future Directions for Optical Information Processing.

DTIC Science & Technology

1981-03-01

h . The i reference point source simultaneously illuminates the i member of a family of n phase-encoding Aiffusers (e.g. shower glass , ground glass ...diffuser (ground glass ) section illuminated with a plane wave [35.37). The n(n-1) - 4(3) - 12 crosstalk terms have been distributed into the noise...for 2x2 input Fig. 6. Outnut of processor analogous to that array, l.Sx magnifier, ground glass diffuser of Fig. 5, but using spherical wavefront and

An insight to the eruption mechanism of volcanic rocks in North Tibet: Project TITAN

NASA Astrophysics Data System (ADS)

He, R.; Gao, R.; Li, Q.

2013-12-01

Since Cenozoic continent-continental collision between India and Asia [Yin and Harrison, 2000], many surface features happened within the plateau were prominent. As one of them, high-to-ultra potassic lavas of Neogene, even younger, are widely distributed in NW Tibet, as shown in Figure1. Obvious petrological and geochemical characteristics of those lavas [Turner et al., 1993; Deng et al., 1996; Hacker et al., 2000; Ding et al., 2003; Williams et al., 2004; Chung et al., 2005; Luo et al., 2006; Guo et al., 2006] were presumably associated with extensional collapse of the lithospheric mantle [Deng et al., 1998; Li et al., 2000; Ding et al., 2003; Williams et al., 2004; Chung et al., 2005; Luo et al., 2006; Guo et al., 2006], which started at about 4Ma [Yin et al., 1999] and still goes on [Lin et al., 2002]. (1) What kinetics happened within the lithosphere beneath the lava region since Late Neogene? (2) What kind of mechanism leads to the lava eruption, it is only the result of far-long effect of northward subduction of the India plate, or directly related to the south margin of the Asian lithosphere, or bilaterally affected by India and Asia plate, or other factors? (3) Why did the strong volcanic activities only wrecked the North Qiangtang terrane, Jinshajiang suture and Hoh Xil terrane, instead of going northward across Altyn Tagh Fault and East Kunlun? As is known, to reveal the scientific secret concealed in lavas within NW Tibet geophysical observations are very necessary and urgent. NW Tibet including North Qiangtang and Hoh Xil is a very tough region for human beings. The project for geophysical observatory in the region is named as TITAN. TITAN has currently made some great progress, such as 103 broadband Seismic observation stations were deployed along longitude 88.5E in recent 5 years, as shown in Figure 1. Some primary results were got, such as (1) P-velocity structure from teleseismic tomography around Shuanghu in central Qiangtang (Figure 2) showed that the central uplift of Qiangtang [Wang et al., 1987; Kapp et al., 2003] surely had a characteristic of suture zone as Shuanghu Suture named by Li et al. [1987, 2001]. (2) P-velocity structure from teleseismic tomography beneath the lava region showed that the low anomalous body of those lavas is not more than 130 km depth, that agrees well with inference of geochemistry evidences [Ding et al., 2003; Williams et al., 2004; Chung et al., 2005; Luo et al., 2006]. (3) Isostatic gravity analysis showed that the lower crust and upper mantle were characterized by much lower density because of serious material loss, which suggested that the lower crust and upper mantle are still strongly interacting. References( be omitted to save)

78 FR 9793 - Airworthiness Directives; Bell Helicopter Textron Helicopters

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-12

...-numbered main rotor hub inboard strap fittings (fittings). This AD requires magnetic particle inspecting..., data, or views. We also invite comments relating to the economic, environmental, energy, or federalism..., perform a magnetic particle inspection (MPI) of each fitting for a crack. If an MPI was already performed...

Students' Performance on a Symmetry Task

ERIC Educational Resources Information Center

Ho, Siew Yin; Logan, Tracy

2013-01-01

This paper describes Singapore and Australian Grade 6 students' (n=1,187) performance on a symmetry task in a recently developed Mathematics Processing Instrument (MPI). The MPI comprised tasks sourced from Australia and Singapore's national assessments, NAPLAN and PSLE. Only half of the cohort solved the item successfully. It is possible that…

WinHPC System Programming | High-Performance Computing | NREL

Science.gov Websites

Programming WinHPC System Programming Learn how to build and run an MPI (message passing interface (mpi.h) and library (msmpi.lib) are. To build from the command line, run... Start > Intel Software Development Tools > Intel C++ Compiler Professional... > C++ Build Environment for applications running

77 FR 41806 - RG Steel Sparrows Point LLC, Formerly Known as Severstal Sparrows Point LLC, a Subsidiary of RG...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-16

... Leased Workers From Echelon Service Company, Sun Associated Industries, INC., MPI Consultants LLC... International, including on-site leased workers from Echelon Service Company, Sun Associated Industries, Inc... Company, Sun Associated Industries, Inc., MPI Consultants LLC, Alliance Engineering, Inc., Washington...

Eliminating the use of intravenous glass bottles using a FOCUS-PDCA model and providing a practical stability reference guide.

PubMed

Maraiki, Fatma; Farooq, Faiyaz; Ahmed, Mohamed

2016-08-01

To identify the intravenous (IV) medications that are prepared in glass bottles at the institution and establish which of these medications can be prepared in flexible IV bags such as polyvinyl chloride (PVC) or non-PVC instead of glass bottles. The cost implication of switching from glass bottles to flexible IV bags was calculated. A study using FOCUS-PDCA model to identify IV medications prepared in glass bottles and establish which of these medications could be prepared in IV bags (PVC or non-PVC). The cost impact of switching from glass bottles to IV plastic bags (including PVC or non-PVC) was calculated. The stability data obtained were used as a reference for updating pharmacy internal IV preparation charts. A total of 17 IV medications were found to be prepared in IV glass bottles. Of these 17 medications, only 8 (47%) were prepared in IV glass bottles due to incompatibility with PVC bags. For 7 (41%) of the medications, of which 6 were monoclonal antibodies (MABs), the reason for preparation in glass bottles was unclear as these medications are compatible with either PVC or non-PVC or both. The potential cost savings associated with switching all of the identified medications to IV plastic bags (either non-PVC or PVC) exceeded $200 000. The elimination of glass bottles within the institution resulted in a significant cost saving. The use of FOCUS-PDCA model can help healthcare institution achieve significant improvements in process and realize significant cost savings. © 2016 Royal Pharmaceutical Society.

Optics survivability support, volume 2

NASA Astrophysics Data System (ADS)

Wild, N.; Simpson, T.; Busdeker, A.; Doft, F.

1993-01-01

This volume of the Optics Survivability Support Final Report contains plots of all the data contained in the computerized Optical Glasses Database. All of these plots are accessible through the Database, but are included here as a convenient reference. The first three pages summarize the types of glass included with a description of the radiation source, test date, and the original data reference. This information is included in the database as a macro button labeled 'LLNL DATABASE'. Following this summary is an Abbe chart showing which glasses are included and where they lie as a function of nu(sub d) and n(sub d). This chart is also callable through the database as a macro button labeled 'ABBEC'.

Pipelines of Progress: An Update on the Glass Ceiling Initiative. A Status Report.

ERIC Educational Resources Information Center

Department of Labor, Washington, DC.

The "glass ceiling" refers to those barriers that have prevented the advancement of women and minorities into the top levels of executive management in major U.S. corporations. In 1991, the U.S. Department of Labor released a report describing the Glass Ceiling Initiative. This document reports on what occurred in the year following the…

Genetic Modifiers of Ovarian Cancer

DTIC Science & Technology

2012-06-01

Ditsch N, Arnold N, Heidemann S, Niederacher D, Preisler-Adams S, Gadzicki D, Varon-Mateeva R, Deissler H, Gehrig A, Sutter C, Kast K, Fiebig B...Gehrig A, Sutter C, Kast K, Fiebig B, Heinritz W, Caldes T, de la Hoya M, Muranen TA, Nevanlinna H, Tischkowitz MD, Spurdle AB, Neuhausen SL, Ding

Coordinated Radar Resource Management for Networked Phased Array Radars

DTIC Science & Technology

2014-12-01

Coordinated radar resource management for networked phased array radars Peter W. Moo and Zhen Ding Radar Sensing & Exploitation Section Defence...15] P.W. Moo . Scheduling for multifunction radar via two-slope benefit functions. Radar, Sonar Navigation, IET, 5(8):884 –894, Oct. 2011. [16] M.I

A Randomized Study Comparing Digital Imaging to Traditional Glass Slide Microscopy for Breast Biopsy and Cancer Diagnosis.

PubMed

Elmore, Joann G; Longton, Gary M; Pepe, Margaret S; Carney, Patricia A; Nelson, Heidi D; Allison, Kimberly H; Geller, Berta M; Onega, Tracy; Tosteson, Anna N A; Mercan, Ezgi; Shapiro, Linda G; Brunyé, Tad T; Morgan, Thomas R; Weaver, Donald L

2017-01-01

Digital whole slide imaging may be useful for obtaining second opinions and is used in many countries. However, the U.S. Food and Drug Administration requires verification studies. Pathologists were randomized to interpret one of four sets of breast biopsy cases during two phases, separated by ≥9 months, using glass slides or digital format (sixty cases per set, one slide per case, n = 240 cases). Accuracy was assessed by comparing interpretations to a consensus reference standard. Intraobserver reproducibility was assessed by comparing the agreement of interpretations on the same cases between two phases. Estimated probabilities of confirmation by a reference panel (i.e., predictive values) were obtained by incorporating data on the population prevalence of diagnoses. Sixty-five percent of responding pathologists were eligible, and 252 consented to randomization; 208 completed Phase I (115 glass, 93 digital); and 172 completed Phase II (86 glass, 86 digital). Accuracy was slightly higher using glass compared to digital format and varied by category: invasive carcinoma, 96% versus 93% ( P = 0.04); ductal carcinoma in situ (DCIS), 84% versus 79% ( P < 0.01); atypia, 48% versus 43% ( P = 0.08); and benign without atypia, 87% versus 82% ( P < 0.01). There was a small decrease in intraobserver agreement when the format changed compared to when glass slides were used in both phases ( P = 0.08). Predictive values for confirmation by a reference panel using glass versus digital were: invasive carcinoma, 98% and 97% (not significant [NS]); DCIS, 70% and 57% ( P = 0.007); atypia, 38% and 28% ( P = 0.002); and benign without atypia, 97% and 96% (NS). In this large randomized study, digital format interpretations were similar to glass slide interpretations of benign and invasive cancer cases. However, cases in the middle of the spectrum, where more inherent variability exists, may be more problematic in digital format. Future studies evaluating the effect these findings exert on clinical practice and patient outcomes are required.

Comprehensive Isotopic and Elemental Analysis of a Multi-Oxide Glass By Multicollector ICP-MS in Isotope Substitution Studies

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

v, Mitroshkov; JV, Ryan

2016-04-07

Multicollector ICP-MS was used to comprehensively analyze different types of isotopically-modified glass created in order to investigate the processes of glass corrosion in the water. The analytical methods were developed for the analyses of synthesized, isotopically-modified solid glass and the release of glass constituents upon contact with deionized water. To validate the methods, results from an acid digestion sample of the Analytical Reference Glass (ARG) showed good agreement when compared to data from multiple prior analyses on the same glass [Smith-1]. In this paper, we present the results of this comprehensive analysis from the acid digestion of six types ofmore » isotopically-modified glass and the release of glass constituents into water corrosion after one year of aqueous corrosion.« less

Performance Evaluation of Remote Memory Access (RMA) Programming on Shared Memory Parallel Computers

NASA Technical Reports Server (NTRS)

Jin, Hao-Qiang; Jost, Gabriele; Biegel, Bryan A. (Technical Monitor)

2002-01-01

The purpose of this study is to evaluate the feasibility of remote memory access (RMA) programming on shared memory parallel computers. We discuss different RMA based implementations of selected CFD application benchmark kernels and compare them to corresponding message passing based codes. For the message-passing implementation we use MPI point-to-point and global communication routines. For the RMA based approach we consider two different libraries supporting this programming model. One is a shared memory parallelization library (SMPlib) developed at NASA Ames, the other is the MPI-2 extensions to the MPI Standard. We give timing comparisons for the different implementation strategies and discuss the performance.

Development of mpi_EPIC model for global agroecosystem modeling

DOE PAGES

Kang, Shujiang; Wang, Dali; Jeff A. Nichols; ...

2014-12-31

Models that address policy-maker concerns about multi-scale effects of food and bioenergy production systems are computationally demanding. We integrated the message passing interface algorithm into the process-based EPIC model to accelerate computation of ecosystem effects. Simulation performance was further enhanced by applying the Vampir framework. When this enhanced mpi_EPIC model was tested, total execution time for a global 30-year simulation of a switchgrass cropping system was shortened to less than 0.5 hours on a supercomputer. The results illustrate that mpi_EPIC using parallel design can balance simulation workloads and facilitate large-scale, high-resolution analysis of agricultural production systems, management alternatives and environmentalmore » effects.« less

Impact of phenanthrene on the properties of biogeochemical interfaces in soil: A two-layer column study

NASA Astrophysics Data System (ADS)

Reichel, Katharina; Totsche, Kai Uwe

2013-04-01

Biogeochemical interfaces in soils (Totsche et al. 2010) are the "hot spots" of microbial activity and the processing of organic compounds in soils. The production and relocation of mobile organic matter (MOM) and biocolloids like microorganisms are key processes for the formation and depth propagation of biogeochemical interfaces in soils (BGI). Phenanthrene (PHE) has been shown to affect microbial communities in soils (Ding et al. 2012) and may induce shifts in MOM quantity and quality (amount, type and properties of MOM). We hypothesize that the properties of BGI in soil change significantly due to the presence of PHE. The objectives of this study are (i) to evaluate the effect of PHE on soil microbial communities and on MOM quantity and quality under flow conditions with single- and two-layer column experiments and (ii) to assess the role of these processes for the physicochemical, mechanical and sorptive properties of BGI in soils. The soil columns were operated under water-unsaturated conditions. The top layer (source layer, SL, 2 cm) is made of sieved soil material (Luvisol, Scheyern, Germany) spiked with PHE (0.2 mg/g). The bottom layer (reception layer, RL, 10 cm) comprised the same soil without PHE. PHE-free columns were conducted in parallel as reference. Release and transport of MOM in mature soil of a single-layer column experiment was found to depend on the transport regime. The release of larger sized MOM (>0.45 µm) was restricted to an increased residence time during flow interruptions. Steady flow conditions favor the release of smaller MOM (<0.45 µm). Compared to the reference, in the two-layer column experiments higher OC concentrations were detected in the effluent from PHE spiked columns after enhanced flow interruptions (26d, 52d). That indicated the PHE influenced production or mobilization of MOM. Parallel factor analysis of fluorescence excitation and emission matrices revealed the presence of a constant DOM background and two new unknown components in the effluent, probably PHE metabolites. The emergence of new components emphasizes the role of metabolization processes in the release of MOM. The identification of key microbial actors and communities are currently in progress. Totsche, K.U. et al. (2010): Biogeochemical interfaces in soil: The interdisciplinary challenge for soil science. J. Plant Nutr. Soil Sci., 173(1), 88-99 Ding, G.-C., Heuer, H. & Smalla, K. (2012): Dynamics of bacterial communities in two unpolluted soils after spiking with phenanthrene: soil type specific and common responders. Front Microbio 10.3389/fmicb.2012.00290.

Antarctic ice-core water (USGS49) – A new isotopic reference material for δ2H and δ18O measurements of water

USGS Publications Warehouse

Lorenz, Jennifer M.; Qi, Haiping; Coplen, Tyler B.

2017-01-01

As a result of the scarcity of isotopic reference waters for daily use, a new secondary isotopic reference material for international distribution has been prepared from ice-core water from the Amundsen–Scott South Pole Station. This isotopic reference material, designated as USGS49, was filtered, homogenised, loaded into glass ampoules, sealed with a torch, autoclaved to eliminate biological activity and measured by dual-inlet isotope-ratio mass spectrometry. The δ2H and δ18O values of USGS49 are −394.7 ± 0.4 and −50.55 ± 0.04 mUr (where mUr = 0.001 = ‰), respectively, relative to VSMOW, on scales normalised such that the δ2H and δ18O values of SLAP reference water are, respectively, −428 and −55.5 mUr. Each uncertainty is an estimated expanded uncertainty (U = 2uc) about the reference value that provides an interval that has about a 95% probability of encompassing the true value. This isotopic reference material is intended as one of two isotopic reference waters for daily normalisation of stable hydrogen and oxygen isotopic analysis of water with an isotope-ratio mass spectrometer or a laser absorption spectrometer. It is available by the case of 144 glass ampoules or as a set of sixteen glass ampoules containing 5 ml of water in each ampoule.

Glass composition and solution speciation effects on stage III dissolution

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

Trivelpiece, Cory L.; Rice, Jarret A.; Pantano, Carlo G.

To understand and mitigate the onset of Stage III corrosion of multicomponent oxides waste glasses. Stage III refers to a resumption of the high initial rate of glass dissolution in some glass samples that have otherwise exhibited dissolution at the much lower residual rate for a long time (Stage II). Although the onset of Stage III is known to occur concurrently with the precipitation of particular alteration products, the root cause of the transition is still unknown. Certain glass compositions (notably AFCI) and high pH environmental conditions are also associated with this observed transition.

Applying Bayesian Item Selection Approaches to Adaptive Tests Using Polytomous Items

ERIC Educational Resources Information Center

Penfield, Randall D.

2006-01-01

This study applied the maximum expected information (MEI) and the maximum posterior-weighted information (MPI) approaches of computer adaptive testing item selection to the case of a test using polytomous items following the partial credit model. The MEI and MPI approaches are described. A simulation study compared the efficiency of ability…

Optimising the Parallelisation of OpenFOAM Simulations

DTIC Science & Technology

2014-06-01

UNCLASSIFIED UNCLASSIFIED Optimising the Parallelisation of OpenFOAM Simulations Shannon Keough Maritime Division Defence...Science and Technology Organisation DSTO-TR-2987 ABSTRACT The OpenFOAM computational fluid dynamics toolbox allows parallel computation of...performance of a given high performance computing cluster with several OpenFOAM cases, running using a combination of MPI libraries and corresponding MPI

32 CFR 637.2 - Use of MPI and DAC Detectives/Investigators.

Code of Federal Regulations, 2011 CFR

2011-07-01

... employed in the following investigations: (a) Offenses for which the maximum punishment listed in the Table of Maximum Punishment, Manual for Courts-Martial, United States, 2002 is confinement for 1 year or... MPI. The same punishment criteria apply. (b) Property-related offenses when the value is less than $1...

32 CFR 637.2 - Use of MPI and DAC Detectives/Investigators.

Code of Federal Regulations, 2014 CFR

2014-07-01

... employed in the following investigations: (a) Offenses for which the maximum punishment listed in the Table of Maximum Punishment, Manual for Courts-Martial, United States, 2002 is confinement for 1 year or... MPI. The same punishment criteria apply. (b) Property-related offenses when the value is less than $1...

32 CFR 637.2 - Use of MPI and DAC Detectives/Investigators.

Code of Federal Regulations, 2013 CFR

2013-07-01

... employed in the following investigations: (a) Offenses for which the maximum punishment listed in the Table of Maximum Punishment, Manual for Courts-Martial, United States, 2002 is confinement for 1 year or... MPI. The same punishment criteria apply. (b) Property-related offenses when the value is less than $1...

32 CFR 637.2 - Use of MPI and DAC Detectives/Investigators.

Code of Federal Regulations, 2012 CFR

2012-07-01

... employed in the following investigations: (a) Offenses for which the maximum punishment listed in the Table of Maximum Punishment, Manual for Courts-Martial, United States, 2002 is confinement for 1 year or... MPI. The same punishment criteria apply. (b) Property-related offenses when the value is less than $1...

Cheetah: A Framework for Scalable Hierarchical Collective Operations

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

Graham, Richard L; Gorentla Venkata, Manjunath; Ladd, Joshua S

2011-01-01

Collective communication operations, used by many scientific applications, tend to limit overall parallel application performance and scalability. Computer systems are becoming more heterogeneous with increasing node and core-per-node counts. Also, a growing number of data-access mechanisms, of varying characteristics, are supported within a single computer system. We describe a new hierarchical collective communication framework that takes advantage of hardware-specific data-access mechanisms. It is flexible, with run-time hierarchy specification, and sharing of collective communication primitives between collective algorithms. Data buffers are shared between levels in the hierarchy reducing collective communication management overhead. We have implemented several versions of the Message Passingmore » Interface (MPI) collective operations, MPI Barrier() and MPI Bcast(), and run experiments using up to 49, 152 processes on a Cray XT5, and a small InfiniBand based cluster. At 49, 152 processes our barrier implementation outperforms the optimized native implementation by 75%. 32 Byte and one Mega-Byte broadcasts outperform it by 62% and 11%, respectively, with better scalability characteristics. Improvements relative to the default Open MPI implementation are much larger.« less

Characterization of the cellular and antitumor effects of MPI-0479605, a small-molecule inhibitor of the mitotic kinase Mps1.

PubMed

Tardif, Keith D; Rogers, Aaron; Cassiano, Jared; Roth, Bruce L; Cimbora, Daniel M; McKinnon, Rena; Peterson, Ashley; Douce, Thomas B; Robinson, Rosann; Dorweiler, Irene; Davis, Thaylon; Hess, Mark A; Ostanin, Kirill; Papac, Damon I; Baichwal, Vijay; McAlexander, Ian; Willardsen, J Adam; Saunders, Michael; Christophe, Hoarau; Kumar, D Vijay; Wettstein, Daniel A; Carlson, Robert O; Williams, Brandi L

2011-12-01

Mps1 is a dual specificity protein kinase that is essential for the bipolar attachment of chromosomes to the mitotic spindle and for maintaining the spindle assembly checkpoint until all chromosomes are properly attached. Mps1 is expressed at high levels during mitosis and is abundantly expressed in cancer cells. Disruption of Mps1 function induces aneuploidy and cell death. We report the identification of MPI-0479605, a potent and selective ATP competitive inhibitor of Mps1. Cells treated with MPI-0479605 undergo aberrant mitosis, resulting in aneuploidy and formation of micronuclei. In cells with wild-type p53, this promotes the induction of a postmitotic checkpoint characterized by the ATM- and RAD3-related-dependent activation of the p53-p21 pathway. In both wild-type and p53 mutant cells lines, there is a growth arrest and inhibition of DNA synthesis. Subsequently, cells undergo mitotic catastrophe and/or an apoptotic response. In xenograft models, MPI-0479605 inhibits tumor growth, suggesting that drugs targeting Mps1 may have utility as novel cancer therapeutics.

Finite magnetic relaxation in x-space magnetic particle imaging: Comparison of measurements and ferrohydrodynamic models

PubMed Central

Dhavalikar, R; Hensley, D; Maldonado-Camargo, L; Croft, L R; Ceron, S; Goodwill, P W; Conolly, S M

2016-01-01

Magnetic Particle Imaging (MPI) is an emerging tomographic imaging technology that detects magnetic nanoparticle tracers by exploiting their non-linear magnetization properties. In order to predict the behavior of nanoparticles in an imager, it is possible to use a non-imaging MPI relaxometer or spectrometer to characterize the behavior of nanoparticles in a controlled setting. In this paper we explore the use of ferrohydrodynamic magnetization equations for predicting the response of particles in an MPI relaxometer. These include a magnetization equation developed by Shliomis (Sh) which has a constant relaxation time and a magnetization equation which uses a field-dependent relaxation time developed by Martsenyuk, Raikher and Shliomis (MRSh). We compare the predictions from these models with measurements and with the predictions based on the Langevin function that assumes instantaneous magnetization response of the nanoparticles. The results show good qualitative and quantitative agreement between the ferrohydrodynamic models and the measurements without the use of fitting parameters and provide further evidence of the potential of ferrohydrodynamic modeling in MPI. PMID:27867219

Optimizing NEURON Simulation Environment Using Remote Memory Access with Recursive Doubling on Distributed Memory Systems.

PubMed

Shehzad, Danish; Bozkuş, Zeki

2016-01-01

Increase in complexity of neuronal network models escalated the efforts to make NEURON simulation environment efficient. The computational neuroscientists divided the equations into subnets amongst multiple processors for achieving better hardware performance. On parallel machines for neuronal networks, interprocessor spikes exchange consumes large section of overall simulation time. In NEURON for communication between processors Message Passing Interface (MPI) is used. MPI_Allgather collective is exercised for spikes exchange after each interval across distributed memory systems. The increase in number of processors though results in achieving concurrency and better performance but it inversely affects MPI_Allgather which increases communication time between processors. This necessitates improving communication methodology to decrease the spikes exchange time over distributed memory systems. This work has improved MPI_Allgather method using Remote Memory Access (RMA) by moving two-sided communication to one-sided communication, and use of recursive doubling mechanism facilitates achieving efficient communication between the processors in precise steps. This approach enhanced communication concurrency and has improved overall runtime making NEURON more efficient for simulation of large neuronal network models.

Optimizing NEURON Simulation Environment Using Remote Memory Access with Recursive Doubling on Distributed Memory Systems

PubMed Central

Bozkuş, Zeki

2016-01-01

Increase in complexity of neuronal network models escalated the efforts to make NEURON simulation environment efficient. The computational neuroscientists divided the equations into subnets amongst multiple processors for achieving better hardware performance. On parallel machines for neuronal networks, interprocessor spikes exchange consumes large section of overall simulation time. In NEURON for communication between processors Message Passing Interface (MPI) is used. MPI_Allgather collective is exercised for spikes exchange after each interval across distributed memory systems. The increase in number of processors though results in achieving concurrency and better performance but it inversely affects MPI_Allgather which increases communication time between processors. This necessitates improving communication methodology to decrease the spikes exchange time over distributed memory systems. This work has improved MPI_Allgather method using Remote Memory Access (RMA) by moving two-sided communication to one-sided communication, and use of recursive doubling mechanism facilitates achieving efficient communication between the processors in precise steps. This approach enhanced communication concurrency and has improved overall runtime making NEURON more efficient for simulation of large neuronal network models. PMID:27413363

Multipath interference test method for distributed amplifiers

NASA Astrophysics Data System (ADS)

Okada, Takahiro; Aida, Kazuo

2005-12-01

A method for testing distributed amplifiers is presented; the multipath interference (MPI) is detected as a beat spectrum between the multipath signal and the direct signal using a binary frequency shifted keying (FSK) test signal. The lightwave source is composed of a DFB-LD that is directly modulated by a pulse stream passing through an equalizer, and emits the FSK signal of the frequency deviation of about 430MHz at repetition rate of 80-100 kHz. The receiver consists of a photo-diode and an electrical spectrum analyzer (ESA). The base-band power spectrum peak appeared at the frequency of the FSK frequency deviation can be converted to amount of MPI using a calibration chart. The test method has improved the minimum detectable MPI as low as -70 dB, compared to that of -50 dB of the conventional test method. The detailed design and performance of the proposed method are discussed, including the MPI simulator for calibration procedure, computer simulations for evaluating the error caused by the FSK repetition rate and the fiber length under test and experiments on singlemode fibers and distributed Raman amplifier.

Reproducibility of a silicone-based test food to masticatory performance evaluation by different sieve methods.

PubMed

Sánchez-Ayala, Alfonso; Vilanova, Larissa Soares Reis; Costa, Marina Abrantes; Farias-Neto, Arcelino

2014-01-01

The aim of this study was to evaluate the reproducibility of the condensation silicone Optosil Comfort® as an artificial test food for masticatory performance evaluation. Twenty dentate subjects with mean age of 23.3±0.7 years were selected. Masticatory performance was evaluated using the simple (MPI), the double (IME) and the multiple sieve methods. Trials were carried out five times by three examiners: three times by the first, and once by the second and third examiners. Friedman's test was used to find the differences among time trials. Reproducibility was determined by the intra-class correlation (ICC) test (α=0.05). No differences among time trials were found, except for MPI-4 mm (p=0.022) from the first examiner results. The intra-examiner reproducibility (ICC) of almost all data was high (ICC≥0.92, p<0.001), being moderate only for MPI-0.50 mm (ICC=0.89, p<0.001). The inter-examiner reproducibility was high (ICC>0.93, p<0.001) for all results. For the multiple sieve method, the average mean of absolute difference from repeated measurements were lower than 1 mm. This trend was observed only from MPI-0.50 to MPI-1.4 for the single sieve method, and from IME-0.71/0.50 to IME-1.40/1.00 for the double sieve method. The results suggest that regardless of the method used, the reproducibility of Optosil Comfort® is high.

LV dyssynchrony as assessed by phase analysis of gated SPECT myocardial perfusion imaging in patients with Wolff-Parkinson-White syndrome.

PubMed

Chen, Chun; Li, Dianfu; Miao, Changqing; Feng, Jianlin; Zhou, Yanli; Cao, Kejiang; Lloyd, Michael S; Chen, Ji

2012-07-01

The purpose of this study was to evaluate left ventricular (LV) mechanical dyssynchrony in patients with Wolff-Parkinson-White (WPW) syndrome pre- and post-radiofrequency catheter ablation (RFA) using phase analysis of gated single photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI). Forty-five WPW patients were enrolled and had gated SPECT MPI pre- and 2-3 days post-RFA. Electrophysiological study (EPS) was used to locate accessory pathways (APs) and categorize the patients according to the AP locations (septal, left and right free wall). Electrocardiography (ECG) was performed pre- and post-RFA to confirm successful elimination of the APs. Phase analysis of gated SPECT MPI was used to assess LV dyssynchrony pre- and post-RFA. Among the 45 patients, 3 had gating errors, and thus 42 had SPECT phase analysis. Twenty-two patients (52.4%) had baseline LV dyssynchrony. Baseline LV dyssynchrony was more prominent in the patients with septal APs than in the patients with left or right APs (p < 0.05). RFA improved LV synchrony in the entire cohort and in the patients with septal APs (p < 0.01). Phase analysis of gated SPECT MPI demonstrated that LV mechanical dyssynchrony can be present in patients with WPW syndrome. Septal APs result in the greatest degree of LV mechanical dyssynchrony and afford the most benefit after RFA. This study supports further investigation in the relationship between electrical and mechanical activation using EPS and phase analysis of gated SPECT MPI.

Improving results of surgery for fecal peritonitis due to perforated colorectal disease: A single center experience.

PubMed

Mineccia, Michela; Zimmitti, Giuseppe; Ribero, Dario; Giraldi, Francesco; Bertolino, Franco; Brambilla, Romeo; Ferrero, Alessandro

2016-01-01

fecal peritonitis due to colorectal perforation is a dramatic event characterized by high mortality. Our study aims at determining how results of sigmoid resection (eventually extended to upper rectum) for colorectal perforation with fecal peritonitis changed in recent years and which factors affected eventual changes. Seventy-four patients were operated on at our institution (2005-2014) for colorectal perforation with fecal peritonitis and were divided into two numerically equal groups (operated on before (ERA1-group) and after (ERA2-group) May 2010). Mannheim Peritonitis Index (MPI) was calculated for each patient. Characteristics of two groups were compared. Predictors of postoperative outcomes were identified. Postoperative overall complications, major complications, and mortality occurred in 59%, 28%, and 18% of cases, respectively, and were less frequent in ERA2-group (51%, 16%, and 8%, respectively), compared to ERA1-group (68%, 41%, and 27%, respectively; p = .155, .02, and .032, respectively). Such results paralleled lower MPI values in ERA2-group, compared to ERA1-group (23(16-39) vs. 28(21-43), p = .006). Using receiver operating characteristic analysis, the best cut-off value for MPI for predicting postoperative complications and mortality was 28.5. MPI>28 was the only independent predictor of postoperative overall (p = .009, OR = 4.491) and major complications (p < .001, OR = 23.182) and was independently associated with a higher risk of mortality (p = .016, OR = 13.444), as well as duration of preoperative peritonitis longer than 24 h (p = .045, OR = 17.099). results of surgery for colorectal perforation with fecal peritonitis have improved over time, matching a concurrent decrease of MPI values and a better preoperative patient management. MPI value may help in selecting patients benefitting from surgical treatment. Copyright © 2015 IJS Publishing Group Limited. Published by Elsevier Ltd. All rights reserved.

The Atlantic Multidecadal Variability in surface and deep ocean temperature and salinity fields from unperturbed climate simulations

NASA Astrophysics Data System (ADS)

Zanchettin, D.; Jungclaus, J. H.

2013-12-01

Large multidecadal fluctuations in basin-average sea-surface temperature (SST) are a known feature of observed, reconstructed and simulated variability in the North Atlantic Ocean. This phenomenon is often referred to as Multidecadal Atlantic Variability or AMV. Historical AMV fluctuations are associated with analog basin-scale changes in sea-surface salinity, so that warming corresponds to salinification and cooling to freshening [Polyakov et al., 2005]. The surface imprint of the AMV further corresponds to same-sign fluctuations in the shallow ocean and with opposite-sign fluctuations in the deep ocean for both temperature and salinity [Polyakov et al., 2005]. This out-of-phase behavior reflects the thermohaline overturning circulation shaping North Atlantic's low-frequency variability. Several processes contribute to the AMV, involving both ocean-atmosphere coupled processes and deep ocean circulation [e.g., Grossmann and Klotzbach, 2009]. In particular, recirculation in the North Atlantic subpolar gyre region of salinity anomalies from Arctic freshwater export may trigger multidecadal variability in the Atlantic meridional overturning circulation, and therefore may be part of the AMV [Jungclaus et al., 2005; Dima and Lohmann, 2007]. With this contribution, we aim to improve the physical interpretation of the AMV by investigating spatial and temporal patterns of temperature and salinity fields in the shallow and deep ocean. We focus on two unperturbed millennial-scale simulations performed with the Max Planck Institute Earth system model in its paleo (MPI-ESM-P) and low-resolution (MPI-ESM-LR) configurations, which provide reference control climates for assessments of pre-industrial and historical climate simulations. The two model configurations only differ for the presence, in MPI-ESM-LR, of an active module for dynamical vegetation. We use spatial-average indices and empirical orthogonal functions/principal components to track the horizontal and vertical propagation of temperature and salinity anomalies related to the AMV. In particular, we discuss the potential predictability of multidecadal fluctuations in North Atlantic SSTs based on indices derived from the sea-surface salinity field. We show how the two simulations provide AMV realizations with some distinguishable characteristics, e.g., the typical fluctuations' frequencies and the linkage with the North Atlantic meridional overturning and gyre circulations. We further show how information gained by investigating different definitions of the AMV [Zanchettin et al., 2013] helps designing numerical sensitivity studies for understanding the mechanism(s) behind this phenomenon, concerning both its origin and global impacts. References Dima, M., and G. Lohmann [2007], J. Clim., 20, 2706-2719, doi:10.1175/JCLI4174.1 Jungclaus, J.H., et al. [2005], J. Clim., 18, 4013- 4031, doi:10.1175/JCLI3462.1 Polyakov, I. V., et al. [2005], J. Clim., 18:4562-4581 Grossmann, I., and P. J. Klotzbach [2009], J. Geophys. Res., 114, D24107, doi:10.1029/2009JD012728 Zanchettin D., et al. [2013], Clim. Dyn., doi:10.1007/s00382-013-1669-0

Development of synthetic nuclear melt glass for forensic analysis.

PubMed

Molgaard, Joshua J; Auxier, John D; Giminaro, Andrew V; Oldham, C J; Cook, Matthew T; Young, Stephen A; Hall, Howard L

A method for producing synthetic debris similar to the melt glass produced by nuclear surface testing is demonstrated. Melt glass from the first nuclear weapon test (commonly referred to as trinitite) is used as the benchmark for this study. These surrogates can be used to simulate a variety of scenarios and will serve as a tool for developing and validating forensic analysis methods.

Simultaneous dual-radionuclide myocardial perfusion imaging with a solid-state dedicated cardiac camera.

PubMed

Ben-Haim, Simona; Kacperski, Krzysztof; Hain, Sharon; Van Gramberg, Dean; Hutton, Brian F; Erlandsson, Kjell; Sharir, Tali; Roth, Nathaniel; Waddington, Wendy A; Berman, Daniel S; Ell, Peter J

2010-08-01

We compared simultaneous dual-radionuclide (DR) stress and rest myocardial perfusion imaging (MPI) with a novel solid-state cardiac camera and a conventional SPECT camera with separate stress and rest acquisitions. Of 27 consecutive patients recruited, 24 (64.5+/-11.8 years of age, 16 men) were injected with 74 MBq of (201)Tl (rest) and 250 MBq (99m)Tc-MIBI (stress). Conventional MPI acquisition times for stress and rest are 21 min and 16 min, respectively. Rest (201)Tl for 6 min and simultaneous DR 15-min list mode gated scans were performed on a D-SPECT cardiac scanner. In 11 patients DR D-SPECT was performed first and in 13 patients conventional stress (99m)Tc-MIBI SPECT imaging was performed followed by DR D-SPECT. The DR D-SPECT data were processed using a spill-over and scatter correction method. DR D-SPECT images were compared with rest (201)Tl D-SPECT and with conventional SPECT images by visual analysis employing the 17-segment model and a five-point scale (0 normal, 4 absent) to calculate the summed stress and rest scores. Image quality was assessed on a four-point scale (1 poor, 4 very good) and gut activity was assessed on a four-point scale (0 none, 3 high). Conventional MPI studies were abnormal at stress in 17 patients and at rest in 9 patients. In the 17 abnormal stress studies DR D-SPECT MPI showed 113 abnormal segments and conventional MPI showed 93 abnormal segments. In the nine abnormal rest studies DR D-SPECT showed 45 abnormal segments and conventional MPI showed 48 abnormal segments. The summed stress and rest scores on conventional SPECT and DR D-SPECT were highly correlated (r=0.9790 and 0.9694, respectively). The summed scores of rest (201)Tl D-SPECT and DR-DSPECT were also highly correlated (r=0.9968, p<0.0001 for all). In six patients stress perfusion defects were significantly larger on stress DR D-SPECT images, and five of these patients were imaged earlier by D-SPECT than by conventional SPECT. Fast and high-quality simultaneous DR MPI is feasible with D-SPECT in a single imaging session with comparable diagnostic performance and image quality to conventional SPECT and to a separate rest (201)Tl D-SPECT acquisition.

Studies of LA-ICP-MS on quartz glasses at different wavelengths of a Nd:YAG laser.

PubMed

Becker, J S; Tenzler, D

2001-07-01

The capability of LA-ICP-MS for determination of trace impurities in transparent quartz glasses was investigated. Due to low or completely lacking absorption of laser radiation, laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) proves difficult on transparent solids, and in particular the quantification of measurement results is problematic in these circumstances. Quartz glass reference materials of various compositions were studied by using a Nd:YAG laser system with focused laser radiation of wavelengths of 1064 nm, 532 nm and 266 nm, and an ICP-QMS (Elan 6000, Perkin Elmer). The influence of ICP and laser ablation conditions in the analysis of quartz glasses of different compositions was investigated, with the laser power density in the region of interaction between laser radiation and solid surface determining the ablation process. The trace element concentration was determined via calibration curves recorded with the aid of quartz glass reference materials. Under optimized measuring conditions the correlation coefficients of the calibration curves are in the range of 0.9-1. The relative sensitivity factors of the trace elements determined in the quartz glass matrix are 0.1-10 for most of the trace elements studied by LA-ICP-MS. The detection limits of the trace elements in quartz glass are in the low ng/g to pg/g range.

The influence of hunger on meal to pellet intervals in barred owls

USGS Publications Warehouse

Duke, G.E.; Fuller, M.R.; Huberty, B.J.

1980-01-01

1. Barred owls fed at a sub-maintenance (SM) level had significantly (P < 0.01) longer meal to pellet intervals (MPI)/g eaten/kg body weight (BW) than those fed at an above maintenance (AM) level; MPI/g per kg for owls fed at a maintenance (M) level was intermediate but significantly (P < 0.01) different from both SM and AM.2. During SM feeding, MPI/g per kg gradually increased.3. The proportion of a meal occurring in a pellet was less in “hungry” owls whether losing weight (SM) or gaining (AM) as compared to owls maintaining their normal body weight (M).4. SM fed owls appear to be able to increase digestion time as well as thoroughness of digestion.

Contaminant studies in the Sierra Nevadas

USGS Publications Warehouse

Sparling, Don; Fellers, Gary M.

2002-01-01

1. 1. Barred owls fed at a sub-maintenance (SM) level had significantly (P < 0.01) longer meal to pellet intervals (MPI)/g eaten/kg body weight (BW) than those fed at an above maintenance (AM) level; MPI/g per kg for owls fed at a maintenance (M) level was intermediate but significantly (P < 0.01) different from both SM and AM. 2. 2. During SM feeding, MPI/g per kg gradually increased. 3. 3. The proportion of a meal occurring in a pellet was less in ?hungry? owls whether losing weight (SM) or gaining (AM) as compared to owls maintaining their normal body weight (M). 4. 4. SM fed owls appear to be able to increase digestion time as well as thoroughness of digestion.

Parallel PAB3D: Experiences with a Prototype in MPI

NASA Technical Reports Server (NTRS)

Guerinoni, Fabio; Abdol-Hamid, Khaled S.; Pao, S. Paul

1998-01-01

PAB3D is a three-dimensional Navier Stokes solver that has gained acceptance in the research and industrial communities. It takes as computational domain, a set disjoint blocks covering the physical domain. This is the first report on the implementation of PAB3D using the Message Passing Interface (MPI), a standard for parallel processing. We discuss briefly the characteristics of tile code and define a prototype for testing. The principal data structure used for communication is derived from preprocessing "patching". We describe a simple interface (COMMSYS) for MPI communication, and some general techniques likely to be encountered when working on problems of this nature. Last, we identify levels of improvement from the current version and outline future work.

A Posteriori Error Bounds for the Empirical Interpolation Method

DTIC Science & Technology

2010-03-18

paramètres (x̄1, x̄2) ≡ µ ∈ DII ≡ [0.4, 0.6]2 et α = 0.1 fixé, les résultats sont similaires au cas d’un seul paramètre (Fig. 2). 1. Introduction...and denote the set of all distinct multi-indices β of dimension P of length I by MPI . The cardinality of MPI is given by card (MPI ) = ( P+I−1 I...operations, and we compute the interpolation errors ‖F (β)(·; τ) − F (β)M (·; τ)‖L∞(Ω), 0 < |β| < p − 1, for all τ ∈ Φ, in O(nΦMN ) ∑p−1 j=0 card (MPj

An MPI-based MoSST core dynamics model

NASA Astrophysics Data System (ADS)

Jiang, Weiyuan; Kuang, Weijia

2008-09-01

Distributed systems are among the main cost-effective and expandable platforms for high-end scientific computing. Therefore scalable numerical models are important for effective use of such systems. In this paper, we present an MPI-based numerical core dynamics model for simulation of geodynamo and planetary dynamos, and for simulation of core-mantle interactions. The model is developed based on MPI libraries. Two algorithms are used for node-node communication: a "master-slave" architecture and a "divide-and-conquer" architecture. The former is easy to implement but not scalable in communication. The latter is scalable in both computation and communication. The model scalability is tested on Linux PC clusters with up to 128 nodes. This model is also benchmarked with a published numerical dynamo model solution.

Targeted Nanoparticles for Kidney Cancer Therapy

DTIC Science & Technology

2012-10-01

24 hrs. Clonogenic survival was assessed 7-10 days after CNT incubation after plating 200-300 cells/well (Figure 7). Similar trends were seen using... ferritin on angiogenesis. Proc Natl Acad Sci U S A. 2009;106(2):570-5. PMCID: 2626744. 4. Burke A, Ding X, Singh R, Kraft RA, Levi-Polyachenko N, Rylander

Targeted Approaches to Overcoming Endocrine Resistance in Breast Cancer

DTIC Science & Technology

2012-08-01

kinase B CD049340 BIRC5 Effector cell peptidase receptor 1 NM_001012271 BUB1 BUB1 budding uninhibited by benzimidazoles 1 homolog AF053305 CDC20 Cell...P ≤ 0.0001). Among these were BUB1 (bud- ding uninhibited by benzimidazoles 1 homolog), BIRC5/ Survivin, CDCA8 (cell division cycle-associated

Amino Acids in Nectar Enhance Longevity of Female Culex quinquefasciatus

DTIC Science & Technology

2010-01-01

via a piece of a saturated cotton dental wick (1 cm 4.5 cm) (Richmond Dental , Charlotte, NC). This assay was conducted separately from the...Ding, J., Wang, J.-L., Brakefield, P.M., Carey , J.R., Zwann, B.J., 2008. Amino acid sources in the adult diet do not affect lifespan and fecundity

On the Delta Sequence of the Thue-Morse Sequence

DTIC Science & Technology

2007-02-27

S. Plouffe, B.E. Sagan, A relative of the Thue-Morse sequence, in For- mal power series and algebraic combinatorics (Montreal, PQ, 1992), Discrete ... Math . 139, 455–461, 1995. [2] J.-P. Allouche, J. Shallit, The ubiquitous Prouhet-Thue-Morse se- quence, In C. Ding, T. Helleseth,and H. Niederreiter

Anzio Beachhead, 22 January - 25 May 1944

DTIC Science & Technology

1990-01-01

l ............. ........................ 2 Littoria ,ind the Rig’ht Flank .......... ......................... .. . /. i. 1,11m P. La ,,u... Bella and Cisterna.. .......... ........................... ... 29 Each Building Became a Fortrcss ......... ....................... .. Tanks Take...the Allies on the Garigliano, they the American Fifth Army attacked across the would draw ba, i: Qnough troops to check a la -ding. Garigliano on 18

Biohazard Detoxification Method Utilizing Magnetic Particles

DTIC Science & Technology

2007-05-01

configurations (noted by the yellow in the flow tube region). These data highlight the importance of the magnetic field gradient in particle capture...Weyhers, F. Specht , J.S. Lucks, Int. J. Pharm. 138(1996) 85. [9] Z.L. Liu, Z.H. Ding, K.L. Yao, J. Magn. Magn. Mater. 265(2003) 98. [10] P.A. Dresco

The Genomic Actions and Functional Implications of Nuclear PRLr in Human Breast Carcinoma

DTIC Science & Technology

2010-03-01

pregnant mice; loss of this process may contribute to 171 gestational diabetes mellitus (Karnik, et al. 2007). 172 Ingenuity Pathway Analysis (IPA...of pancreatic beta-cells in pregnant mice and promotes gestational 403 diabetes mellitus . Science 318 806-809. 404 Kim J, Choi TG, Ding Y, Kim Y, Ha

The Neurobiological Basis and Potential Modification of Emotional Intelligence through Affective / Behavioral Training

DTIC Science & Technology

2013-04-01

alertness (Banks and Dinges, 2007; Punjabi et al., 2003; Van Dongen and Maislin, 2003). Relative to being well rested, prolonged sleep debt may also...Sleep Research Society Sleep credit, grey matter and emotion 7 Punjabi , N. M., Bandeen-Roche, K. and Young, T. Predictors of objective sleep tendency in

Tolerance of Escherichia coli to Fluoroquinolone Antibiotics Depends on Specific Components of the SOS Response Pathway

PubMed Central

Theodore, Alyssa; Lewis, Kim; Vulić, Marin

2013-01-01

Bacteria exposed to bactericidal fluoroquinolone (FQ) antibiotics can survive without becoming genetically resistant. Survival of these phenotypically resistant cells, commonly called “persisters,” depends on the SOS gene network. We have examined mutants in all known SOS-regulated genes to identify functions essential for tolerance in Escherichia coli. The absence of DinG and UvrD helicases and the Holliday junction processing enzymes RuvA and RuvB leads to a decrease in survival. Analysis of the respective mutants indicates that, in addition to repair of double-strand breaks, tolerance depends on the repair of collapsed replication forks and stalled transcription complexes. Mutation in recF results in increased survival, which identifies RecAF recombination as a poisoning mechanism not previously linked to FQ lethality. DinG acts upstream of SOS promoting its induction, whereas RuvAB participates in repair only. UvrD directly promotes all repair processes initiated by FQ-induced damage and prevents RecAF-dependent misrepair, making it one of the crucial SOS functions required for tolerance. PMID:24077306

Tolerance of Escherichia coli to fluoroquinolone antibiotics depends on specific components of the SOS response pathway.

PubMed

Theodore, Alyssa; Lewis, Kim; Vulic, Marin

2013-12-01

Bacteria exposed to bactericidal fluoroquinolone (FQ) antibiotics can survive without becoming genetically resistant. Survival of these phenotypically resistant cells, commonly called "persisters," depends on the SOS gene network. We have examined mutants in all known SOS-regulated genes to identify functions essential for tolerance in Escherichia coli. The absence of DinG and UvrD helicases and the Holliday junction processing enzymes RuvA and RuvB leads to a decrease in survival. Analysis of the respective mutants indicates that, in addition to repair of double-strand breaks, tolerance depends on the repair of collapsed replication forks and stalled transcription complexes. Mutation in recF results in increased survival, which identifies RecAF recombination as a poisoning mechanism not previously linked to FQ lethality. DinG acts upstream of SOS promoting its induction, whereas RuvAB participates in repair only. UvrD directly promotes all repair processes initiated by FQ-induced damage and prevents RecAF-dependent misrepair, making it one of the crucial SOS functions required for tolerance.

Characterization of low concentration uranium glass working materials

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

Eppich, G. R.; Wimpenny, J. B.; Leever, M. E.

A series of uranium-doped silicate glasses were created at (Lawrence Livermore National Laboratory) LLNL, to be used as working reference material analogs for low uranium concentration research. Specifically, the aim of this effort was the generation of well-characterized glasses spanning a range of concentrations and compositions, and of sufficient homogeneity in uranium concentration and isotopic composition, for instrumentation research and development purposes. While the glasses produced here are not intended to replace or become standard materials for uranium concentration or uranium isotopic composition, it is hoped that they will help fill a current gap, providing low-level uranium glasses sufficient formore » methods development and method comparisons within the limitations of the produced glass suite. Glasses are available for research use by request.« less

Comparison of CTAC and prone imaging for the detection of coronary artery disease using CZT SPECT.

PubMed

Ito, Shimpei; Endo, Akihiro; Okada, Taiji; Nakamura, Taku; Sugamori, Takashi; Takahashi, Nobuyuki; Yoshitomi, Hiroyuki; Tanabe, Kazuaki

2017-10-01

Cadmium-zinc-telluride (CZT) cameras have improved the evaluation of patients with chest pain. However, inferior/inferolateral attenuation artifacts similar to those seen with conventional Anger cameras persist. We added prone acquisitions and CT attenuation correction (CTAC) to the standard supine image acquisition and analyzed the resulting examinations. Seventy-two patients referred for invasive coronary angiography (CAG), and who also underwent rest/stress myocardial perfusion imaging (MPI) on a CZT camera in the supine and prone positions plus CTAC imaging, to examine known or suspected CAD between April 2013 and March 2014 were included. A sixteen-slice CT scan acquired on a SPECT/CT scanner between rest and stress imaging provided data for iterative reconstruction. Sensitivity, specificity, accuracy, and positive and negative likelihood ratios (LRs) were calculated to compare MPI with CAG on a per-patient basis. Per-patient sensitivity, specificity, and accuracy of supine images to predict coronary abnormalities on CAG were 35% [95% confidence interval (CI) 19-52], 86% (95% CI 80-92), and 74% (95% CI 66-82); those of prone imaging were 65% (95% CI 45-81), 82% (95% CI 76-87), and 78% (95% CI 68-85); and those of CTAC were 59% (95% CI 41-71), 93% (95% CI 87-97), and 85% (95% CI 76-91), respectively. Prone acquisition and CTAC images improve the ability to assess the inferior/inferolateral area.

Cardiac CT for myocardial ischaemia detection and characterization--comparative analysis.

PubMed

Bucher, A M; De Cecco, C N; Schoepf, U J; Wang, R; Meinel, F G; Binukrishnan, S R; Spearman, J V; Vogl, T J; Ruzsics, B

2014-11-01

The assessment of patients presenting with symptoms of myocardial ischaemia remains one of the most common and challenging clinical scenarios faced by physicians. Current imaging modalities are capable of three-dimensional, functional and anatomical views of the heart and as such offer a unique contribution to understanding and managing the pathology involved. Evidence has accumulated that visual anatomical coronary evaluation does not adequately predict haemodynamic relevance and should be complemented by physiological evaluation, highlighting the importance of functional assessment. Technical advances in CT technology over the past decade have progressively moved cardiac CT imaging into the clinical workflow. In addition to anatomical evaluation, cardiac CT is capable of providing myocardial perfusion parameters. A variety of CT techniques can be used to assess the myocardial perfusion. The single energy first-pass CT and dual energy first-pass CT allow static assessment of myocardial blood pool. Dynamic cardiac CT imaging allows quantification of myocardial perfusion through time-resolved attenuation data. CT-based myocardial perfusion imaging (MPI) is showing promising diagnostic accuracy compared with the current reference modalities. The aim of this review is to present currently available myocardial perfusion techniques with a focus on CT imaging in light of recent clinical investigations. This article provides a comprehensive overview of currently available CT approaches of static and dynamic MPI and presents the results of corresponding clinical trials.

A satellite simulator for TRMM PR applied to climate model simulations

NASA Astrophysics Data System (ADS)

Spangehl, T.; Schroeder, M.; Bodas-Salcedo, A.; Hollmann, R.; Riley Dellaripa, E. M.; Schumacher, C.

2017-12-01

Climate model simulations have to be compared against observation based datasets in order to assess their skill in representing precipitation characteristics. Here we use a satellite simulator for TRMM PR in order to evaluate simulations performed with MPI-ESM (Earth system model of the Max Planck Institute for Meteorology in Hamburg, Germany) performed within the MiKlip project (https://www.fona-miklip.de/, funded by Federal Ministry of Education and Research in Germany). While classical evaluation methods focus on geophysical parameters such as precipitation amounts, the application of the satellite simulator enables an evaluation in the instrument's parameter space thereby reducing uncertainties on the reference side. The CFMIP Observation Simulator Package (COSP) provides a framework for the application of satellite simulators to climate model simulations. The approach requires the introduction of sub-grid cloud and precipitation variability. Radar reflectivities are obtained by applying Mie theory, with the microphysical assumptions being chosen to match the atmosphere component of MPI-ESM (ECHAM6). The results are found to be sensitive to the methods used to distribute the convective precipitation over the sub-grid boxes. Simple parameterization methods are used to introduce sub-grid variability of convective clouds and precipitation. In order to constrain uncertainties a comprehensive comparison with sub-grid scale convective precipitation variability which is deduced from TRMM PR observations is carried out.

Sensitivity analysis for parametric generalized implicit quasi-variational-like inclusions involving P-[eta]-accretive mappings

NASA Astrophysics Data System (ADS)

Kazmi, K. R.; Khan, F. A.

2008-01-01

In this paper, using proximal-point mapping technique of P-[eta]-accretive mapping and the property of the fixed-point set of set-valued contractive mappings, we study the behavior and sensitivity analysis of the solution set of a parametric generalized implicit quasi-variational-like inclusion involving P-[eta]-accretive mapping in real uniformly smooth Banach space. Further, under suitable conditions, we discuss the Lipschitz continuity of the solution set with respect to the parameter. The technique and results presented in this paper can be viewed as extension of the techniques and corresponding results given in [R.P. Agarwal, Y.-J. Cho, N.-J. Huang, Sensitivity analysis for strongly nonlinear quasi-variational inclusions, Appl. MathE Lett. 13 (2002) 19-24; S. Dafermos, Sensitivity analysis in variational inequalities, Math. Oper. Res. 13 (1988) 421-434; X.-P. Ding, Sensitivity analysis for generalized nonlinear implicit quasi-variational inclusions, Appl. Math. Lett. 17 (2) (2004) 225-235; X.-P. Ding, Parametric completely generalized mixed implicit quasi-variational inclusions involving h-maximal monotone mappings, J. Comput. Appl. Math. 182 (2) (2005) 252-269; X.-P. Ding, C.L. Luo, On parametric generalized quasi-variational inequalities, J. Optim. Theory Appl. 100 (1999) 195-205; Z. Liu, L. Debnath, S.M. Kang, J.S. Ume, Sensitivity analysis for parametric completely generalized nonlinear implicit quasi-variational inclusions, J. Math. Anal. Appl. 277 (1) (2003) 142-154; R.N. Mukherjee, H.L. Verma, Sensitivity analysis of generalized variational inequalities, J. Math. Anal. Appl. 167 (1992) 299-304; M.A. Noor, Sensitivity analysis framework for general quasi-variational inclusions, Comput. Math. Appl. 44 (2002) 1175-1181; M.A. Noor, Sensitivity analysis for quasivariational inclusions, J. Math. Anal. Appl. 236 (1999) 290-299; J.Y. Park, J.U. Jeong, Parametric generalized mixed variational inequalities, Appl. Math. Lett. 17 (2004) 43-48].

Experimental and simulation studies on the behavior of signal harmonics in magnetic particle imaging.

PubMed

Murase, Kenya; Konishi, Takashi; Takeuchi, Yuki; Takata, Hiroshige; Saito, Shigeyoshi

2013-07-01

Our purpose in this study was to investigate the behavior of signal harmonics in magnetic particle imaging (MPI) by experimental and simulation studies. In the experimental studies, we made an apparatus for MPI in which both a drive magnetic field (DMF) and a selection magnetic field (SMF) were generated with a Maxwell coil pair. The MPI signals from magnetic nanoparticles (MNPs) were detected with a solenoid coil. The odd- and even-numbered harmonics were calculated by Fourier transformation with or without background subtraction. The particle size of the MNPs was measured by transmission electron microscopy (TEM), dynamic light-scattering, and X-ray diffraction methods. In the simulation studies, the magnetization and particle size distribution of MNPs were assumed to obey the Langevin theory of paramagnetism and a log-normal distribution, respectively. The odd- and even-numbered harmonics were calculated by Fourier transformation under various conditions of DMF and SMF and for three different particle sizes. The behavior of the harmonics largely depended on the size of the MNPs. When we used the particle size obtained from the TEM image, the simulation results were most similar to the experimental results. The similarity between the experimental and simulation results for the even-numbered harmonics was better than that for the odd-numbered harmonics. This was considered to be due to the fact that the odd-numbered harmonics were more sensitive to background subtraction than were the even-numbered harmonics. This study will be useful for a better understanding, optimization, and development of MPI and for designing MNPs appropriate for MPI.

Vibrational and electronic investigations, NLO, FMO analysis on a hetarylazoindole disperse dye by density functional theory

NASA Astrophysics Data System (ADS)

Çatıkkaş, Berna; Aktan, Ebru; Yalçın, Ergin

2016-08-01

This work deals with the optimized molecular structure, vibrational spectra, nonlinear optic (NLO) and frontier molecule orbital (FMO) properties of 1-Methyl-2-phenyl-3-(1,3,4-thiadiazol-2-yldiazenyl)-1H-indole (MPI) by quantum chemical calculations. The Fourier transform infrared (FT-MIR and FT-FIR) and Raman spectra of 1-Methyl-2-phenyl-3-(1,3,4-thiadiazol-2-yldiazenyl)-1H-indole (MPI) were recorded in the region (4000-400 cm-1 and 400-30 cm-1) and (3200-92 cm-1), respectively. The analysis and complete vibrational assignments of the fundamental modes of the MPI molecule were carried out by using the observed FT-IR and FT-Raman data and calculated Total Energy Distribution (TED) according to Scaled Quantum Mechanics procedure. The calculated geometrical parameters of the MPI molecule are in agreement with the obtained values from XRD studies. On the other hand, the difference between the scaled and observed wavenumber values of the most of the fundamentals are very small. 1H NMR and 13C NMR chemical shift values, and energy gap between LUMO-HOMO and molecular electrostatic potential (MEP) were investigated by using density functional theory (B3LYP) methods. UV/Visible spectra and λ maximum absorption values, the oscillator strengths in the chloroform, methanol and DMSO solvation in combination with different basis sets were calculated by using the time-dependent density functional theory (TD-DFT). Additionally, the predicted nonlinear optical (NLO) properties of the MPI are quite greater than that of urea at the B3LYP/6-31++G(d,p) level.

Psychometric Properties of the Multidimensional Pain Inventory Applied to Brazilian Patients with Orofacial Pain.

PubMed

Zucoloto, Miriane Lucindo; Maroco, João; Duarte Bonini Campos, Juliana Alvares

2015-01-01

To evaluate the psychometric properties of the Multidimensional Pain Inventory (MPI) in a Brazilian sample of patients with orofacial pain. A total of 1,925 adult patients, who sought dental care in the School of Dentistry of São Paulo State University's Araraquara campus, were invited to participate; 62.5% (n=1,203) agreed to participate. Of these, 436 presented with orofacial pain and were included. The mean age was 39.9 (SD=13.6) years and 74.5% were female. Confirmatory factor analysis was conducted using χ²/df, comparative fit index, goodness of fit index, and root mean square error of approximation as indices of goodness of fit. Convergent validity was estimated by the average variance extracted and composite reliability, and internal consistency by Cronbach's alpha standardized coefficient (α). The stability of the models was tested in independent samples (test and validation; dental pain and orofacial pain). The factorial invariance was estimated by multigroup analysis (Δχ²). Factorial, convergent validity, and internal consistency were adequate in all three parts of the MPI. To achieve this adequate fit for Part 1, item 15 needed to be deleted (λ=0.13). Discriminant validity was compromised between the factors "activities outside the home" and "social activities" of Part 3 of the MPI in the total sample, validation sample, and in patients with dental pain and with orofacial pain. A strong invariance between different subsamples from the three parts of the MPI was detected. The MPI produced valid, reliable, and stable data for pain assessment among Brazilian patients with orofacial pain.

An automatic alignment tool to improve repeatability of left ventricular function and dyssynchrony parameters in serial gated myocardial perfusion SPECT studies

PubMed Central

Zhou, Yanli; Faber, Tracy L.; Patel, Zenic; Folks, Russell D.; Cheung, Alice A.; Garcia, Ernest V.; Soman, Prem; Li, Dianfu; Cao, Kejiang; Chen, Ji

2013-01-01

Objective Left ventricular (LV) function and dyssynchrony parameters measured from serial gated single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) using blinded processing had a poorer repeatability than when manual side-by-side processing was used. The objective of this study was to validate whether an automatic alignment tool can reduce the variability of LV function and dyssynchrony parameters in serial gated SPECT MPI. Methods Thirty patients who had undergone serial gated SPECT MPI were prospectively enrolled in this study. Thirty minutes after the first acquisition, each patient was repositioned and a gated SPECT MPI image was reacquired. The two data sets were first processed blinded from each other by the same technologist in different weeks. These processed data were then realigned by the automatic tool, and manual side-by-side processing was carried out. All processing methods used standard iterative reconstruction and Butterworth filtering. The Emory Cardiac Toolbox was used to measure the LV function and dyssynchrony parameters. Results The automatic tool failed in one patient, who had a large, severe scar in the inferobasal wall. In the remaining 29 patients, the repeatability of the LV function and dyssynchrony parameters after automatic alignment was significantly improved from blinded processing and was comparable to manual side-by-side processing. Conclusion The automatic alignment tool can be an alternative method to manual side-by-side processing to improve the repeatability of LV function and dyssynchrony measurements by serial gated SPECT MPI. PMID:23211996

The predictive value of chronic kidney disease for assessing cardiovascular events under consideration of pretest probability for coronary artery disease in patients who underwent stress myocardial perfusion imaging.

PubMed

Furuhashi, Tatsuhiko; Moroi, Masao; Joki, Nobuhiko; Hase, Hiroki; Masai, Hirofumi; Kunimasa, Taeko; Fukuda, Hiroshi; Sugi, Kaoru

2013-02-01

Pretest probability of coronary artery disease (CAD) facilitates diagnosis and risk stratification of CAD. Stress myocardial perfusion imaging (MPI) and chronic kidney disease (CKD) are established major predictors of cardiovascular events. However, the role of CKD to assess pretest probability of CAD has been unclear. This study evaluates the role of CKD to assess the predictive value of cardiovascular events under consideration of pretest probability in patients who underwent stress MPI. Patients with no history of CAD underwent stress MPI (n = 310; male = 166; age = 70; CKD = 111; low/intermediate/high pretest probability = 17/194/99) and were followed for 24 months. Cardiovascular events included cardiac death and nonfatal acute coronary syndrome. Cardiovascular events occurred in 15 of the 310 patients (4.8 %), but not in those with low pretest probability which included 2 CKD patients. In patients with intermediate to high pretest probability (n = 293), multivariate Cox regression analysis identified only CKD [hazard ratio (HR) = 4.88; P = 0.022) and summed stress score of stress MPI (HR = 1.50; P < 0.001) as independent and significant predictors of cardiovascular events. Cardiovascular events were not observed in patients with low pretest probability. In patients with intermediate to high pretest probability, CKD and stress MPI are independent predictors of cardiovascular events considering the pretest probability of CAD in patients with no history of CAD. In assessing pretest probability of CAD, CKD might be an important factor for assessing future cardiovascular prognosis.

Hybrid MPI-OpenMP Parallelism in the ONETEP Linear-Scaling Electronic Structure Code: Application to the Delamination of Cellulose Nanofibrils.

PubMed

Wilkinson, Karl A; Hine, Nicholas D M; Skylaris, Chris-Kriton

2014-11-11

We present a hybrid MPI-OpenMP implementation of Linear-Scaling Density Functional Theory within the ONETEP code. We illustrate its performance on a range of high performance computing (HPC) platforms comprising shared-memory nodes with fast interconnect. Our work has focused on applying OpenMP parallelism to the routines which dominate the computational load, attempting where possible to parallelize different loops from those already parallelized within MPI. This includes 3D FFT box operations, sparse matrix algebra operations, calculation of integrals, and Ewald summation. While the underlying numerical methods are unchanged, these developments represent significant changes to the algorithms used within ONETEP to distribute the workload across CPU cores. The new hybrid code exhibits much-improved strong scaling relative to the MPI-only code and permits calculations with a much higher ratio of cores to atoms. These developments result in a significantly shorter time to solution than was possible using MPI alone and facilitate the application of the ONETEP code to systems larger than previously feasible. We illustrate this with benchmark calculations from an amyloid fibril trimer containing 41,907 atoms. We use the code to study the mechanism of delamination of cellulose nanofibrils when undergoing sonification, a process which is controlled by a large number of interactions that collectively determine the structural properties of the fibrils. Many energy evaluations were needed for these simulations, and as these systems comprise up to 21,276 atoms this would not have been feasible without the developments described here.

Nuclear Cardiology Practice in Asia: Analysis of Radiation Exposure and Best Practice for Myocardial Perfusion Imaging　- Results From the IAEA Nuclear Cardiology Protocols Cross-Sectional Study (INCAPS).

PubMed

Pascual, Thomas N B; Mercuri, Mathew; El-Haj, Noura; Bom, Henry Hee-Sung; Lele, Vikram; Al-Mallah, Mouaz H; Luxenburg, Osnat; Karthikeyan, Ganesan; Vitola, Joao; Mahmarian, John J; Better, Nathan; Shaw, Leslee J; Rehani, Madan M; Kashyap, Ravi; Paez, Diana; Dondi, Maurizio; Einstein, Andrew J

2017-03-24

This paper examines the current status of radiation exposure to patients in myocardial perfusion imaging (MPI) in Asia.Methods and Results:Laboratories voluntarily provided information on MPI performed over a 1-week period. Eight best practice criteria regarding MPI were predefined by an expert panel. Implementation of ≥6 best practices (quality index [QI] ≥6) was pre-specified as a desirable goal for keeping radiation exposure at a low level. Radiation effective dose (ED) in 1,469 patients and QI of 69 laboratories in Asia were compared against data from 239 laboratories in the rest of the world (RoW). Mean ED was significantly higher in Asia (11.4 vs. 9.6 mSv; P<0.0001), with significantly lower doses in South-East vs. East Asia (9.7 vs. 12.7 mSv; P<0.0001). QI in Asia was lower than in RoW. In comparison with RoW, Asian laboratories used thallium more frequently, used weight-based technetium dosing less frequently, and trended towards a lower rate of stress-only imaging. MPI radiation dose in Asia is higher than that in the RoW and linked to less consistent use of laboratory best practices such as avoidance of thallium, weight-based dosing, and use of stress-only imaging. Given that MPI is performed in Asia within a diverse array of medical contexts, laboratory-specific adoption of best practices offers numerous opportunities to improve quality of care.

SurF: an innovative framework in biosecurity and animal health surveillance evaluation.

PubMed

Muellner, Petra; Watts, Jonathan; Bingham, Paul; Bullians, Mark; Gould, Brendan; Pande, Anjali; Riding, Tim; Stevens, Paul; Vink, Daan; Stärk, Katharina Dc

2018-05-16

Surveillance for biosecurity hazards is being conducted by the New Zealand Competent Authority, the Ministry for Primary Industries (MPI) to support New Zealand's biosecurity system. Surveillance evaluation should be an integral part of the surveillance life cycle, as it provides a means to identify and correct problems and to sustain and enhance the existing strengths of a surveillance system. The surveillance evaluation Framework (SurF) presented here was developed to provide a generic framework within which the MPI biosecurity surveillance portfolio, and all of its components, can be consistently assessed. SurF is an innovative, cross-sectoral effort that aims to provide a common umbrella for surveillance evaluation in the animal, plant, environment and aquatic sectors. It supports the conduct of the following four distinct components of an evaluation project: (i) motivation for the evaluation, (ii) scope of the evaluation, (iii) evaluation design and implementation and (iv) reporting and communication of evaluation outputs. Case studies, prepared by MPI subject matter experts, are included in the framework to guide users in their assessment. Three case studies were used in the development of SurF in order to assure practical utility and to confirm usability of SurF across all included sectors. It is anticipated that the structured approach and information provided by SurF will not only be of benefit to MPI but also to other New Zealand stakeholders. Although SurF was developed for internal use by MPI, it could be applied to any surveillance system in New Zealand or elsewhere. © 2018 2018 The Authors. Transboundary and Emerging Diseases Published by Blackwell Verlag GmbH.

LV dyssynchrony as assessed by phase analysis of gated SPECT myocardial perfusion imaging in patients with Wolff-Parkinson-White syndrome

PubMed Central

Chen, Chun; Miao, Changqing; Feng, Jianlin; Zhou, Yanli; Cao, Kejiang; Lloyd, Michael S.; Chen, Ji

2013-01-01

Purpose The purpose of this study was to evaluate left ventricular (LV) mechanical dyssynchrony in patients with Wolff-Parkinson-White (WPW) syndrome pre- and post-radiofrequency catheter ablation (RFA) using phase analysis of gated single photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI). Methods Forty-five WPW patients were enrolled and had gated SPECT MPI pre- and 2–3 days post-RFA. Electrophysiological study (EPS) was used to locate accessory pathways (APs) and categorize the patients according to the AP locations (septal, left and right free wall). Electrocardiography (ECG) was performed pre- and post-RFA to confirm successful elimination of the APs. Phase analysis of gated SPECT MPI was used to assess LV dyssynchrony pre- and post-RFA. Results Among the 45 patients, 3 had gating errors, and thus 42 had SPECT phase analysis. Twenty-two patients (52.4 %) had baseline LV dyssynchrony. Baseline LV dyssynchrony was more prominent in the patients with septal APs than in the patients with left or right APs (p<0.05). RFA improved LV synchrony in the entire cohort and in the patients with septal APs (p<0.01). Conclusion Phase analysis of gated SPECT MPI demonstrated that LV mechanical dyssynchrony can be present in patients with WPW syndrome. Septal APs result in the greatest degree of LV mechanical dyssynchrony and afford the most benefit after RFA. This study supports further investigation in the relationship between electrical and mechanical activation using EPS and phase analysis of gated SPECT MPI. PMID:22532253

IR Li2Ga2GeS6 nanocrystallized GeS2-Ga2S3-Li2S electroconductive chalcogenide glass with good nonlinearity

PubMed Central

Liu, Qiming; Zhang, Peng

2014-01-01

GeS2-Ga2S3-Li2S electroconductive glasses were prepared by the conventional melt-quenching method through carefully controlling the heating rate. Comparing with the reference of glass-forming region, our investigated GeS2-Ga2S3-Li2S system was extended to the cation ratio of 0–20% Li with around 40% Ga. GeS2-Ga2S3-Li2S glass-ceramics containing IR Li2Ga2GeS6 nonlinear nanocrystals were obtained by the more carefully controlled heating rate. Its optical nonlinearity was investigated by the Maker fringe measurements, the maximum second harmonic intensity was observed to be 0.35 of the reference Z-cut quartz. IR Li2Ga2GeS6 nonlinear crystals were directly obtained at the composition of 40GeS2-30GaS1.5-30LiS0.5. PMID:25030713

A Naval Marksmanship Training Transfer Study: The Use of Indoor Simulated Marksmanship Trainers to Train for Live Fire

DTIC Science & Technology

2012-03-01

on the standard Navy Handgun Qualification Course. Results partially supported the hypotheses. The simulation group showed greater improvement in MPI...standard Navy Handgun Qualification Course. Results partially supported the hypotheses. The simulation group showed greater improvement in MPI than the...14 3. Navy Handgun Qualification Course Firing Sequence ..................15 F. PROCEDURES

Performance Comparison of HPF and MPI Based NAS Parallel Benchmarks

NASA Technical Reports Server (NTRS)

Saini, Subhash

1997-01-01

Compilers supporting High Performance Form (HPF) features first appeared in late 1994 and early 1995 from Applied Parallel Research (APR), Digital Equipment Corporation, and The Portland Group (PGI). IBM introduced an HPF compiler for the IBM RS/6000 SP2 in April of 1996. Over the past two years, these implementations have shown steady improvement in terms of both features and performance. The performance of various hardware/ programming model (HPF and MPI) combinations will be compared, based on latest NAS Parallel Benchmark results, thus providing a cross-machine and cross-model comparison. Specifically, HPF based NPB results will be compared with MPI based NPB results to provide perspective on performance currently obtainable using HPF versus MPI or versus hand-tuned implementations such as those supplied by the hardware vendors. In addition, we would also present NPB, (Version 1.0) performance results for the following systems: DEC Alpha Server 8400 5/440, Fujitsu CAPP Series (VX, VPP300, and VPP700), HP/Convex Exemplar SPP2000, IBM RS/6000 SP P2SC node (120 MHz), NEC SX-4/32, SGI/CRAY T3E, and SGI Origin2000. We would also present sustained performance per dollar for Class B LU, SP and BT benchmarks.

Performance of hybrid programming models for multiscale cardiac simulations: preparing for petascale computation.

PubMed

Pope, Bernard J; Fitch, Blake G; Pitman, Michael C; Rice, John J; Reumann, Matthias

2011-10-01

Future multiscale and multiphysics models that support research into human disease, translational medical science, and treatment can utilize the power of high-performance computing (HPC) systems. We anticipate that computationally efficient multiscale models will require the use of sophisticated hybrid programming models, mixing distributed message-passing processes [e.g., the message-passing interface (MPI)] with multithreading (e.g., OpenMP, Pthreads). The objective of this study is to compare the performance of such hybrid programming models when applied to the simulation of a realistic physiological multiscale model of the heart. Our results show that the hybrid models perform favorably when compared to an implementation using only the MPI and, furthermore, that OpenMP in combination with the MPI provides a satisfactory compromise between performance and code complexity. Having the ability to use threads within MPI processes enables the sophisticated use of all processor cores for both computation and communication phases. Considering that HPC systems in 2012 will have two orders of magnitude more cores than what was used in this study, we believe that faster than real-time multiscale cardiac simulations can be achieved on these systems.

PyPele Rewritten To Use MPI

NASA Technical Reports Server (NTRS)

Hockney, George; Lee, Seungwon

2008-01-01

A computer program known as PyPele, originally written as a Pythonlanguage extension module of a C++ language program, has been rewritten in pure Python language. The original version of PyPele dispatches and coordinates parallel-processing tasks on cluster computers and provides a conceptual framework for spacecraft-mission- design and -analysis software tools to run in an embarrassingly parallel mode. The original version of PyPele uses SSH (Secure Shell a set of standards and an associated network protocol for establishing a secure channel between a local and a remote computer) to coordinate parallel processing. Instead of SSH, the present Python version of PyPele uses Message Passing Interface (MPI) [an unofficial de-facto standard language-independent application programming interface for message- passing on a parallel computer] while keeping the same user interface. The use of MPI instead of SSH and the preservation of the original PyPele user interface make it possible for parallel application programs written previously for the original version of PyPele to run on MPI-based cluster computers. As a result, engineers using the previously written application programs can take advantage of embarrassing parallelism without need to rewrite those programs.

Message Passing vs. Shared Address Space on a Cluster of SMPs

NASA Technical Reports Server (NTRS)

Shan, Hongzhang; Singh, Jaswinder Pal; Oliker, Leonid; Biswas, Rupak

2000-01-01

The convergence of scalable computer architectures using clusters of PCs (or PC-SMPs) with commodity networking has become an attractive platform for high end scientific computing. Currently, message-passing and shared address space (SAS) are the two leading programming paradigms for these systems. Message-passing has been standardized with MPI, and is the most common and mature programming approach. However message-passing code development can be extremely difficult, especially for irregular structured computations. SAS offers substantial ease of programming, but may suffer from performance limitations due to poor spatial locality, and high protocol overhead. In this paper, we compare the performance of and programming effort, required for six applications under both programming models on a 32 CPU PC-SMP cluster. Our application suite consists of codes that typically do not exhibit high efficiency under shared memory programming. due to their high communication to computation ratios and complex communication patterns. Results indicate that SAS can achieve about half the parallel efficiency of MPI for most of our applications: however, on certain classes of problems SAS performance is competitive with MPI. We also present new algorithms for improving the PC cluster performance of MPI collective operations.

Novel magnetic multicore nanoparticles designed for MPI and other biomedical applications: From synthesis to first in vivo studies

PubMed Central

Taupitz, Matthias; Ariza de Schellenberger, Angela; Kosch, Olaf; Eberbeck, Dietmar; Wagner, Susanne; Trahms, Lutz; Hamm, Bernd; Schnorr, Jörg

2018-01-01

Synthesis of novel magnetic multicore particles (MCP) in the nano range, involves alkaline precipitation of iron(II) chloride in the presence of atmospheric oxygen. This step yields green rust, which is oxidized to obtain magnetic nanoparticles, which probably consist of a magnetite/maghemite mixed-phase. Final growth and annealing at 90°C in the presence of a large excess of carboxymethyl dextran gives MCP very promising magnetic properties for magnetic particle imaging (MPI), an emerging medical imaging modality, and magnetic resonance imaging (MRI). The magnetic nanoparticles are biocompatible and thus potential candidates for future biomedical applications such as cardiovascular imaging, sentinel lymph node mapping in cancer patients, and stem cell tracking. The new MCP that we introduce here have three times higher magnetic particle spectroscopy performance at lower and middle harmonics and five times higher MPS signal strength at higher harmonics compared with Resovist®. In addition, the new MCP have also an improved in vivo MPI performance compared to Resovist®, and we here report the first in vivo MPI investigation of this new generation of magnetic nanoparticles. PMID:29300729

Incorporation de particules de verre post-consommation dans un enrobe bitumineux de type ESG14

NASA Astrophysics Data System (ADS)

Lachance Tremblay, Eric

In 2008, around 244,000 tons of glass was produced by the Quebec population. From this number, 128,000 tons were collected by various means of collection. Glass recycling is problematic because all the glass that cannot be classified according to the type can't be used to manufacture new products. It is therefore necessary to find new sources of uses for this material. Because the use of recycled materials in road structure material is beneficial from an environmental and sometimes structural point of view, the idea of using recycled glass into asphalt mixture was recently studied at the LCMB. Nowadays, the use of recycled glass in asphalt mixture is not regulated by the MTQ. This research goal was to verify the possibility of using recycled glass particles in a ESG14 asphalt mixture while maintaining equivalent properties and performance compared to a conventional mix. Different dosages of recycled glass particles have been studied to evaluate the effect of glass on the asphalt mixture volumetric characteristics, the ability of compaction and the rutting resistance. These mixes were formulated according to the LC formulation of the MTQ. The first part allowed selecting an optimal dosage of recycled glass particles. Thereafter, the thermo mechanical performance (resistance to low temperatures (TSRST), complex modulus (E*) and resistance to fatigue cracking), physical characteristics (macro texture and surface grip) and durability (resistance to water damage) of the asphalt mixture with the optimal dosage were evaluated and compared with a reference mixture. The results show that the ESG14 mixture with recycled glass formulated with the LC method is more susceptible to rutting than the reference mixture. Therefore, a reduction of the bitumen content can increase the rutting resistance while conserving equivalent properties to a conventional mix regarding resistance to low temperatures, complex modulus, resistance to fatigue cracking as well as the physical characteristics. Therefore, the use of recycled in glass seems to modify the asphalt behavior and increase the moisture susceptibility.

A Randomized Study Comparing Digital Imaging to Traditional Glass Slide Microscopy for Breast Biopsy and Cancer Diagnosis

PubMed Central

Elmore, Joann G.; Longton, Gary M.; Pepe, Margaret S.; Carney, Patricia A.; Nelson, Heidi D.; Allison, Kimberly H.; Geller, Berta M.; Onega, Tracy; Tosteson, Anna N. A.; Mercan, Ezgi; Shapiro, Linda G.; Brunyé, Tad T.; Morgan, Thomas R.; Weaver, Donald L.

2017-01-01

Background: Digital whole slide imaging may be useful for obtaining second opinions and is used in many countries. However, the U.S. Food and Drug Administration requires verification studies. Methods: Pathologists were randomized to interpret one of four sets of breast biopsy cases during two phases, separated by ≥9 months, using glass slides or digital format (sixty cases per set, one slide per case, n = 240 cases). Accuracy was assessed by comparing interpretations to a consensus reference standard. Intraobserver reproducibility was assessed by comparing the agreement of interpretations on the same cases between two phases. Estimated probabilities of confirmation by a reference panel (i.e., predictive values) were obtained by incorporating data on the population prevalence of diagnoses. Results: Sixty-five percent of responding pathologists were eligible, and 252 consented to randomization; 208 completed Phase I (115 glass, 93 digital); and 172 completed Phase II (86 glass, 86 digital). Accuracy was slightly higher using glass compared to digital format and varied by category: invasive carcinoma, 96% versus 93% (P = 0.04); ductal carcinoma in situ (DCIS), 84% versus 79% (P < 0.01); atypia, 48% versus 43% (P = 0.08); and benign without atypia, 87% versus 82% (P < 0.01). There was a small decrease in intraobserver agreement when the format changed compared to when glass slides were used in both phases (P = 0.08). Predictive values for confirmation by a reference panel using glass versus digital were: invasive carcinoma, 98% and 97% (not significant [NS]); DCIS, 70% and 57% (P = 0.007); atypia, 38% and 28% (P = 0.002); and benign without atypia, 97% and 96% (NS). Conclusions: In this large randomized study, digital format interpretations were similar to glass slide interpretations of benign and invasive cancer cases. However, cases in the middle of the spectrum, where more inherent variability exists, may be more problematic in digital format. Future studies evaluating the effect these findings exert on clinical practice and patient outcomes are required. PMID:28382226

Plutonium immobilization in glass and ceramics

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

Knecht, D.A.; Murphy, W.M.

1996-05-01

The Materials Research Society Nineteenth Annual Symposium on the Scientific Basis for Nuclear Waste Management was held in Boston on November 27 to December 1, 1995. Over 150 papers were presented at the Symposium dealing with all aspects of nuclear waste management and disposal. Fourteen oral sessions and on poster session included a Plenary session on surplus plutonium dispositioning and waste forms. The proceedings, to be published in April, 1996, will provide a highly respected, referred compilation of the state of scientific development in the field of nuclear waste management. This paper provides a brief overview of the selected Symposiummore » papers that are applicable to plutonium immobilization and plutonium waste form performance. Waste forms that were described at the Symposium cover most of the candidate Pu immobilization options under consideration, including borosilicate glass with a melting temperature of 1150 {degrees}C, a higher temperature (1450 {degrees}C) lanthanide glass, single phase ceramics, multi-phase ceramics, and multi-phase crystal-glass composites (glass-ceramics or slags). These Symposium papers selected for this overview provide the current status of the technology in these areas and give references to the relevant literature.« less

Impact of motion and partial volume effects correction on PET myocardial perfusion imaging using simultaneous PET-MR

NASA Astrophysics Data System (ADS)

Petibon, Yoann; Guehl, Nicolas J.; Reese, Timothy G.; Ebrahimi, Behzad; Normandin, Marc D.; Shoup, Timothy M.; Alpert, Nathaniel M.; El Fakhri, Georges; Ouyang, Jinsong

2017-01-01

PET is an established modality for myocardial perfusion imaging (MPI) which enables quantification of absolute myocardial blood flow (MBF) using dynamic imaging and kinetic modeling. However, heart motion and partial volume effects (PVE) significantly limit the spatial resolution and quantitative accuracy of PET MPI. Simultaneous PET-MR offers a solution to the motion problem in PET by enabling MR-based motion correction of PET data. The aim of this study was to develop a motion and PVE correction methodology for PET MPI using simultaneous PET-MR, and to assess its impact on both static and dynamic PET MPI using 18F-Flurpiridaz, a novel 18F-labeled perfusion tracer. Two dynamic 18F-Flurpiridaz MPI scans were performed on healthy pigs using a PET-MR scanner. Cardiac motion was tracked using a dedicated tagged-MRI (tMR) sequence. Motion fields were estimated using non-rigid registration of tMR images and used to calculate motion-dependent attenuation maps. Motion correction of PET data was achieved by incorporating tMR-based motion fields and motion-dependent attenuation coefficients into image reconstruction. Dynamic and static PET datasets were created for each scan. Each dataset was reconstructed as (i) Ungated, (ii) Gated (end-diastolic phase), and (iii) Motion-Corrected (MoCo), each without and with point spread function (PSF) modeling for PVE correction. Myocardium-to-blood concentration ratios (MBR) and apparent wall thickness were calculated to assess image quality for static MPI. For dynamic MPI, segment- and voxel-wise MBF values were estimated by non-linear fitting of a 2-tissue compartment model to tissue time-activity-curves. MoCo and Gating respectively decreased mean apparent wall thickness by 15.1% and 14.4% and increased MBR by 20.3% and 13.6% compared to Ungated images (P  <  0.01). Combined motion and PSF correction (MoCo-PSF) yielded 30.9% (15.7%) lower wall thickness and 82.2% (20.5%) higher MBR compared to Ungated data reconstructed without (with) PSF modeling (P  <  0.01). For dynamic PET, mean MBF across all segments were comparable for MoCo (0.72  ±  0.21 ml/min/ml) and Gating (0.69  ±  0.18 ml/min/ml). Ungated data yielded significantly lower mean MBF (0.59  ±  0.16 ml/min/ml). Mean MBF for MoCo-PSF was 0.80  ±  0.22 ml/min/ml, which was 37.9% (25.0%) higher than that obtained from Ungated data without (with) PSF correction (P  <  0.01). The developed methodology holds promise to improve the image quality and sensitivity of PET MPI studies performed using PET-MR.

Run for the Gold: Small Town Fun(ding) Runs.

ERIC Educational Resources Information Center

Morris, Judson H., Jr.

This paper examines the organization, planning, development, and staging of foot races, bicycle races, or multi-event competitions as fund raisers for public or private groups in rural areas. Local businesses often assist in sponsoring such events in order to get free advertising and make money from newcomers drawn to the event. Organizers must be…

Computing Trust from Revision History

DTIC Science & Technology

2006-01-01

Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington VA 22202-4302. Respondents should be aware that...University of Maryland in Baltimore County, Baltimore, Maryland, USA dingli1@umbc.edu Abstract A new model of distributed, collaborative information ...evolution is emerging. As exemplified in Wikipedia, online collaborative information repositories are being generated, updated, and maintained by a

Flight Attendant Work/Rest Patterns, Alertness, and Performance Assessment: Field Validation of Biomathematical Fatigue Modeling

DTIC Science & Technology

2012-09-01

of ma- rine pilots working extended hours. Chronobiology International, 25(2), 399-411. Goel, N., & Dinges, D.F. (2011). Behavioral and genetic...Differences in sleep, light, and circadian phase in offshore 18:00-06:00 h and 19:00-07:00 h shift workers. Chronobiology International, 25(2&3

75 FR 27576 - J.N. “Ding” Darling National Wildlife Refuge, Lee County, FL

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-17

... DEPARTMENT OF THE INTERIOR Fish and Wildlife Service [FWS-R4-R-2010-N052; 40136-1265-0000-S3] J.N. ``Ding'' Darling National Wildlife Refuge, Lee County, FL AGENCY: Fish and Wildlife Service, Interior... variety of species in a highly developed landscape. The city of Sanibel, Lee County, Sanibel-Captiva...

The surface pH of glass ionomer cavity lining agents.

PubMed

Woolford, M J

1989-12-01

It is considered that acid release from the surface of glass ionomer (polyalkenoate) cements may be associated with early pulpal sensitivity following the use of these materials. This study was carried out to examine the surface pH of different types of glass ionomer lining cements using a flat-ended pH electrode. It was found that the surface pH remains low for this group of materials during the first hour of setting. Different types of glass ionomer lining cement were also shown to behave differently when considering acid release from the surface. Conclusions regarding the behaviour of glass ionomers should only be made with reference to the specific material tested.

Diversity, culture and the glass ceiling.

PubMed

Wilson, Eleanor

2014-01-01

A reference to the term, the glass ceiling, has come to embody more than gender equality among women and men. Today the term embraces the quest of all minorities and their journey towards equality in the workplace. The purpose of this article is to bring attention to the subject of diversity, culture, and the glass ceiling. The article will discuss the history of the glass ceiling and how its broadened meaning is relevant in today's workplace. It will also provide statistics showing how diversity and culture are lacking among the top echelon of today's executives, the barriers faced by minorities as they journey towards executive leadership, and how to overcome these barriers to truly shatter the glass ceiling.

High-Performance Data Analysis Tools for Sun-Earth Connection Missions

NASA Technical Reports Server (NTRS)

Messmer, Peter

2011-01-01

The data analysis tool of choice for many Sun-Earth Connection missions is the Interactive Data Language (IDL) by ITT VIS. The increasing amount of data produced by these missions and the increasing complexity of image processing algorithms requires access to higher computing power. Parallel computing is a cost-effective way to increase the speed of computation, but algorithms oftentimes have to be modified to take advantage of parallel systems. Enhancing IDL to work on clusters gives scientists access to increased performance in a familiar programming environment. The goal of this project was to enable IDL applications to benefit from both computing clusters as well as graphics processing units (GPUs) for accelerating data analysis tasks. The tool suite developed in this project enables scientists now to solve demanding data analysis problems in IDL that previously required specialized software, and it allows them to be solved orders of magnitude faster than on conventional PCs. The tool suite consists of three components: (1) TaskDL, a software tool that simplifies the creation and management of task farms, collections of tasks that can be processed independently and require only small amounts of data communication; (2) mpiDL, a tool that allows IDL developers to use the Message Passing Interface (MPI) inside IDL for problems that require large amounts of data to be exchanged among multiple processors; and (3) GPULib, a tool that simplifies the use of GPUs as mathematical coprocessors from within IDL. mpiDL is unique in its support for the full MPI standard and its support of a broad range of MPI implementations. GPULib is unique in enabling users to take advantage of an inexpensive piece of hardware, possibly already installed in their computer, and achieve orders of magnitude faster execution time for numerically complex algorithms. TaskDL enables the simple setup and management of task farms on compute clusters. The products developed in this project have the potential to interact, so one can build a cluster of PCs, each equipped with a GPU, and use mpiDL to communicate between the nodes and GPULib to accelerate the computations on each node.

Reference commercial high-level waste glass and canister definition

NASA Astrophysics Data System (ADS)

Slate, S. C.; Ross, W. A.; Partain, W. L.

1981-09-01

Technical data and performance characteristics of a high level waste glass and canister intended for use in the design of a complete waste encapsulation package suitable for disposal in a geologic repository are presented. The borosilicate glass contained in the stainless steel canister represents the probable type of high level waste product that is produced in a commercial nuclear-fuel reprocessing plant. Development history is summarized for high level liquid waste compositions, waste glass composition and characteristics, and canister design. The decay histories of the fission products and actinides (plus daughters) calculated by the ORIGEN-II code are presented.

Glass Ceiling for Women in Higher Education.

ERIC Educational Resources Information Center

Schedler, Petra; Glastra, Folke; Hake, Barry

2003-01-01

Discusses the place of women in higher education in the Netherlands. Suggests that it is not a question of numbers but of orientation, field, and the glass ceiling. Asserts that despite some improvement, higher education may be one of the last bastions against the recognition of women's worth. (Contains 42 references.) (JOW)

Representative of America: Creating Inclusion in the Senior Executive Service

DTIC Science & Technology

2012-02-27

to reach the upper echelons of organizations in America. According to a 1995 study commissioned by the Federal Glass Ceiling Commission, “97% of the...There is a direct correlation between the similarity/attraction theory and the Glass Ceiling and barriers in DoD that may be a Purple Ceiling (senior...managers who are former military officers).17 The Glass Ceiling refers to obstacles that often confront ethnic groups and females as they attempt

Distribution of N2O in the atmosphere under global warming - a simulation study with the MPI Earth System Model

NASA Astrophysics Data System (ADS)

Kracher, Daniela; Manzini, Elisa; Reick, Christian H.; Schultz, Martin; Stein, Olaf

2014-05-01

Climate change is driven by an increasing release of anthropogenic greenhouse gases (GHGs) such as carbon dioxide and nitrous oxide (N2O). Besides fossil fuel burning, also land use change and land management are anthropogenic sources of GHGs. Especially inputs of reactive nitrogen via fertilizer and deposition lead to enhanced emissions of N2O. One effect of a drastic future increase in surface temperature is a modification of atmospheric circulation, e.g. an accelerated Brewer Dobson circulation affecting the exchange between troposphere and stratosphere. N2O is inert in the troposphere and decayed only in the stratosphere. Thus, changes in atmospheric circulation, especially changes in the exchange between troposphere and stratosphere, will affect the atmospheric transport, decay, and distribution of N2O. In our study we assess the impact of global warming on atmospheric circulation and implied effects on the distribution and lifetime of atmospheric N2O. As terrestrial N2O emissions are highly determined by inputs of reactive nitrogen - the location of which being determined by human choice - we examine in particular the importance of latitudinal source regions of N2O for its global distribution. For this purpose we apply the Max Planck Institute Earth System Model, MPI-ESM. MPI-ESM consists of the atmospheric general circulation model ECHAM, the land surface model JSBACH, and MPIOM/HAMOCC representing ocean circulation and ocean biogeochemistry. Prognostic atmospheric N2O concentrations in MPI-ESM are determined by land N2O emissions, ocean N2O exchange and atmospheric tracer transport. As stratospheric chemistry is not explicitly represented in MPI-ESM, stratospheric decay rates of N2O are prescribed from a MACC MOZART simulation.

Response properties of the refractory auditory nerve fiber.

PubMed

Miller, C A; Abbas, P J; Robinson, B K

2001-09-01

The refractory characteristics of auditory nerve fibers limit their ability to accurately encode temporal information. Therefore, they are relevant to the design of cochlear prostheses. It is also possible that the refractory property could be exploited by prosthetic devices to improve information transfer, as refractoriness may enhance the nerve's stochastic properties. Furthermore, refractory data are needed for the development of accurate computational models of auditory nerve fibers. We applied a two-pulse forward-masking paradigm to a feline model of the human auditory nerve to assess refractory properties of single fibers. Each fiber was driven to refractoriness by a single (masker) current pulse delivered intracochlearly. Properties of firing efficiency, latency, jitter, spike amplitude, and relative spread (a measure of dynamic range and stochasticity) were examined by exciting fibers with a second (probe) pulse and systematically varying the masker-probe interval (MPI). Responses to monophasic cathodic current pulses were analyzed. We estimated the mean absolute refractory period to be about 330 micros and the mean recovery time constant to be about 410 micros. A significant proportion of fibers (13 of 34) responded to the probe pulse with MPIs as short as 500 micros. Spike amplitude decreased with decreasing MPI, a finding relevant to the development of computational nerve-fiber models, interpretation of gross evoked potentials, and models of more central neural processing. A small mean decrement in spike jitter was noted at small MPI values. Some trends (such as spike latency-vs-MPI) varied across fibers, suggesting that sites of excitation varied across fibers. Relative spread was found to increase with decreasing MPI values, providing direct evidence that stochastic properties of fibers are altered under conditions of refractoriness.

Effect of balloon mitral valvotomy on left ventricular function in rheumatic mitral stenosis.

PubMed

Rajesh, Gopalan Nair; Sreekumar, Pradeep; Haridasan, Vellani; Sajeev, C G; Bastian, Cicy; Vinayakumar, D; Kadermuneer, P; Mathew, Dolly; George, Biju; Krishnan, M N

Mitral stenosis (MS) is found to produce left ventricular (LV) dysfunction in some studies. We sought to study the left ventricular function in patients with rheumatic MS undergoing balloon mitral valvotomy (BMV). Ours is the first study to analyze effect of BMV on mitral annular plane systolic excursion (MAPSE), and to quantify prevalence of longitudinal left ventricular dysfunction in rheumatic MS. In this prospective cohort study, we included 43 patients with severe rheumatic mitral stenosis undergoing BMV. They were compared to twenty controls whose distribution of age and gender were similar to that of patients. The parameters compared were LV ejection fraction (EF) by modified Simpson's method, mitral annular systolic velocity (MASV), MAPSE, mitral annular early diastolic velocity (E'), and myocardial performance index (MPI). These parameters were reassessed immediately following BMV and after 3 months of procedure. MASV, MAPSE, E', and EF were significantly lower and MPI was higher in mitral stenosis group compared to controls. Impaired longitudinal LV function was present in 77% of study group. MAPSE and EF did not show significant change after BMV while MPI, MASV, and E' improved significantly. MASV and E' showed improvement immediately after BMV, while MPI decreased only at 3 months follow-up. There were significantly lower mitral annular motion parameters including MAPSE in patients with rheumatic mitral stenosis. Those with atrial fibrillation had higher MPI. Immediately after BMV, there was improvement in LV long axis function with a gradual improvement in global LV function. There was no significant change of MAPSE after BMV. Copyright © 2015 Cardiological Society of India. Published by Elsevier B.V. All rights reserved.

Improvement of the myocardial performance index in atrial fibrilation patients treated with amiodarone after cardioversion.

PubMed

Besli, Feyzullah; Basar, Cengiz; Kecebas, Mesut; Turker, Yasin

2015-03-01

This study evaluated the response to electrical cardioversion (EC) and the effect on the myocardial performance index (MPI) in patients with persistent and long-standing persistent atrial fibrillation (AF). We enrolled 103 patients (mean age 69.6 ± 8.9 years, 40.7% males) with a diagnosis of persistent and long-standing persistent AF. EC was applied to all patients after one g of amiodarone administration. Echocardiographic findings before EC were compared in patients with successful versus unsuccessful cardioversions and in patients with maintained sinus rhythm (SR) versus those with AF recurrence at the end of the first month. We also compared echocardiographic data before EC versus at the end of the first month in the same patients with maintained SR. SR was achieved in 72.8% of patients and was continued at the end of the first month in 69.3% of the patients. The MPI value of all patients was found to be 0.73 ± 0.21. The size of the left atrium was determined to be an independent predictor of the maintenance of SR at 1 month. In subgroup analyses, when we compared echocardiographic findings before EC and at the end of the first month in patients with maintained SR, the MPI (0.66 ± 0.14 vs 0.56 ± 0.09, p < 0.001) values were significantly decreased. Our study is the first to show impairment of the MPI, which is an indicator of systolic and diastolic function, in patients with persistent and long-standing persistent AF and improvement of the MPI after successful EC.

Nuclear cardiology practices and radiation exposure in Africa: results from the IAEA Nuclear Cardiology Protocols Study (INCAPS).

PubMed

Bouyoucef, Salah E; Mercuri, Mathew; Pascual, Thomas N; Allam, Adel H; Vangu, Mboyo; Vitola, João V; Better, Nathan; Karthikeyan, Ganesan; Mahmarian, John J; Rehani, Madan M; Kashyap, Ravi; Dondi, Maurizio; Paez, Diana; Einstein, Andrew J

While nuclear myocardial perfusion imaging (MPI) offers many benefits to patients with known or suspected cardiovascular disease, concerns exist regarding radiation-associated health effects. Little is known regarding MPI practice in Africa. We sought to characterise radiation doses and the use of MPI best practices that could minimise radiation in African nuclear cardiology laboratories, and compare these to practice worldwide. Demographics and clinical characteristics were collected for a consecutive sample of 348 patients from 12 laboratories in six African countries over a one-week period from March to April 2013. Radiation effective dose (ED) was estimated for each patient. A quality index (QI) enumerating adherence to eight best practices, identified a priori by an IAEA expert panel, was calculated for each laboratory. We compared these metrics with those from 7 563 patients from 296 laboratories outside Africa. Median (interquartile range) patient ED in Africa was similar to that of the rest of the world [9.1 (5.1-15.6) vs 10.3 mSv (6.8-12.6), p = 0.14], although a larger proportion of African patients received a low ED, ≤ 9 mSv targeted in societal recommendations (49.7 vs 38.2%, p < 0.001). Bestpractice adherence was higher among African laboratories (QI score: 6.3 ± 1.2 vs 5.4 ± 1.3, p = 0.013). However, median ED varied significantly among African laboratories (range: 2.0-16.3 mSv; p < 0.0001) and QI range was 4-8. Patient radiation dose from MPI in Africa was similar to that in the rest of the world, and adherence to best practices was relatively high in African laboratories. Nevertheless there remain opportunities to further reduce radiation exposure to African patients from MPI.

Current worldwide nuclear cardiology practices and radiation exposure: results from the 65 country IAEA Nuclear Cardiology Protocols Cross-Sectional Study (INCAPS).

PubMed

Einstein, Andrew J; Pascual, Thomas N B; Mercuri, Mathew; Karthikeyan, Ganesan; Vitola, João V; Mahmarian, John J; Better, Nathan; Bouyoucef, Salah E; Hee-Seung Bom, Henry; Lele, Vikram; Magboo, V Peter C; Alexánderson, Erick; Allam, Adel H; Al-Mallah, Mouaz H; Flotats, Albert; Jerome, Scott; Kaufmann, Philipp A; Luxenburg, Osnat; Shaw, Leslee J; Underwood, S Richard; Rehani, Madan M; Kashyap, Ravi; Paez, Diana; Dondi, Maurizio

2015-07-07

To characterize patient radiation doses from nuclear myocardial perfusion imaging (MPI) and the use of radiation-optimizing 'best practices' worldwide, and to evaluate the relationship between laboratory use of best practices and patient radiation dose. We conducted an observational cross-sectional study of protocols used for all 7911 MPI studies performed in 308 nuclear cardiology laboratories in 65 countries for a single week in March-April 2013. Eight 'best practices' relating to radiation exposure were identified a priori by an expert committee, and a radiation-related quality index (QI) devised indicating the number of best practices used by a laboratory. Patient radiation effective dose (ED) ranged between 0.8 and 35.6 mSv (median 10.0 mSv). Average laboratory ED ranged from 2.2 to 24.4 mSv (median 10.4 mSv); only 91 (30%) laboratories achieved the median ED ≤ 9 mSv recommended by guidelines. Laboratory QIs ranged from 2 to 8 (median 5). Both ED and QI differed significantly between laboratories, countries, and world regions. The lowest median ED (8.0 mSv), in Europe, coincided with high best-practice adherence (mean laboratory QI 6.2). The highest doses (median 12.1 mSv) and low QI (4.9) occurred in Latin America. In hierarchical regression modelling, patients undergoing MPI at laboratories following more 'best practices' had lower EDs. Marked worldwide variation exists in radiation safety practices pertaining to MPI, with targeted EDs currently achieved in a minority of laboratories. The significant relationship between best-practice implementation and lower doses indicates numerous opportunities to reduce radiation exposure from MPI globally. © The Author 2015. Published by Oxford University Press on behalf of the European Society of Cardiology.

Current worldwide nuclear cardiology practices and radiation exposure: results from the 65 country IAEA Nuclear Cardiology Protocols Cross-Sectional Study (INCAPS)

PubMed Central

Einstein, Andrew J.; Pascual, Thomas N. B.; Mercuri, Mathew; Karthikeyan, Ganesan; Vitola, João V.; Mahmarian, John J.; Better, Nathan; Bouyoucef, Salah E.; Hee-Seung Bom, Henry; Lele, Vikram; Magboo, V. Peter C.; Alexánderson, Erick; Allam, Adel H.; Al-Mallah, Mouaz H.; Flotats, Albert; Jerome, Scott; Kaufmann, Philipp A.; Luxenburg, Osnat; Shaw, Leslee J.; Underwood, S. Richard; Rehani, Madan M.; Kashyap, Ravi; Paez, Diana; Dondi, Maurizio

2015-01-01

Aims To characterize patient radiation doses from nuclear myocardial perfusion imaging (MPI) and the use of radiation-optimizing ‘best practices’ worldwide, and to evaluate the relationship between laboratory use of best practices and patient radiation dose. Methods and results We conducted an observational cross-sectional study of protocols used for all 7911 MPI studies performed in 308 nuclear cardiology laboratories in 65 countries for a single week in March–April 2013. Eight ‘best practices’ relating to radiation exposure were identified a priori by an expert committee, and a radiation-related quality index (QI) devised indicating the number of best practices used by a laboratory. Patient radiation effective dose (ED) ranged between 0.8 and 35.6 mSv (median 10.0 mSv). Average laboratory ED ranged from 2.2 to 24.4 mSv (median 10.4 mSv); only 91 (30%) laboratories achieved the median ED ≤ 9 mSv recommended by guidelines. Laboratory QIs ranged from 2 to 8 (median 5). Both ED and QI differed significantly between laboratories, countries, and world regions. The lowest median ED (8.0 mSv), in Europe, coincided with high best-practice adherence (mean laboratory QI 6.2). The highest doses (median 12.1 mSv) and low QI (4.9) occurred in Latin America. In hierarchical regression modelling, patients undergoing MPI at laboratories following more ‘best practices’ had lower EDs. Conclusion Marked worldwide variation exists in radiation safety practices pertaining to MPI, with targeted EDs currently achieved in a minority of laboratories. The significant relationship between best-practice implementation and lower doses indicates numerous opportunities to reduce radiation exposure from MPI globally. PMID:25898845

Impact of insurance carrier, prior authorization, and socioeconomic status on appropriate use of SPECT myocardial perfusion imaging in private community-based office practice.

PubMed

Doukky, Rami; Hayes, Kathleen; Frogge, Nathan; Nazir, Noreen T; Collado, Fareed M; Williams, Kim A

2015-05-01

The impact of health insurance carrier and socioeconomic status (SES) on the adherence to appropriate use criteria (AUC) for radionuclide myocardial perfusion imaging (MPI) is unknown. Health insurance carrier's prior authorization and patient's SES impact adherence to AUC for MPI in a fee-for-service setting. We conducted a prospective cohort study of 1511 consecutive patients who underwent outpatient MPI in a multi-site, office-based, fee-for-service setting. The patients were stratified according to the 2009 AUC into appropriate/uncertain appropriateness and inappropriate use groups. Insurance status was categorized as Medicare (does not require prior authorization) vs commercial (requires prior authorization). Socioeconomic status was determined by the median household income in the ZIP code of residence. The proportion of patients with Medicare was 33% vs 67% with commercial insurance. The rate of inappropriate use was higher among patients with commercial insurance vs Medicare (55% vs 24%; P < 0.001); this difference was not significant after adjusting for confounders known to impact AUC determination (odds ratio: 1.06, 95% confidence interval: 0.62-1.82, P = 0.82). The mean annual household income in the residential areas of patients with inappropriate use as compared to those with appropriate/uncertain use was $72 000 ± 21 000 vs $68 000 ± 20 000, respectively (P < 0.001). After adjusting for covariates known to impact AUC determination, SES (top vs bottom quartile income area) was not independently predictive of inappropriate MPI use (odds ratio: 0.9, 95% confidence interval: 0.53-1.52, P = 0.69). Insurance carriers prior authorization and SES do not seem to play a significant role in determining physicians adherence to AUC for MPI. © 2015 Wiley Periodicals, Inc.

Early myocardial damage assessment in dystrophinopathies using (99)Tc(m)-MIBI gated myocardial perfusion imaging.

PubMed

Zhang, Li; Liu, Zhe; Hu, Ke-You; Tian, Qing-Bao; Wei, Ling-Ge; Zhao, Zhe; Shen, Hong-Rui; Hu, Jing

2015-01-01

Early detection of muscular dystrophy (MD)-associated cardiomyopathy is important because early medical treatment may slow cardiac remodeling and attenuate symptoms of cardiac dysfunction; however, no sensitive and standard diagnostic method for MD at an earlier stage has been well-recognized. Thus, the aim of this study was to test the early diagnostic value of technetium 99m-methoxyisobutylisonitrile ((99)Tc(m)-MIBI) gated myocardial perfusion imaging (G-MPI) for MD. Ninety-one patients underwent (99)Tc(m)-MIBI G-MPI examinations when they were diagnosed with Duchenne muscular dystrophy (DMD) (n=77) or Becker muscular dystrophy (BMD; n=14). (99)Tc(m)-MIBI G-MPI examinations were repeated in 43 DMD patients who received steroid treatments for 2 years as a follow-up examination. Myocardial defects were observed in nearly every segment of the left ventricular wall in both DMD and BMD patients compared with controls, especially in the inferior walls and the apices by using (99)Tc(m)-MIBI G-MPI. Cardiac wall movement impairment significantly correlated with age in the DMD and BMD groups (r s=0.534 [P<0.05] and r s=0.784 [P<0.05], respectively). Intermittent intravenous doses of glucocorticoids and continuation with oral steroid treatments significantly improved myocardial function in DMD patients (P<0.05), but not in BMD patients. (99)Tc(m)-MIBI G-MPI is a sensitive and safe approach for early evaluation of cardiomyopathy in patients with DMD or BMD, and can serve as a candidate method for the evaluation of progression, prognosis, and assessment of the effect of glucocorticoid treatment in these patients.

Nuclear cardiology practices and radiation exposure in Africa: results from the IAEA Nuclear Cardiology Protocols Study (INCAPS)

PubMed Central

Bouyoucef, Salah E; Mercuri, Mathew; Einstein, Andrew J; Pascual, Thomas NB; Kashyap, Ravi; Dondi, Maurizio; Paez, Diana; Allam, Adel H; Vangu, Mboyo; Vitola, João V; Better, Nathan; Karthikeyan, Ganesan; Mahmarian, John J; Rehani, Madan M; Einstein, Andrew J

2017-01-01

Summary Objective: While nuclear myocardial perfusion imaging (MPI) offers many benefits to patients with known or suspected cardiovascular disease, concerns exist regarding radiationassociated health effects. Little is known regarding MPI practice in Africa. We sought to characterise radiation doses and the use of MPI best practices that could minimise radiation in African nuclear cardiology laboratories, and compare these to practice worldwide. Methods: Demographics and clinical characteristics were collected for a consecutive sample of 348 patients from 12 laboratories in six African countries over a one-week period from March to April 2013. Radiation effective dose (ED) was estimated for each patient. A quality index (QI) enumerating adherence to eight best practices, identified a priori by an IAEA expert panel, was calculated for each laboratory. We compared these metrics with those from 7 563 patients from 296 laboratories outside Africa. Results: to that of the rest of the world [9.1 (5.1–15.6) vs 10.3 mSv (6.8–12.6), p = 0.14], although a larger proportion of African patients received a low ED, ≤ 9 mSv targeted in societal recommendations (49.7 vs 38.2%, p < 0.001). Bestpractice adherence was higher among African laboratories (QI score: 6.3 ± 1.2 vs 5.4 ± 1.3, p = 0.013). However, median ED varied significantly among African laboratories (range: 2.0–16.3 mSv; p < 0.0001) and QI range was 4–8. Conclusion: Patient radiation dose from MPI in Africa was similar to that in the rest of the world, and adherence to best practices was relatively high in African laboratories. Nevertheless there remain opportunities to further reduce radiation exposure to African patients from MPI. PMID:28906538

Constraining a land-surface model with multiple observations by application of the MPI-Carbon Cycle Data Assimilation System V1.0

NASA Astrophysics Data System (ADS)

Schürmann, Gregor J.; Kaminski, Thomas; Köstler, Christoph; Carvalhais, Nuno; Voßbeck, Michael; Kattge, Jens; Giering, Ralf; Rödenbeck, Christian; Heimann, Martin; Zaehle, Sönke

2016-09-01

We describe the Max Planck Institute Carbon Cycle Data Assimilation System (MPI-CCDAS) built around the tangent-linear version of the JSBACH land-surface scheme, which is part of the MPI-Earth System Model v1. The simulated phenology and net land carbon balance were constrained by globally distributed observations of the fraction of absorbed photosynthetically active radiation (FAPAR, using the TIP-FAPAR product) and atmospheric CO2 at a global set of monitoring stations for the years 2005 to 2009. When constrained by FAPAR observations alone, the system successfully, and computationally efficiently, improved simulated growing-season average FAPAR, as well as its seasonality in the northern extra-tropics. When constrained by atmospheric CO2 observations alone, global net and gross carbon fluxes were improved, despite a tendency of the system to underestimate tropical productivity. Assimilating both data streams jointly allowed the MPI-CCDAS to match both observations (TIP-FAPAR and atmospheric CO2) equally well as the single data stream assimilation cases, thereby increasing the overall appropriateness of the simulated biosphere dynamics and underlying parameter values. Our study thus demonstrates the value of multiple-data-stream assimilation for the simulation of terrestrial biosphere dynamics. It further highlights the potential role of remote sensing data, here the TIP-FAPAR product, in stabilising the strongly underdetermined atmospheric inversion problem posed by atmospheric transport and CO2 observations alone. Notwithstanding these advances, the constraint of the observations on regional gross and net CO2 flux patterns on the MPI-CCDAS is limited through the coarse-scale parametrisation of the biosphere model. We expect improvement through a refined initialisation strategy and inclusion of further biosphere observations as constraints.

Does classification of persons with fibromyalgia into Multidimensional Pain Inventory subgroups detect differences in outcome after a standard chronic pain management program?

PubMed Central

Verra, Martin L; Angst, Felix; Brioschi, Roberto; Lehmann, Susanne; Keefe, Francis J; Staal, J Bart; de Bie, Rob A; Aeschlimann, André

2009-01-01

INTRODUCTION: The present study aimed to replicate and validate the empirically derived subgroup classification based on the Multidimensional Pain Inventory (MPI) in a sample of highly disabled fibromyalgia (FM) patients. Second, it examined how the identified subgroups differed in their response to an intensive, interdisciplinary inpatient pain management program. METHODS: Participants were 118 persons with FM who experienced persistent pain and were disabled. Subgroup classification was conducted by cluster analysis using MPI subscale scores at entry to the program. At program entry and discharge, participants completed the MPI, Medical Outcomes Study Short Form-36, Hospital Anxiety and Depression Scale and Coping Strategies Questionnaire. RESULTS: Cluster analysis identified three subgroups in the highly disabled sample that were similar to those described by other studies using less disabled samples of FM. The dysfunctional subgroup (DYS; 36% of the sample) showed the highest level of depression, the interpersonally distressed subgroup (ID; 24%) showed a modest level of depression and the adaptive copers subgroup (AC; 38%) showed the lowest depression scores in the MPI (negative mood), Medical Outcomes Study Short Form-36 (mental health), Hospital Anxiety and Depression Scale (depression) and Coping Strategies Questionnaire (catastrophizing). Significant differences in treatment outcome were observed among the three subgroups in terms of reduction of pain severity (as assessed using the MPI). The effect sizes were 1.42 for DYS, 1.32 for AC and 0.62 for ID (P=0.004 for pairwise comparison of ID-AC and P=0.018 for ID-DYS). DISCUSSION: These findings underscore the importance of assessing individuals’ differences in how they adjust to FM. PMID:20011715

Future cardiac events in patients with ischemic ECG changes during adenosine infusion as a myocardial stress agent and normal cardiac scan.

PubMed

Amer, Hamid; Niaz, Khalid; Hatazawa, Jun; Gasmelseed, Ahmed; Samiri, Hussain Al; Al Othman, Maram; Hammad, Mai Al

2017-11-01

We sought to determine the prognostic importance of adenosine-induced ischemic ECG changes in patients with normal single-photon emission computed tomography myocardial perfusion images (MPI). We carried out a retrospective analysis of 765 patients undergoing adenosine MPI between January 2013 and January 2015. Patients with baseline ECG abnormalities and/or abnormal scan were excluded. Overall, 67 (8.7%) patients had ischemic ECG changes during adenosine infusion in the form of ST depression of 1 mm or more. Of these, 29 [43% (3.8% of all patients)] had normal MPI (positive ECG group). An age-matched and sex-matched group of 108 patients with normal MPI without ECG changes served as control participants (negative ECG group). During a mean follow-up duration of 33.3±6.1 months, patients in the positive ECG group did not have significantly more adverse cardiac events than those in the negative ECG group. One (0.9%) patient in the negative ECG group had a nonfatal myocardial infarction (0.7% annual event rate after a negative MPI). Also in this group, two (1.8%) patients admitted with a diagnosis of CAD where they have been ruled out by angiography. A fourth case in this, in the negative ECG group, was admitted because of heart failure that proved to be secondary to a pulmonary cause and not CAD. A case only in the positive ECG group was admitted as a CAD that was ruled out by coronary angiography. Patients with normal myocardial perfusion scintigraphy in whom ST-segment depression develops during adenosine stress test appear to have no increased risk for future cardiac events compared with similar patients without ECG evidence of ischemia.

Nonlinear characterization of silver nanocrystals incorporated tellurite glasses for fiber development

NASA Astrophysics Data System (ADS)

Zhou, Zhiguang; Tan, Wenjiang; Si, Jinhai; Zhan, Huan; He, Jianli; Lin, Aoxiang

2011-12-01

To develop high nonlinear optical fibers for all-optical switching applications, 7.5 wt% AgNO3 was incorporated into tellurite glasses with composition of 75TeO2-20ZnO-5Na2CO3 (TZN75) under precisely-controlled experimental conditions to form 7.5Ag-TZN75 glass. Surface Plasmon resonance absorption peak of Ag nanocrystals embedded in 7.5Ag-TZN75 glass was found to center at 552 nm. By degenerated four-wave mixing method, the non-resonant nonlinear refractive index, n2, of 7.5Ag-TZN75 glass was measured to be 7.54×10-19 m2•W-1 at 1500 nm, about 3 times of the reference TZN75 glass without any dopant and 27 times of the silicate glasses and fibers, and the response time is about 1 picosecond.

Assessing the contribution of different factors in RegCM4.3 regional climate model projections using the Factor Separation method over the Med-CORDEX domain

NASA Astrophysics Data System (ADS)

Zsolt Torma, Csaba; Giorgi, Filippo

2014-05-01

A set of regional climate model (RCM) simulations applying dynamical downscaling of global climate model (GCM) simulations over the Mediterranean domain specified by the international initiative Coordinated Regional Downscaling Experiment (CORDEX) were completed with the Regional Climate Model RegCM, version RegCM4.3. Two GCMs were selected from the Coupled Model Intercomparison Project Phase 5 (CMIP5) ensemble to provide the driving fields for the RegCM: HadGEM2-ES (HadGEM) and MPI-ESM-MR (MPI). The simulations consist of an ensemble including multiple physics configurations and different "Reference Concentration Pathways" (RCP4.5 and RCP8.5). In total 15 simulations were carried out with 7 model physics configurations with varying convection and land surface schemes. The horizontal grid spacing of the RCM simulations is 50 km and the simulated period in all cases is 1970-2100 (1970-2099 in case of HadGEM driven simulations). This ensemble includes a combination of experiments in which different model components are changed individually and in combination, and thus lends itself optimally to the application of the Factor Separation (FS) method. This study applies the FS method to investigate the contributions of different factors, along with their synergy, on a set of regional climate model (RCM) projections for the Mediterranean region. The FS method is applied to 6 projections for the period 1970-2100 performed with the regional model RegCM4.3 over the Med-CORDEX domain. Two different sets of factors are intercompared, namely the driving global climate model (HadGEM and MPI) boundary conditions against two model physics settings (convection scheme and irrigation). We find that both the GCM driving conditions and the model physics provide important contributions, depending on the variable analyzed (surface air temperature and precipitation), season (winter vs. summer) and time horizon into the future, while the synergy term mostly tends to counterbalance the contributions of the individual factors. We demonstrate the usefulness of the FS method to assess different sources of uncertainty in RCM-based regional climate projections.

Magnetic particle imaging: from proof of principle to preclinical applications

NASA Astrophysics Data System (ADS)

Knopp, T.; Gdaniec, N.; Möddel, M.

2017-07-01

Tomographic imaging has become a mandatory tool for the diagnosis of a majority of diseases in clinical routine. Since each method has its pros and cons, a variety of them is regularly used in clinics to satisfy all application needs. Magnetic particle imaging (MPI) is a relatively new tomographic imaging technique that images magnetic nanoparticles with a high spatiotemporal resolution in a quantitative way, and in turn is highly suited for vascular and targeted imaging. MPI was introduced in 2005 and now enters the preclinical research phase, where medical researchers get access to this new technology and exploit its potential under physiological conditions. Within this paper, we review the development of MPI since its introduction in 2005. Besides an in-depth description of the basic principles, we provide detailed discussions on imaging sequences, reconstruction algorithms, scanner instrumentation and potential medical applications.

Reference-point-independent dynamics of molecular liquids and glasses in the tensorial formalism

NASA Astrophysics Data System (ADS)

Schilling, Rolf

2002-05-01

We apply the tensorial formalism to the dynamics of molecular liquids and glasses. This formalism separates the degrees of freedom into translational and orientational ones. Using the Mori-Zwanzig projection formalism, the equations of motion for the tensorial density correlators Slmn,l'm'n'(q-->,t) are derived. For this we show how to choose the slow variables such that the resulting Mori-Zwanzig equations are covariant under a change of the reference point of the body fixed frame. We also prove that the memory kernels obtained from mode-coupling theory (MCT) including all approximations preserve the covariance. This covariance makes, e.g., the glass transition point, the two universal scaling laws and particularly the corresponding exponents independent on the reference point and on the mass and moments of inertia, i.e., they only depend on the properties of the potential energy landscape. Finally, we show that the corresponding MCT questions for linear molecules can be obtained from those for arbitrary molecules and that they differ from earlier equations that are not covariant.

Military Interoperable Digital Hospital Testbed

DTIC Science & Technology

2012-07-01

Subject outcome measures include blood pressure, waist circumference, weight, body mass index (BMI), body fat, HDL cholesterol, triglycerides , glucose ...master patient index (MPI), 625 duplicate chest x-rays and CT scans of the head between sending and receiving institution (taken within 0-7 days) were... Index (MPI) software. The report included chest x-rays (CPT 71010 and 71020) and CT scans of the head (CPT 70450) for the stated time periods. The

Lactoferrin conjugated iron oxide nanoparticles for targeting brain glioma cells in magnetic particle imaging

NASA Astrophysics Data System (ADS)

Tomitaka, Asahi; Arami, Hamed; Gandhi, Sonu; Krishnan, Kannan M.

2015-10-01

Magnetic Particle Imaging (MPI) is a new real-time imaging modality, which promises high tracer mass sensitivity and spatial resolution directly generated from iron oxide nanoparticles. In this study, monodisperse iron oxide nanoparticles with median core diameters ranging from 14 to 26 nm were synthesized and their surface was conjugated with lactoferrin to convert them into brain glioma targeting agents. The conjugation was confirmed with the increase of the hydrodynamic diameters, change of zeta potential, and Bradford assay. Magnetic particle spectrometry (MPS), performed to evaluate the MPI performance of these nanoparticles, showed no change in signal after lactoferrin conjugation to nanoparticles for all core diameters, suggesting that the MPI signal is dominated by Néel relaxation and thus independent of hydrodynamic size difference or presence of coating molecules before and after conjugations. For this range of core sizes (14-26 nm), both MPS signal intensity and spatial resolution improved with increasing core diameter of nanoparticles. The lactoferrin conjugated iron oxide nanoparticles (Lf-IONPs) showed specific cellular internalization into C6 cells with a 5-fold increase in MPS signal compared to IONPs without lactoferrin, both after 24 h incubation. These results suggest that Lf-IONPs can be used as tracers for targeted brain glioma imaging using MPI.

Nanoparticle encapsulation in red blood cells enables blood-pool magnetic particle imaging hours after injection

NASA Astrophysics Data System (ADS)

Rahmer, J.; Antonelli, A.; Sfara, C.; Tiemann, B.; Gleich, B.; Magnani, M.; Weizenecker, J.; Borgert, J.

2013-06-01

Magnetic particle imaging (MPI) is a new medical imaging approach that is based on the nonlinear magnetization response of super-paramagnetic iron oxide nanoparticles (SPIOs) injected into the blood stream. To date, real-time MPI of the bolus passage of an approved MRI SPIO contrast agent injected into the tail vein of living mice has been demonstrated. However, nanoparticles are rapidly removed from the blood stream by the mononuclear phagocyte system. Therefore, imaging applications for long-term monitoring require the repeated administration of bolus injections, which complicates quantitative comparisons due to the temporal variations in concentration. Encapsulation of SPIOs into red blood cells (RBCs) has been suggested to increase the blood circulation time of nanoparticles. This work presents first evidence that SPIO-loaded RBCs can be imaged in the blood pool of mice several hours after injection using MPI. This finding is supported by magnetic particle spectroscopy performed to quantify the iron concentration in blood samples extracted from the mice 3 and 24 h after injection of SPIO-loaded RBCs. Based on these results, new MPI applications can be envisioned, such as permanent 3D real-time visualization of the vessel tree during interventional procedures, bleeding monitoring after stroke, or long-term monitoring and treatment control of cardiovascular diseases.

Implementing Multidisciplinary and Multi-Zonal Applications Using MPI

NASA Technical Reports Server (NTRS)

Fineberg, Samuel A.

1995-01-01

Multidisciplinary and multi-zonal applications are an important class of applications in the area of Computational Aerosciences. In these codes, two or more distinct parallel programs or copies of a single program are utilized to model a single problem. To support such applications, it is common to use a programming model where a program is divided into several single program multiple data stream (SPMD) applications, each of which solves the equations for a single physical discipline or grid zone. These SPMD applications are then bound together to form a single multidisciplinary or multi-zonal program in which the constituent parts communicate via point-to-point message passing routines. Unfortunately, simple message passing models, like Intel's NX library, only allow point-to-point and global communication within a single system-defined partition. This makes implementation of these applications quite difficult, if not impossible. In this report it is shown that the new Message Passing Interface (MPI) standard is a viable portable library for implementing the message passing portion of multidisciplinary applications. Further, with the extension of a portable loader, fully portable multidisciplinary application programs can be developed. Finally, the performance of MPI is compared to that of some native message passing libraries. This comparison shows that MPI can be implemented to deliver performance commensurate with native message libraries.

Determining post-test risk in a national sample of stress nuclear myocardial perfusion imaging reports: Implications for natural language processing tools.

PubMed

Levy, Andrew E; Shah, Nishant R; Matheny, Michael E; Reeves, Ruth M; Gobbel, Glenn T; Bradley, Steven M

2018-04-25

Reporting standards promote clarity and consistency of stress myocardial perfusion imaging (MPI) reports, but do not require an assessment of post-test risk. Natural Language Processing (NLP) tools could potentially help estimate this risk, yet it is unknown whether reports contain adequate descriptive data to use NLP. Among VA patients who underwent stress MPI and coronary angiography between January 1, 2009 and December 31, 2011, 99 stress test reports were randomly selected for analysis. Two reviewers independently categorized each report for the presence of critical data elements essential to describing post-test ischemic risk. Few stress MPI reports provided a formal assessment of post-test risk within the impression section (3%) or the entire document (4%). In most cases, risk was determinable by combining critical data elements (74% impression, 98% whole). If ischemic risk was not determinable (25% impression, 2% whole), inadequate description of systolic function (9% impression, 1% whole) and inadequate description of ischemia (5% impression, 1% whole) were most commonly implicated. Post-test ischemic risk was determinable but rarely reported in this sample of stress MPI reports. This supports the potential use of NLP to help clarify risk. Further study of NLP in this context is needed.

Recent developments in bend-insensitive and ultra-bend-insensitive fibers

NASA Astrophysics Data System (ADS)

Boivin, David; de Montmorillon, Louis-Anne; Provost, Lionel; Montaigne, Nelly; Gooijer, Frans; Aldea, Eugen; Jensma, Jaap; Sillard, Pierre

2010-02-01

Designed to overcome the limitations in case of extreme bending conditions, Bend- and Ultra-Bend-Insensitive Fibers (BIFs and UBIFs) appear as ideal solutions for use in FTTH networks and in components, pigtails or patch-cords for ever demanding applications such as military or sensing. Recently, however, questions have been raised concerning the Multi-Path-Interference (MPI) levels in these fibers. Indeed, they are potentially subject to interferences between the fundamental mode and the higher-order mode that is also bend resistant. This MPI is generated because of discrete discontinuities such as staples, bends and splices/connections that occur on distance scales that become comparable to the laser coherent length. In this paper, we will demonstrate the high MPI tolerance of all-solid single-trench-assisted BIFs and UBIFs. We will present the first comprehensive study combining theoretical and experimental points of view to quantify the impact of fusion splices on coherent MPI. To be complete, results for mechanical splices will also be reported. Finally, we will show how the single-trench- assisted concept combined with the versatile PCVD process allows to tightly control the distributions of fibers characteristics. Such controls are needed to massively produce BIFs and to meet the more stringent specifications of the UBIFs.

Toward Abstracting the Communication Intent in Applications to Improve Portability and Productivity

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

Mintz, Tiffany M; Hernandez, Oscar R; Kartsaklis, Christos

Programming with communication libraries such as the Message Passing Interface (MPI) obscures the high-level intent of the communication in an application and makes static communication analysis difficult to do. Compilers are unaware of communication libraries specifics, leading to the exclusion of communication patterns from any automated analysis and optimizations. To overcome this, communication patterns can be expressed at higher-levels of abstraction and incrementally added to existing MPI applications. In this paper, we propose the use of directives to clearly express the communication intent of an application in a way that is not specific to a given communication library. Our communicationmore » directives allow programmers to express communication among processes in a portable way, giving hints to the compiler on regions of computations that can be overlapped with communication and relaxing communication constraints on the ordering, completion and synchronization of the communication imposed by specific libraries such as MPI. The directives can then be translated by the compiler into message passing calls that efficiently implement the intended pattern and be targeted to multiple communication libraries. Thus far, we have used the directives to express point-to-point communication patterns in C, C++ and Fortran applications, and have translated them to MPI and SHMEM.« less

Atmospheric corrosion performance of different steels in early exposure in the coastal area region West Java, Indonesia

NASA Astrophysics Data System (ADS)

Nuraini, Lutviasari; Prifiharni, Siska; Priyotomo, Gadang; Sundjono, Gunawan, Hadi; Purawiardi, Ibrahim

2018-05-01

The performance of carbon steel, galvanized steel and aluminium after one month exposed in the atmospheric coastal area, which is in Limbangan and Karangsong Beach, West Java, Indonesia was evaluated. The corrosion rate was determined by weight loss method and the morphology of the steel after exposed was observed by Scanning Electron Microscopy(SEM)/Energy Dispersive X-Ray Analysis(EDX). The site was monitored to determine the chloride content in the marine atmosphere. Then, the corrosion products formed at carbon steel were characterized by X-Ray diffraction (XRD). The result showed the aggressively corrosion in Karangsong beach, indicated from the corrosion rate of carbon steel, galvanized steel and aluminium were 38.514 mpy; 4.7860 mpy and 0.5181 mpy, respectively. While in Limbangan Beach the corrosion rate of specimen carbon steel, galvanized steel and aluminium were 3.339; 0.219 and 0.166 mpy, respectively. The chloride content was found to be the main factor that influences in the atmospheric corrosion process in this area. Chloride content accumulated in Karangsong and Limbangan was 497 mg/m2.day and 117 mg/m2.day, respectively. The XRD Analysis on each carbon steel led to the characterization of a complex mixture of iron oxides phases.

High frequency QRS ECG predicts ischemic defects during myocardial perfusion imaging

NASA Technical Reports Server (NTRS)

2004-01-01

Changes in high frequency QRS components of the electrocardiogram (HF QRS ECG) (150-250 Hz) are more sensitive than changes in conventional ST segments for detecting myocardial ischemia. We investigated the accuracy of 12-lead HF QRS ECG in detecting ischemia during adenosine tetrofosmin myocardial perfusion imaging (MPI). 12-lead HF QRS ECG recordings were obtained from 45 patients before and during adenosine technetium-99 tetrofosmin MPI tests. Before the adenosine infusions, recordings of HF QRS were analyzed according to a morphological score that incorporated the number, type and location of reduced amplitude zones (RAZs) present in the 12 leads. During the adenosine infusions, recordings of HF QRS were analyzed according to the maximum percentage changes (in both the positive and negative directions) that occurred in root mean square (RMS) voltage amplitudes within the 12 leads. The best set of prospective HF QRS criteria had a sensitivity of 94% and a specificity of 83% for correctly identifying the MPI result. The sensitivity of simultaneous ST segment changes (18%) was significantly lower than that of any individual HF QRS criterion (P less than 0.00l). Analysis of 12-lead HF QRS ECG is highly sensitive and specific for detecting ischemic perfusion defects during adenosine MPI stress tests and significantly more sensitive than analysis of conventional ST segments.

High frequency QRS ECG predicts ischemic defects during myocardial perfusion imaging

NASA Technical Reports Server (NTRS)

Rahman, Atiar

2006-01-01

Background: Changes in high frequency QRS components of the electrocardiogram (HF QRS ECG) (150-250 Hz) are more sensitive than changes in conventional ST segments for detecting myocardial ischemia. We investigated the accuracy of 12-lead HF QRS ECG in detecting ischemia during adenosine tetrofosmin myocardial perfusion imaging (MPI). Methods and Results: 12-lead HF QRS ECG recordings were obtained from 45 patients before and during adenosine technetium-99 tetrofosmin MPI tests. Before the adenosine infusions, recordings of HF QRS were analyzed according to a morphological score that incorporated the number, type and location of reduced amplitude zones (RAZs) present in the 12 leads. During the adenosine infusions, recordings of HF QRS were analyzed according to the maximum percentage changes (in both the positive and negative directions) that occurred in root mean square (RMS) voltage amplitudes within the 12 leads. The best set of prospective HF QRS criteria had a sensitivity of 94% and a specificity of 83% for correctly identifying the MPI result. The sensitivity of simultaneous ST segment changes (18%) was significantly lower than that of any individual HF QRS criterion (P<0.001). Conclusions: Analysis of 12-lead HF QRS ECG is highly sensitive and specific for detecting ischemic perfusion defects during adenosine MPI stress tests and significantly more sensitive than analysis of conventional ST segments.

An automated protocol for performance benchmarking a widefield fluorescence microscope.

PubMed

Halter, Michael; Bier, Elianna; DeRose, Paul C; Cooksey, Gregory A; Choquette, Steven J; Plant, Anne L; Elliott, John T

2014-11-01

Widefield fluorescence microscopy is a highly used tool for visually assessing biological samples and for quantifying cell responses. Despite its widespread use in high content analysis and other imaging applications, few published methods exist for evaluating and benchmarking the analytical performance of a microscope. Easy-to-use benchmarking methods would facilitate the use of fluorescence imaging as a quantitative analytical tool in research applications, and would aid the determination of instrumental method validation for commercial product development applications. We describe and evaluate an automated method to characterize a fluorescence imaging system's performance by benchmarking the detection threshold, saturation, and linear dynamic range to a reference material. The benchmarking procedure is demonstrated using two different materials as the reference material, uranyl-ion-doped glass and Schott 475 GG filter glass. Both are suitable candidate reference materials that are homogeneously fluorescent and highly photostable, and the Schott 475 GG filter glass is currently commercially available. In addition to benchmarking the analytical performance, we also demonstrate that the reference materials provide for accurate day to day intensity calibration. Published 2014 Wiley Periodicals Inc. Published 2014 Wiley Periodicals Inc. This article is a US government work and, as such, is in the public domain in the United States of America.

NASA Tech Briefs, April 2008

NASA Technical Reports Server (NTRS)

2008-01-01

Topics covered include: Gas Sensors Based on Coated and Doped Carbon Nanotubes; Tactile Robotic Topographical Mapping Without Force or Contact Sensors; Thin-Film Magnetic-Field-Response Fluid-Level Sensor for Non-Viscous Fluids; Progress in Development of Improved Ion-Channel Biosensors; Simulating Operation of a Complex Sensor Network; Using Transponders on the Moon to Increase Accuracy of GPS; Controller for Driving a Piezoelectric Actuator at Resonance; Coaxial Electric Heaters; Dual-Input AND Gate From Single-Channel Thin-Film FET; High-Density, High-Bandwidth, Multilevel Holographic Memory; Fabrication of Gate-Electrode Integrated Carbon-Nanotube Bundle Field Emitters; Hydroxide-Assisted Bonding of Ultra-Low-Expansion Glass; Photochemically Synthesized Polyimides; Optimized Carbonate and Ester-Based Li-Ion Electrolytes; Compact 6-DOF Stage for Optical Adjustments; Ultrasonic/Sonic Impacting Penetrators; Miniature, Lightweight, One-Time-Opening Valve; Supplier Management System; Improved CLARAty Functional-Layer/Decision-Layer Interface; JAVA Stereo Display Toolkit; Remote-Sensing Time Series Analysis, a Vegetation Monitoring Tool; PyPele Rewritten To Use MPI; Data Assimilation Cycling for Weather Analysis; Hydrocyclone/Filter for Concentrating Biomarkers from Soil; Activating STAT3 Alpha for Promoting Healing of Neurons; and Probing a Spray Using Frequency-Analyzed Light Scattering.

Molecular Dynamics Simulation Study of the Capacitive Performance of a Binary Mixture of Ionic Liquids near an Onion-like Carbon Electrode.

PubMed

Li, Song; Feng, Guang; Fulvio, Pasquale F; Hillesheim, Patrick C; Liao, Chen; Dai, Sheng; Cummings, Peter T

2012-09-06

An equimolar mixture of 1-methyl-1-propylpyrrolidinium bis(trifluoromethylsulfonyl)imide ([C3mpy][Tf2N]), 1-methyl-1-butylpiperidinium bis(trifluoromethylsulfonyl)imide ([C4mpip][Tf2N]) was investigated by classic molecular dynamics (MD) simulation. Differential scanning calorimetry (DSC) measurements verified that the binary mixture exhibited lower glass transition temperature than either of the pure room-temperature ionic liquids (RTILs). Moreover, the binary mixture gave rise to higher conductivity than the neat RTILs at lower temperature range. In order to study its capacitive performance in supercapacitors, simulations were performed of the mixture, and the neat RTILs used as electrolytes near an onion-like carbon (OLC) electrode at varying temperatures. The differential capacitance exhibited independence of the electrical potential applied for three electrolytes, which is in agreement with previous work on OLC electrodes in a different RTILs. Positive temperature dependence of the differential capacitance was observed, and it was dominated by the electrical double layer (EDL) thickness, which is for the first time substantiated in MD simulation.

Remote sensing of a coupled carbon-water-energy-radiation balances from the Globe to plot scales

NASA Astrophysics Data System (ADS)

Ryu, Y.; Jiang, C.; Huang, Y.; Kim, J.; Hwang, Y.; Kimm, H.; Kim, S.

2016-12-01

Advancements in near-surface and satellite remote sensing technologies have enabled us to monitor the global terrestrial ecosystems at multiple spatial and temporal scales. An emergent challenge is how to formulate a coupled water, carbon, energy, radiation, and nitrogen cycles from remote sensing. Here, we report Breathing Earth System Simulator (BESS), which coupled radiation (shortwave, longwave, PAR, diffuse PAR), carbon (gross primary productivity, ecosystem respiration, net ecosystem exchange), water (evaporation), and energy (latent and sensible heat) balances across the global land at 1 km resolution, 8 daily between 2000 and 2015 using multiple satellite remote sensing. The performance of BESS was tested against field observations (FLUXNET, BSRN) and other independent products (MPI-BGC, MODIS, GLASS). We found that the coupled model, BESS showed on par with, or better performance than the other products which computed land surface fluxes individually. Lastly, we show one plot-level study conducted in a paddy rice to demonstrate how to couple radiation, carbon, water, nitrogen balances with a series of near-surface spectral sensors.

High Performance Pillared Vanadium Oxide Cathode for Lithium Ion Batteries

DTIC Science & Technology

2015-04-24

As a result, two major approaches have been taken to increase electrode- electrolyte interfacial area while minimizing lithium diffusion lengths...Performance Pillared Vanadium Oxide Cathode for Lithium Ion Batteries Siu on Tung, Krista L. Hawthorne, Yi Ding, James Mainero, and Levi T. Thompson...Automotive Research Development and Engineering Center, Warren, MI 48387, USA Keywords: nanostructured materials, lithium ion batteries, cathode

HOXC9-Induced Differentiation in Neuroblastoma Development

DTIC Science & Technology

2014-10-01

Neuroblastoma Development PRINCIPAL INVESTIGATOR: Han-Fei Ding RECIPIENT: Georgia Health Sciences University Research Institute, Inc... Neuroblastoma  Development   5a. CONTRACT NUMBER 5b. GRANT NUMBER W81XWH-12-1-0613 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S...role in determining the differentiation states of neuroblastoma tumors, with higher levels of HOXC9 promoting differentiation. At the cellular level

The p53-Deficient Mouse as a Breast Cancer Model

DTIC Science & Technology

1995-10-01

M.A. Gryka , F.Z. Bischoff, M.A. Tain- Halachmi, R.T. Bronson, and R.A. Weinberg. 1994. Tumor sky, and S.H. Friend. 1990. Germ line p53 mutations in a...J. Kassel, M.A. Gryka , F.Z. Bischoff, Weaver-Feldhaus, W. Ding, Z. Gholami, P. Soderkvist, L. M.A. Tainsky, and S.H. Friend. 1990. Germ line p53

In Search of a Good Critique

ERIC Educational Resources Information Center

Perlmutter, David D.

2013-01-01

Some job candidates seem to be doing well only to fall flat in one venue: They ace the teaching demo and the dinner meeting, but stumble during the research talk. Perhaps the candidate was disorganized, too strident, or just long-winded and boring. Whatever the cause, the outcome is a strong negative ding when it comes time to vote on the hire.…

In the eyes of the beholder: Understanding subtypes of social withdrawal among young Chinese children.

PubMed

Cheah, Charissa S L; Xu, Yiyuan

2015-06-01

In this commentary on Ding et al. (Brit. J. Dev. Psychol., 2015; 33, 159-173), we focus on the following: (1) the authors' use of vignettes portraying various prototypes of withdrawn children and (2) the cultural interpretation of their findings. We end with some suggestions for future research. © 2015 The British Psychological Society.

Micro-PIXE analysis of silicate reference standards

USGS Publications Warehouse

Czamanske, G.K.; Sisson, T.W.; Campbell, J.L.; Teesdale, W.J.

1993-01-01

The accuracy and precision of the University of Guelph proton microprobe have been evaluated through trace-element analysis of well-characterized silicate glasses and minerals, including BHVO-1 glass, Kakanui augite and hornblende, and ten other natural samples of volcanic glass, amphibole, pyroxene, and garnet. Using the 2.39 wt% Mo in a NIST steel as the standard, excellent precision and agreement between reported and analyzed abundances were obtained for Fe, Ni, Cu, Zn, Ga, Rb, Sr, Y, Zr, and Nb. -from Authors

Size, Shape, and Arrangement of Cellulose Microfibril in Higher Plant Cell Walls

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

Ding, S. Y.

2013-01-01

Plant cell walls from maize (Zea mays L.) are imaged using atomic force microscopy (AFM) at the sub-nanometer resolution. We found that the size and shape of fundamental cellulose elementary fibril (CEF) is essentially identical in different cell wall types, i.e., primary wall (PW), parenchyma secondary wall (pSW), and sclerenchyma secondary wall (sSW), which is consistent with previously proposed 36-chain model (Ding et al., 2006, J. Agric. Food Chem.). The arrangement of individual CEFs in these wall types exhibits two orientations. In PW, CEFs are horizontally associated through their hydrophilic faces, and the planar faces are exposed, forming ribbon-like macrofibrils.more » In pSW and sSW, CEFs are vertically oriented, forming layers, in which hemicelluloses are interacted with the hydrophobic faces of the CEF and serve as spacers between CEFs. Lignification occurs between CEF-hemicelluloses layers in secondary walls. Furthermore, we demonstrated quantitative analysis of plant cell wall accessibility to and digestibility by different cellulase systems at real-time using chemical imaging (e.g., stimulated Raman scattering) and fluorescence microscopy of labeled cellulases (Ding et al., 2012, Science, in press).« less

Managers' Beliefs about the Glass Ceiling: Interpersonal and Organizational Factors

ERIC Educational Resources Information Center

Elacqua, Tina C.; Beehr, Terry A.; Hansen, Curtiss P.; Webster, Jennica

2009-01-01

The glass ceiling refers to the difficulty of women trying to be promoted into the top management levels. The present study examined managers' potential explanations, implicit or explicit, for why women rarely reach the top hierarchical levels in their own organization. Among 685 managers at a large Midwestern insurance company, a model was…

Fabrication and characterization of high impact hybrid matrix composites from thermoset resin and dyneema-glass fabric reinforcement

NASA Astrophysics Data System (ADS)

Patel, R. H.; Sharma, S.; Pansuriya, T.; Malgani, E. V.; Sevkani, V.

2018-05-01

Hybrid composites have been fabricated by hand lay-up technique with epoxy resin and diethylene tri amine as a hardener for high impact energy absorption with sandwich stacking of different reinforcements of dyneema and glass fabric. High impact grade composites are nowadays gaining a lot of importance in the field of high mechanical load bearing applications, ballistics and bulletproofing. The present work emphases on the fabrication and mechanical properties of the hybrid composites of cut resistant dyneema fabric along with glass fabric reinforced in the thermosetting resin. i.e. epoxy. The prime importance while fabricating such materials have been given to the processing along with selection of the raw materials. High impact resistive materials with low density and henceforth low weight have been manufactured and characterized by IZOD impact tester, UTM, Archimedes density meter and SEM. Throughout the work, satisfactory results have been obtained. Impact resistance was observed to be boosted three times as that of the reference sample of glass fabric and epoxy. The density of the hybrid composite is observed to be 25% as that of the reference sample.

Characterization and optimization of a new high-average power laser glass

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

Bayramian, A.

A new High-Average Power laser glass with favorable thermal-mechanical properties was recently developed by Schott Glass Technologies. We refer to this glass as APG-2, although it does not have an official designation. Fracture studies were conducted which verified the thermomechanical utility of the glass. Consequently, the glass was a promising candidate for a variety of applications such as a Kerr-lens mode-locked short-pulse laser. As a result, cavity designs and optical parameters were calculated to test this hypothesis, and characterization of the lasing properties began. The glass was lased for the first time, and laser slope efficiencies were measured at variousmore » output couplings. Laser efficiencies were observed to drop radically when the pump light duty cycle was increased from 10% to unity. When the new laser glass was compared to commercially available laser glasses LG-750 and APG-1, something appeared to be inhibiting smooth laser action. Further investigations indicated that the thermal lens in the new glass was much larger than in the other glasses making the laser resonator unstable. This thermal lens was then modeled and quantified in a separate experiment.« less

Fortran code for SU(3) lattice gauge theory with and without MPI checkerboard parallelization

NASA Astrophysics Data System (ADS)

Berg, Bernd A.; Wu, Hao

2012-10-01

We document plain Fortran and Fortran MPI checkerboard code for Markov chain Monte Carlo simulations of pure SU(3) lattice gauge theory with the Wilson action in D dimensions. The Fortran code uses periodic boundary conditions and is suitable for pedagogical purposes and small scale simulations. For the Fortran MPI code two geometries are covered: the usual torus with periodic boundary conditions and the double-layered torus as defined in the paper. Parallel computing is performed on checkerboards of sublattices, which partition the full lattice in one, two, and so on, up to D directions (depending on the parameters set). For updating, the Cabibbo-Marinari heatbath algorithm is used. We present validations and test runs of the code. Performance is reported for a number of currently used Fortran compilers and, when applicable, MPI versions. For the parallelized code, performance is studied as a function of the number of processors. Program summary Program title: STMC2LSU3MPI Catalogue identifier: AEMJ_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEMJ_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 26666 No. of bytes in distributed program, including test data, etc.: 233126 Distribution format: tar.gz Programming language: Fortran 77 compatible with the use of Fortran 90/95 compilers, in part with MPI extensions. Computer: Any capable of compiling and executing Fortran 77 or Fortran 90/95, when needed with MPI extensions. Operating system: Red Hat Enterprise Linux Server 6.1 with OpenMPI + pgf77 11.8-0, Centos 5.3 with OpenMPI + gfortran 4.1.2, Cray XT4 with MPICH2 + pgf90 11.2-0. Has the code been vectorised or parallelized?: Yes, parallelized using MPI extensions. Number of processors used: 2 to 11664 RAM: 200 Mega bytes per process. Classification: 11.5. Nature of problem: Physics of pure SU(3) Quantum Field Theory (QFT). This is relevant for our understanding of Quantum Chromodynamics (QCD). It includes the glueball spectrum, topological properties and the deconfining phase transition of pure SU(3) QFT. For instance, Relativistic Heavy Ion Collision (RHIC) experiments at the Brookhaven National Laboratory provide evidence that quarks confined in hadrons undergo at high enough temperature and pressure a transition into a Quark-Gluon Plasma (QGP). Investigations of its thermodynamics in pure SU(3) QFT are of interest. Solution method: Markov Chain Monte Carlo (MCMC) simulations of SU(3) Lattice Gauge Theory (LGT) with the Wilson action. This is a regularization of pure SU(3) QFT on a hypercubic lattice, which allows approaching the continuum SU(3) QFT by means of Finite Size Scaling (FSS) studies. Specifically, we provide updating routines for the Cabibbo-Marinari heatbath with and without checkerboard parallelization. While the first is suitable for pedagogical purposes and small scale projects, the latter allows for efficient parallel processing. Targetting the geometry of RHIC experiments, we have implemented a Double-Layered Torus (DLT) lattice geometry, which has previously not been used in LGT MCMC simulations and enables inside and outside layers at distinct temperatures, the lower-temperature layer acting as the outside boundary for the higher-temperature layer, where the deconfinement transition goes on. Restrictions: The checkerboard partition of the lattice makes the development of measurement programs more tedious than is the case for an unpartitioned lattice. Presently, only one measurement routine for Polyakov loops is provided. Unusual features: We provide three different versions for the send/receive function of the MPI library, which work for different operating system +compiler +MPI combinations. This involves activating the correct row in the last three rows of our latmpi.par parameter file. The underlying reason is distinct buffer conventions. Running time: For a typical run using an Intel i7 processor, it takes (1.8-6) E-06 seconds to update one link of the lattice, depending on the compiler used. For example, if we do a simulation on a small (4 * 83) DLT lattice with a statistics of 221 sweeps (i.e., update the two lattice layers of 4 * (4 * 83) links each 221 times), the total CPU time needed can be 2 * 4 * (4 * 83) * 221 * 3 E-06 seconds = 1.7 minutes, where 2 — two layers of lattice 4 — four dimensions 83 * 4 — lattice size 221 — sweeps of updating 6 E-06 s mdash; average time to update one link variable. If we divide the job into 8 parallel processes, then the real time is (for negligible communication overhead) 1.7 mins / 8 = 0.2 mins.

A New Biocompatible and Antibacterial Phosphate Free Glass-Ceramic for Medical Applications

NASA Astrophysics Data System (ADS)

Cabal, Belén; Alou, Luís; Cafini, Fabio; Couceiro, Ramiro; Sevillano, David; Esteban-Tejeda, Leticia; Guitián, Francisco; Torrecillas, Ramón; Moya, José S.

2014-06-01

In the attempt to find valid alternatives to classic antibiotics and in view of current limitations in the efficacy of antimicrobial-coated or loaded biomaterials, this work is focused on the development of a new glass-ceramic with antibacterial performance together with safe biocompatibility. This bactericidal glass-ceramic composed of combeite and nepheline crystals in a residual glassy matrix has been obtained using an antimicrobial soda-lime glass as a precursor. Its inhibitory effects on bacterial growth and biofilm formation were proved against five biofilm-producing reference strains. The biocompatibility tests by using mesenchymal stem cells derived from human bone indicate an excellent biocompatibility.

A New Biocompatible and Antibacterial Phosphate Free Glass-Ceramic for Medical Applications

PubMed Central

Cabal, Belén; Alou, Luís; Cafini, Fabio; Couceiro, Ramiro; Sevillano, David; Esteban-Tejeda, Leticia; Guitián, Francisco; Torrecillas, Ramón; Moya, José S.

2014-01-01

In the attempt to find valid alternatives to classic antibiotics and in view of current limitations in the efficacy of antimicrobial-coated or loaded biomaterials, this work is focused on the development of a new glass-ceramic with antibacterial performance together with safe biocompatibility. This bactericidal glass-ceramic composed of combeite and nepheline crystals in a residual glassy matrix has been obtained using an antimicrobial soda-lime glass as a precursor. Its inhibitory effects on bacterial growth and biofilm formation were proved against five biofilm-producing reference strains. The biocompatibility tests by using mesenchymal stem cells derived from human bone indicate an excellent biocompatibility. PMID:24961911

Mesoscale Phase Field Modeling of Glass Strengthening Under Triaxial Compression

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

Li, Yulan; Sun, Xin

2015-09-28

Recent hydraulic bomb and confined sleeve tests on transparent armor glass materials such as borosilicate glass and soda-lime glass showed that the glass strength was a function of confinement pressure. The measured stress-strain relation is not a straight line as most brittle materials behave under little or no confinement. Moreover, borosilicate glass exhibited a stronger compressive strength when compared to soda-lime glass, even though soda-lime has higher bulk and shear moduli as well as apparent yield strength. To better understand these experimental findings, a mesoscale phase field model is developed to simulate the nonlinear stress versus strain behaviors under confinementmore » by considering heterogeneity formation under triaxial compression and the energy barrier of a micro shear banding event (referred to as pseudo-slip hereafter) in the amorphous glass. With calibrated modeling parameters, the simulation results demonstrate that the developed phase field model can quantitatively predict the pressure-dependent strength, and it can also explain the difference between the two types of glasses from the perspective of energy barrier associated with a pseudo-slip event.« less

Enhancing nurses' roles to improve quality and efficiency of non-medical cardiac stress tests.

PubMed

Bernhardt, Lizelle; Ross, Lisa; Greaves, Claire

Myocardial perfusion imaging (MPI) is a test that aids the diagnosis of coronary heart disease, of which pharmacological stress is a key component. An increase in demand had resulted in a 42 week waiting time for MPI in Leicester. This article looks at how implementing non-medically led stress tests reduced this waiting list. It discusses the obstacles involved and the measures needed to make the service a success.

Hybrid MPI+OpenMP Programming of an Overset CFD Solver and Performance Investigations

NASA Technical Reports Server (NTRS)

Djomehri, M. Jahed; Jin, Haoqiang H.; Biegel, Bryan (Technical Monitor)

2002-01-01

This report describes a two level parallelization of a Computational Fluid Dynamic (CFD) solver with multi-zone overset structured grids. The approach is based on a hybrid MPI+OpenMP programming model suitable for shared memory and clusters of shared memory machines. The performance investigations of the hybrid application on an SGI Origin2000 (O2K) machine is reported using medium and large scale test problems.

Indirect spectrophotometric determination of trace cyanide with cationic porphyrins.

PubMed

Ishii, H; Kohata, K

1991-05-01

Three highly sensitive methods for the determination of cyanide have been developed, based on the fact that the complexation of silver ions with three cationic porphyrins, 5,10,15,20-tetrakis-(1-methyl-2-pyridinio)porphine [T(2-MPy)P], 5,10,15,20-tetrakis(1-methyl-3-pyridinio)porphine [T(3-MPy)P] and 5,10,15,20-tetrakis(1-methyl-4-pyridinio)porphine [T(4-MPy)P], in alkaline media is inhibited by cyanide and the decrease in absorbance of the silver(II) complex is proportional to the cyanide concentration. Sensitivities of the procedures developed are 0.133, 0.126 and 0.234 ng/cm(2), respectively for an absorbance of 0.001. Cadmium(II), copper(II), mercury(II), zinc(II), iodide and sulfide interfere with the cyanide determination. One of the proposed methods was applied to the determination of cyanide in waste-water samples, with satisfactory results.

Potential Application of a Graphical Processing Unit to Parallel Computations in the NUBEAM Code

NASA Astrophysics Data System (ADS)

Payne, J.; McCune, D.; Prater, R.

2010-11-01

NUBEAM is a comprehensive computational Monte Carlo based model for neutral beam injection (NBI) in tokamaks. NUBEAM computes NBI-relevant profiles in tokamak plasmas by tracking the deposition and the slowing of fast ions. At the core of NUBEAM are vector calculations used to track fast ions. These calculations have recently been parallelized to run on MPI clusters. However, cost and interlink bandwidth limit the ability to fully parallelize NUBEAM on an MPI cluster. Recent implementation of double precision capabilities for Graphical Processing Units (GPUs) presents a cost effective and high performance alternative or complement to MPI computation. Commercially available graphics cards can achieve up to 672 GFLOPS double precision and can handle hundreds of thousands of threads. The ability to execute at least one thread per particle simultaneously could significantly reduce the execution time and the statistical noise of NUBEAM. Progress on implementation on a GPU will be presented.

Comparison of the oral and rectal mucosal and colonic serosal microcirculations of healthy, anesthetized horses.

PubMed

Kieffer, Philip J; Williams, Jarred M; Shepard, Molly K; Giguère, Steeve; Epstein, Kira L

2018-01-01

The objectives of the study were to: i) determine baseline microvascular perfusion indices (MPI) and assess their repeatability in healthy horses under general anesthesia, and ii) compare the MPIs of 3 microvascular beds (oral mucosa, colonic serosa, and rectal mucosa). Healthy adult horses were anesthetized and sidestream dark field microscopy was used to collect video loops of the oral mucosa, rectal mucosa, and colonic serosa under normotensive conditions without cardiovascular support drugs; videos were later analyzed to produce MPIs. Baseline MPI values were determined for each site, which included the total vessel density (TVD), perfused vessel density (PVD), portion perfused vessels (PPV), and microcirculatory flow index (MFI). Differences in MPIs between microvascular beds were not statistically significant. Repeatability of the measurements varied for each MPI. In particular, the site of sampling had a profound effect on the repeatability of the PPV measurements and should be considered in future studies.

Comparison of the oral and rectal mucosal and colonic serosal microcirculations of healthy, anesthetized horses

PubMed Central

Kieffer, Philip J.; Williams, Jarred M.; Shepard, Molly K.; Giguère, Steeve; Epstein, Kira L.

2018-01-01

The objectives of the study were to: i) determine baseline microvascular perfusion indices (MPI) and assess their repeatability in healthy horses under general anesthesia, and ii) compare the MPIs of 3 microvascular beds (oral mucosa, colonic serosa, and rectal mucosa). Healthy adult horses were anesthetized and sidestream dark field microscopy was used to collect video loops of the oral mucosa, rectal mucosa, and colonic serosa under normotensive conditions without cardiovascular support drugs; videos were later analyzed to produce MPIs. Baseline MPI values were determined for each site, which included the total vessel density (TVD), perfused vessel density (PVD), portion perfused vessels (PPV), and microcirculatory flow index (MFI). Differences in MPIs between microvascular beds were not statistically significant. Repeatability of the measurements varied for each MPI. In particular, the site of sampling had a profound effect on the repeatability of the PPV measurements and should be considered in future studies. PMID:29382969

Review of progress in magnetic particle inspection

NASA Astrophysics Data System (ADS)

Eisenmann, David J.; Enyart, Darrel; Lo, Chester; Brasche, Lisa

2014-02-01

Magnetic particle inspection (MPI) has been widely utilized for decades, and sees considerable use in the aerospace industry with a majority of the steel parts being inspected with MPI at some point in the lifecycle. Typical aircraft locations inspected are landing gear, engine components, attachment hardware, and doors. In spite of its numerous applications the method remains poorly understood, and there are many aspects of that method which would benefit from in-depth study. This shortcoming is due to the fact that MPI combines the complicated nature of electromagnetics, metallurgical material effects, fluid-particle motion dynamics, and physiological human factors into a single inspection. To promote understanding of the intricate method issues that affect sensitivity, or to assist with the revision of industry specifications and standards, research studies will be prioritized through the guidance of a panel of industry experts, using an approach which has worked successfully in the past to guide fluorescent penetrant inspection (FPI) research efforts.

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

Katti, Amogh; Di Fatta, Giuseppe; Naughton III, Thomas J

Future extreme-scale high-performance computing systems will be required to work under frequent component failures. The MPI Forum's User Level Failure Mitigation proposal has introduced an operation, MPI_Comm_shrink, to synchronize the alive processes on the list of failed processes, so that applications can continue to execute even in the presence of failures by adopting algorithm-based fault tolerance techniques. This MPI_Comm_shrink operation requires a fault tolerant failure detection and consensus algorithm. This paper presents and compares two novel failure detection and consensus algorithms. The proposed algorithms are based on Gossip protocols and are inherently fault-tolerant and scalable. The proposed algorithms were implementedmore » and tested using the Extreme-scale Simulator. The results show that in both algorithms the number of Gossip cycles to achieve global consensus scales logarithmically with system size. The second algorithm also shows better scalability in terms of memory and network bandwidth usage and a perfect synchronization in achieving global consensus.« less

PCTDSE: A parallel Cartesian-grid-based TDSE solver for modeling laser-atom interactions

NASA Astrophysics Data System (ADS)

Fu, Yongsheng; Zeng, Jiaolong; Yuan, Jianmin

2017-01-01

We present a parallel Cartesian-grid-based time-dependent Schrödinger equation (TDSE) solver for modeling laser-atom interactions. It can simulate the single-electron dynamics of atoms in arbitrary time-dependent vector potentials. We use a split-operator method combined with fast Fourier transforms (FFT), on a three-dimensional (3D) Cartesian grid. Parallelization is realized using a 2D decomposition strategy based on the Message Passing Interface (MPI) library, which results in a good parallel scaling on modern supercomputers. We give simple applications for the hydrogen atom using the benchmark problems coming from the references and obtain repeatable results. The extensions to other laser-atom systems are straightforward with minimal modifications of the source code.

Preliminary characterisation of new glass reference materials (GSA-1G, GSC-1G, GSD-1G and GSE-1G) by laser ablation-inductively coupled plasma-mass spectrometry using 193 nm, 213 nm and 266 nm wavelengths

USGS Publications Warehouse

Guillong, M.; Hametner, K.; Reusser, E.; Wilson, S.A.; Gunther, D.

2005-01-01

New glass reference materials GSA-1G, GSC-1G, GSD-1G and GSE-1G have been characterised using a prototype solid state laser ablation system capable of producing wavelengths of 193 nm, 213 nm and 266 nm. This system allowed comparison of the effects of different laser wavelengths under nearly identical ablation and ICP operating conditions. The wavelengths 213 nm and 266 nm were also used at higher energy densities to evaluate the influence of energy density on quantitative analysis. In addition, the glass reference materials were analysed using commercially available 266 nm Nd:YAG and 193 nm ArF excimer lasers. Laser ablation analysis was carried out using both single spot and scanning mode ablation. Using laser ablation ICP-MS, concentrations of fifty-eight elements were determined with external calibration to the NIST SRM 610 glass reference material. Instead of applying the more common internal standardisation procedure, the total concentration of all element oxide concentrations was normalised to 100%. Major element concentrations were compared with those determined by electron microprobe. In addition to NIST SRM 610 for external calibration, USGS BCR-2G was used as a more closely matrix-matched reference material in order to compare the effect of matrix-matched and non matrix-matched calibration on quantitative analysis. The results show that the various laser wavelengths and energy densities applied produced similar results, with the exception of scanning mode ablation at 266 nm without matrix-matched calibration where deviations up to 60% from the average were found. However, results acquired using a scanning mode with a matrix-matched calibration agreed with results obtained by spot analysis. The increased abundance of large particles produced when using a scanning ablation mode with NIST SRM 610, is responsible for elemental fractionation effects caused by incomplete vaporisation of large particles in the ICP.

On the reduced lifetime of nitrous oxide due to climate change induced acceleration of the Brewer-Dobson circulation as simulated by the MPI Earth System Model

NASA Astrophysics Data System (ADS)

Kracher, D.; Manzini, E.; Reick, C. H.; Schultz, M. G.; Stein, O.

2014-12-01

Greenhouse gas induced climate change will modify the physical conditions of the atmosphere. One of the projected changes is an acceleration of the Brewer-Dobson circulation in the stratosphere, as it has been shown in many model studies. This change in the stratospheric circulation consequently bears an effect on the transport and distribution of atmospheric components such as N2O. Since N2O is involved in ozone destruction, a modified distribution of N2O can be of importance for ozone chemistry. N2O is inert in the troposphere and decays only in the stratosphere. Thus, changes in the exchange between troposphere and stratosphere can also affect the stratospheric sink of N2O, and consequently its atmospheric lifetime. N2O is a potent greenhouse gas with a global warming potential of currently approximately 300 CO2-equivalents in a 100-year perspective. A faster decay in atmospheric N2O mixing ratios, i.e. a decreased atmospheric lifetime of N2O, will also reduce its global warming potential. In order to assess the impact of climate change on atmospheric circulation and implied effects on the distribution and lifetime of atmospheric N2O, we apply the Max Planck Institute Earth System Model, MPI-ESM. MPI-ESM consists of the atmospheric general circulation model ECHAM, the land surface model JSBACH, and MPIOM/HAMOCC representing ocean circulation and ocean biogeochemistry. Prognostic atmospheric N2O concentrations in MPI-ESM are determined by land N2O emissions, ocean-atmosphere N2O exchange and atmospheric tracer transport. As stratospheric chemistry is not explicitly represented in MPI-ESM, stratospheric decay rates of N2O are prescribed from a MACC MOZART simulation. Increasing surface temperatures and CO2 concentrations in the stratosphere impact atmospheric circulation differently. Thus, we conduct a series of transient runs with the atmospheric model of MPI-ESM to isolate different factors governing a shift in atmospheric circulation. From those transient simulations we diagnose decreasing tropospheric N2O concentrations, increased transport of N2O from the troposphere to the stratosphere, and increasing stratospheric decay of N2O leading to a reduction in atmospheric lifetime of N2O, in dependency to climate change evolution.

The influence of an atmospheric Two-Way coupled model system on the predictability of extratropical cyclones

NASA Astrophysics Data System (ADS)

Schuster, Mareike; Thürkow, Markus; Weiher, Stefan; Kirchner, Ingo; Ulbrich, Uwe; Will, Andreas

2016-04-01

A general bias of global atmosphere ocean models, and also of the MPI-ESM, is an under-representation of the high latitude cyclone activity and an overestimation of the mid latitude cyclone activity in the North Atlantic, thus representing the extra-tropical storm track too zonal. We will show, that this effect can be antagonized by applying an atmospheric Two-Way Coupling (TWC). In this study we present a newly developed Two-Way Coupled model system, which is based on the MPI-ESM, and show that it is able to capture the mean storm track location more accurate. It also influences the sub-decadal deterministic predictability of extra-tropical cyclones and shows significantly enhanced skill compared to the "uncoupled" MPI-ESM standalone system. This study evaluates a set of hindcast experiments performed with said Two-Way Coupled model system. The regional model COSMO CLM is Two-Way Coupled to the atmosphere of the global Max-Plack-Institute Earth System Model (MPI-ESM) and therefore integrates and exchanges the state of the atmosphere every 10 minutes (MPI-TWC-ESM). In the coupled source region (North Atlantic), mesoscale processes which are relevant for the formation and early-stage development of cyclones are expected to be better represented, and therefore influence the large scale dynamics of the target region (Europe). The database covers 102 "uncoupled" years and 102 Two-Way Coupled years of the recent climate (1960-2010). Results are validated against the ERA-Interim reanalysis. Besides the climatological point of view, the design of this single model ensemble allows for an analysis of the predictability of the first and second leadyears of the hindcasts. As a first step to understand the improved predictability of cyclones, we will show a detailed analysis of climatologies for specific cyclone categories, sorted by season and region. Especially for cyclones affecting Europe, the TWC is capable to counteract the AOGCM's biases in the North Atlantic. Also, cyclones which are generated in the northern North Atlantic and the Labrador Sea are to an extraordinary extent underestimated in the "uncoupled" MPI-ESM - for the latter region the TWC can balance this shortcoming. In the Northern Hemisphere annual mean statistics the TWC does not change the distribution of the strength of cyclones, but it changes the distribution of the lifetime of cyclones.

Bioactive glasses: Importance of structure and properties in bone regeneration

NASA Astrophysics Data System (ADS)

Hench, Larry L.; Roki, Niksa; Fenn, Michael B.

2014-09-01

This review provides a brief background on the applications, mechanisms and genetics involved with use of bioactive glass to stimulate regeneration of bone. The emphasis is on the role of structural changes of the bioactive glasses, in particular Bioglass, which result in controlled release of osteostimulative ions. The review also summarizes the use of Raman spectroscopy, referred to hereto forward as bio-Raman spectroscopy, to obtain rapid, real time in vitro analysis of human cells in contact with bioactive glasses, and the osteostimulative dissolution ions that lead to osteogenesis. The bio-Raman studies support the results obtained from in vivo studies of bioactive glasses, as well as extensive cell and molecular biology studies, and thus offers an innovative means for rapid screening of new bioactive materials while reducing the need for animal testing.

Study of glass hydrometer calibration by hydrostatic weighting

NASA Astrophysics Data System (ADS)

Chen, Chaoyun; Wang, Jintao; Li, Zhihao; Zhang, Peiman

2016-01-01

Glass hydrometers are simple but effective instruments for measuring the density of liquids. Glass hydrometers calibration based on the Archimedes law, using silicon ring as a reference standard solid density, n-tridecane with density stability and low surface tension as the standard working liquid, based on hydrostatic weighing method designs a glass hydrometer calibration system. Glass hydrometer calibration system uses CCD image measurement system to align the scale of hydrometer and liquid surface, with positioning accuracy of 0.01 mm. Surface tension of the working liquid is measured by Whihemy plate. According to twice glass hydrometer weighing in the air and liquid can calculate the correction value of the current scale. In order to verify the validity of the principle of the hydrostatic weighing method of glass hydrometer calibration system, for measuring the density range of (770-790) kg/m3, with a resolution of 0.2 kg/m3 of hydrometer. The results of measurement compare with the Physikalisch-Technische Bundesanstalt(PTB) ,verifying the validity of the calibration system.

Advances in Parallel Computing and Databases for Digital Pathology in Cancer Research

DTIC Science & Technology

2016-11-13

these technologies and how we have used them in the past. We are interested in learning more about the needs of clinical pathologists as we continue to...such as image processing and correlation. Further, High Performance Computing (HPC) paradigms such as the Message Passing Interface (MPI) have been...Defense for Research and Engineering. such as pMatlab [4], or bcMPI [5] can significantly reduce the need for deep knowledge of parallel computing. In

A comprehensive study of MPI parallelism in three-dimensional discrete element method (DEM) simulation of complex-shaped granular particles

NASA Astrophysics Data System (ADS)

Yan, Beichuan; Regueiro, Richard A.

2018-02-01

A three-dimensional (3D) DEM code for simulating complex-shaped granular particles is parallelized using message-passing interface (MPI). The concepts of link-block, ghost/border layer, and migration layer are put forward for design of the parallel algorithm, and theoretical scalability function of 3-D DEM scalability and memory usage is derived. Many performance-critical implementation details are managed optimally to achieve high performance and scalability, such as: minimizing communication overhead, maintaining dynamic load balance, handling particle migrations across block borders, transmitting C++ dynamic objects of particles between MPI processes efficiently, eliminating redundant contact information between adjacent MPI processes. The code executes on multiple US Department of Defense (DoD) supercomputers and tests up to 2048 compute nodes for simulating 10 million three-axis ellipsoidal particles. Performance analyses of the code including speedup, efficiency, scalability, and granularity across five orders of magnitude of simulation scale (number of particles) are provided, and they demonstrate high speedup and excellent scalability. It is also discovered that communication time is a decreasing function of the number of compute nodes in strong scaling measurements. The code's capability of simulating a large number of complex-shaped particles on modern supercomputers will be of value in both laboratory studies on micromechanical properties of granular materials and many realistic engineering applications involving granular materials.

DISP: Optimizations towards Scalable MPI Startup

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

Fu, Huansong; Pophale, Swaroop S; Gorentla Venkata, Manjunath

2016-01-01

Despite the popularity of MPI for high performance computing, the startup of MPI programs faces a scalability challenge as both the execution time and memory consumption increase drastically at scale. We have examined this problem using the collective modules of Cheetah and Tuned in Open MPI as representative implementations. Previous improvements for collectives have focused on algorithmic advances and hardware off-load. In this paper, we examine the startup cost of the collective module within a communicator and explore various techniques to improve its efficiency and scalability. Accordingly, we have developed a new scalable startup scheme with three internal techniques, namelymore » Delayed Initialization, Module Sharing and Prediction-based Topology Setup (DISP). Our DISP scheme greatly benefits the collective initialization of the Cheetah module. At the same time, it helps boost the performance of non-collective initialization in the Tuned module. We evaluate the performance of our implementation on Titan supercomputer at ORNL with up to 4096 processes. The results show that our delayed initialization can speed up the startup of Tuned and Cheetah by an average of 32.0% and 29.2%, respectively, our module sharing can reduce the memory consumption of Tuned and Cheetah by up to 24.1% and 83.5%, respectively, and our prediction-based topology setup can speed up the startup of Cheetah by up to 80%.« less

MPIRUN: A Portable Loader for Multidisciplinary and Multi-Zonal Applications

NASA Technical Reports Server (NTRS)

Fineberg, Samuel A.; Woodrow, Thomas S. (Technical Monitor)

1994-01-01

Multidisciplinary and multi-zonal applications are an important class of applications in the area of Computational Aerosciences. In these codes, two or more distinct parallel programs or copies of a single program are utilized to model a single problem. To support such applications, it is common to use a programming model where a program is divided into several single program multiple data stream (SPMD) applications, each of which solves the equations for a single physical discipline or grid zone. These SPMD applications are then bound together to form a single multidisciplinary or multi-zonal program in which the constituent parts communicate via point-to-point message passing routines. One method for implementing the message passing portion of these codes is with the new Message Passing Interface (MPI) standard. Unfortunately, this standard only specifies the message passing portion of an application, but does not specify any portable mechanisms for loading an application. MPIRUN was developed to provide a portable means for loading MPI programs, and was specifically targeted at multidisciplinary and multi-zonal applications. Programs using MPIRUN for loading and MPI for message passing are then portable between all machines supported by MPIRUN. MPIRUN is currently implemented for the Intel iPSC/860, TMC CM5, IBM SP-1 and SP-2, Intel Paragon, and workstation clusters. Further, MPIRUN is designed to be simple enough to port easily to any system supporting MPI.

Dynamic CT perfusion imaging of the myocardium: a technical note on improvement of image quality.

PubMed

Muenzel, Daniela; Kabus, Sven; Gramer, Bettina; Leber, Vivian; Vembar, Mani; Schmitt, Holger; Wildgruber, Moritz; Fingerle, Alexander A; Rummeny, Ernst J; Huber, Armin; Noël, Peter B

2013-01-01

To improve image and diagnostic quality in dynamic CT myocardial perfusion imaging (MPI) by using motion compensation and a spatio-temporal filter. Dynamic CT MPI was performed using a 256-slice multidetector computed tomography scanner (MDCT). Data from two different patients-with and without myocardial perfusion defects-were evaluated to illustrate potential improvements for MPI (institutional review board approved). Three datasets for each patient were generated: (i) original data (ii) motion compensated data and (iii) motion compensated data with spatio-temporal filtering performed. In addition to the visual assessment of the tomographic slices, noise and contrast-to-noise-ratio (CNR) were measured for all data. Perfusion analysis was performed using time-density curves with regions-of-interest (ROI) placed in normal and hypoperfused myocardium. Precision in definition of normal and hypoperfused areas was determined in corresponding coloured perfusion maps. The use of motion compensation followed by spatio-temporal filtering resulted in better alignment of the cardiac volumes over time leading to a more consistent perfusion quantification and improved detection of the extend of perfusion defects. Additionally image noise was reduced by 78.5%, with CNR improvements by a factor of 4.7. The average effective radiation dose estimate was 7.1±1.1 mSv. The use of motion compensation and spatio-temporal smoothing will result in improved quantification of dynamic CT MPI using a latest generation CT scanner.

A comparison of echocardiographic variables of right ventricular function with exercise capacity after bosentan treatment in patients with pulmonary arterial hypertension: Results from a multicenter, prospective, cohort study.

PubMed

Kim, Hyungseop; Bae Lee, Jin; Park, Jae-Hyeong; Yoo, Byung-Su; Son, Jang-Won; Yang, Dong Heon; Lee, Bong-Ryeol

2017-01-01

Bosentan reduces pulmonary arterial pressure and improves exercise capacity in patients with pulmonary arterial hypertension (PAH). However, there are limited data regarding the extent to which the changes in echocardiographic variables reflect improvements in exercise capacity. We aimed to assess the improvement of echocardiographic variables and exercise capacity after 6 months of bosentan treatment for PAH. We performed a prospective study from June 2012 to June 2015 in seven participating medical centers. Echocardiography, including tissue Doppler imaging (TDI) and the 6-minute walk test distance (6MWD), was performed at baseline and after 6 months of bosentan treatment. We analyzed 19 patients with PAH: seven with congenital shunt, six with collagen vascular disease, and six with idiopathic PAH. After bosentan treatment, mean 6MWD increased by 50 meters. Right ventricle (RV) systolic pressure, tricuspid annular plane systolic excursion, myocardial performance index (MPI) derived from TDI (MPI-TDI) of RV and left ventricle (LV), RV fractional area change, and RV ejection fraction were significantly improved. In particular, the magnitude of RV and LV MPI-TDI showed good correlation with changes in the 6MWD. The magnitude of RV and LV MPI-TDI was strongly associated with improvements in exercise capacity. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 45:28-34, 2017. © 2016 Wiley Periodicals, Inc.

Experience of low-dose aminophylline use to relieve minor adverse effects of dipyridamole in patients undergoing stress myocardial perfusion imaging.

PubMed

Lin, Li-Fan; Cheng, Cheng-Yi; Hou, Cheng-Han; Ku, Chih-Hung; Tseng, Neng-Chuan; Shen, Daniel H Y

2014-06-01

Intravenous administration of aminophylline is widely adopted to reverse dipyridamole-related adverse effects (AEs) during stress myocardial perfusion imaging (MPI). The study aimed to investigate the efficacy of lower-dose aminophylline to relieve minor AEs. 2,250 consecutive patients undergoing dipyridamole-stressed MPI were enrolled. Information concerning AE occurrence and dosages of aminophylline was collected to evaluate the efficacy of lower-dose aminophylline. A logistic regression was used to determine independent predictors of dipyridamole-related AE occurrence. No severe AE was noted. Overall mild AE incidence was 37.0% (833/2,250 patients). Initial low-dose (25 mg) aminophylline relieved symptoms in 98.8% of patients with mild AEs (823/833 patients). An extra 25 mg aminophylline sufficed to reverse all such AEs. Mean body mass index (BMI) differed significantly between patients with and without any AE [25.6 vs 25.1 (P = .009)]. There was no significant difference between two subgroups in mean age, male gender prevalence, body height and weight, dipyridamole dose/BMI, or prevalence of significant perfusion defect(s) on MPI. Multivariable logistic regression demonstrated BMI remained the independent predictor of dipyridamole-related AE occurrence (odds ratio 1.028, 95% confidence interval 1.007-1.049, P = .01). Low-dose (≦50 mg, and usually 25 mg) aminophylline seems sufficient to relieve mild dipyridamole-related AEs during stress MPI.

Corrosion Inhibition of Cold-rolled Low Carbon Steel with Pulse Fiber Laser Ablation in Water

NASA Astrophysics Data System (ADS)

Chan, Sze Ney; Wong, Wai Yin; Walvekar, Rashmi; Kadhum, Abdul Amir H.; Khalid, Mohammad; Lim, Kean Long

2018-04-01

This study aims at the use of a fiber laser for modifying the surface properties of cold-rolled low carbon steel via a pulse laser ablation technique in water. The effect on the corrosion behavior of the fiber laser-treated metal surface was investigated in NaCl and HCl environments. Electrochemical tests showed significant improvement in the corrosion resistance of the laser-treated sample in NaCl, with an increase in open-circuit potential (OCP) from - 0.65 to - 0.60 V and an inhibition efficiency of 89.22% as obtained from the impedance study. Such improvement was less significant in an acidic environment. Lower corrosion rates of 20.9 mpy and 5.819 × 103 mpy were obtained for the laser-treated samples in neutral and acidic electrolytes, respectively, than the corrosion rates obtained for the as-received samples (33.2 mpy and 11.98 × 103 mpy). Morphological analysis indicated a passive film built by spherical grains of regular size on the metal surface after laser treatment. The corrosion inhibition effects in NaCl were evident by the nonexistence of the common corrosion products of lepidocrocite and crystalline structures that were seen on as-received samples; only polyhedral crystals with micrograins grown on them were seen covering the laser-treated surface. Therefore, the laser treatment using a fiber laser source improved the corrosion resistance of cold-rolled low carbon steel.

Sleep and Predicted Cognitive Performance of New Cadets during Cadet Basic Training at the United States Military Academy

DTIC Science & Technology

2005-09-01

7 B. SLEEP ARCHITECTURE..................................7 1. Circadian Rhythm and Human Sleep Drive...body temperature. Van Dongen & Dinges, 2000 ....10 Figure 2. EEG of Human Brain Activity During Sleep. http://ist-socrates.berkeley.edu/~jmp...the predicted levels of human performance based on circadian rhythms , amount and quality of sleep, and combines cognitive performance 5 predictions

Fatigue and its Effect on Performance in Military Environments

DTIC Science & Technology

2007-01-01

orne and orne , 1985). operational environments share common characteristics such as long work hours, working conditions that vary from boring to...operations Desert Shield and Desert Storm (Interim No. NAMrL-1377). Pensacola, FL: Naval Aerospace Medical research Laboratory. Dinges, D.F., orne , K.T. and... orne , E.C. (1985) “Assessing Performance upon Abrupt Awakening from Naps during Quasi-Continuous operations”, Behavior Research Methods, Instruments

The Role of BRCA1 in Lethal Prostate Cancer

DTIC Science & Technology

2011-08-01

Research Program, Orlando FL -13- 2010;70:3136-3139. Published OnlineFirst April 13, 2010.Cancer Res Michelangelo Fiorentino, Gregory Judson...Massachusetts oda and L. Mucci share senior authorship. ding Author: Michelangelo Fiorentino, Center for Molecular Pathology, Dana-Farber Cancer...2010 3139 ciation for Cancer Research on August 24, 2011rnals.org Tumor Expression of BRCA1 and Lethal Prostate Cancer Michelangelo Fiorentino

Ding Dong, You've Got Mail! A Lab Activity for Teaching the Internet of Things

ERIC Educational Resources Information Center

Frydenberg, Mark

2017-01-01

Connecting ordinary devices to the Internet is a defining characteristic of the Internet of Things. In this hands-on lab activity, students will connect a wireless doorbell to the Internet using a Raspberry Pi computer. By modifying and running a program on the Raspberry Pi to send an email or text message notifying a recipient that someone is at…

Interdiction and Conventional Strategy: Prevailing Perceptions

DTIC Science & Technology

1990-06-01

Andrew Vallance of the RAF Command and Staff College; Air Vice-Marshal R. A. Mason (Ret.); Air Chief Marshal Sir Michael Armitage, Royal College of...The RAND Corporation, N-1743-PAE, September 1981. Dinges, Edward A., and Richard H. Sinnreich, "Battlefield Interdiction: Old Tenn. New Problem...34 Military Affairs, October 1988. McDow, Richard H., Air Interdiction Targeting Priorities, Air University, Maxwell AFB, 1985. Molnar, Alexander

Abrasion Resistance and Mechanical Properties of Waste-Glass-Fiber-Reinforced Roller-compacted Concrete

NASA Astrophysics Data System (ADS)

Yildizel, S. A.; Timur, O.; Ozturk, A. U.

2018-05-01

The potential use of waste glass fibers in roller-compacted concrete (RCC) was investigated with the aim to improve its performance and reduce environmental effects. The research was focused on the abrasion resistance and compressive and flexural strengths of the reinforced concrete relative to those of reference mixes without fibers. The freeze-thaw resistance of RCC mixes was also examined. It was found that the use of waste glass fibers at a rate of 2 % increased the abrasion resistance of the RCC mixes considerably.

Acousto-Optic Applications for Multichannel Adaptive Optical Processor

DTIC Science & Technology

1992-06-01

AO cell and the two- channel line-scan camera system described in Subsection 4.1. The AO material for this IntraAction AOD-70 device was flint glass (n...Single-Channel 1.68 (flint glass ) 60,.0 AO Cell Multichannel 2.26 (TeO 2) 20.0 AO Cell Beam splitter 1.515 ( glass ) 50.8 Multichannel correlation was...Tone Intermodulation Dynamic Ranges of Longitudinal TeO2 Bragg Cells for Several Acoustic Power Densities 4-92 f f2 f 3 1 t SOURCE: Reference 21 TR-92

Biomedical imaging and therapy with physically and physiologically tailored magnetic nanoparticles

NASA Astrophysics Data System (ADS)

Khandhar, Amit Praful

Magnetic particle imaging (MPI) and magnetic fluid hyperthermia (MFH) are emerging imaging and therapy approaches that have the potential to improve diagnostic safety and disease management of heart disease and cancer - the number 1 and 2 leading causes of deaths in the United States. MPI promises real-time, tomographic and quantitative imaging of superparamagnetic iron oxide nanoparticle (SPION) tracers distributed in vivo, and is targeted to offer a safer angiography alternative for its first clinical application. MFH uses ac-fields to dissipate heat from SPIONs that can be delivered locally to promote hyperthermia therapy (~42°C) in cancer cells. Both technologies use safe radiofrequency magnetic fields to exploit the fundamental magnetic relaxation properties of superparamagnetic iron oxide nanoparticles (SPIONs), which must be tailored for optimal imaging in the case of MPI, and maximum hyperthermia potency in the case of MFH. Furthermore, the magnetic core and shell of SPIONs are both central to the optimization process; the shell, in particular, bridges the translational gap between the optimized core and its safe and effective use in the physiological environment. Unfortunately, existing SPIONs that were originally designed as MRI contrast agents lack the basic physical properties that enable the clinical translation of MPI and MFH. In this work, the core and shell of monodisperse SPIONs were optimized in concert to accomplish two equally important objectives: (1) biocompatibility, and (2) MPI and MFH efficacy of SPIONs in physiological environments. Critically, it was found that the physical and physiological responses of SPIONs are coupled, and impacting one can have consequences on the other. It was shown that the poly(ethylene glycol) (PEG)-based shell when properly optimized reduced protein adsorption to SPION surface and phagocytic uptake in macrophages - both prerequisites for designing long-circulating SPIONs. In MPI, tailoring the surface coating reduced protein adsorption and improved colloidal stability, which were critical in retaining the magnetization relaxation properties of the SPIONs. The improvements in surface coatings enabled the use of larger SPION cores (> 20 nm core diameter), which were used to demonstrate benchmark-imaging performance in some of the world's first MPI scanners at Philips Medical Imaging and University of California, Berkeley. In MFH, it was shown for the first time that optimization of heat loss from SPIONs (W/g) is possible by tailoring the core size and size distribution for the given ac-field conditions. Biodistribution and blood circulation studies in mice showed that SPIONs accumulated primarily in the liver and spleen with minimal renal involvement, and demonstrated gradual clearance. Circulation time was evaluated using the MPI signal detected over time in blood, which offered insight on the relevant circulation time for angiography applications. In comparison with carboxy-dextran coated ResovistRTM SPIONs, the PEG-coated SPIONs developed in this work circulated substantially longer; furthermore, reducing the hydrodynamic diameter showed a 4.5x improvement in blood half-life. The work presented in this thesis demonstrates that the combined effort in optimizing the core and shell properties of SPIONs enhances biocompatibility and efficacy, with the in vivo studies providing critical feedback on the success (or failure) of the optimization process. Future work will entail designing functionalized SPIONs for targeting specific disease sites, which will further enable the molecular level diagnosis and therapy of diseases.

Deep Learning for Prediction of Obstructive Disease From Fast Myocardial Perfusion SPECT: A Multicenter Study.

PubMed

Betancur, Julian; Commandeur, Frederic; Motlagh, Mahsaw; Sharir, Tali; Einstein, Andrew J; Bokhari, Sabahat; Fish, Mathews B; Ruddy, Terrence D; Kaufmann, Philipp; Sinusas, Albert J; Miller, Edward J; Bateman, Timothy M; Dorbala, Sharmila; Di Carli, Marcelo; Germano, Guido; Otaki, Yuka; Tamarappoo, Balaji K; Dey, Damini; Berman, Daniel S; Slomka, Piotr J

2018-03-12

The study evaluated the automatic prediction of obstructive disease from myocardial perfusion imaging (MPI) by deep learning as compared with total perfusion deficit (TPD). Deep convolutional neural networks trained with a large multicenter population may provide improved prediction of per-patient and per-vessel coronary artery disease from single-photon emission computed tomography MPI. A total of 1,638 patients (67% men) without known coronary artery disease, undergoing stress 99m Tc-sestamibi or tetrofosmin MPI with new generation solid-state scanners in 9 different sites, with invasive coronary angiography performed within 6 months of MPI, were studied. Obstructive disease was defined as ≥70% narrowing of coronary arteries (≥50% for left main artery). Left ventricular myocardium was segmented using clinical nuclear cardiology software and verified by an expert reader. Stress TPD was computed using sex- and camera-specific normal limits. Deep learning was trained using raw and quantitative polar maps and evaluated for prediction of obstructive stenosis in a stratified 10-fold cross-validation procedure. A total of 1,018 (62%) patients and 1,797 of 4,914 (37%) arteries had obstructive disease. Area under the receiver-operating characteristic curve for disease prediction by deep learning was higher than for TPD (per patient: 0.80 vs. 0.78; per vessel: 0.76 vs. 0.73: p < 0.01). With deep learning threshold set to the same specificity as TPD, per-patient sensitivity improved from 79.8% (TPD) to 82.3% (deep learning) (p < 0.05), and per-vessel sensitivity improved from 64.4% (TPD) to 69.8% (deep learning) (p < 0.01). Deep learning has the potential to improve automatic interpretation of MPI as compared with current clinical methods. Copyright © 2018 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Usefulness for Predicting Cardiac Events After Orthotopic Liver Transplantation of Myocardial Perfusion Imaging and Dobutamine Stress Echocardiography Preoperatively.

PubMed

Snipelisky, David; Ray, Jordan; Vallabhajosyula, Saraschandra; Matcha, Gautam; Squier, Samuel; Lewis, Jacob; Holliday, Rex; Aggarwal, Niti; Askew, J Wells; Shapiro, Brian; Anavekar, Nandan

2017-04-01

Patients undergoing orthotopic liver transplantation have high rates of cardiac morbidity and mortality. Although guidelines recommend noninvasive stress testing as part of the preoperative evaluation, little data have evaluated clinical outcomes following orthotopic liver transplantation. A retrospective study at 2 high-volume liver transplantation centers was performed. All patients undergoing noninvasive stress testing (myocardial perfusion imaging [MPI] or dobutamine stress echocardiography [DSE]) over a 5-year period were included. Descriptive analyses, including clinical outcomes and perioperative and postoperative ischemic events, were performed. Comparisons were made between subsets of patients within each stress modality based on abnormal versus normal results. A total of 506 patients were included, of which 343 underwent DSE and 163 MPI. Few patients had abnormal results, with 19 (5.5%) in the DSE group and 13 (8%) in the MPI group. Perioperative and postoperative cardiac complications were low (n = 20, 5.8% and n = 3, 0.9% in DSE group and n = 15, 9.2% and n = 3, 1.8% in MPI group). Comparisons between abnormal versus normal findings showed a trend toward periprocedural cardiac complications in the abnormal DSE group (n = 3, 15.8% vs n = 17, 5.25%; p = 0.09) with no difference in 6-month postprocedural complications (n = 0 vs n = 3, 0.9%; p = 1.0). In the MPI group, a trend toward periprocedural ischemic complications (n = 3, 23.1% vs n = 12, 8%; p = 0.1) was noted with no difference in 6-month postprocedural complications (n = 0 vs n = 3, 2%; p = 1.0). In conclusion, our study found a significantly lower than reported cardiac event rate. In addition, it demonstrated that ischemic cardiac events are uncommon in patients with normal stress testing. Copyright © 2017 Elsevier Inc. All rights reserved.

The Effect of Higher Than Recommended Protein Feedings Post-Exercise on Recovery Following Downhill Running in Masters Triathletes.

PubMed

Doering, Thomas M; Reaburn, Peter R; Borges, Nattai R; Cox, Gregory R; Jenkins, David G

2017-02-01

Following exercise-induced muscle damage (EIMD), masters athletes take longer to recover than younger athletes. The purpose of this study was to determine the effect of higher than recommended postexercise protein feedings on the recovery of knee extensor peak isometric torque (PIT), perceptions of recovery, and cycling time trial (TT) performance following EIMD in masters triathletes. Eight masters triathletes (52 ± 2 y, V̇O 2max , 51.8 ± 4.2 ml•kg -1 •min -1 ) completed two trials separated by seven days in a randomized, doubleblind, crossover study. Trials consisted of morning PIT testing and a 30-min downhill run followed by an eight-hour recovery. During recovery, a moderate (MPI; 0.3 g•kg -1 •bolus -1 ) or high (0.6 g•kg -1 •bolus -1 ) protein intake (HPI) was consumed in three bolus feedings at two hour intervals commencing immediately postexercise. PIT testing and a 7 kJ•kg -1 cycling TT were completed postintervention. Perceptions of recovery were assessed pre- and postexercise. The HPI did not significantly improve recovery compared with MPI (p > .05). However, comparison of within-treatment change shows the HPI provided a moderate beneficial effect (d = 0.66), attenuating the loss of afternoon PIT (-3.6%, d = 0.09) compared with the MPI (-8.6%, d = 0.24). The HPI provided a large beneficial effect (d = 0.83), reducing perceived fatigue over the eight-hour recovery (d = 1.25) compared with the MPI (d = 0.22). Despite these effects, cycling performance was unchanged (HPI = 2395 ± 297 s vs. MPI = 2369 ± 278 s; d = 0.09). In conclusion, doubling the recommended postexercise protein intake did not significantly improve recovery in masters athletes; however, HPI provided moderate to large beneficial effects on recovery that may be meaningful following EIMD.

WImpiBLAST: web interface for mpiBLAST to help biologists perform large-scale annotation using high performance computing.

PubMed

Sharma, Parichit; Mantri, Shrikant S

2014-01-01

The function of a newly sequenced gene can be discovered by determining its sequence homology with known proteins. BLAST is the most extensively used sequence analysis program for sequence similarity search in large databases of sequences. With the advent of next generation sequencing technologies it has now become possible to study genes and their expression at a genome-wide scale through RNA-seq and metagenome sequencing experiments. Functional annotation of all the genes is done by sequence similarity search against multiple protein databases. This annotation task is computationally very intensive and can take days to obtain complete results. The program mpiBLAST, an open-source parallelization of BLAST that achieves superlinear speedup, can be used to accelerate large-scale annotation by using supercomputers and high performance computing (HPC) clusters. Although many parallel bioinformatics applications using the Message Passing Interface (MPI) are available in the public domain, researchers are reluctant to use them due to lack of expertise in the Linux command line and relevant programming experience. With these limitations, it becomes difficult for biologists to use mpiBLAST for accelerating annotation. No web interface is available in the open-source domain for mpiBLAST. We have developed WImpiBLAST, a user-friendly open-source web interface for parallel BLAST searches. It is implemented in Struts 1.3 using a Java backbone and runs atop the open-source Apache Tomcat Server. WImpiBLAST supports script creation and job submission features and also provides a robust job management interface for system administrators. It combines script creation and modification features with job monitoring and management through the Torque resource manager on a Linux-based HPC cluster. Use case information highlights the acceleration of annotation analysis achieved by using WImpiBLAST. Here, we describe the WImpiBLAST web interface features and architecture, explain design decisions, describe workflows and provide a detailed analysis.

Literature-based compound profiling: application to toxicogenomics.

PubMed

Frijters, Raoul; Verhoeven, Stefan; Alkema, Wynand; van Schaik, René; Polman, Jan

2007-11-01

To reduce continuously increasing costs in drug development, adverse effects of drugs need to be detected as early as possible in the process. In recent years, compound-induced gene expression profiling methodologies have been developed to assess compound toxicity, including Gene Ontology term and pathway over-representation analyses. The objective of this study was to introduce an additional approach, in which literature information is used for compound profiling to evaluate compound toxicity and mode of toxicity. Gene annotations were built by text mining in Medline abstracts for retrieval of co-publications between genes, pathology terms, biological processes and pathways. This literature information was used to generate compound-specific keyword fingerprints, representing over-represented keywords calculated in a set of regulated genes after compound administration. To see whether keyword fingerprints can be used for assessment of compound toxicity, we analyzed microarray data sets of rat liver treated with 11 hepatotoxicants. Analysis of keyword fingerprints of two genotoxic carcinogens, two nongenotoxic carcinogens, two peroxisome proliferators and two randomly generated gene sets, showed that each compound produced a specific keyword fingerprint that correlated with the experimentally observed histopathological events induced by the individual compounds. By contrast, the random sets produced a flat aspecific keyword profile, indicating that the fingerprints induced by the compounds reflect biological events rather than random noise. A more detailed analysis of the keyword profiles of diethylhexylphthalate, dimethylnitrosamine and methapyrilene (MPy) showed that the differences in the keyword fingerprints of these three compounds are based upon known distinct modes of action. Visualization of MPy-linked keywords and MPy-induced genes in a literature network enabled us to construct a mode of toxicity proposal for MPy, which is in agreement with known effects of MPy in literature. Compound keyword fingerprinting based on information retrieved from literature is a powerful approach for compound profiling, allowing evaluation of compound toxicity and analysis of the mode of action.