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Sample records for prospective ecg-gated 256-slice

  1. A Case of Coronary Cameral Fistula with Associated Aneurysm: Role of ECG Gated 256- Slice Dual Source Multidetector Computed Tomography in Diagnosis

    PubMed Central

    Garg, Lalit; Rissam, Harmeet Kaur; Puri, Sunil Kumar

    2016-01-01

    We report an interesting case of coronary cameral fistula with associated aneurysmal dilatation of coronary artery. The complete evaluation including anatomical relationships with surrounding vascular and non-vascular structures can be achieved with ECG gated multi-detector computed tomography (MDCT). MDCT has many advantages over echocardiography and digital subtraction catheter angiography, because of its ability to demonstrate the fistula separate from surrounding cardiovascular structures along with any aneurysm or obstruction in its course. Thus, MDCT is emerging as the initial non-invasive imaging technique for comprehensive preoperative evaluation of these rare congenital anomalies for cardiovascular surgeons to achieve better operative assessibity and outcome. PMID:27437325

  2. Dose reduction of up to 89% while maintaining image quality in cardiovascular CT achieved with prospective ECG gating

    NASA Astrophysics Data System (ADS)

    Londt, John H.; Shreter, Uri; Vass, Melissa; Hsieh, Jiang; Ge, Zhanyu; Adda, Olivier; Dowe, David A.; Sabllayrolles, Jean-Louis

    2007-03-01

    We present the results of dose and image quality performance evaluation of a novel, prospective ECG-gated Coronary CT Angiography acquisition mode (SnapShot Pulse, LightSpeed VCT-XT scanner, GE Healthcare, Waukesha, WI), and compare it to conventional retrospective ECG gated helical acquisition in clinical and phantom studies. Image quality phantoms were used to measure noise, slice sensitivity profile, in-plane resolution, low contrast detectability and dose, using the two acquisition modes. Clinical image quality and diagnostic confidence were evaluated in a study of 31 patients scanned with the two acquisition modes. Radiation dose reduction in clinical practice was evaluated by tracking 120 consecutive patients scanned with the prospectively gated scan mode. In the phantom measurements, the prospectively gated mode resulted in equivalent or better image quality measures at dose reductions of up to 89% compared to non-ECG modulated conventional helical scans. In the clinical study, image quality was rated excellent by expert radiologist reviewing the cases, with pathology being identical using the two acquisition modes. The average dose to patients in the clinical practice study was 5.6 mSv, representing 50% reduction compared to a similar patient population scanned with the conventional helical mode.

  3. Coronary Artery Stent Evaluation Using a Vascular Model at 64-Detector Row CT: Comparison between Prospective and Retrospective ECG-Gated Axial Scans

    PubMed Central

    Furui, Shigeru; Kuwahara, Sadatoshi; Mehta, Dhruv; Kaminaga, Tatsuro; Miyazawa, Akiyoshi; Ueno, Yasunari; Konno, Kumiko

    2009-01-01

    Objective We wanted to evaluate the performance of prospective electrocardiogram (ECG)-gated axial scans for assessing coronary stents as compared with retrospective ECG-gated helical scans. Materials and Methods As for a vascular model of the coronary artery, a tube of approximately 2.5-mm inner diameter was adopted and as for stents, three (Bx-Velocity, Express2, and Micro Driver) different kinds of stents were inserted into the tube. Both patent and stenotic models of coronary artery were made by instillating different attenuation (396 vs. 79 Hounsfield unit [HU]) of contrast medium within the tube in tube model. The models were scanned with two types of scan methods with a simulated ECG of 60 beats per minute and using display field of views (FOVs) of 9 and 18 cm. We evaluated the in-stent stenosis visually, and we measured the attenuation values and the diameter of the patent stent lumen. Results The visualization of the stent lumen of the vascular models was improved with using the prospective ECG-gated axial scans and a 9-cm FOV. The inner diameters of the vascular models were underestimated with mean measurement errors of -1.10 to -1.36 mm. The measurement errors were smaller with using the prospective ECG-gated axial scans (Bx-Velocity and Express2, p < 0.0001; Micro Driver, p = 0.0004) and a 9-cm FOV (all stents: p < 0.0001), as compared with the other conditions, respectively. The luminal attenuation value was overestimated in each condition. For the luminal attenuation measurement, the use of prospective ECG-gated axial scans provided less measurement error compared with the retrospective ECG-gated helical scans (all stents: p < 0.0001), and the use of a 9-cm FOV tended to decrease the measurement error. Conclusion The visualization of coronary stents is improved by the use of prospective ECG-gated axial scans and using a small FOV with reduced blooming artifacts and increased spatial resolution. PMID:19412509

  4. Coronary Stent Artifact Reduction with an Edge-Enhancing Reconstruction Kernel – A Prospective Cross-Sectional Study with 256-Slice CT

    PubMed Central

    Tan, Stéphanie; Soulez, Gilles; Diez Martinez, Patricia; Larrivée, Sandra; Stevens, Louis-Mathieu; Goussard, Yves; Mansour, Samer; Chartrand-Lefebvre, Carl

    2016-01-01

    Purpose Metallic artifacts can result in an artificial thickening of the coronary stent wall which can significantly impair computed tomography (CT) imaging in patients with coronary stents. The objective of this study is to assess in vivo visualization of coronary stent wall and lumen with an edge-enhancing CT reconstruction kernel, as compared to a standard kernel. Methods This is a prospective cross-sectional study involving the assessment of 71 coronary stents (24 patients), with blinded observers. After 256-slice CT angiography, image reconstruction was done with medium-smooth and edge-enhancing kernels. Stent wall thickness was measured with both orthogonal and circumference methods, averaging thickness from diameter and circumference measurements, respectively. Image quality was assessed quantitatively using objective parameters (noise, signal to noise (SNR) and contrast to noise (CNR) ratios), as well as visually using a 5-point Likert scale. Results Stent wall thickness was decreased with the edge-enhancing kernel in comparison to the standard kernel, either with the orthogonal (0.97 ± 0.02 versus 1.09 ± 0.03 mm, respectively; p<0.001) or the circumference method (1.13 ± 0.02 versus 1.21 ± 0.02 mm, respectively; p = 0.001). The edge-enhancing kernel generated less overestimation from nominal thickness compared to the standard kernel, both with the orthogonal (0.89 ± 0.19 versus 1.00 ± 0.26 mm, respectively; p<0.001) and the circumference (1.06 ± 0.26 versus 1.13 ± 0.31 mm, respectively; p = 0.005) methods. The edge-enhancing kernel was associated with lower SNR and CNR, as well as higher background noise (all p < 0.001), in comparison to the medium-smooth kernel. Stent visual scores were higher with the edge-enhancing kernel (p<0.001). Conclusion In vivo 256-slice CT assessment of coronary stents shows that the edge-enhancing CT reconstruction kernel generates thinner stent walls, less overestimation from nominal thickness, and better image quality

  5. Application of Prospective ECG-Gated High-Pitch 128-Slice Dual-Source CT Angiography in the Diagnosis of Congenital Extracardiac Vascular Anomalies in Infants and Children

    PubMed Central

    Wang, Ximing; Duan, Yanhua; Xu, Wenjian; Li, Haiou; Cao, Ting; Liu, Xuejun; Ji, Xiaopeng; Cheng, Zhaoping; Wang, Anbiao

    2014-01-01

    Purpose To investigate the value of prospective ECG-gated high-pitch 128-slice dual-source CT (DSCT) angiography in the diagnosis of congenital extracardiac vascular anomalies in infants and children in comparison with transthoracic echocardiography (TTE). Methods Eighty consecutive infants or children clinically diagnosed of congenital heart disease and suspected with extracardiac vascular anomaly were enrolled, and 75 patients were finally included in this prospective study. All patients underwent prospective ECG-gated high-pitch DSCT angiography after TTE with an interval of 1–7 days. The diagnostic accuracy and sensitivity of high-pitch DSCT angiography and TTE were compared according to the surgical/CCA findings. The image quality of DSCT was assessed using a five-point scale. The effective radiation dose (ED) was calculated. Results A total of 17 congenital heart diseases and 162 separate extracardiac vascular anomalies were confirmed by surgical/CCA findings in 75 patients. The diagnostic accuracy of high-pitch DSCT angiography and TTE was 99.67% and 97.89%, respectively. The sensitivity of high-pitch DSCT angiography and TTE was 97.53% and 79.62%, respectively. There was significant difference regarding to the diagnostic accuracy and the sensitivity between high-pitch DSCT angiography and TTE (χ2 = 23.561 and 28.013, P<0.05). The agreement on the image quality scoring of DSCT between the two observers was excellent (κ = 0.81), and the mean score of image quality was 4.1±0.7. The mean ED of DSCT was 0.29±0.08 mSv. Conclusions Prospective ECG-gated high-pitch 128-slice DSCT angiography with low radiation dose and high diagnostic accuracy has higher sensitivity compared to TTE in the detection of congenital extracardiac vascular anomalies in infants and children. PMID:25546178

  6. CT angiography of neonates and infants: comparison of radiation dose and image quality of target mode prospectively ECG-gated 320-MDCT and ungated helical 64-MDCT.

    PubMed

    Jadhav, Siddharth P; Golriz, Farahnaz; Atweh, Lamya A; Zhang, Wei; Krishnamurthy, Rajesh

    2015-02-01

    OBJECTIVE. The purpose of this study was to evaluate the radiation dose and image quality of target mode prospectively ECG-gated volumetric CT angiography (CTA) performed with a 320-MDCT scanner compared with the radiation dose and image quality of ungated helical CTA performed with a 64-MDCT scanner. MATERIALS AND METHODS. An experience with CTA for cardiovascular indications in neonates and infants 0-6 months old was retrospectively assessed. Radiation doses and quantitative and qualitative image quality scores of 28 CTA examinations performed with a 320-MDCT scanner and volumetric target mode prospective ECG gating plus iterative reconstruction (target mode) were compared with the doses and scores of 28 CTA examinations performed with a 64-MDCT scanner and ungated helical scanning plus filtered back projection reconstruction (ungated mode). All target mode studies were performed during free breathing. Seven ungated CTA examinations (25%) were performed with general endotracheal anesthesia. The findings of 17 preoperative CTA examinations performed in target mode were also compared with surgical reports for evaluation of diagnostic accuracy. RESULTS. All studies performed with target mode technique were diagnostic for the main clinical indication. Effective doses were significantly lower in the target mode group (0.51 ± 0.19 mSv) compared with the ungated mode group (4.8 ± 1.4 mSv) (p < 0.0001). Quantitative analysis revealed no statistically significant difference between the two groups with respect to signal-to-noise ratio (of pulmonary artery and aorta) and contrast-to-noise ratio. Subjective image quality was significantly better with target mode than with ungated mode (p < 0.0001). CONCLUSION. Target mode prospectively ECG-gated volumetric scanning with iterative reconstruction performed with a 320-MDCT scanner has several benefits in cardiovascular imaging of neonates and infants, including low radiation dose, improved image quality, high diagnostic

  7. Evaluation of exposure dose reduction in multislice CT coronary angiography (MS-CTA) with prospective ECG-gated helical scan

    NASA Astrophysics Data System (ADS)

    Ota, Takamasa; Tsuyuki, Masaharu; Okumura, Miwa; Sano, Tomonari; Kondo, Takeshi; Takase, Shinichi

    2008-03-01

    A novel low-dose ECG-gated helical scan method to investigate coronary artery diseases was developed. This method uses a high pitch for scanning (based on the patient's heart rate) and X-rays are generated only during the optimal cardiac phases. The dose reduction was obtained using a two-level approach: 1) To use a 64-slice CT scanner (Aquilion, Toshiba, Otawara, Tochigi, Japan) with a scan speed of 0.35 s/rot. to helically scan the heart at a high pitch based on the patient's heart rate. By changing the pitch from the conventional 0.175 to 0.271 for a heart rate of 60 bpm, the exposure dose was reduced to 65%. 2) To employ tube current gating that predicts the timing of optimal cardiac phases from the previous cardiac cycle and generates X-rays only during the required cardiac phases. The combination of high speed scanning with a high pitch and appropriate X-ray generation only in the cardiac phases from 60% to 90% allows the exposure dose to be reduced to 5.6 mSv for patients with a heart rate lower than 65 bpm. This is a dose reduction of approximately 70% compared to the conventional scanning method recommended by the manufacturer when segmental reconstruction is considered. This low-dose protocol seamlessly allows for wide scan ranges (e.g., aortic dissection) with the benefits of ECG-gated helical scanning: smooth continuity for longitudinal direction and utilization of data from all cardiac cycles.

  8. The feasibility of sub-millisievert coronary CT angiography with low tube voltage, prospective ECG gating, and a knowledge-based iterative model reconstruction algorithm.

    PubMed

    Park, Chul Hwan; Lee, Joohee; Oh, Chisuk; Han, Kyung Hwa; Kim, Tae Hoon

    2015-12-01

    We evaluated the feasibility of sub-millisievert (mSv) coronary CT angiography (CCTA) using low tube voltage, prospective ECG gating, and a knowledge-based iterative model reconstruction algorithm. Twenty-four non-obese healthy subjects (M:F 13:11; mean age 50.2 ± 7.8 years) were enrolled. Three sets of CT images were reconstructed using three different reconstruction methods: filtered back projection (FBP), iterative reconstruction (IR), and knowledge-based iterative model reconstruction (IMR). The scanning parameters were as follows: step-and-shoot axial scanning, 80 kVp, and 200 mAs. On the three sets of CT images, the attenuation and image noise values were measured at the aortic root. The signal-to-noise ratio (SNR) and the contrast-to-noise ratio (CNR) were calculated at the proximal right coronary artery and the left main coronary artery. The qualitative image quality of the CCTA with IMR was assessed using a 4-point grading scale (grade 1, poor; grade 4, excellent). The mean radiation dose of the CCTA was 0.89 ± 0.09 mSv. The attenuation values with IMR were not different from those of other reconstruction methods. The image noise with IMR was significantly lower than with IR and FBP. Compared to FBP, the noise reduction rate of IMR was 69 %. The SNR and CNR of CCTA with IMR were significantly higher than with FBP or IR. On the qualitative analysis with IMR, all included segments were diagnostic (grades 2, 3, and 4), and the mean image quality score was 3.6 ± 0.6. In conclusion, CCTA with low tube voltage, prospective ECG gating, and an IMR algorithm might be a feasible method that allows for sub-millisievert radiation doses and good image quality when used with non-obese subjects. PMID:26521066

  9. CT Coronary Angiography: 256-Slice and 320-Detector Row Scanners

    PubMed Central

    Hsiao, Edward M.; Rybicki, Frank J.; Steigner, Michael

    2010-01-01

    Multidetector computed tomography (MDCT) has rapidly evolved from 4-detector row systems in 1998 to 256-slice and 320-detector row CT systems. With smaller detector element size and faster gantry rotation speed, spatial and temporal resolution of the 64-detector MDCT scanners have made coronary artery imaging a reliable clinical test. Wide-area coverage MDCT, such as the 256-slice and 320-detector row MDCT scanners, has enabled volumetric imaging of the entire heart free of stair-step artifacts at a single time point within one cardiac cycle. It is hoped that these improvements will be realized with greater diagnostic accuracy of CT coronary angiography. Such scanners hold promise in performing a rapid high quality “triple rule-out” test without high contrast load, improved myocardial perfusion imaging, and even four-dimensional CT subtraction angiography. These emerging technical advances and novel applications will continue to change the way we study coronary artery disease beyond detecting luminal stenosis. PMID:20425186

  10. Performance characterstics of a commerical ECG gate

    SciTech Connect

    Graham, M.; Cavailloles, F.; Ritchie, J.L.; Williams, D.L.; Hamilton, G.W.

    1980-04-01

    A commercial ECG gate was tested to evaluate its ability to predict accurately the time of end-systole. The predicted times followed the manufacturer's specifications quite well. These times were compared with the actual times of end-systole as determined by computer-derived left-ventricular time-activity curves using Tc-99m-labeled red blood cells. Although there was moderate scatter, the predicted times of end-systole correlated well with the actual time (n = 59, r = 0.829). If the left-ventricular ejection fraction was calculated using the predicted time of end-systole, the error would be 0.03, or less, for 95% of the subjects.

  11. A method for the determination of ECG gate signal delays

    SciTech Connect

    Wery, R.; Hill, J.; Dworkin, H.J.

    1981-06-01

    A simple device using a rotating radioactive source was developed to monitor the presence of a delay between the patient's R wave and the gate signal being sent to the computer. Three commercial ECG gates were tested and significant delays were found in two of them. Identical patient data evaluated using ECG gates with and without significant delays produced calculated left-ventricular ejection fractions of 0.05 and 0.64, respectively.

  12. ECG gated NMR-CT for cardiovascular diseases

    SciTech Connect

    Nishikawa, J.; Ohtake, T.; Machida, K.; Iio, M.; Yoshimoto, N.; Sugimoto, T.

    1985-05-01

    The authors have been applying ECG gated NMR-CT to mainly patients with myocardial infarction (MI), and hypertrophic cardiomyopathy (HCM). Thirteen patients with MI, 8 with HCM and 5 without any heart diseases were studied by ECG gated NMR imaging (spin-echo technique, TR: depends on patient heart rate, TE: 35 and 70 msec.) with 0.35 T superconducting magnet. On NMR images (MRI), the authors examined the wall thickness, wall motion and T/sub 2/ relaxation time in the area of diseased myocardium. The lesions of old MI were depicted as the area of thin wall and T/sub 2/ relaxation time of those lesions were similar to the area of non-infarcted myocardium. The lesions of recent MI (up to 3.5 months from the recent attack) were shown as the same wall thickness as the non-infarcted myocardium and the area of prolonged T/sub 2/ relaxation time compared with that of non-infarcted myocardium. MRI demonstrated diffusely thick myocardium in all patients with HCM. T/sub 2/ relaxation time of the areas of HCM was almost the same as that of normal myocardium, and it's difference among each ventricular wall in patients with HCM was not statistically significant. The authors conclude that ECG gated NMR-CT offers 3-D morphological information of the heart without any contrast material nor radioisotopes. ECG gated MRI provides the useful informations to diagnose MI, especially in the differential diagnosis between old and recent MI.

  13. Measurement of ventricular function by ECG gating during atrial fibrillation

    SciTech Connect

    Bacharach, S.L.; Green, M.V.; Bonow, R.O.; Findley, S.L.; Ostrow, H.G.; Johnston, G.S.

    1981-03-01

    The assumptions necessary to perform ECG-gated cardiac studies are seemingly not valid for patients in atrial fibrillation (AF). To evaluate the effect of AF on equilibrium gated scintigraphy, beat-by-beat measurements of left-ventricular function were made on seven subjects in AF (mean heart rate 64 bpm), using a high-efficiency nonimaging detector. The parameters evaluated were ejection fraction (EF), time to end-systole (TES), peak rates of ejection and filling (PER,PFR), and their times of occurrence (TPER, TPFR). By averaging together single-beat values of EF, PER, etc., it was possible to determine the true mean values of these parameters. The single-beam mean values were compared with the corresponding parameters calculated from one ECG-gated time-activity curve (TAC) obtained by superimposing all the single-beat TACs irrespective of their length. For this population with slow heart rates, we find that the values for EF, etc., produced from ECG-gated time-activity curves, are very similar to those obtained from the single-beat data. Thus use of ECG gating at low heart rates may allow reliable estimation of average cardiac function even in subjects with AF.

  14. Diagnostic quality of time-averaged ECG-gated CT data

    NASA Astrophysics Data System (ADS)

    Klein, Almar; Oostveen, Luuk J.; Greuter, Marcel J. W.; Hoogeveen, Yvonne; Schultze Kool, Leo J.; Slump, Cornelis H.; Renema, W. Klaas Jan

    2009-02-01

    Purpose: ECG-gated CTA allows visualization of the aneurysm and stentgraft during the different phases of the cardiac cycle, although with a lower SNR per cardiac phase than without ECG gating using the same dose. In our institution, abdominal aortic aneurysm (AAA) is evaluated using non-ECG-gated CTA. Some common CT scanners cannot reconstruct a non-gated volume from ECG-gated acquired data. In order to obtain the same diagnostic image quality, we propose offline temporal averaging of the ECG-gated data. This process, though straightforward, is fundamentally different from taking a non-gated scan, and its result will certainly differ as well. The purpose of this study is to quantitatively investigate how good off-line averaging approximates a non-gated scan. Method: Non-gated and ECG-gated CT scans have been performed on a phantom (Catphan 500). Afterwards the phases of the ECG-gated CTA data were averaged to create a third dataset. The three sets are compared with respect to noise properties (NPS) and frequency response (MTF). To study motion artifacts identical scans were acquired on a programmable dynamic phantom. Results and Conclusions: The experiments show that the spatial frequency content is not affected by the averaging process. The minor differences observed for the noise properties and motion artifacts are in favor of the averaged data. Therefore the averaged ECG-gated phases can be used for diagnosis. This enables the use of ECG-gating for research on stentgrafts in AAA, without impairing clinical patient care.

  15. The influence of novel CT reconstruction technique and ECG-gated technique on image quality and patient dose of cardiac computed tomography.

    PubMed

    Dyakov, I; Stoinova, V; Groudeva, V; Vassileva, J

    2015-07-01

    The aim of the present study was to compare image quality and patient dose in cardiac computed tomography angiography (CTA) in terms of volume computed tomography dose index (CTDI vol), dose length product (DLP) and effective dose, when changing from filtered back projection (FBP) to adaptive iterative dose reduction (AIDR) reconstruction techniques. Further aim was to implement prospective electrocardiogram (ECG) gating for patient dose reduction. The study was performed with Aquilion ONE 320-row CT of Toshiba Medical Systems. Analysis of cardiac CT protocols was performed before and after integration of the new software. The AIDR technique showed more than 50 % reduction in CTDIvol values and 57 % in effective dose. The subjective evaluation of clinical images confirmed the adequate image quality acquired by the AIDR technique. The preliminary results indicated significant dose reduction when using prospective ECG gating by keeping the adequate diagnostic quality of clinical images. PMID:25836680

  16. ECG gated NMR-CT for cardiovascular diseases

    SciTech Connect

    Nishikawa, J.; Machida, K.; Iio, M.; Yoshimoto, N.; Sugimoto, T.; Kawaguchi, H.; Mano, H.

    1984-01-01

    The authors applied NMR-CT to cardiac study with ECG gated technique to evaluate the left ventricular (LV) function and compared it with cardiovascular nuclear medicine study (NM). The NMR-CT machine has resistive air-core magnet with 0.15 Tesla. The saturation recovery image or inversion recovery image were obtained as 256 x 256 matrix and 15 mm in thickness. The study population was ten patients who were evaluated both by NMR image and by NM performed within one week interval. The heart muscle was able to be visualized without any contrast material nor radioisotopes in inversion recovery images, whereas saturation recovery images failed to separate heart muscle from blood pool. The wall motions of LV in both methods were well correlated except for inferior wall. The values of ejection fraction in NMR image were moderately low, but two modalities showed satisfactory correlation (r=0.85). The region of myocardial infarction was revealed as wall thinning and/or wall motion abnormality. It is still preliminary to draw a conclusion, however, it can be said that in the evaluation of LV function, method by NMR might be of equal value to those of NM. It can be certain that eventually gated NMR-CT will become more effective method for various aspects of cardiovascular evaluation.

  17. Coronary lesion complexity assessed by SYNTAX score in 256-slice dual-source MDCT angiography

    PubMed Central

    Yüceler, Zeyneb; Kantarcı, Mecit; Tanboğa, İbrahim Halil; Sade, Recep; Kızrak, Yeşim; Pirimoğlu, Berhan; Bayraktutan, Ümmügülsüm; Oğul, Hayri; Aksakal, Enbiya

    2016-01-01

    PURPOSE The SYNTAX Score (SS) has an important role in grading the complexity of coronary artery disease (CAD) in patients undergoing revascularization. Noninvasive determination of SS prior to invasive coronary angiography (ICA) might optimize patient management. We aimed to evaluate the agreement between ICA and multidetector computed tomography (MDCT) while testing the diagnostic effectiveness of SS-MDCT. METHODS Our study included 108 consecutive patients who underwent both MDCT angiography with a 256-slice dual-source MDCT system and ICA within 14±3 days. SS was calculated for both ICA and MDCT coronary angiography. Spearman’s rank correlation coefficient was used to evaluate the association of SS-MDCT with SS-ICA, and Bland-Altman analysis was performed. RESULTS The degree of agreement between SS-ICA and SS-MDCT was moderate. The mean SS-MDCT was 14.5, whereas the mean SS-ICA was 15.9. After dividing SS into three groups (high [≥33], intermediate [23–32], and low [≤22] subgroups), agreement analysis was repeated. There was a significant correlation between SS-MDCT and SS-ICA in the low SS group (r=0.63, P = 0.043) but no significant correlation in the high SS group (r=0.036, P = 0.677). The inter-test agreement analysis showed at least moderate agreement, whereas thrombotic lesions and the type of bifurcation lesion showed fair agreement. CONCLUSION The calculation of SS-MDCT by adapting SS-ICA parameters achieved nearly the same degree of precision as SS-ICA and was better than SS-ICA, especially in the low SS group. PMID:27328718

  18. Non-ECG-Gated Myocardial Perfusion MRI Using Continuous Magnetization-Driven Radial Sampling

    PubMed Central

    Sharif, Behzad; Dharmakumar, Rohan; Arsanjani, Reza; Thomson, Louise; Merz, C. Noel Bairey; Berman, Daniel S.; Li, Debiao

    2014-01-01

    Purpose Establishing a high-resolution non-ECG-gated first-pass perfusion (FPP) cardiac MRI technique may improve accessibility and diagnostic capability of FPP imaging. We propose a non-ECG-gated FPP imaging technique using continuous magnetization-driven golden-angle radial acquisition. The main purpose of this preliminary study is to evaluate whether, in the simple case of single-slice 2D imaging, adequate myocardial contrast can be obtained for accurate visualization of hypoperfused territories in the setting of myocardial ischemia. Methods A T1-weighted pulse sequence with continuous golden-angle radial sampling was developed for non-ECG-gated FPP imaging. A sliding-window scheme with no temporal acceleration was used to reconstruct 8 frames/second. Canines were imaged at 3T with and without coronary stenosis using the proposed scheme and a conventional magnetization-prepared ECG-gated FPP method. Results Our studies showed that the proposed non-ECG-gated method is capable of generating high-resolution (1.7×1.7×6 mm3) artifact-free FPP images of a single slice at high heart rates (92±21 beats/minute), while matching the performance of conventional FPP imaging in terms of hypoperfused-to-normal myocardial contrast-to-noise ratio (proposed: 5.18±0.70, conventional: 4.88±0.43). Furthermore, the detected perfusion defect areas were consistent with the conventional FPP images. Conclusion Non-ECG-gated FPP imaging using optimized continuous golden-angle radial acquisition achieves desirable image quality (i.e., adequate myocardial contrast, high spatial resolution, and minimal artifacts) in the setting of ischemia. PMID:24443160

  19. Evaluation of radiation dose of triple rule-out coronary angiography protocols with different scan length using 256-slice CT

    NASA Astrophysics Data System (ADS)

    Tsai, Chia-Jung; Lee, Jason J. S.; Chen, Liang-Kuang; Mok, Greta S. P.; Hsu, Shih-Ming; Wu, Tung-Hsin

    2011-10-01

    Triple rule-out coronary CT angiography (TRO-CTA) is a new approach for providing noninvasive visualization of coronary arteries with simultaneous evaluation of pulmonary arteries, thoracic aorta and other intrathoracic structures. The increasing use of TRO-CTA examination with longer scan length is associated with the concerns about radiation dose and their corresponding cancer risk. The purpose of this study is to evaluate organ dose and effective dose for the TRO-CTA examination with 2 scan lengths: TRO std and TRO ext, using 256-slice CT. TRO-CTA examinations were performed on a 256-slice CT scanner without ECG-based tube current modulation. Absorbed organ doses were measured using an anthropomorphic phantom and thermal-luminance dosimeters (TLDs). Effective dose was determined by taking a sum of the measured absorbed organ doses multiplied with the tissue weighting factor based on ICRP-103, and compared to that calculated using the dose-length product (DLP) method. We obtained high organ doses in the thyroid, esophagus, breast, heart and lung in both TRO-CTA protocols. Effective doses of the TRO std and TRO ext protocols with the phantom method were 26.37 and 42.49 mSv, while those with the DLP method were 19.68 and 38.96 mSv, respectively. Our quantitative dose information establishes a relationship between radiation dose and scanning length, and can provide a practical guidance to best clinical practice.

  20. ECG gating of thallium-201 myocardial images: effect on detection of ischemic heart disease

    SciTech Connect

    McKillop, J.H.; Fawcett, H.D.; Baumert, J.E.; McDougall, I.R.; DeBusk, R.F.; Harrison, D.C.; Goris, M.L.

    1981-03-01

    Using the angiographic findings as the standard, we have examined the sensitivity and specificity of ECG-gated static thallium-201 myocardial images in 54 patients undergoing selective coronary arteriography. Gated and nongated images, each in anterior, 45 LAO, and 65 LAO projections, were processed by interpolative background subtraction. They were then analyzed separately by four independent observers who were unaware of patient identity, the results of coronary arteriography, and which studies were gated or nonongated. No significant differences were observed between the gated and ngated images regarding sensitivity or specificity, the detection rate for reversible myocardial ischmia, the accuracy of prediction of arteriographic extent of disease, or the degree of inter-or intraobserver variability. We conclude that ECG-gated acquisition of Tl-201 images does not produce any significant advantages, at least when interpolative background subtraction is used.

  1. Effect of heart rate on the diagnostic accuracy of 256-slice computed tomography angiography in the detection of coronary artery stenosis: ROC curve analysis

    PubMed Central

    WANG, GANG; WU, YIFEN; ZHANG, ZHENTAO; ZHENG, XIAOLIN; ZHANG, YULAN; LIANG, MANQIU; YUAN, HUANCHU; SHEN, HAIPING; LI, DEWEI

    2016-01-01

    The aim of the present study was to investigate the effect of heart rate (HR) on the diagnostic accuracy of 256-slice computed tomography angiography (CTA) in the detection of coronary artery stenosis. Coronary imaging was performed using a Philips 256-slice spiral CT, and receiver operating characteristic (ROC) curve analysis was conducted to evaluate the diagnostic value of 256-slice CTA in coronary artery stenosis. The HR of the research subjects in the study was within a certain range (39–107 bpm). One hundred patients suspected of coronary heart disease underwent 256-slice CTA examination. The cases were divided into three groups: Low HR (HR <75 bpm), moderate HR (75≤ HR <90 bpm) and high HR (HR ≥90 bpm). For the three groups, two observers independently assessed the image quality for all coronary segments on a four-point ordinal scale. An image quality of grades 1–3 was considered diagnostic, while grade 4 was non-diagnostic. A total of 97.76% of the images were diagnostic in the low-HR group, 96.86% in the moderate-HR group and 95.80% in the high-HR group. According to the ROC curve analysis, the specificity of CTA in diagnosing coronary artery stenosis was 98.40, 96.00 and 97.60% in the low-, moderate- and high-HR groups, respectively. In conclusion, 256-slice coronary CTA can be used to clearly show the main segments of the coronary artery and to effectively diagnose coronary artery stenosis. Within the range of HRs investigated, HR was found to have no significant effect on the diagnostic accuracy of 256-slice coronary CTA for coronary artery stenosis. PMID:27168831

  2. Infant Cardiac CT Angiography with 64-Slice and 256-Slice CT: Comparison of Radiation Dose and Image Quality Using a Pediatric Phantom

    PubMed Central

    Mok, Greta S. P.; Wu, Tung-Hsin

    2012-01-01

    Background The aims of this study were to investigate the image quality and radiation exposure of pediatric protocols for cardiac CT angiography (CTA) in infants under one year of age. Methodology/Principal Findings Cardiac CTA examinations were performed using an anthropomorphic phantom representing a 1-year-old child scanned with non-electrocardiogram-gated (NG), retrospectively electrocardiogram-gated helical (RGH) and prospectively electrocardiogram-gated axial (PGA) techniques in 64-slice and 256-slice CT scanners. The thermoluminescent dosimeters (TLD) were used for direct organ dose measurement, while dose-length product and effective mAs were also used to estimate the patient dose. For image quality, noise and signal-to-noise-ratio (SNR) were assessed based on regions-of-interest drawn on the reconstructed CT images, and were compared with the proposed cardiac image quantum index (CIQI). Estimated dose results were in accordant to the measured doses. The NG scan showed the best image quality in terms of noise and SNR. The PGA scan had better image quality than the RGH scan with 83.70% dose reduction. Noise and SNR were also corresponded to the proposed CIQI. Conclusions/Significance The PGA scan protocol was a good choice in balancing radiation exposure and image quality for infant cardiac CTA. We also suggested that the effective mAs and the CIQI were suitable in assessing the tradeoffs between radiation dose and image quality for cardiac CTA in infants. These results are useful for future implementation of dose reduction strategies in pediatric cardiac CTA protocols. PMID:23185380

  3. ECG-gated emission computed tomography of the cardiac blood pool

    SciTech Connect

    Moore, M.L.; Murphy, P.H.; Burdine, J.A.

    1980-01-01

    ECG-gated cross-sectional images of the cardiac blood pool were produced using a specially constructed emission computed tomographic scanner. A pair of large-field-of-view cameras were mounted in opposition in a gantry that rotates 360/sup 0/ about the patient. The coordinates of each detected event, the output of a physiological synchronizer, and the position of the camera heads were input to a dedicated minicomputer which was used to produce the images. Display as a movie permitted evaluation of regional and global wall motion in cross section without the disadvantages of superimposed blood pools as obtained in nontomographic views.

  4. Three dimensional quantification of left ventricular wall motion by ECG-gated blood pool emission tomography

    SciTech Connect

    Underwood, S.R.; Walton, S.; Laming, P.J.; Jarritt, P.H.; Ell, P.J.; Emanuel, R.W.; Swanton, R.H.

    1985-05-01

    ECG-gated blood pool emission tomography is a relatively new technique, and this study establishes a simple method for displaying the three dimensional data obtained, determines a normal range for ejection fraction in all regions of the left ventricle, and compares wall motion in abnormal subjects with that determined by X-ray contrast ventriculography. The short axis sections dividing the ventricle in slices from apex to base, were used to calculate ejection fraction for all parts of the ventricle and the results were plotted on a single colour coded circular image. The apex was represented in the centre, the base around the circumference, and all other parts of the ventricle were represented in between. The image was divided into 15 segments, and normal segmental ejection fraction was defined as within two standard deviations of the mean in a group of 10 normal subjects. In 25 subjects with coronary artery disease, motion of the anterior, apical, and inferior walls agreed in every case with the right anterior oblique contrast ventriculogram, but in 12 of these, the three dimensional ejection fraction image showed abnormal septal motion, and in a further 3, abnormal lateral wall motion in addition. In the 12 subjects there was disease of the left anterior descending coronary artery, and in the further 3 there was left circumflex disease. ECG-gated blood pool emission tomography thus provides an accurate quantitative assessment of left ventricular wall motion in three dimensions, and has significant advantages over conventional planar techniques.

  5. Comparison between echocardiographic and non-ECG-gated CT measurements in dogs.

    PubMed

    Laborda-Vidal, P; Maddox, T W; Navarro-Cubas, X; Dukes-McEwan, J; McConnell, J F

    2015-03-28

    The aim of this study was to compare echocardiographic measurements with non-ECG-gated contrast-enhanced cardiac CT measurements in dogs. Fifty-seven dogs were included in the study. The following echocardiographic parameters were measured: M-mode interventricular septum in diastole and systole, left ventricular internal diameter in diastole and systole, left ventricular free wall in diastole and systole, 2D left atrial maximal diameter, 2D left atrium to aorta ratio in diastole, 2D aortic annulus in systole and 2D pulmonary annulus in diastole and systole. CT measurements were obtained from multiplanar reconstruction images, replicating the imaging planes used for 2D measurements on echocardiography. It was not possible to discriminate between systole and diastole. The results showed moderate Lin's concordance correlation coefficients between the left ventricular internal diameter in systole (0.77), the aortic annuli (0.84) and the pulmonary annuli in diastole (0.78) and systole (0.80). Low coefficients were obtained between the other parameters. Bland-Altman plots for the parameters with highest concordance correlation coefficients were calculated. They suggested equivalence between the measurements of the aortic annuli. Equivalence was not seen between the remaining echocardiographic and CT measurements. Therefore, non-ECG-gated CT is not a reliable way of quantitatively assessing cardiac size. PMID:25694270

  6. Respiratory Motion Detection and Correction in ECG-Gated SPECT: a New Approach

    PubMed Central

    Bitarafan, Ahmad; Rajabi, Hossein; Gruy, Bernhard; Rustgou, Feridoon; Sharafi, Ali Akbar; Firoozabady, Hasan; Yaghoobi, Nahid; Malek, Hadi; Pirich, Christian; Langesteger, Werner

    2008-01-01

    .001 versus y = 0.8046x + 5.1704; r = 0.89, p < 0.001). Nineteen (19/26) patients (73.1%) showed abnormal myocardial perfusion scans with reversible regional myocardial defects; of the 19 patients, 14 (14/26) patients underwent coronary angiography. Conclusion Respiratory induced motion can be successfully corrected simultaneously with the use of ECG-gated SPECT in MPI studies using this proposed technique. Moreover, the use of ECG-gated SPECT improved image quality, especially in the inferior and septal regions that are mostly affected by diaphragmatic attenuation. However, the effect of respiratory correction depends mainly on the patient respiratory pattern and may be clinically relevant in certain cases. PMID:19039264

  7. Automated segmentation and tracking of coronary arteries in ECG-gated cardiac CT scans

    NASA Astrophysics Data System (ADS)

    Zhou, Chuan; Chan, Heang-Ping; Chughtai, Aamer; Patel, Smita; Agarwal, Prachi; Hadjiiski, Lubomir M.; Sahiner, Berkman; Wei, Jun; Ge, Jun; Kazerooni, Ella A.

    2008-03-01

    Cardiac CT has been reported to be an effective means for clinical diagnosis of coronary artery plaque disease. We are investigating the feasibility of developing a computer-assisted image analysis (CAA) system to assist radiologist in detection of coronary artery plaque disease in ECG-gated cardiac CT scans. The heart region was first extracted using morphological operations and an adaptive EM thresholding method. Vascular structures in the heart volume were enhanced by 3D multi-scale filtering and analysis of the eigenvalues of Hessian matrices using a vessel enhancement response function specially designed for coronary arteries. The enhanced vascular structures were then segmented by an EM estimation method. Finally, our newly developed 3D rolling balloon vessel tracking method (RBVT) was used to track the segmented coronary arteries. Starting at two manually identified points located at the origins of left and right coronary artery (LCA and RCA), the RBVT method moved a sphere of adaptive diameter along the vessels, tracking the vessels and identifying its branches automatically to generate the left and right coronary arterial trees. Ten cardiac CT scans that contained various degrees of coronary artery diseases were used as test data set for our vessel segmentation and tracking method. Two experienced thoracic radiologists visually examined the computer tracked coronary arteries on a graphical interface to count untracked false-negative (FN) branches (segments). A total of 27 artery segments were identified to be FNs in the 10 cases, ranging from 0 to 6 FN segments in each case. No FN artery segment was found in 2 cases.

  8. An integrated bioimpedance—ECG gating technique for respiratory and cardiac motion compensation in cardiac PET

    NASA Astrophysics Data System (ADS)

    Koivumäki, Tuomas; Nekolla, Stephan G.; Fürst, Sebastian; Loher, Simone; Vauhkonen, Marko; Schwaiger, Markus; Hakulinen, Mikko A.

    2014-10-01

    Respiratory motion may degrade image quality in cardiac PET imaging. Since cardiac PET studies often involve cardiac gating by ECG, a separate respiratory monitoring system is required increasing the logistic complexity of the examination, in case respiratory gating is also needed. Thus, we investigated the simultaneous acquisition of both respiratory and cardiac gating signals using II limb lead mimicking electrode configuration during cardiac PET scans of 11 patients. In addition to conventional static and ECG-gated images, bioimpedance technique was utilized to generate respiratory- and dual-gated images. The ability of the bioimpedance technique to monitor intrathoracic respiratory motion was assessed estimating cardiac displacement between end-inspiration and -expiration. The relevance of dual gating was evaluated in left ventricular volume and myocardial wall thickness measurements. An average 7.6  ±  3.3 mm respiratory motion was observed in the study population. Dual gating showed a small but significant increase (4 ml, p = 0.042) in left ventricular myocardial volume compared to plain cardiac gating. In addition, a thinner myocardial wall was observed in dual-gated images (9.3  ±  1.3 mm) compared to cardiac-gated images (11.3  ±  1.3 mm, p = 0.003). This study shows the feasibility of bioimpedance measurements for dual gating in a clinical setting. The method enables simultaneous acquisition of respiratory and cardiac gating signals using a single device with standard ECG electrodes.

  9. ECG-gated blood pool tomography in the determination of left ventricular volume, ejection fraction, and wall motion

    SciTech Connect

    Underwood, S.R.; Ell, P.J.; Jarritt, P.H.; Emanuel, R.W.; Swanton, R.H.

    1984-01-01

    ECG-gated blood pool tomography promises to provide a ''gold standard'' for noninvasive measurement of left ventricular volume, ejection fraction, and wall motion. This study compares these measurements with those from planar radionuclide imaging and contrast ventriculography. End diastolic and end systolic blood pool images were acquired tomographically using an IGE400A rotating gamma camera and Star computer, and slices were reconstructed orthogonal to the long axis of the heart. Left ventricular volume was determined by summing the areas of the slices, and wall motion was determined by comparison of end diastolic and end systolic contours. In phantom experiments this provided an accurate measurement of volume (r=0.98). In 32 subjects who were either normal or who had coronary artery disease left ventricular volume (r=0.83) and ejection fraction (r=0.89) correlated well with those using a counts based planar technique. In 16 of 18 subjects who underwent right anterior oblique X-ray contrast ventriculography, tomographic wall motion agreed for anterior, apical, and inferior walls, but abnormal septal motion which was not apparent by contrast ventriculography, was seen in 12 subjects tomographically. All 12 had disease of the left anterior descending coronary artery and might have been expected to have abnormal septal motion. ECG-gated blood pool tomography can thus determine left ventricular volume and ejection fraction accurately, and provides a global description of wall motion in a way that is not possible from any single planar image.

  10. [ECG-gated myocardial SPECT with 99mTc-MIBI in patients with right ventricular infarction].

    PubMed

    Kumita, S; Mizumura, S; Cho, K; Kijima, T; Kumazaki, T; Tetsuou, Y; Sakai, S; Sano, J; Kusama, Y; Munakata, K

    1996-06-01

    Although 99mTc-pyrophosphate (PYP) myocardial scintigraphy has so far been widely used for the diagnosis of right ventricular infarction, PYP accumulation disappears within one week or so. To evaluate the myocardial condition of the right ventricle alternatively, myocardial SPECT with 99mTc-MIBI was performed in 16 patients with acute inferior left ventricular infarction, and ECG-gated myocardial SPECT data acquisition was accompanied in 14 of 16 patients. Right ventricular perfusion defect was observed in 4 of 16 patients (RVI (+) group), and the remains were negative (RVI (-) group). Then, right ventricular count increase rate (RV %WT) of MIBI from end-diastole to end-systole was calculated using an automated method which was developed for quantification of wall thickening in our laboratory. The RV %WT was conceived to be an objective index representing right ventricular contractility. RVI (+) group (n = 3) as compared with RVI (-) group (n = 11) had significant lower RV %WT (26.7 +/- 3.2 vs. 49.6 +/- 14.2; p < 0.01). In conclusion, ECG-gated myocardial SPECT with MIBI was considered to be useful for assessment of myocardial perfusion and contractility of right ventricle. PMID:8741508

  11. Coronary Plaque Characteristics Assessed by 256-Slice Coronary CT Angiography and Association with High-Sensitivity C-Reactive Protein in Symptomatic Patients with Type 2 Diabetes

    PubMed Central

    Zhang, Jinling; Lv, Zhehao; Zhao, Deli; Liu, Lili; Wan, Yong; Fan, Tingting; Li, Huimin; Guan, Ying; Liu, Bailu

    2016-01-01

    Little is known regarding plaque distribution, composition, and the association with inflammation in type 2 diabetes mellitus (DM2). This study aimed to assess the relationship between coronary plaque subtypes and high-sensitivity C-reactive protein levels. Coronary CTA were performed in 98 symptomatic DM2 patients and 107 non-DM2 patients using a 256-slice CT. The extent and types of plaque as well as luminal narrowing were evaluated. Patients with DM2 were more likely to have significant stenosis (>50%) with calcified plaques in at least one coronary segment (p < 0.01); the prevalence rates of diffuse calcified plaques in the DM2 and non-DM2 groups were 31.6% and 4.7%, respectively (p < 0.01). Plasma hs-CRP levels in DM2 with calcified plaques were higher compared with values obtained for the non-DM2 group (p < 0.01). In conclusion, combination of coronary CTA and hs-CRP might improve risk stratification in symptomatic DM2 patients. PMID:27579325

  12. Coronary Plaque Characteristics Assessed by 256-Slice Coronary CT Angiography and Association with High-Sensitivity C-Reactive Protein in Symptomatic Patients with Type 2 Diabetes.

    PubMed

    Zhang, Jinling; Lv, Zhehao; Zhao, Deli; Liu, Lili; Wan, Yong; Fan, Tingting; Li, Huimin; Guan, Ying; Liu, Bailu; Yang, Qi

    2016-01-01

    Little is known regarding plaque distribution, composition, and the association with inflammation in type 2 diabetes mellitus (DM2). This study aimed to assess the relationship between coronary plaque subtypes and high-sensitivity C-reactive protein levels. Coronary CTA were performed in 98 symptomatic DM2 patients and 107 non-DM2 patients using a 256-slice CT. The extent and types of plaque as well as luminal narrowing were evaluated. Patients with DM2 were more likely to have significant stenosis (>50%) with calcified plaques in at least one coronary segment (p < 0.01); the prevalence rates of diffuse calcified plaques in the DM2 and non-DM2 groups were 31.6% and 4.7%, respectively (p < 0.01). Plasma hs-CRP levels in DM2 with calcified plaques were higher compared with values obtained for the non-DM2 group (p < 0.01). In conclusion, combination of coronary CTA and hs-CRP might improve risk stratification in symptomatic DM2 patients. PMID:27579325

  13. ECG-gated blood-pool study of carotid arterial pulsation as a sign of stenosis: concise communication

    SciTech Connect

    Winston, M.A.; Cohen, S.N.

    1983-06-01

    The large elastic arteries, such as the carotids, pulsate (expand and contract) in synchrony with the heart beat. These pulsations should be reduced by significant stenosis. This hypothesis was studied in 15 men by obtaining sequential ECG-gated labeled blood-pool images of these vessels in anterior and lateral oblique views. These were computer processed by a functional program that displays each pixel with an intensity proportional to its change in activity level during the cardiac cycle. Blank areas indicated lack of pulsation and were correlated with angiographic studies. The blank skip areas were present when there was 50% or greater narrowing in arterial diameter (94% sensitivity) but were not seen in patients with normal or minimally diseased vessels (25% or less narrowing). They were present inconsistently in the four vessels with 25 to 50% narrowing.

  14. Idiopathic hypertrophic sub-aortic stenosis (IHSS): a new diagnostic method using ECG-gated thallium-201 myocardial scintigraphy.

    PubMed

    Garty, I; Flatau, E; Bloch, L

    1985-12-01

    A new diagnostic method for idiopathic hypertrophic sub-aortic stenosis (IHSS), using synchronized ECG gated 201Tl myocardial scintigraphy, is described. Twenty patients previously diagnosed as IHSS were evaluated by sequential three-view ECG gated 201Tl and 45 degrees left anterior oblique multigated (MUGA) cardiac blood pool imaging (Group A). The results were compared with two control groups: 20 patients with no previous history of heart disease (Group B), and 20 patients with coronary ischaemic heart disease (Group C). We suggest the following combination of scintigraphic signs as typical and diagnostic to obstructive IHSS: Elevated left ventricular ejection fraction (mean 83.9% +/- 6.15S.D. versus 72.5% +/- 5.35S.D. and 51.2% +/- 13.65S.D. in Groups B and C respectively); Systolic left ventricular cavity obliteration (71% of obstructive IHSS patients versus 0% in Groups B and C); A ratio of more than 1.3:1 in septal to free wall thickness (100% of patients with IHSS); Perfusion/wall-motion mismatch of septum was demonstrated in all (100%) of patients with IHSS (versus 0% in Group B and 10% in Group C). We suggest this last finding as a new specific diagnostic sign for IHSS, with the ability to differentiate between patients with ischaemic coronary heart disease and IHSS patients; whilst both groups may present chest pains, the first group was characterized by 'matching' of perfusion and motion of the affected myocardial wall while the patients with IHSS had 'mismatching' of these parameters. We suggest gated 201Tl myocardial scintigraphy as an additional sensitive tool for the early diagnosis and evaluation of IHSS patients. PMID:3831851

  15. [Left ventricular early diastolic filling and atrial contribution assessed by ECG-gated cardiac blood pool scintigraphy].

    PubMed

    Kondo, T; Hishida, H; Furuta, T; Sawano, T; Kurokawa, H; Kiriyama, T; Kato, Y; Watanabe, Y; Mizuno, Y; Takeuchi, A

    1986-01-01

    This study evaluated early diastolic left ventricular (LV) filling and the atrial contribution to ventricular filling in patients (pts) with various heart diseases using ECG-gated cardiac blood pool scintigraphy. Conventional equilibrium list mode ECG-gated cardiac blood pool scintigraphy was performed for 19 normal subjects (N) as controls, 104 pts with old myocardial infarction (OMI), 19 pts with essential hypertension (HT), seven pts with idiopathic hypertrophic subaortic stenosis (IHSS), three pts with non-obstructive hypertrophic cardiomyopathy (HCM), 19 pts with pure mitral stenosis (MS) and one pt with both MS and aortic regurgitation to evaluate early diastolic LV filling. The LV stroke counts corresponding to stroke volume and the early diastolic LV peak filling rate (DdV/dt) were obtained from the LV time-activity curve and its first derivative. Then the DdV/dt was normalized by stroke counts. The DdV/dt was significantly lower in pts with OMI (4.34 +/- 1.02/sec, p less than 0.001), HT (3.93 +/- 0.70/sec, p less than 0.001), IHSS (4.23 +/- 1.59/sec, p less than 0.01) and MS (4.56 +/- 1.05/sec, p less than 0.01) than in N (5.93 +/- 1.26/sec). Then, in OMI, the DdV/dt correlated significantly (r = -0.45, p less than 0.05) with infarct size (% abnormal contracting segment = %ACS) obtained by contrast left ventriculography. Furthermore, in pts with HT, the DdV/dt correlated significantly (r = -0.59, p less than 0.02) with the left ventricular mean wall thickness obtained by M-mode echocardiography. In pts with MS, the DdV/dt also correlated significantly (r = 0.73, p less than 0.001) with the mitral orifice area obtained by two-dimensional echocardiography. However, it has been difficult to assess the atrial contribution to ventricular filling by conventional ECG-gated cardiac blood pool scintigraphy, because the LV time-activity curve in the late diastolic phase was distorted and unreliable, whenever a minimal variation of the R-R interval occurred

  16. Noninvasive assessment of coronary artery disease by multislice spiral computed tomography using a new retrospectively ECG-gated image reconstruction technique.

    PubMed

    Sato, Yuichi; Matsumoto, Naoya; Kato, Masahiko; Inoue, Fumio; Horie, Toshiyuki; Kusama, Junji; Yoshimura, Akihiro; Imazeki, Takako; Fukui, Takahiro; Furuhashi, Satoru; Takahashi, Motoichiro; Kanmatsuse, Katsuo

    2003-05-01

    The present study was designed to investigate the accuracy of multislice spiral computed tomography (MSCT) in detecting coronary artery disease, compared with coronary angiography (CAG), using a new retrospectively ECG-gated reconstruction method that reduced cardiac motion artifact. The study group comprised 54 consecutive patients undergoing MSCT and CAG. MSCT was performed using a SOMATOM Volume Zoom (4-detector-row, Siemens, Germany) with slice thickness 1.0 mm, pitch 1.5 (table feed: 1.5 mm per rotation) and gantry rotation time 500 ms. Metoprolol (20-60 mg) was administered orally prior to MSCT imaging. ECG-gated image reconstruction was performed with the reconstruction window (250 ms) positioned immediately before atrial contraction in order to reduce the cardiac motion artifact caused by the abrupt diastolic ventricular movement occurring during the rapid filling and atrial contraction periods. Following inspection of the volume rendering images, multiplanar reconstruction images and axial images of the left main coronary artery (LMCA), left anterior descending artery (LAD), left circumflex artery (LCx) and right coronary artery (RCA) were obtained and evaluated for luminal narrowing. The results were compared with those obtained by CAG. Of 216 coronary arteries, 206 (95.4%) were assessable; 10 arteries were excluded from the analysis because of severe calcification (n=4), stents (n=3) or insufficient contrast enhancement (n=3). The sensitivity to detect coronary stenoses >or=50% was 93.5% and the specificity to define luminal narrowing <50% was 97.2%. The positive predictive value and the negative predictive value were 93.5% and 97.2%, respectively. The sensitivity was still satisfactory (80.6%) even when non-assessable arteries were included in the analysis. The new retrospectively ECG-gated reconstruction method for MSCT has excellent diagnostic accuracy in detecting significant coronary artery stenoses. PMID:12736477

  17. Abdominal Aortic Intimal Flap Motion Characterization in Acute Aortic Dissection: Assessed with Retrospective ECG-Gated Thoracoabdominal Aorta Dual-Source CT Angiography

    PubMed Central

    Yang, Shifeng; Li, Xia; Chao, Baoting; Wu, Lebin; Cheng, Zhaoping; Duan, Yanhua; Wu, Dawei; Zhan, Yiqiang; Chen, Jiuhong; Liu, Bo; Ji, Xiaopeng; Nie, Pei; Wang, Ximing

    2014-01-01

    Objectives To evaluate the feasibility of dose-modulated retrospective ECG-gated thoracoabdominal aorta CT angiography (CTA) assessing abdominal aortic intimal flap motion and investigate the motion characteristics of intimal flap in acute aortic dissection (AAD). Materials and Methods 49 patients who had thoracoabdominal aorta retrospective ECG-gated CTA scan were enrolled. 20 datasets were reconstructed in 5% steps between 0 and 95% of the R-R interval in each case. The aortic intimal flap motion was assessed by measuring the short axis diameters of the true lumen and false lumen 2 cm above of celiac trunk ostium in different R-R intervals. Intimal flap motion and configuration was assessed by two independent observers. Results In these 49 patients, 37 had AAD, 7 had intramural hematoma, and 5 had negative result for acute aortic disorder. 620 datasets of 31 patients who showed double lumens in abdominal aorta were enrolled in evaluating intimal flap motion. The maximum and minimum true lumen diameter were 12.2±4.1 mm (range 2.6∼17.4) and 6.7±4.1 mm (range 0∼15.3) respectively. The range of intimal flap motion in all patients was 5.5±2.6 mm (range 1.8∼10.2). The extent of maximum true lumen diameter decreased during a cardiac cycle was 49.5%±23.5% (range 12%∼100%). The maximum motion phase of true lumen diameter was in systolic phase (5%∼40% of R-R interval). Maximum and minimum intimal flap motion was at 15% and 75% of the R-R interval respectively. Intimal flap configuration had correlation with the phase of cardiac cycle. Conclusions Abdominal intimal flap position and configuration varied greatly during a cardiac cycle. Retrospective ECG-gated thoracoabdominal aorta CTA can reflect the actual status of the true lumen and provide more information about true lumen collapse. This information may be helpful to diagnosis and differential diagnosis of dynamic abstraction. PMID:24503676

  18. The effect of head size/shape, miscentering, and bowtie filter on peak patient tissue doses from modern brain perfusion 256-slice CT: How can we minimize the risk for deterministic effects?

    SciTech Connect

    Perisinakis, Kostas; Seimenis, Ioannis; Tzedakis, Antonis; Papadakis, Antonios E.; Damilakis, John

    2013-01-15

    Purpose: To determine patient-specific absorbed peak doses to skin, eye lens, brain parenchyma, and cranial red bone marrow (RBM) of adult individuals subjected to low-dose brain perfusion CT studies on a 256-slice CT scanner, and investigate the effect of patient head size/shape, head position during the examination and bowtie filter used on peak tissue doses. Methods: The peak doses to eye lens, skin, brain, and RBM were measured in 106 individual-specific adult head phantoms subjected to the standard low-dose brain perfusion CT on a 256-slice CT scanner using a novel Monte Carlo simulation software dedicated for patient CT dosimetry. Peak tissue doses were compared to corresponding thresholds for induction of cataract, erythema, cerebrovascular disease, and depression of hematopoiesis, respectively. The effects of patient head size/shape, head position during acquisition and bowtie filter used on resulting peak patient tissue doses were investigated. The effect of eye-lens position in the scanned head region was also investigated. The effect of miscentering and use of narrow bowtie filter on image quality was assessed. Results: The mean peak doses to eye lens, skin, brain, and RBM were found to be 124, 120, 95, and 163 mGy, respectively. The effect of patient head size and shape on peak tissue doses was found to be minimal since maximum differences were less than 7%. Patient head miscentering and bowtie filter selection were found to have a considerable effect on peak tissue doses. The peak eye-lens dose saving achieved by elevating head by 4 cm with respect to isocenter and using a narrow wedge filter was found to approach 50%. When the eye lies outside of the primarily irradiated head region, the dose to eye lens was found to drop to less than 20% of the corresponding dose measured when the eye lens was located in the middle of the x-ray beam. Positioning head phantom off-isocenter by 4 cm and employing a narrow wedge filter results in a moderate reduction of

  19. Assessment of systolic thickening with thallium-201 ECG-gated single-photon emission computed tomography: A parameter for local left ventricular function

    SciTech Connect

    Mochizuki, T.; Murase, K.; Fujiwara, Y.; Tanada, S.; Hamamoto, K.; Tauxe, W.N. )

    1991-08-01

    The authors measured left ventricular (LV) systolic thickening expressed as a systolic thickening ratio in 28 patients, using 201Tl ECG-gated SPECT. Five normals, 15 patients with prior myocardial infarction, 5 with hypertrophic cardiomyopathy, and 3 with dilated cardiomyopathy were studied. The systolic thickening ratio was calculated as ((end-systolic--end-diastolic pixel counts) divided by end-diastolic pixel counts), using the circumferential profile technique of both end-diastolic and end-systolic short axial images. Functional images of the systolic thickening ratio were also displayed with the bull's-eye method. The mean systolic thickening ratio thus calculated were as follows: normals, 0.53 {plus minus} 0.05 (mean {plus minus} 1 s.d.); non-transmural prior myocardial infarction, 0.33 {plus minus} 0.09; transmural prior myocardial infarction, 0.14 {plus minus} 0.05; hypertrophic cardiomyopathy in relatively nonhypertrophied areas, 0.56 {plus minus} 0.11; hypertrophic cardiomyopathy in hypertrophied areas, 0.23 {plus minus} 0.07; and dilated cardiomyopathy, 0.19 {plus minus} 0.02. The systolic thickening ratio analysis by gated thallium SPECT offers a unique approach for assessing LV function.

  20. Assessment of the evaluation of liver T1 mapping imaging applying virtual ECG gating on a modified look-locker inversion recovery (MOLLI) pulse sequence

    NASA Astrophysics Data System (ADS)

    Yu, Seung-Man; Goo, Eun-Hoe; Lee, Suk-Jun; Choe, Bo-Young

    2014-10-01

    A T1 mapping calculation error may occur in a physicochemical environment with large relaxivity. We evaluated through a simulated electrocardiogram (ECG) the administration of a contrast with high relaxivity and its effect on the heart rate by using a modified Look-Locker inversion recovery (MOLLI) pulse sequence. The agarose 2% phantom of high relaxivity environment was developed by diluting gadoxetic acid magnetic resonance imaging (MRI) T1 contrast media. The gold standard T1 determination was based on coronal single section imaging with a 2D inversion-recovery turbo spin echo sequence (2D-IRTSE) in a 3T MR unit. Using the identical 3T MR scanner, we acquired T1 mapping for the MOLLI pulse sequence with various virtual heart rates. T1 mapping data of the two different pulse sequences ( i.e., 2D-IRTSE and MOLLI) were measured to investigate the accuracy and the specificity. An in vivo study was conducted in the same manner as the phantom experiments for liver T1 mapping imaging in three healthy volunteers. The MOLLI pulse sequence showed an error rate of less than 10% at a contrast agent concentration of 0.4 mmol/L, and significant error, compared with the reference value, was observed at 0.6 mmol/L or higher. The percentage error of the T1 value did not correlated with the RR ( i.e., the time between heart beats) change that was observed (P =.270). Based on the in-vivo liver test, T1 mapping imaging of an abdominal organ as the liver can be successfully achieved using the applied virtual ECG gating on the MOLLI sequence.

  1. Erroneous cardiac ECG-gated PET list-mode trigger events can be retrospectively identified and replaced by an offline reprocessing approach: first results in rodents

    NASA Astrophysics Data System (ADS)

    Böning, Guido; Todica, Andrei; Vai, Alessandro; Lehner, Sebastian; Xiong, Guoming; Mille, Erik; Ilhan, Harun; la Fougère, Christian; Bartenstein, Peter; Hacker, Marcus

    2013-11-01

    The assessment of left ventricular function, wall motion and myocardial viability using electrocardiogram (ECG)-gated [18F]-FDG positron emission tomography (PET) is widely accepted in human and in preclinical small animal studies. The nonterminal and noninvasive approach permits repeated in vivo evaluations of the same animal, facilitating the assessment of temporal changes in disease or therapy response. Although well established, gated small animal PET studies can contain erroneous gating information, which may yield to blurred images and false estimation of functional parameters. In this work, we present quantitative and visual quality control (QC) methods to evaluate the accuracy of trigger events in PET list-mode and physiological data. Left ventricular functional analysis is performed to quantify the effect of gating errors on the end-systolic and end-diastolic volumes, and on the ejection fraction (EF). We aim to recover the cardiac functional parameters by the application of the commonly established heart rate filter approach using fixed ranges based on a standardized population. In addition, we propose a fully reprocessing approach which retrospectively replaces the gating information of the PET list-mode file with appropriate list-mode decoding and encoding software. The signal of a simultaneously acquired ECG is processed using standard MATLAB vector functions, which can be individually adapted to reliably detect the R-peaks. Finally, the new trigger events are inserted into the PET list-mode file. A population of 30 mice with various health statuses was analyzed and standard cardiac parameters such as mean heart rate (119 ms ± 11.8 ms) and mean heart rate variability (1.7 ms ± 3.4 ms) derived. These standard parameter ranges were taken into account in the QC methods to select a group of nine optimal gated and a group of eight sub-optimal gated [18F]-FDG PET scans of mice from our archive. From the list-mode files of the optimal gated group, we

  2. ECG Gated Ultrasonic Small Animal Imaging.

    PubMed

    Liu, Jian-Hung; Jeng, Geng-Shi; Wu, Tung-Ke; Li, Pai-Chi

    2005-01-01

    Echocardiography is a routine clinical procedure to diagnose cardiac functions. The organic structure of the mouse is similar to that of human so that murine echocardiography has potentially become an effective tool for the assessment of human cardiovascular disease. However, clinical ultrasonic imaging systems are not suitable for murine cardiac imaging due to its limited spatial and temporal resolution. Thus, high frequency ultrasonic imaging (≥ 20 MHz) is necessary in order to provide spatial resolution at the order of 100 μm. Furthermore, due to the lack of transducer arrays at such a high frequency, single-element transducer with mechanical scanning is typically used. Thus the frame rate is insufficient for imaging the quick motion of the mouse. In this paper, a high frequency ultrasonic imaging system with electrocardiography gating is built in order to provide both high spatial resolution and high temporal effecting resolution. The system utilizes the R-wave trigger signal from murine electrocardiography. Image data are acquired in either the block scanning mode or the line scanning mode. In block scanning, murine cardiac images in systole and diastole can be retrospectively reconstructed with a short data acquisition time. In line scanning, on the other hand, images during the entire cardiac cycle can be obtained. It is demonstrated that the effective frame rate can be up to 2 kHz, which is only limited by the pulse repetition rate of the system. PMID:17282556

  3. Comprehensive Evaluation of Cardiac Hydatid Using 256 Slice Dual Source CT: One Stop Shop

    PubMed Central

    Sethi, Sonali; Gupta, Nishant; Goel, Vandana; Puri, Sunil Kumar

    2015-01-01

    Hydatid disease results from infection with larval stage of Echinococcus granulosus tapeworm. Dogs and other canines are the definitive hosts; Human beings are common accidental intermediate hosts. Liver is the most common organ to be involved in this condition. Cardiac hydatid, seen in only 0.5 to 2% cases, is a rare entity because of myocardial contractility. Larvae reach the myocardium through coronary circulation. Among various locations of cardiac hydatid, due to its rich coronary arterial supply Left ventricle (LV) myocardium is the most common site of involvement followed by interventricular septum and right ventricle. Rare locations include pericardium, right atrium and left atrium. A 50-year-old woman presented with dyspnoea for 11 months, chest X-ray showed a well defined, homogenous left paracardiac mass, which is not separable from left heart border. Transthoracic echocardiography revealed a complex multicystic mass lesion abutting antero-lateral wall of left ventricle. Contrast enhanced computed tomography showed a well-circumscribed multicystic mass lesion with honeycomb appearance arising from myocardium of anterolateral wall of left ventricle. Indirect haemagglutination test for hydatid disease was positive. At surgery the cyst was seen to arise from LV myocardium. It was incised and grape like contents were evacuated. The cavity was irrigated with scolicidal solution. Thereafter, the cyst was marsupialised. Histopathological examination revealed grape like cyst contents consistent with the diagnosis of hydatid cyst. PMID:26557591

  4. Comparison Between Prospectively Electrocardiogram-Gated High-Pitch Mode and Retrospectively Electrocardiogram-Gated Mode for Dual-Source CT Coronary Angiography

    PubMed Central

    Koplay, Mustafa; Celik, Mahmut; Avcı, Ahmet; Erdogan, Hasan; Demir, Kenan; Sivri, Mesut; Nayman, Alaaddin

    2015-01-01

    Summary Background We aimed to report the image quality, relationship between heart rate and image quality, amount of contrast agent given to the patients and radiation doses in coronary CT angiography (CTA) obtained by using high-pitch prospectively ECG-gated “Flash Spiral” technique (method A) or retrospectively ECG-gated technique (method B) using 128×2-slice dual-source CT. Material/Methods A total of 110 patients who were evaluated with method A and method B technique with a 128×2-detector dual-source CT device were included in the study. Patients were divided into three groups based on their heart rates during the procedure, and a relationship between heart rate and image quality were evaluated. The relationship between heart rate, gender and radiation dose received by the patients was compared. Results A total of 1760 segments were evaluated in terms of image quality. Comparison of the relationship between heart rate and image quality revealed a significant difference between heart rate <60 beats/min group and >75 beats/min group whereas <60 beats/min and 60–75 beats/min groups did not differ significantly. The average effective dose for coronary CTA was calculated as 1.11 mSv (0.47–2.01 mSv) for method A and 8.22 mSv (2.19–12.88 mSv) for method B. Conclusions Method A provided high quality images with doses as low as <1 mSv in selected patients who have low heart rates with a high negative predictive value to rule out coronary artery disease. Although method B increases the amount of effective dose, it provides high diagnostic quality images for patients who have a high heart rate and arrhythmia which makes it is difficult to obtain images. PMID:26767072

  5. Respiratory-gated segment reconstruction for radiation treatment planning using 256-slice CT-scanner during free breathing

    NASA Astrophysics Data System (ADS)

    Mori, Shinichiro; Endo, Masahiro; Kohno, Ryosuke; Minohara, Shinichi; Kohno, Kazutoshi; Asakura, Hiroshi; Fujiwara, Hideaki; Murase, Kenya

    2005-04-01

    The conventional respiratory-gated CT scan technique includes anatomic motion induced artifacts due to the low temporal resolution. They are a significant source of error in radiotherapy treatment planning for the thorax and upper abdomen. Temporal resolution and image quality are important factors to minimize planning target volume margin due to the respiratory motion. To achieve high temporal resolution and high signal-to-noise ratio, we developed a respiratory gated segment reconstruction algorithm and adapted it to Feldkamp-Davis-Kress algorithm (FDK) with a 256-detector row CT. The 256-detector row CT could scan approximately 100 mm in the cranio-caudal direction with 0.5 mm slice thickness in one rotation. Data acquisition for the RS-FDK relies on the assistance of the respiratory sensing system by a cine scan mode (table remains stationary). We evaluated RS-FDK in phantom study with the 256-detector row CT and compared it with full scan (FS-FDK) and HS-FDK results with regard to volume accuracy and image noise, and finally adapted the RS-FDK to an animal study. The RS-FDK gave a more accurate volume than the others and it had the same signal-to-noise ratio as the FS-FDK. In the animal study, the RS-FDK visualized the clearest edges of the liver and pulmonary vessels of all the algorithms. In conclusion, the RS-FDK algorithm has a capability of high temporal resolution and high signal-to-noise ratio. Therefore it will be useful when combined with new radiotherapy techniques including image guided radiation therapy (IGRT) and 4D radiation therapy.

  6. Assessments of Coronary Artery Visibility and Radiation Dose in Infants with Congenital Heart Disease on Cardiac 128-slice CT and on Cardiac 64-slice CT.

    PubMed

    Cui, Y; Huang, M; Zheng, J; Li, J; Liu, H; Liang, C

    2016-01-01

    The aim of this study was to compare the coronary artery visibility and radiation dose in infants with CHD on cardiac 128-slice CT and on cardiac 64-slice CT. The images of 200 patients were analyzed in this study, 100 patients were selected randomly from a group of 789 infants (<1 years old) with CHD undergoing 128-slice CT prospective ECG-triggered axial scan, and 100 were selected randomly from 911 infants with CHD undergoing 64-slice CT retrospective ECG-gated spiral scan. The visibility of coronary artery segments was graded on a four-point scale. The coronary arteries were considered to be detected or visible when grade was 2 or higher. The visibility of the coronary artery segments and the radiation dose was compared between the two groups. Except for the rate of LM (96 vs. 99%), the detection rates of the total, LAD, LCX, RCA, and the proximal segment of the RCA in the 256-slice CT group were significantly higher than those in the 64-slice CT group (51.7, 53.33, 33.67, 53.33, and 99 vs. 34.8, 34.33, 18, 30.67, and 75%, respectively). The counts of visibility score (4/3/2/1) for the LM and the proximal segment of the RCA were 62/22/12/4 and 56/20/17/7, respectively, in the 128-slice CT group and 17/42/30/1 and 9/30/38/25, respectively, in the 64-slice CT group. There were significant differences, especially for score 4 and 3, between the two groups. The radiation dose in the 128-slice CT group was significantly decreased than those in the 64-slice CT group (CTDIvol 1.88 ± 0.51 vs. 5.61 ± 0.63 mGy; SSDE 4.48 ± 1.15 vs. 13.97 ± 1.52 mGy; effective radiation dose 1.36 ± 0.44 vs. 4.06 ± 0.7 mSv). With reduced radiation dose, the visibility of the coronary artery in infants with CHD via prospective ECG-triggered mode on a 128-slice CT is superior to that of the 64-slice CT using retrospective ECG-gated spiral mode. PMID:26271472

  7. Diagnostic accuracy of sub-mSv prospective ECG-triggering cardiac CT in young infant with complex congenital heart disease.

    PubMed

    Gao, Wei; Zhong, Yu Min; Sun, Ai Min; Wang, Qian; Ouyang, Rong Zhen; Hu, Li Wei; Qiu, Han Sheng; Wang, Shi Yu; Li, Jian Ying

    2016-06-01

    To explore the clinical value and evaluate the diagnostic accuracy of sub-mSv low-dose prospective ECG-triggering cardiac CT (CCT) in young infants with complex congenital heart disease (CHD). A total of 102 consecutive infant patients (53 boys and 49 girls with mean age of 2.9 ± 2.4 m and weight less than 5 kg) with complex CHD were prospectively enrolled. Scans were performed on a 64-slice high definition CT scanner with low dose prospective ECG-triggering mode and reconstructed with 80 % adaptive statistical iterative reconstruction algorithm. All studies were performed during free breathing with sedation. The subjective image quality was evaluated by 5-point grading scale and interobserver variability was calculated. The objective image noise (standard deviation, SD) and contrast to noise ratio (CNR) was calculated. The effective radiation dose from the prospective ECG-triggering mode was recorded and compared with the virtual conventional retrospective ECG-gating mode. The detection rate for the origin of coronary artery was calculated. All patients also underwent echocardiography before CCT examination. 81 patients had surgery and their preoperative CCT and echocardiography findings were compared with the surgical results and sensitivity, specificity, positive and negative predictive values and accuracy were calculated for separate cardiovascular anomalies. Heart rates were 70-161 beats per minute (bpm) with mean value of 129.19 ± 14.52 bpm. The effective dose of 0.53 ± 0.15 mSv in the prospective ECG-triggering cardiac CT was lower than the calculated value in a conventional retrospective ECG-gating mode (2.00 ± 0.35 mSv) (p < 0.001). The mean CNR and SD were 28.19 ± 13.00 and 15.75 ± 3.61HU, respectively. The image quality scores were 4.31 ± 0.36 and 4.29 ± 0.41 from reviewer 1 and 2 respectively with an excellent agreement between them (Kappa = 0.85). The detection rate for the origins of the left and right coronary

  8. Carotid artery and aortic arch imaging with ECG gating in DSA

    SciTech Connect

    Francis, D.A.; Sheldon, J.J.; Soila, K.; Tobias, J.

    1985-06-01

    New computer software for gated digital subtraction angiography imaging was used to study 57 patients over 3 months. Better mask registration on isolated sets of systolic and diastolic images improved image quality. Detail of vessel outline and lesion was better than that seen on nongated images.

  9. Temporally Targeted Imaging Method Applied to ECG Gated Computed Tomography: Preliminary Phantom and In Vivo Experience

    PubMed Central

    Nett, Brian E.; Leng, Shuai; Zambelli, Joseph N.; Reeder, Scott B.; Speidel, Michael A.; Chen, Guang-Hong

    2009-01-01

    Rationale and Objectives Existing cardiac imaging methods do not allow for improved temporal resolution when considering a targeted region of interest (ROI). The imaging method presented here enables improved temporal resolution for ROI imaging (namely, a reconstruction volume smaller than the complete field of view). Clinically, temporally targeted reconstruction would not change the primary means of reconstructing and evaluating images, but rather would enable the adjunct technique of ROI imaging, with improved temporal resolution compared with standard reconstruction (~20% smaller temporal scan window). In gated cardiac CT scans improved temporal resolution directly translates into a reduction in motion artifacts for rapidly moving objects such as the coronary arteries. Materials and Methods Retrospectively electrocardiogram gated coronary angiography data from a 64-slice CT system were utilized. A motion phantom simulating the motion profile of a coronary artery was constructed and scanned. Additionally, an in vivo study was performed using a porcine model. Comparisons between the new reconstruction technique and the standard reconstruction are given for an ROI centered on the right coronary artery, and a pulmonary ROI. Results In both a well controlled motion model and a porcine model results show a decrease in motion induced artifacts including motion blur and streak artifacts from contrast enhanced vessels within the targeted ROIs, as assessed through both qualitative and quantitative observations. Conclusion Temporally targeted reconstruction techniques demonstrate the potential to reduce motion artifacts in coronary CT. Further study is warranted to demonstrate the conditions under which this technique will offer direct clinical utility. Improvement in temporal resolution for gated cardiac scans has implications for improving: contrast enhanced CT angiography, calcium scoring, and assessment of the pulmonary anatomy. PMID:18078912

  10. ECG-gated, mechanical and electromechanical wave imaging of cardiovascular tissues in vivo.

    PubMed

    Pernot, Mathieu; Fujikura, Kana; Fung-Kee-Fung, Simon D; Konofagou, Elisa E

    2007-07-01

    In simplistic terms, the motion of the heart can be summarized as an active contraction and passive relaxation of the myocardium. However, the local motion of cardiovascular tissues over the course of an entire cardiac cycle results from various transient events such as the valves closing/opening, sudden changes in blood pressure and electrical conduction of the myocardium. The transient motion generated by most of these events occurs within a very short time (on the order of 1 ms) and cannot be imaged correctly with conventional imaging systems, due to their limited temporal resolution. In this paper, we propose a method for imaging this rapid transient motion of tissues in cardiovascular applications. Our method is based on imaging tissues with ultrasound at high frame rates (up to 8000 fps) by synchronizing the two-dimensional (2D) image acquisition on the electrocardiogram (ECG) signals. In vivo feasibility is demonstrated in anesthetized mice. The propagation of several transient mechanical waves was imaged in different regions of the myocardium and the wave phase velocities were found to be between 0.44 m/s and 5 m/s. These waves may be generated by either a purely mechanical effects or through electromechanical coupling in the myocardium depending on the phase of the cardiac cycle, in which they occur. The abdominal aorta was also imaged using the same technique and the propagation of a mechanical pulse wave was imaged. The pulse wave velocity was measured and the Young's modulus of the vessel wall was derived based on the Moens-Korteweg equation. This method could potentially be used for mapping the stiffness of the myocardium and the artery walls and may lead to the early diagnosis of cardiovascular diseases. PMID:17507146

  11. 256-slice CT coronary angiography in atrial fibrillation: The impact of mean heart rate and heart rate variability on image quality

    NASA Astrophysics Data System (ADS)

    Chen, Liang-Kuang; Hsu, Shih-Ming; Mok, Greta S. P.; Law, Wei-Yip; Lu, Kun-Mu; Yang, Ching-Ching; Wu, Tung-Hsin

    2011-08-01

    The aim of this study was to evaluate the image quality of 256-MDCT in atrial fibrillation and to compare the findings with those among patients in sinus rhythm.MaterialsAll reconstructed images were evaluated by two independent experienced readers blinded to patient information, heart rate, and ECG results to assess the diagnostic quality of images of the coronary artery segments using axial images, multi-planar reformations, maximum intensity projections, and volume rendering technique.ResultsNo statistical significance was detected in terms of the overall image quality between patients in sinus rhythm and with atrial fibrillation. Pearson's correlation analysis showed no significant association between image quality and mean heart rate no matter for patients in sinus rhythm or with atrial fibrillation. Similarly, there was no correlation between image quality and heart rate variability for either patients in sinus rhythm or with atrial fibrillation. Our results showed that the optimal reconstruction window depends on patient's HR, and the pattern for patients in atrial fibrillation is similar to that obtained from non-atrial fibrillation patients.ConclusionThis study shows the potential of using 256-MDCT coronary angiography in patients with atrial fibrillation. Our results suggest that when appropriate reconstruction timing window is applied, patients with atrial fibrillation do not have to be excluded from MDCT coronary angiographic examinations.

  12. Biodiversity Prospecting.

    ERIC Educational Resources Information Center

    Sittenfeld, Ana; Lovejoy, Annie

    1994-01-01

    Examines the use of biodiversity prospecting as a method for tropical countries to value biodiversity and contribute to conservation upkeep costs. Discusses the first agreement between a public interest organization and pharmaceutical company for the extraction of plant and animal materials in Costa Rica. (LZ)

  13. Quantitative analysis of arterial flow properties for detection of non-calcified plaques in ECG-gated coronary CT angiography

    NASA Astrophysics Data System (ADS)

    Wei, Jun; Zhou, Chuan; Chan, Heang-Ping; Chughtai, Aamer; Agarwal, Prachi; Kuriakose, Jean; Hadjiiski, Lubomir; Patel, Smita; Kazerooni, Ella

    2015-03-01

    We are developing a computer-aided detection system to assist radiologists in detection of non-calcified plaques (NCPs) in coronary CT angiograms (cCTA). In this study, we performed quantitative analysis of arterial flow properties in each vessel branch and extracted flow information to differentiate the presence and absence of stenosis in a vessel segment. Under rest conditions, blood flow in a single vessel branch was assumed to follow Poiseuille's law. For a uniform pressure distribution, two quantitative flow features, the normalized arterial compliance per unit length (Cu) and the normalized volumetric flow (Q) along the vessel centerline, were calculated based on the parabolic Poiseuille solution. The flow features were evaluated for a two-class classification task to differentiate NCP candidates obtained by prescreening as true NCPs and false positives (FPs) in cCTA. For evaluation, a data set of 83 cCTA scans was retrospectively collected from 83 patient files with IRB approval. A total of 118 NCPs were identified by experienced cardiothoracic radiologists. The correlation between the two flow features was 0.32. The discriminatory ability of the flow features evaluated as the area under the ROC curve (AUC) was 0.65 for Cu and 0.63 for Q in comparison with AUCs of 0.56-0.69 from our previous luminal features. With stepwise LDA feature selection, volumetric flow (Q) was selected in addition to three other luminal features. With FROC analysis, the test results indicated a reduction of the FP rates to 3.14, 1.98, and 1.32 FPs/scan at sensitivities of 90%, 80%, and 70%, respectively. The study indicated that quantitative blood flow analysis has the potential to provide useful features for the detection of NCPs in cCTA.

  14. In-vivo regional myocardial perfusion measurements in a porcine model by ECG-gated multislice computed tomography

    NASA Astrophysics Data System (ADS)

    Stantz, Keith M.; Liang, Yun; Meyer, Cristopher A.; Teague, Shawn; Stecker, Michael; Hutchins, Gary; McLennan, Gordon; Persohn, Scott

    2003-05-01

    Purpose: To evaluate whether functional multi-slice computed tomography (MSCT) can identify regional areas of normally perfused and ischemic myocardium in a porcine model. Material and Methods: Three out bred pigs, two of which had ameroids surgically implanted to constrict flow within the LAD and LCx coronary arteries, were injected with 25 mL of iopromide (Isovue) at a rate of 5 mL/second via the femoral or jugular vein. Sixty axial scans along the short axis of the heart was acquired on a 16-slice CT scanner (Philips MX8000-IDT) triggered at end-diastole of the cardiac cycle and acquiring an image within 270 msec. A second series of scans were taken after an intravenous injection of a vasodilator, 150 μg/kg/min of adenosine. ROIs were drawn around the myocardial tissue and the resulting time-density curves were used to extract perfusion values. Results: Determination of the myocardial perfusion and fractional blood volume implementing three different perfusion models. A 5-point averaging or 'smoothing' algorithm was employed to effectively filter the data due to its noisy nature. The (preliminary) average perfusion and fractional blood volume values over selected axial slices for the pig without an artificially induced stenosis were measured to be 84 +/- 22 mL/min/100g-tissue and 0.17 +/- 0.04 mL/g-tissue, the former is consistent with PET scan and EBCT results. The pig with a stenosis in the left LAD coronary artery showed a reduced global perfusion value -- 45 mL/min/100g-tissue. Correlations in regional perfusion values relative to the stenosis were weak. During the infusion of adenosine, averaged perfusion values for the three subjects increased by 46 (+/-45) percent, comparable to increases measured with PET. Conclusion: Quantifying global perfusion values using MDCT appear encouraging. Future work will focus resolving the systematic effects from noise due to signal fluctuation from the porcine tachyardia (80-93 BPM) and provide a more robust measurement of regional myocardial perfusion throughout the heart.

  15. Prospective Optimization

    PubMed Central

    Sejnowski, Terrence J.; Poizner, Howard; Lynch, Gary; Gepshtein, Sergei; Greenspan, Ralph J.

    2014-01-01

    Human performance approaches that of an ideal observer and optimal actor in some perceptual and motor tasks. These optimal abilities depend on the capacity of the cerebral cortex to store an immense amount of information and to flexibly make rapid decisions. However, behavior only approaches these limits after a long period of learning while the cerebral cortex interacts with the basal ganglia, an ancient part of the vertebrate brain that is responsible for learning sequences of actions directed toward achieving goals. Progress has been made in understanding the algorithms used by the brain during reinforcement learning, which is an online approximation of dynamic programming. Humans also make plans that depend on past experience by simulating different scenarios, which is called prospective optimization. The same brain structures in the cortex and basal ganglia that are active online during optimal behavior are also active offline during prospective optimization. The emergence of general principles and algorithms for goal-directed behavior has consequences for the development of autonomous devices in engineering applications. PMID:25328167

  16. Prospect redux

    NASA Technical Reports Server (NTRS)

    Jacquemoud, S.; Ustin, S. L.; Verdebout, J.; Schmuck, G.; Andreoli, G.; Hosgood, B.

    1995-01-01

    The remote estimation of leaf biochemical content from spaceborne platforms has been the subject of many studies aimed at better understanding of terrestrial ecosystem functioning. The major ecological processes involved in exchange of matter and energy, like photosynthesis, primary production, evaportranspiration, respiration, and decomposition can be related to plant properties e.g., chlorophyll, water, protein, cellulose and lignin contents. As leaves represent the most important plant surfaces interacting with solar energy, a top priority has been to relate optical properties to biochemical constituents. Two different approaches have been considered: first, statistical correlations between the leaf reflectance (or transmittance) and biochemical content, and second, physically based models of leaf scattering and absorption developed using the laws of optics. Recently reviewed by Verdebout et al., the development of models of leaf optical properties has resulted in better understanding of the interaction of light with plant leaves. Present radiative transfer models mainly use chlorophyll and/or water contents as input parameters to calculate leaf reflectance. Inversion of these models allows to retrieve these constituents from spectrophotometric measurements. Conel et al. recently proposed a two-stream Kubelka-Munk model to analyze the influence of protein, cellulose, lignin, and starch on leaf reflectance, but in fact, the estimation of leaf biochemistry from remote sensing is still an open question. In order to clarify it, a laboratory experiment associating visible/infrared spectra of plan leaves both with physical measurements and biochemical analyses was conducted at the Joint Research Center during the summer of 1993. This unique data set has been used to upgrade the PROSPECT model, by including leaf biochemistry.

  17. Myocardial bridging of the right coronary artery inside the right atrial myocardium identified by ECG-gated 64-slice multidetector computed tomography angiography.

    PubMed

    Chen, Chien-Cheng; Chen, Huan-Wu; Fu, Chen-Ju; Lin, Fen-Chiung; Wen, Ming-Shien; Liu, Yuan-Chang

    2010-01-01

    A myocardial bridge (MB) is defined as an intramyocardial course of a major epicardial coronary artery, and it is mainly confined to the left ventricle and the left anterior descending coronary artery. There are rare reports of right coronary MB seen during angiographic examination. Herein, we present a 49 year-old man with right coronary artery MB without luminal narrowing in the diastolic and systolic phases of electrocardiography-gated computed tomography images. The value of multi-detector computed tomography for the detection of anatomical variants in the cardiovascular system is further discussed. PMID:20438676

  18. Prospective memory: A comparative perspective

    PubMed Central

    Crystal, Jonathon D.; Wilson, A. George

    2014-01-01

    Prospective memory consists of forming a representation of a future action, temporarily storing that representation in memory, and retrieving it at a future time point. Here we review the recent development of animal models of prospective memory. We review experiments using rats that focus on the development of time-based and event-based prospective memory. Next, we review a number of prospective-memory approaches that have been used with a variety of non-human primates. Finally, we review selected approaches from the human literature on prospective memory to identify targets for development of animal models of prospective memory. PMID:25101562

  19. Applied Astronomy: Asteroid Prospecting

    NASA Astrophysics Data System (ADS)

    Elvis, M.

    2013-09-01

    In the age of asteroid mining the ability to find promising ore-bearing bodies will be valuable. This will give rise to a new discipline- "Applied Astronomy". Just as most geologists work in industry, not in academia, the same will be true of astronomers. Just how rare or common ore-rich asteroids are likely to be, and the skills needed to assay their value, are discussed here, with an emphasis on remote - telescopic - methods. Also considered are the resources needed to conduct extensive surveys of asteroids for prospecting purposes, and the cost and timescale involved. The longer-term need for applied astronomers is also covered.

  20. Prospective bonding applications

    NASA Astrophysics Data System (ADS)

    Ancenay, H.; Benazet, D.

    1981-07-01

    Adhesive bonding in industry and in the laboratory is surveyed and prospects for its wider utilization are assessed. The economic impact of bonding technology on industry is discussed. Research is reviewed, centering on the development of nondestructive testing and inspection techniques. Traditional (wood) as well as new materials susceptible to bonding are considered. Applications in construction and civil engineering, in aeronautics, and in the automobile industry are covered. The use of glues in mechanical constructions, in assembling cylindrical parts, and in metal-metal bonding are examined. Hybrid assembling and bonding of composite materials are included.

  1. Methane Clathrate Hydrate Prospecting

    NASA Technical Reports Server (NTRS)

    Duxbury, N.; Romanovsky, V.

    2003-01-01

    A method of prospecting for methane has been devised. The impetus for this method lies in the abundance of CH4 and the growing shortages of other fuels. The method is intended especially to enable identification of subpermafrost locations where significant amounts of methane are trapped in the form of methane gas hydrate (CH4(raised dot)6H2O). It has been estimated by the U.S. Geological Survey that the total CH4 resource in CH4(raised dot) 6H2O exceeds the energy content of all other fossil fuels (oil, coal, and natural gas from non-hydrate sources). Also, CH4(raised dot)6H2O is among the cleanest-burning fuels, and CH4 is the most efficient fuel because the carbon in CH4 is in its most reduced state. The method involves looking for a proxy for methane gas hydrate, by means of the combination of a thermal-analysis submethod and a field submethod that does not involve drilling. The absence of drilling makes this method easier and less expensive, in comparison with prior methods of prospecting for oil and natural gas. The proposed method would include thermoprospecting in combination with one more of the other non-drilling measurement techniques, which could include magneto-telluric sounding and/or a subsurface-electrical-resistivity technique. The method would exploit the fact that the electrical conductivity in the underlying thawed region is greater than that in the overlying permafrost.

  2. The Prospects Study and Desegregation.

    ERIC Educational Resources Information Center

    Puma, Michael J.

    1997-01-01

    Argues that greater caution is required when drawing conclusions from statistical results than the Armor study has done, and describes the "Prospects" study (begun in 1989), the largest longitudinal study of educational outcomes conducted in the United States. "Prospects" provides much data useful in evaluating the school desegregation situation…

  3. Prospective Memory Performance across Adolescence

    ERIC Educational Resources Information Center

    Wang, Lijuan; Kliegel, Matthias; Yang, Zhiliang; Liu, Wei

    2006-01-01

    In the present study, the authors explored age differences in event-based prospective memory (PM) across adolescence. The tasks consisted of an ongoing task (OT; i.e., personality questionnaire items, math problems) and an embedded prospective task that required participants to remember to make a special response whenever they encountered a PM cue…

  4. Prospect Theory and Coercive Bargaining

    ERIC Educational Resources Information Center

    Butler, Christopher K.

    2007-01-01

    Despite many applications of prospect theory's concepts to explain political and strategic phenomena, formal analyses of strategic problems using prospect theory are rare. Using Fearon's model of bargaining, Tversky and Kahneman's value function, and an existing probability weighting function, I construct a model that demonstrates the differences…

  5. Prospects at high energies

    SciTech Connect

    Quigg, C.

    1988-11-01

    I discuss some possibilities for neutrino experiments in the fixed-target environment of the SPS, Tevatron, and UNK, with their primary proton beams of 0.4, 0.9, and 3.0 TeV. The emphasis is on unfinished business: issues that have been recognized for some time, but not yet resolved. Then I turn to prospects for proton-proton colliders to explore the 1-TeV scale. I review the motivation for new physics in the neighborhood of 1 TeV and mention some discovery possibilities for high-energy, high-luminosity hadron colliders and the implications they would have for neutrino physics. I raise the possibility of the direct study of neutrino interactions in hadron colliders. I close with a report on the status of the SSC project. 38 refs., 17 figs.

  6. Prospecting with neutrinos

    NASA Astrophysics Data System (ADS)

    Bell, Peter M.

    One of the latest attempts to explore the interface between physics and geophysics is the extravagant scheme of Alvaro De Rújula, Sheldon Glashow, Robert Wilson, and Georges Charpak, to be published in Physics Reports. In what these theoretical and experimental physicists described recently as “our mad project” (Physics Today, August 1983), a high-energy neutrino beam is to be used as a geophysical prospecting tool.The beam would be able to look for oil, natural gas, and high-atomic-number metal ores, and it would be able to profile the vertical density distribution of the earth. De Rújula et al. come to this project from the world of big physics machines, so it is natural to expect that the “Geotron,” the field instrument to supply and focus the neutrino beam, is to be big also.

  7. Prospects of photoacoustic tomography

    PubMed Central

    Wang, Lihong V.

    2008-01-01

    Commercially available high-resolution three-dimensional optical imaging modalities—including confocal microscopy, two-photon microscopy, and optical coherence tomography—have fundamentally impacted biomedicine. Unfortunately, such tools cannot penetrate biological tissue deeper than the optical transport mean free path (∼1 mm in the skin). Photoacoustic tomography, which combines strong optical contrast and high ultrasonic resolution in a single modality, has broken through this fundamental depth limitation and achieved superdepth high-resolution optical imaging. In parallel, radio frequency-or microwave-induced thermoacoustic tomography is being actively developed to combine radio frequency or microwave contrast with ultrasonic resolution. In this Vision 20∕20 article, the prospects of photoacoustic tomography are envisaged in the following aspects: (1) photoacoustic microscopy of optical absorption emerging as a mainstream technology, (2) melanoma detection using photoacoustic microscopy, (3) photoacoustic endoscopy, (4) simultaneous functional and molecular photoacoustic tomography, (5) photoacoustic tomography of gene expression, (6) Doppler photoacoustic tomography for flow measurement, (7) photoacoustic tomography of metabolic rate of oxygen, (8) photoacoustic mapping of sentinel lymph nodes, (9) multiscale photoacoustic imaging in vivo with common signal origins, (10) simultaneous photoacoustic and thermoacoustic tomography of the breast, (11) photoacoustic and thermoacoustic tomography of the brain, and (12) low-background thermoacoustic molecular imaging. PMID:19175133

  8. ANAIS: Status and prospects

    NASA Astrophysics Data System (ADS)

    Amaré, J.; Cebrián, S.; Cuesta, C.; García, E.; Ginestra, C.; Martínez, M.; Oliván, M. A.; Ortigoza, Y.; Ortiz de Solórzano, A.; Pobes, C.; Puimedón, J.; Sarsa, M. L.; Villar, J. A.; Villar, P.

    2016-07-01

    ANAIS experiment will look for dark matter annual modulation with large mass of ultra-pure NaI(Tl) scintillators at the Canfranc Underground Laboratory (LSC), aiming to confirm the DAMA/LIBRA positive signal in a model-independent way. Two 12.5 kg each NaI(Tl) crystals provided by Alpha Spectra are currently taking data at the LSC. Present status of ANAIS detectors background and general performance is summarized; in particular, thanks to the high light collection efficiency prospects of lowering the threshold down to 1 keVee are reachable. Crystal radiopurity goals are fulfilled for 232Th and 238U chains and 40K activity, although higher than original goal, could be accepted; however, high 210Pb contamination out-of-equilibrium has been identified. More radiopure detectors are being built by Alpha Spectra. The ongoing high quantum efficiency PMT tests and muon veto characterization are also presented. Finally, the sensitivity of the experiment for the annual modulation in the WIMP signal, assuming the already achieved threshold and background in ANAIS-25 is shown. Further improvement should be achieved by reducing both threshold and background, as expected.

  9. German energy technology prospects.

    PubMed

    Popp, M

    1982-12-24

    After more than 25 years of development of nuclear power and almost 10 years of research and development in numerous areas of nonnuclear energy, there is now a good basis for judging the future prospects of energy technologies in the Federal Republic of Germany. The development of nuclear power has provided an important and economically advantageous new source of energy. Further efforts are needed to establish the nuclear fuel cycle in all stages and to exploit the potential of advanced reactors. In all other areas of energy technology, including energy conservation, new energy sources, and coal, economics has turned out to be the key problem, even at today's energy prices. Opportunities to overcome these economic problems through additional R & D are limited. There is some potential for special applications, and there are many technologies that could contribute to the energy supply of developing countries. In general, however, progress in energy conservation and the use of renewable energy sources will depend on the degree to which energy policy measures can improve their economic basis. For some technologies, such as solar thermal power stations and coal liquefaction, large-scale economic deployment cannot be foreseen today. Instead of establishing costly demonstration projects, emphasis will be put on improving key components of these technologies with the aim of having the most advanced technology available when the economic parameters are more favorable. PMID:17770150

  10. Resolution in Electromagnetic Prospecting

    NASA Astrophysics Data System (ADS)

    Aldridge, D. F.; Bartel, L. C.; Knox, H. A.; Schramm, K. A.

    2014-12-01

    Low-frequency electromagnetic (EM) signals are commonly used in geophysical exploration of the shallow subsurface. Sensitivity to conductivity implies they are particularly useful for inferring fluid content of porous media. However, low-frequency EM wavefields are diffusive, and have significantly larger wavelengths compared to seismic signals of equal frequency. The wavelength of a 30 Hz sinusoid propagating with seismic velocity 3000 m/s is 100 m, whereas an analogous EM signal diffusing through a conductive body of 0.1 S/m (clayey shale) has wavelength 1825 m. The larger wavelength has implications for resolution of the EM prospecting method. We are investigating resolving power of the EM method via theoretical and numerical experiments. Normal incidence plane wave reflection/transmission by a thin geologic bed is amenable to analytic solution. Responses are calculated for beds that are conductive or resistive relative to the host rock. Preliminary results indicate the classic seismic resolution/detection limit of bed thickness ~1/8 wavelength is not achieved. EM responses for point or line current sources recorded by general acquisition geometries are calculated with a 3D finite-difference algorithm. These exhibit greater variability which may allow inference of bed thickness. We also examine composite responses of two point scatterers with separation when illuminated by an incident EM field. This is analogous to the Rayleigh resolution problem of estimating angular separation between two light sources. The First Born Approximation implies that perturbations in permittivity, permeability, and conductivity have different scattering patterns, which may be indicators of EM medium properties. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the US Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  11. Bacterial Exopolysaccharides: Functionality and Prospects

    PubMed Central

    Nwodo, Uchechukwu U.; Green, Ezekiel; Okoh, Anthony I.

    2012-01-01

    Diverse structural, functional and valuable polysaccharides are synthesized by bacteria of all taxa and secreted into the external environment. These polysaccharides are referred to as exopolysaccharides and they may either be homopolymeric or heteropolymeric in composition and of diverse high molecular weights (10 to 1000 kDa). The material properties of exopolysaccharides have revolutionized the industrial and medical sectors due to their retinue of functional applications and prospects. These applications have been extensive in areas such as pharmacological, nutraceutical, functional food, cosmeceutical, herbicides and insecticides among others, while prospects includes uses as anticoagulant, antithrombotic, immunomodulation, anticancer and as bioflocculants. Due to the extensive applications of bacterial exopolysaccharides, this overview provides basic information on their physiologic and morphologic functions as well as their applications and prospects in the medical and industrial sectors. PMID:23203046

  12. Scientific knowledge and modern prospecting

    USGS Publications Warehouse

    Neuerburg, G.J.

    1985-01-01

    Modern prospecting is the systematic search for specified and generally ill-exposed components of the Earth's crust known as ore. This prospecting depends entirely on reliable, or scientific knowledge for guidance and for recognition of the search objects. Improvement in prospecting results from additions and refinements to scientific knowledge. Scientific knowledge is an ordered distillation of observations too numerous and too complex in themselves for easy understanding and for effective management. The ordering of these observations is accomplished by an evolutionary hierarchy of abstractions. These abstractions employ simplified descriptions consisting of characterization by selected properties, sampling to represent much larger parts of a phenomenon, generalized mappings of patterns of geometrical and numerical relations among properties, and explanation (theory) of these patterns as functional relations among the selected properties. Each abstraction is predicated on the mode of abstraction anticipated for the next higher level, so that research is a deductive process in which the highest level, theory, is indispensible for the growth and refinement of scientific knowledge, and therefore of prospecting methodology. ?? 1985 Springer-Verlag.

  13. Job Prospects for Civil Engineers.

    ERIC Educational Resources Information Center

    Basta, Nicholas

    1985-01-01

    Government programs and renewed industrial activity have combined with stable enrollments to create bright job prospects for civil engineers. Areas with good opportunities include highway reconstruction and rehabilitation, water-resource management, and new factory construction. The subspecialty of structural engineering has a growing need in…

  14. Job Prospects for Electrical Engineers.

    ERIC Educational Resources Information Center

    Basta, Nicholas

    1986-01-01

    Discusses the career outlook for electrical/electronics engineers. Explains that the number of bachelor degree graduates continues to rise, along with average starting salaries. Reveals that although the availability of jobs in the computer industry is leveling off, prospects in the robotics and telecommunication fields are growing. (TW)

  15. Remote sensors - Prospects and limitations

    NASA Technical Reports Server (NTRS)

    Lehmann, J.

    1973-01-01

    Review of the history, present status, and future prospects and limitations of remote sensing systems for satellite-based earth resources surveys. The objectives and special areas of interest of ongoing sensor development experiments are summarized, and the measurement and performance goals of current potential sensor research is discussed.

  16. 2007 NCLB Prospects Are Fading

    ERIC Educational Resources Information Center

    Hoff, David J.

    2007-01-01

    Supporters and critics of the No Child Left Behind Act (NCLB) agree on only one thing and that the law should be fixed and quickly. However, it looks that Congress will not be able to make much progress in addressing the flaws of NCLB this year. This circumstance will endanger the prospects that the revision of the law might not be completed…

  17. Job Prospects for Aerospace Engineers.

    ERIC Educational Resources Information Center

    Basta, Nicholas

    1987-01-01

    Discusses the recent trends in job opportunities for aerospace engineers. Mentions some of the political, technological, and economic factors affecting the overall employment picture. Includes a description of the job prospects created by the general upswing of the large commercial aircraft market. (TW)

  18. Prospects: Student Outcomes. Final Report.

    ERIC Educational Resources Information Center

    Puma, Michael J.; Karweit, Nancy; Price, Cristofer; Ricciuti, Anne; Thompson, William; Vaden-Kiernan, Michael

    This report is one of a series presenting findings from "Prospects: The Congressionally Mandated Study of Educational Growth and Opportunity." This study, conducted in response to the 1988 Hawkins-Stafford Amendments, was a major effort to examine the effects of Chapter 1 on student achievement and other school-related educational outcomes. Data…

  19. Handbook for Prospective Single Parents.

    ERIC Educational Resources Information Center

    Marindin, Hope

    This handbook for prospective single adoptive parents provides information on locating and adopting a child, necessary clothing and supplies for children of various ages, health and day care arrangements, expenses incurred after adoption, various financial benefits and subsidies available to the adoptive parent, and legal and financial provisions…

  20. Electron Polarimetry: Status and Prospects

    SciTech Connect

    Eugene Chudakov

    2005-04-01

    Polarized electron beams are used widely for DIS, parity violation, and other experiments. I discuss the methods and instrumentation used to measure the electron beam polarization, as well as the prospects for the future facilities. A number of recent achievements and projects are discussed.

  1. Job Prospects for Marine Engineers.

    ERIC Educational Resources Information Center

    Basta, Nicholas

    1986-01-01

    Marine engineering is one of the smaller disciplines that have grown during recent decades. Job prospects in this field, salaries, types of employers (particularly Navy shipbuilding and infrastructure work), and marine/ocean engineers involvement with environmental issues are discussed. (JN)

  2. Job Prospects for Metallurgical Engineering.

    ERIC Educational Resources Information Center

    Basta, Nicholas

    1985-01-01

    Job prospects in mining, metal-extraction, steel, and refining industries are depressed, but technological discoveries are opening up new fields for metallurgical engineers. Enrollment/employment opportunities and salaries in these areas are discussed a well as the roles of foreign competition, plastics applications, and ceramics research and…

  3. Prospective Memory Training in Older Adults.

    ERIC Educational Resources Information Center

    Schmidt, Iris W.; Berg, Ina J.; Deelman, Betto G.

    2001-01-01

    Twenty adults received training in prospective memory; 23 who received training in reducing worries about forgetfulness and 22 controls formed a comparison group. Results of a telephone task and a prospective categorization task revealed significant but small effects for the prospective memory group. After 3 months, the comparison group's…

  4. Prospective errors determine motor learning.

    PubMed

    Takiyama, Ken; Hirashima, Masaya; Nozaki, Daichi

    2015-01-01

    Diverse features of motor learning have been reported by numerous studies, but no single theoretical framework concurrently accounts for these features. Here, we propose a model for motor learning to explain these features in a unified way by extending a motor primitive framework. The model assumes that the recruitment pattern of motor primitives is determined by the predicted movement error of an upcoming movement (prospective error). To validate this idea, we perform a behavioural experiment to examine the model's novel prediction: after experiencing an environment in which the movement error is more easily predictable, subsequent motor learning should become faster. The experimental results support our prediction, suggesting that the prospective error might be encoded in the motor primitives. Furthermore, we demonstrate that this model has a strong explanatory power to reproduce a wide variety of motor-learning-related phenomena that have been separately explained by different computational models. PMID:25635628

  5. Prospects for nuclear safety research

    SciTech Connect

    Beckjord, E.S.

    1995-04-01

    This document is the text of a paper presented by Eric S. Beckjord (Director, Nuclear Regulatory Research/NRC) at the 22nd Water Reactor Safety Meeting in Bethesda, MD in October 1994. The following topics are briefly reviewed: (1) Reactor vessel research, (2) Probabilistic risk assessment, (3) Direct containment heating, (4) Advanced LWR research, (5) Nuclear energy prospects in the US, and (6) Future nuclear safety research. Subtopics within the last category include economics, waste disposal, and health and safety.

  6. Prospects for de-automatization.

    PubMed

    Kihlstrom, John F

    2011-06-01

    Research by Raz and his associates has repeatedly found that suggestions for hypnotic agnosia, administered to highly hypnotizable subjects, reduce or even eliminate Stroop interference. The present paper sought unsuccessfully to extend these findings to negative priming in the Stroop task. Nevertheless, the reduction of Stroop interference has broad theoretical implications, both for our understanding of automaticity and for the prospect of de-automatizing cognition in meditation and other altered states of consciousness. PMID:20356765

  7. Atmospheric neutrinos: Status and prospects

    NASA Astrophysics Data System (ADS)

    Choubey, Sandhya

    2016-07-01

    We present an overview of the current status of neutrino oscillation studies at atmospheric neutrino experiments. While the current data gives some tantalising hints regarding the neutrino mass hierarchy, octant of θ23 and δCP, the hints are not statistically significant. We summarise the sensitivity to these sub-dominant three-generation effects from the next-generation proposed atmospheric neutrino experiments. We next present the prospects of new physics searches such as non-standard interactions, sterile neutrinos and CPT violation studies at these experiments.

  8. Prospects of thermionic power systems

    NASA Technical Reports Server (NTRS)

    Shimada, K.

    1978-01-01

    Potential thermionic power systems for space or terrestrial applications are described so that the development goals can be clearly identified. The thermionic power systems considered are a space nuclear power system, a fossil-fuel thermionic topping steam power system, a solar thermionic topping steam power system, and advanced systems. Attention is given to a discussion of the current status of technology development in thermionic converters and associated elements in power systems. Future prospects of thermionic power systems are also discussed. It is concluded that thermionic conversion has a great potential for a variety of applications.

  9. Advance and prospect of bionanomaterials.

    PubMed

    Cui, Daxiang; Gao, Huajian

    2003-01-01

    Over the past few years, bionanomaterial science has emerged as a new exciting field in which theoretical and experimental studies of structure and function of bionanomaterials have become a focus, and the importance of DNA, RNA, and peptides as bionanomaterials to the fundamental development in biology and nanomaterials has begun to be recognized. In particular, biochemistry, biophysics, biomechanics, thermodynamics, and electronic properties of DNA, RNA, and peptides, as well as intelligent composite biological materials, have become a new interdisciplinary frontier in life science and material science. There is an increasing need for a more systematic study of the basic issues involved in bionanomaterials and a more active participation of researchers in the application domain of such novel materials. Great advances have been and are being made in nanobiochip materials, nanoscale biomimetic materials, nanomotors, nanocomposite materials, interface biomaterials, and nanobiosensor and nano drug delivery systems, with enormous prospect in industrial, defense, and clinical medicine applications. Here we review some of the main advances in this field over the past few years, explore the application prospects, and discuss the concepts, issues, approaches, and challenges, with the aim of stimulating a broader interest in developing bionanomaterials technology. PMID:12790626

  10. Nanocarbon Technologies: Prospects and Risks

    NASA Astrophysics Data System (ADS)

    Kozyrev, S.; Yakutseni, P.

    In this paper we review the current state and prospects of carbon nano-technologies as a new emerging point for atomic-molecular manipulation, design and discovery connected with fullerenes, carbon nanotubes and biology. The merging nanoscale interface between carbon and biology structures are shortly discussed in terms of fundamental insights and possible applications encompassing nanobionics as lessons from animate nature, artificial modifications of living systems as well as multicomponent molecular structures for biology, physics, chemistry, engineering, and medicine. Protein-based as well as carbohydrates-, lipids-, or DNA-based molecular assemblies loaded with nanocarbon are addressed in the context of the engineering systems design. Several examples from our collaborative work are used to demonstrate connections between points of nano and bio and to show how such an interdisciplinary approach has led us to new ideas and applications. Nanocarbons have little similarity with the well-known biologically active substances. There is no oxygen, nitrogen, phosphorous-containing or other typical moieties, such as common pharmacophoric anchors or groups. In the same time fullerenes demonstrated a wide spectrum of biological activity. Mechanisms of their biological action are still unknown. For this reason our work was focused on the computer-based molecular modeling of the action of nanocarbon structures on the well-known biological structures: proteins, DNA, carbohydrates, and lipid molecules. Possible biological hazards, fundamental questions and prospects associated with nano-carbon technologies are highlighted.

  11. Prospective Science Teachers' Conceptions about Astronomical Subjects

    ERIC Educational Resources Information Center

    Küçüközer, Hüseyin

    2007-01-01

    The main objective of this study was to identify prospective science teachers' conceptions on basic astronomical phenomena. A questionnaire consisting of nine open-ended questions was administered to 327 prospective science teachers. The questionnaire was constructed after extensive review of the literature and took into consideration the reported…

  12. Prospective Elemantary Science Teachers' Epistemological Beliefs

    ERIC Educational Resources Information Center

    Macaroglu Akgul, Esra; Oztuna Kaplan, Aysun

    2009-01-01

    This research study examined "prospective elementary science teachers' epistemological beliefs". Forty-nine prospective elementary science teachers participated into research. The research was designed in both quantitative and qualitative manner, within the context of "Special Methods in Science Teaching I" course. Participants' epistemological…

  13. 36 CFR 228.60 - Prospecting permits.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... to the extent necessary for testing and analysis or for the demonstration of the existence of a suitable deposit. (c) Environmental analysis. Prospecting permits will be issued only after submission by... prospecting permit may not cover more than 640 acres. No individual or group may have an interest at any...

  14. Prospect Research: A How-to Guide.

    ERIC Educational Resources Information Center

    Strand, Bobbie J., Ed.; Hunt, Susan, Ed.

    Advice on prospect research to help colleges raise more money from major donors is provided in 14 chapters, and 15 sample forms for processing research are appended. The advice covers how to discover prospects' interests and assets, and the potential match of a donor to the college's needs. Chapters address: collecting, organizing, and evaluating…

  15. Change, Stability and Context: Prospective Teachers' Perceptions

    ERIC Educational Resources Information Center

    Sahin, Abdurrahman; Cokadar, Hulusi

    2009-01-01

    This study aims to explore and compare first-year and fourth-year prospective teachers' perceptions of good teaching, a good teacher, and a good student. A questionnaire with close- and open-ended questions was administered to 142 first-year and 138 fourth-year prospective teachers enrolled in the Faculty of Education at Pamukkale University.…

  16. Petroleum prospecting in the Arab world

    SciTech Connect

    Not Available

    1985-01-01

    This book discusses about oil and gas exploration in the Arab countries. After describing the chemistry and formation of petroleum and steps involved in prospecting, the book surveys the history and results of prospecting in each country. It also provides diagrams, maps, appended reserves and production data, and English equivalent terms.

  17. Prospective Teachers' Perspectives on Microteaching Lesson Study

    ERIC Educational Resources Information Center

    Fernandez, Maria L.; Robinson, Matthew

    2006-01-01

    Microteaching Lesson Study [MLS] is a cooperative learning experience that we felt could challenge our prospective teachers thinking about teaching and support their connection of theory and practice during an initial course on learning to teach mathematics. We studied seventy-four prospective teachers' perspectives on MLS over four sections of…

  18. Radiation detectors: needs and prospects

    SciTech Connect

    Armantrout, G.A.

    1981-01-01

    Important applications for x- and ..gamma..-ray spectroscopy are found in prospecting, materials characterization, environmental monitoring, the life sciences, and nuclear physics. The specific requirements vary for each application with varying degrees of emphasis on either spectrometer resolution, detection efficiency, or both. Since no one spectrometer is ideally suited to this wide range of needs, compromises are usually required. Gas and scintillation spectrometers have reached a level of maturity, and recent interest has concentrated on semiconductor spectrometers. Germanium detectors are showing continuing refinement and are the spectrometers of choice for high resolution applications. The new high-Z semiconductors, such as CdTe and HgI/sub 2/, have shown steady improvement but are limited in both resolution and size and will likely be used only in applications which require their unique properties.

  19. [Radioprotectors: History, Trends and Prospects].

    PubMed

    Gudkov, S V; Popova, N R; Bruskov, V I

    2015-01-01

    The search for ideal protective agents for use in a variety of radiation scenarios has continued for more than six decades. This review describes the history of the major discoveries, shows the chronology of the changes in attitudes, trends and paradigms. The readers are invited to meet with various classes of chemical compounds that have the potential to protect against acute and late effects of ionizing radiation when administered either before or after radiation exposure. The work represents characteristics of radioprotective agents such as a dose reduction factor, time of administration, tissue specificity, toxicity; the mechanisms of their action and practical applications are also described. A separate chapter considers the further development prospects and directions in this field of research. PMID:26394481

  20. Prospecting Rovers for Lunar Exploration

    NASA Technical Reports Server (NTRS)

    Graham, Jerry B.; Vaughn, Jason A.; Farmer, Jeffery T.

    2007-01-01

    A study of lunar rover options for exploring the permanently shadowed regions of the lunar environment is presented. The potential for nearly continuous solar illumination coupled with the potential for water ice, focus exploration planner's attention on the polar regions of the moon. These regions feature craters that scientists have reason to believe may contain water ice. Water ice can be easily converted to fuel cell reactants, breathing oxygen, potable water, and rocket propellant. For these reasons, the NASA Robotic Lunar Exploration Program (RLEP) sponsored a study of potential prospecting rover concepts as one part of the RLEP-2 Pre-Phase A. Numerous vehicle configurations and power, thermal, and communication options are investigated. Rover options in the 400kg to 530kg class are developed which are capable of either confirming the presence of water ice at the poles, or conclusively demonstrating its absence.

  1. Prospects for European labour demand.

    PubMed

    Lindley, R M

    1988-07-01

    The impact of economic and technological trends upon the level and structure of labor demand is examined, exploring the methods used to model the labor market and making special reference to demography and technology. Evidence on recent and prospective changes in labor demand is reviewed for France, Germany, Italy, the Netherlands, and the UK. The models used to explore future employment scenarios usually fail to incorporate the linkages required to fully analyze the various demographic-economic interactions. Further, this is not generally viewed as a limitation, given the time frame of most employment projections and their preoccupation with changes in the structure of labor demand. Medium-term multisectoral models tend to pay more attention to both demographic and technical change, but the treatment of both aspects is limited. The projections provide a framework for considering how both socioeconomic behavior and policy might change to achieve different outcomes. The greater a model's behavioral content, as expressed in its relationships between different variables, the greater the insight obtainable from simulation exercises. The 1st half of the 1970s was characterized by a reduction in German employment, representing the severest of European reactions to the oil crisis. The 2nd half of the decade recorded rapid growth in Italy and the Netherlands. The 1980s started with marked declines in Germany and the UK. Overall, the net gains of the 1970s were lost in the recession following the 2nd oil crisis. In none of the 5 countries studied does any realistic prospect emerge of achieving full employment before 2000. The most optimistic outcome is that unemployment will decline only slowly, it at all. The growth of both new forms and areas of employment will not compensate sufficiently for the loss of jobs elsewhere and the growth of labor supply. The industrial sector will continue to experience change in favor of the service sector but at a slower rate than during

  2. North American tidal power prospects

    NASA Astrophysics Data System (ADS)

    Wayne, W. W., Jr.

    1981-07-01

    Prospects for North American tidal power electrical generation are reviewed. Studies by the US Army Corps of Engineers of 90 possible generation schemes in Cobscook Bay, ME, indicated that maximum power generation rather than dependable capacity was the most economic method. Construction cost estimates for 15 MW bulb units in a single effect mode from basin to the sea are provided; five projects were considered ranging from 110-160 MW. Additional tidal power installations are examined for: Half-Moon Cove, ME (12 MW, 18 ft tide); Cook Inlet, AK, which is shown to pose severe environmental and engineering problems due to fish migration, earthquake hazards, and 300 ft deep silt deposits; and the Bay of Fundy, Canada. This last has a 17.8 MW plant under construction in a 29 ft maximum tide area. Other tidal projects of the Maritime Provinces are reviewed, and it is noted that previous economic evaluations based on an oil price of $16/barrel are in need of revision.

  3. Prospects for Future Helioseismology Missions

    NASA Astrophysics Data System (ADS)

    Scherrer, Philip H.

    The progress afforded by present and past helioseismology missions has been the topic of this and numerous previous conferences. The primary conclusion of the 1983 NASA study on prospects for solar oscillations have been basically confirmed. That is, part of the job can be done on the ground but a significant part can only be done from space. While we have made significant progress, it is also clear that additional opportunities to use helioseismic techniques to better understand stellar interiors remain. Recent advances in local helioseismology in particular point to additional observing requirements. These include larger field of view at high resolution in order to follow magnetic region development, longer baselines in longitude to probe the bottom of the convection zone and below, and a high latitude vantage point to examine processes near the rotation axis. Several possible missions have been discussed recently to address these issues. They include SONAR, Farside Observer, Solar Polar Imager, and Solar Probe. The basic concepts of these missions will be discussed along with the continuing role for enhanced ground based observations.

  4. Prospects for Tokamak Fusion Reactors

    SciTech Connect

    Sheffield, J.; Galambos, J.

    1995-04-01

    This paper first reviews briefly the status and plans for research in magnetic fusion energy and discusses the prospects for the tokamak magnetic configuration to be the basis for a fusion power plant. Good progress has been made in achieving fusion reactor-level, deuterium-tritium (D-T) plasmas with the production of significant fusion power in the Joint European Torus (up to 2 MW) and the Tokamak Fusion Test Reactor (up to 10 MW) tokamaks. Advances on the technologies of heating, fueling, diagnostics, and materials supported these achievements. The successes have led to the initiation of the design phases of two tokamaks, the International Thermonuclear Experimental Reactor (ITER) and the US Toroidal Physics Experiment (TPX). ITER will demonstrate the controlled ignition and extended bum of D-T plasmas with steady state as an ultimate goal. ITER will further demonstrate technologies essential to a power plant in an integrated system and perform integrated testing of the high heat flux and nuclear components required to use fusion energy for practical purposes. TPX will complement ITER by testing advanced modes of steady-state plasma operation that, coupled with the developments in ITER, will lead to an optimized demonstration power plant.

  5. Vibrator for seismic geophysical prospecting

    SciTech Connect

    Bird, J.M.

    1987-04-21

    An improved vibrator system is described for seismic geophysical prospecting, comprising: a vibrator comprising a first part, or dynamic vibrator part (VD) attached to a base plate in contact with the earth and a second part or vibrator stationary part (VS). Sound attenuating ear protection apparatus is described comprising: a pair of air evacuated, sealed chamber members disposably covering the ears of a user to lie between the user eardrums and an ear external source of undesirable sound energy; the air evacuated sealed chamber members each including first and second smooth surface portions with each surface portion having a spherical segment terminated by an annular flange lip shape and being disposable over one external ear of the user with one spherical segment, adjacent the ear being of different, higher mechanical resonance frequency with respect to the other spherical segment distal of the ear; the surface segment distal of the ear; the annular flange lips of the first and second surface portions being joined together in a junction disposed intermediate of the first and second spherical surface portions and perpendicular of the flange lips; resilient suspension means engaged with the head of the user and with the sealed chamber members for supporting the sealed chamber members in selected position over the user external ears.

  6. Structural Correlates of Prospective Memory

    PubMed Central

    Gordon, Brian A; Shelton, Jill T; Bugg, Julie M; McDaniel, Mark A; Head, Denise

    2011-01-01

    Prospective memory (PM) includes the encoding and maintenance of an intention, and the retrieval and execution of this intention at the proper moment in the future. The present study expands upon previous behavioral, electrophysiological, and functional work by examining the association between grey matter volume and PM. Estimates of grey matter volume in theoretically relevant regions of interest (prefrontal, parietal, and medial temporal) were obtained in conjunction with performance on two PM tasks in a sample of 39 cognitively normal and very mildly demented older adults. The first PM task, termed focal in the literature, is supported by spontaneous retrieval of the PM intention whereas the second, termed non-focal, relies on strategic monitoring processes for successful intention retrieval. A positive relationship was observed between medial temporal volume and accuracy on the focal PM task. An examination of medial temporal lobe subregions revealed that this relationship was strongest for the hippocampus, which is considered to support spontaneous memory retrieval. There were no significant structure-behavior associations for the non-focal PM task. These novel results confirm a relationship between behavior and underlying brain structure proposed by the multiprocess theory of PM, and extend findings on cognitive correlates of medial temporal lobe integrity. PMID:21982698

  7. Prospects of ITER Instability Control

    NASA Astrophysics Data System (ADS)

    Kolemen, Egemen

    2015-11-01

    Prospects for real-time MHD stability analysis, plasma response calculations, and their use in ELM, NTM, RWM control and EFC will be discussed. ITER will need various controls to work together in order to achieve the stated goal of Q >= 10 for multiple minutes. These systems will allow operating at high beta while avoiding disruptions that may lead to damage to the reactor. However, it has not yet been demonstrated whether the combined real-time feedback control aim is feasible given the spectrum of plasma instabilities, the quality of the real-time diagnostic measurement/analysis, and the actuator set at ITER. We will explain challenges of instability control for ITER based on experimental and simulation results. We will demonstrate that it will not be possible to parameterize all possible disruption avoidance and ramp down scenarios that ITER may encounter. An alternative approach based on real-time MHD stability analysis and plasma response calculations, and its use in ELM, NTM, RWM control and EFC, will be demonstrated. Supported by the US DOE under DE-AC02-09CH11466.

  8. Nuclear radiation cleanup and uranium prospecting

    DOEpatents

    Mariella, Jr., Raymond P.; Dardenne, Yves M.

    2016-02-02

    Apparatus, systems, and methods for nuclear radiation cleanup and uranium prospecting include the steps of identifying an area; collecting samples; sample preparation; identification, assay, and analysis; and relating the samples to the area.

  9. Hypnosis Attenuates Executive Cost of Prospective Memory.

    PubMed

    Demeter, Gyula; Szendi, István; Juhász, Marianna; Kovács, Zoltán Ambrus; Boncz, István; Keresztes, Attila; Pajkossy, Péter; Racsmány, Mihály

    2016-01-01

    Prospective memory is the ability to formulate and carry out actions at the appropriate time or in the appropriate context. This study aimed to identify the effect of hypnosis on prospective memory performance and to analyze the involvement of executive control processes in intention realization in a hypnotically altered state of consciousness. In 1 experiment, manipulating hypnotic instruction in a within-subject fashion, the authors explored the event-based prospective memory performance of 23 volunteers in 3 conditions: baseline, expectation, and execution. The primary result was that executing prospective memory responses, at the same accuracy rate, produced a significantly lower cost of ongoing responses in terms of response latency in the hypnotic state than in wake condition. PMID:26894423

  10. Procreative beneficence and the prospective parent.

    PubMed

    Herissone-Kelly, P

    2006-03-01

    Julian Savulescu has given clear expression to a principle-that of "procreative beneficence"-which underlies the thought of many contemporary writers on bioethics. The principle of procreative beneficence (PPB) holds that parents or single reproducers are at least prima facie obliged to select the child, out of a range of possible children they might have, who will be likely to lead the best life. My aim in this paper is to argue that prospective parents, just by dint of their being prospective parents, are in fact not obliged to act on PPB. That is, there is something about their filling the role of prospective parents that exempts them from selecting the child with the best life. I urge that it is more realistic to view prospective parents as bound by a principle of acceptable outlook, which holds that they ought not to select children whose lives will contain an unacceptable amount of suffering. PMID:16507665

  11. Vision Trouble Can Dim Life's Prospects

    MedlinePlus

    ... page: https://medlineplus.gov/news/fullstory_160136.html Vision Trouble Can Dim Life's Prospects But it's not ... THURSDAY, July 28, 2016 (HealthDay News) -- People with vision problems may face a higher risk of unemployment, ...

  12. 48 CFR 52.214-6 - Explanation to Prospective Bidders.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 2 2010-10-01 2010-10-01 false Explanation to Prospective....214-6 Explanation to Prospective Bidders. As prescribed in 14.201-6(c)(2), insert the following provision: Explanation to Prospective Bidders (APR 1984) Any prospective bidder desiring an explanation...

  13. Prospecting for marine gas hydrate resources

    USGS Publications Warehouse

    Boswell, Ray; Shipp, Craig; Reichel, Thomas; Shelander, Dianna; Saeki, Tetsuo; Frye, Matthew; Shedd, William; Collett, Timothy S.; McConnell, Daniel R.

    2016-01-01

    As gas hydrate energy assessment matures worldwide, emphasis has evolved away from confirmation of the mere presence of gas hydrate to the more complex issue of prospecting for those specific accumulations that are viable resource targets. Gas hydrate exploration now integrates the unique pressure and temperature preconditions for gas hydrate occurrence with those concepts and practices that are the basis for conventional oil and gas exploration. We have aimed to assimilate the lessons learned to date in global gas hydrate exploration to outline a generalized prospecting approach as follows: (1) use existing well and geophysical data to delineate the gas hydrate stability zone (GHSZ), (2) identify and evaluate potential direct indications of hydrate occurrence through evaluation of interval of elevated acoustic velocity and/or seismic events of prospective amplitude and polarity, (3) mitigate geologic risk via regional seismic and stratigraphic facies analysis as well as seismic mapping of amplitude distribution along prospective horizons, and (4) mitigate further prospect risk through assessment of the evidence of gas presence and migration into the GHSZ. Although a wide range of occurrence types might ultimately become viable energy supply options, this approach, which has been tested in only a small number of locations worldwide, has directed prospect evaluation toward those sand-hosted, high-saturation occurrences that were presently considered to have the greatest future commercial potential.

  14. [Prospective evaluation of antidepressant discontinuation].

    PubMed

    Mourad, I; Lejoyeux, M; Adès, J

    1998-01-01

    The authors prospectively assessed symptoms induced by the interruption of antidepressants in 16 patients (11 women and 5 men), aged from 33 to 85 years (mean = 52.4 +/- 16.4), treated with antidepressants since at least two weeks. All patients were free of alcohol abuse or dependence disorder and of other dependence to psychoactive substances. None of them presented medical illness. Diagnosis were made by separate evaluations by two authors and confirmed with a semistructered assessment instrument: the Schedule for Affective Disorders and Schizophrenia (Lifetime Version). All patients were submitted to a brutal discontinuation of their antidepressant agent. Patients were assessed twice, before the interruption of the antidepressant, and 72 hours later. Effects of antidepressant interruption were assessed by several means. Modification of anxiety and depression were evaluated using the Montgomery Asberg Depression Rating Scale (MADRS) and the Hamilton Anxiety Scale. Symptoms of withdrawal were assessed with Cassano and al.'s scale SESSH including an evaluation of anxiety, agitation, irritability, anergy, difficulty on concentrating, depersonalization, sleep and appetite disorders, muscle pains, nausea, tremor, sweating, altered taste, hyperosmia, paresthesias, photophobia, motor incoordination, dizziness, hyperacousia pain, delirium. Fourteen of the 16 patients (87.5%) presented modifications of their somatic or psychic state 3 days after the interruption of the antidepressant treatment. Most frequent symptoms were: increase in anxiety (31%), increase in irritability (25%), sleep disorders (19%), decrease of anergia and fatigue (19%). Mean scores of anxiety and depression were not significantly modified by the withdrawal. Following TCAs interruption (7 patients) most frequent symptoms were sleep disorders; increase in anxiety, nausea. Among patients withdrawn from SSRIs (6 patients), most frequent symptoms were increase in anxiety, increase in irritability

  15. Prospective Optimization with Limited Resources

    PubMed Central

    Snider, Joseph; Lee, Dongpyo; Poizner, Howard; Gepshtein, Sergei

    2015-01-01

    The future is uncertain because some forthcoming events are unpredictable and also because our ability to foresee the myriad consequences of our own actions is limited. Here we studied how humans select actions under such extrinsic and intrinsic uncertainty, in view of an exponentially expanding number of prospects on a branching multivalued visual stimulus. A triangular grid of disks of different sizes scrolled down a touchscreen at a variable speed. The larger disks represented larger rewards. The task was to maximize the cumulative reward by touching one disk at a time in a rapid sequence, forming an upward path across the grid, while every step along the path constrained the part of the grid accessible in the future. This task captured some of the complexity of natural behavior in the risky and dynamic world, where ongoing decisions alter the landscape of future rewards. By comparing human behavior with behavior of ideal actors, we identified the strategies used by humans in terms of how far into the future they looked (their “depth of computation”) and how often they attempted to incorporate new information about the future rewards (their “recalculation period”). We found that, for a given task difficulty, humans traded off their depth of computation for the recalculation period. The form of this tradeoff was consistent with a complete, brute-force exploration of all possible paths up to a resource-limited finite depth. A step-by-step analysis of the human behavior revealed that participants took into account very fine distinctions between the future rewards and that they abstained from some simple heuristics in assessment of the alternative paths, such as seeking only the largest disks or avoiding the smaller disks. The participants preferred to reduce their depth of computation or increase the recalculation period rather than sacrifice the precision of computation. PMID:26367309

  16. A prospective treatment for sepsis.

    PubMed

    Shahidi Bonjar, Mohammad Rashid; Shahidi Bonjar, Leyla

    2015-01-01

    The present paper proposes a prospective auxiliary treatment for sepsis. There exists no record in the published media on the subject. As an auxiliary therapy, efficacious extracorporeal removal of sepsis-causing bacterial antigens and their toxins (BATs) from the blood of septic patients is discussed. The principal component to this approach is a bacterial polyvalent antibody-column (BPVAC), which selectively traps wide spectrum of BATs from blood in an extracorporeal circuit, and detoxified blood returns back to the patient's body. BPVAC treatment would be a device of targeted medicine. Detoxification is performed under supervision of trained personnel using simple blood-circulating machines in which blood circulates from the patient to BPVAC and back to the patient aseptically. BPVACs' reactive sites consist of carbon nanotubes on which a vast spectra of polyvalent BATs-antibodies are bond to. The devise acts as a biological filter that selectively immobilizes harmful BATs from intoxicated blood; however, no dialysis is involved. For effective neutralization, BPVAC provides large contact surface area with blood. BPVAC approach would have advantages of: 1) urgent neutralization of notorious BATs from blood of septic patients; 2) applicability in parallel with conventional treatments; 3) potential to minimize side effects of the malady; 4) applicability for a vast range of BATs; 5) potential to eliminate contact of BATs with internal tissues and organs; 6) tolerability by patients sensitive to antiserum injections; 7) capability for universal application; 8) affectivity when antibiotic-resistant bacteria are involved and the physician has no or limited access to appropriate antibiotics; and 10) being a single-use, disposable, and stand-alone device. Before using it for clinical trials in human beings, it should pass animal evaluations accurately; however, research works should optimize its implementation in human beings. For optimization, it needs appropriate

  17. Prospective Optimization with Limited Resources.

    PubMed

    Snider, Joseph; Lee, Dongpyo; Poizner, Howard; Gepshtein, Sergei

    2015-09-01

    The future is uncertain because some forthcoming events are unpredictable and also because our ability to foresee the myriad consequences of our own actions is limited. Here we studied how humans select actions under such extrinsic and intrinsic uncertainty, in view of an exponentially expanding number of prospects on a branching multivalued visual stimulus. A triangular grid of disks of different sizes scrolled down a touchscreen at a variable speed. The larger disks represented larger rewards. The task was to maximize the cumulative reward by touching one disk at a time in a rapid sequence, forming an upward path across the grid, while every step along the path constrained the part of the grid accessible in the future. This task captured some of the complexity of natural behavior in the risky and dynamic world, where ongoing decisions alter the landscape of future rewards. By comparing human behavior with behavior of ideal actors, we identified the strategies used by humans in terms of how far into the future they looked (their "depth of computation") and how often they attempted to incorporate new information about the future rewards (their "recalculation period"). We found that, for a given task difficulty, humans traded off their depth of computation for the recalculation period. The form of this tradeoff was consistent with a complete, brute-force exploration of all possible paths up to a resource-limited finite depth. A step-by-step analysis of the human behavior revealed that participants took into account very fine distinctions between the future rewards and that they abstained from some simple heuristics in assessment of the alternative paths, such as seeking only the largest disks or avoiding the smaller disks. The participants preferred to reduce their depth of computation or increase the recalculation period rather than sacrifice the precision of computation. PMID:26367309

  18. Prospective Coding by Spiking Neurons

    PubMed Central

    Brea, Johanni; Gaál, Alexisz Tamás; Senn, Walter

    2016-01-01

    Animals learn to make predictions, such as associating the sound of a bell with upcoming feeding or predicting a movement that a motor command is eliciting. How predictions are realized on the neuronal level and what plasticity rule underlies their learning is not well understood. Here we propose a biologically plausible synaptic plasticity rule to learn predictions on a single neuron level on a timescale of seconds. The learning rule allows a spiking two-compartment neuron to match its current firing rate to its own expected future discounted firing rate. For instance, if an originally neutral event is repeatedly followed by an event that elevates the firing rate of a neuron, the originally neutral event will eventually also elevate the neuron’s firing rate. The plasticity rule is a form of spike timing dependent plasticity in which a presynaptic spike followed by a postsynaptic spike leads to potentiation. Even if the plasticity window has a width of 20 milliseconds, associations on the time scale of seconds can be learned. We illustrate prospective coding with three examples: learning to predict a time varying input, learning to predict the next stimulus in a delayed paired-associate task and learning with a recurrent network to reproduce a temporally compressed version of a sequence. We discuss the potential role of the learning mechanism in classical trace conditioning. In the special case that the signal to be predicted encodes reward, the neuron learns to predict the discounted future reward and learning is closely related to the temporal difference learning algorithm TD(λ). PMID:27341100

  19. Prospective Ukrainian lunar orbiter mission

    NASA Astrophysics Data System (ADS)

    Shkuratov, Y.; Litvinenko, L.; Shulga, V.; Yatskiv, Y.; Kislyuk, V.

    Ukraine has launch vehicles that are able to deliver about 300 kg to the lunar orbit. Future Ukrainian lunar program may propose a polar orbiter. This orbiter should fill principal information gaps in our knowledge about the Moon after Clementine and Lunar Prospector missions and the future missions, like Smart-1, Lunar-A, and Selene. We consider that this can be provided by radar studies of the Moon with supporting optical polarimetric observations from lunar polar orbit. These experiments allow one to better understand global structure of the lunar surface in a wide range of scales, from microns to kilometers. We propose three instruments for the prospective lunar orbiter. They are: a synthetic aperture imaging radar (SAR), ground-penetrating radar (GPR), and imaging polarimeter (IP). The main purpose of SAR is to study with high resolution (50 m) the permanently shadowed sites in the lunar polar regions. These sites are cold traps for volatiles, and have a potential of resource utilization. Possible presence of water ice in the regolith in the sites makes them interesting for permanent manned bases on the Moon. Radar imaging and mapping of other interesting regions could be also planned. Multi-frequencies multi-polarization soun d ing of the lunar surface with GPR can provide information about internal structure of the lunar surface from meters to several hundred meters deep. GPR can be used for measuring the megaregolith layer properties, detection of cryptomaria, and studies of internal structure of the largest craters. IP will be a CCD camera with an additional suite of polarizers. Modest spatial resolution (100 m) should provide a total coverage or a large portion of the lunar surface in oblique viewing basically at large phase angles. Polarization degree at large (>90°) phase angles bears information about characteristic size of the regolith particles. Additional radiophysical experiments are considered with the use of the SAR system, e.g., bistatic radar

  20. Prospect for extreme field science

    NASA Astrophysics Data System (ADS)

    Tajima, T.

    2009-11-01

    The kind of laser extreme light infrastructure (ELI) provides will usher in a class of experiments we have only dreamed of for years. The characteristics that ELI brings in include: the highest intensity ever, large fluence, and relatively high repetition rate. A personal view of the author on the prospect of harnessing this unprecedented opportunity for advancing science of extreme fields is presented. The first characteristic of ELI, its intensity, will allow us to access, as many have stressed already, extreme fields that hover around the Schwinger field or at the very least the neighboring fields in which vacuum begins to behave as a nonlinear medium. In this sense, we are seriously probing the “material” property of vacuum and thus the property that theory of relativity itself described and will entail. We will probe both special theory and general theory of relativity in regimes that have been never tested so far. We may see a glimpse into the reach of relativity or even its breakdown in some extreme regimes. We will learn Einstein and may even go beyond Einstein, if our journey is led. Laser-driven acceleration both by the laser field itself and by the wakefield that is triggered in a plasma is huge. Energies, if not luminosity, we can access, may be unprecedented going far beyond TeV. The nice thing about ELI is that it has relatively high repetition rate and average fluence as compared with other extreme lasers. This high fluence can be a key element that leads to applications to high energy physics, such as gamma-gamma collider driver experiment, and some gamma ray experiments that may be relevant in the frontier of photo-nuclear physics, and atomic energy applications. Needless to say, high fluence is one of most important features that industrial and medical applications may need. If we are lucky, we may see a door opens at the frontier of novel physics that may not be available by any other means. Finally, as the last lecture of this workshop the

  1. Prospect theory in the valuation of health.

    PubMed

    Moffett, Maurice L; Suarez-Almazor, Maria E

    2005-08-01

    Prospect theory is the prominent nonexpected utility theory in the estimation of health state preference scores for quality-adjusted life year calculation. Until recently, the theory was not considered to be developed to the point of implementation in economic analysis. This review focuses on the research and evidence that tests the implementation of prospect theory into health state valuation. The typical application of expected utility theory assumes that a decision maker has stable preferences under conditions of risk and uncertainty. Under prospect theory, preferences are dependent on whether the decision maker regards the outcome of a choice as a gain or loss, relative to a reference point. The conceptual preference for standard gamble utilities in the valuation of health states has led to the development of elicitation techniques. Empirical evidence using these techniques indicates that when individual preferences are elicited, a prospect theory consistent framework appears to be necessary for adequate representation of individual health utilities. The relevance of prospect theory to policy making and resource allocation remains to be established. Societal preferences may not need the same attitudes towards risks as individual preferences, and may remain largely risk neutral. PMID:19807267

  2. Geochemical methods of prospecting for hydrocarbons

    SciTech Connect

    Duchscherer, W. Jr.

    1980-12-01

    Because the commonly used reflection-seismograph exploration technique misses many marginal low-relief structural prospects and regardless of its electronic computer sophistication, overlooks almost all stratigraphic traps, the hydrocarbon exploration industry should take a look at geochemical prospecting methods, which detect geochemical anomalies in the near-surface soils by measuring the thermal dissociation of the soil carbonates that are found overlying hydrocarbon accumulations. To promote understanding of such prospecting techniques, Geochemical Surveys reviews the methods used, the soil-alteration patterns, the lateral and vertical migration of hydrocarbon gases, the halo phenomenon (a ring or annual anomaly), the geochemical modification of sediments, and the data-interpretation and exploration procedures involved in a carbonate ..delta.. C analysis, which measures the residual, stable, cumulative effect of hydrocarbon migration.

  3. Prospect theory for online financial trading.

    PubMed

    Liu, Yang-Yu; Nacher, Jose C; Ochiai, Tomoshiro; Martino, Mauro; Altshuler, Yaniv

    2014-01-01

    Prospect theory is widely viewed as the best available descriptive model of how people evaluate risk in experimental settings. According to prospect theory, people are typically risk-averse with respect to gains and risk-seeking with respect to losses, known as the "reflection effect". People are much more sensitive to losses than to gains of the same magnitude, a phenomenon called "loss aversion". Despite of the fact that prospect theory has been well developed in behavioral economics at the theoretical level, there exist very few large-scale empirical studies and most of the previous studies have been undertaken with micro-panel data. Here we analyze over 28.5 million trades made by 81.3 thousand traders of an online financial trading community over 28 months, aiming to explore the large-scale empirical aspect of prospect theory. By analyzing and comparing the behavior of winning and losing trades and traders, we find clear evidence of the reflection effect and the loss aversion phenomenon, which are essential in prospect theory. This work hence demonstrates an unprecedented large-scale empirical evidence of prospect theory, which has immediate implication in financial trading, e.g., developing new trading strategies by minimizing the impact of the reflection effect and the loss aversion phenomenon. Moreover, we introduce three novel behavioral metrics to differentiate winning and losing traders based on their historical trading behavior. This offers us potential opportunities to augment online social trading where traders are allowed to watch and follow the trading activities of others, by predicting potential winners based on their historical trading behavior. PMID:25330203

  4. Prospect Theory for Online Financial Trading

    PubMed Central

    Martino, Mauro; Altshuler, Yaniv

    2014-01-01

    Prospect theory is widely viewed as the best available descriptive model of how people evaluate risk in experimental settings. According to prospect theory, people are typically risk-averse with respect to gains and risk-seeking with respect to losses, known as the “reflection effect”. People are much more sensitive to losses than to gains of the same magnitude, a phenomenon called “loss aversion”. Despite of the fact that prospect theory has been well developed in behavioral economics at the theoretical level, there exist very few large-scale empirical studies and most of the previous studies have been undertaken with micro-panel data. Here we analyze over 28.5 million trades made by 81.3 thousand traders of an online financial trading community over 28 months, aiming to explore the large-scale empirical aspect of prospect theory. By analyzing and comparing the behavior of winning and losing trades and traders, we find clear evidence of the reflection effect and the loss aversion phenomenon, which are essential in prospect theory. This work hence demonstrates an unprecedented large-scale empirical evidence of prospect theory, which has immediate implication in financial trading, e.g., developing new trading strategies by minimizing the impact of the reflection effect and the loss aversion phenomenon. Moreover, we introduce three novel behavioral metrics to differentiate winning and losing traders based on their historical trading behavior. This offers us potential opportunities to augment online social trading where traders are allowed to watch and follow the trading activities of others, by predicting potential winners based on their historical trading behavior. PMID:25330203

  5. 42 CFR 413.345 - Publication of Federal prospective payment rates.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... RENAL DISEASE SERVICES; OPTIONAL PROSPECTIVELY DETERMINED PAYMENT RATES FOR SKILLED NURSING FACILITIES Prospective Payment for Skilled Nursing Facilities § 413.345 Publication of Federal prospective payment...

  6. Carbohydrate drugs: current status and development prospect.

    PubMed

    Zhang, Yan; Wang, Fengshan

    2015-04-01

    In recent years, there has been a great effort devoted to the investigation of the roles of carbohydrates in various essential biological processes and the development of carbohydrates to therapeutic drugs. This review summarizes the carbohydrate drugs which have been recorded in several pharmacopoeias, marketed, and under development. A prospect of the future development of carbohydrate drugs is discussed as well. PMID:25994058

  7. Prospective Governance. AGB Occasional Paper No. 31.

    ERIC Educational Resources Information Center

    Greer, Darryl G.

    1997-01-01

    Higher education governance structures are ineffective and new structures of "prospective governance" are needed for future success. Trends affecting higher education include financial scarcity, lack of government funding juxtaposed with the growing public demand for better services, and the competitive pressures of commercialization and…

  8. The Swedish Family: Problems, Programs and Prospects.

    ERIC Educational Resources Information Center

    Lindblom, Paul

    1986-01-01

    To clarify issues in the controversy in Sweden concerning the means and ends of family policy, this article analyzes the economic plight of Swedish families with children, elucidates the views of parents and politicians, discusses the changing role and status of women, and considers prospects for the future. Also discussed are work equality and…

  9. CDF Status and B Physics Prospects

    SciTech Connect

    J. Stephen Miller

    2002-10-07

    With extensive upgrades to the detector and electronics, CDF has started collecting data with Run II of the Tevatron. The enhanced silicon coverage and the use of silicon based tracks in the trigger, make CDF well suited for a broad program of B hadron measurements. We present the current status of the experiment and prospects for measurements in Run II.

  10. School Funding Prospects for the States.

    ERIC Educational Resources Information Center

    Sherman, Joel D.; And Others

    1983-01-01

    Discusses factors affecting both school funding demand (including demographic changes and student needs) and the supply of educational funds (such as fiscal capacity and effort, state and local expenditures, and federal aid). Classifies states with favorable, average, and unfavorable funding prospects, based on state rankings for each factor. (RW)

  11. Existing and prospective blast-furnace conditions

    SciTech Connect

    I.G. Tovarovskii; V.I. Bol'shakov; V.P. Lyalyuk; A.E. Merkulov; D. V. Pinchuk

    2009-07-15

    Blast-furnace conditions are investigated by means of a multizone model. The expected performance of prospective technologies is assessed, as well as the trends in blast-furnace processes. The model permits the identification of means of overcoming practical difficulties.

  12. School Food Practices of Prospective Teachers

    ERIC Educational Resources Information Center

    Rossiter, Melissa; Glanville, Theresa; Taylor, Jennifer; Blum, Ilya

    2007-01-01

    Background: Schoolteachers can affect students' eating habits in several ways: through nutrition knowledge, positive role modeling, and avoidance of unhealthy classroom food practices. In this study, the knowledge, attitudes, and eating behaviors of prospective teachers as determinants of intended classroom food practices and the school…

  13. Status and Prospects for Hadron Production Experiments

    SciTech Connect

    Schroeter, Raphaeel

    2010-03-30

    The latest results from the HARP, MIPP and NA61 Hadron Production Experiments are reviewed and their implications for neutrinos physics experiments are discussed. We emphasize three neutrino sources: accelerator-based neutrino beams, advanced neutrino sources and atmospheric neutrinos. Finally, prospects from additional forthcoming hadron production measurements are presented.

  14. Professional Leadership Aspirations of Prospective Women Teachers

    ERIC Educational Resources Information Center

    McMillin, Marvin R.

    1972-01-01

    Results of the study seem to suggest that prospective women teachers are less likely to accept a leadership role as the level of responsibility increases and after an interruption in their career. They are also less likely to accept leadership roles in professional organizations. (Author/BY)

  15. Prospective Elementary School Teachers' Proportional Reasoning

    ERIC Educational Resources Information Center

    Valverde, Gabriela; Castro, Encarnación

    2012-01-01

    We present the findings of a study on prospective elementary teachers' proportional reasoning. After describing some of the teachers' performance in solving multiplicative structure problems that involve ratios and relations of direct proportionality between quantities, we were able to establish classifications of their answers according to…

  16. Aging: Prospects and Issues. Revised. 1976.

    ERIC Educational Resources Information Center

    Davis, Richard H., Ed.

    Completely revised and updated since its first edition in 1973, the book explores an even wider range of concerns regarding gerontology. Part 1 presents an overview of the multiple aspects of gerontology, and includes the following chapters: (1) Aging: Prospects and Issues, Richard H. Davis; (2) Aging: The Psychologist's Perspective, James E.…

  17. Prospective Elementary Teachers' Conceptual Understanding of Integers

    ERIC Educational Resources Information Center

    Reeder, Stacy; Bateiha, Summer

    2016-01-01

    This investigation examined the degree to which prospective elementary teachers had developed a meaningful and conceptual understanding of what integers are and explored their development of models for multiplication with integers that are related to everyday activities. Additionally, this study explored how these understandings informed…

  18. Flower Power: Prospects for Photosynthetic Energy

    ERIC Educational Resources Information Center

    Poole, Alan D.; Williams, Robert H.

    1976-01-01

    This report focuses on the prospects and possibilities for using biomass as an energy source for the United States. However, the greatest potential for utilizing biomass as fuel exists in energy-starved developing nations, since it appears possible to develop biomass technologies keeping capital inputs low in relation to labor inputs. (BT)

  19. Problems and Prospects in Foreign Language Computing.

    ERIC Educational Resources Information Center

    Pusack, James P.

    The problems and prospects of the field of foreign language computing are profiled through a survey of typical implementation, development, and research projects that language teachers may undertake. Basic concepts in instructional design, hardware, and software are first clarified. Implementation projects involving courseware evaluation, textbook…

  20. A Prospective Analysis of Sexual Assault Perpetration

    ERIC Educational Resources Information Center

    Loh, Catherine; Gidycz, Christine; Lobo, Tracy; Luthra, Rohini

    2005-01-01

    This study prospectively evaluated perpetrator risk factors for sexual assault perpetration, including peer influences, beliefs and attitudes about sexuality, alcohol use, and token resistance. Perpetration of sexual assault was evaluated at three time periods: pretest, 3-month follow-up, and 7-month follow-up. Retrospective and prospective…

  1. How Well Do Prospective Teachers Speak?

    ERIC Educational Resources Information Center

    Snyder, Sandra L.

    As part of a study of basic skills of secondary education students, a study was conducted at Pennsylvania State University of the speaking ability of 43 prospective secondary level teachers. A rating instrument was developed based on a list of criteria considered important to teachers by speech communication experts and teacher educators alike.…

  2. Continuing Bonds and Grief: A Prospective Analysis

    ERIC Educational Resources Information Center

    Boelen, Paul A.; Stroebe, Margaret S.; Schut, Henk A. W.; Zijerveld, Annemieke M.

    2006-01-01

    Using data of 56 bereaved individuals, this study examined associations of various manifestations of continuing bonds, assessed at 7-12 months post-loss, with concurrent and prospective (9 months later) symptoms of grief and depression. Among other things it was found that, independent of initial symptom levels, manifestations of continuing bonds…

  3. Testing general relativity: Progress, problems, and prospects

    NASA Technical Reports Server (NTRS)

    Shapiro, I. I.

    1971-01-01

    The results from ground-based experimental testing are presented. Prospects for improving these experiments are discussed. Radar echo time delays, perihelion advance and solar oblateness, time variation of the gravitational constant, and radio wave deflection are considered. Ground-based and spacecraft techniques are compared on an accuracy vs. cost basis.

  4. Labelling of Students by Prospective Teachers.

    ERIC Educational Resources Information Center

    Frerichs, Allen H.; Adelman, Stan I.

    The basic purpose of this study was to determine the effects of telling prospective teachers that a classroom of adolescents, viewed on video tape, were low-achieving students. An experimental group was informed that the adolescents were slow learners having considerable difficulty in school. A control group, observing the same video tape was told…

  5. Prospective associations between loneliness and emotional intelligence.

    PubMed

    Wols, A; Scholte, R H J; Qualter, P

    2015-02-01

    Loneliness has been linked cross-sectionally to emotional skill deficits (e.g., Zysberg, 2012), but missing from the literature is a longitudinal examination of these relationships. The present study fills that gap by examining the prospective relationships between loneliness and emotional functioning in young adolescents in England. One hundred and ninety-six adolescents aged 11-13 years (90 females) took part in the study and completed the youth version of the Mayer-Salovey-Caruso Emotional Intelligence Test (MSCEIT-YV) and the peer-related subscale of the Loneliness and Aloneness Scale for Children and Adolescents (LACA) at two time points, which were 10 months apart. Prospective associations were obtained for male and female adolescents separately using cross-lagged statistical techniques. Our results showed prospective links between understanding and managing emotions and loneliness for both females and males. Perceiving and using emotions were prospectively linked to loneliness in males only. Possible explanations and directions for future research are discussed. PMID:25576768

  6. Lone Tree prospect area, Railroad Valley, Nevada

    SciTech Connect

    Montgomery, S.L.

    1997-02-01

    Continued exploration in the Basin and Range of Nevada has resulted in a number of small field discoveries that confirm widespread oil generation and suggest potential in local prospect settings. One such setting, the Lone Tree prospect area, lies approximately 6.5 mi (10.4 km) southwest of Grant Canyon field in Railroad Valley. Discovered in 1983, this field had produced nearly 20 million bbl of oil by June 1996, mostly from two wells. Oil is entrapped in a slide block of fractured Paleozoic strata juxtaposed against Mississippian source rocks along a detachment fault of probable early Tertiary age. Subsequent exploration has focused on attempts to identify such blocks elsewhere in east-central Nevada, particularly in Railroad and Pine Valleys. Well, gravity, and two-dimensional seismic data suggested the existence of such a block in the Lone Tree area. These data were used as a basis for a three-dimensional seismic survey. Information from this survey identified a prospect at the structural culmination of the interpreted block. The resulting well, the 13-14 Timber Mountain, was commercially unsuccessful but yielded important new data, suggesting a need to revise existing stratigraphy and structural history. In addition, a second prospect, located farther updip, was indicated.

  7. Prospective Teachers' View on Geography Fieldworks

    ERIC Educational Resources Information Center

    Yilmaz, Cevdet; Bilgi, Merve Gorkem

    2011-01-01

    The purposes of the study are to examine thoroughly the components to constitute individual perceptions of prospective teachers concerning important acquisitions of geography fieldworks and to facilitate its applicability as a teaching method through their own observations and suggestions, and in this context to obtain information about the nature…

  8. Teacher Education: Its Problems and Some Prospects

    ERIC Educational Resources Information Center

    Sykes, Gary; Bird, Tom; Kennedy, Mary

    2010-01-01

    Based on an analysis of occupational competence in teaching and teacher education, this article draws together a set of dilemmas that face the field, arguing that an occupational analysis is needed to complement the more common institutional analysis of teacher education. Then, this analysis is used to evaluate the prospects of the reforms that…

  9. Prospects in Computer Assisted Language Lessons.

    ERIC Educational Resources Information Center

    Jamieson, Joan; Chapelle, Carol

    Some prospects for development of computer-assisted language instruction in six language skill areas (grammar, communication, reading, listening, speaking, and writing) are presented. In grammar instruction, a current challenge is to improve judging of student answers, and "intelligent" computer programs that try to identify the student's…

  10. Secondary Education Reform: Retrospect and Prospect.

    ERIC Educational Resources Information Center

    Passow, A. Harry

    In these lectures the author examines current criticisms of secondary education in light of the history of secondary education reform and then discusses future prospects for reform as they relate to the place of secondary education in modern American society. The author begins by presenting a retrospective analysis of a number of studies and…

  11. Prospects of Private Education in China

    ERIC Educational Resources Information Center

    Hua, Wu

    2009-01-01

    Private education contributes a great deal to education in China, but people are confused about the prospects of teacher development, tax problems, property rights problems, remunerations, and so forth. Legal provisions stipulate that private education and public education have the same legal status and rights, but there is still a long way to go…

  12. Perceptions of Prospective Entrants to Teacher Education

    ERIC Educational Resources Information Center

    Taylor, Alexis

    2006-01-01

    The findings of a small-scale study concerning entry into teacher education are presented. Data were collected over four years by questionnaires completed by a total of 140 participants attending Teaching Taster Courses run annually by Brunel University from 1999 to 2002 for prospective students in secondary shortage subjects. The study took place…

  13. Attitude level of prospective science teachers towards assessment

    NASA Astrophysics Data System (ADS)

    Efendi, Ridwan; Rustaman, Nuryani Y.

    2016-02-01

    A descriptive study about attitude level of prospective science teachers towards assessment was conducted with the involvement of 67 prospective science teachers from four state universities in western part of the Indonesian region and middle part of Indonesia region. Data collected by using the questionnaire consisted of four aspects, id est. prospective science teachers attitude towards assessment (cognitive level of assessment, type of assessment, and criterion of evaluation), prospective science teachers instructional practice, internal difficulties that prospective science teachers experienced related to their assessment skills, and the use of assessment process of prospective science teachers. Determination of attitude level detected from prospective science teachers was carried out in descriptive statistics, in the form of respondent average values. Research finding shows that attitude level of prospective science teachers towards assessment can be categorized as "close to constructivist".

  14. External Retrieval Cues Facilitate Prospective Remembering in Children.

    ERIC Educational Resources Information Center

    Meacham, John A.; Colombo, John A.

    1980-01-01

    Young children exhibit improved prospective memory when an external cue is used as a reminder. Children's attempts at prospective remembering may be an important precursor to the development of strategies for retrospective remembering. (JD)

  15. Technology Preview: X-Ray Fused With Magnetic Resonance During Invasive Cardiovascular Procedures

    PubMed Central

    Gutiérrez, Luis F.; de Silva, Ranil; Ozturk, Cengizhan; Sonmez, Merdim; Stine, Annette M.; Raval, Amish N.; Raman, Venkatesh K.; Sachdev, Vandana; Aviles, Ronnier J.; Waclawiw, Myron A.; McVeigh, Elliot R.; Lederman, Robert J.

    2009-01-01

    Background We have developed and validated a system for real-time X-ray fused with magnetic resonance imaging, MRI (XFM), to guide catheter procedures with high spatial precision. Our implementation overlays roadmaps—MRI-derived soft-tissue features of interest—onto conventional X-ray fluoroscopy. We report our initial clinical experience applying XFM, using external fiducial markers, electrocardiogram (ECG)-gating, and automated real-time correction for gantry and table movement. Methods This prospective case series for technical development was approved by the NHLBI Institutional Review Board and included 19 subjects. Multimodality external fiducial markers were affixed to patients’ skin before MRI, which included contrast-enhanced, 3D T1-weighted, or breath-held and ECG-gated 2D steady state free precession imaging at 1.5T. MRI-derived roadmaps were manually segmented while patients were transferred to a calibrated X-ray fluoroscopy system. Image spaces were registered using the fiducial markers and thereafter permitted unrestricted gantry rotation, table panning, and magnification changes. Static and ECG-gated MRI data were transformed from 3D to 2D to correspond with gantry and table position and combined with live X-ray images. Results Clinical procedures included graft coronary arteriography, right ventricular free-wall biopsy, and iliac and femoral artery recanalization and stenting. MRI roadmaps improved operator confidence, and in the biopsy cases, outperformed the best available alternative imaging modality. Registration errors were increased when external fiducial markers were affixed to more mobile skin positions, such as over the abdomen. Conclusion XFM using external fiducial markers is feasible during X-ray guided catheter treatments. Multimodality image fusion may prove a useful adjunct to invasive cardiovascular procedures. PMID:18022851

  16. 42 CFR 412.340 - Fully prospective payment methodology.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 2 2011-10-01 2011-10-01 false Fully prospective payment methodology. 412.340...-Related Costs § 412.340 Fully prospective payment methodology. A hospital paid under the fully prospective payment methodology receives a payment per discharge based on a proportion of the hospital-specific...

  17. Turkish Prospective Teachers' Understanding and Misunderstanding on Global Warming

    ERIC Educational Resources Information Center

    Ocal, A.; Kisoglu, M.; Alas, A.; Gurbuz, H.

    2011-01-01

    The key objective of this study is to determine the Turkish elementary prospective teachers' opinions on global warming. It is also aimed to establish prospective teachers' views about the environmental education in Turkish universities. A true-false type scale was administered to 564 prospective teachers from science education, social studies…

  18. Prospective Memory in a Language-Trained Chimpanzee ("Pan Troglodytes")

    ERIC Educational Resources Information Center

    Beran, Michael J.; Perdue, Bonnie M.; Bramlett, Jessica L.; Menzel, Charles R.; Evans, Theodore A.

    2012-01-01

    Prospective memory involves the encoding, retention, and implementation of an intended future action. Although humans show many forms of prospective memory, less is known about the future oriented processes of nonhuman animals, or their ability to use prospective memory. In this experiment, a chimpanzee named Panzee, who had learned to associate…

  19. 48 CFR 814.203-1 - Transmittal to prospective bidders.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Transmittal to prospective... prospective bidders. The contracting officer should include either a bid envelope or OF 17, Sealed Bid Label, with each invitation for bids furnished by mail or hand delivered to prospective bidders....

  20. 48 CFR 14.203-1 - Transmittal to prospective bidders.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Transmittal to prospective... CONTRACTING METHODS AND CONTRACT TYPES SEALED BIDDING Solicitation of Bids 14.203-1 Transmittal to prospective... contracting office is located in the United States, any solicitation sent to a prospective bidder...

  1. 48 CFR 53.209-1 - Responsible prospective contractors.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 2 2010-10-01 2010-10-01 false Responsible prospective... (CONTINUED) CLAUSES AND FORMS FORMS Prescription of Forms 53.209-1 Responsible prospective contractors. (a) SF 1403 (Rev. 9/88), Preaward Survey of Prospective Contractor (General). SF 1403 is authorized...

  2. 47 CFR 76.960 - Prospective rate reductions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Prospective rate reductions. 76.960 Section 76... MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Cable Rate Regulation § 76.960 Prospective rate reductions... Commission may order the cable operator to implement a prospective rate reduction to the class of...

  3. 48 CFR 514.203-1 - Transmittal to prospective bidders.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false Transmittal to prospective bidders. 514.203-1 Section 514.203-1 Federal Acquisition Regulations System GENERAL SERVICES... to prospective bidders. Prospective bidders, as used in FAR 14.203-1, include both the following:...

  4. 43 CFR 3815.2 - Prospecting and mining.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Prospecting and mining. 3815.2 Section... Mineral Locations in Stock Driveway Withdrawals § 3815.2 Prospecting and mining. All prospecting and mining operations shall be conducted in such manner as to cause no interference with the use of...

  5. 50 CFR 27.64 - Prospecting and mining.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 9 2014-10-01 2014-10-01 false Prospecting and mining. 27.64 Section 27.64 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR... Property § 27.64 Prospecting and mining. Prospecting, locating, or filing mining claims on...

  6. 43 CFR 3815.2 - Prospecting and mining.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 2 2012-10-01 2012-10-01 false Prospecting and mining. 3815.2 Section... Mineral Locations in Stock Driveway Withdrawals § 3815.2 Prospecting and mining. All prospecting and mining operations shall be conducted in such manner as to cause no interference with the use of...

  7. 50 CFR 27.64 - Prospecting and mining.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 8 2011-10-01 2011-10-01 false Prospecting and mining. 27.64 Section 27.64 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR... Property § 27.64 Prospecting and mining. Prospecting, locating, or filing mining claims on...

  8. 43 CFR 3815.2 - Prospecting and mining.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 43 Public Lands: Interior 2 2014-10-01 2014-10-01 false Prospecting and mining. 3815.2 Section... Mineral Locations in Stock Driveway Withdrawals § 3815.2 Prospecting and mining. All prospecting and mining operations shall be conducted in such manner as to cause no interference with the use of...

  9. 50 CFR 27.64 - Prospecting and mining.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Prospecting and mining. 27.64 Section 27.64 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR... Property § 27.64 Prospecting and mining. Prospecting, locating, or filing mining claims on...

  10. 50 CFR 27.64 - Prospecting and mining.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 9 2013-10-01 2013-10-01 false Prospecting and mining. 27.64 Section 27.64 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR... Property § 27.64 Prospecting and mining. Prospecting, locating, or filing mining claims on...

  11. 43 CFR 3815.2 - Prospecting and mining.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 43 Public Lands: Interior 2 2013-10-01 2013-10-01 false Prospecting and mining. 3815.2 Section... Mineral Locations in Stock Driveway Withdrawals § 3815.2 Prospecting and mining. All prospecting and mining operations shall be conducted in such manner as to cause no interference with the use of...

  12. 50 CFR 27.64 - Prospecting and mining.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 9 2012-10-01 2012-10-01 false Prospecting and mining. 27.64 Section 27.64 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR... Property § 27.64 Prospecting and mining. Prospecting, locating, or filing mining claims on...

  13. Turkish Prospective Chemistry Teachers' Beliefs about Chemistry Teaching

    ERIC Educational Resources Information Center

    Boz, Yezdan; Uzuntiryaki, Esen

    2006-01-01

    In order to study the beliefs of Turkish prospective chemistry teachers about teaching chemistry, semi-structured interviews were conducted with 12 prospective teachers. Analysis of the interviews revealed that most of the prospective teachers held intermediate (transition between constructivist and traditional) beliefs about chemistry teaching.…

  14. A Multinomial Model of Event-Based Prospective Memory

    ERIC Educational Resources Information Center

    Smith, Rebekah E.; Bayen, Ute J.

    2004-01-01

    Prospective memory is remembering to perform an action in the future. The authors introduce the 1st formal model of event-based prospective memory, namely, a multinomial model that includes 2 separate parameters related to prospective memory processes. The 1st measures preparatory attentional processes, and the 2nd measures retrospective memory…

  15. Predictors of Time-Based Prospective Memory in Children

    ERIC Educational Resources Information Center

    Mackinlay, Rachael J.; Kliegel, Matthias; Mantyla, Timo

    2009-01-01

    This study identified age differences in time-based prospective memory performance in school-aged children and explored possible cognitive correlates of age-related performance. A total of 56 7- to 12-year-olds performed a prospective memory task in which prospective memory accuracy, ongoing task performance, and time monitoring were assessed.…

  16. Turkish Prospective Chemistry Teachers' Alternative Conceptions about Acids and Bases

    ERIC Educational Resources Information Center

    Boz, Yezdan

    2009-01-01

    The purpose of this study was to obtain prospective chemistry teachers' conceptions about acids and bases concepts. Thirty-eight prospective chemistry teachers were the participants. Data were collected by means of an open-ended questionnaire and semi-structured interviews. Analysis of data indicated that most prospective teachers did not have…

  17. 25 CFR 214.29 - Prospecting; abandonment of mines.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Prospecting; abandonment of mines. 214.29 Section 214.29... RESERVATION LANDS, OKLAHOMA, FOR MINING, EXCEPT OIL AND GAS § 214.29 Prospecting; abandonment of mines. All prospecting or mining operations or the abandonment of a well or mine shall be subject to the approval of...

  18. 25 CFR 214.29 - Prospecting; abandonment of mines.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 25 Indians 1 2012-04-01 2011-04-01 true Prospecting; abandonment of mines. 214.29 Section 214.29... RESERVATION LANDS, OKLAHOMA, FOR MINING, EXCEPT OIL AND GAS § 214.29 Prospecting; abandonment of mines. All prospecting or mining operations or the abandonment of a well or mine shall be subject to the approval of...

  19. 25 CFR 214.29 - Prospecting; abandonment of mines.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 1 2011-04-01 2011-04-01 false Prospecting; abandonment of mines. 214.29 Section 214.29... RESERVATION LANDS, OKLAHOMA, FOR MINING, EXCEPT OIL AND GAS § 214.29 Prospecting; abandonment of mines. All prospecting or mining operations or the abandonment of a well or mine shall be subject to the approval of...

  20. 25 CFR 214.29 - Prospecting; abandonment of mines.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 1 2013-04-01 2013-04-01 false Prospecting; abandonment of mines. 214.29 Section 214.29... RESERVATION LANDS, OKLAHOMA, FOR MINING, EXCEPT OIL AND GAS § 214.29 Prospecting; abandonment of mines. All prospecting or mining operations or the abandonment of a well or mine shall be subject to the approval of...

  1. 25 CFR 214.29 - Prospecting; abandonment of mines.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 25 Indians 1 2014-04-01 2014-04-01 false Prospecting; abandonment of mines. 214.29 Section 214.29... RESERVATION LANDS, OKLAHOMA, FOR MINING, EXCEPT OIL AND GAS § 214.29 Prospecting; abandonment of mines. All prospecting or mining operations or the abandonment of a well or mine shall be subject to the approval of...

  2. Apathy and Prospective Memory in Aging

    PubMed Central

    Esposito, Fabienne; Rochat, Lucien; Juillerat Van der Linden, Anne-Claude; Van der Linden, Martial

    2012-01-01

    Background Apathy is common in aging, but the processes underlying its different components are still unclear. The aim of this study was to examine the relationships between apathy and prospective memory (PM), a process involved in the execution of delayed intentions. Methods Fifty elderly participants completed a PM task and a working memory task. Close relatives of the participants were given the Apathy Inventory, which assesses three dimensions of apathy (lack of initiative, lack of interest, emotional blunting), and a negative mood scale. Results Correlation analyses showed strong relationships between PM and lack of initiative and interest. These relations remain significant even after controlling for global cognitive functioning, working memory, processing speed and negative mood. Conclusion This study sheds new light on the cognitive mechanisms associated with apathy in aging and opens up interesting prospects for psychological intervention. PMID:23277780

  3. Prospective approach to managing antimicrobial drug shortages.

    PubMed

    Griffith, Milena M; Patel, Jean A; Sutton, Sarah H; Bolon, Maureen K; Esterly, John S; Gross, Alan E; Postelnick, Michael J; Zembower, Teresa R; Scheetz, Marc H

    2012-07-01

    Antimicrobial drug shortages continue to increase, with few new therapeutic options available. Nationally, proposals have been offered to alleviate drug shortages; however, these recommendations are unlikely to effect change in the near future. Thus, antimicrobial stewardship leaders in acute care hospitals must develop a prospective management strategy to lessen the impact of these shortages on patient care. Herein, we describe several resources available to aid professionals in antimicrobial stewardship and healthcare epidemiology to manage drug shortages. An effective approach should include prospectively tracking shortages and maximizing inventory by appropriately managing usage. Several tenets should underpin this management. Alternative agents should be rationally chosen before the inventory of the primary agent has reached zero, ethical considerations should be taken into account, and timely notification and communication with key stakeholders should occur throughout the prescribing and dispensing process. PMID:22669238

  4. Video recording technology and its prospects

    NASA Astrophysics Data System (ADS)

    Oshima, Hideo

    1994-06-01

    The progress of broadcasting digitization technologies has produced digital VTRs for field use which are quickly replacing the conventional analog versions. In parallel with these developments, advanced high-density recording and image-data compression technologies have created the possibility for home VTRs to be digitized as well so that they may even be able to record/play back Hi-Vision programs. This paper discusses the current status and future prospects of video recording technology centering on digital VTRs.

  5. Prospects and expectations for unstructured methods

    NASA Technical Reports Server (NTRS)

    Baker, Timothy J.

    1995-01-01

    The last decade has witnessed a vigorous and sustained research effort on unstructured methods for computational fluid dynamics. Unstructured mesh generators and flow solvers have evolved to the point where they are now in use for design purposes throughout the aerospace industry. In this paper we survey the various mesh types, structured as well as unstructured, and examine their relative strengths and weaknesses. We argue that unstructured methodology does offer the best prospect for the next generation of computational fluid dynamics algorithms.

  6. Monograph on prospective developments in oceanology

    NASA Technical Reports Server (NTRS)

    Monin, A. S.

    1986-01-01

    Excerpts from a chapter of a monograph, Oceanology in the Year 2000, which has been prepared for publication at the USSR Academy of Sciences' Institute of Oceanology, is presented. The author of this chapter is A. S. Morin, corresponding member of the USSR Academy of Sciences and director of the oceanology institute. The monograph is said to be the collective work of a group of specialists. Monin views prospective developments of oceanology and oceanology related research and development, technology and expedition research.

  7. The East Flanders Prospective Twin Survey (EFPTS).

    PubMed

    Derom, Catherine A; Vlietinck, Robert F; Thiery, Evert W; Leroy, Fernand O G; Fryns, Jean-Pierre; Derom, Robert M

    2006-12-01

    The East Flanders Prospective Twin Survey (EFPTS) is a prospective, population-based registry of multiple births in the province of East Flanders, Belgium. EFPTS has several unique features: it is population based and prospective, with the possibility of long-term follow-up; the twins (and higher order multiple births) are ascertained at birth; basic perinatal data recorded; chorion type and zygosity established; and since 1969 placental biopsies have been taken and frozen at -20 degrees C for later determination of genetic markers. The EFPTS is the only large register that includes placental data and allows differentiation of 3 subtypes of monozygotic (MZ) twins based on the time of the initial zygotic division: the dichorionic-diamnionic pairs (early, before the 4th day after fertilization), the monochorionic-diamnionic pairs (intermediate, between the 4th and the 7th day post fertilization), and the monochorionic-monoamnionic pairs (late, after the 8-day post fertilization). This added a new dimension to didymology (the science of twins; didymos is the Greek word for twin): the timing of MZ twinning. Studies can be initiated taking into account primary biases, those originating in utero. Such studies could throw new light on the controversy over the validity of the classic twin method, the consequences of early embryological events (before and just after implantation of the embryo), the origin of congenital malformations, the sex proportion of multiples, the gene-environment interactions as far as intrauterine environment is concerned, to name but a few. PMID:17254399

  8. Magnetometry and archaeological prospection in Mexico

    NASA Astrophysics Data System (ADS)

    Barba Pingarron, L.; Laboratorio de Prospeccion Arqueologica

    2013-05-01

    Luis Barba Laboratorio de Prospección Arqueológica Instituto de Investigaciones Antropológicas Universidad Nacional Autonoma de México The first magnetic survey in archaeological prospection was published in 1958 in the first number of Archaeometry, in Oxford. That article marked the beginning of this applications to archaeology. After that, magnetic field measurements have become one of the most important and popular prospection tools. Its most outstanding characteristic is the speed of survey that allows to cover large areas in short time. As a consequence, it is usually the first approach to study a buried archaeological site. The first attempts in Mexico were carried out in 196. Castillo and Urrutia, among other geophysical techniques, used a magnetometer to study the northern part of the main plaza, zocalo, in Mexico City to locate some stone Aztec sculptures. About the same time Morrison et al. in La Venta pyramid used a magnetometer to measure total magnetic field trying to find a substructure. Some years later Brainer and Coe made a magnetic survey to locate large stone Olmec heads in San Lorenzo Tenochtitlan, Veracruz. Technology development has provided everyday more portable and accurate instruments to measure the magnetic field. The first total magnetic field proton magnetometers were followed by differential magnetometers and more recently gradiometers. Presently, multiple sensor magnetometers are widely used in European archaeology. The trend has been to remove the environmental and modern interference and to make more sensitive the instruments to the superficial anomalies related to most of the archaeological sites. There is a close relationship between the geology of the region and the way magnetometry works in archaeological sites. Archaeological prospection in Europe usually needs very sensitive instruments to detect slight magnetic contrast of ditches in old sediments. In contrast, volcanic conditions in Mexico produce large magnetic contrast

  9. [Age-prospective memory-paradox: explanatory hypotheses].

    PubMed

    Azzopardi, Barbara; Auffray, Caroline; Juhel, Jacques

    2015-03-01

    Prospective memory is a complex cognitive function requiring to remember a planned action. For example, this function is particularly important for elderly people to remember taking medication at the appropriate time. The comparison of the performance of old and young peoples on different prospective memory tasks led to two contradictory results, a configuration that has been dubbed "age-prospective memory-paradox". The first set of results of the age-prospective memory-paradox configuration is in keeping with the effects of aging on cognitive functioning, older peoples generally performing less well than younger peoples on laboratory prospective memory tasks. The second set of results is at odds with the first one, as older peoples generally perform better than younger peoples on naturalistic prospective memory tasks. The aim of the present paper is to expose the main explanatory hypotheses of the age related deficit on laboratory prospective memory tasks in one hand and on the age related benefit on naturalistic prospective memory tasks on the other hand. Concerning laboratory prospective memory tasks, the main hypothesis is that the detrimental effect of age would be principally due to negative influence of age on executive control processes and retrospective memory processes involved in this kind of tasks. With respect to naturalistic prospective memory tasks, a higher motivational level and the fact that older people have more frequently recourse to external memory aids and to compensation strategies could explain the better results of older people. PMID:25786425

  10. CDF - Run II Status and Prospects

    SciTech Connect

    Manfred Paulini

    2003-03-17

    After a five year upgrade period, the CDF detector located at the Fermilab Tevatron Collider is back in operation taking high quality data with all subsystems functional. We report on the status of the CDF experiment in Run II and discuss the start-up of the Tevatron accelerator. First physics results from CDF are presented. We also discuss the prospects for B physics in RunII, in particular the measurements of B{sub S}{sup 0} flavour oscillations and CP violation in B decays.

  11. Recent advances and future prospects in choroideremia

    PubMed Central

    Zinkernagel, Martin S; MacLaren, Robert E

    2015-01-01

    Choroideremia is a complex and rare disease that is frequently misdiagnosed due to its similar appearance to classic retinitis pigmentosa. Recent advances in genetic testing have identified specific genetic mutations in many retinal dystrophies, and the identification of the mutation of the CHM gene on the X chromosome 25 years ago has paved the way for gene replacement therapy with the first human trials now underway. This article reviews the epidemiological and pathological features of choroideremia and new prospects in imaging to monitor disease progression, as well as potential treatment approaches for choroideremia. PMID:26648685

  12. The Telescope Array experiment: status and prospects

    NASA Astrophysics Data System (ADS)

    Tokuno, H.; Abbasi, R. U.; Abu-Zayyad, T.; Azuma, R.; Belz, J. W.; Benno, T.; Bergman, D. R.; Blake, S. A.; Brusova, O.; Cady, R.; Cao, Z.; Cheon, B. G.; Chiba, J.; Chikawa, M.; Cho, I. S.; Chung, T.; Cohen, F.; Doura, K.; Doyle, T.; Endo, A.; Fujii, H.; Fukuda, T.; Fukushima, M.; Hayashi, Y.; Hayashi, K.; Hayashida, N.; Hibino, K.; Hiyama, K.; Honda, K.; Huentemeyer, P.; Hughes, G. A.; Iguchi, T.; Ikeda, D.; Ikuta, K.; Inoue, N.; Ishii, T.; Jui, C. C. H.; Kadota, K.; Kakimoto, F.; Kanbe, T.; Kasahara, K.; Kawai, H.; Kawakami, S.; Kawana, S.; Kido, E.; Kondo, Y.; Kwon, Y. J.; Machida, S.; Martens, K.; Matsuda, T.; Matsuyama, T.; Matthews, J. A. J.; Matthews, J. N.; Minamino, M.; Miyata, K.; Mostafa, M.; Murano, Y.; Nakamura, T.; Nam, S.; Nonaka, T.; Ogio, S.; Oh, S.; Ohnishi, M.; Ohoka, H.; Ohshima, A.; Okuda, T.; Ormes, J.; Ozawa, S.; Park, I. H.; Park, J. H.; Rodriguez, D.; Sagawa, H.; Sakurai, N.; Scott, L. M.; Shibata, T.; Shimizu, N.; Shimodaira, H.; Sinnis, G.; Smith, J. D.; Sokolsky, P.; Springer, R. W.; Stratton, S. R.; Suzuki, S.; Takeda, M.; Taketa, A.; Takita, M.; Tameda, Y.; Tanaka, K.; Tanaka, M.; Tanaka, H.; Taylor, M. J.; Teshima, M.; Thomas, J. R.; Thomas, S. B.; Thomson, G. B.; Tomida, T.; Torii, R.; Tsunesada, Y.; Uchihori, Y.; Udo, S.; Unno, Y.; Wada, Y.; Wickwar, V. B.; Wiencke, L. R.; Wilkerson, T. D.; Yamakawa, Y.; Yamaoka, H.; Yang, J.; Yoshida, S.; Yoshii, H.; Yun, Y. H.

    2008-07-01

    Telescope Array (TA) is a hybrid detector of a surface detector array and fluorescence telescopes. This hybrid detector will measure the energy spectrum, anisotropy and composition of ultra-high energy cosmic rays (UHECRs) to identify their origin. The almost construction of the detector has been completed in May 2007, and the detector is running under test and adjustments. The first hybrid observation with the full configuration is planned in beginning of 2008. In this paper the status and prospects of TA detector is described.

  13. Therapeutic Genome Editing: Prospects and Challenges

    PubMed Central

    Cox, David Benjamin Turitz; Platt, Randall Jeffrey; Zhang, Feng

    2015-01-01

    Recent advances in the development of genome editing technologies based on programmable nucleases have significantly improved our ability to make precise changes in the genomes of eukaryotic cells. Genome editing is already broadening our ability to elucidate the contribution of genetics to disease by facilitating the creation of more accurate cellular and animal models of pathological processes. A particularly tantalizing application of programmable nucleases is the potential to directly correct genetic mutations in affected tissues and cells to treat diseases that are refractory to traditional therapies. Here we discuss current progress towards developing programmable nuclease-based therapies as well as future prospects and challenges. PMID:25654603

  14. LHCb Physics and 2010-11 prospects

    SciTech Connect

    Perazzini, Stefano

    2011-10-24

    LHCb is one of the four major experiments operating at the Large Hadron Collider, and is specifically dedicated to the measurement of CP-violation and rare decays in the beauty and charm quark sectors. By employing data from early LHC runs it is possible to assess the performance of the detector and to better understand the potential of the LHCb flavour programme. After a brief introduction of the motivations and of the relevant physics goals, the prospects about key CP-violation and rare decay measurements will be presented. Emphasis will be given to those topics where results with particular sensitivity to New Physics are expected during the 2010-11 run.

  15. A new method for prospect appraisal

    SciTech Connect

    Chen, H.C.; Fang, J.H. )

    1993-01-01

    A new methodology is presented for aggregating individual and fragmentary pieces of geologic information to assess the outcomes of prospect evaluation. The new method is based on possibility, rather than probability theory, and is coupled with multiple-criteria decision-making theory. In essence, the method employs fuzzy implications to gauge satisfaction levels associated with each measure of the characteristics associated with the source, reservoir, seal, and trap. The method is suitable where some data are missing, vague, or subjective. Thus, it is an alternative approach, not a substitute for conventional methods based on probability theory. 16 refs., 7 figs., 4 tabs.

  16. LHCb Physics and 2010-11 prospects

    NASA Astrophysics Data System (ADS)

    Perazzini, Stefano

    2011-10-01

    LHCb is one of the four major experiments operating at the Large Hadron Collider, and is specifically dedicated to the measurement of CP-violation and rare decays in the beauty and charm quark sectors. By employing data from early LHC runs it is possible to assess the performance of the detector and to better understand the potential of the LHCb flavour programme. After a brief introduction of the motivations and of the relevant physics goals, the prospects about key CP-violation and rare decay measurements will be presented. Emphasis will be given to those topics where results with particular sensitivity to New Physics are expected during the 2010-11 run.

  17. Particle physics: recent successes and future prospects

    SciTech Connect

    Wojcicki, S.

    1984-12-01

    There is no doubt that as yet we do not have an ultimate theory of matter and forces in spite of the remarkable successes of the past decade. In this talk the author attempts to summarize briefly the historical background that led us to the present level of understanding, or more specifically to the standard model of particle physics. Subsequently the author describes several difficulties with this picture, continues with some possible indications of new physics, and finally ends with the discussion of the prospects for the future. 32 references.

  18. Levosimendan: The current situation and new prospects.

    PubMed

    Moreno, Nuno; Tavares-Silva, Marta; Lourenço, André P; Oliveira-Pinto, José; Henriques-Coelho, Tiago; Leite-Moreira, Adelino F

    2014-12-01

    Levosimendan is a pyridazinone-dinitrile derivative with positive inotropic and vasodilatory effects that has beneficial effects on myocardial performance. In previous randomized studies levosimendan improved hemodynamics and clinical course, but its effect on prognosis is still unclear. This important issue has limited its use. Although primarily used in the management of acute heart failure syndromes, this new inotropic agent may play a role in other clinical conditions. This review aims to summarize current knowledge on levosimendan and to present future prospects for the use of this drug. PMID:25459636

  19. Chiral xenobiotics bioaccumulations and environmental health prospectives.

    PubMed

    Hussain, Iqbal; ALOthman, Zeid A; Alwarthan, Abdulrahman A; Sanagi, Mohd Marsin; Ali, Imran

    2015-08-01

    The chiral xenobiotics are very dangerous for all of us due to the different enantioselective toxicities of the enantiomers. Besides, these have different enantioselective bioaccumulations and behaviors in our body and other organisms. It is of urgent need to understand the enantioselective bioaccumulations, toxicities, and the health hazards of the chiral xenobiotics. The present article describes the classification, sources of contamination, distribution, enantioselective bioaccumulation, and the toxicities of the chiral xenobiotics. Besides, the efforts are also made to discuss the prevention and remedial measures of the havoc of the chiral xenobiotics. The challenges of the chiral xenobiotics have also been highlighted. Finally, future prospectives are also discussed. PMID:26148690

  20. Systemic lupus erythematosus. A prospective analysis.

    PubMed Central

    Grigor, R; Edmonds, J; Lewkonia, R; Bresnihan, B; Hughes, G R

    1978-01-01

    The spectrum of organ involvement in 50 patients with systemic lupus erythematosus has been assessed in a prospective study. All patients were admitted to hospital electively for 2 days and a complete clinical and laboratory assessment protocol completed. Subsequent hospital admissions depended on clinical status. The overall mean observation period was 29 months. Widespread multisystem involvement was found in every patient. Subclinical abnormalities of respiratory and cerebral function were common even in patients in clinical remission. A more conservative approach than has been generally recommended was used for the management of systemic lupus erythematosus and is supported by the estimated 5-year survival of 98%. PMID:646463

  1. Future Prospects of Low Compression Ignition Engines

    NASA Astrophysics Data System (ADS)

    Azim, M. A.

    2014-01-01

    This study presents a review and analysis of the effects of compression ratio and inlet air preheating on engine performance in order to assess the future prospects of low compression ignition engines. Regulation of the inlet air preheating allows some control over the combustion process in compression ignition engines. Literature shows that low compression ratio and inlet air preheating are more beneficial to internal combustion engines than detrimental. Even the disadvantages due to low compression ratio are outweighed by the advantages due to inlet air preheating and vice versa.

  2. Prospective study of definite caterpillar exposures.

    PubMed

    Balit, Corrine R; Geary, Merilyn J; Russell, Richard C; Isbister, Geoffrey K

    2003-11-01

    Exposure to caterpillars results in a variety of clinical effects depending on the species involved. The aim of this study was to describe the clinical effects from caterpillar exposures within Australia. Cases were recruited prospectively from calls to a poison information centre. Subjects were included if they had a definite exposure and they had collected the caterpillar or cocoon. The caterpillars were identified to genus and species level where possible. There were 36 included cases: two were contact exposures to caterpillar contents, one was an ingestion of a caterpillar and the remaining 33 patients had definite reactions from caterpillar or cocoon exposure. There were five families of caterpillars identified in the study: Arctiidae, Limacodidae, Anthelidae, Lymantriidae and Sphingidae, many of which occur worldwide. Clinical effects ranged from severe pain to an urticarial response depending on the species involved. There were no adverse effects following ingestion in this study. Treatment consisted primarily of removal of the caterpillar or cocoon. Other treatment measures consisted of symptomatic treatment such as ice packs and antihistamines. This is the first prospective study of caterpillar exposures within Australia and demonstrates that exposures can result in a variety of reactions depending on the family and species involved. PMID:14602121

  3. Thorium: Issues and prospects in Malaysia

    SciTech Connect

    AL-Areqi, Wadeeah M.; Majid, Amran Ab.; Sarmani, Sukiman; Bahri, Che Nor Aniza Che Zainul

    2015-04-29

    In Malaysia, thorium exists in minerals and rare earth elements production residue. The average range of thorium content in Malaysian monazite and xenotime minerals was found about 70,000 and 15,000 ppm respectively. About 2,636 tonnes of Malaysian monazite was produced for a period of 5 years (2006-2010) and based on the above data, it can be estimated that Malaysian monazite contains about 184.5 tonnes of thorium. Although thorium can become a major radiological problem to our environment, but with the significant deposit of thorium in Malaysian monazite, it has a prospect as a future alternative fuel in nuclear technology. This paper will discuss the thorium issues in Malaysia especially its long term radiological risks to public health and environment at storage and disposal stages, the prospect of exploring and producing high purity thorium from our rare earth elements minerals for future thorium based reactor. This paper also highlights the holistic approach in thorium recovery from Malaysian rare earth element production residue to reduce its radioactivity and extraction of thorium and rare earth elements from the minerals with minimum radiological impact to health and environment.

  4. Thorium: Issues and prospects in Malaysia

    NASA Astrophysics Data System (ADS)

    AL-Areqi, Wadeeah M.; Majid, Amran Ab.; Sarmani, Sukiman; Bahri, Che Nor Aniza Che Zainul

    2015-04-01

    In Malaysia, thorium exists in minerals and rare earth elements production residue. The average range of thorium content in Malaysian monazite and xenotime minerals was found about 70,000 and 15,000 ppm respectively. About 2,636 tonnes of Malaysian monazite was produced for a period of 5 years (2006-2010) and based on the above data, it can be estimated that Malaysian monazite contains about 184.5 tonnes of thorium. Although thorium can become a major radiological problem to our environment, but with the significant deposit of thorium in Malaysian monazite, it has a prospect as a future alternative fuel in nuclear technology. This paper will discuss the thorium issues in Malaysia especially its long term radiological risks to public health and environment at storage and disposal stages, the prospect of exploring and producing high purity thorium from our rare earth elements minerals for future thorium based reactor. This paper also highlights the holistic approach in thorium recovery from Malaysian rare earth element production residue to reduce its radioactivity and extraction of thorium and rare earth elements from the minerals with minimum radiological impact to health and environment.

  5. Prospective Demographic Study of Cosmetic Surgery Patients

    PubMed Central

    Schlessinger, Daniel; Schlessinger, Bernard

    2010-01-01

    Objectives: The authors sought to examine and assess cosmetic surgery patient demographics as well as age in relation to partner, in a prospective manner, analyzing data for any significant correlations. Design: The authors conducted a prospective study utilizing a survey. Setting: The study was conducted in a private, nonacademic dermatological practice. Participants: Three hundred thirty-six patients participated in this study. Results: Demographics of onabotulinumtoxinA/abobotulinumtoxinA (neurotoxins), fillers, and laser hair removal users were studied. The data show that the average private practice cosmetic surgery patient in this study is a married (67.5%), college-educated or greater (66.9%), employed (74.3%), mother (74.5%). In the fillers category, 50 percent of women were older than their partners, as opposed to 14.8 percent in 2008 Census data. Additionally, women were more educated and employed to a higher percentage than similar women in 2008 Census data. Data on motivations were statistically not significant. Conclusion: Data from this study show potential correlations with Census data norms in marital status and motherhood status categories, but not in the age in relation to partner, education, and employment level categories. Motivations of individuals undergoing cosmetic surgery will need further analysis in future studies. PMID:21103314

  6. Prospective Lymphedema Surveillance in a Clinic Setting.

    PubMed

    Chance-Hetzler, Janet; Armer, Jane; Van Loo, Maggie; Anderson, Blake; Harris, Robin; Ewing, Rebecca; Stewart, Bob

    2015-01-01

    The potential impact of breast cancer-related lymphedema (LE) is quite extensive, yet it often remains under-diagnosed until the later stages. This project examines the effectiveness of prospective surveillance in post-surgical breast cancer patients. A retrospective analysis of 49 out of 100 patients enrolled in a longitudinal prospective study at a Midwestern breast center evaluates: (1) time required for completion of bilateral limb measurements and Lymphedema Breast Cancer Questionnaire (LBCQ); (2) referral to LE management with limb volume increase (LVI) and/or LBCQ symptoms; and (3) cost of LE management at lower LVI (≥5%-≤10%) versus traditional (≥10%). Findings revealed a visit timeframe mean of 40.3 min (range = 25-60); 43.6% of visits were ≤30-min timeframe. Visit and measurement times decreased as clinic staff gained measurement experience; measurement time mean was 17.9 min (range = 16.9-18.9). LBCQ symptoms and LVI were significantly (p < 0.001) correlated to LE referral; six of the nine patients referred (67%) displayed both LBCQ symptoms/LVI. Visits with no symptoms reported did not result in referral, demonstrating the importance of using both indicators when assessing early LE. Lower threshold referral provides compelling evidence of potential cost savings over traditional threshold referral with reported costs of: $3755.00 and $6353.00, respectively (40.9% savings). PMID:26308061

  7. Prospective Elementary Teachers' Development of Fraction Number Sense

    ERIC Educational Resources Information Center

    Utley, Juliana; Reeder, Stacy

    2012-01-01

    Can prospective elementary teachers "unlearn" harmful algorithms used with fractions as they are invited to develop fraction number sense? This study examined the development of prospective elementary teachers' fraction number sense during an intermediate (grades 5-8) mathematics methods course. During this course, participants' were involved in a…

  8. 48 CFR 52.216-5 - Price Redetermination-Prospective.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 2 2013-10-01 2013-10-01 false Price Redetermination....216-5 Price Redetermination—Prospective. As prescribed in 16.205-4, insert the following clause: Price Redetermination—Prospective (OCT 1997) (a) General. The unit prices and the total price stated in this...

  9. 48 CFR 52.216-5 - Price Redetermination-Prospective.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 2 2014-10-01 2014-10-01 false Price Redetermination....216-5 Price Redetermination—Prospective. As prescribed in 16.205-4, insert the following clause: Price Redetermination—Prospective (OCT 1997) (a) General. The unit prices and the total price stated in this...

  10. 48 CFR 52.216-5 - Price Redetermination-Prospective.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 2 2011-10-01 2011-10-01 false Price Redetermination....216-5 Price Redetermination—Prospective. As prescribed in 16.205-4, insert the following clause: Price Redetermination—Prospective (OCT 1997) (a) General. The unit prices and the total price stated in this...

  11. 48 CFR 52.216-5 - Price Redetermination-Prospective.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 2 2012-10-01 2012-10-01 false Price Redetermination....216-5 Price Redetermination—Prospective. As prescribed in 16.205-4, insert the following clause: Price Redetermination—Prospective (OCT 1997) (a) General. The unit prices and the total price stated in this...

  12. Investigating Prospective Teachers' Ability to Write Context-Based Problems

    ERIC Educational Resources Information Center

    Ültay, Neslihan; Donmez Usta, Necla

    2016-01-01

    Purpose: The purpose of this study is to investigate the prospective teachers' ability to write context-based problems about the concepts in radioactivity unit. Methodology: The study is carried out in a university in Turkey with 21 prospective teachers in physics, chemistry and biology in 2014-2015 fall terms. In the study, data are collected…

  13. Prospective Chemistry Teachers' Conceptions of Chemical Thermodynamics and Kinetics

    ERIC Educational Resources Information Center

    Sozbilir, Mustafa; Pinarbasi, Tacettin; Canpolat, Nurtac

    2010-01-01

    This study aimed at identifying specifically prospective chemistry teachers' difficulties in determining the differences between the concepts of chemical thermodynamics and kinetics. Data were collected from 67 prospective chemistry teachers at Kazim Karabekir Education Faculty of Ataturk University in Turkey during 2005-2006 academic year. Data…

  14. Prospective Physics Teachers' Awareness of Radiation and Radioactivity

    ERIC Educational Resources Information Center

    Tasoglu, Aslihan Kartal; Ates, Özlem; Bakaç, Mustafa

    2015-01-01

    The purpose of this study is to investigate prospective physics teachers' knowledge of and attitude towards radiation and radioactivity. Participants of this study are 56 prospective physics teachers. A questionnaire related with the knowledge about radiation and radiation fear was conducted. The results of this study showed that most of the…

  15. Analyzing Perceptions of Prospective Teachers about Their Media Literacy Competencies

    ERIC Educational Resources Information Center

    Recepoglu, Ergun; Ergun, Muammer

    2013-01-01

    The purpose of this study is to analyze perceptions of prospective teachers about their media literacy competencies in terms of different variables. This is a descriptive research in the survey model which tries to detect the current situation. Study group includes 580 prospective teachers from Turkish, Primary School, Social Studies, Science,…

  16. 42 CFR 456.705 - Prospective drug review.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 4 2010-10-01 2010-10-01 false Prospective drug review. 456.705 Section 456.705... (CONTINUED) MEDICAL ASSISTANCE PROGRAMS UTILIZATION CONTROL Drug Use Review (DUR) Program and Electronic Claims Management System for Outpatient Drug Claims § 456.705 Prospective drug review. (a)...

  17. 42 CFR 456.705 - Prospective drug review.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 4 2011-10-01 2011-10-01 false Prospective drug review. 456.705 Section 456.705... (CONTINUED) MEDICAL ASSISTANCE PROGRAMS UTILIZATION CONTROL Drug Use Review (DUR) Program and Electronic Claims Management System for Outpatient Drug Claims § 456.705 Prospective drug review. (a)...

  18. Prospective Primary School Teachers' Misconceptions about States of Matter

    ERIC Educational Resources Information Center

    Tatar, Erdal

    2011-01-01

    The purpose of this study was to identify prospective primary school teachers' misconceptions about the states of matter. The sample of the study was 227 fourth-year prospective primary school teachers in a Department of Primary Education in Turkey. Researcher asked from every participant to write a response to an open ended question about…

  19. 47 CFR 76.940 - Prospective rate reduction.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Prospective rate reduction. 76.940 Section 76.940 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Cable Rate Regulation § 76.940 Prospective rate reduction....

  20. The Development of Prospective Secondary Biology Teachers PCK

    ERIC Educational Resources Information Center

    Brown, Patrick; Friedrichsen, Patricia; Abell, Sandra

    2013-01-01

    In order to understand how prospective teachers develop knowledge for teaching, researchers must identify the types of knowledge that are integral to effective science teaching. This case study investigated how 4 prospective secondary biology teachers' science teaching orientations, knowledge of science learners, and knowledge of instructional…

  1. 48 CFR 52.216-5 - Price Redetermination-Prospective.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 2 2010-10-01 2010-10-01 false Price Redetermination....216-5 Price Redetermination—Prospective. As prescribed in 16.205-4, insert the following clause: Price Redetermination—Prospective (OCT 1997) (a) General. The unit prices and the total price stated in this...

  2. Prospective Secondary Mathematics Teachers' Perspectives and Mathematical Knowledge for Teaching

    ERIC Educational Resources Information Center

    Karagöz-Akar, Gülseren

    2016-01-01

    This study investigated the relationship between prospective secondary mathematics teachers' perspectives and their mathematical knowledge for teaching in action. Data from two prospective teachers' practice-teachings, one in geometry and one in algebra, their lesson plans and self-reflections were analyzed with Teacher Perspectives and Knowledge…

  3. 45 CFR 233.22 - Determining eligibility under prospective budgeting.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 2 2010-10-01 2010-10-01 false Determining eligibility under prospective budgeting. 233.22 Section 233.22 Public Welfare Regulations Relating to Public Welfare OFFICE OF FAMILY... eligibility under prospective budgeting. In States which compute the amount of the assistance...

  4. 45 CFR 233.22 - Determining eligibility under prospective budgeting.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 45 Public Welfare 2 2011-10-01 2011-10-01 false Determining eligibility under prospective budgeting. 233.22 Section 233.22 Public Welfare Regulations Relating to Public Welfare OFFICE OF FAMILY... eligibility under prospective budgeting. In States which compute the amount of the assistance...

  5. Prospective Primary School Teachers' Perceptions on Boiling and Freezing

    ERIC Educational Resources Information Center

    Senocak, Erdal

    2009-01-01

    The aim of this study was to investigate the perceptions of prospective primary school teachers on the physical state of water during the processes of boiling and freezing. There were three stages in the investigation: First, open-ended questions concerning the boiling and freezing of water were given to two groups of prospective primary school…

  6. Prospective Teachers' Experiences in Developing Lessons with Dynamic Mathematics Software

    ERIC Educational Resources Information Center

    Haciomeroglu, Erhan Selcuk; Bu, Lingguo; Schoen, Robert C.; Hohenwarter, Markus

    2011-01-01

    This study sought to examine the development of prospective secondary mathematics teachers' Technological Pedagogical Content Knowledge as they worked individually and in small groups to develop and present lessons with dynamic mathematics software. In a three-semester long study, data were collected from 68 prospective secondary mathematics…

  7. 36 CFR 1005.14 - Prospecting, mining, and mineral leasing.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... mineral leasing. 1005.14 Section 1005.14 Parks, Forests, and Public Property PRESIDIO TRUST COMMERCIAL AND PRIVATE OPERATIONS § 1005.14 Prospecting, mining, and mineral leasing. Prospecting, mining, and the location of mining claims under the general mining laws and leasing under the mineral leasing laws...

  8. 36 CFR 1005.14 - Prospecting, mining, and mineral leasing.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... mineral leasing. 1005.14 Section 1005.14 Parks, Forests, and Public Property PRESIDIO TRUST COMMERCIAL AND PRIVATE OPERATIONS § 1005.14 Prospecting, mining, and mineral leasing. Prospecting, mining, and the location of mining claims under the general mining laws and leasing under the mineral leasing laws...

  9. 36 CFR 1005.14 - Prospecting, mining, and mineral leasing.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... mineral leasing. 1005.14 Section 1005.14 Parks, Forests, and Public Property PRESIDIO TRUST COMMERCIAL AND PRIVATE OPERATIONS § 1005.14 Prospecting, mining, and mineral leasing. Prospecting, mining, and the location of mining claims under the general mining laws and leasing under the mineral leasing laws...

  10. 36 CFR 1005.14 - Prospecting, mining, and mineral leasing.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... mineral leasing. 1005.14 Section 1005.14 Parks, Forests, and Public Property PRESIDIO TRUST COMMERCIAL AND PRIVATE OPERATIONS § 1005.14 Prospecting, mining, and mineral leasing. Prospecting, mining, and the location of mining claims under the general mining laws and leasing under the mineral leasing laws...

  11. 36 CFR 1005.14 - Prospecting, mining, and mineral leasing.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... mineral leasing. 1005.14 Section 1005.14 Parks, Forests, and Public Property PRESIDIO TRUST COMMERCIAL AND PRIVATE OPERATIONS § 1005.14 Prospecting, mining, and mineral leasing. Prospecting, mining, and the location of mining claims under the general mining laws and leasing under the mineral leasing laws...

  12. Prospective Teachers' Beliefs about Problem Solving in Multiple Ways

    ERIC Educational Resources Information Center

    Arikan, Elif Esra

    2016-01-01

    The purpose of this study is to analyze whether prospective teachers believe solving a mathematics problem involves in using different solution methods. 60 mathematics prospective teachers who take the pedagogic training program in a state university were participated in this study. Five open-ended questions were asked. The study was carried out…

  13. Neural Correlates of Prospective Memory across the Lifespan

    ERIC Educational Resources Information Center

    Zollig, Jacqueline; West, Robert; Martin, Mike; Altgassen, Mareike; Lemke, Ulrike; Kliegel, Matthias

    2007-01-01

    Overview: Behavioural data reveal an inverted U-shaped function in the efficiency of prospective memory from childhood to young adulthood to later adulthood. However, prior research has not directly compared processes contributing to age-related variation in prospective memory across the lifespan, hence it is unclear whether the same factors…

  14. 42 CFR 456.705 - Prospective drug review.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 4 2012-10-01 2012-10-01 false Prospective drug review. 456.705 Section 456.705... (CONTINUED) MEDICAL ASSISTANCE PROGRAMS UTILIZATION CONTROL Drug Use Review (DUR) Program and Electronic Claims Management System for Outpatient Drug Claims § 456.705 Prospective drug review. (a)...

  15. 42 CFR 456.705 - Prospective drug review.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 4 2013-10-01 2013-10-01 false Prospective drug review. 456.705 Section 456.705... (CONTINUED) MEDICAL ASSISTANCE PROGRAMS UTILIZATION CONTROL Drug Use Review (DUR) Program and Electronic Claims Management System for Outpatient Drug Claims § 456.705 Prospective drug review. (a)...

  16. 42 CFR 456.705 - Prospective drug review.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 4 2014-10-01 2014-10-01 false Prospective drug review. 456.705 Section 456.705... (CONTINUED) MEDICAL ASSISTANCE PROGRAMS UTILIZATION CONTROL Drug Use Review (DUR) Program and Electronic Claims Management System for Outpatient Drug Claims § 456.705 Prospective drug review. (a)...

  17. Why Teach? Prospective Teachers' Reasons for Entering the Profession.

    ERIC Educational Resources Information Center

    Phillips, Marian B.; Hatch, J. Amos

    This paper details an analysis of prospective early childhood teachers' responses on a university application to the question "Why are you interested in becoming a teacher?" The paper identifies potential sources of strength and vulnerability in students' written responses and offers tentative interpretations that critique prospective early…

  18. A Study of Prospective Teachers' Consumption Patterns on Special Days

    ERIC Educational Resources Information Center

    Saglam, Halil Ibrahim

    2016-01-01

    The purpose of this study was to identify prospective teachers' consumption patterns on special days. The sample was comprised of 29 prospective teachers (22 females and 7 males) who studied Primary School Teaching in the Faculty of Education at Sakarya University during the 2014-2015 Academic Year. The study was designed as a phenomenological…

  19. Prospective Teachers' Problem Solving Skills and Self-Confidence Levels

    ERIC Educational Resources Information Center

    Gursen Otacioglu, Sena

    2008-01-01

    The basic objective of the research is to determine whether the education that prospective teachers in different fields receive is related to their levels of problem solving skills and self-confidence. Within the mentioned framework, the prospective teachers' problem solving and self-confidence levels have been examined under several variables.…

  20. Prospective Teachers' Beliefs about Imaginative Thinking in K-12 Schooling

    ERIC Educational Resources Information Center

    Beghetto, Ronald A.

    2008-01-01

    This study examined prospective teachers' (N=176) beliefs about the role that memorization and imaginative thinking play in K-12 schooling. Results indicate that the majority of prospective teachers (68.5%) believed there was a specific grade that teachers should place more emphasis on the memorization of correct answers rather than encourage…

  1. Motivating Inhibition--Reward Prospect Speeds up Response Cancellation

    ERIC Educational Resources Information Center

    Boehler, Carsten N.; Hopf, Jens-Max; Stoppel, Christian M.; Krebs, Ruth M.

    2012-01-01

    Reward prospect has been demonstrated to facilitate various cognitive and behavioral operations, particularly by enhancing the speed and vigor of processes linked to approaching reward. Studies in this domain typically employed task regimes in which participants' overt responses are facilitated by prospective rewards. In contrast, we demonstrate…

  2. Prospective Teachers' Perceptions on Different Aspects of Portfolio

    ERIC Educational Resources Information Center

    Ok, Ahmet; Erdogan, Mehmet

    2010-01-01

    This qualitative-case study examined how portfolio and portfolio assessment were perceived by prospective teachers. The participants were 23 prospective teachers from seven different teaching areas from a Turkish university. A semi-structured individual interview was conducted. The interview schedule included 15 open-ended questions. The main…

  3. Examining Prospective Science Teachers' Satisfaction with Their Department

    ERIC Educational Resources Information Center

    Erdogan, Mehmet; Usak, Muhammet

    2007-01-01

    The purpose of this study was to explore how satisfied prospective science teachers are with their department (academic staff and administration) at different Faculties of Education in Turkey. For this purpose, Prospective Science Teachers Satisfaction Questionnaire (PSTSQ) was developed by considering related literature. PSTSQ consists of two…

  4. Prospective Teachers Experiences Teaching Mathematics to African American Males

    ERIC Educational Resources Information Center

    Sheppard, Peter

    2009-01-01

    This paper describes an effort to provide prospective teachers opportunities to better understand African American male students and better focus on how they learn mathematics. Prospective teachers spent 15 hours over an eight week span mentoring and tutoring African American males without the guise of practicing teachers. Qualitative data drawn…

  5. Study of Prospective Teachers' Conceptualization of Value Preferences

    ERIC Educational Resources Information Center

    Koruklu, Nermin; Aktamis, Hilal

    2012-01-01

    The purpose of this study was to determine whether there were any changes in the conceptualization of prospective teachers' values preferences during their university studies. The research group was composed of 208 prospective teachers who were studying at Science Education, Social Science Education and Fine Arts Education at Adnan Menderes…

  6. Conversations about the Moon with Prospective Teachers in Japan

    ERIC Educational Resources Information Center

    Suzuki, Mariko

    2003-01-01

    As an instructor in courses for prospective teachers, I am interested in my students' ideas and ways in which they reconstruct their ideas in conversations about science. In the case study presented here, I reflect upon (a) ways in which I engaged prospective teachers in thinking together about their observations of a natural phenomenon, the…

  7. Prospects for Breakthrough Propulsion From Physics

    NASA Technical Reports Server (NTRS)

    Millis, Marc G.

    2004-01-01

    "Space drives", "Warp drives", and "Wormholes:" these concepts may sound like science fiction, but they are being written about in reputable journals. To assess the implications of these emerging prospects for future spaceflight, NASA supported the Breakthrough Propulsion Physics Project from 1996 through 2002. This Project has three grand challenges: (1) Discover propulsion that eliminates the need for propellant; (2) Discover methods to achieve hyper-fast travel; and (3) Discover breakthrough methods to power spacecraft. Because these challenges are presumably far from fruition, and perhaps even impossible, a special emphasis is placed on selecting incremental and affordable research that addresses the critical issues behind these challenges. Of 16 incremental research tasks completed by the project and from other sponsors, about a third were found not to be viable, a quarter have clear opportunities for sequels, and the rest remain unresolved.

  8. Universal doomsday: analyzing our prospects for survival

    NASA Astrophysics Data System (ADS)

    Gerig, Austin; Olum, Ken D.; Vilenkin, Alexander

    2013-05-01

    Given a sufficiently large universe, numerous civilizations almost surely exist. Some of these civilizations will be short-lived and die out relatively early in their development, i.e., before having the chance to spread to other planets. Others will be long-lived, potentially colonizing their galaxy and becoming enormous in size. What fraction of civilizations in the universe are long-lived? The ``universal doomsday'' argument states that long-lived civilizations must be rare because if they were not, we should find ourselves living in one. Furthermore, because long-lived civilizations are rare, our civilization's prospects for long-term survival are poor. Here, we develop the formalism required for universal doomsday calculations and show that while the argument has some force, our future is not as gloomy as the traditional doomsday argument would suggest, at least when the number of early existential threats is small.

  9. Prospects of High Energy Laboratory Astrophysics

    SciTech Connect

    Ng, J.S.T.; Chen, P.; /SLAC

    2006-09-21

    Ultra high energy cosmic rays (UHECR) have been observed but their sources and production mechanisms are yet to be understood. We envision a laboratory astrophysics program that will contribute to the understanding of cosmic accelerators with efforts to: (1) test and calibrate UHECR observational techniques, and (2) elucidate the underlying physics of cosmic acceleration through laboratory experiments and computer simulations. Innovative experiments belonging to the first category have already been done at the SLAC FFTB. Results on air fluorescence yields from the FLASH experiment are reviewed. Proposed future accelerator facilities can provided unprecedented high-energy-densities in a regime relevant to cosmic acceleration studies and accessible in a terrestrial environment for the first time. We review recent simulation studies of nonlinear plasma dynamics that could give rise to cosmic acceleration, and discuss prospects for experimental investigation of the underlying mechanisms.

  10. Prospective study on nutrition transition in China.

    PubMed

    Zhai, Fengying; Wang, Huijun; Du, Shufa; He, Yuna; Wang, Zhihong; Ge, Keyou; Popkin, Barry M

    2009-05-01

    The aim of the prospective study reported here was to examine the effects of social and economic transformation on dietary patterns and nutritional status in China. The study began in 1989 and continued with follow-ups in 1991, 1993, 1997, 2000, and 2004. A total of 5000 subjects aged 18-45 years from 4280 households in nine provinces were included. Weighed records and three consecutive 24-h recalls were used. Over the study period, average consumption of all animal foods except milk increased, while cereal intake decreased. The proportion of animal protein and fat as a percentage of energy also increased. However, vitamin A and calcium intake did not increase and remained low. Child height and weight increased while undernutrition decreased and overweight increased. The results indicate that rapid changes in dietary pattern are associated with economic reforms in China. PMID:19453679