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Sample records for dose statistics resulting

  1. [Results of statistical analysis of the dynamics of ionizing radiation dose fields in the service module of the International Space Station in 2000-2012].

    PubMed

    Mitrikas, V G

    2014-01-01

    The on-going 24th solar cycle (SC) is distinguished from the previous ones by low activity. On the contrary, levels of proton fluxes from galactic cosmic rays (GCR) are high, which increases the proton flow striking the Earth's radiation belts (ERB). Therefore, at present the absorbed dose from ERB protons should be calculated with consideration of the tangible increase of protons intensity built into the model descriptions based on experimental measurements during the minimum between cycles 19 and 20, and the cycle 21 maximum. The absorbed dose from GCR and ERB protons copies galactic protons dynamics, while the ERB electrons dose copies SC dynamics. The major factors that determine the absorbed dose value are SC phase, ISS orbital altitude and shielding of the dosimeter readings of which are used in analysis. The paper presents the results of dynamic analysis of absorbed doses measured by a variety of dosimeters, namely, R-16 (2 ionization chambers), DB8-1, DB8-2, DB8-3, DB8-4 as a function of ISS orbit altitude and SC phase. The existence of annual variation in the absorbed dose dynamics has been confirmed; several additional variations with the periods of 17 and 52 months have been detected. Modulation of absorbed dose variations by the SC and GCR amplitudes has been demonstrated.

  2. Ideas for Effective Communication of Statistical Results

    DOE PAGES

    Anderson-Cook, Christine M.

    2015-03-01

    Effective presentation of statistical results to those with less statistical training, including managers and decision-makers requires planning, anticipation and thoughtful delivery. Here are several recommendations for effectively presenting statistical results.

  3. Reporting Statistical Results in Medical Journals.

    PubMed

    Arifin, Wan Nor; Sarimah, Abdullah; Norsa'adah, Bachok; Najib Majdi, Yaacob; Siti-Azrin, Ab Hamid; Kamarul Imran, Musa; Aniza, Abd Aziz; Naing, Lin

    2016-09-01

    Statistical editors of the Malaysian Journal of Medical Sciences (MJMS) must go through many submitted manuscripts, focusing on the statistical aspect of the manuscripts. However, the editors notice myriad styles of reporting the statistical results, which are not standardised among the authors. This could be due to the lack of clear written instructions on reporting statistics in the guidelines for authors. The aim of this editorial is to briefly outline reporting methods for several important and common statistical results. It will also address a number of common mistakes made by the authors. The editorial will serve as a guideline for authors aiming to publish in the MJMS as well as in other medical journals.

  4. Statistical literacy and sample survey results

    NASA Astrophysics Data System (ADS)

    McAlevey, Lynn; Sullivan, Charles

    2010-10-01

    Sample surveys are widely used in the social sciences and business. The news media almost daily quote from them, yet they are widely misused. Using students with prior managerial experience embarking on an MBA course, we show that common sample survey results are misunderstood even by those managers who have previously done a statistics course. In general, they fare no better than managers who have never studied statistics. There are implications for teaching, especially in business schools, as well as for consulting.

  5. Statistical Literacy and Sample Survey Results

    ERIC Educational Resources Information Center

    McAlevey, Lynn; Sullivan, Charles

    2010-01-01

    Sample surveys are widely used in the social sciences and business. The news media almost daily quote from them, yet they are widely misused. Using students with prior managerial experience embarking on an MBA course, we show that common sample survey results are misunderstood even by those managers who have previously done a statistics course. In…

  6. Statistical characterization of radiation doses from external exposures and relevant contributors in Fukushima prefecture.

    PubMed

    Takahara, Shogo; Abe, Tatsuya; Iijima, Masashi; Shimada, Kazumasa; Shiratori, Yoshitake

    2014-10-01

    In areas contaminated by radioactive materials, well designed dose assessment is necessary in order to protect people from radiation exposure and manage the exposure situation appropriately. Probabilistic dose assessment is a useful method for providing a more complete characterization of information on dose distributions in the population and requires statistically characterized data on pathway-relevant contributors. The objective of this paper is to determine statistical features of contributors to external exposures, as well as to identify causes of variabilities of individual doses to the populations living in areas contaminated by the Fukushima Daiichi Nuclear Power Plant accident. To achieve these objectives, measurements of individual doses and ambient dose rates, as well as surveys of behavioral patterns, were performed between February and April 2012. These were made with the cooperation of indoor workers, outdoor workers, and pensioners living in Fukushima prefecture. On the basis of these results, statistical analyses were performed in order to identify variabilities of contributors. In addition, a multi-regression analysis was done to explore a significant relationship between individual doses and relevant contributors. Results showed that the ambient dose equivalent rate also distributed with lognormal form, and it had variabilities attributable to the spatial distribution of deposited radionuclides. The distribution form of time spent outdoors depends on the characteristics of occupation, and the distributions for indoor workers and outdoor workers were lognormal and normal, respectively. Results of a multiple-regression analysis suggested that such variabilities of contributors give rise to significant differences in individual doses among the populations.

  7. CALUX measurements: statistical inferences for the dose-response curve.

    PubMed

    Elskens, M; Baston, D S; Stumpf, C; Haedrich, J; Keupers, I; Croes, K; Denison, M S; Baeyens, W; Goeyens, L

    2011-09-30

    Chemical Activated LUciferase gene eXpression [CALUX] is a reporter gene mammalian cell bioassay used for detection and semi-quantitative analyses of dioxin-like compounds. CALUX dose-response curves for 2,3,7,8-tetrachlorodibenzo-p-dioxin [TCDD] are typically smooth and sigmoidal when the dose is portrayed on a logarithmic scale. Non-linear regression models are used to calibrate the CALUX response versus TCDD standards and to convert the sample response into Bioanalytical EQuivalents (BEQs). Several complications may arise in terms of statistical inference, specifically and most important is the uncertainty assessment of the predicted BEQ. This paper presents the use of linear calibration functions based on Box-Cox transformations to overcome the issue of uncertainty assessment. Main issues being addressed are (i) confidence and prediction intervals for the CALUX response, (ii) confidence and prediction intervals for the predicted BEQ-value, and (iii) detection/estimation capabilities for the sigmoid and linearized models. Statistical comparisons between different calculation methods involving inverse prediction, effective concentration ratios (ECR(20-50-80)) and slope ratio were achieved with example datasets in order to provide guidance for optimizing BEQ determinations and expand assay performance with the recombinant mouse hepatoma CALUX cell line H1L6.1c3.

  8. The analysis of dose-response curve from bioassays with quantal response: Deterministic or statistical approaches?

    PubMed

    Mougabure-Cueto, G; Sfara, V

    2016-04-25

    Dose-response relations can be obtained from systems at any structural level of biological matter, from the molecular to the organismic level. There are two types of approaches for analyzing dose-response curves: a deterministic approach, based on the law of mass action, and a statistical approach, based on the assumed probabilities distribution of phenotypic characters. Models based on the law of mass action have been proposed to analyze dose-response relations across the entire range of biological systems. The purpose of this paper is to discuss the principles that determine the dose-response relations. Dose-response curves of simple systems are the result of chemical interactions between reacting molecules, and therefore are supported by the law of mass action. In consequence, the shape of these curves is perfectly sustained by physicochemical features. However, dose-response curves of bioassays with quantal response are not explained by the simple collision of molecules but by phenotypic variations among individuals and can be interpreted as individual tolerances. The expression of tolerance is the result of many genetic and environmental factors and thus can be considered a random variable. In consequence, the shape of its associated dose-response curve has no physicochemical bearings; instead, they are originated from random biological variations. Due to the randomness of tolerance there is no reason to use deterministic equations for its analysis; on the contrary, statistical models are the appropriate tools for analyzing these dose-response relations.

  9. Ultralow dose computed tomography attenuation correction for pediatric PET CT using adaptive statistical iterative reconstruction

    SciTech Connect

    Brady, Samuel L.; Shulkin, Barry L.

    2015-02-15

    Purpose: To develop ultralow dose computed tomography (CT) attenuation correction (CTAC) acquisition protocols for pediatric positron emission tomography CT (PET CT). Methods: A GE Discovery 690 PET CT hybrid scanner was used to investigate the change to quantitative PET and CT measurements when operated at ultralow doses (10–35 mA s). CT quantitation: noise, low-contrast resolution, and CT numbers for 11 tissue substitutes were analyzed in-phantom. CT quantitation was analyzed to a reduction of 90% volume computed tomography dose index (0.39/3.64; mGy) from baseline. To minimize noise infiltration, 100% adaptive statistical iterative reconstruction (ASiR) was used for CT reconstruction. PET images were reconstructed with the lower-dose CTAC iterations and analyzed for: maximum body weight standardized uptake value (SUV{sub bw}) of various diameter targets (range 8–37 mm), background uniformity, and spatial resolution. Radiation dose and CTAC noise magnitude were compared for 140 patient examinations (76 post-ASiR implementation) to determine relative dose reduction and noise control. Results: CT numbers were constant to within 10% from the nondose reduced CTAC image for 90% dose reduction. No change in SUV{sub bw}, background percent uniformity, or spatial resolution for PET images reconstructed with CTAC protocols was found down to 90% dose reduction. Patient population effective dose analysis demonstrated relative CTAC dose reductions between 62% and 86% (3.2/8.3–0.9/6.2). Noise magnitude in dose-reduced patient images increased but was not statistically different from predose-reduced patient images. Conclusions: Using ASiR allowed for aggressive reduction in CT dose with no change in PET reconstructed images while maintaining sufficient image quality for colocalization of hybrid CT anatomy and PET radioisotope uptake.

  10. NLO error propagation exercise: statistical results

    SciTech Connect

    Pack, D.J.; Downing, D.J.

    1985-09-01

    Error propagation is the extrapolation and cumulation of uncertainty (variance) above total amounts of special nuclear material, for example, uranium or /sup 235/U, that are present in a defined location at a given time. The uncertainty results from the inevitable inexactness of individual measurements of weight, uranium concentration, /sup 235/U enrichment, etc. The extrapolated and cumulated uncertainty leads directly to quantified limits of error on inventory differences (LEIDs) for such material. The NLO error propagation exercise was planned as a field demonstration of the utilization of statistical error propagation methodology at the Feed Materials Production Center in Fernald, Ohio from April 1 to July 1, 1983 in a single material balance area formed specially for the exercise. Major elements of the error propagation methodology were: variance approximation by Taylor Series expansion; variance cumulation by uncorrelated primary error sources as suggested by Jaech; random effects ANOVA model estimation of variance effects (systematic error); provision for inclusion of process variance in addition to measurement variance; and exclusion of static material. The methodology was applied to material balance area transactions from the indicated time period through a FORTRAN computer code developed specifically for this purpose on the NLO HP-3000 computer. This paper contains a complete description of the error propagation methodology and a full summary of the numerical results of applying the methodlogy in the field demonstration. The error propagation LEIDs did encompass the actual uranium and /sup 235/U inventory differences. Further, one can see that error propagation actually provides guidance for reducing inventory differences and LEIDs in future time periods.

  11. Fewer Doses of HPV Vaccine Result in Immune Response Similar to Three-Dose Regimen

    MedlinePlus

    ... Releases NCI News Note Fewer doses of HPV vaccine result in immune response similar to three-dose ... that two doses of a human papillomavirus (HPV) vaccine, trademarked as Cervarix, resulted in similar serum antibody ...

  12. Dose impact in radiographic lung injury following lung SBRT: Statistical analysis and geometric interpretation

    SciTech Connect

    Yu, Victoria; Kishan, Amar U.; Cao, Minsong; Low, Daniel; Lee, Percy; Ruan, Dan

    2014-03-15

    been demonstrated. Bimodal behavior was observed in the dose distribution of lung injury after SBRT. Novel statistical and geometrical analysis has shown that the systematically quantified low-dose peak at approximately 35 Gy, or 70% prescription dose, is a good indication of a critical dose for injury. The determined critical dose of 35 Gy resembles the critical dose volume limit of 30 Gy for ipsilateral bronchus in RTOG 0618 and results from previous studies. The authors seek to further extend this improved analysis method to a larger cohort to better understand the interpatient variation in radiographic lung injury dose response post-SBRT.

  13. Statistical strategies for averaging EC50 from multiple dose-response experiments.

    PubMed

    Jiang, Xiaoqi; Kopp-Schneider, Annette

    2015-11-01

    In most dose-response studies, repeated experiments are conducted to determine the EC50 value for a chemical, requiring averaging EC50 estimates from a series of experiments. Two statistical strategies, the mixed-effect modeling and the meta-analysis approach, can be applied to estimate average behavior of EC50 values over all experiments by considering the variabilities within and among experiments. We investigated these two strategies in two common cases of multiple dose-response experiments in (a) complete and explicit dose-response relationships are observed in all experiments and in (b) only in a subset of experiments. In case (a), the meta-analysis strategy is a simple and robust method to average EC50 estimates. In case (b), all experimental data sets can be first screened using the dose-response screening plot, which allows visualization and comparison of multiple dose-response experimental results. As long as more than three experiments provide information about complete dose-response relationships, the experiments that cover incomplete relationships can be excluded from the meta-analysis strategy of averaging EC50 estimates. If there are only two experiments containing complete dose-response information, the mixed-effects model approach is suggested. We subsequently provided a web application for non-statisticians to implement the proposed meta-analysis strategy of averaging EC50 estimates from multiple dose-response experiments.

  14. T1 VSAT Fade Compensation Statistical Results

    NASA Technical Reports Server (NTRS)

    Johnson, Sandra K.; Acosta, Roberto; Ugweje, Oke

    2000-01-01

    New satellite communication systems are steadily seeking to use higher frequency bands to accommodate the requirements for additional capacity. At these higher frequencies, propagation impairments that did not significantly affect the signal at lower frequencies begin to have considerable impact. In Ka-band. the next logical commercial frequency band to be used for satellite communication, attenuation of the signal due to rain is a primary concern. An experimental satellite built by NASA, the Advanced Communication Technology Satellite (ACTS). launched in September 1993, is the first U.S. communication satellite operating in the Ka-band. In addition to higher carrier frequencies, a number of other new technologies, including on-board baseband processing. multiple beam antennas, and rain fade detection and compensation techniques, were designed into the ACTS. Verification experiments have been conducted since the launch to characterize the new technologies. The focus of this paper is to characterize the method used by the ACTS TI Very Small Aperture Terminal (TI VSAT) ground stations in detecting the presence of fade in the communication signal and to adaptively compensate for it by the addition of burst rate reduction and forward error correction. Measured data obtained from the ACTS program was used to validate the compensation technique. A software process was developed and demonstrated to statistically characterize the increased availability achieved by the compensation techniques in terms of the bit error rate time enhancement factor. Several improvements to the ACTS technique are discussed and possible implementations for future Ka band system are offered.

  15. Fewer doses of HPV vaccine result in immune response similar to three-dose regimen

    Cancer.gov

    NCI scientists report that two doses of a human papillomavirus (HPV) vaccine, trademarked as Cervarix, resulted in similar serum antibody levels against two of the most carcinogenic types of HPV (16 and 18), compared to a standard three dose regimen.

  16. Low dose dynamic CT myocardial perfusion imaging using a statistical iterative reconstruction method

    SciTech Connect

    Tao, Yinghua; Chen, Guang-Hong; Hacker, Timothy A.; Raval, Amish N.; Van Lysel, Michael S.; Speidel, Michael A.

    2014-07-15

    Purpose: Dynamic CT myocardial perfusion imaging has the potential to provide both functional and anatomical information regarding coronary artery stenosis. However, radiation dose can be potentially high due to repeated scanning of the same region. The purpose of this study is to investigate the use of statistical iterative reconstruction to improve parametric maps of myocardial perfusion derived from a low tube current dynamic CT acquisition. Methods: Four pigs underwent high (500 mA) and low (25 mA) dose dynamic CT myocardial perfusion scans with and without coronary occlusion. To delineate the affected myocardial territory, an N-13 ammonia PET perfusion scan was performed for each animal in each occlusion state. Filtered backprojection (FBP) reconstruction was first applied to all CT data sets. Then, a statistical iterative reconstruction (SIR) method was applied to data sets acquired at low dose. Image voxel noise was matched between the low dose SIR and high dose FBP reconstructions. CT perfusion maps were compared among the low dose FBP, low dose SIR and high dose FBP reconstructions. Numerical simulations of a dynamic CT scan at high and low dose (20:1 ratio) were performed to quantitatively evaluate SIR and FBP performance in terms of flow map accuracy, precision, dose efficiency, and spatial resolution. Results: Forin vivo studies, the 500 mA FBP maps gave −88.4%, −96.0%, −76.7%, and −65.8% flow change in the occluded anterior region compared to the open-coronary scans (four animals). The percent changes in the 25 mA SIR maps were in good agreement, measuring −94.7%, −81.6%, −84.0%, and −72.2%. The 25 mA FBP maps gave unreliable flow measurements due to streaks caused by photon starvation (percent changes of +137.4%, +71.0%, −11.8%, and −3.5%). Agreement between 25 mA SIR and 500 mA FBP global flow was −9.7%, 8.8%, −3.1%, and 26.4%. The average variability of flow measurements in a nonoccluded region was 16.3%, 24.1%, and 937

  17. Low dose dynamic CT myocardial perfusion imaging using a statistical iterative reconstruction method

    PubMed Central

    Tao, Yinghua; Chen, Guang-Hong; Hacker, Timothy A.; Raval, Amish N.; Van Lysel, Michael S.; Speidel, Michael A.

    2014-01-01

    Purpose: Dynamic CT myocardial perfusion imaging has the potential to provide both functional and anatomical information regarding coronary artery stenosis. However, radiation dose can be potentially high due to repeated scanning of the same region. The purpose of this study is to investigate the use of statistical iterative reconstruction to improve parametric maps of myocardial perfusion derived from a low tube current dynamic CT acquisition. Methods: Four pigs underwent high (500 mA) and low (25 mA) dose dynamic CT myocardial perfusion scans with and without coronary occlusion. To delineate the affected myocardial territory, an N-13 ammonia PET perfusion scan was performed for each animal in each occlusion state. Filtered backprojection (FBP) reconstruction was first applied to all CT data sets. Then, a statistical iterative reconstruction (SIR) method was applied to data sets acquired at low dose. Image voxel noise was matched between the low dose SIR and high dose FBP reconstructions. CT perfusion maps were compared among the low dose FBP, low dose SIR and high dose FBP reconstructions. Numerical simulations of a dynamic CT scan at high and low dose (20:1 ratio) were performed to quantitatively evaluate SIR and FBP performance in terms of flow map accuracy, precision, dose efficiency, and spatial resolution. Results: Forin vivo studies, the 500 mA FBP maps gave −88.4%, −96.0%, −76.7%, and −65.8% flow change in the occluded anterior region compared to the open-coronary scans (four animals). The percent changes in the 25 mA SIR maps were in good agreement, measuring −94.7%, −81.6%, −84.0%, and −72.2%. The 25 mA FBP maps gave unreliable flow measurements due to streaks caused by photon starvation (percent changes of +137.4%, +71.0%, −11.8%, and −3.5%). Agreement between 25 mA SIR and 500 mA FBP global flow was −9.7%, 8.8%, −3.1%, and 26.4%. The average variability of flow measurements in a nonoccluded region was 16.3%, 24.1%, and 937

  18. Adaptive dose finding based on t-statistic for dose-response trials.

    PubMed

    Ivanova, Anastasia; Bolognese, James A; Perevozskaya, Inna

    2008-05-10

    The goals of phase II dose-response studies are to prove that the treatment is effective and to choose the dose for further development. Randomized designs with equal allocation to either a high dose and placebo or to each of several doses and placebo are typically used. However, in trials where response is observed relatively quickly, adaptive designs might offer an advantage over equal allocation. We propose an adaptive design for dose-response trials that concentrates the allocation of subjects in one or more areas of interest, for example, near a minimum clinically important effect level, or near some maximal effect level, and also allows for the possibility to stop the trial early if needed. The proposed adaptive design yields higher power to detect a dose-response relationship, higher power in comparison with placebo, and selects the correct dose more frequently compared with a corresponding randomized design with equal allocation to doses.

  19. BENCHMARKING UPGRADED HOTSPOT DOSE CALCULATIONS AGAINST MACCS2 RESULTS

    SciTech Connect

    Brotherton, Kevin

    2009-04-30

    The radiological consequence of interest for a documented safety analysis (DSA) is the centerline Total Effective Dose Equivalent (TEDE) incurred by the Maximally Exposed Offsite Individual (MOI) evaluated at the 95th percentile consequence level. An upgraded version of HotSpot (Version 2.07) has been developed with the capabilities to read site meteorological data and perform the necessary statistical calculations to determine the 95th percentile consequence result. These capabilities should allow HotSpot to join MACCS2 (Version 1.13.1) and GENII (Version 1.485) as radiological consequence toolbox codes in the Department of Energy (DOE) Safety Software Central Registry. Using the same meteorological data file, scenarios involving a one curie release of {sup 239}Pu were modeled in both HotSpot and MACCS2. Several sets of release conditions were modeled, and the results compared. In each case, input parameter specifications for each code were chosen to match one another as much as the codes would allow. The results from the two codes are in excellent agreement. Slight differences observed in results are explained by algorithm differences.

  20. Appropriate statistical methods to compare dose responses of methionine sources.

    PubMed

    Kratzer, D D; Littell, R C

    2006-05-01

    Two sources of methionine (Met) activity are frequently used in commercial feed formulation: DL-2-hydroxy-4-(methylthio) butanoic acid (HMTBA), most commonly available as an 88% solution with 12% water; and DL-methionine (DLM, 99% powder). Despite the fact that both compounds have been in commercial use for over 50 yr, controversy and confusion remain with respect to their relative bioefficacy (RBE). This paper presents a review of the use of a nonlinear common plateau asymptotic regression technique (NLCPAR) that has been used to compare the 2 Met sources with particular emphasis on the validity of the basic assumptions of that model. The thesis of this paper is that the controversy is due, at least in part, to the misapplication of this regression technique to estimate the RBE of HMTBA and DLM. The NLCPAR model is a bioassay with the key dependent assumptions that HMTBA is a dilution of DLM, and that each follows dose-response curves of the same form and approach a common plateau. Because both provide Met activity, it may be considered reasonable to accept these assumptions; however, specifically testing them demonstrated that the assumption of a common dose-response is not supported by data. The common plateau assumption was tested with an alternative approach of fitting nonlinear separate plateaus asymptotic regression (NLSPAR) to a set of 13 published broiler studies in which the NLCPAR model had been used to estimate RBE of HMTBA and DLM. The hypothesis of a common plateau was rejected (P < 0.01), meaning that the conclusion that HMTBA had lower bioefficacy than DLM based on the NLCPAR methodology was not valid. An example using published data demonstrated that the NLSPAR model was a significantly better fit than the NLCPAR model, and showed that HMTBA and DLM followed different dose responses. Consequently, there was no single value for RBE for the entire dose range; rather, the RBE of the 2 compounds varied with use level. The evidence presented here

  1. Statistical analysis of dose heterogeneity in circulating blood: Implications for sequential methods of total body irradiation

    SciTech Connect

    Molloy, Janelle A.

    2010-11-15

    Purpose: Improvements in delivery techniques for total body irradiation (TBI) using Tomotherapy and intensity modulated radiation therapy have been proven feasible. Despite the promise of improved dose conformality, the application of these ''sequential'' techniques has been hampered by concerns over dose heterogeneity to circulating blood. The present study was conducted to provide quantitative evidence regarding the potential clinical impact of this heterogeneity. Methods: Blood perfusion was modeled analytically as possessing linear, sinusoidal motion in the craniocaudal dimension. The average perfusion period for human circulation was estimated to be approximately 78 s. Sequential treatment delivery was modeled as a Gaussian-shaped dose cloud with a 10 cm length that traversed a 183 cm patient length at a uniform speed. Total dose to circulating blood voxels was calculated via numerical integration and normalized to 2 Gy per fraction. Dose statistics and equivalent uniform dose (EUD) were calculated for relevant treatment times, radiobiological parameters, blood perfusion rates, and fractionation schemes. The model was then refined to account for random dispersion superimposed onto the underlying periodic blood flow. Finally, a fully stochastic model was developed using binomial and trinomial probability distributions. These models allowed for the analysis of nonlinear sequential treatment modalities and treatment designs that incorporate deliberate organ sparing. Results: The dose received by individual blood voxels exhibited asymmetric behavior that depended on the coherence among the blood velocity, circulation phase, and the spatiotemporal characteristics of the irradiation beam. Heterogeneity increased with the perfusion period and decreased with the treatment time. Notwithstanding, heterogeneity was less than {+-}10% for perfusion periods less than 150 s. The EUD was compromised for radiosensitive cells, long perfusion periods, and short treatment times

  2. Statistical variability and confidence intervals for planar dose QA pass rates

    SciTech Connect

    Bailey, Daniel W.; Nelms, Benjamin E.; Attwood, Kristopher; Kumaraswamy, Lalith; Podgorsak, Matthew B.

    2011-11-15

    techniques. Results: For the prostate and head/neck cases studied, the pass rates obtained with gamma analysis of high density dose planes were 2%-5% higher than respective %/DTA composite analysis on average (ranging as high as 11%), depending on tolerances and normalization. Meanwhile, the pass rates obtained via local normalization were 2%-12% lower than with global maximum normalization on average (ranging as high as 27%), depending on tolerances and calculation method. Repositioning of simulated low-density sampled grids leads to a distribution of possible pass rates for each measured/calculated dose plane pair. These distributions can be predicted using a binomial distribution in order to establish confidence intervals that depend largely on the sampling density and the observed pass rate (i.e., the degree of difference between measured and calculated dose). These results can be extended to apply to 3D arrays of detectors, as well. Conclusions: Dose plane QA analysis can be greatly affected by choice of calculation metric and user-defined parameters, and so all pass rates should be reported with a complete description of calculation method. Pass rates for low-density arrays are subject to statistical uncertainty (vs. the high-density pass rate), but these sampling errors can be modeled using statistical confidence intervals derived from the sampled pass rate and detector density. Thus, pass rates for low-density array measurements should be accompanied by a confidence interval indicating the uncertainty of each pass rate.

  3. Reviewer Bias for Statistically Significant Results: A Reexamination.

    ERIC Educational Resources Information Center

    Fagley, N. S.; McKinney, I. Jean

    1983-01-01

    Reexamines the article by Atkinson, Furlong, and Wampold (1982) and questions their conclusion that reviewers were biased toward statistically significant results. A statistical power analysis shows the power of their bogus study was low. Low power in a study reporting nonsignificant findings is a valid reason for recommending not to publish.…

  4. The estimation of the measurement results with using statistical methods

    NASA Astrophysics Data System (ADS)

    Velychko, O.; Gordiyenko, T.

    2015-02-01

    The row of international standards and guides describe various statistical methods that apply for a management, control and improvement of processes with the purpose of realization of analysis of the technical measurement results. The analysis of international standards and guides on statistical methods estimation of the measurement results recommendations for those applications in laboratories is described. For realization of analysis of standards and guides the cause-and-effect Ishikawa diagrams concerting to application of statistical methods for estimation of the measurement results are constructed.

  5. Indonesia: statistical sampling technique in validation of radiation sterilisation dose of biological tissue.

    PubMed

    Hilmy, N; Basril, A; Febrida, A

    2003-01-01

    The aim of the work is to find the best solution for statistical sampling technique in validation of radiation sterilization dose (RSD) for biological tissues, according to ISO standard. As a model for sampling are biological tissues retrieved from one cadaver donor which consist of frozen bone grafts (18 packets), lyophilized allografts (68 packets) and demineralized bone powder grafts (40 packets). The size and type of products vary from long bones, cancellous chips to bone powders, tendons and facia lata, that make the number of bioburden per product could not be treated equally. Frozen samples could not be considered as the same production batch with lyophilized samples, because of different processing and irradiation temperature. The minimum number of uniformed samples needed for validation per production batch size, according to ISO 13409, is from 20 to 79 and 20 of them will be used for the test sample size, i.e. 10 for bio-burden determination and the remaining 10 for verification dose. Based on the number of uniformed grafts, statistical sampling can be carried out on lyophilized and demineralized bone grafts, but not on frozen bone grafts. Bioburden determinations were carried out and validated according to ISO 11737-1. Results of average bioburden determination (cfu/per packet), using sample item portion (SIP) = 1, are 5 cfu/packet for lyophilized bone grafts and 4 cfu/packet for demineralized bone powder grafts. Verification doses obtained were 2.40 kGy for lyophilized grafts and 2.24 kGy for demineralized bone powder grafts. The results of verification dose were accepted and the RSD of 25 kGy is substantiated It can be concluded that a statistical sampling technique can be applied if all the grafts produced in the same process such as lyophilized, demineralized as well as frozen are assumed to be in one production batch regardless of sample uniformity such as size, type and weight; for this ISO 13409 can be applied for the validation of RSD.

  6. Statistical image reconstruction for low-dose CT using nonlocal means-based regularization.

    PubMed

    Zhang, Hao; Ma, Jianhua; Wang, Jing; Liu, Yan; Lu, Hongbing; Liang, Zhengrong

    2014-09-01

    Low-dose computed tomography (CT) imaging without sacrifice of clinical tasks is desirable due to the growing concerns about excessive radiation exposure to the patients. One common strategy to achieve low-dose CT imaging is to lower the milliampere-second (mAs) setting in data scanning protocol. However, the reconstructed CT images by the conventional filtered back-projection (FBP) method from the low-mAs acquisitions may be severely degraded due to the excessive noise. Statistical image reconstruction (SIR) methods have shown potentials to significantly improve the reconstructed image quality from the low-mAs acquisitions, wherein the regularization plays a critical role and an established family of regularizations is based on the Markov random field (MRF) model. Inspired by the success of nonlocal means (NLM) in image processing applications, in this work, we propose to explore the NLM-based regularization for SIR to reconstruct low-dose CT images from low-mAs acquisitions. Experimental results with both digital and physical phantoms consistently demonstrated that SIR with the NLM-based regularization can achieve more gains than SIR with the well-known Gaussian MRF regularization or the generalized Gaussian MRF regularization and the conventional FBP method, in terms of image noise reduction and resolution preservation.

  7. Statistical image reconstruction for low-dose CT using nonlocal means-based regularization

    PubMed Central

    Zhang, Hao; Ma, Jianhua; Wang, Jing; Liu, Yan; Lu, Hongbing

    2014-01-01

    Low-dose computed tomography (CT) imaging without sacrifice of clinical tasks is desirable due to the growing concerns about excessive radiation exposure to the patients. One common strategy to achieve low-dose CT imaging is to lower the milliampere-second (mAs) setting in data scanning protocol. However, the reconstructed CT images by the conventional filtered back-projection (FBP) method from the low-mAs acquisitions may be severely degraded due to the excessive noise. Statistical image reconstruction (SIR) methods have shown potentials to significantly improve the reconstructed image quality from the low-mAs acquisitions, wherein the regularization plays a critical role and an established family of regularizations is based on the Markov random field (MRF) model. Inspired by the success of nonlocal means (NLM) in image processing applications, in this work, we propose to explore the NLM-based regularization for SIR to reconstruct low-dose CT images from low-mAs acquisitions. Experimental results with both digital and physical phantoms consistently demonstrated that SIR with the NLM-based regularization can achieve more gains than SIR with the well-known Gaussian MRF regularization or the generalized Gaussian MRF regularization and the conventional FBP method, in terms of image noise reduction and resolution preservation. PMID:24881498

  8. Quality Control of High-Dose-Rate Brachytherapy: Treatment Delivery Analysis Using Statistical Process Control

    SciTech Connect

    Able, Charles M.; Bright, Megan; Frizzell, Bart

    2013-03-01

    Purpose: Statistical process control (SPC) is a quality control method used to ensure that a process is well controlled and operates with little variation. This study determined whether SPC was a viable technique for evaluating the proper operation of a high-dose-rate (HDR) brachytherapy treatment delivery system. Methods and Materials: A surrogate prostate patient was developed using Vyse ordnance gelatin. A total of 10 metal oxide semiconductor field-effect transistors (MOSFETs) were placed from prostate base to apex. Computed tomography guidance was used to accurately position the first detector in each train at the base. The plan consisted of 12 needles with 129 dwell positions delivering a prescribed peripheral dose of 200 cGy. Sixteen accurate treatment trials were delivered as planned. Subsequently, a number of treatments were delivered with errors introduced, including wrong patient, wrong source calibration, wrong connection sequence, single needle displaced inferiorly 5 mm, and entire implant displaced 2 mm and 4 mm inferiorly. Two process behavior charts (PBC), an individual and a moving range chart, were developed for each dosimeter location. Results: There were 4 false positives resulting from 160 measurements from 16 accurately delivered treatments. For the inaccurately delivered treatments, the PBC indicated that measurements made at the periphery and apex (regions of high-dose gradient) were much more sensitive to treatment delivery errors. All errors introduced were correctly identified by either the individual or the moving range PBC in the apex region. Measurements at the urethra and base were less sensitive to errors. Conclusions: SPC is a viable method for assessing the quality of HDR treatment delivery. Further development is necessary to determine the most effective dose sampling, to ensure reproducible evaluation of treatment delivery accuracy.

  9. The (mis)reporting of statistical results in psychology journals.

    PubMed

    Bakker, Marjan; Wicherts, Jelte M

    2011-09-01

    In order to study the prevalence, nature (direction), and causes of reporting errors in psychology, we checked the consistency of reported test statistics, degrees of freedom, and p values in a random sample of high- and low-impact psychology journals. In a second study, we established the generality of reporting errors in a random sample of recent psychological articles. Our results, on the basis of 281 articles, indicate that around 18% of statistical results in the psychological literature are incorrectly reported. Inconsistencies were more common in low-impact journals than in high-impact journals. Moreover, around 15% of the articles contained at least one statistical conclusion that proved, upon recalculation, to be incorrect; that is, recalculation rendered the previously significant result insignificant, or vice versa. These errors were often in line with researchers' expectations. We classified the most common errors and contacted authors to shed light on the origins of the errors.

  10. Characterization of adaptive statistical iterative reconstruction algorithm for dose reduction in CT: A pediatric oncology perspective

    SciTech Connect

    Brady, S. L.; Yee, B. S.; Kaufman, R. A.

    2012-09-15

    Purpose: This study demonstrates a means of implementing an adaptive statistical iterative reconstruction (ASiR Trade-Mark-Sign ) technique for dose reduction in computed tomography (CT) while maintaining similar noise levels in the reconstructed image. The effects of image quality and noise texture were assessed at all implementation levels of ASiR Trade-Mark-Sign . Empirically derived dose reduction limits were established for ASiR Trade-Mark-Sign for imaging of the trunk for a pediatric oncology population ranging from 1 yr old through adolescence/adulthood. Methods: Image quality was assessed using metrics established by the American College of Radiology (ACR) CT accreditation program. Each image quality metric was tested using the ACR CT phantom with 0%-100% ASiR Trade-Mark-Sign blended with filtered back projection (FBP) reconstructed images. Additionally, the noise power spectrum (NPS) was calculated for three common reconstruction filters of the trunk. The empirically derived limitations on ASiR Trade-Mark-Sign implementation for dose reduction were assessed using (1, 5, 10) yr old and adolescent/adult anthropomorphic phantoms. To assess dose reduction limits, the phantoms were scanned in increments of increased noise index (decrementing mA using automatic tube current modulation) balanced with ASiR Trade-Mark-Sign reconstruction to maintain noise equivalence of the 0% ASiR Trade-Mark-Sign image. Results: The ASiR Trade-Mark-Sign algorithm did not produce any unfavorable effects on image quality as assessed by ACR criteria. Conversely, low-contrast resolution was found to improve due to the reduction of noise in the reconstructed images. NPS calculations demonstrated that images with lower frequency noise had lower noise variance and coarser graininess at progressively higher percentages of ASiR Trade-Mark-Sign reconstruction; and in spite of the similar magnitudes of noise, the image reconstructed with 50% or more ASiR Trade-Mark-Sign presented a more

  11. STATISTICAL ANALYSIS OF TANK 19F FLOOR SAMPLE RESULTS

    SciTech Connect

    Harris, S.

    2010-09-02

    Representative sampling has been completed for characterization of the residual material on the floor of Tank 19F as per the statistical sampling plan developed by Harris and Shine. Samples from eight locations have been obtained from the tank floor and two of the samples were archived as a contingency. Six samples, referred to in this report as the current scrape samples, have been submitted to and analyzed by SRNL. This report contains the statistical analysis of the floor sample analytical results to determine if further data are needed to reduce uncertainty. Included are comparisons with the prior Mantis samples results to determine if they can be pooled with the current scrape samples to estimate the upper 95% confidence limits (UCL95%) for concentration. Statistical analysis revealed that the Mantis and current scrape sample results are not compatible. Therefore, the Mantis sample results were not used to support the quantification of analytes in the residual material. Significant spatial variability among the current scrape sample results was not found. Constituent concentrations were similar between the North and South hemispheres as well as between the inner and outer regions of the tank floor. The current scrape sample results from all six samples fall within their 3-sigma limits. In view of the results from numerous statistical tests, the data were pooled from all six current scrape samples. As such, an adequate sample size was provided for quantification of the residual material on the floor of Tank 19F. The uncertainty is quantified in this report by an UCL95% on each analyte concentration. The uncertainty in analyte concentration was calculated as a function of the number of samples, the average, and the standard deviation of the analytical results. The UCL95% was based entirely on the six current scrape sample results (each averaged across three analytical determinations).

  12. STATISTICAL ANALYSIS OF TANK 18F FLOOR SAMPLE RESULTS

    SciTech Connect

    Harris, S.

    2010-09-02

    Representative sampling has been completed for characterization of the residual material on the floor of Tank 18F as per the statistical sampling plan developed by Shine [1]. Samples from eight locations have been obtained from the tank floor and two of the samples were archived as a contingency. Six samples, referred to in this report as the current scrape samples, have been submitted to and analyzed by SRNL [2]. This report contains the statistical analysis of the floor sample analytical results to determine if further data are needed to reduce uncertainty. Included are comparisons with the prior Mantis samples results [3] to determine if they can be pooled with the current scrape samples to estimate the upper 95% confidence limits (UCL{sub 95%}) for concentration. Statistical analysis revealed that the Mantis and current scrape sample results are not compatible. Therefore, the Mantis sample results were not used to support the quantification of analytes in the residual material. Significant spatial variability among the current sample results was not found. Constituent concentrations were similar between the North and South hemispheres as well as between the inner and outer regions of the tank floor. The current scrape sample results from all six samples fall within their 3-sigma limits. In view of the results from numerous statistical tests, the data were pooled from all six current scrape samples. As such, an adequate sample size was provided for quantification of the residual material on the floor of Tank 18F. The uncertainty is quantified in this report by an upper 95% confidence limit (UCL{sub 95%}) on each analyte concentration. The uncertainty in analyte concentration was calculated as a function of the number of samples, the average, and the standard deviation of the analytical results. The UCL{sub 95%} was based entirely on the six current scrape sample results (each averaged across three analytical determinations).

  13. Planck 2015 results. XVI. Isotropy and statistics of the CMB

    NASA Astrophysics Data System (ADS)

    Planck Collaboration; Ade, P. A. R.; Aghanim, N.; Akrami, Y.; Aluri, P. K.; Arnaud, M.; Ashdown, M.; Aumont, J.; Baccigalupi, C.; Banday, A. J.; Barreiro, R. B.; Bartolo, N.; Basak, S.; Battaner, E.; Benabed, K.; Benoît, A.; Benoit-Lévy, A.; Bernard, J.-P.; Bersanelli, M.; Bielewicz, P.; Bock, J. J.; Bonaldi, A.; Bonavera, L.; Bond, J. R.; Borrill, J.; Bouchet, F. R.; Boulanger, F.; Bucher, M.; Burigana, C.; Butler, R. C.; Calabrese, E.; Cardoso, J.-F.; Casaponsa, B.; Catalano, A.; Challinor, A.; Chamballu, A.; Chiang, H. C.; Christensen, P. R.; Church, S.; Clements, D. L.; Colombi, S.; Colombo, L. P. L.; Combet, C.; Contreras, D.; Couchot, F.; Coulais, A.; Crill, B. P.; Cruz, M.; Curto, A.; Cuttaia, F.; Danese, L.; Davies, R. D.; Davis, R. J.; de Bernardis, P.; de Rosa, A.; de Zotti, G.; Delabrouille, J.; Désert, F.-X.; Diego, J. M.; Dole, H.; Donzelli, S.; Doré, O.; Douspis, M.; Ducout, A.; Dupac, X.; Efstathiou, G.; Elsner, F.; Enßlin, T. A.; Eriksen, H. K.; Fantaye, Y.; Fergusson, J.; Fernandez-Cobos, R.; Finelli, F.; Forni, O.; Frailis, M.; Fraisse, A. A.; Franceschi, E.; Frejsel, A.; Frolov, A.; Galeotta, S.; Galli, S.; Ganga, K.; Gauthier, C.; Ghosh, T.; Giard, M.; Giraud-Héraud, Y.; Gjerløw, E.; González-Nuevo, J.; Górski, K. M.; Gratton, S.; Gregorio, A.; Gruppuso, A.; Gudmundsson, J. E.; Hansen, F. K.; Hanson, D.; Harrison, D. L.; Henrot-Versillé, S.; Hernández-Monteagudo, C.; Herranz, D.; Hildebrandt, S. R.; Hivon, E.; Hobson, M.; Holmes, W. A.; Hornstrup, A.; Hovest, W.; Huang, Z.; Huffenberger, K. M.; Hurier, G.; Jaffe, A. H.; Jaffe, T. R.; Jones, W. C.; Juvela, M.; Keihänen, E.; Keskitalo, R.; Kim, J.; Kisner, T. S.; Knoche, J.; Kunz, M.; Kurki-Suonio, H.; Lagache, G.; Lähteenmäki, A.; Lamarre, J.-M.; Lasenby, A.; Lattanzi, M.; Lawrence, C. R.; Leonardi, R.; Lesgourgues, J.; Levrier, F.; Liguori, M.; Lilje, P. B.; Linden-Vørnle, M.; Liu, H.; López-Caniego, M.; Lubin, P. M.; Macías-Pérez, J. F.; Maggio, G.; Maino, D.; Mandolesi, N.; Mangilli, A.; Marinucci, D.; Maris, M.; Martin, P. G.; Martínez-González, E.; Masi, S.; Matarrese, S.; McGehee, P.; Meinhold, P. R.; Melchiorri, A.; Mendes, L.; Mennella, A.; Migliaccio, M.; Mikkelsen, K.; Mitra, S.; Miville-Deschênes, M.-A.; Molinari, D.; Moneti, A.; Montier, L.; Morgante, G.; Mortlock, D.; Moss, A.; Munshi, D.; Murphy, J. A.; Naselsky, P.; Nati, F.; Natoli, P.; Netterfield, C. B.; Nørgaard-Nielsen, H. U.; Noviello, F.; Novikov, D.; Novikov, I.; Oxborrow, C. A.; Paci, F.; Pagano, L.; Pajot, F.; Pant, N.; Paoletti, D.; Pasian, F.; Patanchon, G.; Pearson, T. J.; Perdereau, O.; Perotto, L.; Perrotta, F.; Pettorino, V.; Piacentini, F.; Piat, M.; Pierpaoli, E.; Pietrobon, D.; Plaszczynski, S.; Pointecouteau, E.; Polenta, G.; Popa, L.; Pratt, G. W.; Prézeau, G.; Prunet, S.; Puget, J.-L.; Rachen, J. P.; Rebolo, R.; Reinecke, M.; Remazeilles, M.; Renault, C.; Renzi, A.; Ristorcelli, I.; Rocha, G.; Rosset, C.; Rossetti, M.; Rotti, A.; Roudier, G.; Rubiño-Martín, J. A.; Rusholme, B.; Sandri, M.; Santos, D.; Savelainen, M.; Savini, G.; Scott, D.; Seiffert, M. D.; Shellard, E. P. S.; Souradeep, T.; Spencer, L. D.; Stolyarov, V.; Stompor, R.; Sudiwala, R.; Sunyaev, R.; Sutton, D.; Suur-Uski, A.-S.; Sygnet, J.-F.; Tauber, J. A.; Terenzi, L.; Toffolatti, L.; Tomasi, M.; Tristram, M.; Trombetti, T.; Tucci, M.; Tuovinen, J.; Valenziano, L.; Valiviita, J.; Van Tent, B.; Vielva, P.; Villa, F.; Wade, L. A.; Wandelt, B. D.; Wehus, I. K.; Yvon, D.; Zacchei, A.; Zibin, J. P.; Zonca, A.

    2016-09-01

    We test the statistical isotropy and Gaussianity of the cosmic microwave background (CMB) anisotropies using observations made by the Planck satellite. Our results are based mainly on the full Planck mission for temperature, but also include some polarization measurements. In particular, we consider the CMB anisotropy maps derived from the multi-frequency Planck data by several component-separation methods. For the temperature anisotropies, we find excellent agreement between results based on these sky maps over both a very large fraction of the sky and a broad range of angular scales, establishing that potential foreground residuals do not affect our studies. Tests of skewness, kurtosis, multi-normality, N-point functions, and Minkowski functionals indicate consistency with Gaussianity, while a power deficit at large angular scales is manifested in several ways, for example low map variance. The results of a peak statistics analysis are consistent with the expectations of a Gaussian random field. The "Cold Spot" is detected with several methods, including map kurtosis, peak statistics, and mean temperature profile. We thoroughly probe the large-scale dipolar power asymmetry, detecting it with several independent tests, and address the subject of a posteriori correction. Tests of directionality suggest the presence of angular clustering from large to small scales, but at a significance that is dependent on the details of the approach. We perform the first examination of polarization data, finding the morphology of stacked peaks to be consistent with the expectations of statistically isotropic simulations. Where they overlap, these results are consistent with the Planck 2013 analysis based on the nominal mission data and provide our most thorough view of the statistics of the CMB fluctuations to date.

  14. Characterization of statistical prior image constrained compressed sensing (PICCS): II. Application to dose reduction

    SciTech Connect

    Lauzier, Pascal Theriault; Chen Guanghong

    2013-02-15

    Purpose: The ionizing radiation imparted to patients during computed tomography exams is raising concerns. This paper studies the performance of a scheme called dose reduction using prior image constrained compressed sensing (DR-PICCS). The purpose of this study is to characterize the effects of a statistical model of x-ray detection in the DR-PICCS framework and its impact on spatial resolution. Methods: Both numerical simulations with known ground truth and in vivo animal dataset were used in this study. In numerical simulations, a phantom was simulated with Poisson noise and with varying levels of eccentricity. Both the conventional filtered backprojection (FBP) and the PICCS algorithms were used to reconstruct images. In PICCS reconstructions, the prior image was generated using two different denoising methods: a simple Gaussian blur and a more advanced diffusion filter. Due to the lack of shift-invariance in nonlinear image reconstruction such as the one studied in this paper, the concept of local spatial resolution was used to study the sharpness of a reconstructed image. Specifically, a directional metric of image sharpness, the so-called pseudopoint spread function (pseudo-PSF), was employed to investigate local spatial resolution. Results: In the numerical studies, the pseudo-PSF was reduced from twice the voxel width in the prior image down to less than 1.1 times the voxel width in DR-PICCS reconstructions when the statistical model was not included. At the same noise level, when statistical weighting was used, the pseudo-PSF width in DR-PICCS reconstructed images varied between 1.5 and 0.75 times the voxel width depending on the direction along which it was measured. However, this anisotropy was largely eliminated when the prior image was generated using diffusion filtering; the pseudo-PSF width was reduced to below one voxel width in that case. In the in vivo study, a fourfold improvement in CNR was achieved while qualitatively maintaining sharpness

  15. Ventilatory effects of low-dose paraoxon result from central muscarinic effects

    SciTech Connect

    Houze, Pascal; Pronzola, Laetita; Kayouka, Maya; Villa, Antoine; Debray, Marcel; Baud, Frederic J.

    2008-12-01

    Paraoxon induces respiratory toxicity. Atropine completely reversed parathion- and paraoxon-induced respiratory toxicity. The aim of this study was to assess the peripheral or central origin of ventilatory effects of low-dose paraoxon. Male Sprague-Dawley rats were given paraoxon 0.215 mg/kg subcutaneously and treated with either atropine (10 mg/kg sc) or ascending doses of methylatropine of 5.42 (equimolar to that of atropine), 54.2, and 542 mg/kg administered subcutaneously 30 min after paraoxon. Ventilation at rest was assessed using whole-body plethysmography and rat temperature using infra-red telemetry. Results are expressed as mean {+-} SE. Statistical analysis used two-way ANOVA for repeated measurements. Paraoxon induced a significant decrease in temperature 30 min after injection lasting the 90 min of the study period. This effect was partially corrected by atropine, but not by methylatropine whatever the dose. Paraoxon induced a decrease in respiratory rate resulting from an increase in expiratory time associated with an increase in tidal volume. Atropine completely reversed the ventilatory effects of low-dose paraoxon while the equimolar dose of methylatropine had no significant effects. The 54.2 and 542 mg/kg doses of methylatropine had no significant effects. Atropine crosses the blood-brain barrier and reverses peripheral and central muscarinic effects. In contrast, methylatropine does not cross the blood-brain barrier. Atropine completely reversed the ventilatory effects of low-dose paraoxon, while methylatropine had no significant effects at doses up to 100-fold the equimolar dose of atropine. We conclude that the ventilatory effects of low-dose paraoxon are mediated by disrupted muscarinic signaling in the central nervous system.

  16. Full dose reduction potential of statistical iterative reconstruction for head CT protocols in a predominantly pediatric population

    PubMed Central

    Mirro, Amy E.; Brady, Samuel L.; Kaufman, Robert. A.

    2016-01-01

    Purpose To implement the maximum level of statistical iterative reconstruction that can be used to establish dose-reduced head CT protocols in a primarily pediatric population. Methods Select head examinations (brain, orbits, sinus, maxilla and temporal bones) were investigated. Dose-reduced head protocols using an adaptive statistical iterative reconstruction (ASiR) were compared for image quality with the original filtered back projection (FBP) reconstructed protocols in phantom using the following metrics: image noise frequency (change in perceived appearance of noise texture), image noise magnitude, contrast-to-noise ratio (CNR), and spatial resolution. Dose reduction estimates were based on computed tomography dose index (CTDIvol) values. Patient CTDIvol and image noise magnitude were assessed in 737 pre and post dose reduced examinations. Results Image noise texture was acceptable up to 60% ASiR for Soft reconstruction kernel (at both 100 and 120 kVp), and up to 40% ASiR for Standard reconstruction kernel. Implementation of 40% and 60% ASiR led to an average reduction in CTDIvol of 43% for brain, 41% for orbits, 30% maxilla, 43% for sinus, and 42% for temporal bone protocols for patients between 1 month and 26 years, while maintaining an average noise magnitude difference of 0.1% (range: −3% to 5%), improving CNR of low contrast soft tissue targets, and improving spatial resolution of high contrast bony anatomy, as compared to FBP. Conclusion The methodology in this study demonstrates a methodology for maximizing patient dose reduction and maintaining image quality using statistical iterative reconstruction for a primarily pediatric population undergoing head CT examination. PMID:27056425

  17. Standard error of inverse prediction for dose-response relationship: approximate and exact statistical inference.

    PubMed

    Demidenko, Eugene; Williams, Benjamin B; Flood, Ann Barry; Swartz, Harold M

    2013-05-30

    This paper develops a new metric, the standard error of inverse prediction (SEIP), for a dose-response relationship (calibration curve) when dose is estimated from response via inverse regression. SEIP can be viewed as a generalization of the coefficient of variation to regression problem when x is predicted using y-value. We employ nonstandard statistical methods to treat the inverse prediction, which has an infinite mean and variance due to the presence of a normally distributed variable in the denominator. We develop confidence intervals and hypothesis testing for SEIP on the basis of the normal approximation and using the exact statistical inference based on the noncentral t-distribution. We derive the power functions for both approaches and test them via statistical simulations. The theoretical SEIP, as the ratio of the regression standard error to the slope, is viewed as reciprocal of the signal-to-noise ratio, a popular measure of signal processing. The SEIP, as a figure of merit for inverse prediction, can be used for comparison of calibration curves with different dependent variables and slopes. We illustrate our theory with electron paramagnetic resonance tooth dosimetry for a rapid estimation of the radiation dose received in the event of nuclear terrorism.

  18. Sharing brain mapping statistical results with the neuroimaging data model

    PubMed Central

    Maumet, Camille; Auer, Tibor; Bowring, Alexander; Chen, Gang; Das, Samir; Flandin, Guillaume; Ghosh, Satrajit; Glatard, Tristan; Gorgolewski, Krzysztof J.; Helmer, Karl G.; Jenkinson, Mark; Keator, David B.; Nichols, B. Nolan; Poline, Jean-Baptiste; Reynolds, Richard; Sochat, Vanessa; Turner, Jessica; Nichols, Thomas E.

    2016-01-01

    Only a tiny fraction of the data and metadata produced by an fMRI study is finally conveyed to the community. This lack of transparency not only hinders the reproducibility of neuroimaging results but also impairs future meta-analyses. In this work we introduce NIDM-Results, a format specification providing a machine-readable description of neuroimaging statistical results along with key image data summarising the experiment. NIDM-Results provides a unified representation of mass univariate analyses including a level of detail consistent with available best practices. This standardized representation allows authors to relay methods and results in a platform-independent regularized format that is not tied to a particular neuroimaging software package. Tools are available to export NIDM-Result graphs and associated files from the widely used SPM and FSL software packages, and the NeuroVault repository can import NIDM-Results archives. The specification is publically available at: http://nidm.nidash.org/specs/nidm-results.html. PMID:27922621

  19. Sharing brain mapping statistical results with the neuroimaging data model.

    PubMed

    Maumet, Camille; Auer, Tibor; Bowring, Alexander; Chen, Gang; Das, Samir; Flandin, Guillaume; Ghosh, Satrajit; Glatard, Tristan; Gorgolewski, Krzysztof J; Helmer, Karl G; Jenkinson, Mark; Keator, David B; Nichols, B Nolan; Poline, Jean-Baptiste; Reynolds, Richard; Sochat, Vanessa; Turner, Jessica; Nichols, Thomas E

    2016-12-06

    Only a tiny fraction of the data and metadata produced by an fMRI study is finally conveyed to the community. This lack of transparency not only hinders the reproducibility of neuroimaging results but also impairs future meta-analyses. In this work we introduce NIDM-Results, a format specification providing a machine-readable description of neuroimaging statistical results along with key image data summarising the experiment. NIDM-Results provides a unified representation of mass univariate analyses including a level of detail consistent with available best practices. This standardized representation allows authors to relay methods and results in a platform-independent regularized format that is not tied to a particular neuroimaging software package. Tools are available to export NIDM-Result graphs and associated files from the widely used SPM and FSL software packages, and the NeuroVault repository can import NIDM-Results archives. The specification is publically available at: http://nidm.nidash.org/specs/nidm-results.html.

  20. Impact of adaptive statistical iterative reconstruction on radiation dose in evaluation of trauma patients

    PubMed Central

    Maxfield, Mark W.; Schuster, Kevin M.; McGillicuddy, Edward A.; Young, Calvin J.; Ghita, Monica; Bokhari, S.A. Jamal; Oliva, Isabel B.; Brink, James A.; Davis, Kimberly A.

    2013-01-01

    BACKGROUND A recent study showed that computed tomographic (CT) scans contributed 93% of radiation exposure of 177 patients admitted to our Level I trauma center. Adaptive statistical iterative reconstruction (ASIR) is an algorithm that reduces the noise level in reconstructed images and therefore allows the use of less ionizing radiation during CT scans without significantly affecting image quality. ASIR was instituted on all CT scans performed on trauma patients in June 2009. Our objective was to determine if implementation of ASIR reduced radiation dose without compromising patient outcomes. METHODS We identified 300 patients activating the trauma system before and after the implementation of ASIR imaging. After applying inclusion criteria, 245 charts were reviewed. Baseline demographics, presenting characteristics, number of delayed diagnoses, and missed injuries were recorded. The postexamination volume CT dose index (CTDIvol) and dose-length product (DLP)reported by the scanner for CT scans of the chest, abdomen, and pelvis and CT scans of the brain and cervical spine were recorded. Subjective image quality was compared between the two groups. RESULTS For CT scans of the chest, abdomen, and pelvis, the mean CTDIvol(17.1 mGy vs. 14.2 mGy; p < 0.001) and DLP (1,165 mGy·cm vs. 1,004 mGy·cm; p < 0.001) was lower for studies performed with ASIR. For CT scans of the brain and cervical spine, the mean CTDIvol(61.7 mGy vs. 49.6 mGy; p < 0.001) and DLP (1,327 mGy·cm vs. 1,067 mGy·cm; p < 0.001) was lower for studies performed with ASIR. There was no subjective difference in image quality between ASIR and non-ASIR scans. All CT scans were deemed of good or excellent image quality. There were no delayed diagnoses or missed injuries related to CT scanning identified in either group. CONCLUSION Implementation of ASIR imaging for CT scans performed on trauma patients led to a nearly 20% reduction in ionizing radiation without compromising outcomes or image quality

  1. Planck 2013 results. XXIII. Isotropy and statistics of the CMB

    NASA Astrophysics Data System (ADS)

    Planck Collaboration; Ade, P. A. R.; Aghanim, N.; Armitage-Caplan, C.; Arnaud, M.; Ashdown, M.; Atrio-Barandela, F.; Aumont, J.; Baccigalupi, C.; Banday, A. J.; Barreiro, R. B.; Bartlett, J. G.; Bartolo, N.; Battaner, E.; Battye, R.; Benabed, K.; Benoît, A.; Benoit-Lévy, A.; Bernard, J.-P.; Bersanelli, M.; Bielewicz, P.; Bobin, J.; Bock, J. J.; Bonaldi, A.; Bonavera, L.; Bond, J. R.; Borrill, J.; Bouchet, F. R.; Bridges, M.; Bucher, M.; Burigana, C.; Butler, R. C.; Cardoso, J.-F.; Catalano, A.; Challinor, A.; Chamballu, A.; Chary, R.-R.; Chiang, H. C.; Chiang, L.-Y.; Christensen, P. R.; Church, S.; Clements, D. L.; Colombi, S.; Colombo, L. P. L.; Couchot, F.; Coulais, A.; Crill, B. P.; Cruz, M.; Curto, A.; Cuttaia, F.; Danese, L.; Davies, R. D.; Davis, R. J.; de Bernardis, P.; de Rosa, A.; de Zotti, G.; Delabrouille, J.; Delouis, J.-M.; Désert, F.-X.; Diego, J. M.; Dole, H.; Donzelli, S.; Doré, O.; Douspis, M.; Ducout, A.; Dupac, X.; Efstathiou, G.; Elsner, F.; Enßlin, T. A.; Eriksen, H. K.; Fantaye, Y.; Fergusson, J.; Finelli, F.; Forni, O.; Frailis, M.; Franceschi, E.; Frommert, M.; Galeotta, S.; Ganga, K.; Giard, M.; Giardino, G.; Giraud-Héraud, Y.; González-Nuevo, J.; Górski, K. M.; Gratton, S.; Gregorio, A.; Gruppuso, A.; Hansen, F. K.; Hansen, M.; Hanson, D.; Harrison, D. L.; Helou, G.; Henrot-Versillé, S.; Hernández-Monteagudo, C.; Herranz, D.; Hildebrandt, S. R.; Hivon, E.; Hobson, M.; Holmes, W. A.; Hornstrup, A.; Hovest, W.; Huffenberger, K. M.; Jaffe, A. H.; Jaffe, T. R.; Jones, W. C.; Juvela, M.; Keihänen, E.; Keskitalo, R.; Kim, J.; Kisner, T. S.; Knoche, J.; Knox, L.; Kunz, M.; Kurki-Suonio, H.; Lagache, G.; Lähteenmäki, A.; Lamarre, J.-M.; Lasenby, A.; Laureijs, R. J.; Lawrence, C. R.; Leahy, J. P.; Leonardi, R.; Leroy, C.; Lesgourgues, J.; Liguori, M.; Lilje, P. B.; Linden-Vørnle, M.; López-Caniego, M.; Lubin, P. M.; Macías-Pérez, J. F.; Maffei, B.; Maino, D.; Mandolesi, N.; Mangilli, A.; Marinucci, D.; Maris, M.; Marshall, D. J.; Martin, P. G.; Martínez-González, E.; Masi, S.; Massardi, M.; Matarrese, S.; Matthai, F.; Mazzotta, P.; McEwen, J. D.; Meinhold, P. R.; Melchiorri, A.; Mendes, L.; Mennella, A.; Migliaccio, M.; Mikkelsen, K.; Mitra, S.; Miville-Deschênes, M.-A.; Molinari, D.; Moneti, A.; Montier, L.; Morgante, G.; Mortlock, D.; Moss, A.; Munshi, D.; Murphy, J. A.; Naselsky, P.; Nati, F.; Natoli, P.; Netterfield, C. B.; Nørgaard-Nielsen, H. U.; Noviello, F.; Novikov, D.; Novikov, I.; Osborne, S.; Oxborrow, C. A.; Paci, F.; Pagano, L.; Pajot, F.; Paoletti, D.; Pasian, F.; Patanchon, G.; Peiris, H. V.; Perdereau, O.; Perotto, L.; Perrotta, F.; Piacentini, F.; Piat, M.; Pierpaoli, E.; Pietrobon, D.; Plaszczynski, S.; Pogosyan, D.; Pointecouteau, E.; Polenta, G.; Ponthieu, N.; Popa, L.; Poutanen, T.; Pratt, G. W.; Prézeau, G.; Prunet, S.; Puget, J.-L.; Rachen, J. P.; Racine, B.; Räth, C.; Rebolo, R.; Reinecke, M.; Remazeilles, M.; Renault, C.; Renzi, A.; Ricciardi, S.; Riller, T.; Ristorcelli, I.; Rocha, G.; Rosset, C.; Rotti, A.; Roudier, G.; Rubiño-Martín, J. A.; Ruiz-Granados, B.; Rusholme, B.; Sandri, M.; Santos, D.; Savini, G.; Scott, D.; Seiffert, M. D.; Shellard, E. P. S.; Souradeep, T.; Spencer, L. D.; Starck, J.-L.; Stolyarov, V.; Stompor, R.; Sudiwala, R.; Sureau, F.; Sutter, P.; Sutton, D.; Suur-Uski, A.-S.; Sygnet, J.-F.; Tauber, J. A.; Tavagnacco, D.; Terenzi, L.; Toffolatti, L.; Tomasi, M.; Tristram, M.; Tucci, M.; Tuovinen, J.; Türler, M.; Valenziano, L.; Valiviita, J.; Van Tent, B.; Varis, J.; Vielva, P.; Villa, F.; Vittorio, N.; Wade, L. A.; Wandelt, B. D.; Wehus, I. K.; White, M.; Wilkinson, A.; Yvon, D.; Zacchei, A.; Zonca, A.

    2014-11-01

    The two fundamental assumptions of the standard cosmological model - that the initial fluctuations are statistically isotropic and Gaussian - are rigorously tested using maps of the cosmic microwave background (CMB) anisotropy from the Planck satellite. The detailed results are based on studies of four independent estimates of the CMB that are compared to simulations using a fiducial ΛCDM model and incorporating essential aspects of the Planck measurement process. Deviations from isotropy have been found and demonstrated to be robust against component separation algorithm, mask choice, and frequency dependence. Many of these anomalies were previously observed in the WMAP data, and are now confirmed at similar levels of significance (about 3σ). However, we find little evidence of non-Gaussianity, with the exception of a few statistical signatures that seem to be associated with specific anomalies. In particular, we find that the quadrupole-octopole alignment is also connected to a low observed variance in the CMB signal. A power asymmetry is now found to persist on scales corresponding to about ℓ = 600 and can be described in the low-ℓ regime by a phenomenological dipole modulation model. However, any primordial power asymmetry is strongly scale-dependent and does not extend toarbitrarily small angular scales. Finally, it is plausible that some of these features may be reflected in the angular power spectrum of the data, which shows a deficit of power on similar scales. Indeed, when the power spectra of two hemispheres defined by a preferred direction are considered separately, one shows evidence of a deficit in power, while its opposite contains oscillations between odd and even modes that may be related to the parity violation and phase correlations also detected in the data. Although these analyses represent a step forward in building an understanding of the anomalies, a satisfactory explanation based on physically motivated models is still lacking.

  2. Statistical Analysis of Tank 5 Floor Sample Results

    SciTech Connect

    Shine, E. P.

    2013-01-31

    Sampling has been completed for the characterization of the residual material on the floor of Tank 5 in the F-Area Tank Farm at the Savannah River Site (SRS), near Aiken, SC. The sampling was performed by Savannah River Remediation (SRR) LLC using a stratified random sampling plan with volume-proportional compositing. The plan consisted of partitioning the residual material on the floor of Tank 5 into three non-overlapping strata: two strata enclosed accumulations, and a third stratum consisted of a thin layer of material outside the regions of the two accumulations. Each of three composite samples was constructed from five primary sample locations of residual material on the floor of Tank 5. Three of the primary samples were obtained from the stratum containing the thin layer of material, and one primary sample was obtained from each of the two strata containing an accumulation. This report documents the statistical analyses of the analytical results for the composite samples. The objective of the analysis is to determine the mean concentrations and upper 95% confidence (UCL95) bounds for the mean concentrations for a set of analytes in the tank residuals. The statistical procedures employed in the analyses were consistent with the Environmental Protection Agency (EPA) technical guidance by Singh and others [2010]. Savannah River National Laboratory (SRNL) measured the sample bulk density, nonvolatile beta, gross alpha, and the radionuclide1, elemental, and chemical concentrations three times for each of the composite samples. The analyte concentration data were partitioned into three separate groups for further analysis: analytes with every measurement above their minimum detectable concentrations (MDCs), analytes with no measurements above their MDCs, and analytes with a mixture of some measurement results above and below their MDCs. The means, standard deviations, and UCL95s were computed for the analytes in the two groups that had at least some measurements

  3. STATISTICAL ANALYSIS OF TANK 5 FLOOR SAMPLE RESULTS

    SciTech Connect

    Shine, E.

    2012-03-14

    Sampling has been completed for the characterization of the residual material on the floor of Tank 5 in the F-Area Tank Farm at the Savannah River Site (SRS), near Aiken, SC. The sampling was performed by Savannah River Remediation (SRR) LLC using a stratified random sampling plan with volume-proportional compositing. The plan consisted of partitioning the residual material on the floor of Tank 5 into three non-overlapping strata: two strata enclosed accumulations, and a third stratum consisted of a thin layer of material outside the regions of the two accumulations. Each of three composite samples was constructed from five primary sample locations of residual material on the floor of Tank 5. Three of the primary samples were obtained from the stratum containing the thin layer of material, and one primary sample was obtained from each of the two strata containing an accumulation. This report documents the statistical analyses of the analytical results for the composite samples. The objective of the analysis is to determine the mean concentrations and upper 95% confidence (UCL95) bounds for the mean concentrations for a set of analytes in the tank residuals. The statistical procedures employed in the analyses were consistent with the Environmental Protection Agency (EPA) technical guidance by Singh and others [2010]. Savannah River National Laboratory (SRNL) measured the sample bulk density, nonvolatile beta, gross alpha, radionuclide, inorganic, and anion concentrations three times for each of the composite samples. The analyte concentration data were partitioned into three separate groups for further analysis: analytes with every measurement above their minimum detectable concentrations (MDCs), analytes with no measurements above their MDCs, and analytes with a mixture of some measurement results above and below their MDCs. The means, standard deviations, and UCL95s were computed for the analytes in the two groups that had at least some measurements above their

  4. Statistical Analysis Of Tank 5 Floor Sample Results

    SciTech Connect

    Shine, E. P.

    2012-08-01

    Sampling has been completed for the characterization of the residual material on the floor of Tank 5 in the F-Area Tank Farm at the Savannah River Site (SRS), near Aiken, SC. The sampling was performed by Savannah River Remediation (SRR) LLC using a stratified random sampling plan with volume-proportional compositing. The plan consisted of partitioning the residual material on the floor of Tank 5 into three non-overlapping strata: two strata enclosed accumulations, and a third stratum consisted of a thin layer of material outside the regions of the two accumulations. Each of three composite samples was constructed from five primary sample locations of residual material on the floor of Tank 5. Three of the primary samples were obtained from the stratum containing the thin layer of material, and one primary sample was obtained from each of the two strata containing an accumulation. This report documents the statistical analyses of the analytical results for the composite samples. The objective of the analysis is to determine the mean concentrations and upper 95% confidence (UCL95) bounds for the mean concentrations for a set of analytes in the tank residuals. The statistical procedures employed in the analyses were consistent with the Environmental Protection Agency (EPA) technical guidance by Singh and others [2010]. Savannah River National Laboratory (SRNL) measured the sample bulk density, nonvolatile beta, gross alpha, and the radionuclide, elemental, and chemical concentrations three times for each of the composite samples. The analyte concentration data were partitioned into three separate groups for further analysis: analytes with every measurement above their minimum detectable concentrations (MDCs), analytes with no measurements above their MDCs, and analytes with a mixture of some measurement results above and below their MDCs. The means, standard deviations, and UCL95s were computed for the analytes in the two groups that had at least some measurements

  5. Statistical methods for clinical verification of dose response parameters related to esophageal stricture and AVM obliteration from radiotherapy

    NASA Astrophysics Data System (ADS)

    Mavroidis, Panayiotis; Lind, Bengt K.; Theodorou, Kyriaki; Laurell, Göran; Fernberg, Jan-Olof; Lefkopoulos, Dimitrios; Kappas, Constantin; Brahme, Anders

    2004-08-01

    The purpose of this work is to provide some statistical methods for evaluating the predictive strength of radiobiological models and the validity of dose-response parameters for tumour control and normal tissue complications. This is accomplished by associating the expected complication rates, which are calculated using different models, with the clinical follow-up records. These methods are applied to 77 patients who received radiation treatment for head and neck cancer and 85 patients who were treated for arteriovenous malformation (AVM). The three-dimensional dose distribution delivered to esophagus and AVM nidus and the clinical follow-up results were available for each patient. Dose-response parameters derived by a maximum likelihood fitting were used as a reference to evaluate their compatibility with the examined treatment methodologies. The impact of the parameter uncertainties on the dose-response curves is demonstrated. The clinical utilization of the radiobiological parameters is illustrated. The radiobiological models (relative seriality and linear Poisson) and the reference parameters are validated to prove their suitability in reproducing the treatment outcome pattern of the patient material studied (through the probability of finding a worse fit, area under the ROC curve and khgr2 test). The analysis was carried out for the upper 5 cm of the esophagus (proximal esophagus) where all the strictures are formed, and the total volume of AVM. The estimated confidence intervals of the dose-response curves appear to have a significant supporting role on their clinical implementation and use.

  6. Statistics

    Cancer.gov

    Links to sources of cancer-related statistics, including the Surveillance, Epidemiology and End Results (SEER) Program, SEER-Medicare datasets, cancer survivor prevalence data, and the Cancer Trends Progress Report.

  7. Austrian results from Matroshka poncho and organ dose determination

    NASA Astrophysics Data System (ADS)

    Hajek, M.; Bergmann, R.; Fugger, M.; Vana, N.

    Cosmic rays in low-earth orbits LEO primarily consist of high-energy charged particles originating from galactic cosmic radiation GCR energetic solar particle events SPE and trapped radiation belts These radiations of high linear energy transfer LET generally inflict greater biological damage than that resulting from typical terrestrial radiation hazards Particle and energy spectra are attenuated in interaction processes within shielding structures and within the human body Reliable assessment of health risks to astronaut crews is pivotal in the design of future expeditions into interplanetary space and requires knowledge of absorbed radiation doses in critical radiosensitive organs and tissues The European Space Agency ESA Matroshka experiment---conducted under the aegis of the German Aerospace Center DLR ---is aimed at simulating an astronaut s body during extravehicular activities EVA Matroshka basically consists of a human phantom torso attached to a base structure and covered with a protective carbon-fibre container acting as a spacesuit model The phantom is divided into 33 tissue-equivalent polyurethane slices of specific density for tissue and organs Natural bones are embedded Channels and cut-outs enable accommodation of active and passive radiation monitors The torso is dressed by a skin-equivalent poncho which is also designed for dosimeter integration The phantom houses in total 7 active and more than 6000 passive radiation sensors Thereof the Atomic Institute of the Austrian Universities ATI provided more than

  8. Patient-specific minimum-dose imaging protocols for statistical image reconstruction in C-arm cone-beam CT using correlated noise injection

    NASA Astrophysics Data System (ADS)

    Wang, A. S.; Stayman, J. W.; Otake, Y.; Khanna, A. J.; Gallia, G. L.; Siewerdsen, J. H.

    2014-03-01

    Purpose: A new method for accurately portraying the impact of low-dose imaging techniques in C-arm cone-beam CT (CBCT) is presented and validated, allowing identification of minimum-dose protocols suitable to a given imaging task on a patient-specific basis in scenarios that require repeat intraoperative scans. Method: To accurately simulate lower-dose techniques and account for object-dependent noise levels (x-ray quantum noise and detector electronics noise) and correlations (detector blur), noise of the proper magnitude and correlation was injected into the projections from an initial CBCT acquired at the beginning of a procedure. The resulting noisy projections were then reconstructed to yield low-dose preview (LDP) images that accurately depict the image quality at any level of reduced dose in both filtered backprojection and statistical image reconstruction. Validation studies were conducted on a mobile C-arm, with the noise injection method applied to images of an anthropomorphic head phantom and cadaveric torso across a range of lower-dose techniques. Results: Comparison of preview and real CBCT images across a full range of techniques demonstrated accurate noise magnitude (within ~5%) and correlation (matching noise-power spectrum, NPS). Other image quality characteristics (e.g., spatial resolution, contrast, and artifacts associated with beam hardening and scatter) were also realistically presented at all levels of dose and across reconstruction methods, including statistical reconstruction. Conclusion: Generating low-dose preview images for a broad range of protocols gives a useful method to select minimum-dose techniques that accounts for complex factors of imaging task, patient-specific anatomy, and observer preference. The ability to accurately simulate the influence of low-dose acquisition in statistical reconstruction provides an especially valuable means of identifying low-dose limits in a manner that does not rely on a model for the nonlinear

  9. Fewer doses of HPV vaccine result in immune response similar to three-dose regimen | Division of Cancer Prevention

    Cancer.gov

    NCI scientists report that two doses of a human papillomavirus (HPV) vaccine, trademarked as Cervarix, resulted in similar serum antibody levels against two of the most carcinogenic types of HPV (16 and 18), compared to a standard three dose regimen. Among women who received only one dose, antibody levels were also high and remained stable four years after vaccination. The results suggest that fewer doses of an HPV vaccine may confer necessary long-term protection against new infection and appeared Nov. 4, 2013, in Cancer Prevention Research... |

  10. Rigorous results of nonequilibrium statistical physics and their experimental verification

    NASA Astrophysics Data System (ADS)

    Pitaevskii, Lev P.

    2011-06-01

    Rigorous relations of nonequilibrium statistical physics are discussed. An arbitrary system brought into a strongly nonequilibrium state by an external time-dependent impact is considered. Based on the Hamiltonian formalism of classical mechanics, the Bochkov-Kuzovlev equality, the Jarzynski equality, and Crooks reversal relations valid for fluctuations in the work done on a system are derived. Verification of these equalities in mechanical experiments with a torsion pendulum and biological objects (folded ribonucleic acids) is described.

  11. Cryptosporidium Infection Risk: Results of New Dose-Response Modeling.

    PubMed

    Messner, Michael J; Berger, Philip

    2016-10-01

    Cryptosporidium human dose-response data from seven species/isolates are used to investigate six models of varying complexity that estimate infection probability as a function of dose. Previous models attempt to explicitly account for virulence differences among C. parvum isolates, using three or six species/isolates. Four (two new) models assume species/isolate differences are insignificant and three of these (all but exponential) allow for variable human susceptibility. These three human-focused models (fractional Poisson, exponential with immunity and beta-Poisson) are relatively simple yet fit the data significantly better than the more complex isolate-focused models. Among these three, the one-parameter fractional Poisson model is the simplest but assumes that all Cryptosporidium oocysts used in the studies were capable of initiating infection. The exponential with immunity model does not require such an assumption and includes the fractional Poisson as a special case. The fractional Poisson model is an upper bound of the exponential with immunity model and applies when all oocysts are capable of initiating infection. The beta Poisson model does not allow an immune human subpopulation; thus infection probability approaches 100% as dose becomes huge. All three of these models predict significantly (>10x) greater risk at the low doses that consumers might receive if exposed through drinking water or other environmental exposure (e.g., 72% vs. 4% infection probability for a one oocyst dose) than previously predicted. This new insight into Cryptosporidium risk suggests additional inactivation and removal via treatment may be needed to meet any specified risk target, such as a suggested 10(-4) annual risk of Cryptosporidium infection.

  12. Imprecision in predicted dose from /sup 137/Cs resulting from biological variability

    SciTech Connect

    Dunning, D.E. Jr.; Schwarz, G.

    1981-01-01

    The variability of observed values of human metabolic and physiological characteristics which influence estimates of dose from ingestion of a unit of Cesium-137 activity, and the subsequent predicted total-body dose commitment is analyzed. The analysis is based on extensive literature review and statistical comparison of parameter variability, correlation and reliability. (PSB)

  13. Comparison between Pre-log and Post-log Statistical Models in Ultra-Low-Dose CT Reconstruction.

    PubMed

    Fu, Lin; Lee, Tzu-Cheng; Kim, Soo Mee; Alessio, Adam; Kinahan, Paul; Chang, Zhiqian; Sauer, Ken; Kalra, Mannudeep; De Man, Bruno

    2016-11-09

    X-ray detectors in clinical computed tomography (CT) usually operate in current-integrating mode. Their complicated signal statistics often lead to intractable likelihood functions for practical use in model-based image reconstruction (MBIR). It is therefore desirable to design simplified statistical models without losing the essential factors. Depending on whether the CT transmission data are logarithmically transformed, pre-log and post-log models are two major categories of choices in CT MBIR. Both being approximations, it remains an open question whether one model can notably improve image quality over the other on real scanners. In this study, we develop and compare several pre-log and post-log MBIR algorithms under a unified framework. Their reconstruction accuracy based on simulation and clinical datasets are evaluated. The results show that pre-log MBIR can achieve notably better quantitative accuracy than post-log MBIR in ultra-low-dose CT, although in less extreme cases, post-log MBIR with handcrafted pre-processing remains a competitive alternative. Pre-log MBIR could play a growing role in emerging ultra-low-dose CT applications.

  14. Statistical microeconomics and commodity prices: theory and empirical results.

    PubMed

    Baaquie, Belal E

    2016-01-13

    A review is made of the statistical generalization of microeconomics by Baaquie (Baaquie 2013 Phys. A 392, 4400-4416. (doi:10.1016/j.physa.2013.05.008)), where the market price of every traded commodity, at each instant of time, is considered to be an independent random variable. The dynamics of commodity market prices is given by the unequal time correlation function and is modelled by the Feynman path integral based on an action functional. The correlation functions of the model are defined using the path integral. The existence of the action functional for commodity prices that was postulated to exist in Baaquie (Baaquie 2013 Phys. A 392, 4400-4416. (doi:10.1016/j.physa.2013.05.008)) has been empirically ascertained in Baaquie et al. (Baaquie et al. 2015 Phys. A 428, 19-37. (doi:10.1016/j.physa.2015.02.030)). The model's action functionals for different commodities has been empirically determined and calibrated using the unequal time correlation functions of the market commodity prices using a perturbation expansion (Baaquie et al. 2015 Phys. A 428, 19-37. (doi:10.1016/j.physa.2015.02.030)). Nine commodities drawn from the energy, metal and grain sectors are empirically studied and their auto-correlation for up to 300 days is described by the model to an accuracy of R(2)>0.90-using only six parameters.

  15. Bronchoscopic phototherapy at comparable dose rates: Early results

    SciTech Connect

    Pass, H.I.; Delaney, T.; Smith, P.D.; Bonner, R.; Russo, A.

    1989-05-01

    Photodynamic therapy is a recently introduced treatment for surface malignancies. Since January 1987, 10 patients with endobronchial neoplasms have had bronchoscopic photodynamic therapy at similar dose rates (400 mW/cm) for total atelectasis (2), carinal narrowing with respiratory insufficiency (2), or partial obstruction without collapse (4). Two patients underwent photodynamic therapy as a preliminary to immunotherapy. Histologies included endobronchial metastases (colon, ovary, melanoma, and sarcoma, 1 each; and renal cell, 3) and primary lung cancer (3). The 2 patients with total atelectasis had complete reexpansion after photodynamic therapy, which permitted eventual sleeve lobectomy in 1. Carinal narrowing was ameliorated in the 2 patients seen with inspiratory stridor, thereby permitting hospital discharge. Endoscopically resected fragments after photodynamic therapy exhibited avascular necrosis. These data support further controlled studies of photodynamic therapy by thoracic surgical oncologists to define its limitations as well as to improve and expand its efficacy as a palliative or surgical adjuvant.

  16. SU-E-I-86: Ultra-Low Dose Computed Tomography Attenuation Correction for Pediatric PET CT Using Adaptive Statistical Iterative Reconstruction (ASiR™)

    SciTech Connect

    Brady, S; Shulkin, B

    2015-06-15

    Purpose: To develop ultra-low dose computed tomography (CT) attenuation correction (CTAC) acquisition protocols for pediatric positron emission tomography CT (PET CT). Methods: A GE Discovery 690 PET CT hybrid scanner was used to investigate the change to quantitative PET and CT measurements when operated at ultra-low doses (10–35 mAs). CT quantitation: noise, low-contrast resolution, and CT numbers for eleven tissue substitutes were analyzed in-phantom. CT quantitation was analyzed to a reduction of 90% CTDIvol (0.39/3.64; mGy) radiation dose from baseline. To minimize noise infiltration, 100% adaptive statistical iterative reconstruction (ASiR) was used for CT reconstruction. PET images were reconstructed with the lower-dose CTAC iterations and analyzed for: maximum body weight standardized uptake value (SUVbw) of various diameter targets (range 8–37 mm), background uniformity, and spatial resolution. Radiation organ dose, as derived from patient exam size specific dose estimate (SSDE), was converted to effective dose using the standard ICRP report 103 method. Effective dose and CTAC noise magnitude were compared for 140 patient examinations (76 post-ASiR implementation) to determine relative patient population dose reduction and noise control. Results: CT numbers were constant to within 10% from the non-dose reduced CTAC image down to 90% dose reduction. No change in SUVbw, background percent uniformity, or spatial resolution for PET images reconstructed with CTAC protocols reconstructed with ASiR and down to 90% dose reduction. Patient population effective dose analysis demonstrated relative CTAC dose reductions between 62%–86% (3.2/8.3−0.9/6.2; mSv). Noise magnitude in dose-reduced patient images increased but was not statistically different from pre dose-reduced patient images. Conclusion: Using ASiR allowed for aggressive reduction in CTAC dose with no change in PET reconstructed images while maintaining sufficient image quality for co

  17. SU-F-BRB-10: A Statistical Voxel Based Normal Organ Dose Prediction Model for Coplanar and Non-Coplanar Prostate Radiotherapy

    SciTech Connect

    Tran, A; Yu, V; Nguyen, D; Woods, K; Low, D; Sheng, K

    2015-06-15

    Purpose: Knowledge learned from previous plans can be used to guide future treatment planning. Existing knowledge-based treatment planning methods study the correlation between organ geometry and dose volume histogram (DVH), which is a lossy representation of the complete dose distribution. A statistical voxel dose learning (SVDL) model was developed that includes the complete dose volume information. Its accuracy of predicting volumetric-modulated arc therapy (VMAT) and non-coplanar 4π radiotherapy was quantified. SVDL provided more isotropic dose gradients and may improve knowledge-based planning. Methods: 12 prostate SBRT patients originally treated using two full-arc VMAT techniques were re-planned with 4π using 20 intensity-modulated non-coplanar fields to a prescription dose of 40 Gy. The bladder and rectum voxels were binned based on their distances to the PTV. The dose distribution in each bin was resampled by convolving to a Gaussian kernel, resulting in 1000 data points in each bin that predicted the statistical dose information of a voxel with unknown dose in a new patient without triaging information that may be collectively important to a particular patient. We used this method to predict the DVHs, mean and max doses in a leave-one-out cross validation (LOOCV) test and compared its performance against lossy estimators including mean, median, mode, Poisson and Rayleigh of the voxelized dose distributions. Results: SVDL predicted the bladder and rectum doses more accurately than other estimators, giving mean percentile errors ranging from 13.35–19.46%, 4.81–19.47%, 22.49–28.69%, 23.35–30.5%, 21.05–53.93% for predicting mean, max dose, V20, V35, and V40 respectively, to OARs in both planning techniques. The prediction errors were generally lower for 4π than VMAT. Conclusion: By employing all dose volume information in the SVDL model, the OAR doses were more accurately predicted. 4π plans are better suited for knowledge-based planning than

  18. Explanation of Two Anomalous Results in Statistical Mediation Analysis

    ERIC Educational Resources Information Center

    Fritz, Matthew S.; Taylor, Aaron B.; MacKinnon, David P.

    2012-01-01

    Previous studies of different methods of testing mediation models have consistently found two anomalous results. The first result is elevated Type I error rates for the bias-corrected and accelerated bias-corrected bootstrap tests not found in nonresampling tests or in resampling tests that did not include a bias correction. This is of special…

  19. Monte Carlo dose calculations and radiobiological modelling: analysis of the effect of the statistical noise of the dose distribution on the probability of tumour control.

    PubMed

    Buffa, F M; Nahum, A E

    2000-10-01

    The aim of this work is to investigate the influence of the statistical fluctuations of Monte Carlo (MC) dose distributions on the dose volume histograms (DVHs) and radiobiological models, in particular the Poisson model for tumour control probability (tcp). The MC matrix is characterized by a mean dose in each scoring voxel, d, and a statistical error on the mean dose, sigma(d); whilst the quantities d and sigma(d) depend on many statistical and physical parameters, here we consider only their dependence on the phantom voxel size and the number of histories from the radiation source. Dose distributions from high-energy photon beams have been analysed. It has been found that the DVH broadens when increasing the statistical noise of the dose distribution, and the tcp calculation systematically underestimates the real tumour control value, defined here as the value of tumour control when the statistical error of the dose distribution tends to zero. When increasing the number of energy deposition events, either by increasing the voxel dimensions or increasing the number of histories from the source, the DVH broadening decreases and tcp converges to the 'correct' value. It is shown that the underestimation of the tcp due to the noise in the dose distribution depends on the degree of heterogeneity of the radiobiological parameters over the population; in particular this error decreases with increasing the biological heterogeneity, whereas it becomes significant in the hypothesis of a radiosensitivity assay for single patients, or for subgroups of patients. It has been found, for example, that when the voxel dimension is changed from a cube with sides of 0.5 cm to a cube with sides of 0.25 cm (with a fixed number of histories of 10(8) from the source), the systematic error in the tcp calculation is about 75% in the homogeneous hypothesis, and it decreases to a minimum value of about 15% in a case of high radiobiological heterogeneity. The possibility of using the error

  20. Statistical Differences in Time-Distance Helioseismology Results

    NASA Astrophysics Data System (ADS)

    Hess Webber, Shea A.; Pesnell, William D.; Duvall, Thomas; Cameron, Robert; Birch, A. C.

    2016-05-01

    Time-distance helioseismology studies phase correlations in solar wave modes. We use these techniques to investigate the phase differences in f-mode wave propagation within a coronal hole feature and without. We isolate the coronal hole boundary location using edge detection techniques on SDO AIA data. We then use this location information to inform the analysis of the corresponding HMI time-distance velocity tracked data product, provided by Stanford's JSOC archive. We look at time-distance results inside the coronal hole, outside the coronal hole, the coronal hole data as a whole, and an independent quiet sun region. We use Student's t-Test to evaluate the significance of the differences between the various regions.

  1. Examining the Statistical Rigor of Test and Evaluation Results in the Live, Virtual and Constructive Environment

    DTIC Science & Technology

    2011-06-01

    exercise events do not necessarily require statistically defendable results. In an OT&E experiment, the results may often require statistical rigor...EXAMINING THE STATISTICAL RIGOR OF TEST AND EVALUATION RESULTS IN THE LIVE, VIRTUAL AND CONSTRUCTIVE...Department of Defense, or the U.S. Government. AFIT/IOA/ENS/11-06 EXAMINING THE STATISTICAL RIGOR OF TEST AND EVALUATION RESULTS IN THE LIVE, VIRTUAL

  2. Dose-response relationships and extrapolation in toxicology - Mechanistic and statistical considerations

    EPA Science Inventory

    Controversy on toxicological dose-response relationships and low-dose extrapolation of respective risks is often the consequence of misleading data presentation, lack of differentiation between types of response variables, and diverging mechanistic interpretation. In this chapter...

  3. Statistical analysis plan for evaluating low‐ vs. standard‐dose alteplase in the ENhanced Control of Hypertension and Thrombolysis strokE stuDy (ENCHANTED)

    PubMed Central

    Woodward, Mark; Arima, Hisatomi; Chen, Xiaoying; Lindley, Richard I.; Wang, Xia; Chalmers, John

    2015-01-01

    Background The ENhanced Control of Hypertension And Thrombolysis strokE stuDy trial is a 2 × 2 quasi‐factorial active‐comparison, prospective, randomized, open, blinded endpoint clinical trial that is evaluating in thrombolysis‐eligible acute ischemic stroke patients whether: (1) low‐dose (0·6 mg/kg body weight) intravenous alteplase has noninferior efficacy and lower risk of symptomatic intracerebral hemorrhage compared with standard‐dose (0·9 mg/kg body weight) intravenous alteplase; and (2) early intensive blood pressure lowering (systolic target 130–140 mmHg) has superior efficacy and lower risk of any intracerebral hemorrhage compared with guideline‐recommended blood pressure control (systolic target <180 mmHg). Objective To outline in detail the predetermined statistical analysis plan for the ‘alteplase dose arm’ of the study. Methods All data collected by participating researchers will be reviewed and formally assessed. Information pertaining to the baseline characteristics of patients, their process of care, and the delivery of treatments will be classified, and for each item, appropriate descriptive statistical analyses are planned with appropriate comparisons made between randomized groups. For the trial outcomes, the most appropriate statistical comparisons to be made between groups are planned and described. Results A statistical analysis plan was developed for the results of the alteplase dose arm of the study that is transparent, available to the public, verifiable, and predetermined before completion of data collection. Conclusions We have developed a predetermined statistical analysis plan for the ENhanced Control of Hypertension And Thrombolysis strokE stuDy alteplase dose arm which is to be followed to avoid analysis bias arising from prior knowledge of the study findings. PMID:26283139

  4. An empirical approach to sufficient similarity in dose-responsiveness: Utilization of statistical distance as a similarity measure.

    EPA Science Inventory

    Using statistical equivalence testing logic and mixed model theory an approach has been developed, that extends the work of Stork et al (JABES,2008), to define sufficient similarity in dose-response for chemical mixtures containing the same chemicals with different ratios ...

  5. Total Ionizing Dose Results and Displacement Damage Results for Candidate Spacecraft Electronics for NASA

    NASA Technical Reports Server (NTRS)

    Cochran, Donna J.; Kniffin, Scott D.; LaBel, Kenneth A.; OBryan, Martha V.; Reed, Robert A.; Ladbury, Ray L.; Howard, James W., Jr.; Poivey, Christian; Buchner, Stephen P.; Marshall, Cheryl J.

    2003-01-01

    We present data on the vulnerability of a variety of candidate spacecraft electronics to total ionizing dose and displacement damage. Devices tested include optoelectronics, digital, analog, linear bipolar devices, hybrid devices, Analog-to-Digital Converters (ADCs), and Digital-to-Analog Converters (DACs), among others.

  6. Current Total Ionizing Dose Results and Displacement Damage Results for Candidate Spacecraft Electronics for NASA

    NASA Technical Reports Server (NTRS)

    Cochran, Donna J.; Kniffin, Scott D.; LaBel, Kenneth A.; OBryan, Martha V.; Reed, Robert A.; Ladbury, Ray L.; Howard, James W., Jr.; Poivey, Christian; Buchner, Stephen P.; Marshall, Cheryl J.

    2004-01-01

    We present data on the vulnerability of a variety of candidate spacecraft electronics to total ionizing dose and displacement damage. Devices tested include optoelectronics, digital, analog, linear bipolar devices, hybrid devices, Analog-to-Digital Converters (ADCs), and Digital-to-Analog Converters (DACS), among others.

  7. Recent Total Ionizing Dose Results and Displacement Damage Results for Candidate Spacecraft Electronics for NASA

    NASA Technical Reports Server (NTRS)

    Cochran, Donna J.; Buchner, Stephen P.; Irwin, Tim L.; LaBel, Kenneth A.; Marshall, Cheryl J.; Reed, Robert A.; Sanders, Anthony B.; Hawkins, Donald K.; Flanigan, Ryan J.; Cox, Stephen R.

    2005-01-01

    We present data on the vulnerability of a variety of candidate spacecraft electronics to total ionizing dose and displacement damage. Devices tested include optoelectronics, digital, analog, linear bipolar devices, hybrid devices, Analog-to- Digital Converters (ADCs), and Digital-to-Analog Converters (DACs), among others. T

  8. Recommendations for describing statistical studies and results in general readership science and engineering journals.

    PubMed

    Gardenier, John S

    2012-12-01

    This paper recommends how authors of statistical studies can communicate to general audiences fully, clearly, and comfortably. The studies may use statistical methods to explore issues in science, engineering, and society or they may address issues in statistics specifically. In either case, readers without explicit statistical training should have no problem understanding the issues, the methods, or the results at a non-technical level. The arguments for those results should be clear, logical, and persuasive. This paper also provides advice for editors of general journals on selecting high quality statistical articles without the need for exceptional work or expense. Finally, readers are also advised to watch out for some common errors or misuses of statistics that can be detected without a technical statistical background.

  9. A method of estimating conceptus doses resulting from multidetector CT examinations during all stages of gestation

    SciTech Connect

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

    2010-12-15

    Purpose: Current methods for the estimation of conceptus dose from multidetector CT (MDCT) examinations performed on the mother provide dose data for typical protocols with a fixed scan length. However, modified low-dose imaging protocols are frequently used during pregnancy. The purpose of the current study was to develop a method for the estimation of conceptus dose from any MDCT examination of the trunk performed during all stages of gestation. Methods: The Monte Carlo N-Particle (MCNP) radiation transport code was employed in this study to model the Siemens Sensation 16 and Sensation 64 MDCT scanners. Four mathematical phantoms were used, simulating women at 0, 3, 6, and 9 months of gestation. The contribution to the conceptus dose from single simulated scans was obtained at various positions across the phantoms. To investigate the effect of maternal body size and conceptus depth on conceptus dose, phantoms of different sizes were produced by adding layers of adipose tissue around the trunk of the mathematical phantoms. To verify MCNP results, conceptus dose measurements were carried out by means of three physical anthropomorphic phantoms, simulating pregnancy at 0, 3, and 6 months of gestation and thermoluminescence dosimetry (TLD) crystals. Results: The results consist of Monte Carlo-generated normalized conceptus dose coefficients for single scans across the four mathematical phantoms. These coefficients were defined as the conceptus dose contribution from a single scan divided by the CTDI free-in-air measured with identical scanning parameters. Data have been produced to take into account the effect of maternal body size and conceptus position variations on conceptus dose. Conceptus doses measured with TLD crystals showed a difference of up to 19% compared to those estimated by mathematical simulations. Conclusions: Estimation of conceptus doses from MDCT examinations of the trunk performed on pregnant patients during all stages of gestation can be made

  10. Crop identification technology assessment for remote sensing. (CITARS) Volume 9: Statistical analysis of results

    NASA Technical Reports Server (NTRS)

    Davis, B. J.; Feiveson, A. H.

    1975-01-01

    Results are presented of CITARS data processing in raw form. Tables of descriptive statistics are given along with descriptions and results of inferential analyses. The inferential results are organized by questions which CITARS was designed to answer.

  11. Can use of adaptive statistical iterative reconstruction reduce radiation dose in unenhanced head CT? An analysis of qualitative and quantitative image quality

    PubMed Central

    Heggen, Kristin Livelten; Pedersen, Hans Kristian; Andersen, Hilde Kjernlie; Martinsen, Anne Catrine T

    2016-01-01

    Background Iterative reconstruction can reduce image noise and thereby facilitate dose reduction. Purpose To evaluate qualitative and quantitative image quality for full dose and dose reduced head computed tomography (CT) protocols reconstructed using filtered back projection (FBP) and adaptive statistical iterative reconstruction (ASIR). Material and Methods Fourteen patients undergoing follow-up head CT were included. All patients underwent full dose (FD) exam and subsequent 15% dose reduced (DR) exam, reconstructed using FBP and 30% ASIR. Qualitative image quality was assessed using visual grading characteristics. Quantitative image quality was assessed using ROI measurements in cerebrospinal fluid (CSF), white matter, peripheral and central gray matter. Additionally, quantitative image quality was measured in Catphan and vendor’s water phantom. Results There was no significant difference in qualitative image quality between FD FBP and DR ASIR. Comparing same scan FBP versus ASIR, a noise reduction of 28.6% in CSF and between −3.7 and 3.5% in brain parenchyma was observed. Comparing FD FBP versus DR ASIR, a noise reduction of 25.7% in CSF, and −7.5 and 6.3% in brain parenchyma was observed. Image contrast increased in ASIR reconstructions. Contrast-to-noise ratio was improved in DR ASIR compared to FD FBP. In phantoms, noise reduction was in the range of 3 to 28% with image content. Conclusion There was no significant difference in qualitative image quality between full dose FBP and dose reduced ASIR. CNR improved in DR ASIR compared to FD FBP mostly due to increased contrast, not reduced noise. Therefore, we recommend using caution if reducing dose and applying ASIR to maintain image quality. PMID:27583169

  12. Application of a statistical software package for analysis of large patient dose data sets obtained from RIS.

    PubMed

    Fazakerley, J; Charnock, P; Wilde, R; Jones, R; Ward, M

    2010-01-01

    For the purpose of patient dose audit, clinical audit and radiology workload analysis, data from Radiology Information Systems (RIS) at many hospitals are collected using a database and the analysis was automated using a statistical package and Visual Basic coding. The database is a Structured Query Language database, which can be queried using an off-the-shelf statistical package, Statistica. Macros were created to automatically format the data to a consistent format between different hospitals ready for analysis. These macros can also be used to automate further analysis such as detailing mean kV, mAs and entrance surface dose per room and per gender. Standard deviation and standard error of the mean are also generated. Graphs can also be generated to illustrate the trends in doses between different variables such as room and gender. Collectively, this information can be used to generate a report. A process that once could take up to 1 d to complete now takes around 1 h. A major benefit in providing the service to hospital trusts is that less resource is now required to report on RIS data, making the possibility of continuous dose audit more likely. Time that was spent on sorting through data can now be spent on improving the analysis to provide benefit to the customer. Using data sets from RIS is a good way to perform dose audits as the huge numbers of data available provide the bases for very accurate analysis. Using macros written in Statistica Visual Basic has helped sort and consistently analyse these data. Being able to analyse by exposure factors has provided a more detailed report to the customer.

  13. Patient doses in CT examinations in 18 countries: initial results from International Atomic Energy Agency projects.

    PubMed

    Muhogora, W E; Ahmed, N A; Beganovic, A; Benider, A; Ciraj-Bjelac, O; Gershan, V; Gershkevitsh, E; Grupetta, E; Kharita, M H; Manatrakul, N; Milakovic, M; Ohno, K; Ben Omrane, L; Ptacek, J; Schandorf, C; Shabaan, M S; Stoyanov, D; Toutaoui, N; Wambani, J S; Rehani, M M

    2009-09-01

    The purpose of this prospective study at 73 facilities in 18 countries in Africa, Asia and Eastern Europe was to investigate if the CT doses to adult patients in developing countries are higher than international standards. The dose assessment was performed in terms of weighted computed tomography dose index (CTDIw) and dose length product (DLP) for chest, chest (high resolution), lumbar spine, abdomen and pelvis CT examinations using standard methods. Except in one case, the mean CTDIw values were below diagnostic reference level (DRL) while for DLP, 17 % of situations were above DRLs. The resulting CT images were of adequate quality for diagnosis. The CTDIw and DLP data presented herein are largely similar to those from two recent national surveys. The study has shown a stronger need to create awareness and training of radiology personnel as well as monitoring of radiation doses in many developing countries so as to conform to the ALARA principle.

  14. Calculating the peak skin dose resulting from fluoroscopically guided interventions. Part I: Methods.

    PubMed

    Jones, A Kyle; Pasciak, Alexander S

    2011-11-15

    While direct measurement of the peak skin dose resulting from a fluoroscopically-guided procedure is possible, the decision must be made a priori at additional cost and time. It is most often the case that the need for accurate knowledge of the peak skin dose is realized only after a procedure has been completed, or after a suspected reaction has been discovered. Part I of this review article discusses methods for calculating the peak skin dose across a range of clinical scenarios. In some cases, a wealth of data are available, while in other cases few data are available and additional data must be measured in order to estimate the peak skin dose. Data may be gathered from a dose report, the DICOM headers of images, or from staff and physician interviews. After data are gathered, specific steps must be followed to convert dose metrics, such as the reference point air kerma (K(a,r)) or the kerma area product (KAP), into peak skin dose. These steps require knowledge of other related factors, such as the f-factor and the backscatter factor, tables of which are provided in this manuscript. Sources of error and the impact of these errors on the accuracy of the final estimate of the peak skin dose are discussed.

  15. Test Results of Total Ionizing Dose Conducted at the Jet Propulsion Laboratory

    NASA Technical Reports Server (NTRS)

    Rivas, Rosa M.; Johnston, Allan H.; Miyahira, Tetsuo F.; Rax, Bernard G.; Wiedeman, Michael D.

    2004-01-01

    This paper reports recent Total Ionizing Dose (TID) test results obtained at JPL. Several device samples were analyzed exhibiting significant failure levels and ELDRS effects under biased and unbiased condition.

  16. Dosimetric study of the effective doses resulting during dental X-ray and panoramic radiography

    NASA Astrophysics Data System (ADS)

    Shousha, Hany A.; Abd-El Hafez, A. I.; Ahmad, Fawzia

    2011-01-01

    The panoramic image is one of the most commonly used radiographic examinations in dentistry, owing to its low dose and large area for evaluation, including bone and teeth in the same image. Although digital images are usually reported to deliver a lower radiation dose to the patient, conventional images are still available, especially in countries where digital systems are not widely economically available. Dentists should weigh the benefits of dental radiographs against the consequences of increasing a patient's exposure to radiation, the effects of which accumulate from multiple sources over time. The "as low as reasonably achievable" principle should be followed to minimize the exposure to radiation. The purpose of this investigation is to measure the absorbed radiation doses at 12 anatomical sites of a Rando-phantom and calculate the effective doses result from a full-mouth survey and panoramic radiography. Organ-absorbed doses are measured using thermoluminescent dosimeters (TLD 100) and effective organ doses (μ Sv) are estimated according to the International Commission on Radiological Protection in 2007. The total effective dose results from the panoramic imaging system have so far been below those obtained using the full-mouth survey technique used in intra-oral radiographic examination.

  17. Radiological environmental dose assessment methods and compliance dose results for 2015 operations at the Savannah River Site

    SciTech Connect

    Jannik, G. T.; Dixon, K. L.

    2016-09-01

    This report presents the environmental dose assessment methods and the estimated potential doses to the offsite public from 2015 Savannah River Site (SRS) atmospheric and liquid radioactive releases. Also documented are potential doses from special-case exposure scenarios - such as the consumption of deer meat, fish, and goat milk.

  18. A survey of patient doses from conventional diagnostic radiology examinations: first results from Serbia and Montenegro.

    PubMed

    Ciraj, Olivera; Kosutic, Dusko; Kovacevic, Milojko; Markovic, Srpko

    Diagnostic reference levels provide framework to reduce variability. The aim of this study is to establish, for the first time, a baseline for national diagnostic reference levels in Serbia and Montenegro for the most common X-ray examination types. Measurements of patient dose using kerma-area product meter and entrance surface air kerma assessment were performed on at least ten patients for each examination type, in each of 16 randomly selected hospitals in Serbia and Montenegro, so that a total of 3,026 procedures for nine different examination categories were included in the survey. Exposure settings and individual data were recorded for each patient. Mean, median and third quartile values of patient doses are reported. Results have shown wide variation of mean hospital doses, with factor of four for barium enema to 23 for thoracic spine radiography. Entrance surface air kerma were compared with previously published diagnostic reference levels (DRL) proposed by Commission of European Communities (CEC). Doses for all studied examination types except chest radiography were within European DRL. The reasons for dose variation are discussed. Survey data are aimed to help in development of an on-going national quality assurance and quality control programme in diagnostic radiology. The findings emphasize the importance of regular patient dose measurement to ensure that patient doses are kept as low as reasonable achievable.

  19. A Bayesian analysis of uncertainties on lung doses resulting from occupational exposures to uranium.

    PubMed

    Puncher, M; Birchall, A; Bull, R K

    2013-09-01

    In a recent epidemiological study, Bayesian estimates of lung doses were calculated in order to determine a possible association between lung dose and lung cancer incidence resulting from occupational exposures to uranium. These calculations, which produce probability distributions of doses, used the human respiratory tract model (HRTM) published by the International Commission on Radiological Protection (ICRP) with a revised particle transport clearance model. In addition to the Bayesian analyses, point estimates (PEs) of doses were also provided for that study using the existing HRTM as it is described in ICRP Publication 66. The PEs are to be used in a preliminary analysis of risk. To explain the differences between the PEs and Bayesian analysis, in this paper the methodology was applied to former UK nuclear workers who constituted a subset of the study cohort. The resulting probability distributions of lung doses calculated using the Bayesian methodology were compared with the PEs obtained for each worker. Mean posterior lung doses were on average 8-fold higher than PEs and the uncertainties on doses varied over a wide range, being greater than two orders of magnitude for some lung tissues. It is shown that it is the prior distributions of the parameters describing absorption from the lungs to blood that are responsible for the large difference between posterior mean doses and PEs. Furthermore, it is the large prior uncertainties on these parameters that are mainly responsible for the large uncertainties on lung doses. It is concluded that accurate determination of the chemical form of inhaled uranium, as well as the absorption parameter values for these materials, is important for obtaining unbiased estimates of lung doses from occupational exposures to uranium for epidemiological studies. Finally, it should be noted that the inferences regarding the PEs described here apply only to the assessments of cases provided for the epidemiological study, where central

  20. Up-dosing with bilastine results in improved effectiveness in cold contact urticaria

    PubMed Central

    Krause, K; Spohr, A; Zuberbier, T; Church, M K; Maurer, M

    2013-01-01

    Background Cold contact urticaria (CCU) is characterized by itchy wheal and flare responses due to the release of histamine and other pro-inflammatory mediators after exposure to cold. The treatment of choice is nonsedating antihistamines, dosages of which may be increased up to fourfold if standard doses are ineffective. Here, we assess the effects of a standard 20 mg dose and up-dosing to 40 and 80 mg of bilastine in reducing the symptoms of CCU and inflammatory mediator release following cold challenge. Methods Twenty patients with CCU were included in this randomized, crossover, double-blind, placebo-controlled 12-week study. They received placebo, 20, 40 or 80 mg of bilastine daily each for 7 days with 14-day washout periods. The primary readout was change in critical temperature thresholds (CTT). Secondary readouts were changes in pruritus, levels of histamine IL-6, IL-8 and TNF-α collected by skin microdialysis and safety and tolerability of bilastine. Results Bilastine 20 mg was highly effective (P < 0.0001) in reducing CTT. Up-dosing to 80 mg significantly (P < 0.04) increased its effectiveness. At this dose, 19 of 20 (95%) patients responded to treatment, with 12 of 20 (60%) becoming symptom free. Only one patient was refractory to treatment. Microdialysis levels of histamine, IL-6 and IL-8 assessed 1–3 h after cold challenge were significantly (P < 0.05) decreased following up-dosing with 80 mg bilastine. Bilastine treat-ment was well tolerated without evidence of increased sedation with dose escala-tion. Conclusions Bilastine was effective in reducing the symptoms of patients with CCU. Increased efficacy of bilastine with fourfold up-dosing was without sedation and supports urticaria treatment guidelines. PMID:23742030

  1. A graphical user interface (GUI) toolkit for the calculation of three-dimensional (3D) multi-phase biological effective dose (BED) distributions including statistical analyses.

    PubMed

    Kauweloa, Kevin I; Gutierrez, Alonso N; Stathakis, Sotirios; Papanikolaou, Niko; Mavroidis, Panayiotis

    2016-07-01

    A toolkit has been developed for calculating the 3-dimensional biological effective dose (BED) distributions in multi-phase, external beam radiotherapy treatments such as those applied in liver stereotactic body radiation therapy (SBRT) and in multi-prescription treatments. This toolkit also provides a wide range of statistical results related to dose and BED distributions. MATLAB 2010a, version 7.10 was used to create this GUI toolkit. The input data consist of the dose distribution matrices, organ contour coordinates, and treatment planning parameters from the treatment planning system (TPS). The toolkit has the capability of calculating the multi-phase BED distributions using different formulas (denoted as true and approximate). Following the calculations of the BED distributions, the dose and BED distributions can be viewed in different projections (e.g. coronal, sagittal and transverse). The different elements of this toolkit are presented and the important steps for the execution of its calculations are illustrated. The toolkit is applied on brain, head & neck and prostate cancer patients, who received primary and boost phases in order to demonstrate its capability in calculating BED distributions, as well as measuring the inaccuracy and imprecision of the approximate BED distributions. Finally, the clinical situations in which the use of the present toolkit would have a significant clinical impact are indicated.

  2. Preliminary results of radiation dose escalation for locally advanced nasopharyngeal carcinoma

    SciTech Connect

    Kwong, Dora L.W. . E-mail: dlwkwong@hkucc.hku.hk; Sham, Jonathan S.T.; Leung, Lucullus H.T.; Cheng, Ashley C.K.; Ng, W.M.; Kwong, Philip W.K.; Lui, W.M.; Yau, C.C.; Wu, P.M.; Wei, William; Au, Gordon

    2006-02-01

    Purpose: To study the safety and efficacy of dose escalation in tumor for locally advanced nasopharyngeal carcinoma (NPC). Methods and Materials: From September 2000 to June 2004, 50 patients with T3-T4 NPC were treated with intensity-modulated radiotherapy (IMRT). Fourteen patients had Stage III and 36 patients had Stage IVA-IVB disease. The prescribed dose was 76 Gy to gross tumor volume (GTV), 70 Gy to planning target volume (PTV), and 72 Gy to enlarged neck nodes (GTVn). All doses were given in 35 fractions over 7 weeks. Thirty-four patients also had concurrent cisplatin and induction or adjuvant PF (cisplatin and 5-fluorouracil). Results: The average mean dose achieved in GTV, GTVn, and PTV were 79.5 Gy, 75.3 Gy, and 74.6 Gy, respectively. The median follow-up was 25 months, with 4 recurrences: 2 locoregional and 2 distant failures. All patients with recurrence had IMRT alone without chemotherapy. The 2-year locoregional control rate, distant metastases-free and disease-free survivals were 95.7%, 94.2%, and 93.1%, respectively. One treatment-related death caused by adjuvant chemotherapy occurred. The 2-year overall survival was 92.1%. Conclusions: Dose escalation to 76 Gy in tumor is feasible with T3-T4 NPC and can be combined with chemotherapy. Initial results showed good local control and survival.

  3. Interpreting Statistical Significance Test Results: A Proposed New "What If" Method.

    ERIC Educational Resources Information Center

    Kieffer, Kevin M.; Thompson, Bruce

    As the 1994 publication manual of the American Psychological Association emphasized, "p" values are affected by sample size. As a result, it can be helpful to interpret the results of statistical significant tests in a sample size context by conducting so-called "what if" analyses. However, these methods can be inaccurate…

  4. Preliminary Results of Indoor Radon/thoron Concentrations and Terrestrial Gamma Doses in Gejiu, Yunnan, China

    SciTech Connect

    Ishikawa, Tetsuo; Tokonami, Shinji; Kobayashi, Yosuke; Yoshinaga, Shinji; Sun Quafu; Min Xiangdong

    2008-08-07

    A preliminary survey on indoor radon/thoron and external gamma ray dose rate was conducted for houses in Gejiu city and its neighboring village in Yunnan Province, China. As a result of the radon/thoron measurements for about 50 houses, very high thoron concentrations were found in some hoses (maximum: 7,900 Bq/m{sup 3}). The mean annual dose from thoron decay products was estimated to be larger than that from radon decay products (2.9 mSv vs. 1.6 mSv). Further dosimetric and epidemiological studies are needed to investigate the possible effects of radon and thoron.

  5. Radiation doses resulting from variations in spent fuel/waste management systems without Monitored Retrievable Storage

    SciTech Connect

    Schneider, K.J.; Pelto, P.J.; Lavender, J.C.; Daling, P.M.; Fecht, B.A.

    1987-02-01

    This paper presents results of analyses of radiological dose impacts on the public and the workers of nine potential transportation-related changes in the operation of a hypothetical high-level waste management system that does not include a Monitored Retrievable Storage (MRS) facility. The analyses were performed for the US Department of Energy (DOE) to determine if some of the benefits proposed for the improved performance waste management system (one with an MRS facility) could also benefit the authorized system (one without an MRS facility). The study showed that most of the alternatives evaluated would reduce the radiation doses to the public and the workers. Of the alternatives evaluated, the primary means for reducing these radiation doses is to increase the capacity of the transportation casks.

  6. 42 CFR 82.25 - When will NIOSH report dose reconstruction results, and to whom?

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false When will NIOSH report dose reconstruction results, and to whom? 82.25 Section 82.25 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES METHODS FOR CONDUCTING...

  7. 42 CFR 82.4 - How Will DOL Use the Results of the NIOSH Dose Reconstructions?

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES METHODS FOR CONDUCTING DOSE RECONSTRUCTION UNDER... reconstruction results together with information on cancer diagnosis and other personal information provided to... probability that the cancer of the covered employee was caused by radiation exposure at a covered facility...

  8. High-Dose-Rate Prostate Brachytherapy Consistently Results in High Quality Dosimetry

    SciTech Connect

    White, Evan C.; Kamrava, Mitchell R.; Demarco, John; Park, Sang-June; Wang, Pin-Chieh; Kayode, Oluwatosin; Steinberg, Michael L.; Demanes, D. Jeffrey

    2013-02-01

    Purpose: We performed a dosimetry analysis to determine how well the goals for clinical target volume coverage, dose homogeneity, and normal tissue dose constraints were achieved with high-dose-rate (HDR) prostate brachytherapy. Methods and Materials: Cumulative dose-volume histograms for 208 consecutively treated HDR prostate brachytherapy implants were analyzed. Planning was based on ultrasound-guided catheter insertion and postoperative CT imaging; the contoured clinical target volume (CTV) was the prostate, a small margin, and the proximal seminal vesicles. Dosimetric parameters analyzed for the CTV were D90, V90, V100, V150, and V200. Dose to the urethra, bladder, bladder balloon, and rectum were evaluated by the dose to 0.1 cm{sup 3}, 1 cm{sup 3}, and 2 cm{sup 3} of each organ, expressed as a percentage of the prescribed dose. Analysis was stratified according to prostate size. Results: The mean prostate ultrasound volume was 38.7 {+-} 13.4 cm{sup 3} (range: 11.7-108.6 cm{sup 3}). The mean CTV was 75.1 {+-} 20.6 cm{sup 3} (range: 33.4-156.5 cm{sup 3}). The mean D90 was 109.2% {+-} 2.6% (range: 102.3%-118.4%). Ninety-three percent of observed D90 values were between 105 and 115%. The mean V90, V100, V150, and V200 were 99.9% {+-} 0.05%, 99.5% {+-} 0.8%, 25.4% {+-} 4.2%, and 7.8% {+-} 1.4%. The mean dose to 0.1 cm{sup 3}, 1 cm{sup 3}, and 2 cm{sup 3} for organs at risk were: Urethra: 107.3% {+-} 3.0%, 101.1% {+-} 14.6%, and 47.9% {+-} 34.8%; bladder wall: 79.5% {+-} 5.1%, 69.8% {+-} 4.9%, and 64.3% {+-} 5.0%; bladder balloon: 70.3% {+-} 6.8%, 59.1% {+-} 6.6%, and 52.3% {+-} 6.2%; rectum: 76.3% {+-} 2.5%, 70.2% {+-} 3.3%, and 66.3% {+-} 3.8%. There was no significant difference between D90 and V100 when stratified by prostate size. Conclusions: HDR brachytherapy allows the physician to consistently achieve complete prostate target coverage and maintain normal tissue dose constraints for organs at risk over a wide range of target volumes.

  9. Use of the Jackknife Statistic To Establish the External Validity of Discriminant Analysis Results.

    ERIC Educational Resources Information Center

    Daniel, Larry G.

    That the jackknifing technique is superior to traditional techniques for assessing the external validity of statistical results of discriminant analysis is defended. Traditional approaches assessed include: (1) the empirical method, in which the discriminant function coefficients (DFCs) obtained in a given analysis are applied to predict group…

  10. Statistical evaluation of characteristic SDDLV-induced stress resultants to discriminate between undamaged and damaged elements

    NASA Astrophysics Data System (ADS)

    Hansen, L. M.; Johansen, R. J.; Ulriksen, M. D.; Tcherniak, D.; Damkilde, L.

    2015-07-01

    The stochastic dynamic damage location vector (SDDLV) method utilizes the vectors from the kernel of a damaged-induced transfer function matrix change to localize damages in a structure. The kernel vectors associated with the lowest singular values are converted into static pseudo-loads and applied alternately to an undamaged reference model with known stiffness matrix, hereby, theoretically, yielding characteristic stress resultants approaching zero in the damaged elements. At present, the discrimination between potentially damaged elements and undamaged ones is typically conducted on the basis of modified characteristic stress resultants, which are compared to a pre-defined tolerance value, without any thorough statistical evaluation. In the present paper, it is tested whether three widely-used statistical pattern-recognition-based damage-detection methods can provide an effective statistical evaluation of the characteristic stress resultants, hence facilitating general discrimination between damaged and undamaged elements. The three detection methods in question enable outlier analysis on the basis of, respectively, Euclidian distance, Hotelling's T2 statistics, and Mahalanobis distance. The study of the applicability of these methods is based on experimentally obtained accelerations of a cantilevered residential-sized wind turbine blade subjected to an unmeasured multi-impulse load. The characteristic stress resultants are derived by applying the static pseudo-loads to a representative finite element (FE) model of the actual blade.

  11. Measuring Classroom Management Expertise (CME) of Teachers: A Video-Based Assessment Approach and Statistical Results

    ERIC Educational Resources Information Center

    König, Johannes

    2015-01-01

    The study aims at developing and exploring a novel video-based assessment that captures classroom management expertise (CME) of teachers and for which statistical results are provided. CME measurement is conceptualized by using four video clips that refer to typical classroom management situations in which teachers are heavily challenged…

  12. Using the Descriptive Bootstrap to Evaluate Result Replicability (Because Statistical Significance Doesn't)

    ERIC Educational Resources Information Center

    Spinella, Sarah

    2011-01-01

    As result replicability is essential to science and difficult to achieve through external replicability, the present paper notes the insufficiency of null hypothesis statistical significance testing (NHSST) and explains the bootstrap as a plausible alternative, with a heuristic example to illustrate the bootstrap method. The bootstrap relies on…

  13. Probabilistic dose-response modeling: case study using dichloromethane PBPK model results.

    PubMed

    Marino, Dale J; Starr, Thomas B

    2007-12-01

    A revised assessment of dichloromethane (DCM) has recently been reported that examines the influence of human genetic polymorphisms on cancer risks using deterministic PBPK and dose-response modeling in the mouse combined with probabilistic PBPK modeling in humans. This assessment utilized Bayesian techniques to optimize kinetic variables in mice and humans with mean values from posterior distributions used in the deterministic modeling in the mouse. To supplement this research, a case study was undertaken to examine the potential impact of probabilistic rather than deterministic PBPK and dose-response modeling in mice on subsequent unit risk factor (URF) determinations. Four separate PBPK cases were examined based on the exposure regimen of the NTP DCM bioassay. These were (a) Same Mouse (single draw of all PBPK inputs for both treatment groups); (b) Correlated BW-Same Inputs (single draw of all PBPK inputs for both treatment groups except for bodyweights (BWs), which were entered as correlated variables); (c) Correlated BW-Different Inputs (separate draws of all PBPK inputs for both treatment groups except that BWs were entered as correlated variables); and (d) Different Mouse (separate draws of all PBPK inputs for both treatment groups). Monte Carlo PBPK inputs reflect posterior distributions from Bayesian calibration in the mouse that had been previously reported. A minimum of 12,500 PBPK iterations were undertaken, in which dose metrics, i.e., mg DCM metabolized by the GST pathway/L tissue/day for lung and liver were determined. For dose-response modeling, these metrics were combined with NTP tumor incidence data that were randomly selected from binomial distributions. Resultant potency factors (0.1/ED(10)) were coupled with probabilistic PBPK modeling in humans that incorporated genetic polymorphisms to derive URFs. Results show that there was relatively little difference, i.e., <10% in central tendency and upper percentile URFs, regardless of the case

  14. Long-term results of breast cancer irradiation treatment with low-dose-rate external irradiation

    SciTech Connect

    Pierquin, Bernard; Tubiana, Maurice . E-mail: maurice.tubiana@biomedicale.univ-paris5.fr; Pan, Camille; Lagrange, Jean-Leon; Calitchi, Elie; Otmezguine, Yves

    2007-01-01

    Purpose: The aim of this study was to assess beam therapy with low-dose-rate (LDR) external irradiation in a group of patients with breast cancer. Methods and Materials: This trial compared, from 1986 to 1989, patients with advanced breast cancer treated either by conventional fractionation or low-dose-rate (LDR) external radiotherapy (dose-rate 15 mGy/min, 5 sessions of 9 Gy delivered on 5 consecutive days). Results: A total of 21 patients were included in the fractionated therapy arm. At follow-up 15 years after treatment, 7 local recurrences had occurred, 3 patients had died of cancer, 18 patients were alive, 10 were without evidence of disease, and 6 had evidence of disease. A total of 22 patients had been included in the LDR arm of the study. Of these, 11 had received a dose of 45 Gy; thereafter, in view of severe local reactions, the dose was reduced to 35 Gy. There was no local recurrence in patients who had received 45 Gy, although there were 2 local recurrences among the 11 patients after 35 Gy. The sequelae were severe in patients who received 45 Gy but were comparable to those observed in patients treated by fractionated radiotherapy who received 35 Gy. The higher efficacy of tumor control in patients treated by LDR irradiation as well as the lower tolerance of normal tissue are probably related to the lack of repopulation. Conclusion: Although the patient numbers in this study are limited, based on our study results we conclude that the data for LDR irradiation are encouraging and that further investigation is warranted.

  15. Results of Dose Control and Measurement Plans Appliedfor SPEAR3 Commissioning Year (FY04)

    SciTech Connect

    Khater, Hesham; Liu, James; Prinz, Alyssa; Allan, Jim; Rokni, Sayed; /SLAC

    2007-02-12

    Dose control and measurement plans for the SPEAR3 Booster and storage ring have taken place during the SPEAR3 commissioning. The initial commissioning period (SPEAR3 start-up) covered the time period from the beginning of November 2003 to the early part of March 2004. The period from the beginning of March to the beginning of August 2004 has been mostly dedicated to the scientific program. The initial commissioning period was characterized with frequent injection and significantly higher losses. In comparison, the scientific program period was characterized with more stable beam operation with limited number of injections per day and lower beam losses. Three types of dose measurements, passive, active and special measurements, were implemented around the SPEAR3 Booster and storage ring. Based on the expected radiation hazards, several dose control measures were adopted at several stages of the commissioning. In the early stages of commissioning, areas within 4.5 m from the walls of the Booster and storage ring were designated as Radiation Areas (RA). Areas outside RA were classified as Radiologically Controlled Area (RCA). Access to these areas required less training than the radiation areas. A monthly review of the accelerator operation conditions and radiation measurement results were used to determine the changes needed for the RA classification status and associated dose control measures.

  16. Higher Chest Wall Dose Results in Improved Locoregional Outcome in Patients Receiving Postmastectomy Radiation

    SciTech Connect

    Panoff, Joseph E.; Takita, Cristiane; Hurley, Judith; Reis, Isildinha M.; Zhao, Wei; Rodgers, Steven E.; Gunaseelan, Vijayalakshmi; Wright, Jean L.

    2012-03-01

    Purpose: Randomized trials demonstrating decreased locoregional recurrence (LRR) and improved overall survival (OS) in women receiving postmastectomy radiation therapy (PMRT) used up to 50 Gy to the chest wall (CW), but in practice, many centers boost the CW dose to {>=}60 Gy, despite lack of data supporting this approach. We evaluated the relationship between CW dose and clinical outcome. Methods and Materials: We retrospectively reviewed medical records of 582 consecutively treated patients who received PMRT between January 1999 and December 2009. We collected data on patient, disease, treatment characteristics, and outcomes of LRR, progression-free survival (PFS) and OS. Results: Median follow-up from the date of diagnosis was 44.7 months. The cumulative 5-year incidence of LRR as first site of failure was 6.2%. CW dose for 7% (43 patients) was {<=}50.4 Gy (range, 41.4-50.4 Gy) and 93% received >50.4 Gy (range, 52.4-74.4 Gy). A CW dose of >50.4 Gy vs. {<=}50.4 Gy was associated with lower incidence of LRR, a 60-month rate of 5.7% (95% confidence interval [CI], 3.7-8.2) vs. 12.7% (95% CI, 4.5-25.3; p = 0.054). Multivariate hazard ratio (HR) for LRR controlling for race, receptor status, and stage was 2.62 (95% CI, 1.02-7.13; p = 0.042). All LRR in the low-dose group occurred in patients receiving 50 to 50.4 Gy. Lower CW dose was associated with worse PFS (multivariate HR, 2.73; 95% CI, 1.64-4.56; p < 0.001) and OS (multivariate HR, 3.88; 95% CI, 2.16-6.99; p < 0.001). Conclusions: The addition of a CW boost above 50.4 Gy resulted in improved locoregional control and survival in this cohort patients treated with PMRT for stage II-III breast cancer. The addition of a CW boost to standard-dose PMRT is likely to benefit selected high-risk patients. The optimal technique, target volume, and patient selection criteria are unknown. The use of a CW boost should be studied prospectively, as has been done in the setting of breast conservation.

  17. A statistical comparison of impact and ambient testing results from the Alamosa Canyon Bridge

    SciTech Connect

    Doebling, S.W.; Farrar, C.R.; Cornwell, P.

    1996-12-31

    In this paper, the modal properties of the Alamosa Canyon Bridge obtained using ambient data are compared to those obtained from impact hammer vibration tests. Using ambient sources of excitation to determine the modal characteristics of large civil engineering structures is desirable for several reasons. The forced vibration testing of such structures generally requires a large amount of specialized equipment and trained personnel making the tests quite expensive. Also, an automated health monitoring system for a large civil structure will most likely use ambient excitation. A modal identification procedure based on a statistical Monte Carlo analysis using the Eigensystem Realization Algorithm is used to compute the modal parameters and their statistics. The results show that for most of the measured modes, the differences between the modal frequencies of the ambient and hammer data sets are statistically significant. However, the differences between the corresponding damping ratio results are not statistically significant. Also, one of the modes identified from the hammer test data was not identifiable from the ambient data set.

  18. SU-E-J-204: Radiation Dose to Patients Resulting From Image Guidance Procedures and AAPM TG-180 Update

    SciTech Connect

    Ding, G; Alaei, P

    2014-06-01

    Purpose: Image-guided radiation therapy (IGRT) is the new paradigm for patient positioning and target localization in radiotherapy. Daily imaging procedures add additional dose to the patient's treatment volume and normal tissues and may expose the organs at risk to unaccounted doses. This presentation is to update the progress of AAPM TG-180 which aims to provide strategies to quantify and account the dose from both MV and kV imaging in patient treatment planning. Methods: Our current knowledge on image guidance dose is presented. A summary of doses from image guidance procedures delivered to patients in relationship with therapeutic doses is given. Different techniques in reducing the image guidance dose are summarized. Typical organ doses resulting from different image acquisition procedures used in IGRT are tabulated. Results: Many techniques to reduce the imaging doses are available in clinical applications. There are large variations between dose to bone and dose to soft tissues for x-rays at kilovoltage energy range. Methods for clinical implementation of accounting for the imaging dose from an imaging procedure are available. Beam data from imaging systems can be generated by combining Monte Carlo simulations and experimental measurements for commissioning imaging beams in the treatment planning. Conclusion: The current treatment planning systems are not yet equipped to perform patient specific dose calculations resulting from kV imaging procedures. The imaging dose from current kV image devices has been significantly reduced and is generally much less than that resulting from MV. Because the magnitude of kV imaging dose is significantly low and the variation between patients is modest, it is feasible to estimate dose based on imaging producers or protocols using tabulated values which provides an alternative to accomplish the task of accounting and reporting imaging doses.

  19. Activation of hip prostheses in high energy radiotherapy and resultant dose to nearby tissue.

    PubMed

    Keehan, Stephanie; Smith, Ryan L; Millar, Jeremy; Esser, Max; Taylor, Michael L; Lonski, Peta; Kron, Tomas; Franich, Rick D

    2017-03-01

    High energy radiotherapy can produce contaminant neutrons through the photonuclear effect. Patients receiving external beam radiation therapy to the pelvis may have high-density hip prostheses. Metallic materials such as those in hip prostheses, often have high cross-sections for neutron interaction. In this study, Thackray (UK) prosthetic hips have been irradiated by 18 MV radiotherapy beams to evaluate the additional dose to patients from the activation products. Hips were irradiated in- and out-of field at various distances from the beam isocenter to assess activation caused in-field by photo-activation, and neutron activation which occurs both in and out-of-field. NaI(Tl) scintillator detectors were used to measure the subsequent gamma-ray emissions and their half-lives. High sensitivity Mg, Cu, P doped LiF thermoluminescence dosimeter chips (TLD-100H) were used to measure the subsequent dose at the surface of a prosthesis over the 12 h following an in-field irradiation of 10,000 MU to a hip prosthesis located at the beam isocenter in a water phantom. (53) Fe, (56) Mn, and (52) V were identified within the hip following irradiation by radiotherapy beams. The dose measured at the surface of a prosthesis following irradiation in a water phantom was 0.20 mGy over 12 h. The dose at the surface of prostheses irradiated to 200 MU was below the limit of detection (0.05 mGy) of the TLD100H. Prosthetic hips are activated by incident photons and neutrons in high energy radiotherapy, however, the dose resulting from activation is very small.

  20. 42 CFR 82.26 - How will NIOSH report dose reconstruction results?

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES METHODS FOR CONDUCTING DOSE RECONSTRUCTION UNDER... dose reconstruction, justification for the decision, and if possible, a quantitative estimate of...

  1. 42 CFR 82.26 - How will NIOSH report dose reconstruction results?

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES METHODS FOR CONDUCTING DOSE RECONSTRUCTION UNDER... dose reconstruction, justification for the decision, and if possible, a quantitative estimate of...

  2. 42 CFR 82.26 - How will NIOSH report dose reconstruction results?

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES METHODS FOR CONDUCTING DOSE RECONSTRUCTION UNDER... dose reconstruction, justification for the decision, and if possible, a quantitative estimate of...

  3. 42 CFR 82.26 - How will NIOSH report dose reconstruction results?

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES METHODS FOR CONDUCTING DOSE RECONSTRUCTION UNDER... dose reconstruction, justification for the decision, and if possible, a quantitative estimate of...

  4. 42 CFR 82.26 - How will NIOSH report dose reconstruction results?

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES METHODS FOR CONDUCTING DOSE RECONSTRUCTION UNDER... dose reconstruction, justification for the decision, and if possible, a quantitative estimate of...

  5. New Statistical Results on the Angular Distribution of Gamma-Ray Bursts

    SciTech Connect

    Balazs, Lajos G.; Horvath, Istvan; Vavrek, Roland

    2008-05-22

    We presented the results of several statistical tests of the randomness in the angular sky-distribution of gamma-ray bursts in BATSE Catalog. Thirteen different tests were presented based on Voronoi tesselation, Minimal spanning tree and Multifractal spectrum for five classes (short1, short2, intermediate, long1, long2) of gamma-ray bursts, separately. The long1 and long2 classes are distributed randomly. The intermediate subclass, in accordance with the earlier results of the authors, is distributed non-randomly. Concerning the short subclass earlier statistical tests also suggested some departure from the random distribution, but not on a high enough confidence level. The new tests presented in this article suggest also non-randomness here.

  6. Electron Attachment to SF(6) Under Well Defined Conditions: Comparison of Statistical Modeling Results to Experiments

    DTIC Science & Technology

    2007-08-01

    Avogadro constant , EA is the electron affinity (at 0 K, by definition), AS" is the entropy change due to electron attachment at temperature T, and...measure rate constants for electron attachment to SF6 and thermal detachment from SF6’. In a recent series of papers, these results were combined...hexafluoride Statistical theory Rate constants 16. SECURITY CLASSIFICATION OF: a. REPORT UNCL b. ABSTRACT UNCL c. THIS PAGE UNCL 17. LIMITATION OF

  7. Results of 1 year of clinical experience with independent dose calculation software for VMAT fields

    PubMed Central

    Colodro, Juan Fernando Mata; Berna, Alfredo Serna; Puchades, Vicente Puchades; Amores, David Ramos; Baños, Miguel Alcaraz

    2014-01-01

    It is widely accepted that a redundant independent dose calculation (RIDC) must be included in any treatment planning verification procedure. Specifically, volumetric modulated arc therapy (VMAT) technique implies a comprehensive quality assurance (QA) program in which RIDC should be included. In this paper, the results obtained in 1 year of clinical experience are presented. Eclipse from Varian is the treatment planning system (TPS), here in use. RIDC were performed with the commercial software; Diamond® (PTW) which is capable of calculating VMAT fields. Once the plan is clinically accepted, it is exported via Digital Imaging and Communications in Medicine (DICOM) to RIDC, together with the body contour, and then a point dose calculation is performed, usually at the isocenter. A total of 459 plans were evaluated. The total average deviation was -0.3 ± 1.8% (one standard deviation (1SD)). For higher clearance the plans were grouped by location in: Prostate, pelvis, abdomen, chest, head and neck, brain, stereotactic radiosurgery, lung stereotactic body radiation therapy, and miscellaneous. The highest absolute deviation was -0.8 ± 1.5% corresponding to the prostate. A linear fit between doses calculated by RIDC and by TPS produced a correlation coefficient of 0.9991 and a slope of 1.0023. These results are very close to those obtained in the validation process. This agreement led us to consider this RIDC software as a valuable tool for QA in VMAT plans. PMID:25525309

  8. Results of 1 year of clinical experience with independent dose calculation software for VMAT fields.

    PubMed

    Colodro, Juan Fernando Mata; Berna, Alfredo Serna; Puchades, Vicente Puchades; Amores, David Ramos; Baños, Miguel Alcaraz

    2014-10-01

    It is widely accepted that a redundant independent dose calculation (RIDC) must be included in any treatment planning verification procedure. Specifically, volumetric modulated arc therapy (VMAT) technique implies a comprehensive quality assurance (QA) program in which RIDC should be included. In this paper, the results obtained in 1 year of clinical experience are presented. Eclipse from Varian is the treatment planning system (TPS), here in use. RIDC were performed with the commercial software; Diamond(®) (PTW) which is capable of calculating VMAT fields. Once the plan is clinically accepted, it is exported via Digital Imaging and Communications in Medicine (DICOM) to RIDC, together with the body contour, and then a point dose calculation is performed, usually at the isocenter. A total of 459 plans were evaluated. The total average deviation was -0.3 ± 1.8% (one standard deviation (1SD)). For higher clearance the plans were grouped by location in: Prostate, pelvis, abdomen, chest, head and neck, brain, stereotactic radiosurgery, lung stereotactic body radiation therapy, and miscellaneous. The highest absolute deviation was -0.8 ± 1.5% corresponding to the prostate. A linear fit between doses calculated by RIDC and by TPS produced a correlation coefficient of 0.9991 and a slope of 1.0023. These results are very close to those obtained in the validation process. This agreement led us to consider this RIDC software as a valuable tool for QA in VMAT plans.

  9. Novel, single-dose, topical treatment of tinea pedis using terbinafine: results of a dose-finding clinical trial.

    PubMed

    de Chauvin, Martine Feuilhade; Viguié-Vallanet, Claude; Kienzler, Jean-Luc; Larnier, Catherine

    2008-01-01

    Tinea pedis is the most common dermatophytosis requiring topical antifungals for at least 1-4 weeks. To determine the effectiveness of a novel topical single dose formulation of terbinafine (film forming solution-FFS) in the treatment of tinea pedis, 344 outpatients from 43 dermatological centres in France and Bulgaria suffering from tinea pedis with possible extension to soles confirmed by mycological examination (direct and culture) were evaluated for efficacy of terbinafine 1%, 5%, 10% FFS in a randomised double blind vehicle controlled parallel group dose finding study. Evaluations were carried out at baseline, 1 and 6 weeks after a single application of FFS. Effective treatment rate based on negative mycology (direct and culture) and minimal signs and symptoms (two or less with only mild recorded) was measured at week 6. Effective treatment rates at week 6 with terbinafine 1%, 5% and 10% FFS were 66%, 70%, 61% compared with 18% with placebo. All three active preparations were shown to be significantly superior to placebo (P < 0.001). Terbinafine 1% and 5% FFS were shown to be non-inferior to terbinafine 10% FFS. Terbinafine 1% FFS is an effective, safe dose for the treatment of tinea pedis. This novel product represents a significant advance with the enhanced compliance and convenience that it offers.

  10. Statistics of interacting networks with extreme preferred degrees: Simulation results and theoretical approaches

    NASA Astrophysics Data System (ADS)

    Liu, Wenjia; Schmittmann, Beate; Zia, R. K. P.

    2012-02-01

    Network studies have played a central role for understanding many systems in nature - e.g., physical, biological, and social. So far, much of the focus has been the statistics of networks in isolation. Yet, many networks in the world are coupled to each other. Recently, we considered this issue, in the context of two interacting social networks. In particular, We studied networks with two different preferred degrees, modeling, say, introverts vs. extroverts, with a variety of ``rules for engagement.'' As a first step towards an analytically accessible theory, we restrict our attention to an ``extreme scenario'': The introverts prefer zero contacts while the extroverts like to befriend everyone in the society. In this ``maximally frustrated'' system, the degree distributions, as well as the statistics of cross-links (between the two groups), can depend sensitively on how a node (individual) creates/breaks its connections. The simulation results can be reasonably well understood in terms of an approximate theory.

  11. Dual effects of phytoestrogens result in u-shaped dose-response curves.

    PubMed Central

    Almstrup, Kristian; Fernández, Mariana F; Petersen, Jørgen H; Olea, Nicolas; Skakkebaek, Niels E; Leffers, Henrik

    2002-01-01

    Endocrine disruptors can affect the endocrine system without directly interacting with receptors, for example, by interfering with the synthesis or metabolism of steroid hormones. The aromatase that converts testosterone to 17beta-estradiol is a possible target. In this paper we describe an assay that simultaneously detects aromatase inhibition and estrogenicity. The principle is similar to that of other MCF-7 estrogenicity assays, but with a fixed amount of testosterone added. The endogenous aromatase activity in MCF-7 cells converts some of the testosterone to 17beta-estradiol, which is assayed by quantifying differences in the expression level of the estrogen-induced pS2 mRNA. Potential aromatase inhibitors can be identified by a dose-dependent reduction in the pS2 mRNA expression level after exposure to testosterone and the test compound. Using this assay, we have investigated several compounds, including synthetic chemicals and phytoestrogens, for aromatase inhibition. The phytoestrogens, except genistein, were aromatase inhibitors at low concentrations (< 1 micro M) but estrogenic at higher concentrations (greater than or equal to 1 micro M), resulting in U-shaped dose-response curves. None of the tested synthetic chemicals were aromatase inhibitors. The low-dose aromatase inhibition distinguished phytoestrogens from other estrogenic compounds and may partly explain reports about antiestrogenic properties of phytoestrogens. Aromatase inhibition may play an important role in the protective effects of phytoestrogens against breast cancer. PMID:12153753

  12. Estimating the Error in Statistical HAMR Object Populations Resulting from Simplified Radiation Pressure Modeling

    NASA Astrophysics Data System (ADS)

    Flegel, S.; Vörsmann, P.; Wiedemann, C.; Kebschull, C.; Braun, V.; Möckel, M.; Gelhaus, J.; Krag, H.; Klinkrad, H.

    2012-09-01

    The high-area-to-mass ratio (HAMR) object population in ESA's MASTER-2009 software (Meteoroid and Space Debris Terrestrial Environment Reference) is dominated by Multi-Layer Insulation debris at large sizes. The underlying model employs two independent mechanisms whereby Multi-Layer Insulation debris is created. These mechanisms are fragmentation events on the one hand and a deterioration process leading to the continuous release of larger objects on the other hand. All debris source models used to create the MASTER debris population rely on a semi-analytical propagator to model the major secular and long periodic orbit perturbations. The orbit parameters of HAMR objects are highly susceptive to radiation pressure effects which can result in fast secular and periodic changes for area-to-mass ratios above about 1 square meter per kilogram. The implementation of radiation pressure in this propagator is limited to the effects of solar irradiation on a spherical object and using a cylindrical Earth shadow. The current paper discusses the applicability of such a simplified theory to large statistical HAMR object populations where the main objective is not to predict the exact future location of a single object but rather to give a correct representation of the overall distribution of all HAMR objects. The basis for the current study is given by a numerical propagator which is supported by published observation results. Initially, the effects of object orientation, Earth albedo and thermal radiation on the orbit evolution are discussed. Results from published observations and simulation results give insight into the validity of the implemented model. Fundamental differences between the orbit prediction of this refined numerical propagator and the semi-analytical propagator are looked at with a view towards large statistical populations. To this end, a plausible, statistical, population of HAMR objects is propagated over an extended time period using both propagation

  13. No difference found in time to publication by statistical significance of trial results: a methodological review

    PubMed Central

    Jefferson, L; Cooper, E; Hewitt, C; Torgerson, T; Cook, L; Tharmanathan, P; Cockayne, S; Torgerson, D

    2016-01-01

    Objective Time-lag from study completion to publication is a potential source of publication bias in randomised controlled trials. This study sought to update the evidence base by identifying the effect of the statistical significance of research findings on time to publication of trial results. Design Literature searches were carried out in four general medical journals from June 2013 to June 2014 inclusive (BMJ, JAMA, the Lancet and the New England Journal of Medicine). Setting Methodological review of four general medical journals. Participants Original research articles presenting the primary analyses from phase 2, 3 and 4 parallel-group randomised controlled trials were included. Main outcome measures Time from trial completion to publication. Results The median time from trial completion to publication was 431 days (n = 208, interquartile range 278–618). A multivariable adjusted Cox model found no statistically significant difference in time to publication for trials reporting positive or negative results (hazard ratio: 0.86, 95% CI 0.64 to 1.16, p = 0.32). Conclusion In contrast to previous studies, this review did not demonstrate the presence of time-lag bias in time to publication. This may be a result of these articles being published in four high-impact general medical journals that may be more inclined to publish rapidly, whatever the findings. Further research is needed to explore the presence of time-lag bias in lower quality studies and lower impact journals. PMID:27757242

  14. EPA/NMED/LANL 1998 water quality results: Statistical analysis and comparison to regulatory standards

    SciTech Connect

    B. Gallaher; T. Mercier; P. Black; K. Mullen

    2000-02-01

    Four governmental agencies conducted a round of groundwater, surface water, and spring water sampling at the Los Alamos National Laboratory during 1998. Samples were split among the four parties and sent to independent analytical laboratories. Results from three of the agencies were available for this study. Comparisons of analytical results that were paired by location and date were made between the various analytical laboratories. The results for over 50 split samples analyzed for inorganic chemicals, metals, and radionuclides were compared. Statistical analyses included non-parametric (sign test and signed-ranks test) and parametric (paired t-test and linear regression) methods. The data pairs were tested for statistically significant differences, defined by an observed significance level, or p-value, less than 0.05. The main conclusion is that the laboratories' performances are similar across most of the analytes that were measured. In some 95% of the laboratory measurements there was agreement on whether contaminant levels exceeded regulatory limits. The most significant differences in performance were noted for the radioactive suite, particularly for gross alpha particle activity and Sr-90.

  15. Statistical analysis of aquifer-test results for nine regional aquifers in Louisiana

    USGS Publications Warehouse

    Martin, Angel; Early, D.A.

    1987-01-01

    This report, prepared as part of the Gulf Coast Regional Aquifer-System Analysis project, presents a compilation, summarization, and statistical analysis of aquifer-test results for nine regional aquifers in Louisiana. These are from youngest to oldest: The alluvial, Pleistocene, Evangeline, Jasper, Catahoula, Cockfield, Sparta, Carrizo, and Wilcox aquifers. Approximately 1,500 aquifer tests in U.S. Geological Survey files in Louisiana were examined and 1,001 were input to a computer file. Analysis of the aquifer test results and plots that describe aquifer hydraulic characteristics were made for each regional aquifer. Results indicate that, on the average, permeability (hydraulic conductivity) generally tends to decrease from the youngest aquifers to the oldest. The most permeable aquifers in Louisiana are the alluvial and Pleistocene aquifers; whereas, the least permeable are the Carrizo and Wilcox aquifers. (Author 's abstract)

  16. Compendium of Current Total Ionizing Dose Results and Displacement Damage Results for Candidate Spacecraft Electronics for NASA

    NASA Technical Reports Server (NTRS)

    Cochran, Donna J.; O'Bryan, Martha V.; Buchner, Stephen P.; Poivey, Christian; Ladbury, Ray L.; LaBel, Kenneth A.

    2007-01-01

    Sensitivity of a variety of candidate spacecraft electronics to total ionizing dose and displacement damage is studied. Devices tested include optoelectronics, digital, analog, linear bipolar devices, and hybrid devices.

  17. Parameter sampling capabilities of sequential and simultaneous data assimilation: II. Statistical analysis of numerical results

    NASA Astrophysics Data System (ADS)

    Fossum, Kristian; Mannseth, Trond

    2014-11-01

    We assess and compare parameter sampling capabilities of one sequential and one simultaneous Bayesian, ensemble-based, joint state-parameter (JS) estimation method. In the companion paper, part I (Fossum and Mannseth 2014 Inverse Problems 30 114002), analytical investigations lead us to propose three claims, essentially stating that the sequential method can be expected to outperform the simultaneous method for weakly nonlinear forward models. Here, we assess the reliability and robustness of these claims through statistical analysis of results from a range of numerical experiments. Samples generated by the two approximate JS methods are compared to samples from the posterior distribution generated by a Markov chain Monte Carlo method, using four approximate measures of distance between probability distributions. Forward-model nonlinearity is assessed from a stochastic nonlinearity measure allowing for sufficiently large model dimensions. Both toy models (with low computational complexity, and where the nonlinearity is fairly easy to control) and two-phase porous-media flow models (corresponding to down-scaled versions of problems to which the JS methods have been frequently applied recently) are considered in the numerical experiments. Results from the statistical analysis show strong support of all three claims stated in part I.

  18. Results of dose sensors measurements in the middle-Earth orbit for the period of 2009-2015

    NASA Astrophysics Data System (ADS)

    Protopopov, Grigory; Shatov, Pavel; Tasenko, Sergey; Lyakhov, Igor; Makarova, Nina; Balashov, Sergey; Sitnikova, Ninel

    2016-07-01

    The measurements results of space radiation exposure on electronic components carried out by dose sensors are presented in the paper. Dose sensors operate on metal-nitride-oxide-semiconductor dosimetry pricniple. The flight data have been receiving for more than 6 years. The measurements results are compared with others flight data on different orbits. The analysis of the received data from 2009 to 2015 allows us to find out the periods with sharp increase of dose rate and to define values of such increases. We had analyzed space radiation characteristics data from other monitoring systems (such as GOES, Electro-L) in dates of dose rate sharp increase. Results of the analysis of dose rate increase, which had been fixed by TID sensors in 2015, will be presented in full paper. We had calculated average dose rates for different space models in the middle-Earth orbit (AE8, AE9 and others) and determined the most relevant models to the experimental data (with account for relaxation effect of dose sensor outputs). The comparison results for different models will be presented in the full paper. We had used different approaches for simulating of dose sensors shielding geometry, such as semi-sphere, semi-infinite plate, sector analysis, with taking account of different shielding elements. The analysis results of shielding configuration influence on calculated values of dose rate will be presented in the full paper.

  19. Statistical analysis of real-time, enviromental radon monitoring results at the Fernald Enviromental Management Project

    SciTech Connect

    Liu, Ning; Spitz, H.B.; Tomezak, L.

    1996-02-01

    A comprehensive real-time, environmental radon monitoring program is being conducted at the Fernald Environmental Management Project, where a large quantity of radium-bearing residues have been stored in two covered earth-bermed silos. Statistical analyses was conducted to determine what impact radon emitted by the radium bearing materials contained in the silos has on the ambient radon concentration at the Fernald Environmental Management Project site. The distribution that best describes the outdoor radon monitoring data was determined before statistical analyses were conducted. Random effects associated with the selection of radon monitoring locations were accommodated by using nested and nested factorial classification models. The Project site was divided into four general areas according to their characteristics and functions: (1) the silo area, where the radium-bearing waste is stored; (2) the production/administration area; (3) the perimeter area, or fence-line, of the Fernald Environmental Management Project site; and (4) a background area, located approximately 13 km from the Fernald Environmental Management Project site, representing the naturally-occurring radon concentration. A total of 15 continuous, hourly readout radon monitors were installed to measure the outdoor radon concentration. Measurement results from each individual monitor were found to be log-normally distributed. A series of contrast tests, which take random effects into account, were performed to compare the radon concentration between different areas of the site. These comparisons demonstrate that the radon concentrations in the production/administration area and the perimeter area are statistically equal to the natural background, whereas the silo area is significantly higher than background. The study also showed that the radon concentration in the silo area was significantly reduced after a sealant barrier was applied to the contents of the silos. 10 refs., 6 figs., 8 tabs.

  20. Teachers' Statistical Problem Solving with Dynamic Technology: Research Results across Multiple Institutions

    ERIC Educational Resources Information Center

    Lee, Hollylynne Stohl; Kersaint, Gladis; Harper, Suzanne; Driskell, Shannon O.; Leatham, Keith R.

    2012-01-01

    This study examined a random stratified sample (n = 62) of prospective teachers' work across eight institutions on three tasks that utilized dynamic statistical software. The authors considered how teachers utilized their statistical knowledge and technological statistical knowledge to engage in cycles of investigation. This paper characterizes…

  1. Vigabatrin pediatric dosing information for refractory complex partial seizures: results from a population dose-response analysis.

    PubMed

    Nielsen, Jace C; Tolbert, Dwain; Patel, Mahlaqa; Kowalski, Kenneth G; Wesche, David L

    2014-12-01

    We predicted vigabatrin dosages for adjunctive therapy for pediatric patients with refractory complex partial seizures (rCPS) that would produce efficacy comparable to that observed for approved adult dosages. A dose-response model related seizure-count data to vigabatrin dosage to identify dosages for pediatric rCPS patients. Seizure-count data were obtained from three pediatric and two adult rCPS clinical trials. Dosages were predicted for oral solution and tablet formulations. Predicted oral solution dosages to achieve efficacy comparable to that of a 1 g/day adult dosage were 350 and 450 mg/day for patients with body weight ranges 10-15 and >15-20 kg, respectively. Predicted oral solution dosages for efficacy comparable to a 3 g/day adult dosage were 1,050 and 1,300 mg/day for weight ranges 10-15 and >15-20 kg, respectively. Predicted tablet dosage for efficacy comparable to a 1 g/day adult dosage was 500 mg/day for weight ranges 25-60 kg. Predicted tablet dosage for efficacy comparable to a 3 g/day adult dosage was 2,000 mg for weight ranges 25-60 kg. Vigabatrin dosages were identified for pediatric rCPS patients with body weights ≥10 kg.

  2. A Review of Asteroid Rotation Statistics with and without the Results from Wide-field Surveys

    NASA Astrophysics Data System (ADS)

    Warner, Brian D.; Harris, Alan W.; Stephens, Robert D.

    2015-11-01

    Several recent wide-field surveys, e.g., Waszczak et al. (2015) and Chang et al. (2015), have added more than 10,000 asteroid rotation rates to the asteroid lightcurve database (LCDB), Warner et al. (2009). In previous works, Harris et al. (2012), Warner et al. (2011), we explored the possible effects on asteroid rotational statistics with the large infusion of results from such surveys, especially if using “sparse” data sets, e.g., those with fewer than 60 data points from a short span of 2-4 nights.Now that such data sets exist, we examine asteroid rotation statistics with and without the results from the surveys, looking at two specific points: 1) the possible biases introduced when using survey data and 2) assuming that the stated results are statistically useful, what the larger data set now tells us about asteroid rotation rates.For point #1, there appears to be the expected substantial biases against low amplitude and very short or long period lightcurves with the period problems stemming from the observing cadence and limited number of observations. Furthermore, the two latest surveys found periods for only about 20% of all observed objects, meaning that only the “easier” results were found. While the two surveys tended to go deeper and, therefore, work smaller objects, that raises yet another bias: success in finding a period depends on brightness. As a result, we would urge caution when interpreting spin properties versus size.For point #2, we first note that the vast majority of objects observed by the two surveys were in the broad regions of the inner or outer main-belt. Significantly, less than 10 NEAs were observed. For this reason, it makes it difficult to compare the effects of YORP, as seen by rotation rate distribution, on small asteroids at different distances. When considering main-belt objects with 10 < D < 40 km, the difference between plots with and without survey data show essentially the same Mawellian-like distribution.

  3. Dose Escalation and Quality of Life in Patients With Localized Prostate Cancer Treated With Radiotherapy: Long-Term Results of the Dutch Randomized Dose-Escalation Trial (CKTO 96-10 Trial)

    SciTech Connect

    Al-Mamgani, Abrahim; Putten, Wim L.J. van; Wielen, Gerard J. van der; Levendag, Peter C.; Incrocci, Luca

    2011-03-15

    Purpose: To assess the impact of dose escalation of radiotherapy on quality of life (QoL) in prostate cancer patients. Patients and Methods: Three hundred prostate cancer patients participating in the Dutch randomized trial (CKTO 69-10) comparing 68 Gy with 78 Gy were the subject of this analysis. These patients filled out the SF-36 QoL questionnaire before radiotherapy (baseline) and 6, 12, 24, and 36 months thereafter. Changes in QoL over time of {>=}10 points were considered clinically relevant. Repeated-measures regression analyses were applied to estimate and test the QoL changes over time, the differences between the two arms, and for association with a number of covariates. Results: At 3-year follow-up, the summary score physical health was 73.2 for the 68-Gy arm vs. 71.6 for the 78-Gy arm (p = 0.81), and the summary score mental health was 76.7 for the 68-Gy arm vs. 76.1 for the 78-Gy arm (p = 0.97). Statistically significant (p < 0.01) deterioration in QoL scores over time was registered in both arms in six scales. The deterioration over time was more pronounced in the high-dose arm for most scales. However, clinically relevant deterioration (>10 points) was seen for only two scales. None of the tested covariates were significantly correlated with QoL scores. Conclusion: Dose escalation did not result in significant deterioration of QoL in prostate cancer patients. In both randomization arms, statistically significant decreases in QoL scores over time were seen in six scales. The deterioration of QoL was more pronounced in the physical than in the mental health domain and in some scales more in the high- than in the low-dose arm, but the differences between arms were not statistically significant.

  4. Statistical model based iterative reconstruction in clinical CT systems. Part III. Task-based kV/mAs optimization for radiation dose reduction

    PubMed Central

    Li, Ke; Gomez-Cardona, Daniel; Hsieh, Jiang; Lubner, Meghan G.; Pickhardt, Perry J.; Chen, Guang-Hong

    2015-01-01

    Purpose: For a given imaging task and patient size, the optimal selection of x-ray tube potential (kV) and tube current-rotation time product (mAs) is pivotal in achieving the maximal radiation dose reduction while maintaining the needed diagnostic performance. Although contrast-to-noise (CNR)-based strategies can be used to optimize kV/mAs for computed tomography (CT) imaging systems employing the linear filtered backprojection (FBP) reconstruction method, a more general framework needs to be developed for systems using the nonlinear statistical model-based iterative reconstruction (MBIR) method. The purpose of this paper is to present such a unified framework for the optimization of kV/mAs selection for both FBP- and MBIR-based CT systems. Methods: The optimal selection of kV and mAs was formulated as a constrained optimization problem to minimize the objective function, Dose(kV,mAs), under the constraint that the achievable detectability index d′(kV,mAs) is not lower than the prescribed value of d℞′ for a given imaging task. Since it is difficult to analytically model the dependence of d′ on kV and mAs for the highly nonlinear MBIR method, this constrained optimization problem is solved with comprehensive measurements of Dose(kV,mAs) and d′(kV,mAs) at a variety of kV–mAs combinations, after which the overlay of the dose contours and d′ contours is used to graphically determine the optimal kV–mAs combination to achieve the lowest dose while maintaining the needed detectability for the given imaging task. As an example, d′ for a 17 mm hypoattenuating liver lesion detection task was experimentally measured with an anthropomorphic abdominal phantom at four tube potentials (80, 100, 120, and 140 kV) and fifteen mA levels (25 and 50–700) with a sampling interval of 50 mA at a fixed rotation time of 0.5 s, which corresponded to a dose (CTDIvol) range of [0.6, 70] mGy. Using the proposed method, the optimal kV and mA that minimized dose for the

  5. High-dose-rate brachytherapy for intranasal tumours in dogs: results of a pilot study.

    PubMed

    Klueter, S; Krastel, D; Ludewig, E; Reischauer, A; Heinicke, F; Pohlmann, S; Wolf, U; Grevel, V; Hildebrandt, G

    2006-12-01

    This prospective study describes the feasibility and toxicity of (192)Iridium high-dose-rate (HDR) brachytherapy as an alternative strategy for the treatment of canine intranasal tumours. Fifteen dogs with malignant intranasal tumours were treated twice weekly using a hypofractionated protocol with eight fractions, 5 Gy per fraction, resulting in a total dose of 40 Gy. Acute and chronic adverse side-effects appeared to be rare. Only 7% of the acute side-effects and 5% of the chronic were classified as severe (grade 3). Eight dogs showed clinical complete remission, and five dogs had partial remission, with a resolution of tumour-related symptoms. Magnetic resonance imaging showed a reduced tumour mass in 12 cases. Median survival time was 17 months (range 4-48 months), with four dogs (three without disease) still alive. Median time to recurrence of these dogs was 14 months. In nine dogs, progression or recurrence of the tumour was the cause of death. This study suggests that HDR brachytherapy is feasible and well tolerated.

  6. Exhaling a budesonide inhaler through the nose results in a significant reduction in dose requirement of budesonide nasal spray in patients having asthma with rhinitis.

    PubMed

    Shaikh, W A

    1999-01-01

    Budesonide, an inhaled corticosteroid is used routinely in the treatment of bronchial asthma and rhinitis. Although inhaled corticosteroids in therapeutic doses are unlikely to result in systemic side effects, there is as yet skepticism about their routine and prolonged use. The aim of this study was to determine whether budesonide inhalation through a metered dose inhaler, when exhaled through the nose could result in a reduction in the dose requirement of budesonide metered nasal spray in patients having perennial allergic asthma with rhinitis. This study was an open, parallel, comparative, crossover trial in which 49 young patients having perennial allergic asthma with rhinitis were divided into two groups and administered either a combination of budesonide metered dose inhaler with a budesonide nasal spray or a budesonide inhaler alone, which was to be exhaled through the nose. Both groups were later crossed over and weekly symptom scores and peak nasal inspiratory flow rates were monitored during each phase of the study. Finally, patients who volunteered from both groups were instructed to note the reduction in dose requirement of budesonide nasal spray while using a budesonide inhaler and exhaling it through the nose. The results of this study reveal that when a budesonide inhaler is exhaled through the nose, it results in an improvement in symptom scores and peak nasal inspiratory flow rates, which were significantly less than those obtained in the group using both a budesonide nasal spray and a metered dose inhaler. In addition, exhaling budesonide through the nose results in a 40.1% reduction in the dose requirement of a budesonide nasal spray, which is statistically significant (p < 0.001).

  7. Determination of errors in derived magnetic field directions in geosynchronous orbit: results from a statistical approach

    DOE PAGES

    Chen, Yue; Cunningham, Gregory; Henderson, Michael

    2016-09-21

    This study aims to statistically estimate the errors in local magnetic field directions that are derived from electron directional distributions measured by Los Alamos National Laboratory geosynchronous (LANL GEO) satellites. First, by comparing derived and measured magnetic field directions along the GEO orbit to those calculated from three selected empirical global magnetic field models (including a static Olson and Pfitzer 1977 quiet magnetic field model, a simple dynamic Tsyganenko 1989 model, and a sophisticated dynamic Tsyganenko 2001 storm model), it is shown that the errors in both derived and modeled directions are at least comparable. Second, using a newly developedmore » proxy method as well as comparing results from empirical models, we are able to provide for the first time circumstantial evidence showing that derived magnetic field directions should statistically match the real magnetic directions better, with averaged errors  < ∼ 2°, than those from the three empirical models with averaged errors  > ∼ 5°. In addition, our results suggest that the errors in derived magnetic field directions do not depend much on magnetospheric activity, in contrast to the empirical field models. Finally, as applications of the above conclusions, we show examples of electron pitch angle distributions observed by LANL GEO and also take the derived magnetic field directions as the real ones so as to test the performance of empirical field models along the GEO orbits, with results suggesting dependence on solar cycles as well as satellite locations. This study demonstrates the validity and value of the method that infers local magnetic field directions from particle spin-resolved distributions.« less

  8. Determination of errors in derived magnetic field directions in geosynchronous orbit: results from a statistical approach

    NASA Astrophysics Data System (ADS)

    Chen, Yue; Cunningham, Gregory; Henderson, Michael

    2016-09-01

    This study aims to statistically estimate the errors in local magnetic field directions that are derived from electron directional distributions measured by Los Alamos National Laboratory geosynchronous (LANL GEO) satellites. First, by comparing derived and measured magnetic field directions along the GEO orbit to those calculated from three selected empirical global magnetic field models (including a static Olson and Pfitzer 1977 quiet magnetic field model, a simple dynamic Tsyganenko 1989 model, and a sophisticated dynamic Tsyganenko 2001 storm model), it is shown that the errors in both derived and modeled directions are at least comparable. Second, using a newly developed proxy method as well as comparing results from empirical models, we are able to provide for the first time circumstantial evidence showing that derived magnetic field directions should statistically match the real magnetic directions better, with averaged errors < ˜ 2°, than those from the three empirical models with averaged errors > ˜ 5°. In addition, our results suggest that the errors in derived magnetic field directions do not depend much on magnetospheric activity, in contrast to the empirical field models. Finally, as applications of the above conclusions, we show examples of electron pitch angle distributions observed by LANL GEO and also take the derived magnetic field directions as the real ones so as to test the performance of empirical field models along the GEO orbits, with results suggesting dependence on solar cycles as well as satellite locations. This study demonstrates the validity and value of the method that infers local magnetic field directions from particle spin-resolved distributions.

  9. ENVISAT ASAR satellite offshore wind resource statistics in Iceland compared to NORA10 model results

    NASA Astrophysics Data System (ADS)

    Bay Hasager, Charlotte; Badger, Merete; Rugaard Furevik, Birgitte; Nawri, Nikolai; Nína Petersen, Guðrún; Björnsson, Halldór; Ferhat Bingol, Ferhat; Clausen, Niels-Erik

    2014-05-01

    In Iceland the offshore regions have been investigated from satellite images from the Envisat Advanced Synthetic Aperture Radar (SAR) from the European Space Agency. The data have been retrieved from 2002 to 2012. Each satellite image has been calibrated and thereafter the CMOD5.N geophysical model function has been used to calculate the wind speed. Each resulting pixel is 1 km by 1 km. The wind direction is taken from the US Navy Operational Global Atmospheric Prediction System (NOGAPS) model. It has much lower spatial resolution and therefore the model wind directions are interpolated in space and time before performing the SAR-based wind retrieval. In total 2,500 images have been processed. This results in average 300 overlapping images. More data were available in the northern part of Iceland; therefore the number of overlapping samples is around 400 here and only 200 at the southern coast. The wind resource statistics of mean wind speed, Weibull scale and shape parameters and energy density have been calculated using the Satellite-WAsP (S-WAsP) program. The coastline of Iceland is complex. The individual wind maps from SAR reveal a multitude of atmospheric phenomena including lee effects and gap flows in the fjords. The wind resource statistics shows the mean wind speed to range from 5 to 8 m/s at 10 m height above the sea level. Selected case study areas are being defined for further investigation. SAR-derived wind maps have the advantage of covering the coastal zone. Further offshore the SAR-derived winds will be compared to the NORA10 atmospheric model results and scatterometer winds. In Iceland the wind resources on land are promising for wind energy application but it is not yet exploited. The study on the offshore wind resource is useful as pre-feasibility in case this clean energy resource is to be exploited at a later stage. The work is part of the Nordic Icewind project.

  10. Statistical Analysis of Deflation in Covariance and Resultant Pc Values for AQUA, AURA and TERRA

    NASA Technical Reports Server (NTRS)

    Hasan, Syed O.

    2016-01-01

    This presentation will display statistical analysis performed for raw conjunction CDMs received for the EOS Aqua, Aura and Terra satellites within the period of February 2015 through July 2016. The analysis performed indicates a discernable deflation in covariance calculated at the JSpOC after the utilization of the dynamic drag consider parameter was implemented operationally in May 2015. As a result, the overall diminution in the conjunction plane intersection of the primary and secondary objects appears to be leading to reduced probability of collision (Pc) values for these conjunction events. This presentation also displays evidence for this theory with analysis of Pc trending plots using data calculated by the SpaceNav CRMS system.

  11. Convergence and shear statistics in galaxy clusters as a result of Monte Carlo simulations

    NASA Astrophysics Data System (ADS)

    Poplavsky, Alexander

    2016-03-01

    In this paper the influence of galaxy cluster halo environment on the deflection properties of its galaxies is investigated. For this purpose circular and elliptical projected cluster haloes obeying Einasto density profiles are modelled in the \\varLambdaCDM cosmological model. By Monte-Carlo simulations external shear and convergence are calculated for random positions of a test galaxy within its cluster. Throughout the simulations the total virial mass, profile concentration and slope parameters are varied both for cluster and its galaxies. The cluster is composed of smooth matter distribution (intergalactic gas and dark matter) and randomly placed galaxies. As a result of multiple simulation runs robust statistical estimations of external shear and convergence are derived for variable cluster characteristics and its redshift. In addition, the models for external shear and convergence are applied for the galaxy lens seen through the cluster IRC-0218.

  12. Statistical analysis of the inherent variability in the results of evolutionary debris models

    NASA Astrophysics Data System (ADS)

    Lidtke, Aleksander A.; Lewis, Hugh G.; Armellin, Roberto

    2017-04-01

    Space debris simulations, e.g. those performed by the Inter-Agency Debris Coordination Committee (Liou et al., 2013), showed that the number of objects in orbit is likely to increase. This study analyses the uncertainty in the results of space debris simulations performed using semi-stochastic models that necessitate the use of Monte Carlo simulations, which are often used by the Inter-Agency Debris Coordination Committee, amongst other studies. Statistics of the possible numbers of objects in orbit and collisions over the next 200 years are generated for the ;mitigation only; scenario using a sample of 25,000 Monte Carlo runs. Bootstraps on the mean, median, variance, skewness and kurtosis of these distributions are performed. It is shown that the distribution of the objects predicted to be on-orbit becomes log-normal as collisions occur, and that Monte Carlo samples larger than traditionally used are needed to capture the debris simulation uncertainty.

  13. Exact statistical results for binary mixing and reaction in variable density turbulence

    NASA Astrophysics Data System (ADS)

    Ristorcelli, J. R.

    2017-02-01

    We report a number of rigorous statistical results on binary active scalar mixing in variable density turbulence. The study is motivated by mixing between pure fluids with very different densities and whose density intensity is of order unity. Our primary focus is the derivation of exact mathematical results for mixing in variable density turbulence and we do point out the potential fields of application of the results. A binary one step reaction is invoked to derive a metric to asses the state of mixing. The mean reaction rate in variable density turbulent mixing can be expressed, in closed form, using the first order Favre mean variables and the Reynolds averaged density variance, ⟨ρ2⟩ . We show that the normalized density variance, ⟨ρ2⟩ , reflects the reduction of the reaction due to mixing and is a mix metric. The result is mathematically rigorous. The result is the variable density analog, the normalized mass fraction variance ⟨c2⟩ used in constant density turbulent mixing. As a consequence, we demonstrate that use of the analogous normalized Favre variance of the mass fraction, c″ ⁣2˜ , as a mix metric is not theoretically justified in variable density turbulence. We additionally derive expressions relating various second order moments of the mass fraction, specific volume, and density fields. The central role of the density specific volume covariance ⟨ρ v ⟩ is highlighted; it is a key quantity with considerable dynamical significance linking various second order statistics. For laboratory experiments, we have developed exact relations between the Reynolds scalar variance ⟨c2⟩ its Favre analog c″ ⁣2˜ , and various second moments including ⟨ρ v ⟩ . For moment closure models that evolve ⟨ρ v ⟩ and not ⟨ρ2⟩ , we provide a novel expression for ⟨ρ2⟩ in terms of a rational function of ⟨ρ v ⟩ that avoids recourse to Taylor series methods (which do not converge for large density differences). We have derived

  14. High-Dose Conformal Radiotherapy Reduces Prostate Cancer-Specific Mortality: Results of a Meta-analysis

    SciTech Connect

    Viani, Gustavo Arruda; Godoi Bernardes da Silva, Lucas; Stefano, Eduardo Jose

    2012-08-01

    Purpose: To determine in a meta-analysis whether prostate cancer-specific mortality (PCSM), biochemical or clinical failure (BCF), and overall mortality (OM) in men with localized prostate cancer treated with conformal high-dose radiotherapy (HDRT) are better than those in men treated with conventional-dose radiotherapy (CDRT). Methods and Materials: The MEDLINE, Embase, CANCERLIT, and Cochrane Library databases, as well as the proceedings of annual meetings, were systematically searched to identify randomized, controlled studies comparing conformal HDRT with CDRT for localized prostate cancer. Results: Five randomized, controlled trials (2508 patients) that met the study criteria were identified. Pooled results from these randomized, controlled trials showed a significant reduction in the incidence of PCSM and BCF rates at 5 years in patients treated with HDRT (p = 0.04 and p < 0.0001, respectively), with an absolute risk reduction (ARR) of PCSM and BCF at 5 years of 1.7% and 12.6%, respectively. Two trials evaluated PCSM with 10 years of follow up. The pooled results from these trials showed a statistical benefit for HDRT in terms of PCSM (p = 0.03). In the subgroup analysis, trials that used androgen deprivation therapy (ADT) showed an ARR for BCF of 12.9% (number needed to treat = 7.7, p < 0.00001), whereas trials without ADT had an ARR of 13.6% (number needed to treat = 7, p < 0.00001). There was no difference in the OM rate at 5 and 10 years (p = 0.99 and p = 0.11, respectively) between the groups receiving HDRT and CDRT. Conclusions: This meta-analysis is the first study to show that HDRT is superior to CDRT in preventing disease progression and prostate cancer-specific death in trials that used conformational technique to increase the total dose. Despite the limitations of our study in evaluating the role of ADT and HDRT, our data show no benefit for HDRT arms in terms of BCF in trials with or without ADT.

  15. DYNAMIC STABILITY OF THE SOLAR SYSTEM: STATISTICALLY INCONCLUSIVE RESULTS FROM ENSEMBLE INTEGRATIONS

    SciTech Connect

    Zeebe, Richard E.

    2015-01-01

    Due to the chaotic nature of the solar system, the question of its long-term stability can only be answered in a statistical sense, for instance, based on numerical ensemble integrations of nearby orbits. Destabilization of the inner planets, leading to close encounters and/or collisions can be initiated through a large increase in Mercury's eccentricity, with a currently assumed likelihood of ∼1%. However, little is known at present about the robustness of this number. Here I report ensemble integrations of the full equations of motion of the eight planets and Pluto over 5 Gyr, including contributions from general relativity. The results show that different numerical algorithms lead to statistically different results for the evolution of Mercury's eccentricity (e{sub M}). For instance, starting at present initial conditions (e{sub M}≃0.21), Mercury's maximum eccentricity achieved over 5 Gyr is, on average, significantly higher in symplectic ensemble integrations using heliocentric rather than Jacobi coordinates and stricter error control. In contrast, starting at a possible future configuration (e{sub M}≃0.53), Mercury's maximum eccentricity achieved over the subsequent 500 Myr is, on average, significantly lower using heliocentric rather than Jacobi coordinates. For example, the probability for e{sub M} to increase beyond 0.53 over 500 Myr is >90% (Jacobi) versus only 40%-55% (heliocentric). This poses a dilemma because the physical evolution of the real system—and its probabilistic behavior—cannot depend on the coordinate system or the numerical algorithm chosen to describe it. Some tests of the numerical algorithms suggest that symplectic integrators using heliocentric coordinates underestimate the odds for destabilization of Mercury's orbit at high initial e{sub M}.

  16. Voluntarily exposure to a single, high dose of probiotic Escherichia coli results in prolonged colonisation.

    PubMed

    Wassenaar, T M; Beimfohr, C; Geske, T; Zimmermann, K

    2014-12-01

    The ability of probiotic Escherichia coli to colonise the human gut was determined in a volunteer study following national (German) regulations. Five persons voluntarily took a single, high dose of Symbioflor®2, which contains 6 different probiotic E. coli genotypes, to assess tolerance of the product, after which presence of E. coli in their faeces was tested for a follow-up period of 30 weeks. Intake of the product did not result in severe side effect in any of the individuals, though mild side effects were observed. Stool analysis showed that the probiotic E. coli had colonised all five persons for a period of 10 to 30 weeks (mean: 18.7 weeks, median: 25.7 weeks). In two individuals there was evidence of competition between host E. coli and probiotic E. coli, while in two others total E. coli levels increased persistently with at least a factor of 10 as a result of the received dose. In one individual, who had lacked detectable levels of faecal E. coli at the start of the post-authorisation safety study, long-term colonisation was established, first by probiotic E. coli exclusively, which were later replaced by host E. coli strains. In four out of five individuals, total E. coli faecal counts were higher on average than at the start of the experiment, while in none total levels exceeded 5×107 cfu/g. When the specific genotypes of the 6 probiotic E. coli were analysed, it was found that one and the same common genotype was responsible for prolonged colonisation in all five individuals.

  17. Statistical Results on Filtering and Epi-convergence for Learning-Based Model Predictive Control

    DTIC Science & Technology

    2011-12-17

    be described by ordinary differential equations (ODE’s). The second part provides proofs concerning the epi-convergence of different statistical...and statistical identi cation (or learning) of unmodeled dynamics, for dynamical systems that can be described by ordinary di erential equations (ODE’s... differential equations (ODE’s). The second part is found in Section 4 and pro- vides proofs concerning the epi-convergence of different statistical

  18. Statistical analyses of the U.S. Air Force Bioventing Initiative results

    SciTech Connect

    Leeson, A.; Kumar, P.; Hinchee, R.E.; Downey, D.; Vogel, C.M.; Sayles, G.D.; Miller, R.N.

    1995-12-31

    The US Air Force`s Bioventing Initiative has involved conducting field treatability studies to evaluate bioventing feasibility at more than 120 sites throughout the US. At those sites where feasibility studies produced positive results, pilot-scale bioventing systems were installed and operated for 1 year. The results from the pilot-scale bioventing systems have been used to develop a large database from which to determine the most important parameters to be used in evaluating whether to implement bioventing. Data generated from the Bioventing Initiative were subjected to a thorough statistical analysis to determine which parameters correlate with BTEX and TPH biodegradation rates. The study involved in situ respiration test data, soil gas permeability test data, and soil chemistry and nutrient data from each site. Results from the Bioventing Initiative demonstrated that some biodegradation occurred at virtually all sites regardless of site conditions. Data collected from the sites demonstrate that even sites with low nutrient levels exhibit significant microbial activity and will therefore respond well to bioventing.

  19. Standard dosing of amikacin and gentamicin in critically ill patients results in variable and subtherapeutic concentrations.

    PubMed

    Roger, Claire; Nucci, Bastian; Molinari, Nicolas; Bastide, Sophie; Saissi, Gilbert; Pradel, Gael; Barbar, Saber; Aubert, Clément; Lloret, Sophie; Elotmani, Loubna; Polge, Anne; Lefrant, Jean-Yves; Roberts, Jason A; Muller, Laurent

    2015-07-01

    Low peak plasma concentrations (Cmax) of amikacin and gentamicin are reported in intensive care unit (ICU) patients after administration of the first dose. The present study aimed to describe the proportion of ICU patients in whom an adequate Cmax was achieved throughout the course of therapy. Septic ICU patients with an indication for intravenous amikacin or gentamicin were eligible for inclusion in this single-centre observational study. The first and subsequent doses and the corresponding Cmax values were recorded. The target Cmax was ≥60mg/L for amikacin and ≥30mg/L for gentamicin. Amikacin and gentamicin plasma concentrations were available in 66 and 24 patients, respectively (59±17 years; 79±19kg; height 169±12cm; SAPS II score 46±19). Pulmonary, abdominal and urinary tract infections were diagnosed in 64 patients. Culture-positive infection was confirmed in 65 patients (72%). A target first Cmax was achieved in 17/90 patients (19%). For amikacin, the target Cmax was achieved in 16/66 patients (24%) after the initial dose. In the 50 remaining patients, a change in dosing was performed in 14 patients, leading adequate peak plasma level in 2 patients. For gentamicin, the targeted Cmax was achieved in only 1/24 patient (4%) after the initial dose and was never achieved after the third dose. In conclusion, standard dosing of amikacin or gentamicin led to adequate Cmax in only 19% of patients. Subtherapeutic Cmax were not significantly corrected after subsequent doses.

  20. A guideline for reporting results of statistical analysis in Japanese Journal of Clinical Oncology.

    PubMed

    Fukuda, H; Ohashi, Y

    1997-06-01

    The paper gives guidelines to authors on the use of statistics, including statistical considerations when designing studies. Information on this article plus a list of other recommended books is available on the World Wide Web (http:/(/)wwwinfo.ncc.go.jp/jjco/) in Japanese as well as English.

  1. "What If" Analyses: Ways to Interpret Statistical Significance Test Results Using EXCEL or "R"

    ERIC Educational Resources Information Center

    Ozturk, Elif

    2012-01-01

    The present paper aims to review two motivations to conduct "what if" analyses using Excel and "R" to understand the statistical significance tests through the sample size context. "What if" analyses can be used to teach students what statistical significance tests really do and in applied research either prospectively to estimate what sample size…

  2. Statistical methods for a three-period crossover design in which high dose cannot be used first.

    PubMed

    Peace, K E; Koch, G G

    1993-03-01

    Design and analysis methods for the three-period crossover trial defined by the sequences: (D0, D1, D2), (D1, D0, D2), and (D1, D2, D0), where D0 is a placebo, and D1 and D2 are a low dose and a high dose of a drug, respectively, are developed. This design may be used when investigators are unwilling to administer a higher dose of a new drug to a patient before administering a lower dose. In using this design, patients should be randomized to sequences in blocks that are integer multiples of 3. Both parametric and non-parametric analysis methods are based on contrasts that capture intrapatient variability only and provide unbiased estimates and hypothesis tests of pairwise differences between carryover, direct dose, and period effects. The design and methods are illustrated with data reflecting the cognitive component of the Alzheimer's disease assessment scale collected in a large clinical trial of Tacrine at doses of 0, 40, and 80 mg/day.

  3. Low kilovoltage peak (kVp) with an adaptive statistical iterative reconstruction algorithm in computed tomography urography: evaluation of image quality and radiation dose

    PubMed Central

    Zhou, Zhiguo; Chen, Haixi; Wei, Wei; Zhou, Shanghui; Xu, Jingbo; Wang, Xifu; Wang, Qingguo; Zhang, Guixiang; Zhang, Zhuoli; Zheng, Linfeng

    2016-01-01

    Purpose: The purpose of this study was to evaluate the image quality and radiation dose in computed tomography urography (CTU) images acquired with a low kilovoltage peak (kVp) in combination with an adaptive statistical iterative reconstruction (ASiR) algorithm. Methods: A total of 45 subjects (18 women, 27 men) who underwent CTU with kV assist software for automatic selection of the optimal kVp were included and divided into two groups (A and B) based on the kVp and image reconstruction algorithm: group A consisted of patients who underwent CTU with a 80 or 100 kVp and whose images were reconstructed with the 50% ASiR algorithm (n=32); group B consisted of patients who underwent CTU with a 120 kVp and whose images were reconstructed with the filtered back projection (FBP) algorithm (n=13). The images were separately reconstructed with volume rendering (VR) and maximum intensity projection (MIP). Finally, the image quality was evaluated using an image score, CT attenuation, image noise, the contrast-to-noise ratio (CNR) of the renal pelvis-to-abdominal visceral fat and the signal-to-noise ratio (SNR) of the renal pelvis. The radiation dose was assessed using volume CT dose index (CTDIvol), dose-length product (DLP) and effective dose (ED). Results: For groups A and B, the subjective image scores for the VR reconstruction images were 3.9±0.4 and 3.8±0.4, respectively, while those for the MIP reconstruction images were 3.8±0.4 and 3.6±0.6, respectively. No significant difference was found (p>0.05) between the two groups’ image scores for either the VR or MIP reconstruction images. Additionally, the inter-reviewer image scores did not significantly differ (p>0.05). The mean attenuation of the bilateral renal pelvis in group A was significantly higher than that in group B (271.4±57.6 vs. 221.8±35.3 HU, p<0.05), whereas the image noise in group A was significantly lower than that in group B (7.9±2.1 vs. 10.5±2.3 HU, p<0.05). The CNR and SNR in group A were

  4. Statistical Analyses of White-Light Flares: Two Main Results about Flare Behaviour

    NASA Astrophysics Data System (ADS)

    Dal, Hasan Ali

    2012-08-01

    We present two main results, based on models and the statistical analyses of 1672 U-band flares. We also discuss the behaviour of white-light flares. In addition, the parameters of the flares detected from two years of observations on CR Dra are presented. By comparing with flare parameters obtained from other UV Ceti-type stars, we examine the behaviour of the optical flare processes along with the spectral types. Moreover, we aimed, using large white-light flare data, to analyse the flare time-scales with respect to some results obtained from X-ray observations. Using SPSS V17.0 and GraphPad Prism V5.02 software, the flares detected from CR Dra were modelled with the OPEA function, and analysed with the t-Test method to compare similar flare events in other stars. In addition, using some regression calculations in order to derive the best histograms, the time-scales of white-light flares were analysed. Firstly, CR Dra flares have revealed that white-light flares behave in a similar way as their counterparts observed in X-rays. As can be seen in X-ray observations, the electron density seems to be a dominant parameter in white-light flare process, too. Secondly, the distributions of the flare time-scales demonstrate that the number of observed flares reaches a maximum value in some particular ratios, which are 0.5, or its multiples, and especially positive integers. The thermal processes might be dominant for these white-light flares, while non-thermal processes might be dominant in the others. To obtain better results for the behaviour of the white-light flare process along with the spectral types, much more stars in a wide spectral range, from spectral type dK5e to dM6e, must be observed in white-light flare patrols.

  5. WE-G-18A-04: 3D Dictionary Learning Based Statistical Iterative Reconstruction for Low-Dose Cone Beam CT Imaging

    SciTech Connect

    Bai, T; Yan, H; Shi, F; Jia, X; Jiang, Steve B.; Lou, Y; Xu, Q; Mou, X

    2014-06-15

    Purpose: To develop a 3D dictionary learning based statistical reconstruction algorithm on graphic processing units (GPU), to improve the quality of low-dose cone beam CT (CBCT) imaging with high efficiency. Methods: A 3D dictionary containing 256 small volumes (atoms) of 3x3x3 voxels was trained from a high quality volume image. During reconstruction, we utilized a Cholesky decomposition based orthogonal matching pursuit algorithm to find a sparse representation on this dictionary basis of each patch in the reconstructed image, in order to regularize the image quality. To accelerate the time-consuming sparse coding in the 3D case, we implemented our algorithm in a parallel fashion by taking advantage of the tremendous computational power of GPU. Evaluations are performed based on a head-neck patient case. FDK reconstruction with full dataset of 364 projections is used as the reference. We compared the proposed 3D dictionary learning based method with a tight frame (TF) based one using a subset data of 121 projections. The image qualities under different resolutions in z-direction, with or without statistical weighting are also studied. Results: Compared to the TF-based CBCT reconstruction, our experiments indicated that 3D dictionary learning based CBCT reconstruction is able to recover finer structures, to remove more streaking artifacts, and is less susceptible to blocky artifacts. It is also observed that statistical reconstruction approach is sensitive to inconsistency between the forward and backward projection operations in parallel computing. Using high a spatial resolution along z direction helps improving the algorithm robustness. Conclusion: 3D dictionary learning based CBCT reconstruction algorithm is able to sense the structural information while suppressing noise, and hence to achieve high quality reconstruction. The GPU realization of the whole algorithm offers a significant efficiency enhancement, making this algorithm more feasible for potential

  6. SOLAR LIMB PROMINENCE CATCHER AND TRACKER (SLIPCAT): AN AUTOMATED SYSTEM AND ITS PRELIMINARY STATISTICAL RESULTS

    SciTech Connect

    Wang Yuming; Cao Hao; Chen Junhong; Zhang Tengfei; Yu Sijie; Zheng Huinan; Shen Chenglong; Wang, S.; Zhang Jie

    2010-07-10

    In this paper, we present an automated system, which has the capability to catch and track solar limb prominences based on observations from the extreme-ultraviolet (EUV) 304 A passband. The characteristic parameters and their evolution, including height, position angle, area, length, and brightness, are obtained without manual interventions. By applying the system to the STEREO-B/SECCHI/EUVI 304 A data during 2007 April-2009 October, we obtain a total of 9477 well-tracked prominences and a catalog of these events available online. A detailed analysis of these prominences suggests that the system has a rather good performance. We have obtained several interesting statistical results based on the catalog. Most prominences appear below the latitude of 60{sup 0} and at the height of about 26 Mm above the solar surface. Most of them are quite stable during the period they are tracked. Nevertheless, some prominences have an upward speed of more than 100 km s{sup -1}, and some others show significant downward and/or azimuthal speeds. There are strong correlations among the brightness, area, and height. The expansion of a prominence is probably one major cause of its fading during the rising or erupting process.

  7. AN UPDATED CATALOG OF M33 CLUSTERS AND CANDIDATES: UBVRI PHOTOMETRY AND SOME STATISTICAL RESULTS

    SciTech Connect

    Ma Jun

    2012-08-15

    We present UBVRI photometry for 392 star clusters and candidates in the field of M33, which are selected from the most recent star cluster catalog. In this catalog, the authors listed star clusters' parameters such as cluster positions, magnitudes, colors in the UBVRIJHK{sub s} filters, and so on. However, a large fraction of objects in this catalog do not have previously published photometry. Photometry is performed using archival images from the Local Group Galaxies Survey, which covers 0.8 deg{sup 2} along the major axis of M33. Detailed comparisons show that, in general, our photometry is consistent with previous measurements. Positions (right ascension and declination) for some clusters are corrected here. Combined with previous literature, ours constitute a large sample of M33 star clusters. Based on this cluster sample, we present some statistical results: none of the youngest M33 clusters ({approx}10{sup 7} yr) have masses approaching 10{sup 5} M{sub Sun} ; roughly half the star clusters are consistent with the 10{sup 4}-10{sup 5} M{sub Sun} mass models; the continuous distribution of star clusters along the model line indicates that M33 star clusters have been formed continuously from the epoch of the first star cluster formation until recent times; and there are {approx}50 star clusters which are overlapped with the Galactic globular clusters on the color-color diagram, and these clusters are old globular cluster candidates in M33.

  8. Electron attachment to SF6 under well defined conditions: comparison of statistical modeling results to experiments

    NASA Astrophysics Data System (ADS)

    Miller, T. M.; Viggiano, A. A.; Troe, J.

    2008-05-01

    Experiments were carried out using a flowing-afterglow Langmuir-probe apparatus to measure rate constants for electron attachment to SF6 and thermal detachment from SF6-. In a recent series of papers, these results were combined with new and existing data on nondissociative and dissociative attachment to SF6 and compared to statistical modeling of the various processes involved in the stabilization of the ionic products of attachment. This paper gives a summary of those findings. The major conclusions are: (a) only the ground electronic state of SF6- needs to be invoked to explain available data; (b) the electron affinity of SF6 is higher than previously thought, namely, EA(SF6) = 1.20 (± 0.05) eV; (c) the endothermicity of the dissociative electron attachment reaction that yields SF5- is 0.41 eV (± 0.05) eV at 0 K; (d) combining these two numbers gives the bond energy D0o(F—SF5-) = 1.61 (± 0.05) eV.

  9. Offsite radiation doses from Hanford Operations for the years 1983 through 1987: A comparison of results calculated by two methods

    SciTech Connect

    Soldat, J.K.

    1989-10-01

    This report compares the results of the calculation of potential radiation doses to the public by two different environmental dosimetric systems for the years 1983 through 1987. Both systems project the environmental movement of radionuclides released with effluents from Hanford operations; their concentrations in air, water, and foods; the intake of radionuclides by ingestion and inhalation; and, finally, the potential radiation doses from radionuclides deposited in the body and from external sources. The first system, in use for the past decade at Hanford, calculates radiation doses in terms of 50-year cumulative dose equivalents to body organs and to the whole body, based on the methodology defined in ICRP Publication 2. This system uses a suite of three computer codes: PABLM, DACRIN, and KRONIC. In the new system, 50-year committed doses are calculated in accordance with the recommendations of the ICRP Publications 26 and 30, which were adopted by the US Department of Energy (DOE) in 1985. This new system calculates dose equivalent (DE) to individual organs and effective dose equivalent (EDE). The EDE is a risk-weighted DE that is designed to be an indicator of the potential health effects arising from the radiation dose. 16 refs., 1 fig., 38 tabs.

  10. Compendium of Single-Event Latchup and Total Ionizing Dose Test Results of Commercial Analog to Digital Converters

    NASA Technical Reports Server (NTRS)

    Irom, Farokh; Agarwal, Shri G.

    2012-01-01

    This paper reports single-event latchup and total dose results for a variety of analog to digital converters targeted for possible use in NASA spacecraft's. The compendium covers devices tested over the last 15 years.

  11. Exploring discrepancies between quantitative validation results and the geomorphic plausibility of statistical landslide susceptibility maps

    NASA Astrophysics Data System (ADS)

    Steger, Stefan; Brenning, Alexander; Bell, Rainer; Petschko, Helene; Glade, Thomas

    2016-06-01

    Empirical models are frequently applied to produce landslide susceptibility maps for large areas. Subsequent quantitative validation results are routinely used as the primary criteria to infer the validity and applicability of the final maps or to select one of several models. This study hypothesizes that such direct deductions can be misleading. The main objective was to explore discrepancies between the predictive performance of a landslide susceptibility model and the geomorphic plausibility of subsequent landslide susceptibility maps while a particular emphasis was placed on the influence of incomplete landslide inventories on modelling and validation results. The study was conducted within the Flysch Zone of Lower Austria (1,354 km2) which is known to be highly susceptible to landslides of the slide-type movement. Sixteen susceptibility models were generated by applying two statistical classifiers (logistic regression and generalized additive model) and two machine learning techniques (random forest and support vector machine) separately for two landslide inventories of differing completeness and two predictor sets. The results were validated quantitatively by estimating the area under the receiver operating characteristic curve (AUROC) with single holdout and spatial cross-validation technique. The heuristic evaluation of the geomorphic plausibility of the final results was supported by findings of an exploratory data analysis, an estimation of odds ratios and an evaluation of the spatial structure of the final maps. The results showed that maps generated by different inventories, classifiers and predictors appeared differently while holdout validation revealed similar high predictive performances. Spatial cross-validation proved useful to expose spatially varying inconsistencies of the modelling results while additionally providing evidence for slightly overfitted machine learning-based models. However, the highest predictive performances were obtained for

  12. High dose intensity combination chemotherapy for advanced epithelial ovarian carcinoma: results of a pilot study.

    PubMed Central

    Sweetenham, J. W.; McKendrick, J. J.; Jones, D. H.; Whitehouse, J. M.; Williams, C. J.

    1990-01-01

    Retrospective studies have recently demonstrated a significant correlation between dose intensity of chemotherapy and response rates and survival in various diseases including epithelial ovarian carcinoma. As part of a proposed randomised trial to assess the effect of dose intensity on outcome in ovarian carcinoma, a pilot study has been undertaken to determine the toxicity and efficacy of the high intensity therapy. Nineteen patients with advanced ovarian carcinoma received initial treatment with cisplatin 120 mg m-2 i.v. day 1, and cyclophosphamide 1,000 mg-2 i.v. day 1, given at 21-day intervals for six cycles. The average relative dose intensity of this therapy is 1.14 when compared with the CHAP regimen. Severe toxicity was experienced by most patients. The median received average relative dose intensity was 0.90, with only one patient receiving treatment to the proposed intensity. Randomised studies of the effect of dose intensity in ovarian carcinoma are essential, but an initial step must be to assess whether the proposed high dose treatment can be delivered. PMID:2155645

  13. Appropriateness of reporting statistical results in orthodontics: the dominance of P values over confidence intervals.

    PubMed

    Polychronopoulou, Argy; Pandis, Nikolaos; Eliades, Theodore

    2011-02-01

    The purpose of this study was to search the orthodontic literature and determine the frequency of reporting of confidence intervals (CIs) in orthodontic journals with an impact factor. The six latest issues of the American Journal of Orthodontics and Dentofacial Orthopedics, the European Journal of Orthodontics, and the Angle Orthodontist were hand searched and the reporting of CIs, P values, and implementation of univariate or multivariate statistical analyses were recorded. Additionally, studies were classified according to the type/design as cross-sectional, case-control, cohort, and clinical trials, and according to the subject of the study as growth/genetics, behaviour/psychology, diagnosis/treatment, and biomaterials/biomechanics. The data were analyzed using descriptive statistics followed by univariate examination of statistical associations, logistic regression, and multivariate modelling. CI reporting was very limited and was recorded in only 6 per cent of the included published studies. CI reporting was independent of journal, study area, and design. Studies that used multivariate statistical analyses had a higher probability of reporting CIs compared with those using univariate statistical analyses. Misunderstanding of the use of P values and CIs may have important implications in implementation of research findings in clinical practice.

  14. Thermospheric and geomagnetic responses to interplanetary coronal mass ejections observed by ACE and GRACE: Statistical results

    NASA Astrophysics Data System (ADS)

    Krauss, S.; Temmer, M.; Veronig, A.; Baur, O.; Lammer, H.

    2015-10-01

    For the period July 2003 to August 2010, the interplanetary coronal mass ejection (ICME) catalogue maintained by Richardson and Cane lists 106 Earth-directed events, which have been measured in situ by plasma and field instruments on board the ACE satellite. We present a statistical investigation of the Earth's thermospheric neutral density response by means of accelerometer measurements collected by the Gravity Recovery And Climate Experiment (GRACE) satellites, which are available for 104 ICMEs in the data set, and its relation to various geomagnetic indices and characteristic ICME parameters such as the impact speed (vmax), southward magnetic field strength (Bz). The majority of ICMEs causes a distinct density enhancement in the thermosphere, with up to a factor of 8 compared to the preevent level. We find high correlations between ICME Bz and thermospheric density enhancements (≈0.9), while the correlation with the ICME impact speed is somewhat smaller (≈0.7). The geomagnetic indices revealing the highest correlations are Dst and SYM-H(≈0.9); the lowest correlations are obtained for Kp and AE (≈0.7), which show a nonlinear relation with the thermospheric density enhancements. Separating the response for the shock-sheath region and the magnetic structure of the ICME, we find that the Dst and SYM-H reveal a tighter relation to the Bz minimum in the magnetic structure of the ICME, whereas the polar cap indices show higher correlations with the Bz minimum in the shock-sheath region. Since the strength of the Bz component—either in the sheath or in the magnetic structure of the ICME—is highly correlated (≈0.9) with the neutral density enhancement, we discuss the possibility of satellite orbital decay estimates based on magnetic field measurements at L1, i.e., before the ICME hits the Earth magnetosphere. These results are expected to further stimulate progress in space weather understanding and applications regarding satellite operations.

  15. Statistical mechanics of two hard spheres in a spherical pore, exact analytic results in D dimension

    NASA Astrophysics Data System (ADS)

    Urrutia, Ignacio; Szybisz, Leszek

    2010-03-01

    This work is devoted to the exact statistical mechanics treatment of simple inhomogeneous few-body systems. The system of two hard spheres (HSs) confined in a hard spherical pore is systematically analyzed in terms of its dimensionality D. The canonical partition function and the one- and two-body distribution functions are analytically evaluated and a scheme of iterative construction of the D +1 system properties is presented. We analyze in detail both the effect of high confinement, when particles become caged, and the low density limit. Other confinement situations are also studied analytically and several relations between the two HSs in a spherical pore, two sticked HSs in a spherical pore, and two HSs on a spherical surface partition functions are traced. These relations make meaningful the limiting caging and low density behavior. Turning to the system of two HSs in a spherical pore, we also analytically evaluate the pressure tensor. The thermodynamic properties of the system are discussed. To accomplish this statement we purposely focus in the overall characteristics of the inhomogeneous fluid system, instead of concentrate in the peculiarities of a few-body system. Hence, we analyze the equation of state, the pressure at the wall, and the fluid-substrate surface tension. The consequences of new results about the spherically confined system of two HSs in D dimension on the confined many HS system are investigated. New constant coefficients involved in the low density limit properties of the open and closed systems of many HS in a spherical pore are obtained for arbitrary D. The complementary system of many HS which surrounds a HS (a cavity inside of a bulk HS system) is also discussed.

  16. Multileaf Collimator Tracking Improves Dose Delivery for Prostate Cancer Radiation Therapy: Results of the First Clinical Trial

    SciTech Connect

    Colvill, Emma; Booth, Jeremy T.; O'Brien, Ricky T.; Eade, Thomas N.; Kneebone, Andrew B.; Poulsen, Per R.; Keall, Paul J.

    2015-08-01

    Purpose: To test the hypothesis that multileaf collimator (MLC) tracking improves the consistency between the planned and delivered dose compared with the dose without MLC tracking, in the setting of a prostate cancer volumetric modulated arc therapy trial. Methods and Materials: Multileaf collimator tracking was implemented for 15 patients in a prostate cancer radiation therapy trial; in total, 513 treatment fractions were delivered. During each treatment fraction, the prostate trajectory and treatment MLC positions were collected. These data were used as input for dose reconstruction (multiple isocenter shift method) to calculate the treated dose (with MLC tracking) and the dose that would have been delivered had MLC tracking not been applied (without MLC tracking). The percentage difference from planned for target and normal tissue dose-volume points were calculated. The hypothesis was tested for each dose-volume value via analysis of variance using the F test. Results: Of the 513 fractions delivered, 475 (93%) were suitable for analysis. The mean difference and standard deviation between the planned and treated MLC tracking doses and the planned and without-MLC tracking doses for all 475 fractions were, respectively, PTV D{sub 99%} −0.8% ± 1.1% versus −2.1% ± 2.7%; CTV D{sub 99%} −0.6% ± 0.8% versus −0.6% ± 1.1%; rectum V{sub 65%} 1.6% ± 7.9% versus −1.2% ± 18%; and bladder V{sub 65%} 0.5% ± 4.4% versus −0.0% ± 9.2% (P<.001 for all dose-volume results). Conclusion: This study shows that MLC tracking improves the consistency between the planned and delivered doses compared with the modeled doses without MLC tracking. The implications of this finding are potentially improved patient outcomes, as well as more reliable dose-volume data for radiobiological parameter determination.

  17. Relation Between Dose of Loop Diuretics and Outcomes in a Heart Failure Population: Results of the ESCAPE Trial

    PubMed Central

    Hasselblad, Vic; Stough, Wendy Gattis; Shah, Monica R.; Lokhnygina, Yuliya; O’Connor, Christopher M.; Califf, Robert M.; Adams, Kirkwood F.

    2007-01-01

    Background We examined the relation of maximal in-hospital diuretic dose to weight loss, changes in renal function, and mortality in hospitalised heart failure (HF) patients. Methods In ESCAPE, 395 patients received diuretics in-hospital. Weight was measured at baseline, discharge, and every other day before discharge. Weight loss was defined as the difference between baseline and last in-hospital weight. Mortality was assessed using a log-logistic model with non-zero background. Results Median weight loss: 2.8 kg (0.7, 6.1); mean: 3.7 kg (22% of values <0). Weight loss and maximum in-hospital dose were correlated (p = 0.0007). Baseline weight, length of stay, and baseline brain natriuretic peptide were significant predictors of weight loss. After adjusting for these, dose was not a significant predictor of weight loss. A strong relation between dose and mortality was seen (p = 0.003), especially at >300 mg/day. Dose remained a significant predictor of mortality after adjusting for baseline variables that significantly predicted mortality. Correlation between maximal dose and creatinine level change was not significant (r = 0.043; p = 0.412) Conclusions High diuretic doses during HF hospitalisation are associated with increased mortality and poor 6-month outcome. PMID:17719273

  18. Mainstreaming Remedial Mathematics Students in Introductory Statistics: Results Using a Randomized Controlled Trial

    ERIC Educational Resources Information Center

    Logue, Alexandra W.; Watanabe-Rose, Mari

    2014-01-01

    This study used a randomized controlled trial to determine whether students, assessed by their community colleges as needing an elementary algebra (remedial) mathematics course, could instead succeed at least as well in a college-level, credit-bearing introductory statistics course with extra support (a weekly workshop). Researchers randomly…

  19. Flipped Statistics Class Results: Better Performance than Lecture over One Year Later

    ERIC Educational Resources Information Center

    Winquist, Jennifer R.; Carlson, Keith A.

    2014-01-01

    In this paper, we compare an introductory statistics course taught using a flipped classroom approach to the same course taught using a traditional lecture based approach. In the lecture course, students listened to lecture, took notes, and completed homework assignments. In the flipped course, students read relatively simple chapters and answered…

  20. Is the applicability of fractal statistics to sedimentary structures the result of scale-invariant stochastic processes or deterministic chaos

    SciTech Connect

    Turcotte, D.L. )

    1991-03-01

    Fractal statistics are the only statistics that are scale invariant. Examples in tectonics include distributions of faults, displacements on faults, distributions and permeabilities of fractures, and distributions of folds. Many aspects of sedimentology are also fractal including distributions of sedimentary sequences, variations in permeability, and shapes of boundaries. Since the underlying processes are likely to be scale invariant, it is reasonable to conclude that the number-size statistics of oil fields will be fractal. Log-normal statistics are often applied; they are not scale invariant. Two explanations for fractal statistics can be given. They may be the result of scale-invariant stochastic processes. Random walk (Brownian noise) is one example. Topography generally resembles Brownian noise, a power-law spectrum with fractal dimension D = 1.5. Alternatively fractal statistics can be the result of deterministic chaos. Turbulent flows are examples of deterministic chaos, the governing equations are deterministic but the resulting flows are statistical. Tectonic displacements can be shown to be the result of deterministic chaos; it is likely that erosion is another example.

  1. Increasing the dose of television advertising in a national antismoking media campaign: results from a randomised field trial

    PubMed Central

    McAfee, Tim; Davis, Kevin C; Shafer, Paul; Patel, Deesha; Alexander, Robert; Bunnell, Rebecca

    2017-01-01

    Background While antismoking media campaigns have demonstrated effectiveness, less is known about the country-level effects of increased media dosing. The 2012 US Tips From Former Smokers (Tips) campaign generated approximately 1.6 million quit attempts overall; however, the specific dose–response from the campaign was only assessed by self-report. Objective Assess the impact of higher ad exposure during the 2013 Tips campaign on quit-related behaviours and intentions, campaign awareness, communication about campaign, and disease knowledge. Methods A 3-month national media buy was supplemented within 67 (of 190) randomly selected local media markets. Higher-dose markets received media buys 3 times that of standard-dose markets. We compared outcomes of interest using data collected via web-based surveys from nationally representative, address-based probability samples of 5733 cigarette smokers and 2843 non-smokers. Results In higher-dose markets, 87.2% of smokers and 83.9% of non-smokers recalled television campaign exposure versus 75.0% of smokers and 73.9% of non-smokers in standard-dose markets. Among smokers overall, the relative quit attempt rate was 11% higher in higher-dose markets (38.8% vs 34.9%; p<0.04). The higher-dose increase was larger in African-Americans (50.9% vs 31.8%; p<0.01). Smokers in higher-dose markets without a mental health condition, with a chronic health condition, or with only some college education made quit attempts at a higher rate than those in standard-dose markets. Non-smokers in higher-dose markets were more likely to talk with family or friends about smoking dangers (43.1% vs 35.7%; p<0.01) and had greater knowledge of smoking-related diseases. Conclusions The US 2013 Tips antismoking media campaign compared standard and higher doses by randomisation of local media markets. Results demonstrate the effectiveness of a higher dose for engaging non-smokers and further increasing quit attempts among smokers, especially African

  2. Results of the Phase I Dose-Escalating Study of Motexafin Gadolinium With Standard Radiotherapy in Patients With Glioblastoma Multiforme

    SciTech Connect

    Ford, Judith M. Seiferheld, Wendy; Alger, Jeffrey R.; Wu, Genevieve; Endicott, Thyra J.; Mehta, Minesh; Curran, Walter; Phan, See-Chun

    2007-11-01

    Purpose: Motexafin gadolinium (MGd) is a putative radiation enhancer initially evaluated in patients with brain metastases. This Phase I trial studied the safety and tolerability of a 2-6-week course (10-22 doses) of MGd with radiotherapy for glioblastoma multiforme. Methods and Materials: A total of 33 glioblastoma multiforme patients received one of seven MGd regimens starting at 10 doses of 4 mg/kg/d MGd and escalating to 22 doses of 5.3 mg/kg/d MGd (5 or 10 daily doses then three times per week). The National Cancer Institute Cancer Therapy Evaluation Program toxicity and stopping rules were applied. Results: The maximal tolerated dose was 5.0 mg/kg/d MGd (5 d/wk for 2 weeks, then three times per week) for 22 doses. The dose-limiting toxicity was reversible transaminase elevation. Adverse reactions included rash/pruritus (45%), chills/fever (30%), and self-limiting vesiculobullous rash of the thumb and fingers (42%). The median survival of 17.6 months prompted a case-matched analysis. In the case-matched analysis, the MGd patients had a median survival of 16.1 months (n = 31) compared with the matched Radiation Therapy Oncology Group database patients with a median survival of 11.8 months (hazard ratio, 0.43; 95% confidence interval, 0.20-0.94). Conclusion: The maximal tolerated dose of MGd with radiotherapy for glioblastoma multiforme in this study was 5 mg/kg/d for 22 doses (daily for 2 weeks, then three times weekly). The baseline survival calculations suggest progression to Phase II trials is appropriate, with the addition of MGd to radiotherapy with concurrent and adjuvant temozolomide.

  3. Differences in Clinical Results After LINAC-Based Single-Dose Radiosurgery Versus Fractionated Stereotactic Radiotherapy for Patients With Vestibular Schwannomas

    SciTech Connect

    Combs, Stephanie E.; Welzel, Thomas; Schulz-Ertner, Daniela; Huber, Peter E.; Debus, Juergen

    2010-01-15

    Purpose: To evaluate the outcomes of patients with vestibular schwannoma (VS) treated with fractionated stereotactic radiotherapy (FSRT) vs. those treated with stereotactic radiosurgery (SRS). Methods and Materials: This study is based on an analysis of 200 patients with 202 VSs treated with FSRT (n = 172) or SRS (n = 30). Patients with tumor progression and/or progression of clinical symptoms were selected for treatment. In 165 out of 202 VSs (82%), RT was performed as the primary treatment for VS, and for 37 VSs (18%), RT was conducted for tumor progression after neurosurgical intervention. For patients receiving FSRT, a median total dose of 57.6 Gy was prescribed, with a median fractionation of 5 x 1.8 Gy per week. For patients who underwent SRS, a median single dose of 13 Gy was prescribed to the 80% isodose. Results: FSRT and SRS were well tolerated. Median follow-up time was 75 months. Local control was not statistically different for both groups. The probability of maintaining the pretreatment hearing level after SRS with doses of <=13 Gy was comparable to that of FSRT. The radiation dose for the SRS group (<=13 Gy vs. >13 Gy) significantly influenced hearing preservation rates (p = 0.03). In the group of patients treated with SRS doses of <=13 Gy, cranial nerve toxicity was comparable to that of the FSRT group. Conclusions: FSRT and SRS are both safe and effective alternatives for the treatment of VS. Local control rates are comparable in both groups. SRS with doses of <=13 Gy is a safe alternative to FSRT. While FSRT can be applied safely for the treatment of VSs of all sizes, SRS should be reserved for smaller lesions.

  4. Mayak Worker Dosimetry System 2008 (MWDS-2008): assessment of internal dose from measurement results of plutonium activity in urine.

    PubMed

    Khokhryakov, Victor V; Khokhryakov, Valentin F; Suslova, Klara G; Vostrotin, Vadim V; Vvedensky, Vladimir E; Sokolova, Alexandra B; Krahenbuhl, Melinda P; Birchall, Alan; Miller, Scott C; Schadilov, Anatoly E; Ephimov, Alexander V

    2013-04-01

    A new modification of the prior human lung compartment plutonium model, Doses-2005, has been described. The modified model was named "Mayak Worker Dosimetry System-2008" (MWDS-2008). In contrast to earlier models developed for workers at the Mayak Production Association (Mayak PA), the new model more correctly describes plutonium biokinetics and metabolism in pulmonary lymph nodes. The MWDS-2008 also provides two sets of doses estimates: one based on bioassay data and the other based on autopsy data, where available. The algorithm of internal dose calculation from autopsy data will be described in a separate paper. Results of comparative analyses of Doses-2005 and MWDS-2008 are provided. Perspectives on the further development of plutonium dosimetry are discussed.

  5. US Geological Survey nutrient preservation experiment : experimental design, statistical analysis, and interpretation of analytical results

    USGS Publications Warehouse

    Patton, Charles J.; Gilroy, Edward J.

    1999-01-01

    Data on which this report is based, including nutrient concentrations in synthetic reference samples determined concurrently with those in real samples, are extensive (greater than 20,000 determinations) and have been published separately. In addition to confirming the well-documented instability of nitrite in acidified samples, this study also demonstrates that when biota are removed from samples at collection sites by 0.45-micrometer membrane filtration, subsequent preservation with sulfuric acid or mercury (II) provides no statistically significant improvement in nutrient concentration stability during storage at 4 degrees Celsius for 30 days. Biocide preservation had no statistically significant effect on the 30-day stability of phosphorus concentrations in whole-water splits from any of the 15 stations, but did stabilize Kjeldahl nitrogen concentrations in whole-water splits from three data-collection stations where ammonium accounted for at least half of the measured Kjeldahl nitrogen.

  6. Effect of experimental parameters and resulting analytical signal statistics in laser-induced breakdown spectroscopy

    NASA Astrophysics Data System (ADS)

    Klus, Jakub; Pořízka, Pavel; Prochazka, David; Novotný, Jan; Novotný, Karel; Kaiser, Jozef

    2016-12-01

    The purpose of this work is to provide detailed study of statistical behavior of different types of analytical signals in typical of Laser-Induced Breakdown Spectroscopy (LIBS) measurements. The main goal of this work is to justify usage of arithmetic mean and standard deviation as statistical estimates of expected value of selected analytical signal. In contrary to the general assumption that LIBS data show Gaussian distribution, this paper deals with the hypothesis that the data rather demonstrate Generalized Extreme Value Distribution. The study is realized on 10 selected lines measured on NIST glass standard. In order to cover wide range of possible applications three different spectra internal standardization techniques and their influence on distribution were studied. Finally, assuming that the data comes from a single distribution and the central limit theorem is valid, the influence of accumulations on the line distribution is examined and discussed. Statistical tools used and described in this paper can be utilized by other researchers to confirm their hypotheses and verify utilization of Gaussian distribution or even novel data processing methods.

  7. Methods used to calculate doses resulting from inhalation of Capstone depleted uranium aerosols.

    PubMed

    Miller, Guthrie; Cheng, Yung Sung; Traub, Richard J; Little, Tom T; Guilmette, Raymond A

    2009-03-01

    The methods used to calculate radiological and toxicological doses to hypothetical persons inside either a U.S. Army Abrams tank or Bradley Fighting Vehicle that has been perforated by depleted uranium munitions are described. Data from time- and particle-size-resolved measurements of depleted uranium aerosol as well as particle-size-resolved measurements of aerosol solubility in lung fluids for aerosol produced in the breathing zones of the hypothetical occupants were used. The aerosol was approximated as a mixture of nine monodisperse (single particle size) components corresponding to particle size increments measured by the eight stages plus the backup filter of the cascade impactors used. A Markov Chain Monte Carlo Bayesian analysis technique was employed, which straightforwardly calculates the uncertainties in doses. Extensive quality control checking of the various computer codes used is described.

  8. Whole organ and islet of Langerhans dosimetry for calculation of absorbed doses resulting from imaging with radiolabeled exendin

    PubMed Central

    van der Kroon, Inge; Woliner-van der Weg, Wietske; Brom, Maarten; Joosten, Lieke; Frielink, Cathelijne; Konijnenberg, Mark W.; Visser, Eric P.; Gotthardt, Martin

    2017-01-01

    Radiolabeled exendin is used for non-invasive quantification of beta cells in the islets of Langerhans in vivo. High accumulation of radiolabeled exendin in the islets raised concerns about possible radiation-induced damage to these islets in man. In this work, islet absorbed doses resulting from exendin-imaging were calculated by combining whole organ dosimetry with small scale dosimetry for the islets. Our model contains the tissues with high accumulation of radiolabeled exendin: kidneys, pancreas and islets. As input for the model, data from a clinical study (radiolabeled exendin distribution in the human body) and from a preclinical study with Biobreeding Diabetes Prone (BBDP) rats (islet-to-exocrine uptake ratio, beta cell mass) were used. We simulated 111In-exendin and 68Ga-exendin absorbed doses in patients with differences in gender, islet size, beta cell mass and radiopharmaceutical uptake in the kidneys. In all simulated cases the islet absorbed dose was small, maximum 1.38 mGy for 68Ga and 66.0 mGy for 111In. The two sources mainly contributing to the islet absorbed dose are the kidneys (33–61%) and the islet self-dose (7.5–57%). In conclusion, all islet absorbed doses are low (<70 mGy), so even repeated imaging will hardly increase the risk on diabetes. PMID:28067253

  9. Statistical analysis of results of carcinogenicity studies of synthetic vitreous fibres at Research and Consulting Company, Geneva.

    PubMed

    Rossiter, C E; Chase, J R

    1995-10-01

    Five inhalation studies of synthetic vitreous fibres have recently investigated experimental tumorigenic responses to four different refractory ceramic fibres (RCF), two fibre glasses, one stone (rock) wool and one slag wool. Except for one RCF, the source materials were typical commercial products. Three studies included positive control groups exposed to chrysotile or crocidolite asbestos. The studies were conducted using state-of-the-art technologies for fibre size separation, fibre lofting and nose-only inhalation exposure. The target average fibre size was 20 microns long by 1 micron diameter. Hamsters exposed to a kaolin RCF yielded a mesothelioma rate of 38%, but no lung cancers. There were no tumours among the chrysotile-exposed hamsters. At the highest dose of 30 mg m-3 in rat studies, the commercial RCF all produced significant numbers of lung tumours, and some mesotheliomas. The fourth RCF, which had been heat-treated to simulate an after-service fibre, did not produce a significant excess of lung cancers, but did produce one mesothelioma. A rat multi-dose experiment with three lower doses of the kaolin RCF yielded one mesothelioma among 379 rats, but no excess of lung tumours. The overall dose-response relation for lung cancer did not appear to be linear, consistent with the possibility of a threshold close to the Maximum Tolerated Dose. No insulation wool (glass, stone or slag) exposure group had a lung tumour rate that differed statistically significantly from the tumour rate for the respective concurrent control groups, sham-exposed to filtered air. There was no significant difference in the total tumour rates between the four insulation wool groups and the control animals, and no significant dose-response relation above the respective sham-exposed control tumour rates. The total lung tumour rates for rats in both chrysotile and crocidolite exposure groups were significantly raised. One animal in each asbestos-exposed group developed a mesothelioma

  10. Dose-response approaches for nuclear receptor-mediated modes of action for liver carcinogenicity: Results of a workshop.

    PubMed

    Andersen, Melvin E; Preston, R Julian; Maier, Andrew; Willis, Alison M; Patterson, Jacqueline

    2014-01-01

    A public workshop, organized by a Steering Committee of scientists from government, industry, universities and research organizations, was held at the National Institute of Environmental Health Sciences (NIEHS) in September, 2010. The workshop explored the dose-response implications of toxicant modes of action (MOA) mediated by nuclear receptors. The dominant paradigm in human health risk assessment has been linear extrapolation without a threshold for cancer, and estimation of sub-threshold doses for non-cancer and (in appropriate cases) cancer endpoints. However, recent publications question the application of dose-response modeling approaches with a threshold. The growing body of molecular toxicology information and computational toxicology tools has allowed for exploration of the presence or absence of sub-threshold doses for a number of receptor-mediated MOAs. The workshop explored the development of dose-response approaches for nuclear receptor-mediated liver cancer, within a MOA Human Relevance Framework (HRF). Case studies addressed activation of the AHR, the CAR and the PPARα. This article describes the workshop process, key issues discussed and conclusions. The value of an interactive workshop approach to apply current MOA/HRF frameworks was demonstrated. The results may help direct research on the MOA and dose-response of receptor-based toxicity, since there are commonalities for many receptors in the basic pathways involved for late steps in the MOA, and similar data gaps in early steps. Three additional papers in this series describe the results and conclusions for each case-study receptor regarding its MOA, relevance of the MOA to humans and the resulting dose-response implications.

  11. The breaking load method - Results and statistical modification from the ASTM interlaboratory test program

    NASA Technical Reports Server (NTRS)

    Colvin, E. L.; Emptage, M. R.

    1992-01-01

    The breaking load test provides quantitative stress corrosion cracking data by determining the residual strength of tension specimens that have been exposed to corrosive environments. Eight laboratories have participated in a cooperative test program under the auspices of ASTM Committee G-1 to evaluate the new test method. All eight laboratories were able to distinguish between three tempers of aluminum alloy 7075. The statistical analysis procedures that were used in the test program do not work well in all situations. An alternative procedure using Box-Cox transformations shows a great deal of promise. An ASTM standard method has been drafted which incorporates the Box-Cox procedure.

  12. New results in omega photoproduction using high-statistics data obtained from CLAS at Jefferson Lab

    SciTech Connect

    Williams, Michael

    2009-01-01

    High-statistics differential cross sections and spin density matrix elements for the reaction {gamma}p --> p{omega} have been measured using the CLAS at Jefferson Lab for center-of-mass energies, W, from threshold up to 2.84 GeV. An event-based partial wave analysis (PWA) has also been performed on the data. This analysis benefits from access to the world's first high precision spin density matrix element measurements, available to the event-based PWA through the decay distribution of omega-->pi+pi-pi0. Strong evidence has been found for nucleon resonance contributions.

  13. Supercomputing enabling exhaustive statistical analysis of genome wide association study data: Preliminary results.

    PubMed

    Reumann, Matthias; Makalic, Enes; Goudey, Benjamin W; Inouye, Michael; Bickerstaffe, Adrian; Bui, Minh; Park, Daniel J; Kapuscinski, Miroslaw K; Schmidt, Daniel F; Zhou, Zeyu; Qian, Guoqi; Zobel, Justin; Wagner, John; Hopper, John L

    2012-01-01

    Most published GWAS do not examine SNP interactions due to the high computational complexity of computing p-values for the interaction terms. Our aim is to utilize supercomputing resources to apply complex statistical techniques to the world's accumulating GWAS, epidemiology, survival and pathology data to uncover more information about genetic and environmental risk, biology and aetiology. We performed the Bayesian Posterior Probability test on a pseudo data set with 500,000 single nucleotide polymorphism and 100 samples as proof of principle. We carried out strong scaling simulations on 2 to 4,096 processing cores with factor 2 increments in partition size. On two processing cores, the run time is 317h, i.e. almost two weeks, compared to less than 10 minutes on 4,096 processing cores. The speedup factor is 2,020 that is very close to the theoretical value of 2,048. This work demonstrates the feasibility of performing exhaustive higher order analysis of GWAS studies using independence testing for contingency tables. We are now in a position to employ supercomputers with hundreds of thousands of threads for higher order analysis of GWAS data using complex statistics.

  14. Dose reduction efforts for pediatric head CT imaging in Washington State trauma centers: follow-up survey results

    PubMed Central

    Kanal, Kalpana M.; Rivara, Frederick P.; Jarvik, Jeffrey G.; Vavilala, Monica S.

    2014-01-01

    Purpose To examine variation in pediatric trauma head CT imaging protocols in Washington State trauma centers (TCs) in 2012 and compare to a previous survey conducted in 2008/09. Methods A mixed-mode (online and paper) survey was sent to all adult and pediatric Washington State TCs (levels 1–5). Respondents provided information about the CT scanner used for pediatric head scans and technical information about pediatric dose reduction protocols. Mean head effective dose and organ dose for a female baby were estimated. Results were compared to previous data. Results Sixty-one of 76 TCs responded to the 2012 survey (response rate 80.3%; response rate in 2008/09 survey was 76%). In 2012, 91.7% reported having a dedicated pediatric protocol (87.7% in 2008/09). Protective shielding use ranged from 80 to 100% across both survey years. In 2012, 2.5 times more TCs provided sufficient information to conduct dose calculations than in 2008/09. Estimated mean CTDIvol was 23.1 mGy in 2012, compared to 34.8 mGy in 2008/09 (p=0.01). Estimated mean DLP was also significantly lower in 2012 than 2009/08 (307.6 mGy*cm vs. 430.1 mGy*cm, respectively; p=0.04). Wide variation in mean effective dose was observed for level 3 and 4 TCs in 2012, similar to variation observed in 2008/09 among level 4 TCs. Mean organ dose was significantly lower in 2012 for eye lens and brain, but higher for thyroid than 2008/09 (p<0.05). Conclusions While most Washington State TCs employ dose reduction protocols for pediatric head CTs, and some measures were lower in 2012, variation in protocols use and estimated dose continues to exist. More complete responses in 2012 suggest improved understanding of the importance of pediatric dose reduction efforts. Education and institutional protocols are necessary to reduce pediatric radiation dose from head CTs. PMID:24360905

  15. The cross-cut statistic and its sensitivity to bias in observational studies with ordered doses of treatment.

    PubMed

    Rosenbaum, Paul R

    2016-03-01

    A common practice with ordered doses of treatment and ordered responses, perhaps recorded in a contingency table with ordered rows and columns, is to cut or remove a cross from the table, leaving the outer corners--that is, the high-versus-low dose, high-versus-low response corners--and from these corners to compute a risk or odds ratio. This little remarked but common practice seems to be motivated by the oldest and most familiar method of sensitivity analysis in observational studies, proposed by Cornfield et al. (1959), which says that to explain a population risk ratio purely as bias from an unobserved binary covariate, the prevalence ratio of the covariate must exceed the risk ratio. Quite often, the largest risk ratio, hence the one least sensitive to bias by this standard, is derived from the corners of the ordered table with the central cross removed. Obviously, the corners use only a portion of the data, so a focus on the corners has consequences for the standard error as well as for bias, but sampling variability was not a consideration in this early and familiar form of sensitivity analysis, where point estimates replaced population parameters. Here, this cross-cut analysis is examined with the aid of design sensitivity and the power of a sensitivity analysis.

  16. Long-term results of low dose total body irradiation for advanced non-Hodgkin lymphoma.

    PubMed

    Lybeert, M L; Meerwaldt, J H; Deneve, W

    1987-08-01

    Sixty-eight patients received fractionated low dose total body irradiation (LTBI) as treatment for non-Hodgkin lymphoma (NHL) at the Rotterdamsch Radio-Therapeutisch Instituut (RRTI) in the period 1973-1979. Ninety percent (61/68) of these patients had advanced disease (Stage III + IV). According to current malignancy grade classifications, 34 patients had low grade NHL, 10 intermediate, and 19 high grade. In 5 cases no exact grading was possible. LTBI was given 3 times a week, midline dose 0.1 Gy, using 6 or 25 MeV photons to a mean total dose of 1.78 Gy. Initial response rate for low, intermediate, and high grade NHL was resp. 84, 42, and 40%. The main prognostic factor for survival and recurrence-free survival (RFS) was malignancy grade. Probability of uncorrected survival at 10 years for low, intermediate, and high grade was resp. 34, 0 and 0%. Probability of RFS at 10 years was resp. 19, 0, and 0%. Neither stage nor sex had any influence on survival. Age was reversely correlated with survival, but was not correlated with RFS. Influence of prior therapy (18 patients) on survival and RFS was separately analyzed. Neither survival nor RFS of unfavorable histologic type NHL (high and intermediate grade) was influenced. On the other hand patients with a favorable histologic type NHL (low grade) had a significantly (p less than 0.05) better RFS if they received LTBI as initial treatment, but survival was not significantly influenced. RFS at 5 and 10 years of patients who received LTBI as first treatment was respectively 32% and 27%. No treatment related complications were noted. Subsequent chemotherapy in case of relapse was not hampered by previous LTBI. The high response rate and extended RFS, without maintenance therapy, makes LTBI a preferable first line treatment for patients with advanced stage low grade NHL.

  17. Safety of the first dose of fingolimod for multiple sclerosis: results of an open-label clinical trial

    PubMed Central

    2014-01-01

    Background In patients with relapsing-remitting MS (RRMS) fingolimod prevents disease relapses and delays disability progression. First dose administration of fingolimod is associated with a transient, dose-dependent decrease in heart rate (HR) in the 6 hours after drug intake. The aim of the study is to to assess safety and tolerability of the first dose of fingolimod in a cohort of Italian patients with RRMS without alternative therapeutic options. Methods Open-label, single arm, multicentre study. After the first dose of fingolimod, patients were observed for 6 hours and had their vital signs monitored hourly. Extended on-site monitoring was provided when required. Results Of the 906 patients enrolled in the study, most (95.2%) did not experience any adverse event (AE) following fingolimod administration. Cardiovascular AEs occurred in 18 patients and included bradycardia (1.3%), first-and second-degree atrioventricular block (0.1% and 0.2%), palpitations (0.1%), sinus arrhythmia (0.1%) and ventricular premature beats (0.1%). All events were self-limiting and did not require any intervention. Extended monitoring was required in 34 patients. Conclusions These results, in a population who better resembled real-world clinical practice in terms of concomitant diseases and medications, are consistent with previous clinical trials and confirmed that the first dose administration of fingolimod is generally safe and well tolerated. Trial registration EudraCT 2011-000770-60 PMID:24690227

  18. Blood phenylalanine concentrations in patients with PAH-deficient hyperphenylalaninaemia off diet without and with three different single oral doses of tetrahydrobiopterin: assessing responsiveness in a model of statistical process control.

    PubMed

    Lindner, M; Gramer, G; Garbade, S F; Burgard, P

    2009-08-01

    Tetrahydrobiopterin (BH(4)) cofactor loading is a standard procedure to differentiate defects of BH(4) metabolism from phenylalanine hydroxylase (PAH) deficiency. BH(4) responsiveness also exists in PAH-deficient patients with high residual PAH activity. Unexpectedly, single cases with presumed nil residual PAH activity have been reported to be BH(4) responsive, too. BH(4) responsiveness has been defined either by a >or=30% reduction of blood Phe concentration after a single BH(4) dose or by a decline greater than the individual circadian Phe level variation. Since both methods have methodological disadvantages, we present a model of statistical process control (SPC) to assess BH(4) responsiveness. Phe levels in 17 adult PKU patients of three phenotypic groups off diet were compared without and with three different single oral dosages of BH(4) applied in a double-blind randomized cross-over design. Results are compared for >or=30% reduction and SPC. The effect of BH(4) by >or=30% reduction was significant for groups (p < 0.01) but not for dose (p = 0.064), with no interaction of group with dose (p = 0.24). SPC revealed significant effects for group (p < 0.01) and the interaction for group with dose (p < 0.05) but not for dose alone (p = 0.87). After one or more loadings, seven patients would be judged to be BH(4) responsive either by the 30% criterion or by the SPC model, but only three by both. Results for patients with identical PAH genotype were not very consistent within (for different BH(4) doses) and between the two models. We conclude that a comparison of protein loadings without and with BH(4) combined with a standardized procedure for data analysis and decision would increase the reliability of diagnostic results.

  19. Results of autologous transplantation in lymphoma are not improved by increasing the dose of etoposide in the BEAM regimen: a single-centre sequential-cohort study.

    PubMed

    Martín, A; Caballero, M D; Pérez-Simón, J A; López-Holgado, N; Mateos, M V; Cañizo, M C; Miguel, J F San

    2004-10-01

    We have undertaken a retrospective sequential-cohort analysis of 131 lymphoma patients treated with the BEAM regimen and autologous stem cell transplantation, to compare BEAM at standard doses (sBEAM; n = 67 from May 1990 to April 1995) and BEAM with escalated etoposide dose from 800 to 1600 mg/m(2) (eBEAM; n = 64 from May 1995 to June 1999). Transplant-related mortality and incidence of secondary malignancies were similar in both groups. Disease progression was significantly lower in indolent lymphoma (IL) patients receiving eBEAM (7 vs 43%), although survival was comparable due to a higher toxic mortality in the eBEAM group. The 5-year event-free survival and overall survival were better in Hodgkin's disease (HD) patients treated with eBEAM (70 and 77%, respectively) compared to sBEAM (58 and 69%, respectively), but the difference was not statistically significant. In aggressive lymphomas, no difference was detected between groups. Our results indicate that while escalation of the etoposide doses in the BEAM conditioning regimen does not appear to improve outcome, encouraging results in IL and HD may warrant further studies.

  20. Measurements of natural radioactivity and the resulting radiation doses from commercial granites.

    PubMed

    Aydarous, A Sh; Zeghib, Sadek; Al-Dughmah, Mohammed

    2010-12-01

    Saudi Arabia is becoming a relatively large market for local and foreign marble and granite use in dwellings. Due to increasing concern about environmental radiological protection, different types of locally widely used granite tiles were collected from different suppliers in the Jeddah province, Saudi Arabia. The analysis for these granite tiles for gamma radiation was conducted by means of a high-resolution HPGe gamma-spectroscopy system. The activity concentrations of (232)Th, (226)Ra and 40K in the selected granite samples ranged from 4.9 to 144, 9.7 to 133 and 168 to 1806 Bq kg(-1), respectively. The data were compared with other granite types and building materials used all over the world. The absorbed dose rates, effective dose rates, radium equivalent activities as well as the radiation hazard indices were estimated. The radium equivalent activities (Ra(eq)) are lower than the limit of 370 Bq kg(-1) set by the Organisation for Economic Cooperation and Development (Exposure to radiation from the natural radioactivity in building materials. Report by a Group of Experts of the OECD, Nuclear Energy Agency, OECD, Paris, 1979) except in three samples.

  1. A method for calculating Bayesian uncertainties on internal doses resulting from complex occupational exposures.

    PubMed

    Puncher, M; Birchall, A; Bull, R K

    2012-08-01

    Estimating uncertainties on doses from bioassay data is of interest in epidemiology studies that estimate cancer risk from occupational exposures to radionuclides. Bayesian methods provide a logical framework to calculate these uncertainties. However, occupational exposures often consist of many intakes, and this can make the Bayesian calculation computationally intractable. This paper describes a novel strategy for increasing the computational speed of the calculation by simplifying the intake pattern to a single composite intake, termed as complex intake regime (CIR). In order to assess whether this approximation is accurate and fast enough for practical purposes, the method is implemented by the Weighted Likelihood Monte Carlo Sampling (WeLMoS) method and evaluated by comparing its performance with a Markov Chain Monte Carlo (MCMC) method. The MCMC method gives the full solution (all intakes are independent), but is very computationally intensive to apply routinely. Posterior distributions of model parameter values, intakes and doses are calculated for a representative sample of plutonium workers from the United Kingdom Atomic Energy cohort using the WeLMoS method with the CIR and the MCMC method. The distributions are in good agreement: posterior means and Q(0.025) and Q(0.975) quantiles are typically within 20 %. Furthermore, the WeLMoS method using the CIR converges quickly: a typical case history takes around 10-20 min on a fast workstation, whereas the MCMC method took around 12-72 hr. The advantages and disadvantages of the method are discussed.

  2. Investigations of DNA damage induction and repair resulting from cellular exposure to high dose-rate pulsed proton beams

    NASA Astrophysics Data System (ADS)

    Renis, M.; Borghesi, M.; Favetta, M.; Malfa, G.; Manti, L.; Romano, F.; Schettino, G.; Tomasello, B.; Cirrone, G. A. P.

    2013-07-01

    Studies regarding the radiobiological effects of low dose radiation, microbeam irradiation services have been developed in the world and today laser acceleration of protons and heavy ions may be used in radiation therapy. The application of different facilities is essential for studying bystander effects and relating signalling phenomena in different cells or tissues. In particular the use of ion beams results advantageous in cancer radiotherapy compared to more commonly used X-rays, since the ability of ions in delivering lethal amount of doses into the target tumour avoiding or limiting damage to the contiguous healthy tissues. At the INFN-LNS in Catania, a multidisciplinary radiobiology group is strategically structured aimed to develop radiobiological research, finalised to therapeutic applications, compatible with the use of high dose laser-driven ion beams. The characteristic non-continuous dose rates with several orders of magnitude of laser-driven ion beams makes this facility very interesting in the cellular systems' response to ultra-high dose rates with non-conventional pulse time intervals cellular studies. Our group have projected to examine the effect of high dose laser-driven ion beams on two cellular types: foetal fibroblasts (normal control cells) and DU145 (prostate cancer cells), studying the modulation of some different bio-molecular parameters, in particular cell proliferation and viability, DNA damage, redox cellular status, morphological alterations of both the cytoskeleton components and some cell organelles and the possible presence of apoptotic or necrotic cell death. Our group performed preliminary experiments with high energy (60 MeV), dose rate of 10 Gy/min, doses of 1, 2, 3 Gy and LET 1 keV/μm on human foetal fibroblasts (control cells). We observed that cell viability was not influenced by the characteristics of the beam, the irradiation conditions or the analysis time. Conversely, DNA damage was present at time 0, immediately

  3. Investigations of DNA damage induction and repair resulting from cellular exposure to high dose-rate pulsed proton beams

    SciTech Connect

    Renis, M.; Malfa, G.; Tomasello, B.; Borghesi, M.; Schettino, G.; Favetta, M.; Romano, F.; Cirrone, G. A. P.; Manti, L.

    2013-07-26

    Studies regarding the radiobiological effects of low dose radiation, microbeam irradiation services have been developed in the world and today laser acceleration of protons and heavy ions may be used in radiation therapy. The application of different facilities is essential for studying bystander effects and relating signalling phenomena in different cells or tissues. In particular the use of ion beams results advantageous in cancer radiotherapy compared to more commonly used X-rays, since the ability of ions in delivering lethal amount of doses into the target tumour avoiding or limiting damage to the contiguous healthy tissues. At the INFN-LNS in Catania, a multidisciplinary radiobiology group is strategically structured aimed to develop radiobiological research, finalised to therapeutic applications, compatible with the use of high dose laser-driven ion beams. The characteristic non-continuous dose rates with several orders of magnitude of laser-driven ion beams makes this facility very interesting in the cellular systems' response to ultra-high dose rates with non-conventional pulse time intervals cellular studies. Our group have projected to examine the effect of high dose laser-driven ion beams on two cellular types: foetal fibroblasts (normal control cells) and DU145 (prostate cancer cells), studying the modulation of some different bio-molecular parameters, in particular cell proliferation and viability, DNA damage, redox cellular status, morphological alterations of both the cytoskeleton components and some cell organelles and the possible presence of apoptotic or necrotic cell death. Our group performed preliminary experiments with high energy (60 MeV), dose rate of 10 Gy/min, doses of 1, 2, 3 Gy and LET 1 keV/μm on human foetal fibroblasts (control cells). We observed that cell viability was not influenced by the characteristics of the beam, the irradiation conditions or the analysis time. Conversely, DNA damage was present at time 0, immediately

  4. Do intervention fidelity and dose influence outcomes? Results from the move to improve worksite physical activity program.

    PubMed

    Wilson, Mark G; Basta, Tania B; Bynum, Bethany H; DeJoy, David M; Vandenberg, Robert J; Dishman, Rod K

    2010-04-01

    The purpose of this paper is to evaluate the implementation of the Move to Improve worksite physical activity program using a four step framework that includes the following: (i) defining the active ingredients, (ii) using good methods to measure implementation, (iii) monitoring implementation and (iv) relating implementation to outcomes. The intervention active ingredients consisted of a goal setting behavior change program, a team competition and environmental supports. Intervention fidelity and dose were measured by surveys administered to site co-ordinators, team captains and employees. Implementation was monitored by the use of biweekly assessments that tracked individual physical activity levels and through weekly reports of the project director and site co-ordinators. Latent growth modeling was conducted to determine whether intervention outcomes were affected by site implementation (i.e. fidelity) and/or participation by employees (i.e. dose). Results showed high levels of intervention fidelity, moderate to high levels of intervention dose delivered and moderate levels of the intervention dose received. Level of implementation affected the degree of change in vigorous physical activity (Mean = 5.4 versus 2.2; chi(2) = 4.9, df = 1), otherwise outcome measures were unaffected by fidelity and dose. These findings suggest that practitioners should focus more energy assuring that the core components are fully implemented and be less concerned about the level of participation.

  5. The dipeptidyl peptidase-4 inhibitor linagliptin exhibits time- and dose-dependent localization in kidney, liver, and intestine after intravenous dosing: results from high resolution autoradiography in rats.

    PubMed

    Greischel, Andreas; Binder, Rudolf; Baierl, Juergen

    2010-09-01

    Linagliptin is an orally active dipeptidyl peptidase-4 (DPP-4) inhibitor that is under development for the treatment of type 2 diabetes and shows dose-dependent pharmacokinetics in rats and humans. With microscopic autoradiography, the dose dependence of cellular distribution of [(3)H]linagliptin-related radioactivity was investigated in kidney at 3 h after intravenous injection of 7.4, 100, and 2000 microg/kg [(3)H]linagliptin. Furthermore, distribution of radioactivity in kidney, liver, and small intestine was investigated in relation to time (2 min, 3 h, and 192 h) after intravenous injection of 7.4 microg/kg [(3)H]linagliptin. The localization of radioactivity in the kidney at 3 h after administration of 7.4, 100, and 2000 microg/kg [(3)H]linagliptin changed with increasing dose from cortical glomeruli and parts of proximal tubule parts to parts of medullar proximal tubule. In addition, the compound distribution in the kidney shifted with time after administration of 7.4 microg/kg [(3)H]linagliptin from glomeruli (2 min) to the lower parts of proximal tubules (192 h). The radioactivity within proximal tubules was located primarily in the brush border. In the liver, the radioactivity persisted mainly around the portal triads and in the bile duct from 2 min to 192 h. In the small intestine, the radioactivity shifted from the lamina propria (2 min) to the surface of the villi and/or intestinal lumen (192 h). In conclusion, the cellular distribution pattern of [(3)H]linagliptin-related radioactivity reflected the known distribution of DPP-4. Together with the persistence of binding, this result supports the high relevance of DPP-4 binding of linagliptin for its pharmacokinetics and pharmacodynamics.

  6. Treatment results of high dose cabergoline as an adjuvant therapy in six patients with established severe ovarian hyper stimulation syndrome

    PubMed Central

    Saharkhiz, Nasrin; Akbari Sene, Azadeh; Salehpour, Saghar; Tamimi, Maryam; Vasheghani Farahani, Masoumeh; Sheibani, Kourosh

    2014-01-01

    Background: The beneficial role of cabergoline as a prophylactic agent to prevent ovarian hyper stimulation syndrome (OHSS) among high-risk patients has been demonstrated in previous studies. But data for its role as a treatment for established severe OHSS is still limited. We represent the treatment results of high dose oral cabergoline in management of six patients after the syndrome is established. Case: High-dose oral cabergoline (1 mg daily for eight days) was prescribed as an adjuvant to symptomatic treatment for six hospitalized patients with established severe OHSS following infertility treatment cycles. In two cases OHSS resolved rapidly despite the occurrence of ongoing pregnancy. Conclusion: Considering the treatment outcomes of our patients, high dose cabergoline did not eliminate the need for traditional treatments, but it was a relatively effective and safe therapy in management of established severe OHSS, and prevented the increase in its severity following the occurrence of pregnancy. PMID:25469130

  7. Importance of dose-rate and cell proliferation in the evaluation of biological experimental results

    NASA Technical Reports Server (NTRS)

    Curtis, S. B.

    1994-01-01

    The nuclei of cells within the bodies of astronauts traveling on extended missions outside the geomagnetosphere will experience single traversals of particles with high Linear Energy Transfer (LET) (e.g., one iron ion per one hundred years, on average) superimposed on a background of tracks with low LET (approximately one proton every two to three days, and one helium ion per month). In addition, some cell populations within the body will be proliferating, thus possibly providing increasing numbers of cells with 'initiated' targets for subsequent radiation hits. These temporal characteristics are not generally reproduced in laboratory experimental protocols. Implications of the differences in the temporal patterns of radiation delivery between conventionally designed radiation biology experiments and the pattern to be experienced in space are examined and the importance of dose-rate and cell proliferation are pointed out in the context of radiation risk assessment on long mission in space.

  8. The principal results of the International Immune Tolerance Study: a randomized dose comparison.

    PubMed

    Hay, Charles R M; DiMichele, Donna M

    2012-02-09

    The International Immune Tolerance Study was a multicenter, prospective, randomized comparison of high-dose (HD; 200 IU/kg/d) and low-dose (LD; 50 IU/kg 3 times/week) factor VIII regimens in 115 "good-risk," severe high-titer inhibitor hemophilia A subjects. Sixty-six of 115 subjects reached the defined study end points: success, n = 46 (69.7%); partial response, n = 3 (4.5%); and failure, n = 17 (25.8%). Successes did not differ between treatment arms (24 of 58 LD vs 22/57 HD, P = .909). The times taken to achieve a negative titer (P = .027), a normal recovery (P = .002), and tolerance (P = .116, nonsignificant) were shorter with the HD immune tolerance induction (ITI). Peak historical (P = .026) and on-ITI (P = .002) titers were correlated inversely with success, but only peak titer on ITI predicted outcome in a multivariate analysis (P = .002). LD subjects bled more often (odds ratio, 2.2; P = .0019). The early bleed rate/month was 0.62 (LD) and 0.28 (HD; P = .000 24), decreasing by 90% once negative titers were achieved. Bleeding was absent in 8 of 58 LD versus 21 of 57 HD subjects (P = .0085). One hundred twenty-four central catheter infections were reported in 41 subjects (19 LD); infection frequency did not differ between the treatment arms. Neither bleeding nor infection influenced outcome. Although it was stopped early for futility and safety considerations, this trial contributed valuable data toward evidence-based ITI practice.

  9. Exploring 100+ Year Variability with DASCH: Statistical Methods and Recent Results.

    NASA Astrophysics Data System (ADS)

    Miller, George Franklin; Grindlay, Jonathan E.; Los, Edward

    2014-06-01

    The Digital Access to a Sky Century at Harvard (DASCH) project is currently digitizing the roughly 500,000 photographic plates maintained by the Harvard College Observatory. The Harvard plate collection covers each point of the sky roughly 500 to 3000 times from 1885 to 1992, with limiting magnitudes ranging from B=14-18 mag and photometric accuracy within ±0.1 mag. Production scanning (roughly 400 plates/day) is proceeding in Galactic coordinates from the North Galactic Pole and is currently at roughly 40 degrees galactic latitude. The vastness of these data makes DASCH unique in its ability to systematically study variability on decade-long time scales across the entire sky. We are developing new statistical mining techniques to predictively identify the many classes of stellar variability and explore their long-term behavior, as well as discover new unusual cases/classes of variability. Most recently, we are working to implement wavelet-based algorithms into our mining routines, better allowing us to analyze localized non-periodic signals. Here we report on the progress of our mining and machine learning routines, as well as share several of the exciting new discoveries that are being made with DASCH. We gratefully acknowledge support from NSF grants AST-0407380, AST-0909073 and AST-1313370.

  10. CRITICAL HEIGHT FOR THE DESTABILIZATION OF SOLAR PROMINENCES: STATISTICAL RESULTS FROM STEREO OBSERVATIONS

    SciTech Connect

    Liu Kai; Wang Yuming; Wang Shui; Shen Chenglong

    2012-01-10

    At which height is a prominence inclined to be unstable, or where is the most probable critical height for the prominence destabilization? This question was statistically studied based on 362 solar limb prominences well recognized by Solar Limb Prominence Catcher and Tracker from 2007 April to the end of 2009. We found that there are about 71% disrupted prominences (DPs), among which about 42% of them did not erupt successfully and about 89% of them experienced a sudden destabilization process. After a comprehensive analysis of the DPs, we discovered the following: (1) Most DPs become unstable at a height of 0.06-0.14 R{sub Sun} from the solar surface, and there are two most probable critical heights at which a prominence is very likely to become unstable, the first one is 0.13 R{sub Sun} and the second one is 0.19 R{sub Sun }. (2) An upper limit for the erupting velocity of eruptive prominences (EPs) exists, which decreases following a power law with increasing height and mass; accordingly, the kinetic energy of EPs has an upper limit too, which decreases as the critical height increases. (3) Stable prominences are generally longer and heavier than DPs, and not higher than 0.4 R{sub Sun }. (4) About 62% of the EPs were associated with coronal mass ejections (CMEs); but there is no difference in apparent properties between EPs associated with CMEs and those that are not.

  11. Some results on the statistics of hull perimeters in large planar triangulations and quadrangulations

    NASA Astrophysics Data System (ADS)

    Guitter, Emmanuel

    2016-11-01

    The hull perimeter at distance d in a planar map with two marked vertices at distance k from each other is the length of the closed curve separating these two vertices and lying at distance d from the first one (d\\lt k). We study the statistics of hull perimeters in large random planar triangulations and quadrangulations as a function of both k and d. Explicit expressions for the probability density of the hull perimeter at distance d, as well as for the joint probability density of hull perimeters at distances d 1 and d 2, are obtained in the limit of infinitely large k. We also consider the situation where the distance d at which the hull perimeter is measured corresponds to a finite fraction of k. The various laws that we obtain are identical for triangulations and for quadrangulations, up to a global rescaling. Our approach is based on recursion relations recently introduced by the author which determine the generating functions of so-called slices, i.e. pieces of maps with appropriate distance constraints. It is indeed shown that the map decompositions underlying these recursion relations are intimately linked to the notion of hull perimeters and provide a simple way to fully control them.

  12. Safety and immunogenicity of the PRAME cancer immunotherapeutic in metastatic melanoma: results of a phase I dose escalation study

    PubMed Central

    Gutzmer, R; Rivoltini, L; Levchenko, E; Testori, A; Utikal, J; Ascierto, P A; Demidov, L; Grob, J J; Ridolfi, R; Schadendorf, D; Queirolo, P; Santoro, A; Loquai, C; Dreno, B; Hauschild, A; Schultz, E; Lesimple, T P; Vanhoutte, N; Salaun, B; Gillet, M; Jarnjak, S; De Sousa Alves, P M; Louahed, J; Brichard, V G; Lehmann, F F

    2016-01-01

    Purpose The PRAME tumour antigen is expressed in several tumour types but in few normal adult tissues. A dose-escalation phase I/II study (NCT01149343) assessed the safety, immunogenicity and clinical activity of the PRAME immunotherapeutic (recombinant PRAME protein (recPRAME) with the AS15 immunostimulant) in patients with advanced melanoma. Here, we report the phase I dose-escalation study segment. Patients and methods Patients with stage IV PRAME-positive melanoma were enrolled to 3 consecutive cohorts to receive up to 24 intramuscular injections of the PRAME immunotherapeutic. The RecPRAME dose was 20, 100 or 500 µg in cohorts 1, 2 and 3, respectively, with a fixed dose of AS15. Adverse events (AEs), including predefined dose-limiting toxicity (DLT) and the anti-PRAME humoral response (ELISA), were coprimary end points. Cellular immune responses were evaluated using in vitro assays. Results 66 patients were treated (20, 24 and 22 in the respective cohorts). AEs considered by the investigator to be causally related were mostly grade 1 or 2 injection site symptoms, fatigue, chills, fever and headache. Two DLTs (grade 3 brain oedema and proteinuria) were recorded in two patients in two cohorts (cohorts 2 and 3). All patients had detectable anti-PRAME antibodies after four immunisations. Percentages of patients with predefined PRAME-specific-CD4+T-cell responses after four immunisations were similar in each cohort. No CD8+ T-cell responses were detected. Conclusions The PRAME immunotherapeutic had an acceptable safety profile and induced similar anti-PRAME-specific humoral and cellular immune responses in all cohorts. As per protocol, the phase II study segment was initiated to further evaluate the 500 µg PRAME immunotherapeutic dose. Trial registration number NCT01149343, Results. PMID:27843625

  13. How to interpret the results of medical time series data analysis: Classical statistical approaches versus dynamic Bayesian network modeling

    PubMed Central

    Onisko, Agnieszka; Druzdzel, Marek J.; Austin, R. Marshall

    2016-01-01

    Background: Classical statistics is a well-established approach in the analysis of medical data. While the medical community seems to be familiar with the concept of a statistical analysis and its interpretation, the Bayesian approach, argued by many of its proponents to be superior to the classical frequentist approach, is still not well-recognized in the analysis of medical data. Aim: The goal of this study is to encourage data analysts to use the Bayesian approach, such as modeling with graphical probabilistic networks, as an insightful alternative to classical statistical analysis of medical data. Materials and Methods: This paper offers a comparison of two approaches to analysis of medical time series data: (1) classical statistical approach, such as the Kaplan–Meier estimator and the Cox proportional hazards regression model, and (2) dynamic Bayesian network modeling. Our comparison is based on time series cervical cancer screening data collected at Magee-Womens Hospital, University of Pittsburgh Medical Center over 10 years. Results: The main outcomes of our comparison are cervical cancer risk assessments produced by the three approaches. However, our analysis discusses also several aspects of the comparison, such as modeling assumptions, model building, dealing with incomplete data, individualized risk assessment, results interpretation, and model validation. Conclusion: Our study shows that the Bayesian approach is (1) much more flexible in terms of modeling effort, and (2) it offers an individualized risk assessment, which is more cumbersome for classical statistical approaches. PMID:28163973

  14. Dumb-bell galaxies in southern clusters: Catalog and preliminary statistical results

    NASA Technical Reports Server (NTRS)

    Vettolani, G.; Gregorini, L.; Parma, P.; Deruiter, H. R.

    1990-01-01

    The dominant galaxy of a rich cluster is often an object whose formation and evolution is closely connected to the dynamics of the cluster itself. Hoessel (1980) and Schneider et al. (1983) estimate that 50 percent of the dominant galaxies are either of the dumb-bell type or have companions at projected distances less than 20 kpc, which is far in excess of the number expected from chance projection (see also Rood and Leir 1979). Presently there is no complete sample of these objects, with the exception of the listing of dumb-bell galaxies in BM type I and I-II clusters in the Abell statistical sample of Rood and Leir (1979). Recent dynamical studies of dumb-bell galaxies in clusters (Valentijn and Casertano, 1988) still suffer from inhomogeneity of the sample. The fact that it is a mixture of optically and radio selected objects may have introduced an unknown biases, for instance if the probability of radio emission is enhanced by the presence of close companions (Stocke, 1978, Heckman et al. 1985, Vettolani and Gregorini 1988) a bias could be present in their velocity distribution. However, this situation is bound to improve: a new sample of Abell clusters in the Southern Hemisphere has been constructed (Abell et al., 1988 hereafter ACO), which has several advantages over the original northern catalog. The plate material (IIIaJ plates) is of better quality and reaches fainter magnitudes. This makes it possible to classify the cluster types with a higher degree of accuracy, as well as to fainter magnitudes. The authors therefore decided to reconsider the whole problem constructing a new sample of dumb-bell galaxies homogeneously selected from the ACO survey. Details of the classification criteria are given.

  15. Results of animal studies suggest a nonlinear dose-response relationship for benzene effects

    SciTech Connect

    Parodi, S.; Taningher, M. ); Lutz, W.K. ); Colacci, A.; Mazzullo, M.; Grilli, S. )

    1989-07-01

    Considering the very large industrial usage of benzene, studies in risk assessment aimed at the evaluation of carcinogenic risk at low levels of exposure are important. Animal data can offer indications about what could happen in humans and provide more diverse information than epidemiological data with respect to dose-response consideration. The authors have considered experiments investigating metabolism, short-term genotoxicity tests, DNA adduct formation, and carcinogenicity long-term tests. According to the different experiments, a saturation of benzene metabolism and benzene effects in terms of genotoxicity seems evident above 30 to 100 ppm. Below 30 to 60 ppm the initiating effect of benzene seems to be linear for a large interval of dosages, at least judging from DNA adduct formation. Potential lack of a promoting effect of benzene (below 10 ppm) could generate a sublinear response at nontoxic levels of exposure. This possibility was suggested by epidemiological data in humans and is not confirmed or excluded by their observations with animals.

  16. Is received dose from ingested soil independent of soil PAH concentrations?-Animal model results.

    PubMed

    Peters, Rachel E; James, Kyle; Cave, Mark; Wickstrom, Mark; Siciliano, Steven D

    2016-09-01

    Polycyclic aromatic hydrocarbon (PAH) bioavailability from ingested soils will vary between soils; however, the nature of this variation is not well characterized. A juvenile swine model was used to link external exposure to internal benzo[a]pyrene (BaP) and anthracene exposure following oral PAH ingestion of 27 different impacted site soils, soots, or spiked artificial soils. Internal exposure of BaP and anthracene, represented by area under the plasma-time curve, did not relate to soil concentration in impacted site soils, but did relate in spiked artificial soil. Point of departure modeling identified soil PAH concentrations greater than 1900 mg kg(-1) as the point where area under the curve becomes proportional to external dose. A BaP internal exposure below 1900 mg kg(-1) had an upper 95% confidence interval estimate of 33% of external exposure. Weak relationships between soil:simulated gastrointestinal fluid PAH partitioning and area under the curve values suggest that differences in internal PAH exposure between soils may not be dominated by differences in PAH partitioning. The data seem to best support exposure assessment assuming constant internal PAH exposure below soil concentrations of 1900 mg kg(-1) . However, because constant internal exposure would challenge several existing paradigms, a bioavailability estimate of 33% of the external exposure is suggested as a likely workable solution. Environ Toxicol Chem 2016;35:2261-2269. © 2016 SETAC.

  17. An application of combining results from multiple methods—statistical evaluation of uncertainty for NIST SRM 1508a

    NASA Astrophysics Data System (ADS)

    Hornikova, A.; Zhang, N. F.; Welch, M. J.; Tai, S.

    2006-06-01

    NIST standard reference materials (SRMs) are certified reference materials that are developed at NIST and provided to laboratories (industry, government and academia) for assessment and improvement of measurement quality. This paper details the statistical analysis related to the recertification of SRM 1508a, benzoylecgonine (cocaine metabolite) in freeze-dried urine, to incorporate new data. The recertification is based on combining measurement results from different measurement methods and time periods. Several different statistical models and corresponding estimators were considered for the certified value, its standard uncertainty and its expanded uncertainty.

  18. Stringent test of the statistical quasiclassical trajectory model for the H+3 exchange reaction: a comparison with rigorous statistical quantum mechanical results.

    PubMed

    Aoiz, F J; González-Lezana, T; Sáez Rábanos, V

    2007-11-07

    A complete formulation of a statistical quasiclassical trajectory (SQCT) model is presented in this work along with a detailed comparison with results obtained with the statistical quantum mechanical (SQM) model for the H+ +D2 and H+ +H2 reactions. The basic difference between the SQCT and the SQM models lies in the fact that trajectories instead of wave functions are propagated in the entrance and exit channels. Other than this the two formulations are entirely similar and both comply with the principle of detailed balance and conservation of parity. Reaction probabilities, and integral and differential cross sections (DCS's) for these reactions at different levels of product's state resolution and from various initial states are shown and discussed. The agreement is in most cases excellent and indicates that the effect of tunneling through the centrifugal barrier is negligible. Some differences are found, however, between state resolved observables calculated by the SQCT and the SQM methods which makes use of the centrifugal sudden (coupled states) approximation (SQM-CS). When this approximation is removed and the full close coupling treatment is used in the SQM model (SQM-CC), an almost perfect agreement is achieved. This shows that the SQCT is sensitive enough to show the relatively small inaccuracies resulting from the decoupling inherent to the CS approximation. In addition, the effect of ignoring the parity conservation is thoroughly examined. This effect is in general minor except in particular cases such as the DCS from initial rotational state j=0. It is shown, however, that in order to reproduce the sharp forward and backward peaks the conservation of parity has to be taken into account.

  19. SRS 2010 Vegetation Inventory GeoStatistical Mapping Results for Custom Reaction Intensity and Total Dead Fuels.

    SciTech Connect

    Edwards, Lloyd A.; Paresol, Bernard

    2014-09-01

    This report of the geostatistical analysis results of the fire fuels response variables, custom reaction intensity and total dead fuels is but a part of an SRS 2010 vegetation inventory project. For detailed description of project, theory and background including sample design, methods, and results please refer to USDA Forest Service Savannah River Site internal report “SRS 2010 Vegetation Inventory GeoStatistical Mapping Report”, (Edwards & Parresol 2013).

  20. 42 CFR 82.27 - How can claimants obtain reviews of their NIOSH dose reconstruction results by NIOSH?

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... radiation exposures of DOE or AWE employees that could substantially increase the level of radiation doses... the level of radiation doses estimated in the completed dose reconstructions. (c) When NIOSH...

  1. 42 CFR 82.27 - How can claimants obtain reviews of their NIOSH dose reconstruction results by NIOSH?

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... radiation exposures of DOE or AWE employees that could substantially increase the level of radiation doses... the level of radiation doses estimated in the completed dose reconstructions. (c) When NIOSH...

  2. 42 CFR 82.27 - How can claimants obtain reviews of their NIOSH dose reconstruction results by NIOSH?

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... radiation exposures of DOE or AWE employees that could substantially increase the level of radiation doses... the level of radiation doses estimated in the completed dose reconstructions. (c) When NIOSH...

  3. Statistical analyses of fracture toughness results for two irradiated high-copper welds

    SciTech Connect

    Nanstad, R.K.; McCabe, D.E.; Haggag, F.M.; Bowman, K.O.; Downing, D.J.

    1990-01-01

    The objectives of the Heavy-Section Steel Irradiation Program Fifth Irradiation Series were to determine the effects of neutron irradiation on the transition temperature shift and the shape of the K{sub Ic} curve described in Sect. 6 of the ASME Boiler and Pressure Vessel Code. Two submerged-arc welds with copper contents of 0.23 and 0.31% were commercially fabricated in 215-mm-thick plates. Charpy V-notch (CVN) impact, tensile, drop-weight, and compact specimens up to 203.2 mm thick (1T, 2T, 4T, 6T, and 8T C(T)) were tested to provide a large data base for unirradiated material. Similar specimens with compacts up to 4T were irradiated at about 288{degrees}C to a mean fluence of about 1.5 {times} 10{sup 19} neutrons/cm{sup 2} (>1 MeV) in the Oak Ridge Research Reactor. Both linear-elastic and elastic-plastic fracture mechanics methods were used to analyze all cleavage fracture results and local cleavage instabilities (pop-ins). Evaluation of the results showed that the cleavage fracture toughness values determined at initial pop-ins fall within the same scatter band as the values from failed specimens; thus, they were included in the data base for analysis (all data are designated K{sub Jc}).

  4. The Solid Rocket Motor Slag Population: Results of a Radar-based Regressive Statistical Evaluation

    NASA Technical Reports Server (NTRS)

    Horstman, Matthew F.; Xu, Yu-Lin

    2008-01-01

    Solid rocket motor (SRM) slag has been identified as a significant source of man-made orbital debris. The propensity of SRMs to generate particles of 100 m and larger has caused concern regarding their contribution to the debris environment. Radar observation, rather than in-situ gathered evidence, is currently the only measurable source for the NASA/ODPO model of the on-orbit slag population. This simulated model includes the time evolution of the resultant orbital populations using a historical database of SRM launches, propellant masses, and estimated locations and times of tail-off. However, due to the small amount of observational evidence, there can be no direct comparison to check the validity of this model. Rather than using the assumed population developed from purely historical and physical assumptions, a regressional approach was used which utilized the populations observed by the Haystack radar from 1996 to present. The estimated trajectories from the historical model of slag sources, and the corresponding plausible detections by the Haystack radar, were identified. Comparisons with observational data from the ensuing years were made, and the SRM model was altered with respect to size and mass production of slag particles to reflect the historical data obtained. The result is a model SRM population that fits within the bounds of the observed environment.

  5. Latin American dose survey results in mammography studies under IAEA programme: radiological protection of patients in medical exposures (TSA3).

    PubMed

    Mora, Patricia; Blanco, Susana; Khoury, Helen; Leyton, Fernando; Cárdenas, Juan; Defaz, María Yolanda; Garay, Fernando; Telón, Flaviano; Aguilar, Juan Garcia; Roas, Norma; Gamarra, Mirtha; Blanco, Daniel; Quintero, Ana Rosa; Nader, Alejandro

    2015-03-01

    Latin American countries (Argentina, Brazil, Chile, Costa Rica, Cuba, Ecuador, El Salvador, Guatemala, Mexico, Nicaragua, Paraguay, Uruguay and Venezuela) working under the International Atomic Energy Agency (IAEA) Technical Cooperation Programme: TSA3 Radiological Protection of Patients in Medical Exposures have joined efforts in the optimisation of radiation protection in mammography practice. Through surveys of patient doses, the region has a unique database of diagnostic reference levels for analogue and digital equipment that will direct future optimisation activities towards the early detection of breast cancer among asymptomatic women. During RLA9/057 (2007-09) 24 institutions participated with analogue equipment in a dose survey. Regional training on methodology and measurement equipment was addressed in May 2007. The mean glandular dose (DG) was estimated using the incident kerma in air and relevant conversion coefficients for both projections craneo caudal and mediolateral oblique (CC and MLO). For Phase 2, RLA9/067 (2010-11), it was decided to include also digital systems in order to see their impact in future dose optimisation activities. Any new country that joined the project received training in the activities through IAEA expert missions. Twenty-nine new institutions participated (9 analogue and 20 digital equipment). A total of 2262 patient doses were collected during this study and from them D(G) (mGy) for both projections were estimated for each institution and country. Regional results (75 percentile in mGy) show for CC and MLO views, respectively: RLA9/057 (analogue) 2.63 and 3.17; RLA/067: 2.57 and 3.15 (analogue) and 2.69 and 2.90 (digital). Regarding only digital equipment for CC and MLO, respectively, computed radiography systems showed 2.59 and 2.78 and direct digital radiography (DDR) systems 2.78 and 3.04. Based on the IAEA Basic Safety Standard (BSS) reference dose (3 mGy), it can be observed that there is enough room to start

  6. Statistical results describing the bandwidth and coherence coefficient of whistler mode waves using THEMIS waveform data

    NASA Astrophysics Data System (ADS)

    Gao, X.; Li, W.; Thorne, R. M.; Bortnik, J.; Angelopoulos, V.; Lu, Q.; Tao, X.; Wang, S.

    2014-11-01

    The bandwidths and coherence coefficients of lower band whistler mode waves are analyzed using Time History of Events and Macroscale Interactions during Substorms (THEMIS) waveform data for rising tones, falling tones, and hiss-like emissions separately. We also evaluate their dependences on the spatial location, electron density, the ratio of plasma frequency to local electron gyrofrequency (fpe/fce), and the wave amplitude. Our results show that the bandwidth normalized by the local electron gyrofrequency (fce) of rising and falling tones is very narrow (~0.01 fce), smaller than that of the hiss-like emissions (~0.025 fce). Meanwhile, the normalized bandwidth of discrete emissions gradually decreases with increasing wave amplitude, whereas that of hiss-like emissions increases slowly. The coherence coefficient of rising and falling tones is extremely large (~1), while the coherence coefficient of hiss-like emissions is smaller but is still larger than 0.5. For all categories of whistler mode waves, the normalized bandwidth increases at larger L shells. Furthermore, the normalized bandwidth is positively correlated with local fpe/fce but is inversely correlated with the electron density. Interactions between radiation belt electrons and whistler mode waves have been widely described by quasi-linear diffusion theory. Our results suggest that although quasi-linear theory is not entirely applicable for modeling electron interactions with rising and falling tones due to their narrow bandwidth and high coherence coefficient, it is suitable to treat wave-particle interactions between electrons and low-amplitude hiss-like emissions. Moreover, the correlations between the normalized bandwidth of chorus waves (especially the discrete emissions) and other parameters may provide insights for the generation mechanism of chorus waves.

  7. Unrealistic statistics: how average constitutive coefficients can produce non-physical results.

    PubMed

    Robertson, Daniel; Cook, Douglas

    2014-12-01

    The coefficients of constitutive models are frequently averaged in order to concisely summarize the complex, nonlinear, material properties of biomedical materials. However, when dealing with nonlinear systems, average inputs (e.g. average constitutive coefficients) often fail to generate average behavior. This raises an important issue because average nonlinear constitutive coefficients of biomedical materials are commonly reported in the literature. This paper provides examples which demonstrate that average constitutive coefficients applied to nonlinear constitutive laws in the field of biomedical material characterization can fail to produce average stress-strain responses and in some cases produce non-physical responses. Results are presented from a literature survey which indicates that approximately 90% of tissue measurement studies that employ a nonlinear constitutive model report average nonlinear constitutive coefficients. We suggest that reviewers and editors of future measurement studies discourage the reporting of average nonlinear constitutive coefficients. Reporting of individual coefficient sets for each test sample should be considered and discussed as designation for a "best practice" in the field of biomedical material characterization.

  8. A Consumer's Guide to Benchmark Dose Models: Results of U.S. EPA Testing of 14 Dichotomous, 8 Continuous, and 6 Developmental Models (Presentation)

    EPA Science Inventory

    Benchmark dose risk assessment software (BMDS) was designed by EPA to generate dose-response curves and facilitate the analysis, interpretation and synthesis of toxicological data. Partial results of QA/QC testing of the EPA benchmark dose software (BMDS) are presented. BMDS pr...

  9. The Solid Rocket Motor Slag Population: Results of a Radar-Based Regressive Statistical Evaluation

    NASA Astrophysics Data System (ADS)

    Horstman, Matthew

    estimated locations and times of tail-off to produce and propagate the SRM debris clouds. Comparisons with radar data from the ensuing years were made, and the SRM model was altered with respect to size and mass production of slag particles to reflect the populations estimated from the data. The result is a model SRM population that fits within the bounds of the observed environment and estimates of the production and contribution of SRM debris to the environment.

  10. The Solid Rocket Motor Slag Population: Results of a Radar-Based Regressive Statistical Evaluation

    NASA Technical Reports Server (NTRS)

    Horstman, Matthew F.; Xu, Yu-Lin

    2008-01-01

    estimated locations and times of tailoff to produce and propagate the SRM debris clouds. Comparisons with radar data from the ensuing years were made, and the SRM model was altered with respect to size and mass production of slag particles to reflect the populations estimated from the data. The result is a model SRM population that fits within the bounds of the observed environment and estimates of the production and contribution of SRM debris to the environment.

  11. 42 CFR 82.4 - How Will DOL Use the Results of the NIOSH Dose Reconstructions?

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... reconstruction results together with information on cancer diagnosis and other personal information provided to... probability that the cancer of the covered employee was caused by radiation exposure at a covered facility...

  12. 42 CFR 82.4 - How Will DOL Use the Results of the NIOSH Dose Reconstructions?

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... reconstruction results together with information on cancer diagnosis and other personal information provided to... probability that the cancer of the covered employee was caused by radiation exposure at a covered facility...

  13. 42 CFR 82.4 - How Will DOL Use the Results of the NIOSH Dose Reconstructions?

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... reconstruction results together with information on cancer diagnosis and other personal information provided to... probability that the cancer of the covered employee was caused by radiation exposure at a covered facility...

  14. 42 CFR 82.4 - How Will DOL Use the Results of the NIOSH Dose Reconstructions?

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... reconstruction results together with information on cancer diagnosis and other personal information provided to... probability that the cancer of the covered employee was caused by radiation exposure at a covered facility...

  15. Statistical results from the Virginia Tech propagation experiment using the Olympus 12, 20, and 30 GHz satellite beacons

    NASA Technical Reports Server (NTRS)

    Stutzman, Warren L.; Safaai-Jazi, A.; Pratt, Timothy; Nelson, B.; Laster, J.; Ajaz, H.

    1993-01-01

    Virginia Tech has performed a comprehensive propagation experiment using the Olympus satellite beacons at 12.5, 19.77, and 29.66 GHz (which we refer to as 12, 20, and 30 GHz). Four receive terminals were designed and constructed, one terminal at each frequency plus a portable one with 20 and 30 GHz receivers for microscale and scintillation studies. Total power radiometers were included in each terminal in order to set the clear air reference level for each beacon and also to predict path attenuation. More details on the equipment and the experiment design are found elsewhere. Statistical results for one year of data collection were analyzed. In addition, the following studies were performed: a microdiversity experiment in which two closely spaced 20 GHz receivers were used; a comparison of total power and Dicke switched radiometer measurements, frequency scaling of scintillations, and adaptive power control algorithm development. Statistical results are reported.

  16. Low dose cadmium poisoning results in sustained ERK phosphorylation and caspase activation

    SciTech Connect

    Martin, Patrick . E-mail: pmartin@unice.fr; Poggi, Marie Christine . E-mail: poggi@unice.fr; Chambard, Jean Claude . E-mail: chambard@unice.fr; Boulukos, Kim E. . E-mail: boulukos@unice.fr; Pognonec, Philippe . E-mail: pognonec@unice.fr

    2006-11-24

    Cadmium poisoning has been known to result in a wide variety of cellular responses, including oxidative stress and kinase activation. It has been reported that ERK is activated following acute cadmium exposure, and this response is commonly seen as a classical ERK survival mechanism. Here, we analyzed different cell types for their responses to low concentrations of cadmium poisoning. We found that there is an association between cell susceptibility to cadmium toxicity and ERK activation. This activation is atypical, since it consists of a sustained ERK phosphorylation, that lasts up to 6 days post stimulation. This activation is associated with the appearance of cleaved caspases 8 and 3, processed PARP, and irreversible damage. Pharmacological inhibition of ERK phosphorylation results in the ability of cells to resist cadmium poisoning. Our data indicate that low cadmium concentrations result in an unconventional ERK sustained phosphorylation, which in turn leads to death signaling.

  17. The dose dependence of glucocorticoid-inducible gene expression results from changes in the number of transcriptionally active templates.

    PubMed Central

    Ko, M S; Nakauchi, H; Takahashi, N

    1990-01-01

    Glucocorticoid hormones induce the transcription of genes having glucocorticoid response elements in a dose dependent manner. To determine whether this dose dependence represents a response of individual templates or of the mass of templates, we introduced a bacterial beta-galactosidase gene linked to the glucocorticoid-inducible enhancer/promoter of the mouse mammary tumor virus (MTV) into Ltk- cells and obtained stable transformants containing a single or a few templates per cell. Visual inspection and flow cytometry analysis by enzyme histochemistry assay for beta-galactosidase revealed that individual cells showed very heterogeneous beta-galactosidase activity after 48 h induction with dexamethasone. When the glucocorticoid concentration was increased, an increasing cell population producing beta-galactosidase was observed. These phenomena were probably not due to heterogeneity of template copy number or to a predetermined cellular state among individual cells, since cells forming a single small colony gave similar results. This was also supported by data showing that recloned cells retained both their responsiveness to the glucocorticoid hormone and their digestion pattern in Southern blotting analyses. These results indicate that the dose dependent increase of glucocorticoid-inducible gene expression is caused by an increase in the number of transcriptionally active templates. Images Fig. 1. Fig. 3. Fig. 4. Fig. 5. Fig. 8. PMID:2167833

  18. Comparison of dose estimates using the buildup-factor method and a Baryon transport code (BRYNTRN) with Monte Carlo results

    NASA Technical Reports Server (NTRS)

    Shinn, Judy L.; Wilson, John W.; Nealy, John E.; Cucinotta, Francis A.

    1990-01-01

    Continuing efforts toward validating the buildup factor method and the BRYNTRN code, which use the deterministic approach in solving radiation transport problems and are the candidate engineering tools in space radiation shielding analyses, are presented. A simplified theory of proton buildup factors assuming no neutron coupling is derived to verify a previously chosen form for parameterizing the dose conversion factor that includes the secondary particle buildup effect. Estimates of dose in tissue made by the two deterministic approaches and the Monte Carlo method are intercompared for cases with various thicknesses of shields and various types of proton spectra. The results are found to be in reasonable agreement but with some overestimation by the buildup factor method when the effect of neutron production in the shield is significant. Future improvement to include neutron coupling in the buildup factor theory is suggested to alleviate this shortcoming. Impressive agreement for individual components of doses, such as those from the secondaries and heavy particle recoils, are obtained between BRYNTRN and Monte Carlo results.

  19. Results of loading doses of aspartame by two phenylketonuric (PKU) children compared with two normal children.

    PubMed

    Koch, R; Schaeffler, G; Shaw, N F

    1976-11-01

    Separate tolerance tests with aspartame at 34 mg/kg-day and phenylalanine at 19 mg/kg-day were compared. The results reveal that slight serum elevation of phenylalanine and tyrosine occurred in the two PKU and the normal healthy adolescents. It would appear that the phenylalanine in the sweetener aspartame is small enough to be of little clinical significance.

  20. Preliminary On-Orbit Neutron Dose Equivalent and Energy Spectrum Results from the ISS-RAD Fast Neutron Detector (FND)

    NASA Technical Reports Server (NTRS)

    Semones, Edward; Leitgab, Martin

    2016-01-01

    The ISS-RAD instrument was activated on ISS on February 1st, 2016. Integrated in ISS-RAD, the Fast Neutron Detector (FND) performs, for the first time on ISS, routine and precise direct neutron measurements between 0.5 and 8 MeV. Preliminary results for neutron dose equivalent and neutron flux energy distributions from online/on-board algorithms and offline ground analyses will be shown, along with comparisons to simulated data and previously measured neutron spectral data. On-orbit data quality and pre-launch analysis validation results will be discussed as well.

  1. Higher rate of microscopic hematuria in elderly patients who take regular doses of aspirin: Result from AHAP Study

    PubMed Central

    Moudi, Emadouddin; Hosseini, Seyed-Reza; Bijani, Ali

    2016-01-01

    Background: Aspirin is the most widely used drug in medicine for cardiovascular and as recently for its role in cancer prevention. Although the risk of bleeding events increased following regular use of aspirin, little is known about the association of aspirin and hematuria. The present study aimed to evaluate the association of regular aspirin use and microscopic hematuria in elderly. Methods: In this study, we have extracted the data of elderly people who participated in Amirkola Health and Aging Project (AHAP) and taking regular doses of aspirin. The prevalence of microscopic hematuria was compared between the elderly who took aspirin regularly and those who did not take it. Results: A total of 1243 individuals (54.22% males, 45.78% females) were entered in to the study. Two hundred and eighty-four (23%) elderly took regular doses of aspirin. Microscopic hematuria was seen in 305 (24.54%) elderly. The prevalence of microscopic hematuria was 27.27% in regular users of aspirin and 23.72% in non-users of aspirin (P=0.126). The prevalence of microscopic hematuria was significantly higher among the regular users of aspirin compared to non-users in multiple logistic regression analysis (P=0.035, OR=1.40, 95%CI: 1.02-1.92). Conclusion: Taking regular doses of aspirin was accompanied with higher rate of microscopic hematuria in the elderly. PMID:27999646

  2. Estimates of inhalation doses resulting from the possible use of phospho-gypsum plaster-board in Australian homes.

    PubMed

    O'Brien, R S; Peggie, J R; Leith, I S

    1995-04-01

    Current materials used as internal lining in Australian buildings are based on natural gypsum of low radium content. A study was carried out to estimate the contribution to the annual effective dose due to airborne contamination from chemical by-product gypsum plaster-board of higher radium content if it were used as an internal lining. The 226Ra content and 222Rn exhalation rate were measured for several samples of the plaster-board, and the behavior of 222Rn and its progeny (218Po, 214Pb, 214Bi, and 214Po) in a typical building was modeled numerically, using the results of the exhalation rate measurements as input. For building ventilation rates greater than approximately 0.5 air changes per hour, the contribution to the total annual effective dose from inhalation of 222Rn and its progeny exhaled from the phospho-gypsum plaster-board is estimated to be below 1 mSv. This contribution is reduced if the surface of the plaster-board is coated with paint or cardboard, or if the very fine particles are removed from the phospho-gypsum during manufacture of the plaster-board. The effective doses arising from dust generation during the installation of the plaster-board are also estimated to be below 1 mSv. The recommended action level of 200 Bq m-3 for radon in air in Australia corresponds to an annual effective dose of approximately 6 mSv. The study indicates that the suggested acceptable level of 185 Bq kg-1 for the 226Ra concentration in the plaster-board may be too restrictive under Australian conditions.

  3. Low-Dose Gamma Irradiation of Decellularized Heart Valves Results in Tissue Injury in Vitro and in Vivo

    PubMed Central

    Helder, Meghana R. K.; Hennessy, Ryan S.; Spoon, Daniel B.; Tefft, Brandon J.; Witt, Tyra A.; Marler, Ronald J.; Pislaru, Sorin V.; Simari, Robert D.; Stulak, John M.; Lerman, Amir

    2017-01-01

    Background Decellularized heart valves are emerging as a potential alternative to current bioprostheses for valve replacement. While techniques of decellularization have been thoroughly examined, terminal sterilization techniques have not received the same scrutiny. Methods This study evaluated low dose gamma irradiation as a sterilization method for decellularized heart valves. Incubation of valves and transmission electron microscopy evaluation after different doses of gamma irradiation were used to determine the optimal dose of gamma irradiation. Quantitative evaluation of mechanical properties was done by tensile mechanical testing of isolated cusps. Sterilize decellularized heart valves were tested in a sheep model (n=3, 1 1,500 Gy and 2 3,000 Gy) of pulmonary valve replacement. Results Valves sterilized with gamma radiation between 1,000 Gy and 3,000 Gy were found to be optimal with in-vitro testing. However, with in-vivo showed deteriorating valve function within 2 months. On explant the valve with 1,500 Gy gamma irradiation showed signs of endocarditis with neutrophils on hematoxylin and eosin staining, positive gram stain resembling streptococcus infection. The 3,000 Gy valves had no evidence of infection, but the hematoxylin and eosin staining showed evidence of wound remodeling with macrophages and fibroblasts. Tensile strength testing showed decreased strength (0 Gy-2.53±0.98 MPa, 1,500 Gy-2.03±1.23 MPa, 3,000 Gy-1.26±0.90 MPa) with increasing levels of irradiation. Conclusions Low dose gamma irradiation does not maintain the mechanical integrity of valves and the balance between sterilization and damage may not be able to be achieved with gamma irradiation. Other methods of terminal sterilization must be pursued and evaluated. PMID:26453425

  4. Cinacalcet HCl and Concurrent Low-dose Vitamin D Improves Treatment of Secondary Hyperparathyroidism in Dialysis Patients Compared with Vitamin D Alone: The ACHIEVE Study Results

    PubMed Central

    Fishbane, Steven; Shapiro, Warren B.; Corry, Dalila B.; Vicks, Steven L.; Roppolo, Michael; Rappaport, Kenneth; Ling, Xiang; Goodman, William G.; Turner, Stewart; Charytan, Chaim

    2008-01-01

    Background and objectives: Patients with chronic kidney disease (CKD) receiving dialysis often develop secondary hyperparathyroidism with disturbed calcium and phosphorus metabolism. The National Kidney Foundation-Kidney Disease Outcomes Quality Initiative (KDOQI) was established to guide treatment practices for these disorders. The ACHIEVE study was designed to test two treatment strategies for achieving KDOQI goals. Design, setting, participants, measurements: Individuals on hemodialysis treated with vitamin D sterols were enrolled in this 33-week study. Subjects were randomly assigned to treatment with either cinacalcet and low-dose vitamin D (Cinacalcet-D) or flexible vitamin D alone (Flex-D) to achieve KDOQI-recommended bone mineral targets. ACHIEVE included a 6-week screening phase, including vitamin D washout, a 16-week dose-titration phase, and an 11-week assessment phase. Results: Of 173 subjects enrolled, 83% of Cinacalcet-D and 67% of Flex-D subjects completed the study. A greater proportion of Cinacalcet-D versus Flex-D subjects had a ≥30% reduction in parathyroid hormone (PTH) (68% versus 36%, P < 0.001) as well as PTH ≤300 pg/ml (44% versus 23%, P = 0.006). The proportion of subjects simultaneously achieving targets for intact PTH (150–300 pg/ml) and calcium-phosphorus product (Ca×P) (<55 mg2/dl2) was also greater (21% versus 14%), but this was not statistically significant. This was attributable to 19% of Cinacalcet-D subjects with a PTH value below the KDOQI target range. Conclusions: Achievement of KDOQI targets was difficult, especially with Flex-D. Maintaining calcium and phosphorus target values precluded the use of vitamin D doses necessary to lower PTH to within the narrow target range and highlighted limitations inherent to the KDOQI treatment algorithm. PMID:18945995

  5. Late Gastrointestinal Toxicity After Dose-Escalated Conformal Radiotherapy for Early Prostate Cancer: Results From the UK Medical Research Council RT01 Trial (ISRCTN47772397)

    SciTech Connect

    Syndikus, Isabel; Morgan, Rachel C.; Sydes, Matthew R.; Graham, John D.; Dearnaley, David P.

    2010-07-01

    Purpose: In men with localized prostate cancer, dose-escalated conformal radiotherapy (CFRT) improves efficacy outcomes at the cost of increased toxicity. We present a detailed analysis to provide further information about the incidence and prevalence of late gastrointestinal side effects. Methods and Materials: The UK Medical Research Council RT01 trial included 843 men with localized prostate cancer, who were treated for 6 months with neoadjuvant radiotherapy and were randomly assigned to either 64-Gy or 74-Gy CFRT. Toxicity was evaluated before CFRT and during long-term follow-up using Radiation Therapy Oncology Group (RTOG) grading, the Late Effects on Normal Tissue: Subjective, Objective, Management (LENT/SOM) scale, and Royal Marsden Hospital assessment scores. Patients regularly completed Functional Assessment of Cancer Therapy--Prostate (FACT-P) and University of California, Los Angeles, Prostate Cancer Index (UCLA-PCI) questionnaires. Results: In the dose-escalated group, the hazard ratio (HR) for rectal bleeding (LENT/SOM grade {>=}2) was 1.55 (95% CI, 1.17-2.04); for diarrhea (LENT/SOM grade {>=}2), the HR was 1.79 (95% CI, 1.10-2.94); and for proctitis (RTOG grade {>=}2), the HR was 1.64 (95% CI, 1.20-2.25). Compared to baseline scores, the prevalence of moderate and severe toxicities generally increased up to 3 years and than lessened. At 5 years, the cumulative incidence of patient-reported severe bowel problems was 6% vs. 8% (standard vs. escalated, respectively) and severe distress was 4% vs. 5%, respectively. Conclusions: There is a statistically significant increased risk of various adverse gastrointestinal events with dose-escalated CFRT. This remains at clinically acceptable levels, and overall prevalence ultimately decreases with duration of follow-up.

  6. Local Control Following Permanent Prostate Brachytherapy: Effect of High Biologically Effective Dose on Biopsy Results and Oncologic Outcomes

    SciTech Connect

    Stone, Nelson N.; Stock, Richard G.; Cesaretti, Jamie A.; Unger, Pam

    2010-02-01

    Purpose: To determine factors that influence local control and systemic relapse in patients undergoing permanent prostate brachytherapy (PPB). Methods and Materials: A total of 584 patients receiving PPB alone or PPB with external beam radiation therapy (19.5%) agreed to undergo prostate biopsy (PB) at 2 years postimplantion and yearly if results were positive or if the prostate-specific antigen (PSA) level increased. Short-term hormone therapy was used with 280 (47.9%) patients. Radiation doses were converted to biologically effective doses (BED) (using alpha/beta = 2). Comparisons were made by chi-square analysis and linear regression. Survival was determined by the Kaplan-Meier method. Results: The median PSA concentration was 7.1 ng/ml, and the median follow-up period was 7.1 years. PB results were positive for 48/584 (8.2%) patients. Positive biopsy results by BED group were as follows: 22/121 (18.2%) patients received a BED of <=150 Gy; 15/244 (6.1%) patients received >150 to 200 Gy; and 6/193 (3.1%; p < 0.001) patients received >200 Gy. Significant associations of positive PB results by risk group were low-risk group BED (p = 0.019), intermediate-risk group hormone therapy (p = 0.011) and BED (p = 0.040), and high-risk group BED (p = 0.004). Biochemical freedom from failure rate at 7 years was 82.7%. Biochemical freedom from failure rate by PB result was 84.7% for negative results vs. 59.2% for positive results (p < 0.001). Cox regression analysis revealed significant associations with BED (p = 0.038) and PB results (p = 0.002) in low-risk patients, with BED (p = 0.003) in intermediate-risk patients, and with Gleason score (p = 0.006), PSA level (p < 0.001), and PB result (p = 0.038) in high-risk patients. Fifty-three (9.1%) patients died, of which eight deaths were due to prostate cancer. Cause-specific survival was 99.2% for negative PB results vs. 87.6% for positive PB results (p < 0.001). Conclusions: Higher radiation doses are required to achieve local

  7. Evaluating the statistical conclusion validity of weighted mean results in meta-analysis by analysing funnel graph diagrams.

    PubMed

    Elvik, R

    1998-03-01

    The validity of weighted mean results estimated in meta-analysis has been criticized. This paper presents a set of simple statistical and graphical techniques that can be used in meta-analysis to evaluate common points of criticism. The graphical techniques are based on funnel graph diagrams. Problems and techniques for dealing with them that are discussed include: (1) the so-called 'apples and oranges' problem, stating that mean results in meta-analysis tend to gloss over important differences that should be highlighted. A test of the homogeneity of results is described for testing the presence of this problem. If results are highly heterogeneous, a random effects model of meta-analysis is more appropriate than the fixed effects model of analysis. (2) The possible presence of skewness in a sample of results. This can be tested by comparing the mode, median and mean of the results in the sample. (3) The possible presence of more than one mode in a sample of results. This can be tested by forming a frequency distribution of the results and examining the shape of this distribution. (4) The sensitivity of the mean to the possible presence of atypical results (outliers) can be tested by comparing the overall mean to the mean of all results except the one suspected of being atypical. (5) The possible presence of publication bias can be tested by visual inspection of funnel graph diagrams in which data points have been sorted according to statistical significance and direction of effect. (6) The possibility of underestimating the standard error of the mean in meta-analyses by using multiple, correlated results from the same study as the unit of analysis can be addressed by using the jack-knife technique for estimating the uncertainty of the mean. Brief examples, taken from road safety research, are given of all these techniques.

  8. Exact results in nonequilibrium statistical mechanics: Formalism and applications in chemical kinetics and single-molecule free energy estimation

    NASA Astrophysics Data System (ADS)

    Adib, Artur B.

    In the last two decades or so, a collection of results in nonequilibrium statistical mechanics that departs from the traditional near-equilibrium framework introduced by Lars Onsager in 1931 has been derived, yielding new fundamental insights into far-from-equilibrium processes in general. Apart from offering a more quantitative statement of the second law of thermodynamics, some of these results---typified by the so-called "Jarzynski equality"---have also offered novel means of estimating equilibrium quantities from nonequilibrium processes, such as free energy differences from single-molecule "pulling" experiments. This thesis contributes to such efforts by offering three novel results in nonequilibrium statistical mechanics: (a) The entropic analog of the Jarzynski equality; (b) A methodology for estimating free energies from "clamp-and-release" nonequilibrium processes; and (c) A directly measurable symmetry relation in chemical kinetics similar to (but more general than) chemical detailed balance. These results share in common the feature of remaining valid outside Onsager's near-equilibrium regime, and bear direct applicability in protein folding kinetics as well as in single-molecule free energy estimation.

  9. Differential cytokine induction by doses of lipopolysaccharide and monophosphoryl lipid A that result in equivalent early endotoxin tolerance.

    PubMed Central

    Henricson, B E; Benjamin, W R; Vogel, S N

    1990-01-01

    The phenomenon of early endotoxin tolerance, which is induced by sublethal injection of lipopolysaccharide (LPS), results in a protracted period of hyporesponsiveness that is most profound at 3 to 4 days after injection and is marked by reduced cytokine production after a challenge injection of LPS. Early endotoxin tolerance is also induced by the nontoxic LPS derivative monophosphoryl lipid A (MPL), although much more of the monophosphoryl derivative is required to produce a state of tolerance equivalent to that evoked by LPS. In this study, equivalent tolerance-inducing doses of LPS and MPL were tested, and the levels of cytokines induced by LPS and MPL were compared. Although induced levels of colony-stimulating factor were comparable following doses of LPS and MPL that elicited an equivalent state of early endotoxin tolerance, levels of tumor necrosis factor, interleukin-6, and interferon were significantly lower in MPL-injected animals. These results suggest that the lowered toxicity of MPL may be related to its elicitation of significantly lower levels of potentially toxic intermediaries such as tumor necrosis factor, interferon, and interleukin-6. PMID:1695201

  10. The magnitude of neurotoxicity in patients with multiple myeloma and the impact of dose modifications: results from the population-based PROFILES registry.

    PubMed

    Beijers, Antoinetta J M; Oerlemans, Simone; Mols, Floortje; Eurelings, Marijke; Minnema, Monique C; Vreugdenhil, Art; van de Poll-Franse, Lonneke V

    2017-04-01

    The aim of this analysis is to assess (1) self-reported chemotherapy-induced peripheral neuropathy (CIPN) symptoms; (2) its association with sociodemographic and clinical characteristics; and (3) treatment dose modifications and its influence on the magnitude of neurotoxicity in a population-based cohort of patients with multiple myeloma (MM). MM patients (n = 156), diagnosed between 2000 and 2014, filled out the EORTC QLQ-CIPN20 (65% response). Data on treatment, outcomes, and dose modifications were extracted from the medical files. Fifty-three percent of patients reported at least one and on average three neuropathy symptoms that bothered them the most during the past week, with tingling toes/feet as most reported. In multivariate analysis, thalidomide, especially higher cumulative dose, was associated with neuropathy (β = 0.26, CI 95% 0.27-15.34, p = 0.04) and CIPN was not associated with age, sex, time since last course of therapy, number of prior therapies, osteoarthritis, or diabetes. Dose modifications were often applied (65%). Although not statistically significant, a trend towards higher sensory (22 vs. 15 vs. 12, p = 0.22) and motor neuropathy scores (21 vs. 15 vs. 11, p = 0.36) was observed among patients receiving dose modification because of CIPN (31%) compared to those receiving a dose modification for another reason or no dose modification, without altering treatment response. CIPN is a common dose limiting side effect in patients with MM. Severity of CIPN was mainly affected by treatment with thalidomide. In spite of dose modifications, patients still reported somewhat higher neuropathy scores without altered response rates. Early dose modification based on a more reliable tool for CIPN measurements may prove value.

  11. Impact of Assimilation on Heavy Rainfall Simulations Using WRF Model: Sensitivity of Assimilation Results to Background Error Statistics

    NASA Astrophysics Data System (ADS)

    Rakesh, V.; Kantharao, B.

    2017-03-01

    Data assimilation is considered as one of the effective tools for improving forecast skill of mesoscale models. However, for optimum utilization and effective assimilation of observations, many factors need to be taken into account while designing data assimilation methodology. One of the critical components that determines the amount and propagation observation information into the analysis, is model background error statistics (BES). The objective of this study is to quantify how BES in data assimilation impacts on simulation of heavy rainfall events over a southern state in India, Karnataka. Simulations of 40 heavy rainfall events were carried out using Weather Research and Forecasting Model with and without data assimilation. The assimilation experiments were conducted using global and regional BES while the experiment with no assimilation was used as the baseline for assessing the impact of data assimilation. The simulated rainfall is verified against high-resolution rain-gage observations over Karnataka. Statistical evaluation using several accuracy and skill measures shows that data assimilation has improved the heavy rainfall simulation. Our results showed that the experiment using regional BES outperformed the one which used global BES. Critical thermo-dynamic variables conducive for heavy rainfall like convective available potential energy simulated using regional BES is more realistic compared to global BES. It is pointed out that these results have important practical implications in design of forecast platforms while decision-making during extreme weather events

  12. Characterization of Chlamydial Genital Infection Resulting from Sexual Transmission from Male to Female Guinea Pigs and Determination of Infectious Dose

    PubMed Central

    Rank, Roger G.; Bowlin, Anne K.; Reed, Ronald L.; Darville, Toni

    2003-01-01

    A major problem in the study of chlamydial genital infections in animal models has been the use of varied doses of chlamydiae for infection in different laboratories. It is clearly desirable to use a dose which approximates that of natural sexual infection, but that dose to date has not been determined because of the inability of researchers to quantify chlamydiae in semen. Fortunately, sexual transmission of chlamydiae has been described for the guinea pig model of infection with the chlamydial agent of guinea pig inclusion conjunctivitis (GPIC). In this study, we undertook to determine the approximate infection dose in actual sexual transmission by comparing the kinetics of infection in female guinea pigs acquired via sexual contact to those of genital infections induced artificially with known quantities of chlamydiae. Groups of guinea pigs were infected intravaginally with 104, 103, 102, and 101 inclusion-forming units (IFU) of GPIC, and the kinetics of the infection were determined. Infection with 102 IFU produced infections with lower peak levels than those in animals receiving 104 or 103 IFU. Seventy percent of animals receiving 102 IFU became infected, while 100 and 79% of animals receiving 104 and 103 IFU, respectively, became infected. Animals receiving 102 IFU also had a longer incubation period. Of 19 animals that mated with infected males, 63.2% became infected, with an infection course which was not significantly different than that of the 102-IFU-infected group. The data suggest that female guinea pigs received approximately 102 IFU by sexual transmission. Of interest was the observation that the guinea pigs infected by sexual transmission shed organisms for a significantly shorter time period than that of any group that was artificially infected. This result suggests that there may be factors associated with semen which passively transfer antimicrobial activity to the female or enhance the innate host response in the female. Immunization of females

  13. Characterization of chlamydial genital infection resulting from sexual transmission from male to female guinea pigs and determination of infectious dose.

    PubMed

    Rank, Roger G; Bowlin, Anne K; Reed, Ronald L; Darville, Toni

    2003-11-01

    A major problem in the study of chlamydial genital infections in animal models has been the use of varied doses of chlamydiae for infection in different laboratories. It is clearly desirable to use a dose which approximates that of natural sexual infection, but that dose to date has not been determined because of the inability of researchers to quantify chlamydiae in semen. Fortunately, sexual transmission of chlamydiae has been described for the guinea pig model of infection with the chlamydial agent of guinea pig inclusion conjunctivitis (GPIC). In this study, we undertook to determine the approximate infection dose in actual sexual transmission by comparing the kinetics of infection in female guinea pigs acquired via sexual contact to those of genital infections induced artificially with known quantities of chlamydiae. Groups of guinea pigs were infected intravaginally with 10(4), 10(3), 10(2), and 10(1) inclusion-forming units (IFU) of GPIC, and the kinetics of the infection were determined. Infection with 10(2) IFU produced infections with lower peak levels than those in animals receiving 10(4) or 10(3) IFU. Seventy percent of animals receiving 10(2) IFU became infected, while 100 and 79% of animals receiving 10(4) and 10(3) IFU, respectively, became infected. Animals receiving 10(2) IFU also had a longer incubation period. Of 19 animals that mated with infected males, 63.2% became infected, with an infection course which was not significantly different than that of the 10(2)-IFU-infected group. The data suggest that female guinea pigs received approximately 10(2) IFU by sexual transmission. Of interest was the observation that the guinea pigs infected by sexual transmission shed organisms for a significantly shorter time period than that of any group that was artificially infected. This result suggests that there may be factors associated with semen which passively transfer antimicrobial activity to the female or enhance the innate host response in the female

  14. Outcomes of High-Dose-Rate Interstitial Brachytherapy in the Treatment of Locally Advanced Cervical Cancer: Long-term Results

    SciTech Connect

    Pinn-Bingham, Melva; Puthawala, Ajmel A.; Syed, A.M. Nisar; Sharma, Anil; DiSaia, Philip; Berman, Michael; Tewari, Krishnansu S.; Randall-Whitis, Leslie; Mahmood, Usama; Ramsinghani, Nilam; Kuo, Jeffrey; Chen, Wen-Pin; McLaren, Christine E.

    2013-03-01

    Purpose: The purpose of this study was to determine locoregional control (LRC), disease-free survival (DFS), and toxicity of high-dose-rate interstitial brachytherapy (HDR-ISBT) in the treatment of locally advanced cervical cancer. Methods and Materials: Between March 1996 and May 2009, 116 patients with cervical cancer were treated. Of these, 106 (91%) patients had advanced disease (International Federation of Gynecology and Obstetrics stage IIB-IVA). Ten patients had stage IB, 48 had stage II, 51 had stage III, and 7 had stage IVA disease. All patients were treated with a combination of external beam radiation therapy (EBRT) to the pelvis (5040 cGy) and 2 applications of HDR-ISBT to a dose of 3600 cGy to the implanted volume. Sixty-one percent of patients also received interstitial hyperthermia, and 94 (81%) patients received chemotherapy. Results: Clinical LRC was achieved in 99 (85.3%) patients. Three-year DFS rates were 59%, 67%, 71%, and 57% for patients with stage IB, II, III, and IVA disease, respectively. The 5-year DFS and overall survival rates for the entire group were 60% and 44%, respectively. Acute and late toxicities were within acceptable limits. Conclusions: Locally advanced cervical cancer patients for whom intracavitary BT is unsuitable can achieve excellent LRC and OS with a combination of EBRT and HDR-ISBT.

  15. Accelerated partial breast irradiation in the elderly: 5-year results of high-dose rate multi-catheter brachytherapy

    PubMed Central

    2014-01-01

    Objective To evaluate clinical outcome after accelerated partial breast irradiation (APBI) in the elderly after high-dose-rate interstitial multi-catheter brachytherapy (HIBT). Methods and materials Between 2005 and 2013, 70 patients underwent APBI using HIBT. Catheter implant was performed intra or post-operatively (referred patients) after lumpectomy and axillary sentinel lymph node dissection. Once the pathological results confirmed the indication of APBI, planification CT-scan was performed to deliver 34 Gy/10f/5d or 32 Gy/8f/4d. Dose-volume adaptation was manually achieved (graphical optimization). Dosimetric results and clinical outcome were retrospectively analyzed. Physician cosmetic evaluation was reported. Results With a median follow-up of 60.9 months [4.6 – 90.1], median age was 80.7 years [62 – 93.1]. Regarding APBI ASTRO criteria, 61.4%, 18.6% and 20% were classified as suitable, cautionary and non-suitable respectively. Axillary sentinel lymph node dissection was performed in 94.3%; 8 pts (11.5%) presented an axillary involvement. A median dose of 34 Gy [32 – 35] in 8 to 10 fractions was delivered. Median CTV was 75.2 cc [16.9 – 210], median D90 EQD2 was 43.3 Gy [35 – 72.6] and median DHI was 0.54 [0.19 – 0.74]. One patient experienced ipsilateral recurrence (5-year local free recurrence rate: 97.6%. Five-year specific and overall survival rates were 97.9% and 93.2% respectively. Thirty-four patients (48%) presented 47 late complications classified grade 1 (80.8%) and grade 2 (19.2%) with no grade ≥ 3. Cosmetic results were considered excellent/good for 67 pts (95.7%). Conclusion APBI using HIBT and respecting strict rules of implantation and planification, represents a smart alternative between no post-operative irradiation and whole breast irradiation delivered over 6 consecutive weeks. PMID:24886680

  16. Statistical analysis of results from the 1995 survey of CFC consumption on US Navy ships. Technical report

    SciTech Connect

    Burns, K.C.; Smith, D.E.

    1995-08-01

    The production of chlorofluorocarbon (CFC) refrigerants will cease in the United States at the end of 1995. The Naval Sea Systems Command (NAVSEA) needs to monitor total fleet requirements of CFCs until they are phased out. Stockpile requirements for ozone-depleting substances were determined from the results of a survey covering the period from 1 May 1993 to 30 April 1994. A second survey was conducted for the period from 1 May 1994 to 30 April 1995 for two primary reasons: to provide additional nformation on reserve requirements and to measure the effects of policies designed to reduce fleet CFC consumption. This report provides a statistical analysis of the data from the new survey, which includes reported usage for CFC-ll, CFC-12, and CFC-114. The new results are compared to those from the earlier survey, showing a significant reduction in CFC usage. Summary information in the report can be used to refine estimates of reserve requirements.

  17. PHA-stimulated immune-responsiveness in mercury-dosed zebra finches does not match results from environmentally exposed songbirds.

    PubMed

    Caudill, Mitchell T; Spear, Eliza L; Varian-Ramos, Claire W; Cristol, Daniel A

    2015-04-01

    Dietary mercury exposure is associated with suppressed immune responsiveness in birds. This study examined the immune-responsiveness of domestic zebra finches (Taeniopygia guttata) experimentally exposed to mercury through their diet. We used the phytohemagglutinin (PHA) skin-swelling test to assay the effect of two modes of mercury exposure. Some finches received exposure to mercury only after reaching sexual maturity, while others were maintained on a mercury-dosed diet throughout life, including development. Each bird received one of five dietary concentrations of methylmercury cysteine (0.0, 0.3, 0.6, 1.2 or 2.4 ppm). In contrast to a study on wild songbirds at a mercury-contaminated site, we detected no relationship between mercury level and immunological response to PHA, regardless of mode of exposure. This result represents the first major difference found by our laboratory between wild birds exposed to environmental mercury and captive birds experimentally exposed to mercury.

  18. Exposure to low doses (20 cGy) of Hze results in spatial memory impairment in rats.

    NASA Astrophysics Data System (ADS)

    Britten, Richard; Johnson, Angela; Davis, Leslie; Green-Mitchell, Shamina; Chabriol, Olivia; Sanford, Larry; Drake, Richard

    INTRODUCTION. Current models predict that the astronauts on a mission to a deep space destination, such as Mars, will be exposed to 25 cGy of Galactic cosmic radiation (GCR). The long-term consequence of exposure to such doses is largely unknown, but given that 1.3 Gy of X-rays has been reported to lead to long-term cognitive deficits (Shore et al, 1976) and that CGR have an RBE of 2-5, it is likely that the predicted 25 cGy of GCR will lead to defects in the cognitive ability of the astronauts during and after the mission. Our studies are designed to help define the GCR dose that will lead to defects in complex working memory, and also to elucidate the mechanisms whereby hadronic radiation diminishes neurocognitive function. The identification of such processes would provide an opportunity for post-mission surveillance, and hopefully will lead to intervention strategies that will ameliorate or attenuate GCR-induced neurocognitive deficits. MATERIALS METHODS. Four-week old male Wistar rats were exposed to either X-rays or 1 GeV 56Fe. At three or six months post exposure the performance of the rats in the Barnes' Maze (Spatial memory) was established. The duration and frequency of REM sleep was also monitored to determine if the neurocognitive deficits arose due to reduced memory consolidation as a result of diminished REM sleep. We used a novel, but maturing technique, called MALDI-MS imaging (or MALDI-MSI), to identify specific regions of the brain where the neuroproteome differs in rats that have developed spatial memory impairments. RESULTS. 11.5 Gy of X-rays led to reduced performance in the Barnes's maze. In contrast, exposure to 20 cGy of Hze (1 GeV 56Fe) resulted in a significant impairment of spatial memory performance as measured in the Barnes' Maze, which was manifested by an increase in relative escape latency REL over a 5 day testing period. Such an increase in REL could arise from the rats becoming less able, or perhaps less willing, to locate the

  19. Photospheric Magnetic Field Properties of Flaring vs. Flare-Quiet Active Regions I: Data, General Approach, and Statistical Results

    NASA Astrophysics Data System (ADS)

    Leka, K. D.; Barnes, G.

    2003-05-01

    Photospheric vector magnetic field data from the U. Hawai`i Imaging Vector Magnetograph are examined for pre-event signatures unique to solar energetic phenomena. Parameters are constructed from B(x,y) to describe (for example) the distributions of the field, spatial gradients of the field, vertical current, current helicity, ''twist'' parameter α and magnetic shear angles. A quantitative statistical approach employing discriminant analysis and Hotelling's T2-test is applied to the magnitude and temporal evolution of parameters from 24 flare-event and flare-quiet epochs from seven active regions. We demonstrate that (1) when requiring a flare-unique signature, numerous candidate parameters are nullified by considering flare-quiet epochs, (2) a more robust method exists for estimating error rates than conventional ''truth tables'', (3) flaring and flare-quiet populations do not necessarily have low error rates for classification even when statistically distinguishable, and that (4) simultaneous consideration of a large number of variables is required to produce acceptable error rates. That is, when the parameters are considered individually, they show little ability to differentiate between the two populations; multi-variable combinations can discriminate the populations and/or result in perfect classification tables. In lieu of constructing a single all-variable discriminant function to quantify the flare-predictive power of the parameters considered, we devise a method whereby all permutations of the four-variable discriminant functions are ranked by Hotelling's T2. We present those parameters (e.g. the temporal increase of the kurtosis of the spatial distribution of the vertical current density) which consistently appear in the best combinations, indicating that they may play an important role in defining a pre-event photospheric state. While no single combination is clearly the best discriminator, we demonstrate here the requisite approach: include flare

  20. Atmospheric transport and deposition of radionuclides released after the Fukushima Dai-chi accident and resulting effective dose

    NASA Astrophysics Data System (ADS)

    Marzo, Giuseppe A.

    2014-09-01

    On 11 March 2011 an earthquake off the Pacific coast of the Fukushima prefecture generated a tsunami that hit Fukushima Dai-ichi and Fukushima Da-ini Nuclear Power Plants. From 12 March a significant amount of radioactive material was released into the atmosphere and dispersed worldwide. Among the most abundant radioactive species released were iodine and cesium isotopes. By means of an atmospheric dispersion Lagrangian code and publicly available meteorological data, the atmospheric dispersion of 131I, 134Cs, and 137Cs have been simulated for three months after the event with a spatial resolution of 0.5° × 0.5° globally. The simulation has been validated by comparison to publicly available measurements collected in 206 locations worldwide. Sensitivity analysis shows that release height of the radionuclides, wet deposition velocity, and source term are the parameters with the most impact on the simulation results. The simulation shows that the radioactive plume, consisting of about 200 PBq by adding contributions from 131I, 134Cs, and 137Cs, has been transported over the entire northern hemisphere depositing up to 1.2 MBq m-2 nearby the NPPs to less than 20 Bq m-2 in Europe. The consequent effective dose to the population over a 50-year period, calculated by considering both external and internal pathways of exposure, is found to be about 40 mSv in the surroundings of Fukushima Dai-ichi, while other countries in the northern hemisphere experienced doses several orders of magnitude lower suggesting a small impact on the population health elsewhere.

  1. Results of a safety trial on single-dose treatments with 400 mcg/kg of ivermectin in bancroftian filariasis.

    PubMed

    Cartel, J L; Moulia-Pelat, J P; Glaziou, P; Nguyen, L N; Chanteau, S; Roux, J F

    1992-12-01

    Two groups of Polynesian Wuchereria bancrofti carriers, 17 females aged 21 to 84 years and 20 males aged 26 to 57 years, in whom microfilaraemia ranged from 1 to 10,121 mf/ml and from 1 to 6,484 mf/ml, respectively, were given a supervised singledose treatment with 400 mcg/kg of ivermectin. Carriers were examined and questioned regarding their experience of adverse reactions, which were graded 0 to 3 according to severity, at 6, 12 and 24 hours and at 4 days after treatment. Biological examinations which included determination of microfilaraemia, complete blood count, liver function tests and assessment of creatinine and urea levels were performed at 4 days before and 4 days after treatment. Adverse reactions were observed in 65% of female and in 70% of male carriers; they were of grade > or = 2 in 35% of carriers in both groups. None as considered serious; they all disappeared in 24-48 hours. The main symptoms were headache, fever > or = 37.5 degrees C and myalgia in females. One male vomited 3 hours after treatment; as a result the drug was not ingested and no decrease of microfilaraemia was noted. Twelve days afterwards, he was given a second 400 mcg/kg dose, he experienced again a grade 1 reaction and his microfilaraemia fell to zero. The 37 carriers in the present study were matched with 37 other Polynesian carriers treated with a 100 mcg/kg single dose of ivermectin in previous trials for pretreatment mf density and sex: no significant difference could be found in adverse reactions between the 2 treatment groups.(ABSTRACT TRUNCATED AT 250 WORDS)

  2. High-Dose-Rate Rotte 'Y' Applicator Brachytherapy for Definitive Treatment of Medically Inoperable Endometrial Cancer: 10-Year Results

    SciTech Connect

    Coon, Devin; Beriwal, Sushil Heron, Dwight E.; Kelley, Joseph L.; Edwards, Robert P.; Sukumvanich, Paniti; Zorn, Kristin K.; Krivak, Thomas C.

    2008-07-01

    Purpose: To assess the intermediate clinical outcomes of medically inoperable patients with endometrial cancer treated with definitive Rotte 'Y' applicator high-dose-rate brachytherapy (HDRB) over a 10-year period. Methods and Materials: Forty-nine inoperable patients were treated with HDRB from 1997 to 2007. Forty three (84%) were markedly obese (body mass index >35 kg/m{sup 2}). Thirty-one patients (63.3%) underwent two-dimensional treatment planning, whereas 18 patients (36.7%) underwent three-dimensional treatment planning. Thirty five of the patients (71.4%) were first treated with external beam radiotherapy (EBRT). For patients receiving EBRT in addition to HDRB, the median Y-applicator dose was 20 Gy in 5 fractions; for patients receiving HDRB alone it was 35 Gy in 5 fractions. All patients received two Y-applicator treatments per day. Results: Median follow-up time for all patients was 33 months. Acute HDRB toxicities were limited to Grade 1 and 2 occurring in 5 patients. One patient had a myocardial infarction. Four patients had late Grade 2 or 3 toxicity. Three patients had local recurrence (median time to recurrence, 16 months). The 3- and 5-year actuarial cause-specific survival rates were 93% and 87%, respectively; the overall survival rate was 83% and 42%, respectively, at 3 and 5 years. Conclusions: Twice-daily HDRB using a Y-applicator is a well-tolerated and efficacious regimen for the definitive treatment of medically inoperable patients with early-stage endometrial cancer. The recent incorporation of three-dimensional treatment planning has the potential to further decrease treatment morbidities.

  3. Prevalence of Hyperthyroidism Following Exposure During Childhood or Adolescence to Radioiodines from the Chornobyl Nuclear Accident: Dose-Response Results from the Ukrainian-American Cohort Study

    PubMed Central

    Hatch, M.; Furukawa, K.; Brenner, A.; Olinjyk, V.; Ron, E.; Zablotska, L.; Terekhova, G.; McConnell, R.; Markov, V.; Shpak, V.; Ostroumova, E.; Bouville, A.; Tronko, M.

    2013-01-01

    Relatively few data are available on the prevalence of hyperthyroidism (TSH concentrations of < 0.3 mIU/L, with normal or elevated concentrations of free T4) in individuals exposed to radioiodines at low levels. The accident at the Chornobyl (Chernobyl) nuclear plant in Ukraine on April 26, 1986 exposed large numbers of residents to radioactive fallout, principally to iodine-131 (I-131) (mean and median doses = 0.6 Gray (Gy) and 0.2 Gy). We investigated the relationship of I-131 and prevalent hyperthyroidism among 11,853 individuals exposed as children or adolescents in Ukraine who underwent an in-depth, standardized thyroid gland screening examination 12–14 years later. Radioactivity measurements taken shortly after the accident were available for all subjects and were used to estimate individual thyroid doses. We identified 76 cases of hyperthyroidism (11 overt, 65 subclinical). Using logistic regression, we tested a variety of continuous risk models and conducted categorical analyses for all subjects combined and for females (53 cases, n=5,767) and males (23 cases, n=6,086) separately, but found no convincing evidence of a dose response relationship between I-131 and hyperthyroidism. There was some suggestion of elevated risk among females in an analysis based on a dichotomous dose model with a threshold of 0.5 Gy chosen empirically (OR=1.86, P=0.06), but the statistical significance level was reduced (P=0.13) in a formal analysis with an estimated threshold. In summary, after a thorough exploration of the data, we found no statistically significant dose response relationship between individual I-131 thyroid doses and prevalent hyperthyroidism. PMID:21128800

  4. Assessing Fun Items' Effectiveness in Increasing Learning of College Introductory Statistics Students: Results of a Randomized Experiment

    ERIC Educational Resources Information Center

    Lesser, Lawrence M.; Pearl, Dennis K.; Weber, John J., III

    2016-01-01

    There has been a recent emergence of scholarship on the use of fun in the college statistics classroom, with at least 20 modalities identified. While there have been randomized experiments that suggest that fun can enhance student achievement or attitudes in statistics, these studies have generally been limited to one particular fun modality or…

  5. Estimating Optimal Dose of Twice-Weekly Gemcitabine for Concurrent Chemoradiotherapy in Unresectable Pancreatic Carcinoma: Mature Results of GEMRT-01 Phase I Trial

    SciTech Connect

    Girard, Nicolas; Mornex, Francoise; Bossard, Nadine; Ychou, Marc; Chauffert, Bruno; Wautot, Virginie

    2010-08-01

    Purpose: To accurately determine the maximal tolerated dose, feasibility, and antitumor activity of concurrent chemoradiotherapy including twice-weekly gemcitabine in patients with unresectable pancreatic adenocarcinoma. Methods and Materials: Eligible patients with histologically proven adenocarcinoma of the pancreas were included in this Phase I trial. Radiotherapy was delivered to a total dose of 50 Gy. Concurrent chemotherapy with twice-weekly gemcitabine was administered during the 5 weeks of radiotherapy, from an initial dose of 30 mg/m{sup 2}. The gemcitabine doses were escalated in 10-mg/m{sup 2} increments in a three-plus-three design, until dose-limiting toxicities were observed. Results: A total of 35 patients were included in the trial. The feasibility of chemoradiotherapy was high, because all the patients received the planned total radiation dose, and 26 patients (74%) received {>=}70% of the planned chemotherapy dose. The mean total delivered dose of gemcitabine was 417 mg/m{sup 2} (i.e., 77% of the prescribed dose). The maximal tolerated dose of twice-weekly gemcitabine was 70 mg/m{sup 2}. Of the 35 patients, 13 had a partial response (37%) and 21 had stable disease (60%). Overall, the median survival and the 6-, 12-, and 18-month survival rates were 10.6 months and 82%, 31%, and 11%, respectively. Survival was significantly longer in patients with an initial performance status of 0 or 1 (p = .004). Conclusion: Our mature data have indicated that gemcitabine doses can be increased {<=}70 mg/m{sup 2}, when delivered twice-weekly with concurrent radiotherapy. This combination shows promises to achieve better recurrence-free and overall survival. These results will serve as a basis for further implementation of the multimodal treatment of locally advanced pancreatic carcinoma.

  6. Population pharmacokinetics of piperacillin in the early phase of septic shock: does standard dosing result in therapeutic plasma concentrations?

    PubMed

    Öbrink-Hansen, Kristina; Juul, Rasmus Vestergaard; Storgaard, Merete; Thomsen, Marianne Kragh; Hardlei, Tore Forsingdal; Brock, Birgitte; Kreilgaard, Mads; Gjedsted, Jakob

    2015-11-01

    Antibiotic dosing in septic shock patients poses a challenge for clinicians due to the pharmacokinetic (PK) variability seen in this patient population. Piperacillin-tazobactam is often used for empirical treatment, and initial appropriate dosing is crucial for reducing mortality. Accordingly, we determined the pharmacokinetic profile of piperacillin (4 g) every 8 h, during the third consecutive dosing interval, in 15 patients treated empirically for septic shock. We developed a population pharmacokinetic model to assess empirical dosing and to simulate alternative dosing regimens and modes of administration. Time above the MIC (T>MIC) predicted for each patient was evaluated against clinical breakpoint MIC for Pseudomonas aeruginosa (16 mg/liter). Pharmacokinetic-pharmacodynamic (PK/PD) targets evaluated were 50% fT>4×MIC and 100% fT>MIC. A population PK model was developed using NONMEM, and data were best described by a two-compartment model. Central and intercompartmental clearances were 3.6 liters/h (relative standard error [RSE], 15.7%) and 6.58 liters/h (RSE, 16.4%), respectively, and central and peripheral volumes were 7.3 liters (RSE, 11.8%) and 3.9 liters (RSE, 9.7%), respectively. Piperacillin plasma concentrations varied considerably between patients and were associated with levels of plasma creatinine. Patients with impaired renal function were more likely to achieve predefined PK/PD targets than were patients with preserved or augmented renal function. Simulations of alternative dosing regimens showed that frequent intermittent bolus dosing as well as dosing by extended and continuous infusion increases the probability of attaining therapeutic plasma concentrations. For septic shock patients with preserved or augmented renal function, dose increment or prolonged infusion of the drug needs to be considered. (This study has been registered at ClinicalTrials.gov under registration no. NCT02306928.).

  7. Low-dose-rate brachytherapy for patients with transurethral resection before implantation in prostate cancer. Long-term results

    PubMed Central

    Prada, Pedro J.; Anchuelo, Javier; Blanco, Ana García; Payá, Gema; Cardenal, Juan; Acuña, Enrique; Ferri, María; Vázquez, Andrés; Pacheco, Maite; Sanchez, Jesica

    2016-01-01

    ABSTRACT Objectives We analyzed the long-term oncologic outcome for patients with prostate cancer and transurethral resection who were treated using low-dose-rate (LDR) prostate brachytherapy. Methods and Materials From January 2001 to December 2005, 57 consecutive patients were treated with clinically localized prostate cancer. No patients received external beam radiation. All of them underwent LDR prostate brachytherapy. Biochemical failure was defined according to the “Phoenix consensus”. Patients were stratified as low and intermediate risk based on The Memorial Sloan Kettering group definition. Results The median follow-up time for these 57 patients was 104 months. The overall survival according to Kaplan-Meier estimates was 88% (±6%) at 5 years and 77% (±6%) at 12 years. The 5 and 10 years for failure in tumour-free survival (TFS) was 96% and respectively (±2%), whereas for biochemical control was 94% and respectively (±3%) at 5 and 10 years, 98% (±1%) of patients being free of local recurrence. A patient reported incontinence after treatment (1.7%). The chronic genitourinary complains grade I were 7% and grade II, 10%. At six months 94% of patients reported no change in bowel function. Conclusions The excellent long-term results and low morbidity presented, as well as the many advantages of prostate brachytherapy over other treatments, demonstrates that brachytherapy is an effective treatment for patients with transurethral resection and clinical organ-confined prostate cancer. PMID:27136466

  8. Randomized Noninferiority Trial of Reduced High-Dose Volume Versus Standard Volume Radiation Therapy for Muscle-Invasive Bladder Cancer: Results of the BC2001 Trial (CRUK/01/004)

    SciTech Connect

    Huddart, Robert A.; Hall, Emma; Hussain, Syed A.; Jenkins, Peter; Rawlings, Christine; Tremlett, Jean; Crundwell, Malcolm; Adab, Fawzi A.; Sheehan, Denise; Syndikus, Isabel; Hendron, Carey; Lewis, Rebecca; Waters, Rachel; James, Nicholas D.

    2013-10-01

    Purpose: To test whether reducing radiation dose to uninvolved bladder while maintaining dose to the tumor would reduce side effects without impairing local control in the treatment of muscle-invasive bladder cancer. Methods and Materials: In this phase III multicenter trial, 219 patients were randomized to standard whole-bladder radiation therapy (sRT) or reduced high-dose volume radiation therapy (RHDVRT) that aimed to deliver full radiation dose to the tumor and 80% of maximum dose to the uninvolved bladder. Participants were also randomly assigned to receive radiation therapy alone or radiation therapy plus chemotherapy in a partial 2 × 2 factorial design. The primary endpoints for the radiation therapy volume comparison were late toxicity and time to locoregional recurrence (with a noninferiority margin of 10% at 2 years). Results: Overall incidence of late toxicity was less than predicted, with a cumulative 2-year Radiation Therapy Oncology Group grade 3/4 toxicity rate of 13% (95% confidence interval 8%, 20%) and no statistically significant differences between groups. The difference in 2-year locoregional recurrence free rate (RHDVRT − sRT) was 6.4% (95% confidence interval −7.3%, 16.8%) under an intention to treat analysis and 2.6% (−12.8%, 14.6%) in the “per-protocol” population. Conclusions: In this study RHDVRT did not result in a statistically significant reduction in late side effects compared with sRT, and noninferiority of locoregional control could not be concluded formally. However, overall low rates of clinically significant toxicity combined with low rates of invasive bladder cancer relapse confirm that (chemo)radiation therapy is a valid option for the treatment of muscle-invasive bladder cancer.

  9. Assessment of the effective dose equivalent for external photon radiation. Volume 1, Calculational results for beam and point source geometries: Final report

    SciTech Connect

    Reece, W.D.; Poston, J.W.; Xu, X.G.

    1993-02-01

    Beginning in January 1994, US nuclear power plants must change the way that they determine the radiation exposure to their workforce. At that time, revisions to Title 10 Part 20 of the Code of Federal Regulations will be in force requiring licensees to evaluate worker radiation exposure using a risk-based methodology termed the ``effective dose equivalent.`` A research project was undertaken to improve upon the conservative method presently used for assessing effective dose equivalent. In this project effective dose equivalent was calculated using a mathematical model of the human body, and tracking photon interactions for a wide variety of radiation source geometries using Monte Carlo computer code simulations. Algorithms were then developed to relate measurements of the photon flux on the surface of the body (as measured by dosimeters) to effective dose equivalent. This report (Volume I of a two-part study) describes: the concept of effective dose equivalent, the evolution of the concept and its incorporation into regulations, the variations in human organ susceptibility to radiation, the mathematical modeling and calculational techniques used, the results of effective dose equivalent calculations for a broad range of photon energiesand radiation source geometries. The study determined that for beam radiation sources the highest effective dose equivalent occurs for beams striking the front of the torso. Beams striking the rear of the torsoproduce the next highest effective dose equivalent, with effective dose equivalent falling significantly as one departs from these two orientations. For point sources, the highest effective dose equivalent occurs when the sources are in contact with the body on the front of the torso. For females the highest effective dose equivalent occurs when the source is on the sternum, for males when it is on the gonads.

  10. Effect of background and transport dose on the results of the personal dose equivalent Hp(10) measurements in photon fields obtained during the intercomparison 2013 of the African region.

    PubMed

    Arib, M; Herrati, A; Dari, F; Lounis-Mokrani, Z

    2015-12-01

    As part of the intercomparison on the measurement of personal dose equivalent Hp(10), jointly organised by the International Atomic Energy Agency and the Algerian Secondary Standard Dosimetry Laboratory, for the African region, up to 12 dosemeters were added to the packages of the 28 participants to evaluate the background and transport dose (BGTD), received by the dosemeters before and after their irradiation at the SSDL (environmental irradiations, scanning process at the airports, etc.). Out of the 28 participants, only 17 reported the corresponding BGTD measured values, which lied between 0.03 and 0.8 mSv. The mean measured value of BG was (0.25±0.14) mSv, which is significantly high compared with the lowest dose value used in the intercomparison exercise. The BGTD correction shifted the overall results of the intercomparison from an overestimation of dose (∼8 % before applying BGT dose correction) to an underestimation of dose (-9 % after correction). The measurement protocol and the detailed analysis of the results and applied corrections are discussed in this paper.

  11. Recommendations to the Technical Steering Panel regarding approach for estimating individual radiation doses resulting from releases of radionuclides to the Columbia River

    SciTech Connect

    Napier, B.A.; Brothers, A.J.

    1992-07-01

    At the direction of the Technical Steering Panel (TSP) of the Hanford Environmental Dose Reconstruction (HEDR) Project, Battelle staff have reviewed and analyzed available data regarding possible historical radiation doses to individuals resulting from radionuclide releases to the Columbia River. The objective of this review was to recommend to the TSP the spatial and temporal scope and level of effort on Columbia River work to most effectively extend work performed in Phase I of the project (PNL 1991a, PNL 1991b) to meet the project objectives. A number of options were analyzed. Four stretches of the Columbia River and adjacent Pacific coastal waters were defined and investigated for four time periods. Radiation doses arising from ten potentially major exposure pathways were evaluated for each of the time/location combinations, and several alternative methods were defined for estimating the doses from each pathway. Preliminary cost estimates were also developed for implementing dose estimation activities for each of the possible combinations.

  12. Dose-response approaches for nuclear receptor-mediated modes of action for liver carcinogenicity: Results of a workshop

    EPA Science Inventory

    A public workshop, organized by a Steering Committee of scientists from government, industry, universities, and research organizations, was held at the National Institute of Environmental Health Sciences (NIEHS) in September, 2010. The workshop explored the dose-response implicat...

  13. A comparison of dose results from the Clean Air Act Assessment Package-1988, personal computer (CAP88-PC), version 3 to previous versions.

    PubMed

    Rhoads, Kathleen; Snyder, Sandra; Staven, Lissa

    2013-08-01

    Computer software packages approved by the U.S. Environmental Protection Agency (U.S. EPA), including CAP88-PC, are used by U.S. Department of Energy (U.S. DOE) sites to demonstrate compliance with the radionuclide air emission standard under the Clean Air Act. CAP88-PC version 3, was approved by the U.S. EPA in February 2006 for use by U.S. DOE facilities. Version 3 incorporates several major changes that have the potential to affect calculated doses relative to calculations using earlier versions. This analysis examined the types and magnitudes of changes to dose estimates for specific radionuclides calculated using the version 3 software compared with the previous versions. For parent radionuclides and for the total dose from radionuclide chains, total effective dose calculated with version 3 was compared to effective dose equivalent calculated with previous versions. Various comparisons were also performed to determine which of the updates in version 3 accounted for changes in overall dose estimates. CAP88-PC version 3 would produce substantially different results relative to previous versions of the code for a number of radionuclides, including some isotopes that may be present at U.S. DOE facilities, as well as those used for industrial and medical applications. In general, doses for many radionuclides were lower using version 3 but doses for a few key radionuclides increased relative to the previous versions.

  14. Pharmacodynamics of non-break weekly paclitaxel (Taxol) and pharmacokinetics of Cremophor-EL vehicle: results of a dose-escalation study.

    PubMed

    Briasoulis, Evangelos; Karavasilis, Vasilis; Tzamakou, Eleftheria; Haidou, Constantina; Piperidou, Christina; Pavlidis, Nicholas

    2002-06-01

    We characterized the toxicity and determined the maximum tolerated dose of non-break weekly paclitaxel (Taxol) in chemotherapy-naive cancer patients, and studied pharmacokinetics of the formulation vehicle Cremophor-EL with this schedule. Twenty-three patients with primary refractory solid tumors received weekly paclitaxel at the dose range of 70-200 mg/m2. As dose-limiting toxicity we defined granulocytopenia grade > or =2 causing a treatment delay for more than 2 weeks, or febrile neutropenia or grade >2 organ-specific toxicity. Plasma kinetics of Cremophor-EL were analyzed over the first five courses of treatment. Non-break weekly paclitaxel was feasible at doses up to 110 mg/m2, while granulocytopenia precluded scheduled administration of doses > or =130 mg/m2. Clinically relevant peripheral neurotoxicity tended to occur at around 1500 mg/m2 cumulative dosage at weekly doses > or =110 mg/m2. Detectable Cremophor-EL levels were found in all pre-dose samples, but there was no evidence of accumulation up to the sixth course. Our results, discussed in the light of an overview of published data, suggest that chronic weekly administration of paclitaxel is feasible and with a lack of significant accumulation of Cremophor-EL levels at doses up to 90 mg/m2.

  15. A COMPARISON OF DOSE RESULTS FROM THE CLEAN AIR ACT ASSESSMENT PACKAGE-1988, PERSONAL COMPUTER (CAP88-PC), VERSION 3 TO PREVIOUS VERSIONS

    SciTech Connect

    Rhoads, Kathleen; Snyder, Sandra F.; Staven, Lissa H.

    2013-08-01

    EPA-approved computer software packages, including CAP88-PC, are used by Department of Energy sites to demonstrate compliance with the radionuclide air emission standard under the Clean Air Act. The most recent update, CAP88-PC version 3, was approved by EPA in February 2006 for use by Department of Energy facilities. Version 3 incorporates several major changes that have the potential to affect calculated doses relative to calculations using earlier versions. This analysis examined the types and magnitudes of changes to dose estimates for specific radionuclides calculated using the version 3 software compared with the previous versions. Total effective dose calculated with version 3 was compared to effective dose equivalent calculated with previous versions for parent radionuclides and for the total dose from radionuclide chains. Various comparisons were also performed to determine which of the updates in version 3 accounted for changes in overall dose estimates. CAP88-PC version 3 would produce substantially different results relative to previous versions of the code for a number of radionuclides, including some isotopes that may be present at Department of Energy facilities, as well as those used for industrial and medical applications. In general, doses for many radionuclides are lower using version 3 but doses for a few key radionuclides would be higher.

  16. Extended Statistical Short-Range Guidance for Peak Wind Speed Analyses at the Shuttle Landing Facility: Phase II Results

    NASA Technical Reports Server (NTRS)

    Lambert, Winifred C.

    2003-01-01

    This report describes the results from Phase II of the AMU's Short-Range Statistical Forecasting task for peak winds at the Shuttle Landing Facility (SLF). The peak wind speeds are an important forecast element for the Space Shuttle and Expendable Launch Vehicle programs. The 45th Weather Squadron and the Spaceflight Meteorology Group indicate that peak winds are challenging to forecast. The Applied Meteorology Unit was tasked to develop tools that aid in short-range forecasts of peak winds at tower sites of operational interest. A seven year record of wind tower data was used in the analysis. Hourly and directional climatologies by tower and month were developed to determine the seasonal behavior of the average and peak winds. Probability density functions (PDF) of peak wind speed were calculated to determine the distribution of peak speed with average speed. These provide forecasters with a means of determining the probability of meeting or exceeding a certain peak wind given an observed or forecast average speed. A PC-based Graphical User Interface (GUI) tool was created to display the data quickly.

  17. Impact of coronal mass ejections on the Earth's thermosphere and geoeffectiveness observed by ACE and GRACE: Statistical results

    NASA Astrophysics Data System (ADS)

    Krauss, Sandro; Temmer, Manuela; Veronig, Astrid; Baur, Oliver

    2016-04-01

    For the period July 2003 to August 2010, the interplanetary coronal mass ejection (ICME) catalogue maintained by Richardson and Cane lists 106 Earth-directed events, which have been measured in situ by plasma and field instruments on board the ACE satellite. We present a statistical investigation of the Earth's thermospheric neutral density response by means of accelerometer measurements collected by the Gravity Recovery And Climate Experiment (GRACE) satellites, which are available for 104 ICMEs in the data set. We relate the thermospheric density increase to various geomagnetic indices (e.g. Dst, AE, Kp, a-indices, ...) and characteristic ICME parameters (impact speed, southward magnetic field strength Bz). We find high correlations between the ICME Bz and thermospheric density enhancements as well as with most of the geomagnetic indices. Separating the response for the shock-sheath region and the magnetic structure of the ICME, we find for instance that the Dst and SYM-H indices reveal a tighter relation to the Bz minimum in the magnetic structure of the ICME, whereas the polar cap indices show higher correlations with the Bz minimum in the shock-sheath region. These results are expected to further stimulate progress in space weather understanding and applications regarding satellite operations.

  18. Localized Low-Dose Radiotherapy for Follicular Lymphoma: History, Clinical Results, Mechanisms of Action, and Future Outlooks

    SciTech Connect

    Ganem, Gerard; Cartron, Guillaume; Girinsky, Theodore; Haas, Rick L.M.; Cosset, Jean Marc; Solal-Celigny, Philippe

    2010-11-15

    The extreme radiosensitivity of indolent lymphomas was reported in the early years of radiotherapy (RT). The efficacy of low-dose total body irradiation (1.5-2 Gy) was particularly demonstrative. Higher doses were considered appropriate for localized disease. The optimal (or conventional) dose of curative RT derived from the early studies was determined to be 30-35 Gy. Nevertheless, in older series addressing the tumoricidal radiation dose in non-Hodgkin's lymphomas, investigators noted that a significant number of 'nodular' lymphomas were controlled with a dose of <22 Gy for >3 years. The idea of reintroducing localized low-dose radiotherapy (LDRT) for indolent non-Hodgkin's lymphomas came from a clinical observation. The first study showing the high efficacy of LDRT (4 Gy in two fractions of 2 Gy within 3 days) in selected patients with chemoresistant, indolent, non-Hodgkin's lymphomas was published in 1994. Since this first report, at least eight series of patients treated with localized LDRT have been published, showing a 55% complete response rate in irradiated sites, with a median duration of 15-42 months. How LDRT induces lymphoma cell death remains partly unknown. However, some important advances have recently been reported. Localized LDRT induces an apoptosis of follicular lymphoma cells. This apoptotic cell death elicits an immune response mediated by macrophages and dendritic cells. Follicular lymphoma is probably an ideal model to explore these mechanisms. This review also discusses the future of LDRT for follicular lymphoma.

  19. High-dose-rate intraluminal brachytherapy prior to external radiochemotherapy in locally advanced esophageal cancer: preliminary results

    PubMed Central

    Safaei, Afsaneh Maddah; Ghalehtaki, Reza; Khanjani, Nezhat; Farazmand, Borna; Babaei, Mohammad

    2017-01-01

    Purpose Dysphagia is a common initial presentation in locally advanced esophageal cancer and negatively impacts patient quality of life and treatment compliance. To induce fast relief of dysphagia in patients with potentially operable esophageal cancer high-dose-rate (HDR) brachytherapy was applied prior to definitive radiochemotherapy. Material and methods In this single arm phase II clinical trial between 2013 to 2014 twenty patients with locally advanced esophageal cancer (17 squamous cell and 3 adenocarcinoma) were treated with upfront 10 Gy HDR brachytherapy, followed by 50.4 Gy external beam radiotherapy (EBRT) and concurrent chemotherapy with cisplatin/5-fluorouracil. Results Tumor response, as measured by endoscopy and/or computed tomography scan, revealed complete remission in 16 and partial response in 4 patients (overall response rate 100%). Improvement of dysphagia was induced by brachytherapy within a few days and maintained up to the end of treatment in 80% of patients. No differences in either response rate or dysphagia resolution were found between squamous cell and adenocarcinoma histology. The grade 2 and 3 acute pancytopenia or bicytopenia reported in 4 patients, while sub-acute adverse effects with painful ulceration was seen in five patients, occurring after a median of 2 months. A perforation developed in one patient during the procedure of brachytherapy that resolved successfully with immediate surgery. Conclusions Brachytherapy before EBRT was a safe and effective procedure to induce rapid and durable relief from dysphagia, especially when combined with EBRT. PMID:28344601

  20. A Simple Low-dose X-ray CT Simulation from High-dose Scan.

    PubMed

    Zeng, Dong; Huang, Jing; Bian, Zhaoying; Niu, Shanzhou; Zhang, Hua; Feng, Qianjin; Liang, Zhengrong; Ma, Jianhua

    2015-10-01

    Low-dose X-ray computed tomography (CT) simulation from high-dose scan is required in optimizing radiation dose to patients. In this study, we propose a simple low-dose CT simulation strategy in sinogram domain using the raw data from high-dose scan. Specially, a relationship between the incident fluxes of low- and high- dose scans is first determined according to the repeated projection measurements and analysis. Second, the incident flux level of the simulated low-dose scan is generated by properly scaling the incident flux level of high-dose scan via the determined relationship in the first step. Third, the low-dose CT transmission data by energy integrating detection is simulated by adding a statistically independent Poisson noise distribution plus a statistically independent Gaussian noise distribution. Finally, a filtered back-projection (FBP) algorithm is implemented to reconstruct the resultant low-dose CT images. The present low-dose simulation strategy is verified on the simulations and real scans by comparing it with the existing low-dose CT simulation tool. Experimental results demonstrated that the present low-dose CT simulation strategy can generate accurate low-dose CT sinogram data from high-dose scan in terms of qualitative and quantitative measurements.

  1. SU-E-J-06: Additional Imaging Guidance Dose to Patient Organs Resulting From X-Ray Tubes Used in CyberKnife Image Guidance System

    SciTech Connect

    Sullivan, A; Ding, G

    2015-06-15

    Purpose: The use of image-guided radiation therapy (IGRT) has become increasingly common, but the additional radiation exposure resulting from repeated image guidance procedures raises concerns. Although there are many studies reporting imaging dose from different image guidance devices, imaging dose for the CyberKnife Robotic Radiosurgery System is not available. This study provides estimated organ doses resulting from image guidance procedures on the CyberKnife system. Methods: Commercially available Monte Carlo software, PCXMC, was used to calculate average organ doses resulting from x-ray tubes used in the CyberKnife system. There are seven imaging protocols with kVp ranging from 60 – 120 kV and 15 mAs for treatment sites in the Cranium, Head and Neck, Thorax, and Abdomen. The output of each image protocol was measured at treatment isocenter. For each site and protocol, Adult body sizes ranging from anorexic to extremely obese were simulated since organ dose depends on patient size. Doses for all organs within the imaging field-of-view of each site were calculated for a single image acquisition from both of the orthogonal x-ray tubes. Results: Average organ doses were <1.0 mGy for every treatment site and imaging protocol. For a given organ, dose increases as kV increases or body size decreases. Higher doses are typically reported for skeletal components, such as the skull, ribs, or clavicles, than for softtissue organs. Typical organ doses due to a single exposure are estimated as 0.23 mGy to the brain, 0.29 mGy to the heart, 0.08 mGy to the kidneys, etc., depending on the imaging protocol and site. Conclusion: The organ doses vary with treatment site, imaging protocol and patient size. Although the organ dose from a single image acquisition resulting from two orthogonal beams is generally insignificant, the sum of repeated image acquisitions (>100) could reach 10–20 cGy for a typical treatment fraction.

  2. Normal tissue complication probability (NTCP) modelling using spatial dose metrics and machine learning methods for severe acute oral mucositis resulting from head and neck radiotherapy

    PubMed Central

    Dean, Jamie A; Wong, Kee H; Welsh, Liam C; Jones, Ann-Britt; Schick, Ulrike; Newbold, Kate L; Bhide, Shreerang A; Harrington, Kevin J; Nutting, Christopher M; Gulliford, Sarah L

    2016-01-01

    Background and Purpose Severe acute mucositis commonly results from head and neck (chemo)radiotherapy. A predictive model of mucositis could guide clinical decision-making and inform treatment planning. We aimed to generate such a model using spatial dose metrics and machine learning. Material and Methods Predictive models of severe acute mucositis were generated using radiotherapy dose (dose-volume and spatial dose metrics) and clinical data. Penalised logistic regression, support vector classification and random forest classification (RFC) models were generated and compared. Internal validation was performed (with 100-iteration cross-validation), using multiple metrics, including area under the receiver operating characteristic curve (AUC) and calibration slope, to assess performance. Associations between covariates and severe mucositis were explored using the models. Results The dose-volume-based models (standard) performed equally to those incorporating spatial information. Discrimination was similar between models, but the RFCstandard had the best calibration. The mean AUC and calibration slope for this model were 0.71 (s.d.=0.09) and 3.9 (s.d.=2.2), respectively. The volumes of oral cavity receiving intermediate and high doses were associated with severe mucositis. Conclusions The RFCstandard model performance is modest-to-good, but should be improved, and requires external validation. Reducing the volumes of oral cavity receiving intermediate and high doses may reduce mucositis incidence. PMID:27240717

  3. High-Dose-Rate Interstitial Brachytherapy as Monotherapy for Clinically Localized Prostate Cancer: Treatment Evolution and Mature Results

    SciTech Connect

    Zamboglou, Nikolaos; Tselis, Nikolaos; Baltas, Dimos; Buhleier, Thomas; Martin, Thomas; Milickovic, Natasa; Papaioannou, Sokratis; Ackermann, Hanns; Tunn, Ulf W.

    2013-03-01

    Purpose: To report the clinical outcome of high-dose-rate (HDR) interstitial (IRT) brachytherapy (BRT) as sole treatment (monotherapy) for clinically localized prostate cancer. Methods and Materials: Between January 2002 and December 2009, 718 consecutive patients with clinically localized prostate cancer were treated with transrectal ultrasound (TRUS)-guided HDR monotherapy. Three treatment protocols were applied; 141 patients received 38.0 Gy using one implant in 4 fractions of 9.5 Gy with computed tomography-based treatment planning; 351 patients received 38.0 Gy in 4 fractions of 9.5 Gy, using 2 implants (2 weeks apart) and intraoperative TRUS real-time treatment planning; and 226 patients received 34.5 Gy, using 3 single-fraction implants of 11.5 Gy (3 weeks apart) and intraoperative TRUS real-time treatment planning. Biochemical failure was defined according to the Phoenix consensus, and toxicity was evaluated using Common Toxicity Criteria for Adverse Events version 3. Results: The median follow-up time was 52.8 months. The 36-, 60-, and 96-month biochemical control and metastasis-free survival rates for the entire cohort were 97%, 94%, and 90% and 99%, 98%, and 97%, respectively. Toxicity was scored per event, with 5.4% acute grade 3 genitourinary and 0.2% acute grade 3 gastrointestinal toxicity. Late grade 3 genitourinary and gastrointestinal toxicities were 3.5% and 1.6%, respectively. Two patients developed grade 4 incontinence. No other instance of grade 4 or greater acute or late toxicity was reported. Conclusion: Our results confirm IRT-HDR-BRT is safe and effective as monotherapy for clinically localized prostate cancer.

  4. [Study on the safety and efficacy of sitafloxacin at a dose of 100 mg once a day--results of the use-results survey].

    PubMed

    Hori, Seiji; Uchino, Kazuhiro; Matsumoto, Takuyuki; Yamaguchi, Hiroki; Takahashi, Megumi; Hamajima, Satoko; Nukui, Kaori; Eda, Hisano; Shiina, Akiko; Takita, Atsushi; Yamanouchi, Naoki; Mizuno, Masami; Okutani, Yukihiro

    2014-06-01

    Sitafloxacin (STFX, Gracevit 50 mg, fine granules 10%), an oral quinolone antibacterial agent, was approved additionally for administration at a dose of 100 mg once a day in August 2011. A use-results survey on STFX 100 mg/day was performed from December 2011 to May 2013. In total, 1,186 case cards were collected from 226 medical institutions and 1,089 cases were subjected to a safety evaluation and 1,069 were subjected to an efficacy evaluation. The incidence of adverse drug reactions (ADRs) was 2.11% (23/1,089 cases) and no serious ADRs were observed. The major ADR was diarrhea at 1.10% (12/1,089 cases). Of these 12 cases, 10 cases developed symptoms within 4 days of treatment. All of them, except one case that could not be followed up, either recovered or improved. Nonsteroidal anti-inflammatory drugs of the phenyl acetate and propionate types, which require caution when coadministered with STFX, were used concomitantly by 17.6% (192/1,089 cases) of patients but no central nervous system ADRs were observed. The overall efficacy rate was 96.4% (1,030/1,069 cases) and by types of infections, it was 97.0% (387/399 cases) for respiratory tract infections, 96.7% (353/365 cases) for urinary tract infections, 94.7% (36/38 cases) for gynecological infections, 92.3% (132/143 cases) for otorhinolaryngological infections, 98.4% (122/124 cases) for dental and oral surgical infections. The efficacy rate in every category of site of infection exceeded 90%. The overall eradication rate was 94.4% (185/196 strains) including Gram-positive bacteria at 95.4% (62/65 strains), Gram-negative bacteria at 92.2% (94/102 strains), anaerobes at 100.0% (11/11 strains) and atypical bacteria at 100.0% (18/18 strains). In conclusion, this use-results survey confirmed that STFX 100 mg/day is an effective administration with no serious problems in its safety profile and efficacy rate of over 90% in every category of site of infection.

  5. Doses measured using AEC on direct digital radiographic (DDR) X-rays systems: updated results with an RP 162 perspective.

    PubMed

    Bowden, L; Faulkner, R; Gallagher, A; O'Connor, U; Walsh, C; Dowling, A; O'Reilly, G

    2013-02-01

    As digital technology in diagnostic radiology systems becomes more prevalent, there is a need to provide comparative dose information for these new systems. This is needed in particular for testing the automatic exposure control (AEC) devices on direct digital radiography (DDR) systems as there is no consensus on the receptor dose level in the current guidelines. The new European Commission RP 162 document sets the suspension level for the 'verification of kerma at receptor entrance in computed radiography and DDR systems under AEC' as ≥10 µGy. This document also notes that alternate methodologies are acceptable, and may require adjustment in the suspension level if used. This study provides a range of typical doses under AEC for DDR systems, for a variety measurement methodologies, including that described in RP 162.

  6. The Libraries of the National Statistical Offices in the World. Comments on the Results of an Enquiry.

    ERIC Educational Resources Information Center

    Kullmer, Hans K.

    Defined in terms of their institutional role and historical development, national statistical libraries are discussed in the context of present structures, size, personnel situation, technical equipment, financial structure, general and specific activities, areas of specialization, and growth rate, as well as the interlibrary cooperative efforts…

  7. Risk of brain tumours in relation to estimated RF dose from mobile phones: results from five Interphone countries

    PubMed Central

    Armstrong, B K; Bowman, J D; Giles, G G; Hours, M; Krewski, D; McBride, M; Parent, M E; Sadetzki, S; Woodward, A; Brown, J; Chetrit, A; Figuerola, J; Hoffmann, C; Jarus-Hakak, A; Montestruq, L; Nadon, L; Richardson, L; Villegas, R; Vrijheid, M

    2011-01-01

    Objectives The objective of this study was to examine the associations of brain tumours with radio frequency (RF) fields from mobile phones. Methods Patients with brain tumour from the Australian, Canadian, French, Israeli and New Zealand components of the Interphone Study, whose tumours were localised by neuroradiologists, were analysed. Controls were matched on age, sex and region and allocated the ‘tumour location’ of their matched case. Analyses included 553 glioma and 676 meningioma cases and 1762 and 1911 controls, respectively. RF dose was estimated as total cumulative specific energy (TCSE; J/kg) absorbed at the tumour's estimated centre taking into account multiple RF exposure determinants. Results ORs with ever having been a regular mobile phone user were 0.93 (95% CI 0.73 to 1.18) for glioma and 0.80 (95% CI 0.66 to 0.96) for meningioma. ORs for glioma were below 1 in the first four quintiles of TCSE but above 1 in the highest quintile, 1.35 (95% CI 0.96 to 1.90). The OR increased with increasing TCSE 7+ years before diagnosis (p-trend 0.01; OR 1.91, 95% CI 1.05 to 3.47 in the highest quintile). A complementary analysis in which 44 glioma and 135 meningioma cases in the most exposed area of the brain were compared with gliomas and meningiomas located elsewhere in the brain showed increased ORs for tumours in the most exposed part of the brain in those with 10+ years of mobile phone use (OR 2.80, 95% CI 1.13 to 6.94 for glioma). Patterns for meningioma were similar, but ORs were lower, many below 1.0. Conclusions There were suggestions of an increased risk of glioma in long-term mobile phone users with high RF exposure and of similar, but apparently much smaller, increases in meningioma risk. The uncertainty of these results requires that they be replicated before a causal interpretation can be made. PMID:21659469

  8. Long-term results of a pilot study of low dose cranial-spinal irradiation for cerebellar medulloblastoma

    SciTech Connect

    Brand, W.N.; Schneider, P.A.; Tokars, R.P.

    1987-11-01

    Between May 1974 and March 1983, 44 children with histologically verified cerebellar medulloblastoma were seen for post-operative cranial-spinal irradiation following attempted total tumor removal. Six patients were excluded from review because they received all or part of their treatment at another institution (3 patients) or did not complete the planned course of irradiation (3 patients). All of the 38 remaining patients were treated by a previously described technique on a 4 MeV Linear Accelerator with 55 Gy delivered to the primary tumor site. Prior to December 1978, 19 consecutive children (Group A) had spinal prophylactic doses of 30-40 Gy and brain prophylactic doses of 40-50 Gy. After the date, 25 Gy was given to the cranial-spinal axis of 19 consecutive children (Group B). This lower dose was arbitrarily selected with the hope of reducing morbidity in treated survivors and achieving the same tumor control. Risk factors that define good and poor prognosis were evaluated for each group, and there were no differences noted. Myelography and CSF cytology were not routinely performed. Follow-up for the 38 patients ranges from 20 months to 124 months. For the low risk patients, survival (12/15 or 80%) was independent of cranial-spinal radiation dose (Group A 6/8, Group B 6/7). For the high risk patients survival was poor (9/23 or 39%), not dependent on cranial-spinal radiation dose (Group A 5/11, Group B 4/12), and associated with failure at the primary site (10/14), often with CSF seeding (8/10). The other 4 failures include 2 who had moved outside the United States (details of failure are unknown), 1 with supratentorial, CSF seeding and distant metastases, and 1 with distant metastasis only.

  9. Pharmacokinetics of fixed-dose combination of tenofovir disoproxil fumarate, lamivudine, and efavirenz: results of a randomized, crossover, bioequivalence study.

    PubMed

    Abhyankar, Dhiraj; Shedage, Ashish; Gole, Milind; Raut, Preeti

    2016-06-17

    The objective of this study was to assess the bioequivalence between a fixed-dose combination of tenofovir disoproxil fumarate/lamivudine/efavirenz 300/300/600 mg and the individual innovator products. A randomized, balanced, open-label, two-sequence, two-treatment, two-period, single dose, crossover study in 48 healthy adults was conducted. Dosing was separated by a washout period of 32 days. Twenty-seven blood samples were collected in each period from pre-dose to 72 h post-dose. The data of 45 subjects were analyzed for pharmacokinetics and safety. Ninety percent CIs of geometric mean ratio on Cmax, AUC0-t, and AUC0-inf for tenofovir and lamivudine and on Cmax and AUC0-72 for efavirenz were within the acceptance criteria (80-125%). For tenofovir disoproxil fumarate, the Tmax, Kel, and t1/2 values for the test and reference products were 1.02 versus 0.91 h, 0.04 versus 0.04/h, 18.67 versus 18.46 h, respectively. For lamivudine, the Tmax, Kel, and t1/2 values were: 1.38 versus 1.30 h, 0.21 versus 0.19/h, 3.44 versus 3.91 h, respectively. For efavirenz, the Tmax values for the test and reference products were 3.71 and 3.65 h, respectively. Both the treatments were well tolerated. Our findings suggest that the tested formulation is bioequivalent to the innovators' formulations, and both treatments were well tolerated.

  10. Low-dose irradiation prior to bone marrow transplantation results in ATM activation and increased lethality in Atm-deficient mice.

    PubMed

    Pietzner, J; Merscher, B M; Baer, P C; Duecker, R P; Eickmeier, O; Fußbroich, D; Bader, P; Del Turco, D; Henschler, R; Zielen, S; Schubert, R

    2016-04-01

    Ataxia telangiectasia is a genetic instability syndrome characterized by neurodegeneration, immunodeficiency, severe bronchial complications, hypersensitivity to radiotherapy and an elevated risk of malignancies. Repopulation with ATM-competent bone marrow-derived cells (BMDCs) significantly prolonged the lifespan and improved the phenotype of Atm-deficient mice. The aim of the present study was to promote BMDC engraftment after bone marrow transplantation using low-dose irradiation (IR) as a co-conditioning strategy. Atm-deficient mice were transplanted with green fluorescent protein-expressing, ATM-positive BMDCs using a clinically relevant non-myeloablative host-conditioning regimen together with TBI (0.2-2.0 Gy). IR significantly improved the engraftment of BMDCs into the bone marrow, blood, spleen and lung in a dose-dependent manner, but not into the cerebellum. However, with increasing doses, IR lethality increased even after low-dose IR. Analysis of the bronchoalveolar lavage fluid and lung histochemistry revealed a significant enhancement in the number of inflammatory cells and oxidative damage. A delay in the resolution of γ-H2AX-expression points to an insufficient double-strand break repair capacity following IR with 0.5 Gy in Atm-deficient splenocytes. Our results demonstrate that even low-dose IR results in ATM activation. In the absence of ATM, low-dose IR leads to increased inflammation, oxidative stress and lethality in the Atm-deficient mouse model.

  11. Bendamustine, thalidomide and dexamethasone combination therapy for relapsed/refractory myeloma patients: results of the MUKone randomized dose selection trial.

    PubMed

    Schey, Steve; Brown, Sarah R; Tillotson, Avie-Lee; Yong, Kwee; Williams, Cathy; Davies, Faith; Morgan, Gareth; Cavenagh, Jamie; Cook, Gordon; Cook, Mark; Orti, Guillermo; Morris, Curly; Sherratt, Debbie; Flanagan, Louise; Gregory, Walter; Cavet, James

    2015-08-01

    There is a significant unmet need in effective therapy for relapsed myeloma patients once they become refractory to bortezomib and lenalidomide. While data from the front line setting suggest bendamustine is superior to melphalan, there is no information defining optimal bendamustine dose in multiply-treated patients. We report a multi-centre randomized two-stage phase 2 trial simultaneously assessing deliverability and activity of two doses of bendamustine (60 mg/m2 vs. 100 mg/m2) days 1 and 8, thalidomide (100 mg) days 1-21 and low dose dexamethasone (20 mg) days 1, 8, 15 and 22 of a 28-d cycle. Ninety-four relapsing patients were treated on trial, with a median three prior treatment lines. A pre-planned interim deliverability and activity assessment led to closure of the 100 mg/m2 arm due to excess cytopenias, and led to amendment of entry criteria for cytopenias. Non-haematological toxicities including thromboembolism and neurotoxicity were infrequent. In the 60 mg/m2 arm, treatment was deliverable in 61.1% subjects and the partial response rate was 46.3% in the study eligible population, with 7.5 months progression-free survival. This study demonstrates bendamustine at 60 mg/m2 twice per month with thalidomide and dexamethasone is deliverable for repeated cycles in heavily pre-treated myeloma patients and has substantial clinical activity.

  12. Ibandronate dose response is associated with increases in bone mineral density and reductions in clinical fractures: results of a meta-analysis.

    PubMed

    Sebba, Anthony I; Emkey, Ronald D; Kohles, Joseph D; Sambrook, Philip N

    2009-03-01

    This meta-analysis pooled data from the four phase III clinical trials of ibandronate to assess the relationship between ibandronate dose, changes in bone mineral density, and rates of both clinical and non-vertebral fractures. Individual patient data from the intent-to-treat population of the BONE, IV fracture prevention, MOBILE, and DIVA studies were included for analysis. The relationship between ibandronate dose and bone mineral density at both the lumbar spine and at the total hip was assessed qualitatively. The relationship between lumbar spine bone mineral density and clinical fracture rate, and the relationship between total hip bone mineral density and non-vertebral fracture rate, were assessed both qualitatively and using mathematical models. A total of 8710 patients were included in this analysis. Both lumbar spine and total hip bone mineral density were observed to increase with increasing ibandronate dose. The incidence of all clinical fractures was observed to decrease as lumbar spine bone mineral density increased. A statistically significant inverse linear relationship was observed between percent change in lumbar spine bone mineral density and the rate of clinical fractures (P=0.005). A non-significant curvilinear relationship was observed between percent change in total hip bone mineral density and non-vertebral fracture rate. Increased ibandronate exposure is associated with increasing gains in the lumbar spine bone mineral density and decreasing clinical fracture rates. A non-linear relationship may exist between increases in the total hip bone mineral density and non-vertebral fracture rate.

  13. Results of Hematopoietic Stem Cell Transplantation After Treatment With Different High-Dose Total-Body Irradiation Regimens in Five Dutch Centers

    SciTech Connect

    Loes van Kempen-Harteveld, M. Brand, Ronald; Kal, Henk B.; Verdonck, Leo F.; Hofman, Pieter; Schattenberg, Anton V.; Maazen, Richard W. van der; Cornelissen, Jan J.; Eijkenboom, Wil M.H.; Lelie, Johannes P. van der; Oldenburger, Foppe; Barge, Renee M.; Biezen, Anja van; Vossen, Jaak M.J.J.; Noordijk, Evert M.; Struikmans, Henk

    2008-08-01

    Purpose: To evaluate results of high-dose total-body irradiation (TBI) regimens for hematopoietic stem cell transplantation. Methods and Materials: A total of 1,032 patients underwent TBI in one or two fractions before autologous or allogeneic hematologic stem cell transplantation for acute leukemia and non-Hodgkin's lymphoma. The TBI regimens were normalized by using the biological effective dose (BED) concept. The BED values were divided into three dose groups. Study end points were relapse incidence (RI), non-relapse mortality (NRM), relapse-free survival (RFS), and overall survival (OS). Multivariate analysis was performed, stratified by disease. Results: In the highest TBI dose group, RI was significantly lower and NRM was higher vs. the lower dose groups. However, a significant influence on RFS and OS was not found. Relapses in the eye region were found only after shielding to very low doses. Age was of significant influence on OS, RFS, and NRM in favor of younger patients. The NRM of patients older than 40 years significantly increased, and OS decreased. There was no influence of age on RI. Men had better OS and RFS and lower NRM. Type of transplantation significantly influenced RI and NRM for patients with acute leukemia and non-Hodgkin's lymphoma. There was no influence on RFS and OS. Conclusions: Both RI and NRM were significantly influenced by the size of the BED of single-dose or two-fraction TBI regimens; OS and RFS were not. Age was of highly significant influence on NRM, but there was no influence of age on RI. Hyperfractionated TBI with a high BED might be useful, assuming NRM can be reduced.

  14. Encephalopathy is the dose-limiting toxicity of intravenous hepsulfam: results of a phase I trial in patients with advanced hematological malignancies.

    PubMed

    Larson, R A; Geller, R B; Janisch, L; Milton, J; Grochow, L B; Ratain, M J

    1995-01-01

    Hepsulfam is a bisulfamic ester which is similar in structure to busulfan and is believed to act as a bifunctional alkylator inducing both DNA-DNA and DNA-protein crosslinks. Prior studies in patients with refractory solid tumors have identified the dose-limiting toxicity of hepsulfam to be cumulative myelosuppression resulting in prolonged leukopenia and thrombocytopenia. This phase I trial was designed to determine the maximally tolerated dose of hepsulfam administered intravenously in patients with refractory leukemias and other advanced hematologic malignancies. Hepsulfam was administered as a 30-min or 2-h intravenous infusion to 21 patients with advanced leukemia or multiple myeloma. All patients had been extensively treated and had progressive disease. Cycles were repeated every 5 weeks. Cohorts of patients were treated at 360, 480, 640, and 800 mg/m2. The dose-limiting toxicity of intravenous hepsulfam was severe encephalopathy. The single patient treated at 800 mg/m2 became comatose within 48 h and required 3 weeks for his mental status to return to baseline. There were, however, no irreversible neurological sequelae. Several patients treated at 640 mg/m2 had clinical evidence of toxic deliriums and slowing of alpha rhythm waves on electroencephalograms indicative of a gray-matter encephalopathy. When hepsulfam was infused over 30 min, patients complained of uncomfortable parasthesias, but when the drug was administered over 2 h, these acute symptoms were less common. Myelosuppression was observed in most patients. Among those patients who had some suppression of their leukemia, peripheral blood counts recovered to pretreatment levels after 3-5 weeks. Apart from CNS toxicity, non-hematologic toxicity was minimal. Pharmacokinetic studies demonstrated rapid clearance of hepsulfam so that the drug was not reliably detected in the plasma after 24 h. The recommended phase II dose of hepsulfam as a single 2-h intravenous infusion is 480 mg/m2, but this dose

  15. Effect of artificial insemination protocol and dose of frozen/thawed stallion semen on pregnancy results in mares.

    PubMed

    Govaere, J L J; Hoogewijs, M K; De Schauwer, C; De Vliegher, S; Van Soom, A; Duchateau, L; de Kruif, A

    2014-06-01

    Deep intra-uterine insemination is commonly accepted as a routine procedure for artificial insemination in horses. The motives and principles of deep insemination are well described, but the equipment used may differ. In this trial, the efficiency of two different insemination pipettes for deep intra-uterine insemination in the mare was compared with insemination into the uterine body using commercially available frozen-thawed semen of two stallions of proven fertility. These inseminations were performed using two different doses. The semi-flexible Minitube pipette was compared with a newly designed insemination device with a more flexible telescopic insemination catheter (Ghent device). The semi-flexible Minitube pipette performed better than the newly designed insemination device with respect to pregnancy outcome (p = 0.008). The superiority of deep horn insemination over uterine body insemination was reflected by the better pregnancy rates obtained after deep insemination using the same low doses (30.6% better pregnancy rates) (p = 0.0123).

  16. Literature review of some selected types of results and statistical analyses of total-ozone data. [for the ozonosphere

    NASA Technical Reports Server (NTRS)

    Myers, R. H.

    1976-01-01

    The depletion of ozone in the stratosphere is examined, and causes for the depletion are cited. Ground station and satellite measurements of ozone, which are taken on a worldwide basis, are discussed. Instruments used in ozone measurement are discussed, such as the Dobson spectrophotometer, which is credited with providing the longest and most extensive series of observations for ground based observation of stratospheric ozone. Other ground based instruments used to measure ozone are also discussed. The statistical differences of ground based measurements of ozone from these different instruments are compared to each other, and to satellite measurements. Mathematical methods (i.e., trend analysis or linear regression analysis) of analyzing the variability of ozone concentration with respect to time and lattitude are described. Various time series models which can be employed in accounting for ozone concentration variability are examined.

  17. Results on Dose Distributions in a Human Body from the Matroshka-R Experiment onboard the ISS Obtained with the Tissue-Equivalent Spherical Phantom

    NASA Astrophysics Data System (ADS)

    Shurshakov, Vyacheslav; Nikolaev, Igor; Kartsev, Ivan; Tolochek, Raisa; Lyagushin, Vladimir

    The tissue-equivalent spherical phantom (32 kg mass, 35 cm diameter and 10 cm central spherical cave) made in Russia has been used on board the ISS in Matroshka-R experiment for more than 10 years. Both passive and active space radiation detectors can be located inside the phantom and on its surface. Due to the specially chosen phantom shape and size, the chord length distributions of the detector locations are attributed to self-shielding properties of the critical organs in a human body. Originally the spherical phantom was installed in the star board crew cabin of the ISS Service Module, then in the Piers-1, MIM-2, and MIM-1 modules of the ISS Russian segment, and finally in JAXA Kibo module. Total duration of the detector exposure is more than 2000 days in 9 sessions of the space experiment. In the first phase of the experiment with the spherical phantom the dose measurements were realized with only passive detectors (thermoluminescent and solid state track detectors). The detectors are placed inside the phantom along the axes of 20 containers and on the phantom outer surface in 32 pockets of the phantom jacket. After each session the passive detectors are returned to the ground. The results obtained show the dose difference on the phantom surface as much as a factor of 2, the highest dose being usually observed close to the outer wall of the compartment, and the lowest dose being in the opposite location along the phantom diameter. However, because of the ISS module shielding properties an inverse dose distribution in a human body can be observed when the dose rate maximum is closer to the geometrical center of the module. Maximum dose rate measured in the phantom is obviously due to the action of two radiation sources, namely, galactic cosmic rays (GCR) and Earth’ radiation belts. Minimum dose rate is produced mainly by the strongly penetrating GCR particles and is mostly observed behind more than 5 g/cm2 tissue shielding. Critical organ doses, mean

  18. Single versus repeated doses of ivermectin and diethylcarbamazine for the treatment of Wuchereria bancrofti var. pacifica microfilaremia. Results at 12 months of a double-blind study.

    PubMed

    Cartel, J L; Spiegel, A; Nguyen Ngnoc, L; Cardines, R; Plichart, R; Martin, P M; Roux, J F

    1991-12-01

    In October 1989, 58 apparently healthy Polynesian Wuchereria bancrofti carriers in whom microfilarial (mf) density was greater than or equal to 100 mf/ml were randomly allocated to treatment groups receiving single doses of either ivermectin at 100 mcg/kg or diethylcarbamazine (DEC) at 3 and 6 mg/kg. Six months later, half of the carriers initially treated with ivermectin 100 mcg/kg or DEC 3 mg/kg were given a second similar dose while the rest were given a placebo. By day 360 (6 months after retreatment), comparison of adjusted geometric mean mf counts per group indicated that (i) among the 3 treatments given once a year the DEC 6 mg/kg dose resulted in the highest efficacy, (ii) nevertheless, regarding either ivermectin 100 mcg/kg or DEC 3 mg/kg, 2 successive doses resulted in higher efficacy than one annual dose and (iii) though no significant difference could be evidenced between efficacy of ivermectin 100 mcg/kg and DEC 3 mg/kg given twice a year, DEC seemed to sustain the mf reduction for a longer period of time. During the 3 days following retreatment, adverse reactions (mild to moderate) were observed in 46% of carriers treated with microfilaricidal drugs and in 20% of those treated with placebo. These results suggest that single dose therapy with either DEC or ivermectin is safe and effective for prevention of lymphatic filariasis due to Wuchereria bancrofti in French Polynesia. The real impact on transmission by the vector, Aedes polynesiensis, of the complete negativation of microfilaremia observed during the previous part of the trial in carriers treated with ivermectin should be evaluated in a community-based trial including entomological study.(ABSTRACT TRUNCATED AT 250 WORDS)

  19. High Dose Vitamin D Therapy for Chronic Pain in Children and Adolescents with Sickle Cell Disease: Results of a Randomized Double Blind Pilot Study

    PubMed Central

    I, Osunkwo; TR, Ziegler; J, Alvarez; C, McCracken; K, Cherry; CE, Osunkwo; SF, Ofori-Acquah; S, Ghosh; A, Ogunbobode; J, Rhodes; JR, Eckman; CD, Dampier; V, Tangpricha

    2012-01-01

    Summary We report results of a pilot study of high-dose vitamin D in sickle cell disease (SCD). Subjects were followed for 6 months after receiving a six-week course of oral high-dose cholecalciferol or placebo. Vitamin D insufficiency and deficiency was present at baseline in 82.5% and 52.5% of subjects, respectively. Subjects who received high-dose vitamin D achieved higher serum 25-hydroxyvitamin D, experienced fewer pain days per week, and had higher physical activity quality-of-life scores. These findings suggest a potential benefit of vitamin D in reducing the number of pain days in SCD. Larger prospective studies with longer duration are needed to confirm these effects. PMID:22924607

  20. [Forecast of collective radiation dose decrease of the population of Belarus as the result of optimization of moveable potassium contents in soils contaminated by 137Cs].

    PubMed

    Putiatin, Iu V; Adianova, O B

    2010-01-01

    Results of study on an efficiency of potassium moveable content for decrease of a collective dose from 137Cs to the population of Belarus are presented. On the basis of the "cost-benefit" analysis it is shown, that expenses for decreasing averted collective dose due to increase of potassium contents on arable lands amounts to more than 80 thousand US dollars per 1 man.-Sv depending on density of soil contamination of rural districts by 137Cs. It is found that high effect (costs less than 40 thousand US dollars per 1 man.-Sv on hectare of arable land) on averted collective dose from 137Cs at cultivation of cereals can be expected at an optimization of mobile potassium contents in sod-podzolic loamy sand soils with density of 137Cs contamination more than 925 kBq/m2, sand soils--more than 1184, light loam soils--more than 629 kBq/m2.

  1. A statistical approach for site error correction in lightning location networks with DF/TOA technique and its application results

    NASA Astrophysics Data System (ADS)

    Lu, Tao; Chen, Mingli; Du, Yaping; Qiu, Zongxu

    2017-02-01

    Lightning location network (LLN) with DF/TOA (direction-finder/time-of-arrival) combined technique has been widely used in the world. However, the accuracy of the lightning data from such LLNs has still been restricted by "site error", especially for those detected only by two DF/TOA sensors. In this paper we practice a statistical approach for evaluation and correction of "site error" for DF/TOA type LLN based on its lightning data. By comparing lightning locations recorded by at least 4 sensors between DF and TOA techniques, the spatial characteristics of "site error" for each sensor in the network can be obtained. The obtained "site error" then can be used to improve the accuracy of lightning locations especially those recorded by only 2 sensors. With this approach, the "site error" patterns for 23 sensors in Yunnan LLN are obtained. The features of these site error patterns are in good consistency with those in literature. Significant differences in lightning locations before and after "site error" corrections indicate that the proposed approach works effectively.

  2. Healthy birth weight results in higher vitamin A storage in neonate piglets administered high-dose supplements

    PubMed Central

    Heying, Emily K; Hovel, Elizabeth

    2015-01-01

    A proposed intervention for newborn infants in countries with suspected vitamin A (VA) deficiency is to administer 50,000 IU retinyl palmitate at birth to reduce mortality risk. However, no studies have investigated birth weight effects. In this study, low birth weight (LBW; <1 kg, n = 18) and healthy birth weight (HBW) piglets (>1.5 kg, n = 18) from VA-depleted sows were dosed with 25,000 or 50,000 IU retinyl palmitate (26.2 or 52.4 µmol retinol equivalents) at birth to compare VA reserves. Blood was collected at varying times (n = 3–5/time/dose), and piglets were killed at 12 or 24 h for blood, liver, kidneys, spleen, lungs, adrenal gland, and intestinal contents. HBW piglets had significantly higher birth, death, and organ weights than LBW (P < 0.0001 for all). HBW and LBW piglets, which received VA, had higher liver and kidney VA concentrations (0.18 ± 0.09, 0.24 ± 0.10 µmol/g liver and 13.4 ± 4.1, 14.2 ± 4.5 nmol/g kidney, respectively) than controls (n = 10) (0.051 ± 0.01 µmol/g liver and 1.01 ± 0.43 nmol/g kidney) (P = 0.0061 and < 0.0001, respectively). Total liver (9.75 ± 5.16 µmol) and kidney retinol (204 ± 79.1 nmol) were higher in HBW than LBW piglets (P < 0.0001). Extrahepatic tissues, except lung, had higher VA concentration than controls (P < 0.0001). Serum retinol and ester concentrations were higher in treated than control piglets (P = 0.0028, P < 0.0001, respectively), and significantly changed during the times sampled (P = 0.022, P = 0.011, respectively). Peak serum retinyl ester concentrations, which occurred at 3 h, were higher in piglets that received 50,000 IU (4.2 ± 4.4 µmol/L) than 25,000 IU (2.7 ± 2.3 µmol/L) (P = 0.031). Regardless of dose amount, HBW piglets stored more supplemental VA than LBW piglets when administered at birth. PMID:25681469

  3. TOWARD COMPLETE STATISTICS OF MASSIVE BINARY STARS: PENULTIMATE RESULTS FROM THE CYGNUS OB2 RADIAL VELOCITY SURVEY

    SciTech Connect

    Kobulnicky, Henry A.; Lundquist, Michael J.; Burke, Jamison; Chapman, James; Keller, Erica; Lester, Kathryn; Rolen, Emily K.; Topel, Eric; Bhattacharjee, Anirban; Smullen, Rachel A.; Álvarez, Carlos A. Vargas; Runnoe, Jessie C.; Dale, Daniel A.; Brotherton, Michael M.; Kiminki, Daniel C. E-mail: jburke2@swarthmore.edu E-mail: kelle22e@mtholyoke.edu E-mail: emily.k.rolen@vanderbilt.edu

    2014-08-01

    We analyze orbital solutions for 48 massive multiple-star systems in the Cygnus OB2 association, 23 of which are newly presented here, to find that the observed distribution of orbital periods is approximately uniform in log P for P < 45 days, but it is not scale-free. Inflections in the cumulative distribution near 6 days, 14 days, and 45 days suggest key physical scales of ≅0.2, ≅0.4, and ≅1 A.U. where yet-to-be-identified phenomena create distinct features. No single power law provides a statistically compelling prescription, but if features are ignored, a power law with exponent β ≅ –0.22 provides a crude approximation over P = 1.4-2000 days, as does a piece-wise linear function with a break near 45 days. The cumulative period distribution flattens at P > 45 days, even after correction for completeness, indicating either a lower binary fraction or a shift toward low-mass companions. A high degree of similarity (91% likelihood) between the Cyg OB2 period distribution and that of other surveys suggests that the binary properties at P ≲ 25 days are determined by local physics of disk/clump fragmentation and are relatively insensitive to environmental and evolutionary factors. Fully 30% of the unbiased parent sample is a binary with period P < 45 days. Completeness corrections imply a binary fraction near 55% for P < 5000 days. The observed distribution of mass ratios 0.2 < q < 1 is consistent with uniform, while the observed distribution of eccentricities 0.1 < e < 0.6 is consistent with uniform plus an excess of e ≅ 0 systems. We identify six stars, all supergiants, that exhibit aperiodic velocity variations of ∼30 km s{sup –1} attributed to atmospheric fluctuations.

  4. Statistics Clinic

    NASA Technical Reports Server (NTRS)

    Feiveson, Alan H.; Foy, Millennia; Ploutz-Snyder, Robert; Fiedler, James

    2014-01-01

    Do you have elevated p-values? Is the data analysis process getting you down? Do you experience anxiety when you need to respond to criticism of statistical methods in your manuscript? You may be suffering from Insufficient Statistical Support Syndrome (ISSS). For symptomatic relief of ISSS, come for a free consultation with JSC biostatisticians at our help desk during the poster sessions at the HRP Investigators Workshop. Get answers to common questions about sample size, missing data, multiple testing, when to trust the results of your analyses and more. Side effects may include sudden loss of statistics anxiety, improved interpretation of your data, and increased confidence in your results.

  5. Threshold dose for peanut: risk characterization based upon published results from challenges of peanut-allergic individuals.

    PubMed

    Taylor, Steve L; Crevel, Rene W R; Sheffield, David; Kabourek, Jamie; Baumert, Joseph

    2009-06-01

    Population thresholds for peanut are unknown. However, lowest- and no-observed adverse effect levels (LOAELs and NOAELs) are published for an unknown number of peanut-allergic individuals. Publications were screened for LOAELs and NOAELs from blinded, low-dose oral challenges. Data were obtained from 185 peanut-allergic individuals (12 publications). Data were analyzed by interval-censoring survival analysis and three probability distribution models fitted to it (Log-Normal, Log-Logistic, and Weibull) to estimate the ED(10). All three models described the data well and provided ED(10)'s in close agreement: 17.6, 17.0, and 14.6 mg of whole peanut for the Log-Normal, Log-Logistic, and Weibull models, respectively. The 95% lower confidence intervals for the ED(10)'s were 9.2, 8.1, and 6.0mg of whole peanut for the Log-Normal, Log-Logistic, and Weibull models, respectively. The modeling of individual NOAELs and LOAELs identified from three different types of published studies - diagnostic series, threshold studies, and immunotherapy trials - yielded significantly different whole peanut ED(10)'s of 11.9 mg for threshold studies, 18.0mg for diagnostic series and 65.5mg for immunotherapy trials; patient selection and other biases may have influenced the estimates. These data and risk assessment models provide the type of information that is necessary to establish regulatory thresholds for peanut.

  6. The Protective Effect of Low-Dose Aspirin against Colorectal Cancer Is Unlikely Explained by Selection Bias: Results from Three Different Study Designs in Clinical Practice

    PubMed Central

    Cea Soriano, Lucía; Soriano-Gabarró, Montse; García Rodríguez, Luis A.

    2016-01-01

    Background We conducted three differently designed nested case–control studies to evaluate whether the protective effect of low-dose aspirin against colorectal cancer (CRC) is explained by selection bias. Methods Using a large validated UK primary care database, we followed different cohorts of patients, who varied in their demographic and clinical characteristics, to identify first ever cases of CRC. In Studies 1 and 2, two cohorts were followed, i) new users of low-dose aspirin at start of follow-up (N = 170,336 in Study 1, N = 171,527 in Study 2) and either ii) non-users of low-dose aspirin (Study 1, N = 170,336) or new users of paracetamol (Study 2, N = 149,597) at start of follow-up. In Study 3 a single cohort of individuals näive to low-dose aspirin at the start of observation was followed. Controls were selected using incidence sampling and logistic regression used to obtain an unbiased estimate of the incidence rate ratio (RR) with 95% confidence intervals (CIs). Low-dose aspirin exposure was analyzed ‘as-treated’ before the index date (CRC date for cases, random date for controls). Results In the three studies, median (maximum) follow-up was 5.1 (12), 5.8 (12) and 7.5 (13) years, respectively. 3033 incident CRC cases were identified in Study 1, 3174 in Study 2, and 12,333 in Study 3. Current use of low-dose aspirin was associated with a significantly reduced risk of 34%, 29% and 31% in the three studies, respectively; corresponding RRs (95% CIs) were 0.66 (0.60–0.73), 0.71 (0.63–0.80) and 0.69 (0.64–0.74). In each study, significantly reduced risks of CRC were seen when low-dose aspirin was used for primary or secondary cardiovascular disease prevention, in both sexes, and across all age groups evaluated. Conclusion Low-dose aspirin is associated with a significantly reduced risk of CRC. The consistency of our findings across different studies makes selection bias an unlikely explanation. PMID:27428004

  7. Description of statistical methods and a routine for determining the parameters of a model in processing experimental results

    NASA Technical Reports Server (NTRS)

    Usikov, D. A.

    1980-01-01

    A computer routine is suggested for selecting the optimum parameters of a theoretical model and determining the errors in them due to errors in physical measurements and for evaluating the conformity of theory with the experiment. The paper describes the specification sequence for the input data and the format of the calculation results. Sample printouts are appended.

  8. Teaching Science in Five Countries: Results From the TIMSS 1999 Video Study. Statistical Analysis Report. NCES 2006-011

    ERIC Educational Resources Information Center

    Roth, Kathleen J.; Druker, Stephen L.; Garnier, Helen E.; Lemmens, Meike; Chen, Catherine; Kawanaka, Takako; Rasmussen, Dave; Trubacova, Svetlana; Warvi, Dagmar; Okamoto, Yukari; Stigler, James; Gallimore, Ronald

    2006-01-01

    This report presents the results of a study of eighth-grade science teaching, conducted as part of the Third International Mathematics and Science Study (TIMSS) 1999 Video Study. The Video Study is a supplement to the TIMSS 1999 student assessment, a successor to the TIMSS 1995 student assessment. The TIMSS 1999 Video Study had the broad purpose…

  9. Risk of gastrointestinal complications associated to NSAIDs, low-dose aspirin and their combinations: Results of a pharmacovigilance reporting system.

    PubMed

    Rafaniello, Concetta; Ferrajolo, Carmen; Sullo, Maria Giuseppa; Sessa, Maurizio; Sportiello, Liberata; Balzano, Antonio; Manguso, Francesco; Aiezza, Maria Luisa; Rossi, Francesco; Scarpignato, Carmelo; Capuano, Annalisa

    2016-02-01

    Gastrointestinal (GI) complications are one of the most limiting cause of use of NSAIDs. Beyond others well defined factors, history of peptic ulcer, older age, Helicobacter pylori infection and use of gastrotoxic drugs may affect their GI safety profile. In particular, the risk of GI complications associated to the use of antiplatelet drugs, especially low-dose acetylsalicylic acid (LDA) should deserve much attention. However, only few studies have focused on the effect of combination LDA/NSAIDs on the GI tract compared with the monotherapy and much less studies assessed this effect with multiple NSAIDs use. We aimed to characterize the GI safety profile of NSAIDs and LDA as monotherapy or their combinations in real-life conditions by analysing spontaneous adverse drug reactions (ADRs) reporting system in a Southern Italy. We used the case/non-case method in the Italian Pharmacovigilance Network (RNF). Cases were reports of GI events in the RNF between January 2007 and December 2011. Non-cases were all other reports during the same period. The association between NSAID and suspected GI ADRs was calculated using the reporting odds ratio (ROR) with 95% confidence intervals as a measure of disproportionality while adjusting for age, and concomitant use of antineoplastic agents or drugs for cardiovascular diseases. Sub-analysis were performed within the NSAID class. Among the 2816 adverse drug reactions recorded, we identified 374 (13.3%) cases of GI complications. Upper GI complications were the most frequently reported type of events. The highest associations were found for the combined use of NSAIDs and/or LDA, whilst the lowest associations were for their respective monotherapy. Looking at individual NSAIDs the highest association with GI events was observed for ketorolac exposure followed by nimesulide, diclofenac, aspirin, ketoprofen, and ibuprofen. This study highlights the primary role of the national spontaneous reporting system to bring out potential signals

  10. STATISTICAL ANALYSIS ON FUNCTIONAL AND RADIOGRAPHIC RESULTS AFTER USE OF LOCKED VOLAR PLATE FOR FRACTURES OF THE DISTAL RADIUS

    PubMed Central

    Machado, Daniel Gonçalves; da Cruz Cerqueira, Sergio Auto; Rodarte, Rodrigo Ribeiro Pinho; de Souza Araújo Netto, Carlos Alberto; de Mathias, Marcelo Bezerra

    2015-01-01

    Objectives: To evaluate the functional results from using a fixed-angle locked volar plate for treating fractures of the distal extremity of the radius, using the DASH (disorders of the arm, shoulder and hand) questionnaire and its radiographic correlation with the Lidström classification. Methods: Thirty patients with unstable fractures of the distal extremity of the radius were evaluated after they had undergone a surgical procedure consisting of open reduction and internal fixation using a fixed-angle locked volar plate, at the Military Police Central Hospital of Rio de Janeiro between 2008 and 2009. The results were assessed based on range of motion, DASH protocol scores and radiographies with the Lidström classification. Results: The mean age of the patients in the study was 51 years. The mean DASH score was 11.9 points. It was observed that the radiographic findings did not influence the DASH score. It was found that flexion, pronation, supination and radial deviation correlated with the DASH score. Conclusions: The study showed that subjective functional outcomes using the DASH protocol, obtained from using a locked volar plate to treat fractures of the distal extremity of the radius, are influenced by the range of motion, and especially by the flexion, supination, pronation and radial deviation of the wrist after surgery. There is no correlation between the radiological parameters of either the normal or the operated radius, and the subjective functional outcomes assessed using the DASH protocol. PMID:27042637

  11. DS02R1: Improvements to Atomic Bomb Survivors' Input Data and Implementation of Dosimetry System 2002 (DS02) and Resulting Changes in Estimated Doses.

    PubMed

    Cullings, H M; Grant, E J; Egbert, S D; Watanabe, T; Oda, T; Nakamura, F; Yamashita, T; Fuchi, H; Funamoto, S; Marumo, K; Sakata, R; Kodama, Y; Ozasa, K; Kodama, K

    2017-01-01

    high dose estimates to 4 Gy to reduce the effect of dose error, and improved methods for calculating averaged shielding transmission factors that are used to calculate doses for survivors without detailed shielding input data. Input data changes are summarized and described here in some detail, along with the resulting changes in dose estimates and a simple description of changes in risk estimates for solid cancer mortality. This and future RERF publications will refer to the new dose estimates described herein as "DS02R1 doses."

  12. Efficacy and safety of desmopressin orally disintegrating tablet in patients with central diabetes insipidus: results of a multicenter open-label dose-titration study.

    PubMed

    Arima, Hiroshi; Oiso, Yutaka; Juul, Kristian Vinter; Nørgaard, Jens Peter

    2013-01-01

    Central diabetes insipidus (CDI) is associated with arginine vasopressin (AVP) deficiency with resultant polyuria and polydipsia. Intranasal desmopressin provides physiological replacement but oral formulations are preferred for their ease of administration. This study aimed to demonstrate the efficacy and safety of desmopressin orally disintegrating tablet (ODT) in the treatment of Japanese patients with CDI, and confirm that antidiuresis is maintained on switching from intranasal desmopressin to desmopressin ODT. A total of 20 patients aged 6-75 years with CDI were included in this 4-week multicenter, open-label study. Following observation, patients switched from intranasal desmopressin to desmopressin ODT with titration to optimal dose over ≤5 days at the study site. Following three consecutive doses with stable patient fluid balance, patients were discharged with visits at Weeks 2 and 4. Following titration from intranasal desmopressin to ODT, the mean 24-hour urine volume was unchanged, indicating similar antidiuresis with both formulations. The proportion of patients with endpoint measurements (urine osmolality, 24-hour urine volume, hourly diuresis rate and urine-specific gravity) within normal range at Days 1-2 (intranasal desmopressin) and Week 4 (desmopressin ODT) was similar. The mean daily dose ratio of intranasal desmopressin to desmopressin ODT (Week 4) was 1:24 but a wide range was observed across individuals to maintain adequate antidiuretic effect. Hyponatraemia was generally mild and managed by dose titration. Desmopressin ODT achieved sufficient antidiuretic control compared to intranasal therapy and was well tolerated over long-term treatment. The wide range of intranasal:ODT dose ratios underline the importance of individual titration.

  13. Isobio software: biological dose distribution and biological dose volume histogram from physical dose conversion using linear-quadratic-linear model

    PubMed Central

    Jaikuna, Tanwiwat; Khadsiri, Phatchareewan; Chawapun, Nisa; Saekho, Suwit

    2017-01-01

    Purpose To develop an in-house software program that is able to calculate and generate the biological dose distribution and biological dose volume histogram by physical dose conversion using the linear-quadratic-linear (LQL) model. Material and methods The Isobio software was developed using MATLAB version 2014b to calculate and generate the biological dose distribution and biological dose volume histograms. The physical dose from each voxel in treatment planning was extracted through Computational Environment for Radiotherapy Research (CERR), and the accuracy was verified by the differentiation between the dose volume histogram from CERR and the treatment planning system. An equivalent dose in 2 Gy fraction (EQD2) was calculated using biological effective dose (BED) based on the LQL model. The software calculation and the manual calculation were compared for EQD2 verification with pair t-test statistical analysis using IBM SPSS Statistics version 22 (64-bit). Results Two and three-dimensional biological dose distribution and biological dose volume histogram were displayed correctly by the Isobio software. Different physical doses were found between CERR and treatment planning system (TPS) in Oncentra, with 3.33% in high-risk clinical target volume (HR-CTV) determined by D90%, 0.56% in the bladder, 1.74% in the rectum when determined by D2cc, and less than 1% in Pinnacle. The difference in the EQD2 between the software calculation and the manual calculation was not significantly different with 0.00% at p-values 0.820, 0.095, and 0.593 for external beam radiation therapy (EBRT) and 0.240, 0.320, and 0.849 for brachytherapy (BT) in HR-CTV, bladder, and rectum, respectively. Conclusions The Isobio software is a feasible tool to generate the biological dose distribution and biological dose volume histogram for treatment plan evaluation in both EBRT and BT. PMID:28344603

  14. Statistical analyses of the results of 25 years of beach litter surveys on the south-eastern North Sea coast.

    PubMed

    Schulz, Marcus; Clemens, Thomas; Förster, Harald; Harder, Thorsten; Fleet, David; Gaus, Silvia; Grave, Christel; Flegel, Imme; Schrey, Eckart; Hartwig, Eike

    2015-08-01

    In the North Sea, the amount of litter present in the marine environment represents a severe environmental problem. In order to assess the magnitude of the problem and measure changes in abundance, the results of two beach litter monitoring programmes were compared and analysed for long-term trends applying multivariate techniques. Total beach litter pollution was persistently high. Spatial differences in litter abundance made it difficult to identify long-term trends: Partly more than 8000 litter items year(-1) were recorded on a 100 m long survey site on the island of Scharhörn, while the survey site on the beach on the island of Amrum revealed abundances lower by two orders of magnitude. Beach litter was dominated by plastic with mean proportions of 52%-91% of total beach litter. Non-parametric time series analyses detected many significant trends, which, however, did not show any systematic spatial patterns. Cluster analyses partly led to groupings of beaches according to their expositions to sources of litter, wind and currents. Surveys in short intervals of one to two weeks were found to give higher annual sums of beach litter than the quarterly surveys of the OSPAR method. Surveys at regular intervals of four weeks to five months would make monitoring results more reliable.

  15. Long-term efficacy of single-dose treatment with 400 micrograms.kg-1 of ivermectin in bancroftian filariasis: results at one year.

    PubMed

    Moulia-Pelat, J P; Glaziou, P; Nguyen, L N; Chanteau, S; Martin, P M; Cartel, J L

    1993-12-01

    In April 1992, a safety trial was performed with a single dose of ivermectin 400 micrograms.kg-1 (IVER 400). In 37 bancroftian filariasis carriers, 6 and 12 months after IVER 400 treatment, the microfilaremia recurrences were 3.2% and 13.5%, respectively. As compared to results from other studies with diethylcarbamazine and IVER at different dosages and periodicities, the dosage of IVER 400 seems the most effective; but a yearly intake might not be sufficient.

  16. Thematic accuracy of the 1992 National Land-Cover Data for the eastern United States: Statistical methodology and regional results

    USGS Publications Warehouse

    Stehman, S.V.; Wickham, J.D.; Smith, J.H.; Yang, L.

    2003-01-01

    The accuracy of the 1992 National Land-Cover Data (NLCD) map is assessed via a probability sampling design incorporating three levels of stratification and two stages of selection. Agreement between the map and reference land-cover labels is defined as a match between the primary or alternate reference label determined for a sample pixel and a mode class of the mapped 3×3 block of pixels centered on the sample pixel. Results are reported for each of the four regions comprising the eastern United States for both Anderson Level I and II classifications. Overall accuracies for Levels I and II are 80% and 46% for New England, 82% and 62% for New York/New Jersey (NY/NJ), 70% and 43% for the Mid-Atlantic, and 83% and 66% for the Southeast.

  17. TU-EF-204-03: Task-Based KV and MAs Optimization for Radiation Dose Reduction in CT: From FBP to Statistical Model-Based Iterative Reconstruction (MBIR)

    SciTech Connect

    Gomez-Cardona, D; Li, K; Lubner, M G; Pickhardt, P J; Chen, G-H

    2015-06-15

    Purpose: The introduction of the highly nonlinear MBIR algorithm to clinical CT systems has made CNR an invalid metric for kV optimization. The purpose of this work was to develop a task-based framework to unify kV and mAs optimization for both FBP- and MBIR-based CT systems. Methods: The kV-mAs optimization was formulated as a constrained minimization problem: to select kV and mAs to minimize dose under the constraint of maintaining the detection performance as clinically prescribed. To experimentally solve this optimization problem, exhaustive measurements of detectability index (d’) for a hepatic lesion detection task were performed at 15 different mA levels and 4 kV levels using an anthropomorphic phantom. The measured d’ values were used to generate an iso-detectability map; similarly, dose levels recorded at different kV-mAs combinations were used to generate an iso-dose map. The iso-detectability map was overlaid on top of the iso-dose map so that for a prescribed detectability level d’, the optimal kV-mA can be determined from the crossing between the d’ contour and the dose contour that corresponds to the minimum dose. Results: Taking d’=16 as an example: the kV-mAs combinations on the measured iso-d’ line of MBIR are 80–150 (3.8), 100–140 (6.6), 120–150 (11.3), and 140–160 (17.2), where values in the parentheses are measured dose values. As a Result, the optimal kV was 80 and optimal mA was 150. In comparison, the optimal kV and mA for FBP were 100 and 500, which corresponded to a dose level of 24 mGy. Results of in vivo animal experiments were consistent with the phantom results. Conclusion: A new method to optimize kV and mAs selection has been developed. This method is applicable to both linear and nonlinear CT systems such as those using MBIR. Additional dose savings can be achieved by combining MBIR with this method. This work was partially supported by an NIH grant R01CA169331 and GE Healthcare. K. Li, D. Gomez-Cardona, M. G

  18. Cognitive Results of CANTAB Tests and Their Change Due to the First Dose of Donepezil May Predict Treatment Efficacy in Alzheimer Disease

    PubMed Central

    Kuzmickienė, Jurgita; Kaubrys, Gintaras

    2015-01-01

    Background Ability to predict the efficacy of treatment in Alzheimer disease (AD) may be very useful in clinical practice. Cognitive predictors should be investigated alongside with the demographic, genetic, and other predictors of treatment efficacy. The aim of this study was to establish whether the baseline measures of CANTAB tests and their changes due to the first donepezil dose are able to predict the efficacy of treatment after 4 months of therapy. We also compared the predictive value of cognitive, clinical, and demographic predictors of treatment efficacy in AD. Material/Methods Seventy-two AD patients (62 treatment-naïve and 10 donepezil-treated) and 30 controls were enrolled in this prospective, randomized, rater-blinded, follow-up study. Treatment-naïve AD patients were randomized to 2 groups to take the first donepezil dose after the first or second CANTAB testing, separated by 4 hours. Follow-up Test 3 was performed 4 months after the initial assessment. Results The groups were similar in age, education, gender, Hachinski index, and depression. General Regression Models (GRM) have shown that cognitive changes after the first dose of donepezil in PAL (t-values for regression coefficients from 3.43 to 6.44), PRMd (t=4.33), SWM (t=5.85) test scores, and baseline results of PAL (t=2.57–2.86), PRM (t=3.08), and CRT (t=3.42) tests were significant predictors of long-term donepezil efficacy in AD (p<0.05). Conclusions The cognitive changes produced by the first donepezil dose in CANTAB PAL, PRM, and SWM test measures are able to predict the long-term efficacy of donepezil in AD. Baseline PAL, PRM, and CRT test results were significant predictors. PMID:26656642

  19. Cognitive Results of CANTAB Tests and Their Change Due to the First Dose of Donepezil May Predict Treatment Efficacy in Alzheimer Disease.

    PubMed

    Kuzmickienė, Jurgita; Kaubrys, Gintaras

    2015-12-14

    BACKGROUND Ability to predict the efficacy of treatment in Alzheimer disease (AD) may be very useful in clinical practice. Cognitive predictors should be investigated alongside with the demographic, genetic, and other predictors of treatment efficacy. The aim of this study was to establish whether the baseline measures of CANTAB tests and their changes due to the first donepezil dose are able to predict the efficacy of treatment after 4 months of therapy. We also compared the predictive value of cognitive, clinical, and demographic predictors of treatment efficacy in AD. MATERIAL AND METHODS Seventy-two AD patients (62 treatment-naïve and 10 donepezil-treated) and 30 controls were enrolled in this prospective, randomized, rater-blinded, follow-up study. Treatment-naïve AD patients were randomized to 2 groups to take the first donepezil dose after the first or second CANTAB testing, separated by 4 hours. Follow-up Test 3 was performed 4 months after the initial assessment. RESULTS The groups were similar in age, education, gender, Hachinski index, and depression. General Regression Models (GRM) have shown that cognitive changes after the first dose of donepezil in PAL (t-values for regression coefficients from 3.43 to 6.44), PRMd (t=4.33), SWM (t=5.85) test scores, and baseline results of PAL (t=2.57-2.86), PRM (t=3.08), and CRT (t=3.42) tests were significant predictors of long-term donepezil efficacy in AD (p<0.05). CONCLUSIONS The cognitive changes produced by the first donepezil dose in CANTAB PAL, PRM, and SWM test measures are able to predict the long-term efficacy of donepezil in AD. Baseline PAL, PRM, and CRT test results were significant predictors.

  20. The addition of computer simulated noise to investigate radiation dose and image quality in images with spatial correlation of statistical noise: an example application to X-ray CT of the brain.

    PubMed

    Britten, A J; Crotty, M; Kiremidjian, H; Grundy, A; Adam, E J

    2004-04-01

    This study validates a method to add spatially correlated statistical noise to an image, applied to transaxial X-ray CT images of the head to simulate exposure reduction by up to 50%. 23 patients undergoing routine head CT had three additional slices acquired for validation purposes, two at the same clinical 420 mAs exposure and one at 300 mAs. Images at the level of the cerebrospinal fluid filled ventricles gave readings of noise from a single image, with subtraction of image pairs to obtain noise readings from non-uniform tissue regions. The spatial correlation of the noise was determined and added to the acquired 420 mAs image to simulate images at 340 mAs, 300 mAs, 260 mAs and 210 mAs. Two radiologists assessed the images, finding little difference between the 300 mAs simulated and acquired images. The presence of periventricular low density lesions (PVLD) was used as an example of the effect of simulated dose reduction on diagnostic accuracy, and visualization of the internal capsule was used as a measure of image quality. Diagnostic accuracy for the diagnosis of PVLD did not fall significantly even down to 210 mAs, though visualization of the internal capsule was poorer at lower exposure. Further work is needed to investigate means of measuring statistical noise without the need for uniform tissue areas, or image pairs. This technique has been shown to allow sufficiently accurate simulation of dose reduction and image quality degradation, even when the statistical noise is spatially correlated.

  1. Software pipeline for midsagittal corpus callosum thickness profile processing : automated segmentation, manual editor, thickness profile generator, group-wise statistical comparison and results display.

    PubMed

    Adamson, Chris; Beare, Richard; Walterfang, Mark; Seal, Marc

    2014-10-01

    This paper presents a fully automated pipeline for thickness profile evaluation and analysis of the human corpus callosum (CC) in 3D structural T 1-weighted magnetic resonance images. The pipeline performs the following sequence of steps: midsagittal plane extraction, CC segmentation algorithm, quality control tool, thickness profile generation, statistical analysis and results figure generator. The CC segmentation algorithm is a novel technique that is based on a template-based initialisation with refinement using mathematical morphology operations. The algorithm is demonstrated to have high segmentation accuracy when compared to manual segmentations on two large, publicly available datasets. Additionally, the resultant thickness profiles generated from the automated segmentations are shown to be highly correlated to those generated from the ground truth segmentations. The manual editing tool provides a user-friendly environment for correction of errors and quality control. Statistical analysis and a novel figure generator are provided to facilitate group-wise morphological analysis of the CC.

  2. Imaging task-based optimal kV and mA selection for CT radiation dose reduction: from filtered backprojection (FBP) to statistical model based iterative reconstruction (MBIR)

    NASA Astrophysics Data System (ADS)

    Li, Ke; Gomez-Cardona, Daniel; Lubner, Meghan G.; Pickhardt, Perry J.; Chen, Guang-Hong

    2015-03-01

    Optimal selections of tube potential (kV) and tube current (mA) are essential in maximizing the diagnostic potential of a given CT technology while minimizing radiation dose. The use of a lower tube potential may improve image contrast, but may also require a significantly higher tube current to compensate for the rapid decrease of tube output at lower tube potentials. Therefore, the selection of kV and mA should take those kinds of constraints as well as the specific diagnostic imaging task in to consideration. For conventional quasi-linear CT systems employing linear filtered back-projection (FBP) image reconstruction algorithm, the optimization of kV-mA combinations are relatively straightforward, as neither spatial resolution nor noise texture has significant dependence on kV and mA settings. In these cases, zero-frequency analysis such as contrast-to-noise ratio (CNR) or normalized CNR by dose (CNRD) can be used for optimal kV-mA selection. The recently introduced statistical model-based iterative reconstruction (MBIR) method, however, has introduced new challenges to optimal kV and mA selection, as both spatial resolution and noise texture become closely correlated with kV and mA. In this work, a task-based approach based on modern signal detection theory and the corresponding frequency-dependent analysis has been proposed to perform the kV and mA optimization for both FBP and MBIR. By performing exhaustive measurements of task-based detectability index through the technically accessible kV-mA parameter space, iso-detectability contours were generated and overlaid on top of iso-dose contours, from which the kV-mA pair that minimize dose yet still achieving the desired detectability level can be identified.

  3. Single-dose intra-procedural ceftriaxone during endoscopic ultrasound fine-needle aspiration of pancreatic cysts is safe and effective: results from a single tertiary center

    PubMed Central

    Klein, Amir; Qi, Rose; Nagubandi, Shyam; Lee, Eric; Kwan, Vu

    2017-01-01

    Background Endoscopic ultrasound (EUS) with fine-needle aspiration (FNA) is universally used for the investigation and diagnosis of pancreatic cystic lesions (PCL). Infectious complications following EUS-FNA of PCL are rare. Antibiotic prophylaxis to reduce the risk of infection is recommended; however, there is no consensus on the optimal regimen or route of administration. Potential advantages of a single-dose intravenous (IV) antibiotic over a prolonged oral regimen include simplicity, guaranteed delivery and fewer antibiotic related adverse events, but there are only limited data to support this. We aimed to investigate the safety and efficacy of a single 1 g dose of IV ceftriaxone in preventing infectious complications following EUS-FNA of PCL. Methods A retrospective analysis was conducted of EUS-FNA of PCL procedures performed at our center. We reviewed patient medical records for any presentation to a hospital in our district within 30 days of the procedure. An infectious complication was defined as fever/rigors, or bacteremia, or abdominal pain accompanied by imaging or laboratory results suggestive of infection, within 30 days of the procedure. Data collection included patient demographics, procedural data and outcome. Results EUS-FNA of 204 PCL (mean size 18.0 mm) was performed. Successful fluid aspiration was achieved in 94% of cases. Single-dose IV ceftriaxone was given in 146/204 (72%) cases. Four patients had a complication (pancreatitis n=1, post-procedural pain n=3). No infectious complications and no IV antibiotic-related adverse events were identified. Conclusion A single dose of IV ceftriaxone appears to be a safe, effective and convenient intervention for preventing infectious complications after FNA. PMID:28243046

  4. Long-Term Results After High-Dose Radiotherapy and Adjuvant Hormones in Prostate Cancer: How Curable Is High-Risk Disease?

    SciTech Connect

    Zapatero, Almudena; Garcia-Vicente, Feliciano; Martin de Vidales, Carmen; Cruz Conde, Alfonso; Ibanez, Yamile; Fernandez, Inmaculada; Rabadan, Mariano

    2011-12-01

    Purpose: To analyze long-term outcome and prognostic factors for high-risk prostate cancer defined by National Comprehensive Cancer Network criteria treated with high-dose radiotherapy and androgen deprivation in a single institution. Methods and Materials: A total of 306 patients treated between 1995 and 2007 in a radiation dose-escalation program fulfilled the National Comprehensive Cancer Network high-risk criteria. Median International Commission on Radiation Units and Measurements radiation dose was 78 Gy (range, 66.0-84.1 Gy). Long-term androgen deprivation (LTAD) was administered in 231 patients, short-term androgen deprivation (STAD) in 59 patients, and no hormones in 16 patients. The Phoenix (nadir plus 2 ng/mL) consensus definition was used for biochemical control. Multivariate analysis was performed to determine the independent prognostic impact of clinical and treatment factors. Median follow-up time was 64 months (range, 24-171 months). Results: The actuarial overall survival at 5 and 10 years was 95.7% and 89.8%, respectively, and the corresponding biochemical disease-free survival (bDFS) was 89.5% and 67.2%, respectively. Fourteen patients (4.6%) developed distant metastasis. Multivariate analysis showed that Gleason score >7 (p = 0.001), pretreatment prostate-specific antigen (PSA) level >20 ng/mL (p = 0.037), higher radiation dose (p = 0.005), and the use of adjuvant LTAD vs. STAD (p = 0.011) were independent prognostic factors affecting bDFS in high-risk disease. The 5-year bDFS for patients treated with LTAD plus radiotherapy dose >78 Gy was 97%. Conclusions: For high-risk patients the present series showed that the use of LTAD in conjunction with higher doses (>78 Gy) of radiotherapy was associated with improved biochemical tumor control. We observed that the presence of Gleason sum >7 and pretreatment PSA level >20 ng/mL in the same patient represents a 6.8 times higher risk of PSA failure. These men could be considered for clinical trials with

  5. Estimating statistical uncertainty of Monte Carlo efficiency-gain in the context of a correlated sampling Monte Carlo code for brachytherapy treatment planning with non-normal dose distribution.

    PubMed

    Mukhopadhyay, Nitai D; Sampson, Andrew J; Deniz, Daniel; Alm Carlsson, Gudrun; Williamson, Jeffrey; Malusek, Alexandr

    2012-01-01

    Correlated sampling Monte Carlo methods can shorten computing times in brachytherapy treatment planning. Monte Carlo efficiency is typically estimated via efficiency gain, defined as the reduction in computing time by correlated sampling relative to conventional Monte Carlo methods when equal statistical uncertainties have been achieved. The determination of the efficiency gain uncertainty arising from random effects, however, is not a straightforward task specially when the error distribution is non-normal. The purpose of this study is to evaluate the applicability of the F distribution and standardized uncertainty propagation methods (widely used in metrology to estimate uncertainty of physical measurements) for predicting confidence intervals about efficiency gain estimates derived from single Monte Carlo runs using fixed-collision correlated sampling in a simplified brachytherapy geometry. A bootstrap based algorithm was used to simulate the probability distribution of the efficiency gain estimates and the shortest 95% confidence interval was estimated from this distribution. It was found that the corresponding relative uncertainty was as large as 37% for this particular problem. The uncertainty propagation framework predicted confidence intervals reasonably well; however its main disadvantage was that uncertainties of input quantities had to be calculated in a separate run via a Monte Carlo method. The F distribution noticeably underestimated the confidence interval. These discrepancies were influenced by several photons with large statistical weights which made extremely large contributions to the scored absorbed dose difference. The mechanism of acquiring high statistical weights in the fixed-collision correlated sampling method was explained and a mitigation strategy was proposed.

  6. Significant results: statistical or clinical?

    PubMed Central

    2016-01-01

    The null hypothesis significance test method is popular in biological and medical research. Many researchers have used this method for their research without exact knowledge, though it has both merits and shortcomings. Readers will know its shortcomings, as well as several complementary or alternative methods, as such the estimated effect size and the confidence interval. PMID:27066201

  7. Chemoprophylaxis of leprosy with a single dose of 25 mg per kg rifampin in the southern Marquesas; results after four years.

    PubMed

    Cartel, J L; Chanteau, S; Moulia-Pelat, J P; Plichart, R; Glaziou, P; Boutin, J P; Roux, J F; Grosset, J H

    1992-09-01

    In January-February 1988, a program of chemoprophylaxis for leprosy, using a single 25 mg/kg dose of rifampin, was conducted among 2786 (98.7%) inhabitants of the Southern Marquesas and 3144 South Marquesan "emigrants" and their families. Among the treated population, during the 4 years which followed the implementation of the program, two leprosy patients were detected, one of whom can be considered as a failure of chemoprophylaxis because she was not known by the leprosy control unit. During the same period (1988-1991), a decrease in detection rates for leprosy in the entire French Polynesian population has been observed, an event which makes the interpretation of these findings very difficult. Nevertheless, according to presently available data, the effectiveness of chemoprophylaxis with a single dose of 25 mg/kg rifampin is estimated to be about 40% to 50%. When considering not only the results of the present study but also the financial and logistic constraints raised by such a program, one is led to the conclusion that chemoprophylaxis, even with a single dose of rifampin, is not likely to become an effective component of leprosy control programs.

  8. Stereotactic Body Radiotherapy for Recurrent Squamous Cell Carcinoma of the Head and Neck: Results of a Phase I Dose-Escalation Trial

    SciTech Connect

    Heron, Dwight E.; Ferris, Robert L.; Karamouzis, Michalis; Andrade, Regiane S.; Deeb, Erin L.; Burton, Steven; Gooding, William E.; Branstetter, Barton F.; Mountz, James M.; Johnson, Jonas T.; Argiris, Athanassios; Grandis, Jennifer R.; Lai, Stephen Y.

    2009-12-01

    Purpose: To evaluate the safety and efficacy of stereotactic body radiotherapy (SBRT) in previously irradiated patients with squamous cell carcinoma of the head and neck (SCCHN). Patients and Methods: In this Phase I dose-escalation clinical trial, 25 patients were treated in five dose tiers up to 44 Gy, administered in 5 fractions over a 2-week course. Response was assessed according to the Response Evaluation Criteria in Solid Tumors and [{sup 18}F]-fluorodeoxyglucose standardized uptake value change on positron emission tomography-computed tomography (PET-CT). Results: No Grade 3/4 or dose-limiting toxicities occurred. Four patients had Grade 1/2 acute toxicities. Four objective responses were observed, for a response rate of 17% (95% confidence interval 2%-33%). The maximum duration of response was 4 months. Twelve patients had stable disease. Median time to disease progression was 4 months, and median overall survival was 6 months. Self-reported quality of life was not significantly affected by treatment. Fluorodeoxyglucose PET was a more sensitive early-measure response to treatment than CT volume changes. Conclusion: Reirradiation up to 44 Gy using SBRT is well tolerated in the acute setting and warrants further evaluation in combination with conventional and targeted therapies.

  9. Increasing Dose of Autologous Bone Marrow Mononuclear Cells Transplantation Is Related to Stroke Outcome: Results from a Pooled Analysis of Two Clinical Trials

    PubMed Central

    Escudero, Irene; Zapata, Elena; de la Torre Laviana, Francisco Javier; Carmona, Magdalena; Piñero, Pilar; Bustamante, Alejandro; Lebrato, Lucía; Cabezas, Juan Antonio; Gonzalez, Alejandro; de Freitas, Grabriel R.; Montaner, Joan

    2016-01-01

    Background and Purpose. BM-MNC transplantation improves recovery in experimental models of ischemic stroke. Clinical trials are ongoing to test efficacy in stroke patients. However, whether cell dose is related to outcomes is not known. Methods. We performed a pooling data analysis of two pilot clinical trials with autologous BM-MNCs transplantation in ischemic stroke patients. Cell dose and route were analyzed to evaluate their relation to good outcome (m-Rankin scale [mRS] score 0–2) at 6 months. Results. Twenty-two patients were included. A median of 153 × 106 (±121 × 106) BM-MNCs was injected. Intra-arterial route was used in 77.3% of cases. A higher number of cells injected were associated with better outcomes at 180 days (390 × 106 [320–422] BM-MNCs injected in those patients with mRS of 0–2 at 6 months versus 130 × 106 [89–210] in those patients with mRS 3–6, p = 0.015). In the intra-arterially treated patients, a strong correlation between dose of cells and disability was found (r = −0.63, p = 0.006). A cut point of 310 × 106 injected cells predicted good outcome with 80% sensitivity and 88.2% specificity. Conclusions. Similar to preclinical studies, a higher dose of autologous BM-MNC was related to better outcome in stroke patients, especially when more than 310 × 106 cells are injected. Further interventional studies are warranted to confirm these data. PMID:27525011

  10. Predictors for Rectal and Intestinal Acute Toxicities During Prostate Cancer High-Dose 3D-CRT: Results of a Prospective Multicenter Study

    SciTech Connect

    Vavassori, Vittorio; Fiorino, Claudio . E-mail: fiorino.claudio@hsr.it; Rancati, Tiziana; Magli, Alessandro; Fellin, Gianni; Baccolini, Michela; Bianchi, Carla; Cagna, Emanuela; Mauro, Flora A.; Monti, Angelo F.; Munoz, Fernando; Stasi, Michele; Franzone, Paola; Valdagni, Riccardo

    2007-04-01

    Purpose: To find predictors for rectal and intestinal acute toxicity in patients with prostate cancer treated with {>=}70 Gy conformal radiotherapy. Methods and Materials: Between July 2002 and March 2004, 1,132 patients were entered into a cooperative study (AIROPROS01-02). Toxicity was scored using the Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer scale and by considering the changes (before and after treatment) of the scores of a self-administered questionnaire on rectal/intestinal toxicity. The correlation with a number of parameters was assessed by univariate and multivariate analyses. Concerning the questionnaire, only moderate/severe complications were considered. Results: Of 1,132 patients, 1,123 were evaluable. Of these patients, 375, 265, and 28 had Grade 1, 2, and 3 Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer toxicity, respectively. The mean rectal dose was the most predictive parameter (p = 0.0004; odds ratio, 1.035) for Grade 2 or worse toxicity, and the use of anticoagulants/antiaggregants (p 0.02; odds ratio, 0.63) and hormonal therapy (p = 0.04, odds ratio, 0.65) were protective. The questionnaire-based scoring revealed that a greater mean rectal dose was associated with a greater risk of bleeding; larger irradiated volumes were associated with frequency, tenesmus, incontinence, and bleeding; hormonal therapy was protective against frequency and tenesmus; hemorrhoids were associated with a greater risk of tenesmus and bleeding; and diabetes associated highly with diarrhea. Conclusion: The mean rectal dose correlated with acute rectal/intestinal toxicity in three-dimensional conformal radiotherapy for prostate cancer, and hormonal therapy and the use of anticoagulants/antiaggregants were protective. According to the moderate/severe injury scores on the self-assessed questionnaire, several clinical and dose-volume parameters were independently predictive for

  11. Lack of radiological and clinical benefit over two years of low dose prednisolone for rheumatoid arthritis: results of a randomised controlled trial

    PubMed Central

    Capell, H; Madhok, R; Hunter, J; Porter, D; Morrison, E; Larkin, J; Thomson, E; Hampson, R; Poon, F

    2004-01-01

    Background: Evidence for disease modifying activity of low dose corticosteroid treatment in rheumatoid arthritis is contradictory. Studies showing radiological benefit suggest that continued treatment is required to sustain the effect. Objective: To evaluate the effect of low dose oral prednisolone in early rheumatoid arthritis on disease activity over two years. Design: Double blind placebo controlled trial. Methods: Patients with rheumatoid arthritis, duration <3 years (n = 167), were started on a disease modifying antirheumatic drug (DMARD; sulphasalazine) and allocated by stratified randomisation to prednisolone 7 mg/day or placebo. Primary outcome measure was radiological damage, assessed by the modified Sharp method. Clinical benefit was a secondary outcome. A proactive approach to identifying and treating corticosteroid adverse events was adopted. Patients who discontinued sulphasalazine were offered an alternative DMARD. Results: 90 of 257 patients eligible for the study refused to participate (more women than men). Of those enrolled, 84% were seropositive for rheumatoid factor, median age 56 years, median disease duration 12 months, female to male ratio 1.8:1. Prednisolone was given to 84 patients; of these 73% continued prednisolone and 70% sulphasalazine at 2 years. Of the 83 patients on placebo, 80% continued placebo and 64% sulphasalazine at 2 years. There were no significant differences in radiological score or clinical and laboratory measures at 0 and 2 years. Conclusions: Low dose prednisolone conferred no radiological or clinical benefit on patients maintained on a DMARD over two years. Low dose corticosteroids have no role in the routine management of rheumatoid arthritis treated with conventional disease modifying drugs. PMID:15194574

  12. Radiation dose in coronary angiography and intervention: initial results from the establishment of a multi-centre diagnostic reference level in Queensland public hospitals

    PubMed Central

    Crowhurst, James A; Whitby, Mark; Thiele, David; Halligan, Toni; Westerink, Adam; Crown, Suzanne; Milne, Jillian

    2014-01-01

    Introduction Radiation dose to patients undergoing invasive coronary angiography (ICA) is relatively high. Guidelines suggest that a local benchmark or diagnostic reference level (DRL) be established for these procedures. This study sought to create a DRL for ICA procedures in Queensland public hospitals. Methods Data were collected for all Cardiac Catheter Laboratories in Queensland public hospitals. Data were collected for diagnostic coronary angiography (CA) and single-vessel percutaneous intervention (PCI) procedures. Dose area product (PKA), skin surface entrance dose (KAR), fluoroscopy time (FT), and patient height and weight were collected for 3 months. The DRL was set from the 75th percentile of the PKA. Results 2590 patients were included in the CA group where the median FT was 3.5 min (inter-quartile range = 2.3–6.1). Median KAR = 581 mGy (374–876). Median PKA = 3908 uGym2 (2489–5865) DRL = 5865 uGym2. 947 patients were included in the PCI group where median FT was 11.2 min (7.7–17.4). Median KAR = 1501 mGy (928–2224). Median PKA = 8736 uGym2 (5449–12,900) DRL = 12,900 uGym2. Conclusion This study established a benchmark for radiation dose for diagnostic and interventional coronary angiography in Queensland public facilities. PMID:26229649

  13. Hypofractionated High-Dose Proton Beam Therapy for Stage I Non-Small-Cell Lung Cancer: Preliminary Results of A Phase I/II Clinical Study

    SciTech Connect

    Hata, Masaharu . E-mail: mhata@syd.odn.ne.jp; Tokuuye, Koichi; Kagei, Kenji; Sugahara, Shinji; Nakayama, Hidetsugu; Fukumitsu, Nobuyoshi; Hashimoto, Takayuki; Mizumoto, Masashi; Ohara, Kiyoshi; Akine, Yasuyuki

    2007-07-01

    Purpose: To present treatment outcomes of hypofractionated high-dose proton beam therapy for Stage I non-small-cell lung cancer (NSCLC). Methods and Materials: Twenty-one patients with Stage I NSCLC (11 with Stage IA and 10 with Stage IB) underwent hypofractionated high-dose proton beam therapy. At the time of irradiation, patient age ranged from 51 to 85 years (median, 74 years). Nine patients were medically inoperable because of comorbidities, and 12 patients refused surgical resection. Histology was squamous cell carcinoma in 6 patients, adenocarcinoma in 14, and large cell carcinoma in 1. Tumor size ranged from 10 to 42 mm (median, 25 mm) in maximum diameter. Three and 18 patients received proton beam irradiation with total doses of 50 Gy and 60 Gy in 10 fractions, respectively, to primary tumor sites. Results: Of 21 patients, 2 died of cancer and 2 died of pneumonia at a median follow-up period of 25 months. The 2-year overall and cause-specific survival rates were 74% and 86%, respectively. All but one of the irradiated tumors were controlled during the follow-up period. Five patients showed recurrences 6-29 months after treatment, including local progression and new lung lesions outside of the irradiated volume in 1 and 4 patients, respectively. The local progression-free and disease-free rates were 95% and 79% at 2 years, respectively. No therapy-related toxicity of Grade {>=}3 was observed. Conclusions: Hypofractionated high-dose proton beam therapy seems feasible and effective for Stage I NSCLC. Proton beams may contribute to enhanced efficacy and lower toxicity in the treatment of patients with Stage I NSCLC.

  14. Results.

    ERIC Educational Resources Information Center

    Zemsky, Robert; Shaman, Susan; Shapiro, Daniel B.

    2001-01-01

    Describes the Collegiate Results Instrument (CRI), which measures a range of collegiate outcomes for alumni 6 years after graduation. The CRI was designed to target alumni from institutions across market segments and assess their values, abilities, work skills, occupations, and pursuit of lifelong learning. (EV)

  15. Dose-dependent change in biomarkers during neoadjuvant endocrine therapy with fulvestrant: results from NEWEST, a randomized Phase II study.

    PubMed

    Kuter, Irene; Gee, Julia M W; Hegg, Roberto; Singer, Christian F; Badwe, Rajendra A; Lowe, Elizabeth S; Emeribe, Ugochi A; Anderson, Elizabeth; Sapunar, Francisco; Finlay, Pauline; Nicholson, Robert I; Bines, José; Harbeck, Nadia

    2012-05-01

    NEWEST (Neoadjuvant Endocrine Therapy for Women with Estrogen-Sensitive Tumors) is the first study to compare biological and clinical activity of fulvestrant 500 versus 250 mg in the neoadjuvant breast cancer setting. We hypothesized that fulvestrant 500 mg may be superior to 250 mg in blocking estrogen receptor (ER) signaling and growth. A multicenter, randomized, open-label, Phase II study was performed to compare fulvestrant 500 mg (500 mg/month plus 500 mg on day 14 of month 1) versus fulvestrant 250 mg/month for 16 weeks prior to surgery in postmenopausal women with ER+ locally advanced breast cancer. Core biopsies at baseline, week 4, and surgery were assessed for biomarker changes. Primary endpoint: change in Ki67 labeling index (LI) from baseline to week 4 determined by automated computer imaging system (ACIS). Secondary endpoints: ER protein expression and function; progesterone receptor (PgR) expression; tumor response; tolerability. ER and PgR were examined retrospectively using the H score method. A total of 211 patients were randomized (fulvestrant 500 mg: n = 109; 250 mg: n = 102). At week 4, fulvestrant 500 mg resulted in greater reduction of Ki67 LI and ER expression versus 250 mg (-78.8 vs. -47.4% [p < 0.0001] and -25.0 vs. -13.5% [p = 0.0002], respectively [ACIS]); PgR suppression was not significantly different (-22.7 vs. -17.6; p = 0.5677). However, H score detected even greater suppression of ER (-50.3 vs. -13.7%; p < 0.0001) and greater PgR suppression (-80.5 vs. -46.3%; p = 0.0018) for fulvestrant 500 versus 250 mg. At week 16, tumor response rates were 22.9 and 20.6% for fulvestrant 500 and 250 mg, respectively, with considerable decline in all markers by both ACIS and H score. No detrimental effects on endometrial thickness or bone markers and no new safety concerns were identified. This provides the first evidence of greater biological activity for fulvestrant 500 versus 250 mg in depleting ER expression, function, and growth.

  16. Paricalcitol versus cinacalcet plus low-dose vitamin D therapy for the treatment of secondary hyperparathyroidism in patients receiving haemodialysis: results of the IMPACT SHPT study

    PubMed Central

    Ketteler, Markus; Martin, Kevin J.; Wolf, Myles; Amdahl, Michael; Cozzolino, Mario; Goldsmith, David; Sharma, Amit; Marx, Steven; Khan, Samina

    2012-01-01

    Background Optimal treatment for secondary hyperparathyroidism (SHPT) has not been defined. The IMPACT SHPT (ClinicalTrials.gov identifier: NCT00977080) study assessed whether dose-titrated paricalcitol plus supplemental cinacalcet only for hypercalcaemia is superior to cinacalcet plus low-dose vitamin D in controlling intact parathyroid hormone (iPTH) levels in patients with SHPT on haemodialysis. Methods In this 28-week, multicentre, open-label Phase 4 study, participants were randomly selected to receive paricalcitol or cinacalcet plus low-dose vitamin D. Randomization and analyses were stratified by mode of paricalcitol administration [intravenous (IV) or oral]. The primary efficacy end point was the proportion of subjects who achieved a mean iPTH value of 150–300 pg/mL during Weeks 21–28. Results Of 272 subjects randomized, 268 received one or more dose of study drug; 101 in the IV and 110 in the oral stratum with two or more values during Weeks 21–28 were included in the primary analysis. In the IV stratum, 57.7% of subjects in the paricalcitol versus 32.7% in the cinacalcet group (P = 0.016) achieved the primary end point. In the oral stratum, the corresponding proportions of subjects were 54.4% for paricalcitol and 43.4% for cinacalcet (P = 0.260). Cochran–Mantel–Haenszel analysis, controlling for stratum, revealed overall superiority of paricalcitol (56.0%) over cinacalcet (38.2%; P = 0.010) in achieving iPTH 150–300 pg/mL during Weeks 21–28. Hypercalcaemia occurred in 4 (7.7%) and 0 (0%) of paricalcitol-treated subjects in the IV and oral strata, respectively. Hypocalcaemia occurred in 46.9% and 54.7% of cinacalcet-treated subjects in the IV and oral strata, respectively. Conclusion Paricalcitol versus cinacalcet plus low-dose vitamin D provided superior control of iPTH, with low incidence of hypercalcaemia. PMID:22387567

  17. SU-C-18C-06: Radiation Dose Reduction in Body Interventional Radiology: Clinical Results Utilizing a New Imaging Acquisition and Processing Platform

    SciTech Connect

    Kohlbrenner, R; Kolli, KP; Taylor, A; Kohi, M; Fidelman, N; LaBerge, J; Kerlan, R; Gould, R

    2014-06-01

    Purpose: To quantify the patient radiation dose reduction achieved during transarterial chemoembolization (TACE) procedures performed in a body interventional radiology suite equipped with the Philips Allura Clarity imaging acquisition and processing platform, compared to TACE procedures performed in the same suite equipped with the Philips Allura Xper platform. Methods: Total fluoroscopy time, cumulative dose area product, and cumulative air kerma were recorded for the first 25 TACE procedures performed to treat hepatocellular carcinoma (HCC) in a Philips body interventional radiology suite equipped with Philips Allura Clarity. The same data were collected for the prior 85 TACE procedures performed to treat HCC in the same suite equipped with Philips Allura Xper. Mean values from these cohorts were compared using two-tailed t tests. Results: Following installation of the Philips Allura Clarity platform, a 42.8% reduction in mean cumulative dose area product (3033.2 versus 1733.6 mGycm∧2, p < 0.0001) and a 31.2% reduction in mean cumulative air kerma (1445.4 versus 994.2 mGy, p < 0.001) was achieved compared to similar procedures performed in the same suite equipped with the Philips Allura Xper platform. Mean total fluoroscopy time was not significantly different between the two cohorts (1679.3 versus 1791.3 seconds, p = 0.41). Conclusion: This study demonstrates a significant patient radiation dose reduction during TACE procedures performed to treat HCC after a body interventional radiology suite was converted to the Philips Allura Clarity platform from the Philips Allura Xper platform. Future work will focus on evaluation of patient dose reduction in a larger cohort of patients across a broader range of procedures and in specific populations, including obese patients and pediatric patients, and comparison of image quality between the two platforms. Funding for this study was provided by Philips Healthcare, with 5% salary support provided to authors K. Pallav

  18. Radiation Doses to Members of the U.S. Population from Ubiquitous Radionuclides in the Body: Part 3, Results, Variability, and Uncertainty

    SciTech Connect

    Watson, David J.; Strom, Daniel J.

    2011-02-25

    This paper is part three of a three-part series investigating annual effective doses to residents of the United States from intakes of ubiquitous radionuclides, including radionuclides occurring naturally, radionuclides whose concentrations are technologically enhanced, and anthropogenic radionuclides. The radionuclides of interest are the 238U series (14 nuclides), the actinium series (headed by 235U; 11 nuclides), and the 232Th series (11 nuclides); primordial radionuclides 87Rb and 40K; cosmogenic and fallout radionuclides 14C and 3H; and purely anthropogenic radionuclides 137Cs-137mBa, 129I and 90Sr-90Y. This series of papers explicitly excludes intakes from inhaling 222Rn, 220Rn, and their short-lived decay products; it also excludes intakes of radionuclides in occupational and medical settings. Part one reviewed, summarized, characterized, and grouped all published and some unpublished data for U.S. residents on ubiquitous radionuclide concentrations in tissues and organs. Part two described the methods used to organize the data collected in part one and segregate it into the ages and genders defined by the study, imputed missing values from the existing data, apportioned activity in bone, and imputed activity in hollow organ contents and the remainder of the body. This paper estimates equivalent doses to target tissues from source regions and maps target tissues to lists of tissues with International Commission on Radiation Protection (ICRP) tissue-weighting factors or to surrogate tissue regions when there is no direct match. Effective doses, using ICRP tissue-weighting factors recommended in 1977, 1990, and 2007, are then calculated, and an upper bound of variability of the effective dose is estimated by calculating the average coefficients of variation (CV), assuming all variance is due to variability. Most of the data were for adult males, whose average annual effective dose is estimated to be 337 μSv (CV = 0.65, geometric mean = 283 μSv, geometric

  19. Statistical comparison of the results from six analytical chemistry laboratories of the mercury content of muscle tissue of two species of sharks.

    PubMed

    Walker, T I

    1977-01-01

    Statistical tests were carried out on the results of chemical analysis for total mercury concentrations of replicate samples of muscle tissue of school shark Galeorhinus australis (Macleay) and gummy shark Mustelus antarcticus Guenther from six independent analytical laboratories. These tests showed that one laboratory produced results 9% below the overall average of all results, another 1% below average while the other four were all 5% above average. Moreover, one laboratory had significantly lower scatter of results than the others, and the percentage scatter (standard error expressed as a percentage of the mean) in two of the laboratories tended to diminish as the magnitude of the results increased. Correction for what were concluded to be wild points indicated that the scatter for all laboratories was below 14%.

  20. Monotherapeutic High-Dose-Rate Brachytherapy for Prostate Cancer: Five-Year Results of an Extreme Hypofractionation Regimen With 54 Gy in Nine Fractions

    SciTech Connect

    Yoshioka, Yasuo; Konishi, Koji; Sumida, Iori; Takahashi, Yutaka; Isohashi, Fumiaki; Ogata, Toshiyuki; Koizumi, Masahiko; Yamazaki, Hideya; Nonomura, Norio; Okuyama, Akihiko; Inoue, Takehiro

    2011-06-01

    Purpose: To evaluate an extreme hypofractionation regimen with 54 Gy in nine fractions provided by high-dose-rate (HDR) brachytherapy as monotherapy for prostate cancer by reporting 5-year clinical results. Methods and Materials: Between 1996 and 2005, 112 patients with localized prostate cancer were treated with HDR brachytherapy without external beam radiotherapy. Of the 112 patients, 15 were considered low risk, 29 intermediate risk, and 68 as high risk. The prescribed dose was uniformly 54 Gy in nine fractions within 5 days. Of the 112 patients, 94 also received hormonal therapy. The median follow-up time was 5.4 years. Results: All the patients safely completed the treatment regimen. The 5-year prostate-specific antigen (PSA) failure-free, local control, disease-free survival, and overall survival rate was 83%, 97%, 87%, and 96%, respectively. The 5-year PSA failure-free rate for low-, intermediate-, and high-risk patients was 85% (95% confidence interval, 66-100%), 93% (95% confidence interval, 83-100%), and 79% (95% confidence interval, 69-89%), respectively. The significant prognostic factors for PSA failure were the initial PSA level (p = .029) and younger age (p = .019). The maximal toxicities observed were Grade 3 using the Common Terminology Criteria for Adverse Events, version 3.0, for both acute and late toxicity (6 and 3 patients had acute and late Grade 3 toxicity, respectively). Late Grade 2 toxicity was observed in 13 patients. Conclusion: Monotherapeutic HDR brachytherapy with an extreme hypofractionation regimen of 54 Gy in nine fractions associated with hormonal therapy was feasible, and its toxicity was acceptable. The interim tumor control rate at a median 5.4 years was promising, even for patients with locally advanced disease. This dose-fractionation scheme might be referred to by other terms, such as stereotactic body radiotherapy. Studies with longer follow-up periods and from multiple institutions are needed to confirm the efficacy of

  1. Five Years' Experience Treating Locally Advanced Cervical Cancer With Concurrent Chemoradiotherapy and High-Dose-Rate Brachytherapy: Results From a Single Institution

    SciTech Connect

    Parker, Kate; Gallop-Evans, Eve; Hanna, Louise Adams, Malcolm

    2009-05-01

    Purpose: To assess the clinical outcomes after concurrent cisplatin chemotherapy and radiotherapy (RT) followed by high-dose-rate brachytherapy for locally advanced carcinoma of the cervix and perform a multivariate analysis of the prognostic factors. Methods and Materials: The outcomes were analyzed for all women treated between 1999 and 2004 with concurrent cisplatin chemotherapy and RT followed by high-dose-rate brachytherapy. Kaplan-Meier analysis was used for overall survival (OS), local control (LC), and distant control (DC). The Cox proportional hazards model was used to perform multivariate analysis of the prognostic variables. Results: The standard regimen comprised whole pelvic external RT 45 Gy in 25 fractions with concurrent weekly cisplatin 40 mg/m{sup 2}, followed by four high-dose-rate brachytherapy insertions of 6 Gy. Patients with radiologically enlarged para-aortic lymph nodes underwent extended-field RT. Of 92 patients, the OS rate was 72% at 2 years and 55% at 5 years. The LC rate was 76% at 2 years and 67% at 5 years. The DC rate was 68% at 2 years and 48% at 5 years. The most important prognostic factor for OS, LC, and DC was the pretreatment hemoglobin. For OS, the tumor size and the presence of enlarged lymph nodes were also important. For LC, the number of brachytherapy insertions was important; and for DC, the number of chemotherapy treatments was important. Of the patients, 4% experienced late Grade 3 or 4 toxicity. Conclusion: The results of our study have shown that the regimen is effective, with acceptable long-term side effects. In this cohort, the most important prognostic factor was the pretreatment hemoglobin level, a disease-related factor. However, more effective systemic treatments are needed.

  2. Treatment of Locally Advanced Vaginal Cancer With Radiochemotherapy and Magnetic Resonance Image-Guided Adaptive Brachytherapy: Dose-Volume Parameters and First Clinical Results

    SciTech Connect

    Dimopoulos, Johannes C.A.; Schmid, Maximilian P.; Fidarova, Elena; Berger, Daniel; Kirisits, Christian; Poetter, Richard

    2012-04-01

    Purpose: To investigate the clinical feasibility of magnetic resonance image-guided adaptive brachytherapy (IGABT) for patients with locally advanced vaginal cancer and to report treatment outcomes. Methods and Materials: Thirteen patients with vaginal cancer were treated with external beam radiotherapy (45-50.4 Gy) plus IGABT with or without chemotherapy. Distribution of International Federation of Gynecology and Obstetrics stages among patients were as follows: 4 patients had Stage II cancer, 5 patients had Stage III cancer, and 4 patients had Stage IV cancer. The concept of IGABT as developed for cervix cancer was transferred and adapted for vaginal cancer, with corresponding treatment planning and reporting. Doses were converted to the equivalent dose in 2 Gy, applying the linear quadratic model ({alpha}/{beta} = 10 Gy for tumor; {alpha}/{beta} = 3 for organs at risk). Endpoints studied were gross tumor volume (GTV), dose-volume parameters for high-risk clinical target volume (HRCTV), and organs at risk, local control (LC), adverse side effects, and survival. Results: The mean GTV ({+-} 1 standard deviation) at diagnosis was 45.3 ({+-}30) cm{sup 3}, and the mean GTV at brachytherapy was 10 ({+-}14) cm{sup 3}. The mean D90 for the HRCTV was 86 ({+-}13) Gy. The mean D2cc for bladder, urethra, rectum, and sigmoid colon were 80 ({+-}20) Gy, 76 ({+-}16) Gy, 70 ({+-}9) Gy, and 60 ({+-}9) Gy, respectively. After a median follow-up of 43 months (range, 19-87 months), one local recurrence and two distant metastases cases were observed. Actuarial LC and overall survival rates at 3 years were 92% and 85%. One patient with Stage IVA and 1 patient with Stage III disease experienced fistulas (one vesicovaginal, one rectovaginal), and 1 patient developed periurethral necrosis. Conclusions: The concept of IGABT, originally developed for treating cervix cancer, appears to be applicable to vaginal cancer treatment with only minor adaptations. Dose-volume parameters for HRCTV and

  3. Estimating thyroid dose in pediatric CT exams from surface dose measurement

    NASA Astrophysics Data System (ADS)

    Al-Senan, Rani; Mueller, Deborah L.; Hatab, Mustapha R.

    2012-07-01

    The purpose of this study was to investigate the possibility of estimating pediatric thyroid doses from CT using surface neck doses. Optically stimulated luminescence dosimeters were used to measure the neck surface dose of 25 children ranging in ages between one and three years old. The neck circumference for each child was measured. The relationship between obtained surface doses and thyroid dose was studied using acrylic phantoms of various sizes and with holes of different depths. The ratios of hole-to-surface doses were used to convert patients' surface dose to thyroid dose. ImPACT software was utilized to calculate thyroid dose after applying the appropriate age correction factors. A paired t-test was performed to compare thyroid doses from our approach and ImPACT. The ratio of thyroid to surface dose was found to be 1.1. Thyroid doses ranged from 20 to 80 mGy. Comparison showed no statistical significance (p = 0.18). In addition, the average of surface dose variation along the z-axis in helical scans was studied and found to range between 5% (in 10 cm diameter phantom/24 mm collimation/pitch 1.0) and 8% (in 16 cm diameter phantom/12 mm collimation/pitch 0.7). We conclude that surface dose is an acceptable predictor for pediatric thyroid dose from CT. The uncertainty due to surface dose variability may be reduced if narrower collimation is used with a pitch factor close to 1.0. Also, the results did not show any effect of thyroid depth on the measured dose.

  4. Long-term results of high-dose-rate brachytherapy in the primary treatment of medically inoperable stage I-II endometrial carcinoma

    SciTech Connect

    Niazi, Tamim M.; Souhami, Luis . E-mail: luis.souhami@muhc.mcgill.ca; Portelance, Lorraine; Bahoric, Boris; Gilbert, Lucy; Stanimir, Gerald

    2005-11-15

    Purpose: Total-abdominal hysterectomy and bilateral salpingo-oophorectomy (TAHBSO) is the gold-standard therapy for patients with endometrial carcinoma. However, patients with high operative risks are usually treated with radiation therapy (RT) alone. The goal of this study was to update our experience of high-dose-rate brachytherapy (HDRB), with or without external-beam irradiation (EBRT), for such patients. Methods and Materials: Between 1984 and 2003, 38 patients with Stage I and Stage II adenocarcinoma of the endometrium considered high operative risk received RT as the primary treatment. The median age was 74.1 years. Before 1996, the local extent of the disease was assessed by an examination under anesthesia (EUA) and by EUA and magnetic resonance imaging (MRI) thereafter. Eight patients (21%) were treated with combined HDRB and EBRT, and 30 patients (79%) were treated with with HDRB alone. The median HDRB dose was 23.9 Gy, typically delivered in 3 fractions in a weekly schedule. The median EBRT dose was 42 Gy. Results: At a median follow-up of 57.5 months for patients at risk, 11 patients (29%) have failed: 6 patients (16%) locally, 4 patients (10.5%) distantly, and 1 patient (3%) locally and distantly. Local failure was established by biopsy, and 4 patients were salvaged by TAHBSO. Higher stage and higher grade were both associated with increased failure rate. The 15-year disease-specific survival (DSS) was 78% for all stages, 90% for Stage I, and 42% for Stage II (p < 0.0001). The 15-year DSS was 91% for Grade I and 67% for Grade II and III combined (p = 0.0254). Patients with Stage I disease established by MRI (11 patients) and who received a total HDRB dose of 30 Gy had a DSS rate of 100% at 10 years. Four patients experienced late toxicities: 1 Grade II and 3 Grade III or IV. Conclusion: Medically inoperable Stage I endometrial carcinoma may be safely and effectively treated with HDRB as the primary therapy. In selected Stage I patients, our results are

  5. Efficacy and safety of concentration-controlled everolimus with reduced-dose cyclosporine in Japanese de novo renal transplant patients: 12-month results

    PubMed Central

    2013-01-01

    Background No study to date has evaluated the efficacy and safety of everolimus with reduced-exposure cyclosporine in Japanese de-novo renal transplant (RTx) patients. Methods This 12-month, multicenter, open-label study randomized (1:1) 122 Japanese de-novo RTx patients to either an everolimus regimen (1.5 mg/day starting dose (target trough: 3 to 8 ng/ml) + reduced-dose cyclosporine) or a mycophenolate mofetil (MMF) regimen (2 g/day + standard dose cyclosporine). All patients received basiliximab and corticosteroids. Key endpoints at month 12 were composite efficacy failure (treated biopsy-proven acute rejection, graft loss, death, or loss to follow-up) and renal function (estimated glomerular filtration rate; Modification of Diet in Renal Disease-4). Results Clear cyclosporine exposure reduction was achieved in the everolimus group throughout the study (52% reduction at month 12). Month 12 efficacy failure rates showed everolimus 1.5 mg to be non-inferior to MMF (11.5% vs. 11.5%). The median estimated glomerular filtration rate at month 12 was 58.00 ml/minute/1.73 m2 in the everolimus group versus 55.25 ml/minute/1.73 m2 in the MMF group (P = 0.063). Overall, the incidence of adverse events was comparable between the groups with some differences in line with the known safety profile of the treatments. The everolimus group had a higher incidence of wound healing events and edema, whereas a higher rate of cytomegalovirus infections was reported in the MMF group. Conclusions This study confirmed the efficacy of everolimus 1.5 mg/day (target trough: 3 to 8 ng/ml) in Japanese RTx patients for preventing acute rejection, while allowing for substantial cyclosporine sparing. Renal function and safety findings were comparable with previous reports from other RTx populations. Trial registration ClinicalTrials.gov number: NCT00658320 PMID:23866828

  6. Initial Results of a Phase I Dose-Escalation Trial of Concurrent and Maintenance Erlotinib and Reirradiation for Recurrent and New Primary Head-and-Neck Cancer

    SciTech Connect

    Rusthoven, Kyle E.; Feigenberg, Steven J.; Raben, David; Kane, Madeleine; Song, John I.; Nicolaou, Nicos; Mehra, Ranee; Burtness, Barbara; Ridge, John; Swing, Robyn; Lango, Miriam; Cohen, Roger; Jimeno, Antonio; Chen Changhu

    2010-11-15

    Purpose: To present the first report of a Phase I trial evaluating concurrent and maintenance erlotinib and reirradiation in patients with recurrent or secondary primary head-and-neck cancer (HNC). Methods and Materials: Patients with recurrent or new primary HNC with an interval of at least 6 months since prior radiation were eligible. Patients were treated in 3 sequential cohorts: Cohort I, 100 mg of erlotinib daily with reirradiation at 61.6 Gy in 28 fractions; Cohort II, 150 mg of erlotinib with 61.6 Gy in 28 fractions; and Cohort III, 150 mg of erlotinib with 66 Gy in 30 fractions. Maintenance erlotinib started immediately after reirradiation at 150 mg daily and was continued for 2 years or until disease progression or dose-limiting toxicity. Dose-limiting toxicities were defined as any Grade 4 or 5 toxicity or a toxicity-related delay in radiation therapy of greater than 7 days. Results: Fourteen patients were accrued, 3 to Cohort I, 4 to Cohort II, and 7 to Cohort III. Thirteen patients were evaluable for toxicity. Median follow-up was 8.4 months overall and 15.1 months for surviving patients. One patient had a dose-limiting toxicity in Cohort III. This patient declined initial percutaneous endoscopic gastrostomy tube placement, was hospitalized with Grade 3 dysphagia and aspiration, and required a delay in radiation therapy of greater than 7 days. No Grade 4 acute toxicity was observed. Acute Grade 3 toxicity occurred in 9 of 13 patients. No erlotinib-related toxicity of Grade 3 or greater was observed during maintenance therapy. One patient had Grade 5 carotid hemorrhage 6 months after reirradiation, and another patient had Grade 3 osteoradionecrosis. Conclusions: Reirradiation (66 Gy in 2.2 Gy fractions) with concurrent and maintenance erlotinib (150 mg daily) for recurrent or new primary HNC is feasible.

  7. An Adaptive Staggered Dose Design for a Normal Endpoint.

    PubMed

    Wu, Joseph; Menon, Sandeep; Chang, Mark

    2015-01-01

    In a clinical trial where several doses are compared to a control, a multi-stage design that combines both the selection of the best dose and the confirmation of this selected dose is desirable. An example is the two-stage drop-the-losers or pick-the-winner design, where inferior doses are dropped after interim analysis. Selection of target dose(s) can be based on ranking of observed effects, hypothesis testing with adjustment for multiplicity, or other criteria at interim stages. A number of methods have been proposed and have made significant gains in trial efficiency. However, many of these designs started off with all doses with equal allocation and did not consider prioritizing the doses using existing dose-response information. We propose an adaptive staggered dose procedure that allows explicit prioritization of doses and applies error spending scheme that favors doses with assumed better responses. This design starts off with only a subset of the doses and adaptively adds new doses depending on interim results. Using simulation, we have shown that this design performs better in terms of increased statistical power than the drop-the-losers design given strong prior information of dose response.

  8. Whole-brain radiotherapy and high-dose methylprednisolone for elderly patients with primary central nervous system lymphoma: Results of North Central Cancer Treatment Group (NCCTG) 96-73-51

    SciTech Connect

    Laack, Nadia N.; Ballman, Karla V.; Brown, Paul B.; O'Neill, Brian Patrick . E-mail: boneill@mayo.edu

    2006-08-01

    Purpose: The aim of this study was to evaluate the efficacy, toxicity, and survival of whole-brain radiotherapy-treated (WBRT) and high-dose methylprednisolone (HDMP)-treated in elderly patients with primary central nervous system lymphoma (PCNSL). Methods and Materials: Patients with PCNSL who were 70 years and older received 1 g of methylprednisolone daily for 5 days, 30 days after WBRT. Patients then received 1 g of methylprednisolone every 28 days until progression. The primary endpoint was overall survival (OS) at 6 months. Results were compared with those in patients on the previous North Central Cancer Treatment Group (NCCTG) trial who received pre-WBRT cytoxan, adriamycin, vincristine, prednisone (CHOP) and high-dose cytarabine (CHOP-WBRT). A planned interim analysis was performed. The current regimen would be considered inactive if survival was not improved from patients treated with CHOP-WBRT. Results: Nineteen patients were accrued between 1998 and 2003. Median age was 76 years. Interim analysis revealed a 6-month survival of 33%, resulting in closure of the trial. Toxicity, OS, and event-free survival (EFS) were similar to those in patients more than 70 years of age who received CHOP-WBRT. The subgroup of patients who received HDMP had longer OS (12.1 vs. 7.0 months, p = 0.76) and EFS (11.7 vs. 4.0 months, p = 0.04) compared with the CHOP-WBRT patients alive 60 days after the start of treatment. Conclusions: Patients on-study long enough to receive HDMP had prolongation of OS and EFS compared to patients receiving CHOP-WBRT. Although the numbers of patients are too small for statistical conclusions, the HDMP regimen deserves further study.

  9. BPA exposure during in vitro oocyte maturation results in dose-dependent alterations to embryo development rates, apoptosis rate, sex ratio and gene expression.

    PubMed

    Ferris, Jacqueline; Mahboubi, Kiana; MacLusky, Neil; King, W Allan; Favetta, Laura A

    2016-01-01

    Alterations in the oocyte's environment can negatively affect embryo development. Oocyte quality, which can determine embryonic viability, is easily perturbed, thus factors affecting normal oocyte maturation are a concern. Bisphenol A (BPA) is an endocrine disrupting chemical that elicits a variety of reproductive effects. BPA has previously been found to disrupt meiosis, however the embryonic effects in mammals are not well documented. Here, bovine oocytes were matured in vitro with and without BPA treatment. Resulting embryos exhibited decreased embryonic development rates, increased apoptosis, and a skewed sex ratio. Gene expression in blastocysts was not altered, whereas treatment with 15ng/mL BPA resulted in increased expression of several of the genes studies, however this increase was largely due to a vehicle effect. BPA exposure during oocyte maturation in vitro can therefore, in a dose-dependent way, decrease oocyte and embryo quality and developmental potential and affect gene expression of developmentally important transcripts.

  10. High doses of lercanidipine are better tolerated than other dihydropyridines in hypertensive patients with metabolic syndrome: results from the TOLERANCE study

    PubMed Central

    Barrios, V; Escobar, C; de la Figuera, M; Honorato, J; Llisterri, J L; Segura, J; Calderón, A

    2008-01-01

    Aims/Introduction The TOlerabilidad de LERcanidipino 20 mg frente a Amlodipino y Nifedipino en CondicionEs normales de uso study was aimed to compare the tolerability of high doses of lercanidipine with amlodipine and nifedipine gastro-intestinal therapeutic system (GITS) in the treatment of hypertension in daily clinical practice. Patients/methods Essential hypertensives ≥ 18 years, treated during at least 1 month with lercanidipine 20 mg, amlodipine 10 mg or nifedipine GITS 60 mg, after a previous treatment course of at least 1 month with half the dose of the corresponding drugs were included. We present the data of the subgroup of patients with metabolic syndrome (MetS). Results Three hundred and thirty-seven of the 650 study population fulfilled criteria of MetS, 233 (69.1%) on lercanidipine and 104 (30.9%) on amlodipine/nifedipine GITS. Overall, a significantly lower proportion of lercanidipine-treated patients showed adverse reactions (ARs) when compared with patients receiving other-dihydropyridines (DHPs) (60.1% vs. 73.1%, p = 0.003). Similarly, the most common vasodilation-related ARs (oedema, swelling, flushing and headache) were significantly less frequent in lercanidipine group (all p < 0.01). Conclusion In conclusion, lercanidipine appears to exhibit a better tolerability profile and less vasodilation-related ARs compared with other DHPs in hypertensive patients with MetS. PMID:18355238

  11. Predictors of and health- and fall-related program outcomes resulting from complete and adequate doses of a fall risk reduction program.

    PubMed

    Mielenz, Thelma J; Durbin, Laura L; Hertzberg, Fern; Nobile-Hernandez, Diana; Jia, Haomiao

    2016-10-07

    Falls are dangerous and costly for older adults. The A Matter of Balance/Volunteer Lay Leader (AMOB/VLL) program is an evidence-based fall risk reduction program that could help reduce this burden. This study introduced a door-through-door transportation program to improve program delivery (N = 126). Characteristics predicting completion of all eight AMOB/VLL sessions were identified using logistic regression. Individual growth models were employed to determine the immediate, intermediate, and long-term goal outcomes resulting from receiving an adequate dose of the program (five to eight sessions). Self-restriction of activities due to fear of falling (OR 5.04, 95 % CI 1.86-13.69) and a lower frequency of moderate and vigorous physical activity (OR 1.14, 95 % CI 1.04-1.27) were significantly predictive of receiving a complete dose. Three outcome goals were significant, including (1) immediate-improved self-efficacy of managing medications and treatments, (2) intermediate-reduced activity limitations, and (3) intermediate-reduced physical disability. Self-restriction of activities due to a fear of falling and physical activity levels may be simple and effective screening questions to prevent AMOB/VLL attrition. In our study, those who did receive the program improved on a specific type of self-efficacy and on self-reported physical functioning.

  12. A Statistical Description of the Types and Severities of Accidents Involving Tractor Semi-Trailers, Updated Results for 1992-1996

    SciTech Connect

    BLOWER,DANIEL F.; CLAUSS,DAVID B.

    1999-10-01

    This report provides a statistical description of the types and severities of tractor semi-trailer accidents involving at least one fatality. The data were developed for use in risk assessments of hazardous materials transportation. A previous study (SAND93-2580) reviewed the availability of accident data, identified the TIFA (Trucks Involved in Fatal Accidents) as the best source of accident data for accidents involving heavy trucks, and provided statistics on accident data collected between 1980 and 1990. The current study is an extension of the previous work and describes data collected for heavy truck accidents occurring between 1992 and 1996. The TIFA database created at the University of Michigan Transportation Research Institute was extensively utilized. Supplementary data on collision and fire severity, which was not available in the TIFA database, were obtained by reviewing police reports and interviewing responders and witnesses for selected TEA accidents. The results are described in terms of frequencies of different accident types and cumulative distribution functions for the peak contact velocity, rollover skid distance, effective fire temperature, fire size, fire separation, and fire duration.

  13. The dynamics of the H(+) + D(2) reaction: a comparison of quantum mechanical wavepacket, quasi-classical and statistical-quasi-classical results.

    PubMed

    Jambrina, P G; Aoiz, F J; Bulut, N; Smith, Sean C; Balint-Kurti, G G; Hankel, M

    2010-02-07

    A detailed study of the proton exchange reaction H(+) + D(2)(v = 0, j = 0) --> HD + D(+) on its ground 1(1)A' potential energy surface has been carried out using 'exact' close-coupled quantum mechanical wavepacket (WP-EQM), quasi-classical trajectory (QCT), and statistical quasi-classical trajectory (SQCT) calculations for a range of collision energies starting from the reaction threshold to 1.3 eV. The WP-EQM calculations include all total angular momenta up to J(max) = 50, and therefore the various dynamical observables are converged up to 0.6 eV. It has been found that it is necessary to include all Coriolis couplings to obtain reliable converged results. Reaction probabilities obtained using the different methods are thoroughly compared as a function of the total energy for a series of J values. Comparisons are also made of total reaction cross sections as function of the collision energy, and rate constants. In addition, opacity functions, integral cross sections (ICS) and differential cross sections (DCS) are presented at 102 meV, 201.3 meV and 524.6 meV collision energy. The agreement between the three sets of results is only qualitative. The QCT calculations fail to describe the overall reactivity and most of the dynamical observables correctly. At low collision energies, the QCT method is plagued by the lack of conservation of zero point energy, whilst at higher collision energies and/or total angular momenta, the appearance of an effective repulsive potential associated with the centrifugal motion "over" the well causes a substantial decrease of the reactivity. In turn, the statistical models overestimate the reactivity over the whole range of collision energies as compared with the WP-EQM method. Specifically, at sufficiently high collision energies the reaction cannot be deemed to be statistical and important dynamical effects seem to be present. In general the WP-EQM results lie in between those obtained using the QCT and SQCT methods. One of the main

  14. SU-E-J-08: Comparison of Unintended Radiation Doses to Organs at Risk Resulting From the Out-Of-Field Therapeutic Beams and From Image-Guidance X-Ray Procedures

    SciTech Connect

    Ding, G; Wang, L

    2015-06-15

    Purpose: The unintended radiation dose to organs at risk (OAR) can be contributed from imaging guidance procedures as well as from leakage and scatter of therapeutic beams. This study compares the imaging dose with the unintended out-of-field therapeutic dose to patient sensitive organs. Methods: The Monte Carlo EGSnrc user codes, BEAMnrc and DOSXYZnrc, were used to simulate kV X-ray sources from imaging devices as well as the therapeutic IMRT/VMAT beams and to calculate doses to target and OARs on patient treatment planning CT images. The accuracy of the Monte Carlo simulations was benchmarked against measurements in phantoms. The dose-volume histogram was utilized in analyzing the patient organ doses. Results: The dose resulting from Standard Head kV-CBCT scans to bone and soft tissues ranges from 0.7 to 1.1 cGy and from 0.03 to 0.3 cGy, respectively. The dose resulting from Thorax scans on the chest to bone and soft tissues ranges from 1.1 to 1.8 cGy and from 0.3 to 0.6 cGy, respectively. The dose resulting from Pelvis scans on the abdomen to bone and soft tissues range from 3.2 to 4.2 cGy and from 1.2 to 2.2 cGy, respectively. The out-of-field doses to OAR are sensitive to the distance between the treated target and the OAR. For a typical Head-and-Neck IMRT/VMAT treatment the out-of-field doses to eyes are 1–3% of the target dose, or 2–6 cGy per fraction. Conclusion: The imaging doses to OAR are predictable based on the imaging protocols used when OARs are within the imaged volume and can be estimated and accounted for by using tabulated values. The unintended out-of-field doses are proportional to the target dose, strongly depend on the distance between the treated target and OAR, and are generally higher comparing to the imaging dose. This work was partially supported by Varian research grant VUMC40590.

  15. A Prospective Cohort Study to Compare Treatment Results Between 2 Fractionation Schedules of High-Dose-Rate Intracavitary Brachytherapy (HDR-ICBT) in Patients With Cervical Cancer

    SciTech Connect

    Huang, Eng-Yen; Sun, Li-Min; Lin, Hao; Lan, Jen-Hong; Chanchien, Chan-Chao; Huang, Yu-Jie; Wang, Chang-Yu; Wang, Chong-Jong

    2013-01-01

    Purpose: To compare the treatment results of 2 fractionation schedules for high-dose-rate intracavitary brachytherapy (HDR-ICBT) in patients with cervical cancer. Methods and Materials: From June 2001 through January 2008, 267 patients with stage IB-IVA cervical cancer were enrolled in the study. All patients underwent 4-field pelvic irradiation and HDR-ICBT. The median central and parametrial doses were 39.6 Gy and 45 Gy, respectively. Patient underwent either 6 Gy Multiplication-Sign 4 (HDR-4) (n=144) or 4.5 Gy Multiplication-Sign 6 (HDR-6) (n=123) to point A of ICBT using {sup 192}Ir isotope twice weekly. The rates of overall survival, locoregional failure, distant metastasis, proctitis, cystitis, and enterocolitis were compared between HDR-4 and HDR-6. Results: There were no significant differences in the demographic data between HDR-4 and HDR-6 except for total treatment time. The 5-year proctitis rates were 23.0% and 21.5% in HDR-4 and HDR-6 (P=.399), respectively. The corresponding rates of grade 2-4 proctitis were 18.7% and 9.6% (P=.060). The corresponding rates of grades 3-4 proctitis were 5.2% and 1.3% (P=.231). Subgroup analysis revealed that HDR-4 significantly increased grade 2-4 proctitis in patients aged {>=}62 years old (P=.012) but not in patients aged <62 years (P=.976). The rates of overall survival, locoregional failure, distant metastasis, cystitis, and enterocolitis were not significantly different between HDR-4 and HDR-6 schedules. Conclusion: The small fraction size of HDR-ICBT is associated with grade 2 proctitis without compromise of prognosis in elderly patients. This schedule is suggested for patients who tolerate an additional 2 applications of HDR-ICBT.

  16. Phase II Trial of Combined High-Dose-Rate Brachytherapy and External Beam Radiotherapy for Adenocarcinoma of the Prostate: Preliminary Results of RTOG 0321

    SciTech Connect

    Hsu, I-Chow; Bae, Kyounghwa; Shinohara, Katsuto; Pouliot, Jean; Purdy, James; Ibbott, Geoffrey; Speight, Joycelyn; Vigneault, Eric; Ivker, Robert M.D.; Sandler, Howard M.D.

    2010-11-01

    Purpose: To estimate the rate of late Grade 3 or greater genitourinary (GU) and gastrointestinal (GI) adverse events (AEs) after treatment with external beam radiotherapy and prostate high-dose-rate (HDR) brachytherapy. Methods and Materials: Each participating institution submitted computed tomography-based HDR brachytherapy dosimetry data electronically for credentialing and for each study patient. Patients with locally confined Stage T1c-T3b prostate cancer were eligible for the present study. All patients were treated with 45 Gy in 25 fractions using external beam radiotherapy and one HDR implant delivering 19 Gy in two fractions. All AEs were graded according to the Common Terminology Criteria for Adverse Events, version 3.0. Late GU/GI AEs were defined as those occurring >9 months from the start of the protocol treatment, in patients with {>=}18 months of potential follow-up. Results: A total of 129 patients from 14 institutions were enrolled in the present study. Of the 129 patients, 125 were eligible, and AE data were available for 112 patients at analysis. The pretreatment characteristics of the patients were as follows: Stage T1c-T2c, 91%; Stage T3a-T3b, 9%; prostate-specific antigen level {<=}10 ng/mL, 70%; prostate-specific antigen level >10 but {<=}20 ng/mL, 30%; and Gleason score 2-6, 10%; Gleason score 7, 72%; and Gleason score 8-10, 18%. At a median follow-up of 29.6 months, three acute and four late Grade 3 GU/GI AEs were reported. The estimated rate of late Grade 3-5 GU and GI AEs at 18 months was 2.56%. Conclusion: This is the first prospective, multi-institutional trial of computed tomography-based HDR brachytherapy and external beam radiotherapy. The technique and doses used in the present study resulted in acceptable levels of AEs.

  17. Optical laser scanning of a leucodye micelle gel: preliminary results of a 3D dose verification of an IMRT treatment for a brain tumor

    NASA Astrophysics Data System (ADS)

    Vandecasteele, J.; De Deene, Y.

    2013-06-01

    In the present study an in-house developed leucodye micelle gel was used in combination with an in-house developed optical laser scanner for the 3D dose verification of an IMRT treatment of a pituitary adenoma. In an initial prospective study, a gel measured depth dose distribution of a square 6 MV photon beam was compared with an ion chamber measurement. In a second experiment, the gel and scanner were used to verify a clinical dose distribution on a recently installed linear accelerator. The calibration procedure is identified as the major source of dose deviations.

  18. Statistical Inference

    NASA Astrophysics Data System (ADS)

    Khan, Shahjahan

    Often scientific information on various data generating processes are presented in the from of numerical and categorical data. Except for some very rare occasions, generally such data represent a small part of the population, or selected outcomes of any data generating process. Although, valuable and useful information is lurking in the array of scientific data, generally, they are unavailable to the users. Appropriate statistical methods are essential to reveal the hidden "jewels" in the mess of the row data. Exploratory data analysis methods are used to uncover such valuable characteristics of the observed data. Statistical inference provides techniques to make valid conclusions about the unknown characteristics or parameters of the population from which scientifically drawn sample data are selected. Usually, statistical inference includes estimation of population parameters as well as performing test of hypotheses on the parameters. However, prediction of future responses and determining the prediction distributions are also part of statistical inference. Both Classical or Frequentists and Bayesian approaches are used in statistical inference. The commonly used Classical approach is based on the sample data alone. In contrast, increasingly popular Beyesian approach uses prior distribution on the parameters along with the sample data to make inferences. The non-parametric and robust methods are also being used in situations where commonly used model assumptions are unsupported. In this chapter,we cover the philosophical andmethodological aspects of both the Classical and Bayesian approaches.Moreover, some aspects of predictive inference are also included. In the absence of any evidence to support assumptions regarding the distribution of the underlying population, or if the variable is measured only in ordinal scale, non-parametric methods are used. Robust methods are employed to avoid any significant changes in the results due to deviations from the model

  19. Statistical Inference

    NASA Astrophysics Data System (ADS)

    Khan, Shahjahan

    Often scientific information on various data generating processes are presented in the from of numerical and categorical data. Except for some very rare occasions, generally such data represent a small part of the population, or selected outcomes of any data generating process. Although, valuable and useful information is lurking in the array of scientific data, generally, they are unavailable to the users. Appropriate statistical methods are essential to reveal the hidden “jewels” in the mess of the row data. Exploratory data analysis methods are used to uncover such valuable characteristics of the observed data. Statistical inference provides techniques to make valid conclusions about the unknown characteristics or parameters of the population from which scientifically drawn sample data are selected. Usually, statistical inference includes estimation of population parameters as well as performing test of hypotheses on the parameters. However, prediction of future responses and determining the prediction distributions are also part of statistical inference. Both Classical or Frequentists and Bayesian approaches are used in statistical inference. The commonly used Classical approach is based on the sample data alone. In contrast, increasingly popular Beyesian approach uses prior distribution on the parameters along with the sample data to make inferences. The non-parametric and robust methods are also being used in situations where commonly used model assumptions are unsupported. In this chapter,we cover the philosophical andmethodological aspects of both the Classical and Bayesian approaches.Moreover, some aspects of predictive inference are also included. In the absence of any evidence to support assumptions regarding the distribution of the underlying population, or if the variable is measured only in ordinal scale, non-parametric methods are used. Robust methods are employed to avoid any significant changes in the results due to deviations from the model

  20. Risk of Late Toxicity in Men Receiving Dose-Escalated Hypofractionated Intensity Modulated Prostate Radiation Therapy: Results From a Randomized Trial

    SciTech Connect

    Hoffman, Karen E. Voong, K. Ranh; Pugh, Thomas J.; Skinner, Heath; Levy, Lawrence B.; Takiar, Vinita; Choi, Seungtaek; Du, Weiliang; Frank, Steven J.; Johnson, Jennifer; Kanke, James; Kudchadker, Rajat J.; Lee, Andrew K.; Mahmood, Usama; McGuire, Sean E.; Kuban, Deborah A.

    2014-04-01

    Objective: To report late toxicity outcomes from a randomized trial comparing conventional and hypofractionated prostate radiation therapy and to identify dosimetric and clinical parameters associated with late toxicity after hypofractionated treatment. Methods and Materials: Men with localized prostate cancer were enrolled in a trial that randomized men to either conventionally fractionated intensity modulated radiation therapy (CIMRT, 75.6 Gy in 1.8-Gy fractions) or to dose-escalated hypofractionated IMRT (HIMRT, 72 Gy in 2.4-Gy fractions). Late (≥90 days after completion of radiation therapy) genitourinary (GU) and gastrointestinal (GI) toxicity were prospectively evaluated and scored according to modified Radiation Therapy Oncology Group criteria. Results: 101 men received CIMRT and 102 men received HIMRT. The median age was 68, and the median follow-up time was 6.0 years. Twenty-eight percent had low-risk, 71% had intermediate-risk, and 1% had high-risk disease. There was no difference in late GU toxicity in men treated with CIMRT and HIMRT. The actuarial 5-year grade ≥2 GU toxicity was 16.5% after CIMRT and 15.8% after HIMRT (P=.97). There was a nonsignificant numeric increase in late GI toxicity in men treated with HIMRT compared with men treated with CIMRT. The actuarial 5-year grade ≥2 GI toxicity was 5.1% after CIMRT and 10.0% after HIMRT (P=.11). In men receiving HIMRT, the proportion of rectum receiving 36.9 Gy, 46.2 Gy, 64.6 Gy, and 73.9 Gy was associated with the development of late GI toxicity (P<.05). The 5-year actuarial grade ≥2 GI toxicity was 27.3% in men with R64.6Gy ≥ 20% but only 6.0% in men with R64.6Gy < 20% (P=.016). Conclusions: Dose-escalated IMRT using a moderate hypofractionation regimen (72 Gy in 2.4-Gy fractions) can be delivered safely with limited grade 2 or 3 late toxicity. Minimizing the proportion of rectum that receives moderate and high dose decreases the risk of late rectal toxicity after this

  1. Acoustic dose and acoustic dose-rate.

    PubMed

    Duck, Francis

    2009-10-01

    Acoustic dose is defined as the energy deposited by absorption of an acoustic wave per unit mass of the medium supporting the wave. Expressions for acoustic dose and acoustic dose-rate are given for plane-wave conditions, including temporal and frequency dependencies of energy deposition. The relationship between the acoustic dose-rate and the resulting temperature increase is explored, as is the relationship between acoustic dose-rate and radiation force. Energy transfer from the wave to the medium by means of acoustic cavitation is considered, and an approach is proposed in principle that could allow cavitation to be included within the proposed definitions of acoustic dose and acoustic dose-rate.

  2. High-dose therapy and autologous peripheral blood stem cell transplantation in multiple myeloma: up-front or rescue treatment? Results of a multicenter sequential randomized clinical trial.

    PubMed

    Fermand, J P; Ravaud, P; Chevret, S; Divine, M; Leblond, V; Belanger, C; Macro, M; Pertuiset, E; Dreyfus, F; Mariette, X; Boccacio, C; Brouet, J C

    1998-11-01

    Results to date indicate that high-dose therapy (HDT) with autologous stem cell support improves survival of patients with symptomatic multiple myeloma (MM). We performed a multicenter, sequential, randomized trial designed to assess the optimal timing of HDT and autotransplantation. Among 202 enrolled patients who were up to 56 years old, 185 were randomly assigned to receive HDT and peripheral blood stem cell (PBSC) autotransplantation (early HDT group, n = 91) or a conventional-dose chemotherapy (CCT) regimen (late HDT group, n = 94). In the late HDT group, HDT and transplantation were performed as rescue treament, in case of primary resistance to CCT or at relapse in responders. PBSC were collected before randomization, after mobilization by chemotherapy, and, in the two groups, HDT was preceded by three or four treatments with vincristine, doxorubicin, and methylprednisolone. Data were analyzed on an intent-to-treat basis using a sequential design. Within a median follow-up of 58 months, estimated median overall survival (OS) was 64.6 months in the early HDT group and 64 months in the late group. Survival curves were not different (P = .92, log-rank test). Median event-free survival (EFS) was 39 months in the early HDT group whereas median time between randomization and CCT failure was 13 months in the late group. Average time without symptoms, treatment, and treatment toxicity (TWiSTT) were 27.8 months (95% confidence interval [CI]; range, 23.8 to 31.8) and 22.3 months (range, 16.0 to 28.6) in the two groups, respectively. HDT with PBSC transplantation obtained a median OS exceeding 5 years in young patients with symptomatic MM, whether performed early, as first-line therapy, or late, as rescue treatment. Early HDT may be preferred because it is associated with a shorter period of chemotherapy.

  3. Antibody persistence and immunologic memory in children vaccinated with 4 doses of pneumococcal conjugate vaccines: Results from 2 long-term follow-up studies

    PubMed Central

    Wysocki, Jacek; Brzostek, Jerzy; Konior, Ryszard; Panzer, Falko G.; François, Nancy A.; Ravula, Sudheer M.; Kolhe, Devayani A.; Song, Yue; Dieussaert, Ilse; Schuerman, Lode; Borys, Dorota

    2017-01-01

    ABSTRACT To investigate long-term antibody persistence following the administration of the 10-valent pneumococcal non-typeable Haemophilus influenzae protein D conjugate vaccine (PHiD-CV), we present results of 2 follow-up studies assessing antibody persistence following 2 3+1 schedules up to 4 (NCT00624819 – Study A) and 5 years (NCT00891176 – Study B) post-booster vaccination. In Study A, antibody persistence was measured one, 2 and 4 years post-booster in children previously primed and boosted with PHiD-CV, or primed with the 7-valent pneumococcal conjugate vaccine (7vCRM) and boosted with either PHiD-CV or 7vCRM. In Study B, PHiD-CV was co-administered with meningococcal vaccines, and pneumococcal antibody persistence was measured 2, 3 and 5 years post-booster. An age-matched control group, unvaccinated against Streptococcus pneumoniae, was enrolled in Study A, allowing assessment of immunologic memory by administration of one dose of PHiD-CV to both primed (4 years post-booster) and unprimed 6-year-old children. Four years post-booster (Study A), antibody concentrations and opsonophagocytic activity (OPA) titers remained higher compared to the pre-booster timepoint, with no major differences between the 3 primed groups. Antibody persistence was also observed in Study B, with minimal differences between groups. The additional PHiD-CV dose administered 4 years post-booster in Study A elicited more robust immune responses in primed children than in unprimed children. Long-term serotype-specific antibody persistence and robust immunologic memory responses observed in these 2 studies suggest induction of long-term protection against pneumococcal disease after PHiD-CV vaccination. PMID:27736293

  4. Antibody persistence and immunologic memory in children vaccinated with 4 doses of pneumococcal conjugate vaccines: Results from 2 long-term follow-up studies.

    PubMed

    Wysocki, Jacek; Brzostek, Jerzy; Konior, Ryszard; Panzer, Falko G; François, Nancy A; Ravula, Sudheer M; Kolhe, Devayani A; Song, Yue; Dieussaert, Ilse; Schuerman, Lode; Borys, Dorota

    2016-10-13

    To investigate long-term antibody persistence following the administration of the 10-valent pneumococcal non-typeable Haemophilus influenzae protein D conjugate vaccine (PHiD-CV), we present results of 2 follow-up studies assessing antibody persistence following 2 3+1 schedules up to 4 (NCT00624819 - Study A) and 5 years (NCT00891176 - Study B) post-booster vaccination. In Study A, antibody persistence was measured one, 2 and 4 years post-booster in children previously primed and boosted with PHiD-CV, or primed with the 7-valent pneumococcal conjugate vaccine (7vCRM) and boosted with either PHiD-CV or 7vCRM. In Study B, PHiD-CV was co-administered with meningococcal vaccines, and pneumococcal antibody persistence was measured 2, 3 and 5 years post-booster. An age-matched control group, unvaccinated against Streptococcus pneumoniae, was enrolled in Study A, allowing assessment of immunologic memory by administration of one dose of PHiD-CV to both primed (4 years post-booster) and unprimed 6-year-old children. Four years post-booster (Study A), antibody concentrations and opsonophagocytic activity (OPA) titers remained higher compared to the pre-booster timepoint, with no major differences between the 3 primed groups. Antibody persistence was also observed in Study B, with minimal differences between groups. The additional PHiD-CV dose administered 4 years post-booster in Study A elicited more robust immune responses in primed children than in unprimed children. Long-term serotype-specific antibody persistence and robust immunologic memory responses observed in these 2 studies suggest induction of long-term protection against pneumococcal disease after PHiD-CV vaccination.

  5. [Descriptive statistics].

    PubMed

    Rendón-Macías, Mario Enrique; Villasís-Keever, Miguel Ángel; Miranda-Novales, María Guadalupe

    2016-01-01

    Descriptive statistics is the branch of statistics that gives recommendations on how to summarize clearly and simply research data in tables, figures, charts, or graphs. Before performing a descriptive analysis it is paramount to summarize its goal or goals, and to identify the measurement scales of the different variables recorded in the study. Tables or charts aim to provide timely information on the results of an investigation. The graphs show trends and can be histograms, pie charts, "box and whiskers" plots, line graphs, or scatter plots. Images serve as examples to reinforce concepts or facts. The choice of a chart, graph, or image must be based on the study objectives. Usually it is not recommended to use more than seven in an article, also depending on its length.

  6. Statistical and Prediction modeling of the Ka Band Using Experimental Results from ACTS Propagation Terminals at 20.185 and 27.505 GHZ

    NASA Technical Reports Server (NTRS)

    Ogunwuyi, Oluwatosin O.

    2004-01-01

    With the increase in demand for wireless communication services, most of the operating frequency bands have become very congested. The increase of wireless costumers is only fractional contribution to this phenomenon. The demand for more services such as video streams and internet explorer which require a lot of band width has been a more significant contributor to the congestion in a communication system. One way to increase the amount of information or data per unit of time transmitted with in a wireless communication system is to use a higher radio frequency. However in spite the advantage available in the using higher frequency bands such as, the Ka-band, higher frequencies also implies short wavelengths. And shorter wavelengths are more susceptible to rain attenuation. Until the Advanced Communication Technology Satellite (ACTS) was launched, the Ka- band frequency was virtually unused - the majority of communication satellites operated in lower frequency bands called the C- and Ku- bands. Ka-band is desirable because its higher frequency allows wide bandwidth applications, smaller spacecraft and ground terminal components, and stronger signal strength. Since the Ka-band is a high frequency band, the millimeter wavelengths of the signals are easily degraded by rain. This problem known as rain fade or rain attenuation The Advanced Communication Technology Satellite (ACTS) propagation experiment has collected 5 years of Radio Frequency (RF) attenuation data from December 1993 to November 1997. The objective of my summer work is to help develop the statistics and prediction techniques that will help to better characterize the Ka Frequency band. The statistical analysis consists of seasonal and cumulative five-year attenuation statistics for the 20.2 and 27.5 GHz. The cumulative five-year results give the link outage that occurs for a given link margin. The experiment has seven ground station terminals that can be attributed to a unique rain zone climate. The

  7. Statistical Reference Datasets

    National Institute of Standards and Technology Data Gateway

    Statistical Reference Datasets (Web, free access)   The Statistical Reference Datasets is also supported by the Standard Reference Data Program. The purpose of this project is to improve the accuracy of statistical software by providing reference datasets with certified computational results that enable the objective evaluation of statistical software.

  8. Results of a statistical approach to rainfall estimation using Nimbus 5 6.7 micrometers and 11.5 micrometers THIR data

    NASA Technical Reports Server (NTRS)

    Ormsby, J. P.

    1979-01-01

    Nimbus 5 6.7 mm and 11.5 mm temperature humidity infrared radiometer (THIR) data were used in a simple multiple regression scheme to test the feasibility of using these data to estimate hourly rainfall. Throughout the test area (85 W to 105 W and 45 N to 30 N) subareas (8 deg x 6 deg) were chosen from which point to point and areal statistics were obtained. Four subsets of data were used. The first consisted of only those surface stations indicating precipitation whose latitude and longitude coincided with the THIR grid points. A second used surface stations 0.1 degree from the THIR grid points. The third was a combination of subsets one and two. A reciprocal distance weighting scheme was used to derive precipitation values in data sparse areas. A fourth subset was made using these data combined with the data from subsets one and two. Point estimates resulted in negative correlations between estimated and grid derived "surface" precipitation. One degree areal estimates showed a slight improvement with a correlation coefficient of approximately 0.11. Single regression areal estimates resulted in correlations of approximately 0.11 and 0.20 for the 6.7 mm and 11.5 mm data respectively. These poor results were attributed to problems which are inherent in the satellite data (location errors, short temporal span of data, wavelength of sensors, etc.) and the lack of sufficient surface data to better verify the satellite estimate.

  9. 70 Gy Versus 80 Gy in Localized Prostate Cancer: 5-Year Results of GETUG 06 Randomized Trial;Prostate cancer; Dose escalation; Conformal radiotherapy; Randomized trial

    SciTech Connect

    Beckendorf, Veronique; Guerif, Stephane; Le Prise, Elisabeth; Cosset, Jean-Marc; Bougnoux, Agnes; Chauvet, Bruno; Salem, Naji; Chapet, Olivier; Bourdain, Sylvain; Bachaud, Jean-Marc; Maingon, Philippe; Hannoun-Levi, Jean-Michel; Malissard, Luc; Simon, Jean-Marc; Pommier, Pascal; Hay, Men; Dubray, Bernard; Lagrange, Jean-Leon; Luporsi, Elisabeth; Bey, Pierre

    2011-07-15

    Purpose: To perform a randomized trial comparing 70 and 80 Gy radiotherapy for prostate cancer. Patients and Methods: A total of 306 patients with localized prostate cancer were randomized. No androgen deprivation was allowed. The primary endpoint was biochemical relapse according to the modified 1997-American Society for Therapeutic Radiology and Oncology and Phoenix definitions. Toxicity was graded using the Radiation Therapy Oncology Group 1991 criteria and the late effects on normal tissues-subjective, objective, management, analytic scales (LENT-SOMA) scales. The patients' quality of life was scored using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire 30-item cancer-specific and 25-item prostate-specific modules. Results: The median follow-up was 61 months. According to the 1997-American Society for Therapeutic Radiology and Oncology definition, the 5-year biochemical relapse rate was 39% and 28% in the 70- and 80-Gy arms, respectively (p = .036). Using the Phoenix definition, the 5-year biochemical relapse rate was 32% and 23.5%, respectively (p = .09). The subgroup analysis showed a better biochemical outcome for the higher dose group with an initial prostate-specific antigen level >15 ng/mL. At the last follow-up date, 26 patients had died, 10 of their disease and none of toxicity, with no differences between the two arms. According to the Radiation Therapy Oncology Group scale, the Grade 2 or greater rectal toxicity rate was 14% and 19.5% for the 70- and 80-Gy arms (p = .22), respectively. The Grade 2 or greater urinary toxicity was 10% at 70 Gy and 17.5% at 80 Gy (p = .046). Similar results were observed using the LENT-SOMA scale. Bladder toxicity was more frequent at 80 Gy than at 70 Gy (p = .039). The quality-of-life questionnaire results before and 5 years after treatment were available for 103 patients with no differences found between the 70- and 80-Gy arms. Conclusion: High-dose radiotherapy provided a

  10. An intercomparison of a large ensemble of statistical downscaling methods for Europe: Overall results from the VALUE perfect predictor cross-validation experiment

    NASA Astrophysics Data System (ADS)

    Gutiérrez, Jose Manuel; Maraun, Douglas; Widmann, Martin; Huth, Radan; Hertig, Elke; Benestad, Rasmus; Roessler, Ole; Wibig, Joanna; Wilcke, Renate; Kotlarski, Sven

    2016-04-01

    VALUE is an open European network to validate and compare downscaling methods for climate change research (http://www.value-cost.eu). A key deliverable of VALUE is the development of a systematic validation framework to enable the assessment and comparison of both dynamical and statistical downscaling methods. This framework is based on a user-focused validation tree, guiding the selection of relevant validation indices and performance measures for different aspects of the validation (marginal, temporal, spatial, multi-variable). Moreover, several experiments have been designed to isolate specific points in the downscaling procedure where problems may occur (assessment of intrinsic performance, effect of errors inherited from the global models, effect of non-stationarity, etc.). The list of downscaling experiments includes 1) cross-validation with perfect predictors, 2) GCM predictors -aligned with EURO-CORDEX experiment- and 3) pseudo reality predictors (see Maraun et al. 2015, Earth's Future, 3, doi:10.1002/2014EF000259, for more details). The results of these experiments are gathered, validated and publicly distributed through the VALUE validation portal, allowing for a comprehensive community-open downscaling intercomparison study. In this contribution we describe the overall results from Experiment 1), consisting of a European wide 5-fold cross-validation (with consecutive 6-year periods from 1979 to 2008) using predictors from ERA-Interim to downscale precipitation and temperatures (minimum and maximum) over a set of 86 ECA&D stations representative of the main geographical and climatic regions in Europe. As a result of the open call for contribution to this experiment (closed in Dec. 2015), over 40 methods representative of the main approaches (MOS and Perfect Prognosis, PP) and techniques (linear scaling, quantile mapping, analogs, weather typing, linear and generalized regression, weather generators, etc.) were submitted, including information both data

  11. Interferon beta-1a for the maintenance of remission in patients with Crohn's disease: results of a phase II dose-finding study

    PubMed Central

    2009-01-01

    Background Crohn's disease (CD) and multiple sclerosis (MS) share common pathogenic processes. Interferon (IFN) beta-1a is effective and generally well tolerated in patients with MS and has been shown to down-regulate the expression of interleukin-12, a cytokine that is thought to be involved in mucosal degeneration in CD. IFN beta-1a therefore offers promise as a treatment for CD. Methods In this multicentre, double-blind, placebo-controlled, phase II, dose-finding study, patients with steroid-induced clinical remissions of CD were randomized 1:1:1:1 to subcutaneous IFN beta-1a: 66 mcg three times weekly (tiw), 44 mcg tiw, 44 mcg twice weekly (biw), or matching placebo tiw with steroid tapering. The primary endpoint was the proportion of patients relapse-free at Week 26. Safety was also assessed. Results This study was terminated early following a planned interim analysis at 26 weeks. Of the planned 192 patients, 67 were randomized to treatment: placebo (n = 16), or IFN beta-1a 44 mcg biw (n = 17), 44 mcg tiw (n = 16) or 66 mcg tiw (n = 18). In total, 20/67 patients (29.9%) completed 26 weeks and 7 patients (10.4%) completed 52 weeks. The proportion of patients who remained relapse-free at Week 26 did not differ significantly between the placebo group (5/16, 31%) and the IFN beta-1a 44 mcg biw (6/17, 35%; p = 0.497), 44 mcg tiw (7/16, 44%; p = 0.280) or 66 mcg tiw (2/18, 11%; p = 0.333) groups. There was little difference between treatment groups in secondary efficacy endpoints. IFN beta-1a was generally well tolerated at all doses. Adverse events (AEs) were generally mild or moderate in IFN beta-1a-treated patients, with the most common AEs (influenza-like symptoms, headache, injection-site reactions) being similar to those reported with IFN beta-1a in MS. Conclusion There was no difference in efficacy between patients with CD receiving IFN beta-1a or placebo. However, these results should be considered in the context of the low patient numbers and high dropout

  12. Intensified High-Dose Chemoradiotherapy With Induction Chemotherapy in Patients With Locally Advanced Non-Small-Cell Lung Cancer-Safety and Toxicity Results Within a Prospective Trial

    SciTech Connect

    Poettgen, Christoph; Eberhardt, Wilfried E.; Gauler, Thomas; Krbek, Thomas; Berkovic, Katharina; Abu Jawad, Jehad; Korfee, Soenke; Teschler, Helmut; Stamatis, Georgios; Stuschke, Martin

    2010-03-01

    Purpose: To analyze the toxicity profile of an intensified definitive chemoradiotherapy (CRT) schedule in patients with locally advanced non-small-cell lung cancer (Stage IIIA N2/selected IIIB) treated within a prospective multicenter trial. Patients and Methods: After mediastinoscopy and routine staging procedures, three cycles of induction chemotherapy (cisplatin 50 mg/m{sup 2}, Days 1 and 8; paclitaxel 175 mg/m{sup 2} Day 1, every 21 days) were planned, followed by concurrent CRT (accelerated-hyperfractionated regimen, 45 Gy, 2 x 1.5 Gy/d, cisplatin 50 mg/m{sup 2}, Days 64 and 71, vinorelbine 20 mg/m{sup 2}, Days 64 and 71). At 45 Gy, a multidisciplinary panel decision was made regarding operability. Inoperable patients received definitive radiotherapy (total dose 65 or 71 Gy, depending on the mean lung dose) with additional concurrent chemotherapy (cisplatin 40 mg/m{sup 2}, Day 85; vinorelbine 15 mg/m{sup 2}, Days 85 and 92). Results: A total of 28 patients (23 men and 5 women; median age, 58 years; range 41-73; Stage IIIA in 3 and Stage IIIB in 25) were judged ineligible for surgery by the multidisciplinary panel and underwent definitive CRT (75% of the patients received 71 Gy). The maximum toxicity (Grade 3 or greater) during induction chemotherapy included leukopenia (11%) and anemia (4%). During concurrent CRT, leukopenia (Grade 3 or greater) was observed in 39% of the patients. The maximal nonhematologic toxicity during concurrent CRT included esophagitis (Grade 3 or greater) in 18% and pneumonitis (Grade 3 or greater) in 4% of the patients. At 3 years, the locoregional control rate was 52% (95% confidence interval, 29-75%) and the overall survival rate was 31% (95% confidence interval, 12-50%). Conclusion: This intensified treatment protocol with induction chemotherapy and concurrent CRT, including hyperfractionated-accelerated RT, showed only moderate toxicity and proved feasible. This treatment represents the definitive CRT arm of our ongoing

  13. Hypofractionated High-Dose Radiation Therapy for Prostate Cancer: Long-Term Results of a Multi-Institutional Phase II Trial

    SciTech Connect

    Fonteyne, Valerie; Soete, Guy; Arcangeli, Stefano; De Neve, Wilfried; Rappe, Bernard; Storme, Guy; Strigari, Lidia; Arcangeli, Giorgio; De Meerleer, Gert

    2012-11-15

    Purpose: To report late gastrointestinal (GI) and genitourinary (GU) toxicity, biochemical and clinical outcomes, and overall survival after hypofractionated radiation therapy for prostate cancer (PC). Methods and Materials: Three institutions included 113 patients with T1 to T3N0M0 PC in a phase II study. Patients were treated with 56 Gy in 16 fractions over 4 weeks. Late toxicity was scored using Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer criteria extended with additional symptoms. Biochemical outcome was reported according to the Phoenix definition for biochemical failure. Results: The incidence of late GI and GU toxicity was low. The 3-year actuarial risk of developing late GU and GI toxicity of grade {>=}2 was 13% and 8% respectively. Five-year biochemical non-evidence of disease (bNED) was 94%. Risk group, T stage, and deviation from planned hormone treatment were significant predictive factors for bNED. Deviation from hormone treatment remained significant in multivariate analysis. Five-year clinical non evidence of disease and overall survival was 95% and 91% respectively. No patient died from PC. Conclusions: Hypofractionated high-dose radiation therapy is a valuable treatment option for patients with PC, with excellent biochemical and clinical outcome and low toxicity.

  14. Statistical methods applied to the study of opinion formation models: a brief overview and results of a numerical study of a model based on the social impact theory

    NASA Astrophysics Data System (ADS)

    Bordogna, Clelia María; Albano, Ezequiel V.

    2007-02-01

    The aim of this paper is twofold. On the one hand we present a brief overview on the application of statistical physics methods to the modelling of social phenomena focusing our attention on models for opinion formation. On the other hand, we discuss and present original results of a model for opinion formation based on the social impact theory developed by Latané. The presented model accounts for the interaction among the members of a social group under the competitive influence of a strong leader and the mass media, both supporting two different states of opinion. Extensive simulations of the model are presented, showing that they led to the observation of a rich scenery of complex behaviour including, among others, critical behaviour and phase transitions between a state of opinion dominated by the leader and another dominated by the mass media. The occurrence of interesting finite-size effects reveals that, in small communities, the opinion of the leader may prevail over that of the mass media. This observation is relevant for the understanding of social phenomena involving a finite number of individuals, in contrast to actual physical phase transitions that take place in the thermodynamic limit. Finally, we give a brief outlook of open questions and lines for future work.

  15. Statistical Short-Range Guidance for Peak Wind Speed Forecasts on Kennedy Space Center/Cape Canaveral Air Force Station: Phase I Results

    NASA Technical Reports Server (NTRS)

    Lambert, Winifred C.; Merceret, Francis J. (Technical Monitor)

    2002-01-01

    This report describes the results of the ANU's (Applied Meteorology Unit) Short-Range Statistical Forecasting task for peak winds. The peak wind speeds are an important forecast element for the Space Shuttle and Expendable Launch Vehicle programs. The Keith Weather Squadron and the Spaceflight Meteorology Group indicate that peak winds are challenging to forecast. The Applied Meteorology Unit was tasked to develop tools that aid in short-range forecasts of peak winds at tower sites of operational interest. A 7 year record of wind tower data was used in the analysis. Hourly and directional climatologies by tower and month were developed to determine the seasonal behavior of the average and peak winds. In all climatologies, the average and peak wind speeds were highly variable in time. This indicated that the development of a peak wind forecasting tool would be difficult. Probability density functions (PDF) of peak wind speed were calculated to determine the distribution of peak speed with average speed. These provide forecasters with a means of determining the probability of meeting or exceeding a certain peak wind given an observed or forecast average speed. The climatologies and PDFs provide tools with which to make peak wind forecasts that are critical to safe operations.

  16. A simulation study of the strength of evidence in the recommendation of medications based on two trials with statistically significant results

    PubMed Central

    Ioannidis, John P. A.

    2017-01-01

    A typical rule that has been used for the endorsement of new medications by the Food and Drug Administration is to have two trials, each convincing on its own, demonstrating effectiveness. “Convincing” may be subjectively interpreted, but the use of p-values and the focus on statistical significance (in particular with p < .05 being coined significant) is pervasive in clinical research. Therefore, in this paper, we calculate with simulations what it means to have exactly two trials, each with p < .05, in terms of the actual strength of evidence quantified by Bayes factors. Our results show that different cases where two trials have a p-value below .05 have wildly differing Bayes factors. Bayes factors of at least 20 in favor of the alternative hypothesis are not necessarily achieved and they fail to be reached in a large proportion of cases, in particular when the true effect size is small (0.2 standard deviations) or zero. In a non-trivial number of cases, evidence actually points to the null hypothesis, in particular when the true effect size is zero, when the number of trials is large, and when the number of participants in both groups is low. We recommend use of Bayes factors as a routine tool to assess endorsement of new medications, because Bayes factors consistently quantify strength of evidence. Use of p-values may lead to paradoxical and spurious decision-making regarding the use of new medications. PMID:28273140

  17. The impact of x-ray tube stabilization on localized radiation dose in axial CT scans: initial results in CTDI phantoms

    NASA Astrophysics Data System (ADS)

    Mathieu, Kelsey B.; McNitt-Gray, Michael F.; Cody, Dianna D.

    2016-10-01

    Rise, fall, and stabilization of the x-ray tube output occur immediately before and after data acquisition on some computed tomography (CT) scanners and are believed to contribute additional dose to anatomy facing the x-ray tube when it powers on or off. In this study, we characterized the dose penalty caused by additional radiation exposure during the rise, stabilization, and/or fall time (referred to as overscanning). A 32 cm CT dose-index (CTDI) phantom was scanned on three CT scanners: GE Healthcare LightSpeed VCT, GE Healthcare Discovery CT750 HD, and Siemens Somatom Definition Flash. Radiation exposure was detected for various x-ray tube start acquisition angles using a 10 cm pencil ionization chamber placed in the peripheral chamber hole at the phantom’s 12 o’clock position. Scan rotation time, ionization chamber location, phantom diameter, and phantom centering were varied to quantify their effects on the dose penalty caused by overscanning. For 1 s single, axial rotations, CTDI at the 12 o’clock chamber position (CTDI100, 12:00) was 6.1%, 4.0%, and 4.4% higher when the start angle of the x-ray tube was aligned at the top of the gantry (12 o’clock) versus when the start angle was aligned at 9 o’clock for the Siemens Flash, GE CT750 HD, and GE VCT scanner, respectively. For the scanners’ fastest rotation times (0.285 s for the Siemens and 0.4 s for both GE scanners), the dose penalties increased to 22.3%, 10.7%, and 10.5%, respectively, suggesting a trade-off between rotation speed and the dose penalty from overscanning. In general, overscanning was shown to have a greater radiation dose impact for larger diameter phantoms, shorter rotation times, and to peripheral phantom locations. Future research is necessary to determine an appropriate method for incorporating the localized dose penalty from overscanning into standard dose metrics, as well as to assess the impact on organ dose.

  18. Water-quality trends in the nation’s rivers and streams, 1972–2012—Data preparation, statistical methods, and trend results

    USGS Publications Warehouse

    Oelsner, Gretchen P.; Sprague, Lori A.; Murphy, Jennifer C.; Zuellig, Robert E.; Johnson, Henry M.; Ryberg, Karen R.; Falcone, James A.; Stets, Edward G.; Vecchia, Aldo V.; Riskin, Melissa L.; De Cicco, Laura A.; Mills, Taylor J.; Farmer, William H.

    2017-04-04

    Since passage of the Clean Water Act in 1972, Federal, State, and local governments have invested billions of dollars to reduce pollution entering rivers and streams. To understand the return on these investments and to effectively manage and protect the Nation’s water resources in the future, we need to know how and why water quality has been changing over time. As part of the National Water-Quality Assessment Project, of the U.S. Geological Survey’s National Water-Quality Program, data from the U.S. Geological Survey, along with multiple other Federal, State, Tribal, regional, and local agencies, have been used to support the most comprehensive assessment conducted to date of surface-water-quality trends in the United States. This report documents the methods used to determine trends in water quality and ecology because these methods are vital to ensuring the quality of the results. Specific objectives are to document (1) the data compilation and processing steps used to identify river and stream sites throughout the Nation suitable for water-quality, pesticide, and ecology trend analysis, (2) the statistical methods used to determine trends in target parameters, (3) considerations for water-quality, pesticide, and ecology data and streamflow data when modeling trends, (4) sensitivity analyses for selecting data and interpreting trend results with the Weighted Regressions on Time, Discharge, and Season method, and (5) the final trend results at each site. The scope of this study includes trends in water-quality concentrations and loads (nutrient, sediment, major ion, salinity, and carbon), pesticide concentrations and loads, and metrics for aquatic ecology (fish, invertebrates, and algae) for four time periods: (1) 1972–2012, (2) 1982–2012, (3) 1992–2012, and (4) 2002–12. In total, nearly 12,000 trends in concentration, load, and ecology metrics were evaluated in this study; there were 11,893 combinations of sites, parameters, and trend periods. The

  19. Multicriteria optimization of the spatial dose distribution

    SciTech Connect

    Schlaefer, Alexander; Viulet, Tiberiu; Muacevic, Alexander; Fürweger, Christoph

    2013-12-15

    Purpose: Treatment planning for radiation therapy involves trade-offs with respect to different clinical goals. Typically, the dose distribution is evaluated based on few statistics and dose–volume histograms. Particularly for stereotactic treatments, the spatial dose distribution represents further criteria, e.g., when considering the gradient between subregions of volumes of interest. The authors have studied how to consider the spatial dose distribution using a multicriteria optimization approach.Methods: The authors have extended a stepwise multicriteria optimization approach to include criteria with respect to the local dose distribution. Based on a three-dimensional visualization of the dose the authors use a software tool allowing interaction with the dose distribution to map objectives with respect to its shape to a constrained optimization problem. Similarly, conflicting criteria are highlighted and the planner decides if and where to relax the shape of the dose distribution.Results: To demonstrate the potential of spatial multicriteria optimization, the tool was applied to a prostate and meningioma case. For the prostate case, local sparing of the rectal wall and shaping of a boost volume are achieved through local relaxations and while maintaining the remaining dose distribution. For the meningioma, target coverage is improved by compromising low dose conformality toward noncritical structures. A comparison of dose–volume histograms illustrates the importance of spatial information for achieving the trade-offs.Conclusions: The results show that it is possible to consider the location of conflicting criteria during treatment planning. Particularly, it is possible to conserve already achieved goals with respect to the dose distribution, to visualize potential trade-offs, and to relax constraints locally. Hence, the proposed approach facilitates a systematic exploration of the optimal shape of the dose distribution.

  20. Descriptive statistics.

    PubMed

    Shi, Runhua; McLarty, Jerry W

    2009-10-01

    In this article, we introduced basic concepts of statistics, type of distributions, and descriptive statistics. A few examples were also provided. The basic concepts presented herein are only a fraction of the concepts related to descriptive statistics. Also, there are many commonly used distributions not presented herein, such as Poisson distributions for rare events and exponential distributions, F distributions, and logistic distributions. More information can be found in many statistics books and publications.

  1. Potent response of QS-21 as a vaccine adjuvant in the skin when delivered with the Nanopatch, resulted in adjuvant dose sparing

    PubMed Central

    Ng, Hwee-Ing; Fernando, Germain J. P.; Depelsenaire, Alexandra C. I.; Kendall, Mark A. F.

    2016-01-01

    Adjuvants play a key role in boosting immunogenicity of vaccines, particularly for subunit protein vaccines. In this study we investigated the induction of antibody response against trivalent influenza subunit protein antigen and a saponin adjuvant, QS-21. Clinical trials of QS-21 have demonstrated the safety but, also a need of high dose for optimal immunity, which could possibly reduce patient acceptability. Here, we proposed the use of a skin delivery technology – the Nanopatch – to reduce both adjuvant and antigen dose but also retain its immune stimulating effects when compared to the conventional needle and syringe intramuscular (IM) delivery. We have demonstrated that Nanopatch delivery to skin requires only 1/100th of the IM antigen dose to induce equivalent humoral response. QS-21 enhanced humoral response in both skin and muscle route. Additionally, Nanopatch has demonstrated 30-fold adjuvant QS-21 dose sparing while retaining immune stimulating effects compared to IM. QS-21 induced localised, controlled cell death in the skin, suggesting that the danger signals released from dead cells contributed to the enhanced immunogenicity. Taken together, these findings demonstrated the suitability of reduced dose of QS-21 and the antigen using the Nanopatch to enhance humoral responses, and the potential to increase patient acceptability of QS-21 adjuvant. PMID:27404789

  2. Potent response of QS-21 as a vaccine adjuvant in the skin when delivered with the Nanopatch, resulted in adjuvant dose sparing.

    PubMed

    Ng, Hwee-Ing; Fernando, Germain J P; Depelsenaire, Alexandra C I; Kendall, Mark A F

    2016-07-11

    Adjuvants play a key role in boosting immunogenicity of vaccines, particularly for subunit protein vaccines. In this study we investigated the induction of antibody response against trivalent influenza subunit protein antigen and a saponin adjuvant, QS-21. Clinical trials of QS-21 have demonstrated the safety but, also a need of high dose for optimal immunity, which could possibly reduce patient acceptability. Here, we proposed the use of a skin delivery technology - the Nanopatch - to reduce both adjuvant and antigen dose but also retain its immune stimulating effects when compared to the conventional needle and syringe intramuscular (IM) delivery. We have demonstrated that Nanopatch delivery to skin requires only 1/100(th) of the IM antigen dose to induce equivalent humoral response. QS-21 enhanced humoral response in both skin and muscle route. Additionally, Nanopatch has demonstrated 30-fold adjuvant QS-21 dose sparing while retaining immune stimulating effects compared to IM. QS-21 induced localised, controlled cell death in the skin, suggesting that the danger signals released from dead cells contributed to the enhanced immunogenicity. Taken together, these findings demonstrated the suitability of reduced dose of QS-21 and the antigen using the Nanopatch to enhance humoral responses, and the potential to increase patient acceptability of QS-21 adjuvant.

  3. Statistical Software.

    ERIC Educational Resources Information Center

    Callamaras, Peter

    1983-01-01

    This buyer's guide to seven major types of statistics software packages for microcomputers reviews Edu-Ware Statistics 3.0; Financial Planning; Speed Stat; Statistics with DAISY; Human Systems Dynamics package of Stats Plus, ANOVA II, and REGRESS II; Maxistat; and Moore-Barnes' MBC Test Construction and MBC Correlation. (MBR)

  4. Statistical Diversions

    ERIC Educational Resources Information Center

    Petocz, Peter; Sowey, Eric

    2008-01-01

    As a branch of knowledge, Statistics is ubiquitous and its applications can be found in (almost) every field of human endeavour. In this article, the authors track down the possible source of the link between the "Siren song" and applications of Statistics. Answers to their previous five questions and five new questions on Statistics are presented.

  5. Absorbed Dose and Dose Equivalent Calculations for Modeling Effective Dose

    NASA Technical Reports Server (NTRS)

    Welton, Andrew; Lee, Kerry

    2010-01-01

    While in orbit, Astronauts are exposed to a much higher dose of ionizing radiation than when on the ground. It is important to model how shielding designs on spacecraft reduce radiation effective dose pre-flight, and determine whether or not a danger to humans is presented. However, in order to calculate effective dose, dose equivalent calculations are needed. Dose equivalent takes into account an absorbed dose of radiation and the biological effectiveness of ionizing radiation. This is important in preventing long-term, stochastic radiation effects in humans spending time in space. Monte carlo simulations run with the particle transport code FLUKA, give absorbed and equivalent dose data for relevant shielding. The shielding geometry used in the dose calculations is a layered slab design, consisting of aluminum, polyethylene, and water. Water is used to simulate the soft tissues that compose the human body. The results obtained will provide information on how the shielding performs with many thicknesses of each material in the slab. This allows them to be directly applicable to modern spacecraft shielding geometries.

  6. Safety and pharmacokinetic profiles of phosphorodiamidate morpholino oligomers with activity against ebola virus and marburg virus: results of two single-ascending-dose studies.

    PubMed

    Heald, Alison E; Iversen, Patrick L; Saoud, Jay B; Sazani, Peter; Charleston, Jay S; Axtelle, Tim; Wong, Michael; Smith, William B; Vutikullird, Apinya; Kaye, Edward

    2014-11-01

    Two identical single-ascending-dose studies evaluated the safety and pharmacokinetics (PK) of AVI-6002 and AVI-6003, two experimental combinations of phosphorodiamidate morpholino oligomers with positive charges (PMOplus) that target viral mRNA encoding Ebola virus and Marburg virus proteins, respectively. Both AVI-6002 and AVI-6003 were found to suppress disease in virus-infected nonhuman primates in previous studies. AVI-6002 (a combination of AVI-7537 and AVI-7539) or AVI-6003 (a combination of AVI-7287 and AVI-7288) were administered as sequential intravenous (i.v.) infusions of a 1:1 fixed dose ratio of the two subcomponents. In each study, 30 healthy male and female subjects between 18 and 50 years of age were enrolled in six-dose escalation cohorts of five subjects each and received a single i.v. infusion of active study drug (0.005, 0.05, 0.5, 1.5, 3, and 4.5 mg/kg per component) or placebo in a 4:1 ratio. Both AVI-6002 and AVI-6003 were safe and well tolerated at the doses studied. A maximum tolerated dose was not observed in either study. The four chemically similar PMOplus components exhibited generally similar PK profiles. The mean peak plasma concentration and area under the concentration-time curve values of the four components exhibited dose-proportional PK. The estimated plasma half-life of all four components was 2 to 5 h. The safety of the two combinations and the PK of the four components were similar, regardless of the target RNA sequence.

  7. High-dose therapy autotransplantation/intensification vs continued standard chemotherapy in multiple myeloma in first remission. Results of a non-randomized study from a single institution.

    PubMed

    Bladé, J; Esteve, J; Rives, S; Martínez, C; Rovira, M; Urbano-Ispizua, A; Marín, P; Carreras, E; Montserrat, E

    2000-10-01

    The purpose of this study was to analyze the outcome of patients with multiple myeloma (MM) responding to initial chemotherapy who received intensification with high-dose therapy/autotransplantation (HDT) as compared to that of those who were continued on standard chemotherapy. From 1 January 1990 to 30 June 1998, 64 patients with MM who were younger than 65 years achieved a response to initial chemotherapy. Due to referral reasons, patients preference or inclusion in trials, 31 patients received HDT as early intensification while 33 were continued on standard chemotherapy. The presenting features were similar in both groups, except for the median age, which was lower in the HDT group (53 vs 58 years, P = 0.007). Complete response negative immunofixation - (CR) was achieved in 12 of 31 (39%) patients intensified with HDT and in two of 33 (6%) patients who were continued on conventional chemotherapy (P = 0.002). Event-free survival (EFS) was significantly longer in the HDT group (median, 43 vs 21 months; P = 0.007). Overall survival (OS) was not significantly different between groups (median, 62 vs 38 months; P = 0.21). However, patients in the HDT group who achieved CR had an EFS (median, 51 vs 31 months; P = 0.03) as well as an OS (median, not reached vs 50 months; P = 0.0006) significantly longer than those achieving a lower degree of response. In conclusion, this non-randomized study shows that early HDT increases CR rate and prolongs EFS. In addition, these results highlight CR as a crucial step for achieving long-lasting disease control and prolonged survival in patients with MM.

  8. Results of combined photodynamic therapy (PDT) and high dose rate brachytherapy (HDR) in treatment of obstructive endobronchial non-small cell lung cancer

    NASA Astrophysics Data System (ADS)

    Weinberg, Benjamin D.; Allison, Ron R.; Sibata, Claudio; Parent, Teresa; Downie, Gordon

    2009-06-01

    We reviewed the outcome of combined photodynamic therapy (PDT) and high dose rate brachytherapy (HDR) for patients with symptomatic obstruction from endobronchial non-small cell lung cancer. Methods: Nine patients who received combined PDT and HDR for endobronchial cancers were identified and their charts reviewed. The patients were eight males and one female aged 52-73 at diagnosis, initially presenting with various stages of disease: stage IA (N=1), stage IIA (N=1), stage III (N=6), and stage IV (N=1). Intervention was with HDR (500 cGy to 5 mm once weekly for 3 weeks) and PDT (2 mg/kg Photofrin, followed by 200 J/cm2 illumination 48 hours post infusion). Treatment group 1 (TG-1, N=7) received HDR first; Treatment group 2 (TG-2, N=2) received PDT first. Patients were followed by regular bronchoscopies. Results: Treatments were well tolerated, all patients completed therapy, and none were lost to follow-up. In TG-1, local tumor control was achieved in six of seven patients for: 3 months (until death), 15 months, 2+ years (until death), 2+ years (ongoing), and 5+ years (ongoing, N=2). In TG-2, local control was achieved in only one patient, for 84 days. Morbidities included: stenosis and/or other reversible benign local tissue reactions (N=8); photosensitivity reaction (N=2), and self-limited pleural effusion (N=2). Conclusions: Combined HDR/PDT treatment for endobronchial tumors is well tolerated and can achieve prolonged local control with acceptable morbidity when PDT follows HDR and when the spacing between treatments is one month or less. This treatment regimen should be studied in a larger patient population.

  9. Fear based Education or Curiosity based Education as an Example of Earthquake and Natural Disaster Education: Results of Statistical Study in Primary Schools in Istanbul-Turkey

    NASA Astrophysics Data System (ADS)

    Ozcep, T.; Ozcep, F.

    2012-04-01

    Natural disaster reduction focuses on the urgent need for prevention activities to reduce loss of life, damage to property, infrastructure and environment, and the social and economic disruption caused by natural hazards. One of the most important factors in reduction of the potential damage of earthquakes is trained manpower. To understanding the causes of earthquakes and other natural phenomena (landslides, avalanches, floods, volcanoes, etc.) is one of the pre-conditions to show a conscious behavior. The aim of the study is to analysis and to investigate, how earthquakes and other natural phenomena are perceived by the students and the possible consequences of this perception, and their effects of reducing earthquake damage. One of the crucial questions is that is our education system fear or curiosity based education system? Effects of the damages due to earthquakes have led to look like a fear subject. In fact, due to the results of the effects, the earthquakes are perceived scary phenomena. In the first stage of the project, the learning (or perception) levels of earthquakes and other natural disasters for the students of primary school are investigated with a survey. Aim of this survey study of earthquakes and other natural phenomena is that have the students fear based or curiosity based approaching to the earthquakes and other natural events. In the second stage of the project, the path obtained by the survey are evaluated with the statistical point of approach. A questionnaire associated with earthquakes and natural disasters are applied to primary school students (that total number of them is approximately 700 pupils) to measure the curiosity and/or fear levels. The questionnaire consists of 17 questions related to natural disasters. The questions are: "What is the Earthquake ?", "What is power behind earthquake?", "What is the mental response during the earthquake ?", "Did we take lesson from earthquake's results ?", "Are you afraid of earthquake

  10. Age related randomized comparison of sequentially applied high-dose versus intermediate dose cytosine arabinoside in combination with mitoxantrone (S-HAM) in the treatment of relapsed and refractory acute myeloid leukemia: study design and preliminary results.

    PubMed

    Hiddemann, W; Aul, C; Maschmeyer, G; Lathan, B; Köppler, H; Hoffmann, R; Grüneisen, T; Donhuijsen-Ant, R; Ludwig, W D; Balleisen, L

    1989-02-01

    In a prospective randomized trial, the pending question was addressed whether Cytosine arabinoside (Ara-C) should be applied at high or intermediate dose to patients with relapsed or refractory acute myeloid leukemia. Based upon the previously established regimen of the sequential application of Ara-C and Mitoxantrone (S-HAM) patients below 60 years of age were randomized to receive Ara-C at either 3.0 g/m2 vs 1.0 g/m2 per dose while older patients were randomly assigned to either 1.0 g/m2 or 0.5 g/m2 Ara-C. At the present early stage 51 patients have entered the study and 37 are currently evaluable for response and toxicity. Complete remissions were achieved in 14 of 28 patients below 60 years of age and in 3 of 8 older cases. Predominant side effects consisted of nausea and vomiting, diarrhea and stomatitis. Further recruitment of patients and longer follow-up is required for the assessment of the various treatment arms.

  11. Photospheric Magnetic Field Properties of Flaring vs. Flare-Quiet Active Regions II: A Magnetic Charge Topology Model and Statistical Results

    NASA Astrophysics Data System (ADS)

    Barnes, G.; Leka, K. D.; Longcope, D. W.

    2003-05-01

    The complexity of the coronal magnetic field extrapolated from a Magnetic Charge Topology (MCT) model, is examined for pre-event signatures unique to solar energetic phenomena. Although extensive use has been made of quantities measured at the photosphere, it is important to consider the magnetic field in the corona, where (for example) the hard X-ray signatures of energy release in solar flares are observed. By quantifying the inferred coronal magnetic topology we are no longer limited to considering solely the magnetic state of the photosphere. MCT is applied to temporally sampled photospheric magnetic data from the U. Hawai`i Imaging Vector Magnetograph, for 24 flare-event and flare-quiet epochs from seven active regions. We outline the methodology employed for automating the application of MCT to large data sets of complex active regions: partitioning the observed Bz at the photosphere, assigning a charge to each partition, and using this charge distribution to extrapolate the field in the corona. From the resulting field we compute the connectivity matrix ψ ij, the location of null points and the intersection of separatrix surfaces, i.e. separator field lines. Parameters are constructed to describe, for example, the magnetic connectivities, the magnetic flux in those connections, and the number of separators. Examining particular events results in no obvious trends in the magnitude and temporal evolution of the parameters just prior to flare events. Thus, we employ the same quantitative statistical approach outlined in Leka and Barnes [this session], i.e. applying discriminant analysis and Hotelling's T2-test, and ranking all four-variable discriminant functions as a proxy for a single all-variable discriminant function. We present those parameters which consistently appear in the best combinations, indicating that they may play an important role in defining a pre-event coronal state. This work was performed under Air Force Office of Scientific Research

  12. Evaluation of Rifampin's Transporter Inhibitory and CYP3A Inductive Effects on the Pharmacokinetics of Venetoclax, a BCL-2 Inhibitor: Results of a Single- and Multiple-Dose Study.

    PubMed

    Agarwal, Suresh K; Hu, Beibei; Chien, David; Wong, Shekman L; Salem, Ahmed Hamed

    2016-11-01

    Venetoclax is a selective, potent, first-in-class B-cell lymphoma-2 inhibitor that has demonstrated clinical efficacy in a variety of hematological malignancies. A single-dose and multiple-dose rifampin study was conducted to evaluate the effect of CYP3A induction and transporter inhibition on the pharmacokinetics of venetoclax. Subjects received a single dose of venetoclax 200 mg on day 1 of period 1 and days 1 and 14 of period 2, a single dose of rifampin 600 mg on day 1 of period 2, and rifampin 600 mg once daily on days 5 through 17 of period 2. Blood samples were collected up to 96 hours after each venetoclax dose on day 1 of period 1 and days 1 and 14 of period 2. Compared with venetoclax alone, coadministration with a single dose of rifampin increased venetoclax Cmax and AUC∞ by 106% (90%CI, 73%-145%) and 78% (90%CI, 50%-111%), respectively, whereas coadministration with multiple doses of rifampin decreased venetoclax Cmax and AUC∞ by 42% (90%CI, 31%-52%) and 71% (90%CI, 66%-76%), respectively. It was possible to isolate the net effect of chronic CYP3A induction from acute P-glycoprotein (P-gp) inhibition by comparing venetoclax exposures following coadministration with multiple doses of rifampin versus a single dose of rifampin, which showed that CYP3A induction decreased venetoclax Cmax and AUC by 72% and 84%, respectively. These results are consistent with venetoclax being a P-gp substrate and indicate that CYP3A plays a major role in venetoclax metabolism. Prescribers should consider agents with little or no CYP3A induction during treatment with venetoclax.

  13. Radiation dose in coronary angiography and intervention: initial results from the establishment of a multi-centre diagnostic reference level in Queensland public hospitals

    SciTech Connect

    Crowhurst, James A; Whitby, Mark; Thiele, David; Halligan, Toni; Westerink, Adam; Crown, Suzanne; Milne, Jillian

    2014-09-15

    Radiation dose to patients undergoing invasive coronary angiography (ICA) is relatively high. Guidelines suggest that a local benchmark or diagnostic reference level (DRL) be established for these procedures. This study sought to create a DRL for ICA procedures in Queensland public hospitals. Data were collected for all Cardiac Catheter Laboratories in Queensland public hospitals. Data were collected for diagnostic coronary angiography (CA) and single-vessel percutaneous intervention (PCI) procedures. Dose area product (P{sub KA}), skin surface entrance dose (K{sub AR}), fluoroscopy time (FT), and patient height and weight were collected for 3 months. The DRL was set from the 75th percentile of the P{sub KA.} 2590 patients were included in the CA group where the median FT was 3.5 min (inter-quartile range = 2.3–6.1). Median K{sub AR} = 581 mGy (374–876). Median P{sub KA} = 3908 uGym{sup 2} (2489–5865) DRL = 5865 uGym{sup 2}. 947 patients were included in the PCI group where median FT was 11.2 min (7.7–17.4). Median K{sub AR} = 1501 mGy (928–2224). Median P{sub KA} = 8736 uGym{sup 2} (5449–12,900) DRL = 12,900 uGym{sup 2}. This study established a benchmark for radiation dose for diagnostic and interventional coronary angiography in Queensland public facilities.

  14. 2,3,7,8-Tetrachlorodibenzo-P-Dioxin (Tcdd) Dose-Response Studies: Preliminary Literature Search Results and Request for Additional Studies

    EPA Science Inventory

    EPA invited the public to comment on the preliminary list of in vivo mammalian dose-response citations for 2,3,7,8 tetrachlorodibenzo-p-dioxin (TCDD). This list was compiled as a first step in the development of EPA’s response to the National Academy of Sciences comments (NAS, 2...

  15. Dose-mass inverse optimization for minimally moving thoracic lesions.

    PubMed

    Mihaylov, I B; Moros, E G

    2015-05-21

    In the past decade, several different radiotherapy treatment plan evaluation and optimization schemes have been proposed as viable approaches, aiming for dose escalation or an increase of healthy tissue sparing. In particular, it has been argued that dose-mass plan evaluation and treatment plan optimization might be viable alternatives to the standard of care, which is realized through dose-volume evaluation and optimization. The purpose of this investigation is to apply dose-mass optimization to a cohort of lung cancer patients and compare the achievable healthy tissue sparing to that one achievable through dose-volume optimization. Fourteen non-small cell lung cancer (NSCLC) patient plans were studied retrospectively. The range of tumor motion was less than 0.5 cm and motion management in the treatment planning process was not considered. For each case, dose-volume (DV)-based and dose-mass (DM)-based optimization was performed. Nine-field step-and-shoot IMRT was used, with all of the optimization parameters kept the same between DV and DM optimizations. Commonly used dosimetric indices (DIs) such as dose to 1% the spinal cord volume, dose to 50% of the esophageal volume, and doses to 20 and 30% of healthy lung volumes were used for cross-comparison. Similarly, mass-based indices (MIs), such as doses to 20 and 30% of healthy lung masses, 1% of spinal cord mass, and 33% of heart mass, were also tallied. Statistical equivalence tests were performed to quantify the findings for the entire patient cohort. Both DV and DM plans for each case were normalized such that 95% of the planning target volume received the prescribed dose. DM optimization resulted in more organs at risk (OAR) sparing than DV optimization. The average sparing of cord, heart, and esophagus was 23, 4, and 6%, respectively. For the majority of the DIs, DM optimization resulted in lower lung doses. On average, the doses to 20 and 30% of healthy lung were lower by approximately 3 and 4%, whereas lung

  16. Dose-mass inverse optimization for minimally moving thoracic lesions

    NASA Astrophysics Data System (ADS)

    Mihaylov, I. B.; Moros, E. G.

    2015-05-01

    In the past decade, several different radiotherapy treatment plan evaluation and optimization schemes have been proposed as viable approaches, aiming for dose escalation or an increase of healthy tissue sparing. In particular, it has been argued that dose-mass plan evaluation and treatment plan optimization might be viable alternatives to the standard of care, which is realized through dose-volume evaluation and optimization. The purpose of this investigation is to apply dose-mass optimization to a cohort of lung cancer patients and compare the achievable healthy tissue sparing to that one achievable through dose-volume optimization. Fourteen non-small cell lung cancer (NSCLC) patient plans were studied retrospectively. The range of tumor motion was less than 0.5 cm and motion management in the treatment planning process was not considered. For each case, dose-volume (DV)-based and dose-mass (DM)-based optimization was performed. Nine-field step-and-shoot IMRT was used, with all of the optimization parameters kept the same between DV and DM optimizations. Commonly used dosimetric indices (DIs) such as dose to 1% the spinal cord volume, dose to 50% of the esophageal volume, and doses to 20 and 30% of healthy lung volumes were used for cross-comparison. Similarly, mass-based indices (MIs), such as doses to 20 and 30% of healthy lung masses, 1% of spinal cord mass, and 33% of heart mass, were also tallied. Statistical equivalence tests were performed to quantify the findings for the entire patient cohort. Both DV and DM plans for each case were normalized such that 95% of the planning target volume received the prescribed dose. DM optimization resulted in more organs at risk (OAR) sparing than DV optimization. The average sparing of cord, heart, and esophagus was 23, 4, and 6%, respectively. For the majority of the DIs, DM optimization resulted in lower lung doses. On average, the doses to 20 and 30% of healthy lung were lower by approximately 3 and 4%, whereas lung

  17. Impact of Safety-Related Dose Reductions or Discontinuations on Sustained Virologic Response in HCV-Infected Patients: Results from the GUARD-C Cohort

    PubMed Central

    Foster, Graham R.; Coppola, Carmine; Derbala, Moutaz; Ferenci, Peter; Orlandini, Alessandra; Reddy, K. Rajender; Tallarico, Ludovico; Shiffman, Mitchell L.; Ahlers, Silke; Bakalos, Georgios; Hassanein, Tarek

    2016-01-01

    Background Despite the introduction of direct-acting antiviral agents for chronic hepatitis C virus (HCV) infection, peginterferon alfa/ribavirin remains relevant in many resource-constrained settings. The non-randomized GUARD-C cohort investigated baseline predictors of safety-related dose reductions or discontinuations (sr-RD) and their impact on sustained virologic response (SVR) in patients receiving peginterferon alfa/ribavirin in routine practice. Methods A total of 3181 HCV-mono-infected treatment-naive patients were assigned to 24 or 48 weeks of peginterferon alfa/ribavirin by their physician. Patients were categorized by time-to-first sr-RD (Week 4/12). Detailed analyses of the impact of sr-RD on SVR24 (HCV RNA <50 IU/mL) were conducted in 951 Caucasian, noncirrhotic genotype (G)1 patients assigned to peginterferon alfa-2a/ribavirin for 48 weeks. The probability of SVR24 was identified by a baseline scoring system (range: 0–9 points) on which scores of 5 to 9 and <5 represent high and low probability of SVR24, respectively. Results SVR24 rates were 46.1% (754/1634), 77.1% (279/362), 68.0% (514/756), and 51.3% (203/396), respectively, in G1, 2, 3, and 4 patients. Overall, 16.9% and 21.8% patients experienced ≥1 sr-RD for peginterferon alfa and ribavirin, respectively. Among Caucasian noncirrhotic G1 patients: female sex, lower body mass index, pre-existing cardiovascular/pulmonary disease, and low hematological indices were prognostic factors of sr-RD; SVR24 was lower in patients with ≥1 vs. no sr-RD by Week 4 (37.9% vs. 54.4%; P = 0.0046) and Week 12 (41.7% vs. 55.3%; P = 0.0016); sr-RD by Week 4/12 significantly reduced SVR24 in patients with scores <5 but not ≥5. Conclusions In conclusion, sr-RD to peginterferon alfa-2a/ribavirin significantly impacts on SVR24 rates in treatment-naive G1 noncirrhotic Caucasian patients. Baseline characteristics can help select patients with a high probability of SVR24 and a low probability of sr-RD with

  18. Explorations in statistics: statistical facets of reproducibility.

    PubMed

    Curran-Everett, Douglas

    2016-06-01

    Learning about statistics is a lot like learning about science: the learning is more meaningful if you can actively explore. This eleventh installment of Explorations in Statistics explores statistical facets of reproducibility. If we obtain an experimental result that is scientifically meaningful and statistically unusual, we would like to know that our result reflects a general biological phenomenon that another researcher could reproduce if (s)he repeated our experiment. But more often than not, we may learn this researcher cannot replicate our result. The National Institutes of Health and the Federation of American Societies for Experimental Biology have created training modules and outlined strategies to help improve the reproducibility of research. These particular approaches are necessary, but they are not sufficient. The principles of hypothesis testing and estimation are inherent to the notion of reproducibility in science. If we want to improve the reproducibility of our research, then we need to rethink how we apply fundamental concepts of statistics to our science.

  19. Breast cancer risk from low-dose exposures to ionizing radiation: results of parallel analysis of three exposed populations of women

    SciTech Connect

    Land, C.E.; Boice, J.D. Jr.; Shore, R.E.; Norman, J.E.; Tokunaga, M.

    1980-08-01

    Breast cancer incidence data were analyzed from three populations of women exposed to ionizing radiation: survivors of the Hiroshima and Nagasaki atomic bombs, patients in Massachusetts tuberculosis sanitoria who were exposed to multiple chest fluoroscopies, and patients treated by X-rays for acute postpartum mastitis in Rochester, New York. Parallel analyses by radiation dose, age at exposure, and time after exposure suggested that risk of radiation-induced cancer increased approximately linearly with increasing dose and was heavily dependent on age at exposure; however, the risk was otherwise remarkably similar among the three populations, at least for ages 10 to 40 years at exposure, and followed the same temporal pattern of occurrence as did breast cancer incidence in nonexposed women of similar ages.

  20. Low-dose benznidazole treatment results in parasite clearance and attenuates heart inflammatory reaction in an experimental model of infection with a highly virulent Trypanosoma cruzi strain

    PubMed Central

    Cevey, Ágata Carolina; Mirkin, Gerardo Ariel; Penas, Federico Nicolás; Goren, Nora Beatriz

    2015-01-01

    Chagas disease, caused by Trypanosoma cruzi, is the main cause of dilated cardiomyopathy in the Americas. Antiparasitic treatment mostly relies on benznidazole (Bzl) due to Nifurtimox shortage or unavailability. Both induce adverse drug effects (ADE) of varied severity in many patients, leading to treatment discontinuation or abandonment. Since dosage may influence ADE, we aimed to assess Bzl efficacy in terms of parasiticidal and anti-inflammatory activity, using doses lower than those previously reported. BALB/c mice infected with the T. cruzi RA strain were treated with different doses of Bzl. Parasitaemia, mortality and weight change were assessed. Parasite load, tissue infiltrates and inflammatory mediators were studied in the heart. Serum creatine kinase (CK) activity was determined as a marker of heart damage. The infection-independent anti-inflammatory properties of Bzl were studied in an in vitro model of LPS-treated cardiomyocyte culture. Treatment with 25 mg/kg/day Bzl turned negative the parasitological parameters, induced a significant decrease in IL-1β, IL-6 and NOS2 in the heart and CK activity in serum, to normal levels. No mortality was observed in infected treated mice. Primary cultured cardiomyocytes treated with Bzl showed that inflammatory mediators were reduced via inhibition of the NF-κB pathway. A Bzl dose lower than that previously reported for treatment of experimental Chagas disease exerts adequate antiparasitic and anti-inflammatory effects leading to parasite clearance and tissue healing. This may be relevant to reassess the dose currently used for the treatment of human Chagas disease, aiming to minimize ADE. PMID:26862474

  1. Analgesic Efficacy of a New Immediate-Release/Extended-Release Formulation of Ibuprofen: Results From Single- and Multiple-Dose Postsurgical Dental Pain Studies.

    PubMed

    Christensen, Steven; Paluch, Ed; Jayawardena, Shyamalie; Daniels, Stephen; Meeves, Suzanne

    2016-08-22

    Analgesic effects of ibuprofen immediate-release/extended-release (IR/ER) 600-mg tablets were evaluated in 2 randomized, double-blind, placebo-controlled dental pain studies. Patients 16-40 years old with moderate-severe pain following third-molar extraction received single-dose ibuprofen 600 mg IR/ER (formulation A or B), naproxen sodium 220 mg, or placebo (2:2:2:1; study 1) or 4 doses of ibuprofen 600 mg IR/ER (formulation A) or placebo (1:1; study 2). In study 1 (n = 196), mean (standard deviation [SD]) time-weighted sum of pain intensity difference scores for placebo, ibuprofen IR/ER A, ibuprofen IR/ER B, and naproxen, respectively, were 0.05 (9.2), 16.87 (9.4), 17.34 (10.5), and 12.66 (10.0) over 0-12 hours and -0.03 (4.1), 6.57 (4.4), 7.14 (5.2), and 5.14 (5.0) over 8-12 hours (all P < .001 vs placebo). In study 2 (n = 106), mean (SD) time-weighted sum of pain relief and pain intensity difference scores were 18.2 (20.0) versus 41.5 (21.0) at 0-12 hours and 10.3 (12.0) versus 18.4 (12.1) at 8-12 hours for placebo versus ibuprofen IR/ER, respectively (P < .001 for both); efficacy was sustained over each of the four 12-hour dosing intervals with ibuprofen. Gastrointestinal adverse events predominated with placebo both after study medication administration and after rescue medication use, if applicable. Ibuprofen 600 mg IR/ER provided safe and effective analgesia after single and multiple doses.

  2. Planck intermediate results. VII. Statistical properties of infrared and radio extragalactic sources from the Planck Early Release Compact Source Catalogue at frequencies between 100 and 857 GHz

    NASA Astrophysics Data System (ADS)

    Planck Collaboration; Ade, P. A. R.; Aghanim, N.; Argüeso, F.; Arnaud, M.; Ashdown, M.; Atrio-Barandela, F.; Aumont, J.; Baccigalupi, C.; Balbi, A.; Banday, A. J.; Barreiro, R. B.; Battaner, E.; Benabed, K.; Benoît, A.; Bernard, J.-P.; Bersanelli, M.; Bethermin, M.; Bhatia, R.; Bonaldi, A.; Bond, J. R.; Borrill, J.; Bouchet, F. R.; Burigana, C.; Cabella, P.; Cardoso, J.-F.; Catalano, A.; Cayón, L.; Chamballu, A.; Chary, R.-R.; Chen, X.; Chiang, L.-Y.; Christensen, P. R.; Clements, D. L.; Colafrancesco, S.; Colombi, S.; Colombo, L. P. L.; Coulais, A.; Crill, B. P.; Cuttaia, F.; Danese, L.; Davis, R. J.; de Bernardis, P.; de Gasperis, G.; de Zotti, G.; Delabrouille, J.; Dickinson, C.; Diego, J. M.; Dole, H.; Donzelli, S.; Doré, O.; Dörl, U.; Douspis, M.; Dupac, X.; Efstathiou, G.; Enßlin, T. A.; Eriksen, H. K.; Finelli, F.; Forni, O.; Fosalba, P.; Frailis, M.; Franceschi, E.; Galeotta, S.; Ganga, K.; Giard, M.; Giardino, G.; Giraud-Héraud, Y.; González-Nuevo, J.; Górski, K. M.; Gregorio, A.; Gruppuso, A.; Hansen, F. K.; Harrison, D.; Henrot-Versillé, S.; Hernández-Monteagudo, C.; Herranz, D.; Hildebrandt, S. R.; Hivon, E.; Hobson, M.; Holmes, W. A.; Jaffe, T. R.; Jaffe, A. H.; Jagemann, T.; Jones, W. C.; Juvela, M.; Keihänen, E.; Kisner, T. S.; Kneissl, R.; Knoche, J.; Knox, L.; Kunz, M.; Kurinsky, N.; Kurki-Suonio, H.; Lagache, G.; Lähteenmäki, A.; Lamarre, J.-M.; Lasenby, A.; Lawrence, C. R.; Leonardi, R.; Lilje, P. B.; López-Caniego, M.; Macías-Pérez, J. F.; Maino, D.; Mandolesi, N.; Maris, M.; Marshall, D. J.; Martínez-González, E.; Masi, S.; Massardi, M.; Matarrese, S.; Mazzotta, P.; Melchiorri, A.; Mendes, L.; Mennella, A.; Mitra, S.; Miville-Deschènes, M.-A.; Moneti, A.; Montier, L.; Morgante, G.; Mortlock, D.; Munshi, D.; Murphy, J. A.; Naselsky, P.; Nati, F.; Natoli, P.; Nørgaard-Nielsen, H. U.; Noviello, F.; Novikov, D.; Novikov, I.; Osborne, S.; Pajot, F.; Paladini, R.; Paoletti, D.; Partridge, B.; Pasian, F.; Patanchon, G.; Perdereau, O.; Perotto, L.; Perrotta, F.; Piacentini, F.; Piat, M.; Pierpaoli, E.; Plaszczynski, S.; Pointecouteau, E.; Polenta, G.; Ponthieu, N.; Popa, L.; Poutanen, T.; Pratt, G. W.; Prunet, S.; Puget, J.-L.; Rachen, J. P.; Reach, W. T.; Rebolo, R.; Reinecke, M.; Renault, C.; Ricciardi, S.; Riller, T.; Ristorcelli, I.; Rocha, G.; Rosset, C.; Rowan-Robinson, M.; Rubiño-Martín, J. A.; Rusholme, B.; Sajina, A.; Sandri, M.; Savini, G.; Scott, D.; Smoot, G. F.; Starck, J.-L.; Sudiwala, R.; Suur-Uski, A.-S.; Sygnet, J.-F.; Tauber, J. A.; Terenzi, L.; Toffolatti, L.; Tomasi, M.; Tristram, M.; Tucci, M.; Türler, M.; Valenziano, L.; Van Tent, B.; Vielva, P.; Villa, F.; Vittorio, N.; Wade, L. A.; Wandelt, B. D.; White, M.; Yvon, D.; Zacchei, A.; Zonca, A.

    2013-02-01

    We make use of the Planck all-sky survey to derive number counts and spectral indices of extragalactic sources - infrared and radio sources - from the Planck Early Release Compact Source Catalogue (ERCSC) at 100 to 857 GHz (3 mm to 350 μm). Three zones (deep, medium and shallow) of approximately homogeneous coverage are used to permit a clean and controlled correction for incompleteness, which was explicitly not done for the ERCSC, as it was aimed at providing lists of sources to be followed up. Our sample, prior to the 80% completeness cut, contains between 217 sources at 100 GHz and 1058 sources at 857 GHz over about 12 800 to 16 550 deg2 (31 to 40% of the sky). After the 80% completeness cut, between 122 and 452 and sources remain, with flux densities above 0.3 and 1.9 Jy at 100 and 857 GHz. The sample so defined can be used for statistical analysis. Using the multi-frequency coverage of the Planck High Frequency Instrument, all the sources have been classified as either dust-dominated (infrared galaxies) or synchrotron-dominated (radio galaxies) on the basis of their spectral energy distributions (SED). Our sample is thus complete, flux-limited and color-selected to differentiate between the two populations. We find an approximately equal number of synchrotron and dusty sources between 217 and 353 GHz; at 353 GHz or higher (or 217 GHz and lower) frequencies, the number is dominated by dusty (synchrotron) sources, as expected. For most of the sources, the spectral indices are also derived. We provide for the first time counts of bright sources from 353 to 857 GHz and the contributions from dusty and synchrotron sources at all HFI frequencies in the key spectral range where these spectra are crossing. The observed counts are in the Euclidean regime. The number counts are compared to previously published data (from earlier Planck results, Herschel, BLAST, SCUBA, LABOCA, SPT, and ACT) and models taking into account both radio or infrared galaxies, and covering a

  3. Statistical Diversions

    ERIC Educational Resources Information Center

    Petocz, Peter; Sowey, Eric

    2008-01-01

    In this article, the authors focus on hypothesis testing--that peculiarly statistical way of deciding things. Statistical methods for testing hypotheses were developed in the 1920s and 1930s by some of the most famous statisticians, in particular Ronald Fisher, Jerzy Neyman and Egon Pearson, who laid the foundations of almost all modern methods of…

  4. Double blind study on efficacy and safety of single doses of ivermectin and diethylcarbamazine for treatment of Polynesian Wuchereria bancrofti carriers. Results at six months.

    PubMed

    Cartel, J L; Spiegel, A; Nguyen, L; Genelle, B; Roux, J F

    1991-03-01

    In 1989, a double-blind trial was implemented in Tahiti to compare both efficacy and tolerability of single doses of ivermectin and diethylcarbamazine (DEC) for treatment of Wuchereria bancrofti carriers. Of 58 carriers, in whom microfilarial (mf) density was greater than or equal to 100 mf/ml, 23, 24 and 11 were randomly allocated to treatment with respectively ivermectin 100 mcg/kg, DEC 3 and DEC 6 mg/kg. One week after treatment, clearance of microfilaremia was complete in 22 of the 23 carriers treated with ivermectin and in one only of the 35 treated with DEC. Adjusted geometric mean for mf densities was significantly lower (p less than 0.001) in carriers treated with ivermectin than in those treated with DEC at one, but neither at 3 (p = 0.26) nor at 6 months (p = 0.63). At 3 and 6 months, mf levels were 14 and 28%, 21.6 and 19.4%, and 10.2 and 8.4% of pretreatment mf levels in carriers treated respectively with ivermectin 100 mcg/kg, DEC 3 and DEC 6 mg/kg. Side effects were experienced by 51 carriers (88%) of whom only 8 (14%) suffered a grade 3 reaction. Onset and intensity of side effects were significantly associated (p less than 0.01) with both pretreatment mf densities and peripheral blood parasite clearance. Efficacy of ivermectin single dose was superior to that of DEC single dose in terms of immediate mf clearance but not in terms of sustained mf decrease at 6 months.

  5. Low-dose radiation exposure and carcinogenesis.

    PubMed

    Suzuki, Keiji; Yamashita, Shunichi

    2012-07-01

    Absorption of energy from ionizing radiation by the genetic material in the cell leads to damage to DNA, which in turn leads to cell death, chromosome aberrations and gene mutations. While early or deterministic effects result from organ and tissue damage caused by cell killing, latter two are considered to be involved in the initial events that lead to the development of cancer. Epidemiological studies have demonstrated the dose-response relationships for cancer induction and quantitative evaluations of cancer risk following exposure to moderate to high doses of low-linear energy transfer radiation. A linear, no-threshold model has been applied to assessment of the risks resulting from exposure to moderate and high doses of ionizing radiation; however, a statistically significant increase has hardly been described for radiation doses below 100 mSv. This review summarizes our current knowledge of the physical and biological features of low-dose radiation and discusses the possibilities of induction of cancer by low-dose radiation.

  6. Quick Statistics

    MedlinePlus

    ... population, or about 25 million Americans, has experienced tinnitus lasting at least five minutes in the past ... by NIDCD Epidemiology and Statistics Program staff: (1) tinnitus prevalence was obtained from the 2008 National Health ...

  7. Estimation of the fluence of high-energy electron bursts produced by thunderclouds and the resulting radiation doses received in aircraft

    NASA Astrophysics Data System (ADS)

    Dwyer, J. R.; Smith, D. M.; Uman, M. A.; Saleh, Z.; Grefenstette, B.; Hazelton, B.; Rassoul, H. K.

    2010-05-01

    Using recent X-ray and gamma-ray observations of terrestrial gamma-ray flashes (TGFs) from spacecraft and of natural and rocket-triggered lightning from the ground, along with detailed models of energetic particle transport, we calculate the fluence (integrated flux) of high-energy (million electronvolt) electrons, X rays, and gamma rays likely to be produced inside or near thunderclouds in high electric field regions. We find that the X-ray/gamma-ray fluence predicted for lightning leaders propagating inside thunderclouds agrees well with the fluence calculated for TGFs, suggesting a possible link between these two phenomena. Furthermore, based on reasonable meteorological assumptions about the magnitude and extent of the electric fields, we estimate that the fluence of high-energy runaway electrons can reach biologically significant levels at aircraft altitudes. If an aircraft happened to be in or near the high-field region when either a lightning discharge or a TGF event is occurring, then the radiation dose received by passengers and crew members inside that aircraft could potentially approach 0.1 Sv (10 rem) in less than 1 ms. Considering that commercial aircraft are struck by lightning, on average, one to two times per year, the risk of such large radiation doses should be investigated further.

  8. Intensive dose ifosfamide, carboplatin, and etoposide followed by autologous stem cell rescue: results of a phase I/II study in breast cancer patients.

    PubMed

    Fields, K K; Perkins, J P; Hiemenz, J W; Zorsky, P E; Janssen, W E; Kronish, L E; Machak, M C; Elfenbein, G J

    1993-01-01

    We have recently treated 66 women with breast cancer with escalating doses of ifosfamide, carboplatin, and etoposide (ICE) followed by autologous stem cell rescue (ASCR). Patients received ifosfamide (6000-24,000 mg m-2), carboplatin (1200-2100 mg m-2), and etoposide (1800-3000 mg m-2) divided over 6 days with ASCR 48 h after completion of chemotherapy. Our patient population consisted of seven patients with stage II disease with eight or more positive nodes being treated in the adjuvant setting, 16 patients with a history of stage III or inflammatory breast cancer, and 43 patients with stage IV disease. Six patients were not evaluable for response due to early death from infection (three patients) and incomplete restaging (three patients). The overall response rate in patients with measurable metastatic disease was 50%. Of those patients with stage II disease, 85% remain alive and progression-free with a median follow-up of greater than one year. The two most frequent toxicities encountered were reversible elevations of liver function tests and mucositis/enteritis. The dose-limiting toxicities were central nervous system toxicity and nephrotoxicity.

  9. RESRAD-BUILD: A computer model for analyzing the radiological doses resulting from the remediation and occupancy of buildings contaminated with radioactive material

    SciTech Connect

    Yu, C.; LePoire, D.J.; Jones, L.G.

    1994-11-01

    The RESRAD-BUILD computer code is a pathway analysis model designed to evaluate the potential radiological dose incurred by an individual who works or lives in a building contaminated with radioactive material. The transport of radioactive material inside the building from one compartment to another is calculated with an indoor air quality model. The air quality model considers the transport of radioactive dust particulates and radon progeny due to air exchange, deposition and resuspension, and radioactive decay and ingrowth. A single run of the RESRAD-BUILD code can model a building with up to: three compartments, 10 distinct source geometries, and 10 receptor locations. A shielding material can be specified between each source-receptor pair for external gamma dose calculations. Six exposure pathways are considered in the RESRAD-BUILD code: (1) external exposure directly from the source; (2) external exposure to materials deposited on the floor; (3) external exposure due to air submersion; (4) inhalation of airborne radioactive particulates; (5) inhalation of aerosol indoor radon progeny; and (6) inadvertent ingestion of radioactive material, either directly from the sources or from materials deposited on the surfaces of the building compartments. 4 refs., 23 figs., 4 tabs.

  10. Stupid statistics!

    PubMed

    Tellinghuisen, Joel

    2008-01-01

    The method of least squares is probably the most powerful data analysis tool available to scientists. Toward a fuller appreciation of that power, this work begins with an elementary review of statistics fundamentals, and then progressively increases in sophistication as the coverage is extended to the theory and practice of linear and nonlinear least squares. The results are illustrated in application to data analysis problems important in the life sciences. The review of fundamentals includes the role of sampling and its connection to probability distributions, the Central Limit Theorem, and the importance of finite variance. Linear least squares are presented using matrix notation, and the significance of the key probability distributions-Gaussian, chi-square, and t-is illustrated with Monte Carlo calculations. The meaning of correlation is discussed, including its role in the propagation of error. When the data themselves are correlated, special methods are needed for the fitting, as they are also when fitting with constraints. Nonlinear fitting gives rise to nonnormal parameter distributions, but the 10% Rule of Thumb suggests that such problems will be insignificant when the parameter is sufficiently well determined. Illustrations include calibration with linear and nonlinear response functions, the dangers inherent in fitting inverted data (e.g., Lineweaver-Burk equation), an analysis of the reliability of the van't Hoff analysis, the problem of correlated data in the Guggenheim method, and the optimization of isothermal titration calorimetry procedures using the variance-covariance matrix for experiment design. The work concludes with illustrations on assessing and presenting results.

  11. Using fludarabine to reduce exposure to alkylating agents in children with sickle cell disease receiving busulfan, cyclophosphamide, and antithymocyte globulin transplant conditioning: results of a dose de-escalation trial.

    PubMed

    Horan, John T; Haight, Ann; Dioguardi, Jacqueline Lagerlof; Brown, Clark; Grizzle, Audrey; Shelman, Chiani; Kanter, Julie; Hale, Greg; Nieder, Michael; Benton, Melody; Kasow, Kimberly A; Abraham, Allistair; Chiang, Kuang-Yueh

    2015-05-01

    High-dose busulfan, cyclophosphamide, and antithymocyte globulin (BU-CY-ATG) is the most commonly used conditioning regimen in HLA-matched related hematopoietic cell transplantation for children with sickle cell disease. Disease-free survival with this regimen is now approximately 95%; however, it produces significant morbidity. We hypothesized we could create a less toxic regimen by adding fludarabine (FLU) to BU-CY-ATG and reduce the dosages of busulfan and cyclophosphamide. We conducted a multicenter dose de-escalation trial with the objective of decreasing the doses of busulfan and cyclophosphamide by 50% and 55%, respectively. Using day +28 donor-predominant chimerism as a surrogate endpoint for sustained engraftment, we completed the first 2 of 4 planned levels, enrolling 6 patients at each and reducing the total dose of cyclophosphamide from 200 mg/kg to 90 mg/kg. On the third level, which involved a reduction of i.v. busulfan from 12.8 mg/kg to 9.6 mg/kg, the first 2 patients had host-predominant T cell chimerism, which triggered trial-stopping rules. All 14 patients survive disease-free. No patients suffered severe regimen-related toxicity. Our results suggest BU-FLU-CY-ATG using lower dose CY could be a less toxic yet effective regimen. Further evaluation of this regimen in a full-scale clinical trial is warranted.

  12. [Results of measuring neutrons doses and energy spectra inside Russian segment of the International Space Station in experiment "Matryoshka-R" using bubble detectors during the ISS-24-34 missions].

    PubMed

    Khulapko, S V; Liagushin, V I; Arkhangel'skiĭ, V V; Shurshakov, V A; Smith, M; Ing, H; Machrafi, R; Nikolaev, I V

    2014-01-01

    The paper presents the results of calculating the equivalent dose from and energy spectrum of neutrons in the right-hand crewquarters in module Zvezda of the ISS Russian segment. Dose measurements were made in the period between July, 2010 and November, 2012 (ISS Missions 24-34) by research equipment including the bubble dosimeter as part of experiment "Matryoshka-R". Neutron energy spectra in the crewquarters are in good agreement with what has been calculated for the ISS USOS and, earlier, for the MIR orbital station. The neutron dose rate has been found to amount to 196 +/- 23 microSv/d on Zvezda panel-443 (crewquarters) and 179 +/- 16 microSv/d on the "Shielding shutter" surface in the crewquarters.

  13. Postoperative irradiation of carcinoma of the head of the pancreas area: Short-time tolerance and results to precision high-dose technique in 18 patients

    SciTech Connect

    Nguyen, T.D.; Bugat, R.; Combes, P.F.

    1982-07-01

    During the period from January 1977-August 1979, 18 patients with biopsy-proven pancreas duct or ampullary adenocarcinoma with no distant or liver metastases underwent external beam radiation therapy following laparotomy. With the use of a 25 MEV photon beam and a four field ''box'' technique, the dose delivered to the target volume identified with radio-opaque clips at laparotomy was 6000 rad in six weeks, while largely sparing the spinal cord, kidney, liver and gut. All patients subjected to low fat, gluten free diet completed treatment as planned without any acute reaction. Three patients developed delayed pancreatic insufficiency. According to actuarial survival analysis and low morbidity such an approach may lead to increased survival in patients with pancreatic cancer.

  14. Data required for testicular dose calculation during radiotherapy of seminoma

    SciTech Connect

    Mazonakis, Michalis; Kokona, Georgiana; Varveris, Haralambos; Damilakis, John; Gourtsoyiannis, Nicholas

    2006-07-15

    The purpose of this study was to provide the required data for the direct calculation of testicular dose resulting from radiotherapy in patients with seminoma. Paraortic (PA) treatment fields and dog-leg (DL) portals including paraortic and ipsilateral pelvic nodes were simulated on a male anthropomorphic phantom equipped with an artificial testicle. Anterior and posterior irradiations were performed for five different PA and DL field dimensions. Dose measurements were carried out using a calibrated ionization chamber. The dependence of testicular dose upon the distance separating the testicle from the treatment volume and upon the tissue thickness at the entrance point of the beam was investigated. A clamshell lead shield was used to reduce testicular dose. The scattered dose to testicle was measured in nine patients using thermoluminescent dosimeters. Phantom and patient exposures were generated with a 6 MV x-ray beam. Linear and nonlinear regression analysis was employed to obtain formulas describing the relation between the radiation dose to an unshielded and/or shielded testicle with the field size and the distance from the inferior field edge. Correction factors showing the variation of testicular dose with the patient thickness along beam axis were found. Bland-Altman statistical analysis showed that testicular dose obtained by the proposed calculation method may differ from the measured dose value by less than 25%. The current study presents a method providing reasonable estimations of testicular dose for individual patients undergoing PA or DL radiotherapy.

  15. Can point doses predict volumetric dose to rectum and bladder: a CT-based planning study in high dose rate intracavitary brachytherapy of cervical carcinoma?

    PubMed Central

    Patil, V M; Patel, F D; Chakraborty, S; Oinam, A S; Sharma, S C

    2011-01-01

    Objective Point doses, as defined by the International Commission on Radiation Units and Measurements (ICRU), are classically used to evaluate doses to the rectum and bladder in high dose rate intracavitary brachytherapy (HDR-ICBT) in cervical cancer. Several studies have shown good correlation between the ICRU point doses and the volumetric doses to these organs. In the present study we attempted to evaluate whether this correlation could be used to predict the volumetric doses to these organs. Methods A total of 150 HDR-ICBT insertions performed between December 2006 and June 2008 were randomly divided into two groups. Group A (n=50) was used to derive the correlation between the point and volumetric doses using regression analysis. This was tested in Group B (n=100) insertions using studentised residuals and Bland–Altman plots. Results Significant correlations were obtained for all volumetric doses and ICRU point doses for rectum and bladder in Group A insertions. The strongest correlation was found for the dose to 2 cc volumes (D2cc). The correlation coefficients for bladder and rectal D2cc versus the respective ICRU point doses were 0.82 and 0.77, respectively (p<0.001). Statistical validation of equations generated in Group B showed mean studentised residual values of 0.001 and 0.000 for the bladder and rectum. However, Bland–Altman analysis showed that the error range for these equations for bladder and rectum were ±64% and ±41% of the point A dose, respectively, which makes these equations unreliable for clinical use. Conclusion Volumetric imaging is essential to obtain proper information about volumetric doses. PMID:21511749

  16. Inhibition of ovulation by administration of estetrol in combination with drospirenone or levonorgestrel: Results of a phase II dose-finding pilot study

    PubMed Central

    Duijkers, Ingrid J.M.; Klipping, Christine; Zimmerman, Yvette; Appels, Nicole; Jost, Maud; Maillard, Catherine; Mawet, Marie; Foidart, Jean-Michel; Coelingh Bennink, Herjan J. T.

    2015-01-01

    Abstract Objectives The aim of the study was to evaluate the efficacy of different dosages of estetrol (E4) combined with one of two progestins in suppressing the pituitary–ovarian axis and ovulation in healthy premenopausal women. Methods This was an open, parallel, phase II, dose-finding, pilot study performed in healthy women aged 18 to 35 years with a documented ovulatory cycle before treatment. For three consecutive cycles in a 24/4-day regimen, participants received 5 mg or 10 mg E4/3 mg drospirenone (DRSP); 5 mg, 10 mg or 20 mg E4/150 μg levonorgestrel; or 20 μg ethinylestradiol (EE)/3 mg DRSP as comparator. Pituitary–ovarian axis activity and the occurrence of ovulation were evaluated by monitoring follicular size, serum levels of follicle-stimulating hormone, luteinising hormone, estradiol and progesterone during treatment cycles 1 and 3. Endometrial thickness was evaluated throughout the trial, and the return of ovulation was evaluated after the last intake of medication. Results A total of 109 women were included in the trial. No ovulation occurred in any treatment group. Ovarian activity inhibition seemed proportional to the E4 dosage: the highest suppression was observed in the 20 mg E4 group and was very similar to that observed with EE/DRSP. Endometrial thickness was suppressed to the same extent in all groups. Post-treatment ovulation occurred in all participants between 17 and 21 days after the last active treatment. The study combinations were well tolerated and safe. Conclusions Combined with a progestin, E4 adequately suppresses ovarian activity, particularly when given at a dosage above 10 mg/day. Chinese Abstract 摘要 目的 这项研究的目的是评估不同剂量的雌四醇联合两种孕激素中的其中一种对垂体-卵巢轴以及健康的绝经前妇女的排卵方面的抑制疗效。 方法 这是一个在18到35岁的健康女性中进行的开放的、平行的,关于II期药物剂量探索的初步研究,这些女

  17. Seasonal precipitation forecasts for selected regions in West Africa using circulation type classifications in combination with further statistical approaches - Conceptual framework and first results

    NASA Astrophysics Data System (ADS)

    Bliefernicht, Jan; Laux, Patrik; Waongo, Moussa; Kunstmann, Harald

    2015-04-01

    Providing valuable forecasts of the seasonal precipitation amount for the upcoming rainy season is one of the big challenges for the national weather services in West Africa. Every year a harmonized forecast of the seasonal precipitation amount for the West African region is issued by the national weather services within the PRESAO framework. The PREASO forecast is based on various statistical approaches ranging from a simple subjective analog method based on the experiences of a meteorological expert to objective regression-based approaches by using various sources of input information such as predicted monsoon winds or observed sea surface temperature anomalies close to the West African coastline. The objective of this study is to perform an evaluation of these techniques for selected West African regions and to introduce classification techniques in the current operational practices and to combine these approaches with further techniques for an additional refinement of the forecasting procedure. We use a fuzzy-rule based technique for a classification of (sub-) monthly large-scale atmospheric and oceanic patterns which are combined to further statistical approaches such as an analog method and a data depth approach for the prediction of the (sub-) seasonal precipitation amounts and additional precipitation indices. The study regions are located from the Edges of the Sahel region in the North of Burkina Faso to the coastline of Ghana. A novel precipitation archive based on daily observations provided by the meteorological services of Burkina Faso and Ghana is the basis for the predictands and is used as reference for model evaluation. The performance of the approach is evaluated over a long period (e.g. 50 years) using cross-validation techniques and sophisticated verification measures for an evaluation of a probability forecast. The precipitation forecast of the classification techniques are also compared to the techniques of the PREASAO community, the

  18. Treatment of rheumatoid arthritis (RA) in India-how and by whom: results from a speciality clinic-use of low-dose methotrexate (MTX) was inexplicably suboptimal.

    PubMed

    Malaviya, Anand N; Gogia, S B

    2016-09-01

    This study was conducted in order to study (a) seropositive RA patients for their prior caregivers, diagnosis makers, drugs and doses taken and (b) the disease status at the first visit and the last visit, from the standpoint of whether they received optimum or suboptimum DMARD treatment. Prospectively entered data were extracted from a rheumatology-specific electronic health record for demography, diagnostic delay, prior caregivers, diagnosis makers, intake of DMARDs and glucocorticoids and disease activity state at first presentation and at the last visit using structured query language. Among 316 patients, prior caregivers were orthopaedicians (73.4 %), alternative systems of medicine practitioners (62 %), internists (38 %), rheumatologists (35.8 %), general practitioners (17 %) and others (12 %). The diagnosis of RA was made by rheumatologists (55.6 %), orthopaedicians (21 %), internists (12.6 %), physiotherapists (3.5 %), homeopaths (2.8 %), general practitioner (2.1 %), neurologists (1.4 %) and Ayurvedic physicians (0.7 %). The mean and the median diagnostic delay among 142 patients where information was available were 18 and 8.5 months, respectively (SD +23.2). Thirty-two percent of the patients had early disease, 48 % established disease and 20 % late disease at presentation. Sixty-six percent of the patients had taken DMARDs-methotrexate (56 %), hydroxychloroquine (46.2 %), leflunomide (18.7 %) and sulfasalazine (20.6 %)-and often in combinations. Different preparations, doses and schedules of glucocorticoids were taken orally or parentally by 51 %. Only one (0.3 %) patient had taken biological DMARDs prior to visiting this clinic. High or moderate disease activity was present in 84 % at the first clinic visit that fell to 14 % at the last clinic visit. The majority of patients with RA were treated by orthopaedicians and practitioners of alternative systems of medicine with only a third by rheumatologists. In 80 % of patients, the

  19. Model-based Iterative Reconstruction: Effect on Patient Radiation Dose and Image Quality in Pediatric Body CT

    PubMed Central

    Dillman, Jonathan R.; Goodsitt, Mitchell M.; Christodoulou, Emmanuel G.; Keshavarzi, Nahid; Strouse, Peter J.

    2014-01-01

    Purpose To retrospectively compare image quality and radiation dose between a reduced-dose computed tomographic (CT) protocol that uses model-based iterative reconstruction (MBIR) and a standard-dose CT protocol that uses 30% adaptive statistical iterative reconstruction (ASIR) with filtered back projection. Materials and Methods Institutional review board approval was obtained. Clinical CT images of the chest, abdomen, and pelvis obtained with a reduced-dose protocol were identified. Images were reconstructed with two algorithms: MBIR and 100% ASIR. All subjects had undergone standard-dose CT within the prior year, and the images were reconstructed with 30% ASIR. Reduced- and standard-dose images were evaluated objectively and subjectively. Reduced-dose images were evaluated for lesion detectability. Spatial resolution was assessed in a phantom. Radiation dose was estimated by using volumetric CT dose index (CTDIvol) and calculated size-specific dose estimates (SSDE). A combination of descriptive statistics, analysis of variance, and t tests was used for statistical analysis. Results In the 25 patients who underwent the reduced-dose protocol, mean decrease in CTDIvol was 46% (range, 19%–65%) and mean decrease in SSDE was 44% (range, 19%–64%). Reduced-dose MBIR images had less noise (P > .004). Spatial resolution was superior for reduced-dose MBIR images. Reduced-dose MBIR images were equivalent to standard-dose images for lungs and soft tissues (P > .05) but were inferior for bones (P = .004). Reduced-dose 100% ASIR images were inferior for soft tissues (P < .002), lungs (P < .001), and bones (P < .001). By using the same reduced-dose acquisition, lesion detectability was better (38% [32 of 84 rated lesions]) or the same (62% [52 of 84 rated lesions]) with MBIR as compared with 100% ASIR. Conclusion CT performed with a reduced-dose protocol and MBIR is feasible in the pediatric population, and it maintains diagnostic quality. © RSNA, 2013 Online supplemental

  20. Statistical Inference: The Big Picture.

    PubMed

    Kass, Robert E

    2011-02-01

    Statistics has moved beyond the frequentist-Bayesian controversies of the past. Where does this leave our ability to interpret results? I suggest that a philosophy compatible with statistical practice, labelled here statistical pragmatism, serves as a foundation for inference. Statistical pragmatism is inclusive and emphasizes the assumptions that connect statistical models with observed data. I argue that introductory courses often mis-characterize the process of statistical inference and I propose an alternative "big picture" depiction.

  1. Monte Carlo Bayesian Inference on a Statistical Model of Sub-gridcolumn Moisture Variability Using High-resolution Cloud Observations . Part II; Sensitivity Tests and Results

    NASA Technical Reports Server (NTRS)

    da Silva, Arlindo M.; Norris, Peter M.

    2013-01-01

    Part I presented a Monte Carlo Bayesian method for constraining a complex statistical model of GCM sub-gridcolumn moisture variability using high-resolution MODIS cloud data, thereby permitting large-scale model parameter estimation and cloud data assimilation. This part performs some basic testing of this new approach, verifying that it does indeed significantly reduce mean and standard deviation biases with respect to the assimilated MODIS cloud optical depth, brightness temperature and cloud top pressure, and that it also improves the simulated rotational-Ramman scattering cloud optical centroid pressure (OCP) against independent (non-assimilated) retrievals from the OMI instrument. Of particular interest, the Monte Carlo method does show skill in the especially difficult case where the background state is clear but cloudy observations exist. In traditional linearized data assimilation methods, a subsaturated background cannot produce clouds via any infinitesimal equilibrium perturbation, but the Monte Carlo approach allows finite jumps into regions of non-zero cloud probability. In the example provided, the method is able to restore marine stratocumulus near the Californian coast where the background state has a clear swath. This paper also examines a number of algorithmic and physical sensitivities of the new method and provides guidance for its cost-effective implementation. One obvious difficulty for the method, and other cloud data assimilation methods as well, is the lack of information content in the cloud observables on cloud vertical structure, beyond cloud top pressure and optical thickness, thus necessitating strong dependence on the background vertical moisture structure. It is found that a simple flow-dependent correlation modification due to Riishojgaard (1998) provides some help in this respect, by better honoring inversion structures in the background state.

  2. Dose error analysis for a scanned proton beam delivery system

    NASA Astrophysics Data System (ADS)

    Coutrakon, G.; Wang, N.; Miller, D. W.; Yang, Y.

    2010-12-01

    All particle beam scanning systems are subject to dose delivery errors due to errors in position, energy and intensity of the delivered beam. In addition, finite scan speeds, beam spill non-uniformities, and delays in detector, detector electronics and magnet responses will all contribute errors in delivery. In this paper, we present dose errors for an 8 × 10 × 8 cm3 target of uniform water equivalent density with 8 cm spread out Bragg peak and a prescribed dose of 2 Gy. Lower doses are also analyzed and presented later in the paper. Beam energy errors and errors due to limitations of scanning system hardware have been included in the analysis. By using Gaussian shaped pencil beams derived from measurements in the research room of the James M Slater Proton Treatment and Research Center at Loma Linda, CA and executing treatment simulations multiple times, statistical dose errors have been calculated in each 2.5 mm cubic voxel in the target. These errors were calculated by delivering multiple treatments to the same volume and calculating the rms variation in delivered dose at each voxel in the target. The variations in dose were the result of random beam delivery errors such as proton energy, spot position and intensity fluctuations. The results show that with reasonable assumptions of random beam delivery errors, the spot scanning technique yielded an rms dose error in each voxel less than 2% or 3% of the 2 Gy prescribed dose. These calculated errors are within acceptable clinical limits for radiation therapy.

  3. Lengthening of Insect Development on Bt Zone Results in Adult Emergence Asynchrony: Does It Influence the Effectiveness of the High Dose/Refuge Zone Strategy?

    PubMed Central

    Gryspeirt, Aiko; Grégoire, Jean-Claude

    2012-01-01

    The “High Dose/Refuge” strategy (HD/R) is the currently recommended Insect Resistance Management strategy (IRM) to limit resistance development to Bacillus thuringiensis (Bt) plants. This strategy requires planting a “refuge zone” composed of non-Bt plants suitable for the target insect and in close proximity to a “Bt zone” expressing a high toxin concentration. One of the main assumptions is that enough susceptible adults mate with resistant insects. However, previous studies have suggested that the high toxin concentration produced by Bt plants induces slower insect development, creating an asynchrony in emergence between the refuge and the Bt zone and leading to assortative mating between adults inside each zone. Here, we develop a deterministic model to estimate the impact of toxin concentration, emergence asynchrony and refuge zone size on the effectiveness of the HD/R strategy. We conclude that emergence asynchrony only affects resistance when toxin concentration is high and resistance is recessive. Resistance develops more rapidly and survival of susceptible insects is higher at lower toxin concentration, but in such situations, resistance is insensitive to emergence asynchrony. PMID:23202319

  4. Nutrient intake and nutrient patterns and risk of lung cancer among heavy smokers: results from the COSMOS screening study with annual low-dose CT.

    PubMed

    Gnagnarella, Patrizia; Maisonneuve, Patrick; Bellomi, Massimo; Rampinelli, Cristiano; Bertolotti, Raffaella; Spaggiari, Lorenzo; Palli, Domenico; Veronesi, Giulia

    2013-06-01

    The role of nutrients in lung cancer aetiology remains controversial and has never been evaluated in the context of screening. Our aim was to investigate the role of single nutrients and nutrient patterns in the aetiology of lung cancer in heavy smokers. Asymptomatic heavy smokers (≥20 pack-years) were invited to undergo annual low-dose computed tomography. We assessed diet using a self-administered food frequency questionnaire and collected information on multivitamin supplement use. We performed principal component analysis identifying four nutrient patterns and used Cox proportional Hazards regression to assess the association between nutrients and nutrients patterns and lung cancer risk. During a mean follow-up of 5.7 years, 178 of 4,336 participants were diagnosed with lung cancer by screening. We found a significant risk reduction of lung cancer with increasing vegetable fat consumption (HR for highest vs. lowest quartile = 0.50, 95% CI = 0.31-0.80; P-trend = 0.02). Participants classified in the high "vitamins and fiber" pattern score had a significant risk reduction of lung cancer (HR = 0.57; 95% CI = 0.36-0.90, P-trend = 0.01). Among heavy smokers enrolled in a screening trial, high vegetable fat intake and adherence to the "vitamin and fiber" nutrient pattern were associated with reduced lung cancer incidence.

  5. Comparable Renal Function at 6 Months with Tacrolimus Combined with Fixed-Dose Sirolimus or MMF: Results of a Randomized Multicenter Trial in Renal Transplantation.

    PubMed

    Van Gurp, Eveline; Bustamante, Jesus; Franco, Antonio; Rostaing, Lionel; Becker, Thomas; Rondeau, Eric; Czajkowski, Zenon; Rydzewski, Andrzej; Alarcon, Antonio; Bachleda, Petr; Samlik, Jiri; Burmeister, Dirk; Pallardo, Luis; Moal, Marie-Christine; Rutkowski, Boleslaw; Wlodarczyk, Zbigniew

    2010-01-01

    In a multicenter trial, renal transplant recipients were randomized to tacrolimus with fixed-dose sirolimus (Tac/SRL, N = 318) or tacrolimus with MMF (Tac/MMF, N = 316). Targeted tacrolimus trough levels were lower in the Tac/SRL group after day 14. The primary endpoint was renal function at 6 months using creatinine clearance (Cockcroft-Gault) and was comparable at 66.4 mL/min (SE 1.4) with Tac/SRL and at 65.2mL/min (SE 1.3) with Tac/MMF (completers). Biopsy-confirmed acute rejection was 15.1% (Tac/SRL) and 12.3% (Tac/MMF). In both groups, graft survival was 93% and patient survival was 99.0%. Premature withdrawal due to an adverse event was twice as high in the Tac/SRL group, 15.1% versus 6.3%. Hypercholesterolemia incidence was higher with Tac/SRL (P < .05) while CMV, leukopenia, and diarrhea incidences were higher with Tac/MMF (P < .05). The incidence of any antidiabetic treatment for >30 consecutive days in previously nondiabetic patients was 17.8%, Tac/SRL, and 24.8%, Tac/MMF. Evaluation at 6 months showed comparable renal function using tacrolimus/sirolimus and tacrolimus/MMF regimens.

  6. Derived Reference Doses (RfDs) for the environmental degradates of the herbicides alachlor and acetochlor: results of an independent expert panel deliberation.

    PubMed

    Gadagbui, Bernard; Maier, Andrew; Dourson, Michael; Parker, Ann; Willis, Alison; Christopher, John P; Hicks, Lebelle; Ramasamy, Santhini; Roberts, Stephen M

    2010-01-01

    An independent peer expert panel was convened under the auspices of the Alliance for Risk Assessment (ARA) to review toxicology data and derive oral Reference Doses (RfDs) for four environmental degradates of the acetanilide herbicides, alachlor and acetochlor. The degradates included in this evaluation were (1) alachlor tertiary-ethanesulfonic acid (ESA), (2) alachlor tertiary-oxanilic acid (OXA), (3) acetochlor ESA, and (4) acetochlor OXA. Each degradate was judged to have sufficient data for developing low to medium confidence RfD, with use of an additional uncertainty factor (UF) to cover data gaps. Body weight decreases were identified as the most sensitive treatment-related adverse effect for RfD development. A composite UF of 1000 (10 for human variability in sensitivity, 10 for interspecies differences in sensitivity, and 10 for subchronic to chronic and database deficiency combined; i.e., 10(A)x10(H)x10(S&D)) for each degradate was considered reasonable, while noting that an argument could be made for an UF of 3000 (10(A)x10(H)x30(S&D)). Based on the available data, an oral RfD of 0.2 mg/kg-day is recommended for both acetochlor ESA and acetochlor OXA and an oral RfD of 0.8 mg/kg-day is recommended for both alachlor ESA and alachlor OXA.

  7. Statistics Revelations

    ERIC Educational Resources Information Center

    Chicot, Katie; Holmes, Hilary

    2012-01-01

    The use, and misuse, of statistics is commonplace, yet in the printed format data representations can be either over simplified, supposedly for impact, or so complex as to lead to boredom, supposedly for completeness and accuracy. In this article the link to the video clip shows how dynamic visual representations can enliven and enhance the…

  8. TEAMS: Toxicity- and Efficacy-based Dose Insertion Design with Adaptive Model Selection for Phase I/II Dose-Escalation Trials in Oncology

    PubMed Central

    Guo, Wentian; Ni, Yang; Ji, Yuan

    2015-01-01

    Summary In many oncology clinical trials it is necessary to insert new candidate doses when the prespecified doses are poorly elicited. Formal statistical designs with dose insertion are lacking. We propose a dose insertion design for phase I/II clinical trials in oncology based on both efficacy and toxicity outcomes. We also implement Bayesian model selection during the course of the trial so that better models can be adaptively chosen to achieve more accurate inference. The new design, TEAMS, achieves great operating characteristics in extensive simulation studies due to its ability to adaptively insert new doses as well as perform model selection. As a result, appropriate doses are inserted when necessary and desirable doses are selected with higher probabilities at the end of the trial. PMID:26528377

  9. QuickStats: Number of Deaths Resulting from Unintentional Carbon Monoxide Poisoning,* by Month and Year - National Vital Statistics System, United States, 2010-2015.

    PubMed

    2017-03-03

    During 2010-2015, a total of 2,244 deaths resulted from unintentional carbon monoxide poisoning, with the highest numbers of deaths each year occurring in winter months. In 2015, a total of 393 deaths resulting from unintentional carbon monoxide poisoning occurred, with 36% of the deaths occurring in December, January, or February.

  10. High-Dose Hypofractionated Proton Beam Radiation Therapy Is Safe and Effective for Central and Peripheral Early-Stage Non-Small Cell Lung Cancer: Results of a 12-Year Experience at Loma Linda University Medical Center

    SciTech Connect

    Bush, David A.; Cheek, Gregory; Zaheer, Salman; Wallen, Jason; Mirshahidi, Hamid; Katerelos, Ari; Grove, Roger; Slater, Jerry D.

    2013-08-01

    Purpose: We update our previous reports on the use of hypofractionated proton beam radiation therapy for early-stage lung cancer patients. Methods and Materials: Eligible subjects had biopsy-proven non-small cell carcinoma of the lung and were medically inoperable or refused surgery. Clinical workup required staging of T1 or T2, N0, M0. Subjects received hypofractionated proton beam therapy to the primary tumor only. The dose delivered was sequentially escalated from 51 to 60 Gy, then to 70 Gy in 10 fractions over 2 weeks. Endpoints included toxicity, pulmonary function, overall survival (OS), disease-specific survival (DSS), and local control (LC). Results: One hundred eleven subjects were analyzed for treatment outcomes. The patient population had the following average characteristics; age 73.2 years, tumor size 3.6 cm, and 1.33 L forced expiratory volume in 1 second. The entire group showed improved OS with increasing dose level (51, 60, and 70 Gy) with a 4-year OS of 18%, 32%, and 51%, respectively (P=.006). Peripheral T1 tumors exhibited LC of 96%, DSS of 88%, and OS of 60% at 4 years. Patients with T2 tumors showed a trend toward improved LC and survival with the 70-Gy dose level. On multivariate analysis, larger tumor size was strongly associated with increased local recurrence and decreased survival. Central versus peripheral location did not correlate with any outcome measures. Clinical radiation pneumonitis was not found to be a significant complication, and no patient required steroid therapy after treatment for radiation pneumonitis. Pulmonary function was well maintained 1 year after treatment. Conclusions: High-dose hypofractionated proton therapy achieves excellent outcomes for lung carcinomas that are peripherally or centrally located. The 70-Gy regimen has been adopted as standard therapy for T1 tumors at our institution. Larger T2 tumors show a trend toward improved outcomes with higher doses, suggesting that better results could be seen with

  11. Statistical Significance Is Not a "Kosher Certificate" for Observed Effects: A Critical Analysis of the Two-Step Approach to the Evaluation of Empirical Results.

    ERIC Educational Resources Information Center

    Cahan, Sorel

    2000-01-01

    Shows why the two-step approach proposed by D. Robinson and J. Levine (1997) is inappropriate for the evaluation of empirical results and reiterates the preferred approach of increased sample size and the computation of confidence intervals. (SLD)

  12. Lack of significant effect of bilastine administered at therapeutic and supratherapeutic doses and concomitantly with ketoconazole on ventricular repolarization: results of a thorough QT study (TQTS) with QT-concentration analysis.

    PubMed

    Tyl, Benoît; Kabbaj, Meriam; Azzam, Sara; Sologuren, Ander; Valiente, Román; Reinbolt, Elizabeth; Roupe, Kathryn; Blanco, Nathalie; Wheeler, William

    2012-06-01

    The effect of bilastine on cardiac repolarization was studied in 30 healthy participants during a multiple-dose, triple-dummy, crossover, thorough QT study that included 5 arms: placebo, active control (400 mg moxifloxacin), bilastine at therapeutic and supratherapeutic doses (20 mg and 100 mg once daily, respectively), and bilastine 20 mg administered with ketoconazole 400 mg. Time-matched, triplicate electrocardiograms (ECGs) were recorded with 13 time points extracted predose and 16 extracted over 72 hours post day 4 dosing. Four QT/RR corrections were implemented: QTcB; QTcF; a linear individual correction (QTcNi), the primary correction; and a nonlinear one (QTcNnl). Moxifloxacin was associated with a significant increase in QTcNi at all time points between 1 and 12 hours, inclusively. Bilastine administration at 20 mg and 100 mg had no clinically significant impact on QTc (maximum increase in QTcNi, 5.02 ms; upper confidence limit [UCL] of the 1-sided, 95% confidence interval, 7.87 ms). Concomitant administration of ketoconazole and bilastine 20 mg induced a clinically relevant increase in QTc (maximum increase in QTcNi, 9.3 ms; UCL, 12.16 ms). This result was most likely related to the cardiac effect of ketoconazole because for all time points, bilastine plasma concentrations were lower than those observed following the supratherapeutic dose.

  13. Combining entacapone with levodopa/DDCI improves clinical status and quality of life in Parkinson's Disease (PD) patients experiencing wearing-off, regardless of the dosing frequency: results of a large multicentre open-label study.

    PubMed

    Onofrj, M; Thomas, A; Vingerhoets, F; Martin, W; Giménez-Roldán, S; Azulay, J-P; Bernhard, G; Schmidt, W; Markabi, S

    2004-08-01

    The efficacy of entacapone and its impact on patient quality of life (QOL) was investigated in an open-label study of 899 patients with idiopathic Parkinson's Disease (PD) experiencing wearing-off fluctuations. Patients were divided into 3 groups (3, 4 or 5 doses daily) based on their current levodopa dosage frequency. Patients received 200 mg entacapone with each levodopa/dopa-decarboxylase inhibitor (DDCI) dose, while continuing their same levodopa/DDCI dosage regimen for 4 weeks. Primary efficacy measure was the Investigators' Clinical Global Impression of Change (CGIC). Patient QoL was assessed using the validated 8-item Parkinson's Disease Questionnaire (PDQ-8). Investigators' CGIC revealed that 76.5% of entacapone treated patients experienced an improvement in global status after 4 weeks. Treatment with entacapone was also associated with improvement in patient QoL, with a mean reduction (improvement) in PDQ-8 score of 1.8 from baseline. This study confirms and extends the results of earlier studies demonstrating that, independent of dosing frequency, completing levodopa/DDCI therapy with entacapone provides clinically relevant improvements in global status and QoL in PD patients experiencing wearing-off on their current levodopa dosing frequency.

  14. Order Statistics and Nonparametric Statistics.

    DTIC Science & Technology

    2014-09-26

    Topics investigated include the following: Probability that a fuze will fire; moving order statistics; distribution theory and properties of the...problem posed by an Army Scientist: A fuze will fire when at least n-i (or n-2) of n detonators function within time span t. What is the probability of

  15. Statistical Optics

    NASA Astrophysics Data System (ADS)

    Goodman, Joseph W.

    2000-07-01

    The Wiley Classics Library consists of selected books that have become recognized classics in their respective fields. With these new unabridged and inexpensive editions, Wiley hopes to extend the life of these important works by making them available to future generations of mathematicians and scientists. Currently available in the Series: T. W. Anderson The Statistical Analysis of Time Series T. S. Arthanari & Yadolah Dodge Mathematical Programming in Statistics Emil Artin Geometric Algebra Norman T. J. Bailey The Elements of Stochastic Processes with Applications to the Natural Sciences Robert G. Bartle The Elements of Integration and Lebesgue Measure George E. P. Box & Norman R. Draper Evolutionary Operation: A Statistical Method for Process Improvement George E. P. Box & George C. Tiao Bayesian Inference in Statistical Analysis R. W. Carter Finite Groups of Lie Type: Conjugacy Classes and Complex Characters R. W. Carter Simple Groups of Lie Type William G. Cochran & Gertrude M. Cox Experimental Designs, Second Edition Richard Courant Differential and Integral Calculus, Volume I RIchard Courant Differential and Integral Calculus, Volume II Richard Courant & D. Hilbert Methods of Mathematical Physics, Volume I Richard Courant & D. Hilbert Methods of Mathematical Physics, Volume II D. R. Cox Planning of Experiments Harold S. M. Coxeter Introduction to Geometry, Second Edition Charles W. Curtis & Irving Reiner Representation Theory of Finite Groups and Associative Algebras Charles W. Curtis & Irving Reiner Methods of Representation Theory with Applications to Finite Groups and Orders, Volume I Charles W. Curtis & Irving Reiner Methods of Representation Theory with Applications to Finite Groups and Orders, Volume II Cuthbert Daniel Fitting Equations to Data: Computer Analysis of Multifactor Data, Second Edition Bruno de Finetti Theory of Probability, Volume I Bruno de Finetti Theory of Probability, Volume 2 W. Edwards Deming Sample Design in Business Research

  16. Calculation of effective dose.

    PubMed

    McCollough, C H; Schueler, B A

    2000-05-01

    The concept of "effective dose" was introduced in 1975 to provide a mechanism for assessing the radiation detriment from partial body irradiations in terms of data derived from whole body irradiations. The effective dose is the mean absorbed dose from a uniform whole-body irradiation that results in the same total radiation detriment as from the nonuniform, partial-body irradiation in question. The effective dose is calculated as the weighted average of the mean absorbed dose to the various body organs and tissues, where the weighting factor is the radiation detriment for a given organ (from a whole-body irradiation) as a fraction of the total radiation detriment. In this review, effective dose equivalent and effective dose, as established by the International Commission on Radiological Protection in 1977 and 1990, respectively, are defined and various methods of calculating these quantities are presented for radionuclides, radiography, fluoroscopy, computed tomography and mammography. In order to calculate either quantity, it is first necessary to estimate the radiation dose to individual organs. One common method of determining organ doses is through Monte Carlo simulations of photon interactions within a simplified mathematical model of the human body. Several groups have performed these calculations and published their results in the form of data tables of organ dose per unit activity or exposure. These data tables are specified according to particular examination parameters, such as radiopharmaceutical, x-ray projection, x-ray beam energy spectra or patient size. Sources of these organ dose conversion coefficients are presented and differences between them are examined. The estimates of effective dose equivalent or effective dose calculated using these data, although not intended to describe the dose to an individual, can be used as a relative measure of stochastic radiation detriment. The calculated values, in units of sievert (or rem), indicate the amount of

  17. Understanding Undergraduate Statistical Anxiety

    ERIC Educational Resources Information Center

    McKim, Courtney

    2014-01-01

    The purpose of this study was to understand undergraduate students' views of statistics. Results reveal that students with less anxiety have a higher interest in statistics and also believe in their ability to perform well in the course. Also students who have a more positive attitude about the class tend to have a higher belief in their…

  18. Evaluation of Long-term Outcomes of Correction of Severe Blepharoptosis with Advancement of External Levator Muscle Complex: Descriptive Statistical Analysis of the Results

    PubMed Central

    INNOCENTI, ALESSANDRO; MORI, FRANCESCO; MELITA, DARIO; DREASSI, EMANUELA; CIANCIO, FRANCESCO; INNOCENTI, MARCO

    2017-01-01

    Aim: Evaluation of long-term results after aponeurotic blepharoptosis correction with external levator muscle complex advancement. Patients and Methods: We carried out a retrospective study with medical record review of 20 patients (40 eyes) affected by bilateral aponeurotic moderate and severe ptosis who underwent primary surgery between January 2010 and December 2013. Criteria for outcome evaluations included 3-year postoperative follow-up of upper margin reflex index (uMRD) and symmetry. Results: 3-Year postoperative follow-up showed 17 (85%) cases of successful correction of ptosis and three cases (15%) showed partial success. Two eyes showed hypocorrection, while one eye was overcorrected. The symmetry was maintained in all patients except for the oldest. Conclusion: External superior levator advancement is an effective procedure for moderate and severe aponeurotic blepharoptosis correction, and establishes good long-term eyelid position and symmetry. PMID:28064228

  19. 3H And 90Sr In Urine Radiobioassay Intercomparison Results From The Intercomparison Studies Program At Oak Ridge National Laboratory: Statistical Analysis Of Laboratory Performance

    SciTech Connect

    Bores, Norman; Schultz, Michael K

    2009-01-01

    The Intercomparison Studies Program (ISP) at the Oak Ridge National Laboratory (ORNL, Oak Ridge, TN USA) provides natural-matrix human urine quality-assurance/quality-control (QA/QC) samples to radiobioassay analysis laboratories. Samples are provided to these laboratories as 'single-blind' or 'double-blind' unknowns, spiked with radioactive-solution standards at 'low' levels (e.g., 0.7-7 Bq g{sup -1} for {sup 3}H and 0.7-7 Bq kg{sup -1} for {sup 90}Sr). Participants use the results as a tool for self-evaluation and a measure of performance. In this paper, sample preparation and the results of testing during the years 2001-2005 for {sup 3}H and {sup 90}Sr are presented and discussed.

  20. Truth, Damn Truth, and Statistics

    ERIC Educational Resources Information Center

    Velleman, Paul F.

    2008-01-01

    Statisticians and Statistics teachers often have to push back against the popular impression that Statistics teaches how to lie with data. Those who believe incorrectly that Statistics is solely a branch of Mathematics (and thus algorithmic), often see the use of judgment in Statistics as evidence that we do indeed manipulate our results. In the…

  1. Overview of results from the WaterTox intercalibration and environmental testing phase II program: Part 1, statistical analysis of blind sample testing.

    PubMed

    Ronco, A; Gagnon, P; Diaz-Baez, M C; Arkhipchuk, V; Castillo, G; Castillo, L E; Dutka, B J; Pica-Granados, Y; Ridal, J; Srivastava, R C; Sánchez, A

    2002-01-01

    There is an urgent need to evaluate the presence of toxicants in waters used for human consumption and to develop strategies to reduce and prevent their contamination. The International Development Research Centre undertook an intercalibration project to develop and validate a battery of bioassays for toxicity testing of water samples. The project was carried out in two phases by research institutions from eight countries that formed the WaterTox network. Results for the first phase were reported in the special September 2000 issue of Environmental Toxicology. Phase II involved toxicity screening tests of environmental and blind samples (chemical solutions of unknown composition to participating laboratories) using the following battery: Daphnia magna, Hydra attenuata, seed root inhibition with Lactuca sativa, and Selenastrum capricornutum. This battery was also used to assess potential toxicity in concentrated (10x) water samples. Results are presented for a set of six blind samples sent to the participating laboratories over a 1-year period. Analyses were performed for each bioassay to evaluate variations among laboratories of responses to negative controls, violations of test quality control criteria, false positive responses induced by sample concentration, and variability within and between labs of responses to toxic samples. Analyses of the data from all bioassays and labs provided comparisons of false positive rates (based on blind negative samples), test sensitivities to a metal or organic toxicant, and interlaboratory test variability. Results indicate that the battery was reliable in detecting toxicity when present. However, some false positives were identified with a concentrated soft-water sample and with the Lactuca and Hydra (sublethal end-point) tests. Probabilities of detecting false positives for individual and combined toxic responses of the four bioassays are presented. Overall, interlaboratory comparisons indicate a good reliability of the

  2. Relevance of biotic pathways to the long-term regulation of nuclear waste disposal. Estimation of radiation dose to man resulting from biotic transport: the BIOPORT/MAXI1 software package. Volume 5

    SciTech Connect

    McKenzie, D.H.; Cadwell, L.L.; Gano, K.A.; Kennedy, W.E. Jr.; Napier, B.A.; Peloquin, R.A.; Prohammer, L.A.; Simmons, M.A.

    1985-10-01

    BIOPORT/MAXI1 is a collection of five computer codes designed to estimate the potential magnitude of the radiation dose to man resulting from biotic transport processes. Dose to man is calculated for ingestion of agricultural crops grown in contaminated soil, inhalation of resuspended radionuclides, and direct exposure to penetrating radiation resulting from the radionuclide concentrations established in the available soil surface by the biotic transport model. This document is designed as both an instructional and reference document for the BIOPORT/MAXI1 computer software package and has been written for two major audiences. The first audience includes persons concerned with the mathematical models of biological transport of commercial low-level radioactive wastes and the computer algorithms used to implement those models. The second audience includes persons concerned with exercising the computer program and exposure scenarios to obtain results for specific applications. The report contains sections describing the mathematical models, user operation of the computer programs, and program structure. Input and output for five sample problems are included. In addition, listings of the computer programs, data libraries, and dose conversion factors are provided in appendices.

  3. [Evaluation by statistical brain perfusion SPECT analysis on MRI findings, kana pick-out test and Mini-Mental State Examination results in patients with forgetfulness].

    PubMed

    Nakatsuka, Hiroki; Matsubara, Ichirou; Ohtani, Haruhiko

    2003-04-01

    The aim of this single photon emission computed tomography(SPECT) study was to determine the abnormality of the regional cerebral blood flow(rCBF) using a three-dimensional stereotactic surface projection (3 D-SSP) in 18 patients who were referred to the hospital because of forgetfulness. Two intergroup comparison by 3 D-SSP analysis was conducted based on MRI, kana pick-out test and Mini-Mental State Examination (MMSE) results. Of the MRI findings, in the brain atrophy group, rCBF was decreased in the posterior cingulate gyrus, medial temporal structure and parieto-temporal association cortex; these rCBF-decreased areas are similar to the Alzheimer disease pattern. In the group where the MMSE was normal but the kana pick-out test was abnormal, rCBF was decreased in the posterior cingulate gyrus and cinguloparietal transitional area. In the group where both the MMSE and kana pick-out test were abnormal, rCBF was decreased in the parieto-temporal association cortex, temporal cortex and medial temporal structure. These results suggest that 3 D-SSP analysis of the SPECT with MMSE and the kana pick-out test provides the possibility of early diagnosis of initial stage of Alzheimer's disease.

  4. Estimation of the Dose and Dose Rate Effectiveness Factor

    NASA Technical Reports Server (NTRS)

    Chappell, L.; Cucinotta, F. A.

    2013-01-01

    Current models to estimate radiation risk use the Life Span Study (LSS) cohort that received high doses and high dose rates of radiation. Transferring risks from these high dose rates to the low doses and dose rates received by astronauts in space is a source of uncertainty in our risk calculations. The solid cancer models recommended by BEIR VII [1], UNSCEAR [2], and Preston et al [3] is fitted adequately by a linear dose response model, which implies that low doses and dose rates would be estimated the same as high doses and dose rates. However animal and cell experiments imply there should be curvature in the dose response curve for tumor induction. Furthermore animal experiments that directly compare acute to chronic exposures show lower increases in tumor induction than acute exposures. A dose and dose rate effectiveness factor (DDREF) has been estimated and applied to transfer risks from the high doses and dose rates of the LSS cohort to low doses and dose rates such as from missions in space. The BEIR VII committee [1] combined DDREF estimates using the LSS cohort and animal experiments using Bayesian methods for their recommendation for a DDREF value of 1.5 with uncertainty. We reexamined the animal data considered by BEIR VII and included more animal data and human chromosome aberration data to improve the estimate for DDREF. Several experiments chosen by BEIR VII were deemed inappropriate for application to human risk models of solid cancer risk. Animal tumor experiments performed by Ullrich et al [4], Alpen et al [5], and Grahn et al [6] were analyzed to estimate the DDREF. Human chromosome aberration experiments performed on a sample of astronauts within NASA were also available to estimate the DDREF. The LSS cohort results reported by BEIR VII were combined with the new radiobiology results using Bayesian methods.

  5. Effects of mometasone furoate/formoterol fumarate fixed-dose combination formulation on chronic obstructive pulmonary disease (COPD): results from a 52-week Phase III trial in subjects with moderate-to-very severe COPD

    PubMed Central

    Doherty, Dennis E; Tashkin, Donald P; Kerwin, Edward; Knorr, Barbara A; Shekar, Tulin; Banerjee, Sibabrata; Staudinger, Heribert

    2012-01-01

    Rationale The purpose of this study was to investigate the clinical efficacy and safety of a fixed-dose combination of mometasone furoate/formoterol fumarate (MF/F) administered via a metered-dose inhaler in subjects with moderate-to-very severe chronic obstructive pulmonary disease (COPD). Methods This multicenter, double-blind, placebo-controlled trial had a 26-week treatment period and a 26-week safety extension. Subjects (n = 1196), at least 40 years old, were current or ex-smokers randomized to twice-daily inhaled MF/F 400/10 μg, MF/F 200/10 μg, MF 400 μg, F 10 μg, or placebo. The trial’s co-primary endpoints were mean changes from baseline, as area under the curve (AUC), in forced expiratory volume (FEV1) over 0–12 hours (AUC0–12 h FEV1) with MF/F versus MF, and in morning (AM) pre-dose (trough) FEV1 with MF/F versus F after 13 weeks of treatment. Key secondary endpoints were the effects of MF/F on respiratory health status using the Saint George’s Respiratory Questionnaire (SGRQ), symptom-free nights, partly stable COPD at 26 weeks, and time to first COPD exacerbation. Results The largest improvements in AUC0–12 h FEV1 were observed with MF/F 400/10 μg and MF/F 200/10 μg. Serial spirometry results demonstrated that bronchodilator effects with MF/F occurred rapidly (within 5 minutes), persisted for 12 hours after dosing, and were sustained over the 26-week treatment period. Similar findings were observed for AM pre-dose FEV1, for which effects were further investigated, excluding subjects whose AM FEV1 data were incorrectly collected after 2 days from the last dose of study treatment. Improvements in SGRQ scores surpassed the minimum clinically important difference of more than four units with both MF/F treatments. At 26 weeks, no notable between-treatment differences in the occurrence and nature of adverse events (AEs) were reported. No unexpected AEs were observed. Overall, 90 subjects reported AEs considered to be treatment-related, the

  6. [Statistics quantum satis].

    PubMed

    Pestana, Dinis

    2013-01-01

    Statistics is a privileged tool in building knowledge from information, since the purpose is to extract from a sample limited information conclusions to the whole population. The pervasive use of statistical software (that always provides an answer, the question being adequate or not), and the absence of statistics to confer a scientific flavour to so much bad science, has had a pernicious effect on some disbelief on statistical research. Would Lord Rutherford be alive today, it is almost certain that he would not condemn the use of statistics in research, as he did in the dawn of the 20th century. But he would indeed urge everyone to use statistics quantum satis, since to use bad data, too many data, and statistics to enquire on irrelevant questions, is a source of bad science, namely because with too many data we can establish statistical significance of irrelevant results. This is an important point that addicts of evidence based medicine should be aware of, since the meta analysis of two many data will inevitably establish senseless results.

  7. The effect of endocrine responsiveness on high-risk breast cancer treated with dose-intensive chemotherapy: results of International Breast Cancer Study Group Trial 15-95 after prolonged follow-up

    PubMed Central

    Colleoni, M.; Sun, Z.; Martinelli, G.; Basser, R. L.; Coates, A. S.; Gelber, R. D.; Green, M. D.; Peccatori, F.; Cinieri, S.; Aebi, S.; Viale, G.; Price, K. N.; Goldhirsch, A.

    2009-01-01

    Background: The role of adjuvant dose-intensive chemotherapy and its efficacy according to baseline features has not yet been established. Patients and methods: Three hundred and forty-four patients were randomized to receive seven courses of standard-dose chemotherapy (SD-CT) or three cycles of dose-intensive epirubicin and cyclophosphamide (epirubicin 200 mg/m2 plus cyclophosphamide 4 mg/m2 with filgrastim and progenitor cell support). All patients were assigned tamoxifen at the completion of chemotherapy. The primary end point was disease-free survival (DFS). This paper updates the results and explores patterns of recurrence according to predicting baseline features. Results: At 8.3-years median follow-up, patients assigned DI-EC had a significantly better DFS compared with those assigned SD-CT [8-year DFS percent 47% and 37%, respectively, hazard ratio (HR) 0.76; 95% confidence interval 0.58–1.00; P = 0.05]. Only patients with estrogen receptor (ER)-positive disease benefited from the DI-EC (HR 0.61; 95% confidence interval 0.39, 0.95; P = 0.03). Conclusions: After prolonged follow-up, DI-EC significantly improved DFS, but the effect was observed only in patients with ER-positive disease, leading to the hypothesis that efficacy of DI-EC may relate to its endocrine effects. Further studies designed to confirm the importance of endocrine responsiveness in patients treated with dose-intensive chemotherapy are encouraged. PMID:19468030

  8. High Dose Atorvastatin Decreases Cellular Markers of Immune Activation Without Affecting HIV-1 RNA Levels: Results of a Double-Blind Randomized Placebo Controlled Clinical Trial

    DTIC Science & Technology

    2011-02-15

    cholesterol -depleting agents, such as 3-hydroxy- 3-methyl-glutaryl-coenzyme A (HMG-CoA) reductase inhibitors ( statins ), reduces HIV-1 particle production [5...Furthermore, virions derived from cholesterol -depleted cells demonstrate reduced infectivity in vitro [5]. In addition, statins have dem- onstrated...studies revealed that substantial statin - induced decreases in cholesterol resulted in declines in HIV-1 production [5]. We therefore chose the highest

  9. Statistical Neurodynamics.

    NASA Astrophysics Data System (ADS)

    Paine, Gregory Harold

    1982-03-01

    The primary objective of the thesis is to explore the dynamical properties of small nerve networks by means of the methods of statistical mechanics. To this end, a general formalism is developed and applied to elementary groupings of model neurons which are driven by either constant (steady state) or nonconstant (nonsteady state) forces. Neuronal models described by a system of coupled, nonlinear, first-order, ordinary differential equations are considered. A linearized form of the neuronal equations is studied in detail. A Lagrange function corresponding to the linear neural network is constructed which, through a Legendre transformation, provides a constant of motion. By invoking the Maximum-Entropy Principle with the single integral of motion as a constraint, a probability distribution function for the network in a steady state can be obtained. The formalism is implemented for some simple networks driven by a constant force; accordingly, the analysis focuses on a study of fluctuations about the steady state. In particular, a network composed of N noninteracting neurons, termed Free Thinkers, is considered in detail, with a view to interpretation and numerical estimation of the Lagrange multiplier corresponding to the constant of motion. As an archetypical example of a net of interacting neurons, the classical neural oscillator, consisting of two mutually inhibitory neurons, is investigated. It is further shown that in the case of a network driven by a nonconstant force, the Maximum-Entropy Principle can be applied to determine a probability distribution functional describing the network in a nonsteady state. The above examples are reconsidered with nonconstant driving forces which produce small deviations from the steady state. Numerical studies are performed on simplified models of two physical systems: the starfish central nervous system and the mammalian olfactory bulb. Discussions are given as to how statistical neurodynamics can be used to gain a better

  10. Statistics 101 for Radiologists.

    PubMed

    Anvari, Arash; Halpern, Elkan F; Samir, Anthony E

    2015-10-01

    Diagnostic tests have wide clinical applications, including screening, diagnosis, measuring treatment effect, and determining prognosis. Interpreting diagnostic test results requires an understanding of key statistical concepts used to evaluate test efficacy. This review explains descriptive statistics and discusses probability, including mutually exclusive and independent events and conditional probability. In the inferential statistics section, a statistical perspective on study design is provided, together with an explanation of how to select appropriate statistical tests. Key concepts in recruiting study samples are discussed, including representativeness and random sampling. Variable types are defined, including predictor, outcome, and covariate variables, and the relationship of these variables to one another. In the hypothesis testing section, we explain how to determine if observed differences between groups are likely to be due to chance. We explain type I and II errors, statistical significance, and study power, followed by an explanation of effect sizes and how confidence intervals can be used to generalize observed effect sizes to the larger population. Statistical tests are explained in four categories: t tests and analysis of variance, proportion analysis tests, nonparametric tests, and regression techniques. We discuss sensitivity, specificity, accuracy, receiver operating characteristic analysis, and likelihood ratios. Measures of reliability and agreement, including κ statistics, intraclass correlation coefficients, and Bland-Altman graphs and analysis, are introduced.

  11. Overhead Image Statistics

    SciTech Connect

    Vijayaraj, Veeraraghavan; Cheriyadat, Anil M; Bhaduri, Budhendra L; Vatsavai, Raju; Bright, Eddie A

    2008-01-01

    Statistical properties of high-resolution overhead images representing different land use categories are analyzed using various local and global statistical image properties based on the shape of the power spectrum, image gradient distributions, edge co-occurrence, and inter-scale wavelet coefficient distributions. The analysis was performed on a database of high-resolution (1 meter) overhead images representing a multitude of different downtown, suburban, commercial, agricultural and wooded exemplars. Various statistical properties relating to these image categories and their relationship are discussed. The categorical variations in power spectrum contour shapes, the unique gradient distribution characteristics of wooded categories, the similarity in edge co-occurrence statistics for overhead and natural images, and the unique edge co-occurrence statistics of downtown categories are presented in this work. Though previous work on natural image statistics has showed some of the unique characteristics for different categories, the relationships for overhead images are not well understood. The statistical properties of natural images were used in previous studies to develop prior image models, to predict and index objects in a scene and to improve computer vision models. The results from our research findings can be used to augment and adapt computer vision algorithms that rely on prior image statistics to process overhead images, calibrate the performance of overhead image analysis algorithms, and derive features for better discrimination of overhead image categories.

  12. Dose esclation in radioimmunotherapy based on projected whole body dose

    SciTech Connect

    Wahl, R.L.; Kaminski, M.S.; Regan, D.

    1994-05-01

    A variety of approaches have been utilized in conducting phase I radioimmunotherapy dose-escalation trials. Escalation of dose has been based on graded increases in administered mCi; mCi/kg; or mCi/m2. It is also possible to escalate dose based on tracer-projected marrow, blood or whole body radiation dose. We describe our results in performing a dose-escalation trial in patients with non-Hodgkin lymphoma based on escalating administered whole-body radiation dose. The mCi dose administered was based on a patient-individualized tracer projected whole-body dose. 25 patients were entered on the study. RIT with 131 I anti-B-1 was administered to 19 patients. The administered dose was prescribed based on the projected whole body dose, determined from patient-individualized tracer studies performed prior to RIT. Whole body dose estimates were based on the assumption that the patient was an ellipsoid, with 131 antibody kinetics determined using a whole-body probe device acquiring daily conjugate views of 1 minute duration/view. Dose escalation levels proceeded with 10 cGy increments from 25 cGy whole-body and continues, now at 75 cGy. The correlation among potential methods of dose escalation and toxicity was assessed. Whole body radiation dose by probe was strongly correlated with the blood radiation dose determined from sequential blood sampling during tracer studies (r=.87). Blood radiation dose was very weakly correlated with mCi dose (r=.4) and mCi/kg (r=.45). Whole body radiation dose appeared less well-correlated with injected dose in mCi (r=.6), or mCi/kg (r=.64). Toxicity has been infrequent in these patients, but appears related to increasing whole body dose. Non-invasive determination of whole-body radiation dose by gamma probe represents a non-invasive method of estimating blood radiation dose, and thus of estimating bone marrow radiation dose.

  13. Results of Phase II Randomized Study of Low-Dose Decitabine with or without Valproic Acid in Patients with Myelodysplastic Syndrome and Acute Myelogenous Leukemia

    PubMed Central

    Issa, Jean Pierre; Garcia-Manero, Guillermo; Huang, Xuelin; Cortes, Jorge; Ravandi, Farhad; Jabbour, Elias; Borthakur, Gautam; Brandt, Mark; Pierce, Sherry; Kantarjian, Hagop

    2014-01-01

    Background Hypomethylating agents have shown activity in myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). Pre-clinical and single-arm trials have suggested that adding histone deacetylase (HDAC) inhibitors may synergize the epigenetic modulation of hypomethylating agents and improve treatment results. Study Aim To evaluate the possible benefit of adding valproic acid, an HDAC inhibitor, to decitabine, in the treatment of MDS and AML. Methods Patients with higher risk MDS or with AML and age 60 years or older were eligible. Patients were randomized in a Bayesian response-adaptive design to decitabine 20mg/m2 intravenously (IV) daily for 5 days or to decitabine with valproic acid 50mg/1kg orally daily for 7 days. Courses were repeated every 4 to 6 weeks. A maximum of 150 patients were to be treated. Results A total of 149 patients were treated on study, including 87 patients with MDS and 62 patients with AML. The median age was 69 years (range 20 to 89 years; 42% ≥ 70 years). Overall, 34% of patients achieved CR and 55% had an objective response. The median survival was 11.9 months and the estimated 2-year survival rate was 27%. Outcome was not different with the addition of valproic acid to decitabine versus decitabine alone in relation to CR, overall response, or survival. Subset analyses did not demonstrate a benefit within the MDS or AML categories. Toxicities were higher with the combination, in particular neurotoxicity. Conclusions Adding valproic acid to decitabine was not associated with improved outcome in the treatment of MDS or elderly AML. Future therapies may consider combining hypomethylating agents with better HDAC inhibitors and using different schedules. PMID:25336333

  14. Outcome of Reinduction Chemotherapy with a Modified Dose of Idarubicin for Children with Marrow-Relapsed Acute Lymphoblastic Leukemia: Results of the Childhood Acute Lymphoblastic Leukemia (CALL)-0603 Study

    PubMed Central

    2017-01-01

    This multicenter, prospective trial was conducted to develop an effective and safe reinduction regimen for marrow-relapsed pediatric acute lymphoblastic leukemia (ALL) by modifying the dose of idarubicin. Between 2006 and 2009, the trial accrued 44 patients, 1 to 21 years old with first marrow-relapsed ALL. The reinduction regimen comprised prednisolone, vincristine, L-asparaginase, and idarubicin (10 mg/m2/week). The idarubicin dose was adjusted according to the degree of myelosuppression. The second complete remission (CR2) rate was 72.7%, obtained by 54.2% of patients with early relapse < 24 months after initial diagnosis and 95.0% of those with late relapse (P = 0.002). Five patients entered remission with extended treatment, resulting in a final CR2 rate of 84.1%. The CR2 rate was not significantly different according to the idarubicin dose. The induction death rate was 2.3% (1/44). The 5-year event-free and overall survival rates were 22.2% ± 6.4% and 27.3% ± 6.7% for all patients, 4.2% ± 4.1% and 8.3% ± 5.6% for early relapsers, and 43.8% ± 11.4% and 50.0% ± 11.2% for late relapsers, respectively. Early relapse and slow response to reinduction chemotherapy were predictors of poor outcomes. In conclusion, a modified dose of idarubicin was effectively incorporated into the reinduction regimen for late marrow-relapsed ALL with a low toxic death rate. However, the CR2 rate for early relapsers was suboptimal, and the second remission was not durable in most patients. PMID:28244291

  15. TESS-based dose-response using pediatric clonidine exposures

    SciTech Connect

    Benson, Blaine E. . E-mail: jebenson@salud.unm.edu; Spyker, Daniel A.; Troutman, William G.; Watson, William A. . E-mail: http://www.aapcc.org/

    2006-06-01

    Objective: The toxic and lethal doses of clonidine in children are unclear. This study was designed to determine whether data from the American Association of Poison Control Centers Toxic Exposure Surveillance System (TESS) could be utilized to determine a dose-response relationship for pediatric clonidine exposure. Methods: 3458 single-substance clonidine exposures in children <6 years of age reported to TESS from January 2000 through December 2003 were examined. Dose ingested, age, and medical outcome were available for 1550 cases. Respiratory arrest cases (n = 8) were classified as the most severe of the medical outcome categories (Arrest, Major, Moderate, Mild, and No effect). Exposures reported as a 'taste or lick' (n = 51) were included as a dose of 1/10 of the dosage form involved. Dose ranged from 0.4 to 1980 (median 13) {mu}g/kg. Weight was imputed based on a quadratic estimate of weight for age. Dose certainty was coded as exact (26% of cases) or not exact (74%). Medical outcome (response) was examined via logistic regression using SAS JMP (release 5.1). Results: The logistic model describing medical outcome (P < 0.0001) included Log dose/kg (P 0.0000) and Certainty (P = 0.045). Conclusion: TESS data can provide the basis for a statistically sound description of dose-response for pediatric clonidine poisoning exposures.

  16. Effect of Embolization Material in the Calculation of Dose Deposition in Arteriovenous Malformations

    NASA Astrophysics Data System (ADS)

    De la Cruz, O. O. Galván; Lárraga-Gutiérrez, J. M.; Moreno-Jiménez, S.; Célis-López, M. A.

    2010-12-01

    In this work it is studied the impact of the incorporation of high Z materials (embolization material) in the dose calculation for stereotactic radiosurgery treatment for arteriovenous malformations. A statistical analysis is done to establish the variables that may impact in the dose calculation. To perform the comparison pencil beam (PB) and Monte Carlo (MC) calculation algorithms were used. The comparison between both dose calculations shows that PB overestimates the dose deposited. The statistical analysis, for the quantity of patients of the study (20), shows that the variable that may impact in the dose calculation is the volume of the high Z material in the arteriovenous malformation. Further studies have to be done to establish the clinical impact with the radiosurgery result.

  17. Measurement of 226Ra, 232Th, 137Cs and 40K activities of Wheat and Corn Products in Ilam Province – Iran and Resultant Annual Ingestion Radiation Dose

    PubMed Central

    CHANGIZI, Vahid; SHAFIEI, Elham; ZAREH, Mohammad Reza

    2013-01-01

    Background: Background: Natural background radiation is the main source of human exposure to radioactive material. Soils naturally have radioactive mineral contents. The aim of this study is to determine natural (238 U, 232 Th, 40 K) and artificial (137 Cs) radioactivity levels in wheat and corn fields of Eilam province. Methods: HPGe detector was used to measure the concentration activity of 238 U and 232 Th series, 40 K and 137 Cs in wheat and corn samples taken from different regions of Eilam province, in Iran. Results: In wheat and corn samples, the average activity concentrations of 226 Ra, 232 Th, 40 K and 137 Cs were found to be 1, 67, 0.5, 91.73, 0.01 and 0.81, 0.85, 101.52, 0.07 Bq/kg (dry weight), respectively. H ex and H in in the present work are lower than 1. The average value of H ex was found to be 0.02 and 0.025 and average value of H in to be found 0.025 and 0.027 in wheat fields samples and corn samples in Eilam provinces, respectively. The obtained values of AGDE are 30.49 mSv/yr for wheat filed samples and 37.89 mSv/yr for corn samples; the AEDE rate values are 5.28 mSv/yr in wheat filed samples and this average value was found to be 6.13 mSv/yr in corn samples in Eilam. Transfer factors (TFs) of long lived radionuclide such as 137 Cs, 226 Ra, 232 Th and 40 K from soils to corn and wheat plants have been studied by radiotracer experiments. Conclusion: The natural radioactivity levels in Eilam province are not at the range of high risk of morbidity and are under international standards. PMID:26056646

  18. ``Models'' CAVEAT EMPTOR!!!: ``Toy Models Too-Often Yield Toy-Results''!!!: Statistics, Polls, Politics, Economics, Elections!!!: GRAPH/Network-Physics: ``Equal-Distribution for All'' TRUMP-ED BEC ``Winner-Take-All'' ``Doctor Livingston I Presume?''

    NASA Astrophysics Data System (ADS)

    Preibus-Norquist, R. N. C.-Grover; Bush-Romney, G. W.-Willard-Mitt; Dimon, J. P.; Adelson-Koch, Sheldon-Charles-David-Sheldon; Krugman-Axelrod, Paul-David; Siegel, Edward Carl-Ludwig; D. N. C./O. F. P./''47''%/50% Collaboration; R. N. C./G. O. P./''53''%/49% Collaboration; Nyt/Wp/Cnn/Msnbc/Pbs/Npr/Ft Collaboration; Ftn/Fnc/Fox/Wsj/Fbn Collaboration; Lb/Jpmc/Bs/Boa/Ml/Wamu/S&P/Fitch/Moodys/Nmis Collaboration

    2013-03-01

    ``Models''? CAVEAT EMPTOR!!!: ``Toy Models Too-Often Yield Toy-Results''!!!: Goldenfeld[``The Role of Models in Physics'', in Lects.on Phase-Transitions & R.-G.(92)-p.32-33!!!]: statistics(Silver{[NYTimes; Bensinger, ``Math-Geerks Clearly-Defeated Pundits'', LATimes, (11/9/12)])}, polls, politics, economics, elections!!!: GRAPH/network/net/...-PHYSICS Barabasi-Albert[RMP (02)] (r,t)-space VERSUS(???) [Where's the Inverse/ Dual/Integral-Transform???] (Benjamin)Franklin(1795)-Fourier(1795; 1897;1822)-Laplace(1850)-Mellin (1902) Brillouin(1922)-...(k,)-space, {Hubbard [The World According to Wavelets,Peters (96)-p.14!!!/p.246: refs.-F2!!!]},and then (2) Albert-Barabasi[]Bose-Einstein quantum-statistics(BEQS) Bose-Einstein CONDENSATION (BEC) versus Bianconi[pvt.-comm.; arXiv:cond-mat/0204506; ...] -Barabasi [???] Fermi-Dirac

  19. Informal Statistics Help Desk

    NASA Technical Reports Server (NTRS)

    Young, M.; Koslovsky, M.; Schaefer, Caroline M.; Feiveson, A. H.

    2017-01-01

    Back by popular demand, the JSC Biostatistics Laboratory and LSAH statisticians are offering an opportunity to discuss your statistical challenges and needs. Take the opportunity to meet the individuals offering expert statistical support to the JSC community. Join us for an informal conversation about any questions you may have encountered with issues of experimental design, analysis, or data visualization. Get answers to common questions about sample size, repeated measures, statistical assumptions, missing data, multiple testing, time-to-event data, and when to trust the results of your analyses.

  20. What can be learned from epidemiologic studies of persons exposed to low doses of radiation?

    SciTech Connect

    Gilbert, E.S.

    1993-04-01

    The main objective of radiation risk assessment is to determine the risk of various adverse health effects associated with exposure to low doses and low dose rates. Extrapolation of risks from studies of persons exposed at high doses (generally exceeding 1 Sv) and dose rates has been the primary approach used to achieve this objective. The study of Japanese atomic bomb survivors in Hiroshima and Nagasaki has played an especially important role in risk assessment efforts. A direct assessment of the dose-response function based on studies of persons exposed at low doses and dose rates is obviously desirable. This paper focuses on the potential of both current and future nuclear workers studies for investigating the dose-response functions at low doses, and also discusses analyses making use of the low dose portion of the atomic bomb survivor data. Difficulties in using these data are the statistical imprecision of estimated dose-response parameters, and potential bias resulting from confounding factors and from uncertainties in dose estimates.

  1. Objective method to report planner-independent skin/rib maximal dose in balloon-based high dose rate (HDR) brachytherapy for breast cancer

    SciTech Connect

    Kim, Yongbok; Trombetta, Mark G.

    2011-04-15

    Purpose: An objective method was proposed and compared with a manual selection method to determine planner-independent skin and rib maximal dose in balloon-based high dose rate (HDR) brachytherapy planning. Methods: The maximal dose to skin and rib was objectively extracted from a dose volume histogram (DVH) of skin and rib volumes. A virtual skin volume was produced by expanding the skin surface in three dimensions (3D) external to the breast with a certain thickness in the planning computed tomography (CT) images. Therefore, the maximal dose to this volume occurs on the skin surface the same with a conventional manual selection method. The rib was also delineated in the planning CT images and its maximal dose was extracted from its DVH. The absolute (Abdiff=|D{sub max}{sup Man}-D{sub max}{sup DVH}|) and relative (Rediff[%]=100x(|D{sub max}{sup Man}-D{sub max}{sup DVH}|)/D{sub max}{sup DVH}) maximal skin and rib dose differences between the manual selection method (D{sub max}{sup Man}) and the objective method (D{sub max}{sup DVH}) were measured for 50 balloon-based HDR (25 MammoSite and 25 Contura) patients. Results: The average{+-}standard deviation of maximal dose difference was 1.67%{+-}1.69% of the prescribed dose (PD). No statistical difference was observed between MammoSite and Contura patients for both Abdiff and Rediff[%] values. However, a statistically significant difference (p value <0.0001) was observed in maximal rib dose difference compared with maximal skin dose difference for both Abdiff (2.30%{+-}1.71% vs 1.05%{+-}1.43%) and Rediff[%] (2.32%{+-}1.79% vs 1.21%{+-}1.41%). In general, rib has a more irregular contour and it is more proximally located to the balloon for 50 HDR patients. Due to the inverse square law factor, more dose difference was observed in higher dose range (D{sub max}>90%) compared with lower dose range (D{sub max}<90%): 2.16%{+-}1.93% vs 1.19%{+-}1.25% with p value of 0.0049. However, the Rediff[%] analysis eliminated the

  2. Low-dose radiation epidemiology studies: status and issues.

    PubMed

    Shore, Roy E

    2009-11-01

    Although the Japanese atomic bomb study and radiotherapy studies have clearly documented cancer risks from high-dose radiation exposures, radiation risk assessment groups have long recognized that protracted or low exposures to low-linear energy transfer radiations are key radiation protection concerns because these are far more common than high-exposure scenarios. Epidemiologic studies of human populations with low-dose or low dose-rate exposures are one approach to addressing those concerns. A number of large studies of radiation workers (Chernobyl clean-up workers, U.S. and Chinese radiological technologists, and the 15-country worker study) or of persons exposed to environmental radiation at moderate to low levels (residents near Techa River, Semipalatinsk, Chernobyl, or nuclear facilities) have been conducted. A variety of studies of medical radiation exposures (multiple-fluoroscopy, diagnostic (131)I, scatter radiation doses from radiotherapy, etc.) also are of interest. Key results from these studies are summarized and compared with risk estimates from the Japanese atomic bomb study. Ideally, one would like the low-dose and low dose-rate studies to guide radiation risk estimation regarding the shape of the dose-response curve, DDREF (dose and dose-rate effectiveness factor), and risk at low doses. However, the degree to which low-dose studies can do so is subject to various limitations, especially those pertaining to dosimetric uncertainties and limited statistical power. The identification of individuals who are particularly susceptible to radiation cancer induction also is of high interest in terms of occupational and medical radiation protection. Several examples of studies of radiation-related cancer susceptibility are discussed, but none thus far have clearly identified radiation-susceptible genotypes.

  3. Survey of computed tomography scanners in Taiwan: Dose descriptors, dose guidance levels, and effective doses

    SciTech Connect

    Tsai, H. Y.; Tung, C. J.; Yu, C. C.; Tyan, Y. S.

    2007-04-15

    The IAEA and the ICRP recommended dose guidance levels for the most frequent computed tomography (CT) examinations to promote strategies for the optimization of radiation dose to CT patients. A national survey, including on-site measurements and questionnaires, was conducted in Taiwan in order to establish dose guidance levels and evaluate effective doses for CT. The beam quality and output and the phantom doses were measured for nine representative CT scanners. Questionnaire forms were completed by respondents from facilities of 146 CT scanners out of 285 total scanners. Information on patient, procedure, scanner, and technique for the head and body examinations was provided. The weighted computed tomography dose index (CTDI{sub w}), the dose length product (DLP), organ doses and effective dose were calculated using measured data, questionnaire information and Monte Carlo simulation results. A cost-effective analysis was applied to derive the dose guidance levels on CTDI{sub w} and DLP for several CT examinations. The mean effective dose{+-}standard deviation distributes from 1.6{+-}0.9 mSv for the routine head examination to 13{+-}11 mSv for the examination of liver, spleen, and pancreas. The surveyed results and the dose guidance levels were provided to the national authorities to develop quality control standards and protocols for CT examinations.

  4. Electron beam dose calculations.

    PubMed

    Hogstrom, K R; Mills, M D; Almond, P R

    1981-05-01

    Electron beam dose distributions in the presence of inhomogeneous tissue are calculated by an algorithm that sums the dose distribution of individual pencil beams. The off-axis dependence of the pencil beam dose distribution is described by the Fermi-Eyges theory of thick-target multiple Coulomb scattering. Measured square-field depth-dose data serve as input for the calculations. Air gap corrections are incorporated and use data from'in-air' measurements in the penumbra of the beam. The effective depth, used to evaluate depth-dose, and the sigma of the off-axis Gaussian spread against depth are calculated by recursion relations from a CT data matrix for the material underlying individual pencil beams. The correlation of CT number with relative linear stopping power and relative linear scattering power for various tissues is shown. The results of calculations are verified by comparison with measurements in a 17 MeV electron beam from the Therac 20 linear accelerator. Calculated isodose lines agree nominally to within 2 mm of measurements in a water phantom. Similar agreement is observed in cork slabs simulating lung. Calculations beneath a bone substitute illustrate a weakness in the calculation. Finally a case of carcinoma in the maxillary antrum is studied. The theory suggests an alternative method for the calculation of depth-dose of rectangular fields.

  5. A method for estimating occupational radiation dose to individuals, using weekly dosimetry data

    SciTech Connect

    Mitchell, T.J.; Ostrouchov, G.; Frome, E.L.; Kerr, G.D.

    1993-12-01

    Statistical analyses of data from epidemiologic studies of workers exposed to radiation have been based on recorded annual radiation doses. It is usually assumed that the annual dose values are known exactly, although it is generally recognized that the data contain uncertainty due to measurement error and bias. We propose the use of a probability distribution to describe an individual`s dose during a specific period of time. Statistical methods for estimating this dose distribution are developed. The methods take into account the ``measurement error`` that is produced by the dosimetry system, and the bias that was introduced by policies that lead to right censoring of small doses as zero. The method is applied to a sample of dose histories obtained from hard copy dosimetry records at Oak Ridge National Laboratory (ORNL). The result of this evaluation raises serious questions about the validity of the historical personnel dosimetry data that is currently being used in low-dose studies of nuclear industry workers. In particular, it appears that there was a systematic underestimation of doses for ORNL workers. This could result in biased estimates of dose-response coefficients and their standard errors.

  6. Statistics at a glance.

    PubMed

    Ector, Hugo

    2010-12-01

    I still remember my first book on statistics: "Elementary statistics with applications in medicine and the biological sciences" by Frederick E. Croxton. For me, it has been the start of pursuing understanding statistics in daily life and in medical practice. It was the first volume in a long row of books. In his introduction, Croxton pretends that"nearly everyone involved in any aspect of medicine needs to have some knowledge of statistics". The reality is that for many clinicians, statistics are limited to a "P < 0.05 = ok". I do not blame my colleagues who omit the paragraph on statistical methods. They have never had the opportunity to learn concise and clear descriptions of the key features. I have experienced how some authors can describe difficult methods in a well understandable language. Others fail completely. As a teacher, I tell my students that life is impossible without a basic knowledge of statistics. This feeling has resulted in an annual seminar of 90 minutes. This tutorial is the summary of this seminar. It is a summary and a transcription of the best pages I have detected.

  7. Efficacy and safety of betahistine treatment in patients with Meniere’s disease: primary results of a long term, multicentre, double blind, randomised, placebo controlled, dose defining trial (BEMED trial)

    PubMed Central

    Adrion, Christine; Fischer, Carolin Simone; Wagner, Judith; Gürkov, Robert; Mansmann, Ulrich

    2016-01-01

    Study question What is the long term efficacy of betahistine dihydrochloride on the incidence of vertigo attacks in patients with Meniere’s disease, compared with placebo? Methods The BEMED trial is a multicentre, double blind, randomised, placebo controlled, three arm, parallel group, phase III, dose defining superiority trial conducted in 14 German tertiary referral centres (for neurology or ear, nose, and throat). Adults aged 21-80 years (mean age 56 years) with definite unilateral or bilateral Meniere’s disease were recruited from March 2008 to November 2012. Participants received placebo (n=74), low dose betahistine (2×24 mg daily, (n=73)), or high dose betahistine (3×48 mg daily, (n=74)) over nine months. The primary outcome was the number of attacks per 30 days, based on patients’ diaries during a three month assessment period at months seven to nine. An internet based randomisation schedule performed a concealed 1:1:1 allocation, stratified by study site. Secondary outcomes included the duration and severity of attacks, change in quality of life scores, and several observer-reported parameters to assess changes in audiological and vestibular function. Study answer and limitations Incidence of attacks related to Meniere’s disease did not differ between the three treatment groups (P=0.759). Compared with placebo, attack rate ratios were 1.036 (95% confidence interval 0.942 to 1.140) and 1.012 (0.919 to 1.114) for low dose and high dose betahistine, respectively. The overall monthly attack rate fell significantly by the factor 0.758 (0.705 to 0.816; P<0.001). The population based, mean monthly incidence averaged over the assessment period was 2.722 (1.304 to 6.309), 3.204 (1.345 to 7.929), and 3.258 (1.685 to 7.266) for the placebo, low dose betahistine, and high dose betahistine groups, respectively. Results were consistent for all secondary outcomes. Treatment was well tolerated with no unexpected safety findings. Without a control group of

  8. Statistical iterative reconstruction using adaptive fractional order regularization

    PubMed Central

    Zhang, Yi; Wang, Yan; Zhang, Weihua; Lin, Feng; Pu, Yifei; Zhou, Jiliu

    2016-01-01

    In order to reduce the radiation dose of the X-ray computed tomography (CT), low-dose CT has drawn much attention in both clinical and industrial fields. A fractional order model based on statistical iterative reconstruction framework was proposed in this study. To further enhance the performance of the proposed model, an adaptive order selection strategy, determining the fractional order pixel-by-pixel, was given. Experiments, including numerical and clinical cases, illustrated better results than several existing methods, especially, in structure and texture preservation. PMID:27231604

  9. Long term dose monitoring onboard the European Columbus module of the international space station (ISS) in the frame of DOSIS and DOSIS 3D project - results from the active instruments

    NASA Astrophysics Data System (ADS)

    Burmeister, Soenke; Berger, Thomas; Reitz, Guenther; Boehme, Matthias; Haumann, Lutz; Labrenz, Johannes

    Besides the effects of the microgravity environment, and the psychological and psychosocial problems encountered in confined spaces, radiation is the main health detriment for long duration human space missions. The radiation environment encountered in space differs in nature from that on earth, consisting mostly of high energetic ions from protons up to iron, resulting in radiation levels far exceeding the ones encountered on earth for occupational radiation workers. Accurate knowledge of the physical characteristics of the space radiation field in dependence on the solar activity, the orbital parameters and the different shielding configurations of the International Space Station ISS is therefore needed. For the investigation of the spatial and temporal distribution of the radiation field inside the European COLUMBUS module the experiment DOSIS (Dose Distribution Inside the ISS) under the lead of DLR has been launched on July 15 (th) 2009 with STS-127 to the ISS. The experimental package was transferred from the Space Shuttle into COLUMBUS on July 18 (th) . It consists of a combination of passive detector packages (PDP) distributed at 11 locations inside the European Columbus Laboratory and two active radiation detectors (Dosimetry Telescopes = DOSTELs) with a DDPU (DOSTEL Data and Power Unit) in a Nomex pouch (DOSIS MAIN BOX) mounted at a fixed location beneath the European Physiology Module rack (EPM) inside COLUMBUS. The active components of the DOSIS experiment were operational from July 18 (th) 2009 to June 16 (th) 2011. After refurbishment the hardware has been reactivated on May 15 (th) 2012 as active part of the DOSIS 3D experiment and provides continuous data since this activation. The presentation will focus on the latest results from the two DOSTEL instruments as absorbed dose, dose equivalent and the related LET spectra gathered within the DOSIS (2009 - 2011) and DOSIS 3D (2012 - 2014) experiment. The CAU contributions to DOSIS and DOSIS 3D are

  10. Understanding Solar Flare Statistics

    NASA Astrophysics Data System (ADS)

    Wheatland, M. S.

    2005-12-01

    A review is presented of work aimed at understanding solar flare statistics, with emphasis on the well known flare power-law size distribution. Although avalanche models are perhaps the favoured model to describe flare statistics, their physical basis is unclear, and they are divorced from developing ideas in large-scal