Biostatistics with emphasis on life table survival rate calculations (including Kaplan Meier) and the logrank test

International Nuclear Information System (INIS)

Mould, Richard F.

1995-01-01

Purpose/Objective: To explain some of the most useful statistical calculation procedures which are relevant to radiation oncologists and to provide insights on what tests and procedures should be used in various situations such as when survival rates and their associated standard errors have to be determined. To describe some of the problems and pitfalls in clinical trial designs which have to be overcome if a trial is to have the possibility of reaching a successful conclusion. To review methods of computing criteria to quantitatively describe criteria of success (eg. quality of life, long-term survival, cure) of radiation oncology and to suggest possible future statistical improvements in this area. Chi-Squared Test: The chi-squared test is probably the most useful of the tests of statistical significance for the radiation oncologist. Applications will be described, including goodness of fit tests and 2x2 contingency tables which are the simplest of the generalized nxm contingency tables. Degrees of Freedom and P<0.05 for Significance Testing: An Introduction will be given to the meaning of P<0.05 in relation to significance testing and the use of tables of critical values of a test statistic (eg. chi-squared) which are given as a function of degrees of freedom and P-values. Survival Rate Calculations for Grouped and Ungrouped Data: The life-table method (sometimes termed the actuarial method) will be explained for both grouped data (eg. survival times grouped in annual intervals for patients who have died and for those who are still alive or lost to follow-up) and for ungrouped data (when individual survival times are used). The method for ungrouped data is variously termed the Kaplan-Meier or Product Limit method. Logrank Test: This is the most useful test for comparison of the survival experience of two groups of patients and its use will be explained. In part the computation is similar to that for the Kaplan-Meier/Product Limit method

Biostatistics with emphasis on life table survival rate calculations (including Kaplan Meier) and the logrank test

Energy Technology Data Exchange (ETDEWEB)

Mould, Richard F

1995-07-01

Purpose/Objective: To explain some of the most useful statistical calculation procedures which are relevant to radiation oncologists and to provide insights on what tests and procedures should be used in various situations such as when survival rates and their associated standard errors have to be determined. To describe some of the problems and pitfalls in clinical trial designs which have to be overcome if a trial is to have the possibility of reaching a successful conclusion. To review methods of computing criteria to quantitatively describe criteria of success (eg. quality of life, long-term survival, cure) of radiation oncology and to suggest possible future statistical improvements in this area. Chi-Squared Test: The chi-squared test is probably the most useful of the tests of statistical significance for the radiation oncologist. Applications will be described, including goodness of fit tests and 2x2 contingency tables which are the simplest of the generalized nxm contingency tables. Degrees of Freedom and P<0.05 for Significance Testing: An Introduction will be given to the meaning of P<0.05 in relation to significance testing and the use of tables of critical values of a test statistic (eg. chi-squared) which are given as a function of degrees of freedom and P-values. Survival Rate Calculations for Grouped and Ungrouped Data: The life-table method (sometimes termed the actuarial method) will be explained for both grouped data (eg. survival times grouped in annual intervals for patients who have died and for those who are still alive or lost to follow-up) and for ungrouped data (when individual survival times are used). The method for ungrouped data is variously termed the Kaplan-Meier or Product Limit method. Logrank Test: This is the most useful test for comparison of the survival experience of two groups of patients and its use will be explained. In part the computation is similar to that for the Kaplan-Meier/Product Limit method.

RBPJ and EphrinB2 as Molecular Targets to Treat Brain Arteriovenous Malformation in Notch4 Induced Mouse Model

Science.gov (United States)

2017-10-01

of time for mutant mice to moribundity. We recorded numbers of subjects at risk at 0, 25, 50, 75, 100 days old and use the number to generate Kaplan ...Meier curve. We obtained Kaplan -Meier analysis data showed that time to moribundity doubled in Notch4iGOF- EC;RbpjiΔEC mice, as compared to

A review and comparison of methods for recreating individual patient data from published Kaplan-Meier survival curves for economic evaluations: a simulation study.

Science.gov (United States)

Wan, Xiaomin; Peng, Liubao; Li, Yuanjian

2015-01-01

In general, the individual patient-level data (IPD) collected in clinical trials are not available to independent researchers to conduct economic evaluations; researchers only have access to published survival curves and summary statistics. Thus, methods that use published survival curves and summary statistics to reproduce statistics for economic evaluations are essential. Four methods have been identified: two traditional methods 1) least squares method, 2) graphical method; and two recently proposed methods by 3) Hoyle and Henley, 4) Guyot et al. The four methods were first individually reviewed and subsequently assessed regarding their abilities to estimate mean survival through a simulation study. A number of different scenarios were developed that comprised combinations of various sample sizes, censoring rates and parametric survival distributions. One thousand simulated survival datasets were generated for each scenario, and all methods were applied to actual IPD. The uncertainty in the estimate of mean survival time was also captured. All methods provided accurate estimates of the mean survival time when the sample size was 500 and a Weibull distribution was used. When the sample size was 100 and the Weibull distribution was used, the Guyot et al. method was almost as accurate as the Hoyle and Henley method; however, more biases were identified in the traditional methods. When a lognormal distribution was used, the Guyot et al. method generated noticeably less bias and a more accurate uncertainty compared with the Hoyle and Henley method. The traditional methods should not be preferred because of their remarkable overestimation. When the Weibull distribution was used for a fitted model, the Guyot et al. method was almost as accurate as the Hoyle and Henley method. However, if the lognormal distribution was used, the Guyot et al. method was less biased compared with the Hoyle and Henley method.

C-reactive protein-to-albumin ratio is a predictor of hepatitis B virus related decompensated cirrhosis: time-dependent receiver operating characteristics and decision curve analysis.

Science.gov (United States)

Huang, Si-Si; Xie, Dong-Mei; Cai, Yi-Jing; Wu, Jian-Min; Chen, Rui-Chong; Wang, Xiao-Dong; Song, Mei; Zheng, Ming-Hua; Wang, Yu-Qun; Lin, Zhuo; Shi, Ke-Qing

2017-04-01

Hepatitis B virus (HBV) infection remains a major health problem and HBV-related-decompensated cirrhosis (HBV-DC) usually leads to a poor prognosis. Our aim was to determine the utility of inflammatory biomarkers in predicting mortality of HBV-DC. A total of 329 HBV-DC patients were enrolled. Survival estimates for the entire study population were generated using the Kaplan-Meier method. The prognostic values for model for end-stage liver disease (MELD) score, Child-Pugh score, and inflammatory biomarkers neutrophil/lymphocyte ratio, C-reactive protein-to-albumin ratio (CAR), and lymphocyte-to-monocyte ratio (LMR) for HBV-DC were compared using time-dependent receiver operating characteristic curves and time-dependent decision curves. The survival time was 23.1±15.8 months. Multivariate analysis identified age, CAR, LMR, and platelet count as prognostic independent risk factors. Kaplan-Meier analysis indicated that CAR of at least 1.0 (hazard ratio, 7.19; 95% confidence interval, 4.69-11.03), and LMR less than 1.9 (hazard ratio, 2.40; 95% confidence interval, 1.69-3.41) were independently associated with mortality of HBV-DC. The time-dependent receiver operating characteristic indicated that CAR showed the best performance in predicting mortality of HBV-DC compared with LMR, MELD score, and Child-Pugh score. The results were also confirmed by time-dependent decision curves. CAR and LMR were associated with the prognosis of HBV-DC. CAR was superior to LMR, MELD score, and Child-Pugh score in HBV-DC mortality prediction.

Targeting Peripheral-Derived Regulatory T Cells as a Means of Enhancing Immune Responses Directed against Prostate Cancer

Science.gov (United States)

2017-08-01

28 weeks) to complete this study. Furthermore, using Kaplan - Meier survival curves, we have discovered that TR AMP; L ck-cre; Klf2fl/fl mice do...3 2 Thymus Spleen Thymus Spleen FoxP3 FoxP3 Figure 2. Kaplan -Meier survival curve. TRAMP (black) versus TRAMP; Lck-cre; Klf2fl/fl (red) survival

Bias and precision of methods for estimating the difference in restricted mean survival time from an individual patient data meta-analysis

Directory of Open Access Journals (Sweden)

Béranger Lueza

2016-03-01

Full Text Available Abstract Background The difference in restricted mean survival time ( rmstD t ∗ $$ rmstD\\left({t}^{\\ast}\\right $$ , the area between two survival curves up to time horizon t ∗ $$ {t}^{\\ast } $$ , is often used in cost-effectiveness analyses to estimate the treatment effect in randomized controlled trials. A challenge in individual patient data (IPD meta-analyses is to account for the trial effect. We aimed at comparing different methods to estimate the rmstD t ∗ $$ rmstD\\left({t}^{\\ast}\\right $$ from an IPD meta-analysis. Methods We compared four methods: the area between Kaplan-Meier curves (experimental vs. control arm ignoring the trial effect (Naïve Kaplan-Meier; the area between Peto curves computed at quintiles of event times (Peto-quintile; the weighted average of the areas between either trial-specific Kaplan-Meier curves (Pooled Kaplan-Meier or trial-specific exponential curves (Pooled Exponential. In a simulation study, we varied the between-trial heterogeneity for the baseline hazard and for the treatment effect (possibly correlated, the overall treatment effect, the time horizon t ∗ $$ {t}^{\\ast } $$ , the number of trials and of patients, the use of fixed or DerSimonian-Laird random effects model, and the proportionality of hazards. We compared the methods in terms of bias, empirical and average standard errors. We used IPD from the Meta-Analysis of Chemotherapy in Nasopharynx Carcinoma (MAC-NPC and its updated version MAC-NPC2 for illustration that included respectively 1,975 and 5,028 patients in 11 and 23 comparisons. Results The Naïve Kaplan-Meier method was unbiased, whereas the Pooled Exponential and, to a much lesser extent, the Pooled Kaplan-Meier methods showed a bias with non-proportional hazards. The Peto-quintile method underestimated the rmstD t ∗ $$ rmstD\\left({t}^{\\ast}\\right $$ , except with non-proportional hazards at t ∗ $$ {t}^{\\ast } $$ = 5 years. In the presence of treatment effect

Dynamic Model of Kaplan Turbine Regulating System Suitable for Power System Analysis

Directory of Open Access Journals (Sweden)

Jie Zhao

2015-01-01

Full Text Available Accurate modeling of Kaplan turbine regulating system is of great significance for grid security and stability analysis. In this paper, Kaplan turbine regulating system model is divided into the governor system model, the blade control system model, and the turbine and water diversion system model. The Kaplan turbine has its particularity, and the on-cam relationship between the wicket gate opening and the runner blade angle under a certain water head on the whole range was obtained by high-order curve fitting method. Progressively the linearized Kaplan turbine model, improved ideal Kaplan turbine model, and nonlinear Kaplan turbine model were developed. The nonlinear Kaplan turbine model considered the correction function of the blade angle on the turbine power, thereby improving the model simulation accuracy. The model parameters were calculated or obtained by the improved particle swarm optimization (IPSO algorithm. For the blade control system model, the default blade servomotor time constant given by value of one simplified the modeling and experimental work. Further studies combined with measured test data verified the established model accuracy and laid a foundation for further research into the influence of Kaplan turbine connecting to the grid.

Applying Kaplan-Meier to Item Response Data

Science.gov (United States)

McNeish, Daniel

2018-01-01

Some IRT models can be equivalently modeled in alternative frameworks such as logistic regression. Logistic regression can also model time-to-event data, which concerns the probability of an event occurring over time. Using the relation between time-to-event models and logistic regression and the relation between logistic regression and IRT, this…

Image scaling curve generation

NARCIS (Netherlands)

2012-01-01

The present invention relates to a method of generating an image scaling curve, where local saliency is detected in a received image. The detected local saliency is then accumulated in the first direction. A final scaling curve is derived from the detected local saliency and the image is then

Image scaling curve generation.

NARCIS (Netherlands)

2011-01-01

The present invention relates to a method of generating an image scaling curve, where local saliency is detected in a received image. The detected local saliency is then accumulated in the first direction. A final scaling curve is derived from the detected local saliency and the image is then

Deciphering the Adaptive Immune Response to Ovarian Cancer

Science.gov (United States)

2013-10-01

positive for CD8þ TIL. Conversely, of the cases that were positive for CD8þ TIL, approximately half also contained CD20þ TIL. By Kaplan –Meier analysis...and D). Scale bars: 100 mm (A and B) or 50 mm (C and D). Representative of 5 tumor samples. E, Kaplan –Meier curves showing that the presence of both...CH, Subramanian S, van de Rijn M, Turbin D, et al. Intraepithelial T cells and prognosis in ovarian carcinoma: novel associations with stage, tumor

Meier-Gorlin syndrome

NARCIS (Netherlands)

Munnik, S.A. de; Hoefsloot, E.H.; Roukema, J.; Schoots, J.; Knoers, N.V.A.M.; Brunner, H.G.; Jackson, A.P.; Bongers, E.M.H.F.

2015-01-01

Meier-Gorlin syndrome (MGS) is a rare autosomal recessive primordial dwarfism disorder, characterized by microtia, patellar applasia/hypoplasia, and a proportionate short stature. Associated clinical features encompass feeding problems, congenital pulmonary emphysema, mammary hypoplasia in females

Algorithm for Automatic Generation of Curved and Compound Twills

Institute of Scientific and Technical Information of China (English)

WANG Mei-zhen; WANG Fu-mei; WANG Shan-yuan

2005-01-01

A new arithmetic using matrix left-shift functions for the quicker generation of curved and compound twills is introduced in this paper. A matrix model for the generation of regular, curved and compound twill structures is established and its computing simulation realization are elaborated. Examples of the algorithm applying in the simulation and the automatic generation of curved and compound twills in fabric CAD are obtained.

Meier-Gorlin syndrome

OpenAIRE

de Munnik, Sonja A; Hoefsloot, Elisabeth H; Roukema, Jolt; Schoots, Jeroen; Knoers, Nine V A M; Brunner, Han G; Jackson, Andrew P; Bongers, Ernie M H F

2015-01-01

Meier-Gorlin syndrome (MGS) is a rare autosomal recessive primordial dwarfism disorder, characterized by microtia, patellar applasia/hypoplasia, and a proportionate short stature. Associated clinical features encompass feeding problems, congenital pulmonary emphysema, mammary hypoplasia in females and urogenital anomalies, such as cryptorchidism and hypoplastic labia minora and majora. Typical facial characteristics during childhood comprise a small mouth with full lips and micro-retrognathia...

Dose-response curves from incomplete data

International Nuclear Information System (INIS)

Groer, P.G.

1978-01-01

Frequently many different responses occur in populations (animal or human) exposed to ionizing radiation. To obtain a dose-response curve, the exposed population is first divided into sub-groups whose members received the same radiation dose. To estimate the response, the fraction of subjects in each sub-group that showed the particular response of interest is determined. These fractions are plotted against dose to give the dose-response curve. This procedure of plotting the fractions versus the radiation dose is not the correct way to estimate the time distribution for a particular response at the different dose levels. Other observed responses competed for the individuals in the exposed population and therefore prevented manifestation of the complete information on the response-time distribution for one specific response. Such data are called incomplete in the statistical literature. A procedure is described which uses the by now classical Kaplan-Meier estimator, to establish dose-response curves from incomplete data under the assumption that the different observed responses are statistically independent. It is demonstrated that there is insufficient information in the observed survival functions to estimate the time distribution for one particular response if the assumption of independence is dropped. In addition, it is not possible to determine from the data (i.e. type of response and when it occurred) whether or not the different response-time distributions are independent. However, it is possible to give sharp bounds between which the response has to lie. This implies that for incomplete data, only a 'dose-response band' can be established if independence of the competing responses cannot be assumed. Examples are given using actual data to illustrate the estimation procedures

Generation dependent cancer targeting potential of poly(propyleneimine) dendrimer.

Science.gov (United States)

Kesharwani, Prashant; Tekade, Rakesh K; Jain, Narendra K

2014-07-01

Dendrimer-mediated delivery of bioactive is a successful and widely explored concept. This paper desribes comparative data pertaining to generation dependent cancer targeting propensity of Poly(propyleneimine) (PPI) dendrimers. This debut report reportsthe drug targeting and antciancer potential of different dendrimer generations. PPI dendrimers of different generations (3.0G, 4.0G and 5.0G) were synthesized and loaded with Melphalan. Results from loading, hemolysis, hematologic, cytotoxicty and flow cytometry assay depicted that as the generation of dendrimer increased from fourth to fifth, the only parameter i.e. toxicty is increased exponentionally. However, others parameters, i.e. loading, sustained release behavior, and targeting efficacy increased negligibly. Kaplan-Meier survival curves clearly depicted comparable therapeutic potential of PPI4M with PPI5M. In vivo investigations in Balb/c mice again favored 4.0G PPI dendrimer to be preferable nanocarrier for anticancer drug delivery owing to analogous anticancer potential. The outcomes of the investigation evidently projects 4.0G PPI dendrimer over 3.0G and 5.0G dendrimer in respect of its drug delivery benefit as well as superior biocompatibility. Thus, much against the common belief, 4.0G PPI dendrimers may be considered to be optimum in respect of drug delivery precluding the use of much more toxic 5.0G PPI dendrimer, which offers no benefit over 4.0G. Copyright © 2014 Elsevier Ltd. All rights reserved.

Elevated plasma vitamin B12 levels and cancer prognosis: A population-based cohort study

DEFF Research Database (Denmark)

Arendt, Johan Frederik Håkonsen; Farkas, Dora Kormendine; Pedersen, Lars

2015-01-01

patients without a plasma Cbl measurement. Patients treated with Cbl were excluded. Survival probability was assessed using Kaplan-Meier curves. Mortality risk ratios (MRR) were computed using Cox proportional hazard regression, adjusted for age, sex, calendar year, cancer stage and comorbidity, scored...

Third-line Targeted Therapy in Metastatic Renal Cell Carcinoma: Results from the International Metastatic Renal Cell Carcinoma Database Consortium

DEFF Research Database (Denmark)

Wells, J Connor; Stukalin, Igor; Norton, Craig

2017-01-01

and were included in the analysis. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Patients were analyzed for overall survival (OS) and progression-free survival using Kaplan-Meier curves, and were evaluated for overall response. Cox regression analyses were used to determine the statistical association...

The impact of engagement in street-based income generation activities on stimulant drug use cessation among people who inject drugs.

Science.gov (United States)

Ti, Lianping; Richardson, Lindsey; DeBeck, Kora; Nguyen, Paul; Montaner, Julio; Wood, Evan; Kerr, Thomas

2014-08-01

Despite the growing prevalence of illicit stimulant drug use internationally, and the widespread involvement of people who inject drugs (IDU) within street-based drug markets, little is known about the impact of different types of street-based income generation activities on the cessation of stimulant use among IDU. Data were derived from an open prospective cohort of IDU in Vancouver, Canada. We used Kaplan-Meier methods and Cox proportional hazards regression to examine the effect of different types of street-based income generation activities (e.g., sex work, drug dealing, and scavenging) on time to cessation of stimulant use. Between December, 2005 and November, 2012, 887 IDU who use stimulant drugs (cocaine, crack cocaine, or crystal methamphetamine) were prospectively followed-up for a median duration of 47 months. In Kaplan-Meier analyses, compared to those who did not engage in street-based income generation activities, participants who reported sex work, drug dealing, scavenging, or more than one of these activities were significantly less likely to report stimulant drug use cessation (all pstreet-based income generation activity remained significantly associated with a slower time to stimulant drug cessation (all p<0.005). Our findings highlight the urgent need for strategies to address stimulant dependence, including novel pharmacotherapies. Also important, structural interventions, such as low-threshold employment opportunities, availability of supportive housing, legal reforms regarding drug use, and evidence-based approaches that reduce harm among IDU are urgently required. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Analyzing survival curves at a fixed point in time for paired and clustered right-censored data

Science.gov (United States)

Su, Pei-Fang; Chi, Yunchan; Lee, Chun-Yi; Shyr, Yu; Liao, Yi-De

2018-01-01

In clinical trials, information about certain time points may be of interest in making decisions about treatment effectiveness. Rather than comparing entire survival curves, researchers can focus on the comparison at fixed time points that may have a clinical utility for patients. For two independent samples of right-censored data, Klein et al. (2007) compared survival probabilities at a fixed time point by studying a number of tests based on some transformations of the Kaplan-Meier estimators of the survival function. However, to compare the survival probabilities at a fixed time point for paired right-censored data or clustered right-censored data, their approach would need to be modified. In this paper, we extend the statistics to accommodate the possible within-paired correlation and within-clustered correlation, respectively. We use simulation studies to present comparative results. Finally, we illustrate the implementation of these methods using two real data sets. PMID:29456280

Age at sexual initiation and factors associated with it among youths ...

African Journals Online (AJOL)

Bernt Lindtjorn

Objective: The objective of the study was to determine the median age at first sexual intercourse and the associated .... Wollo Zone, Amhara National Regional State, North East ..... censored. Urba n. Rura l. Residence rural/urban. Fig 2: Kaplan Meier curve showing log survival for ..... renting and selling pornography films.

Epilepsy in Rett syndrome--lessons from the Rett networked database

DEFF Research Database (Denmark)

Nissenkorn, Andreea; Levy-Drummer, Rachel S; Bondi, Ori

2015-01-01

collected. Statistical analysis was done using the IBM SPSS Version 21 software, logistic regression, and Kaplan-Meier survival curves. RESULTS: Epilepsy was present in 68.1% of the patients, with uncontrolled seizures in 32.6% of the patients with epilepsy. Mean age of onset of epilepsy was 4...

The S-curve for forecasting waste generation in construction projects.

Science.gov (United States)

Lu, Weisheng; Peng, Yi; Chen, Xi; Skitmore, Martin; Zhang, Xiaoling

2016-10-01

Forecasting construction waste generation is the yardstick of any effort by policy-makers, researchers, practitioners and the like to manage construction and demolition (C&D) waste. This paper develops and tests an S-curve model to indicate accumulative waste generation as a project progresses. Using 37,148 disposal records generated from 138 building projects in Hong Kong in four consecutive years from January 2011 to June 2015, a wide range of potential S-curve models are examined, and as a result, the formula that best fits the historical data set is found. The S-curve model is then further linked to project characteristics using artificial neural networks (ANNs) so that it can be used to forecast waste generation in future construction projects. It was found that, among the S-curve models, cumulative logistic distribution is the best formula to fit the historical data. Meanwhile, contract sum, location, public-private nature, and duration can be used to forecast construction waste generation. The study provides contractors with not only an S-curve model to forecast overall waste generation before a project commences, but also with a detailed baseline to benchmark and manage waste during the course of construction. The major contribution of this paper is to the body of knowledge in the field of construction waste generation forecasting. By examining it with an S-curve model, the study elevates construction waste management to a level equivalent to project cost management where the model has already been readily accepted as a standard tool. Copyright © 2016 Elsevier Ltd. All rights reserved.

Genetics Home Reference: Meier-Gorlin syndrome

Science.gov (United States)

... Additional NIH Resources (1 link) National Institute of Neurological Disorders and Stroke: Microcephaly Information Page Educational Resources (10 links) Boston Children's Hospital: Growth Problems Disease InfoSearch: Meier-Gorlin syndrome ...

ON THE TOPOLOGY OF MECHANISMS DESIGNED FOR CURVES GENERATION

Directory of Open Access Journals (Sweden)

MEREUTA Elena

2008-07-01

Full Text Available The paper presents some mechanisms used for generating simple or complex curves. The mechanisms are shown in different positions and for some special curves the demonstrations are performed.

Curvature Entropy for Curved Profile Generation

Directory of Open Access Journals (Sweden)

Koichiro Sato

2012-03-01

Full Text Available In a curved surface design, the overall shape features that emerge from combinations of shape elements are important. However, controlling the features of the overall shape in curved profiles is difficult using conventional microscopic shape information such as dimension. Herein two types of macroscopic shape information, curvature entropy and quadrature curvature entropy, quantitatively represent the features of the overall shape. The curvature entropy is calculated by the curvature distribution, and represents the complexity of a shape (one of the overall shape features. The quadrature curvature entropy is an improvement of the curvature entropy by introducing a Markov process to evaluate the continuity of a curvature and to approximate human cognition of the shape. Additionally, a shape generation method using a genetic algorithm as a calculator and the entropy as a shape generation index is presented. Finally, the applicability of the proposed method is demonstrated using the side view of an automobile as a design example.

Numerical investigation of hub clearance flow in a Kaplan turbine

Science.gov (United States)

Wu, H.; Feng, J. J.; Wu, G. K.; Luo, X. Q.

2012-11-01

In this paper, the flow field considering the hub clearance flow in a Kaplan turbine has been investigated through using the commercial CFD code ANSYS CFX based on high-quality structured grids generated by ANSYS ICEM CFD. The turbulence is simulated by k-ω based shear stress transport (SST) turbulence model together with automatic near wall treatments. Four kinds of simulations have been conducted for the runner geometry without hub clearance, with only the hub front clearance, with only the rear hub clearance, and with both front and rear clearance. The analysis of the obtained results is focused on the flow structure of the hub clearance flow, the effect on the turbine performance including hydraulic efficiency and cavitation performance, which can improve the understanding on the flow field in a Kaplan turbine.

Numerical investigation of hub clearance flow in a Kaplan turbine

International Nuclear Information System (INIS)

Wu, H; Feng, J J; Wu, G K; Luo, X Q

2012-01-01

In this paper, the flow field considering the hub clearance flow in a Kaplan turbine has been investigated through using the commercial CFD code ANSYS CFX based on high-quality structured grids generated by ANSYS ICEM CFD. The turbulence is simulated by k-ω based shear stress transport (SST) turbulence model together with automatic near wall treatments. Four kinds of simulations have been conducted for the runner geometry without hub clearance, with only the hub front clearance, with only the rear hub clearance, and with both front and rear clearance. The analysis of the obtained results is focused on the flow structure of the hub clearance flow, the effect on the turbine performance including hydraulic efficiency and cavitation performance, which can improve the understanding on the flow field in a Kaplan turbine.

Birth interval and its predictors among married women in Dabat ...

African Journals Online (AJOL)

2008-12-30

Birth intervals (time between two successive live births) if short are associated with diverse complications. We assessed birth interval and its predictors among 613 married women who gave birth from January 1 to December 30, 2008. Data were collected in April 2012. Life table and Kaplan-Meier curve were used to ...

Role of IKK-alpha in the EGFR Signaling Regulation

Science.gov (United States)

2014-09-01

expression. (E) Kaplan -Meier overall survival curves of IKKin breast cancer patient data set. 16 Reference 1. Lo, H. W., Xia, W., Wei, Y...150- 100- 50- 150- 100- Twist1 AKT1-p AKT-T C 250- 150- 100- N-cad P1 P2 P3 TGFβ - - - + + - + + - - + - - + + + - - + - - + + + 50- Vimentin 150- 100

Bandwidth increasing mechanism by introducing a curve fixture to the cantilever generator

Energy Technology Data Exchange (ETDEWEB)

Liu, Weiqun, E-mail: weiqunliu@home.swjtu.edu.cn; Liu, Congzhi; Ren, Bingyu; Zhu, Qiao; Hu, Guangdi [School of Mechanical Engineering, Southwest Jiaotong University, 610031 Chengdu (China); Yang, Weiqing [School of Materials Science and Engineering, Southwest Jiaotong University, 610031 Chengdu (China)

2016-07-25

A nonlinear wideband generator architecture by clamping the cantilever beam generator with a curve fixture is proposed. Devices with different nonlinear stiffness can be obtained by properly choosing the fixture curve according to the design requirements. Three available generator types are presented and discussed for polynomial curves. Experimental investigations show that the proposed mechanism effectively extends the operation bandwidth with good power performance. Especially, the simplicity and easy feasibility allow the mechanism to be widely applied for vibration generators in different scales and environments.

Research of Cubic Bezier Curve NC Interpolation Signal Generator

Directory of Open Access Journals (Sweden)

Shijun Ji

2014-08-01

Full Text Available Interpolation technology is the core of the computer numerical control (CNC system, and the precision and stability of the interpolation algorithm directly affect the machining precision and speed of CNC system. Most of the existing numerical control interpolation technology can only achieve circular arc interpolation, linear interpolation or parabola interpolation, but for the numerical control (NC machining of parts with complicated surface, it needs to establish the mathematical model and generate the curved line and curved surface outline of parts and then discrete the generated parts outline into a large amount of straight line or arc to carry on the processing, which creates the complex program and a large amount of code, so it inevitably introduce into the approximation error. All these factors affect the machining accuracy, surface roughness and machining efficiency. The stepless interpolation of cubic Bezier curve controlled by analog signal is studied in this paper, the tool motion trajectory of Bezier curve can be directly planned out in CNC system by adjusting control points, and then these data were put into the control motor which can complete the precise feeding of Bezier curve. This method realized the improvement of CNC trajectory controlled ability from the simple linear and circular arc to the complex project curve, and it provides a new way for economy realizing the curve surface parts with high quality and high efficiency machining.

Automatic generation and analysis of solar cell IV curves

Science.gov (United States)

Kraft, Steven M.; Jones, Jason C.

2014-06-03

A photovoltaic system includes multiple strings of solar panels and a device presenting a DC load to the strings of solar panels. Output currents of the strings of solar panels may be sensed and provided to a computer that generates current-voltage (IV) curves of the strings of solar panels. Output voltages of the string of solar panels may be sensed at the string or at the device presenting the DC load. The DC load may be varied. Output currents of the strings of solar panels responsive to the variation of the DC load are sensed to generate IV curves of the strings of solar panels. IV curves may be compared and analyzed to evaluate performance of and detect problems with a string of solar panels.

MAINTAINANCE OF KAPLAN TURBINE TO ENHANCE THE EFFICIENCY

OpenAIRE

Mr. Shakti Prasanna Khadanga*; Nitish Kumar; Milind Kumar Singh; L. Raj Kumar

2016-01-01

Hydro power plant is the source of renewable energy which leads to reduction in burning of fossil fuels. So the environment is no longer polluted. This project depicts how sediment erosion occurs in Kaplan turbine and the various components of Kaplan turbine where actually erosion takes place. It reduces efficiency [7] and life of hydro power turbine but also causes problems in operations and maintenance. We conducted some necessary test on Kaplan turbine in fluid power laboratory. We are d...

Análisis de supervivencia en presencia de riesgos competitivos: estimadores de la probabilidad de suceso Survival analysis with competing risks: estimating failure probability

Directory of Open Access Journals (Sweden)

Javier Llorca

2004-10-01

Full Text Available Objetivo: Mostrar el efecto de los riesgos competitivos de muerte en el análisis de supervivencia. Métodos: Se presenta un ejemplo sobre la supervivencia libre de rechazo tras un trasplante cardíaco, en el que la muerte antes de desarrollar el rechazo actúa como riesgo competitivo. Mediante una simulación se comparan el estimador de Kaplan-Meier y el modelo de decrementos múltiples. Resultados: El método de Kaplan-Meier sobrestima el riesgo de rechazo. A continuación, se expone la aplicación del modelo de decrementos múltiples para el análisis de acontecimientos secundarios (en el ejemplo, la muerte tras el rechazo. Finalmente, se discuten las asunciones propias del método de Kaplan-Meier y las razones por las que no puede ser aplicado en presencia de riesgos competitivos. Conclusiones: El análisis de supervivencia debe ajustarse por los riesgos competitivos de muerte para evitar la sobrestimación del riesgo de fallo que se produce con el método de Kaplan-Meier.Objective: To show the impact of competing risks of death on survival analysis. Method: We provide an example of survival time without chronic rejection after heart transplantation, where death before rejection acts as a competing risk. Using a computer simulation, we compare the Kaplan-Meier estimator and the multiple decrement model. Results: The Kaplan-Meier method overestimated the probability of rejection. Next, we illustrate the use of the multiple decrement model to analyze secondary end points (in our example: death after rejection. Finally, we discuss Kaplan-Meier assumptions and why they fail in the presence of competing risks. Conclusions: Survival analysis should be adjusted for competing risks of death to avoid overestimation of the risk of rejection produced with the Kaplan-Meier method.

[Survival analysis with competing risks: estimating failure probability].

Science.gov (United States)

Llorca, Javier; Delgado-Rodríguez, Miguel

2004-01-01

To show the impact of competing risks of death on survival analysis. We provide an example of survival time without chronic rejection after heart transplantation, where death before rejection acts as a competing risk. Using a computer simulation, we compare the Kaplan-Meier estimator and the multiple decrement model. The Kaplan-Meier method overestimated the probability of rejection. Next, we illustrate the use of the multiple decrement model to analyze secondary end points (in our example: death after rejection). Finally, we discuss Kaplan-Meier assumptions and why they fail in the presence of competing risks. Survival analysis should be adjusted for competing risks of death to avoid overestimation of the risk of rejection produced with the Kaplan-Meier method.

Meier-Gorlin syndrome Clinical genetics and genomics

NARCIS (Netherlands)

S. de Munnik (Sonja); E.H. Hoefsloot (Lies); J. Roukema (Jolt); J. Schoots (Jeroen); N.V.A.M. Knoers (Nine); H.G. Brunner; A.P. Jackson (Andrew); E. Bongers (Ernie)

2015-01-01

textabstractMeier-Gorlin syndrome (MGS) is a rare autosomal recessive primordial dwarfism disorder, characterized by microtia, patellar applasia/hypoplasia, and a proportionate short stature. Associated clinical features encompass feeding problems, congenital pulmonary emphysema, mammary hypoplasia

Meier-Gorlin syndrome Clinical genetics and genomics

NARCIS (Netherlands)

De Munnik, Sonja A.; Hoefsloot, Elisabeth H.; Roukema, Jolt; Schoots, Jeroen; Knoers, Nine Vam; Brunner, Han G.; Jackson, Andrew P.; Bongers, Ernie Mhf

2015-01-01

Meier-Gorlin syndrome (MGS) is a rare autosomal recessive primordial dwarfism disorder, characterized by microtia, patellar applasia/hypoplasia, and a proportionate short stature. Associated clinical features encompass feeding problems, congenital pulmonary emphysema, mammary hypoplasia in females

Kaplan SpellRead. What Works Clearinghouse Intervention Report

Science.gov (United States)

What Works Clearinghouse, 2007

2007-01-01

"Kaplan SpellRead" (formerly known as "SpellRead Phonological Auditory Training"[R]) is a literacy program for struggling readers in grades 2 or above, including special education students, English language learners, and students more than two years below grade level in reading. "Kaplan SpellRead" integrates the…

Optimization of Kaplan turbines. A contribution to economic efficiency; Optimierung von Kaplan-Turbinen. Ein Beitrag zur Betriebswirtschaftlichkeit

Energy Technology Data Exchange (ETDEWEB)

Sevcik, Petr

2009-07-01

The Kaplan turbine has the best theoretical efficiency chart in the total range of operation. In order to achieve these good properties, the turbine has to be adjusted optimally. In general, these settings are performed by the manufacturer of turbines during commissioning. In practice one often meets Kaplan turbines where the scenery does not correspond to the optimal control line. The author of the contribution under consideration reports on possible causes for these errors and also methods of how this scenery can be optimized cost-effectively and how to minimize power losses.

On a framework for generating PoD curves assisted by numerical simulations

Energy Technology Data Exchange (ETDEWEB)

Subair, S. Mohamed, E-mail: prajagopal@iitm.ac.in; Agrawal, Shweta, E-mail: prajagopal@iitm.ac.in; Balasubramaniam, Krishnan, E-mail: prajagopal@iitm.ac.in; Rajagopal, Prabhu, E-mail: prajagopal@iitm.ac.in [Indian Institute of Technology Madras, Department of Mechanical Engineering, Chennai, T.N. (India); Kumar, Anish; Rao, Purnachandra B.; Tamanna, Jayakumar [Indira Gandhi Centre for Atomic Research, Metallurgy and Materials Group, Kalpakkam, T.N. (India)

2015-03-31

The Probability of Detection (PoD) curve method has emerged as an important tool for the assessment of the performance of NDE techniques, a topic of particular interest to the nuclear industry where inspection qualification is very important. The conventional experimental means of generating PoD curves though, can be expensive, requiring large data sets (covering defects and test conditions), and equipment and operator time. Several methods of achieving faster estimates for PoD curves using physics-based modelling have been developed to address this problem. Numerical modelling techniques are also attractive, especially given the ever-increasing computational power available to scientists today. Here we develop procedures for obtaining PoD curves, assisted by numerical simulation and based on Bayesian statistics. Numerical simulations are performed using Finite Element analysis for factors that are assumed to be independent, random and normally distributed. PoD curves so generated are compared with experiments on austenitic stainless steel (SS) plates with artificially created notches. We examine issues affecting the PoD curve generation process including codes, standards, distribution of defect parameters and the choice of the noise threshold. We also study the assumption of normal distribution for signal response parameters and consider strategies for dealing with data that may be more complex or sparse to justify this. These topics are addressed and illustrated through the example case of generation of PoD curves for pulse-echo ultrasonic inspection of vertical surface-breaking cracks in SS plates.

Interview with Danny Kaplan

Science.gov (United States)

Rossman, Allan; Kaplan, Danny

2017-01-01

Danny Kaplan is DeWitt Wallace Professor of Mathematics and Computer Science at Macalester College. He received Macalester's Excellence in teaching Award in 2006 and the CAUSE/USCOTS Lifetime Achievement Award in 2017. This interview took place via email on March 4-June 17, 2017. Topics covered in the interview include: (1) the current state of…

Design of a Kaplan turbine for a wide range of operating head -Curved draft tube design and model test verification-

Science.gov (United States)

KO, Pohan; MATSUMOTO, Kiyoshi; OHTAKE, Norio; DING, Hua

2016-11-01

As for turbomachine off-design performance improvement is challenging but critical for maximising the performing area. In this paper, a curved draft tube for a medium head Kaplan type hydro turbine is introduced and discussed for its significant effect on expanding operating head range. Without adding any extra structure and working fluid for swirl destruction and damping, a carefully designed outline shape of draft tube with the selected placement of center-piers successfully supresses the growth of turbulence eddy and the transport of the swirl to the outlet. Also, more kinetic energy is recovered and the head lost is improved. Finally, the model test results are also presented. The obvious performance improvement was found in the lower net head area, where the maximum efficiency improvement was measured up to 20% without compromising the best efficiency point. Additionally, this design results in a new draft tube more compact in size and so leads to better construction and manufacturing cost performance for prototype. The draft tube geometry parameter designing process was concerning the best efficiency point together with the off-design points covering various water net heads and discharges. The hydraulic performance and flow behavior was numerically previewed and visualized by solving Reynolds-Averaged Navier-Stokes equations with Shear Stress Transport turbulence model. The simulation was under the assumption of steady-state incompressible turbulence flow inside the flow passage, and the inlet boundary condition was the carefully simulated flow pattern from the runner outlet. For confirmation, the corresponding turbine efficiency performance of the entire operating area was verified by model test.

Time trends in recurrence of juvenile nasopharyngeal angiofibroma: Experience of the past 4 decades.

Science.gov (United States)

Mishra, Anupam; Mishra, Subhash Chandra

2016-01-01

An analysis of time distribution of juvenile nasopharyngeal angiofibroma (JNA) from the last 4 decades is presented. Sixty recurrences were analyzed as per actuarial survival. SPSS software was used to generate Kaplan-Meier (KM) curves and time distributions were compared by Log-rank, Breslow and Tarone-Ware test. The overall recurrence rate was 17.59%. Majority underwent open transpalatal approach(es) without embolization. The probability of detecting a recurrence was 95% in first 24months and comparison of KM curves of 4 different time periods was not significant. This is the first and largest series to address the time-distribution. The required follow up period is 2years. Our recurrence is just half of the largest series (reported so far) suggesting the superiority of transpalatal techniques. The similarity of curves suggests less likelihood for recent technical advances to influence the recurrence that as per our hypothesis is more likely to reflect tumor biology per se. Copyright © 2016 Elsevier Inc. All rights reserved.

A generative Bezier curve model for surf-zone tracking in coastal image sequences

CSIR Research Space (South Africa)

Burke, Michael G

2017-09-01

Full Text Available This work introduces a generative Bezier curve model suitable for surf-zone curve tracking in coastal image sequences. The model combines an adaptive curve parametrised by control points governed by local random walks with a global sinusoidal motion...

Role of IKK-alpha in EGFR Signaling Regulation

Science.gov (United States)

2013-09-01

heatmap. (B) Low expression of ΙΚΚα in TNBC cell lines. (C) Low expression of ΙΚΚα in TNBC cell lines. (D) Kaplan -Meier overall survival curves of...0.2 150- 100- 50- 150- 100- 0.5 50- 50- - - + + - + - + Vimentin E-cad N-cad 150- 100- 50- 150- 100- Twist1 AKT-p AKT-T C 250- 150- 100- N-cad P1 P2 P3

Short-term mortality in patients with myocardial injury and myocardial infarction type 1 and type 2

DEFF Research Database (Denmark)

Sarkisian, Laura; Saaby, L.; Poulsen, T. S.

2015-01-01

-year period we prospectively studied hospitalized patients having cardiac troponin I (cTnI) measured on clinical indication. The diagnosis of type 1 and type 2 MI was according to the universal definition involving a rising and/or falling pattern of cTnI values above the decision limit of 30 ng/L. c....... The results are depicted in the figure (Kaplan-Meier curves, log-rank-test; p-value...

Meier-Gorlin syndrome Clinical genetics and genomics

OpenAIRE

Munnik, Sonja; Hoefsloot, Lies; Roukema, Jolt; Schoots, Jeroen; Knoers, Nine; Brunner, H.G.; Jackson, Andrew; Bongers, Ernie

2015-01-01

textabstractMeier-Gorlin syndrome (MGS) is a rare autosomal recessive primordial dwarfism disorder, characterized by microtia, patellar applasia/hypoplasia, and a proportionate short stature. Associated clinical features encompass feeding problems, congenital pulmonary emphysema, mammary hypoplasia in females and urogenital anomalies, such as cryptorchidism and hypoplastic labia minora and majora. Typical facial characteristics during childhood comprise a small mouth with full lips and micro-...

Water hammer 2 phase analysis hydraulic system with a Kaplan turbine

OpenAIRE

Dudlik, A.; Koutnik, J.

2009-01-01

This investigation has been carried out for a case of sudden closing of a Kaplan turbine from a runaway operation. This work has been done at Fraunhofer UMSICHT, supported by VH. The runaway case has been selected as it is known that the discharge through a Kaplan turbine increases with its speed, and may reach up to twice the value of nominal discharge. The simulation model consists of: - penstock - Kaplan turbine (modelled with a valve characteristic) - draft tube All hydraulic pipe element...

The strategy curve. A method for representing and interpreting generator bidding strategies

International Nuclear Information System (INIS)

Lucas, N.; Taylor, P.

1995-01-01

The pool is the novel trading arrangement at the heart of the privatized electricity market in England and Wales. This central role in the new system makes it crucial that it is seen to function efficiently. Unfortunately, it is governed by a set of complex rules, which leads to a lack of transparency, and this makes monitoring of its operation difficult. This paper seeks to provide a method for illuminating one aspect of the pool, that of generator bidding behaviour. We introduce the concept of a strategy curve, which is a concise device for representing generator bidding strategies. This curve has the appealing characteristic of directly revealing any deviation in the bid price of a genset from the costs of generating electricity. After a brief discussion about what constitutes price and cost in this context we present a number of strategy curves for different days and provide some interpretation of their form, based in part on our earlier work with game theory. (author)

Computer Aided Design of Kaplan Turbine Piston with SolidWorks

OpenAIRE

Camelia Jianu

2010-01-01

The paper presents the steps for 3D computer aided design (CAD) of Kaplan turbine piston made in SolidWorks.The present paper is a tutorial for a Kaplan turbine piston 3D geometry, which is dedicaded to the Parts Sketch and Parts Features design and Drawing Geometry and Drawing Annotation.

Survival of Patients With Cervical Cancer in Rural India

OpenAIRE

Vinoda Thulaseedharan, Jissa; Malila, Nea; Swaminathan, Rajaraman; Esmy Pulikottil, Okuru; Hakama, Matti; Muwonge, Richard; Sankaranarayanan, Rengaswamy

2015-01-01

Background: Patients’ survival after diagnosis of cervical cancer is indirectly influenced by socio-economic factors. We evaluated this survival and its socio-economic determinants in a rural population in south India. Methods: We assessed 165 women diagnosed with cervical cancer from the routine care control arm of a randomized screening trial conducted in rural south India. Kaplan-Meier curves were plotted to illustrate the observed survival of cancer patients. The effect of socio-econom...

Comparison of numerical and experimental results of the flow in the U9 Kaplan turbine model

Energy Technology Data Exchange (ETDEWEB)

Petit, O; Nilsson, H [Division of Fluid Mechanics, Chalmers University of Technology, Hoersalsvaegen 7A, SE-41296 Goeteborg (Sweden); Mulu, B; Cervantes, M, E-mail: olivierp@chalmers.s [Division of Fluid Mechanics, Luleaa University of Technology, SE-971 87 Luleaa (Sweden)

2010-08-15

The present work compares simulations made using the OpenFOAM CFD code with experimental measurements of the flow in the U9 Kaplan turbine model. Comparisons of the velocity profiles in the spiral casing and in the draft tube are presented. The U9 Kaplan turbine prototype located in Porjus and its model, located in Alvkarleby, Sweden, have curved inlet pipes that lead the flow to the spiral casing. Nowadays, this curved pipe and its effect on the flow in the turbine is not taken into account when numerical simulations are performed at design stage. To study the impact of the inlet pipe curvature on the flow in the turbine, and to get a better overview of the flow of the whole system, measurements were made on the 1:3.1 model of the U9 turbine. Previously published measurements were taken at the inlet of the spiral casing and just before the guide vanes, using the laser Doppler anemometry (LDA) technique. In the draft tube, a number of velocity profiles were measured using the LDA techniques. The present work extends the experimental investigation with a horizontal section at the inlet of the draft tube. The experimental results are used to specify the inlet boundary condition for the numerical simulations in the draft tube, and to validate the computational results in both the spiral casing and the draft tube. The numerical simulations were realized using the standard k-e model and a block-structured hexahedral wall function mesh.

Comparison of numerical and experimental results of the flow in the U9 Kaplan turbine model

Science.gov (United States)

Petit, O.; Mulu, B.; Nilsson, H.; Cervantes, M.

2010-08-01

The present work compares simulations made using the OpenFOAM CFD code with experimental measurements of the flow in the U9 Kaplan turbine model. Comparisons of the velocity profiles in the spiral casing and in the draft tube are presented. The U9 Kaplan turbine prototype located in Porjus and its model, located in Älvkarleby, Sweden, have curved inlet pipes that lead the flow to the spiral casing. Nowadays, this curved pipe and its effect on the flow in the turbine is not taken into account when numerical simulations are performed at design stage. To study the impact of the inlet pipe curvature on the flow in the turbine, and to get a better overview of the flow of the whole system, measurements were made on the 1:3.1 model of the U9 turbine. Previously published measurements were taken at the inlet of the spiral casing and just before the guide vanes, using the laser Doppler anemometry (LDA) technique. In the draft tube, a number of velocity profiles were measured using the LDA techniques. The present work extends the experimental investigation with a horizontal section at the inlet of the draft tube. The experimental results are used to specify the inlet boundary condition for the numerical simulations in the draft tube, and to validate the computational results in both the spiral casing and the draft tube. The numerical simulations were realized using the standard k-e model and a block-structured hexahedral wall function mesh.

Comparison of numerical and experimental results of the flow in the U9 Kaplan turbine model

International Nuclear Information System (INIS)

Petit, O; Nilsson, H; Mulu, B; Cervantes, M

2010-01-01

The present work compares simulations made using the OpenFOAM CFD code with experimental measurements of the flow in the U9 Kaplan turbine model. Comparisons of the velocity profiles in the spiral casing and in the draft tube are presented. The U9 Kaplan turbine prototype located in Porjus and its model, located in Alvkarleby, Sweden, have curved inlet pipes that lead the flow to the spiral casing. Nowadays, this curved pipe and its effect on the flow in the turbine is not taken into account when numerical simulations are performed at design stage. To study the impact of the inlet pipe curvature on the flow in the turbine, and to get a better overview of the flow of the whole system, measurements were made on the 1:3.1 model of the U9 turbine. Previously published measurements were taken at the inlet of the spiral casing and just before the guide vanes, using the laser Doppler anemometry (LDA) technique. In the draft tube, a number of velocity profiles were measured using the LDA techniques. The present work extends the experimental investigation with a horizontal section at the inlet of the draft tube. The experimental results are used to specify the inlet boundary condition for the numerical simulations in the draft tube, and to validate the computational results in both the spiral casing and the draft tube. The numerical simulations were realized using the standard k-e model and a block-structured hexahedral wall function mesh.

Predicting long-term graft survival in adult kidney transplant recipients

Directory of Open Access Journals (Sweden)

Brett W Pinsky

2012-01-01

Full Text Available The ability to accurately predict a population′s long-term survival has important implications for quantifying the benefits of transplantation. To identify a model that can accurately predict a kidney transplant population′s long-term graft survival, we retrospectively studied the United Network of Organ Sharing data from 13,111 kidney-only transplants completed in 1988- 1989. Nineteen-year death-censored graft survival (DCGS projections were calculated and com-pared with the population′s actual graft survival. The projection curves were created using a two-part estimation model that (1 fits a Kaplan-Meier survival curve immediately after transplant (Part A and (2 uses truncated observational data to model a survival function for long-term projection (Part B. Projection curves were examined using varying amounts of time to fit both parts of the model. The accuracy of the projection curve was determined by examining whether predicted sur-vival fell within the 95% confidence interval for the 19-year Kaplan-Meier survival, and the sample size needed to detect the difference in projected versus observed survival in a clinical trial. The 19-year DCGS was 40.7% (39.8-41.6%. Excellent predictability (41.3% can be achieved when Part A is fit for three years and Part B is projected using two additional years of data. Using less than five total years of data tended to overestimate the population′s long-term survival, accurate prediction of long-term DCGS is possible, but requires attention to the quantity data used in the projection method.

PLANAR MECHANISMS USED FOR GENERATING CURVE LINE TRANSLATION MOTION

Directory of Open Access Journals (Sweden)

Ovidiu ANTONESCU

2015-05-01

Full Text Available The curve line translation motion can be generated in the particular form of the circular translation, through mono-mobile mechanisms with articulated links of simple parallelogram type (with a fixed side or through transmission with toothed belt with a fixed wheel. Also, the circular translation can be generated through planar mechanisms with two cylindrical gears with a fixed central wheel. It is mentioned that the two cylindrical gearings of the Fergusson mechanisms are both exterior and interior.

Estimating a population cumulative incidence under calendar time trends

DEFF Research Database (Denmark)

Hansen, Stefan N; Overgaard, Morten; Andersen, Per K

2017-01-01

BACKGROUND: The risk of a disease or psychiatric disorder is frequently measured by the age-specific cumulative incidence. Cumulative incidence estimates are often derived in cohort studies with individuals recruited over calendar time and with the end of follow-up governed by a specific date....... It is common practice to apply the Kaplan-Meier or Aalen-Johansen estimator to the total sample and report either the estimated cumulative incidence curve or just a single point on the curve as a description of the disease risk. METHODS: We argue that, whenever the disease or disorder of interest is influenced...

Maternal smoking during pregnancy and the risk of pediatric cardiovascular diseases of the offspring: A population-based cohort study with up to 18-years of follow up.

Science.gov (United States)

Leybovitz-Haleluya, Noa; Wainstock, Tamar; Landau, Daniella; Sheiner, Eyal

2018-06-01

Cigarette smoke is a well-known reproductive toxicant. We aimed to study the long-term effect of cigarette smoking during pregnancy on the risk for childhood cardiovascular morbidity of the offspring. A population-based cohort analysis was performed comparing total and subtypes of cardiovascular related pediatric hospitalizations among offspring of smoking mothers versus offspring of non-smoking mothers. The analysis included all singletons born between the years 1999-2014.A Kaplan-Meier survival curve was used to compare the cumulative cardiovascular morbidity, and a Cox proportional hazards model was constructed to adjust for confounders. The study population included 242,342 newborns which met inclusion criteria; among them 2861 were born to smoking mothers. Offspring of smoking mothers had higher rates of cardiovascular-related hospitalizations (1.3% vs. 0.6%, OR 2.1, 95% CI 1.5-2.9; p < 0.001; Kaplan-Meier log-rank test p < 0.001). Smoking exposure during pregnancy is associated with an increased risk for long-term pediatric cardiovascular morbidity of the offspring. Copyright © 2018 Elsevier Inc. All rights reserved.

Dynamic Model of Kaplan Turbine Regulating System Suitable for Power System Analysis

OpenAIRE

Zhao, Jie; Wang, Li; Liu, Dichen; Wang, Jun; Zhao, Yu; Liu, Tian; Wang, Haoyu

2015-01-01

Accurate modeling of Kaplan turbine regulating system is of great significance for grid security and stability analysis. In this paper, Kaplan turbine regulating system model is divided into the governor system model, the blade control system model, and the turbine and water diversion system model. The Kaplan turbine has its particularity, and the on-cam relationship between the wicket gate opening and the runner blade angle under a certain water head on the whole range was obtained by high-o...

Exponential Decay Nonlinear Regression Analysis of Patient Survival Curves: Preliminary Assessment in Non-Small Cell Lung Cancer

Science.gov (United States)

Stewart, David J.; Behrens, Carmen; Roth, Jack; Wistuba, Ignacio I.

2010-01-01

Background For processes that follow first order kinetics, exponential decay nonlinear regression analysis (EDNRA) may delineate curve characteristics and suggest processes affecting curve shape. We conducted a preliminary feasibility assessment of EDNRA of patient survival curves. Methods EDNRA was performed on Kaplan-Meier overall survival (OS) and time-to-relapse (TTR) curves for 323 patients with resected NSCLC and on OS and progression-free survival (PFS) curves from selected publications. Results and Conclusions In our resected patients, TTR curves were triphasic with a “cured” fraction of 60.7% (half-life [t1/2] >100,000 months), a rapidly-relapsing group (7.4%, t1/2=5.9 months) and a slowly-relapsing group (31.9%, t1/2=23.6 months). OS was uniphasic (t1/2=74.3 months), suggesting an impact of co-morbidities; hence, tumor molecular characteristics would more likely predict TTR than OS. Of 172 published curves analyzed, 72 (42%) were uniphasic, 92 (53%) were biphasic, 8 (5%) were triphasic. With first-line chemotherapy in advanced NSCLC, 87.5% of curves from 2-3 drug regimens were uniphasic vs only 20% of those with best supportive care or 1 drug (p<0.001). 54% of curves from 2-3 drug regimens had convex rapid-decay phases vs 0% with fewer agents (p<0.001). Curve convexities suggest that discontinuing chemotherapy after 3-6 cycles “synchronizes” patient progression and death. With postoperative adjuvant chemotherapy, the PFS rapid-decay phase accounted for a smaller proportion of the population than in controls (p=0.02) with no significant difference in rapid-decay t1/2, suggesting adjuvant chemotherapy may move a subpopulation of patients with sensitive tumors from the relapsing group to the cured group, with minimal impact on time to relapse for a larger group of patients with resistant tumors. In untreated patients, the proportion of patients in the rapid-decay phase increased (p=0.04) while rapid-decay t1/2 decreased (p=0.0004) with increasing

Three-generation neutrino oscillations in curved spacetime

Energy Technology Data Exchange (ETDEWEB)

Zhang, Yu-Hao, E-mail: yhzhang1994@gmail.com; Li, Xue-Qian, E-mail: lixq@nankai.edu.cn

2016-10-15

Three-generation MSW effect in curved spacetime is studied and a brief discussion on the gravitational correction to the neutrino self-energy is given. The modified mixing parameters and corresponding conversion probabilities of neutrinos after traveling through celestial objects of constant densities are obtained. The method to distinguish between the normal hierarchy and inverted hierarchy is discussed in this framework. Due to the gravitational redshift of energy, in some extreme situations, the resonance energy of neutrinos might be shifted noticeably and the gravitational effect on the self-energy of neutrino becomes significant at the vicinities of spacetime singularities.

Computer Aided Design of Kaplan Turbine Piston with\tSolidWorks

Directory of Open Access Journals (Sweden)

Camelia Jianu

2010-10-01

Full Text Available The paper presents the steps for 3D computer aided design (CAD of Kaplan turbine piston made in SolidWorks.The present paper is a tutorial for a Kaplan turbine piston 3D geometry, which is dedicaded to the Parts Sketch and Parts Features design and Drawing Geometry and Drawing Annotation.

Analysis of the Kaplan turbine draft tube effect

International Nuclear Information System (INIS)

Motycak, L; Skotak, A; Obrovsky, J

2010-01-01

The aim of this paper is to present information about possible problems and errors which can appear during numerical analyses of low head Kaplan turbines with a view to the runner - draft tube interaction. The setting of numerical model, grid size, used boundary conditions are the interface definition between runner and draft tube are discussed. There are available data from physical model tests which gives a great opportunity to compare CFD and experiment results and on the basis of this comparison to determine the approach to the CFD flow modeling. The main purpose for the Kaplan turbine model measurement was to gather the information about real flow field. The model tests were carried out in new hydraulic laboratory of CKD Blansko Engineering. The model tests were focused on the detailed velocity measurements downstream of the runner by differential pressure probe and on the velocity measurement downstream of the draft tube elbow by Particle Image Velocimetry method (PIV). The data from CFD simulation were compared to the velocity measurement results. In the paper also the design of the original draft tube modification due to flow improvement is discussed in the case of the Kaplan turbine uprating project. The results of the draft tube modification were confirmed by model tests in the hydraulic laboratory as well.

Analysis of the Kaplan turbine draft tube effect

Energy Technology Data Exchange (ETDEWEB)

Motycak, L; Skotak, A; Obrovsky, J, E-mail: motycak.vhs@cbeng.c [CKD Blansko Engineering, a.s., Capkova 2357/5, Blansko 67801 (Czech Republic)

2010-08-15

The aim of this paper is to present information about possible problems and errors which can appear during numerical analyses of low head Kaplan turbines with a view to the runner - draft tube interaction. The setting of numerical model, grid size, used boundary conditions are the interface definition between runner and draft tube are discussed. There are available data from physical model tests which gives a great opportunity to compare CFD and experiment results and on the basis of this comparison to determine the approach to the CFD flow modeling. The main purpose for the Kaplan turbine model measurement was to gather the information about real flow field. The model tests were carried out in new hydraulic laboratory of CKD Blansko Engineering. The model tests were focused on the detailed velocity measurements downstream of the runner by differential pressure probe and on the velocity measurement downstream of the draft tube elbow by Particle Image Velocimetry method (PIV). The data from CFD simulation were compared to the velocity measurement results. In the paper also the design of the original draft tube modification due to flow improvement is discussed in the case of the Kaplan turbine uprating project. The results of the draft tube modification were confirmed by model tests in the hydraulic laboratory as well.

Analysis of the Kaplan turbine draft tube effect

Science.gov (United States)

Motycak, L.; Skotak, A.; Obrovsky, J.

2010-08-01

The aim of this paper is to present information about possible problems and errors which can appear during numerical analyses of low head Kaplan turbines with a view to the runner - draft tube interaction. The setting of numerical model, grid size, used boundary conditions are the interface definition between runner and draft tube are discussed. There are available data from physical model tests which gives a great opportunity to compare CFD and experiment results and on the basis of this comparison to determine the approach to the CFD flow modeling. The main purpose for the Kaplan turbine model measurement was to gather the information about real flow field. The model tests were carried out in new hydraulic laboratory of CKD Blansko Engineering. The model tests were focused on the detailed velocity measurements downstream of the runner by differential pressure probe and on the velocity measurement downstream of the draft tube elbow by Particle Image Velocimetry method (PIV). The data from CFD simulation were compared to the velocity measurement results. In the paper also the design of the original draft tube modification due to flow improvement is discussed in the case of the Kaplan turbine uprating project. The results of the draft tube modification were confirmed by model tests in the hydraulic laboratory as well.

Persistent fatigue in young athletes: measuring the clinical course and identifying variables affecting clinical recovery.

Science.gov (United States)

Locke, S; Osborne, M; O'Rourke, P

2011-02-01

The objective of this paper is to measure the clinical course (months) in young athletes with persistent fatigue and to identify any covariates affecting the duration of recovery. This was a prospective longitudinal study of 68 athletes; 87% were elite (42 males, 26 females), aged 20.5±3.74 years (SD), who presented with the symptom of persistent fatigue. The collective duration to full clinical recovery was estimated using Kaplan-Meier product-limit curves, and covariates associated with prolonging recovery were identified from Cox proportional hazard models. The median recovery was 5 months (range 1-60 months). The range of presenting symptom duration was 0.5-36 months. The covariates identified were an increased duration of presenting symptoms [hazard ratio (HR), 1.06; 95% confidence interval (CI), 1.02-1.12; P=0.005] and the response of serum cortisol concentration to a standard exercise challenge (HR, 1.92; 95% CI, 1.09-3.38; P=0.03). Delay in recovery was not associated with categories of fatigue that included medical, training-related diagnoses, or other causes. In conclusion, the fatigued athlete represents a significant clinical problem with a median recovery of 5 months, whose collective clinical course to recovery can be estimated by Kaplan-Meier curves and appears to be a continuum. © 2009 John Wiley & Sons A/S.

Survival curves to support quality improvement in hospitals with excess 30-day mortality after acute myocardial infarction, cerebral stroke and hip fracture: a before-after study.

Science.gov (United States)

Kristoffersen, Doris Tove; Helgeland, Jon; Waage, Halfrid Persdatter; Thalamus, Jacob; Clemens, Dirk; Lindman, Anja Schou; Rygh, Liv Helen; Tjomsland, Ole

2015-03-25

To evaluate survival curves (Kaplan-Meier) as a means of identifying areas in the clinical pathway amenable to quality improvement. Observational before-after study. In Norway, annual public reporting of nationwide 30-day in-and-out-of-hospital mortality (30D) for three medical conditions started in 2011: first time acute myocardial infarction (AMI), stroke and hip fracture; reported for 2009. 12 of 61 hospitals had statistically significant lower/higher mortality compared with the hospital mean. Three hospitals with significantly higher mortality requested detailed analyses for quality improvement purposes: Telemark Hospital Trust Skien (AMI and stroke), Østfold Hospital Trust Fredrikstad (stroke), Innlandet Hospital Trust Gjøvik (hip fracture). Survival curves, crude and risk-adjusted 30D before (2008-2009) and after (2012-2013). Unadjusted survival curves for the outlier hospitals were compared to curves based on pooled data from the other hospitals for the 30-day period 2008-2009. For patients admitted with AMI (Skien), stroke (Fredrikstad) and hip fracture (Gjøvik), the curves suggested increased mortality from the initial part of the clinical pathway. For stroke (Skien), increased mortality appeared after about 8 days. The curve profiles were thought to reflect suboptimal care in various phases in the clinical pathway. This informed improvement efforts. For 2008-2009, hospital-specific curves differed from other hospitals: borderline significant for AMI (p=0.064), highly significant (p≤0.005) for the remainder. After intervention, no difference was found (p>0.188). Before-after comparison of the curves within each hospital revealed a significant change for Fredrikstad (p=0.006). For the three hospitals, crude 30D declined and they were non-outliers for risk-adjusted 30D for 2013. Survival curves as a supplement to 30D may be useful for identifying suboptimal care in the clinical pathway, and thus informing design of quality improvement projects

Improved Governing of Kaplan Turbine Hydropower Plants Operating Island Grids

OpenAIRE

Gustafsson, Martin

2013-01-01

To reduce the consequences of a major fault in the electric power grid, functioning parts of the grid can be divided into smaller grid islands. The grid islands are operated isolated from the power network, which places new demands on a faster frequency regulation. This thesis investigates a Kaplan turbine hydropower plant operating an island grid. The Kaplan turbine has two control signals, the wicket gate and the turbine blade positions, controlling the mechanical power. The inputs are comb...

Interaction between daily load demand curve and management of hydro-thermal generation system

International Nuclear Information System (INIS)

Granelli, G.; Montagna, M.; Pasini, G.; Innorta, M.; Marannino, P.

1993-01-01

The influence that the behaviour of the daily load demand curve has on the management of a hydro-thermal generation system is considered. The aim of this paper is to show the improvements that can be achieved by suitable load management techniques capable of flattening the load demand curve. The analysis is carried out by using a hydro-thermal scheduling program and a thermal unit dynamic dispatch procedure. The possibility of properly re-committing the available thermal units is also taken into account. The economical and technical convenience of shutting down less economical thermal units operating near the lower generations limits is verified. Finally, some considerations are made about the possible use of the thermal generation incremental costs as a tool for planning the end users' kWh prices, even in the short term. The results refer to a system with characteristics similar to those of the Italian one. In determining the daily load demand curves, the characteristics of load demand in Italy as well as in other European countries are taken into account

Kaplan og Norton bør læses af hele ledelsen

DEFF Research Database (Denmark)

Bukh, Per Nikolaj

2009-01-01

Anmeldelse af "Eksekveringsgevinsten - Øget konkurrencekraft med fokuseret strategi og drift", Robert S. Kaplan & David P. Norton, 2009, Gyldendal Business. Udgivelsesdato: 8. april......Anmeldelse af "Eksekveringsgevinsten - Øget konkurrencekraft med fokuseret strategi og drift", Robert S. Kaplan & David P. Norton, 2009, Gyldendal Business. Udgivelsesdato: 8. april...

Kaplan-Narayanan-Neuberger lattice fermions pass a perturbative test

International Nuclear Information System (INIS)

Aoki, S.; Levien, R.B.

1995-01-01

We test perturbatively a recent scheme for implementing chiral fermions on the lattice, proposed by Kaplan and modified by Narayanan and Neuberger, using as our testing ground the chiral Schwinger model. The scheme is found to reproduce the desired form of the effective action, whose real part is gauge invariant and whose imaginary part gives the correct anomaly in the continuum limit, once technical problems relating to the necesary infinite extent of the extra dimension are properly addressed. The indications from this study are that the Kaplan-Narayanan-Neuberger scheme has a good chance at being a correct lattice regularization of chiral gauge theories

Comparative evaluation of fracture and defect in reciproc and rotary files in severe curved root canals

Directory of Open Access Journals (Sweden)

Mahdis Bagherian

2015-03-01

Full Text Available Introduction: Root canal instrumentation is an important phase in root canal therapy. Since success in endodontic treatment depends on file defect and fracture, the aim of this study was to compare the evaluation of defect and fracture in rotary and reciproc files in severe curved root canals. Materials & Methods: In this experimental study, 60 mesial canals of human closed apex molars with more than 30° canal curvature were randomly divided into two groups. In first group M-two rotary files number# 15, 20, and 25 and in second group R25 reciproc file were used for filing, respectively. A ×8 magnifier was applied to evaluate the defect or fracture presence in each side and if it were observed, a new file would be replaced. Therefore, the number of prepared canals with each file and fractured or defective files and the place of fracture in root canal were recorded. Kaplan Meier curve and log rank test were done by using SPSS v.22. Results: In rotary group, seven and two files were fractured and defected, respectively and four files were fractured and no defect was observed in reciproc group. Although the mean of the number of prepared canals until fracture or defect in rotary and reciproc groups was 3.3 and 7.06, respectively, there were no significant differences between two systems. All file’s fractures occurred in apical regions . Conclusion: The results showed that there was no significant difference in defects or fractures of rotary and reciproc systems. Reciproc instruments can be more effective than rotary ones because the root canal preparation in rotary instruments is longer than in reciproc system.

Generation of large-scale PV scenarios using aggregated power curves

DEFF Research Database (Denmark)

Nuño Martinez, Edgar; Cutululis, Nicolaos Antonio

2017-01-01

The contribution of solar photovoltaic (PV) power to the generation is becoming more relevant in modern power system. Therefore, there is a need to model the variability large-scale PV generation accurately. This paper presents a novel methodology to generate regional PV scenarios based...... on aggregated power curves rather than traditional physical PV conversion models. Our approach is based on hourly mesoscale reanalysis irradiation data and power measurements and do not require additional variables such as ambient temperature or wind speed. It was used to simulate the PV generation...... on the German system between 2012 and 2015 showing high levels of correlation with actual measurements (93.02–97.60%) and small deviations from the expected capacity factors (0.02–1.80%). Therefore, we are confident about the ability of the proposed model to accurately generate realistic large-scale PV...

Case Report: Meier-Gorlin syndrome: Report of an additional patient ...

African Journals Online (AJOL)

We report a 7 year old female child with the classical triad of Meier-Gorlin syndrome (MGS), (microtia, absent patella and short stature). She had the characteristic facial features, with normal mentality and defective speech, skeletal abnormalities, conductive hearing loss, cystitis and normal growth hormone level.

Improvements of a Kaplan type small turbine: Forbedre og vidreutvikle en Kaplan småturbin

OpenAIRE

Fjærvold, Lars

2012-01-01

The goal with this master thesis was to establish Hill diagrams and improve a Kaplan turbine intended for use in Afghanistan. The turbine efficiency has been tested in setting 1 and 2. Turbine efficiency in setting 3 and 4 could not be tested because the runner blades interfere with the housing making it impossible to rotate the turbine. The efficiency was tested with an effective pressure head ranging from 2 to 8 meters. Best efficiency point was not reached because of limitations in the te...

Numerical generation of boundary-fitted curvilinear coordinate systems for arbitrarily curved surfaces

International Nuclear Information System (INIS)

Takagi, T.; Miki, K.; Chen, B.C.J.; Sha, W.T.

1985-01-01

A new method is presented for numerically generating boundary-fitted coordinate systems for arbitrarily curved surfaces. The three-dimensional surface has been expressed by functions of two parameters using the geometrical modeling techniques in computer graphics. This leads to new quasi-one- and two-dimensional elliptic partial differential equations for coordinate transformation. Since the equations involve the derivatives of the surface expressions, the grids geneated by the equations distribute on the surface depending on its slope and curvature. A computer program GRID-CS based on the method was developed and applied to a surface of the second order, a torus and a surface of a primary containment vessel for a nuclear reactor. These applications confirm that GRID-CS is a convenient and efficient tool for grid generation on arbitrarily curved surfaces

Metastatic volume: an old oncologic concept and a new prognostic factor for stage IV melanoma patients.

Science.gov (United States)

Panasiti, V; Curzio, M; Roberti, V; Lieto, P; Devirgiliis, V; Gobbi, S; Naspi, A; Coppola, R; Lopez, T; di Meo, N; Gatti, A; Trevisan, G; Londei, P; Calvieri, S

2013-01-01

The last melanoma staging system of the 2009 American Joint Committee on Cancer takes into account, for stage IV disease, the serum levels of lactate dehydrogenase (LDH) and the site of distant metastases. Our aim was to compare the significance of metastatic volume, as evaluated at the time of stage IV melanoma diagnosis, with other clinical predictors of prognosis. We conducted a retrospective multicentric study. To establish which variables were statistically correlated both with death and survival time, contingency tables were evaluated. The overall survival curves were compared using the Kaplan-Meier method. Metastatic volume and number of affected organs were statistically related to death. In detail, patients with a metastatic volume >15 cm(3) had a worse prognosis than those with a volume lower than this value (survival probability at 60 months: 6.8 vs. 40.9%, respectively). The Kaplan-Meier method confirmed that survival time was significantly related to the site(s) of metastases, to elevated LDH serum levels and to melanoma stage according to the latest system. Our results suggest that metastatic volume may be considered as a useful prognostic factor for survival among melanoma patients.

The effect of semirigid dressings on below-knee amputations.

Science.gov (United States)

MacLean, N; Fick, G H

1994-07-01

The effect of using semirigid dressings (SRDs) on the residual limb of individuals who have had below-knee amputations as a consequence of peripheral vascular disease was investigated, with the primary question being: Does the time to readiness for prosthetic fitting for patients treated with the SRDs differ from that of patients treated with soft dressings? Forty patients entered the study and were alternately assigned to one of two groups. Nineteen patients were assigned to the SRD group, and 21 patients were assigned to the soft dressing group. The time from surgery to readiness for prosthetic fitting was recorded for each patient. Kaplan-Meier survival curves were generated for each group, and the results were analyzed with the log-rank test. There was a difference between the two curves, and an examination of the curves suggests that the expected time to readiness for prosthetic fitting for patients treated with the SRDs would be less than half that of patients treated with soft dressings. The results suggest that a patient may be ready for prosthetic fitting sooner if treated with SRDs instead of soft dressings.

A neural network driving curve generation method for the heavy-haul train

Directory of Open Access Journals (Sweden)

Youneng Huang

2016-05-01

Full Text Available The heavy-haul train has a series of characteristics, such as the locomotive traction properties, the longer length of train, and the nonlinear train pipe pressure during train braking. When the train is running on a continuous long and steep downgrade railway line, the safety of the train is ensured by cycle braking, which puts high demands on the driving skills of the driver. In this article, a driving curve generation method for the heavy-haul train based on a neural network is proposed. First, in order to describe the nonlinear characteristics of train braking, the neural network model is constructed and trained by practical driving data. In the neural network model, various nonlinear neurons are interconnected to work for information processing and transmission. The target value of train braking pressure reduction and release time is achieved by modeling the braking process. The equation of train motion is computed to obtain the driving curve. Finally, in four typical operation scenarios, comparing the curve data generated by the method with corresponding practical data of the Shuohuang heavy-haul railway line, the results show that the method is effective.

Reporting of loss to follow-up information in randomised controlled trials with time-to-event outcomes: a literature survey

Directory of Open Access Journals (Sweden)

Bender Ralf

2011-09-01

Full Text Available Abstract Background To assess the reporting of loss to follow-up (LTFU information in articles on randomised controlled trials (RCTs with time-to-event outcomes, and to assess whether discrepancies affect the validity of study results. Methods Literature survey of all issues of the BMJ, Lancet, JAMA, and New England Journal of Medicine published between 2003 and 2005. Eligible articles were reports of RCTs including at least one Kaplan-Meier plot. Articles were classified as "assessable" if sufficient information was available to assess LTFU. In these articles, LTFU information was derived from Kaplan-Meier plots, extracted from the text, and compared. Articles were then classified as "consistent" or "not consistent". Sensitivity analyses were performed to assess the validity of study results. Results 319 eligible articles were identified. 187 (59% were classified as "assessable", as they included sufficient information for evaluation; 140 of 319 (44% presented consistent LTFU information between the Kaplan-Meier plot and text. 47 of 319 (15% were classified as "not consistent". These 47 articles were included in sensitivity analyses. When various imputation methods were used, the results of a chi2-test applied to the corresponding 2 × 2 table changed and hence were not robust in about half of the studies. Conclusions Less than half of the articles on RCTs using Kaplan-Meier plots provide assessable and consistent LTFU information, thus questioning the validity of the results and conclusions of many studies presenting survival analyses. Authors should improve the presentation of both Kaplan-Meier plots and LTFU information, and reviewers of study publications and journal editors should critically appraise the validity of the information provided.

["That flesh, pink and perishable": analysis of disease-free survival analysis in breast cancer in Gipuzkoa (Spain) in the presence of competing risks].

Science.gov (United States)

Martínez-Camblor, Pablo; Larrañaga, Nerea; Sarasqueta, Cristina; Mitxelena, María José; Basterretxea, Mikel

2009-01-01

To analyze time of disease-free survival and relative survival in women diagnosed with breast cancer in the province of Gipuzkoa within the context of competing risks by assessing differences between the direct use of the Kaplan-Meier estimator and the multiple decrement method on the one hand, and relative survival on the other. All registered breast cancer cases in Gipuzkoa in 1995 and 1996 with stages other than stage IV were included. An 8-year follow-up for recurrence and a 10-year follow-up for survival were performed. Time of disease-free survival was studied by the multiple decrement model. Observed survival and survival corrected by the expected mortality in the population (relative survival) were also studied. Estimation of the probability of recurrence at 8 years with the multiple decrement method was 8.8% lower than that obtained with the Kaplan-Meier method. The difference between the observed and relative survival rates at 10 years was 10.8%. Both results show how, in this case, the Kaplan-Meier estimator overestimates both the probability of recurrence and that of mortality from the disease. Two issues are often overlooked when performing survival analyses: firstly, because of the lack of independence between survival time and censoring time, the results obtained by the Kaplan-Meier estimator are uninterpretable; secondly, it is an incontrovertible fact that one way or another, everyone causes failures. In this approach, survival analyses must take into account the probability of failure in the general population of reference. The results obtained in this study show that superficial use of the Kaplan Meier estimator overestimates both the probability of recurrence and that of mortality caused by the disease.

Eigentumors for prediction of treatment failure in patients with early-stage breast cancer using dynamic contrast-enhanced MRI: a feasibility study

Science.gov (United States)

Chan, H. M.; van der Velden, B. H. M.; E Loo, C.; Gilhuijs, K. G. A.

2017-08-01

We present a radiomics model to discriminate between patients at low risk and those at high risk of treatment failure at long-term follow-up based on eigentumors: principal components computed from volumes encompassing tumors in washin and washout images of pre-treatment dynamic contrast-enhanced (DCE-) MR images. Eigentumors were computed from the images of 563 patients from the MARGINS study. Subsequently, a least absolute shrinkage selection operator (LASSO) selected candidates from the components that contained 90% of the variance of the data. The model for prediction of survival after treatment (median follow-up time 86 months) was based on logistic regression. Receiver operating characteristic (ROC) analysis was applied and area-under-the-curve (AUC) values were computed as measures of training and cross-validated performances. The discriminating potential of the model was confirmed using Kaplan-Meier survival curves and log-rank tests. From the 322 principal components that explained 90% of the variance of the data, the LASSO selected 28 components. The ROC curves of the model yielded AUC values of 0.88, 0.77 and 0.73, for the training, leave-one-out cross-validated and bootstrapped performances, respectively. The bootstrapped Kaplan-Meier survival curves confirmed significant separation for all tumors (P  <  0.0001). Survival analysis on immunohistochemical subgroups shows significant separation for the estrogen-receptor subtype tumors (P  <  0.0001) and the triple-negative subtype tumors (P  =  0.0039), but not for tumors of the HER2 subtype (P  =  0.41). The results of this retrospective study show the potential of early-stage pre-treatment eigentumors for use in prediction of treatment failure of breast cancer.

Learning curve for the management of tyrosine kinase inhibitors as the first line of treatment for patients with metastatic renal cancer.

Science.gov (United States)

Lendínez-Cano, G; Osman García, I; Congregado Ruiz, C B; Conde Sánchez, J M; Medina López, R A

2018-03-07

To analyse the learning curve for the management of tyrosine kinase inhibitors as the first line of treatment for patients with metastatic renal cancer. We evaluated 32 consecutive patients treated in our department for metastatic renal cancer with tyrosine kinase inhibitors (pazopanib or sunitinib) as first-line treatment between September 2012 and November 2015. We retrospectively analysed this sample. We measured the time to the withdrawal of the first-line treatment, the time to progression and overall survival using Kaplan-Meier curves. The learning curve was analysed with the cumulative sum (CUSUM) methodology. In our series, the median time to the withdrawal of the first-line treatment was 11 months (95% CI 4.9-17.1). The mean time to progression was 30.4 months (95% CI 22.7-38.1), and the mean overall survival was 34.9 months (95% CI 27.8-42). By applying the CUSUM methodology, we obtained a graph for the CUSUM value of the time to withdrawal of the first-line treatment (CUSUM TW), observing 3 well-differentiated phases: phase 1 or initial learning phase (1-15), phase 2 (16-26) in which the management of the drug progressively improved and phase 3 (27-32) of maximum experience or mastery of the management of these drugs. The number of treated patients needed to achieve the proper management of these patients was estimated at 15. Despite the limitations of the sample size and follow-up time, we estimated (in 15 patients) the number needed to reach the necessary experience in the management of these patients with tyrosine kinase inhibitors. We observed no relationship between the time to the withdrawal of the first-line treatment for any cause and progression. Copyright © 2018 AEU. Publicado por Elsevier España, S.L.U. All rights reserved.

Some Supplementary Methods for the Analysis of the Delis-Kaplan Executive Function System

Science.gov (United States)

Crawford, John R.; Garthwaite, Paul H.; Sutherland, David; Borland, Nicola

2011-01-01

Supplementary methods for the analysis of the Delis-Kaplan Executive Function System (Delis, Kaplan, & Kramer, 2001) are made available, including (a) quantifying the number of abnormally low achievement scores exhibited by an individual and accompanying this with an estimate of the percentage of the normative population expected to exhibit at…

Multi-objective shape optimization of runner blade for Kaplan turbine

International Nuclear Information System (INIS)

Power machines LMZ, Saint Petersburg (Russian Federation))" data-affiliation=" (OJSC Power machines LMZ, Saint Petersburg (Russian Federation))" >Semenova, A; Power machines LMZ, Saint Petersburg (Russian Federation))" data-affiliation=" (OJSC Power machines LMZ, Saint Petersburg (Russian Federation))" >Pylev, I; Chirkov, D; Lyutov, A; Chemy, S; Skorospelov, V

2014-01-01

Automatic runner shape optimization based on extensive CFD analysis proved to be a useful design tool in hydraulic turbomachinery. Previously the authors developed an efficient method for Francis runner optimization. It was successfully applied to the design of several runners with different specific speeds. In present work this method is extended to the task of a Kaplan runner optimization. Despite of relatively simpler blade shape, Kaplan turbines have several features, complicating the optimization problem. First, Kaplan turbines normally operate in a wide range of discharges, thus CFD analysis of each variant of the runner should be carried out for several operation points. Next, due to a high specific speed, draft tube losses have a great impact on the overall turbine efficiency, and thus should be accurately evaluated. Then, the flow in blade tip and hub clearances significantly affects the velocity profile behind the runner and draft tube behavior. All these features are accounted in the present optimization technique. Parameterization of runner blade surface using 24 geometrical parameters is described in details. For each variant of runner geometry steady state three-dimensional turbulent flow computations are carried out in the domain, including wicket gate, runner, draft tube, blade tip and hub clearances. The objectives are maximization of efficiency in best efficiency and high discharge operation points, with simultaneous minimization of cavitation area on the suction side of the blade. Multiobjective genetic algorithm is used for the solution of optimization problem, requiring the analysis of several thousands of runner variants. The method is applied to optimization of runner shape for several Kaplan turbines with different heads

Multi-objective shape optimization of runner blade for Kaplan turbine

Science.gov (United States)

Semenova, A.; Chirkov, D.; Lyutov, A.; Chemy, S.; Skorospelov, V.; Pylev, I.

2014-03-01

Automatic runner shape optimization based on extensive CFD analysis proved to be a useful design tool in hydraulic turbomachinery. Previously the authors developed an efficient method for Francis runner optimization. It was successfully applied to the design of several runners with different specific speeds. In present work this method is extended to the task of a Kaplan runner optimization. Despite of relatively simpler blade shape, Kaplan turbines have several features, complicating the optimization problem. First, Kaplan turbines normally operate in a wide range of discharges, thus CFD analysis of each variant of the runner should be carried out for several operation points. Next, due to a high specific speed, draft tube losses have a great impact on the overall turbine efficiency, and thus should be accurately evaluated. Then, the flow in blade tip and hub clearances significantly affects the velocity profile behind the runner and draft tube behavior. All these features are accounted in the present optimization technique. Parameterization of runner blade surface using 24 geometrical parameters is described in details. For each variant of runner geometry steady state three-dimensional turbulent flow computations are carried out in the domain, including wicket gate, runner, draft tube, blade tip and hub clearances. The objectives are maximization of efficiency in best efficiency and high discharge operation points, with simultaneous minimization of cavitation area on the suction side of the blade. Multiobjective genetic algorithm is used for the solution of optimization problem, requiring the analysis of several thousands of runner variants. The method is applied to optimization of runner shape for several Kaplan turbines with different heads.

Mathematical, numerical and experimental analysis of the swirling flow at a Kaplan runner outlet

International Nuclear Information System (INIS)

Muntean, S; Ciocan, T; Susan-Resiga, R F; Cervantes, M; Nilsson, H

2012-01-01

The paper presents a novel mathematical model for a-priori computation of the swirling flow at Kaplan runners outlet. The model is an extension of the initial version developed by Susan-Resiga et al [1], to include the contributions of non-negligible radial velocity and of the variable rothalpy. Simple analytical expressions are derived for these additional data from three-dimensional numerical simulations of the Kaplan turbine. The final results, i.e. velocity components profiles, are validated against experimental data at two operating points, with the same Kaplan runner blades opening, but variable discharge.

Mathematical, numerical and experimental analysis of the swirling flow at a Kaplan runner outlet

Science.gov (United States)

Muntean, S.; Ciocan, T.; Susan-Resiga, R. F.; Cervantes, M.; Nilsson, H.

2012-11-01

The paper presents a novel mathematical model for a-priori computation of the swirling flow at Kaplan runners outlet. The model is an extension of the initial version developed by Susan-Resiga et al [1], to include the contributions of non-negligible radial velocity and of the variable rothalpy. Simple analytical expressions are derived for these additional data from three-dimensional numerical simulations of the Kaplan turbine. The final results, i.e. velocity components profiles, are validated against experimental data at two operating points, with the same Kaplan runner blades opening, but variable discharge.

Spline Trajectory Algorithm Development: Bezier Curve Control Point Generation for UAVs

Science.gov (United States)

Howell, Lauren R.; Allen, B. Danette

2016-01-01

A greater need for sophisticated autonomous piloting systems has risen in direct correlation with the ubiquity of Unmanned Aerial Vehicle (UAV) technology. Whether surveying unknown or unexplored areas of the world, collecting scientific data from regions in which humans are typically incapable of entering, locating lost or wanted persons, or delivering emergency supplies, an unmanned vehicle moving in close proximity to people and other vehicles, should fly smoothly and predictably. The mathematical application of spline interpolation can play an important role in autopilots' on-board trajectory planning. Spline interpolation allows for the connection of Three-Dimensional Euclidean Space coordinates through a continuous set of smooth curves. This paper explores the motivation, application, and methodology used to compute the spline control points, which shape the curves in such a way that the autopilot trajectory is able to meet vehicle-dynamics limitations. The spline algorithms developed used to generate these curves supply autopilots with the information necessary to compute vehicle paths through a set of coordinate waypoints.

A reconstructed melanoma data set for evaluating differential treatment benefit according to biomarker subgroups

Directory of Open Access Journals (Sweden)

Jaya M. Satagopan

2017-06-01

Full Text Available The data presented in this article are related to the research article entitled “Measuring differential treatment benefit across marker specific subgroups: the choice of outcome scale” (Satagopan and Iasonos, 2015 [1]. These data were digitally reconstructed from figures published in Larkin et al. (2015 [2]. This article describes the steps to digitally reconstruct patient-level data on time-to-event outcome and treatment and biomarker groups using published Kaplan-Meier survival curves. The reconstructed data set and the corresponding computer programs are made publicly available to enable further statistical methodology research.

The 434(G>C) polymorphism in the eosinophil cationic protein gene and its association with tissue eosinophilia in oral squamous cell carcinomas

DEFF Research Database (Denmark)

Pereira, Michele C; Oliveira, Denise T; Olivieri, Eloísa H R

2010-01-01

OBJECTIVE: The aim of this study was to investigate the prevalence of the Eosinophil cationic protein (ECP)-gene polymorphism 434(G>C) in oral squamous cell carcinoma (OSCC) patients and its association with tumor-associated tissue eosinophilia (TATE), demographic, clinical, and microscopic...... of ECP-gene polymorphism 434(G>C) with TATE, demographic, clinical, and microscopic variables in OSCC patients. Disease-free survival and overall survival were calculated by the Kaplan-Meier product-limit actuarial method and the comparison of the survival curves were performed using log rank test...

Restaging and Survival Analysis of 4036 Ovarian Cancer Patients According to the 2013 FIGO Classification for Ovarian, Fallopian Tube, and Primary Peritoneal Cancer

DEFF Research Database (Denmark)

Rosendahl, Mikkel; Høgdall, Claus Kim; Mosgaard, Berit Jul

2016-01-01

OBJECTIVE: With the 2013 International Federation of Gynecology and Obstetrics (FIGO) staging for ovarian, fallopian tube, and primary peritoneal cancer, the number of substages changed from 10 to 14. Any classification of a malignancy should easily assign patients to prognostic groups, refer....... MATERIALS AND METHODS: Demographic, surgical, histological, and survival data from 4036 ovarian cancer patients were used in the analysis. Five-year survival rates (5YSR) and hazard ratios for the old and revised FIGO staging were calculated using Kaplan-Meier curves and Cox regression. RESULTS: A total...

Influence of Body Mass Index on Tumor Pathology and Survival in Uterine Cancer

DEFF Research Database (Denmark)

Bjerrum Kristensen, Anne; Hare-Bruun, Helle; Høgdall, Claus Kim

2017-01-01

OBJECTIVE: To evaluate the influence of body mass index (BMI) on endometrial tumor pathology, stage and complication rate and to identify individual prognostic factors, such as BMI, in types I and II endometrial cancer. DESIGN: Register study included all Danish women who underwent surgery...... I and II endometrial cancer were retrieved. Kaplan-Meier plot was used to illustrate differences in survival in relation to BMI. Log-rank test was used to demonstrate difference between the curves. Cox regression hazard model was used to estimate hazard ratios (HR) of the effect of BMI on overall...

Prognostic value of preoperative dynamic contrast-enhanced MRI perfusion parameters for high-grade glioma patients

Energy Technology Data Exchange (ETDEWEB)

Ulyte, Agne [Vilnius University, Faculty of Medicine, Vilnius (Lithuania); Katsaros, Vasileios K. [General Anticancer and Oncological Hospital ' ' St. Savvas' ' , Department of Advanced Imaging Modalities - CT and MRI, Athens (Greece); University of Athens, Department of Neurosurgery, Evangelismos Hospital, Athens (Greece); Liouta, Evangelia; Stranjalis, Georgios [University of Athens, Department of Neurosurgery, Evangelismos Hospital, Athens (Greece); Boskos, Christos [University of Athens, Department of Neurosurgery, Evangelismos Hospital, Athens (Greece); General Anticancer and Oncological Hospital ' ' St. Savvas' ' , Department of Radiation Oncology, Athens (Greece); Papanikolaou, Nickolas [Champalimaud Foundation, Department of Radiology, Centre for the Unknown, Lisbon (Portugal); Usinskiene, Jurgita [National Cancer Institute, Vilnius (Lithuania); Affidea Lietuva, Vilnius (Lithuania); Bisdas, Sotirios [University College London Hospitals, Department of Neuroradiology, The National Hospital for Neurology and Neurosurgery, London (United Kingdom)

2016-12-15

The prognostic value of the dynamic contrast-enhanced (DCE) MRI perfusion and its histogram analysis-derived metrics is not well established for high-grade glioma (HGG) patients. The aim of this prospective study was to investigate DCE perfusion transfer coefficient (K{sup trans}), vascular plasma volume fraction (v{sub p}), extracellular volume fraction (v{sub e}), reverse transfer constant (k{sub ep}), and initial area under gadolinium concentration time curve (IAUGC) as predictors of progression-free (PFS) and overall survival (OS) in HGG patients. Sixty-nine patients with suspected anaplastic astrocytoma or glioblastoma underwent preoperative DCE-MRI scans. DCE perfusion whole tumor region histogram parameters, clinical details, and PFS and OS data were obtained. Univariate, multivariate, and Kaplan-Meier survival analyses were conducted. Receiver operating characteristic (ROC) curve analysis was employed to identify perfusion parameters with the best differentiation performance. On univariate analysis, v{sub e} and skewness of v{sub p} had significant negative impacts, while k{sub ep} had significant positive impact on OS (P < 0.05). v{sub e} was also a negative predictor of PFS (P < 0.05). Patients with lower v{sub e} and IAUGC had longer median PFS and OS on Kaplan-Meier analysis (P < 0.05). K{sup trans} and v{sub e} could also differentiate grade III from IV gliomas (area under the curve 0.819 and 0.791, respectively). High v{sub e} is a consistent predictor of worse PFS and OS in HGG glioma patients. v{sub p} skewness and k{sub ep} are also predictive for OS. K{sup trans} and v{sub e} demonstrated the best diagnostic performance for differentiating grade III from IV gliomas. (orig.)

Kaplan turbine tip vortex cavitation - analysis and prevention

Science.gov (United States)

Motycak, L.; Skotak, A.; Kupcik, R.

2012-11-01

The work is focused on one type of Kaplan turbine runner cavitation - a tip vortex cavitation. For detailed description of the tip vortex, the CFD analysis is used. On the basis of this analysis it is possible to estimate the intensity of cavitating vortex core, danger of possible blade surface and runner chamber cavitation pitting. In the paper, the ways how to avoid the pitting effect of the tip vortex are described. In order to prevent the blade surface against pitting, the following possibilities as the change of geometry of the runner blade, dimension of tip clearance and finally the installation of the anti-cavitation lips are discussed. The knowledge of the shape and intensity of the tip vortex helps to design the anti-cavitation lips more sophistically. After all, the results of the model tests of the Kaplan runner with or without anti-cavitation lips and the results of the CFD analysis are compared.

Practical Constraint K-Segment Principal Curve Algorithms for Generating Railway GPS Digital Map

Directory of Open Access Journals (Sweden)

Dewang Chen

2013-01-01

Full Text Available In order to obtain a decent trade-off between the low-cost, low-accuracy Global Positioning System (GPS receivers and the requirements of high-precision digital maps for modern railways, using the concept of constraint K-segment principal curves (CKPCS and the expert knowledge on railways, we propose three practical CKPCS generation algorithms with reduced computational complexity, and thereafter more suitable for engineering applications. The three algorithms are named ALLopt, MPMopt, and DCopt, in which ALLopt exploits global optimization and MPMopt and DCopt apply local optimization with different initial solutions. We compare the three practical algorithms according to their performance on average projection error, stability, and the fitness for simple and complex simulated trajectories with noise data. It is found that ALLopt only works well for simple curves and small data sets. The other two algorithms can work better for complex curves and large data sets. Moreover, MPMopt runs faster than DCopt, but DCopt can work better for some curves with cross points. The three algorithms are also applied in generating GPS digital maps for two railway GPS data sets measured in Qinghai-Tibet Railway (QTR. Similar results like the ones in synthetic data are obtained. Because the trajectory of a railway is relatively simple and straight, we conclude that MPMopt works best according to the comprehensive considerations on the speed of computation and the quality of generated CKPCS. MPMopt can be used to obtain some key points to represent a large amount of GPS data. Hence, it can greatly reduce the data storage requirements and increase the positioning speed for real-time digital map applications.

CURVES AND AESTHETIC SURFACES GENERATED BY THE R-R-RTR MECHANISM

Directory of Open Access Journals (Sweden)

Liliana LUCA

2013-05-01

Full Text Available Let’s consider a mechanism having two driving elements with revolving movements and a RTR dyad, with elements of null length and aesthetic tracks of a point are determined on a rod, for various linear movement laws of driving elements. The generated curves revolve around x and y axes and aesthetic surfaces result.

Meier-Gorlin syndrome.

Science.gov (United States)

de Munnik, Sonja A; Hoefsloot, Elisabeth H; Roukema, Jolt; Schoots, Jeroen; Knoers, Nine V A M; Brunner, Han G; Jackson, Andrew P; Bongers, Ernie M H F

2015-09-17

Meier-Gorlin syndrome (MGS) is a rare autosomal recessive primordial dwarfism disorder, characterized by microtia, patellar applasia/hypoplasia, and a proportionate short stature. Associated clinical features encompass feeding problems, congenital pulmonary emphysema, mammary hypoplasia in females and urogenital anomalies, such as cryptorchidism and hypoplastic labia minora and majora. Typical facial characteristics during childhood comprise a small mouth with full lips and micro-retrognathia. During ageing, a narrow, convex nose becomes more prominent. The diagnosis MGS should be considered in patients with at least two of the three features of the clinical triad of microtia, patellar anomalies, and pre- and postnatal growth retardation. In patients with short stature and/or microtia, the patellae should be assessed with care by ultrasonography before age 6 or radiography thereafter. Mutations in one of five genes (ORC1, ORC4, ORC6, CDT1, and CDC6) of the pre-replication complex, involved in DNA-replication, are detected in approximately 67-78% of patients with MGS. Patients with ORC1 and ORC4 mutations appear to have the most severe short stature and microcephaly. Management should be directed towards in-depth investigation, treatment and prevention of associated problems, such as growth retardation, feeding problems, hearing loss, luxating patellae, knee pain, gonarthrosis, and possible pulmonary complications due to congenital pulmonary emphysema with or without broncho- or laryngomalacia. Growth hormone treatment is ineffective in most patients with MGS, but may be effective in patients in whom growth continues to decrease after the first year of life (usually growth velocity normalizes after the first year) and with low levels of IGF1. At present, few data is available about reproduction of females with MGS, but the risk of premature labor might be increased. Here, we propose experience-based guidelines for the regular care and treatment of MGS patients.

MO-DE-207B-03: Improved Cancer Classification Using Patient-Specific Biological Pathway Information Via Gene Expression Data

Energy Technology Data Exchange (ETDEWEB)

Young, M; Craft, D [Massachusetts General Hospital and Harvard Medical School, Boston, MA (United States)

2016-06-15

Purpose: To develop an efficient, pathway-based classification system using network biology statistics to assist in patient-specific response predictions to radiation and drug therapies across multiple cancer types. Methods: We developed PICS (Pathway Informed Classification System), a novel two-step cancer classification algorithm. In PICS, a matrix m of mRNA expression values for a patient cohort is collapsed into a matrix p of biological pathways. The entries of p, which we term pathway scores, are obtained from either principal component analysis (PCA), normal tissue centroid (NTC), or gene expression deviation (GED). The pathway score matrix is clustered using both k-means and hierarchical clustering, and a clustering is judged by how well it groups patients into distinct survival classes. The most effective pathway scoring/clustering combination, per clustering p-value, thus generates various ‘signatures’ for conventional and functional cancer classification. Results: PICS successfully regularized large dimension gene data, separated normal and cancerous tissues, and clustered a large patient cohort spanning six cancer types. Furthermore, PICS clustered patient cohorts into distinct, statistically-significant survival groups. For a suboptimally-debulked ovarian cancer set, the pathway-classified Kaplan-Meier survival curve (p = .00127) showed significant improvement over that of a prior gene expression-classified study (p = .0179). For a pancreatic cancer set, the pathway-classified Kaplan-Meier survival curve (p = .00141) showed significant improvement over that of a prior gene expression-classified study (p = .04). Pathway-based classification confirmed biomarkers for the pyrimidine, WNT-signaling, glycerophosphoglycerol, beta-alanine, and panthothenic acid pathways for ovarian cancer. Despite its robust nature, PICS requires significantly less run time than current pathway scoring methods. Conclusion: This work validates the PICS method to improve

Prita Meier, Swahili Port Cities: The Architecture of Elsewhere

OpenAIRE

Longair, Sarah

2018-01-01

Prita Meier’s Swahili Port Cities: the Architecture of Elsewhere is a highly original and important contribution to scholarship on East Africa, and more widely for scholars interested in complicating how we understand the formation of global cities and border zone societies. It is not a conventional architectural history, yet it places buildings, in particular the coral and lime stone constructions found on the Swahili coast, at its heart. Meier uses the “materiality of city life” to offer “a...

Kaplan kõneles Iraagis rahust / Raivo Nikiforov ; interv. Eda Post

Index Scriptorium Estoniae

Nikiforov, Raivo

2005-01-01

Tapa väljaõppekeskuse kaplan leitnant Raivo Nikiforov käis Bagdadis Eesti rahuvalvajatele jõulujumalateenistust pidamas ning eestlaste elu jälgimas. Iraagi missioonist, rahuvalvajate elamistingimustest

Next-Generation Intensity-Duration-Frequency Curves for Hydrologic Design in Snow-Dominated Environments

Science.gov (United States)

Yan, Hongxiang; Sun, Ning; Wigmosta, Mark; Skaggs, Richard; Hou, Zhangshuan; Leung, Ruby

2018-02-01

There is a renewed focus on the design of infrastructure resilient to extreme hydrometeorological events. While precipitation-based intensity-duration-frequency (IDF) curves are commonly used as part of infrastructure design, a large percentage of peak runoff events in snow-dominated regions are caused by snowmelt, particularly during rain-on-snow (ROS) events. In these regions, precipitation-based IDF curves may lead to substantial overestimation/underestimation of design basis events and subsequent overdesign/underdesign of infrastructure. To overcome this deficiency, we proposed next-generation IDF (NG-IDF) curves, which characterize the actual water reaching the land surface. We compared NG-IDF curves to standard precipitation-based IDF curves for estimates of extreme events at 376 Snowpack Telemetry (SNOTEL) stations across the western United States that each had at least 30 years of high-quality records. We found standard precipitation-based IDF curves at 45% of the stations were subject to underdesign, many with significant underestimation of 100 year extreme events, for which the precipitation-based IDF curves can underestimate water potentially available for runoff by as much as 125% due to snowmelt and ROS events. The regions with the greatest potential for underdesign were in the Pacific Northwest, the Sierra Nevada Mountains, and the Middle and Southern Rockies. We also found the potential for overdesign at 20% of the stations, primarily in the Middle Rockies and Arizona mountains. These results demonstrate the need to consider snow processes in the development of IDF curves, and they suggest use of the more robust NG-IDF curves for hydrologic design in snow-dominated environments.

Statistically generated weighted curve fit of residual functions for modal analysis of structures

Science.gov (United States)

Bookout, P. S.

1995-01-01

A statistically generated weighting function for a second-order polynomial curve fit of residual functions has been developed. The residual flexibility test method, from which a residual function is generated, is a procedure for modal testing large structures in an external constraint-free environment to measure the effects of higher order modes and interface stiffness. This test method is applicable to structures with distinct degree-of-freedom interfaces to other system components. A theoretical residual function in the displacement/force domain has the characteristics of a relatively flat line in the lower frequencies and a slight upward curvature in the higher frequency range. In the test residual function, the above-mentioned characteristics can be seen in the data, but due to the present limitations in the modal parameter evaluation (natural frequencies and mode shapes) of test data, the residual function has regions of ragged data. A second order polynomial curve fit is required to obtain the residual flexibility term. A weighting function of the data is generated by examining the variances between neighboring data points. From a weighted second-order polynomial curve fit, an accurate residual flexibility value can be obtained. The residual flexibility value and free-free modes from testing are used to improve a mathematical model of the structure. The residual flexibility modal test method is applied to a straight beam with a trunnion appendage and a space shuttle payload pallet simulator.

Curvature Entropy for Curved Profile Generation

OpenAIRE

Ujiie, Yoshiki; Kato, Takeo; Sato, Koichiro; Matsuoka, Yoshiyuki

2012-01-01

In a curved surface design, the overall shape features that emerge from combinations of shape elements are important. However, controlling the features of the overall shape in curved profiles is difficult using conventional microscopic shape information such as dimension. Herein two types of macroscopic shape information, curvature entropy and quadrature curvature entropy, quantitatively represent the features of the overall shape. The curvature entropy is calculated by the curvature distribu...

Comparison of Exposure in the Kaplan Versus the Kocher Approach in the Treatment of Radial Head Fractures.

Science.gov (United States)

Barnes, Leslie Fink; Lombardi, Joseph; Gardner, Thomas R; Strauch, Robert J; Rosenwasser, Melvin P

2018-01-01

The aim of this study was to compare the complete visible surface area of the radial head, neck, and coronoid in the Kaplan and Kocher approaches to the lateral elbow. The hypothesis was that the Kaplan approach would afford greater visibility due to the differential anatomy of the intermuscular planes. Ten cadavers were dissected with the Kaplan and Kocher approaches, and the visible surface area was measured in situ using a 3-dimensional digitizer. Six measurements were taken for each approach by 2 surgeons, and the mean of these measurements were analyzed. The mean surface area visible with the lateral collateral ligament (LCL) preserved in the Kaplan approach was 616.6 mm 2 in comparison with the surface area of 136.2 mm 2 visible in the Kocher approach when the LCL was preserved. Using a 2-way analysis of variance, the difference between these 2 approaches was statistically significant. When the LCL complex was incised in the Kocher approach, the average visible surface area of the Kocher approach was 456.1 mm 2 and was statistically less than the Kaplan approach. The average surface area of the coronoid visible using a proximally extended Kaplan approach was 197.8 mm 2 . The Kaplan approach affords significantly greater visible surface area of the proximal radius than the Kocher approach.

Prior history of non-melanoma skin cancer is associated with increased mortality in patients with chronic lymphocytic leukemia

Science.gov (United States)

Toro, Jorge R.; Blake, Patrick W.; Björkholm, Magnus; Kristinsson, Sigurdur Y.; Wang, Zhuoqiao; Landgren, Ola

2009-01-01

We investigated whether a previous diagnosis of non-melanoma skin cancer among chronic lymphocytic leukemia patients is a predictor of poor outcome. Using the Swedish Cancer Registry, we conducted a population-based study to evaluate the survival patterns among chronic lymphocytic leukemia patients with and without non-melanoma skin cancer. Cox proportional hazards regression models were used and Kaplan-Meier curves were constructed. Of a total of 12,041 chronic lymphocytic leukemia cases identified, 236 cases, including 111 squamous cell cancer, had a prior history of non-melanoma skin cancer. Chronic lymphocytic leukemia patients with a prior history of non-melanoma skin cancer had a 1.29-fold (95% CI 1.10–1.52; p=0.0024) increased risk of dying; and those with a history of squamous cell cancer had a further elevated 1.86-fold (95% CI 1.46–2.36; p<0.0001) risk of dying. Kaplan-Meier plots showed that patients with a history of non-melanoma skin cancer, particularly those with squamous cell cancer, had significantly poorer survival than chronic lymphocytic leukemia patients without non-melanoma skin cancer (p<0.0001; log-rank test). Non-melanoma skin cancer may be a novel clinical predictor of worse chronic lymphocytic leukemia outcome. PMID:19794092

Next-Generation Intensity-Duration-Frequency Curves for Hydrologic Design in Snow-Dominated Environments

Energy Technology Data Exchange (ETDEWEB)

Yan, Hongxiang [Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland Washington United States; Sun, Ning [Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland Washington United States; Wigmosta, Mark [Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland Washington United States; Distinguished Faculty Fellow, Department of Civil and Environmental Engineering, University of Washington, Seattle Washington United States; Skaggs, Richard [Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland Washington United States; Hou, Zhangshuan [Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland Washington United States; Leung, Ruby [Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland Washington United States

2018-02-01

There is a renewed focus on the design of infrastructure resilient to extreme hydrometeorological events. While precipitation-based intensity-duration-frequency (IDF) curves are commonly used as part of infrastructure design, a large percentage of peak runoff events in snow-dominated regions are caused by snowmelt, particularly during rain-on-snow (ROS) events. In these regions, precipitation-based IDF curves may lead to substantial over-/under-estimation of design basis events and subsequent over-/under-design of infrastructure. To overcome this deficiency, we proposed next-generation IDF (NG-IDF) curves, which characterize the actual water reaching the land surface. We compared NG-IDF curves to standard precipitation-based IDF curves for estimates of extreme events at 376 Snowpack Telemetry (SNOTEL) stations across the western United States that each had at least 30 years of high-quality records. We found standard precipitation-based IDF curves at 45% of the stations were subject to under-design, many with significant under-estimation of 100-year extreme events, for which the precipitation-based IDF curves can underestimate water potentially available for runoff by as much as 125% due to snowmelt and ROS events. The regions with the greatest potential for under-design were in the Pacific Northwest, the Sierra Nevada Mountains, and the Middle and Southern Rockies. We also found the potential for over-design at 20% of the stations, primarily in the Middle Rockies and Arizona mountains. These results demonstrate the need to consider snow processes in the development of IDF curves, and they suggest use of the more robust NG-IDF curves for hydrologic design in snow-dominated environments.

Neoadjuvant treatment and adjuvant radiotherapy for patients with high risk prostate cancer and radical prostatectomy

International Nuclear Information System (INIS)

Scorticati, Carlos; Aguilar, Jorge A.; Gonzalez Granda, Pablo; Mendez, Fernando; Montiel, Raul; Rege, Eduardo; Alvarez, Patricio; Lopez, Miguel A.; Rizzi, Alfredo; Mazza, Osvaldo

2009-01-01

Introduction and Objectives: To analyze the results of the treatment in patients with cancer of prostate of high risk. Material and Method: Retrospective and observational analysis of 130 patients operated by CAP of high risk (criteria of D'Amico) average 41,48 months, divided in form nonrandomized in three groups 1: radical prostatectomy, 2: neoadjuvant hormonoterapy (BAC) + PR, 3: BAC + PR + x-ray (RT). Statistical analysis: multivaried, test of curved Chi2 and p statistical and of Kaplan Meier. Results: Biochemical relapse 68 patients (52.3%), average 23,37 months. Without differences according to therapeutic modality (p: 0.043). In the multivaried analysis of the 3 factors of presurgical, single risk we found a statistically significant relation in the coexistence of the 3 factors with the presence of positive margin in the PR piece. (p: 0,002). The analysis to make or not, neoadjuvant BAC without significant difference (p: 0,403) evaluating in such the rate of M+, actuarial global survival according to curves of Kaplan Meier to 5 and 10 years (P: 0,5257) and survival 5 actuarial specific cancer to and 10a (P: 0,2165). Conclusions: Without significant differences in: RB, clinical progression, pathological relapse, global and specific survival, rate of positive surgical margins. The 3 criteria of D'Amico were predictive of positive surgical margins and RB, the patients with RB in group 2 presented/displayed greater risk of clinical progression, the PR demonstrated a global survival and specify actuarial to 10 years greater to 50%, considering it therapeutic an option been worth. (authors) [es

Left ventricular dyssynchrony assessed by gated SPECT phase analysis is an independent predictor of death in patients with advanced coronary artery disease and reduced left ventricular function not undergoing cardiac resynchronization therapy

Energy Technology Data Exchange (ETDEWEB)

Uebleis, Christopher; Hellweger, Stefan; Lehner, Sebastian; Haug, Alexander; Bartenstein, Peter; Cumming, Paul; Hacker, Marcus [Ludwig-Maximilians University, Department of Nuclear Medicine, Munich (Germany); Laubender, Ruediger Paul [Ludwig-Maximilians University, Institute of Medical Informatics, Biometry, and Epidemiology (IBE), Munich (Germany); Becker, Alexander [Ludwig-Maximilians University, Medical Department I, Munich (Germany); Sohn, Hae-Young [Ludwig-Maximilians University, Medical Department Innenstadt, Munich (Germany); Van Kriekinge, Serge D.; Slomka, Piotr J. [Cedars-Sinai Medical Center, Los Angeles, CA (United States); UCLA, David Geffen School of Medicine, Los Angeles, CA (United States)

2012-10-15

Left ventricular (LV) mechanical dyssynchrony (LVMD) was assessed by gated single-photon emission CT myocardial perfusion imaging (MPI) as an independent predictor of death from any cause in patients with known coronary artery disease (CAD) and reduced LV function. Between 2001 and 2010, 135 patients (64 {+-} 11 years of age, 84 % men) with known CAD, reduced LV ejection fraction (LVEF, 38 {+-} 15 %) and without an implanted cardiac resynchronization therapy device underwent gated MPI at rest. LV functional evaluation, which included phase analysis, was conducted to identify patients with LVMD. Kaplan-Meier survival curves were calculated for death of any cause during a mean follow-up of 2.0 {+-} 1.7 years. Uni- and multivariate Cox proportional hazards regression models were calculated to identify independent predictors of death from any cause. Of the 135 patients, 30 (22 %) died during follow-up (18 cardiac deaths and 12 deaths from other causes). Kaplan-Meier curves showed a significantly shorter survival time in the patients with severely reduced LVEF (<30 %, n = 45) or with LVMD (n = 81, log-rank test P <0.005). Cox models identified LVMD, LVEF <30 % and a total perfusion deficit at rest of {>=}20 % as independent predictors of death from any cause. While patients with LVEF <30 % in conjunction with LVMD had similar survival times irrespective of whether they had early revascularization or medical therapy, those patients with LVEF {>=}30% and LVMD who underwent revascularization had significantly longer survival. In patients with known CAD and reduced LV function, dyssynchrony of the LV is an independent predictor of death from any cause. (orig.)

Compliance with Supportive Periodontal Treatment in Patients with Dental Implants.

Science.gov (United States)

Hu, Kai-Fang; Lin, Ying-Chu; Ho, Kun-Yen; Chou, Yu-Hsiang

The need for dental implants is increasing, and supportive periodontal treatment can achieve long-term success and prevent peri-implantitis. Contributing factors to noncompliance with long-term scheduled supportive periodontal treatment remain unclear. To investigate whether demographic and clinical characteristics are associated with noncompliance, the authors analyzed data for patients who had received dental implants. The authors recruited patients participating in a supportive periodontal treatment program after receiving permanent prostheses on implants placed from 2005 to 2013. Demographic data and dental treatment histories were collected. Compliance was defined as a record of participation in a standard supportive periodontal treatment program for at least 1 year. The chi-square test, log-rank test, Kaplan-Meier survival curve, and Cox proportional hazards model were used for statistical analysis. The study included 120 patients (259 implants, 60% compliance). The two groups (compliant and noncompliant) differed significantly in frequency distributions for sex (P = .0017), educational level (P = .0325), and histories of substance use (P = .0016), periodontitis (P = .0005), and root planing or flap surgery (P = .0002). The Kaplan-Meier survival curves and log-rank test showed that increases in cumulative continuation rates were significantly associated with male sex (P = .0025); body mass index ≥ 24 kg/m² (P = .0093); and a history of periodontitis (P implant placement, root planing or flap surgery was the crucial factor in determining compliance with supportive periodontal treatment. However, well-designed large-scale studies with a larger sample size are needed to confirm the findings of this study.

Individualism, Nationalism, and Universalism: The Educational Ideals of Mordecai M. Kaplan's Philosophy of Jewish Education

Science.gov (United States)

Ackerman, Ari

2008-01-01

This article will examine educational ideals by exploring the relation between the individual, the collective, and humanity in Kaplan's Jewish and educational philosophy. Generally the goals of individualism, nationalism, and universalism are seen as mutually exclusive. By contrast, Kaplan argues for the symbiotic relationship between…

A method for the rapid generation of nonsequential light-response curves of chlorophyll fluorescence.

Science.gov (United States)

Serôdio, João; Ezequiel, João; Frommlet, Jörg; Laviale, Martin; Lavaud, Johann

2013-11-01

Light-response curves (LCs) of chlorophyll fluorescence are widely used in plant physiology. Most commonly, LCs are generated sequentially, exposing the same sample to a sequence of distinct actinic light intensities. These measurements are not independent, as the response to each new light level is affected by the light exposure history experienced during previous steps of the LC, an issue particularly relevant in the case of the popular rapid light curves. In this work, we demonstrate the proof of concept of a new method for the rapid generation of LCs from nonsequential, temporally independent fluorescence measurements. The method is based on the combined use of sample illumination with digitally controlled, spatially separated beams of actinic light and a fluorescence imaging system. It allows the generation of a whole LC, including a large number of actinic light steps and adequate replication, within the time required for a single measurement (and therefore named "single-pulse light curve"). This method is illustrated for the generation of LCs of photosystem II quantum yield, relative electron transport rate, and nonphotochemical quenching on intact plant leaves exhibiting distinct light responses. This approach makes it also possible to easily characterize the integrated dynamic light response of a sample by combining the measurement of LCs (actinic light intensity is varied while measuring time is fixed) with induction/relaxation kinetics (actinic light intensity is fixed and the response is followed over time), describing both how the response to light varies with time and how the response kinetics varies with light intensity.

Solar updraft power generator with radial and curved vanes

Science.gov (United States)

Hafizh, Hadyan; Hamsan, Raziff; Zamri, Aidil Azlan Ahmad; Keprawi, Mohamad Fairuz Mohamad; Shirato, Hiromichi

2018-02-01

Solar radiation is the largest source of energy available on earth and the solar updraft power generator (SUPG) is a renewable energy facility capable of harnessing its abundant power. Unlike the conventional wind turbines that harness natural wind in the atmosphere and often encounter with the intermittent issue or even complete cut-off from airflow, the SUPG creates artificial wind as a result of solar-induced convective flows. However, the SUPG has an inherent low total efficiency due to the conversion of thermal energy into pressure energy. Acknowledging the low efficiency and considering its potential as a renewable energy facility, the current work aims to increase the total efficiency by installing a series of guide walls inside the collector. Two types of guide walls were used i.e. radial and curved vanes. The result with curved vanes showed that the updraft velocity is higher compare to those without vanes. About 18% and 64% improvement of updraft velocity and mechanical power were attained respectively. Furthermore, it was observed that the role of radial vanes configuration was more to produce a smooth updraft velocity profile rather than increasing the total efficiency.

Canonical generators of the cohomology of moduli of parabolic bundles on curves

International Nuclear Information System (INIS)

Biswas, I.; Raghavendra, N.

1994-11-01

We determine generators of the rational cohomology algebras of moduli spaces of parabolic vector bundles on a curve, under some 'primality' conditions on the parabolic datum. These generators are canonical in a precise sense. Our results are new even for usual vector bundles (i.e., vector bundles without parabolic structure) whose rank is greater than 2 and is coprime to the degree; in this case, they are generalizations of a theorem of Newstead on the moduli of vector bundles of rank 2 and odd degree. (author). 11 refs

Kaplan turbine tip vortex cavitation – analysis and prevention

International Nuclear Information System (INIS)

Motycak, L; Skotak, A; Kupcik, R

2012-01-01

The work is focused on one type of Kaplan turbine runner cavitation – a tip vortex cavitation. For detailed description of the tip vortex, the CFD analysis is used. On the basis of this analysis it is possible to estimate the intensity of cavitating vortex core, danger of possible blade surface and runner chamber cavitation pitting. In the paper, the ways how to avoid the pitting effect of the tip vortex are described. In order to prevent the blade surface against pitting, the following possibilities as the change of geometry of the runner blade, dimension of tip clearance and finally the installation of the anti-cavitation lips are discussed. The knowledge of the shape and intensity of the tip vortex helps to design the anti-cavitation lips more sophistically. After all, the results of the model tests of the Kaplan runner with or without anti-cavitation lips and the results of the CFD analysis are compared.

Axial U(1) current in Grabowska and Kaplan's formulation

Science.gov (United States)

Hamada, Yu; Kawai, Hikaru

2017-06-01

Recently, Grabowska and Kaplan [Phys. Rev. Lett. 116, 211602 (2016); Phys. Rev. D 94, 114504 (2016)] suggested a nonperturbative formulation of a chiral gauge theory, which consists of the conventional domain-wall fermion and a gauge field that evolves by gradient flow from one domain wall to the other. We introduce two sets of domain-wall fermions belonging to complex conjugate representations so that the effective theory is a 4D vector-like gauge theory. Then, as a natural definition of the axial-vector current, we consider a current that generates simultaneous phase transformations for the massless modes in 4 dimensions. However, this current is exactly conserved and does not reproduce the correct anomaly. In order to investigate this point precisely, we consider the mechanism of the conservation. We find that this current includes not only the axial current on the domain wall but also a contribution from the bulk, which is nonlocal in the sense of 4D fields. Therefore, the local current is obtained by subtracting the bulk contribution from it.

Comparative Study of Barotrauma Risk during Fish Passage through Kaplan Turbines

Energy Technology Data Exchange (ETDEWEB)

Richmond, Marshall C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Hydrology Group; Romero-Gomez, Pedro [Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Hydrology Group; Serkowski, John A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Hydrology Group; Rakowski, Cynthia L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Hydrology Group; Graf, Michael J. [Voith Hydro, York, PA (United States)

2015-10-01

Rapid pressure changes in hydroelectric turbine flows can cause barotrauma that can be hazardous to the passage of fish, in particular migratory juvenile salmonids. Although numerous laboratory tests have evaluated the effect of rapid decompression in fish species of relevance, numerical modeling studies offer the advantage of predicting, for new turbine designs, the potential risks of mortality and injury from rapid pressure change during turbine passage. However, rapid pressure change is only one of several hydraulic risks encountered by fish during turbine passage in addition to blade strike, shear, and turbulence. To better understand the role of rapid pressure changes, the present work focuses on the application of a computational fluid dynamics based method for evaluating the risk of pressure-related mortality to fish passing through an early 1960s era original hydroelectric Kaplan turbine at Wanapum Dam (Columbia River, Washington), and a modern advanced Kaplan turbine installed in 2005. The results show that the modeling approach acceptably reproduced the nadir pressure distributions compared to field data previously collected at the site using an autonomous sensor. Our findings show that the new advanced-design unit performs better, in terms of reduced barotrauma risk to fish from exposure to low pressures, than the original turbine unit. The outcomes allow for comparative analyses of turbine designs and operations prior to installation, an advantage that can potentially be integrated in the process of designing new turbine units to achieve superior environmental performance. Overall, the results show that modern turbine designs can achieve the multiple objectives of increasing power generation, lowering cavitation potential, and reducing barotrauma risks to passing fish.

De 'wraak van de geografie' volgens Robert D. Kaplan

NARCIS (Netherlands)

Mamadouh, V.

2013-01-01

De Amerikaanse publicist Robert D. Kaplan heeft een nieuwe bestseller, De wraak van de geografie, waarin hij het belang van geografie voor de internationale politiek uit de doeken doet. Zijn roep om meer aandacht voor geografie is echter erg eenzijdig en een miskenning van alles waar ons vak voor

Unsteady load on an oscillating Kaplan turbine runner

Science.gov (United States)

Puolakka, O.; Keto-Tokoi, J.; Matusiak, J.

2013-02-01

A Kaplan turbine runner oscillating in turbine waterways is subjected to a varying hydrodynamic load. Numerical simulation of the related unsteady flow is time-consuming and research is very limited. In this study, a simplified method based on unsteady airfoil theory is presented for evaluation of the unsteady load for vibration analyses of the turbine shaft line. The runner is assumed to oscillate as a rigid body in spin and axial heave, and the reaction force is resolved into added masses and dampings. The method is applied on three Kaplan runners at nominal operating conditions. Estimates for added masses and dampings are considered to be of a magnitude significant for shaft line vibration. Moderate variation in the added masses and minor variation in the added dampings is found in the frequency range of interest. Reference results for added masses are derived by solving the boundary value problem for small motions of inviscid fluid using the finite element method. Good correspondence is found in the added mass estimates of the two methods. The unsteady airfoil method is considered accurate enough for design purposes. Experimental results are needed for validation of unsteady load analyses.

«Esa corporeidad mortal y rosa»: análisis del tiempo libre de enfermedad del cáncer de mama en Gipuzkoa en presencia de riesgos competitivos "That deadly and pink corporeity": Analysis of disease-free survival analysis in breast cancer in Gipuzkoa (Spain in the presence of competing risks

Directory of Open Access Journals (Sweden)

Pablo Martínez-Camblor

2009-12-01

Full Text Available Objetivo: Analizar el tiempo de supervivencia libre de enfermedad y la supervivencia relativa en mujeres diagnosticadas de cáncer de mama en la provincia de Gipuzkoa en un contexto de riesgos competitivos, valorando las diferencias encontradas entre el uso directo del estimador de Kaplan-Meier y el método de decrementos múltiples por un lado y la supervivencia relativa por otro. Métodos: Se consideraron todos los casos de cáncer de mama registrados en la provincia de Gipuzkoa durante los años 1995 y 1996 en estadio distinto del IV, y se hizo un seguimiento de 8 años para la recidiva y de 10 años para la supervivencia. Se analizó el tiempo de supervivencia libre de enfermedad mediante el método de decrementos múltiples. Asimismo, también se analizó el tiempo de supervivencia observado y corregido por la mortalidad esperada de la población, conocido como supervivencia relativa. Resultados: La estimación de la probabilidad de recidiva a los 8 años por el método de decrementos múltiples es un 8,8% inferior a la obtenida por el método de Kaplan-Meier. La diferencia entre la supervivencia observada y la relativa a los 10 años es del 10,8%. Ambos resultados indican que, en este caso, el método de Kaplan-Meier sobrestima tanto la probabilidad de recaída como la de muerte por la enfermedad. Conclusiones: Dos cuestiones que muchas veces se obvian al realizar un análisis de supervivencia son, por un lado, que la no independencia entre el tiempo de supervivencia y el tiempo de censura hacen no interpretables los resultados obtenidos por el estimador de Kaplan-Meier, y por otro el hecho, hasta hora incuestionable, de que de una manera u otra todos causamos fallo y, desde este planteamiento, en el estudio del tiempo de supervivencia hay que tener presente la probabilidad de fallo en la población general de referencia. En los resultados obtenidos se observa que utilizar de manera superficial el estimador de Kaplan-Meier comporta una

Carotid flow velocity/diameter ratio is a predictor of cardiovascular events in hypertensive patients

DEFF Research Database (Denmark)

Bellinazzi, Vera R; Cipolli, José A; Pimenta, Marcio V

2015-01-01

AD) greater than the median value presented the worst clinical outcome compared to those with isolated sFV less than the median value or sAD greater than the median value, suggesting an additive effect of these two variables. Further, Kaplan-Meier analysis demonstrated worse outcome for individuals with s...... intima-media thickness and clinically defined high cardiovascular risk did not. Furthermore, area under the receiver-operating characteristic curve for sFV/sAD was higher than that for Framingham risk score (0.77 versus 0.64; P = 0.045), whereas adding sFV/sAD to the Framingham risk factors resulted...

Growth pattern of colorectal liver metastasis as a marker of recurrence risk

DEFF Research Database (Denmark)

Eefsen, R L; Vermeulen, P B; Christensen, I J

2015-01-01

from patient and pathology records. Histological GP were evaluated and related to recurrence free and OS. Kaplan-Meier curves, log-rank test and Cox regression analysis were used. The 5-year OS was 41.8% (95% CI 33.8-49.8%). Growth pattern evaluation of the largest liver metastasis was possible in 224...... free survival (RFS) than patients resected for non-desmoplastic liver metastases (p=0.05). When patients were stratified according to neo-adjuvant treatment in the multivariate Cox regression model, hazard ratios for RFS compared to desmoplastic were: pushing (HR=1.37, 95% CI 0.93-2.02, p=0...

Mortality impact of positive blood cultures in patients with suspected community-acquired bacteraemia. A Danish population-based cohort study

DEFF Research Database (Denmark)

Søgaard, Mette; Nørgaard, Mette; Sørensen, Henrik Toft

2009-01-01

for age, gender, coexisting chronic diseases, marital status, use of immunosuppressives, and calendar period. Further, we conducted analyses restricted to patients a discharge diagnose of infectious diseases (ICD-10 codes A00-B99). Results: In total, 1,665 (8.2%) patients had positive blood culture...... System. We computed Kaplan-Meier curves and product limit estimates for the main study variables. Next, time-dependent Cox regression analyses was used to compare the risk of death in patients with positive blood cultures and patients with negative cultures at days 0-7, 8-30, and 31-180, controlling...

Application of remote sensing and geographical information system for generation of runoff curve number

Science.gov (United States)

Meshram, S. Gajbhiye; Sharma, S. K.; Tignath, S.

2017-07-01

Watershed is an ideal unit for planning and management of land and water resources (Gajbhiye et al., IEEE international conference on advances in technology and engineering (ICATE), Bombay, vol 1, issue 9, pp 23-25, 2013a; Gajbhiye et al., Appl Water Sci 4(1):51-61, 2014a; Gajbhiye et al., J Geol Soc India (SCI-IF 0.596) 84(2):192-196, 2014b). This study aims to generate the curve number, using remote sensing and geographical information system (GIS) and the effect of slope on curve number values. The study was carried out in Kanhaiya Nala watershed located in Satna district of Madhya Pradesh. Soil map, Land Use/Land cover and slope map were generated in GIS Environment. The CN parameter values corresponding to various soil, land cover, and land management conditions were selected from Natural Resource Conservation Service (NRCS) standard table. Curve number (CN) is an index developed by the NRCS, to represent the potential for storm water runoff within a drainage area. The CN for a drainage basin is estimated using a combination of land use, soil, and antecedent soil moisture condition (AMC). In present study effect of slope on CN values were determined. The result showed that the CN unadjusted value are higher in comparison to CN adjusted with slope. Remote sensing and GIS is very reliable technique for the preparation of most of the input data required by the SCS curve number model.

Prognostic significance of transient myocardial ischaemia after first acute myocardial infarction: five year follow up study

DEFF Research Database (Denmark)

Mickley, H; Nielsen, J R; Berning, J

1995-01-01

infarction. MAIN OUTCOME MEASURES: Relation of ambulatory ST segment depression, exercise test variables, and left ventricular ejection fraction to subsequent objective (cardiac death or myocardial infarction) or subjective (need for coronary revascularisation) events. RESULTS: 23 of the 123 patients had...... an association between transient ST segment depression and an adverse long term outcome was found (Kaplan-Meier analysis; P = 0.004). The presence of exercise induced angina identified a similar proportion of patients with a poor prognosis (Kaplan-Meier analysis; P ... ST segment depression had high specificity but poor sensitivity. The presence of exercise induced ST segment depression was of no value in predicting combined cardiac events. Indeed, patients without exertional ST segment depression were at increased risk of future objective end points (Kaplan...

Lagrangian Curves on Spectral Curves of Monopoles

International Nuclear Information System (INIS)

Guilfoyle, Brendan; Khalid, Madeeha; Ramon Mari, Jose J.

2010-01-01

We study Lagrangian points on smooth holomorphic curves in TP 1 equipped with a natural neutral Kaehler structure, and prove that they must form real curves. By virtue of the identification of TP 1 with the space LE 3 of oriented affine lines in Euclidean 3-space, these Lagrangian curves give rise to ruled surfaces in E 3 , which we prove have zero Gauss curvature. Each ruled surface is shown to be the tangent lines to a curve in E 3 , called the edge of regression of the ruled surface. We give an alternative characterization of these curves as the points in E 3 where the number of oriented lines in the complex curve Σ that pass through the point is less than the degree of Σ. We then apply these results to the spectral curves of certain monopoles and construct the ruled surfaces and edges of regression generated by the Lagrangian curves.

Influence of Working Environment on Fatigue Life Time Duration for Runner Blades of Kaplan Turbines

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Ana-Maria Budai

2010-10-01

Full Text Available The paper present an analytical analyzes refer to influence of working environment on life time duration in service of runner blades of Kaplan turbines. The study are made using only analytical method, the entry dates being obtained from measurements made in situ for a Kaplan turbine. To calculate the maximum number of stress cycles whereupon the runner blades work without any damage it was used an analytical relation known in specialized literatures under the name of Morrow’s relation. To estimate fatigue life time duration will be used a formula obtained from one of most common cumulative damage methodology taking in consideration the real exploitation conditions of a specified Kaplan turbine.

Research on the cavitation characteristic of Kaplan turbine under sediment flow condition

International Nuclear Information System (INIS)

Weili, L; Jinling, L; Xingqi, L; Yuan, L

2010-01-01

The sediment concentration in many rivers in our world is very high, and the Kaplan turbine running in these rivers are usually seriously abraded. Since the existence of sand, the probability of cavitation is greatly enhanced. Under the joint action and mutual promotion of cavitation and sand erosion, serious abrasion could be made, the hydraulic performance of the Kaplan turbine may be descended, and the safety and stability of turbine are greatly threatened. Therefore, it is very important and significant to investigate the cavitation characteristic of Kaplan turbine under sediment flow condition. In this paper, numerical simulation of cavitation characteristic in pure water and solid-liquid two-phase flow in Kaplan turbine was performed. The solid-liquid two-fluid model were adopted in the numerical simulation, and the pressure, velocity and particle concentration distributive regularity on turbine blade surface under different diameter and concentration was revealed. Particle trajectory model was used to investigate the region and degree of runner blade abrasion in different conditions. The results showed that serious sand abrasion could be found near the blade head and outlet in large flow rate working condition. Relatively slight abrasion may be found near blade flange in small flow rate working condition. The more the sediment concentration and the large the sand diameter, the serious the runner is abraded, and the greater the efficiency is decreased. further analysis of the combined effects of wear and abrasion was performed. The result shows that the cavitation in silt flow is more serious than in pure water. The runner cavitation performance become worse under high sand concentration and large particle diameter, and the efficiency decrease greatly with the increase of sediment concentration.

Research on the cavitation characteristic of Kaplan turbine under sediment flow condition

Energy Technology Data Exchange (ETDEWEB)

Weili, L; Jinling, L; Xingqi, L; Yuan, L, E-mail: liaoweili2004@163.co [Institute of Water Resources and Hydro-Electric Engineering, Xi' an University of Technology No.5 South Jinhua Road, Xi' an, Shaanxi, 710048 (China)

2010-08-15

The sediment concentration in many rivers in our world is very high, and the Kaplan turbine running in these rivers are usually seriously abraded. Since the existence of sand, the probability of cavitation is greatly enhanced. Under the joint action and mutual promotion of cavitation and sand erosion, serious abrasion could be made, the hydraulic performance of the Kaplan turbine may be descended, and the safety and stability of turbine are greatly threatened. Therefore, it is very important and significant to investigate the cavitation characteristic of Kaplan turbine under sediment flow condition. In this paper, numerical simulation of cavitation characteristic in pure water and solid-liquid two-phase flow in Kaplan turbine was performed. The solid-liquid two-fluid model were adopted in the numerical simulation, and the pressure, velocity and particle concentration distributive regularity on turbine blade surface under different diameter and concentration was revealed. Particle trajectory model was used to investigate the region and degree of runner blade abrasion in different conditions. The results showed that serious sand abrasion could be found near the blade head and outlet in large flow rate working condition. Relatively slight abrasion may be found near blade flange in small flow rate working condition. The more the sediment concentration and the large the sand diameter, the serious the runner is abraded, and the greater the efficiency is decreased. further analysis of the combined effects of wear and abrasion was performed. The result shows that the cavitation in silt flow is more serious than in pure water. The runner cavitation performance become worse under high sand concentration and large particle diameter, and the efficiency decrease greatly with the increase of sediment concentration.

Research on the cavitation characteristic of Kaplan turbine under sediment flow condition

Science.gov (United States)

Weili, L.; Jinling, L.; Xingqi, L.; Yuan, L.

2010-08-01

The sediment concentration in many rivers in our world is very high, and the Kaplan turbine running in these rivers are usually seriously abraded. Since the existence of sand, the probability of cavitation is greatly enhanced. Under the joint action and mutual promotion of cavitation and sand erosion, serious abrasion could be made, the hydraulic performance of the Kaplan turbine may be descended, and the safety and stability of turbine are greatly threatened. Therefore, it is very important and significant to investigate the cavitation characteristic of Kaplan turbine under sediment flow condition. In this paper, numerical simulation of cavitation characteristic in pure water and solid-liquid two-phase flow in Kaplan turbine was performed. The solid-liquid two-fluid model were adopted in the numerical simulation, and the pressure, velocity and particle concentration distributive regularity on turbine blade surface under different diameter and concentration was revealed. Particle trajectory model was used to investigate the region and degree of runner blade abrasion in different conditions. The results showed that serious sand abrasion could be found near the blade head and outlet in large flow rate working condition. Relatively slight abrasion may be found near blade flange in small flow rate working condition. The more the sediment concentration and the large the sand diameter, the serious the runner is abraded, and the greater the efficiency is decreased. further analysis of the combined effects of wear and abrasion was performed. The result shows that the cavitation in silt flow is more serious than in pure water. The runner cavitation performance become worse under high sand concentration and large particle diameter, and the efficiency decrease greatly with the increase of sediment concentration.

The development of a new algorithm to calculate a survival function in non-parametric ways

International Nuclear Information System (INIS)

Ahn, Kwang Won; Kim, Yoon Ik; Chung, Chang Hyun; Kim, Kil Yoo

2001-01-01

In this study, a generalized formula of the Kaplan-Meier method is developed. The idea of this algorithm is that the result of the Kaplan-Meier estimator is the same as that of the redistribute-to-the right algorithm. Hence, the result of the Kaplan-Meier estimator is used when we redistribute to the right. This can be explained as the following steps, at first, the same mass is distributed to all the points. At second, when you reach the censored points, you must redistribute the mass of that point to the right according to the following rule; to normalize the masses, which are located to the right of the censored point, and redistribute the mass of the censored point to the right according to the ratio of the normalized mass. Until now, we illustrate the main idea of this algorithm.The meaning of that idea is more efficient than PL-estimator in the sense that it decreases the mass of after that area. Just like a redistribute to the right algorithm, this method is enough for the probability theory

Registry of Hospital das Clínicas of the University of São Paulo Medical School: first official solid organ and tissue transplantation report - 2008

Directory of Open Access Journals (Sweden)

Estela Azeka

2009-02-01

Full Text Available OBJECTIVE: The aim of this study was to report a single center experience of organ and tissue transplantation INTRODUCTION: This is the first report of organ and tissue transplantation at the Hospital das Clínicas of the University of Sao Paulo Medical School. METHODS: We collected data from each type of organ transplantation from 2002 to 2007. The data collected were patient characteristics and actuarial survival Kaplan-Meier curves at 30 days, one year, and five years RESULTS: There were a total of 3,321 transplants at our institution and the 5-year survival curve ranged from 53% to 88%. CONCLUSION: This report shows that solid organ and tissue transplants are feasible within the institution and allow us to expect that the quality of transplantation will improve in the future.

Numerical simulation of turbulence flow in a Kaplan turbine -Evaluation on turbine performance prediction accuracy-

International Nuclear Information System (INIS)

Ko, P; Kurosawa, S

2014-01-01

The understanding and accurate prediction of the flow behaviour related to cavitation and pressure fluctuation in a Kaplan turbine are important to the design work enhancing the turbine performance including the elongation of the operation life span and the improvement of turbine efficiency. In this paper, high accuracy turbine and cavitation performance prediction method based on entire flow passage for a Kaplan turbine is presented and evaluated. Two-phase flow field is predicted by solving Reynolds-Averaged Navier-Stokes equations expressed by volume of fluid method tracking the free surface and combined with Reynolds Stress model. The growth and collapse of cavitation bubbles are modelled by the modified Rayleigh-Plesset equation. The prediction accuracy is evaluated by comparing with the model test results of Ns 400 Kaplan model turbine. As a result that the experimentally measured data including turbine efficiency, cavitation performance, and pressure fluctuation are accurately predicted. Furthermore, the cavitation occurrence on the runner blade surface and the influence to the hydraulic loss of the flow passage are discussed. Evaluated prediction method for the turbine flow and performance is introduced to facilitate the future design and research works on Kaplan type turbine

Numerical simulation of turbulence flow in a Kaplan turbine -Evaluation on turbine performance prediction accuracy-

Science.gov (United States)

Ko, P.; Kurosawa, S.

2014-03-01

The understanding and accurate prediction of the flow behaviour related to cavitation and pressure fluctuation in a Kaplan turbine are important to the design work enhancing the turbine performance including the elongation of the operation life span and the improvement of turbine efficiency. In this paper, high accuracy turbine and cavitation performance prediction method based on entire flow passage for a Kaplan turbine is presented and evaluated. Two-phase flow field is predicted by solving Reynolds-Averaged Navier-Stokes equations expressed by volume of fluid method tracking the free surface and combined with Reynolds Stress model. The growth and collapse of cavitation bubbles are modelled by the modified Rayleigh-Plesset equation. The prediction accuracy is evaluated by comparing with the model test results of Ns 400 Kaplan model turbine. As a result that the experimentally measured data including turbine efficiency, cavitation performance, and pressure fluctuation are accurately predicted. Furthermore, the cavitation occurrence on the runner blade surface and the influence to the hydraulic loss of the flow passage are discussed. Evaluated prediction method for the turbine flow and performance is introduced to facilitate the future design and research works on Kaplan type turbine.

Comparison of Pathologic Response Evaluation Systems after Anthracycline with/without Taxane-Based Neoadjuvant Chemotherapy among Different Subtypes of Breast Cancers.

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Hee Jin Lee

Full Text Available Several methods are used to assess the pathologic response of breast cancer after neoadjuvant chemotherapy (NAC to predict clinical outcome. However, the clinical utility of these systems for each molecular subtype of breast cancer is unclear. Therefore, we applied six pathologic response assessment systems to specific subtypes of breast cancer and compared the results.Five hundred and eighty eight breast cancer patients treated with anthracycline with/without taxane-based NAC were retrospectively analyzed, and the ypTNM stage, residual cancer burden (RCB, residual disease in breast and nodes (RDBN, tumor response ratio, Sataloff's classification, and Miller-Payne grading system were evaluated. The results obtained for each assessment system were analyzed in terms of patient survival.In triple-negative tumors, all systems were significantly associated with disease-free survival and Kaplan-Meier survival curves for disease-free survival were clearly separated by all assessment methods. For HR+/HER2- tumors, systems assessing the residual tumor (ypTNM stage, RCB, and RDBN had prognostic significance. However, for HER2+ tumors, the association between patient survival and the pathologic response assessment results varied according to the system used, and none resulted in distinct Kaplan-Meier curves.Most of the currently available pathologic assessment systems used after anthracycline with/without taxane-based NAC effectively classified triple-negative breast cancers into groups showing different prognoses. The pathologic assessment systems evaluating residual tumors only also had prognostic significance in HR+/HER2- tumors. However, new assessment methods are required to effectively evaluate the pathologic response of HR+/HER2+ and HR-/HER2+ tumors to anthracycline with/without taxane-based NAC.

The Veterans Affairs Saint Louis University mental status exam (SLUMS exam) and the Mini-mental status exam as predictors of mortality and institutionalization.

Science.gov (United States)

Cruz-Oliver, D M; Malmstrom, T K; Allen, C M; Tumosa, N; Morley, J E

2012-07-01

To evaluate predictive validity of cognitive dysfunction of the Saint Louis University mental status (SLUMS) exam or mini-mental state exam (MMSE) for institutionalization and mortality after 7.5-years. Longitudinal study. Geriatric Research, Education and Clinical Center Veterans Affairs Hospital St. Louis, MO. Patients (N=705) were screened for cognitive dysfunction in 2003 using the SLUMS exam and MMSE, and mortality and institutionalization up to 7.5-years later were evaluated as outcome measures. The associations between outcome measures and MMSE and SLUMS exam total scores, and cognitive status were examined using Kaplan-Meier curves and Cox proportional-hazards regression. Five hundred thirty-three charts were reviewed, 176/533(33%) patients had died and 31/526 (6%) were institutionalized during 7.5-year follow-up period. All subjects were male with a mean age of 75 years and most had high school education or greater (71%). MMSE dementia, SLUMS dementia (ps<.001) and MCI (p<.05) groups had significantly lower survival rates than normal cognition group in the Kaplan-Meier curves. Scores classified as dementia on SLUMS (HR=2.4, 95% CI 1.6-3.7; p <.001) or MMSE (HR=2.3, 95% CI 1.5-3.6; p <.001) both predicted mortality and, also, institutionalization (SLUMS: HR=3.5, 95% CI 1.3-9.1; p <.01; MMSE: HR=3.8, 95% CI 1.6-9.0; p <.001) after adjustment for covariates. Unadjusted SLUMS exam MCI predicted morality (HR=1.5, 95% CI 1.1-2.2; p <.019) but not institutionalization. The SLUMS exam and MMSE both predict mortality and institutionalization for male patients screened as positive for dementia.

Adjuvant Medications That Improve Survival after Locoregional Therapy.

Science.gov (United States)

Boas, F Edward; Ziv, Etay; Yarmohammadi, Hooman; Brown, Karen T; Erinjeri, Joseph P; Sofocleous, Constantinos T; Harding, James J; Solomon, Stephen B

2017-07-01

To determine if outpatient medications taken at the time of liver tumor embolization or ablation affect survival. A retrospective review was done of 2,032 liver tumor embolization, radioembolization, and ablation procedures performed in 1,092 patients from June 2009 to April 2016. Pathology, hepatocellular carcinoma (HCC) stage (American Joint Committee on Cancer), neuroendocrine tumor (NET) grade, initial locoregional therapy, overall survival after initial locoregional therapy, Child-Pugh score, Eastern Cooperative Oncology Group performance status, Charlson Comorbidity Index, and outpatient medications taken at the time of locoregional therapy were analyzed for each patient. Kaplan-Meier survival curves were calculated for patients taking 29 medications or medication classes (including prescription and nonprescription medications) for reasons unrelated to their primary cancer diagnosis. Kaplan-Meier curves were compared using the log-rank test. For patients with HCC initially treated with embolization (n = 304 patients), the following medications were associated with improved survival when taken at the time of embolization: beta-blockers (P = .0007), aspirin (P = .0008) and other nonsteroidal antiinflammatory drugs (P = .009), proton pump inhibitors (P = .004), and antivirals for hepatitis B or C (P = .01). For colorectal liver metastases initially treated with ablation (n = 172 patients), beta-blockers were associated with improved survival when taken at the time of ablation (P = .02). Aspirin and beta-blockers are associated with significantly improved survival when taken at the time of embolization for HCC. Aspirin was not associated with survival differences after locoregional therapy for NET or colorectal liver metastases, suggesting an HCC-specific effect. Copyright © 2017 SIR. Published by Elsevier Inc. All rights reserved.

Retinitis pigmentosa reduces the risk of proliferative diabetic retinopathy: a nationwide population-based cohort study.

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Yuh-Fang Chen

Full Text Available PURPOSE: To study the association between retinitis pigmentosa (RP and the progression of diabetic retinopathy (DR. METHODS: Using the Longitudinal Health Insurance Database 2000 of Taiwan, we identified individuals with an initial diagnosis for RP during the period of 1997-2008. A non-RP comparison group, 10-fold frequency matched by sex, age, index year and the year of diabetes diagnosed, were randomly selected from the same database. The occurrence of DR was observed for all subjects until the end of 2009. The Kaplan-Meier curves were used to illustrate the cumulative probability of developing DR for the RP group and comparison groups. The hazard ratio (HR of DR for the RP group relative to the comparison group was estimated using Cox proportional hazards model after adjusting for potential confounders. RESULTS: The Kaplan-Meier curves were not statistically significant different between the RP group and the comparison group. However, the RP group had a higher cumulative probability of developing DR during the first six to seven years. The cumulative probability kept increasing and became higher in the comparison group but remained unchanged in the RP group. The HR for the RP patients comparing with the comparison group was 0.96 (95% confidence interval (CI = 0.43-2.14. Stratified by severity, RP was associated with a non-statistically significant reduced risk of proliferative DR (PDR (HR = 0.70, 95% CI = 0.16-3.14. The HR for non-proliferative DR (NPDR was 1.08 (95% CI = 0.40-2.86. CONCLUSION: In this study, RP was not statistically significant associated with the incidence of DR.

Prognostic value of MLH1 promoter methylation in male patients with esophageal squamous cell carcinoma.

Science.gov (United States)

Wu, Dongping; Chen, Xiaoying; Xu, Yan; Wang, Haiyong; Yu, Guangmao; Jiang, Luping; Hong, Qingxiao; Duan, Shiwei

2017-04-01

The DNA mismatch repair (MMR) gene MutL homolog 1 ( MLH1 ) is critical for the maintenance of genomic integrity. Methylation of the MLH1 gene promoter was identified as a prognostic marker for numerous types of cancer including glioblastoma, colorectal, ovarian and gastric cancer. The present study aimed to determine whether MLH1 promoter methylation was associated with survival in male patients with esophageal squamous cell carcinoma (ESCC). Formalin-fixed, paraffin-embedded ESCC tissues were collected from 87 male patients. MLH1 promoter methylation was assessed using the methylation-specific polymerase chain reaction approach. Kaplan-Meier survival curves and log-rank tests were used to evaluate the association between MLH1 promoter methylation and overall survival (OS) in patients with ESCC. Cox regression analysis was used to obtain crude and multivariate hazard ratios (HR), and 95% confidence intervals (CI). The present study revealed that MLH1 promoter methylation was observed in 53/87 (60.9%) of male patients with ESCC. Kaplan-Meier survival analysis demonstrated that MLH1 promoter hypermethylation was significantly associated with poorer prognosis in patients with ESCC (P=0.048). Multivariate survival analysis revealed that MLH1 promoter hypermethylation was an independent predictor of poor OS in male patients with ESCC (HR=1.716; 95% CI=1.008-2.921). Therefore, MLH1 promoter hypermethylation may be a predictor of prognosis in male patients with ESCC.

Glioblastoma: does the pre-treatment geometry matter? A postcontrast T1 MRI-based study

International Nuclear Information System (INIS)

Perez-Beteta, Julian; Martinez-Gonzalez, Alicia; Molina, David; Amo-Salas, Mariano; Luque, Belen; Perez-Garcia, Victor M.; Arregui, Elena; Calvo, Manuel; Borras, Jose M.; Lopez, Carlos; Claramonte, Marta; Barcia, Juan A.; Iglesias, Lidia; Avecillas, Josue; Albillo, David; Navarro, Miguel; Villanueva, Jose M.; Paniagua, Juan C.; Perez-Romasanta, Luis; Martino, Juan; Velasquez, Carlos; Asenjo, Beatriz; Benavides, Manuel; Herruzo, Ismael; Delgado, Maria del Carmen; Valle, Ana del; Falkov, Anthony; Schucht, Philippe; Arana, Estanislao

2017-01-01

The potential of a tumour's volumetric measures obtained from pretreatment MRI sequences of glioblastoma (GBM) patients as predictors of clinical outcome has been controversial. Mathematical models of GBM growth have suggested a relation between a tumour's geometry and its aggressiveness. A multicenter retrospective clinical study was designed to study volumetric and geometrical measures on pretreatment postcontrast T1 MRIs of 117 GBM patients. Clinical variables were collected, tumours segmented, and measures computed including: contrast enhancing (CE), necrotic, and total volumes; maximal tumour diameter; equivalent spherical CE width and several geometric measures of the CE ''rim''. The significance of the measures was studied using proportional hazards analysis and Kaplan-Meier curves. Kaplan-Meier and univariate Cox survival analysis showed that total volume [p = 0.034, Hazard ratio (HR) = 1.574], CE volume (p = 0.017, HR = 1.659), spherical rim width (p = 0.007, HR = 1.749), and geometric heterogeneity (p = 0.015, HR = 1.646) were significant parameters in terms of overall survival (OS). Multivariable Cox analysis for OS provided the later two parameters as age-adjusted predictors of OS (p = 0.043, HR = 1.536 and p = 0.032, HR = 1.570, respectively). Patients with tumours having small geometric heterogeneity and/or spherical rim widths had significantly better prognosis. These novel imaging biomarkers have a strong individual and combined prognostic value for GBM patients. (orig.)

Computer Aided Design of the Link-Fork Head-Piston Assembly of the Kaplan Turbine with Solidworks

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Camelia Jianu

2010-10-01

Full Text Available The paper presents the steps for 3D computer aided design (CAD of the link-fork head-piston assembly of the Kaplan turbine made in SolidWorks.The present paper is a tutorial for a Kaplan turbine assembly 3D geometry, which is dedicated to the Assembly design and Drawing Geometry and Drawing Annotation.

Surfactant Effect on the Average Flow Generation Near Curved Interface

Science.gov (United States)

Klimenko, Lyudmila; Lyubimov, Dmitry

2018-02-01

The present work is devoted to the average flow generation near curved interface with a surfactant adsorbed on the surface layer. The investigation was carried out for a liquid drop embedded in a viscous liquid with a different density. The liquid flows inside and outside the drop are generated by small amplitude and high frequency vibrations. Surfactant exchange between the drop surface and the surrounding liquid is limited by the process of adsorption-desorption. It was assumed that the surfactant is soluble in the surrounding liquid, but not soluble in the liquid drop. Surrounding liquid and the liquid in the drop are considered incompressible. Normal and shear viscous stresses balance at the interface is performed under the condition that the film thickness of the adsorbed surfactant is negligible. The problem is solved under assumption that the shape of the drop in the presence of adsorbed surfactant remains spherical symmetry. The effective boundary conditions for the tangential velocity jump and shear stress jump, describing the above generation have been obtained by matched asymptotic expansions method. The conditions under which the drop surface can be considered as a quasi-solid are determined. It is shown that in the case of the significant effect of surfactant on the surface tension, the dominant mechanism for the generation is the Schlichting mechanisms under vibrations.

Detection of angiogenesis-dependent parameters by functional MRI: Correlation between histomorphology and evaluation of clinical relevance as prognostic factor for the example of cervical carcinoma

International Nuclear Information System (INIS)

Hawighorst, H.; Knopp, M.V.; Schoenberg, S.O.; Essig, M.; Kaick, G. van; Schaeffer, U.; Knapstein, P.G.; Weikel, W.

1998-01-01

Purpose: Purpose of this study is to compare functional MRI parameters with histomorphological markers of tumor microvessel density (MVD) and permeability (vascular endothelial growth factor) and to determine the ultimate value of both approaches by correlation with disease outcome in patients with primary cancer of the uterine cervix. Method: Pharmacokinetic parameters were calculated from contrast-enhanced dynamic MR imaging series in 37 patients with biopsy-proven primary cervical cancer. On the operative whole mount specimens, histomorphological markers of tumor angiogenesis (MVD, VEGF) were compared with the MRI-derived parameters. For MRI and histomorphological data, Kaplan-Meier survival curves were calculated and compared using logrank statistics. Results: Significant (p [de

Magnitude of bacteraemia predicts one-year mortality

DEFF Research Database (Denmark)

Gradel, Kim Oren; Schønheyder, Henrik Carl; Søgaard, Mette

Objectives: All hospitals in our region use the BacT/Alert® blood culture (BC) system with a 3-bottle BC set for adults. We hypothesized that the magnitude of bacteremia (i.e., number of positive bottles in the initial BC set) predicted one-year mortality. Methods In a population-based study we...... with a BC index of 1 (i.e., one positive bottle) were chosen as the reference group. We computed Kaplan-Meier curves and performed Cox regression analyses to estimate mortality rate ratios (MRRs) with 95 % confidence intervals [CIs] 30 and 365 days after the initial BC sampling date, first in crude analyses...... mortality....

Anterolateral Knee Extra-articular Stabilizers: A Robotic Sectioning Study of the Anterolateral Ligament and Distal Iliotibial Band Kaplan Fibers.

Science.gov (United States)

Geeslin, Andrew G; Chahla, Jorge; Moatshe, Gilbert; Muckenhirn, Kyle J; Kruckeberg, Bradley M; Brady, Alex W; Coggins, Ashley; Dornan, Grant J; Getgood, Alan M; Godin, Jonathan A; LaPrade, Robert F

2018-05-01

The individual kinematic roles of the anterolateral ligament (ALL) and the distal iliotibial band Kaplan fibers in the setting of anterior cruciate ligament (ACL) deficiency require further clarification. This will improve understanding of their potential contribution to residual anterolateral rotational laxity after ACL reconstruction and may influence selection of an anterolateral extra-articular reconstruction technique, which is currently a matter of debate. Hypothesis/Purpose: To compare the role of the ALL and the Kaplan fibers in stabilizing the knee against tibial internal rotation, anterior tibial translation, and the pivot shift in ACL-deficient knees. We hypothesized that the Kaplan fibers would provide greater tibial internal rotation restraint than the ALL in ACL-deficient knees and that both structures would provide restraint against internal rotation during a simulated pivot-shift test. Controlled laboratory study. Ten paired fresh-frozen cadaveric knees (n = 20) were used to investigate the effect of sectioning the ALL and the Kaplan fibers in ACL-deficient knees with a 6 degrees of freedom robotic testing system. After ACL sectioning, sectioning was randomly performed for the ALL and the Kaplan fibers. An established robotic testing protocol was utilized to assess knee kinematics when the specimens were subjected to a 5-N·m internal rotation torque (0°-90° at 15° increments), a simulated pivot shift with 10-N·m valgus and 5-N·m internal rotation torque (15° and 30°), and an 88-N anterior tibial load (30° and 90°). Sectioning of the ACL led to significantly increased tibial internal rotation (from 0° to 90°) and anterior tibial translation (30° and 90°) as compared with the intact state. Significantly increased internal rotation occurred with further sectioning of the ALL (15°-90°) and Kaplan fibers (15°, 60°-90°). At higher flexion angles (60°-90°), sectioning the Kaplan fibers led to significantly greater internal rotation

Can a polynomial interpolation improve on the Kaplan-Yorke dimension?

International Nuclear Information System (INIS)

Richter, Hendrik

2008-01-01

The Kaplan-Yorke dimension can be derived using a linear interpolation between an h-dimensional Lyapunov exponent λ (h) >0 and an h+1-dimensional Lyapunov exponent λ (h+1) <0. In this Letter, we use a polynomial interpolation to obtain generalized Lyapunov dimensions and study the relationships among them for higher-dimensional systems

Adding gauge fields to Kaplan's fermions

International Nuclear Information System (INIS)

Blum, T.; Kaerkkaeinen, L.

1994-01-01

We experiment with adding dynamical gauge field to Kaplan (defect) fermions. In the case of U(1) gauge theory we use an inhomogeneous Higgs mechanism to restrict the 3d gauge dynamics to a planar 2d defect. In our simulations the 3d theory produce the correct 2d gauge dynamics. We measure fermion propagators with dynamical gauge fields. They posses the correct chiral structure. The fermions at the boundary of the support of the gauge field (waveguide) are non-chiral, and have a mass two times heavier than the chiral modes. Moreover, these modes cannot be excited by a source at the defect; implying that they are dynamically decoupled. We have also checked that the anomaly relation is fullfilled for the case of a smooth external gauge field. (orig.)

Numerical and in-situ investigations of water hammer effects in Drava river Kaplan turbine hydropower plants

International Nuclear Information System (INIS)

Bergant, A; Gregorc, B; Gale, J

2012-01-01

This paper deals with critical flow regimes that may induce unacceptable water hammer in Kaplan turbine hydropower plants. Water hammer analysis should be performed for normal, emergency and catastrophic operating conditions. Hydropower plants with Kaplan turbines are usually comprised of relatively short inlet and outlet conduits. The rigid water hammer theory can be used for this case. For hydropower plants with long penstocks the elastic water hammer should be used. Some Kaplan turbine units are installed in systems with long open channels. In this case, water level oscillations in the channels should be carefully investigated. Computational results are compared with results of measurements in recently rehabilitated seven Drava river hydroelectric power plants in Slovenia. Water hammer in the six power plants is controlled by appropriate adjustment of the wicket gates and runner blades closing/opening manoeuvres. Due to very long inflow and outflow open channels in Zlatolicje HPP a special vaned pressure regulating device attenuates extreme pressures in Kaplan turbine flow-passage system and controls unsteady flow in both open channels. Comparisons of results include normal operating regimes. The agreement between computed and measured results is reasonable.

Numerical and in-situ investigations of water hammer effects in Drava river Kaplan turbine hydropower plants

Science.gov (United States)

Bergant, A.; Gregorc, B.; Gale, J.

2012-11-01

This paper deals with critical flow regimes that may induce unacceptable water hammer in Kaplan turbine hydropower plants. Water hammer analysis should be performed for normal, emergency and catastrophic operating conditions. Hydropower plants with Kaplan turbines are usually comprised of relatively short inlet and outlet conduits. The rigid water hammer theory can be used for this case. For hydropower plants with long penstocks the elastic water hammer should be used. Some Kaplan turbine units are installed in systems with long open channels. In this case, water level oscillations in the channels should be carefully investigated. Computational results are compared with results of measurements in recently rehabilitated seven Drava river hydroelectric power plants in Slovenia. Water hammer in the six power plants is controlled by appropriate adjustment of the wicket gates and runner blades closing/opening manoeuvres. Due to very long inflow and outflow open channels in Zlatoličje HPP a special vaned pressure regulating device attenuates extreme pressures in Kaplan turbine flow-passage system and controls unsteady flow in both open channels. Comparisons of results include normal operating regimes. The agreement between computed and measured results is reasonable.

Impact of BCL2 and p53 on postmastectomy radiotherapy response in high-risk breast cancer. A subgroup analysis of DBCG82 b

DEFF Research Database (Denmark)

Kyndi, M.; Sorensen, F.B.; Alsner, J.

2008-01-01

-Meier probability plots showed a significantly improved overall survival after PMRT for the BCL2 positive subgroup, whereas practically no survival improvement was seen after PMRT for the BCL2 negative subgroup. In multivariate analysis of OS, however, no significant interaction was found between BCL2......Purpose. To examine p53 and BCL2 expression in high-risk breast cancer patients randomized to postmastectomy radiotherapy (PMRT). Patients and methods. The present analysis included 1000 of 3 083 high-risk breast cancer patients randomly assigned to PMRT in the DBCG82 b&c studies. Tissue microarray......, Kaplan-Meier probability plots, Log-rank test, and Cox univariate and multivariate regression analyses. Results. p53 accumulation was not significantly associated with increased overall mortality, DM or LRR probability in univariate or multivariate Cox regression analyses. Kaplan-Meier probability plots...

Meier-Gorlin syndrome: Growth and secondary sexual development of a microcephalic primordial dwarfism disorder

NARCIS (Netherlands)

de Munnik, Sonja A.; Otten, Barto J.; Schoots, Jeroen; Bicknell, Louise S.; Aftimos, Salim; Al-Aama, Jumana Y.; van Bever, Yolande; Bober, Michael B.; Borm, George F.; Clayton-Smith, Jill; Deal, Cheri L.; Edrees, Alaa Y.; Feingold, Murray; Fryer, Alan; van Hagen, Johanna M.; Hennekam, Raoul C.; Jansweijer, Maaike C. E.; Johnson, Diana; Kant, Sarina G.; Opitz, John M.; Ramadevi, A. Radha; Reardon, Willie; Ross, Alison; Sarda, Pierre; Schrander-Stumpel, Constance T. R. M.; Sluiter, A. Erik; Temple, I. Karen; Terhal, Paulien A.; Toutain, Annick; Wise, Carol A.; Wright, Michael; Skidmore, David L.; Samuels, Mark E.; Hoefsloot, Lies H.; Knoers, Nine V. A. M.; Brunner, Han G.; Jackson, Andrew P.; Bongers, Ernie M. H. F.

2012-01-01

MeierGorlin syndrome (MGS) is a rare autosomal recessive disorder characterized by primordial dwarfism, microtia, and patellar aplasia/hypoplasia. Recently, mutations in the ORC1, ORC4, ORC6, CDT1, and CDC6 genes, encoding components of the pre-replication complex, have been identified. This complex

Meier-Gorlin syndrome: Growth and secondary sexual development of a microcephalic primordial dwarfism disorder

NARCIS (Netherlands)

de Munnik, S.A.; Otten, B.J.; Schoots, J.; Bicknell, L.S.; Aftimos, S.; Al-Aama, J.Y.; van Bever, Y.; Bober, M.B.; Borm, G.F.; Clayton-Smith, J.; Deal, C.L.; Edrees, A.Y.; Feingold, M.; Fryer, A.; van Hagen, J.M.; Hennekam, R.C.M.; Jansweijer, M.C.E.; Johnson, D.; Kant, S.G.; Opitz, J.M.; Ramadevi, A.R.; Reardon, W.; Ross, A.; Sarda, P.; Schrander-Stumpel, C.T.R.M.; Sluiter, A.E.; Temple, I.K.; Terhal, P.A.; Toutain, A.; Wise, C.A.; Wright, M.; Skidmore, D.L.; Samuels, M.E.; Hoefsloot, L.H.; Knoers, N.V.A.M.; Brunner, H.G.; Jackson, A.P.; Bongers, M.H.F.

2012-01-01

Meier-Gorlin syndrome (MGS) is a rare autosomal recessive disorder characterized by primordial dwarfism, microtia, and patellar aplasia/hypoplasia. Recently, mutations in the ORC1, ORC4, ORC6, CDT1, and CDC6 genes, encoding components of the pre-replication complex, have been identified. This

Challenges in risk estimation using routinely collected clinical data: The example of estimating cervical cancer risks from electronic health-records.

Science.gov (United States)

Landy, Rebecca; Cheung, Li C; Schiffman, Mark; Gage, Julia C; Hyun, Noorie; Wentzensen, Nicolas; Kinney, Walter K; Castle, Philip E; Fetterman, Barbara; Poitras, Nancy E; Lorey, Thomas; Sasieni, Peter D; Katki, Hormuzd A

2018-06-01

Electronic health-records (EHR) are increasingly used by epidemiologists studying disease following surveillance testing to provide evidence for screening intervals and referral guidelines. Although cost-effective, undiagnosed prevalent disease and interval censoring (in which asymptomatic disease is only observed at the time of testing) raise substantial analytic issues when estimating risk that cannot be addressed using Kaplan-Meier methods. Based on our experience analysing EHR from cervical cancer screening, we previously proposed the logistic-Weibull model to address these issues. Here we demonstrate how the choice of statistical method can impact risk estimates. We use observed data on 41,067 women in the cervical cancer screening program at Kaiser Permanente Northern California, 2003-2013, as well as simulations to evaluate the ability of different methods (Kaplan-Meier, Turnbull, Weibull and logistic-Weibull) to accurately estimate risk within a screening program. Cumulative risk estimates from the statistical methods varied considerably, with the largest differences occurring for prevalent disease risk when baseline disease ascertainment was random but incomplete. Kaplan-Meier underestimated risk at earlier times and overestimated risk at later times in the presence of interval censoring or undiagnosed prevalent disease. Turnbull performed well, though was inefficient and not smooth. The logistic-Weibull model performed well, except when event times didn't follow a Weibull distribution. We have demonstrated that methods for right-censored data, such as Kaplan-Meier, result in biased estimates of disease risks when applied to interval-censored data, such as screening programs using EHR data. The logistic-Weibull model is attractive, but the model fit must be checked against Turnbull non-parametric risk estimates. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

XRF and XANES Data for Kaplan U Paper

Science.gov (United States)

The dataset contains two XRF images of iron and uranium distribution on plant roots and a database of XANES data used to produce XANES spectra figure for Figure 7 in the published paper.This dataset is associated with the following publication:Kaplan, D., R. Kukkadapu, J. Seaman, B. Arey, A. Dohnalkova, S. Buettner, D. Li, T. Varga, K. Scheckel, and P. Jaffe. Iron Mineralogy and Uranium-Binding Environment in the Rhizosphere of a Wetland Soil. D. Barcelo SCIENCE OF THE TOTAL ENVIRONMENT. Elsevier BV, AMSTERDAM, NETHERLANDS, 569: 53-64, (2016).

Fatigue Analysis of an Outer Bearing Bush of a Kaplan Turbine

Directory of Open Access Journals (Sweden)

Doina Frunzaverde

2011-01-01

Full Text Available The paper presents the fatigue analysis of an outer bearing bush of aKaplan turbine. This outer bush, together with an inner one, bear thepin lever - trunion - blade subassembly of the runner blade operatingmechanism. For modeling and simulation, SolidWorks software is used.

Calculating the dielectric anisotropy of nematic liquid crystals: a reinvestigation of the Maier–Meier theory

International Nuclear Information System (INIS)

Ran, Zhang; Jun, He; Zeng-Hui, Peng; Li, Xuan

2009-01-01

This paper investigates the average dielectric permittivity (ε-bar ) in the Maier–Meier theory for calculating the dielectric anisotropy (Δε) of nematic liquid crystals. For the reason that ε-bar of nematics has the same expression as the dielectric permittivity of the isotropic state, the Onsager equation for isotropic dielectric was used to calculate it. The computed ε-bar shows reasonable agreement with the results of the numerical methods used in the literature. Molecular parameters, such as the polarizability and its anisotropy, the dipole moment and its angle with the molecular long axis, were taken from semi-empirical quantum chemistry (MOCPAC/AM1) modeling. The calculated values of Δε according to the Maier–Meier equation are in good agreement with the experimental results for the investigated compounds having different core structures and polar substituents. (condensed matter: structure, thermal and mechanical properties)

Serum level of soluble urokinase-type plasminogen activator receptor is a strong and independent predictor of survival in human immunodeficiency virus infection

DEFF Research Database (Denmark)

Sidenius, N; Sier, C.F.M.; Ullum, H

2000-01-01

levels of soluble uPAR (suPAR) in patients with advanced HIV-1 disease and whether the serum level of suPAR is predictive of clinical outcome. Using an enzyme-linked immunosorbent assay, the level of suPAR was measured retrospectively in serum samples from 314 patients with HIV-1 infection. By Kaplan......-Meier and Cox regression analyses, the serum suPAR levels were correlated to survival with AIDS-related death as the end point. High levels of serum suPAR (greater than median) were associated with poor overall survival, and Kaplan-Meier analysis on patients stratified by suPAR level demonstrated a continuous...

Simulating Supernova Light Curves

Energy Technology Data Exchange (ETDEWEB)

Even, Wesley Paul [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dolence, Joshua C. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2016-05-05

This report discusses supernova light simulations. A brief review of supernovae, basics of supernova light curves, simulation tools used at LANL, and supernova results are included. Further, it happens that many of the same methods used to generate simulated supernova light curves can also be used to model the emission from fireballs generated by explosions in the earth’s atmosphere.

Simulating Supernova Light Curves

International Nuclear Information System (INIS)

Even, Wesley Paul; Dolence, Joshua C.

2016-01-01

This report discusses supernova light simulations. A brief review of supernovae, basics of supernova light curves, simulation tools used at LANL, and supernova results are included. Further, it happens that many of the same methods used to generate simulated supernova light curves can also be used to model the emission from fireballs generated by explosions in the earth's atmosphere.

Perturbative analysis for Kaplan's lattice chiral fermions

International Nuclear Information System (INIS)

Aoki, S.; Hirose, H.

1994-01-01

Perturbation theory for lattice fermions with domain wall mass terms is developed and is applied to investigate the chiral Schwinger model formulated on the lattice by Kaplan's method. We calculate the effective action for gauge fields to one loop, and find that it contains a longitudinal component even for anomaly-free cases. From the effective action we obtain gauge anomalies and Chern-Simons currents without ambiguity. We also show that the current corresponding to the fermion number has a nonzero divergence and it flows off the wall into the extra dimension. Similar results are obtained for a proposal by Shamir, who used a constant mass term with free boundaries instead of domain walls

Pressure drop-flow rate curves for single-phase steam in Combustion Engineering type steam generator U-tubes during severe accidents

Energy Technology Data Exchange (ETDEWEB)

Fynan, Douglas A.; Ahn, Kwang-Il, E-mail: kiahn@kaeri.re.kr

2016-12-15

Highlights: • Pressure drop-flow rate curves for superheated steam in U-tubes were generated. • Forward flow of hot steam is favored in the longer and taller U-tubes. • Reverse flow of cold steam is favored in short U-tubes. • Steam generator U-tube bundle geometry and tube diameter are important. • Need for correlation development for natural convention heat transfer coefficient. - Abstract: Characteristic pressure drop-flow rate curves are generated for all row numbers of the OPR1000 steam generators (SGs), representative of Combustion Engineering (CE) type SGs featuring square bend U-tubes. The pressure drop-flow rate curves are applicable to severe accident natural circulations of single-phase superheated steam during high pressure station blackout sequences with failed auxiliary feedwater and dry secondary side which are closely related to the thermally induced steam generator tube rupture event. The pressure drop-flow rate curves which determine the recirculation rate through the SG tubes are dependent on the tube bundle geometry and hydraulic diameter of the tubes. The larger CE type SGs have greater variation of tube length and height as a function of row number with forward flow of steam favored in the longer and taller high row number tubes and reverse flow favored in the short low row number tubes. Friction loss, natural convection heat transfer coefficients, and temperature differentials from the primary to secondary side are dominant parameters affecting the recirculation rate. The need for correlation development for natural convection heat transfer coefficients for external flow over tube bundles currently not modeled in system codes is discussed.

Estimating Loss to Follow-Up in HIV-Infected Patients on Antiretroviral Therapy: The Effect of the Competing Risk of Death in Zambia and Switzerland

Science.gov (United States)

Mwango, Albert; Stringer, Jeffrey; Ledergerber, Bruno; Mulenga, Lloyd; Bucher, Heiner C.; Westfall, Andrew O.; Calmy, Alexandra; Boulle, Andrew; Chintu, Namwinga; Egger, Matthias; Chi, Benjamin H.

2011-01-01

Background Loss to follow-up (LTFU) is common in antiretroviral therapy (ART) programmes. Mortality is a competing risk (CR) for LTFU; however, it is often overlooked in cohort analyses. We examined how the CR of death affected LTFU estimates in Zambia and Switzerland. Methods and Findings HIV-infected patients aged ≥18 years who started ART 2004–2008 in observational cohorts in Zambia and Switzerland were included. We compared standard Kaplan-Meier curves with CR cumulative incidence. We calculated hazard ratios for LTFU across CD4 cell count strata using cause-specific Cox models, or Fine and Gray subdistribution models, adjusting for age, gender, body mass index and clinical stage. 89,339 patients from Zambia and 1,860 patients from Switzerland were included. 12,237 patients (13.7%) in Zambia and 129 patients (6.9%) in Switzerland were LTFU and 8,498 (9.5%) and 29 patients (1.6%), respectively, died. In Zambia, the probability of LTFU was overestimated in Kaplan-Meier curves: estimates at 3.5 years were 29.3% for patients starting ART with CD4 cells Switzerland since only few patients died. The results from Cox and Fine and Gray models were similar: in Zambia the risk of loss to follow-up and death increased with decreasing CD4 counts at the start of ART, whereas in Switzerland there was a trend in the opposite direction, with patients with higher CD4 cell counts more likely to be lost to follow-up. Conclusions In ART programmes in low-income settings the competing risk of death can substantially bias standard analyses of LTFU. The CD4 cell count and other prognostic factors may be differentially associated with LTFU in low-income and high-income settings. PMID:22205933

Red cell distribution width and its association with mortality in neonatal sepsis.

Science.gov (United States)

Martin, Snehal L; Desai, Saumil; Nanavati, Ruchi; Colah, Roshan B; Ghosh, Kanjaksha; Mukherjee, Malay B

2018-01-08

Neonatal sepsis is a major cause of mortality in the developing countries. However, with current severity scores and laboratory parameters, predicting outcomes of neonatal sepsis is a serious challenge. Red cell distribution width (RDW) is a readily available pragmatic means to predict outcomes of various comorbidities in adults and children, without causing any additional blood loss. However, its utility in neonates remains unexplored. Hence, the objective of the present study was to evaluate the association of RDW with neonatal sepsis and its role as a predictive marker for mortality. This Prospective observational study was carried out in a Level IIIB NICU for a period of 3 years. It involved comparison of RDW values of septic neonates with those of controls (matched for gestational age and birth weight) with an equal allocation ratio. A total of 251 septic neonates along with 251 controls >28 weeks of gestational age were enrolled. The RDW was derived from complete blood count done within first 6 hours of life. After arranging the RDW (median; interquartile range (IQR)), the values were categorized as those above the 50th percentile i.e. ≥20% and those below the 50th percentile i.e. rates of the above two groups were assessed using the Kaplan-Meier curve and the log rank test. RDW levels were significantly higher among the neonatal sepsis cases (19.90%) as compared to the controls (18.90%) with a p value of < .001. RDW was significantly higher amongst the nonsurvivors than survivors (p < .003). Kaplan-Meier curve showed that septic neonates having RDW values ≥20% had significantly increased mortality (p < .02) with a hazard ratio of 0.5. High RDW is associated with neonatal sepsis and is an independent outcome predictor for mortality associated with neonatal sepsis.

Heat transfer and pressure drop characteristics of the tube bank fin heat exchanger with fin punched with flow redistributors and curved triangular vortex generators

Science.gov (United States)

Liu, Song; Jin, Hua; Song, KeWei; Wang, LiangChen; Wu, Xiang; Wang, LiangBi

2017-10-01

The heat transfer performance of the tube bank fin heat exchanger is limited by the air-side thermal resistance. Thus, enhancing the air-side heat transfer is an effective method to improve the performance of the heat exchanger. A new fin pattern with flow redistributors and curved triangular vortex generators is experimentally studied in this paper. The effects of the flow redistributors located in front of the tube stagnation point and the curved vortex generators located around the tube on the characteristics of heat transfer and pressure drop are discussed in detail. A performance comparison is also carried out between the fins with and without flow redistributors. The experimental results show that the flow redistributors stamped out from the fin in front of the tube stagnation points can decrease the friction factor at the cost of decreasing the heat transfer performance. Whether the combination of the flow redistributors and the curved vortex generators will present a better heat transfer performance depends on the size of the curved vortex generators. As for the studied two sizes of vortex generators, the heat transfer performance is promoted by the flow redistributors for the fin with larger size of vortex generators and the performance is suppressed by the flow redistributors for the fin with smaller vortex generators.

Predicting risk of nonmelanoma skin cancer and premalignant skin lesions in renal transplant recipients.

Science.gov (United States)

Urwin, Helen R; Jones, Peter W; Harden, Paul N; Ramsay, Helen M; Hawley, Carmel M; Nicol, David L; Fryer, Anthony A

2009-06-15

Nonmelanoma skin cancer (NMSC) and associated premalignant lesions represent a major complication after transplantation, particularly in areas with high ultraviolet radiation (UVR) exposure. The American Society of Transplantation has proposed annual NMSC screening for all renal transplant recipients. The aim of this study was to develop a predictive index (PI) that could be used in targeted screening. Data on patient demographics, UVR exposure, and other clinical parameters were collected on 398 adult recipients recruited from the Princess Alexandra Hospital, Brisbane. Structured interview, skin examination, biopsy of lesions, and review of medical/pathologic records were performed. Time to presentation with the first NMSC was assessed using Cox's regression models and Kaplan-Meier estimates used to assess detection of NMSC during screening. Stepwise selection identified age, outdoor UVR exposure, living in a hot climate, pretransplant NMSC, childhood sunburning, and skin type as predictors. The PI generated was used to allocate patients into three screening groups (6 months, 2 years, and 5 years). The survival curves of these groups were significantly different (PPI to enable development of targeted NMSC surveillance strategies.

CXCR4 expression varies significantly among different subtypes of glioblastoma multiforme (GBM) and its low expression or hypermethylation might predict favorable overall survival.

Science.gov (United States)

Ma, Xinlong; Shang, Feng; Zhu, Weidong; Lin, Qingtang

2017-09-01

CXCR4 is an oncogene in glioblastoma multiforme (GBM) but the mechanism of its dysregulation and its prognostic value in GBM have not been fully understood. Bioinformatic analysis was performed by using R2 and the UCSC Xena browser based on data from GSE16011 in GEO datasets and in GBM cohort in TCGA database (TCGA-GBM). Kaplan Meier curves of overall survival (OS) were generated to assess the association between CXCR4 expression/methylation and OS in patients with GBM. GBM patients with high CXCR4 expression had significantly worse 5 and 10 yrs OS (p GBM subtypes, there was an inverse relationship between overall DNA methylation and CXCR4 expression. CXCR4 expression was significantly lower in CpG island methylation phenotype (CIMP) group than in non CIMP group. Log rank test results showed that patients with high CXCR4 methylation (first tertile) had significantly better 5 yrs OS (p = 0.038). CXCR4 expression is regulated by DNA methylation in GBM and its low expression or hypermethylation might indicate favorable OS in GBM patients.

A cyclostationary multi-domain analysis of fluid instability in Kaplan turbines

Science.gov (United States)

Pennacchi, P.; Borghesani, P.; Chatterton, S.

2015-08-01

Hydraulic instabilities represent a critical problem for Francis and Kaplan turbines, reducing their useful life due to increase of fatigue on the components and cavitation phenomena. Whereas an exhaustive list of publications on computational fluid-dynamic models of hydraulic instability is available, the possibility of applying diagnostic techniques based on vibration measurements has not been investigated sufficiently, also because the appropriate sensors seldom equip hydro turbine units. The aim of this study is to fill this knowledge gap and to exploit fully, for this purpose, the potentiality of combining cyclostationary analysis tools, able to describe complex dynamics such as those of fluid-structure interactions, with order tracking procedures, allowing domain transformations and consequently the separation of synchronous and non-synchronous components. This paper will focus on experimental data obtained on a full-scale Kaplan turbine unit, operating in a real power plant, tackling the issues of adapting such diagnostic tools for the analysis of hydraulic instabilities and proposing techniques and methodologies for a highly automated condition monitoring system.

Comparison of colorectal and gastric cancer: Survival and prognostic factors

International Nuclear Information System (INIS)

Moghimi-Dehkordi, Bijan; Safaee, Azadeh; Zali, Mohammad R

2009-01-01

Gastric and colorectal cancers are the most common gastrointestinal malignancies in Iran. We aim to compare the survival rates and prognostic factors between these two cancers. We studied 1873 patients with either gastric or colorectal cancer who were registered in one referral cancer registry center in Tehran, Iran. All patients were followed from their time of diagnosis until December 2006 (as failure time). Survival curves were calculated according to the Kaplan-Meier Method and compared by the Log-rank test. Multivariate analysis of prognostic factors was carried out using the Cox proportional hazard model. Of 1873 patients, there were 746 with gastric cancer and 1138 with colorectal cancer. According to the Kaplan-Meier method 1, 3, 5, and 7-year survival rates were 71.2, 37.8, 25.3, and 19.5%, respectively, in gastric cancer patients and 91.1, 73.1, 61, and 54.9%, respectively, in patients with colorectal cancer. Also, univariate analysis showed that age at diagnosis, sex, grade of tumor, and distant metastasis were of prognostic significance in both cancers ( P < 0.0001). However, in multivariate analysis, only distant metastasis in colorectal cancer and age at diagnosis, grade of tumor, and distant metastasis in colorectal cancer were identified as independent prognostic factors influencing survival. According to our findings, survival is significantly related to histological differentiation of tumor and distant metastasis in colorectal cancer patients and only to distant metastasis in gastric cancer patients. (author)

The preoperative plasma fibrinogen level is an independent prognostic factor for overall survival of breast cancer patients who underwent surgical treatment.

Science.gov (United States)

Wen, Jiahuai; Yang, Yanning; Ye, Feng; Huang, Xiaojia; Li, Shuaijie; Wang, Qiong; Xie, Xiaoming

2015-12-01

Previous studies have suggested that plasma fibrinogen contributes to tumor cell proliferation, progression and metastasis. The current study was performed to evaluate the prognostic relevance of preoperative plasma fibrinogen in breast cancer patients. Data of 2073 consecutive breast cancer patients, who underwent surgery between January 2002 and December 2008 at the Sun Yat-sen University Cancer Center, were retrospectively evaluated. Plasma fibrinogen levels were routinely measured before surgeries. Participants were grouped by the cutoff value estimated by the receiver operating characteristic (ROC) curve analysis. Overall survival (OS) was assessed using Kaplan-Meier analysis, and multivariate Cox proportional hazards regression model was performed to evaluate the independent prognostic value of plasma fibrinogen level. The optimal cutoff value of preoperative plasma fibrinogen was determined to be 2.83 g/L. The Kaplan-Meier analysis showed that patients with high fibrinogen levels had shorter OS than patients with low fibrinogen levels (p factor for OS in breast cancer patients (HR = 1.475, 95% confidence interval (CI): 1.177-1.848, p = 0.001). Subgroup analyses revealed that plasma fibrinogen level was an unfavorable prognostic parameter in stage II-III, Luminal subtypes and triple-negative breast cancer patients. Elevated preoperative plasma fibrinogen was independently associated with poor prognosis in breast cancer patients and may serve as a valuable parameter for risk assessment in breast cancer patients. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Glioblastoma: does the pre-treatment geometry matter? A postcontrast T1 MRI-based study

Energy Technology Data Exchange (ETDEWEB)

Perez-Beteta, Julian; Martinez-Gonzalez, Alicia; Molina, David; Amo-Salas, Mariano; Luque, Belen; Perez-Garcia, Victor M. [Universidad de Castilla-La Mancha, Laboratory of Mathematical Oncology, Edificio Politecnico, Instituto de Matematica Aplicada a la Ciencia y la Ingenieria, Ciudad Real (Spain); Arregui, Elena; Calvo, Manuel; Borras, Jose M.; Lopez, Carlos; Claramonte, Marta [Hospital General de Ciudad Real, Ciudad Real (Spain); Barcia, Juan A.; Iglesias, Lidia; Avecillas, Josue [Hospital Clinico San Carlos, Madrid (Spain); Albillo, David; Navarro, Miguel; Villanueva, Jose M.; Paniagua, Juan C.; Perez-Romasanta, Luis [Hospital Universitario de Salamanca, Salamanca (Spain); Martino, Juan; Velasquez, Carlos [Hospital Marques de Valdecilla, Santander (Spain); Asenjo, Beatriz; Benavides, Manuel; Herruzo, Ismael [Hospital Carlos Haya, Malaga (Spain); Delgado, Maria del Carmen; Valle, Ana del [Universidad de Sevilla, Facultad de Matematicas, Sevilla (Spain); Falkov, Anthony [Auckland Radiation Oncology, Auckland (New Zealand); Schucht, Philippe [Bern Inselspital, Neurosurgery Department, Bern (Switzerland); Arana, Estanislao [Instituto Valenciano de Oncologia, Valencia (Spain)

2017-03-15

The potential of a tumour's volumetric measures obtained from pretreatment MRI sequences of glioblastoma (GBM) patients as predictors of clinical outcome has been controversial. Mathematical models of GBM growth have suggested a relation between a tumour's geometry and its aggressiveness. A multicenter retrospective clinical study was designed to study volumetric and geometrical measures on pretreatment postcontrast T1 MRIs of 117 GBM patients. Clinical variables were collected, tumours segmented, and measures computed including: contrast enhancing (CE), necrotic, and total volumes; maximal tumour diameter; equivalent spherical CE width and several geometric measures of the CE ''rim''. The significance of the measures was studied using proportional hazards analysis and Kaplan-Meier curves. Kaplan-Meier and univariate Cox survival analysis showed that total volume [p = 0.034, Hazard ratio (HR) = 1.574], CE volume (p = 0.017, HR = 1.659), spherical rim width (p = 0.007, HR = 1.749), and geometric heterogeneity (p = 0.015, HR = 1.646) were significant parameters in terms of overall survival (OS). Multivariable Cox analysis for OS provided the later two parameters as age-adjusted predictors of OS (p = 0.043, HR = 1.536 and p = 0.032, HR = 1.570, respectively). Patients with tumours having small geometric heterogeneity and/or spherical rim widths had significantly better prognosis. These novel imaging biomarkers have a strong individual and combined prognostic value for GBM patients. (orig.)

Correlations of Hemoglobin Level and Perioperative Blood Transfusion with the Prognosis of Gastric Cancer: A Retrospective Study.

Science.gov (United States)

Wu, Gang; Zhang, Dai-Yang; Duan, Yu-Han; Zhang, Ying-Qiong; Cui, Xian-Nian; Luo, Zheng

2017-05-23

BACKGROUND This study was designed to explore the correlations of hemoglobin level (Hb) and perioperative blood transfusion with the prognosis of gastric cancer (GC). MATERIAL AND METHODS Our study consisted of 210 patients with GC who all received a D2 radical operation. These patients were assigned into three groups: 68 cases in group A (blood transfusion >5 U); 59 cases in group B (blood transfusion blood transfusion). A 5-year follow-up was conducted to evaluate the disease-free survival of the patients. Univariate analysis was performed to reveal the relationship between the indicators and the patients with GC. Kaplan-Meier method was employed to analyze the survival rate of patients, and Cox regression analysis was applied to determine the independent prognostic factors of GC. RESULTS The univariate analysis indicated that age, perioperative blood transfusion amount, TNM staging, maximal tumor diameter, differentiation degree and invasion degree were associated with the prognosis of GC. The Kaplan-Meier curve showed that the disease-free survival rate was declined in the patients who were older, those received more amount of blood transfusion, those in advanced TNM staging, those had larger tumor diameter, and those with decreased degree of differentiation and invasion. Cox regression analysis indicated that perioperative blood transfusion, maximal tumor diameter and invasion degree were the independent factors affecting disease-free survival of the GC. CONCLUSIONS Our study revealed that large amount of perioperative blood transfusion leads to poor prognosis of GC.

Large mass limit of the continuum theories in Kaplan's formulation

International Nuclear Information System (INIS)

Kawano, T.; Kikukawa, Y.

1994-01-01

Being inspired by Kaplan's proposal for simulating chiral fermions on a lattice, we examine the continuum analogue of his domain-wall construction for two-dimensional chiral Schwinger models. Adopting a slightly unusual dimensional regularization, we explicitly evaluate the one-loop effective action in the limit that the domain-wall mass goes to infinity. For anomaly-free cases, the effective action turns out to be gauge invariant in the two-dimensional sense

Safety, tolerability, and initial efficacy of AZD6140, the first reversible oral adenosine diphosphate receptor antagonist, compared with clopidogrel, in patients with non-ST-segment elevation acute coronary syndrome: primary results of the DISPERSE-2 trial

DEFF Research Database (Denmark)

Cannon, Christopher P; Husted, Steen; Harrington, Robert A

2007-01-01

, or clopidogrel 300-mg loading dose plus 75 mg once daily for up to 12 weeks. RESULTS: The primary end point, the Kaplan-Meier rate of major or minor bleeding through 4 weeks, was 8.1% in the clopidogrel group, 9.8% in the AZD6140 90-mg group, and 8.0% in the AZD6140 180-mg group (p = 0.43 and p = 0.......96, respectively, vs. clopidogrel); the major bleeding rates were 6.9%, 7.1%, and 5.1%, respectively (p = 0.91 and p = 0.35, respectively, vs. clopidogrel). Although not statistically significant, favorable trends were seen in the Kaplan-Meier rates of myocardial infarction (MI) over the entire study period (MI: 5...

Meier-Gorlin syndrome: Report of an additional patient with congenital heart disease

Directory of Open Access Journals (Sweden)

Rabah M. Shawky

2014-10-01

Full Text Available We report a 7 year old female child with the classical triad of Meier-Gorlin syndrome (MGS, (microtia, absent patella and short stature. She had the characteristic facial features, with normal mentality and defective speech, skeletal abnormalities, conductive hearing loss, cystitis and normal growth hormone level. She suffered from recurrent chest infection during the first year of life which improved gradually with age. Although congenital heart is rarely observed in MGS, our patient had in addition fenestrated interatrial septal defect.

Air injection test on a Kaplan turbine: prototype - model comparison

Science.gov (United States)

Angulo, M.; Rivetti, A.; Díaz, L.; Liscia, S.

2016-11-01

Air injection is a very well-known resource to reduce pressure pulsation magnitude in turbines, especially on Francis type. In the case of large Kaplan designs, even when not so usual, it could be a solution to mitigate vibrations arising when tip vortex cavitation phenomenon becomes erosive and induces structural vibrations. In order to study this alternative, aeration tests were performed on a Kaplan turbine at model and prototype scales. The research was focused on efficiency of different air flow rates injected in reducing vibrations, especially at the draft tube and the discharge ring and also in the efficiency drop magnitude. It was found that results on both scales presents the same trend in particular for vibration levels at the discharge ring. The efficiency drop was overestimated on model tests while on prototype were less than 0.2 % for all power output. On prototype, air has a beneficial effect in reducing pressure fluctuations up to 0.2 ‰ of air flow rate. On model high speed image computing helped to quantify the volume of tip vortex cavitation that is strongly correlated with the vibration level. The hydrophone measurements did not capture the cavitation intensity when air is injected, however on prototype, it was detected by a sonometer installed at the draft tube access gallery.

Repair of a Kaplan blade sealing surface without dismantling the turbine; Instandsetzung einer Kaplanschaufel-Dichtflaeche ohne Turbinendemontage

Energy Technology Data Exchange (ETDEWEB)

Drygas, A.; Bauer, K. [E.ON Wasserkraft GmbH, Landshut (Germany)

2008-07-01

In spite of aiming at minimum maintenance costs, runners of Kaplan turbines need to be kept in good repair. Besides preserving their main function as an energy converter, ecological reasons have to be considered as well. The latter aspect accounts for fully functional, safe seals of the pivot-mounted Kaplan runner blades. Advanced wear of the sealing surfaces may require mechanical processing, which formerly called for a costly dismantling of the runner. A newly developed and patented processing device now allows for machining the worn out sealing surfaces without dismantling the runner, thus reducing costs considerably. The device was first successfully applied to a Kaplan turbine runner with a diameter of 5.35 m. The device, so far designed for grinding, will be enhanced for lathing, in order to obtain a process even more efficient when combining lathing and grinding. (orig.)

Scenario analysis for estimating the learning rate of photovoltaic power generation based on learning curve theory in South Korea

International Nuclear Information System (INIS)

Hong, Sungjun; Chung, Yanghon; Woo, Chungwon

2015-01-01

South Korea, as the 9th largest energy consuming in 2013 and the 7th largest greenhouse gas emitting country in 2011, established ‘Low Carbon Green Growth’ as the national vision in 2008, and is announcing various active energy policies that are set to gain the attention of the world. In this paper, we estimated the decrease of photovoltaic power generation cost in Korea based on the learning curve theory. Photovoltaic energy is one of the leading renewable energy sources, and countries all over the world are currently expanding R and D, demonstration and deployment of photovoltaic technology. In order to estimate the learning rate of photovoltaic energy in Korea, both conventional 1FLC (one-factor learning curve), which considers only the cumulative power generation, and 2FLC, which also considers R and D investment were applied. The 1FLC analysis showed that the cost of power generation decreased by 3.1% as the cumulative power generation doubled. The 2FCL analysis presented that the cost decreases by 2.33% every time the cumulative photovoltaic power generation is doubled and by 5.13% every time R and D investment is doubled. Moreover, the effect of R and D investment on photovoltaic technology took after around 3 years, and the depreciation rate of R and D investment was around 20%. - Highlights: • We analyze the learning effects of photovoltaic energy technology in Korea. • In order to calculate the learning rate, we use 1FLC (one-factor learning curve) and 2FLC methods, respectively. • 1FLC method considers only the cumulative power generation. • 2FLC method considers both cumulative power generation and knowledge stock. • We analyze a variety of scenarios by time lag and depreciation rate of R and D investment

Association of versican turnover with all-cause mortality in patients on haemodialysis

DEFF Research Database (Denmark)

Genovese, Federica; Karsdal, Morten A; Leeming, Diana J

2014-01-01

with cardiovascular diseases. The objective of the study was to investigate the association of versican turnover assessed in plasma with survival in haemodialysis patients. METHODS: A specific matrix metalloproteinase-generated neo-epitope fragment of versican (VCANM) was measured in plasma of 364 haemodialysis...... patients with a 5-years follow-up, using a robust competitive enzyme-linked immunosorbent assays. Association between VCANM plasma concentration and survival was assessed by Kaplan-Meier analysis and adjusted Cox model. RESULTS: Haemodialysis patients with plasma VCANM concentrations in the lowest quartile...

Design Curve Generation for 3D SiC Fiber Architecture

Science.gov (United States)

Lang, Jerry; Dicarlo, James A.

2014-01-01

The design tool provides design curves that allow a simple and quick way to examine multiple factors that can influence the processing and key properties of the preforms and their final SiC-reinforced ceramic composites without over obligating financial capital for the fabricating of materials. Tool predictions for process and fiber fraction properties have been validated for a HNS 3D preform.The virtualization aspect of the tool will be used to provide a quick generation of solid models with actual fiber paths for finite element evaluation to predict mechanical and thermal properties of proposed composites as well as mechanical displacement behavior due to creep and stress relaxation to study load sharing characteristic between constitutes for better performance.Tool predictions for the fiber controlled properties of the SiCSiC CMC fabricated from the HNS preforms will be valuated and up-graded from the measurements on these CMC

Titration Curves: Fact and Fiction.

Science.gov (United States)

Chamberlain, John

1997-01-01

Discusses ways in which datalogging equipment can enable titration curves to be measured accurately and how computing power can be used to predict the shape of curves. Highlights include sources of error, use of spreadsheets to generate titration curves, titration of a weak acid with a strong alkali, dibasic acids, weak acid and weak base, and…

Signature Curves Statistics of DNA Supercoils

OpenAIRE

Shakiban, Cheri; Lloyd, Peter

2004-01-01

In this paper we describe the Euclidean signature curves for two dimensional closed curves in the plane and their generalization to closed space curves. The focus will be on discrete numerical methods for approximating such curves. Further we will apply these numerical methods to plot the signature curves related to three-dimensional simulated DNA supercoils. Our primary focus will be on statistical analysis of the data generated for the signature curves of the supercoils. We will try to esta...

The Emission, Lifetimes, and Formation Threshold of the Vegard-Kaplan Transition of Solid Nitrogen Exposed to Far-ultraviolet Radiation

Science.gov (United States)

Lu, Hsiao-Chi; Lo, Jen-Iu; Peng, Yu-Chain; Chou, Sheng-Lung; Lin, Meng-Yeh; Cheng, Bing-Ming

2016-11-01

Irradiation of solid nitrogen at 4 K with far-ultraviolet light from a synchrotron caused excitation to the upper state of the Vegard-Kaplan (VK) system; the emission in that system was simultaneously recorded in wavelength region 200-440 nm. The lifetimes of emission lines for VK (0, 1) to (0, 12) transitions were measured in the range of 2.12 ˜ 2.65 s. The threshold wavelength to observe the VK emission was 175.0 ± 3.5 nm, corresponding to energy 7.08 ± 0.14 eV. This investigation of the generation of icy VK nitrogen enhances our understanding of its photochemistry in space.

THE EMISSION, LIFETIMES, AND FORMATION THRESHOLD OF THE VEGARD–KAPLAN TRANSITION OF SOLID NITROGEN EXPOSED TO FAR-ULTRAVIOLET RADIATION

Energy Technology Data Exchange (ETDEWEB)

Lu, Hsiao-Chi; Lo, Jen-Iu; Peng, Yu-Chain; Chou, Sheng-Lung; Lin, Meng-Yeh; Cheng, Bing-Ming, E-mail: bmcheng@nsrrc.org.tw [National Synchrotron Radiation Research Center, No. 101, Hsin-Ann Road, Hsinchu Science Park, Hsinchu 30076, Taiwan (China)

2016-11-20

Irradiation of solid nitrogen at 4 K with far-ultraviolet light from a synchrotron caused excitation to the upper state of the Vegard–Kaplan (VK) system; the emission in that system was simultaneously recorded in wavelength region 200–440 nm. The lifetimes of emission lines for VK (0, 1) to (0, 12) transitions were measured in the range of 2.12 ∼ 2.65 s. The threshold wavelength to observe the VK emission was 175.0 ± 3.5 nm, corresponding to energy 7.08 ± 0.14 eV. This investigation of the generation of icy VK nitrogen enhances our understanding of its photochemistry in space.

THE EMISSION, LIFETIMES, AND FORMATION THRESHOLD OF THE VEGARD–KAPLAN TRANSITION OF SOLID NITROGEN EXPOSED TO FAR-ULTRAVIOLET RADIATION

International Nuclear Information System (INIS)

Lu, Hsiao-Chi; Lo, Jen-Iu; Peng, Yu-Chain; Chou, Sheng-Lung; Lin, Meng-Yeh; Cheng, Bing-Ming

2016-01-01

Irradiation of solid nitrogen at 4 K with far-ultraviolet light from a synchrotron caused excitation to the upper state of the Vegard–Kaplan (VK) system; the emission in that system was simultaneously recorded in wavelength region 200–440 nm. The lifetimes of emission lines for VK (0, 1) to (0, 12) transitions were measured in the range of 2.12 ∼ 2.65 s. The threshold wavelength to observe the VK emission was 175.0 ± 3.5 nm, corresponding to energy 7.08 ± 0.14 eV. This investigation of the generation of icy VK nitrogen enhances our understanding of its photochemistry in space.

TÜ, TPÜ ja EHI uusi magistreid / Eda Tursk, Hille Roots, Heidi Meier

Index Scriptorium Estoniae

Tursk, Eda

2004-01-01

Tartu ülikooli eesti ja soome-ugri keeleteaduse osakonnas ning kirjanduse ja rahvaluule osakonnas kaitsesid 2003.a. magistritööd Niina Aasmäe, Piret Voll, Larissa Degel, Reet Hendrikson, Tiina Pai, Petar Kehayov, Anna Baidullina, Katrin Ennus, Kristi Jõesaar, Ell Vahtramäe, Lauri Sommer, Andreas Kalkun, Mirjam Hinrikus, Kristel Nõlvak. Tallinna Pedagoogikaülikoolis kaitsesid 2003.a. magistritööd Sirje Nootre, Merike Mägedi, Tiiu Koovit, Heidi Meier, Jaanika Stackhouse, Lilian Ossi, Annika Vamper, Marika Mikkor, Piret Õunapuu, Helin Puksand, Taimi Rosenberg. Eesti Humanitaarinstituudis kaitses 2003.a. magistritööd Merilin Miljan

Determination of PV Generator I-V/P-V Characteristic Curves Using a DC-DC Converter Controlled by a Virtual Instrument

Directory of Open Access Journals (Sweden)

E. Durán

2012-01-01

Full Text Available A versatile measurement system for systematic testing and measurement of the evolution of the I-V characteristic curves of photovoltaic panels or arrays (PV generators is proposed in this paper. The measurement system uses a circuit solution based on DC-DC converters that involves several advantages relative to traditional methods: simple structure, scalability, fast response, and low cost. The measurement of the desired characteristics of PV generators includes high speed of response and high fidelity. The prototype system built is governed by a microcontroller, and experimental results prove the proposed measurement system useful. A virtual instrument (VI was developed for full system control from a computer. The developed system enables monitoring the suitable operation of a PV generator in real time, since it allows comparing its actual curves with those provided by the manufacturer.

Moderate precision of prognostic scoring systems in a consecutive, prospective cohort of 544 patients with metastatic spinal cord compression

DEFF Research Database (Denmark)

Morgen, Søren Schmidt; Nielsen, Dennis Hallager; Larsen, Claus Falck

2014-01-01

and compared to the observed survival. We assessed how precise the scoring systems predicted survival with McNemar's test. The prognostic value was illustrated with Kaplan-Meier curves, and the individual prognostic components were analyzed with Cox regression analysis. RESULTS: The mean age was 65 years...... (range 20-95), and 57 % of the patients were men. The majority of tumors were lung (23 %), prostate (21 %), and breast tumors (18 %). The overall precision of predicted survival was 58.7 % for the Tokuhashi Revised score and 52.9 % for the Tomita score. The observed survival in each of the scoring groups...... was most precise in predicting survival. However, due to the relatively low precision, we suggest that a modification of both scoring systems is necessary....

Equity and improvement in outcome of breast cancer in Denmark

DEFF Research Database (Denmark)

Andreasen, A H; Mouridsen, H T; Andersen, K W

1994-01-01

The trend in the prognosis for female breast cancer patients was investigated by comparing Kaplan-Meier survival curves of different patient cohorts diagnosed during the period 1948-87. The study is based on 71,448 patients from the Danish Cancer Registry. The cohorts were defined by age...... in other parts of Denmark. For patients diagnosed in 1978-87 the prognosis, however, reached an equal level in all parts of the country. Thus, it is reasonable to assume that the national programme introduced in 1977 by the Danish Breast Cancer Cooperative Group (DBCG) has played an important role...... and not only brought about therapeutic improvements in breast cancer treatment in Denmark, but also ensured equity in the outcome on a national scale....

The effect of quitting smoking on the risk of unfavorable events after surgical treatment of oral potentially malignant lesions

DEFF Research Database (Denmark)

Vladimirov, B S; Schiødt, Morten

2009-01-01

smokers at the time of diagnosis and were treated surgically. Patients were advised to quit smoking at each visit. The change of smoking habits and occurrence of unfavorable events were noted during follow-up. Descriptive statistics, Fischer's exact test, Kaplan-Meier curves with log-rank test, and Cox......The aim of this study was to examine if cessation of smoking after surgical excision of oral potentially malignant lesions in smokers reduced the risk of recurrences, development of new lesions or malignancies. 51 patients with oral leukoplakia or erythroplakia were included. They were daily...... proportional hazards model were used for analysis. 16 patients (31%) quit smoking during the observation period. Only one quitter (6%) developed recurrence compared with 11 continuing smokers (33%) (p

Going Large or Going Small in Plant Design: Comparison between a P.P. with three small Kaplan turbines and a P.P. with just one Large Kaplan turbine

Science.gov (United States)

Castro-Otero, C.

2017-04-01

Very often small turbine manufacturers are requested to produce sizeable turbines, too large in terms of physical dimensions, power or designing capacity. In these cases clever alternative solutions should be found to meet customers’ needs. For instance: in the old times twin runner Francis turbines were an option instead of one large machine, or if a too large Pelton turbine cannot be manufactured or designed, a good option is to install a medium size Francis and a small Pelton. Likewise, a similar approach needs to be taken should the manufacturer be asked for a too large Kaplan. Facing this situation a good option is to install three or more small Kaplan turbines. This particular case was studied in depth and after all the considerations had been made, the following question arouse: Is this a way out for the manufacturer or is it really the best option for the customer? The choice made as a way out for the manufacturer became the best option for the customer and a success for both parties. This paper aims to encourage developers and engineering firms to search for more options than the traditional one to find the best option in plant design.

High mortality risk among individuals assumed to be TB-negative can be predicted using a simple test

DEFF Research Database (Denmark)

Rabna, Paulo; Andersen, Andreas; Wejse, Christian

2009-01-01

1007 aTBneg individuals who were enrolled from 2004 to 2006; 4983 age-matched controls were followed for comparison. Plasma suPAR levels were measured using the suPARnostic ELISA. Survival was analysed using Cox regression, ROC curves and Kaplan-Meier analysis. RESULTS: After 3 months of follow......-up, mortality was 21 per 100 person-year-observation (PYO) among aTBneg individuals and three per 100 PYO among the control population [mortality rate ratio (MRR) = 6.92 (95% CI 4.48-10.7)]. SuPAR values ranged between 0.9 and 45 ng/ml in aTBneg individuals. A log-linear relationship was found between su......PAR levels linear range, a 1 ng/ml increase was associated with a 46% increase in the mortality rate: MRR = 1.46 (95% CI 1.34-1.59). The area under the ROC curves was 0.88 for HIV-positive individuals and 0.79 for HIV-negative individuals. CONCLUSIONS: Our study showed...

On the Importance of Accounting for Competing Risks in Pediatric Cancer Trials Designed to Delay or Avoid Radiotherapy: I. Basic Concepts and First Analyses

International Nuclear Information System (INIS)

Tai, Bee-Choo; Grundy, Richard G.; Machin, David

2010-01-01

Purpose: In trials designed to delay or avoid irradiation among children with malignant brain tumor, although irradiation after disease progression is an important event, patients who have disease progression may decline radiotherapy (RT), or those without disease progression may opt for elective RT. To accurately describe the cumulative need for RT in such instances, it is crucial to account for these distinct events and to evaluate how each contributes to the delay or advancement of irradiation via a competing risks analysis. Methods and Materials: We describe the summary of competing events in such trials using competing risks methods based on cumulative incidence functions and Gray's test. The results obtained are contrasted with standard survival methods based on Kaplan-Meier curves, cause-specific hazard functions and log-rank test. Results: The Kaplan-Meier method overestimates all event-specific rates. The cause-specific hazard analysis showed reduction in hazards for all events (A: RT after progression; B: no RT after progression; C: elective RT) among children with ependymoma. For event A, a higher cumulative incidence was reported for ependymoma. Although Gray's test failed to detect any difference (p = 0.331) between histologic subtypes, the log-rank test suggested marginal evidence (p = 0.057). Similarly, for event C, the log-rank test found stronger evidence of reduction in hazard among those with ependymoma (p = 0.005) as compared with Gray's test (p = 0.086). Conclusions: To evaluate treatment differences, failing to account for competing risks using appropriate methodology may lead to incorrect interpretations.

pFAK-Y397 overexpression as both a prognostic and a predictive biomarker for patients with metastatic osteosarcoma.

Science.gov (United States)

Thanapprapasr, Kamolrat; Nartthanarung, Adisak; Thanapprapasr, Duangmani; Jinawath, Artit

2017-01-01

Focal adhesion kinase (FAK) is important for tumor cell survival and metastasis in various cancers. However, its expression and prognostic value in patients with metastatic osteosarcoma remain unknown. We investigated the expression of FAK and its phosphorylated form (pFAK-Y397) in osteosarcoma tissues from 53 patients by immunohistochemistry and evaluated their correlations with clinicopathologic characteristics and outcomes. The prognostic values were assessed using Kaplan-Meier survival and Cox regression analyses. Total FAK and pFAK-Y397 were overexpressed in 48 (90.6%) and 33 (62.3%) cases, respectively. pFAK-Y397 overexpression was correlated with poor histologic response after neoadjuvant chemotherapy in patients with osteosarcoma regardless of the presence of metastasis or not. Kaplan-Meier curve showed that patients with metastatic osteosarcoma with pFAK-Y397 overexpression had significantly worse overall survival (OS) than those with non-overexpression (P = 0.044). Multivariate Cox regression analysis confirmed pFAK-Y397 overexpression as an independent prognostic predictor for OS and post metastases OS (PMOS) (P = 0.017, P = 0.006, respectively). Age at diagnosis was also an independent indicator for PMOS (P = 0.003). However, total FAK expression was not correlated with any clinicopathologic characteristics or OS in patients with metastatic osteosarcoma. In conclusion, our findings identified FAK as a common aberrant protein overexpression in various subtypes of osteosarcoma. pFAK-Y397 overexpression can be used as a prognostic biomarker predicting poor OS for patients with metastatic osteosarcoma, and the expression of pFAK-Y397 differentiated good and poor responders to neoadjuvant chemotherapy.

The prognostic value of metabolic tumor volume in FDG PET/CT evaluation of post-operative survival in patients with esophageal squamous cell cancer

International Nuclear Information System (INIS)

Zhu Wanqi; Yu Jinming; Sun Xiaorong; Xing Ligang; Xie Peng; Sun Xindong; Guo Hongbo; Yang Guoren; Kong Li

2011-01-01

Objective: To evaluate the prognostic value of MTV on 18 F-FDG PET/CT in patients with esophageal cancer. Methods: Forty-nine patients with esophageal cancer underwent 18 F-FDG PET/CT scan before surgery. The median follow-up time for the patients was 29 months (range, 8-57 months). The prognostic significance of MTV, age, sex, histologic grade, SUV max of the primary tumor, tumor size measured on PET/CT, T stage, N stage, M stage, American Joint Committee on Cancer (AJCC) stage, number and location of lymph nodes metastases were assessed by Kaplan-Meier analysis and multivariate Cox model. Results: In the univariate analysis, AJCC stage (χ 2 =16.206, hazard ratio (HR)=1.177, P<0.001), N stage (χ 2 =9.536, HR=10.833, P=0.002), T stage (χ 2 =5.810, HR=2.397, P=0.016), number of lymph nodes metastases (χ 2 =11.423, HR=1.567, P=0.001), and MTV (χ 2 =3.872, HR=2.433, P=0.049) were significant predictors of survival.Multivariate analysis showed that MTV and AJCC stage were independent predictors of survival (χ 2 =4.525, HR 1.170, P=0.033; χ 2 =4.875, HR=3.071, P=0.027). Kaplan-Meier survival curves revealed longer survival time of low-MTV group as compared to high-MTV group (Log-rank, χ 2 =4.186, P=0.041). Conclusion: MTV on 18 F-FDG PET/CT may be an independent prognostic factor in patients with esophageal cancer. (authors)

The Association of Individual and Regional Socioeconomic Status on Initial Peritonitis and Outcomes in Peritoneal Dialysis Patients: A Propensity Score-Matched Cohort Study.

Science.gov (United States)

Wang, Qin; Hu, Ke-Jie; Ren, Ye-Ping; Dong, Jie; Han, Qing-Feng; Zhu, Tong-Ying; Chen, Jiang-Hua; Zhao, Hui-Ping; Chen, Meng-Hua; Xu, Rong; Wang, Yue; Hao, Chuan-Ming; Zhang, Xiao-Hui; Wang, Mei; Tian, Na; Wang, Hai-Yan

2016-01-01

♦ Research indicates that the socioeconomic status (SES) of individuals and the area where they live are related to initial peritonitis and outcomes in peritoneal dialysis (PD). We conducted a retrospective, multi-center cohort study in China to examine these associations. ♦ Data on 2,171 PD patients were collected from 7 centers, including baseline demographic, socioeconomic, and laboratory data. We explored the potential risk factors for initial peritonitis and outcomes using univariate Cox regression and unadjusted binary logistic regression. Then, we used propensity score matching to balance statistically significant risk factors for initial peritonitis and outcomes, and Kaplan-Meier survival analysis to compare differences in peritonitis-free rates between different groups of participants after matching. ♦ A total of 563 (25.9%) initial episodes of peritonitis occurred during the study period. The Kaplan-Meier peritonitis-free rate curve showed high-income patients had a significantly lower risk than low-income patients (p = 0.007) after matching for age, hemoglobin, albumin, and regional SES and PD center. The risk of treatment failure was significantly lower in the high-income than the low-income group after matching for the organism causing peritonitis and PD center: odds ratio (OR) = 0.27 (0.09 - 0.80, p = 0.018). Regional SES and education were not associated with initial peritonitis and outcomes. ♦ Our study demonstrates low individual income is a risk factor for the initial onset of peritonitis and treatment failure after initial peritonitis. Copyright © 2016 International Society for Peritoneal Dialysis.

Censoring: a new approach for detection limits in total-reflection X-ray fluorescence

International Nuclear Information System (INIS)

Pajek, M.; Kubala-Kukus, A.; Braziewicz, J.

2004-01-01

It is shown that the detection limits in the total-reflection X-ray fluorescence (TXRF), which restrict quantification of very low concentrations of trace elements in the samples, can be accounted for using the statistical concept of censoring. We demonstrate that the incomplete TXRF measurements containing the so-called 'nondetects', i.e. the non-measured concentrations falling below the detection limits and represented by the estimated detection limit values, can be viewed as the left random-censored data, which can be further analyzed using the Kaplan-Meier (KM) method correcting for nondetects. Within this approach, which uses the Kaplan-Meier product-limit estimator to obtain the cumulative distribution function corrected for the nondetects, the mean value and median of the detection limit censored concentrations can be estimated in a non-parametric way. The Monte Carlo simulations performed show that the Kaplan-Meier approach yields highly accurate estimates for the mean and median concentrations, being within a few percent with respect to the simulated, uncensored data. This means that the uncertainties of KM estimated mean value and median are limited in fact only by the number of studied samples and not by the applied correction procedure for nondetects itself. On the other hand, it is observed that, in case when the concentration of a given element is not measured in all the samples, simple approaches to estimate a mean concentration value from the data yield erroneous, systematically biased results. The discussed random-left censoring approach was applied to analyze the TXRF detection-limit-censored concentration measurements of trace elements in biomedical samples. We emphasize that the Kaplan-Meier approach allows one to estimate the mean concentrations being substantially below the mean level of detection limits. Consequently, this approach gives a new access to lower the effective detection limits for TXRF method, which is of prime interest for

Clinical outcomes in patients with node-negative breast cancer treated based on the recurrence score results: evidence from a large prospectively designed registry.

Science.gov (United States)

Stemmer, Salomon M; Steiner, Mariana; Rizel, Shulamith; Soussan-Gutman, Lior; Ben-Baruch, Noa; Bareket-Samish, Avital; Geffen, David B; Nisenbaum, Bella; Isaacs, Kevin; Fried, Georgeta; Rosengarten, Ora; Uziely, Beatrice; Svedman, Christer; McCullough, Debbie; Maddala, Tara; Klang, Shmuel H; Zidan, Jamal; Ryvo, Larisa; Kaufman, Bella; Evron, Ella; Karminsky, Natalya; Goldberg, Hadassah; Shak, Steven; Liebermann, Nicky

2017-01-01

The 21-gene Recurrence Score® (RS) assay is a validated prognostic/predictive tool in ER + early-stage breast cancer. However, clinical outcome data from prospective studies in RS ≥ 11 patients are lacking, as are relevant real-life clinical practice data. In this retrospective analysis of a prospectively designed registry, we evaluated treatments/clinical outcomes in patients undergoing RS-testing through Clalit Health Services. The analysis included N0 ER + HER2-negative breast cancer patients who were RS-tested from 1/2006 through 12/2010. Medical records were reviewed to verify treatments/recurrences/survival. The cohort included 1801 patients (median follow-up, 6.2 years). Median age was 60 years, 50.4% were grade 2 and 81.1% had invasive ductal carcinoma; 48.9% had RS < 18, 40.7% RS 18-30, and 10.4% RS ≥ 31, with chemotherapy use of 1.4, 23.7, and 87.2%, respectively. The 5-year Kaplan-Meier estimates for distant recurrence were 0.8, 3.0, and 8.6%, for patients with RS < 18, RS 18-30 and RS ≥ 31, respectively; the corresponding 5-year Kaplan-Meier estimates for breast cancer death were 0.0, 0.9, and 6.2%. Chemotherapy-untreated patients with RS < 11 ( n  = 304) and 11-25 ( n  = 1037) (TAILORx categorizatio n ) had 5-year Kaplan-Meier estimates for distant recurrence risk/breast cancer death of 1.0%/0.0% and 1.3%/0.4%, respectively. Our results extend those of the prospective TAILORx trial: the 5-year Kaplan-Meier estimates for distant recurrence and breast cancer death rate for the RS < 18 patients were very low supporting the use of endocrine therapy alone. Furthermore, in chemotherapy-untreated patients with RS 11-25 (where TAILORx patients were randomized to chemoendocrine or endocrine therapy alone), 5-year distant recurrence rates were also very low, suggesting that chemotherapy would not have conferred clinically meaningful benefit.

Retrospective analysis of dental implants placed and restored by advanced prosthodontic residents.

Science.gov (United States)

Barias, Pamela A; Lee, Damian J; Yuan, Judy Chia-Chun; Sukotjo, Cortino; Campbell, Stephen D; Knoernschild, Kent L

2013-02-01

The purposes of this retrospective clinical review were to: (1) describe the demographics of implant patients, types of implant treatment and implant-supported prostheses in an Advanced Education in Prosthodontic Program, (2) evaluate the survival rate of dental implants placed by prosthodontic residents from 2006 to 2008, and (3) analyze the relationship between resident year of training and implant survival rate. All patients who received dental implants placed by prosthodontic residents from January 2006 to October of 2008 in the Advanced Prosthodontic Program at the University of Illinois at Chicago College of Dentistry were selected for this study. Age, gender, implant diameter, length, implant locations, surgical and restorative detail, and year of prosthodontic residency training were collected and analyzed. Life-table and Kaplan-Meier survival analyses were performed based on implants overall, locations, year of training, and use of a computer-generated surgical guide. A Logrank statistic was performed between implant survival and year of prosthodontic residency training, location, and use of computer-generated surgical guide (α= 0.05). Three hundred and six implants were placed, and of these, seven failed. Life-table and Kaplan-Meier analyses computed a cumulative survival rate (CSR) of 97% for overall implants and implants placed with a computer-generated surgical guide. No statistical difference was found in implant survival rates as a function of year of training (P= 0.85). Dental implants placed by prosthodontic residents had a CSR comparable to previously published studies by other specialties. The year of prosthodontic residency training and implant failure rate did not have any significant relationship. © 2012 by the American College of Prosthodontists.

Investigation of learning and experience curves

Energy Technology Data Exchange (ETDEWEB)

Krawiec, F.; Thornton, J.; Edesess, M.

1980-04-01

The applicability of learning and experience curves for predicting future costs of solar technologies is assessed, and the major test case is the production economics of heliostats. Alternative methods for estimating cost reductions in systems manufacture are discussed, and procedures for using learning and experience curves to predict costs are outlined. Because adequate production data often do not exist, production histories of analogous products/processes are analyzed and learning and aggregated cost curves for these surrogates estimated. If the surrogate learning curves apply, they can be used to estimate solar technology costs. The steps involved in generating these cost estimates are given. Second-generation glass-steel and inflated-bubble heliostat design concepts, developed by MDAC and GE, respectively, are described; a costing scenario for 25,000 units/yr is detailed; surrogates for cost analysis are chosen; learning and aggregate cost curves are estimated; and aggregate cost curves for the GE and MDAC designs are estimated. However, an approach that combines a neoclassical production function with a learning-by-doing hypothesis is needed to yield a cost relation compatible with the historical learning curve and the traditional cost function of economic theory.

18F-Fluorodeoxyglucose PET/CT and dynamic contrast-enhanced MRI as imaging biomarkers in malignant pleural mesothelioma.

Science.gov (United States)

Hall, David O; Hooper, Clare E; Searle, Julie; Darby, Michael; White, Paul; Harvey, John E; Braybrooke, Jeremy P; Maskell, Nick A; Masani, Vidan; Lyburn, Iain D

2018-02-01

The purpose of this study was to compare the use of fluorine-18-fluorodeoxyglucose (F-FDG) PET with computed tomography (CT) and dynamic contrast-enhanced (DCE) MRI to predict prognosis and monitor treatment in malignant pleural mesothelioma. F-FDG PET/CT and DCE-MRI studies carried out as part of the South West Area Mesothelioma Pemetrexed trial were used. F-FDG PET/CT and DCE-MRI studies were carried out before treatment, and after two cycles of chemotherapy, on patients treated with pemetrexed and cisplatin. A total of 73 patients were recruited, of whom 65 had PET/CT and DCE-MRI scans. Baseline measurements from F-FDG PET/CT (maximum standardized uptake value, metabolic tumour volume and total lesion glycolysis) and DCE-MRI (integrated area under the first 90s of the curve and washout slope) were compared with overall survival (OS) using Kaplan-Meier and Cox regression analyses, and changes in imaging measurements were compared with disease progression. PET/CT and DCE-MRI measurements were not correlated with each other. Maximum standardized uptake value, metabolic tumour volume and total lesion glycolysis were significantly related to OS with Cox regression analysis and Kaplan-Meir analysis, and DCE-MRI washout curve shape was significantly related to OS. DCE-MRI curve shape can be combined with F-FDG PET/CT to give additional prognostic information. Changes in measurements were not related to progression-free survival. F-FDG PET/CT and DCE-MRI give prognostic information in malignant pleural mesothelioma. Neither PET/CT nor DCE-MRI is useful for monitoring disease progression.

Cardiovascular Risk Factors and 5-year Mortality in the Copenhagen Stroke Study

DEFF Research Database (Denmark)

Kammersgaard, Lars Peter; Olsen, Tom Skyhøj

2005-01-01

population. METHODS: We studied 905 ischemic stroke patients from the community-based Copenhagen Stroke Study. Patients had a CT scan and stroke severity was measured by the Scandinavian Stroke Scale on admission. A comprehensive evaluation was performed by a standardized medical examination...... and questionnaire for cardiovascular risk factors, age, and sex. Follow-up was performed 5 years after stroke, and data on mortality were obtained for all, except 6, who had left the country. Five-year mortality was calculated by the Kaplan-Meier procedure and the influence of multiple predictors was analyzed...... by Cox proportional hazards analyses adjusted for age, gender, stroke severity, and risk factor profile. RESULTS: In Kaplan-Meier analyses atrial fibrillation (AF), ischemic heart disease, diabetes, and previous stroke were associated with increased mortality, while smoking and alcohol intake were...

Cardiovascular risk factors and 5-year mortality in the Copenhagen Stroke Study

DEFF Research Database (Denmark)

Kammersgaard, Lars Peter; Olsen, Tom Skyhøj

2005-01-01

population. METHODS: We studied 905 ischemic stroke patients from the community-based Copenhagen Stroke Study. Patients had a CT scan and stroke severity was measured by the Scandinavian Stroke Scale on admission. A comprehensive evaluation was performed by a standardized medical examination...... and questionnaire for cardiovascular risk factors, age, and sex. Follow-up was performed 5 years after stroke, and data on mortality were obtained for all, except 6, who had left the country. Five-year mortality was calculated by the Kaplan-Meier procedure and the influence of multiple predictors was analyzed...... by Cox proportional hazards analyses adjusted for age, gender, stroke severity, and risk factor profile. RESULTS: In Kaplan-Meier analyses atrial fibrillation (AF), ischemic heart disease, diabetes, and previous stroke were associated with increased mortality, while smoking and alcohol intake were...

Impact of BCL2 and p53 on postmastectomy radiotherapy response in high-risk breast cancer. A subgroup analysis of DBCG82 b&c

DEFF Research Database (Denmark)

Kyndi, Marianne; Sørensen, Flemming Brandt; Knudsen, Helle

2008-01-01

-Meier probability plots showed a significantly improved overall survival after PMRT for the BCL2 positive subgroup, whereas practically no survival improvement was seen after PMRT for the BCL2 negative subgroup. In multivariate analysis of OS, however, no significant interaction was found between BCL2......PURPOSE: To examine p53 and BCL2 expression in high-risk breast cancer patients randomized to postmastectomy radiotherapy (PMRT). PATIENTS AND METHODS: The present analysis included 1 000 of 3 083 high-risk breast cancer patients randomly assigned to PMRT in the DBCG82 b&c studies. Tissue...... tests, Kaplan-Meier probability plots, Log-rank test, and Cox univariate and multivariate regression analyses. RESULTS: p53 accumulation was not significantly associated with increased overall mortality, DM or LRR probability in univariate or multivariate Cox regression analyses. Kaplan...

Cost development of future technologies for power generation-A study based on experience curves and complementary bottom-up assessments

International Nuclear Information System (INIS)

Neij, Lena

2008-01-01

Technology foresight studies have become an important tool in identifying realistic ways of reducing the impact of modern energy systems on the climate and the environment. Studies on the future cost development of advanced energy technologies are of special interest. One approach widely adopted for the analysis of future cost is the experience curve approach. The question is, however, how robust this approach is, and which experience curves should be used in energy foresight analysis. This paper presents an analytical framework for the analysis of future cost development of new energy technologies for electricity generation; the analytical framework is based on an assessment of available experience curves, complemented with bottom-up analysis of sources of cost reductions and, for some technologies, judgmental expert assessments of long-term development paths. The results of these three methods agree in most cases, i.e. the cost (price) reductions described by the experience curves match the incremental cost reduction described in the bottom-up analysis and the judgmental expert assessments. For some technologies, the bottom-up analysis confirms large uncertainties in future cost development not captured by the experience curves. Experience curves with a learning rate ranging from 0% to 20% are suggested for the analysis of future cost development

Numerical investigation of tip clearance cavitation in Kaplan runners

Science.gov (United States)

Nikiforova, K.; Semenov, G.; Kuznetsov, I.; Spiridonov, E.

2016-11-01

There is a gap between the Kaplan runner blade and the shroud that makes for a special kind of cavitation: cavitation in the tip leakage flow. Two types of cavitation caused by the presence of clearance gap are known: tip vortex cavitation that appears at the core of the rolled up vortex on the blade suction side and tip clearance cavitation that appears precisely in the gap between the blade tip edge and the shroud. In the context of this work numerical investigation of the model Kaplan runner has been performed taking into account variable tip clearance for several cavitation regimes. The focus is put on investigation of structure and origination of mechanism of cavitation in the tip leakage flow. Calculations have been performed with the help of 3-D unsteady numerical model for two-phase medium. Modeling of turbulent flow in this work has been carried out using full equations of Navier-Stokes averaged by Reynolds with correction for streamline curvature and system rotation. For description of this medium (liquid-vapor) simplification of Euler approach is used; it is based on the model of interpenetrating continuums, within the bounds of this two- phase medium considered as a quasi-homogeneous mixture with the common velocity field and continuous distribution of density for both phases. As a result, engineering techniques for calculation of cavitation conditioned by existence of tip clearance in model turbine runner have been developed. The detailed visualization of the flow was carried out and vortex structure on the suction side of the blade was reproduced. The range of frequency with maximum value of pulsation was assigned and maximum energy frequency was defined; it is based on spectral analysis of the obtained data. Comparison between numerical computation results and experimental data has been also performed. The location of cavitation zone has a good agreement with experiment for all analyzed regimes.

Automated Blazar Light Curves Using Machine Learning

Energy Technology Data Exchange (ETDEWEB)

Johnson, Spencer James [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2017-07-27

This presentation describes a problem and methodology pertaining to automated blazar light curves. Namely, optical variability patterns for blazars require the construction of light curves and in order to generate the light curves, data must be filtered before processing to ensure quality.

Feasible Path Generation Using Bezier Curves for Car-Like Vehicle

Science.gov (United States)

Latip, Nor Badariyah Abdul; Omar, Rosli

2017-08-01

When planning a collision-free path for an autonomous vehicle, the main criteria that have to be considered are the shortest distance, lower computation time and completeness, i.e. a path can be found if one exists. Besides that, a feasible path for the autonomous vehicle is also crucial to guarantee that the vehicle can reach the target destination considering its kinematic constraints such as non-holonomic and minimum turning radius. In order to address these constraints, Bezier curves is applied. In this paper, Bezier curves are modeled and simulated using Matlab software and the feasibility of the resulting path is analyzed. Bezier curve is derived from a piece-wise linear pre-planned path. It is found that the Bezier curves has the capability of making the planned path feasible and could be embedded in a path planning algorithm for an autonomous vehicle with kinematic constraints. It is concluded that the length of segments of the pre-planned path have to be greater than a nominal value, derived from the vehicle wheelbase, maximum steering angle and maximum speed to ensure the path for the autonomous car is feasible.

Nested Cohort - R software package

Science.gov (United States)

NestedCohort is an R software package for fitting Kaplan-Meier and Cox Models to estimate standardized survival and attributable risks for studies where covariates of interest are observed on only a sample of the cohort.

Increased expression of CD133 and reduced dystroglycan expression are strong predictors of poor outcome in colon cancer patients

Directory of Open Access Journals (Sweden)

Coco Claudio

2012-09-01

Full Text Available Abstract Background Expression levels of CD133, a cancer stem cell marker, and of the α-subunit of the dystroglycan (α-DG complex, have been previously reported to be altered in colorectal cancers. Methods Expression levels of CD133 and α-DG were assessed by immunohistochemistry in a series of colon cancers and their prognostic significance was evaluated. Results Scattered cells positive for CD133 were rarely detected at the bases of the crypts in normal colonic mucosa while in cancer cells the median percentage of positive cells was 5% (range 0–80. A significant correlation was observed with pT parameter and tumor stage but not with tumor grade and N status. Recurrence and death from disease were significantly more frequent in CD133-high expressing tumors and Kaplan-Meier curves showed a significant separation between high vs low expressor groups for both disease-free (p = 0.002 and overall (p = 0.008 survival. Expression of α-DG was reduced in a significant fraction of tumors but low α-DG staining did not correlate with any of the classical clinical-pathological parameters. Recurrence and death from the disease were significantly more frequent in α-DG-low expressing tumors and Kaplan-Meier curves showed a significant separation between high vs low expressor tumors for both disease-free (p = 0.02 and overall (p = 0.02 survival. Increased expression of CD133, but not loss of α-DG, confirmed to be an independent prognostic parameters at a multivariate analysis associated with an increased risk of recurrence (RR = 2.4; p = 0.002 and death (RR = 2.3; p = 0.003. Conclusions Loss of α-DG and increased CD133 expression are frequent events in human colon cancer and evaluation of CD133 expression could help to identify high-risk colon cancer patients.

Predictive Factors for Visual Field Conversion: Comparison of Scanning Laser Polarimetry and Optical Coherence Tomography.

Science.gov (United States)

Diekmann, Theresa; Schrems-Hoesl, Laura M; Mardin, Christian Y; Laemmer, Robert; Horn, Folkert K; Kruse, Friedrich E; Schrems, Wolfgang A

2018-02-01

The purpose of this study was to compare the ability of scanning laser polarimetry (SLP) and spectral-domain optical coherence tomography (SD-OCT) to predict future visual field conversion of subjects with ocular hypertension and early glaucoma. All patients were recruited from the Erlangen glaucoma registry and examined using standard automated perimetry, 24-hour intraocular pressure profile, and optic disc photography. Peripapillary retinal nerve fiber layer thickness (RNFL) measurements were obtained by SLP (GDx-VCC) and SD-OCT (Spectralis OCT). Positive and negative predictive values (PPV, NPV) were calculated for morphologic parameters of SLP and SD-OCT. Kaplan-Meier survival curves were plotted and log-rank tests were performed to compare the survival distributions. Contingency tables and Venn-diagrams were calculated to compare the predictive ability. The study included 207 patients-75 with ocular hypertension, 85 with early glaucoma, and 47 controls. Median follow-up was 4.5 years. A total of 29 patients (14.0%) developed visual field conversion during follow-up. SLP temporal-inferior RNFL [0.667; 95% confidence interval (CI), 0.281-0.935] and SD-OCT temporal-inferior RNFL (0.571; 95% CI, 0.317-0.802) achieved the highest PPV; nerve fiber indicator (0.923; 95% CI, 0.876-0.957) and SD-OCT mean (0.898; 95% CI, 0.847-0.937) achieved the highest NPV of all investigated parameters. The Kaplan-Meier curves confirmed significantly higher survival for subjects within normal limits of measurements of both devices (P<0.001). Venn diagrams tested with McNemar test statistics showed no significant difference for PPV (P=0.219) or NPV (P=0.678). Both GDx-VCC and SD-OCT demonstrate comparable results in predicting future visual field conversion if taking typical scans for GDx-VCC. In addition, the likelihood ratios suggest that GDx-VCC's nerve fiber indicator<30 may be the most useful parameter to confirm future nonconversion. (http://www.ClinicalTrials.gov number, NTC

A network-based predictive gene-expression signature for adjuvant chemotherapy benefit in stage II colorectal cancer.

Science.gov (United States)

Cao, Bangrong; Luo, Liping; Feng, Lin; Ma, Shiqi; Chen, Tingqing; Ren, Yuan; Zha, Xiao; Cheng, Shujun; Zhang, Kaitai; Chen, Changmin

2017-12-13

The clinical benefit of adjuvant chemotherapy for stage II colorectal cancer (CRC) is controversial. This study aimed to explore novel gene signature to predict outcome benefit of postoperative 5-Fu-based therapy in stage II CRC. Gene-expression profiles of stage II CRCs from two datasets with 5-Fu-based adjuvant chemotherapy (training dataset, n = 212; validation dataset, n = 85) were analyzed to identify the indicator. A systemic approach by integrating gene-expression and protein-protein interaction (PPI) network was implemented to develop the predictive signature. Kaplan-Meier curves and Cox proportional hazards model were used to determine the survival benefit of adjuvant chemotherapy. Experiments with shRNA knock-down were carried out to confirm the signature identified in this study. In the training dataset, we identified 44 PPI sub-modules, by which we separate patients into two clusters (1 and 2) having different chemotherapeutic benefit. A predictor of 11 PPI sub-modules (11-PPI-Mod) was established to discriminate the two sub-groups, with an overall accuracy of 90.1%. This signature was independently validated in an external validation dataset. Kaplan-Meier curves showed an improved outcome for patients who received adjuvant chemotherapy in Cluster 1 sub-group, but even worse survival for those in Cluster 2 sub-group. Similar results were found in both the training and the validation dataset. Multivariate Cox regression revealed an interaction effect between 11-PPI-Mod signature and adjuvant therapy treatment in the training dataset (RFS, p = 0.007; OS, p = 0.006) and the validation dataset (RFS, p = 0.002). From the signature, we found that PTGES gene was up-regulated in CRC cells which were more resistant to 5-Fu. Knock-down of PTGES indicated a growth inhibition and up-regulation of apoptotic markers induced by 5-Fu in CRC cells. Only a small proportion of stage II CRC patients could benefit from adjuvant therapy. The 11-PPI-Mod as

Complementary Chinese herbal medicine therapy improves survival of patients with gastric cancer in Taiwan: A nationwide retrospective matched-cohort study.

Science.gov (United States)

Hung, Kuo-Feng; Hsu, Ching-Ping; Chiang, Jen-Huai; Lin, Hung-Jen; Kuo, Yi-Ting; Sun, Mao-Feng; Yen, Hung-Rong

2017-03-06

Many patients with gastric cancer seek traditional medicine consultations in Asian countries. This study aimed to investigate the prescription of Chinese herbal medicine (CHM) and its benefits for the patients with gastric cancer in Taiwan. From the Registry for Catastrophic Illness Patients Database, we included all patients with gastric cancer whose age at diagnosis was ≥18 from 1997 to 2010 in Taiwan. We used 1:1 frequency matching by age, sex, Charlson comorbidity score, treatment and index year to compare the CHM users and non-CHM users. We used the Cox regression model to compare the hazard ratios (HR) for the risk of mortality and the Kaplan-Meier curve for the survival time. There was a total of 1333 patients in the CHM-cohort and 44786 patients in the non-CHM cohort. After matching, we compared 962 newly diagnosed CHM users and 962 non-CHM users. Adjusted HRs (aHR) were higher among patients of above 60-year-old group, with a Charlson Comorbidity Index score ≥2 before the index date, and those who need surgery combined with chemotherapy or radiotherapy. CHM users had a lower HR of mortality risk (adjusted HR: 0.55, 95% CI: 0.48-0.62). Compared to the non-CHM users, the aHR among CHM-users is 0.37 (95% CI:0.2-0.67) for those who used CHM more than 180 days annually. The Kaplan-Meier curve revealed that the survival probability was higher for complementary CHM-users. Bai-Hua-She-She-Cao (Herba Hedyotidis Diffusae) was the most commonly used single herb and Xiang-Sha-Liu-Jun-Zi-Tang was the most commonly used herbal formula among CHM prescriptions. Complementary CHM improves the overall survival among patients with gastric cancer in Taiwan. Further ethnopharmacological investigations and clinical trials are required to validate the efficacy and safety. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

Prognostic significance of multidrug-resistance protein (MDR-1 in renal clear cell carcinomas: A five year follow-up analysis

Directory of Open Access Journals (Sweden)

Strazzullo Viviana

2006-12-01

Full Text Available Abstract Background A large number of renal cancer patients shows poor or partial response to chemotherapy and the mechanisms have not been still understood. Multi-drug resistance is the principal mechanism by which many cancers develop resistance to chemotherapic drugs. The role of the multi-drug resistant transporter (MDR-1/P-glycoprotein, the gene product of MDR-1, and that one of the so-called multi-drug resistance associated protein (MRP, two energy-dependent efflux pumps, are commonly known to confer drug resistance. We studied MDR-1 expression in selected cases of renal cell carcinoma (RCC, clear cell type, with long-term follow-up, in order to establish its prognostic role and its possible contribution in the choice of post-surgical therapy. Methods MDR-1 has been studied by standard LSAB-HRP immunohistochemical technique, in paraffin embedded RCC samples. Protein expression has been compared to clinical and histopathological data and to disease specific survival of RCC patients, by Kaplan-Meier curve and Cox multivariate regression analyses. Results Two groups of RCCs were obtained by esteeming MDR-1 expression and disease specific survival (obtained with Kaplan-Meier curve and Cox multivariate regression analyses: the first one presents low or absent MDR-1 expression and good survival; the second one is characterized by high MDR-1 expression and significant poor outcome (p p p p Conclusion In our opinion, the results of this study well prove the relationship between MDR-1 expression and worse clinical prognosis in RCC, because MDR-1 over-expressing RCCs can be considered a group of tumours with a more aggressive behavior. This finding outlines a possible role of MDR-1 as prognostic factor, dependent and independent of multidrug resistance. These results could be useful to predict cancer evolution and to choose the appropriate treatment: this is another step that can stimulate further promising and interesting investigations on broader

Optimal FDG PET/CT volumetric parameters for risk stratification in patients with locally advanced non-small cell lung cancer: results from the ACRIN 6668/RTOG 0235 trial

Energy Technology Data Exchange (ETDEWEB)

Salavati, Ali [Hospital of the University of Pennsylvania, Department of Radiology, Philadelphia, PA (United States); University of Minnesota, Department of Radiology, Minneapolis, MN (United States); Duan, Fenghai [Brown University School of Public Health, Department of Biostatistics and Center for Statistical Sciences, Providence, RI (United States); Snyder, Bradley S. [Brown University School of Public Health, Center for Statistical Sciences, Providence, RI (United States); Wei, Bo [Emory University, Department of Biostatistics, Rollins School of Public Health, Atlanta, GA (United States); Houshmand, Sina; Alavi, Abass [Hospital of the University of Pennsylvania, Department of Radiology, Philadelphia, PA (United States); Khiewvan, Benjapa [Hospital of the University of Pennsylvania, Department of Radiology, Philadelphia, PA (United States); Mahidol University, Division of Nuclear Medicine, Department of Radiology, Faculty of Medicine Siriraj Hospital, Bangkok (Thailand); Opanowski, Adam [ACR Center for Research and Innovation, American College of Radiology, Philadelphia, PA (United States); Simone, Charles B. [University of Maryland Medical Center, Department of Radiation Oncology, Baltimore, MD (United States); Siegel, Barry A. [Washington University School of Medicine, Mallinckrodt Institute of Radiology and the Alvin J. Siteman Cancer Center, St, Louis, MO (United States); Machtay, Mitchell [Case Western Reserve University and University Hospitals Case Medical Center, Department of Radiation Oncology, Cleveland, OH (United States)

2017-11-15

In recent years, multiple studies have demonstrated the value of volumetric FDG-PET/CT parameters as independent prognostic factors in patients with non-small cell lung cancer (NSCLC). We aimed to determine the optimal cut-off points of pretreatment volumetric FDG-PET/CT parameters in predicting overall survival (OS) in patients with locally advanced NSCLC and to recommend imaging biomarkers appropriate for routine clinical applications. Patients with inoperable stage IIB/III NSCLC enrolled in ACRIN 6668/RTOG 0235 were included. Pretreatment FDG-PET scans were quantified using semiautomatic adaptive contrast-oriented thresholding and local-background partial-volume-effect-correction algorithms. For each patient, the following indices were measured: metabolic tumor volume (MTV), total lesion glycolysis (TLG), SUVmax, SUVmean, partial-volume-corrected TLG (pvcTLG), and pvcSUVmean for the whole-body, primary tumor, and regional lymph nodes. The association between each index and patient outcome was assessed using Cox proportional hazards regression. Optimal cut-off points were estimated using recursive binary partitioning in a conditional inference framework and used in Kaplan-Meier curves with log-rank testing. The discriminatory ability of each index was examined using time-dependent receiver operating characteristic (ROC) curves and corresponding area under the curve (AUC(t)). The study included 196 patients. Pretreatment whole-body and primary tumor MTV, TLG, and pvcTLG were independently prognostic of OS. Optimal cut-off points were 175.0, 270.9, and 35.5 cm{sup 3} for whole-body TLG, pvcTLG, and MTV, and were 168.2, 239.8, and 17.4 cm{sup 3} for primary tumor TLG, pvcTLG, and MTV, respectively. In time-dependent ROC analysis, AUC(t) for MTV and TLG were uniformly higher than that of SUV measures over all time points. Primary tumor and whole-body parameters demonstrated similar patterns of separation for those patients above versus below the optimal cut

Tourism and solid waste generation in Europe: A panel data assessment of the Environmental Kuznets Curve.

Science.gov (United States)

Arbulú, Italo; Lozano, Javier; Rey-Maquieira, Javier

2015-12-01

The relationship between tourism growth and municipal solid waste (MSW) generation has been, until now, the subject of little research. This is puzzling since the tourism sector is an important MSW generator and, at the same time, is willing to avoid negative impacts from MSW mismanagement. This paper aims to provide tools for tourism and MSW management by assessing the effects of tourism volume, tourism quality and tourism specialization on MSW generation in the UE. This is done using the Environmental Kuznets Curve (EKC) framework. The study considers a panel data for 32 European economies in the 1997-2010 periods. Empirical results support the EKC hypothesis for MSW and shows that northern countries tend to have lower income elasticity than less developed countries; furthermore, results confirm a non-linear and significant effect of tourism arrivals, expenditure per tourist and tourism specialization on MSW generation. Copyright © 2015 Elsevier Ltd. All rights reserved.

The Educational Philosophies of Mordecai Kaplan and Michael Rosenak: Surprising Similarities and Illuminating Differences

Science.gov (United States)

Schein, Jeffrey; Caplan, Eric

2014-01-01

The thoughts of Mordecai Kaplan and Michael Rosenak present surprising commonalities as well as illuminating differences. Similarities include the perception that Judaism and Jewish education are in crisis, the belief that Jewish peoplehood must include commitment to meaningful content, the need for teachers to teach from a position of…

ORIGINAL ARTICLES Antiretroviral treatment for children

African Journals Online (AJOL)

Kaplan-Meier survival estimate for 407 children at 1 year was. 84% (95% ... highly active antiretroviral therapy (HAART) to 3 million people living with HIV I AIDS in ... 5 Furthermore, improvements in growth and body composition parameters,.

Exhausted implanted pulse generator in sacral nerve stimulation for faecal incontinence: What next in daily practice for patients?

Science.gov (United States)

Duchalais, Emilie; Meurette, Guillaume; Perrot, Bastien; Wyart, Vincent; Kubis, Caroline; Lehur, Paul-Antoine

2016-02-01

The efficacy of sacral nerve stimulation in faecal incontinence relies on an implanted pulse generator known to have a limited lifespan. The long-term use of sacral nerve stimulation raises concerns about the true lifespan of generators. The aim of the study was to assess the lifespan of sacral nerve stimulation implanted pulse generators in daily practice, and the outcome of exhausted generator replacement, in faecal incontinent patients. Faecal incontinent patients with pulse generators (Medtronic Interstim™ or InterstimII™) implanted in a single centre from 2001 to 2014 were prospectively followed up. Generator lifespan was measured according to the Kaplan-Meier method. Patients with a generator explanted/turned off before exhaustion were excluded. Morbidity of exhausted generator replacement and the outcome (Cleveland Clinic Florida Faecal Incontinence (CCF-FI) and Faecal Incontinence Quality of Life (FIQL) scores) were recorded. Of 135 patients with an implanted pulse generator, 112 (InterstimII 66) were included. Mean follow-up was 4.9 ± 2.8 years. The generator reached exhaustion in 29 (26%) cases. Overall median lifespan of an implanted pulse generator was approximately 9 years (95% CI 8-9.2). Interstim and InterstimII 25th percentile lifespan was 7.2 (CI 6.4-8.3) and 5 (CI 4-not reached) years, respectively. After exhaustion, generators were replaced, left in place or explanted in 23, 2 and 4 patients, respectively. Generator replacement was virtually uneventful. CCF-FI/FIQL scores remained unchanged after generator replacement (CCF-FI 8 ± 2 vs 7 ± 3; FIQL 3 ± 0.6 vs 3 ± 0.5; p = ns). In this study, the implanted pulse generator observed median lifespan was 9 years. After exhaustion, generators were safely and efficiently replaced. The study also gives insight into long-term needs and costs of sacral nerve stimulation (SNS) therapy.

Analyzing repeated data collected by mobile phones and frequent text messages. An example of Low back pain measured weekly for 18 weeks

DEFF Research Database (Denmark)

Axén, Iben; Bodin, Lennart; Kongsted, Alice

2012-01-01

to recovery? This question was answered using survival analysis, illustrated in Kaplan-Meier curves, Proportional Hazard regression analyses and spline regression analyses. 4: How is the repeatedly measured data associated with baseline (predictor) variables? This question was answered using generalized...... involves some challenges. Vital issues to consider are the within-subject correlation, the between measurement occasion correlation and the presence of missing values. The overall aim of this commentary is to describe different methods of analyzing repeated data. It is meant to give an overview...... for the clinical researcher in order for complex outcome measures to be interpreted in a clinically meaningful way. METHODS: A model data set was formed using data from two clinical studies, where patients with low back pain were followed with weekly text messages for 18 weeks. Different research questions...

Protective effect of Asparagus racemosus root extract against lethal total - body electron beam radiation induced damage in Swiss albino mice

International Nuclear Information System (INIS)

Sharmila, K.P.; Bhandary, B. Satheesh Kumar; Suchetha Kumari, N.; Bhat, Vadish S.; Shetty, Jayaram; Peter, Alex John; Jose, Jerish M.; Fernandes, Ronald

2016-01-01

To investigate the protective effect of Asparagus Racemosus Root ethanolic extract (ARE) in Swiss albino mice against acute lethal total - body Electron beam irradiation. Swiss Albino mice were used for the assessment of radiation induced sickness and 30 day survival analysis. Survival studies were determined using the Kaplan-Meier survival curves. The maximum survival was observed in the experimental mice pretreated with 200 mg/kg.b.wt. of ARE which also reduced the radiation sickness characteristics. This dose was considered as an optimal dose for radioprotection. Treatment of mice with ARE before irradiation delayed the onset of mortality as compared with the untreated irradiated controls. Present findings demonstrate the potential of ARE in mitigating radiation-induced mortality, which may be attributed to its free radical scavenging and increased antioxidant potential

Real-world effectiveness of everolimus-based therapy versus fulvestrant monotherapy in HR(+)/HER2(-) metastatic breast cancer.

Science.gov (United States)

Hao, Yanni; Lin, Peggy L; Xie, Jipan; Li, Nanxin; Koo, Valerie; Ohashi, Erika; Wu, Eric Q; Rogerio, Jaqueline

2015-08-01

Assessing real-world effectiveness of everolimus-based therapy (EVE) versus fulvestrant monotherapy (FUL) among postmenopausal women with hormone receptor-positive (HR(+))/HER2(-) metastatic breast cancer (mBC) after progression on nonsteroidal aromatase inhibitor (NSAI). Medical charts of community-based patients who received EVE or FUL for mBC after NSAI were examined. Progression-free survival (PFS), time on treatment and time to chemotherapy were compared using Kaplan-Meier curves and Cox proportional hazards models adjusting for line of therapy and patient characteristics. 192 patients received EVE and 156 FUL. After adjusting for patient characteristics, EVE was associated with significantly longer PFS than FUL (hazard ratio: 0.71; p = 0.045). EVE was associated with better PFS than FUL among NSAI-refractory postmenopausal HR(+)/HER2(-) mBC patients.

Chest computed tomography scores are predictive of survival in patients with cystic fibrosis awaiting lung transplantation

DEFF Research Database (Denmark)

Loeve, Martine; Hop, Wim C. J.; de Bruijne, Marleen

2012-01-01

Rationale: Up to a third of cystic fibrosis (CF) patients awaiting lung transplantation (LTX) die while waiting. Inclusion of computed tomography (CT) scores may improve survival prediction models such as the lung allocation score (LAS). Objectives: This study investigated the association between...... CT and survival in CF patients screened for LTX. Methods: Clinical data and chest CTs of 411 CF patients screened for LTX between 1990 and 2005 were collected from 17 centers. CTs were scored with the Severe Advanced Lung Disease (SALD) 4-category scoring system, including the components "infection....../inflammation" (INF), air trapping/hypoperfusion (AT), normal/hyperperfusion (NOR) and bulla/cysts (BUL). The volume of each component was computed using semi-automated software. Survival analysis included Kaplan-Meier curves, and Cox-regression models. Measurements and main results: 366 (186 males) out of 411...

Clinical Significance of Preoperative Albumin and Globulin Ratio in Patients with Gastric Cancer Undergoing Treatment

Directory of Open Access Journals (Sweden)

Min-jie Mao

2017-01-01

Full Text Available Background. The pretreatment albumin and globulin ratio (AGR was an inflammation-associated factor which was related to the overall survival in various malignancies. The aim of this study was to evaluate the prognostic value of AGR in patients with gastric cancer. Method. This retrospective study included 862 cases pathologically diagnosed with gastric cancer. All patients were randomly divided into the testing group (431 cases and validation group (431 cases. The relationships of AGR with clinicopathologic characteristics and prognosis were analyzed by Kaplan-Meier and Cox regression methods. Results. In the testing group, the median overall survival was 26.90 months and the cutoff value of AGR was 1.50 based on R language. Kaplan-Meier analysis showed that lower AGR was correlated with poorer overall survival. Multivariate analysis demonstrated that AGR was an independent prognostic factor for overall survival (HR: 0.584, 95% CI = 0.351–0.973, and p = 0.039. In the validation group, the median overall survival was 24.10 months. Lower AGR (≤1.50 also had a significantly poorer overall survival by Kaplan-Meier analysis. According to multivariate analysis, the AGR was also confirmed to be an independent prognostic factor for overall survival (HR: 0.578, 95% CI = 0.373–0.897, and p = 0.015. Conclusions. Our study suggested that the pretreatment AGR could be a prognostic biomarker for overall survival in patients with gastric cancer.

Competing approaches to analysis of failure times with competing risks.

Science.gov (United States)

Farley, T M; Ali, M M; Slaymaker, E

2001-12-15

For the analysis of time to event data in contraceptive studies when individuals are subject to competing causes for discontinuation, some authors have recently advocated the use of the cumulative incidence rate as a more appropriate measure to summarize data than the complement of the Kaplan-Meier estimate of discontinuation. The former method estimates the rate of discontinuation in the presence of competing causes, while the latter is a hypothetical rate that would be observed if discontinuations for the other reasons could not occur. The difference between the two methods of analysis is the continuous time equivalent of a debate that took place in the contraceptive literature in the 1960s, when several authors advocated the use of net (adjusted or single decrement life table rates) rates in preference to crude rates (multiple decrement life table rates). A small simulation study illustrates the interpretation of the two types of estimate - the complement of the Kaplan-Meier estimate corresponds to a hypothetical rate where discontinuations for other reasons did not occur, while the cumulative incidence gives systematically lower estimates. The Kaplan-Meier estimates are more appropriate when estimating the effectiveness of a contraceptive method, but the cumulative incidence estimates are more appropriate when making programmatic decisions regarding contraceptive methods. Other areas of application, such as cancer studies, may prefer to use the cumulative incidence estimates, but their use should be determined according to the application. Copyright 2001 John Wiley & Sons, Ltd.

Wind Turbine Power Curve Design for Optimal Power Generation in Wind Farms Considering Wake Effect

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Jie Tian

2017-03-01

Full Text Available In modern wind farms, maximum power point tracking (MPPT is widely implemented. Using the MPPT method, each individual wind turbine is controlled by its pitch angle and tip speed ratio to generate the maximum active power. In a wind farm, the upstream wind turbine may cause power loss to its downstream wind turbines due to the wake effect. According to the wake model, downstream power loss is also determined by the pitch angle and tip speed ratio of the upstream wind turbine. By optimizing the pitch angle and tip speed ratio of each wind turbine, the total active power of the wind farm can be increased. In this paper, the optimal pitch angle and tip speed ratio are selected for each wind turbine by the exhausted search. Considering the estimation error of the wake model, a solution to implement the optimized pitch angle and tip speed ratio is proposed, which is to generate the optimal control curves for each individual wind turbine off-line. In typical wind farms with regular layout, based on the detailed analysis of the influence of pitch angle and tip speed ratio on the total active power of the wind farm by the exhausted search, the optimization is simplified with the reduced computation complexity. By using the optimized control curves, the annual energy production (AEP is increased by 1.03% compared to using the MPPT method in a case-study of a typical eighty-turbine wind farm.

Utilization of curve offsets in additive manufacturing

Science.gov (United States)

Haseltalab, Vahid; Yaman, Ulas; Dolen, Melik

2018-05-01

Curve offsets are utilized in different fields of engineering and science. Additive manufacturing, which lately becomes an explicit requirement in manufacturing industry, utilizes curve offsets widely. One of the necessities of offsetting is for scaling which is required if there is shrinkage after the fabrication or if the surface quality of the resulting part is unacceptable. Therefore, some post-processing is indispensable. But the major application of curve offsets in additive manufacturing processes is for generating head trajectories. In a point-wise AM process, a correct tool-path in each layer can reduce lots of costs and increase the surface quality of the fabricated parts. In this study, different curve offset generation algorithms are analyzed to show their capabilities and disadvantages through some test cases and improvements on their drawbacks are suggested.

Power forward curves: a managerial perspective

International Nuclear Information System (INIS)

Nagarajan, Shankar

1999-01-01

This chapter concentrates on managerial application of power forward curves, and examines the determinants of electricity prices such as transmission constraints, its inability to be stored in a conventional way, its seasonality and weather dependence, the generation stack, and the swing risk. The electricity forward curve, classical arbitrage, constructing a forward curve, volatilities, and electricity forward curve models such as the jump-diffusion model, the mean-reverting heteroscedastic volatility model, and an econometric model of forward prices are examined. A managerial perspective of the applications of the forward curve is presented covering plant valuation, capital budgeting, performance measurement, product pricing and structuring, asset optimisation, valuation of transmission options, and risk management

Communicating projected survival with treatments for chronic kidney disease: patient comprehension and perspectives on visual aids.

Science.gov (United States)

Dowen, Frances; Sidhu, Karishma; Broadbent, Elizabeth; Pilmore, Helen

2017-09-21

Mortality in end stage renal disease (ESRD) is higher than many malignancies. There is no data about the optimal way to present information about projected survival to patients with ESRD. In other areas, graphs have been shown to be more easily understood than narrative. We examined patient comprehension and perspectives on graphs in communicating projected survival in chronic kidney disease (CKD). One hundred seventy-seven patients with CKD were shown 4 different graphs presenting post transplantation survival data. Patients were asked to interpret a Kaplan Meier curve, pie chart, histogram and pictograph and answer a multi-choice question to determine understanding. We measured interpretation, usefulness and preference for the graphs. Most patients correctly interpreted the graphs. There was asignificant difference in the percentage of correct answers when comparing different graph types (p = 0.0439). The pictograph was correctly interpreted by 81% of participants, the histogram by 79%, pie chart by 77% and Kaplan Meier by 69%. Correct interpretation of the histogram was associated with educational level (p = 0.008) and inversely associated with age > 65 (p = 0.008). Of those who interpreted all four graphs correctly, there was an association with employment (p = 0.001) and New Zealand European ethnicity (p = 0.002). 87% of patients found the graphs useful. The pie chart was the most preferred graph (p 0.002). The readability of the graphs may have been improved with an alternative colour choice, especially in the setting of visual impairment. Visual aids, can be beneficial adjuncts to discussing survival in CKD.

Aplicación y técnicas del análisis de supervivencia en las investigaciones clínicas Application and techniques of survival analysis in clinical research

Directory of Open Access Journals (Sweden)

Anissa Gramatges Ortiz

2002-08-01

Full Text Available Se realizó una actualización sobre el análisis de supervivencia en las investigaciones clínicas. Se expusieron algunos de los conceptos más generales sobre este tipo de análisis y las características de los tiempos de supervivencia.Se abordan temas relacionados con los diferentes métodos que facilitan la estimación de las probabilidades de supervivencia para uno o más grupos de individuos, con la ejemplificación del cálculo de las probabilidades para el método de Kaplan-Meier. Se destaca la comparación de la supervivencia de varios grupos atendiendo a distintos factores que los diferencian, así como también se enuncian algunas de las pruebas estadísticas que nos posibilitan la comparación, como son la prueba log rank y la Breslow, como alternativa de esta cuando se evidencia una divergencia del azar proporcional, es decir, cuando las curvas de supe DE SUPERVI rvivencia se cruzanconcepts of this type of analyses and the characteristics of survival times were presented. Aspects related with the different methods facilitating the estimation of survival probabilities for one or more groups of subjects, including the example of calculation of Kaplan Meier method´s probabilities were dealt with . The survival rates of several groups were compared, taking into consideration various factors that differentiate them. Some of the statistical tests making the comparison possible such as log rank test, and the Breslow test as an alternative of the former when there is a proportional random divergence, that is, when survival curves cross were stated

Endolymphatic sac surgery versus tenotomy of the stapedius and tensor tympani muscles in the management of patients with unilateral definite Meniere's disease.

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Albu, Silviu; Babighian, Gregorio; Amadori, Maurizio; Trabalzini, Franco

2015-12-01

This study aims to compare the outcomes of patients with Meniere's disease submitted to either endolymphatic mastoid shunt (ES) or tenotomy of the stapedius and tensor tympani muscles (TSTM). This is a retrospective chart review of patients treated with ES or TSTM between 2000 and 2010 and followed up for at least 12 months. The main outcomes were represented by: (1) vertigo class, hearing stage and functional level according to the American Academy of Otolaryngology-Head and Neck Surgery criteria; (2) adjustment of dizziness handicap inventory (DHI) and (3) complete and substantial vertigo control using the Kaplan-Meier survival method. Sixty-three patients met the inclusion criteria: 34 underwent ES and 29 TSTM. The baseline demographic characteristics, the hearing stage, the functional level, the DHI and hearing levels were not different between the two groups. No significant difference in vertigo class was demonstrated: 66 % of TSTM patients attained class A compared to 44 % in the ES group (p = 0.14). Kaplan-Meier survival curves specific to class A showed significant differences, favoring TSTM (log-rank test, p = 0.022). TSTM patients demonstrated significantly improved functional level (p = 0.0004) and improved DHI scores (p = 0.001). Eight ES patients (25 %) demanded a second surgical attempt compared to none in the TSTM. Aural fullness was significantly improved in TSTM group (p = 0.01), while the difference in tinnitus improvement was non-significant. Hearing preservation was significantly better in TSTM group (p = 0.001). TSTM is a safe surgical procedure, with significant vertigo control rates, and important hearing preservation rates. More patients and longer follow-up are needed to support our preliminary findings.

Survival and mortality among users and non-users of hydroxyurea with sickle cell disease.

Science.gov (United States)

de Araujo, Olinda Maria Rodrigues; Ivo, Maria Lúcia; Ferreira Júnior, Marcos Antonio; Pontes, Elenir Rose Jardim Cury; Bispo, Ieda Maria Gonçalves Pacce; de Oliveira, Eveny Cristine Luna

2015-01-01

to estimate survival, mortality and cause of death among users or not of hydroxyurea with sickle cell disease. cohort study with retrospective data collection, from 1980 to 2010 of patients receiving inpatient treatment in two Brazilian public hospitals. The survival probability was determined using the Kaplan-Meier estimator, survival calculations (SPSS version 10.0), comparison between survival curves, using the log rank method. The level of significance was p=0.05. of 63 patients, 87% had sickle cell anemia, with 39 using hydroxyurea, with a mean time of use of the drug of 20.0±10.0 years and a mean dose of 17.37±5.4 to 20.94±7.2 mg/kg/day, raising the fetal hemoglobin. In the comparison between those using hydroxyurea and those not, the survival curve was greater among the users (p=0.014). A total of 10 deaths occurred, with a mean age of 28.1 years old, and with Acute Respiratory Failure as the main cause. the survival curve is greater among the users of hydroxyurea. The results indicate the importance of the nurse incorporating therapeutic advances of hydroxyurea in her care actions.

Application of the standard lymphadenectomy in gastric adenocarcinoma

International Nuclear Information System (INIS)

Aguirre Fernandez, Roberto Eduardo; LLera Dominguez, Gerardo de la; Pennon Guerra, Maria; Alvarez Perez, Alvaro

2011-01-01

The 5-years postoperative survival of 132 patients operated on due to gastric adenocarcinoma that underwent lymphadenectomy of the two first ganglionic levels. The results of the epidemiological parameters were determined and the survival by Kaplan-Meier method was defined

J-resistance curves for Inconel 690 and Incoloy 800 nuclear steam generators tubes at room temperature and at 300 °C

Energy Technology Data Exchange (ETDEWEB)

Bergant, Marcos A., E-mail: marcos.bergant@cab.cnea.gov.ar [Gerencia CAREM, Centro Atómico Bariloche (CNEA), Av. Bustillo 9500, San Carlos de Bariloche 8400 (Argentina); Yawny, Alejandro A., E-mail: yawny@cab.cnea.gov.ar [División Física de Metales, Centro Atómico Bariloche (CNEA) / CONICET, Av. Bustillo 9500, San Carlos de Bariloche 8400 (Argentina); Perez Ipiña, Juan E., E-mail: juan.perezipina@fain.uncoma.edu.ar [Grupo Mecánica de Fractura, Universidad Nacional del Comahue / CONICET, Buenos Aires 1400, Neuquén 8300 (Argentina)

2017-04-01

The structural integrity of steam generator tubes is a relevant issue concerning nuclear plant safety. In the present work, J-resistance curves of Inconel 690 and Incoloy 800 nuclear steam generator tubes with circumferential and longitudinal through wall cracks were obtained at room temperature and 300 °C using recently developed non-standard specimens' geometries. It was found that Incoloy 800 tubes exhibited higher J-resistance curves than Inconel 690 for both crack orientations. For both materials, circumferential cracks resulted into higher fracture resistance than longitudinal cracks, indicating a certain degree of texture anisotropy introduced by the tube fabrication process. From a practical point of view, temperature effects have found to be negligible in all cases. The results obtained in the present work provide a general framework for further application to structural integrity assessments of cracked tubes in a variety of nuclear steam generator designs. - Highlights: •Non-standard fracture specimens were obtained from nuclear steam generator tubes. •Specimens with circumferential and longitudinal through-wall cracks were used. •Inconel 690 and Incoloy 800 steam generator tubes were tested at 24 and 300 °C. •Fracture toughness for circumferential cracks was higher than for longitudinal cracks. •Incoloy 800 showed higher fracture toughness than Inconel 690 steam generator tubes.

Intersection numbers of spectral curves

CERN Document Server

Eynard, B.

2011-01-01

We compute the symplectic invariants of an arbitrary spectral curve with only 1 branchpoint in terms of integrals of characteristic classes in the moduli space of curves. Our formula associates to any spectral curve, a characteristic class, which is determined by the laplace transform of the spectral curve. This is a hint to the key role of Laplace transform in mirror symmetry. When the spectral curve is y=\\sqrt{x}, the formula gives Kontsevich--Witten intersection numbers, when the spectral curve is chosen to be the Lambert function \\exp{x}=y\\exp{-y}, the formula gives the ELSV formula for Hurwitz numbers, and when one chooses the mirror of C^3 with framing f, i.e. \\exp{-x}=\\exp{-yf}(1-\\exp{-y}), the formula gives the Marino-Vafa formula, i.e. the generating function of Gromov-Witten invariants of C^3. In some sense this formula generalizes ELSV, Marino-Vafa formula, and Mumford formula.

Surface growth kinematics via local curve evolution

KAUST Repository

Moulton, Derek E.

2012-11-18

A mathematical framework is developed to model the kinematics of surface growth for objects that can be generated by evolving a curve in space, such as seashells and horns. Growth is dictated by a growth velocity vector field defined at every point on a generating curve. A local orthonormal basis is attached to each point of the generating curve and the velocity field is given in terms of the local coordinate directions, leading to a fully local and elegant mathematical structure. Several examples of increasing complexity are provided, and we demonstrate how biologically relevant structures such as logarithmic shells and horns emerge as analytical solutions of the kinematics equations with a small number of parameters that can be linked to the underlying growth process. Direct access to cell tracks and local orientation enables for connections to be made to the underlying growth process. © 2012 Springer-Verlag Berlin Heidelberg.

Treatment of primary tracheal carcinoma. The role of external and endoluminal radiotherapy

International Nuclear Information System (INIS)

Harms, W.; Wannenmacher, M.; Becker, H.; Herth, F.; Gagel, B.

2000-01-01

Background and Purpose: In a retrospective study the role of radiation therapy for the treatment of primary tracheal carcinoma was investigated. Patients and Methods: Between 1984 and 1997, 25 patients with primary tracheal carcinoma were treated with external beam radiotherapy (17 squamous-cell carcinoma [SCC], 8 adenoid cystic carcinoma [ACC], median dose SCC 60 Gy, ACC 55 Gy). An additional brachytherapy boost was carried out in 10/25 patients (median dose SCC 18 Gy, ACC 15 Gy). Ten patients underwent operative treatment. Results: The median survival (Kaplan-Meier) for patients with SCC was 33 months (ACC 94.2). The 1-, 2- and 5-year survival rates (Kaplan-Meier) for patients with SCC were 64.7% (ACC 85.7%), 64.7% (ACC 85.7%), and 26% (ACC 85.7%). Patients with ACC and patients with a complete remission after treatment had a significantly better survival probability (log rank test, p [de

Parental consanguineous marriages and clinical response to chemotherapy in locally advanced breast cancer patients.

Science.gov (United States)

Saadat, Mostafa; Khalili, Maryam; Omidvari, Shahpour; Ansari-Lari, Maryam

2011-03-28

The main aim of the present study was investigating the association between parental consanguinity and clinical response to chemotherapy in females affected with locally advanced breast cancer. A consecutive series of 92 patients were prospectively included in this study. Clinical assessment of treatment was accomplished by comparing initial tumor size with preoperative tumor size using revised RECIST guideline (version 1.1). Clinical response defined as complete response, partial response and no response. The Kaplan-Meier survival analysis were used to evaluate the association of parental marriages (first cousin vs unrelated marriages) and clinical response to chemotherapy (complete and partial response vs no response). Number of courses of chemotherapy was considered as time, in the analysis. Kaplan-Meier analysis revealed that offspring of unrelated marriages had poorer response to chemotherapy (log rank statistic=5.10, df=1, P=0.023). Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Comparative pathogenicity of Vibrio spp., Photobacterium damselae ssp. damselae and five isolates of Aeromonas salmonicida ssp. achromogenes in juvenile Atlantic halibut (Hippoglossus hippoglossus).

Science.gov (United States)

Bowden, T J; Bricknell, I R; Preziosi, B M

2018-01-01

Juvenile Atlantic halibut (~100 mg, Hippoglossus hippoglossus) were exposed to Vibrio proteolyticus, a Vibrio spp. isolate, Photobacterium damselae ssp. damselae and five different isolates of Aeromonas salmonicida ssp. achromogenes via an hour-long bath immersion to ascertain their variation in pathogenicity to this fish species. Results were analysed using Kaplan-Meier survival analysis. Analysis of the data from challenges using A. salmonicida ssp. achromogenes revealed three survival values of zero and a spread of values from 0 to 28.43. Challenges using a Vibrio spp isolate, V. proteolyticus and P. damselae resulted in Kaplan-Meier survival estimates of 31.21, 50.41 and 57.21, respectively. As all bacterial species tested could induce juvenile halibut mortalities, they must all be considered as potential pathogens. However, the degree of pathogenicity of A. salmonicida is isolate dependent. © 2017 John Wiley & Sons Ltd.

Effect of combination therapy with irradiation and ACNU on rectal cancer in mice

Energy Technology Data Exchange (ETDEWEB)

Suzuki, Masahiko; Nakajima, Atsushi; Kato, Koichiro; Eiraku, Hitoshi (Tokyo Medical Coll. (Japan))

1992-03-01

Colon 26, a transplantable strain of colon cancer, was implanted in BALB/C mice, and the effect of combination therapy with irradiation and ACNU on the mice was studied. Regional irradiation with 9 MeV electron beams was administered once without anesthetization, and ACNU was injected intraperitoneally. The 102 mice used as subjects were divided into 6 groups: nontreated group, 3 Gy irradiation group, 9 Gy irradiation group, 20 mg/kg ACNU group, 40 mg/kg ACNU group, and 3 Gy irradiation + 20 mg/kg ACNU group. Antitumor effects were evaluated based on survival time and inhibition of tumor volume growth, which were calculated from mean days of survival, Kaplan-Meier survival rate curves, and tumor volume growth curves, and the results were compared among these 6 groups. In addition, pathological and cytological studies were performed. As a result, antitumor effect was found to be significantly remarkable in the group receiving the combination of irradiation and ACNU compared to any other group given either irradiation or ACNU alone, suggesting that the antitumor effect of irradiation was potentiated by ACNU. (author).

Application of dissociation curve analysis to radiation hybrid panel marker scoring: generation of a map of river buffalo (B. bubalis chromosome 20

Directory of Open Access Journals (Sweden)

Schäffer Alejandro A

2008-11-01

Full Text Available Abstract Background Fluorescence of dyes bound to double-stranded PCR products has been utilized extensively in various real-time quantitative PCR applications, including post-amplification dissociation curve analysis, or differentiation of amplicon length or sequence composition. Despite the current era of whole-genome sequencing, mapping tools such as radiation hybrid DNA panels remain useful aids for sequence assembly, focused resequencing efforts, and for building physical maps of species that have not yet been sequenced. For placement of specific, individual genes or markers on a map, low-throughput methods remain commonplace. Typically, PCR amplification of DNA from each panel cell line is followed by gel electrophoresis and scoring of each clone for the presence or absence of PCR product. To improve sensitivity and efficiency of radiation hybrid panel analysis in comparison to gel-based methods, we adapted fluorescence-based real-time PCR and dissociation curve analysis for use as a novel scoring method. Results As proof of principle for this dissociation curve method, we generated new maps of river buffalo (Bubalus bubalis chromosome 20 by both dissociation curve analysis and conventional marker scoring. We also obtained sequence data to augment dissociation curve results. Few genes have been previously mapped to buffalo chromosome 20, and sequence detail is limited, so 65 markers were screened from the orthologous chromosome of domestic cattle. Thirty bovine markers (46% were suitable as cross-species markers for dissociation curve analysis in the buffalo radiation hybrid panel under a standard protocol, compared to 25 markers suitable for conventional typing. Computational analysis placed 27 markers on a chromosome map generated by the new method, while the gel-based approach produced only 20 mapped markers. Among 19 markers common to both maps, the marker order on the map was maintained perfectly. Conclusion Dissociation curve

MICA: Multiple interval-based curve alignment

Science.gov (United States)

Mann, Martin; Kahle, Hans-Peter; Beck, Matthias; Bender, Bela Johannes; Spiecker, Heinrich; Backofen, Rolf

2018-01-01

MICA enables the automatic synchronization of discrete data curves. To this end, characteristic points of the curves' shapes are identified. These landmarks are used within a heuristic curve registration approach to align profile pairs by mapping similar characteristics onto each other. In combination with a progressive alignment scheme, this enables the computation of multiple curve alignments. Multiple curve alignments are needed to derive meaningful representative consensus data of measured time or data series. MICA was already successfully applied to generate representative profiles of tree growth data based on intra-annual wood density profiles or cell formation data. The MICA package provides a command-line and graphical user interface. The R interface enables the direct embedding of multiple curve alignment computation into larger analyses pipelines. Source code, binaries and documentation are freely available at https://github.com/BackofenLab/MICA

Do clinical data and human papilloma virus genotype influence spontaneous regression in grade I cervical intraepithelial neoplasia?

Science.gov (United States)

Cortés-Alaguero, Caterina; González-Mirasol, Esteban; Morales-Roselló, José; Poblet-Martinez, Enrique

2017-03-15

To determine whether medical history, clinical examination and human papilloma virus (HPV) genotype influence spontaneous regression in cervical intraepithelial neoplasia grade I (CIN-I). We retrospectively evaluated 232 women who were histologically diagnosed as have CIN-I by means of Kaplan-Meier curves, the pattern of spontaneous regression according to the medical history, clinical examination, and HPV genotype. Spontaneous regression occurred in most patients and was influenced by the presence of multiple HPV genotypes but not by the HPV genotype itself. In addition, regression frequency was diminished when more than 50% of the cervix surface was affected or when an abnormal cytology was present at the beginning of follow-up. The frequency of regression in CIN-I is high, making long-term follow-up and conservative management advisable. Data from clinical examination and HPV genotyping might help to anticipate which lesions will regress.

Trends in adult leukemia incidence and survival in Denmark, 1943-2003

DEFF Research Database (Denmark)

Thygesen, Lau Caspar; Nielsen, Ove Juul; Johansen, Christoffer

2009-01-01

The etiology of leukemia is largely unknown. Ecological data indicating trends in incidence and survival can provide information about changes in risk factors, can reflect underlying changes in diagnostic classification, and can measure therapeutic advances. From the records of the Danish Cancer...... Registry with registration starting from 1943, we calculated age-specific, period-specific, and age-standardized (world standard) incidence rates of chronic lymphoid leukemia (CLL), acute lymphoid leukemia (ALL), chronic myeloid leukemia (CML), and acute myeloid leukemia (AML) for persons above the age...... of 18. Kaplan-Meier survival curves and median survival times were calculated. Between 1943 and 2003, there were 26,036 cases of leukemia reported. The age-specific incidence rates of CLL, CML, and AML were higher for older men and women, while the incidence rates of ALL by age were more homogeneous...

Measuring the success of combined intravesical dimethyl sulfoxide and triamcinolone for treatment of bladder pain syndrome/interstitial cystitis.

Science.gov (United States)

Gafni-Kane, Adam; Botros, Sylvia M; Du, Hongyan; Sand, Robert I; Sand, Peter K

2013-02-01

The purpose of this study was to investigate change in bladder capacity as a measure of response to combined intravesical dimethyl sulfoxide (DMSO) and triamcinolone instillations for the treatment of newly diagnosed bladder pain syndrome/interstitial cystitis (BPS/IC). 141 newly diagnosed women were identified retrospectively. 79 were treated with weekly DMSO/triamcinolone instillations. Change in bladder capacity with bladder retrofill, daytime urinary frequency, nocturia episodes per night, and Likert scale symptom scores were reviewed. Wilcoxon signed-rank tests, Wilcoxon rank-sum tests, Spearman's rank correlations, COX regression analysis, and a Kaplan-Meier survival curve were performed. Significant changes (median (25(th)-percentile to 75(th)-percentile) were noted for bladder capacity (75 mL (25 to 130 mL), p measure of response to intravesical DMSO/triamcinolone for newly diagnosed BPS/IC. Clinical outcomes do not differ based upon presence of DO.

Long-Term Safety of In Utero Exposure to Anti-TNFα Drugs for the Treatment of Inflammatory Bowel Disease

DEFF Research Database (Denmark)

Chaparro, M; Verreth, A; Lobaton, T

2018-01-01

OBJECTIVES: The long-term safety of exposure to anti-tumor necrosis factor (anti-TNFα) drugs during pregnancy has received little attention. We aimed to compare the relative risk of severe infections in children of mothers with inflammatory bowel disease (IBD) who were exposed to anti-TNFα drugs...... in utero with that of children who were not exposed to the drugs. METHODS: Retrospective multicenter cohort study. Exposed cohort: children from mothers with IBD receiving anti-TNFα medication (with or without thiopurines) at any time during pregnancy or during the 3 months before conception. Non......-exposed cohort: children from mothers with IBD not treated with anti-TNFα agents or thiopurines at any time during pregnancy or the 3 months before conception. The cumulative incidence of severe infections after birth was estimated using Kaplan-Meier curves, which were compared using the log-rank test. Cox...

Survival pathological prognosis factors in breast cancer

International Nuclear Information System (INIS)

Gonzalez-Longoria Boada, Lourdes B.

2012-01-01

A descriptive and longitudinal study of 273 women with breast cancer belonging to Granma province was carried out from 2003 to 2004, in order to analyze the survival of this female population, reason why the method of Kaplan Meier was used for the calculation of the mentioned variable and the Log Rank test was used for the comparison of curves. Patients with higher survival at 5 years were those who had tumors of 2 cm or less (87.5%), histological grade I (90.3%), nuclear grade I (88.3%), as well as the absence of vascular, lymphatic or lymph node invasion (with 80.6; 74.9 and 6.1% respectively). Also, tumor size, histological and nuclear grade, nodal status, as well as lymphatic and vascular invasion constituted prognosis factors, which favored the individualization of therapeutic behaviors

Treatment-dependent and treatment-independent risk factors associated with the risk of diabetes-related events

DEFF Research Database (Denmark)

Wilke, Thomas; Mueller, Sabrina; Groth, Antje

2015-01-01

BACKGROUND: The aim of this study was to analyse which factors predict the real-world macro-/microvascular event, hospitalisation and death risk in patients with type 2 diabetes mellitus. Furthermore, we aimed to investigate whether there exists both an under- and over-treatment risk...... of these patients. METHODS: We used a German claims/clinical data set covering the years 2010-12. Diabetes-related events were defined as (1) macro-, (2) microvascular events leading to inpatient hospitalisation, (3) other hospitalisations with type 2 diabetes mellitus as main diagnosis, (4) all-cause death and (5......) a composite outcome including all event categories 1-4. Factors associated with event risk were analysed by a Kaplan-Meier curve analysis and by multivariable Cox regression models. RESULTS: 229,042 patients with type 2 diabetes mellitus (mean age 70.2 years; mean CCI 6.03) were included. Among factors...

Carbonic anhydrase IX and response to postmastectomy radiotherapy in high-risk breast cancer: a subgroup analysis of the DBCG82 b and c trials

DEFF Research Database (Denmark)

Kyndi, M.; Sorensen, F.B.; Alsner, J.

2008-01-01

-points were loco-regional recurrence, distant metastases, disease-specific survival and overall survival. Statistical analyses included kappa statistics, chi(2) or exact tests, Kaplan-Meier probability plots, Log-rank test and Cox regression analyses. Results CA IX was assessable in 945 cores. The percentage...

Modelling the survivorship of Nigeria children in their first 10 years of ...

African Journals Online (AJOL)

Fagbamigbe

Conflict of Interest: Authors declared no conflict of interest ... Keywords: Survivorship, Nigeria, children mortality, Kaplan Meier, Brass Indirect method, Prediction ... variables or sex of older siblings, post- neonatal mortality is 12% higher and 2nd ... Relationship between maternal education and child survival in developing ...

Haloperidol versus second-generation antipsychotics in the long-term treatment of schizophrenia.

Science.gov (United States)

Buoli, Massimiliano; Kahn, René S; Serati, Marta; Altamura, A Carlo; Cahn, Wiepke

2016-07-01

The purpose of the study was to compare antipsychotic monotherapies in terms of time to discontinuation in a sample of schizophrenia patients followed-up for 36 months. Two hundred and twenty schizophrenia patients, treated with antipsychotic monotherapy and followed-up in psychiatric outpatient clinics of Universities of Milan and Utrecht were included in the study. A survival analysis (Kaplan-Meier) of the 36-month follow-up period was performed to compare the single treatment groups. End-point was considered as discontinuation of treatment for recurrence, side effects or non-compliance. Patients treated with haloperidol discontinued more than the other groups (Breslow: risperidone p haloperidol group than in the olanzapine group (p haloperidol group than with olanzapine (p haloperidol. In addition, atypical antipsychotics seem to be more protective against recurrences than haloperidol. However, these results should be cautiously interpreted in the light of potential confounder factors such as duration of illness. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Unsteady numerical simulation of the flow in the U9 Kaplan turbine model

International Nuclear Information System (INIS)

Javadi, Ardalan; Nilsson, Håkan

2014-01-01

The Reynolds-averaged Navier-Stokes equations with the RNG k-ε turbulence model closure are utilized to simulate the unsteady turbulent flow throughout the whole flow passage of the U9 Kaplan turbine model. The U9 Kaplan turbine model comprises 20 stationary guide vanes and 6 rotating blades (696.3 RPM), working at best efficiency load (0.71 m 3 /s). The computations are conducted using a general finite volume method, using the OpenFOAM CFD code. A dynamic mesh is used together with a sliding GGI interface to include the effect of the rotating runner. The clearance is included in the guide vane. The hub and tip clearances are also included in the runner. An analysis is conducted of the unsteady behavior of the flow field, the pressure fluctuation in the draft tube, and the coherent structures of the flow. The tangential and axial velocity distributions at three sections in the draft tube are compared against LDV measurements. The numerical result is in reasonable agreement with the experimental data, and the important flow physics close to the hub in the draft tube is captured. The hub and tip vortices and an on-axis forced vortex are captured. The numerical results show that the frequency of the forced vortex in 1/5 of the runner rotation

Unsteady numerical simulation of the flow in the U9 Kaplan turbine model

Science.gov (United States)

Javadi, Ardalan; Nilsson, Håkan

2014-03-01

The Reynolds-averaged Navier-Stokes equations with the RNG k-ε turbulence model closure are utilized to simulate the unsteady turbulent flow throughout the whole flow passage of the U9 Kaplan turbine model. The U9 Kaplan turbine model comprises 20 stationary guide vanes and 6 rotating blades (696.3 RPM), working at best efficiency load (0.71 m3/s). The computations are conducted using a general finite volume method, using the OpenFOAM CFD code. A dynamic mesh is used together with a sliding GGI interface to include the effect of the rotating runner. The clearance is included in the guide vane. The hub and tip clearances are also included in the runner. An analysis is conducted of the unsteady behavior of the flow field, the pressure fluctuation in the draft tube, and the coherent structures of the flow. The tangential and axial velocity distributions at three sections in the draft tube are compared against LDV measurements. The numerical result is in reasonable agreement with the experimental data, and the important flow physics close to the hub in the draft tube is captured. The hub and tip vortices and an on-axis forced vortex are captured. The numerical results show that the frequency of the forced vortex in 1/5 of the runner rotation.

Survey, design, development, and installation of micro hydel power generation

International Nuclear Information System (INIS)

Ijaz, M.

2011-01-01

This paper presents the survey, design, development and installation Of micro hydel power generation using low head Kaplan water turbine. Electricity production from hydro power has been and still is today, the first renewable source used to generate electricity. The development of energy from renewable is very important step in reduction of carbon emissions(CO/sub 2/).

Survival analysis II: Cox regression

NARCIS (Netherlands)

Stel, Vianda S.; Dekker, Friedo W.; Tripepi, Giovanni; Zoccali, Carmine; Jager, Kitty J.

2011-01-01

In contrast to the Kaplan-Meier method, Cox proportional hazards regression can provide an effect estimate by quantifying the difference in survival between patient groups and can adjust for confounding effects of other variables. The purpose of this article is to explain the basic concepts of the

STAT3 inhibitor enhances chemotherapy drug efficacy by ...

African Journals Online (AJOL)

Immunohistochemistry and Kaplan-Meier method of survival analysis were used to determine chemoresistance trends in patients. STAT3 inhibitor treatment, RNAi or ectopic overexpression of STAT3 or MUC1 in NSCLC cells were used to determine their inter-molecular relation and for modulating stemness-related genes.

The influence of obesity on response to tumour necrosis factor-α inhibitors in psoriatic arthritis

DEFF Research Database (Denmark)

Højgaard, Pil; Glintborg, Bente; Kristensen, Lars Erik

2016-01-01

OBJECTIVES: To investigate the impact of obesity on response to the first TNF-α inhibitor (TNFI) treatment course in patients with PsA followed in routine care. METHODS: We performed an observational cohort study based on the Danish and Icelandic biologics registries. Kaplan-Meier plots, Cox and ...

Is there racial/ethnic variance in cervical cancer- specific survival of ...

African Journals Online (AJOL)

incident cervical carcinoma, between 1992 and 1999, in the Surveillance Epidemiology and End Results (SEER) Data was linked with Medicare to examine the impact of race/ethnicity on overall and cancer-specific survival, using Kaplan Meier survival estimates and multivariable Cox Regression model. Results: There was ...

Survival Analysis of Patients with End Stage Renal Disease

Science.gov (United States)

Urrutia, J. D.; Gayo, W. S.; Bautista, L. A.; Baccay, E. B.

2015-06-01

This paper provides a survival analysis of End Stage Renal Disease (ESRD) under Kaplan-Meier Estimates and Weibull Distribution. The data were obtained from the records of V. L. MakabaliMemorial Hospital with respect to time t (patient's age), covariates such as developed secondary disease (Pulmonary Congestion and Cardiovascular Disease), gender, and the event of interest: the death of ESRD patients. Survival and hazard rates were estimated using NCSS for Weibull Distribution and SPSS for Kaplan-Meier Estimates. These lead to the same conclusion that hazard rate increases and survival rate decreases of ESRD patient diagnosed with Pulmonary Congestion, Cardiovascular Disease and both diseases with respect to time. It also shows that female patients have a greater risk of death compared to males. The probability risk was given the equation R = 1 — e-H(t) where e-H(t) is the survival function, H(t) the cumulative hazard function which was created using Cox-Regression.

Medicaid Enrollment Gap Length and Number of Medicaid Enrollment Periods Among US Children

Science.gov (United States)

Schoendorf, Kenneth C.

2014-01-01

Objectives. We examined gap length, characteristics associated with gap length, and number of enrollment periods among Medicaid-enrolled children in the United States. Methods. We linked the 2004 National Health Interview Survey to Medicaid Analytic eXtract files for 1999 through 2008. We examined linkage-eligible children aged 5 to 13 years in the 2004 National Health Interview Survey who disenrolled from Medicaid. We generated Kaplan-Meier curves of time to reenrollment. We used Cox proportional hazards models to assess the effect of sociodemographic variables on time to reenrollment. We compared the percentage of children enrolled 4 or more times across sociodemographic groups. Results. Of children who disenrolled from Medicaid, 35.8%, 47.1%, 63.5%, 70.8%, and 79.1% of children had reenrolled in Medicaid by 6 months, 1, 3, 5, and 10 years, respectively. Children who were younger, poorer, or of minority race/ethnicity or had lower educated parents had shorter gaps in Medicaid and were more likely to have had 4 or more Medicaid enrollment periods. Conclusions. Nearly half of US children who disenrolled from Medicaid reenrolled within 1 year. Children with traditionally high-risk demographic characteristics had shorter gaps in Medicaid enrollment and were more likely to have more periods of Medicaid enrollment. PMID:25033135

Urbanization factors associated with childhood asthma and prematurity: a population-based analysis aged from 0 to 5 years in Taiwan by using Cox regression within a hospital cluster model.

Science.gov (United States)

Lin, Sheng-Chieh; Lin, Hui-Wen

2015-04-01

Childhood asthma and premature birth are both common; however, no studies have reported urbanization association between asthma and prematurity and the duration of prematurity affect asthma development. We use Taiwan Longitudinal Health Insurance Database (LHID) to explore association between asthma and prematurity among children by using a population-based analysis. This is a retrospective cohort study with registration data derived from Taiwan LHID. We evaluated prematurely born infants and children aged prematurely and 13 851 (40.27 per 1000 person-years) controls. The hazard ratio for asthma during 5-year follow-up period was 1.95 (95% confidence interval = 1.67-2.28) among children born prematurely. Boys born prematurely aged 0-2 years were associated with higher asthma rates compared with girls in non-premature and premature groups. Living in urban areas, those born prematurely were associated with higher rates of asthma compared with non-prematurity. Those born prematurely lived in northern region had higher asthma hazard ratio than other regions. Our analyses indicated that sex, age, urbanization level, and geographic region are significantly associated with prematurity and asthma. Based on cumulative asthma-free survival curve generated using the Kaplan-Meier method, infants born prematurely should be closely monitored to see if they would develop asthma until the age of 6 years.

Prevalence and mortality of cancer among HIV-infected inpatients in Beijing, China.

Science.gov (United States)

Yang, Jun; Su, Shu; Zhao, Hongxin; Wang, Dennis; Wang, Jiali; Zhang, Fujie; Zhao, Yan

2016-02-16

Cancer is responsible for elevated HIV-related morbidity and mortality. Research on HIV-infected patients with concurrent cancer is rare in China. The purpose of our study was to investigate the prevalence and risk factors associated with cancer among HIV-infected inpatients in Beijing, and to investigate the mortality and risk factors among HIV-infected inpatients with cancer. Hospital records from a total of 1946 HIV-infected patients were collected from the Beijing Ditan Hospital. The data, from 2008 to 2013, were collected retrospectively. The cancer diagnoses included AIDS-defining cancers (ADC) and non-AIDS defining cancers (NADC). Logistic regression was used to identify risk factors predicting the concurrence of cancer with HIV. Mortality was examined using Kaplan-Meier estimates and Cox proportional hazards models. 7.7 % (149 cases) of all HIV-infected inpatients had concurrent cancer at their first hospital admission; of those, 33.6 % (50 cases) had ADCs, and 66.4 % (99 cases) had NADCs. The most prevalent NADCs were Hodgkin's lymphoma, gastrointestinal cancer, liver cancer, and lung cancer. Patients who did not accept antiretroviral therapy (ART) were more likely to suffer from cancer [AOR = 2.07 (1.42-3.01), p = 0.001]. Kaplan-Meier curves indicated that the survival probability of HIV-positive cancer patients was significantly lower than that of HIV-positive cancer-free patients (log-rank test, p cancer, the mortality was also higher among those who did not receive ART [AHR = 2.19 (1.84-2.61), p cancer concurrence among hospitalized HIV-infected patients was 7.7 %. Concurrent cancer also increased mortality among HIV-infected patients. ART was protective against concurrent cancer as well as mortality among HIV-infected cancer patients. These results highlight the importance of promoting cancer screening and early ART initiation among HIV-infected patients.

Exclusive breastfeeding duration and determinants among Brazilian children under two years of age

Directory of Open Access Journals (Sweden)

Sarah Warkentin

2013-06-01

Full Text Available OBJECTIVE: The present study described the duration and identified the determinants of exclusive breastfeeding. METHODS: The study used data from the Pesquisa Nacional de Demografia e Saúde da Criança e da Mulher 2006 (National Demographic and Health Survey on Women and Children 2006. Data were collected using questionnaires administered by trained professionals and refer to a subsample of 1,704 children aged less than 24 months. The estimated durations of exclusive breastfeeding are presented according to socioeconomic, demographic and epidemiological variables. Kaplan Meier estimator curves were used to produce valid estimates of breastfeeding duration and the Cox's proportional hazards model was fitted to identify risks. RESULTS: The median estimated duration of exclusive breastfeeding was 60 days. The final Cox model consisted of mother's age <20 years (hazard ratio=1.53, 95% confidence interval=1.11-1.48, use of pacifier (hazard ratio=1.53, 95% confidence interval=1.37-1.71, not residing in the country's southeast region (hazard ratio=1.22, 95% confidence interval=1.07-1.40 and socioeconomic status (hazard ratio=1.28, 95% confidence interval=1.06-1.55. CONCLUSION: The Kaplan Meier estimator corrected the underestimated duration of breastfeeding in the country when calculated by the current status methodology. Despite the national efforts done in the last decades to promote breastfeeding, the results indicate that the duration of exclusive breastfeeding is still half of that recommended for this dietary practice to promote health. Ways to revert this situation would be ongoing educational activities involving the educational and health systems, associated with advertising campaigns on television and radio mainly targeting young mothers with low education level and low income, identified as those at high risk of weaning their children early.

Heart transplant outcomes in recipients of Centers for Disease Control (CDC) high risk donors.

Science.gov (United States)

Tsiouris, Athanasios; Wilson, Lynn; Sekar, Rajesh B; Mangi, Abeel A; Yun, James J

2016-12-01

A lack of donor hearts remains a major limitation of heart transplantation. Hearts from Centers for Disease Control (CDC) high-risk donors can be utilized with specific recipient consent. However, outcomes of heart transplantation with CDC high-risk donors are not well known. We sought to define outcomes, including posttransplant hepatitis and human immunodeficiency virus (HIV) status, in recipients of CDC high-risk donor hearts at our institution. All heart transplant recipients from August 2010 to December 2014 (n = 74) were reviewed. Comparison of 1) CDC high-risk donor (HRD) versus 2) standard-risk donor (SRD) groups were performed using chi-squared tests for nominal data and Wilcoxon two-sample tests for continuous variables. Survival was estimated with Kaplan-Meier curves. Of 74 heart transplant recipients reviewed, 66 (89%) received a SRD heart and eight (11%) received a CDC HRD heart. We found no significant differences in recipient age, sex, waiting list 1A status, pretransplant left ventricular assist device (LVAD) support, cytomegalovirus (CMV) status, and graft ischemia times (p = NS) between the HRD and SRD groups. All of the eight HRD were seronegative at the time of transplant. Postoperatively, there was no significant difference in rejection rates at six and 12 months posttransplant. Importantly, no HRD recipients acquired hepatitis or HIV. Survival in HRD versus SRD recipients was not significantly different by Kaplan-Meier analysis (log rank p = 0.644) at five years posttransplant. Heart transplants that were seronegative at the time of transplant had similar posttransplant graft function, rejection rates, and five-year posttransplant survival versus recipients of SRD hearts. At our institution, no cases of hepatitis or HIV occurred in HRD recipients in early follow-up. © 2016 Wiley Periodicals, Inc.

A prospective observational study comparing a physiological scoring system with time-based discharge criteria in pediatric ambulatory surgical patients.

Science.gov (United States)

Armstrong, James; Forrest, Helen; Crawford, Mark W

2015-10-01

Discharge criteria based on physiological scoring systems can be used in the postanesthesia care unit (PACU) to fast-track patients after ambulatory surgery; however, studies comparing physiological scoring systems with traditional time-based discharge criteria are lacking. The purpose of this study was to compare PACU discharge readiness times using physiological vs time-based discharge criteria in pediatric ambulatory surgical patients. We recorded physiological observations from consecutive American Society of Anesthesiologists physical status I-III patients aged 1-18 yr who were admitted to the PACU after undergoing ambulatory surgery in a tertiary academic pediatric hospital. The physiological score was a combination of the Aldrete and Chung systems. Scores were recorded every 15 min starting upon arrival in the PACU. Patients were considered fit for discharge once they attained a score ≥12 (maximum score, 14), provided no score was zero, with the time to achieve a score ≥12 defining the criteria-based discharge (CBD) time. Patients were discharged from the PACU when both the CBD and the existing time-based discharge (TBD) criteria were met. The CBD and TBD data were compared using Kaplan-Meier and log-rank analysis. Observations from 506 children are presented. Median (interquartile range [IQR]) age was 5.5 [2.8-9.9] yr. Median [IQR] CBD and TBD PACU discharge readiness times were 30 [15-45] min and 60 [45-60] min, respectively. Analysis of Kaplan-Meier curves indicated a significant difference in discharge times using the different criteria (hazard ratio, 5.43; 95% confidence interval, 4.51 to 6.53; P < 0.001). All patients were discharged home without incident. This prospective study suggests that discharge decisions based on physiological criteria have the potential for significantly speeding the transit of children through the PACU, thereby enhancing PACU efficiency and resource utilization.

Lymph node density as a prognostic predictor in patients with betel nut-related oral squamous cell carcinoma.

Science.gov (United States)

Chang, Wei-Chin; Lin, Chun-Shu; Yang, Cheng-Yu; Lin, Chih-Kung; Chen, Yuan-Wu

2018-04-01

Lymph node metastasis in oral squamous cell carcinoma (OSCC) is a poor prognostic factor. The histopathologic stage (e.g., pN) is used to evaluate the severity of lymph node metastasis; however, the current staging system insufficiently predicts survival and recurrence. We investigated clinical outcomes and lymph node density (LND) in betel nut-chewing individuals. We retrospectively analyzed 389 betel nut-exposed patients with primary OSCC who underwent surgical resection in 2002-2015. The prognostic significance of LND was evaluated by overall survival (OS) and disease-free survival (DFS) using the Kaplan-Meier method. Kaplan-Meier analyses showed that the 5-year OS and DFS rates in all patients were 60.9 and 48.9%, respectively. Multivariate analysis showed that variables independently prognostic for OS were aged population (hazard ratio [HR] = 1.6, 95% confidence interval [95% CI] = 1.1-2.5; P = .025), and cell differentiation classification (HR = 2.4, 95% CI = 1.4-4.2; P = .002). In pathologic N-positive patients, a receiver operating characteristic (ROC) curve for OS was used and indicated the best cutoff of 0.05, and the multivariate analysis showed that LND was an independent predictor of OS (HR = 2.2, 95% CI = 1.3-3.7; P = .004). Lymph node density, at a cutoff of 0.05, was an independent predictor of OS and DFS. OS and DFS underwent multiple analyses, and LND remained significant. The pathologic N stage had no influence in the OS analysis. LND is a more reliable predictor of survival in betel nut-chewing patients for further post operation adjuvant treatment, such as reoperation or adjuvant radiotherapy.

Statins Reduces the Risk of Dementia in Patients with Late-Onset Depression: A Retrospective Cohort Study.

Science.gov (United States)

Yang, Ya-Hsu; Teng, Hao-Wei; Lai, Yen-Ting; Li, Szu-Yuan; Lin, Chih-Ching; Yang, Albert C; Chan, Hsiang-Lin; Hsieh, Yi-Hsuan; Lin, Chiao-Fan; Hsu, Fu-Ying; Liu, Chih-Kuang; Liu, Wen-Sheng

2015-01-01

Patients with late-onset depression (LOD) have been reported to run a higher risk of subsequent dementia. The present study was conducted to assess whether statins can reduce the risk of dementia in these patients. We used the data from National Health Insurance of Taiwan during 1996-2009. Standardized Incidence Ratios (SIRs) were calculated for LOD and subsequent dementia. The criteria for LOD diagnoses included age ≥65 years, diagnosis of depression after 65 years of age, at least three service claims, and treatment with antidepressants. The time-dependent Cox proportional hazards model was applied for multivariate analyses. Propensity scores with the one-to-one nearest-neighbor matching model were used to select matching patients for validation studies. Kaplan-Meier curve estimate was used to measure the group of patients with dementia living after diagnosis of LOD. Totally 45,973 patients aged ≥65 years were enrolled. The prevalence of LOD was 12.9% (5,952/45,973). Patients with LOD showed to have a higher incidence of subsequent dementia compared with those without LOD (Odds Ratio: 2.785; 95% CI 2.619-2.958). Among patients with LOD, lipid lowering agent (LLA) users (for at least 3 months) had lower incidence of subsequent dementia than non-users (Hazard Ratio = 0.781, 95% CI 0.685-0.891). Nevertheless, only statins users showed to have reduced risk of dementia (Hazard Ratio = 0.674, 95% CI 0.547-0.832) while other LLAs did not, which was further validated by Kaplan-Meier estimates after we used the propensity scores with the one-to-one nearest-neighbor matching model to control the confounding factors. Statins may reduce the risk of subsequent dementia in patients with LOD.

Chemokine-like factor-like MARVEL transmembrane domain-containing 3 expression is associated with a favorable prognosis in esophageal squamous cell carcinoma.

Science.gov (United States)

Han, Tianci; Shu, Tianci; Dong, Siyuan; Li, Peiwen; Li, Weinan; Liu, Dali; Qi, Ruiqun; Zhang, Shuguang; Zhang, Lin

2017-05-01

Decreased expression of human chemokine-like factor-like MARVEL transmembrane domain-containing 3 (CMTM3) has been identified in a number of human tumors and tumor cell lines, including gastric and testicular cancer, and PC3, CAL27 and Tca-83 cell lines. However, the association between CMTM3 expression and the clinicopathological features and prognosis of esophageal squamous cell carcinoma (ESCC) patients remains unclear. The aim of the present study was to investigate the correlation between CMTM3 expression and clinicopathological parameters and prognosis in ESCC. CMTM3 mRNA and protein expression was analyzed in ESCC and paired non-tumor tissues by quantitative real-time polymerase chain reaction, western blotting and immunohistochemical analysis. The Kaplan-Meier method was used to plot survival curves and the Cox proportional hazards regression model was also used for univariate and multivariate survival analysis. The results revealed that CMTM3 mRNA and protein expression levels were lower in 82.5% (30/40) and 75% (30/40) of ESCC tissues, respectively, when compared with matched non-tumor tissues. Statistical analysis demonstrated that CMTM3 expression was significantly correlated with lymph node metastasis (P=0.002) and clinical stage (P<0.001) in ESCC tissues. Furthermore, the survival time of ESCC patients exhibiting low CMTM3 expression was significantly shorter than that of ESCC patients exhibiting high CMTM3 expression (P=0.01). In addition, Kaplan-Meier survival analysis revealed that the overall survival time of patients exhibiting low CMTM3 expression was significantly decreased compared with patients exhibiting high CMTM3 expression (P=0.010). Cox multivariate analysis indicated that CMTM3 protein expression was an independent prognostic predictor for ESCC after resection. This study indicated that CMTM3 expression is significantly decreased in ESCC tissues and CMTM3 protein expression in resected tumors may present an effective prognostic

ITGA3 and ITGB4 expression biomarkers estimate the risks of locoregional and hematogenous dissemination of oral squamous cell carcinoma

International Nuclear Information System (INIS)

Nagata, Masaki; Takahashi, Katsu; Kodama, Naoki; Kawase, Tomoyuki; Hoshina, Hideyuki; Ikeda, Nobuyuki; Shingaki, Susumu; Takagi, Ritsuo; Noman, Arhab A; Suzuki, Kenji; Kurita, Hiroshi; Ohnishi, Makoto; Ohyama, Tokio; Kitamura, Nobutaka; Kobayashi, Takanori; Uematsu, Kohya

2013-01-01

Molecular biomarkers are essential for monitoring treatment effects, predicting prognosis, and improving survival rate in oral squamous cell carcinoma. This study sought to verify the effectiveness of two integrin gene expression ratios as biomarkers. Gene expression analyses of integrin α3 (ITGA3), integrin β4 (ITGB4), CD9 antigen (CD9), and plakoglobin (JUP) by quantitative real-time PCR were conducted on total RNA from 270 OSCC cases. The logrank test, Cox proportional hazards model, and Kaplan-Meier estimates were performed on the gene expression ratios of ITGA3/CD9 and ITGB4/JUP and on the clinicopathological parameters for major clinical events. A high rate (around 80%) of lymph node metastasis was found in cases with a high ITGA3/CD9 ratio (high-ITGA3/CD9) and invasive histopathology (YK4). Primary site recurrence (PSR) was associated with high-ITGA3/CD9, T3-4 (TNM class), and positive margin, indicating that PSR is synergistically influenced by treatment failure and biological malignancy. A high ITGB4/JUP ratio (high-ITGB4/JUP) was revealed to be a primary contributor to distant metastasis without the involvement of clinicopathological factors, suggesting intervention of a critical step dependent on the function of the integrin β4 subunit. Kaplan-Meier curves revealed positive margin as a lethal treatment consequence in high-ITGA3/CD9 and YK4 double-positive cases. Two types of metastatic trait were found in OSCC: locoregional dissemination, which was reflected by high-ITGA3/CD9, and distant metastasis through hematogenous dissemination, uniquely distinguished by high-ITGB4/JUP. The clinical significance of the integrin biomarkers implies that biological mechanisms such as cancer cell motility and anchorage-independent survival are vital for OSCC recurrence and metastasis

Assessing the effect of quantitative and qualitative predictors on gastric cancer individuals survival using hierarchical artificial neural network models.

Science.gov (United States)

Amiri, Zohreh; Mohammad, Kazem; Mahmoudi, Mahmood; Parsaeian, Mahbubeh; Zeraati, Hojjat

2013-01-01

There are numerous unanswered questions in the application of artificial neural network models for analysis of survival data. In most studies, independent variables have been studied as qualitative dichotomous variables, and results of using discrete and continuous quantitative, ordinal, or multinomial categorical predictive variables in these models are not well understood in comparison to conventional models. This study was designed and conducted to examine the application of these models in order to determine the survival of gastric cancer patients, in comparison to the Cox proportional hazards model. We studied the postoperative survival of 330 gastric cancer patients who suffered surgery at a surgical unit of the Iran Cancer Institute over a five-year period. Covariates of age, gender, history of substance abuse, cancer site, type of pathology, presence of metastasis, stage, and number of complementary treatments were entered in the models, and survival probabilities were calculated at 6, 12, 18, 24, 36, 48, and 60 months using the Cox proportional hazards and neural network models. We estimated coefficients of the Cox model and the weights in the neural network (with 3, 5, and 7 nodes in the hidden layer) in the training group, and used them to derive predictions in the study group. Predictions with these two methods were compared with those of the Kaplan-Meier product limit estimator as the gold standard. Comparisons were performed with the Friedman and Kruskal-Wallis tests. Survival probabilities at different times were determined using the Cox proportional hazards and a neural network with three nodes in the hidden layer; the ratios of standard errors with these two methods to the Kaplan-Meier method were 1.1593 and 1.0071, respectively, revealed a significant difference between Cox and Kaplan-Meier (P neural network, and the neural network and the standard (Kaplan-Meier), as well as better accuracy for the neural network (with 3 nodes in the hidden layer

Survival of Root-filled Teeth in the Swedish Adult Population

DEFF Research Database (Denmark)

Fransson, Helena; Dawson, Victoria S; Frisk, Fredrik

2016-01-01

INTRODUCTION: The aim was to assess survival in the Swedish population of teeth treated by nonsurgical root canal treatment during 2009. METHODS: Data from the Swedish Social Insurance Agency were analyzed by Kaplan-Meier analysis to assess cumulative tooth survival during a period of 5-6 years o...

Community Music during the New Deal: The Contributions of Willem Van de Wall and Max Kaplan

Science.gov (United States)

Krikun, Andrew

2010-01-01

Willem Van de Wall (1887-1953) and Max Kaplan (1911-98) built careers spanning music performance, music education, adult education, sociology, social work, music therapy and community music. Willem Van de Wall was a seminal influence on the development of the fields of music therapy and adult education--researching the role of music in…

Impact of BCL2 and p53 on postmastectomy radiotherapy response in high-risk breast cancer. A subgroup analysis of DBCG82 b and c

International Nuclear Information System (INIS)

Kyndi, M.; Alsner, J.; Nielsen, H.M.; Overgaard, J.; Soerensen, F.B.; Knudsen, H.; Overgaard, M.

2008-01-01

Purpose. To examine p53 and BCL2 expression in high-risk breast cancer patients randomized to postmastectomy radiotherapy (PMRT). Patients and methods. The present analysis included 1 000 of 3 083 high-risk breast cancer patients randomly assigned to PMRT in the DBCG82 b and c studies. Tissue microarray sections were stained with immunohistochemistry for p53 and BCL2. Median potential follow-up was 17 years. Clinical endpoints were locoregional recurrence (LRR), distant metastases (DM), overall mortality, and overall survival (OS). Statistical analyses included Kappa statistics, χ2 or exact tests, Kaplan-Meier probability plots, Log-rank test, and Cox univariate and multivariate regression analyses. Results. p53 accumulation was not significantly associated with increased overall mortality, DM or LRR probability in univariate or multivariate Cox regression analyses. Kaplan-Meier probability plots showed reduced OS and improved DM and LRR probabilities after PMRT within subgroups of both p53 negative and p53 positive patients. Negative BCL2 expression was significantly associated with increased overall mortality, DM and LRR probability in multivariate Cox regression analyses. Kaplan-Meier probability plots showed a significantly improved overall survival after PMRT for the BCL2 positive subgroup, whereas practically no survival improvement was seen after PMRT for the BCL2 negative subgroup. In multivariate analysis of OS, however, no significant interaction was found between BCL2 and randomization status. Significant reductions in LRR probability after PMRT were recorded within both the BCL2 positive and BCL2 negative subgroups. Conclusion. p53 was not associated with survival after radiotherapy in high-risk breast cancer, but BCL2 might be

Initial high anti-emetic efficacy of granisetron with dexamethasone is not maintained over repeated cycles.

Science.gov (United States)

de Wit, R.; van den Berg, H.; Burghouts, J.; Nortier, J.; Slee, P.; Rodenburg, C.; Keizer, J.; Fonteyn, M.; Verweij, J.; Wils, J.

1998-01-01

We have reported previously that the anti-emetic efficacy of single agent 5HT3 antagonists is not maintained when analysed with the measurement of cumulative probabilities. Presently, the most effective anti-emetic regimen is a combination of a 5HT3 antagonist plus dexamethasone. We, therefore, assessed the sustainment of efficacy of such a combination in 125 patients, scheduled to receive cisplatin > or = 70 mg m(-2) either alone or in combination with other cytotoxic drugs. Anti-emetic therapy was initiated with 10 mg of dexamethasone and 3 mg of granisetron intravenously, before cisplatin. On days 1-6, patients received 8 mg of dexamethasone and 1 mg of granisetron twice daily by oral administration. Protection was assessed during all cycles and calculated based on cumulative probability analyses using the method of Kaplan-Meier and a model for transitional probabilities. Irrespective of the type of analysis used, the anti-emetic efficacy of granisetron/dexamethasone decreased over cycles. The initial complete acute emesis protection rate of 66% decreased to 30% according to the method of Kaplan-Meier and to 39% using the model for transitional probabilities. For delayed emesis, the initial complete protection rate of 52% decreased to 21% (Kaplan-Meier) and to 43% (transitional probabilities). In addition, we observed that protection failure in the delayed emesis period adversely influenced the acute emesis protection in the next cycle. We conclude that the anti-emetic efficacy of a 5HT3 antagonist plus dexamethasone is not maintained over multiple cycles of highly emetogenic chemotherapy, and that the acute emesis protection is adversely influenced by protection failure in the delayed emesis phase. PMID:9652766

[Comparative evaluation of survival prognosis using MELD or Child-Pugh scores in patients with liver cirrhosis in Chile].

Science.gov (United States)

Sanhueza, Edgar; Contreras, Jorge; Zapata, Rodrigo; Sanhueza, Matías; Elgueta, Fabián; López, Constanza; Jerez, Sigrid; Jerez, Verónica; Delgado, Iris

2017-01-01

Currently, most liver units use the Child-Pugh (CP) or the Model for End-Stage Liver Disease (MELD) scores to establish survival prognosis among patients with liver cirrhosis. Which classification is superior, is not well defined. To compare CP and MELD classification scores to predict survival among adult patients with liver cirrhosis in Chile. Follow-up of 137 consecutive adult patients with liver cirrhosis aged 59 ± 12 years (55% women). The diagnosis was reached by clinical, laboratory and image studies at three different centers of Santiago. Patients were staged with CP and MELD classification scores at baseline and followed over a period of 12 months. The predictive capacity of the scores for survival was analyzed using a multivariate statistical analysis (Kaplan-Meier curves). The most common etiology was alcohol (37.9%). The actuarial survival rate was 79.6% at 12 months of follow-up. When comparing groups with areas under curve of receiver operating characteristic curves (AUROC), there was no statistically significant difference in survival between less severe and advanced disease, assessed with both survival scales. The AUROC for MELD and CP were 0.80 and 0.81, respectively. This clinical study did not find a statistically significant difference between the two classifications for the prediction of 12 months survival in patients with cirrhosis.

A crowdsourced nickel-and-dime approach to analog OBM research: A behavioral economic framework for understanding workforce attrition.

Science.gov (United States)

Henley, Amy J; DiGennaro Reed, Florence D; Reed, Derek D; Kaplan, Brent A

2016-09-01

Incentives are a popular method to achieve desired employee performance; however, research on optimal incentive magnitude is lacking. Behavioral economic demand curves model persistence of responding in the face of increasing cost and may be suitable to examine the reinforcing value of incentives on work performance. The present use-inspired basic study integrated an experiential human operant task within a crowdsourcing platform to evaluate the applicability of behavioral economics for quantifying changes in workforce attrition. Participants included 88 Amazon Mechanical Turk Workers who earned either a $0.05 or $0.10 incentive for completing a progressively increasing response requirement. Analyses revealed statistically significant differences in breakpoint between the two groups. Additionally, a novel translation of the Kaplan-Meier survival-curve analyses for use within a demand curve framework allowed for examination of elasticity of workforce attrition. Results indicate greater inelastic attrition in the $0.05 group. We discuss the benefits of a behavioral economic approach to modeling employee behavior, how the metrics obtained from the elasticity of workforce attrition analyses (e.g., P max ) may be used to set goals for employee behavior while balancing organizational costs, and how economy type may have influenced observed outcomes. © 2016 Society for the Experimental Analysis of Behavior.

The shape of the melting curve and phase transitions in the liquid state

International Nuclear Information System (INIS)

Yahel, Eyal

2014-01-01

The phase diagram of elemental liquids has been found to be surprisingly rich, including variations in the melting curve and transitions in the liquid phase. The effect of these transitions on the shape of the melting curve is reviewed and analyzed. First-order phase transitions intersecting the melting curve imply piecewise continuous melting curves, with solid-solid transitions generating upward kinks or minima and liquid-liquid transitions generating downward kinks or maxima

Spherical images and inextensible curved folding

Science.gov (United States)

Seffen, Keith A.

2018-02-01

In their study, Duncan and Duncan [Proc. R. Soc. London A 383, 191 (1982), 10.1098/rspa.1982.0126] calculate the shape of an inextensible surface folded in two about a general curve. They find the analytical relationships between pairs of generators linked across the fold curve, the shape of the original path, and the fold angle variation along it. They present two special cases of generator layouts for which the fold angle is uniform or the folded curve remains planar, for simplifying practical folding in sheet-metal processes. We verify their special cases by a graphical treatment according to a method of Gauss. We replace the fold curve by a piecewise linear path, which connects vertices of intersecting pairs of hinge lines. Inspired by the d-cone analysis by Farmer and Calladine [Int. J. Mech. Sci. 47, 509 (2005), 10.1016/j.ijmecsci.2005.02.013], we construct the spherical images for developable folding of successive vertices: the operating conditions of the special cases in Duncan and Duncan are then revealed straightforwardly by the geometric relationships between the images. Our approach may be used to synthesize folding patterns for novel deployable and shape-changing surfaces without need of complex calculation.

Interdisciplinary interventional therapy for tracheobronchial stenosis with modern metal net stents; Interdisziplinaere interventionelle Therapie tracheobronchialer Stenosen mit modernen Metallmaschenstents

Energy Technology Data Exchange (ETDEWEB)

Rieger, J.; Linsenmaier, U.; Fedorowski, A.; Pfeifer, K.J. [Ludwig-Maximilians-Universitaet Muenchen (Germany). Inst. fuer Klinische Radiologie; Hautmann, H.; Huber, R.M. [Klinikum Innenstadt der Ludwig-Maximilians-Universitaet Muenchen (Germany). Abteilung Pulmonologie, Medizinische Klinik

2002-08-01

Study objectives: Assessment of the therapeutic potential of tracheobronchial stenting for obstructive tracheobronchial disease, in-vivo comparison of different stent types and development of helpful criteria for choosing the suitable stent type. Material and Methods: Prospective case analysis. Between 1993 and 1999 53 stents were implanted into the tracheobronchial system of 39 consecutive patients with benign or malignant airway obstruction. Every single stent (26 Strecker Stents, 18 Wallstents, 6 Accuflex Nitinolstents, 1 Dumon-, 1 Ruesch- and 1 Palmazstent) was recorded in an unified database. Analysis comprised clinical effectiveness, lung function if possible, relevant complications and radiologic follow-up parameters. The probability of their remaining within the tracheobronchial system, of their remaining undislocated and uncompressed was calculated using Kaplan-Meier analysis for three stent types. Results: Stent placement proved itself to be an effective treatment in 86% of the patients. Resistance could be normalized in 9/9 patients. Kaplan-Meier analysis clearly revealed a higher probability for the Wall- and Nitinolstent to remain within the tracheobronchial system and to remain uncompressed. Dislocation also occurred more rarely. Explanation of the Wallstent, however, if desired, was much more difficult compared to the Strecker stent. The Wallstent also occasionally led to the formation of granulation tissue especially at the proximal stent end and, as such, required reintervention. (orig.) [German] Ziel: Erfassung des therapeutischen Potenzials der Stentbehandlung bei tracheobronchialen Stenosen, in-vivo Vergleich verschiedener Stenttypen und Erarbeitung von geeigneten Kriterien zur Stentwahl. Material und Methodik: Prospektive Fallanalyse. Zwischen 1993 und 1999 wurden insgesamt 53 Stents in das Tracheobronichalsystem von 39 konsekutiven Patienten implantiert. Jeder einzelne Stent (26 Streckerstents, 18 Wallstents, 6 Nitinolstents, ein Dumonstent

The association of donor and recipient age with graft survival in paediatric renal transplant recipients in a European Society for Paediatric Nephrology/European Renal Association-European Dialysis and Transplantation Association Registry study

DEFF Research Database (Denmark)

Chesnaye, Nicholas C.; Van Stralen, Karlijn J.; Bonthuis, Marjolein

2017-01-01

from the ESPN/ERA-EDTA Registry. The effect of donor and recipient age combinations on 5-year graft-failure risk, stratified by donor source, was estimated using Kaplan-Meier survival curves and Cox regression, while adjusting for sex, primary renal diseases with a high risk of recurrence, pre......Background The impact of donor age in paediatric kidney transplantation is unclear. We therefore examined the association of donor-recipient age combinations with graft survival in children. Methods Data for 4686 first kidney transplantations performed in 13 countries in 1990-2013 were extracted......-emptive transplantation, year of transplantation and country. Results The risk of graft failure in older living donors (50-75 years old) was similar to that of younger living donors {adjusted hazard ratio [aHR] 0.74 [95% confidence interval (CI) 0.38-1.47]}. Deceased donor (DD) age was non-linearly associated with graft...

The influence of unilateral oophorectomy on the age of menopause

DEFF Research Database (Denmark)

Rosendahl, M; Simonsen, M K; Kjer, J J

2017-01-01

OBJECTIVE: To determine the age of menopause after premenopausal unilateral oophorectomy (UO) and to establish whether UO at a young age leads to menopause at a younger age than if UO occurs at an older age. METHODS: A cohort of 28 731 women, of whom 17 781 (62%) were menopausal, was investigated....... Information on menopause was obtained from self-reported questionnaires. Surgical data were obtained from the National Patient Register to avoid recollection bias. Age of menopause after UO/not UO was determined using Kaplan-Meier curves. Cox regression was used to identify factors of importance for early...... menopause. RESULTS: UO was performed in 1148 women. Women with UO after the age of 45 years, premenopausal hysterectomy, bilateral oophorectomy and cancer were excluded, leaving 236 in the analysis. Menopause occurred 1.8 years earlier after UO compared to women with two intact ovaries (mean 49.5 vs. 51...

Outcome of lithium prophylaxis: a prospective follow-up of affective disorder patients assigned to high and low serum lithium levels

DEFF Research Database (Denmark)

Vestergaard, Per; Licht, Rasmus Wentzer; Brodersen, Anders Torp

1998-01-01

The purpose of the study was to examine the outcome of long-term lithium treatment in consecutively admitted affective disorder patients assigned to high and low serum lithium levels. A total of 91 patients were diagnosed according to DSM-III criteria and randomly allocated to two open treatment...... groups in which prophylactic lithium was administered in high (serum lithium 0.8-1.0 mmol L-1) and low (serum lithium 0.5-0.8 mmol L-1) doses, respectively. The patients were followed for 2 years or until discontinuation of lithium treatment or readmission to hospital for recurrence of affective illness....... The main outcome of the treatment groups was compared with Kaplan-Meier survival curves and by Cox regression analysis. A total of 31 patients (34%) completed 24 months of prophylactic lithium treatment without recurrence and readmission to hospital. In total, 18 patients (20%) suffered a recurrence...

Increased risk of revision for infection in rheumatoid arthritis patients with total hip replacements

DEFF Research Database (Denmark)

Schrama, Johannes Cornelis; Fenstad, Anne M; Dale, Håvard

2015-01-01

Background and purpose-Medical treatment of rheumatoid arthritis (RA) has changed dramatically over the last 15 years, including immune modulation. We investigated the risk of revision for infection after primary total hip replacement (THR) in patients with rheumatoid arthritis over a 16-year...... period, and compared it with that in THR patients with osteoarthritis (OA).Patients and methods-We identified 13,384 THRs in RA patients and 377,287 THRs in OA patients from 1995 through 2010 in a dataset from the Nordic Arthroplasty Register Association (NARA). Kaplan-Meier survival curves......, with revision for infection as the endpoint, were constructed. Cox regression analyses were performed to calculate the relative risk (RR) of revision for infection adjusted for age, sex, fixation technique, and year of primary surgery.Results-RA patients had a 1.3 times (95% CI 1.0-1.6) higher risk of revision...

Estimating a population cumulative incidence under calendar time trends

DEFF Research Database (Denmark)

Hansen, Stefan N; Overgaard, Morten; Andersen, Per K

2017-01-01

BACKGROUND: The risk of a disease or psychiatric disorder is frequently measured by the age-specific cumulative incidence. Cumulative incidence estimates are often derived in cohort studies with individuals recruited over calendar time and with the end of follow-up governed by a specific date...... by calendar time trends, the total sample Kaplan-Meier and Aalen-Johansen estimators do not provide useful estimates of the general risk in the target population. We present some alternatives to this type of analysis. RESULTS: We show how a proportional hazards model may be used to extrapolate disease risk...... estimates if proportionality is a reasonable assumption. If not reasonable, we instead advocate that a more useful description of the disease risk lies in the age-specific cumulative incidence curves across strata given by time of entry or perhaps just the end of follow-up estimates across all strata...

Association between poor clinical prognosis and sleep duration among breast cancer patients

Directory of Open Access Journals (Sweden)

Thalyta Cristina Mansano-Schlosser

Full Text Available ABSTRACT Objective: to investigate the association between clinical progression and the quality and duration of sleep in women with breast cancer. Method: longitudinal study, with 114 participants, conducted in a hospital in Brazil. The instruments used were: questionnaire for sociodemographic and clinical characterization, Pittsburgh Sleep Quality Index; Beck Depression Inventory and Herth Hope Scale. Data were analyzed through descriptive statistics and survival analyses (outcome: poor clinical progression, using the Kaplan-Meier curve, Log-rank test and Cox proportional model. Results: a higher probability of poor clinical progression was verified in women with sleep durations of less than six hours or nine hours and over (p=.0173. Conclusion: the results suggest the importance of further studies that seek to verify whether the quantitative management of sleep disorders would have an impact on the progression of breast cancer. Women should be encouraged to report sleep problems to nurses.

Predictors of antiviral treatment initiation in hepatitis C virus-infected patients: a Danish cohort study

DEFF Research Database (Denmark)

Hansen, N; Obel, N; Christensen, P B

2009-01-01

Predictive factors for initiation of antiviral therapy in chronically infected hepatitis C virus (HCV) patients are not fully elucidated. The aim of this study was to determine predictive factors for initiation of treatment with standard or pegylated interferon either alone or combined...... with ribavirin. A Danish cohort of individuals chronically infected with HCV was used and observation time was calculated from the date of inclusion in the cohort to date of death, last clinical observation, 1 January 2007, or start of HCV antiviral treatment in treatment-naïve patients. Kaplan-Meier survival...... analysis was used to construct time to event curves. Cox regression was used to determine the incidence rate ratios as estimates of relative risk (RR) and 95% confidence intervals (CI). A total of 1780 patients were enrolled in the study. The cumulative chance of treatment initiation over 5 years was 33...

ASURV: Astronomical SURVival Statistics

Science.gov (United States)

Feigelson, E. D.; Nelson, P. I.; Isobe, T.; LaValley, M.

2014-06-01

ASURV (Astronomical SURVival Statistics) provides astronomy survival analysis for right- and left-censored data including the maximum-likelihood Kaplan-Meier estimator and several univariate two-sample tests, bivariate correlation measures, and linear regressions. ASURV is written in FORTRAN 77, and is stand-alone and does not call any specialized libraries.

First line chemotherapy plus trastuzumab in metastatic breast cancer ...

African Journals Online (AJOL)

First line chemotherapy plus trastuzumab in metastatic breast cancer HER2 positive - Observational institutional study. ... The progression free survival was estimated by the Kaplan-Meier method, from the date of first cycle to the date of progression or at the last consultation, and the median was 12.8 months. Trastuzumab ...

Influence of antiviral therapy on survival of patients with hepatitis B ...

African Journals Online (AJOL)

The mortality rates in two groups were evaluated with Kaplan-Meier estimate. ... 274 (76.9 %) died, with 89 patients belonging to the antiviral group while the ... TACE is different from systemic ... and identification of study participants was not ..... Table 3: Cox regression analysis to deteermine variables associated with overall ...

Clinical outcome among HIV-infected patients starting saquinavir hard gel compared to ritonavir or indinavir

DEFF Research Database (Denmark)

Kirk, O; Mocroft, A; Pradier, C

2001-01-01

-up within the EuroSIDA study. METHODS: Changes in plasma viral load (pVL) and CD4 cell count from baseline were compared between treatment groups. Time to new AIDS-defining events and death were compared in Kaplan--Meier models, and Cox models were established to further assess differences in clinical...

Constructing forward price curves in electricity markets

DEFF Research Database (Denmark)

Fleten, S.-E.; Lemming, Jørgen Kjærgaard

2003-01-01

We present and analyze a method for constructing approximated high-resolution forward price curves in electricity markets. Because a limited number of forward or futures contracts are traded in the market, only a limited picture of the theoretical continuous forward price curve is available...... to the analyst. Our method combines the information contained in observed bid and ask prices with information from the forecasts generated by bottom-up models. As an example, we use information concerning the shape of the seasonal variation from a bottom-up model to improve the forward price curve quoted...

Coupled skinny baker's maps and the Kaplan-Yorke conjecture

Science.gov (United States)

Gröger, Maik; Hunt, Brian R.

2013-09-01

The Kaplan-Yorke conjecture states that for ‘typical’ dynamical systems with a physical measure, the information dimension and the Lyapunov dimension coincide. We explore this conjecture in a neighborhood of a system for which the two dimensions do not coincide because the system consists of two uncoupled subsystems. We are interested in whether coupling ‘typically’ restores the equality of the dimensions. The particular subsystems we consider are skinny baker's maps, and we consider uni-directional coupling. For coupling in one of the possible directions, we prove that the dimensions coincide for a prevalent set of coupling functions, but for coupling in the other direction we show that the dimensions remain unequal for all coupling functions. We conjecture that the dimensions prevalently coincide for bi-directional coupling. On the other hand, we conjecture that the phenomenon we observe for a particular class of systems with uni-directional coupling, where the information and Lyapunov dimensions differ robustly, occurs more generally for many classes of uni-directionally coupled systems (also called skew-product systems) in higher dimensions.

The Factor Structure and Age-Related Factorial Invariance of the Delis-Kaplan Executive Function System (D-KEFS)

Science.gov (United States)

Latzman, Robert D.; Markon, Kristian E.

2010-01-01

There has been an increased interest in the structure of and relations among executive functions.The present study examined the factor structure as well as age-related factorial invariance of the Delis-Kaplan Executive Function System (D-KEFS), a widely used inventory aimed at assessing executive functions. Analyses were first conducted using data…

Cefepime restriction improves gram-negative overall resistance patterns in neonatal intensive care unit

Directory of Open Access Journals (Sweden)

Orlei Ribeiro de Araujo

Full Text Available Antibiotic restriction can be useful in maintaining bacterial susceptibility. The objective of this study was verify if restriction of cefepime, the most frequently used cephalosporin in our neonatal intensive care unit (NICU, would ameliorate broad-spectrum susceptibility of Gram-negative isolates. Nine hundred and ninety-five premature and term newborns were divided into 3 cohorts, according to the prevalence of cefepime use in the unit: Group 1 (n=396 comprised patients admitted from January 2002 to December 2003, period in which cefepime was the most used broad-spectrum antibiotic. Patients in Group 2 (n=349 were admitted when piperacillin/tazobactam replaced cefepime (January to December 2004 and in Group 3 (n=250 when cefepime was reintroduced (January to September 2005. Meropenem was the alternative third-line antibiotic for all groups. Multiresistance was defined as resistance to 2 or more unrelated antibiotics, including necessarily a third or fourth generation cephalosporin, piperacillin/tazobactam or meropenem. Statistics involved Kruskal-Wallis, Mann-Whitney and logrank tests, Kaplan-Meier analysis. Groups were comparable in length of stay, time of mechanical ventilation, gestational age and birth weight. Ninety-eight Gram-negative isolates were analyzed. Patients were more likely to remain free of multiresistant isolates by Kaplan-Meier analysis in Group 2 when compared to Group 1 (p=0.017 and Group 3 (p=0.003. There was also a significant difference in meropenem resistance rates. Cefepime has a greater propensity to select multiresistant Gram-negative pathogens than piperacillin/tazobactam and should not be used extensively in neonatal intensive care.

78 FR 26343 - Exelon Generation Company, LLC; Notice of Application Accepted for Filing, Soliciting Motions To...

Science.gov (United States)

2013-05-06

... mixed-flow Kaplan-type hydraulic turbines. Units 1, 3, 4, 6 and 7 have 47.7-megawatt (MW) generators... plant is integral with the dam and is composed of 13 turbine-generator units, draft tubes, and transformer bays. The first seven turbine-generating units (1-7) are completely enclosed within the powerhouse...

MNS16A minisatellite genotypes in relation to risk of glioma and meningioma and to glioblastoma outcome

DEFF Research Database (Denmark)

Andersson, U.; Osterman, P.; Sjostrom, S.

2009-01-01

was analysed using Kaplan-Meier estimates and equality of survival distributions using the log-rank test and Cox proportional hazard ratios. The MNS16A genotype was not associated with risk of occurrence of glioma, glioblastoma (GBM) or meningioma. For GBM there were median survivals of 15.3, 11.0 and 10...

Pressure pulsation in Kaplan turbines: Prototype-CFD comparison

International Nuclear Information System (INIS)

Rivetti, A; Lucino, C; Liscia, S; Muguerza, D; Avellan, F

2012-01-01

Pressure pulsation phenomena in a large Kaplan turbine are investigated by means of numerical simulations (CFD) and prototype measurements in order to study the dynamic behavior of flow due to the blade passage and its interaction with other components of the turbine. Numerical simulations are performed with the commercial software Ansys CFX code, solving the incompressible Unsteady Reynolds-Averaged-Navier Stokes equations under a finite volume scheme. The computational domain involves the entire machine at prototype scale. Special care is taken in the discretization of the wicket gate overhang and runner blade gap. Prototype measurements are performed using pressure transducers at different locations among the wicket gate outlet and the draft tube inlet. Then, CFD results are compared with temporary signals of prototype measurements at identical locations to validate the numerical model. A detailed analysis was focused on the tip gap flow and the pressure field at the discharge ring. From a rotating reference frame perspective, it is found that the mean pressure fluctuates accordingly the wicket gate passage. Moreover, in prototype measurements the pressure frequency that reveals the presence of modulated cavitation at the discharge ring is distinguished, as also verified from the shape of erosion patches in concordance with the number of wicket gates.

Pressure pulsation in Kaplan turbines: Prototype-CFD comparison

Science.gov (United States)

Rivetti, A.; Lucino1, C.; Liscia, S.; Muguerza, D.; Avellan, F.

2012-11-01

Pressure pulsation phenomena in a large Kaplan turbine are investigated by means of numerical simulations (CFD) and prototype measurements in order to study the dynamic behavior of flow due to the blade passage and its interaction with other components of the turbine. Numerical simulations are performed with the commercial software Ansys CFX code, solving the incompressible Unsteady Reynolds-Averaged-Navier Stokes equations under a finite volume scheme. The computational domain involves the entire machine at prototype scale. Special care is taken in the discretization of the wicket gate overhang and runner blade gap. Prototype measurements are performed using pressure transducers at different locations among the wicket gate outlet and the draft tube inlet. Then, CFD results are compared with temporary signals of prototype measurements at identical locations to validate the numerical model. A detailed analysis was focused on the tip gap flow and the pressure field at the discharge ring. From a rotating reference frame perspective, it is found that the mean pressure fluctuates accordingly the wicket gate passage. Moreover, in prototype measurements the pressure frequency that reveals the presence of modulated cavitation at the discharge ring is distinguished, as also verified from the shape of erosion patches in concordance with the number of wicket gates.

Projection of curves on B-spline surfaces using quadratic reparameterization

KAUST Repository

Yang, Yijun

2010-09-01

Curves on surfaces play an important role in computer aided geometric design. In this paper, we present a hyperbola approximation method based on the quadratic reparameterization of Bézier surfaces, which generates reasonable low degree curves lying completely on the surfaces by using iso-parameter curves of the reparameterized surfaces. The Hausdorff distance between the projected curve and the original curve is controlled under the user-specified distance tolerance. The projected curve is T-G 1 continuous, where T is the user-specified angle tolerance. Examples are given to show the performance of our algorithm. © 2010 Elsevier Inc. All rights reserved.

Socialization into a Civilization: The Dewey-Kaplan Synthesis in American Jewish Schooling in the Early 20th Century

Science.gov (United States)

Jacobs, Benjamin M.

2009-01-01

This historical study focuses on how John Dewey's theory of education as socialization and Mordecai Kaplan's theory of Judaism as a civilization together served as an ideological base and pedagogical framework for the creation of "progressive," "reconstructed" American Jewish school programs in the early 20th century…

Constructing forward price curves in electricity markets

International Nuclear Information System (INIS)

Fleten, Stein-Erik; Lemming, Jacob

2003-01-01

We present and analyze a method for constructing approximated high-resolution forward price curves in electricity markets. Because a limited number of forward or futures contracts are traded in the market, only a limited picture of the theoretical continuous forward price curve is available to the analyst. Our method combines the information contained in observed bid and ask prices with information from the forecasts generated by bottom-up models. As an example, we use information concerning the shape of the seasonal variation from a bottom-up model to improve the forward price curve quoted on the Nordic power exchange

The value of molecular expression of KIT and KIT ligand analysed using real-time polymerase chain reaction and immunohistochemistry as a prognostic indicator for canine cutaneous mast cell tumours.

Science.gov (United States)

Costa Casagrande, T A; de Oliveira Barros, L M; Fukumasu, H; Cogliati, B; Chaible, L M; Dagli, M L Z; Matera, J M

2015-03-01

This study investigated the correlation between KIT gene expression determined by immunohistochemistry and real-time polymerase chain reaction (RT-PCR) and the rate of tumour recurrence and tumour-related deaths in dogs affected with mast cell tumour (MCT). Kaplan-Meier curves were constructed to compare tumour recurrence and tumour-related death between patients. The log-rank test was used to check for significant differences between curves. KIT-I, KIT-II and KIT-III staining patterns were observed in 9 (11.11%), 50 (61.73%) and 22 (27.16%) tumours, respectively. Tumour recurrence rates and tumour-related deaths were not associated with KIT staining patterns (P = 0278, P > 0.05), KIT (P = 0.289, P > 0.05) or KIT ligand (P = 0.106, P > 0.05) gene expression. Despite the lack of association between KIT staining pattern and patient survival time, the results suggest a correlation between aberrant KIT localization and increased proliferative activity of MCTs. RT-PCR seems to be a sensible method for quantitative detection of KIT gene expression in canine MCT, although expressions levels are not correlated with prognosis. © 2013 Blackwell Publishing Ltd.

Usefulness of midregional pro-adrenomedullin as a marker of organ damage and predictor of mortality in patients with sepsis.

Science.gov (United States)

Bernal-Morell, Enrique; García-Villalba, Eva; Vera, Maria Del Carmen; Medina, Blanca; Martinez, Monica; Callejo, Victoria; Valero, Salvador; Cinesi, Cesar; Piñera, Pascual; Alcaraz, Antonia; Marin, Irene; Muñoz, Angeles; Cano, Alfredo

2018-03-01

Midregional proadrenomedullin (MR-proADM) is a prognostic biomarker in patients with community-acquired pneumonia (CAP) and sepsis. In this paper, we examined the ability of MR-proADM to predict organ damage and long-term mortality in sepsis patients, compared to that of procalcitonin, C-reactive protein and lactate. This was a prospective observational cohort, enrolling severe sepsis or septic shock patients admitted to internal service department. The association between biomarkers and 90-day mortality was assessed by Cox regression analysis and Kaplan-Meier curves. The accuracy of biomarkers for mortality was determined by area under the receiver operating characteristic curve (AUROC) analysis. A total of 148 patients with severe sepsis, according to the criteria of the campaign to survive sepsis, were enrolled. Eighty-five (57.4%) had sepsis according to the new criteria of Sepsis-3. MR-proADM showed the best AUROC to predict sepsis as defined by the Sepsis-3 criteria (AUROC of 0.771, 95% CI 0.692-0.850, p scale, especially when scores are low. Copyright © 2017 The British Infection Association. Published by Elsevier Ltd. All rights reserved.

Electro-Mechanical Resonance Curves

Science.gov (United States)

Greenslade, Thomas B., Jr.

2018-01-01

Recently I have been investigating the frequency response of galvanometers. These are direct-current devices used to measure small currents. By using a low-frequency function generator to supply the alternating-current signal and a stopwatch smartphone app to measure the period, I was able to take data to allow a resonance curve to be drawn. This…

Multiple myeloma in Nigeria: An insight to the clinical, laboratory ...

African Journals Online (AJOL)

The average percentage of bone marrow plasmacytosis at diagnosis ... of autologous stem cell transplantation (ASCT) for white, black, and ... Hospital Cancer Registry and Data Collation Institute. .... Figure 1: (a) Kaplan‑Meier survival curve for all myeloma patients, (b) Kaplan‑Meier survival curve for the different sexes b a ...

Projection of curves on B-spline surfaces using quadratic reparameterization

KAUST Repository

Yang, Yijun; Zeng, Wei; Zhang, Hui; Yong, Junhai; Paul, Jean Claude

2010-01-01

Curves on surfaces play an important role in computer aided geometric design. In this paper, we present a hyperbola approximation method based on the quadratic reparameterization of Bézier surfaces, which generates reasonable low degree curves lying

Long-Term Survivors Using Intraoperative Radiotherapy for Recurrent Gynecologic Malignancies

International Nuclear Information System (INIS)

Tran, Phuoc T.; Su Zheng; Hara, Wendy; Husain, Amreen; Teng, Nelson; Kapp, Daniel S.

2007-01-01

Purpose: To analyze the outcomes of therapy and identify prognostic factors for patients treated with surgery followed by intraoperative radiotherapy (IORT) for gynecologic malignancies at a single institution. Methods and Materials: We performed a retrospective review of 36 consecutive patients treated with IORT to 44 sites with mean follow-up of 50 months. The primary site was the cervix in 47%, endometrium in 31%, vulva in 14%, vagina in 6%, and fallopian tubes in 3%. Previous RT had failed in 72% of patients, and 89% had recurrent disease. Of 38 IORT sessions, 84% included maximal cytoreductive surgery, including 18% exenterations. The mean age was 52 years (range, 30-74), mean tumor size was 5 cm (range, 0.5-12), previous disease-free interval was 32 months (range, 0-177), and mean IORT dose was 1,152 cGy (range, 600-1,750). RT and systemic therapy after IORT were given to 53% and 24% of the cohort, respectively. The outcomes measured were locoregional control (LRC), distant metastasis-free survival (DMFS), disease-specific survival (DSS), and treatment-related complications. Results: The Kaplan-Meier 5-year LRC, DMFS, and DSS probability for the whole group was 44%, 51%, and 47%, respectively. For cervical cancer patients, the Kaplan-Meier 5-year LRC, DMFS, and DSS estimate was 45%, 60%, and 46%, respectively. The prognostic factors found on multivariate analysis (p ≤ 0.05) were the disease-free interval for LRC, tumor size for DMFS, and cervical primary, previous surgery, and locoregional relapse for DSS. Our cohort had 10 Grade 3-4 complications associated with treatment (surgery and IORT) and a Kaplan-Meier 5-year Grade 3-4 complication-free survival rate of 72%. Conclusions: Survival for pelvic recurrence of gynecologic cancer is poor (range, 0-25%). IORT after surgery seems to confer long-term local control in carefully selected patients

Simplified tools for measuring retention in care in antiretroviral treatment program in Ethiopia: cohort and current retention in care.

Science.gov (United States)

Assefa, Yibeltal; Worku, Alemayehu; Wouters, Edwin; Koole, Olivier; Haile Mariam, Damen; Van Damme, Wim

2012-01-01

Patient retention in care is a critical challenge for antiretroviral treatment programs. This is mainly because retention in care is related to adherence to treatment and patient survival. It is therefore imperative that health facilities and programs measure patient retention in care. However, the currently available tools, such as Kaplan Meier, for measuring retention in care have a lot of practical limitations. The objective of this study was to develop simplified tools for measuring retention in care. Retrospective cohort data were collected from patient registers in nine health facilities in Ethiopia. Retention in care was the primary outcome for the study. Tools were developed to measure "current retention" in care during a specific period of time for a specific "ART-age group" and "cohort retention" in care among patients who were followed for the last "Y" number of years on ART. "Probability of retention" based on the tool for "cohort retention" in care was compared with "probability of retention" based on Kaplan Meier. We found that the new tools enable to measure "current retention" and "cohort retention" in care. We also found that the tools were easy to use and did not require advanced statistical skills. Both "current retention" and "cohort retention" are lower among patients in the first two "ART-age groups" and "ART-age cohorts" than in subsequent "ART-age groups" and "ART-age cohorts". The "probability of retention" based on the new tools were found to be similar to the "probability of retention" based on Kaplan Meier. The simplified tools for "current retention" and "cohort retention" will enable practitioners and program managers to measure and monitor rates of retention in care easily and appropriately. We therefore recommend that health facilities and programs start to use these tools in their efforts to improve retention in care and patient outcomes.

Simplified tools for measuring retention in care in antiretroviral treatment program in Ethiopia: cohort and current retention in care.

Directory of Open Access Journals (Sweden)

Yibeltal Assefa

Full Text Available INTRODUCTION: Patient retention in care is a critical challenge for antiretroviral treatment programs. This is mainly because retention in care is related to adherence to treatment and patient survival. It is therefore imperative that health facilities and programs measure patient retention in care. However, the currently available tools, such as Kaplan Meier, for measuring retention in care have a lot of practical limitations. The objective of this study was to develop simplified tools for measuring retention in care. METHODS: Retrospective cohort data were collected from patient registers in nine health facilities in Ethiopia. Retention in care was the primary outcome for the study. Tools were developed to measure "current retention" in care during a specific period of time for a specific "ART-age group" and "cohort retention" in care among patients who were followed for the last "Y" number of years on ART. "Probability of retention" based on the tool for "cohort retention" in care was compared with "probability of retention" based on Kaplan Meier. RESULTS: We found that the new tools enable to measure "current retention" and "cohort retention" in care. We also found that the tools were easy to use and did not require advanced statistical skills. Both "current retention" and "cohort retention" are lower among patients in the first two "ART-age groups" and "ART-age cohorts" than in subsequent "ART-age groups" and "ART-age cohorts". The "probability of retention" based on the new tools were found to be similar to the "probability of retention" based on Kaplan Meier. CONCLUSION: The simplified tools for "current retention" and "cohort retention" will enable practitioners and program managers to measure and monitor rates of retention in care easily and appropriately. We therefore recommend that health facilities and programs start to use these tools in their efforts to improve retention in care and patient outcomes.

Mixture models for undiagnosed prevalent disease and interval-censored incident disease: applications to a cohort assembled from electronic health records.

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Cheung, Li C; Pan, Qing; Hyun, Noorie; Schiffman, Mark; Fetterman, Barbara; Castle, Philip E; Lorey, Thomas; Katki, Hormuzd A

2017-09-30

For cost-effectiveness and efficiency, many large-scale general-purpose cohort studies are being assembled within large health-care providers who use electronic health records. Two key features of such data are that incident disease is interval-censored between irregular visits and there can be pre-existing (prevalent) disease. Because prevalent disease is not always immediately diagnosed, some disease diagnosed at later visits are actually undiagnosed prevalent disease. We consider prevalent disease as a point mass at time zero for clinical applications where there is no interest in time of prevalent disease onset. We demonstrate that the naive Kaplan-Meier cumulative risk estimator underestimates risks at early time points and overestimates later risks. We propose a general family of mixture models for undiagnosed prevalent disease and interval-censored incident disease that we call prevalence-incidence models. Parameters for parametric prevalence-incidence models, such as the logistic regression and Weibull survival (logistic-Weibull) model, are estimated by direct likelihood maximization or by EM algorithm. Non-parametric methods are proposed to calculate cumulative risks for cases without covariates. We compare naive Kaplan-Meier, logistic-Weibull, and non-parametric estimates of cumulative risk in the cervical cancer screening program at Kaiser Permanente Northern California. Kaplan-Meier provided poor estimates while the logistic-Weibull model was a close fit to the non-parametric. Our findings support our use of logistic-Weibull models to develop the risk estimates that underlie current US risk-based cervical cancer screening guidelines. Published 2017. This article has been contributed to by US Government employees and their work is in the public domain in the USA. Published 2017. This article has been contributed to by US Government employees and their work is in the public domain in the USA.

Energy dependence of contrast-detail-dose and object-detectability-dose curves for CT scanners

International Nuclear Information System (INIS)

Wagner, L.K.; Cohen, G.

1982-01-01

The energy dependence of contrast-detail-dose (CdD) and object-detectability-dose (OdD) curves for computed tomographic scanners is investigated. The effects of changes in beam energy on perceptibility are shown to be due to changes in signal-to-noise ratio resulting from changes in contrast and photon statistics. Energy-dependence analysis of OdD curves is shown to depend on the atomic composition of the phantom used to generate the curves, while such an analysis of CdD curves is independent of the atomic composition of the phantom. It is also shown that any OdD curve can be generated from CdD curves and that use of this fact rectifies any potential energy-dependent interpretation of CdD curves

[Application of Competing Risks Model in Predicting Smoking Relapse Following Ischemic Stroke].

Science.gov (United States)

Hou, Li-Sha; Li, Ji-Jie; Du, Xu-Dong; Yan, Pei-Jing; Zhu, Cai-Rong

2017-07-01

To determine factors associated with smoking relapse in men who survived from their first stroke. Data were collected through face to face interviews with stroke patients in the hospital, and then repeated every three months via telephone over the period from 2010 to 2014. Kaplan-Meier method and competing risk model were adopted to estimate and predict smoking relapse rates. The Kaplan-Meier method estimated a higher relapse rate than the competing risk model. The four-year relapse rate was 43.1% after adjustment of competing risk. Exposure to environmental tobacco smoking outside of home and workplace (such as bars and restaurants) ( P =0.01), single ( P <0.01), and prior history of smoking at least 20 cigarettes per day ( P =0.02) were significant predictors of smoking relapse. When competing risks exist, competing risks model should be used in data analyses. Smoking interventions should give priorities to those without a spouse and those with a heavy smoking history. Smoking ban in public settings can reduce smoking relapse in stroke patients.

Duration of Psoriatic Skin Disease as Risk Factor for Subsequent Onset of Psoriatic Arthritis

DEFF Research Database (Denmark)

Egeberg, Alexander; Skov, Lone; Zachariae, Claus

2018-01-01

It is unclear whether psoriasis is a progressive disease that requires early aggressive intervention. This population-based study identified patients with psoriasis and psoriatic arthritis (PsA). Survival analysis and Kaplan-Meier life table techniques were used. The study comprised 10,011 psoria......It is unclear whether psoriasis is a progressive disease that requires early aggressive intervention. This population-based study identified patients with psoriasis and psoriatic arthritis (PsA). Survival analysis and Kaplan-Meier life table techniques were used. The study comprised 10......,011 psoriasis patients (severe n = 4,618), and 1,269 patients also had PsA. Incidence of PsA increased with duration of cutaneous symptoms (p = 0.0001). Psoriasis diagnosed before age 20 or 30 years, respectively, suggested a lower risk of PsA than psoriasis diagnosed after age 50 years, yet age at first...... cutaneous symptoms did not predict development of PsA. No clear association with disease severity was found. PsA incidence appeared stable with longer duration of psoriasis, but further data are needed to firmly establish the relationship with age of psoriasis onset....

Section curve reconstruction and mean-camber curve extraction of a point-sampled blade surface.

Directory of Open Access Journals (Sweden)

Wen-long Li

Full Text Available The blade is one of the most critical parts of an aviation engine, and a small change in the blade geometry may significantly affect the dynamics performance of the aviation engine. Rapid advancements in 3D scanning techniques have enabled the inspection of the blade shape using a dense and accurate point cloud. This paper proposes a new method to achieving two common tasks in blade inspection: section curve reconstruction and mean-camber curve extraction with the representation of a point cloud. The mathematical morphology is expanded and applied to restrain the effect of the measuring defects and generate an ordered sequence of 2D measured points in the section plane. Then, the energy and distance are minimized to iteratively smoothen the measured points, approximate the section curve and extract the mean-camber curve. In addition, a turbine blade is machined and scanned to observe the curvature variation, energy variation and approximation error, which demonstrates the availability of the proposed method. The proposed method is simple to implement and can be applied in aviation casting-blade finish inspection, large forging-blade allowance inspection and visual-guided robot grinding localization.

Modular forms and special cycles on Shimura curves (AM-161)

CERN Document Server

Kudla, Stephen S; Yang, Tonghai

2006-01-01

Modular Forms and Special Cycles on Shimura Curves is a thorough study of the generating functions constructed from special cycles, both divisors and zero-cycles, on the arithmetic surface ""M"" attached to a Shimura curve ""M"" over the field of rational numbers. These generating functions are shown to be the q-expansions of modular forms and Siegel modular forms of genus two respectively, valued in the Gillet-Soulé arithmetic Chow groups of ""M"". The two types of generating functions are related via an arithmetic inner product formula. In addition, an analogue of the classical Siegel-Weil

ArcCN-Runoff: An ArcGIS tool for generating curve number and runoff maps

Science.gov (United States)

Zhan, X.; Huang, M.-L.

2004-01-01

The development and the application of ArcCN-Runoff tool, an extension of ESRI@ ArcGIS software, are reported. This tool can be applied to determine curve numbers and to calculate runoff or infiltration for a rainfall event in a watershed. Implementation of GIS techniques such as dissolving, intersecting, and a curve-number reference table improve efficiency. Technical processing time may be reduced from days, if not weeks, to hours for producing spatially varied curve number and runoff maps. An application example for a watershed in Lyon County and Osage County, Kansas, USA, is presented. ?? 2004 Elsevier Ltd. All rights reserved.

Calibration curves for biological dosimetry

International Nuclear Information System (INIS)

Guerrero C, C.; Brena V, M. . E-mail cgc@nuclear.inin.mx

2004-01-01

The generated information by the investigations in different laboratories of the world, included the ININ, in which settles down that certain class of chromosomal leisure it increases in function of the dose and radiation type, has given by result the obtaining of calibrated curves that are applied in the well-known technique as biological dosimetry. In this work is presented a summary of the work made in the laboratory that includes the calibrated curves for gamma radiation of 60 Cobalt and X rays of 250 k Vp, examples of presumed exposure to ionizing radiation, resolved by means of aberration analysis and the corresponding dose estimate through the equations of the respective curves and finally a comparison among the dose calculations in those people affected by the accident of Ciudad Juarez, carried out by the group of Oak Ridge, USA and those obtained in this laboratory. (Author)

ROC-ing along: Evaluation and interpretation of receiver operating characteristic curves.

Science.gov (United States)

Carter, Jane V; Pan, Jianmin; Rai, Shesh N; Galandiuk, Susan

2016-06-01

It is vital for clinicians to understand and interpret correctly medical statistics as used in clinical studies. In this review, we address current issues and focus on delivering a simple, yet comprehensive, explanation of common research methodology involving receiver operating characteristic (ROC) curves. ROC curves are used most commonly in medicine as a means of evaluating diagnostic tests. Sample data from a plasma test for the diagnosis of colorectal cancer were used to generate a prediction model. These are actual, unpublished data that have been used to describe the calculation of sensitivity, specificity, positive predictive and negative predictive values, and accuracy. The ROC curves were generated to determine the accuracy of this plasma test. These curves are generated by plotting the sensitivity (true-positive rate) on the y axis and 1 - specificity (false-positive rate) on the x axis. Curves that approach closest to the coordinate (x = 0, y = 1) are more highly predictive, whereas ROC curves that lie close to the line of equality indicate that the result is no better than that obtained by chance. The optimum sensitivity and specificity can be determined from the graph as the point where the minimum distance line crosses the ROC curve. This point corresponds to the Youden index (J), a function of sensitivity and specificity used commonly to rate diagnostic tests. The area under the curve is used to quantify the overall ability of a test to discriminate between 2 outcomes. By following these simple guidelines, interpretation of ROC curves will be less difficult and they can then be interpreted more reliably when writing, reviewing, or analyzing scientific papers. Copyright © 2016 Elsevier Inc. All rights reserved.

Comparative analysis of costs for the generation of electrical energy in Brazil using the screening curve

International Nuclear Information System (INIS)

Barros, Thaisa C. de; Castrillo, Lazara S.; Xavier, Aline G.; Goncalves, Gabriela de L.; Melo, Julio Angelo

2017-01-01

To meet the demand for electric consumption, it is fundamental to prepare an efficient energy planning that guarantees the safe supply of energy, so that the price of kilowatt-hours for the consumer respects the tariff modality and the socio-environmental impact is the smallest possible. In recent years, alternative sources of energy have been gaining considerable space in the Brazilian generating park. Among the many options for energy supply, choosing the most feasible involves the use of techniques that compare all the costs involved in generating electricity from the sources available in the Brazilian energy matrix. The objective of the work is to show a quick, practical and objective tool that performs this comparison and assists in decision making. The method based on the comparison is the Cost of Energy and the tool for the application of the same are the Screening curves, widely used by the International Atomic Energy Agency (IAEA). In this analysis, the following parameters are considered: operating capacity, toxic gas emission rate, fuel consumption and values, fixed and variable costs of operation and maintenance, investment values for each source, construction time and useful life. It is worth noting that the method does not consider in calculations aspects such as inflation, forced interruptions of the plant and other more specific factors. With the work, it was possible to perform an examination of the costs of the generation technologies available in Brazil and, through the obtained data, the economic viability of the generating parks was discussed through simulations in different scenarios, comparing the sources among themselves. (author)

Comparative analysis of costs for the generation of electrical energy in Brazil using the screening curve

Energy Technology Data Exchange (ETDEWEB)

Barros, Thaisa C. de; Castrillo, Lazara S.; Xavier, Aline G.; Goncalves, Gabriela de L.; Melo, Julio Angelo, E-mail: barros.camara@gmail.com, E-mail: lazaracastrillo@hotmail.com, E-mail: alinegxavier@gmail.com, E-mail: gabilimag_@hotmail.com, E-mail: angelo_mecanic@hotmail.com [Escola Politecnica de Pernambuco (UPE), Recife, PE (Brazil). Departamento de Engenharia Mecanica Industrial

2017-11-01

To meet the demand for electric consumption, it is fundamental to prepare an efficient energy planning that guarantees the safe supply of energy, so that the price of kilowatt-hours for the consumer respects the tariff modality and the socio-environmental impact is the smallest possible. In recent years, alternative sources of energy have been gaining considerable space in the Brazilian generating park. Among the many options for energy supply, choosing the most feasible involves the use of techniques that compare all the costs involved in generating electricity from the sources available in the Brazilian energy matrix. The objective of the work is to show a quick, practical and objective tool that performs this comparison and assists in decision making. The method based on the comparison is the Cost of Energy and the tool for the application of the same are the Screening curves, widely used by the International Atomic Energy Agency (IAEA). In this analysis, the following parameters are considered: operating capacity, toxic gas emission rate, fuel consumption and values, fixed and variable costs of operation and maintenance, investment values for each source, construction time and useful life. It is worth noting that the method does not consider in calculations aspects such as inflation, forced interruptions of the plant and other more specific factors. With the work, it was possible to perform an examination of the costs of the generation technologies available in Brazil and, through the obtained data, the economic viability of the generating parks was discussed through simulations in different scenarios, comparing the sources among themselves. (author)

Association of the AA genotype of the BCL2 (-938C>A) promoter polymorphism with better survival in ovarian cancer.

Science.gov (United States)

Heubner, Martin; Wimberger, Pauline; Otterbach, Friedrich; Kasimir-Bauer, Sabine; Siffert, Winfried; Kimmig, Rainer; Nückel, Holger

2009-01-01

Bcl-2 plays a key role in the regulation of apoptosis. Recently, a novel regulatory single nucleotide polymorphism (-938C>A) in the inhibitory P2 BCL2 promoter was described. In this study we investigated its potential association with survival in epithelial ovarian cancer. Patients (n=110) with primary epithelial ovarian cancer were retrospectively genotyped by pyrosequencing. Genotype distribution was not significantly different between 110 ovarian cancer patients and 120 healthy controls, suggesting that genotypes of this polymorphism do not increase the susceptibility to ovarian cancer. Kaplan-Meier curves showed a significant association of the AA genotype with increased survival (p=0.002). Multivariate analysis revealed that the BCL2-938AC/CC genotype (hazard ratio 4.5; p=0.003) was an independent prognostic factor compared to other prognostic factors such as age, histological grade or tumor stage. The results suggest a role for the BCL2-938C>A polymorphism as a marker for survival in patients with epithelial ovarian cancer.

Randomized controlled study on the effect of adjuvant immunotherapy with OK-432 on malignant gliomas

International Nuclear Information System (INIS)

Shibata, Shobu; Mori, Kazuo; Moriyama, Tadayoshi; Tanaka, Keisei; Moroki, Jiro.

1985-01-01

During periods from January, 1981 to December, 1983, 51 patients (31 malignant astrocytomas, 17 glioblastomas, and others 3) were treated with radiochemotherapy using Nimustine hydrochloride, ACNU (group B) and radiochemoimmunotherapy with Picibanil, OK-432 (group A) by randomized controlled study. Group A consisted of 24 patients and group B of 27 patients. The differences in the background of the two groups were not statistically significant. Survival curves of both groups were shown by the Kaplan-Meier method. The postoperative survival rate at 1 year and 2 years were 70 % and 30 %, respectively, equal in both groups, and the differences between groups A and B were not statistically significant by the Cox-Mantel test. The side effects by group B therapy were most prominent in the bone marrow, and severe leukopenia occurred. However, group A therapy suppressed leukopenia after 2 months. Immunological parameters, such as purified protein derivative skin reaction test did not change, but streptococcal Su-polysaccharide skin reaction test became positive after group A therapy. (author)

Prognostic role of ABO blood type in patients with extranodal natural killer/T cell lymphoma, nasal type: a triple-center study.

Science.gov (United States)

Li, Ya-Jun; Yi, Ping-Yong; Li, Ji-Wei; Liu, Xian-Ling; Tang, Tian; Zhang, Pei-Ying; Jiang, Wen-Qi

2017-07-31

The prognostic significance of ABO blood type for lymphoma is largely unknown. We evaluated the prognostic role of ABO blood type in patients with extranodal natural killer (NK)/T-cell lymphoma (ENKTL). We retrospectively analyzed clinical data of 697 patients with newly diagnosed ENKTL from three cancer centers. The prognostic value of ABO blood type was evaluated using Kaplan-Meier curves and Cox proportional hazard models. The prognostic values of the International Prognostic Index (IPI) and the Korean Prognostic Index (KPI) were also evaluated. Compared with patients with blood type O, those with blood type non-O tended to display elevated baseline serum C-reactive protein levels (P = 0.038), lower rate of complete remission (P = 0.005), shorter progression-free survival (PFS, P 60 years (P KPI in distinguishing between the intermediate-to-low- and high-to-intermediate-risk groups. ABO blood type was an independent predictor of clinical outcome for patients with ENKTL.

Colistin-resistant Enterobacteriaceae infections: clinical and molecular characterization and analysis of in vitro synergy.

Science.gov (United States)

de Maio Carrillho, Claudia M D; Gaudereto, Juliana J; Martins, Roberta Cristina Ruedas; de Castro Lima, Victor Augusto Camarinha; de Oliveira, Larissa M; Urbano, Mariana R; Perozin, Jamile S; Levin, Anna Sara; Costa, Silvia F

2017-03-01

We described 27 polyclonal colistin-resistant Enterobacteriaceae (MIC 4-16 μg/mL) infections (12 pneumonia, 12 urinary tract infection (UTI), two Bacteremia, and one skin/soft tissue infection) in which 74% harbored KPC. The isolates were polyclonal, 6 STs were identified and the colistin resistance was due to chromosome mutations. Eight patients with UTI received monotherapy, and combination therapy was given to 19 patients. Overall mortality was 37%. In vitro synergy using time-kill assay was observed in 14 of 19 (74%) isolates tested; the synergistic effect was observed for almost all isolates for the combination of three drugs: colistin, amikacin, and tigecycline. The Kaplan-Meier survival curve showed no significant difference comparing combination therapy with 2, 3, or more drugs and risk factors associated with death were dialysis and shock. These findings reinforce the fact that colistin in combination with other classes of drugs can be useful in treating infections caused by colistin-resistant CRE. Copyright © 2016 Elsevier Inc. All rights reserved.

ALLOGENEIC STEM CELL TRANSPLANTATION FOR ADULT PATIENTS WITH ACUTE LEUKEMIA – 14 YEARS EXPERIENCE

Directory of Open Access Journals (Sweden)

Jože Pretnar

2004-12-01

Full Text Available Background. This study was designed to evaluate the impact of various prognostic factors on long-term survival and event free survival after allogeneic hematopoietic stem cell transplantation for patients with acute leukemia.Methods and patients. Between years 1989 and 2002 44 patients with acute leukemia (30 with AML and 14 with ALL were transplanted. Survival curves using the Kaplan-Meier method were calculated for patients transplanted with two different sources of stem cells – bone marrow and peripheral blood and separately for patients with female donor.Results. Estimated 10 years survival for AML is 43% and 64% for ALL patients which is not statistically different. There are no significant differences in outcome regarding source of stem cells and in donors’ gender.Conclusions. To conclude, our results show that neither source of stem cells nor donor’s gender has impact on the long-term survival after hematopoietic stem cell transplantation. As published previously patients transplanted beyond the first remission have significantly worse outcome.

Mini-mental state examination as a predictor of mortality among older people referred to secondary mental healthcare.

Science.gov (United States)

Su, Yu-Ping; Chang, Chin-Kuo; Hayes, Richard D; Perera, Gayan; Broadbent, Matthew; To, David; Hotopf, Matthew; Stewart, Robert

2014-01-01

Lower levels of cognitive function have been found to be associated with higher mortality in older people, particularly in dementia, but the association in people with other mental disorders is still inconclusive. Data were analysed from a large mental health case register serving a geographic catchment of 1.23 million residents, and associations were investigated between cognitive function measured by the Mini-Mental State Examination (MMSE) and survival in patients aged 65 years old and over. Cox regressions were carried out, adjusting for age, gender, psychiatric diagnosis, ethnicity, marital status, and area-level socioeconomic index. A total of 6,704 subjects were involved, including 3,368 of them having a dementia diagnosis and 3,336 of them with depression or other diagnoses. Descriptive outcomes by Kaplan-Meier curves showed significant differences between those with normal and impaired cognitive function (MMSE scoremental health services regardless of a dementia diagnosis. Causal pathways between this exposure and outcome (for example, suboptimal healthcare) need further investigation.

Association between age at antiretroviral therapy initiation and 24-month immune response in West-African HIV-infected children

DEFF Research Database (Denmark)

Desmonde, Sophie; Dicko, Fatoumata; Koueta, Fla

2014-01-01

measurements, including one at ART initiation (baseline) were included. CD4 cell gain on ART was estimated using a multivariable linear mixed model adjusted for baseline variables: age, CD4 cell count, sex, first-line ART regimen. Kaplan-Meier survival curves and a Cox proportional hazards regression model...... compared immune recovery for age within 24 months post-ART. RESULTS: Of the 4808 children initiated on ART, 3014 were enrolled at a median age of 5.6 years; 61.2% were immunodeficient. After 12 months, children at least 4 years at baseline had significantly lower CD4 cell gains compared with children less...... these children, 75% reached immune recovery: 12-month rates were significantly highest in all those aged 2-5 years at ART initiation compared with those less than 2 years. Beyond 12 months on ART, immune recovery was significantly lower in children initiated more than 5 years (adjusted hazard ratio: 0.69, 95...

Survival of a cohort of women with cervical cancer diagnosed in a Brazilian cancer center

Directory of Open Access Journals (Sweden)

Claudio Calazan do Carmo

2011-08-01

Full Text Available OBJECTIVE: To assess overall survival of women with cervical cancer and describe prognostic factors associated. METHODS: A total of 3,341 cases of invasive cervical cancer diagnosed at the Brazilian Cancer Institute, Rio de Janeiro, southeastern Brazil, between 1999 and 2004 were selected. Clinical and pathological characteristics and follow-up data were collected. There were performed a survival analysis using Kaplan-Meier curves and a multivariate analysis through Cox model. RESULTS: Of all cases analyzed, 68.3% had locally advanced disease at the time of diagnosis. The 5-year overall survival was 48%. After multivariate analysis, tumor staging at diagnosis was the single variable significantly associated with prognosis (p<0.001. There was seen a dose-response relationship between mortality and clinical staging, ranging from 27.8 to 749.6 per 1,000 cases-year in women stage I and IV, respectively. CONCLUSIONS: The study showed that early detection through prevention programs is crucial to increase cervical cancer survival.

PRAME gene expression profile in medulloblastoma

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Tânia Maria Vulcani-Freitas

2011-02-01

Full Text Available Medulloblastoma is the most common malignant tumors of central nervous system in the childhood. The treatment is severe, harmful and, thus, has a dismal prognosis. As PRAME is present in various cancers, including meduloblastoma, and has limited expression in normal tissues, this antigen can be an ideal vaccine target for tumor immunotherapy. In order to find a potential molecular target, we investigated PRAME expression in medulloblastoma fragments and we compare the results with the clinical features of each patient. Analysis of gene expression was performed by real-time quantitative PCR from 37 tumor samples. The Mann-Whitney test was used to analysis the relationship between gene expression and clinical characteristics. Kaplan-Meier curves were used to evaluate survival. PRAME was overexpressed in 84% samples. But no statistical association was found between clinical features and PRAME overexpression. Despite that PRAME gene could be a strong candidate for immunotherapy since it is highly expressed in medulloblastomas.

A conversation with Drs. Kaplan and Moser about conflicting data, confusing results, and some recent treatment recommendations for the management of hypertension.

Science.gov (United States)

Post, Wendy; Moser, Marvin; Kaplan, Norman

2005-10-01

Following a hypertension symposium in Baltimore, MD, on June 1, 2005, Dr. Wendy Post from the Johns Hopkins University School of Medicine, Baltimore, MD, had the opportunity to interview two of the outstanding hypertension experts in the United States on several controversial issues in hypertension management. Dr. Norman Kaplan is Clinical Professor of Medicine at the Southwestern Health Science Center in Dallas, TX, and Dr. Marvin Moser is Clinical Professor of Medicine at the Yale University School of Medicine, New Haven, CT. Both have been leaders in the field of hypertension treatment and education for more than 40 years. Dr. Kaplan's book Clinical Hypertension has been a standard textbook since 1973 and is now in its ninth edition. Dr. Marvin Moser was the Senior Medical Consultant to the National High Blood Pressure Education Program from 1974 to 2002 and was Chairman of the first Joint National Committee on Detection, Evaluation, and Treatment of High Blood Pressure and a member of the six subsequent committees. His book Clinical Management of Hypertension is in its seventh edition. Drs. Moser and Kaplan were corecipients of the 2004 International Society of Hypertension Award for Outstanding Contributions to Hypertension Treatment and Education and have lectured extensively throughout the United States and overseas.

Principal Curves on Riemannian Manifolds.

Science.gov (United States)

Hauberg, Soren

2016-09-01

Euclidean statistics are often generalized to Riemannian manifolds by replacing straight-line interpolations with geodesic ones. While these Riemannian models are familiar-looking, they are restricted by the inflexibility of geodesics, and they rely on constructions which are optimal only in Euclidean domains. We consider extensions of Principal Component Analysis (PCA) to Riemannian manifolds. Classic Riemannian approaches seek a geodesic curve passing through the mean that optimizes a criteria of interest. The requirements that the solution both is geodesic and must pass through the mean tend to imply that the methods only work well when the manifold is mostly flat within the support of the generating distribution. We argue that instead of generalizing linear Euclidean models, it is more fruitful to generalize non-linear Euclidean models. Specifically, we extend the classic Principal Curves from Hastie & Stuetzle to data residing on a complete Riemannian manifold. We show that for elliptical distributions in the tangent of spaces of constant curvature, the standard principal geodesic is a principal curve. The proposed model is simple to compute and avoids many of the pitfalls of traditional geodesic approaches. We empirically demonstrate the effectiveness of the Riemannian principal curves on several manifolds and datasets.

Contribution of serum FGF21 level to the identification of left ventricular systolic dysfunction and cardiac death.

Science.gov (United States)

Shen, Yun; Zhang, Xueli; Pan, Xiaoping; Xu, Yiting; Xiong, Qin; Lu, Zhigang; Ma, Xiaojing; Bao, Yuqian; Jia, Weiping

2017-08-18

The relationship between fibroblast growth factor 21 (FGF21) and cardiovascular disease has been well established in recent studies. This study aimed to investigate the relationship between FGF21 and left ventricular systolic dysfunction and cardiac death. Two-dimensional echocardiography was used to measure the left ventricular ejection fraction (LVEF) to estimate left ventricular systolic function. The optimal cutoff of FGF21 for identifying left ventricular systolic dysfunction at baseline was analyzed via receiver operating characteristic (ROC) curves. The identification of different serum levels of FGF21 and their association with cardiac death was analyzed via Kaplan-Meier survival curves. Serum FGF21 level was measured by an enzyme-linked immunosorbent assay kit, and serum N-terminal pro-brain natriuretic peptide (NT-pro-BNP) level was determined by a chemiluminescent immunoassay. A total of 253 patients were recruited for this study at baseline. Patients were excluded if they lacked echocardiography or laboratory measurement data, and there were 218 patients enrolled in the final analysis. The average age was 66.32 ± 10.10 years. The optimal cutoff values of FGF21 and NT-pro-BNP for identifying left ventricular systolic dysfunction at baseline were 321.5 pg/mL and 131.3 ng/L, respectively, determined separately via ROC analysis. The areas under the curves were non-significant among FGF21, NT-pro-BNP and FGF21 + NT-pro-BNP as determined by pairwise comparisons. Both a higher serum level of FGF21 and a higher serum level of NT-pro-BNP were independent risk factors for left ventricular systolic dysfunction at baseline (odd ratio (OR) 3.138 [1.037-9.500], P = 0.043, OR 9.207 [2.036-41.643], P = 0.004, separately). Further Kaplan-Meier survival analysis indicated an association between both a higher serum level of FGF21 and a higher serum level of NT-pro-BNP with cardiac death in 5 years [RR 5.000 (1.326-18.861), P = 0.026; RR 9.643 (2

Development of low head Kaplan turbine for power station rehabilitation project

Science.gov (United States)

Lim, S. M.; Ohtake, N.; Kurosawa, S.; Suzuki, T.; Yamasaki, T.; Nishi, H.

2012-11-01

This paper presents the latest Kaplan turbine rehabilitation project for Funagira Power Station in Japan completed by J-POWER Group in collaboration with Toshiba Corporation. Area of rehabilitation was restricted to guide vane and runner. The main goal of the rehabilitation project was to expand the operating range of the existing turbine in terms of discharge and power with high operational stability, low noise as well as high cavitation performance. Computational Fluids Dynamics and model test were used to optimize the shape of guide vane and runner in development stage. Finally, field tests and runner inspection were carried out to confirm the performance of the new turbine. It was found that the new turbine has excellent performance in efficiency, power output, operational stability compared with existing turbine. Moreover, no sign of cavitation on the runner blade surface was observed after 5078 hours of operation near 100% load.

Development of low head Kaplan turbine for power station rehabilitation project

International Nuclear Information System (INIS)

Lim, S M; Ohtake, N; Kurosawa, S; Suzuki, T; Yamasaki, T; Nishi, H

2012-01-01

This paper presents the latest Kaplan turbine rehabilitation project for Funagira Power Station in Japan completed by J-POWER Group in collaboration with Toshiba Corporation. Area of rehabilitation was restricted to guide vane and runner. The main goal of the rehabilitation project was to expand the operating range of the existing turbine in terms of discharge and power with high operational stability, low noise as well as high cavitation performance. Computational Fluids Dynamics and model test were used to optimize the shape of guide vane and runner in development stage. Finally, field tests and runner inspection were carried out to confirm the performance of the new turbine. It was found that the new turbine has excellent performance in efficiency, power output, operational stability compared with existing turbine. Moreover, no sign of cavitation on the runner blade surface was observed after 5078 hours of operation near 100% load.

Learning curves in health professions education.

Science.gov (United States)

Pusic, Martin V; Boutis, Kathy; Hatala, Rose; Cook, David A

2015-08-01

Learning curves, which graphically show the relationship between learning effort and achievement, are common in published education research but are not often used in day-to-day educational activities. The purpose of this article is to describe the generation and analysis of learning curves and their applicability to health professions education. The authors argue that the time is right for a closer look at using learning curves-given their desirable properties-to inform both self-directed instruction by individuals and education management by instructors.A typical learning curve is made up of a measure of learning (y-axis), a measure of effort (x-axis), and a mathematical linking function. At the individual level, learning curves make manifest a single person's progress towards competence including his/her rate of learning, the inflection point where learning becomes more effortful, and the remaining distance to mastery attainment. At the group level, overlaid learning curves show the full variation of a group of learners' paths through a given learning domain. Specifically, they make overt the difference between time-based and competency-based approaches to instruction. Additionally, instructors can use learning curve information to more accurately target educational resources to those who most require them.The learning curve approach requires a fine-grained collection of data that will not be possible in all educational settings; however, the increased use of an assessment paradigm that explicitly includes effort and its link to individual achievement could result in increased learner engagement and more effective instructional design.

Lack of independent significance of a close (<1 mm) circumferential resection margin involvement in esophageal and junctional cancer.

Science.gov (United States)

O'Farrell, N J; Donohoe, C L; Muldoon, C; Costelloe, J M; King, S; Ravi, N; Reynolds, J V

2013-08-01

For rectal cancer, an involved circumferential resection margin (CRM), defined as tumor cells within 1 mm of the CRM, is of established prognostic significance. This definition for the esophagus, however, is controversial, with the UK Royal College of Pathologists (RCP) recommending the 1 mm definition, while the College of American Pathologists (CAP) advises that only tumor cells at the cut margin (0 mm) define an incomplete (R1) resection. The aim of this study was to compare the clinical significance of both definitions in patients with pT3 tumors. CAP- and RCP-defined CRM status in patients treated by surgery only or by multimodal therapy was recorded prospectively in a comprehensive database from May 2003 to May 2011. Kaplan-Meier survival curves were generated, and factors affecting survival were assessed by univariate and multivariate analysis. A total of 157 of 340 patients had pT3 esophageal tumors, with RCP-positive CRM in 60 %, and 18 % by CAP. There were no significant differences between RCP-positive CRM and negative margins for node-positive disease, local recurrence, and survival. CAP-positive CRM was associated with positive nodes (P = 0.036) and poorer survival (P = 0.023). Multivariate analysis revealed nodal invasion to be the only independent prognostic variable (P = 0.004). A CRM margin of CRM.

Power Curve Estimation With Multivariate Environmental Factors for Inland and Offshore Wind Farms

KAUST Repository

Lee, Giwhyun; Ding, Yu; Genton, Marc G.; Xie, Le

2015-01-01

In the wind industry, a power curve refers to the functional relationship between the power output generated by a wind turbine and the wind speed at the time of power generation. Power curves are used in practice for a number of important tasks

Analysis of power curves of Danish and foreign wind turbines

International Nuclear Information System (INIS)

Petersen, H.

1995-12-01

This report describes an analysis of power curves for a number of wind turbines, 30 Danish and 17 foreign - European - wind turbines. The investigation is limited to wind turbines of 150 kW capacity and greater, and to wind turbines for which a power curve is available. The power curves are transformed into a common, uniform presentation in order to facilitate the succeeding treatment, which primarily is the calculation of the production of electrical energy yielded per year. From the known data of the wind turbine, equipped generator power and rotor area and the area swept by the blades, the specific electrical production is calculated in three terms: yield per square meter of rotor area, yield per kW generator power and yield per square meter and per kilowatt generator power. Based on these findings a number of comparisons are established, such as comparisons of conceptual designs and technical- economical evaluations. (au)

Comparison of two methods to determine fan performance curves using computational fluid dynamics

Science.gov (United States)

Onma, Patinya; Chantrasmi, Tonkid

2018-01-01

This work investigates a systematic numerical approach that employs Computational Fluid Dynamics (CFD) to obtain performance curves of a backward-curved centrifugal fan. Generating the performance curves requires a number of three-dimensional simulations with varying system loads at a fixed rotational speed. Two methods were used and their results compared to experimental data. The first method incrementally changes the mass flow late through the inlet boundary condition while the second method utilizes a series of meshes representing the physical damper blade at various angles. The generated performance curves from both methods are compared with an experiment setup in accordance with the AMCA fan performance testing standard.

Vibration analysis of a hydro generator for different operating regimes

Science.gov (United States)

Haţiegan, C.; Pădureanu, I.; Jurcu, M.; Nedeloni, M. D.; Hamat, C. O.; Chioncel, C. P.; Trocaru, S.; Vasile, O.; Bădescu, O.; Micliuc, D.; (Filip Nedeloni, L.; Băra, A.; (Barboni Haţiegan, L.

2017-01-01

Based on experimental measurements, this paper presents the vibration analysis of a hydro generator that equips a Kaplan hydraulic turbine of a Hydropower plant in Romania. This analysis means vibrations measurement to different operating regimes of the hydro generator respectively before installing it and into operation, namely putting off load mode (unexcited and excited) respectively putting on load mode. By comparing, through the experimental results obtained before and after the operation of hydro aggregates are observed vibrations improvements.

The micro-optic photovoltaic behavior of solar cell along with microlens curved glass substrate

International Nuclear Information System (INIS)

Xie, Jin; Wu, Keke; Cheng, Jian; Li, Ping; Zheng, Jiahua

2015-01-01

Highlights: • A microlens array may be micro-ground on curved photovoltaic glass substrate. • Its micro-optical structure absorbs and scatters the inclined light to solar cell. • It increases conversion efficiency and fill factor in weak and inclined lights. • It improves electricity generation by about 4 times in scattered cloudy daylight. • It produces stronger electricity generation in cloudy day than in sunny day. - Abstract: A hybrid of microlens structure and curved surface may produce high value-added micro-optic performance. Hence, the microlens array is proposed on macro curved glass substrate of thin film solar cell. The objective is to understand how the micro-optic behavior of microlens curved array influences indoor power conversion efficiency and outdoor electricity generation. First, the absorptivities of visible light and infrared light were analyzed in connection with the curved microlens sizes; then the microlens curved glass substrate was fabricated by a Computer Numerical Control (CNC) micro-grinding with micro diamond wheel V-tip; finally, its photovoltaic properties and electricity generation were measured, respectively. It is shown that the microlens curved surface may strongly absorb and scatter light to solar cell. It increases the absorptivity of visible light against plane surface, but it decreases the one of infrared light against microlens surface. When it is applied to solar cell, it enhances the power conversion efficiency by 3.4–10.6% under oblique illumination. When it is applied to solar device, it increases the electricity generation of daylight by 119–106% against microlens surface and by 260–419% against traditional plane surface, respectively. The surprising finding is that it produces much larger electricity generation during cloudy day than during sunny day, but traditional plane surface does not so

Relationship between Activities of Daily Living and Readmission within 90 Days in Hospitalized Elderly Patients with Heart Failure

Directory of Open Access Journals (Sweden)

Masahiro Kitamura

2017-01-01

Full Text Available Aims. To examine the relationship between activities of daily living (ADL and readmission within 90 days and assess the cutoff value of ADL to predict readmission in hospitalized elderly patients with heart failure (HF. Methods. This cohort study comprised 589 consecutive patients with HF aged ≥65 years, who underwent cardiac rehabilitation from May 2012 to May 2016 and were discharged home. We investigated patients’ characteristics, basic attributes, and ADL (motor and cognitive Functional Independence Measure [FIM]. We analyzed the data using the unpaired t-test, χ2 test, Cox proportional hazard model, receiver operating characteristic (ROC curve, and Kaplan-Meier method. Results. Of 589 patients, 113 met the criteria, and they were divided into the nonreadmission (n=90 and readmission groups (n=23. Age, body mass index, New York Heart Association class, hemoglobin level, and motor FIM score were significantly different between the two groups (p<0.05. The body mass index (hazard ratio [HR]: 0.87; p<0.05 and motor FIM score (HR: 0.94; p<0.01 remained statistically significant. The cutoff value for the motor FIM score determined by ROC curve analysis was 74.5 points (area under the curve = 0.78; p<0.001. Conclusion. The motor FIM score in elderly patients with HF was an independent predictor of rehospitalization within 90 days.

Implementation of pressurized air injection system in a Kaplan prototype for the reduction of vibration caused by tip vortex cavitation

Science.gov (United States)

Rivetti, A.; Angulo, M.; Lucino, C.; Hene, M.; Capezio, O.; Liscia, S.

2016-11-01

Blade tip cavitation is a well-known phenomenon that affects the performance of large-diameter Kaplan turbines and induces structural vibration. Injection of pressurized air has been found to yield promising results in reducing those damaging effects. In this work, the results of an experimental test of air injection on a 9.5-m-diameter Kaplan turbine are reported. Experiments were performed for several load conditions and for two different net heads. Accelerations, pressure pulsation and noise emission were monitored for every tested condition. Results show that, at the expense of a maximum efficiency drop of 0.2%, air injection induces a decrease on the level of vibration from 57% up to 84%, depending on the load condition. Such decrease is seen to be proportional to the air flow rate, in the range from 0.06 to 0.8‰ (respect to the discharge at the best efficiency point).

Multiwavelength light curve parameters of Cepheid variables

Directory of Open Access Journals (Sweden)

Bhardwaj Anupam

2017-01-01

Full Text Available We present a comparative analysis of theoretical and observed light curves of Cepheid variables using Fourier decomposition. The theoretical light curves at multiple wavelengths are generated using stellar pulsation models for chemical compositions representative of Cepheids in the Galaxy and Magellanic Clouds. The observed light curves at optical (VI, near-infrared (JHKs and mid-infrared (3.6 & 4.5-μm bands are compiled from the literature. We discuss the variation of light curve parameters as a function of period, wavelength and metallicity. Theoretical and observed Fourier amplitude parameters decrease with increase in wavelength while the phase parameters increase with wavelength. We find that theoretical amplitude parameters obtained using canonical mass-luminosity levels exhibit a greater offset with respect to observations when compared to non-canonical relations. We also discuss the impact of variation in convective efficiency on the light curve structure of Cepheid variables. The increase in mixing length parameter results in a zero-point offset in bolometric mean magnitudes and reduces the systematic large difference in theoretical amplitudes with respect to observations.

Considerations for reference pump curves

International Nuclear Information System (INIS)

Stockton, N.B.

1992-01-01

This paper examines problems associated with inservice testing (IST) of pumps to assess their hydraulic performance using reference pump curves to establish acceptance criteria. Safety-related pumps at nuclear power plants are tested under the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code (the Code), Section 11. The Code requires testing pumps at specific reference points of differential pressure or flow rate that can be readily duplicated during subsequent tests. There are many cases where test conditions cannot be duplicated. For some pumps, such as service water or component cooling pumps, the flow rate at any time depends on plant conditions and the arrangement of multiple independent and constantly changing loads. System conditions cannot be controlled to duplicate a specific reference value. In these cases, utilities frequently request to use pump curves for comparison of test data for acceptance. There is no prescribed method for developing a pump reference curve. The methods vary and may yield substantially different results. Some results are conservative when compared to the Code requirements; some are not. The errors associated with different curve testing techniques should be understood and controlled within reasonable bounds. Manufacturer's pump curves, in general, are not sufficiently accurate to use as reference pump curves for IST. Testing using reference curves generated with polynomial least squares fits over limited ranges of pump operation, cubic spline interpolation, or cubic spline least squares fits can provide a measure of pump hydraulic performance that is at least as accurate as the Code required method. Regardless of the test method, error can be reduced by using more accurate instruments, by correcting for systematic errors, by increasing the number of data points, and by taking repetitive measurements at each data point

A Bayesian CUSUM plot: Diagnosing quality of treatment.

Science.gov (United States)

Rosthøj, Steen; Jacobsen, Rikke-Line

2017-12-01

To present a CUSUM plot based on Bayesian diagnostic reasoning displaying evidence in favour of "healthy" rather than "sick" quality of treatment (QOT), and to demonstrate a technique using Kaplan-Meier survival curves permitting application to case series with ongoing follow-up. For a case series with known final outcomes: Consider each case a diagnostic test of good versus poor QOT (expected vs. increased failure rates), determine the likelihood ratio (LR) of the observed outcome, convert LR to weight taking log to base 2, and add up weights sequentially in a plot showing how many times odds in favour of good QOT have been doubled. For a series with observed survival times and an expected survival curve: Divide the curve into time intervals, determine "healthy" and specify "sick" risks of failure in each interval, construct a "sick" survival curve, determine the LR of survival or failure at the given observation times, convert to weights, and add up. The Bayesian plot was applied retrospectively to 39 children with acute lymphoblastic leukaemia with completed follow-up, using Nordic collaborative results as reference, showing equal odds between good and poor QOT. In the ongoing treatment trial, with 22 of 37 children still at risk for event, QOT has been monitored with average survival curves as reference, odds so far favoring good QOT 2:1. QOT in small patient series can be assessed with a Bayesian CUSUM plot, retrospectively when all treatment outcomes are known, but also in ongoing series with unfinished follow-up. © 2017 John Wiley & Sons, Ltd.

Statistics about elliptic curves over finite prime fields

OpenAIRE

Gekeler, Ernst-Ulrich

2006-01-01

We derive formulas for the probabilities of various properties (cyclicity, squarefreeness, generation by random points) of the point groups of randomly chosen elliptic curves over random prime fields.

Estimation of Curve Tracing Time in Supercapacitor based PV Characterization

Science.gov (United States)

Basu Pal, Sudipta; Das Bhattacharya, Konika; Mukherjee, Dipankar; Paul, Debkalyan

2017-08-01

Smooth and noise-free characterisation of photovoltaic (PV) generators have been revisited with renewed interest in view of large size PV arrays making inroads into the urban sector of major developing countries. Such practice has recently been observed to be confronted by the use of a suitable data acquisition system and also the lack of a supporting theoretical analysis to justify the accuracy of curve tracing. However, the use of a selected bank of supercapacitors can mitigate the said problems to a large extent. Assuming a piecewise linear analysis of the V-I characteristics of a PV generator, an accurate analysis of curve plotting time has been possible. The analysis has been extended to consider the effect of equivalent series resistance of the supercapacitor leading to increased accuracy (90-95%) of curve plotting times.

Somatic mutation load of estrogen receptor-positive breast tumors predicts overall survival: an analysis of genome sequence data.

Science.gov (United States)

Haricharan, Svasti; Bainbridge, Matthew N; Scheet, Paul; Brown, Powel H

2014-07-01

Breast cancer is one of the most commonly diagnosed cancers in women. While there are several effective therapies for breast cancer and important single gene prognostic/predictive markers, more than 40,000 women die from this disease every year. The increasing availability of large-scale genomic datasets provides opportunities for identifying factors that influence breast cancer survival in smaller, well-defined subsets. The purpose of this study was to investigate the genomic landscape of various breast cancer subtypes and its potential associations with clinical outcomes. We used statistical analysis of sequence data generated by the Cancer Genome Atlas initiative including somatic mutation load (SML) analysis, Kaplan-Meier survival curves, gene mutational frequency, and mutational enrichment evaluation to study the genomic landscape of breast cancer. We show that ER(+), but not ER(-), tumors with high SML associate with poor overall survival (HR = 2.02). Further, these high mutation load tumors are enriched for coincident mutations in both DNA damage repair and ER signature genes. While it is known that somatic mutations in specific genes affect breast cancer survival, this study is the first to identify that SML may constitute an important global signature for a subset of ER(+) tumors prone to high mortality. Moreover, although somatic mutations in individual DNA damage genes affect clinical outcome, our results indicate that coincident mutations in DNA damage response and signature ER genes may prove more informative for ER(+) breast cancer survival. Next generation sequencing may prove an essential tool for identifying pathways underlying poor outcomes and for tailoring therapeutic strategies.

Application of willis covered stent in the treatment of aneurysms located in the cisternal segment of the internal carotid artery: a pilot comparative study with long-term follow-up results

International Nuclear Information System (INIS)

Zhu Yueqi; Li Minghua; Fang Chun; Wang Wu; Zhang Peilei; Cheng Yingsheng; Tan Huaqiao; Wang Jianbo

2010-01-01

Objective: Complicated aneurysms located in the cisternal segment of the internal carotid artery(ICA-CSA) present unique therapeutic difficulties. This study is to discuss the feasibility of the Willis stent-graft in treating complicated ICA-CSA by comparing its effect with that of coiling therapy. Methods: Willis covered stents were employed in 19 complicated ICA-CSAs (group A), while coils were used in 17 complicated ICA-CSAs (group B). Follow-up angiography was performed to investigate aneurysm recurrence, endoleak and parent artery (PA) stenosis. Kaplan-Meier curves were constructed to compare the recurrence-free and PA stenosis-free rate in both groups. Results: Total exclusion was immediately achieved in 13 ICA-CSAs and minor endoleaks presented in 5 cases in group A. Total or near-total occlusion was achieved in 7 ICA-CSAs, subtotal occlusion in 8 and partial occlusion in 2 cases in group B after coiling. Acute thrombosis occurred in 1 patient in either group and re-hemorrhage happened in 1 patient after coiling. Follow-up angiography in group A revealed that 16 ICA-CSAs were completely isolated, with two parent arteries showing mild in-stent stenosis. Eighteen months after the procedure, Kaplan-Meier analysis showed that the recurrence-free rate was 93.3% and 50%, while the stenosis-free rate of parent artery was 87.5% and 100% in group A and in Group B, respectively. In group A and group Bthe clinical neurological symptoms were fully recovered in 9 and 9, obviously improved in 3 and 5, unchanged in 2 and 2, and aggravated in one and 0 patients, respectively. Conclusion: The implantation of Willis stent-graft is a feasible endovascular therapy for complicated ICA-CSAs. When the parent artery is very tortuous or when the risk that a main collateral branch may be wrongly covered and occluded is present, the implantation of Willis covered stent can not be taken as the treatment of first choice. (authors)

Prognostic value of 18F-fluorodeoxyglucose positron emission tomography/computed tomography in patients with Barcelona Clinic Liver Cancer stages 0 and A hepatocellular carcinomas: a multicenter retrospective cohort study

International Nuclear Information System (INIS)

Hyun, Seung Hyup; Choi, Joon Young; Lee, Kyung-Han; Eo, Jae Seon; Lee, Jeong Won; Na, Sae Jung; Hong, Il Ki; Oh, Jin Kyoung; Chung, Yong An; Song, Bong-Il; Kim, Tae-Sung; Kim, Kyung Sik; Moon, Dae Hyuk; Yun, Mijin

2016-01-01

We evaluated the prognostic value of pretreatment 18 F-fluorodeoxyglucose positron emission tomography with computed tomography (FDG PET/CT) in patients with Barcelona Clinic Liver Cancer (BCLC) stage 0 or A hepatocellular carcinoma (HCC) who had received curative treatment or transarterial chemoembolization (TACE). Between 2009 and 2010, 317 patients diagnosed with HCC at seven hospitals were enrolled. Among these, 195 patients underwent curative treatments including resection, liver transplantation, and radiofrequency ablation. TACE was performed in 122 patients. The tumor-to-normal liver standardized uptake value ratio (TLR) of the primary tumor was measured using pretreatment FDG PET/CT. The prognostic significance of TLR and other clinical variables was assessed using Cox regression models. Differences in the overall survival (OS) associated with TLR or other significant clinical factors were examined using the Kaplan-Meier method. Over a median follow-up period of 46 months, 77 patients died from cancer. In the curative cohort, higher TLR (≥2) was significantly associated with death (hazard ratio [HR] = 2.68; 95 % CI, 1.16-6.15; P = 0.020) in multivariable analysis. Patients with a higher TLR had significantly worse OS than patients with a lower TLR (5-year overall survival, 61 % vs. 79.4 %; P = 0.006). In the TACE cohort, the Model for End-Stage Liver Disease (MELD) score (≥8) was a significant independent prognostic factor for OS (HR = 3.34; 95 % CI, 1.49-7.48; P = 0.003), whereas TLR was not associated with OS. The Kaplan-Meier curves showed significantly poorer OS in patients with higher MELD scores (≥8) than in those with lower MELD scores (5-year survival rate, 33.1 % vs. 79.6 %; P < 0.001). Pretreatment TLR measured using FDG PET/CT was an independent prognostic factor for OS in patients with BCLC stage 0 or A HCC undergoing curative treatment. In contrast, underlying liver function appeared to be important in predicting the prognosis of patients

Evaluation of batroxobin in preventing vascular restenosis in diabetic patients after infrapopliteal arterial angioplasty: a randomized comparative study

International Nuclear Information System (INIS)

Xue Bo; Zhang Peilei; Wang Jue; Li Minghua; Zhao Jungong; Zhu Yueqi; Tan Huaqiao; Wang Jianbo

2011-01-01

Objective: To evaluate batroxobin in preventing vascular restenosis in diabetic patients after infrapopliteal arterial angioplasty through comparing the clinical results of the combination use of batroxobin and aspirin with that of simple use of aspirin. Methods: After a successful angioplasty, fifty-two diabetic patients with symptomatic infrapopliteal obstructions were randomly divided into the study group (n=26) and the control group (n=26). Patients in both groups received 100 aspirin everyday, but the patients in study group additionally received 5 IU batroxobin intravenous drip every day for six times. At the end of the follow-up period lasting for 12 months, magnetic resonance angiography (MRA) or Doppler ultrasonic angiography was performed to check the vessels to see if there was any restenosis or reocclusion. The relief degree of clinical symptoms were observed, and both preoperative and postoperative ankle-brachial index (ABI) were regularly determined and compared. Kaplan-Meier curves were constructed to evaluate restenosis/reocclusion-free rate, limb salvage rate and amputation-free rate. Results: During the follow-up period the occurrence of restenosis/reocclusion in study group and control group was 22.0% and 34.5% respectively (P=0.0307). Statistically significant difference in ABI existed between two groups both after the procedure (P<0.05) and at 12 months after the treatment (P=0.0094). Clinical improvement and tissue healing in study group and control group were observed in 23 and 19 patients respectively (P=0.0544). Twelve months after angioplasty, Kaplan-Meier analysis showed that the restenosis/reocclusion-free rate, the limb salvage rate and the amputation-free rate for study group were 74.0%, 96.2% and 84.6% respectively, while they was 54.8%, 92.3% and 84.6% respectively for control group. Conclusion: The results of this study indicate that the use of the clinical therapeutic efficacy and markedly relieve the symptoms, although this

Predictors of biochemical failure in patients undergoing prostate whole-gland salvage cryotherapy: a novel risk stratification model.

Science.gov (United States)

Spiess, Philippe E; Levy, David A; Mouraviev, Vladimir; Pisters, Louis L; Jones, J Stephen

2013-08-01

the Kaplan-Meier bPFS curves of these risk groups being significantly different (P = 0.02 and cryotherapy. © 2013 BJU International.

Hyperfractionation in carcinoma of the cervix: tumor control and late bowel complications

International Nuclear Information System (INIS)

Viswanathan, Faith Rangad; Varghese, Cherian; Peedicayil, Abraham; Lakshmanan, Jeyaseelan; Narayan, Viswanathan Perungulam

1999-01-01

Purpose: Hyperfractionation has been advocated to improve local tumor control by increasing radiation dose without increasing late normal tissue complications. The aim of this study was to determine if hyperfractionation decreased late bowel complications. Methods and Materials: Thirty patients with Stage II and III cervical cancer were randomized to receive either hyperfractionation or conventional fractionation. Patients were followed for 5 years and monitored for tumor control, recurrence, and bowel complications. The relative risks of tumor control and bowel complications were computed at 1 year and 5 years of follow-up. Kaplan-Meier survival curves were plotted to determine probabilities of being tumor-free and bowel complication-free. Results: There were 15 patients in each group. At 1 year of follow-up, 2 patients in the hyperfractionation group (13%) and 7 patients in the conventional treatment group (45%) had tumor (relative risk [RR] 0.3; 95% confidence interval [CI] 0.1, 1.1; p = 0.054). Delayed bowel complications were seen in 8 patients in the hyperfractionation group and 1 patient in the conventional treatment group (RR 7.5; 95% CI 1.1, 52; p = 0.014). At 5 years, 2 patients in the hyperfractionation group and 8 patients in the conventional treatment group had tumor (RR 0.3; 95% CI 0.1, 1.1; p = 0.04). Delayed bowel complications (Grades 2 and 3) occurred in 9 women in the hyperfractionation group and 2 patients in the conventional group (RR 5.4; 95% CI 1.5, 19.5; p 0.0006). Kaplan-Meier analysis showed that the hyperfractionation group had significantly more bowel complications over the 5 years of follow-up (p 0.024). Conclusion: Hyperfractionation may result in better tumor control both at 1 year and at 5 years following treatment of cervical cancer. However, hyperfractionation could lead to increased late bowel complications and must be used judiciously in the treatment of cervical cancer

Graft survival rate of renal transplantation during a period of 10 years in Iran

Directory of Open Access Journals (Sweden)

Fatemeh Shahbazi

2015-01-01

Full Text Available Background: Kidney transplantation is a preferred treatment for many patients with end-stage renal disease (ESRD and is far more profitable than hemodialysis. Analyzing renal transplantation data can help to evaluate the effectiveness of transplantation interventions. The aim of this study was to determine the organ survival rate after kidney transplantation during a period of 10 years (March 2001-March 2011 among transplanted patients in Arak, Markazi Province, Iran. Materials and Methods: In this historical cohort study, all recipients of kidney transplantation from Arak, Markazi Province, Iran who had medical records in Valiasr Hospital and "charity for kidney patients" of Arak, Markazi Province, Iran during a period of 10 years from March 2001 to March 2011 were included. Data collected by using checklists were completed from patients′ hospital records. Kaplan-Meier method was used to determine the graft cumulative survival rate, log-rank test to compare survival curves in subgroups, and Cox regression model to define the hazard ratio and for ruling out the intervening factors. Statistical analysis was conducted by Statistical Package for the Social Sciences (SPSS 20 and Stata 11. Results: Mean duration of follow-up was 55.43 ± 42.02 months. By using the Kaplan-Meier method, the cumulative probability of graft survival at 1, 3, 5, 7, and 10 years was 99.1, 97.7, 94.3, 85.7, and 62.1%, respectively. The number of dialysis by controlling the effect of other variables had a significant association with the risk of graft failure [hazard ratios and 95% confidence interval (CI: 1.47 (1.02-2.13]. Conclusion: This study showed that the graft survival rate was satisfactory in this community and was similar to the results of single-center studies in the world. Dialysis time after transplantation was a significant predictor of survival in the recipients of kidney transplantation that should be considered.

Outcome of Acute Prosthetic Joint Infections Due to Gram-Negative Bacilli Treated with Open Debridement and Retention of the Prosthesis▿

Science.gov (United States)

Martínez-Pastor, Juan C.; Muñoz-Mahamud, Ernesto; Vilchez, Félix; García-Ramiro, Sebastián; Bori, Guillem; Sierra, Josep; Martínez, José A.; Font, Lluis; Mensa, Josep; Soriano, Alex

2009-01-01

The aim of our study was to evaluate the outcome of acute prosthetic joint infections (PJIs) due to gram-negative bacilli (GNB) treated without implant removal. Patients with an acute PJI due to GNB diagnosed from 2000 to 2007 were prospectively registered. Demographics, comorbidity, type of implant, microbiology data, surgical treatment, antimicrobial therapy, and outcome were recorded. Classification and regression tree analysis, the Kaplan-Meier survival method, and the Cox regression model were applied. Forty-seven patients were included. The mean age was 70.7 years, and there were 15 hip prostheses and 32 knee prostheses. The median number of days from the time of arthroplasty was 20. The most frequent pathogens were members of the Enterobacteriaceae family in 41 cases and Pseudomonas spp. in 20 cases. Among the Enterobacteriaceae, 14 were resistant to ciprofloxacin, while all Pseudomonas aeruginosa isolates were susceptible to ciprofloxacin. The median durations of intravenous and oral antibiotic treatment were 14 and 64 days, respectively. A total of 35 (74.5%) patients were in remission after a median follow-up of 463 days (interquartile range, 344 to 704) days. By use of the Kaplan-Meier survival curve, a C-reactive protein (CRP) concentration of ≤15 mg/dl (P = 0.03) and receipt of a fluoroquinolone, when all GNB isolated were susceptible (P = 0.0009), were associated with a better outcome. By use of a Cox regression model, a CRP concentration of ≤15 mg/dl (odds ratio [OR], 3.57; 95% confidence interval [CI], 1.05 to 12.5; P = 0.043) and receipt of a fluoroquinolone (OR, 9.09; 95% CI, 1.96 to 50; P = 0.005) were independently associated with better outcomes. Open debridement without removal of the implant had a success rate of 74.5%, and the factors associated with good prognosis were a CRP concentration at the time of diagnosis ≤15 mg/dl and treatment with a fluoroquinolone. PMID:19687237

Variability of the Wind Turbine Power Curve

Directory of Open Access Journals (Sweden)

Mahesh M. Bandi

2016-09-01

Full Text Available Wind turbine power curves are calibrated by turbine manufacturers under requirements stipulated by the International Electrotechnical Commission to provide a functional mapping between the mean wind speed v ¯ and the mean turbine power output P ¯ . Wind plant operators employ these power curves to estimate or forecast wind power generation under given wind conditions. However, it is general knowledge that wide variability exists in these mean calibration values. We first analyse how the standard deviation in wind speed σ v affects the mean P ¯ and the standard deviation σ P of wind power. We find that the magnitude of wind power fluctuations scales as the square of the mean wind speed. Using data from three planetary locations, we find that the wind speed standard deviation σ v systematically varies with mean wind speed v ¯ , and in some instances, follows a scaling of the form σ v = C × v ¯ α ; C being a constant and α a fractional power. We show that, when applicable, this scaling form provides a minimal parameter description of the power curve in terms of v ¯ alone. Wind data from different locations establishes that (in instances when this scaling exists the exponent α varies with location, owing to the influence of local environmental conditions on wind speed variability. Since manufacturer-calibrated power curves cannot account for variability influenced by local conditions, this variability translates to forecast uncertainty in power generation. We close with a proposal for operators to perform post-installation recalibration of their turbine power curves to account for the influence of local environmental factors on wind speed variability in order to reduce the uncertainty of wind power forecasts. Understanding the relationship between wind’s speed and its variability is likely to lead to lower costs for the integration of wind power into the electric grid.

3D flyable curves for an autonomous aircraft

Science.gov (United States)

Bestaoui, Yasmina

2012-11-01

The process of conducting a mission for an autonomous aircraft includes determining the set of waypoints (flight planning) and the path for the aircraft to fly (path planning). The autonomous aircraft is an under-actuated system, having less control inputs than degrees of freedom and has two nonholonomic (non integrable) kinematic constraints. Consequently, the set of feasible trajectories will be restricted and the problem of trajectory generation becomes more complicated than a simple interpolation. Care must be taken in the selection of the basic primitives to respect the kinematic and dynamic limitations. The topic of this paper is trajectory generation using parametric curves. The problem can be formulated as follows: to lead the autonomous aircraft from an initial configuration qi to a final configuration qf in the absence of obstacles, find a trajectory q(t) for 0 ≤t ≤ T. The trajectory can be broken down into a geometric path q(s), s being the curvilinear abscissa and s=s(t) a temporal function. In 2D the curves fall into two categories: • Curves whose coordinates have a closed form expressions, for example B-splines, quintic polynomials or polar splines. • Curves whose curvature is a function of their arc length for example clothoids, cubic spirals, quintic or intrinsic splines. Some 3D solutions will be presented in this paper and their effectiveness discussed towards the problem in hand.

Irregular conformal block, spectral curve and flow equations

International Nuclear Information System (INIS)

Choi, Sang Kwan; Rim, Chaiho; Zhang, Hong

2016-01-01

Irregular conformal block is motivated by the Argyres-Douglas type of N=2 super conformal gauge theory. We investigate the classical/NS limit of irregular conformal block using the spectral curve on a Riemann surface with irregular punctures, which is equivalent to the loop equation of irregular matrix model. The spectral curve is reduced to the second order (Virasoro symmetry, SU(2) for the gauge theory) and third order (W_3 symmetry, SU(3)) differential equations of a polynomial with finite degree. The conformal and W symmetry generate the flow equations in the spectral curve and determine the irregular conformal block, hence the partition function of the Argyres-Douglas theory ala AGT conjecture.

Unsatisfactory clinical outcomes of second-generation mobile bearing floating platform total knee arthroplasty: comparing outcomes with fixed bearing after five years minimum.

Science.gov (United States)

Yoon, Jung-Ro; Yang, Jae-Hyuk

2018-03-20

The purpose of this retrospective study was to analyze and compare the clinical and radiologic outcomes of fixed bearing ultracongruent (UC) insert total knee arthroplasty (TKA) and mobile bearing (MB) floating platform TKA using the navigation-assisted gap balancing technique with a minimum follow-up of five years. The study retrospectively enrolled 105 patients who received the UC type fixed bearing insert (group 1) and 95 patients who received the floating platform MB insert (group 2) during the period from August 2009 to June 2012. All surgery was performed using the navigation-assisted gap balancing technique. For strict assessment of gap measurements, the offset-type-force-controlled-spreader-system was used. Radiologic and clinical outcomes were assessed before operation and at the most recent follow-up using the Knee Society Score (KSS) and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score. For statistical analysis, paired sample t tests were used. A p value less than 0.05 was considered significant. Although the radiologic alignments were satisfactory for both groups (99/105 [94%] cases were neutral for group 1 and 90/95 [94%] for group 2), the functional and total WOMAC scores were inferior in group 2 (p bearing exchange. The Kaplan-Meier survivorship rates for groups 1 and 2 at 77 months were 100.0 and 97.9%, respectively. Second-generation MB floating platform TKA cases did not have satisfactory outcomes. There were two cases of insert breakage, which required bearing exchange. Other patients who underwent surgery with second-generation MB floating platform were encouraged to avoid high knee flexion activities, resulting in lower clinical performance.

77 FR 58367 - Exelon Generation Company, LLC; Notice of Application Tendered for Filing With the Commission and...

Science.gov (United States)

2012-09-20

... Avenue, Washington, DC 20001, at (202) 347-7500 or email at [email protected] . i. FERC... integral with the dam and is composed of 13 turbine-generator units, draft tubes, and transformer bays. The... Kaplan-type hydraulic turbines. Units 1, 3, 4, 6 and 7 have 47.7-MW generators; Units 2 and 5 have 36.0...

Establishment and validation of a predictive nomogram model for non-small cell lung cancer patients with chronic hepatitis B viral infection.

Science.gov (United States)

Chen, Shulin; Lai, Yanzhen; He, Zhengqiang; Li, Jianpei; He, Xia; Shen, Rui; Ding, Qiuying; Chen, Hao; Peng, Songguo; Liu, Wanli

2018-05-04

This study aimed to establish an effective predictive nomogram for non-small cell lung cancer (NSCLC) patients with chronic hepatitis B viral (HBV) infection. The nomogram was based on a retrospective study of 230 NSCLC patients with chronic HBV infection. The predictive accuracy and discriminative ability of the nomogram were determined by a concordance index (C-index), calibration plot and decision curve analysis and were compared with the current tumor, node, and metastasis (TNM) staging system. Independent factors derived from Kaplan-Meier analysis of the primary cohort to predict overall survival (OS) were all assembled into a Cox proportional hazards regression model to build the nomogram model. The final model included age, tumor size, TNM stage, treatment, apolipoprotein A-I, apolipoprotein B, glutamyl transpeptidase and lactate dehydrogenase. The calibration curve for the probability of OS showed that the nomogram-based predictions were in good agreement with the actual observations. The C-index of the model for predicting OS had a superior discrimination power compared with the TNM staging system [0.780 (95% CI 0.733-0.827) vs. 0.693 (95% CI 0.640-0.746), P  20.0). The proposed nomogram model resulted in more accurate prognostic prediction for NSCLC patients with chronic HBV infection.

Abnormal early cleavage events predict early embryo demise: sperm oxidative stress and early abnormal cleavage.

Science.gov (United States)

Burruel, Victoria; Klooster, Katie; Barker, Christopher M; Pera, Renee Reijo; Meyers, Stuart

2014-10-13

Human embryos resulting from abnormal early cleavage can result in aneuploidy and failure to develop normally to the blastocyst stage. The nature of paternal influence on early embryo development has not been directly demonstrated although many studies have suggested effects from spermatozoal chromatin packaging, DNA damage, centriolar and mitotic spindle integrity, and plasma membrane integrity. The goal of this study was to determine whether early developmental events were affected by oxidative damage to the fertilizing sperm. Survival analysis was used to compare patterns of blastocyst formation based on P2 duration. Kaplan-Meier survival curves demonstrate that relatively few embryos with short (P2 times reached blastocysts, and the two curves diverged beginning on day 4, with nearly all of the embryos with longer P2 times reaching blastocysts by day 6 (p < .01). We determined that duration of the 2nd to 3rd mitoses were sensitive periods in the presence of spermatozoal oxidative stress. Embryos that displayed either too long or too short cytokineses demonstrated an increased failure to reach blastocyst stage and therefore survive for further development. Although paternal-derived gene expression occurs later in development, this study suggests a specific role in early mitosis that is highly influenced by paternal factors.

Elevated levels of serum nidogen-2 in esophageal squamous cell carcinoma.

Science.gov (United States)

Chai, Annie Wai Yeeng; Cheung, Arthur Kwok Leung; Dai, Wei; Ko, Josephine Mun Yee; Lee, Nikki Pui Yue; Chan, Kin Tak; Law, Simon Ying-Kit; Lung, Maria Li

2018-02-14

Nidogen-2 (NID2), a secretory basement membrane protein, has been implicated as a potential biomarker in ovarian cancer and hepatocellular carcinoma. In this study, we aimed to investigate the utility of detecting serum NID2 levels for identification of esophageal squamous cell carcinoma (ESCC) patients and prediction of poor survival outcome. Using an in-house NID2 enzyme-linked immunosorbent assay (ELISA), serum samples from 101 ESCC patients and 50 healthy controls were screened for their NID2 levels. The serum NID2 levels in ESCC patients (median 24.4 μg/L) are significantly higher (p= 4.3e-09) than that of the healthy controls (median 15.85 μg/L). The receiver operating characteristic (ROC) curve demonstrated an area under the curve of 0.756. At the threshold of 17.95 μg/L, the sensitivity and specificity achieved are 0.76 and 0.63, respectively. Kaplan-Meier survival analysis revealed that patients with high serum NID2 levels (⩾ 32.6 μg/L) have significantly higher risk of death (HR = 1.984, 95% CI: 1.175-3.349; log-rank p-value = 0.012) compared to those with low serum NID2 levels (levels has potential diagnostic and prognostic value for ESCC patients.

PARP-1 serves as a novel molecular marker for hepatocellular carcinoma in a Southern Chinese Zhuang population.

Science.gov (United States)

Li, Jiatong; Dou, Dongwei; Li, Ping; Luo, Wenqi; Lv, Wenxin; Zhang, Chengdong; Song, Xiaowei; Yang, Yuan; Zhang, Yuening; Xu, Yanzhen; Xiao, Feifan; Wei, Yan; Qin, Jian; Li, Hongtao; Yang, Xiaoli

2017-07-01

PARP-1 (poly(ADP-ribose) polymerase-1) plays an important role in tumorigenesis. Since its effects on different populations are varied, this study investigated the impact of PARP-1 on primary hepatocellular carcinoma in a Southern Chinese Zhuang population. We assessed the global PARP-1 messenger RNA expression in patients with hepatocellular carcinoma using The Cancer Genome Atlas dataset. Increased PARP-1 expression, related to alpha-fetoprotein level, was observed. The area under the receiver operating characteristic curve value was 0.833. Kaplan-Meier survival curves indicated that higher PARP-1 expression was not correlated with poorer overall survival and recurrence-free survival. In a Zhuang population, PARP-1 messenger RNA and protein levels were increased in the hepatocellular carcinoma tissue and its adjacent liver tissues as assessed by quantitative polymerase chain reaction, immunohistochemistry, and western blotting. Higher PARP-1 level was associated with a higher tumor stage (p  0.05). Further analysis suggested that H2AX, a PARP-1 protein interaction partner, was coordinated with PARP-1 in hepatocellular carcinoma tumorigenesis. Overall, some new characteristics of PARP-1 expression were noted in the Zhuang population. PARP-1 is a novel promising diagnostic marker for hepatocellular carcinoma in the Southern Chinese Zhuang population.

Bragg Curve, Biological Bragg Curve and Biological Issues in Space Radiation Protection with Shielding

Science.gov (United States)

Honglu, Wu; Cucinotta, F.A.; Durante, M.; Lin, Z.; Rusek, A.

2006-01-01

The space environment consists of a varying field of radiation particles including high-energy ions, with spacecraft shielding material providing the major protection to astronauts from harmful exposure. Unlike low-LET gamma or X-rays, the presence of shielding does not always reduce the radiation risks for energetic charged particle exposure. Since the dose delivered by the charged particle increases sharply as the particle approaches the end of its range, a position known as the Bragg peak, the Bragg curve does not necessarily represent the biological damage along the particle traversal since biological effects are influenced by the track structure of both primary and secondary particles. Therefore, the biological Bragg curve is dependent on the energy and the type of the primary particle, and may vary for different biological endpoints. To achieve a Bragg curve distribution, we exposed cells to energetic heavy ions with the beam geometry parallel to a monolayer of fibroblasts. Qualitative analyses of gamma-H2AX fluorescence, a known marker of DSBs, indicated increased clustering of DNA damage before the Bragg peak, enhanced homogenous distribution at the peak, and provided visual evidence of high linear energy transfer (LET) particle traversal of cells beyond the Bragg peak. A quantitative biological response curve generated for micronuclei (MN) induction across the Bragg curve did not reveal an increased yield of MN at the location of the Bragg peak. However, the ratio of mono-to bi-nucleated cells, which indicates inhibition in cell progression, increased at the Bragg peak location. These results, along with other biological concerns, show that space radiation protection with shielding can be a complicated issue.

Numerical Analysis of Flow in Kaplan Turbine Runner Blades Anticavitation Lip with Modified Hydro-dynamic Profile

Directory of Open Access Journals (Sweden)

Vasile Cojocaru

2011-09-01

Full Text Available In order to increase the lifetime of runner blades of Kaplan turbines damaged by cavitation erosion, an anticavitation lip is attached to the periphery of the runner blades on the suction side. The anticavitation lip overtakes the cavitation pitting which appears between the runner blades and the runner chamber. A blade with the original anticavitation lip was modeled using CAE. The numerical simulations showed the tip vortex position and the source of the cavitation erosion. Using these data, a modified profile of the anticavitation lip was designed.

Computer-aided design of curved surfaces with automatic model generation

Science.gov (United States)

Staley, S. M.; Jerard, R. B.; White, P. R.

1980-01-01

The design and visualization of three-dimensional objects with curved surfaces have always been difficult. The paper given below describes a computer system which facilitates both the design and visualization of such surfaces. The system enhances the design of these surfaces by virtue of various interactive techniques coupled with the application of B-Spline theory. Visualization is facilitated by including a specially built model-making machine which produces three-dimensional foam models. Thus, the system permits the designer to produce an inexpensive model of the object which is suitable for evaluation and presentation.

MEKK1 is a Novel Regulator of the Dmp1-Arf-p53 Pathway and Prognostic Indicator in Breast Cancer

Science.gov (United States)

2012-12-01

hDMP1, INK4a/ARF, p53 or Hdm2 amplification. Kaplan -Meier analyses have been conducted to study the impact for the impact of loss or gain of each locus on...Palma P, Pellegrini S, Fina P et al. Mdm2 gene alterations and mdm2 protein expression in breast carcinomas. J Pathol 1995; 175: 31–38. 21 Turbin DA

Application of Enlisted Force Retention Levels and Career Field Stability

Science.gov (United States)

2017-03-23

APPLICATION OF ENLISTED FORCE RETENTION LEVELS AND CAREER FIELD STABILITY THESIS Presented to the Faculty Department of Operational Sciences ...Fulfillment of the Requirements for the Degree of Master of Science in Operations Research Jamie T. Zimmermann, MS, BS Captain, USAF March 2017...Appendix B. The function proc lifetest is a nonparametric estimate of the survivor function using either the Kaplan-Meier method or the actuarial

Modelos estimados de análisis de supervivencia para el tiempo de permanencia de los estudiantes de la Universidad Francisco de Paula Santander

OpenAIRE

Mawency Vergel Ortega; José Joaquín Martínez Lozano; Eduardo Ibargüen Mondragón

2016-01-01

The article shows factors associated with college desertion. The survival analysis technique allowed to perform a study with students from different programs at the Francisco de Paula Santander University, considering the events: semester, abandonment, punishment, punishment - abandonment. Using the Kaplan-Meier estimator [1], the survival function for each event of interest was estimated and desertion models whose variables were significant at 10% using the semi-parametric met...

Resultado do tratamento cirúrgico das neoplasias do seio piriforme

Directory of Open Access Journals (Sweden)

Costa Claudiney C.

2003-01-01

Full Text Available Os tumores da laringe e hipofaringe apresentam alta incidência no Brasil, sendo o sexto sítio mais comum entre os tumores malignos no sexo masculino. O diagnóstico inicial geralmente é realizado com lesões em estadio clínicos avançados diminuindo o sucesso do tratamento instituído. OBJETIVOS: Avaliar a evolução de 60 pacientes com carcinoma epidermóide de seio piriforme, considerando tratamento instituído, complicações e sobrevida estimada em 5 anos. FORMA DE ESTUDO: Estudo retrospectivo. MÉTODO: Os testes estatístico utilizados foram o método de Kaplan-Meier e o teste exato de Fisher. RESULTADOS: Dos 60 pacientes, 43 foram submetidos a tratamento cirúrgico seguido de radioterapia. Atualmente 27,9% estão vivos sem doença, 11,6% vivos com doença, 9,4% mortos sem doença, 34,8% mortos com doença e perda de seguimento de 16,3%. A complicação pós-operatória mais freqüente foi a fístula cutânea. A recidiva local ocorreu em 5 pacientes, regional em 6, loco-regional em 3 e metástase à distância em 6. Não houve correlação entre margem cirúrgica comprometida e sobrevida em 20 pacientes com recidiva tumoral (Teste de Fisher. Aplicando a curva de sobrevida atuarial pelo método Kaplan-Meier, obtivemos média de sobrevida em 5 anos de 23,2 meses. CONCLUSÃO: A principal complicação pós-operatória foi a fístula cutânea, sendo tratada clinicamente. A margem cirúrgica comprometida não alterou o prognóstico, apesar de ser sempre um dos princípios da cirurgia oncológica. A principal falha no tratamento foi a recidiva locorregional. A curva de sobrevida atuarial (Kaplan-Meier em cinco anos apresentou média de 23,2 meses.

Pesticide mixtures in the Swedish streams: Environmental risks, contributions of individual compounds and consequences of single-substance oriented risk mitigation.

Science.gov (United States)

Gustavsson, Mikael; Kreuger, Jenny; Bundschuh, Mirco; Backhaus, Thomas

2017-11-15

This paper presents the ecotoxicological assessment and environmental risk evaluation of complex pesticide mixtures occurring in freshwater ecosystems in southern Sweden. The evaluation is based on exposure data collected between 2002 and 2013 by the Swedish pesticide monitoring program and includes 1308 individual samples, detecting mixtures of up to 53 pesticides (modal=8). Pesticide mixture risks were evaluated using three different scenarios for non-detects (best-case, worst-case and using the Kaplan-Meier method). The risk of each scenario was analyzed using Swedish Water Quality Objectives (WQO) and trophic-level specific environmental thresholds. Using the Kaplan-Meier method the environmental risk of 73% of the samples exceeded acceptable levels, based on an assessment using Concentration-Addition and WQOs for the individual pesticides. Algae were the most sensitive organism group. However, analytical detection limits, especially for insecticides, were insufficient to analyze concentrations at or near their WQO's. Thus, the risk of the analyzed pesticide mixtures to crustaceans and fish is systematically underestimated. Treating non-detects as being present at their individual limit of detection increased the estimated risk by a factor 100 or more, compared to the best-case or the Kaplan-Meier scenario. Pesticide mixture risks are often driven by only 1-3 compounds. However, the risk-drivers (i.e., individual pesticides explaining the largest share of potential effects) differ substantially between sites and samples, and 83 of the 141 monitored pesticides need to be included in the assessment to account for 95% of the risk at all sites and years. Single-substance oriented risk mitigation measures that would ensure that each individual pesticide is present at a maximum of 95% of its individual WQO, would also reduce the mixture risk, but only from a median risk quotient of 2.1 to a median risk quotient of 1.8. Also, acceptable total risk levels would still

Marginal abatement cost curves for Heavy Duty Vehicles. Background report

Energy Technology Data Exchange (ETDEWEB)

Schroten, A.; Warringa, G.; Bles, M.

2012-09-15

Cost curves were calculated for CO2 abatement technologies for Heavy Duty Vehicles. These curves were elaborated for eight different vehicle categories (six categories of truck and two subcategories), as well as for an 'average' truck and bus. Given that cost curves depend very much on underlying assumptions, the MACH model (Marginal Abatement Costs of Heavy duty vehicles) was developed. This model allows users to enter their own assumptions with respect to parameters like fuel prices and cost and lifetime of individual technologies, with the model then generating new cost curves for the various vehicle categories. This background report contains a description of the model and a summary of the results of several model runs.

La chiesa di Richard Meier a Tor Tre Teste e il suo contributo al consolidamento identitario dei nuovi quartieri romani oltre il GRA / The church designed by Richard Meier in Tor Tre Teste and the identity consolidation in the new roman neighbourhoods beyond the Great Circular Road

Directory of Open Access Journals (Sweden)

Giuseppe Bonaccorso

2014-06-01

Full Text Available Il contributo proposto ha l’obiettivo di analizzare alcuni significativi brani del tessuto urbano della periferia est di Roma, adottando metodi interpretativi legati alla storia, alla società, alla programmazione urbanistica e alla costruzione. Gli aspetti salienti del quadrante orientale della periferia romana verranno così delineati partendo “dal di dentro”, sottolineandone i percorsi, gli spazi e i nuclei compositivi che sono all’origine della struttura e della forma stessa dei quartieri disposti a cavallo del Grande Raccordo Anulare. In questo ambito, si pone l’attenzione su alcuni episodi chiave che vedono protagoniste le nuove chiese che riescono a creare una centralità all’interno dei quartieri periferici sostituendo le biblioteche, le piazze e i centri commerciali.  Analizzando da vicino questi esempi, si scopre come di recente sono state realizzate chiese firmate da architetti di fama internazionale proprio allo scopo di rafforzare, o meglio di costruire, un fattore identitario per ciascun quartiere ubicato nel settore orientale della città. Partendo quindi dal generale si arriva a indagare una chiesa e un quartiere che possono essere considerati un modello da seguire per tutta la periferia a ridosso del GRA: la chiesa giubilare di Dio Padre Misericordioso progettata da Richard Meier nel quartiere di Tor Tre Teste. La sequenzialità degli eventi che hanno contraddistinto il concorso per la progettazione della chiesa, la scelta della proposta di Richard Meier, la complessità del cantiere, l’analisi tecnica, stilistica e simbolica della realizzazione finale sono quindi analizzate nell’ambito del rapporto con il quartiere e del tentativo di realizzare (attraverso di essa un centro di attrazione per tutta la periferia.   The article analyses some significant parts of the urban tissue at the eastern periphery of Rome, using the interpretative methods inherent to history, society, urban programming and construction

Beyond the five-year horizon: long-term outcome of high-risk and inoperable patients undergoing TAVR with first-generation devices.

Science.gov (United States)

Deutsch, Marcus-André; Erlebach, Magdalena; Burri, Melchior; Hapfelmeier, Alexander; Witt, Olivia Ganga; Ziegelmueller, Johannes Amadeus; Wottke, Michael; Ruge, Hendrik; Krane, Markus; Piazza, Nicolo; Bleiziffer, Sabine; Lange, Rüdiger

2018-05-20

We sought to determine the long-term outcome of high-risk patients who underwent transcatheter aortic valve replacement (TAVR) with first-generation devices with a focus on the identification of predictors for mortality and valve durability. Consecutive patients in our prospective single-centre registry undergoing TAVR with first-generation devices (n=214 CoreValve; n=86 SAPIEN) between 06/2007 and 07/2009 were retrospectively analysed (n=300, mean age 81.43±6.55 years, mean STS score 6.5±4.5%). Kaplan-Meier estimates of survival and the Cox proportional hazards model were used to identify independent predictors of all-cause-mortality. At 1, 5, and 7 years, estimated survival rates were 76.0%, 40.2%, and 23.2%, respectively. Age-adjusted baseline predictors of mortality included atrial fibrillation, impaired kidney function, peripheral artery disease, and mitral regurgitation (≥moderate). Baseline risk-adjusted procedure-related predictors for all-cause mortality included acute kidney injury, neurological events, major vascular complications, and major/life-threatening bleeding. At both five and six years, 78.2% of surviving patients were in NYHA Class I or II. PVL was ≤mild in the majority of patients at discharge and throughout follow-up. At seven years, the overall crude cumulative incidence of structural valve deterioration according to the 2017 EAPCI/ESC/EACTS definition was 14.9% (CoreValve 11.8% vs. SAPIEN 22.6%; p=0.01). Seven years after TAVR, 23.2% of high-risk patients were still alive. Independent predictors of all-cause mortality included both patient- and procedure-related factors. With a cumulative incidence of 14.9% at seven years, there is some suggestion that SVD post TAVR may become increasingly relevant during longer-term follow-up.

Reflection curves—new computation and rendering techniques

Directory of Open Access Journals (Sweden)

Dan-Eugen Ulmet

2004-05-01

Full Text Available Reflection curves on surfaces are important tools for free-form surface interrogation. They are essential for industrial 3D CAD/CAM systems and for rendering purposes. In this note, new approaches regarding the computation and rendering of reflection curves on surfaces are introduced. These approaches are designed to take the advantage of the graphics libraries of recent releases of commercial systems such as the OpenInventor toolkit (developed by Silicon Graphics or Matlab (developed by The Math Works. A new relation between reflection curves and contour curves is derived; this theoretical result is used for a straightforward Matlab implementation of reflection curves. A new type of reflection curves is also generated using the OpenInventor texture and environment mapping implementations. This allows the computation, rendering, and animation of reflection curves at interactive rates, which makes it particularly useful for industrial applications.

Resistance within hemodialysis shunts predicts patency.

Science.gov (United States)

Bui, Trung D; Gordon, Ian L; Parashar, Amish; Vo, David; Wilson, Samuel E

2006-01-01

The authors examined the relationship between patency after thrombectomy of clotted dialysis grafts and intraoperative measurements of flow (Q), pressure gradient (PGR), and longitudinal resistance (RL). Eighteen thrombosed arteriovenous (AV) grafts underwent 21 thrombectomies. Pressures at arterial (P1) and venous (P2) ends of the AV grafts were determined with 22-gauge catheters and standard transducers; flow was measured with transit-time probes; arithmetic averaging of waveforms was used to compute mean Q, PGR, and RL. Kaplan-Meier patency curves were analyzed by using log rank methods. Mean patency for all grafts was 164 +/-152 days. For each variable, the 21 measurements were split and the patency curve for the grafts with the 11 lowest value grafts was compared to the curve representing the 10 highest value grafts. The difference between high RL versus low RL patency curves was significant with high-resistance grafts having a median patency of 55 days and low-resistance grafts having a median patency greater than 151 days (p = 0.0089). In contrast, the high Q group median patency was 151 days versus 174 days for the low Q group (p = 0.86). Median patency for the low PGR group was 115 days compared to 62 days for the high PGR group (p = 0.162). Longitudinal resistance within AV grafts, but not flow or pressure gradient, showed a significant correlation with patency after thrombectomy. Increased resistance to flow within AV grafts appears to be an important factor affecting the propensity of dialysis grafts to thrombose.

Efficient pseudorandom generators based on the DDH assumption

NARCIS (Netherlands)

Rezaeian Farashahi, R.; Schoenmakers, B.; Sidorenko, A.; Okamoto, T.; Wang, X.

2007-01-01

A family of pseudorandom generators based on the decisional Diffie-Hellman assumption is proposed. The new construction is a modified and generalized version of the Dual Elliptic Curve generator proposed by Barker and Kelsey. Although the original Dual Elliptic Curve generator is shown to be

Survival of a cohort of women with cervical cancer diagnosed in a Brazilian cancer center Sobrevida de mujeres con cáncer de cuello uterino diagnosticadas en un centro brasileño Sobrevida de mulheres com câncer de colo uterino diagnosticadas em um centro brasileiro

Directory of Open Access Journals (Sweden)

Claudio Calazan do Carmo

2011-08-01

Full Text Available OBJECTIVE: To assess overall survival of women with cervical cancer and describe prognostic factors associated. METHODS: A total of 3,341 cases of invasive cervical cancer diagnosed at the Brazilian Cancer Institute, Rio de Janeiro, southeastern Brazil, between 1999 and 2004 were selected. Clinical and pathological characteristics and follow-up data were collected. There were performed a survival analysis using Kaplan-Meier curves and a multivariate analysis through Cox model. RESULTS: Of all cases analyzed, 68.3% had locally advanced disease at the time of diagnosis. The 5-year overall survival was 48%. After multivariate analysis, tumor staging at diagnosis was the single variable significantly associated with prognosis (pOBJETIVO: Evaluar la sobrevida global de mujeres con cáncer de cuello uterino e identificar factores pronósticos relacionados. MÉTODOS: Todos los 3.341 casos tratados en el Instituto Nacional de Cáncer, Rio de Janeiro, Sureste de Brasil, entre 1999 y 2004 fueron seleccionados y sus datos clínicos, anatomo-patológicos y de seguimiento fueron colectados. Se utilizaron la curva de Kaplan-meier y el modelo de Cox par evaluación de la sobrevida y para análisis logística múltiple, respectivamente. RESULTADOS: De los casos estudiados, 68,3% presentaban enfermedad localmente avanzada. La sobrevida en cinco años fue de 48%. Posterior al análisis múltiple, el estadio clínico al diagnóstico fue la única variable significativamente asociada con el pronóstico (pOBJETIVO: Avaliar a sobrevida global de mulheres com câncer de colo uterino e identificar fatores prognósticos relacionados. MÉTODOS: Todos os 3.341 casos tratados no Instituto Nacional de Câncer, Rio de Janeiro, RJ, entre 1999 e 2004 foram selecionados e seus dados clínicos, anatomo-patológicos e de seguimento foram coletados. Foram utilizados a curva de Kaplan-Meier e o modelo de Cox para avaliação da sobrevida e para análise logística m

How Do We Defend Democratic Education? Lois Weiner and Andy Kaplan Respond to Diane Ravitch's "The Reign of Error"

Science.gov (United States)

Weiner, Lois; Kaplan, Andy

2014-01-01

In this commentary, Andy Kaplan discusses with Lois Weiner, Diane Ravitch's latest book "The Reign of Error," which combines scholarly argument and scrupulous research in defense of democratic education. Weiner notes, the book will prove an important resource in the ongoing struggle for the survival of public schooling. Weiner adds,…

Early Experience with a Modern Generation Knee System: Average 2 Years’ Follow-up

Directory of Open Access Journals (Sweden)

Thomas Paszicsnyek

2015-12-01

Full Text Available Arthritis in the knee is a leading cause of pain and disability with total knee arthroplasty (TKA often the treatment of choice after failure of more conservative treatments. TKA has been demonstrated to be one of the most successful procedures performed.  However, despite the good long-term survivorship rates, patient satisfaction is still an issue post TKA with over 20% of patients exhibiting patient dissatisfaction most commonly due to anterior knee pain (over 18-28% patients and mediolateral or varus-valgus instability.  Recent studies have demonstrated that collateral ligament strains are altered post TKA which may lead to laxity and/or tightness of the ligaments resulting in patient discomfort, pain, stiffness and/or instability post TKA.  As a result, it may be beneficial to ensure ligamentous strains after TKA are similar or close to the native situation.  The purpose of this study was to evaluate the clinical and radiographic results of the Unity Knee™ Total Knee System (Corin Ltd, Cirencester, UK, a modern generation, single-radius total knee replacement (TKR and its accompanying instrumentation which is designed to help maintain proper ligament balance and restore the medial jointline.  A total of 89 knees (89 patients were implanted with the device in a single surgeon series.  All patients were assessed using the American Knee Society Score (AKSS, the Oxford Knee Score (OKS, and radiographs.  There was 1 revision due to infection and Kaplan-Meier survivorship was 98.9% at 2 years.  The mean AKSS knee score for the total cohort was 87.1 ± 7.98 and the mean Oxford Knee score was 45.89 + 3.69. Radiographic review found no signs of radiographic failure in any of the knees. This study demonstrates good survivorship, clinical, and radiographic results at 2 years for this TKR.

The regulatory BCL2 promoter polymorphism (-938C>A) is associated with relapse and survival of patients with oropharyngeal squamous cell carcinoma.

Science.gov (United States)

Lehnerdt, G F; Franz, P; Bankfalvi, A; Grehl, S; Kelava, A; Nückel, H; Lang, S; Schmid, K W; Siffert, W; Bachmann, H S

2009-06-01

Expression of the antiapoptotic and antiproliferative protein B-cell lymphoma 2 (Bcl-2) has been repeatedly shown to be associated with better locoregional control and patients' survival in oropharyngeal squamous cell carcinoma (OSCC). A regulatory (-938C>A) single-nucleotide polymorphism (SNP) in the inhibitory P2 BCL2 gene promoter generates significantly different BCL2 promoter activities and has been associated with outcome in different malignancies. The aim of the present study was to analyze the possible influence of the (-938C>A) SNP on survival of patients suffering from OSCC. One hundred and thirty-three patients with primary OSCC were retrospectively investigated. Bcl-2 expression of tumor cells was demonstrated by means of immunohistochemistry. Both the Bcl-2 expression and the (-938C>A) genotypes were correlated with the patients' survival. The (-938C>A) SNP was significantly related to Bcl-2 expression (P = 0.008). Kaplan-Meier curves revealed a significant association of the -938 SNP with relapse-free (P = 0.0283) and overall survival (P = 0.0247). Multiple Cox regression identified the BCL2 (-938CC) genotype as an independent prognostic factor for relapse [hazard ratio (HR) 1.898, P = 0.021] as well as for death in OSCC patients (HR 1.897, P = 0.013). The (-938C>A) SNP represents a potential novel prognostic marker in patients with OSCC that could help to identify a group of patients at high risk for relapse and death.

Modeling survival: application of the Andersen-Gill model to Yellowstone grizzly bears

Science.gov (United States)

Johnson, Christopher J.; Boyce, Mark S.; Schwartz, Charles C.; Haroldson, Mark A.

2004-01-01

 Wildlife ecologists often use the Kaplan-Meier procedure or Cox proportional hazards model to estimate survival rates, distributions, and magnitude of risk factors. The Andersen-Gill formulation (A-G) of the Cox proportional hazards model has seen limited application to mark-resight data but has a number of advantages, including the ability to accommodate left-censored data, time-varying covariates, multiple events, and discontinuous intervals of risks. We introduce the A-G model including structure of data, interpretation of results, and assessment of assumptions. We then apply the model to 22 years of radiotelemetry data for grizzly bears (Ursus arctos) of the Greater Yellowstone Grizzly Bear Recovery Zone in Montana, Idaho, and Wyoming, USA. We used Akaike's Information Criterion (AICc) and multi-model inference to assess a number of potentially useful predictive models relative to explanatory covariates for demography, human disturbance, and habitat. Using the most parsimonious models, we generated risk ratios, hypothetical survival curves, and a map of the spatial distribution of high-risk areas across the recovery zone. Our results were in agreement with past studies of mortality factors for Yellowstone grizzly bears. Holding other covariates constant, mortality was highest for bears that were subjected to repeated management actions and inhabited areas with high road densities outside Yellowstone National Park. Hazard models developed with covariates descriptive of foraging habitats were not the most parsimonious, but they suggested that high-elevation areas offered lower risks of mortality when compared to agricultural areas.

Systemic treatment with CAR-engineered T cells against PSCA delays subcutaneous tumor growth and prolongs survival of mice

International Nuclear Information System (INIS)

Hillerdal, Victoria; Ramachandran, Mohanraj; Leja, Justyna; Essand, Magnus

2014-01-01

Adoptive transfer of T cells genetically engineered with a chimeric antigen receptor (CAR) has successfully been used to treat both chronic and acute lymphocytic leukemia as well as other hematological cancers. Experimental therapy with CAR-engineered T cells has also shown promising results on solid tumors. The prostate stem cell antigen (PSCA) is a protein expressed on the surface of prostate epithelial cells as well as in primary and metastatic prostate cancer cells and therefore a promising target for immunotherapy of prostate cancer. We developed a third-generation CAR against PSCA including the CD28, OX-40 and CD3 ζ signaling domains. T cells were transduced with a lentivirus encoding the PSCA-CAR and evaluated for cytokine production (paired Student’s t-test), proliferation (paired Student’s t-test), CD107a expression (paired Student’s t-test) and target cell killing in vitro and tumor growth and survival in vivo (Log-rank test comparing Kaplan-Meier survival curves). PSCA-CAR T cells exhibit specific interferon (IFN)-γ and interleukin (IL)-2 secretion and specific proliferation in response to PSCA-expressing target cells. Furthermore, the PSCA-CAR-engineered T cells efficiently kill PSCA-expressing tumor cells in vitro and systemic treatment with PSCA-CAR-engineered T cells significantly delays subcutaneous tumor growth and prolongs survival of mice. Our data confirms that PSCA-CAR T cells may be developed for treatment of prostate cancer

Rhabdomyosarcoma of the lower female genital tract: an analysis of 144 cases.

Science.gov (United States)

Nasioudis, Dimitrios; Alevizakos, Michail; Chapman-Davis, Eloise; Witkin, Steven S; Holcomb, Kevin

2017-08-01

The aim of the present study was to elucidate the clinico-pathological characteristics of female patients with lower genital tract rhabdomyosarcoma (RMS) stratified by age group and investigate their prognosis, using a multi-institutional database. The National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) database was accessed (1973-2013) and a cohort of females diagnosed with RMS of the lower genital tract (vulva, vagina, cervix) was drawn. Five-year overall survival (OS) rate was estimated following generation of Kaplan-Meier curves and compared with the log-rank test. A total of 144 eligible cases were identified; 51.4 and 48.6% originated from the vagina/vulva and the cervix, respectively. Median patient age was 16 years and distant metastases were rare (ten cases). The majority of tumors were of embryonal histology (75.7%). Non-embryonal RMS was more prevalent in the older patient groups. Tumors originating from the cervix were more common among adolescents and premenopausal women. Rate of LN involvement was 52.9 and 20% for vulvovaginal and cervical tumors (p = 0.02). Five-year OS rate was 68.4%; factors associated with better OS were younger age, absence of distant metastasis, embryonal histology, negative LNs, and performance of surgery. For prepubertal girls and adolescents, radical surgery did not confer a survival benefit compared to local tumor excision. RMS of the lower genital tract primarily affects prepubertal girls and adolescents, who have excellent survival rates; however, outcomes for adults remain poor.

The flaws in the detail of an observational study on transcatheter aortic valve implantation versus surgical aortic valve replacement in intermediate-risks patients.

Science.gov (United States)

Barili, Fabio; Freemantle, Nick; Folliguet, Thierry; Muneretto, Claudio; De Bonis, Michele; Czerny, Martin; Obadia, Jean Francois; Al-Attar, Nawwar; Bonaros, Nikolaos; Kluin, Jolanda; Lorusso, Roberto; Punjabi, Prakash; Sadaba, Rafael; Suwalski, Piotr; Benedetto, Umberto; Böning, Andreas; Falk, Volkmar; Sousa-Uva, Miguel; Kappetein, Pieter A; Menicanti, Lorenzo

2017-06-01

The PARTNER group recently published a comparison between the latest generation SAPIEN 3 transcatheter aortic valve implantation (TAVI) system (Edwards Lifesciences, Irvine, CA, USA) and surgical aortic valve replacement (SAVR) in intermediate-risk patients, apparently demonstrating superiority of the TAVI and suggesting that TAVI might be the preferred treatment method in this risk class of patients. Nonetheless, assessment of the non-randomized methodology used in this comparison reveals challenges that should be addressed in order to elucidate the validity of the results. The study by Thourani and colleagues showed several major methodological concerns: suboptimal methods in propensity score analysis with evident misspecification of the propensity scores (PS; no adjustment for the most significantly different covariates: left ventricular ejection fraction, moderate-severe mitral regurgitation and associated procedures); use of PS quintiles rather than matching; inference on not-adjusted Kaplan-Meier curves, although the authors correctly claimed for the need of balancing score adjusting for confounding factors in order to have unbiased estimates of the treatment effect; evidence of poor fit; lack of data on valve-related death.These methodological flaws invalidate direct comparison between treatments and cannot support authors' conclusions that TAVI with SAPIEN 3 in intermediate-risk patients is superior to surgery and might be the preferred treatment alternative to surgery. © The Author 2017. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Tetranectin positive expression in tumour tissue leads to longer survival in Danish women with ovarian cancer. Results from the 'Malova' ovarian cancer study

DEFF Research Database (Denmark)

Heeran, Mel C; Rask, Lene; Høgdall, Claus K

2015-01-01

of the disease. Using tissue arrays we analysed the expression levels in tissues from 166 women with borderline ovarian tumours (BOTs) and 592 women with ovarian cancer (OC). A panel of three antibodies was used for immunohistochemistry: a polyclonal and two monoclonal antibodies. Serum TN was measured using...... found to imply longer OS (p Kaplan-Meier survival analysis performed on all OC cases showed a significantly longer OS (p = 0...

Cetuximab Concomitant with Second-Line Radiation Therapy in Patients with Locally Advanced Recurrent Squamous Cell Head and Neck Cancer

Directory of Open Access Journals (Sweden)

Muge Akmansu

2010-12-01

Full Text Available We presented 9 recurrent head and neck carcinoma patients. Priorly all of them had received radiochemotherapy. We used cetuximab and irradiation concomitantly. Overall survival analysis of the patients was performed using the Kaplan-Meier method on SPSS version 15.0. Based on this calculation, mean follow-up duration is 12.8 months. Mean survival time is 19.8 months and annual mean survival rate is 59.3%.

Tanacetum parthenium leaf extract mediated survival protection in lethally irradiated Swiss albino mice

International Nuclear Information System (INIS)

Shetty, Prashanth; Pooja, S.; Suchetha Kumari, N.; Shetty, Jayaram; Peter, Alex John; Jose, Jerish M.

2016-01-01

Search for less-toxic radioprotectors has spurred interest in the development of natural products. In Ayurveda, the traditional medicine, Tanacetum species have been used to treat ailments since ancient times throughout the world. Effects of the administration of different concentrations of Tanacetum parthenium leaf aqueous extract (TPLA), Tanacetum parthenium leaf ethanolic extract (TPLE) were investigated in Swiss albino mice. Mice (20-25 g) were randomly divided into 8 groups of ten animals each. The control group and the radiation group were treated daily with oral administration of saline for 15 days. Each subgroups of TPLA and TPLE were treated with doses of 50, 100 and 250 mg/kg daily for 15 days. On the 15th day, all were irradiated with 10 Gy whole body irradiation. Survival was observed daily up to 30th post-irradiation day. Data were analysed using the Kaplan-Meier survival curves. The significance difference in survival between control, radiation and treatment groups were observed (P < 0.001). Current studies revealed the protective effect of Tanacetum parthenium rendering high survivability in lethally irradiated mice. (author)

Serum tetranectin is an independent prognostic marker in colorectal cancer and weakly correlated with plasma suPAR, plasma PAI-1 and serum CEA

DEFF Research Database (Denmark)

Høgdall, Claus K; Christensen, Ib J; Stephens, Ross W

2002-01-01

PAR and CEA had a 2.43 increased risk as compared to a patient with median levels of these biochemical markers. Significant correlations were found with Dukes' stages for all the biochemical markers and between the respective biochemical markers. The findings confirm that TN is a strong prognostic factor...... activator (uPAR) and carcinoembryonic antigen (CEA). Significantly shorter survival was found for patients with TN levels below a cut-off point of 7.5 mg/l compared to patients with levels above, as illustrated by Kaplan-Meier curves. By Cox analyses, log TN, log soluble uPAR as well as log CEA were found...... to have an independent prognostic value for survival (log TN: HR = 0.47, 95% CI: 0.29-0.76); log soluble uPAR: HR = 1.65, 95% CI: 1.18-2.31; log CEA: HR = 1.I1, 95% CI: 1.03-1.20). Based on the multivariate model, a patient with a combination of low levels of TN and PAI-1 and elevated levels of soluble u...

Sarcopenia is not associated with morbidity, mortality, or recurrence after esophagectomy for cancer.

Science.gov (United States)

Siegal, Steve R; Dolan, James P; Dewey, Elizabeth N; Guimaraes, Alexander R; Tieu, Brandon H; Schipper, Paul H; Hunter, John G

2018-05-01

Sarcopenia is associated with increased morbidity and mortality in hepatic, pancreatic and colorectal cancer. We examined the effect of sarcopenia on morbidity, mortality, and recurrence after resection for esophageal cancer. Retrospective review of consecutive esophagectomies from 2010 to 2015. Computed tomography studies were analyzed for sarcopenia. Morbidity was analyzed using Fischer's test and survival data with Kaplan Meier curves. The sarcopenic group (n = 127) had lower BMI, later stage disease, and higher incidence of neoadjuvant radiation than those without sarcopenia (n = 46). There were no differences in morbidity or mortality between the groups (p = .75 and p = .31, respectively). Mean length of stay was similar (p = .70). Disease free and overall survival were similar (p = .20 and p = .39, respectively). There is no association between sarcopenia and increased morbidity, mortality and disease-free survival in patients undergoing esophagectomy for cancer. Sarcopenia in esophageal cancer may not portend worse outcomes that have been reported in other solid tumors. Copyright © 2018 Elsevier Inc. All rights reserved.

Patient factors associated with lung transplant referral and waitlist for patients with cystic fibrosis and pulmonary fibrosis.

Science.gov (United States)

Liu, Yuan; Vela, Monica; Rudakevych, Tanya; Wigfield, Christopher; Garrity, Edward; Saunders, Milda R

2017-03-01

Since 2005, the Lung Allocation Score (LAS) has prioritized patient benefit and post-transplant survival, reducing waitlist to transplant time to fibrosis (CF) and pulmonary fibrosis (PF). We analyzed the times from transplant eligibility to referral, work-up and waitlisting using Kaplan-Meier curves and log-rank tests. Overall, the referral rate for transplant-eligible patients was 64%. Of those referred, approximately 36% reach the lung transplant waitlist. Referred CF patients were significantly more likely to reach the transplant waitlist than PF patients (CF 60% vs PF 22%, p < 0.05). In addition, CF patients had a shorter wait from transplant eligibility to waitlist than PF patients (329 vs 2,369 days, respectively [25th percentile], p < 0.05). Patients with PF and CF both faced delays from eligibility to referral and waitlist. Quality improvement efforts are needed to better identify and refer appropriate patients for lung transplant evaluation. Targeted interventions may facilitate more efficient evaluation completion and waitlist appearance. Copyright © 2017 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.

Checking the predictive accuracy of basic symptoms against ultra high-risk criteria and testing of a multivariable prediction model: Evidence from a prospective three-year observational study of persons at clinical high-risk for psychosis.

Science.gov (United States)

Hengartner, M P; Heekeren, K; Dvorsky, D; Walitza, S; Rössler, W; Theodoridou, A

2017-09-01

The aim of this study was to critically examine the prognostic validity of various clinical high-risk (CHR) criteria alone and in combination with additional clinical characteristics. A total of 188 CHR positive persons from the region of Zurich, Switzerland (mean age 20.5 years; 60.2% male), meeting ultra high-risk (UHR) and/or basic symptoms (BS) criteria, were followed over three years. The test battery included the Structured Interview for Prodromal Syndromes (SIPS), verbal IQ and many other screening tools. Conversion to psychosis was defined according to ICD-10 criteria for schizophrenia (F20) or brief psychotic disorder (F23). Altogether n=24 persons developed manifest psychosis within three years and according to Kaplan-Meier survival analysis, the projected conversion rate was 17.5%. The predictive accuracy of UHR was statistically significant but poor (area under the curve [AUC]=0.65, Pthinking of binary at-risk criteria is necessary in order to improve the prognosis of psychotic disorders. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

[Expression and clinical significance of KIAA1199 in primary hepatocellular carcinoma].

Science.gov (United States)

Gu, C J; Ni, Q C; Ni, K; Zhang, S; Qian, H X

2018-05-29

Objective: To investigate the expression and clinical significance of KIAA1199 in primary hepatocellular carcinoma. Methods: A total of 136 cases of primary hepatocellular carcinoma tissues and paired adjacent tissues were collected. Immunohistochemistry and Western blot were used to detect the expression of KIAA1199 in primary hepatocellular carcinoma tissues and paired adjacent tissues. The relationship between KIAA1199 and clinicopathological parameter of primary hepatocellular carcinoma was analyzed. Results: The positive rate of KIAA1199 in primary hepatocellular carcinoma was 82.3% (112/136), which was higher than that in paired para-cancerous tissues (14.7%, 20/136). High expression of KIAA1199 was significantly correlated with age, cirrhosis history, tumor size, tumor number, degree of differentiation, TNM staging and microvenous invasion (MVI) ( P 0.05). The Kaplan-Meier survival curves indicated that high KIAA1199 expression was associated with poor survival ( P hepatocellular carcinoma, which is significantly correlated with the clinicopathological features and prognosis, high expression of KIAA1199 increased the risk of death in patients with primary hepatocellular carcinoma.

SPECT myocardial perfusion imaging. Long-term prognostic value in diabetic patients with and without coronary artery disease

International Nuclear Information System (INIS)

Koehli, M.; Monbaron, D.; Gaillard, R.C.; Ruiz, J.; Prior, J.O.; Bischof Delaloye, A.; Calcagni, M.L.; Fivaz-Arbane, M.; Stauffer, J.C.

2006-01-01

Aim: To determine the long-term prognostic value of SPECT myocardial perfusion imaging (MPI) for the occurrence of cardiovascular events in diabetic patients. Patients, methods: SPECT MPI of 210 consecutive Caucasian diabetic patients were analysed using Kaplan-Meier event-free survival curve and independent predictors were determined by Cox multivariate analyses. Results: Follow-up was complete in 200 (95%) patients with a median period of 3.0 years (0.8-5.0). The population was composed of 114 (57%) men, age 65 ± 10 years, 181 (90.5%) type 2 diabetes mellitus, 50 (25%) with a history of coronary artery disease (CAD) and 98 (49%) presenting chest pain prior to MPI. The prevalence of abnormal MPI was 58%. Patients with a normal MPI had neither cardiac death, nor myocardial infarction, independently of a history of coronary artery disease or chest pain. Among the independent predictors of cardiac death and myocardial infarction, the strongest was abnormal MPI (p 5-fold increase in cardiovascular events. This emphasizes the value of SPECT MPI in predicting and risk-stratifying cardiovascular events in diabetic patients. (orig.)

Increased Prognostic Value of Query Amyloid Late Enhancement Score in Light-Chain Cardiac Amyloidosis.

Science.gov (United States)

Wan, Ke; Sun, Jiayu; Han, Yuchi; Liu, Hong; Yang, Dan; Li, Weihao; Wang, Jie; Cheng, Wei; Zhang, Qing; Zeng, Zhi; Chen, Yucheng

2018-02-23

Late gadolinium enhancement (LGE) pattern is a powerful imaging biomarker for prognosis of cardiac amyloidosis. It is unknown if the query amyloid late enhancement (QALE) score in light-chain (AL) amyloidosis could provide increased prognostic value compared with LGE pattern.Methods and Results:Seventy-eight consecutive patients with AL amyloidosis underwent contrast-enhanced cardiovascular magnetic resonance imaging. Patients with cardiac involvement were grouped by LGE pattern and analyzed using QALE score. Receiver operating characteristic curve was used to identify the optimal cut-off for QALE score in predicting all-cause mortality. Survival of these patients was analyzed with the Kaplan-Meier method and multivariate Cox regression. During a median follow-up of 34 months, 53 of 78 patients died. The optimal cut-off for QALE score to predict mortality at 12-month follow-up was 9.0. On multivariate Cox analysis, QALE score ≥9 (HR, 5.997; 95% CI: 2.665-13.497; Pvalue in AL cardiac amyloidosis. QALE score ≥9 has added value to differentiate prognosis in AL amyloidosis patients with a subendocardial LGE pattern.

P wave dispersion and maximum P wave duration are independently associated with rapid renal function decline.

Science.gov (United States)

Su, Ho-Ming; Tsai, Wei-Chung; Lin, Tsung-Hsien; Hsu, Po-Chao; Lee, Wen-Hsien; Lin, Ming-Yen; Chen, Szu-Chia; Lee, Chee-Siong; Voon, Wen-Chol; Lai, Wen-Ter; Sheu, Sheng-Hsiung

2012-01-01

The P wave parameters measured by 12-lead electrocardiogram (ECG) are commonly used as noninvasive tools to assess for left atrial enlargement. There are limited studies to evaluate whether P wave parameters are independently associated with decline in renal function. Accordingly, the aim of this study is to assess whether P wave parameters are independently associated with progression to renal end point of ≥25% decline in estimated glomerular filtration rate (eGFR). This longitudinal study included 166 patients. The renal end point was defined as ≥25% decline in eGFR. We measured two ECG P wave parameters corrected by heart rate, i.e. corrected P wave dispersion (PWdisperC) and corrected P wave maximum duration (PWdurMaxC). Heart function and structure were measured from echocardiography. Clinical data, P wave parameters, and echocardiographic measurements were compared and analyzed. Forty-three patients (25.9%) reached renal end point. Kaplan-Meier curves for renal end point-free survival showed PWdisperC > median (63.0 ms) (log-rank P = 0.004) and PWdurMaxC > median (117.9 ms) (log-rank Pfunction decline.

Over-expression of Eph and ephrin genes in advanced ovarian cancer: ephrin gene expression correlates with shortened survival

Directory of Open Access Journals (Sweden)

Lincoln Douglas

2006-06-01

Full Text Available Abstract Background Increased expression of Eph receptor tyrosine kinases and their ephrin ligands has been implicated in tumor progression in a number of malignancies. This report describes aberrant expression of these genes in ovarian cancer, the commonest cause of death amongst gynaecological malignancies. Methods Eph and ephrin expression was determined using quantitative real time RT-PCR. Correlation of gene expression was measured using Spearman's rho statistic. Survival was analysed using log-rank analysis and (was visualised by Kaplan-Meier survival curves. Results Greater than 10 fold over-expression of EphA1 and a more modest over-expression of EphA2 were observed in partially overlapping subsets of tumors. Over-expression of EphA1 strongly correlated (r = 0.801; p Conclusion These data imply that increased levels of ephrins A1 and A5 in the presence of high expression of Ephs A1 and A2 lead to a more aggressive tumor phenotype. The known functions of Eph/ephrin signalling in cell de-adhesion and movement may explain the observed correlation of ephrin expression with poor prognosis.

Runaway transient simulation of a model Kaplan turbine

Energy Technology Data Exchange (ETDEWEB)

Liu, S; Liu, D; Wu, Y [State Key Laboratory of Hydroscience and Engineering, Department of Thermal Eng., Tsinghua University, Beijing, 100084 (China); Zhou, D [Water Conservancy and Hydropower Eng., Hohai University, Nanjing. 210098 (China); Nishi, M, E-mail: liushuhong@tsinghua.edu.c [Kyushu Inst. Tech. Senior Academy, Kitakyushu, 804-8550 (Japan)

2010-08-15

The runaway transient is a typical transient process of a hydro power unit, where the rotational speed of a turbine runner rapidly increases up to the runaway speed under a working head as the guide vanes cannot be closed due to some reason at the load rejection. In the present paper, the characteristics of the runaway transient of a model Kaplan turbine having ns = 479(m-kW) is simulated by using a time-dependent CFD technique where equation of rotational motion of runner, continuity equation and unsteady RANS equations with RNG k-{epsilon} turbulence model are solved iteratively. In the calculation, unstructured mesh is used to the whole flow passage, which consists of several sub-domains: entrance, casing, stay vanes + guide vanes, guide section, runner and draft tube. And variable speed sliding mesh technique is used to exchange interface flow information between moving part and stationary part, and three-dimensional unstructured dynamic mesh technique is also adopted to ensure mesh quality. Two cases were treated in the simulation of runaway transient characteristics after load rejection: one is the rated operating condition as the initial condition, and the other is the condition at the maximum head. Regarding the runaway speed, the experimental speed is 1.45 times the initial speed and the calculation is 1.47 times the initial for the former case. In the latter case, the experiment and the calculation are 1.67 times and 1.69 times respectively. From these results, it is recognized that satisfactorily prediction will be possible by using the present numerical method. Further, numerical results show that the swirl in the draft-tube flow becomes stronger in the latter part of the transient process so that a vortex rope will occur in the draft tube and its precession will cause the pressure fluctuations which sometimes affect the stability of hydro power system considerably.

Runaway transient simulation of a model Kaplan turbine

Science.gov (United States)

Liu, S.; Zhou, D.; Liu, D.; Wu, Y.; Nishi, M.

2010-08-01

The runaway transient is a typical transient process of a hydro power unit, where the rotational speed of a turbine runner rapidly increases up to the runaway speed under a working head as the guide vanes cannot be closed due to some reason at the load rejection. In the present paper, the characteristics of the runaway transient of a model Kaplan turbine having ns = 479(m-kW) is simulated by using a time-dependent CFD technique where equation of rotational motion of runner, continuity equation and unsteady RANS equations with RNG k-epsilon turbulence model are solved iteratively. In the calculation, unstructured mesh is used to the whole flow passage, which consists of several sub-domains: entrance, casing, stay vanes + guide vanes, guide section, runner and draft tube. And variable speed sliding mesh technique is used to exchange interface flow information between moving part and stationary part, and three-dimensional unstructured dynamic mesh technique is also adopted to ensure mesh quality. Two cases were treated in the simulation of runaway transient characteristics after load rejection: one is the rated operating condition as the initial condition, and the other is the condition at the maximum head. Regarding the runaway speed, the experimental speed is 1.45 times the initial speed and the calculation is 1.47 times the initial for the former case. In the latter case, the experiment and the calculation are 1.67 times and 1.69 times respectively. From these results, it is recognized that satisfactorily prediction will be possible by using the present numerical method. Further, numerical results show that the swirl in the draft-tube flow becomes stronger in the latter part of the transient process so that a vortex rope will occur in the draft tube and its precession will cause the pressure fluctuations which sometimes affect the stability of hydro power system considerably.

Runaway transient simulation of a model Kaplan turbine

International Nuclear Information System (INIS)

Liu, S; Liu, D; Wu, Y; Zhou, D; Nishi, M

2010-01-01

The runaway transient is a typical transient process of a hydro power unit, where the rotational speed of a turbine runner rapidly increases up to the runaway speed under a working head as the guide vanes cannot be closed due to some reason at the load rejection. In the present paper, the characteristics of the runaway transient of a model Kaplan turbine having ns = 479(m-kW) is simulated by using a time-dependent CFD technique where equation of rotational motion of runner, continuity equation and unsteady RANS equations with RNG k-ε turbulence model are solved iteratively. In the calculation, unstructured mesh is used to the whole flow passage, which consists of several sub-domains: entrance, casing, stay vanes + guide vanes, guide section, runner and draft tube. And variable speed sliding mesh technique is used to exchange interface flow information between moving part and stationary part, and three-dimensional unstructured dynamic mesh technique is also adopted to ensure mesh quality. Two cases were treated in the simulation of runaway transient characteristics after load rejection: one is the rated operating condition as the initial condition, and the other is the condition at the maximum head. Regarding the runaway speed, the experimental speed is 1.45 times the initial speed and the calculation is 1.47 times the initial for the former case. In the latter case, the experiment and the calculation are 1.67 times and 1.69 times respectively. From these results, it is recognized that satisfactorily prediction will be possible by using the present numerical method. Further, numerical results show that the swirl in the draft-tube flow becomes stronger in the latter part of the transient process so that a vortex rope will occur in the draft tube and its precession will cause the pressure fluctuations which sometimes affect the stability of hydro power system considerably.

Analytical Method to Estimate Fatigue Life Time Duration in Service for Runner Blade Mechanism of Kaplan Turbines

Directory of Open Access Journals (Sweden)

Ana – Maria Budai

2010-10-01

Full Text Available The paper present an analytical method that can be used to determianted fatigue life time duration in service for runner blade mechanism of Kaplan turbines. The study was made for lever button of runer blade mechanism using two analytical relation to calculate the maximum number of stress cycles whereupon the mechanism work without any damage. To estimate fatigue life time duration will be used a formula obtained from one of most comon cumulative damage methodology taking in consideration the real exploatation conditions of a specified Kapaln turbine.

Development of an Electronic Medical Record Based Alert for Risk of HIV Treatment Failure in a Low-Resource Setting

Science.gov (United States)

Puttkammer, Nancy; Zeliadt, Steven; Balan, Jean Gabriel; Baseman, Janet; Destiné, Rodney; Domerçant, Jean Wysler; France, Garilus; Hyppolite, Nathaelf; Pelletier, Valérie; Raphael, Nernst Atwood; Sherr, Kenneth; Yuhas, Krista; Barnhart, Scott

2014-01-01

Background The adoption of electronic medical record systems in resource-limited settings can help clinicians monitor patients' adherence to HIV antiretroviral therapy (ART) and identify patients at risk of future ART failure, allowing resources to be targeted to those most at risk. Methods Among adult patients enrolled on ART from 2005–2013 at two large, public-sector hospitals in Haiti, ART failure was assessed after 6–12 months on treatment, based on the World Health Organization's immunologic and clinical criteria. We identified models for predicting ART failure based on ART adherence measures and other patient characteristics. We assessed performance of candidate models using area under the receiver operating curve, and validated results using a randomly-split data sample. The selected prediction model was used to generate a risk score, and its ability to differentiate ART failure risk over a 42-month follow-up period was tested using stratified Kaplan Meier survival curves. Results Among 923 patients with CD4 results available during the period 6–12 months after ART initiation, 196 (21.2%) met ART failure criteria. The pharmacy-based proportion of days covered (PDC) measure performed best among five possible ART adherence measures at predicting ART failure. Average PDC during the first 6 months on ART was 79.0% among cases of ART failure and 88.6% among cases of non-failure (pART initiation were added to PDC, the risk score differentiated between those who did and did not meet failure criteria over 42 months following ART initiation. Conclusions Pharmacy data are most useful for new ART adherence alerts within iSanté. Such alerts offer potential to help clinicians identify patients at high risk of ART failure so that they can be targeted with adherence support interventions, before ART failure occurs. PMID:25390044

Curved Folded Plate Timber Structures

OpenAIRE

Buri, Hans Ulrich; Stotz, Ivo; Weinand, Yves

2011-01-01

This work investigates the development of a Curved Origami Prototype made with timber panels. In the last fifteen years the timber industry has developed new, large size, timber panels. Composition and dimensions of these panels and the possibility of milling them with Computer Numerical Controlled machines shows great potential for folded plate structures. To generate the form of these structures we were inspired by Origami, the Japanese art of paper folding. Common paper tessellations are c...

Discontinuity of the annuity curves. III. Two types of vital variability in Drosophila melanogaster.

Science.gov (United States)

Bychkovskaia, I B; Mylnikov, S V; Mozhaev, G A

2016-01-01

We confirm five-phased construction of Drosophila annuity curves established earlier. Annuity curves were composed of stable five-phase component and variable one. Variable component was due to differences in phase durations. As stable, so variable components were apparent for 60 generations. Stochastic component was described as well. Viability variance which characterize «reaction norm» was apparent for all generation as well. Thus, both types of variability seem to be inherited.

Blade profile optimization of kaplan turbine using cfd analysis

International Nuclear Information System (INIS)

Janjua, A.B.; Khalil, M.S.

2013-01-01

Utilization of hydro-power as renewable energy source is of prime importance in the world now. Hydropower energy is available in abundant in form of falls, canals rivers, dams etc. It means, there are various types of sites with different parameters like flow rate, heads, etc. Depending upon the sites, water turbines are designed and manufactured to avail hydro-power energy. Low head turbines on runof-river are widely used for the purpose. Low head turbines are classified as reaction turbines. For runof-river, depending upon the variety of site data, low head Kaplan turbines are selected, designed and manufactured. For any given site requirement, it becomes very essential to design the turbine runner blades through optimization of the CAD model of blades profile. This paper presents the optimization technique carried out on a complex geometry of blade profile through static and dynamic computational analysis. It is used through change of the blade profile geometry at five different angles in the 3D (Three Dimensional) CAD model. Blade complex geometry and design have been developed by using the coordinates point system on the blade in PRO-E /CREO software. Five different blade models are developed for analysis purpose. Based on the flow rate and heads, blade profiles are analyzed using ANSYS software to check and compare the output results for optimization of the blades for improved results which show that by changing blade profile angle and its geometry, different blade sizes and geometry can be optimized using the computational techniques with changes in CAD models. (author)

Blade Profile Optimization of Kaplan Turbine Using CFD Analysis

Directory of Open Access Journals (Sweden)

Aijaz Bashir Janjua

2013-10-01

Full Text Available Utilization of hydro-power as renewable energy source is of prime importance in the world now. Hydropower energy is available in abundant in form of falls, canals rivers, dams etc. It means, there are various types of sites with different parameters like flow rate, heads, etc. Depending upon the sites, water turbines are designed and manufactured to avail hydro-power energy. Low head turbines on runof-river are widely used for the purpose. Low head turbines are classified as reaction turbines. For runof river, depending upon the variety of site data, low head Kaplan turbines are selected, designed and manufactured. For any given site requirement, it becomes very essential to design the turbine runner blades through optimization of the CAD model of blades profile. This paper presents the optimization technique carried out on a complex geometry of blade profile through static and dynamic computational analysis. It is used through change of the blade profile geometry at five different angles in the 3D (Three Dimensional CAD model. Blade complex geometry and design have been developed by using the coordinates point system on the blade in PRO-E /CREO software. Five different blade models are developed for analysis purpose. Based on the flow rate and heads, blade profiles are analyzed using ANSYS software to check and compare the output results for optimization of the blades for improved results which show that by changing blade profile angle and its geometry, different blade sizes and geometry can be optimized using the computational techniques with changes in CAD models.

Increased expression of IRF8 in tumor cells inhibits the generation of Th17 cells and predicts unfavorable survival of diffuse large B cell lymphoma patients.

Science.gov (United States)

Zhong, Weijie; Xu, Xin; Zhu, Zhigang; Du, Qinghua; Du, Hong; Yang, Li; Ling, Yanying; Xiong, Huabao; Li, Qingshan

2017-07-25

The immunological pathogenesis of diffuse large B cell lymphoma (DLBCL) remains elusive. Searching for new prognostic markers of DLBCL is a crucial focal point for clinical scientists. The aim of the present study was to examine the prognostic value of interferon regulatory factor 8 (IRF8) expression and its effect on the development of Th17 cells in the tumor microenvironment of DLBCL patients. Flow cytometry, immunohistochemistry, and quantitative real-time PCR were used to detect the distribution of Th17 cells and related cytokines and IRF8 in tumor tissues from DLBCL patients. Two DLBCL cell lines (OCI-LY10 and OCI-LY1) with IRF8 knockdown or overexpression and two human B lymphoblast cell lines were co-cultured with peripheral blood mononuclear cells (PBMCs) in vitro to determine the effect of IRF8 on the generation of Th17 cells. Quantitative real-time PCR and Western blotting were used to investigate the involvement of retinoic acid receptor-related orphan receptor gamma t (RORγt) in the effect of IRF8 on Th17 cell generation. The survival of 67 DLBCL patients was estimated using the Kaplan-Meier method and log-rank analysis. The percentage of Th17 cells was lower in DLBCL tumor tissues than in PBMCs and corresponding adjacent benign tissues. Relative expression of interleukin (IL)-17A was lower, whereas that of interferon (IFN)-γ was higher in tumor tissues than in benign tissues. Co-culture with DLBCL cell lines inhibited the generation of Th17 cells in vitro. IRF8 upregulation was detected in DLBCL tumor tissues, and it was associated with decreased DLBCL patient survival. Investigation of the underlying mechanism suggested that IRF8 upregulation in DLBCL, through an unknown mechanism, inhibited Th17 cell generation by suppressing RORγt in neighboring CD4+ T cells. Tumor cells may express soluble or membrane-bound factors that inhibit the expression of RORγt in T cells within the tumor microenvironment. Our findings suggest that IRF8 expression could

Statistical evaluation of a project to estimate fish trajectories through the intakes of Kaplan hydropower turbines

Science.gov (United States)

Sutton, Virginia Kay

This paper examines statistical issues associated with estimating paths of juvenile salmon through the intakes of Kaplan turbines. Passive sensors, hydrophones, detecting signals from ultrasonic transmitters implanted in individual fish released into the preturbine region were used to obtain the information to estimate fish paths through the intake. Aim and location of the sensors affects the spatial region in which the transmitters can be detected, and formulas relating this region to sensor aiming directions are derived. Cramer-Rao lower bounds for the variance of estimators of fish location are used to optimize placement of each sensor. Finally, a statistical methodology is developed for analyzing angular data collected from optimally placed sensors.

Interdisciplinary interventional therapy for tracheobronchial stenosis with modern metal net stents

International Nuclear Information System (INIS)

Rieger, J.; Linsenmaier, U.; Fedorowski, A.; Pfeifer, K.J.; Hautmann, H.; Huber, R.M.

2002-01-01

Study objectives: Assessment of the therapeutic potential of tracheobronchial stenting for obstructive tracheobronchial disease, in-vivo comparison of different stent types and development of helpful criteria for choosing the suitable stent type. Material and Methods: Prospective case analysis. Between 1993 and 1999 53 stents were implanted into the tracheobronchial system of 39 consecutive patients with benign or malignant airway obstruction. Every single stent (26 Strecker Stents, 18 Wallstents, 6 Accuflex Nitinolstents, 1 Dumon-, 1 Ruesch- and 1 Palmazstent) was recorded in an unified database. Analysis comprised clinical effectiveness, lung function if possible, relevant complications and radiologic follow-up parameters. The probability of their remaining within the tracheobronchial system, of their remaining undislocated and uncompressed was calculated using Kaplan-Meier analysis for three stent types. Results: Stent placement proved itself to be an effective treatment in 86% of the patients. Resistance could be normalized in 9/9 patients. Kaplan-Meier analysis clearly revealed a higher probability for the Wall- and Nitinolstent to remain within the tracheobronchial system and to remain uncompressed. Dislocation also occurred more rarely. Explanation of the Wallstent, however, if desired, was much more difficult compared to the Strecker stent. The Wallstent also occasionally led to the formation of granulation tissue especially at the proximal stent end and, as such, required reintervention. (orig.) [de

Radiologic Placement of Tunneled Central Venous Catheters in Pediatric Patients

International Nuclear Information System (INIS)

Kim, Eun Ji; Song, Soon Young; Cho, On Koo; Koh, Byung Hee; Kim, Yong Soo; Jeong, Woo Kyoung; Lee, Yong Ho

2010-01-01

We evaluated the technical success and complication rates associated with the radiological placement of tunneled central venous catheters in pediatric patients. Between May 1, 2005 and March 31, 2008, a total of 46 tunneled central venous catheters were placed in 34 children (M:F = 22:12; mean age, 9.9 years [9 months to 16.8 years]). All procedures were performed under ultrasonographic and fluoroscopic guidance. Follow-up data were obtained through the retrospective review of the medical records. We used the Kaplan-Meier survival method for the evaluation of survival rate of the catheters. All procedures were technically successful. The observed periprocedural complications included hematoma formation in three patients. The mean catheter life was 189.3 days (total, 8710 days; range, 7-810). Catheters were removed due to death (n=9), the end of treatment (n=8), catheter sepsis (n=4), malfunction (n=8), and accidental removal (n=4). The rate of catheter sepsis and malfunction was 0.459 and 0.919 for every 1000 catheter days, respectively. The expected mean catheter life was 479.6 days as per the Kaplan- Meier analysis. The results suggest that the radiologic placement of a tunneled central venous catheter is an effective technique with a high technical success rate and low complication rate

High serum uric acid concentration predicts poor survival in patients with breast cancer.

Science.gov (United States)

Yue, Cai-Feng; Feng, Pin-Ning; Yao, Zhen-Rong; Yu, Xue-Gao; Lin, Wen-Bin; Qian, Yuan-Min; Guo, Yun-Miao; Li, Lai-Sheng; Liu, Min

2017-10-01

Uric acid is a product of purine metabolism. Recently, uric acid has gained much attraction in cancer. In this study, we aim to investigate the clinicopathological and prognostic significance of serum uric acid concentration in breast cancer patients. A total of 443 female patients with histopathologically diagnosed breast cancer were included. After a mean follow-up time of 56months, survival was analysed using the Kaplan-Meier method. To further evaluate the prognostic significance of uric acid concentrations, univariate and multivariate Cox regression analyses were applied. Of the clinicopathological parameters, uric acid concentration was associated with age, body mass index, ER status and PR status. Univariate analysis identified that patients with increased uric acid concentration had a significantly inferior overall survival (HR 2.13, 95% CI 1.15-3.94, p=0.016). In multivariate analysis, we found that high uric acid concentration is an independent prognostic factor predicting death, but insufficient to predict local relapse or distant metastasis. Kaplan-Meier analysis indicated that high uric acid concentration is related to the poor overall survival (p=0.013). High uric acid concentration predicts poor survival in patients with breast cancer, and might serve as a potential marker for appropriate management of breast cancer patients. Copyright © 2017 Elsevier B.V. All rights reserved.

Safety and efficacy of a xenogeneic DNA vaccine encoding for human tyrosinase as adjunctive treatment for oral malignant melanoma in dogs following surgical excision of the primary tumor.

Science.gov (United States)

Grosenbaugh, Deborah A; Leard, A Timothy; Bergman, Philip J; Klein, Mary K; Meleo, Karri; Susaneck, Steven; Hess, Paul R; Jankowski, Monika K; Jones, Pamela D; Leibman, Nicole F; Johnson, Maribeth H; Kurzman, Ilene D; Wolchok, Jedd D

2011-12-01

To evaluate the safety and efficacy of a vaccine containing plasmid DNA with an insert encoding human tyrosinase (ie, huTyr vaccine) as adjunctive treatment for oral malignant melanoma (MM) in dogs. 111 dogs (58 prospectively enrolled in a multicenter clinical trial and 53 historical controls) with stage II or III oral MM (modified World Health Organization staging scale, I to IV) in which locoregional disease control was achieved. 58 dogs received an initial series of 4 injections of huTyr vaccine (102 μg of DNA/injection) administered transdermally by use of a needle-free IM vaccination device. Dogs were monitored for adverse reactions. Surviving dogs received booster injections at 6-month intervals thereafter. Survival time for vaccinates was compared with that of historical control dogs via Kaplan-Meier survival analysis for the outcome of death. Kaplan-Meier analysis of survival time until death attributable to MM was determined to be significantly improved for dogs that received the huTyr vaccine, compared with that of historical controls. However, median survival time could not be determined for vaccinates because dogs as adjunctive treatment for oral MM. Response to DNA vaccination in dogs with oral MM may be useful in development of plasmid DNA vaccination protocols for human patients with similar disease.

Censoring approach to the detection limits in X-ray fluorescence analysis

International Nuclear Information System (INIS)

Pajek, M.; Kubala-Kukus, A.

2004-01-01

We demonstrate that the effect of detection limits in the X-ray fluorescence analysis (XRF), which limits the determination of very low concentrations of trace elements and results in appearance of the so-called 'nondetects', can be accounted for using the statistical concept of censoring. More precisely, the results of such measurements can be viewed as the left random censored data, which can further be analyzed using the Kaplan-Meier method correcting the data for the presence of nondetects. Using this approach, the results of measured, detection limit censored concentrations can be interpreted in a nonparametric manner including the correction for the nondetects, i.e. the measurements in which the concentrations were found to be below the actual detection limits. Moreover, using the Monte Carlo simulation technique we show that by using the Kaplan-Meier approach the corrected mean concentrations for a population of the samples can be estimated within a few percent uncertainties with respect of the simulated, uncensored data. This practically means that the final uncertainties of estimated mean values are limited in fact by the number of studied samples and not by the correction procedure itself. The discussed random-left censoring approach was applied to analyze the XRF detection-limit-censored concentration measurements of trace elements in biomedical samples

Evaluation of the TRPM2 channel as a biomarker in breast cancer using public databases analysis.

Science.gov (United States)

Sumoza-Toledo, Adriana; Espinoza-Gabriel, Mario Iván; Montiel-Condado, Dvorak

Breast cancer is one of the most common malignancies affecting women. Recent investigations have revealed a major role of ion channels in cancer. The transient receptor potential melastatin-2 (TRPM2) is a plasma membrane and lysosomal channel with important roles in cell migration and cell death in immune cells and tumor cells. In this study, we investigated the prognostic value of TRPM2 channel in breast cancer, analyzing public databases compiled in Oncomine™ (Thermo Fisher, Ann Arbor, MI) and online Kaplan-Meier Plotter platforms. The results revealed that TRPM2 mRNA overexpression is significant in situ and invasive breast carcinoma compared to normal breast tissue. Furthermore, multi-gene validation using Oncomine™ showed that this channel is coexpressed with proteins related to cellular migration, transformation, and apoptosis. On the other hand, Kaplan-Meier analysis exhibited that low expression of TRPM2 could be used to predict poor outcome in ER- and HER2+ breast carcinoma patients. TRPM2 is a promising biomarker for aggressiveness of breast cancer, and a potential target for the development of new therapies. Copyright © 2016 Hospital Infantil de México Federico Gómez. Publicado por Masson Doyma México S.A. All rights reserved.

[Expression and clinical significance of 5hmC in bladder urothelial carcinoma].

Science.gov (United States)

Li, Jie; Xu, Yuqiao; Zhang, Zhiwen; Zhang, Ming; Zhang, Zhekai; Zhang, Feng; Li, Qing

2016-02-01

To investigate the expression of 5-hydroxymethylcytosine (5hmC) in bladder urothelial carcinoma (UC) and its clinical significance. The expression of 5hmC in 21 cases of UC tissues and pericarcinous urinary tract epithelium was detected by immunohistochemical staining. Then the expression of 5hmC in the surgical resection of UC tissues in 92 cases was also surveyed. Non parametric U Mann-Whitney test was used to analyze the correlation between 5hmC expression and clinical data. Single factor survival analysis was performed by Kaplan-Meier test. The expression of 5hmC in normal urinary tract epithelium and UC tissues was significantly different, but there was no significant difference in the expression of 5hmC between low and high grades of UC tissues as well as between different TNM grades. Kaplan-Meier single factor survival analysis showed that there was no significant correlation between the 5hmC expression level and the survival rate or the recurrence-free survival of UC patients. The expression level of 5hmC in UC tissues is significantly lower than that in pericarcinous urinary tract epithelium. There is no correlation between the 5hmC expression and the progression, prognosis and recurrence of UC.

Talent in Female Gymnastics: a Survival Analysis Based upon Performance Characteristics.

Science.gov (United States)

Pion, J; Lenoir, M; Vandorpe, B; Segers, V

2015-11-01

This study investigated the link between the anthropometric, physical and motor characteristics assessed during talent identification and dropout in young female gymnasts. 3 cohorts of female gymnasts (n=243; 6-9 years) completed a test battery for talent identification. Performance-levels were monitored over 5 years of competition. Kaplan-Meier and Cox Proportional Hazards analyses were conducted to determine the survival rate and the characteristics that influence dropout respectively. Kaplan-Meier analysis indicated that only 18% of the female gymnasts that passed the baseline talent identification test survived at the highest competition level 5 years later. The Cox Proportional Hazards Model indicated that gymnasts with a score in the best quartile for a specific characteristic significantly increased chances of survival by 45-129%. These characteristics being: basic motor skills (129%), shoulder strength (96%), leg strength (53%) and 3 gross motor coordination items (45-73%). These results suggest that tests batteries commonly used for talent identification in young female gymnasts may also provide valuable insights into future dropout. Therefore, multidimensional test batteries deserve a prominent place in the selection process. The individual test results should encourage trainers to invest in an early development of basic physical and motor characteristics to prevent attrition. © Georg Thieme Verlag KG Stuttgart · New York.

Radiologic Placement of Tunneled Central Venous Catheters in Pediatric Patients

Energy Technology Data Exchange (ETDEWEB)

Kim, Eun Ji; Song, Soon Young; Cho, On Koo; Koh, Byung Hee; Kim, Yong Soo; Jeong, Woo Kyoung; Lee, Yong Ho [Hanyang University College of Medicine, Seoul (Korea, Republic of)

2010-08-15

We evaluated the technical success and complication rates associated with the radiological placement of tunneled central venous catheters in pediatric patients. Between May 1, 2005 and March 31, 2008, a total of 46 tunneled central venous catheters were placed in 34 children (M:F = 22:12; mean age, 9.9 years [9 months to 16.8 years]). All procedures were performed under ultrasonographic and fluoroscopic guidance. Follow-up data were obtained through the retrospective review of the medical records. We used the Kaplan-Meier survival method for the evaluation of survival rate of the catheters. All procedures were technically successful. The observed periprocedural complications included hematoma formation in three patients. The mean catheter life was 189.3 days (total, 8710 days; range, 7-810). Catheters were removed due to death (n=9), the end of treatment (n=8), catheter sepsis (n=4), malfunction (n=8), and accidental removal (n=4). The rate of catheter sepsis and malfunction was 0.459 and 0.919 for every 1000 catheter days, respectively. The expected mean catheter life was 479.6 days as per the Kaplan- Meier analysis. The results suggest that the radiologic placement of a tunneled central venous catheter is an effective technique with a high technical success rate and low complication rate.

Better P-curves: Making P-curve analysis more robust to errors, fraud, and ambitious P-hacking, a Reply to Ulrich and Miller (2015).

Science.gov (United States)

Simonsohn, Uri; Simmons, Joseph P; Nelson, Leif D

2015-12-01

When studies examine true effects, they generate right-skewed p-curves, distributions of statistically significant results with more low (.01 s) than high (.04 s) p values. What else can cause a right-skewed p-curve? First, we consider the possibility that researchers report only the smallest significant p value (as conjectured by Ulrich & Miller, 2015), concluding that it is a very uncommon problem. We then consider more common problems, including (a) p-curvers selecting the wrong p values, (b) fake data, (c) honest errors, and (d) ambitiously p-hacked (beyond p < .05) results. We evaluate the impact of these common problems on the validity of p-curve analysis, and provide practical solutions that substantially increase its robustness. (c) 2015 APA, all rights reserved).

Effect of the interaction among traps on the shape of thermoluminescence glow curves

International Nuclear Information System (INIS)

Marcazzo, J.; Santiago, M.; Spano, F.; Lester, M.; Ortega, F.; Molina, P.; Caselli, E.

2007-01-01

The effect of the interaction among traps on the structure of thermoluminescence glow curves has been investigated by generating numerically simulated glow curves for a wide range of trap parameters. The results reported in this paper provide useful insights which assist in the analysis of experimental glow curves. The most important result shows that it is incorrect to assume beforehand that each peak is related to a specific trapping state. The validity of the quasiequilibrium approximation is briefly discussed

Melanoma Patients with Unknown Primary Site or Nodal Recurrence after Initial Diagnosis Have a Favourable Survival Compared to Those with Synchronous Lymph Node Metastasis and Primary Tumour

OpenAIRE

Weide, Benjamin; Faller, Christine; Els?sser, Margrit; B?ttner, Petra; Pflugfelder, Annette; Leiter, Ulrike; Eigentler, Thomas Kurt; Bauer, J?rgen; Meier, Friedegund; Garbe, Claus

2013-01-01

BACKGROUND: A direct comparison of prognosis between patients with regional lymph node metastases (LNM) detected synchronously with the primary melanoma (primary LNM), patients who developed their first LNM subsequently (secondary LNM) and those with initial LNM in melanoma with unknown primary site (MUP) is missing thus far. PATIENTS AND METHODS: Survival of 498 patients was calculated from the time point of the first macroscopic LNM using Kaplan Meier and multivariate Cox hazard regression ...

Survival analysis

International Nuclear Information System (INIS)

Badwe, R.A.

1999-01-01

The primary endpoint in the majority of the studies has been either disease recurrence or death. This kind of analysis requires a special method since all patients in the study experience the endpoint. The standard method for estimating such survival distribution is Kaplan Meier method. The survival function is defined as the proportion of individuals who survive beyond certain time. Multi-variate comparison for survival has been carried out with Cox's proportional hazard model

Particles and Dirac-type operators on curved spaces

International Nuclear Information System (INIS)

Visinescu, Mihai

2003-01-01

We review the geodesic motion of pseudo-classical particles in curved spaces. Investigating the generalized Killing equations for spinning spaces, we express the constants of motion in terms of Killing-Yano tensors. Passing from the spinning spaces to the Dirac equation in curved backgrounds we point out the role of the Killing-Yano tensors in the construction of the Dirac-type operators. The general results are applied to the case of the four-dimensional Euclidean Taub-Newman-Unti-Tamburino space. From the covariantly constant Killing-Yano tensors of this space we construct three new Dirac-type operators which are equivalent with the standard Dirac operator. Finally the Runge-Lenz operator for the Dirac equation in this background is expressed in terms of the fourth Killing-Yano tensor which is not covariantly constant. As a rule the covariantly constant Killing-Yano tensors realize certain square roots of the metric tensor. Such a Killing-Yano tensor produces simultaneously a Dirac-type operator and the generator of a one-parameter Lie group connecting this operator with the standard Dirac one. On the other hand, the not covariantly constant Killing-Yano tensors are important in generating hidden symmetries. The presence of not covariantly constant Killing-Yano tensors implies the existence of non-standard supersymmetries in point particle theories on curved background. (author)

Meritev izkoristka in nastavitev krmilnih parametrov kaplanove turbine z dolgim cevnim sistemom s primerjalno metodo: Measurement of relative turbine efficiency and adjustment of governing parameters on long penstock Kaplan turbine with comparative method:

OpenAIRE

Trebše, Andrej J.

2004-01-01

The paper deals with efficiency measurement of Kaplan turbine with relative method (index test) and adjustment of operating of runner and guide vane governing system. At certain longer penstocks the looses in conduit at turbineload operation change the net head. On basis of model test on Kaplan turbine and relative turbine efficiency measurement on prototype the turbine governing system was optimized in accordance with comparative method. Prispevek obravnava meritev izkoristka kaplanove tu...

Examining the Latent Structure of the Delis-Kaplan Executive Function System.

Science.gov (United States)

Karr, Justin E; Hofer, Scott M; Iverson, Grant L; Garcia-Barrera, Mauricio A

2018-05-04

The current study aimed to determine whether the Delis-Kaplan Executive Function System (D-KEFS) taps into three executive function factors (inhibition, shifting, fluency) and to assess the relationship between these factors and tests of executive-related constructs less often measured in latent variable research: reasoning, abstraction, and problem solving. Participants included 425 adults from the D-KEFS standardization sample (20-49 years old; 50.1% female; 70.1% White). Eight alternative measurement models were compared based on model fit, with test scores assigned a priori to three factors: inhibition (Color-Word Interference, Tower), shifting (Trail Making, Sorting, Design Fluency), and fluency (Verbal/Design Fluency). The Twenty Questions, Word Context, and Proverb Tests were predicted in separate structural models. The three-factor model fit the data well (CFI = 0.938; RMSEA = 0.047), although a two-factor model, with shifting and fluency merged, fit similarly well (CFI = 0.929; RMSEA = 0.048). A bifactor model fit best (CFI = 0.977; RMSEA = 0.032) and explained the most variance in shifting indicators, but rarely converged among 5,000 bootstrapped samples. When the three first-order factors simultaneously predicted the criterion variables, only shifting was uniquely predictive (p measuring executive-related constructs and provide a framework through which clinicians can interpret D-KEFS results.

The Use of Statistically Based Rolling Supply Curves for Electricity Market Analysis: A Preliminary Look

Energy Technology Data Exchange (ETDEWEB)

Jenkin, Thomas J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Larson, Andrew [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Ruth, Mark F [National Renewable Energy Laboratory (NREL), Golden, CO (United States); King, Ben [U.S. Department of Energy; Spitsen, Paul [U.S. Department of Energy

2018-03-27

In light of the changing electricity resource mixes across the United States, an important question in electricity modeling is how additions and retirements of generation, including additions in variable renewable energy (VRE) generation could impact markets by changing hourly wholesale energy prices. Instead of using resource-intensive production cost models (PCMs) or building and using simple generator supply curves, this analysis uses a 'top-down' approach based on regression analysis of hourly historical energy and load data to estimate the impact of supply changes on wholesale electricity prices, provided the changes are not so substantial that they fundamentally alter the market and dispatch-order driven behavior of non-retiring units. The rolling supply curve (RSC) method used in this report estimates the shape of the supply curve that fits historical hourly price and load data for given time intervals, such as two-weeks, and then repeats this on a rolling basis through the year. These supply curves can then be modified on an hourly basis to reflect the impact of generation retirements or additions, including VRE and then reapplied to the same load data to estimate the change in hourly electricity price. The choice of duration over which these RSCs are estimated has a significant impact on goodness of fit. For example, in PJM in 2015, moving from fitting one curve per year to 26 rolling two-week supply curves improves the standard error of the regression from 16 dollars/MWh to 6 dollars/MWh and the R-squared of the estimate from 0.48 to 0.76. We illustrate the potential use and value of the RSC method by estimating wholesale price effects under various generator retirement and addition scenarios, and we discuss potential limits of the technique, some of which are inherent. The ability to do this type of analysis is important to a wide range of market participants and other stakeholders, and it may have a role in complementing use of or providing

Construction of long-term isochronous stress-strain curves by a modeling of short-term creep curves for a Grade 9Cr-1Mo steel

International Nuclear Information System (INIS)

Kim, Woo-Gon; Yin, Song-Nan; Koo, Gyeong-Hoi

2009-01-01

This study dealt with the construction of long-term isochronous stress-strain curves (ISSC) by a modeling of short-term creep curves for a Grade 9Cr-1Mo steel (G91) which is a candidate material for structural applications in the next generation nuclear reactors as well as in fusion reactors. To do this, tensile material data used in the inelastic constitutive equations was obtained by tensile tests at 550degC. Creep curves were obtained by a series of creep tests with different stress levels of 300MPa to 220MPa at an identical controlled temperature of 550degC. On the basis of these experimental data, the creep curves were characterized by Garofalo's creep model. Three parameters of P 1 , P 2 and P 3 in Garofalo's model were properly optimized by a nonlinear least square fitting (NLSF) analysis. The stress dependency of the three parameters was found to be a linear relationship. But, the P 3 parameter representing the steady state creep rate exhibited a two slope behavior with different stress exponents at a transient stress of about 250 MPa. The long-term creep curves of the G91 steel was modeled by Garofalo's model with only a few short-term creep data. Using the modeled creep curves, the long-term isochronous curves up to 10 5 hours were successfully constructed. (author)

Proposed Spontaneous Generation of Magnetic Fields by Curved Layers of a Chiral Superconductor

Science.gov (United States)

Kvorning, T.; Hansson, T. H.; Quelle, A.; Smith, C. Morais

2018-05-01

We demonstrate that two-dimensional chiral superconductors on curved surfaces spontaneously develop magnetic flux. This geometric Meissner effect provides an unequivocal signature of chiral superconductivity, which could be observed in layered materials under stress. We also employ the effect to explain some puzzling questions related to the location of zero-energy Majorana modes.

EVEREST: Pixel Level Decorrelation of K2 Light Curves

Science.gov (United States)

Luger, Rodrigo; Agol, Eric; Kruse, Ethan; Barnes, Rory; Becker, Andrew; Foreman-Mackey, Daniel; Deming, Drake

2016-10-01

We present EPIC Variability Extraction and Removal for Exoplanet Science Targets (EVEREST), an open-source pipeline for removing instrumental noise from K2 light curves. EVEREST employs a variant of pixel level decorrelation to remove systematics introduced by the spacecraft’s pointing error and a Gaussian process to capture astrophysical variability. We apply EVEREST to all K2 targets in campaigns 0-7, yielding light curves with precision comparable to that of the original Kepler mission for stars brighter than {K}p≈ 13, and within a factor of two of the Kepler precision for fainter targets. We perform cross-validation and transit injection and recovery tests to validate the pipeline, and compare our light curves to the other de-trended light curves available for download at the MAST High Level Science Products archive. We find that EVEREST achieves the highest average precision of any of these pipelines for unsaturated K2 stars. The improved precision of these light curves will aid in exoplanet detection and characterization, investigations of stellar variability, asteroseismology, and other photometric studies. The EVEREST pipeline can also easily be applied to future surveys, such as the TESS mission, to correct for instrumental systematics and enable the detection of low signal-to-noise transiting exoplanets. The EVEREST light curves and the source code used to generate them are freely available online.

Comparison Algorithm Kernels on Support Vector Machine (SVM To Compare The Trend Curves with Curves Online Forex Trading

Directory of Open Access Journals (Sweden)

irfan abbas

2017-01-01

Full Text Available At this time, the players Forex Trading generally still use the data exchange in the form of a Forex Trading figures from different sources. Thus they only receive or know the data rate of a Forex Trading prevailing at the time just so difficult to analyze or predict exchange rate movements future. Forex players usually use the indicators to enable them to analyze and memperdiksi future value. Indicator is a decision making tool. Trading forex is trading currency of a country, the other country's currency. Trading took place globally between the financial centers of the world with the involvement of the world's major banks as the major transaction. Trading Forex offers profitable investment type with a small capital and high profit, with relatively small capital can earn profits doubled. This is due to the forex trading systems exist leverage which the invested capital will be doubled if the predicted results of buy / sell is accurate, but Trading Forex having high risk level, but by knowing the right time to trade (buy or sell, the losses can be avoided. Traders who invest in the foreign exchange market is expected to have the ability to analyze the circumstances and situations in predicting the difference in currency exchange rates. Forex price movements that form the pattern (curve up and down greatly assist traders in making decisions. The movement of the curve used as an indicator in the decision to purchase (buy or sell (sell. This study compares (Comparation type algorithm kernel on Support Vector Machine (SVM to predict the movement of the curve in live time trading forex using the data GBPUSD, 1H. Results of research on the study of the results and discussion can be concluded that the Kernel Dot, Kernel Multiquaric, Kernel Neural inappropriately used for data is non-linear in the case of data forex to follow the pattern of trend curves, because curves generated curved linear (straight and then to type of kernel is the closest curve

Fatigue Analysis of the Piston Rod in a Kaplan Turbine Based on Crack Propagation under Unsteady Hydraulic Loads

International Nuclear Information System (INIS)

Liu, X; Luo, Y Y; Wang, Z W

2014-01-01

As an important component of the blade-control system in Kaplan turbines, piston rods are subjected to fluctuating forces transferred by the turbines blades from hydraulic pressure oscillations. Damage due to unsteady hydraulic loads might generate unexpected down time and high repair cost. In one running hydropower plant, the fracture failure of the piston rod was found twice at the same location. With the transient dynamic analysis, the retainer ring structure of the piston rod existed a relative high stress concentration. This predicted position of the stress concentration agreed well with the actual fracture position in the plant. However, the local strain approach was not able to explain why this position broke frequently. Since traditional structural fatigue analyses use a local stress strain approach to assess structural integrity, do not consider the effect of flaws which can significantly degrade structural life. Using linear elastic fracture mechanism (LEFM) approaches that include the effect of flaws is becoming common practice in many industries. In this research, a case involving a small semi-ellipse crack was taken into account at the stress concentration area, crack growth progress was calculated by FEM. The relationship between crack length and remaining life was obtained. The crack propagation path approximately agreed with the actual fracture section. The results showed that presence of the crack had significantly changed the local stress and strain distributions of the piston rod compared with non-flaw assumption

Fatigue Analysis of the Piston Rod in a Kaplan Turbine Based on Crack Propagation under Unsteady Hydraulic Loads

Science.gov (United States)

Liu, X.; Y Luo, Y.; Wang, Z. W.

2014-03-01

As an important component of the blade-control system in Kaplan turbines, piston rods are subjected to fluctuating forces transferred by the turbines blades from hydraulic pressure oscillations. Damage due to unsteady hydraulic loads might generate unexpected down time and high repair cost. In one running hydropower plant, the fracture failure of the piston rod was found twice at the same location. With the transient dynamic analysis, the retainer ring structure of the piston rod existed a relative high stress concentration. This predicted position of the stress concentration agreed well with the actual fracture position in the plant. However, the local strain approach was not able to explain why this position broke frequently. Since traditional structural fatigue analyses use a local stress strain approach to assess structural integrity, do not consider the effect of flaws which can significantly degrade structural life. Using linear elastic fracture mechanism (LEFM) approaches that include the effect of flaws is becoming common practice in many industries. In this research, a case involving a small semi-ellipse crack was taken into account at the stress concentration area, crack growth progress was calculated by FEM. The relationship between crack length and remaining life was obtained. The crack propagation path approximately agreed with the actual fracture section. The results showed that presence of the crack had significantly changed the local stress and strain distributions of the piston rod compared with non-flaw assumption.

INVESTIGATION OF CURVES SET BY CUBIC DISTRIBUTION OF CURVATURE

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S. A. Ustenko

2014-03-01

Full Text Available Purpose. Further development of the geometric modeling of curvelinear contours of different objects based on the specified cubic curvature distribution and setpoints of curvature in the boundary points. Methodology. We investigate the flat section of the curvilinear contour generating under condition that cubic curvature distribution is set. Curve begins and ends at the given points, where angles of tangent slope and curvature are also determined. It was obtained the curvature equation of this curve, depending on the section length and coefficient c of cubic curvature distribution. The analysis of obtained equation was carried out. As well as, it was investigated the conditions, in which the inflection points of the curve are appearing. One should find such an interval of parameter change (depending on the input data and the section length, in order to place the inflection point of the curvature graph outside the curve section borders. It was determined the dependence of tangent slope of angle to the curve at its arbitrary point, as well as it was given the recommendations to solve a system of integral equations that allow finding the length of the curve section and the coefficient c of curvature cubic distribution. Findings. As the result of curves research, it is found that the criterion for their selection one can consider the absence of inflection points of the curvature on the observed section. Influence analysis of the parameter c on the graph of tangent slope angle to the curve showed that regardless of its value, it is provided the same rate of angle increase of tangent slope to the curve. Originality. It is improved the approach to geometric modeling of curves based on cubic curvature distribution with its given values at the boundary points by eliminating the inflection points from the observed section of curvilinear contours. Practical value. Curves obtained using the proposed method can be used for geometric modeling of curvilinear

Modelling antagonic effect of lactic acid eacteria supernatants on some pathogenic bacteria

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Augustus Caeser Franke Portella

2009-11-01

Full Text Available This work presents a statistical model of survival analysis for three pathogenic bacterial strains (Escherichia coli, Listeria monocytogenes and Staphylococcus aureus, when treated with neutralized and non-neutralized filtered supernatants broth from cultures of Lactobacillus acidhophilus, Lactobacillus rhamnosus and Lactobacillus sake. Survival analysis is a method employed to determine the period of time from an initial stage up to the occurrence of a particular event of interest, as death or a particular culture growth failure. In order to evaluate the potential efficacy of the ahead mentioned lactic acid bacteria when used as bioprotective starters in foods, experimental data were statistically treated and expressed by simple representative curves. Following the methodology of Cox and Kaplan-Meier, it was possible to make the selection of the best bioprotective lactic starter, as a predictive tool for evaluation of shelf life and prevention of eventual risks in fresh sausages and other similar food products.Este trabalho apresenta um modelo estatístico de análise de sobrevivência para três bactérias patogénicas (Escherichia coli, Listeria monocytogenes e Staphylococcus aureus, quando tratados com sobrenadantes filtrados neutralizado e não neutralizado provenientes de culturas de Lactobacillus acidhophilus, Lactobacillus rhamnosus e Lactobacillus sake. A Análise de sobrevivência é um método utilizado para determinar o período de tempo a partir de uma fase inicial até a ocorrência de um determinado evento de interesse, como a morte ou a inibição de uma particular cultura, a fim de avaliar a eficácia potencial das referidas bactérias lácticas quando usadas como bioproteção em alimentos. Os dados experimentais foram tratados estatisticamente, seguindo a metodologia de Cox e Kaplan-Meier e foi possível fazer a seleção dos melhores fermentos láticos bioprotectivos, como uma ferramenta para avaliação preditiva, vida de

Relationship between LAPTM4B Gene Polymorphism and Prognosis of Patients following Tumor Resection for Colorectal and Esophageal Cancers

Science.gov (United States)

Xing, Xiaofang; Du, Hong; Zhou, Chunlian; Zhang, Qingyun; Hao, Chunyi; Wen, Xianzi; Ji, Jiafu

2016-01-01

Background Lysosome-associated transmembrane-4 beta (LAPTM4B) is an oncogene that participates tumorgenesis in a variety of human solid tumors, and it has two alleles named as LAPTM4B*1 and *2. The present study aimed to identify the association of LAPTM4B genotype with clinicopathological features and prognosis in colorectal and esophageal cancer patients. Method Genotypes of LAPTM4B were determined by PCR in 167 colon cancer cases (72 patients in a discovery cohort and 95 patients in a testing cohort), 160 rectal cancer cases and 164 esophageal cancer cases. Association between the LAPTM4B gene polymorphism and clinicopathological variables was calculated by Chi-square test or Fisher’s exact test. Patient survival differences were calculated by the Kaplan-Meier method. Prognostic factors were determined with Log-rank test and Cox regression model. Results LAPTM4B *1/1 was more frequently detected in colon cancer patients with lymph node metastasis and TNM III+IV stages in total colon cancer (discovery + testing cohorts). LAPTM4B *2/2 decreased in recurrent patients in total colon cancer patients (P = 0.045). Kaplan-Meier survival curves and Log-rank test showed that LAPTM4B*1 was correlated with shorter overall survival (OS) in discovery and testing cohorts of colon cancer (P = 0.0254 and 0.0292, respectively), but not in rectal and esophageal cancer cases (P = 0.7669 and 0.9356, respectively). Multivariate analysis showed that LAPTM4B genotype was an independent prognostic factor for OS in total colon cancer [P = 0.004, hazard ratio (HR) = 0.432; 95% confidence interval (CI) = 0.243–0.768], but not in rectal and esophageal cancers (P = 0.791, HR = 1.073, 95% CI = 0.638–1.804 and 0.998, HR = 1.000, 95% CI = 0.663–1.530, respectively). Conclusion These findings suggested that LAPTM4B allele *1 was a risk factor associated with poor prognosis in patients with colon cancer, but not in patients with rectal or esophageal cancers. LAPTM4B genotype status might

Relationship between LAPTM4B Gene Polymorphism and Prognosis of Patients following Tumor Resection for Colorectal and Esophageal Cancers.

Directory of Open Access Journals (Sweden)

Xiaojing Cheng

Full Text Available Lysosome-associated transmembrane-4 beta (LAPTM4B is an oncogene that participates tumorgenesis in a variety of human solid tumors, and it has two alleles named as LAPTM4B*1 and *2. The present study aimed to identify the association of LAPTM4B genotype with clinicopathological features and prognosis in colorectal and esophageal cancer patients.Genotypes of LAPTM4B were determined by PCR in 167 colon cancer cases (72 patients in a discovery cohort and 95 patients in a testing cohort, 160 rectal cancer cases and 164 esophageal cancer cases. Association between the LAPTM4B gene polymorphism and clinicopathological variables was calculated by Chi-square test or Fisher's exact test. Patient survival differences were calculated by the Kaplan-Meier method. Prognostic factors were determined with Log-rank test and Cox regression model.LAPTM4B *1/1 was more frequently detected in colon cancer patients with lymph node metastasis and TNM III+IV stages in total colon cancer (discovery + testing cohorts. LAPTM4B *2/2 decreased in recurrent patients in total colon cancer patients (P = 0.045. Kaplan-Meier survival curves and Log-rank test showed that LAPTM4B*1 was correlated with shorter overall survival (OS in discovery and testing cohorts of colon cancer (P = 0.0254 and 0.0292, respectively, but not in rectal and esophageal cancer cases (P = 0.7669 and 0.9356, respectively. Multivariate analysis showed that LAPTM4B genotype was an independent prognostic factor for OS in total colon cancer [P = 0.004, hazard ratio (HR = 0.432; 95% confidence interval (CI = 0.243-0.768], but not in rectal and esophageal cancers (P = 0.791, HR = 1.073, 95% CI = 0.638-1.804 and 0.998, HR = 1.000, 95% CI = 0.663-1.530, respectively.These findings suggested that LAPTM4B allele *1 was a risk factor associated with poor prognosis in patients with colon cancer, but not in patients with rectal or esophageal cancers. LAPTM4B genotype status might be a useful prognostic indicator for

Subintimal angioplasty for below-the-ankle arterial occlusion in diabetic patients with chronic critical limb ischemia

International Nuclear Information System (INIS)

Xu Ying; Zhu Yueqi; Zhao Jungong; Wang Jianbo; Tan Huaqiao; Cheng Yingsheng; Li Minghua; Wang Jue; Cheng Yongde

2011-01-01

Objective: To assess the feasibility and efficacy of subintimal angioplasty (SA) for the treatment of below-the-arterial occlusion in diabetic patients with chronic critical limb ischemia (CLI). Methods: SA was adopted for 57 diseased lower limbs in 37 diabetic patients with chronic CLI and occlusive disease of the dorsalis pedis artery (DPA) and/or planter artery (PA), who were not suitable candidates for intraluminal angioplasty or bypass surgery. Of the total 57 diseased lower limbs, tissue loss was seen in 31 (54.4%) and pain was reported in 51 (89.5%). SA was carried out to create continuous arterial flow to the foot for limb salvage. Both before and after the procedure the clinical symptoms, DPA or PA pulse volume scores and ankle-brachial indexes (ABI) were determined in all patients, the results were compared and statistically analysed. During the follow-up period, the healing of the wound, the salvage of the diseased limb and the re-stenosis occurrence of the target vessels were evaluated. Kaplan-Meier curves were constructed to evaluate limb salvage, survival rate and freedom from amputation. Results: A total of 66 below-the-ankle arterial lesions were detected in 57 affected limbs. Of the 66 lesions, SA was successfully performed in 55 (83.3%). Before SA the median pulse volume scores and ABIs were 0.33±0.54 and 0.31±0.19 respectively, which became 2.04±1.05 and 0.80±0.14 respectively after SA, the differences in both median pulse volume scores and ABI were statistically significant (P<0.01 for both). One patient (2.7%) died within 30 days after the procedure. Mild complications, such as bleeding, thrombosis or angiospasm etc. occurred in five patents (13.5%). Twelve months after SA. Kaplan-Meier analysis showed that the limb salvage rate was 94.6%, the freedom from amputation was 89.2% and the survival rate was 97.3%. Conclusion: SA of the dorsalis pedis artery and/or planter artery is an effective technique for lower limb salvage in diabetic

Prognostic value of {sup 18}F-DOPA PET/CT at the time of recurrence in patients affected by neuroblastoma

Energy Technology Data Exchange (ETDEWEB)

Piccardo, Arnoldo [Galliera Hospital, Nuclear Medicine Unit, Genoa (Italy); E.O. Ospedali Galliera, Department of Nuclear Medicine, Genoa (Italy); Puntoni, Matteo [Galliera Hospital, Clinical Trial Research Unit, Genoa (Italy); Lopci, Egesta; Fanti, Stefano [Sant' Orsola-Malpighi Hospital, Nuclear Medicine Unit, Bologna (Italy); Conte, Massimo; Sorrentino, Stefania; Garaventa, Alberto [G. Gaslini Children' s Hospital, Department of Hematology-Oncology, Genoa (Italy); Foppiani, Luca [Galliera Hospital, Internal Medicine, Genoa (Italy); Morana, Giovanni [G. Gaslini Children' s Hospital, Department of Pathology and Radiology, Genoa (Italy); Naseri, Mehrdad; Villavecchia, Giampiero [Galliera Hospital, Nuclear Medicine Unit, Genoa (Italy); Cistaro, Angelina [IRMET, PET Centre, Turin (Italy)

2014-06-15

The aim of this study was to investigate the relationship between {sup 123}I-metaiodobenzylguanidine (MIBG) scan semi-quantification and a new {sup 18}F-DOPA positron emission tomography (PET)/CT score in patients with suspected or documented neuroblastoma (NB) relapse and to assess the association between these two parameters and progression-free survival (PFS)/overall survival (OS). We analysed 24 NB patients who had undergone {sup 123}I-MIBG and {sup 18}F-DOPA PET/CT scans at the time of suspected relapse, after applying a proper scoring system for each scan. In time-to-event analyses, the score distributions were regarded as continuous and were categorized in tertiles and medians. We used Kaplan-Meier curves and Cox proportional hazard models for PFS and OS in order to estimate the independent prognostic impact of {sup 123}I-MIBG and {sup 18}F-DOPA PET/CT scans. The {sup 123}I-MIBG and {sup 18}F-DOPA scores were highly and positively correlated (Spearman's rho = 0.8, p < 0.001). Over a median follow-up of 14 months (range 6-82), 12 cases of disease progression and 6 deaths occurred. Multivariate Cox models showed a higher risk of disease progression [hazard ratio (HR) 17.0, 95 % confidence interval (CI) 2.7-109] in NB patients with {sup 123}I-MIBG score > 3 (3rd tertile) and an even higher risk (HR:37.2, 95 % CI 2.4-574) in those with {sup 18}F-DOPA whole-body metabolic burden (WBMB) >7.5 (median), after adjustment for all main clinical/pathological factors considered. Kaplan-Meier analyses showed a significant association with OS (log-rank p = 0.01 and p = 0.03 for {sup 123}I-MIBG and {sup 18}F-DOPA WBMB, respectively). Our results confirm the good agreement between {sup 18}F-DOPA PET/CT and {sup 123}I-MIBG scan in patients affected by NB relapse. In time-to-event analyses, {sup 123}I-MIBG scan and {sup 18}F-DOPA PET/CT scores were independently and significantly associated with disease progression. (orig.)

Comparison of transmission dynamics between Streptococcus uberis and Streptococcus agalactiae intramammary infections.

Science.gov (United States)

Leelahapongsathon, Kansuda; Schukken, Ynte Hein; Pinyopummintr, Tanu; Suriyasathaporn, Witaya

2016-02-01

The objectives of study were to determine the transmission parameters (β), durations of infection, and basic reproductive numbers (R0) of both Streptococcus agalactiae and Streptococcus uberis as pathogens causing mastitis outbreaks in dairy herds. A 10-mo longitudinal study was performed using 2 smallholder dairy herds with mastitis outbreaks caused by Strep. agalactiae and Strep. uberis, respectively. Both herds had poor mastitis control management and did not change their milking management during the entire study period. Quarter milk samples were collected at monthly intervals from all lactating animals in each herd for bacteriological identification. The durations of infection for Strep. uberis intramammary infection (IMI) and Strep. agalactiae IMI were examined using Kaplan-Meier survival curves, and the Kaplan-Meier survival functions for Strep. uberis IMI and Strep. agalactiae IMI were compared using log rank survival-test. The spread of Strep. uberis and Strep. agalactiae through the population was determined by transmission parameter, β, the probability per unit of time that one infectious quarter will infect another quarter, assuming that all other quarters are susceptible. For the Strep. uberis outbreak herd (31 cows), 56 new infections and 28 quarters with spontaneous cure were observed. For the Strep. agalactiae outbreak herd (19 cows), 26 new infections and 9 quarters with spontaneous cure were observed. The duration of infection for Strep. agalactiae (mean=270.84 d) was significantly longer than the duration of infection for Strep. uberis (mean=187.88 d). The transmission parameters (β) estimated (including 95% confidence interval) for Strep. uberis IMI and Strep. agalactiae IMI were 0.0155 (0.0035-0.0693) and 0.0068 (0.0008-0.0606), respectively. The R0 (including 95% confidence interval) during the study were 2.91 (0.63-13.47) and 1.86 (0.21-16.61) for Strep. uberis IMI and Strep. agalactiae IMI, respectively. In conclusion, the transmission

Nonlinear Dynamic of Curved Railway Tracks in Three-Dimensional Space

Science.gov (United States)

Liu, X.; Ngamkhanong, C.; Kaewunruen, S.

2017-12-01

On curved tracks, high-pitch noise pollution can often be a considerable concern of rail asset owners, commuters, and people living or working along the rail corridor. Inevitably, wheel/rail interface can cause a traveling source of sound and vibration, which spread over a long distance of rail network. The sound and vibration can be in various forms and spectra. The undesirable sound and vibration on curves is often called ‘noise,’ includes flanging and squealing noises. This paper focuses on the squeal noise phenomena on curved tracks located in urban environments. It highlights the effect of curve radii on lateral track dynamics. It is important to note that rail freight curve noises, especially for curve squeals, can be observed almost everywhere and every type of track structures. The most pressing noise appears at sharper curved tracks where excessive lateral wheel/rail dynamics resonate with falling friction states, generating a tonal noise problem, so-call ‘squeal’. Many researchers have carried out measurements and simulations to understand the actual root causes of the squeal noise. Most researchers believe that wheel resonance over falling friction is the main cause, whilst a few others think that dynamic mode coupling of wheel and rail may also cause the squeal. Therefore, this paper is devoted to systems thinking the approach and dynamic assessment in resolving railway curve noise problems. The simulations of railway tracks with different curve radii will be carried out to develop state-of-the-art understanding into lateral track dynamics, including rail dynamics, cant dynamics, gauge dynamics and overall track responses.

Repair of Kaplan turbine shaft sealing based on evaluation of hydraulic conditions

International Nuclear Information System (INIS)

Lakatos, K; Szamosi, Z; Bereczkei, S

2012-01-01

This paper has been written to call attention to a potential danger what may occur in Kaplan turbine refurbishments. In Tiszalök hydropower plant, Hungary, the shaft sealing of the refurbished turbine was damaged. In searching for the reasons it was assumed that due to increased internal velocities in the turbine, the pressure at the hub clearance became lower than the atmospheric pressure, and therefore the sealing, which always operated satisfactorily before the refurbishment, had uncertain water supply, dry-running occurred, and after some time the sealing was burnt. First the flow conditions in the turbine and the pressure at the hub clearance were calculated by a one-dimensional flow model. Later this was refined by a two-dimensional approach. The above conclusion was also justified by the data acquisition system and by observing the operation of the small dewatering pump. When the turbine operated at a larger discharge than a certain limit value, then the dewatering pump remained standstill, indicating that no water passed through the shaft sealing. External water supply was then applied, and after this the turbine operated all right.

Repair of Kaplan turbine shaft sealing based on evaluation of hydraulic conditions

Science.gov (United States)

Lakatos, K.; Szamosi, Z.; Bereczkei, S.

2012-11-01

This paper has been written to call attention to a potential danger what may occur in Kaplan turbine refurbishments. In Tiszalök hydropower plant, Hungary, the shaft sealing of the refurbished turbine was damaged. In searching for the reasons it was assumed that due to increased internal velocities in the turbine, the pressure at the hub clearance became lower than the atmospheric pressure, and therefore the sealing, which always operated satisfactorily before the refurbishment, had uncertain water supply, dry-running occurred, and after some time the sealing was burnt. First the flow conditions in the turbine and the pressure at the hub clearance were calculated by a one-dimensional flow model. Later this was refined by a two-dimensional approach. The above conclusion was also justified by the data acquisition system and by observing the operation of the small dewatering pump. When the turbine operated at a larger discharge than a certain limit value, then the dewatering pump remained standstill, indicating that no water passed through the shaft sealing. External water supply was then applied, and after this the turbine operated all right.

The Short-Term and Intermediate-Term Risk of Second Neoplasms After Diagnosis and Treatment of Unilateral Vestibular Schwannoma: Analysis of 9460 Cases

International Nuclear Information System (INIS)

Carlson, Matthew L.; Glasgow, Amy E.; Jacob, Jeffrey T.; Habermann, Elizabeth B.; Link, Michael J.

2016-01-01

Purpose: To determine the incidence of second intracranial neoplasms after the diagnosis and treatment of sporadic vestibular schwannoma (VS). Methods and Materials: Analysis of the Surveillance, Epidemiology, and End Results (SEER) database including all patients identified with a diagnosis of VS and a second intracranial tumor. The Kaplan-Meier method was used to determine the incidence of second tumors while allowing for censoring at loss to follow-up or death. Multivariable associations between treatment modality and second tumor formation were explored using Cox proportional hazards regression analysis. Two illustrative cases are also presented. Results: In all, 9460 patients with unilateral VS were identified between 2004 and 2012. Overall, 66 (0.7%) patients experienced a separate intracranial tumor, benign or malignant, after treatment of VS. Kaplan-Meier estimates for time to second neoplasm at 1, 3, and 5 years were 0.3%, 0.7%, and 0.8%, respectively. Multivariable comparison between VS treatment modalities revealed that the risk of second tumor formation was similar between radiation and surgery (hazard ratio [HR] 0.74; 95% confidence interval [CI] 0.36-1.51; P=.93) but greater for tumors managed with observation alone compared with radiation (HR 2.48; 95% CI 1.31-4.71; P<.01). A total of 6 (0.06%) intracranial malignancies were diagnosed after VS treatment. Kaplan-Meier estimates for time to malignancy at 1, 3, and 5 years were 0%, 0.1%, and 0.1%, respectively. After adjustment for age at diagnosis, sex, and treatment modality, the probability of malignancy after radiation was not greater than after observation alone or microsurgery (HR 4.88; 95% CI 0.85-28.14; P=.08) during the study period. Conclusions: The risk for the development of a second intracranial neoplasm, benign or malignant, at 5 years after treatment of unilateral VS is approximately 0.8%, whereas the risk of acquiring a separate malignancy is 0.1%, or approximately 1 per 1000 cases

Análisis de la recurrencia de cáncer de lengua considerando la presencia de eventos competitivos.

Directory of Open Access Journals (Sweden)

Raúl Vicente Mantilla Quispe

2008-10-01

Full Text Available Objetivo: Estimar la probabilidad de recurrencia en pacientes con cáncer de lengua según la edad, el estado ganglionar patológico y el tipo de tratamiento de los pacientes considerando la muerte antes de la recurrencia como evento competitivo. Material y métodos: Serie de casos retrospectiva de 290 pacientes con cáncer de lengua, con tratamiento en el INEN, entre los años 1977 y 2000. Se excluyeron del estudio 29 pacientes tratados solo con radioterapia. De los 261 pacientes, 31 solo tuvieron tratamiento del tumor primario. Resultados: La recurrencia fue 36,8%, la recurrencia local fue la más frecuente. La incidencia acumulada de la recurrencia a los 5 años, con el método de Kaplan Meier, se estimó en 44,7%, y según el análisis de riesgos competitivos en 42,4%. En el análisis univariado considerando riesgos competitivos, las incidencias acumuladas fueron: 56,8 y 38,9% en pacientes menores o iguales que 45 y mayores que 45 años respectivamente (p = 0,1556, 29,4% y 50,5% en pacientes con ganglios patológicos negativos y positivos, respectivamente (p = 0,0002, y 37,5% en pacientes con cirugía, y 47,4% con radioterapia (p = 0,03. En el análisis multivariado, con regresión de riesgos competitivos, no se encontró diferencia entre los tipos de tratamiento sobre la recurrencia (RR = 1,146, p = 0,620. Conclusiones: La pequeña diferencia entre los resultados del método Kaplan Meier y el que toma en cuenta eventos competitivos se debe a la baja tasa del evento competitivo, más aún por que se trata de muerte no relacionada con la enfermedad. La tasa de recurrencia fue similar al reportado en la literatura. Sólo se encontró diferencia significativa en la tasa de recurrencia en el grupo con compromiso ganglionar positivo. Aunque la comparación con los métodos estándar, Kaplan Meier y Regresión de Cox, muestra resultados similares se deben tener en cuenta los eventos competitivos. (Rev Med Hered 2008;19: 145-151.

The Short-Term and Intermediate-Term Risk of Second Neoplasms After Diagnosis and Treatment of Unilateral Vestibular Schwannoma: Analysis of 9460 Cases

Energy Technology Data Exchange (ETDEWEB)

Carlson, Matthew L., E-mail: carlson.matthew@mayo.edu [Department of Otorhinolaryngology, Mayo Clinic School of Medicine, Rochester, Minnesota (United States); Department of Neurologic Surgery, Mayo Clinic School of Medicine, Rochester, Minnesota (United States); Glasgow, Amy E. [Division of Health Care Policy and Research and the Robert D. and Patricia E. Kern Center for the Science of Health Care Delivery, Mayo Clinic School of Medicine, Rochester, Minnesota (United States); Jacob, Jeffrey T. [Department of Neurologic Surgery, Mayo Clinic School of Medicine, Rochester, Minnesota (United States); Habermann, Elizabeth B. [Division of Health Care Policy and Research and the Robert D. and Patricia E. Kern Center for the Science of Health Care Delivery, Mayo Clinic School of Medicine, Rochester, Minnesota (United States); Link, Michael J. [Department of Otorhinolaryngology, Mayo Clinic School of Medicine, Rochester, Minnesota (United States); Department of Neurologic Surgery, Mayo Clinic School of Medicine, Rochester, Minnesota (United States)

2016-07-15

Purpose: To determine the incidence of second intracranial neoplasms after the diagnosis and treatment of sporadic vestibular schwannoma (VS). Methods and Materials: Analysis of the Surveillance, Epidemiology, and End Results (SEER) database including all patients identified with a diagnosis of VS and a second intracranial tumor. The Kaplan-Meier method was used to determine the incidence of second tumors while allowing for censoring at loss to follow-up or death. Multivariable associations between treatment modality and second tumor formation were explored using Cox proportional hazards regression analysis. Two illustrative cases are also presented. Results: In all, 9460 patients with unilateral VS were identified between 2004 and 2012. Overall, 66 (0.7%) patients experienced a separate intracranial tumor, benign or malignant, after treatment of VS. Kaplan-Meier estimates for time to second neoplasm at 1, 3, and 5 years were 0.3%, 0.7%, and 0.8%, respectively. Multivariable comparison between VS treatment modalities revealed that the risk of second tumor formation was similar between radiation and surgery (hazard ratio [HR] 0.74; 95% confidence interval [CI] 0.36-1.51; P=.93) but greater for tumors managed with observation alone compared with radiation (HR 2.48; 95% CI 1.31-4.71; P<.01). A total of 6 (0.06%) intracranial malignancies were diagnosed after VS treatment. Kaplan-Meier estimates for time to malignancy at 1, 3, and 5 years were 0%, 0.1%, and 0.1%, respectively. After adjustment for age at diagnosis, sex, and treatment modality, the probability of malignancy after radiation was not greater than after observation alone or microsurgery (HR 4.88; 95% CI 0.85-28.14; P=.08) during the study period. Conclusions: The risk for the development of a second intracranial neoplasm, benign or malignant, at 5 years after treatment of unilateral VS is approximately 0.8%, whereas the risk of acquiring a separate malignancy is 0.1%, or approximately 1 per 1000 cases

Contributions to the R-curve behaviour of ceramic materials

International Nuclear Information System (INIS)

Fett, T.

1994-12-01

Several ceramic materials show an increase in crack growth resistance with increasing crack extension. Especially, in case of coarse-grained alumina this ''R-curve effect'' is caused by crack-face interactions in the wake of the advancing crack. Similar effects occur for whisker reinforced ceramics. Due to the crack-face interactions so-called ''bridging stresses'' are generated which transfer forces between the two crack surfaces. A second reason for an increase of crack-growth resistance are stress-induced phase transformations in zirconia ceramics with the tetragonal phase changing to the monoclinic phase. These transformations will affect the stress field in the surroundings of crack tips. The transformation generates a crack-tip transformation zone and, due to the stress balance, also residual stresses in the whole crack region which result in a residual stress intensity factor. This additional stress intensity factor is also a reason for the R-curve behaviour. In this report both effects are outlined in detail. (orig.) [de

Aldo-keto Reductase Family 1 B10 as a Novel Target for Breast Cancer Treatment

Science.gov (United States)

2010-08-01

overexpressed in tested human breast cancer tissues and mediates acetyl-CoA carboxylase-α ( ACCA ) stability, affecting fatty acid de novo synthesis and...9703; Fax. 217-545-3227; E-mail: dcao@siumed.edu Running title: AKR1B10 as a new risk factor for breast cancer Abbreviations used: ACCA , acetyl...The effect of AKR1B10 expression in cancer tissue on patient survival was evaluated with Kaplan - Meier plots, and results showed that AKR1B10

Impact of Comorbidities on Tumor Necrosis Factor Inhibitor Therapy in Psoriatic Arthritis

DEFF Research Database (Denmark)

Ballegaard, Christine; Højgaard, Pil; Dreyer, Lene

2017-01-01

characteristics, disease activity and treatment response and persistence was obtained from the DANBIO registry. Information on comorbidities according to the Charlson Comorbidity Index (CCI) was obtained through linkage with the Danish National Patient Register. Kaplan-Meier plots and Cox proportional hazard...... compared with patients without comorbidities (hazard ratio 1.72, [1.26 to 2.37], p = 0.001). A smaller proportion of patients with a CCI score ≥ 2 achieved European League Against Rheumatism (EULAR) good response (p

Measuring survival time: a probability-based approach useful in healthcare decision-making.

Science.gov (United States)

2011-01-01

In some clinical situations, the choice between treatment options takes into account their impact on patient survival time. Due to practical constraints (such as loss to follow-up), survival time is usually estimated using a probability calculation based on data obtained in clinical studies or trials. The two techniques most commonly used to estimate survival times are the Kaplan-Meier method and the actuarial method. Despite their limitations, they provide useful information when choosing between treatment options.

High income, employment, postgraduate education, and marriage. A suicidal cocktail among psychiatric patients

DEFF Research Database (Denmark)

Agerbo, Esben

2007-01-01

longitudinal data on income, labor market affiliation, educational attainment, and marital and cohabitational status (96,369 patients, 256,619 admissions, and 2727 suicides). MAIN OUTCOME MEASURES: Suicide risks after hospital discharge were depicted using Kaplan-Meier product-limit methods. Hazard ratios (HRs...... is generally associated with low income, unemployment, educational underachievement, and singleness, but this study suggests that the opposite is true among psychiatric patients. However, loss of income, labor market status, and marriage increase the suicide risk....

Improve T Cell Therapy in Neuroblastoma

Science.gov (United States)

2015-09-01

bioluminescence was then measured overtime. The graph is representative of one of 4 experiments using CMV-CTLs from 4 donors. Panel E. Kaplan-Meier...whole-cell vaccine expressing the iC9 gene and labeled with an enhanced firefly luciferase. Tumor growth was measured by in vivo imaging. Panel E...down regulation in LTE -T cells is not caused by specific culture conditions. T lymphocytes were activated with immobilized OKT3 (1 μg ml) and

Protective Role of Comfrey Leave Extracts on UV-induced Zebrafish Fin Damage

OpenAIRE

Cheng, Chien-Chung; Chou, Chi-Yuan; Chang, Yao-Chin; Wang, Hsuan-Wen; Wen, Chi-Chung; Chen, Yau-Hung

2014-01-01

In zebrafish, UV exposure leads to fin malformation phenotypes including fin reduction or absence. The present study evaluated UV-protective activities of comfrey leaves extracts in a zebrafish model by recording fin morphological changes. Chemopreventive effects of comfrey leave extracts were evaluated using Kaplan-Meier analysis and Cox proportional hazards regression. The results showed that (1) the mean times of return to normal fin in the UV+comfrey (50 and 100 ppm) groups were 3.43 and ...

Logging and Agricultural Residue Supply Curves for the Pacific Northwest

Energy Technology Data Exchange (ETDEWEB)

Kerstetter, James D.; Lyons, John Kim

2001-01-01

This report quantified the volume of logging residues at the county level for current timber harvests. The cost of recovering logging residues was determined for skidding, yearding, loading, chipping and transporting the residues. Supply curves were developed for ten candidate conversion sites in the Pacific Northwest Region. Agricultural field residues were also quantified at the county level using five-year average crop yields. Agronomic constraints were applied to arrive at the volumes available for energy use. Collection costs and transportation costs were determined and supply curves generated for thirteen candidate conversion sites.

Experience in the management of ECMO therapy as a mortality risk factor.

Science.gov (United States)

Guilló Moreno, V; Gutiérrez Martínez, A; Romero Berrocal, A; Sánchez Castilla, M; García-Fernández, J

2018-02-01

The extracorporeal oxygenation membrane (ECMO) is a system that provides circulatory and respiratory assistance to patients in cardiac or respiratory failure refractory to conventional treatment. It is a therapy with numerous associated complications and high mortality. Multidisciplinary management and experienced teams increase survival. Our purpose is to evaluate and analyse the effect of the learning curve on mortality. Retrospective and observational study of 31 patients, from January 2012 to December 2015. Patients were separated into 2periods. These periods were divided by the establishment of an ECMO protocol. We compared the quantitative variables by performing the Mann-Whitney U test. For the categorical qualitative variables we performed the chi-square test or Fisher exact statistic as appropriate. The survival curve was computed using the Kaplan-Meier method, and the analysis of statistical significance using the Log-rank test. Data analysis was performed with the STATA programme 14. Survival curves show the tendency to lower mortality in the subsequent period (P=0.0601). The overall mortality rate in the initial period was higher than in the subsequent period (P=0.042). In another analysis, we compared the characteristics of the 2groups and concluded that they were homogeneous. The degree of experience is an independent factor for mortality. The application of a care protocol is fundamental to facilitate the management of ECMO therapy. Copyright © 2017 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.

Impact of tumour volume on prediction of progression-free survival in sinonasal cancer

International Nuclear Information System (INIS)

Hennersdorf, Florian; Mauz, Paul-Stefan; Adam, Patrick; Welz, Stefan; Sievert, Anne; Ernemann, Ulrike; Bisdas, Sotirios

2015-01-01

The present study aimed to analyse potential prognostic factors, with emphasis on tumour volume, in determining progression free survival (PFS) for malignancies of the nasal cavity and the paranasal sinuses. Retrospective analysis of 106 patients with primary sinonasal malignancies treated and followed-up between March 2006 and October 2012. Possible predictive parameters for PFS were entered into univariate and multivariate Cox regression analysis. Kaplan-Meier curve analysis included age, sex, baseline tumour volume (based on MR imaging), histology type, TNM stage and prognostic groups according to the American Joint Committee on Cancer (AJCC) classification. Receiver operating characteristic (ROC) curve analysis concerning the predictive value of tumour volume for recurrence was also conducted. The main histological subgroup consisted of epithelial tumours (77%). The majority of the patients (68%) showed advanced tumour burden (AJCC stage III–IV). Lymph node involvement was present in 18 cases. The mean tumour volume was 26.6 ± 21.2 cm 3 . The median PFS for all patients was 24.9 months (range: 2.5–84.5 months). The ROC curve analysis for the tumour volume showed 58.1% sensitivity and 75.4% specificity for predicting recurrence. Tumour volume, AJCC staging, T- and N- stage were significant predictors in the univariate analysis. Positive lymph node status and tumour volume remained significant and independent predictors in the multivariate analysis. Radiological tumour volume proofed to be a statistically reliable predictor of PFS. In the multivariate analysis, T-, N- and overall AJCC staging did not show significant prognostic value

Flow characteristics of curved ducts

Directory of Open Access Journals (Sweden)

Rudolf P.

2007-10-01

Full Text Available Curved channels are very often present in real hydraulic systems, e.g. curved diffusers of hydraulic turbines, S-shaped bulb turbines, fittings, etc. Curvature brings change of velocity profile, generation of vortices and production of hydraulic losses. Flow simulation using CFD techniques were performed to understand these phenomena. Cases ranging from single elbow to coupled elbows in shapes of U, S and spatial right angle position with circular cross-section were modeled for Re = 60000. Spatial development of the flow was studied and consequently it was deduced that minor losses are connected with the transformation of pressure energy into kinetic energy and vice versa. This transformation is a dissipative process and is reflected in the amount of the energy irreversibly lost. Least loss coefficient is connected with flow in U-shape elbows, biggest one with flow in Sshape elbows. Finally, the extent of the flow domain influenced by presence of curvature was examined. This isimportant for proper placement of mano- and flowmeters during experimental tests. Simulations were verified with experimental results presented in literature.

Complex curve of the two-matrix model and its tau-function

International Nuclear Information System (INIS)

Kazakov, Vladimir A; Marshakov, Andrei

2003-01-01

We study the Hermitian and normal two-matrix models in planar approximation for an arbitrary number of eigenvalue supports. Its planar graph interpretation is given. The study reveals a general structure of the underlying analytic complex curve, different from the hyperelliptic curve of the one-matrix model. The matrix model quantities are expressed through the periods of meromorphic generating differential on this curve and the partition function of the multiple support solution, as a function of filling numbers and coefficients of the matrix potential, is shown to be a quasiclassical tau-function. The relation to N = 1 supersymmetric Yang-Mills theories is discussed. A general class of solvable multi-matrix models with tree-like interactions is considered

Developing Novel Reservoir Rule Curves Using Seasonal Inflow Projections

Science.gov (United States)

Tseng, Hsin-yi; Tung, Ching-pin

2015-04-01

Due to significant seasonal rainfall variations, reservoirs and their flexible operational rules are indispensable to Taiwan. Furthermore, with the intensifying impacts of climate change on extreme climate, the frequency of droughts in Taiwan has been increasing in recent years. Drought is a creeping phenomenon, the slow onset character of drought makes it difficult to detect at an early stage, and causes delays on making the best decision of allocating water. For these reasons, novel reservoir rule curves using projected seasonal streamflow are proposed in this study, which can potentially reduce the adverse effects of drought. This study dedicated establishing new rule curves which consider both current available storage and anticipated monthly inflows with leading time of two months to reduce the risk of water shortage. The monthly inflows are projected based on the seasonal climate forecasts from Central Weather Bureau (CWB), which a weather generation model is used to produce daily weather data for the hydrological component of the GWLF. To incorporate future monthly inflow projections into rule curves, this study designs a decision flow index which is a linear combination of current available storage and inflow projections with leading time of 2 months. By optimizing linear relationship coefficients of decision flow index, the shape of rule curves and the percent of water supply in each zone, the best rule curves to decrease water shortage risk and impacts can be developed. The Shimen Reservoir in the northern Taiwan is used as a case study to demonstrate the proposed method. Existing rule curves (M5 curves) of Shimen Reservoir are compared with two cases of new rule curves, including hindcast simulations and historic seasonal forecasts. The results show new rule curves can decrease the total water shortage ratio, and in addition, it can also allocate shortage amount to preceding months to avoid extreme shortage events. Even though some uncertainties in

Stenting for curved lesions using a novel curved balloon: Preliminary experimental study.

Science.gov (United States)

Tomita, Hideshi; Higaki, Takashi; Kobayashi, Toshiki; Fujii, Takanari; Fujimoto, Kazuto

2015-08-01

Stenting may be a compelling approach to dilating curved lesions in congenital heart diseases. However, balloon-expandable stents, which are commonly used for congenital heart diseases, are usually deployed in a straight orientation. In this study, we evaluated the effect of stenting with a novel curved balloon considered to provide better conformability to the curved-angled lesion. In vitro experiments: A Palmaz Genesis(®) stent (Johnson & Johnson, Cordis Co, Bridgewater, NJ, USA) mounted on the Goku(®) curve (Tokai Medical Co. Nagoya, Japan) was dilated in vitro to observe directly the behavior of the stent and balloon assembly during expansion. Animal experiment: A short Express(®) Vascular SD (Boston Scientific Co, Marlborough, MA, USA) stent and a long Express(®) Vascular LD stent (Boston Scientific) mounted on the curved balloon were deployed in the curved vessel of a pig to observe the effect of stenting in vivo. In vitro experiments: Although the stent was dilated in a curved fashion, stent and balloon assembly also rotated conjointly during expansion of its curved portion. In the primary stenting of the short stent, the stent was dilated with rotation of the curved portion. The excised stent conformed to the curved vessel. As the long stent could not be negotiated across the mid-portion with the balloon in expansion when it started curving, the mid-portion of the stent failed to expand fully. Furthermore, the balloon, which became entangled with the stent strut, could not be retrieved even after complete deflation. This novel curved balloon catheter might be used for implantation of the short stent in a curved lesion; however, it should not be used for primary stenting of the long stent. Post-dilation to conform the stent to the angled vessel would be safer than primary stenting irrespective of stent length. Copyright © 2014 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

Numerical Investigation of the Flow Structure in a Kaplan Draft Tube at Part Load

Science.gov (United States)

Maddahian, R.; Cervantes, M. J.; Sotoudeh, N.

2016-11-01

This research presents numerical simulation of the unsteady flow field inside the draft tube of a Kaplan turbine at part load condition. Due to curvature of streamlines, the ordinary two-equations turbulence models fail to predict the flow features. Therefore, a modification of the Shear Stress Transport (SST-SAS) model is utilized to approximate the turbulent stresses. A guide vane, complete runner and draft tube are considered to insure the real boundary conditions at the draft tube inlet. The outlet boundary is assumed to discharge into the atmosphere. The obtained pressure fluctuations inside the draft tube are in good agreement with available experimental data. In order to further investigate the RVR formation and its movement, the λ2 criterion, relating the position of the vortex core and strength to the second largest Eigen value of the velocity gradient tensor, is employed. The method used for vortex identification shows the flow structure and vortex motion inside the draft tube accurately.

Curve Boxplot: Generalization of Boxplot for Ensembles of Curves.

Science.gov (United States)

Mirzargar, Mahsa; Whitaker, Ross T; Kirby, Robert M

2014-12-01

In simulation science, computational scientists often study the behavior of their simulations by repeated solutions with variations in parameters and/or boundary values or initial conditions. Through such simulation ensembles, one can try to understand or quantify the variability or uncertainty in a solution as a function of the various inputs or model assumptions. In response to a growing interest in simulation ensembles, the visualization community has developed a suite of methods for allowing users to observe and understand the properties of these ensembles in an efficient and effective manner. An important aspect of visualizing simulations is the analysis of derived features, often represented as points, surfaces, or curves. In this paper, we present a novel, nonparametric method for summarizing ensembles of 2D and 3D curves. We propose an extension of a method from descriptive statistics, data depth, to curves. We also demonstrate a set of rendering and visualization strategies for showing rank statistics of an ensemble of curves, which is a generalization of traditional whisker plots or boxplots to multidimensional curves. Results are presented for applications in neuroimaging, hurricane forecasting and fluid dynamics.

Classical black holes: the nonlinear dynamics of curved spacetime.

Science.gov (United States)

Thorne, Kip S

2012-08-03

Numerical simulations have revealed two types of physical structures, made from curved spacetime, that are attached to black holes: tendexes, which stretch or squeeze anything they encounter, and vortexes, which twist adjacent inertial frames relative to each other. When black holes collide, their tendexes and vortexes interact and oscillate (a form of nonlinear dynamics of curved spacetime). These oscillations generate gravitational waves, which can give kicks up to 4000 kilometers per second to the merged black hole. The gravitational waves encode details of the spacetime dynamics and will soon be observed and studied by the Laser Interferometer Gravitational Wave Observatory and its international partners.

JUMPING THE CURVE

Directory of Open Access Journals (Sweden)

René Pellissier

2012-01-01

Full Text Available This paper explores the notion ofjump ing the curve,following from Handy 's S-curve onto a new curve with new rules policies and procedures. . It claims that the curve does not generally lie in wait but has to be invented by leadership. The focus of this paper is the identification (mathematically and inferentially ofthat point in time, known as the cusp in catastrophe theory, when it is time to change - pro-actively, pre-actively or reactively. These three scenarios are addressed separately and discussed in terms ofthe relevance ofeach.

The JUPITER registry: One-year outcomes of transapical aortic valve implantation using a second generation transcatheter heart valve for aortic regurgitation.

Science.gov (United States)

Silaschi, Miriam; Conradi, Lenard; Wendler, Olaf; Schlingloff, Friederike; Kappert, Utz; Rastan, Ardawan J; Baumbach, Hardy; Holzhey, David; Eichinger, Walter; Bader, Ralf; Treede, Hendrik

2018-06-01

We present 1-year outcomes of the post-market registry of a next-generation transcatheter heart valve used for aortic regurgitation (AR). Transcatheter aortic valve replacement (TAVR) is routine in high-risk patients with aortic stenosis but is not recommended for AR. The JenaValve™ (JenaValve Technology GmbH, Munich, Germany) overcomes technical challenges in AR patients through a leaflet clipping mechanism. The JenaValve EvalUation of Long Term Performance and Safety In PaTients with SEvere Aortic Stenosis oR Aortic Insufficiency (JUPITER) Registry is a European study to evaluate safety and effectiveness of this THV. From 2012-2015, 30 patients with AR were enrolled. Mean age was 74.4 ± 9.3 years. Procedural success was 96.7% (29/30). One patient was converted to open surgery. No annular rupture or coronary ostia obstruction occurred. Mortality at 30 days was 10.0% (3/30). Combined safety endpoint was met in 13.3% (4/30). Paravalvular regurgitation was not present/trivial in 84.6% (22/26) and mild in 15.4% (4/26). Rate of permanent pacemaker implantation was 3.8% (1/26). One-year Kaplan-Meier survival was 79.9%, one-year combined efficacy was 73.1% (19/30). No further strokes were observed during 1 year of follow-up. The JenaValve overcomes technical challenges of TAVR in AR through a clipping mechanism. We report satisfactory outcomes of a multicenter registry using the JenaValve for predominant AR, as rate of THV embolization, residual AR and permanent pacemaker implantation was low. One-year results using the JenaValve for AR encourage its use for this indication. © 2017 Wiley Periodicals, Inc.

Thermoeconomic diagnosis and entropy generation paradox

DEFF Research Database (Denmark)

Sigthorsson, Oskar; Ommen, Torben Schmidt; Elmegaard, Brian

2017-01-01

In the entropy generation paradox, the entropy generation number, as a function of heat exchanger effectiveness, counter-intuitively approaches zero in two limits symmetrically from a single maximum. In thermoeconomic diagnosis, namely in the characteristic curve method, the exergy destruction...... to the entropy generation paradox, as a decreased heat exchanger effectiveness (as in the case of an operation anomaly in the component) can counter-intuitively result in decreased exergy destruction rate of the component. Therefore, along with an improper selection of independent variables, the heat exchanger...... increases in case of an operation anomaly in a component. The normalised exergy destruction rate as the dependent variable therefore resolves the relation of the characteristic curve method with the entropy generation paradox....

Going Beyond, Going Further: The Preparation of Acid-Base Titration Curves.

Science.gov (United States)

McClendon, Michael

1984-01-01

Background information, list of materials needed, and procedures used are provided for a simple technique for generating mechanically plotted acid-base titration curves. The method is suitable for second-year high school chemistry students. (JN)

Dual Smarandache Curves of a Timelike Curve lying on Unit dual Lorentzian Sphere

OpenAIRE

Kahraman, Tanju; Hüseyin Ugurlu, Hasan

2016-01-01

In this paper, we give Darboux approximation for dual Smarandache curves of time like curve on unit dual Lorentzian sphere. Firstly, we define the four types of dual Smarandache curves of a timelike curve lying on dual Lorentzian sphere.

Can Low-Resolution Airborne Laser Scanning Data Be Used to Model Stream Rating Curves?

Directory of Open Access Journals (Sweden)

Steve W. Lyon

2015-03-01

Full Text Available This pilot study explores the potential of using low-resolution (0.2 points/m2 airborne laser scanning (ALS-derived elevation data to model stream rating curves. Rating curves, which allow the functional translation of stream water depth into discharge, making them integral to water resource monitoring efforts, were modeled using a physics-based approach that captures basic geometric measurements to establish flow resistance due to implicit channel roughness. We tested synthetically thinned high-resolution (more than 2 points/m2 ALS data as a proxy for low-resolution data at a point density equivalent to that obtained within most national-scale ALS strategies. Our results show that the errors incurred due to the effect of low-resolution versus high-resolution ALS data were less than those due to flow measurement and empirical rating curve fitting uncertainties. As such, although there likely are scale and technical limitations to consider, it is theoretically possible to generate rating curves in a river network from ALS data of the resolution anticipated within national-scale ALS schemes (at least for rivers with relatively simple geometries. This is promising, since generating rating curves from ALS scans would greatly enhance our ability to monitor streamflow by simplifying the overall effort required.

Can low-resolution airborne laser scanning data be used to model stream rating curves?

Science.gov (United States)

Lyon, Steve; Nathanson, Marcus; Lam, Norris; Dahlke, Helen; Rutzinger, Martin; Kean, Jason W.; Laudon, Hjalmar

2015-01-01

This pilot study explores the potential of using low-resolution (0.2 points/m2) airborne laser scanning (ALS)-derived elevation data to model stream rating curves. Rating curves, which allow the functional translation of stream water depth into discharge, making them integral to water resource monitoring efforts, were modeled using a physics-based approach that captures basic geometric measurements to establish flow resistance due to implicit channel roughness. We tested synthetically thinned high-resolution (more than 2 points/m2) ALS data as a proxy for low-resolution data at a point density equivalent to that obtained within most national-scale ALS strategies. Our results show that the errors incurred due to the effect of low-resolution versus high-resolution ALS data were less than those due to flow measurement and empirical rating curve fitting uncertainties. As such, although there likely are scale and technical limitations to consider, it is theoretically possible to generate rating curves in a river network from ALS data of the resolution anticipated within national-scale ALS schemes (at least for rivers with relatively simple geometries). This is promising, since generating rating curves from ALS scans would greatly enhance our ability to monitor streamflow by simplifying the overall effort required.

Prognostic significance of hemoglobin level in patients with congestive heart failure and normal ejection fraction.

Science.gov (United States)

Varadarajan, Padmini; Gandhi, Siddharth; Sharma, Sanjay; Umakanthan, Branavan; Pai, Ramdas G

2006-10-01

Previous studies have shown low hemoglobin (Hb) to have an adverse effect on survival in patients with congestive heart failure (CHF) and reduced left ventricular (LV) ejection fraction (EF); but its effect on survival in patients with CHF and normal EF is not known. This study sought to determine whether low Hb has an effect on survival in patients with both CHF and normal EF. Detailed chart reviews were performed by medical residents on 2,246 patients (48% with normal EF) with a discharge diagnosis of CHF in a large tertiary care hospital from 1990 to 1999. The CHF diagnosis was validated using the Framingham criteria. Mortality data were obtained from the National Death Index. Survival analysis was performed using Kaplan-Meier and Cox regression models. By Kaplan-Meier analysis, low Hb (< 12 gm/dl) compared with normal hemoglobin was associated with a lower 5-year survival in patients with CHF and both normal (38 vs. 50%, p = 0.0008) and reduced (35 vs. 48%, p = 0.0009) EF. Using the Cox regression model, low Hb was an independent predictor of mortality after adjusting for age, gender, renal dysfunction, diabetes mellitus, hypertension, and EF in both groups of patients. Low Hb has an independent adverse effect on survival in patients with CHF and both normal and reduced EF in both groups of patients.

Decreased graft survival in liver transplant recipients of donors with positive blood cultures: a review of the United Network for Organ Sharing dataset.

Science.gov (United States)

Huaman, Moises A; Vilchez, Valery; Mei, Xiaonan; Shah, Malay B; Daily, Michael F; Berger, Jonathan; Gedaly, Roberto

2017-06-01

Liver transplantation using blood culture positive donors (BCPD) has allowed a significant expansion of the donor pool. We aimed to characterize BCPD and assess the outcomes of BCPD liver transplant recipients. We retrieved data from the United Network for Organ Sharing (UNOS) registry on all adults who underwent primary, single-organ deceased-donor liver transplantation in the USA between 2008 and 2013. Patients were classified into two cohorts: the BCPD cohort and the non-BCPD cohort. One-year graft and patient survival were compared between cohorts using Kaplan-Meier estimates and Cox models. A total of 28 961 patients were included. There were 2316 (8.0%) recipients of BCPD. BCPD were more likely to be older, female, black, diabetic, hypertensive, and obese compared to non-BCPD. Graft survival was significantly lower in BCPD recipients compared to non-BCPD recipients (Kaplan-Meier, 0.85 vs. 0.87; P = 0.009). Results remained significant in propensity-matched analysis (P = 0.038). BCPD was independently associated with decreased graft survival (adjusted HR; 1.10, 95% CI 1.01-1.20; P = 0.04). There were no significant differences in patient survival between study groups. BCPD was associated with decreased graft survival in liver transplant recipients. Studies are needed to identify subgroups of BCPD with the highest risk of graft failure and characterize the underlying pathogenic mechanisms. © 2016 Steunstichting ESOT.

Stent placement with the monorail technique for treatment of mesenteric artery stenosis.

Science.gov (United States)

Schaefer, Philipp J; Schaefer, Fritz K W; Hinrichsen, Holger; Jahnke, Thomas; Charalambous, Nikolas; Heller, Martin; Mueller-Huelsbeck, Stefan

2006-04-01

To analyze the immediate and midterm success of stenting of mesenteric arteries by a monorail technique in patients with chronic mesenteric ischemia. In this prospective case series, 19 patients (11 male, 8 female; mean age, 62.9 +/- 10.4 y; range, 36-82 y) with 23 symptomatic stenoses of mesenteric arteries were treated with stent placement by a monorail technique in a radiologic intervention center over a period of 4.5 years. Clinical examinations and duplex sonography were used to evaluate the stents' patency and clinical success. Kaplan-Meier graphs were calculated to analyze the patency and freedom-from-symptom rate. Initial technical success rate was 22/23 (96%). Mean follow-up was 17 months (range, 1-58 mo). Primary patency and primary clinical success rates were 82% and 78%, respectively. According to Kaplan-Meier tables, the patency rates were 96%, 87%, 76%, and 61% at 0, 1, 15, and 24 months, respectively, and the freedom-from-symptom rates were 95%, 90%, 72%, and 54% at 0, 1, 24, and 30 months, respectively. No peri-interventional complications occurred. Two patients died of cardiac failure in the hospital within 30 days after intervention; deaths were not related to the intervention. Stent placement by a monorail technique in mesenteric arteries is an effective and safe treatment for symptomatic stenoses in patients with chronic mesenteric ischemia after a mean follow-up of 17 months.

Prognostic value of pre-treatment DCE-MRI parameters in predicting disease free and overall survival for breast cancer patients undergoing neoadjuvant chemotherapy

International Nuclear Information System (INIS)

Pickles, Martin D.; Manton, David J.; Lowry, Martin; Turnbull, Lindsay W.

2009-01-01

The purpose of this study was to investigate whether dynamic contrast enhanced MRI (DCE-MRI) data, both pharmacokinetic and empirical, can predict, prior to neoadjuvant chemotherapy, which patients are likely to have a shorter disease free survival (DFS) and overall survival (OS) interval following surgery. Traditional prognostic parameters were also included in the survival analysis. Consequently, a comparison of the prognostic value could be made between all the parameters studied. MR examinations were conducted on a 1.5 T system in 68 patients prior to the initiation of neoadjuvant chemotherapy. DCE-MRI consisted of a fast spoiled gradient echo sequence acquired over 35 phases with a mean temporal resolution of 11.3 s. Both pharmacokinetic and empirical parameters were derived from the DCE-MRI data. Kaplan-Meier survival plots were generated for each parameter and group comparisons were made utilising logrank tests. The results from the 54 patients entered into the univariate survival analysis demonstrated that traditional prognostic parameters (tumour grade, hormonal status and size), empirical parameters (maximum enhancement index, enhancement index at 30 s, area under the curve and initial slope) and adjuvant therapies demonstrated significant differences in survival intervals. Further multivariate Cox regression survival analysis revealed that empirical enhancement parameters contributed the greatest prediction of both DFS and OS in the resulting models. In conclusion, this study has demonstrated that in patients who exhibit high levels of perfusion and vessel permeability pre-treatment, evidenced by elevated empirical DCE-MRI parameters, a significantly lower disease free survival and overall survival can be expected.

Prognostic value of pre-treatment DCE-MRI parameters in predicting disease free and overall survival for breast cancer patients undergoing neoadjuvant chemotherapy

Energy Technology Data Exchange (ETDEWEB)

Pickles, Martin D. [Centre for Magnetic Resonance Investigations, Division of Cancer, Postgraduate Medical School, University of Hull, Hull Royal Infirmary, Anlaby Road, Hull, HU3 2JZ (United Kingdom)], E-mail: m.pickles@hull.ac.uk; Manton, David J. [Centre for Magnetic Resonance Investigations, Division of Cancer, Postgraduate Medical School, University of Hull, Hull Royal Infirmary, Anlaby Road, Hull, HU3 2JZ (United Kingdom)], E-mail: d.j.manton@hull.ac.uk; Lowry, Martin [Centre for Magnetic Resonance Investigations, Division of Cancer, Postgraduate Medical School, University of Hull, Hull Royal Infirmary, Anlaby Road, Hull, HU3 2JZ (United Kingdom)], E-mail: m.lowry@hull.ac.uk; Turnbull, Lindsay W. [Centre for Magnetic Resonance Investigations, Division of Cancer, Postgraduate Medical School, University of Hull, Hull Royal Infirmary, Anlaby Road, Hull, HU3 2JZ (United Kingdom)], E-mail: l.w.turnbull@hull.ac.uk

2009-09-15

The purpose of this study was to investigate whether dynamic contrast enhanced MRI (DCE-MRI) data, both pharmacokinetic and empirical, can predict, prior to neoadjuvant chemotherapy, which patients are likely to have a shorter disease free survival (DFS) and overall survival (OS) interval following surgery. Traditional prognostic parameters were also included in the survival analysis. Consequently, a comparison of the prognostic value could be made between all the parameters studied. MR examinations were conducted on a 1.5 T system in 68 patients prior to the initiation of neoadjuvant chemotherapy. DCE-MRI consisted of a fast spoiled gradient echo sequence acquired over 35 phases with a mean temporal resolution of 11.3 s. Both pharmacokinetic and empirical parameters were derived from the DCE-MRI data. Kaplan-Meier survival plots were generated for each parameter and group comparisons were made utilising logrank tests. The results from the 54 patients entered into the univariate survival analysis demonstrated that traditional prognostic parameters (tumour grade, hormonal status and size), empirical parameters (maximum enhancement index, enhancement index at 30 s, area under the curve and initial slope) and adjuvant therapies demonstrated significant differences in survival intervals. Further multivariate Cox regression survival analysis revealed that empirical enhancement parameters contributed the greatest prediction of both DFS and OS in the resulting models. In conclusion, this study has demonstrated that in patients who exhibit high levels of perfusion and vessel permeability pre-treatment, evidenced by elevated empirical DCE-MRI parameters, a significantly lower disease free survival and overall survival can be expected.

Survival and hepatitis status among Asian Americans with hepatocellular carcinoma treated without liver transplantation

Directory of Open Access Journals (Sweden)

Hassan Manal M

2009-02-01

Full Text Available Abstract Background Chronic hepatitis B virus (HBV and hepatitis C virus (HCV are established causes of HCC. HCC patients are often diagnosed late and receive palliative therapies, however, the survival of Asian American patients with HCC treated without transplantation has not been well studied. We reviewed our institution's experience to determine predictors and rates of survival in Asian American HCC patients treated without transplantation. Methods We identified Asian American patients with HCC referred to M. D. Anderson Cancer Center. Patients were tested for HBV and HCV. Survival curves were generated by Kaplan-Meier method. Multivariate Cox proportional hazards regression was used to test the relationship between prognostic factors and survival. Results Of 82 Asian American HCC patients, most had advanced disease (65% and received treatment (68%; however, only 11% had surgical resection. 94% had positive anti-HBc and 61% had positive HBsAg. 20% had positive anti-HCV. There were no significant changes in the rates of HBV and HCV over time. Male gender, high alpha-fetoprotein levels, and stage IV disease were associated with shorter survival Overall median survival was 9.2 months (95% CI 6.5–11.9, and the survival of HCV and HBV patients was not statistically different. Conclusion The survival rate of Asian American patients with advanced HCC, for whom transplantation was not available, was low. Timely hepatitis screening and interventions by primary care physicians may be the most logical solution to reduce the burden of hepatitis-associated HCC among Asian Americans.

Adverse reactions and other factors that impact subsequent blood donation visits.

Science.gov (United States)

Custer, Brian; Rios, Jorge A; Schlumpf, Karen; Kakaiya, Ram M; Gottschall, Jerome L; Wright, David J

2012-01-01

The importance of adverse reactions in terms of donor safety recently has received significant attention, but their role in subsequent donation behavior has not been thoroughly investigated. Six REDS-II blood centers provided data for this analysis. Summary minor and major adverse reaction categories were created. The influence of adverse reactions on donation was examined in two ways: Kaplan-Meier curves were generated to determine the cumulative pattern of first return, and adjusted odds ratios (AORs) for demographic and other factors positively and negatively associated with return were estimated using multivariable logistic regression. Donors who had major reactions had longer times to return than donors with minor or no reactions. The AOR of returning for donors with major reactions was 0.32 (95% confidence interval [CI], 0.28-0.37) and with minor reactions 0.59 (95% CI, 0.56-0.62) when compared to donors who did not have reactions. Conversely, the most important factors positively associated with return were the number of donations in the previous year and increasing age. Subsequent return, whether a major, minor, or no reaction occurred, varied by blood center. Factors that are associated with the risk of having adverse reactions were not substantial influences on the return after adverse reactions. Having an adverse reaction leads to significantly lower odds of subsequent donation irrespective of previous donation history. Factors that have been associated with a greater risk of adverse reactions were not important positive or negative predictors of return after a reaction. © 2011 American Association of Blood Banks.

Functional Polymorphisms of Base Excision Repair Genes XRCC1 and APEX1 Predict Risk of Radiation Pneumonitis in Patients With Non-Small Cell Lung Cancer Treated With Definitive Radiation Therapy

International Nuclear Information System (INIS)

Yin Ming; Liao Zhongxing; Liu Zhensheng; Wang, Li-E; Gomez, Daniel; Komaki, Ritsuko; Wei Qingyi

2011-01-01

Purpose: To explore whether functional single nucleotide polymorphisms (SNPs) of base-excision repair genes are predictors of radiation treatment-related pneumonitis (RP), we investigated associations between functional SNPs of ADPRT, APEX1, and XRCC1 and RP development. Methods and Materials: We genotyped SNPs of ADPRT (rs1136410 [V762A]), XRCC1 (rs1799782 [R194W], rs25489 [R280H], and rs25487 [Q399R]), and APEX1 (rs1130409 [D148E]) in 165 patients with non-small cell lung cancer (NSCLC) who received definitive chemoradiation therapy. Results were assessed by both Logistic and Cox regression models for RP risk. Kaplan-Meier curves were generated for the cumulative RP probability by the genotypes. Results: We found that SNPs of XRCC1 Q399R and APEX1 D148E each had a significant effect on the development of Grade ≥2 RP (XRCC1: AA vs. GG, adjusted hazard ratio [HR] = 0.48, 95% confidence interval [CI], 0.24-0.97; APEX1: GG vs. TT, adjusted HR = 3.61, 95% CI, 1.64-7.93) in an allele-dose response manner (Trend tests: p = 0.040 and 0.001, respectively). The number of the combined protective XRCC1 A and APEX1 T alleles (from 0 to 4) also showed a significant trend of predicting RP risk (p = 0.001). Conclusions: SNPs of the base-excision repair genes may be biomarkers for susceptibility to RP. Larger prospective studies are needed to validate our findings.

A dose-response curve for biodosimetry from a 6 MV electron linear accelerator

Energy Technology Data Exchange (ETDEWEB)

Lemos-Pinto, M.M.P.; Cadena, M.; Santos, N.; Fernandes, T.S.; Borges, E.; Amaral, A., E-mail: marcelazoo@yahoo.com.br [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Departamento de Energia Nuclear

2015-10-15

Biological dosimetry (biodosimetry) is based on the investigation of radiation-induced biological effects (biomarkers), mainly dicentric chromosomes, in order to correlate them with radiation dose. To interpret the dicentric score in terms of absorbed dose, a calibration curve is needed. Each curve should be constructed with respect to basic physical parameters, such as the type of ionizing radiation characterized by low or high linear energy transfer (LET) and dose rate. This study was designed to obtain dose calibration curves by scoring of dicentric chromosomes in peripheral blood lymphocytes irradiated in vitro with a 6 MV electron linear accelerator (Mevatron M, Siemens, USA). Two software programs, CABAS (Chromosomal Aberration Calculation Software) and Dose Estimate, were used to generate the curve. The two software programs are discussed; the results obtained were compared with each other and with other published low LET radiation curves. Both software programs resulted in identical linear and quadratic terms for the curve presented here, which was in good agreement with published curves for similar radiation quality and dose rates. (author)