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Sample records for prognostic index model

  1. The Practicability of a Novel Prognostic Index (PI) Model and Comparison with Nottingham Prognostic Index (NPI) in Stage I-III Breast Cancer Patients Undergoing Surgical Treatment.

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    Wen, Jiahuai; Ye, Feng; Li, Shuaijie; Huang, Xiaojia; Yang, Lu; Xiao, Xiangsheng; Xie, Xiaoming

    2015-01-01

    Previous studies have indicated the prognostic value of various laboratory parameters in cancer patients. This study was to establish a prognostic index (PI) model for breast cancer patients based on the potential prognostic factors. A retrospective study of 1661 breast cancer patients who underwent surgical treatment between January 2002 and December 2008 at Sun Yat-sen University Cancer Center was conducted. Multivariate analysis (Cox regression model) was performed to determine the independent prognostic factors and a prognostic index (PI) model was devised based on these factors. Survival analyses were used to estimate the prognostic value of PI, and the discriminatory ability of PI was compared with Nottingham Prognostic Index (NPI) by evaluating the area under the receiver operating characteristics curves (AUC). The mean survival time of all participants was 123.6 months. The preoperative globulin >30.0g/L, triglyceride >1.10mmol/L and fibrinogen >2.83g/L were identified as risk factors for shorter cancer-specific survival. The novel prognostic index model was established and enrolled patients were classified as low- (1168 patients, 70.3%), moderate- (410 patients, 24.7%) and high-risk groups (83 patients, 5.0%), respectively. Compared with the low-risk group, higher risks of poor clinical outcome were indicated in the moderate-risk group [Hazard ratio (HR): 1.513, 95% confidence interval (CI): 1.169-1.959, p = 0.002] and high-risk group (HR: 2.481, 95%CI: 1.653-3.724, p< 0.001). The prognostic index based on three laboratory parameters was a novel and practicable prognostic tool. It may serve as complement to help predict postoperative survival in breast cancer patients.

  2. A laboratory prognostic index model for patients with advanced non-small cell lung cancer.

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    Arife Ulas

    Full Text Available We aimed to establish a laboratory prognostic index (LPI in advanced non-small cell lung cancer (NSCLC patients based on hematologic and biochemical parameters and to analyze the predictive value of LPI on NSCLC survival.The study retrospectively reviewed 462 patients with advanced NSCLC diagnosed between 2000 and 2010 in a single institution. We developed an LPI that included serum levels of white blood cells (WBC, lactate dehydrogenase (LDH, albumin, calcium, and alkaline phosphatase (ALP, based on the results of a Cox regression analysis. The patients were classified into 3 LPI groups as follows: LPI 0: normal; LPI 1: one abnormal laboratory finding; and LPI 2: at least 2 abnormal laboratory findings.The median follow up period was 44 months; the median overall survival (OS and median progression-free survival (PFS were 11 and 6 months, respectively. A multivariate analysis revealed that the following could be used as independent prognostic factors: an Eastern Cooperative Oncology Group performance status score (ECOG PS ≥2, a high LDH level, serum albumin 10.5 g/dL, number of metastases>2, presence of liver metastases, malignant pleural effusion, or receiving chemotherapy ≥4 cycles. The 1-year OS rates according to LPI 0, LPI 1, and LPI 2 were 54%, 34%, and 17% (p<0.001, respectively and 6-month PFS rates were 44%, 27%, and 15% (p<0.001, respectively. The LPI was a significant predictor for OS (Hazard Ratio (HR: 1.41; 1.05-1.88, p<0.001 and PFS (HR: 1.48; 1.14-1.93, p<0.001.An LPI is an inexpensive, easily accessible and independent prognostic index for advanced NSCLC and may be helpful in making individualized treatment plans and predicting survival rates when combined with clinical parameters.

  3. Prognostic value of a systemic inflammatory response index in metastatic renal cell carcinoma and construction of a predictive model

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    Li, Hongzhao; Chen, Luyao; Li, Xintao; Zhang, Yu; Xie, Yongpeng; Zhang, Xu

    2017-01-01

    Inflammation act as a crucial role in carcinogenesis and tumor progression. In this study, we aim to investigate the prognostic significance of systemic inflammatory biomarkers in metastatic renal cell carcinoma (mRCC) and develop a survival predictive model. One hundred and sixty-one mRCC patients who had undergone cytoreductive nephrectomy were enrolled from January 2006 to December 2013. We created a systemic inflammation response index (SIRI) basing on pretreatment hemoglobin and lymphocyte to monocyte ratio (LMR), and evaluated its associations with overall survival (OS) and clinicopathological features. Pretreatment hemoglobin and LMR both remained as independent factors adjusted for other markers of systemic inflammation responses and conventional clinicopathological parameters. A high SIRI seems to be an independent prognosis predictor of worse OS and was significantly correlated with aggressive tumor behaviors. Inclusion of the SIRI into a prognostic model including Fuhrman grade, histology, tumor necrosis and targeted therapy established a nomogram, which accurately predicted 1-year survival for mRCC patients. The SIRI seems to be a prognostic biomarker in mRCC patients. The proposed nomogram can be applied to predict OS of patients with mRCC after nephrectomy. PMID:28881716

  4. Validation of a prognostic index for Huntington's disease.

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    Long, Jeffrey D; Langbehn, Douglas R; Tabrizi, Sarah J; Landwehrmeyer, Bernhard G; Paulsen, Jane S; Warner, John; Sampaio, Cristina

    2017-02-01

    Characterizing progression in Huntington's disease is important for study the natural course and selecting appropriate participants for clinical trials. The aim was to develop a prognostic index for motor diagnosis in Huntington's disease and examine its predictive performance in external observational studies. The prediagnosis Neuro-biological Predictors of Huntington's Disease study (N = 945 gene-positive) was used to select a Cox regression model for computing a prognostic index. Cross-validation was used for selecting a model with good internal validity performance using the research sites as natural splits of the data set. Then, the external predictive performance was assessed using prediagnosis data from three additional observational studies, The Cooperative Huntington Observational Research Trial (N = 358), TRACK-HD (N = 118), and REGISTRY (N = 480). Model selection yielded a prognostic index computed as the weighted combination of the UHDRS total motor score, Symbol Digit Modalities Test, baseline age, and cytosine-adenine-guanine expansion. External predictive performance was very good for the first two of the three studies, with the third being a much more progressed cohort than the other studies. The databases were pooled and a final Cox regression model was estimated. The regression coefficients were scaled to produce the prognostic index for Huntington's disease, and a normed version, which is scaled relative to a 10-year 50% probability of motor diagnosis. The positive results of this comprehensive validity analysis provide evidence that the prognostic index is generally useful for predicting Huntington's disease progression in terms of risk of future motor diagnosis. The variables for the index are routinely collected in ongoing observational studies and the index can be used to identify cohorts for clinical trial recruitment. © 2016 International Parkinson and Movement Disorder Society. © 2016 International Parkinson and Movement Disorder Society.

  5. Improving the Prognostic Ability through Better Use of Standard Clinical Data - The Nottingham Prognostic Index as an Example.

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    Klaus-Jürgen Winzer

    Full Text Available Prognostic factors and prognostic models play a key role in medical research and patient management. The Nottingham Prognostic Index (NPI is a well-established prognostic classification scheme for patients with breast cancer. In a very simple way, it combines the information from tumor size, lymph node stage and tumor grade. For the resulting index cutpoints are proposed to classify it into three to six groups with different prognosis. As not all prognostic information from the three and other standard factors is used, we will consider improvement of the prognostic ability using suitable analysis approaches.Reanalyzing overall survival data of 1560 patients from a clinical database by using multivariable fractional polynomials and further modern statistical methods we illustrate suitable multivariable modelling and methods to derive and assess the prognostic ability of an index. Using a REMARK type profile we summarize relevant steps of the analysis. Adding the information from hormonal receptor status and using the full information from the three NPI components, specifically concerning the number of positive lymph nodes, an extended NPI with improved prognostic ability is derived.The prognostic ability of even one of the best established prognostic index in medicine can be improved by using suitable statistical methodology to extract the full information from standard clinical data. This extended version of the NPI can serve as a benchmark to assess the added value of new information, ranging from a new single clinical marker to a derived index from omics data. An established benchmark would also help to harmonize the statistical analyses of such studies and protect against the propagation of many false promises concerning the prognostic value of new measurements. Statistical methods used are generally available and can be used for similar analyses in other diseases.

  6. A new prognostic index (MIPI) for patients with advanced-stage mantle cell lymphoma

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    Hoster, Eva; Dreyling, Martin; Klapper, Wolfram; Gisselbrecht, Christian; van Hoof, Achiel; Kluin-Nelemans, Hanneke C.; Pfreundschuh, Michael; Reiser, Marcel; Metzner, Bernd; Einsele, Hermann; Peter, Norma; Jung, Wolfram; Woermann, Bernhard; Ludwig, Wolf-Dieter; Duehrsen, Ulrich; Eimermacher, Hartmut; Wandt, Hannes; Hasford, Joerg; Hiddemann, Wolfgang; Unterhalt, Michael

    2008-01-01

    There is no generally established prognostic index for patients with mantle cell lymphoma (MCL), because the International Prognostic Index (IPI) and Follicular Lymphoma International Prognostic Index (FLIPI) have been developed for diffuse large cell and follicular lymphoma patients, respectively.

  7. Recurrent epithelial ovarian cancer: Validation and improvement of an established prognostic index

    DEFF Research Database (Denmark)

    Gronlund, B; Christensen, Ib Jarle; Bülow-Lehnsby, A L

    2005-01-01

    OBJECTIVES: To validate and improve an established prognostic index in patients with recurrent ovarian cancer. METHODS: A Canadian three-covariate prognostic index (tumour grade at diagnosis, initial performance status, and time to relapse/primary progression (TRP)) was validated in a well...... available), 25.0 (22.1-33.6), 11.3 (8.5-12.9), and 5.2 (3.5-6.3) months, respectively. CONCLUSIONS: A novel prognostic model (the Copenhagen index) for patients with recurrent ovarian cancer is presented.......-defined cohort of comparable Danish patients. Potential parameters to be included in an improved prognostic index were revealed by univariate and multivariate analyses in the Danish validation group. RESULTS: The Canadian index validated in the Danish patient population (n=189) found a statistical significant...

  8. Prognostic Factors and a New Prognostic Index Model for Children and Adolescents with Hodgkin’s Lymphoma Who Underwent Autologous Hematopoietic Stem Cell Transplantation: A Multicenter Study of the Turkish Pediatric Bone Marrow Transplantation Study

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    Vural Kesik

    2016-12-01

    Full Text Available Objective: The prognostic factors and a new childhood prognostic index after autologous hematopoietic stem cell transplantation (AHSCT in patients with relapsed/refractory Hodgkin’s lymphoma (HL were evaluated. Materials and Methods: The prognostic factors of 61 patients who underwent AHSCT between January 1990 and December 2014 were evaluated. In addition, the Age-Adjusted International Prognostic Index and the Childhood International Prognostic Index (CIPI were evaluated for their impact on prognosis. Results: The median age of the 61 patients was 14.8 years (minimummaximum: 5-20 years at the time of AHSCT. There were single relapses in 28 patients, ≥2 relapses in eight patients, and refractory disease in 25 patients. The chemosensitivity/chemorefractory ratio was 36/25. No pretransplant radiotherapy, no remission at the time of transplantation, posttransplant white blood cell count over 10x103/ μL, posttransplant positron emission tomography positivity at day 100, and serum albumin of <2.5 g/dL at diagnosis were correlated with progression-free survival. No remission at the time of transplantation, bone marrow positivity at diagnosis, and relapse after AHSCT were significant parameters for overall survival. Conclusion: The major factors affecting the progression-free and overall survival were clearly demonstrated. A CIPI that uses a lactate dehydrogenase level of 500 IU/L worked well for estimating the prognosis. We recommend AHSCT at first complete remission for relapsed cases, and it should also be taken into consideration for patients with high prognostic scores at diagnosis.

  9. Distributed Prognostics Based on Structural Model Decomposition

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    National Aeronautics and Space Administration — Within systems health management, prognostics focuses on predicting the remaining useful life of a system. In the model-based prognostics paradigm, physics-based...

  10. Concordance for prognostic models with competing risks

    DEFF Research Database (Denmark)

    Wolbers, Marcel; Blanche, Paul; Koller, Michael T

    2014-01-01

    The concordance probability is a widely used measure to assess discrimination of prognostic models with binary and survival endpoints. We formally define the concordance probability for a prognostic model of the absolute risk of an event of interest in the presence of competing risks and relate i...... of the working model. We further illustrate the methods by computing the concordance probability for a prognostic model of coronary heart disease (CHD) events in the presence of the competing risk of non-CHD death.......The concordance probability is a widely used measure to assess discrimination of prognostic models with binary and survival endpoints. We formally define the concordance probability for a prognostic model of the absolute risk of an event of interest in the presence of competing risks and relate...

  11. Model-Based Prognostics of Hybrid Systems

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    Daigle, Matthew; Roychoudhury, Indranil; Bregon, Anibal

    2015-01-01

    Model-based prognostics has become a popular approach to solving the prognostics problem. However, almost all work has focused on prognostics of systems with continuous dynamics. In this paper, we extend the model-based prognostics framework to hybrid systems models that combine both continuous and discrete dynamics. In general, most systems are hybrid in nature, including those that combine physical processes with software. We generalize the model-based prognostics formulation to hybrid systems, and describe the challenges involved. We present a general approach for modeling hybrid systems, and overview methods for solving estimation and prediction in hybrid systems. As a case study, we consider the problem of conflict (i.e., loss of separation) prediction in the National Airspace System, in which the aircraft models are hybrid dynamical systems.

  12. Bacterial brain abscesses: prognostic value of an imaging severity index

    Energy Technology Data Exchange (ETDEWEB)

    Demir, M.K. [Department of Radiology, Trakya University School of Medicine, Edirne (Turkey)]. E-mail: demirkemal@superonline.com; Hakan, T. [Department of Neurosurgery, Haydarpasa Numune Education and Research Hospital, Istanbul (Turkey); Kilicoglu, G. [Department of Radiology, Haydarpasa Numune Education and Research Hospital, Istanbul (Turkey); Ceran, N. [Department of Infectious Disease, Haydarpasa Numune Education and Research Hospital, Istanbul (Turkey); Berkman, M.Z. [Department of Neurosurgery, Haydarpasa Numune Education and Research Hospital, Istanbul (Turkey); Erdem, I. [Department of Infectious Disease, Haydarpasa Numune Education and Research Hospital, Istanbul (Turkey); Goektas, P. [Department of Infectious Disease, Haydarpasa Numune Education and Research Hospital, Istanbul (Turkey)

    2007-06-15

    Aim: To assess the correlation between imaging findings [computed tomography (CT) or magnetic resonance imaging (MRI)] and neurological status before and after the treatment of bacterial brain abscesses. Materials and methods: CT and MRI images of 96 patients with brain abscesses were retrospectively evaluated in terms of the number, location and size of lesions, and the presence and extent of perilesional oedema and midline shift. An imaging severity index (ISI) based on these different radiological parameters was calculated. Initial Glasgow Coma Scale (GCS) scores and ISI were assessed and the prognostic value of these two indices was calculated. The Pearson correlation test, Mann-Whitney test, Chi-square test, receiver-operating characteristic (ROC) analysis, together with comparison of ROC analyses and Fisher's exact test were used. Results: There was a negative correlation between ISI and the initial GCS values: ISI increased as the GCS score decreased, indicating an inverse relationship (r = -0.51, p < 0.0001). There was a significant difference between the ISI and GCS scores of patients with an adverse event compared with patients with good recovery. Outcome was significantly worse in patients with initial ISI over the calculated cut-off values of 8 points or GCS scores under the cut-off value of 13 points. Conclusion: ISI is a useful prognostic indicator for bacterial brain abscess patients and correlates strongly with the patient outcome for all parameters studied. ISI score had a better prognostic value than GCS.

  13. Prognostic significance of the prognostic nutritional index in esophageal cancer patients undergoing neoadjuvant chemotherapy.

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    Nakatani, M; Migita, K; Matsumoto, S; Wakatsuki, K; Ito, M; Nakade, H; Kunishige, T; Kitano, M; Kanehiro, H

    2017-08-01

    Nutritional status is one of the most important issues faced by cancer patients. Several studies have shown that a low preoperative nutritional status is associated with a worse prognosis in patients with various types of cancer, including esophageal cancer (EC). Recently, neoadjuvant chemotherapy (NAC) and/or radiotherapy have been accepted as the standard treatment for resectable advanced EC. However, NAC has the potential to deteriorate the nutritional status of a patient. This study aimed to evaluate the prognostic significance of the nutritional status for EC patients who underwent NAC. We retrospectively reviewed 66 squamous cell EC patients who underwent NAC consisting of docetaxel, cisplatin, and 5-fluorouracil followed by subtotal esophagectomy at Nara Medical University Hospital between January 2009 and August 2015. To assess the patients' nutritional status, the prognostic nutritional index (PNI) before commencing NAC and prior to the operation was calculated as 10 × serum albumin (g/dl) + 0.005 × total lymphocyte count in the peripheral blood (per mm3). The cutoff value of the PNI was set at 45. A multivariable analysis was performed to identify prognostic factors for overall survival (OS) and relapse-free survival (RFS). The mean pre-NAC and preoperative PNI were 50.2 ± 5.7 and 48.1 ± 4.7, respectively (P = 0.005). The PNI decreased following NAC in 44 (66.7%) patients. Before initiating NAC, 9 (13.6%) patients had a low PNI, and 12 (18.2%) patients had a low PNI prior to the operation. The pre-NAC PNI and preoperative PNI were significantly associated with the OS (P = 0.013 and P = 0.004, respectively) and RFS (P = 0.036 and P = 0.005, respectively) rates. The multivariable analysis identified the preoperative PNI as an independent prognostic factor for poor OS and RFS, although the pre-NAC PNI was not an independent predictor. Our results suggest that the preoperative PNI is a useful marker for predicting the long-term outcomes of EC patients

  14. Prognostic nutritional index as a prognostic biomarker for survival in digestive system carcinomas.

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    Zhao, Yang; Xu, Peng; Kang, Huafeng; Lin, Shuai; Wang, Meng; Yang, Pengtao; Dai, Cong; Liu, Xinghan; Liu, Kang; Zheng, Yi; Dai, Zhijun

    2016-12-27

    The prognostic nutritional index (PNI) has been reported to correlate with the prognosis in patients with various malignancies. We performed a meta-analysis to determine the predictive potential of PNI in digestive system cancers. Twenty-three studies with a total of 7,384 patients suffering from digestive system carcinomas were involved in this meta-analysis. A lower PNI was significantly associated with the shorter overall survival (OS) [Hazard Ratio (HR) 1.83, 95% Confidence Interval (CI) 1.62-2.07], the poorer disease-free survival (DFS) (HR 1.85, 95% CI 1.19-2.89), and the higher rate of post-operative complications (HR 2.31, 95% CI 1.63-3.28). In conclusion, PNI was allowed to function as an efficient indicator for the prognosis of patients with digestive system carcinomas.

  15. Re-operative abdominal predictive score: a prognostic model combining Acute Re-intervention Predictive Index and intra-abdominal pressure.

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    Soler-Morejón, Caridad de Dios; Lombardo-Vaillant, Tomás Ariel; Tamargo-Barbeito, Teddy Osmín; Wise, Robert; Malbrain, Manu L N G

    2017-11-22

    The decision to re-operate after abdominal surgery is still difficult, especially in the setting of intra-abdominal sepsis. Mathematical models provide a good aid to both diagnosis and decision-making. A prospective observational study was conducted with 300 patients consecutively admitted to the intensive care unit of an academic institution affiliated to Calixto García Medical Faculty following abdominal surgery from January 2008 to January 2010. The patients were randomly separated (2:1) into estimation and validation groups. Logistic regression analysis was used in the estimation group to develop three models for decision-making related to re-operation including related factors such as age, ARPI, IAP, type of surgery (elective or emergency), and the duration of surgery. The three models developed were validated on the other group. The acute re-operation predictive index-intra-abdominal pressure (ARPI-IAP) model was the best of the three models, with an excellent calibration, using the Hossmer-Lemeshow goodness-of-fit statistical test (C = 9.976, P = 0.267), as well as discrimination (AUC = 0.989; 95% CI: 0.976-1.000). The combination of IAP with ARPI in a mathematical model can add accuracy to the prediction of need for re-operation related to intra-abdominal infectious complications in patients following abdominal surgery. This may be useful in all medical settings, but especially those with limited resources.

  16. Using prognostic models in CLL to personalize approach to clinical care: Are we there yet?

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    Mina, Alain; Sandoval Sus, Jose; Sleiman, Elsa; Pinilla-Ibarz, Javier; Awan, Farrukh T; Kharfan-Dabaja, Mohamed A

    2017-10-28

    Four decades ago, two staging systems were developed to help stratify CLL into different prognostic categories. These systems, the Rai and the Binet staging, depended entirely on abnormal exam findings and evidence of anemia and thrombocytopenia. Better understanding of biologic, genetic, and molecular characteristics of CLL have contributed to better appreciating its clinical heterogeneity. New prognostic models, the GCLLSG prognostic index and the CLL-IPI, emerged. They incorporate biologic and genetic information related to CLL and are capable of predicting survival outcomes and cases anticipated to need therapy earlier in the disease course. Accordingly, these newer models are helping develop better informed surveillance strategies and ultimately tailor treatment intensity according to presence (or lack thereof) of certain prognostic markers. This represents a step towards personalizing care of CLL patients. We anticipate that as more prognostic factors continue to be identified, the GCLLSG prognostic index and CLL-IPI models will undergo further revisions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Improved prognostic stratification using NCCN- and GELTAMO-international prognostic index in patients with diffuse large B-cell lymphoma.

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    Hong, Junshik; Kim, Seok Jin; Chang, Myung Hee; Kim, Jeong-A; Kwak, Jae-Yong; Kim, Jin Seok; Yoon, Dok Hyun; Lee, Won Sik; Do, Young Rok; Kang, Hye Jin; Eom, Hyeon-Seok; Park, Yong; Won, Jong-Ho; Mun, Yeung-Chul; Kim, Hyo Jung; Kwon, Jung Hye; Kong, Jee Hyun; Oh, Sung Yong; Lee, Sunah; Bae, Sung Hwa; Yang, Deok-Hwan; Jun, Hyun Jung; Lee, Ho Sup; Yun, Hwan Jung; Lee, Soon Il; Kim, Min Kyoung; Yi, Jun Ho; Lee, Jae Hoon; Kim, Won Seog; Suh, Cheolwon

    2017-11-03

    The National Comprehensive Cancer Network (NCCN)-International Prognostic Index (IPI) and GELTAMO (Grupo Español de Linfomas/Trasplante Autólogo de Médula Ósea)-IPI were developed to enable better risk prediction of patients with diffuse large B-cell lymphoma (DLBCL). The present study compared the effectiveness of risk prediction between IPI, NCCN-IPI, and GELTAMO-IPI in patients with DLBCL particularly in terms of determining high-risk patients. Among 439 patients who were enrolled to a prospective DLBCL cohort treated with R-CHOP immunochemotherapy, risk groups were classified according to the three IPIs and the prognostic significance of individual IPI factors and IPI models were analyzed and compared. All three IPI effectively separated the analyzed patients into four risk groups according to overall survival (OS). Estimated 5-year OS of patients classified as high-risk according to the IPI was 45.7%, suggesting that the IPI is limited in the selection of patients who are expected to have a poor outcome. In contrast, the 5-year OS of patients stratified as high-risk according to NCCN- and GELTAMO-IPI was 31.4% and 21.9%, respectively. The results indicate that NCCN- and GELTAMO-IPI are better than the IPI in predicting patients with poor prognosis, suggesting the superiority of enhanced, next-generation IPIs for DLBCL.

  18. Prognostic modeling in pediatric acute liver failure.

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    Jain, Vandana; Dhawan, Anil

    2016-10-01

    Liver transplantation (LT) is the only proven treatment for pediatric acute liver failure (PALF). However, over a period of time, spontaneous native liver survival is increasingly reported, making us wonder if we are overtransplanting children with acute liver failure (ALF). An effective prognostic model for PALF would help direct appropriate organ allocation. Only patients who would die would undergo LT, and those who would spontaneously recover would avoid unnecessary LT. Deriving and validating such a model for PALF, however, encompasses numerous challenges. In particular, the heterogeneity of age and etiology in PALF, as well as a lack of understanding of the natural history of the disease, contributed by the availability of LT has led to difficulties in prognostic model development. Several prognostic laboratory variables have been identified, and the incorporation of these variables into scoring systems has been attempted. A reliable targeted prognostic model for ALF in Wilson's disease has been established and externally validated. The roles of physiological, immunological, and metabolomic parameters in prognosis are being investigated. This review discusses the challenges with prognostic modeling in PALF and describes predictive methods that are currently available and in development for the future. Liver Transplantation 22 1418-1430 2016 AASLD. © 2016 by the American Association for the Study of Liver Diseases.

  19. A prognostic index for locoregional recurrence after neoadjuvant chemotherapy.

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    Herrero-Vicent, C; Guerrero-Zotano, A; Gavilá-Gregori, J; Hernández-Blanquisett, A; Sandiego-Contreras, S; Samper-Hiraldo, J M; Guillem-Porta, V; Ruiz-Simón, A

    2016-01-01

    The appropriate selection criteria for breast-conserving surgery (BCS) or mastectomy after neoadjuvant chemotherapy (NAC) are poorly defined. The aim of this study is to analyse the incidence and prognostic factors for locoregional recurrence (LRR) in patients with breast cancer (BC) treated with NAC to develop a prognostic score to help with clinical decision-making. Using our retrospective maintained BC database, we identified 730 patients treated with NAC (327 patients treated with BCS and 403 patients treated with mastectomy) between 1998 and 2014. To identify variables associated with an increased LRR rate, we performed firstly Kaplan-Meier curves, with comparisons among groups using log-rank test, and then, significant variables were included in a multivariate analysis using Cox proportional hazards. The prognostic index was developed by assigning score 0 (favourable) or score 1 (unfavourable) for each significant variable of multivariate analysis and was created separately for patients with BCS and mastectomy. At a median follow-up of 72 months, the 6-year cumulative incidence of LRR was 7.2% ( ± 3%) for BCS and 7.9% ( ± 3%) for mastectomy. By univariate analysis, variables associated with an increased LRR were for BCS: HER2 positive, grade III, ductal carcinoma in situ (DCIS), No-pCR (ypTis, ypN0), and age < 40 years; and for mastectomy, HER2-positive, DCIS, No-pCR, and LVI. By multivariate analysis, variables associated with an increased LRR were for BCS: HER2 positive (HR: 11.1, p = 0.001), DCIS (HR: 3.1, p = 0.005), and age < 40 years (HR: 2.8, p = 0.02); and for mastectomy: HER2 positive (HR: 9.5, p = 0.03), DCIS (HR: 2.7, p = 0.01), No-pCR (HR: 11.4, p = 0.01), and age < 40 years (HR: 2.8, p = 0.006). The score stratified patients into three subsets with statistically different levels of risk for LRR. For BCS, the six-year LRR rates were 3%, 13%, and 33% for the low (score 0, n = 120), intermediate (score 1, n = 95) and high (score 2-3, n = 27) risk

  20. Geriatric Nutritional Risk Index as a Prognostic Factor in Peritoneal Dialysis Patients

    OpenAIRE

    Kang, Seok Hui; Cho, Kyu Hyang; Park, Jong Won; Yoon, Kyung Woo; Do, Jun Young

    2013-01-01

    ♦ Background: The Geriatric Nutritional Risk Index (GNRI) might be a useful screening tool for malnutrition in dialysis patients. However, data concerning the GNRI as a prognostic factor in peritoneal dialysis (PD) patients are scarce.

  1. A prognostic index for locoregional recurrence after neoadjuvant chemotherapy

    OpenAIRE

    Herrero-Vicent, C; Guerrero-Zotano, A; Gavil?-Gregori, J; Hern?ndez-Blanquisett, A; Sandiego-Contreras, S; Samper-Hiraldo, JM; Guillem-Porta, V; Ruiz-Sim?n, A

    2016-01-01

    Background The appropriate selection criteria for breast-conserving surgery (BCS) or mastectomy after neoadjuvant chemotherapy (NAC) are poorly defined. The aim of this study is to analyse the incidence and prognostic factors for locoregional recurrence (LRR) in patients with breast cancer (BC) treated with NAC to develop a prognostic score to help with clinical decision-making. Materials and methods Using our retrospective maintained BC database, we identified 730 patients treated with NAC (...

  2. Expansion of the prognostic assessment of patients with chronic obstructive pulmonary disease : the updated BODE index and the ADO index

    NARCIS (Netherlands)

    Puhan, Milo A.; Garcia-Aymerich, Judith; Frey, Martin; ter Riet, Gerben; Anto, Josep M.; Agusti, Alvar G.; Gomez, Federico P.; Rodriguez-Roisin, Roberto; Moons, Karel G. M.; Kessels, Alphons G.; Held, Ulrike

    2009-01-01

    Background The BODE index (including body-mass index, airflow obstruction, dyspnoea, and exercise capacity) was an important contribution to the prognostic assessment of patients with chronic obstructive pulmonary disease (COPD). However, no study has assessed whether the risk of mortality predicted

  3. Expansion of the prognostic assessment of patients with chronic obstructive pulmonary disease: the updated BODE index and the ADO index

    NARCIS (Netherlands)

    Puhan, Milo A.; Garcia-Aymerich, Judith; Frey, Martin; ter Riet, Gerben; Antó, Josep M.; Agustí, Alvar G.; Gómez, Federico P.; Rodríguez-Roisín, Roberto; Moons, Karel G. M.; Kessels, Alphons G.; Held, Ulrike

    2009-01-01

    Background The BODE index (including body-mass index, airflow obstruction, dyspnoea, and exercise capacity) was an important contribution to the prognostic assessment of patients with chronic obstructive pulmonary disease (COPD). However, no study has assessed whether the risk of mortality predicted

  4. A combined pulmonary function and emphysema score prognostic index for staging in Chronic Obstructive Pulmonary Disease.

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    Boutou, Afroditi K; Nair, Arjun; Douraghi-Zadeh, Dariush; Sandhu, Ranbir; Hansell, David M; Wells, Athol U; Polkey, Michael I; Hopkinson, Nicholas S

    2014-01-01

    Chronic Obstructive Pulmonary Disease (COPD) is characterized by high morbidity and mortality. Lung computed tomography parameters, individually or as part of a composite index, may provide more prognostic information than pulmonary function tests alone. To investigate the prognostic value of emphysema score and pulmonary artery measurements compared with lung function parameters in COPD and construct a prognostic index using a contingent staging approach. Predictors of mortality were assessed in COPD outpatients whose lung computed tomography, spirometry, lung volumes and gas transfer data were collected prospectively in a clinical database. Univariate and multivariate Cox proportional hazard analysis models with bootstrap techniques were used. 169 patients were included (59.8% male, 61.1 years old; Forced Expiratory Volume in 1 second % predicted: 40.5±19.2). 20.1% died; mean survival was 115.4 months. Age (HR = 1.098, 95% Cl = 1.04-1.252) and emphysema score (HR = 1.034, 95% CI = 1.007-1.07) were the only independent predictors of mortality. Pulmonary artery dimensions were not associated with survival. An emphysema score of 55% was chosen as the optimal threshold and 30% and 65% as suboptimals. Where emphysema score was between 30% and 65% (intermediate risk) the optimal lung volume threshold, a functional residual capacity of 210% predicted, was applied. This contingent staging approach separated patients with an intermediate risk based on emphysema score alone into high risk (Functional Residual Capacity ≥210% predicted) or low risk (Functional Residual Capacity Emphysema score-Functional Residual Capacity index might provide a better separation of high and low risk patients with COPD, than other individual predictors alone.

  5. USEFULNESS OF A NEW PROGNOSTIC INDEX FOR ALCOHOLIC HEPATITIS

    Directory of Open Access Journals (Sweden)

    Jazon Romilson de Souza ALMEIDA

    2015-03-01

    Full Text Available Background Alcoholic liver disease is a major cause of end-stage liver disease worldwide and severe forms of alcoholic hepatitis are associated with a high short-term mortality. Objectives To analyze the importance of age-bilirubin-INR-creatinine (ABIC score as an index of mortality and predictor for complications in patients with alcoholic hepatitis. To evaluate its correlation with those complications, with risk of death, as well as the scores model for end stage liver disease (MELD and Maddrey’s discriminat function. Methods A total of 46 medical records of patients who had been hospitalized with alcoholic hepatitis were assessed retrospectively with lab tests on admission and after seven days. Score calculations were carried out and analyzed as well. Results The scores showed positive reciprocal correlation and were associated with both hepatic encephalopathy and ascites. ABIC index, which was classified as high risk, presented as a risk factor for these complications and for death. In univariate logistic regression analysis of mortality, the ABIC index at hospital admission odds ratio was 19.27, whereas after 7 days, it was 41.29. The average survival of patients with ABIC of low and intermediate risk was 61.1 days, and for those with high risk, 26.2 days. Conclusions ABIC index is a predictor factor for complications such as ascites and hepatic encephalopathy, as well as for risk of death. Thus, it is a useful tool for clinical practice.

  6. Correlation analysis between molecular subtypes and Nottingham Prognostic Index in breast cancer.

    Science.gov (United States)

    Zhen, Hongchao; Yang, Liuting; Li, Li; Yu, Junxian; Zhao, Lei; Li, Yingying; Li, Qin

    2017-09-26

    Molecular subtypes and Nottingham Prognostic Index (NPI) are both prognostic models for breast cancer patients. We evaluated the association between molecular subtypes and NPI in 1042 breast cancer patients. The molecular subtypes indicating poorer prognosis were positively correlated to higher NPI (r = 0.138, P = 0.001). ER positive expression and PR high expression were positively correlated with NPI (r = 0.142, P = 0.001; r = 0.139, P = 0.001; respectively) and negatively correlated with histological grade (r = -0.233, P 5.40 were higher in the HER2 overexpression subtype, basal-like subtype, ER-, PR low/negative expression, and Ki67 high expression groups. The excellent consistence was observed between histological grade and molecular subtypes, ER, PR, Ki67. The difference of histological grade between the HER2 positive and negative group was statistically significant. In conclusion, there was closely association between molecular subtypes and NPI in breast cancer. For further comparing the prognostic significance of molecular subtypes and NPI, survival analyses should be performed on the same population in a large-scale prospective study.

  7. Validation, revision and extension of the Mantle Cell Lymphoma International Prognostic Index in a population-based setting.

    Science.gov (United States)

    van de Schans, Saskia A M; Janssen-Heijnen, Maryska L G; Nijziel, Marten R; Steyerberg, Ewout W; van Spronsen, Dick Johan

    2010-09-01

    The aim of this study was to validate the Mantle Cell Lymphoma International Prognostic Index in a population-based cohort and to study the relevance of its revisions. We analyzed data from 178 unselected patients with stage III or IV mantle cell lymphoma, registered between 1994 and 2006 in the Eindhoven Cancer Registry. Follow-up was completed up to January 1(st), 2008. Multiple imputations for missing covariates were used. Validity was assessed by comparing observed survival in our cohort with predicted survival according to the original Mantle cell lymphoma International Prognostic Index. A revised model was constructed with Cox regression analysis. Discrimination was assessed by a concordance statistic ('c'). The original Mantle cell lymphoma International Prognostic Index could stratify our cohort into three distinct risk groups based on Eastern Cooperative Group performance status, white blood cell count, lactate dehydrogenase level, and age, with the discrimination being nearly as good as in the original cohort (c 0.65 versus 0.63). A modified model including performance status in five categories (0/1/2/3/4) instead of two (0-1/2-4), the presence of B-symptoms (yes/no) and sex (male/female) in addition to the original variables resulted in a better prognostic index (c 0.75). The Mantle cell lymphoma International Prognostic Index is a valid tool for risk stratification, comparison of prognosis, and treatment decisions in an unselected Dutch population-based setting. Although the index can be significantly improved, external validation on an independent data set is warranted before broad application of the modified instrument could be recommended.

  8. A Model-based Prognostics Approach Applied to Pneumatic Valves

    Data.gov (United States)

    National Aeronautics and Space Administration — Within the area of systems health management, the task of prognostics centers on predicting when components will fail. Model-based prognostics exploits domain...

  9. A Model-Based Prognostics Approach Applied to Pneumatic Valves

    Data.gov (United States)

    National Aeronautics and Space Administration — Within the area of systems health management, the task of prognostics centers on predicting when components will fail. Model-based prognostics exploits domain...

  10. Physicians' perceptions of the value of prognostic models: the benefits and risks of prognostic confidence.

    Science.gov (United States)

    Hallen, Sarah A M; Hootsmans, Norbert A M; Blaisdell, Laura; Gutheil, Caitlin M; Han, Paul K J

    2015-12-01

    The communication of prognosis in end-of-life (EOL) care is a challenging task that is limited by prognostic uncertainty and physicians' lack of confidence in their prognostic estimates. Clinical prediction models (CPMs) are increasingly common evidence-based tools that may mitigate these problems and facilitate the communication and use of prognostic information in EOL care; however, little is known about physicians' perceptions of the value of these tools. To explore physicians' perceptions of the value of CPMs in EOL care. Qualitative study using semi-structured individual interviews which were analysed using a constant comparative method. Convenience sample of 17 attending physicians representing five different medical specialties at a single large tertiary care medical centre. Physicians perceived CPMs as having three main benefits in EOL care: (i) enhancing their prognostic confidence; (ii) increasing their prognostic authority; and (iii) enabling patient persuasion in circumstances of low prognostic and therapeutic uncertainty. However, physicians also perceived CPMs as having potential risks, which include producing emotional distress in patients and promoting prognostic overconfidence in EOL care. Physicians perceive CPMs as a potentially valuable means of increasing their prognostic confidence, communication and explicit use of prognostic information in EOL care. However, physicians' perceptions of CPMs also indicate a need to establish broad and consistent implementation processes to engage patients in shared decision making in EOL care, to effectively communicate uncertainty in prognostic information and to help both patients and physicians manage uncertainty in EOL care decisions. © 2014 John Wiley & Sons Ltd.

  11. Short-Term Prognostic Index for Breast Cancer: NPI or Lpi

    Directory of Open Access Journals (Sweden)

    V. Van Belle

    2011-01-01

    Full Text Available Axillary lymph node involvement is an important prognostic factor for breast cancer survival but is confounded by the number of nodes examined. We compare the performance of the log odds prognostic index (Lpi, using a ratio of the positive versus negative lymph nodes, with the Nottingham Prognostic Index (NPI for short-term breast cancer specific disease free survival. A total of 1818 operable breast cancer patients treated in the University Hospital of Leuven between 2000 and 2005 were included. The performance of the NPI and Lpi were compared on two levels: calibration and discrimination. The latter was evaluated using the concordance index (cindex, the number of patients in the extreme groups, and difference in event rates between these. The NPI had a significant higher cindex, but a significant lower percentage of patients in the extreme risk groups. After updating both indices, no significant differences between NPI and Lpi were noted.

  12. Prognostic index for chronic- and smoldering-type adult T-cell leukemia-lymphoma.

    Science.gov (United States)

    Katsuya, Hiroo; Shimokawa, Mototsugu; Ishitsuka, Kenji; Kawai, Kazuhiro; Amano, Masahiro; Utsunomiya, Atae; Hino, Ryosuke; Hanada, Shuichi; Jo, Tatsuro; Tsukasaki, Kunihiro; Moriuchi, Yukiyoshi; Sueoka, Eisaburo; Yoshida, Shinichiro; Suzushima, Hitoshi; Miyahara, Masaharu; Yamashita, Kiyoshi; Eto, Tetsuya; Suzumiya, Junji; Tamura, Kazuo

    2017-07-06

    Adult T-cell leukemia-lymphoma (ATL) has been divided into 4 clinical subtypes: acute, lymphoma, chronic, and smoldering. The aim of this study is to develop a novel prognostic index (PI) for chronic and smoldering ATL. We conducted a nationwide retrospective survey on ATL patients, and 248 fully eligible individuals were used in this analysis. In the univariate analysis, sex, performance status, log10 (soluble interleukin-2 receptor [sIL-2R]), neutrophils count, and lymphadenopathy showed values of P < .05 in training samples. A multivariate analysis was performed on these factors, and only log10 (sIL-2R) was identified as an independent prognostic factor in training samples. Using a regression coefficient of this variable, a prognostic model was formulated to identify different levels of risk: indolent ATL-PI (iATL-PI) = 1.51 × log10 (sIL-2R [U/mL]). The values calculated by iATL-PI were divided into 3 groups using a quartile point. In the validation sample, median survival times (MSTs) were 1.6 years, 5.5 years, and not reached for patients in the high-, intermediate-, and low-risk groups, respectively (P < .0001). To make the scoring system clinically practicable, we simplified iATL-PI according to trichotomizing sIL-2R at 1000 and 6000 U/mL, using a quartile point. Patients with more than 6000 U/mL sIL-2R were categorized into the high-risk group, less than and equal to 1000 U/mL into the low-risk group, and the others into the intermediate-risk group, and MSTs were 1.6 years, not reached, and 5.5 years, respectively (P < .0001). iATL-PI has potential as a novel tool for a risk-adapted therapeutic approach. © 2017 by The American Society of Hematology.

  13. Improved risk stratification by the integration of the revised international prognostic scoring system with the myelodysplastic syndromes comorbidity index.

    Science.gov (United States)

    van Spronsen, M F; Ossenkoppele, G J; Holman, R; van de Loosdrecht, A A

    2014-12-01

    Myelodysplastic syndromes (MDS) comprise bone marrow failure diseases with a diverse clinical outcome. For improved risk stratification, the International Prognostic Scoring System (IPSS) has recently been revised (IPSS-R). This single-centre study aimed to validate the IPSS-R and to evaluate prior prognostic scoring systems for MDS. We retrospectively analysed 363 patients diagnosed with MDS according to the FAB criteria between 2000 and 2012. The IPSS, MD Anderson Risk Model Score (MDAS), World Health Organisation (WHO)-classification based Prognostic Scoring System (WPSS), refined WPSS (WPSS-R), IPSS-R and MDS-Comorbidity Index (MDS-CI) were applied to 222 patients considered with primary MDS following the WHO criteria and their prognostic power was investigated. According to the IPSS-R, 18 (8%), 81 (37%), 50 (23%), 43 (19%) and 30 (13%) patients were classified as very low, low, intermediate, high and very high risk with, respectively, a median overall survival of 96 (95% Confidence interval (CI) not reached), 49 (95% CI 34-64), 22 (95% CI 0-49), 19 (95% CI 11-27) and 10 (95% CI 6-13) months (pMDS-CI refined the risk stratification of MDS patients stratified according to the IPSS-R. In conclusion, accounting for the disease status by means of the IPSS-R and comorbidity through the MDS-CI considerably improves the prognostic assessment in MDS patients. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Multicenter validation study of a prognostic index for portal vein tumor thrombosis in hepatocellular carcinoma.

    Science.gov (United States)

    Yu, Jeong Il; Yoon, Sang Min; Park, Hee Chul; Kim, Jong Hoon; Kim, Tae Hyun; Park, Joong-Won; Seong, Jinsil; Lee, Ik Jae; Jang, Hong Seok; Kay, Chul Seung; Kim, Chul Yong; Chie, Eui Kyu; Kim, Jin Hee; Kim, Mi-Sook; Choi, Young Min

    2014-10-01

    We previously reported on a staging system and prognostic index (PITH) for portal vein tumor thrombosis (PVTT) in hepatocellular carcinoma (HCC) patients treated with radiotherapy (RT) at a single institution. The aim of this study is to validate the PITH staging system using data from patients at other institutions and to compare it with other published staging systems. A total of 994 HCC patients with PVTT who were treated with RT between 1998 and 2011 by the Korean Radiation Oncology Group were analyzed retrospectively. All patients were staged using the Cancer of the Liver Italian Program (CLIP), Japanese Integrated Staging (JIS), Okuda, and PITH staging systems, and survival data were analyzed. The likelihood ratio, Akaike information criteria (AIC), time-dependent receiver operating characteristics, and prediction error curve analysis were used to determine discriminatory ability for comparison of staging systems. The median survival was 9.2 months. Compared with the other staging systems, the PITH score gave the highest values for likelihood ratio and lowest AIC values, demonstrating that PITH may be a better prognostic model. Although the values were not significant and differences were not exceptional, the PITH score showed slightly better performance with respect to time-dependent area under curve and integrated Brier score of prediction error curve. The PITH staging system was validated in this multicenter retrospective study and showed better stratification ability in HCC patients with PVTT than other systems.

  15. Cell Proliferation Activity and Prognostic Index in Squamous Cell Lung Carcinoma

    Directory of Open Access Journals (Sweden)

    José Antonio Alvarez-Riesgo

    1998-01-01

    Full Text Available Flow Cytometry (FC has been incorporated into cancer research in relation to its prognostic value together with histological parameters and TNM stages. We have studied by means of FC the cell cycle of 132 samples from male patients with Squamous Cell Lung Carcinoma (SQCLC. All of the patients received curative surgery and the clinical follow-up was 60 months. The clinical and cytometric parameters were evaluated in order to predict the patients’ outcome. The presence of tumoural recurrence and the tumoural stage showed statistical significance associated with survival. The multivariant analysis reveals radiotherapy (p = 0.004 as protective variable and the high S-phase fraction (SPF (p = 0.001 and stage IIIA (p = 0.012 as risk factors. The SPF appears as an independent prognostic factor for overall survival time. We can build a prognostic index representative of different prognostic groups, which allows us to improve the individual monitoring of these patients.

  16. The Enhanced International Prognostic Index for Diffuse Large B-cell Lymphoma.

    Science.gov (United States)

    Yang, Yan; Wang, Lanlan; Ma, Yanna; Han, Tingting; Huang, Mei

    2017-05-01

    To explore the prognostic value of the enhanced International Prognostic Index (NCCN-IPI) for Asian patients with diffuse large B-cell lymphoma (DLBCL) treated in the rituximab era. We performed a retrospective analysis of 176 patients with newly diagnosed DLBCL. The estimated overall survival (OS) and progression-free survival (PFS) of the different risk groups were discriminated by the International Prognostic Index (IPI), the revised International Prognostic Index (R-IPI) and the NCCN-IPI. With a median follow-up of 18 months, at 3 years, the OS was 73% and the PFS was 65%. The 3-year OS for the 4 NCCN-IPI risk groups were 91% versus 80% versus 57% versus 45% (P < 0.001); the 3-year PFS were 77% versus 72% versus 56% versus 26% (P < 0.001). The 3-year OS of the 4 risk groups discriminated by the IPI ranged from 85-55% (P < 0.001); the 3-year PFS ranged from 81-41% (P < 0.001). The 3-year OS of the 3 distinct prognostic groups by the R-IPI ranged from 86-51% (P < 0.001); the 3-year PFS ranged from 86-47% (P < 0.001). The 3-year OS and PFS of the high-risk group according to the NCCN-IPI were lower than the IPI and R-IPI. Using the NCCN-IPI, the outcomes among the risk groups spanned a large range, and the survival of the high-risk group was significantly different from the high-intermediate risk group. The NCCN-IPI is a clinically useful prognostic index for patients with DLBCL treated in the rituximab era, especially for high-risk patients. Copyright © 2017 Southern Society for Clinical Investigation. Published by Elsevier Inc. All rights reserved.

  17. Cumulative Intracranial Tumor Volume Augments the Prognostic Value of Diagnosis-Specific Graded Prognostic Assessment Model for Survival in Patients with Melanoma Cerebral Metastases

    DEFF Research Database (Denmark)

    Hirshman, Brian R; Wilson, Bayard R; Ali, Mir Amaan

    2017-01-01

    intracranial tumor volume (CITV) into the ds-GPA model for melanoma augmented its prognostic value. OBJECTIVE: To determine whether or not CITV augments the ds-GPA prognostic scale for melanoma. METHODS: We analyzed the survival pattern of 344 melanoma patients with BM treated with stereotactic radiosurgery...... (SRS) at separate institutions and validated our findings in an independent cohort of 201 patients. The prognostic value of ds-GPA for melanoma was quantitatively compared with and without the addition of CITV using the net reclassification index (NRI > 0) and integrated discrimination improvement (IDI...... validated these findings that CITV improves the prognostic utility of melanoma ds-GPA in an independent cohort of 201 melanoma cohort. CONCLUSION: The prognostic value of the ds-GPA scale for melanoma BM is enhanced by the incorporation of CITV....

  18. Prognostics

    Data.gov (United States)

    National Aeronautics and Space Administration — Prognostics has received considerable attention recently as an emerging sub-discipline within SHM. Prognosis is here strictly defined as “predicting the time at...

  19. Re-evaluation of Mannheim prognostic index in perforative peritonitis: prognostic role of advanced age. A prospective cohort study.

    Science.gov (United States)

    Neri, Alessandro; Marrelli, Daniele; Scheiterle, Maximilian; Di Mare, Giulio; Sforza, Simone; Roviello, Franco

    2015-01-01

    Peritonitis from perforation of abdominal viscera is associated with high mortality. In western countries individuals older than 65 years constitute a significant proportion of the population and intra abdominal infections are more challenging to manage in these aged patients. This prospective cohort study included 143 consecutive patients operated on for primary perforative peritonitis. The aim of the study was to assess the prognostic efficacy of Mannheim Peritonitis Index (MPI) in a population with a significant proportion of older patients and to substantiate advanced age as an independent prognostic factor. Patients' informations were collected both on hospitalization and after surgical exploration; severity of peritonitis was evaluated using the MPI. The prognostic value of MPI was compared to older age and other clinical variables. The intra-hospital mortality was 25.2%. According to the MPI score, the ROC curve identified 21 as cut-off value with a sensitivity of 86% and a specificity of 59% in predicting the risk of death. MPI score and age over 80 years old resulted independent predictors of mortality at multivariate analysis. In the subgroup of patients with MPI score≥21, the mortality rate was 46.4% for patients older than 80 years old and 38.3% for younger patients (p=0.07); in patients with MPI score<21, the mortality of those aged more than 80 years reached 33.3% compared to 3.4% for younger patients (p=0.001). Age older than 80 years is strongly related to major increase in mortality rates and should be taken into account together with the MPI score in planning the surgical approach and the post-operative care. Copyright © 2014 Surgical Associates Ltd. Published by Elsevier Ltd. All rights reserved.

  20. Body mass index (BMI) may be a prognostic factor for gastric cancer with peritoneal dissemination.

    Science.gov (United States)

    Chen, Shi; Nie, Run-Cong; OuYang, Li-Ying; Li, Yuan-Fang; Xiang, Jun; Zhou, Zhi-Wei; Chen, YingBo; Peng, JunSheng

    2017-02-23

    The aim of this study is to investigate whether body mass index (BMI) is a prognostic factor in gastric cancer patients with peritoneal dissemination. This is a retrospective study consisting of 518 patients with a histological diagnosis of gastric cancer with peritoneal dissemination seen at the Sixth Affiliated Hospital of Sun Yat-Sen University and Sun Yat-sen University Cancer Center between January 2010 and April 2014. Patients were followed until December 2015. Chi-square test and Kaplan-Meier survival analysis were used to compare the clinicopathological variables and prognosis. Univariate analyses showed that significant prognostic factors included palliative gastrectomy (p dissemination, especially in patients who received palliative chemotherapy. BMI is a prognostic factor for patients who have gastric cancer with peritoneal dissemination, especially in those who received palliative chemotherapy.

  1. Model-based Prognostics with Concurrent Damage Progression Processes

    Data.gov (United States)

    National Aeronautics and Space Administration — Model-based prognostics approaches rely on physics-based models that describe the behavior of systems and their components. These models must account for the several...

  2. Prognostic survival model for people diagnosed with invasive cutaneous melanoma.

    Science.gov (United States)

    Baade, Peter D; Royston, Patrick; Youl, Philipa H; Weinstock, Martin A; Geller, Alan; Aitken, Joanne F

    2015-01-31

    The ability of medical practitioners to communicate risk estimates effectively to patients diagnosed with melanoma relies on accurate information about prognostic factors and their impact on survival. This study reports the development of one of the few melanoma prognostic models, called the Melanoma Severity Index (MSI), based on population-based cancer registry data. Data from the Queensland Cancer Registry for people (20-89 years) diagnosed with a single invasive melanoma between 1995 and 2008 (n = 28,654; 1,700 melanoma deaths). Additional clinical information about metastasis, ulceration and positive lymph nodes was manually extracted from pathology forms. Flexible parametric survival models were combined with multivariable fractional polynomial for selecting variables and transformations of continuous variables. Multiple imputation was used for missing covariate values. The MSI contained the variables thickness (transformed, explained 40.6% of variation in survival), body site (additional 1.9% in variation), metastasis (1.8%), positive nodes (0.7%), ulceration (1.3%), age (1.1%). Royston and Sauerbrei's D statistic (measure of discrimination) was 1.50 (95% CI = 1.44, 1.56) and the corresponding RD2 (measure of explained variation) was 0.47 (0.45, 0.49), demonstrating strong explanatory performance. The Harrell-C statistic was 0.88 (0.88, 0.89). Lacking an external validation dataset, we applied internal-external cross validation to demonstrate the consistency of the prognostic information across geographically-defined subsets of the cohort. The MSI provides good ability to predict survival for melanoma patients. Beyond the immediate clinical use, the MSI may have important public health and research applications for evaluations of public health interventions aimed at reducing deaths from melanoma.

  3. Comparison of two prognostic models for acute pulmonary embolism

    Directory of Open Access Journals (Sweden)

    Abd-ElRahim Ibrahim Youssef

    2016-10-01

    Conclusion: (1 There is an agreement to great extent in risk stratification of APE patients by PESI and ESC prognostic models, where mortality rate is increased among high risk classes of both models, (2 ESC prognostic model is more accurate than PESI model in mortality prediction of APE patients especially in the high risk class, (3 echocardiographic evidence of RVD and elevated plasma BNP can help to identify APE patients at increased risk of adverse short-term outcome and (4 integration of RVD assessment by echocardiography and BNP to clinical findings improves the prognostic value of ESC model.

  4. Distributed Damage Estimation for Prognostics based on Structural Model Decomposition

    Data.gov (United States)

    National Aeronautics and Space Administration — Model-based prognostics approaches capture system knowl- edge in the form of physics-based models of components that include how they fail. These methods consist of...

  5. Multiple Damage Progression Paths in Model-based Prognostics

    Data.gov (United States)

    National Aeronautics and Space Administration — Model-based prognostics approaches employ do- main knowledge about a system, its components, and how they fail through the use of physics-based models. Compo- nent...

  6. Albumin-to-alkaline phosphatase ratio: a novel prognostic index for hepatocellular carcinoma.

    Science.gov (United States)

    Chan, Anthony W H; Chan, Stephen L; Mo, Frankie K F; Wong, Grace L H; Wong, Vincent W S; Cheung, Yue-Sun; Chan, Henry L Y; Yeo, Winnie; Lai, Paul B S; To, Ka-Fai

    2015-01-01

    Prognosis of patients with hepatocellular carcinoma (HCC) depends on both tumour extent and hepatic function reserve. Liver function test (LFT) is a basic routine blood test to evaluate hepatic function. We first analysed LFT components and their associated scores in a training cohort of 217 patients who underwent curative surgery to identify LFT parameters with high performance (discriminatory capacity, homogeneity, and monotonicity of gradient). We derived a novel index, albumin-to-alkaline phosphatase ratio (AAPR), which had the highest c-index (0.646) and χ(2) (24.774) among other liver biochemical parameters. The AAPR was an independent prognostic factor for overall and disease-free survival. The adjusted hazard ratio of death and tumour relapse was 2.36 (P = 0.002) and 1.85 (P = 0.010), respectively. The independent prognostic significance of AAPR on top of 5 commonly used and well established staging systems was further confirmed in 2 independent cohorts of patients receiving surgical resection (n = 256) and palliative therapy (n = 425). In summary, the AAPR is a novel index readily derived from a simple low-cost routine blood test and is an independent prognostic indicator for patients with HCC regardless of treatment options.

  7. Novel immunological and nutritional-based prognostic index for gastric cancer.

    Science.gov (United States)

    Sun, Kai-Yu; Xu, Jian-Bo; Chen, Shu-Ling; Yuan, Yu-Jie; Wu, Hui; Peng, Jian-Jun; Chen, Chuang-Qi; Guo, Pi; Hao, Yuan-Tao; He, Yu-Long

    2015-05-21

    To assess the prognostic significance of immunological and nutritional-based indices, including the prognostic nutritional index (PNI), neutrophil-lymphocyte ratio (NLR), and platelet-lymphocyte ratio in gastric cancer. We retrospectively reviewed 632 gastric cancer patients who underwent gastrectomy between 1998 and 2008. Areas under the receiver operating characteristic curve were calculated to compare the predictive ability of the indices, together with estimating the sensitivity, specificity and agreement rate. Univariate and multivariate analyses were performed to identify risk factors for overall survival (OS). Propensity score analysis was performed to adjust variables to control for selection bias. Each index could predict OS in gastric cancer patients in univariate analysis, but only PNI had independent prognostic significance in multivariate analysis before and after adjustment with propensity scoring (hazard ratio, 1.668; 95% confidence interval: 1.368-2.035). In subgroup analysis, a low PNI predicted a significantly shorter OS in patients with stage II-III disease (P = 0.019, P index in gastric cancer.

  8. Octogenarian patients with chronic obstructive pulmonary disease: Characteristics and usefulness of prognostic indexes.

    Science.gov (United States)

    Golpe, Rafael; Suárez-Valor, María; Veres-Racamonde, Alejandro; Cano-Jiménez, Esteban; Martín-Robles, Irene; Sanjuán-López, Pilar; Pérez-de-Llano, Luis

    2017-10-30

    Most studies on chronic obstructive pulmonary disease (COPD) exclude octogenarian patients. Therefore, the disease is not well characterized in this age group. The objective of this study is to analyze the clinical characteristics of octogenarian patients with COPD and the usefulness of the prognostic indexes used most frequently in this age group. Retrospective study of consecutive patients seen at a clinic between 2009 and 2017. The following variables were analyzed: lung function parameters, distribution of clinical phenotypes, income history, mortality, comorbidities and usefulness of the Charlson, BODEX, COTE and CODEX indexes to predict mortality. The sample comprised 698 patients, 82 aged (11.7%)≥80 years old. Mean follow-up time was 47.9±21.8 months. In octogenarian patients, the severity of the COPD, assessed by means of the FEV1% or BODEX index, was similar to that of younger patients, but dyspnea was worse in the elderly group. In these patients, the chronic bronchitis and frequent exacerbator phenotypes were the most frequent, whilst the emphysema phenotype was the least common. Octogenarians had a greater prevalence of cardiovascular comorbidities and renal diseases. Moreover, hospital admissions were more frequent and mortality was higher in these elderly patients. Most prognostic indexes were useful in predicting mortality in elderly patients. CODEX was the most useful index to predict mortality, both in octogenarian and younger patients. Octogenarian patients with COPD have differential characteristics which could imply the need for different therapeutic approaches. Prognostic indexes are useful for predicting mortality in this population. Copyright © 2017 Elsevier España, S.L.U. All rights reserved.

  9. Model-based Prognostics under Limited Sensing

    Data.gov (United States)

    National Aeronautics and Space Administration — Prognostics is crucial to providing reliable condition-based maintenance decisions. To obtain accurate predictions of component life, a variety of sensors are often...

  10. Remote sensing data assimilation for a prognostic phenology model

    Energy Technology Data Exchange (ETDEWEB)

    Thornton, Peter E [ORNL; Stockli, Reto [Colorado State University, Fort Collins

    2008-01-01

    Predicting the global carbon and water cycle requires a realistic representation of vegetation phenology in climate models. However most prognostic phenology models are not yet suited for global applications, and diagnostic satellite data can be uncertain and lack predictive power. We present a framework for data assimilation of Fraction of Photosynthetically Active Radiation absorbed by vegetation (FPAR) and Leaf Area Index (LAI) from the MODerate Resolution Imaging Spectroradiometer (MODIS) to constrain empirical temperature, light, moisture and structural vegetation parameters of a prognostic phenology model. We find that data assimilation better constrains structural vegetation parameters than climate control parameters. Improvements are largest for drought-deciduous ecosystems where correlation of predicted versus satellite-observed FPAR and LAI increases from negative to 0.7-0.8. Data assimilation effectively overcomes the cloud- and aerosol-related deficiencies of satellite data sets in tropical areas. Validation with a 49-year-long phenology data set reveals that the temperature-driven start of season (SOS) is light limited in warm years. The model has substantial skill (R = 0.73) to reproduce SOS inter-annual and decadal variability. Predicted SOS shows a higher inter-annual variability with a negative bias of 5-20 days compared to species-level SOS. It is however accurate to within 1-2 days compared to SOS derived from net ecosystem exchange (NEE) measurements at a FLUXNET tower. The model only has weak skill to predict end of season (EOS). Use of remote sensing data assimilation for phenology model development is encouraged but validation should be extended with phenology data sets covering mediterranean, tropical and arctic ecosystems.

  11. An inflammation-based prognostic index predicts survival advantage after transarterial chemoembolization in hepatocellular carcinoma.

    Science.gov (United States)

    Pinato, David J; Sharma, Rohini

    2012-08-01

    Transarterial chemoembolization (TACE) is the preferred treatment for unresectable, intermediate-stage hepatocellular carcinoma (HCC). However, survival after TACE can be highly variable, suggesting the need for more accurate patient selection to improve therapeutic outcome. We have explored the prognostic ability of the blood neutrophil-to-lymphocyte ratio (NLR), a biomarker of systemic inflammation, as a predictor of survival after TACE. Fifty-four patients with a diagnosis of HCC eligible for TACE were selected. Clinicopathologic variables were collected, including demographics, tumor staging, liver functional reserve, and laboratory variables. Dynamic changes in the NLR before and after TACE were studied as predictors of survival using both a univariate and multivariate Cox regression model. Patients in whom the NLR remained stable or normalized after TACE showed a significant improvement in overall survival of 26 months compared with patients showing a persistently abnormal index (P = 0.006). Other predictors of survival on univariate analysis were Cancer of the Liver Italian Program score (P = 0.05), intrahepatic spread (P = 0.01), tumor diameter > 5 cm (P = 0.02), > 1 TACE (P = 0.01), alpha-fetoprotein ≥ 400 (P = 0.002), and radiologic response to TACE (P analysis. Changes in alpha-fetoprotein after treatment did not predict survival. Patients with a persistently increased NLR have a worse outcome after TACE. NLR is a simple and universally available stratifying biomarker that can help identify patients with a significant survival advantage after TACE. Copyright © 2012 Mosby, Inc. All rights reserved.

  12. Onodera's prognostic nutritional index as a risk factor for mortality in peritoneal dialysis patients.

    Science.gov (United States)

    Kang, Seok Hui; Cho, Kyu Hyang; Park, Jong Won; Yoon, Kyung Woo; Do, Jun Young

    2012-11-01

    The aim of this study was to evaluate the clinical relevance and usefulness of the Onodera's prognostic nutritional index (OPNI) as a prognostic and nutritional indicator in peritoneal dialysis (PD) patients. Patients were divided into 3 groups based on the initial OPNI score: group A (n = 186, 45). Group A was associated with a higher grade according to the Davies risk index than the other groups. Serum creatinine and albumin levels, total lymphocyte count, and fat mass increased with an increase in OPNI. According to the edema index, the correlation coefficient for OPNI was -0.284 and for serum albumin was -0.322. Similarly, according to the C-reactive protein (CRP), the correlation coefficient for OPNI was -0.117 and for serum albumin was -0.169. Multivariate analysis adjusted for age, Davies risk index, CRP, and edema index revealed that the hazard ratios for low OPNI, serum albumin, and CRP were 1.672 (P = 0.003), 1.308 (P = 0.130), and 1.349 (P = 0.083), respectively. Our results demonstrate that the OPNI is a simple method that can be used for predicting the nutritional status and clinical outcome in PD patients.

  13. Complex karyotype in mantle cell lymphoma is a strong prognostic factor for the time to treatment and overall survival, independent of the MCL international prognostic index.

    Science.gov (United States)

    Sarkozy, Clémentine; Terré, Christine; Jardin, Fabrice; Radford, Isabelle; Roche-Lestienne, Catherine; Penther, Dominique; Bastard, Christian; Rigaudeau, Sophie; Pilorge, Sylvain; Morschhauser, Franck; Bouscary, Didier; Delarue, Richard; Farhat, Hassan; Rousselot, Philippe; Hermine, Olivier; Tilly, Hervé; Chevret, Sylvie; Castaigne, Sylvie

    2014-01-01

    Mantle cell lymphoma (MCL) is usually an aggressive disease. However, a few patients do have an "indolent" evolution (iMCL) defined by a long survival time without intensive therapy. Many studies highlight the prognostic role of additional genetic abnormalities, but these abnormalities are not routinely tested for and do not yet influence the treatment decision. We aimed to evaluate the prognostic impact of these additional abnormalities detected by conventional cytogenetic testing, as well as their relationships with the clinical characteristics and their value in identifying iMCL. All consecutive MCL cases diagnosed between 1995 and 2011 at four institutions were retrospectively selected on the basis of an informative karyotype with a t(11;14) translocation at the time of diagnosis. A total of 125 patients were included and followed for an actual median time of 35 months. The median overall survival (OS) and survival without treatment (TFS) were 73.7 and 1.3 months, respectively. In multivariable Cox models, a high mantle cell lymphoma international prognostic index score, a complex karyotype, and blastoid morphology were independently associated with a shortened OS. Spleen enlargement, nodal presentation, extra-hematological involvement, and complex karyotypes were associated with shorter TFS. A score based on these factors allowed for the identification of "indolent" patients (median TFS 107 months) from other patients (median TFS: 1 month). In conclusion, in this multicentric cohort of MCL patients, a complex karyotype was associated with a shorter survival time and allowed for the identification of iMCL at the time of diagnosis. Copyright © 2013 Wiley Periodicals, Inc.

  14. Diagnostic and Prognostic Models for Generator Step-Up Transformers

    Energy Technology Data Exchange (ETDEWEB)

    Vivek Agarwal; Nancy J. Lybeck; Binh T. Pham

    2014-09-01

    In 2014, the online monitoring (OLM) of active components project under the Light Water Reactor Sustainability program at Idaho National Laboratory (INL) focused on diagnostic and prognostic capabilities for generator step-up transformers. INL worked with subject matter experts from the Electric Power Research Institute (EPRI) to augment and revise the GSU fault signatures previously implemented in the Electric Power Research Institute’s (EPRI’s) Fleet-Wide Prognostic and Health Management (FW-PHM) Suite software. Two prognostic models were identified and implemented for GSUs in the FW-PHM Suite software. INL and EPRI demonstrated the use of prognostic capabilities for GSUs. The complete set of fault signatures developed for GSUs in the Asset Fault Signature Database of the FW-PHM Suite for GSUs is presented in this report. Two prognostic models are described for paper insulation: the Chendong model for degree of polymerization, and an IEEE model that uses a loading profile to calculates life consumption based on hot spot winding temperatures. Both models are life consumption models, which are examples of type II prognostic models. Use of the models in the FW-PHM Suite was successfully demonstrated at the 2014 August Utility Working Group Meeting, Idaho Falls, Idaho, to representatives from different utilities, EPRI, and the Halden Research Project.

  15. A clinically based prognostic index for diffuse large B-cell lymphoma with a cut-off at 70 years of age significantly improves prognostic stratification

    DEFF Research Database (Denmark)

    Gang, Anne O.; Pedersen, Michael; d'Amore, Francesco

    2015-01-01

    subtypes. We applied IPI factors to a population-based rituximab-treated cohort of 1990 patients diagnosed 2000-2010 and explored new factors and the optimal prognostic age cut-off for DLBCL. Multivariate-analyses (MVA) confirmed the prognostic value of all IPI factors except the presence of > 1 extranodal...... lesion. The optimal age cut-off was 70 years. In a MVA of albumin, lymphocyte count, sex, immunoglobulin G, bulky disease, hemoglobin and B-symptoms, only albumin was prognostic. We propose: (1) a modified DLBCL prognostic index (DLBCL-PI) including: age (70 years), performance status (PS), lactate...... dehydrogenase (LDH), stage and albumin level, and (2) a separate age-adjusted DLBCL-PI for patients 1 extranodal lesion, however excluding stage....

  16. Model Adaptation for Prognostics in a Particle Filtering Framework

    Data.gov (United States)

    National Aeronautics and Space Administration — One of the key motivating factors for using particle filters for prognostics is the ability to include model parameters as part of the state vector to be estimated....

  17. A Model-based Avionic Prognostic Reasoner (MAPR)

    Data.gov (United States)

    National Aeronautics and Space Administration — The Model-based Avionic Prognostic Reasoner (MAPR) presented in this paper is an innovative solution for non-intrusively monitoring the state of health (SoH) and...

  18. Model-based Prognostics with Fixed-lag Particle Filters

    Data.gov (United States)

    National Aeronautics and Space Administration — Model-based prognostics exploits domain knowl- edge of the system, its components, and how they fail by casting the underlying physical phenom- ena in a...

  19. Expansion of the prognostic assessment of patients with chronic obstructive pulmonary disease: the updated BODE index and the ADO index.

    Science.gov (United States)

    Puhan, Milo A; Garcia-Aymerich, Judith; Frey, Martin; ter Riet, Gerben; Antó, Josep M; Agustí, Alvar G; Gómez, Federico P; Rodríguez-Roisín, Roberto; Moons, Karel G M; Kessels, Alphons G; Held, Ulrike

    2009-08-29

    The BODE index (including body-mass index, airflow obstruction, dyspnoea, and exercise capacity) was an important contribution to the prognostic assessment of patients with chronic obstructive pulmonary disease (COPD). However, no study has assessed whether the risk of mortality predicted by the BODE index matches the observed mortality in different populations. We assessed the calibration of the BODE index, updated it to improve its calibration, and developed and validated a simplified index for use in primary-care settings. We included 232 patients from the Swiss Barmelweid cohort with longstanding and severe COPD and 342 patients from the Spanish Phenotype and Course of COPD cohort study who had had their first hospital admission due to moderate-to-severe COPD. In both cohorts we compared the observed 3-year risk of all-cause mortality with the risk predicted by the BODE index. We then updated the BODE index and developed a simplified ADO index (including age, dyspnoea, and airflow obstruction) from the Swiss cohort, and validated both in the Spanish cohort. Calibration of the BODE index was poor, with relative underprediction of 3-year risk of mortality by 36% in the Swiss cohort (median predicted risk 21.7% [IQR 12.7-31.7] vs 34.1% observed risk; p=0.013) and relative overprediction by 39% in the Spanish cohort (16.7% [12.7-31.7] vs 12.0%; p=0.035). The 3-year risk of mortality predicted by both the updated BODE (median 10.7% [8.1-13.8]) and ADO indices (11.8% [9.1-14.3]) matched the observed mortality in the Spanish cohort well (p=0.99 and p=0.98, respectively). Both the updated BODE and ADO indices could lend support to the prognostic assessment of patients with COPD in specialised and primary-care settings. Such assessment enhances the targeting of treatments to individual patients. Swiss National Science Foundation; Klinik Barmelweid; Fondo de Investigación Sanitaria Ministry of Health, Spain; Agència d'Avaluació de Tecnologia i Recerca M

  20. A framework for quantifying net benefits of alternative prognostic models

    DEFF Research Database (Denmark)

    Rapsomaniki, Eleni; White, Ian R; Wood, Angela M

    2012-01-01

    New prognostic models are traditionally evaluated using measures of discrimination and risk reclassification, but these do not take full account of the clinical and health economic context. We propose a framework for comparing prognostic models by quantifying the public health impact (net benefit......) of the treatment decisions they support, assuming a set of predetermined clinical treatment guidelines. The change in net benefit is more clinically interpretable than changes in traditional measures and can be used in full health economic evaluations of prognostic models used for screening and allocating risk...... reduction interventions. We extend previous work in this area by quantifying net benefits in life years, thus linking prognostic performance to health economic measures; by taking full account of the occurrence of events over time; and by considering estimation and cross-validation in a multiple...

  1. Prognostic Nutritional Index Predicts Severe Complications, Recurrence, and Poor Prognosis in Patients With Colorectal Cancer Undergoing Primary Tumor Resection.

    Science.gov (United States)

    Tokunaga, Ryuma; Sakamoto, Yasuo; Nakagawa, Shigeki; Miyamoto, Yuji; Yoshida, Naoya; Oki, Eiji; Watanabe, Masayuki; Baba, Hideo

    2015-11-01

    The prognostic nutritional index is reportedly related to postoperative outcomes. The aim of this study was to elucidate the clinical importance of the prognostic nutritional index in patients with colorectal cancer who were undergoing primary tumor resection. This is a retrospective study from a single institution. This study was conducted at a colorectal surgery service in an academic teaching hospital. The 556 patients with colorectal cancer who were undergoing surgery between March 2005 and August 2014 were eligible for this study. The preoperative prognostic nutritional index was calculated. Classification and regression tree analysis was performed to determine the prognostic nutritional index cutoff value. The associations of the prognostic nutritional index status with clinicopathological factors and postoperative outcomes were examined using univariate and multivariate analyses. Classification and regression tree analysis demonstrated that 45.5 was the optimal cutoff value. The low status (≤45.5) was correlated with older age, low BMI, low estimated glomerular filtration rate, CEA positivity, carbohydrate antigen 19-9 positivity, preoperative chemotherapy, tumors invading muscular or deeper layers, distant metastasis, poor differentiation, severe postoperative complications, tumor recurrence, and poor survival. In multivariate analysis, the low status was an independent risk factor for severe postoperative complications (OR = 2.06 [95% CI, 1.22-3.50]; p = 0.007) and low overall survival (HR =3.98 [95% CI, 2.38-6.89]; p nutritional index status, not considering the postoperative host status. The preoperative prognostic nutritional index predicts severe complications, recurrence, and poor prognosis in patients with colorectal cancer who are undergoing primary tumor resection. Investigation of the nutritional and immunologic statuses using the prognostic nutritional index could be a useful clinical approach.

  2. Prognostic value of body mass index and waist circumference in patients with chronic heart failure (Spanish REDINSCOR Registry).

    Science.gov (United States)

    Puig, Teresa; Ferrero-Gregori, Andreu; Roig, Eulalia; Vazquez, Rafael; Gonzalez-Juanatey, Jose R; Pascual-Figal, Domingo; Delgado, Juan; Alonso-Pulpon, Luis; Borras, Xavier; Mendez, Ana; Cinca, Juan

    2014-02-01

    To analyze the association between higher body mass index and waist circumference, and the prognostic values of both indicators in total and cardiac mortality in patients with chronic heart failure. The study included 2254 patients who were followed up for 4 years. Obesity was classified as a body mass index ≥30 and overweight as a body mass index of 25.0-29.9. Central obesity was defined as waist circumference ≥88 cm for women and ≥102cm for men. Independent predictors of total and cardiac mortality were assessed in a multivariate Cox model adjusted for confounding variables. Obesity was present in 35% of patients, overweight in 43%, and central obesity in 60%. Body mass index and waist circumference were independent predictors of lower total mortality: hazard ratio=0.84 (P120cm. Mortality was significantly lower in patients with a high body mass index and waist circumference. The results also showed that this protection was lost when these indicators over a certain limit. Copyright © 2013 Sociedad Española de Cardiología. Published by Elsevier Espana. All rights reserved.

  3. A Model-based Prognostics Approach Applied to Pneumatic Valves

    Directory of Open Access Journals (Sweden)

    Matthew J. Daigle

    2011-01-01

    Full Text Available Within the area of systems health management, the task of prognostics centers on predicting when components will fail. Model-based prognostics exploits domain knowledge of the system, its components, and how they fail by casting the underlying physical phenomena in a physics-based model that is derived from first principles. Uncertainty cannot be avoided in prediction, therefore, algorithms are employed that help in managing these uncertainties. The particle filtering algorithm has become a popular choice for model-based prognostics due to its wide applicability, ease of implementation, and support for uncertainty management. We develop a general model-based prognostics methodology within a robust probabilistic framework using particle filters. As a case study, we consider a pneumatic valve from the Space Shuttle cryogenic refueling system. We develop a detailed physics-based model of the pneumatic valve, and perform comprehensive simulation experiments to illustrate our prognostics approach and evaluate its effectiveness and robustness. The approach is demonstrated using historical pneumatic valve data from the refueling system.

  4. Medulloblastoma: evaluation of proliferative index by monoclonal antibody Mib-1, its prognostic correlation and therapeutic implications

    Directory of Open Access Journals (Sweden)

    Ferrari Antonio Fernandes

    2003-01-01

    Full Text Available In the past few years, the monoclonal antibody MIB-1 has been used by researchers in order to retrospectively study paraffin imbibed tumor fragments. The medulloblastoma is the most common malignant central nervous system tumor in childhood. The objectives were: determination of the mean Mib-1 LI value from these patients, as well as the prognostic value of the method.This retrospective study represents an analysis of the cellular proliferation index of posterior fossa medulloblastomas collected from 22 patients at A.C. Camargo Hospital, from January 1990 to December 1999. The histopathological diagnosis was confirmed by H&E and proliferative index (LI was achived with Mib-1 which detects proliferating cells during G1, G2, S and M phases.The results demostrated that the mean Mib-1 was 30,1%, and ranged from 5,2% to 62,0%.In conclusion, this method has prognostic value, has to be used as routine for patients harboring medulloblastomas and the ones who have PI greater than the mean value found in this study, should be treated aggressively.

  5. An intelligent prognostic system for analyzing patients with paraquat poisoning using arterial blood gas indexes.

    Science.gov (United States)

    Hu, Lufeng; Lin, Feiyan; Li, Huaizhong; Tong, Changfei; Pan, Zhifang; Li, Jun; Chen, Huiling

    The arterial blood gas (ABG) test is used to assess gas exchange in the lung, and the acid-base level in the blood. However, it is still unclear whether or not ABG test indexes correlate with paraquat (PQ) poisoning. This study investigates the predictive value of ABG tests in prognosing patients with PQ poisoning; it also identifies the most significant indexes of the ABG test. An intelligent machine learning-based system was established to effectively give prognostic analysis of patients with PQ poisoning based on ABG indexes. In the proposed system, an enhanced support vector machine combined with a feature selection strategy was developed to predict the risk status from a pool of 103 patients (56 males and 47 females); of these, 52 subjects were deceased and 51 patients were alive. The proposed method was rigorously evaluated against the real-life dataset in terms of accuracy, sensitivity, and specificity. Additionally, the feature selection was investigated to identify correlating factors for the risk status. The results demonstrated that there were significant differences in ABG indexes between deceased and alive subjects (p-value <0.01). According to the feature selection, we found that the most important correlated indexes were associated with partial pressure of carbon dioxide (PCO2). This study discovered the relationship between ABG test and poisoning degree to provide a new avenue for prognosing PQ poisoning. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Firm Sustainability Performance Index Modeling

    Directory of Open Access Journals (Sweden)

    Che Wan Jasimah Bt Wan Mohamed Radzi

    2015-12-01

    Full Text Available The main objective of this paper is to bring a model for firm sustainability performance index by applying both classical and Bayesian structural equation modeling (parametric and semi-parametric modeling. Both techniques are considered to the research data collected based on a survey directed to the China, Taiwan, and Malaysia food manufacturing industry. For estimating firm sustainability performance index we consider three main indicators include knowledge management, organizational learning, and business strategy. Based on the both Bayesian and classical methodology, we confirmed that knowledge management and business strategy have significant impact on firm sustainability performance index.

  7. Geriatric Nutritional Risk Index as a prognostic factor in peritoneal dialysis patients.

    Science.gov (United States)

    Kang, Seok Hui; Cho, Kyu Hyang; Park, Jong Won; Yoon, Kyung Woo; Do, Jun Young

    2013-01-01

    The Geriatric Nutritional Risk Index (GNRI) might be a useful screening tool for malnutrition in dialysis patients. However, data concerning the GNRI as a prognostic factor in peritoneal dialysis (PD) patients are scarce. We reviewed the medical records at Yeungnam University Hospital in Korea to identify all adults (>18 years) who received PD; 486 patients were enrolled in the study. The initial low, middle, and high GNRI tertiles included 162, 166, and 158 patients respectively. Significant correlations were noted between the initial GNRI and body mass index, creatinine, albumin, arm circumference, fat mass index, and comorbidities. The cut-off value for the time-averaged GNRI over 1 year was 96.4, and the sensitivity and specificity for a diagnosis of a decline in lean mass were 77.1% and 40.0% respectively. A multivariate analysis adjusted for age, risk according to the Davies comorbidity index, and C-reactive protein showed that an low initial GNRI tertile was associated with mortality in PD patients. The GNRI is a simple method for predicting nutrition status and clinical outcome in PD patients.

  8. Risk factors and prognostic models for perinatal asphyxia at term

    NARCIS (Netherlands)

    Ensing, S.

    2015-01-01

    This thesis will focus on the risk factors and prognostic models for adverse perinatal outcome at term, with a special focus on perinatal asphyxia and obstetric interventions during labor to reduce adverse pregnancy outcomes. For the majority of the studies in this thesis we were allowed to use data

  9. Preoperative prognostic nutritional index and nomogram predicting recurrence-free survival in patients with primary non-muscle-invasive bladder cancer without carcinoma in situ

    Directory of Open Access Journals (Sweden)

    Cui J

    2017-11-01

    Full Text Available Jianfeng Cui,1,* Shouzhen Chen,1,* Qiyu Bo,2 Shiyu Wang,1 Ning Zhang,1 Meng Yu,1 Wenfu Wang,1 Jie Han,3 Yaofeng Zhu,1 Benkang Shi1 1Department of Urology, 2Department of First Operating Room, Qilu Hospital of Shandong University, 3Department of Radiation Oncology, Shandong Cancer Hospital and Institute Affiliated to Shandong University, Jinan, People’s Republic of China *These authors contributed equally to this work Background and objectives: Among the cancers of the urogenital system, bladder cancer is ranked second both in incidence and mortality, and hence, a more accurate estimate of the prognosis for individual patients with non-muscle-invasive bladder cancer (NMIBC is urgently needed. Prognostic nutritional index (PNI which is based on serum albumin levels and peripheral lymphocyte count has been confirmed to have prognostic value in various cancers. The aim of this study was to clarify the prognostic value of PNI in patients with NMIBC.Methods: Data of 329 patients with NMIBC were evaluated retrospectively. Recurrence-free survival (RFS was assessed using the Kaplan–Meier method, and the equivalences of survival curves were tested by log-rank tests. The univariate and multivariate analyses were performed using the Cox proportional hazards regression model. Discrimination of the nomogram was measured by the concordance index. A p-value of <0.05 was considered statistically significant.Results: In univariate analysis, age, tumor focality, tumor size, tumor grade, pathological T stage and preoperative PNI were significantly associated with RFS. Multivariate analysis identified PNI as an independent predictor of RFS in patients with NMIBC. According to these independent predictors, a nomogram for the prediction of recurrence was developed.Conclusion: PNI can be regarded as an independent prognostic factor for predicting RFS in NMIBC. The nomogram could be useful to improve personalized therapy for patients with NMIBC. Keywords: non

  10. Validation, revision and extension of the mantle cell lymphoma international prognostic index in a population-based setting

    NARCIS (Netherlands)

    S.A.M. van de Schans (Saskia); M.L.G. Janssen-Heijnen (Maryska); M.R. Nijzie (Marten); E.W. Steyerberg (Ewout); D.J. van Spronsen (Dick Johan)

    2010-01-01

    textabstractBackground The aim of this study was to validate the Mantle Cell Lymphoma International Prognostic Index in a population-based cohort and to study the relevance of its revisions. Design and Methods We analyzed data from 178 unselected patients with stage III or IV mantle cell lymphoma,

  11. Prognostic Nutritional Index and the Risk of Mortality in Patients With Acute Heart Failure.

    Science.gov (United States)

    Cheng, Yu-Lun; Sung, Shih-Hsien; Cheng, Hao-Min; Hsu, Pai-Feng; Guo, Chao-Yu; Yu, Wen-Chung; Chen, Chen-Huan

    2017-06-25

    Nutritional status has been related to clinical outcomes in patients with heart failure. We assessed the association between nutritional status, indexed by prognostic nutritional index (PNI), and survival in patients hospitalized for acute heart failure. A total of 1673 patients (age 76±13 years, 68% men) hospitalized for acute heart failure in a tertiary medical center were analyzed. PNI was calculated as 10×serum albumin (g/dL)+0.005×total lymphocyte count (per mm(3)). National Death Registry was linked to identify the clinical outcomes of all-cause and cardiovascular death. With increasing tertiles of PNI, age and N-terminal probrain natriuretic peptide decreased, and body mass index, estimated glomerular filtration rate, and hemoglobin increased. During a mean follow-up duration of 31.5 months, a higher PNI tertile was related to better survival free from all-cause and cardiovascular mortality in the total study population and in participants with either reduced or preserved left ventricular ejection fraction. After accounting for age, sex, estimated glomerular filtration rate, left ventricular ejection fraction, serum sodium level, and on-admission systolic blood pressure, PNI was independently associated with cardiovascular death and total mortality (hazard ratio per 1 SD of the natural logarithm of the PNI: 0.76 [95% CI, 0.66-0.87] and 0.79 [95% CI, 0.73-0.87], respectively). In subgroup analyses stratified by age, sex, left ventricular ejection fraction, body mass index, or estimated glomerular filtration rate, PNI was consistently related to mortality. PNI is independently associated with long-term survival in patients hospitalized for acute heart failure with either reduced or preserved left ventricular ejection fraction. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

  12. The prognostic value of pulmonary embolism severity index in acute pulmonary embolism: a meta-analysis

    Science.gov (United States)

    2012-01-01

    Background Prognostic assessment is important for the management of patients with acute pulmonary embolism (APE). Pulmonary Embolism Severity Index (PESI) and simple PESI (sPESI) are new emerged prognostic assessment tools for APE. The aim of this meta-analysis is to assess the accuracy of the PESI and the sPESI to predict prognostic outcomes (all-cause and PE-related mortality, serious adverse events) in APE patients, and compare between these two PESIs. Methods MEDLINE and EMBASE database were searched up to June 2012 using the terms “Pulmonary Embolism Severity Index” and “pulmonary embolism”. Summary odds ratio (OR) with 95% confidence intervals (CIs) for prognostic outcomes in low risk PESI versus high risk PESI were calculated. Summary receiver operating characteristic curve (SROC) used to estimate overall predicting accuracies of prognostic outcomes. Results Twenty-one studies were included in this meta-analysis. The results showed low-risk PESI was significantly associated with lower all-cause mortality (OR 0.13; 95% CI 0.12 to 0.15), PE-related mortality (OR 0.09; 95% CI 0.05 to 0.17) and serious adverse events (OR 0.34; 95% CI 0.29 to 0.41), with no homogeneity across studies. In sPESI subgroup, the OR of all-cause mortality, PE-related mortality, and serious adverse events was 0.10 (95% CI 0.08 to 0.14), 0.09 (95% CI 0.03 to 0.26) and 0.40 (95% CI 0.31 to 0.51), respectively; while in PESI subgroup, the OR was 0.14 (95% CI 0.13 to 0.16), 0.09 (95% CI 0.04 to 0.21), and 0.30 (95% CI 0.23 to 0.38), respectively. For accuracy analysis, the pooled sensitivity, the pooled specificity, and the overall weighted AUC for PESI predicting all-cause mortality was 0.909 (95% CI: 0.900 to 0.916), 0.411 (95% CI: 0.407 to 0.415), and 0.7853±0.0058, respectively; for PE-related mortality, it was 0.953 (95% CI: 0.913 to 0.978), 0.374 (95% CI: 0.360 to 0.388), and 0.8218±0.0349, respectively; for serious adverse events, it was 0.821 (95% CI: 0.795 to 0.845), 0

  13. [Leuko-glycemic index as an in-hospital prognostic marker in patients with ST-segment elevation myocardial infarction].

    Science.gov (United States)

    León-Aliz, Ebrey; Moreno-Martínez, Francisco L; Pérez-Fernández, Guillermo A; Vega-Fleites, Luis F; Rabassa-López-Calleja, Magda A

    2014-01-01

    Blood glucose and white blood cell count on admission have demonstrated prognostic significance in patients with myocardial infarction; leuko-glycemic index, a recently proposed marker, still lacks enough knowledge about its value. To evaluate the leuko-glycemic index as a prognostic marker in patients with ST-segment elevation myocardial infarction. A retrospective study was carried out in 128 patients with ST-segment elevation myocardial infarction, who were admitted between January 2009 and October 2010 in the Intensive Care Unit of the Hospital Dr. Celestino Hernández Robau. Clinical and laboratory data were collected, including glucose and white blood cell count on admission, from which we calculated the leuko-glycemic index and we evaluated its prognostic value. Patients who had a poor outcome such as death, major cardiac complications and failed-thrombolysis, showed higher values of leuko-glycemic index (Pglycemic index was an independent predictor after multivariate analysis. The leuko-glycemic index was associated with an increased occurrence of hospital complications, death and failed-thrombolysis; its pathological value was an independent predictor of in-hospital death and complications in the studied sample. Copyright © 2013 Sociedad Española de Arteriosclerosis. Published by Elsevier España. All rights reserved.

  14. Prognostic value of brachioradialis muscle oxygen saturation index and vascular occlusion test in septic shock patients.

    Science.gov (United States)

    Marín-Corral, J; Claverias, L; Bodí, M; Pascual, S; Dubin, A; Gea, J; Rodriguez, A

    2016-05-01

    To compare rSO2 (muscle oxygen saturation index) static and dynamic variables obtained by NIRS (Near Infrared Spectroscopy) in brachioradialis muscle of septic shock patients and its prognostic implications. Prospective and observational study. Intensive care unit. Septic shock patients and healthy volunteers. The probe of a NIRS device (INVOS 5100) was placed on the brachioradialis muscle during a vascular occlusion test (VOT). Baseline, minimum and maximum rSO2 values, deoxygenation rate (DeOx), reoxygenation slope (ReOx) and delta value. Septic shock patients (n=35) had lower baseline rSO2 (63.8±12.2 vs. 69.3±3.3%, p<0.05), slower DeOx (-0.54±0.31 vs. -0.91±0.35%/s, p=0.001), slower ReOx (2.67±2.17 vs. 9.46±3.5%/s, p<0.001) and lower delta (3.25±5.71 vs. 15.1±3.9%, p<0.001) when compared to healthy subjects (n=20). Among septic shock patients, non-survivors showed lower baseline rSO2 (57.0±9.6 vs. 69.8±11.3%, p=0.001), lower minimum rSO2 (36.0±12.8 vs. 51.3±14.8%, p<0.01) and lower maximum rSO2 values (60.6±10.6 vs. 73.3±11.2%, p<0.01). Baseline rSO2 was a good mortality predictor (AUC 0.79; 95%CI: 0.63-0.94, p<0.01). Dynamic parameters obtained with VOT did not improve the results. Septic shock patients present an important alteration of microcirculation that can be evaluated by NIRS with prognostic implications. Monitoring microvascular reactivity in the brachioradialis muscle using VOT with our device does not seem to improve the prognostic value of baseline rSO2. Copyright © 2015 Elsevier España, S.L.U. and SEMICYUC. All rights reserved.

  15. Prognostic value of an increase in post-exercise ankle-brachial index.

    Science.gov (United States)

    Hammad, Tarek A; Hiatt, William R; Gornik, Heather L; Shishehbor, Mehdi H

    2017-06-01

    Prior studies have assessed the prognostic value of a decrease, not an increase, of the post-exercise ankle-brachial index (ABI) among patients with normal resting results. Thus, we sought to evaluate the prognostic significance of an increase in post-exercise ABI among these patients. From a single center vascular laboratory database between September 2005 and January 2010, we retrospectively identified 1437 consecutive patients with a normal resting ABI (1.00-1.40) and available post-exercise results. We classified them into group 1 (normal subjects; post-exercise ABI drop ⩽ 20%, 58%) and group 2 (post-exercise ABI increase, 42%) after excluding those with an ABI drop > 20% (peripheral artery disease) as they had known disease ( n=192). The primary outcome was to assess the risk of ischemic events, defined as a composite of unadjudicated death, stroke, or myocardial infraction (MACE). Associations between groups and outcomes were examined using multivariable Cox proportional hazard and propensity analyses. Both groups had similar prevalence of cardiovascular comorbidities. In unadjusted analysis, group 2 was more likely to have MACE ( p = 0.001). After adjusting for all baseline characteristics, an increase in post-exercise ABI compared to normal subjects was associated with a higher MACE (adjusted HR: 1.70, 95% CI: 1.14-2.53; p=0.009). This association stayed statistically significant after propensity matching (adjusted HR: 1.80, 95% CI: 1.17-2.76; p=0.007). This hypothesis-generating analysis showed that an increase in post-exercise ABI appears to identify a population with a higher risk for MACE. A prospective study of this association and mechanisms of risk should be conducted.

  16. Model Adaptation for Prognostics in a Particle Filtering Framework

    Directory of Open Access Journals (Sweden)

    Bhaskar Saha

    2011-01-01

    Full Text Available One of the key motivating factors for using particle filters for prognostics is the ability to include model parameters as part of the state vector to be estimated. This performs model adaptation in conjunction with state tracking, and thus, produces a tuned model that can used for long term predictions. This feature of particle filters works in most part due to the fact that they are not subject to the “curse of dimensionality”, i.e. the exponential growth of computational complexity with state dimension. However, in practice, this property holds for “well-designed” particle filters only as dimensionality increases. This paper explores the notion of wellness of design in the context of predicting remaining useful life for individual discharge cycles of Li-ion and Li-Polymer batteries. Prognostic metrics are used to analyze the tradeoff between different model designs and prediction performance. Results demonstrate how sensitivity analysis may be used to arrive at a well-designed prognostic model that can take advantage of the model adaptation properties of a particle filter.

  17. Model Adaptation for Prognostics in a Particle Filtering Framework

    Science.gov (United States)

    Saha, Bhaskar; Goebel, Kai Frank

    2011-01-01

    One of the key motivating factors for using particle filters for prognostics is the ability to include model parameters as part of the state vector to be estimated. This performs model adaptation in conjunction with state tracking, and thus, produces a tuned model that can used for long term predictions. This feature of particle filters works in most part due to the fact that they are not subject to the "curse of dimensionality", i.e. the exponential growth of computational complexity with state dimension. However, in practice, this property holds for "well-designed" particle filters only as dimensionality increases. This paper explores the notion of wellness of design in the context of predicting remaining useful life for individual discharge cycles of Li-ion batteries. Prognostic metrics are used to analyze the tradeoff between different model designs and prediction performance. Results demonstrate how sensitivity analysis may be used to arrive at a well-designed prognostic model that can take advantage of the model adaptation properties of a particle filter.

  18. Performance of the Multidimensional Geriatric Assessment and Multidimensional Prognostic Index in predicting negative outcomes in older adults with cancer.

    Science.gov (United States)

    Giantin, V; Falci, C; De Luca, E; Valentini, E; Iasevoli, M; Siviero, P; Maggi, S; Martella, B; Crepaldi, G; Monfardini, S; Manzato, E

    2018-01-01

    The Multidimensional Geriatric Assessment (MGA) is currently used for assessing geriatric oncological patients, but a new prognostic index - the Multidimensional Prognostic Index (MPI) - has a demonstrated prognostic value in cancer patients too. The present work was designed to compare the MPI and MGA as predictors of 12-month mortality. 160 patients ≥70 years old with locally-advanced or metastatic solid cancers consecutively joining our Geriatric Oncology Program were administered a Comprehensive Geriatric Assessment to calculate their MGA and MPI scores. Geriatric Clinic, Geriatric Surgery Clinic, Medical Oncology Unit, Padova Hospital, Italy. Using Cohen's Kappa coefficient, there was a poor concordance between the MPI and MGA. Severe MPI being associated with a higher mortality risk than Frail in the MGA. The ROC curves indicated that the MPI had a greater discriminatory power for 12-month mortality than the MGA. In our population of elderly cancer patients, the MPI performed better than the MGA in predicting mortality. Further evidence from larger prospective trials is needed to establish whether other geriatric scales, such as the GDS and CIRS-SI, could enhance the value of prognostic indexes applied to elderly cancer patients. © 2016 John Wiley & Sons Ltd.

  19. Prospective clarification of the utility of the palliative prognostic index for patients with advanced cancer in the home care setting.

    Science.gov (United States)

    Hamano, Jun; Kizawa, Yoshiyuki; Maeno, Takami; Nagaoka, Hiroka; Shima, Yasuo; Maeno, Tetsuhiro

    2014-12-01

    This study aimed to prospectively clarify the accuracy of the Palliative Prognostic Index (PPI) for advanced cancer patients in home care settings. The study included 66 advanced cancer patients who received home visiting services between April 2010 and June 2012, and who died at home or in the hospital. Using medical records from initial home visits, we prospectively calculated PPI scores along with sensitivity and specificity. For 3- and 6-week survival, prognostic prediction showed respective sensitivities of 60% and 70.6%, and specificities of 87.0% and 71.9%. The sensitivity of the PPI for advanced cancer patients in home care settings was lower than that reported for patients in palliative care units. Development of prognostic tools suitable for home care settings is needed. © The Author(s) 2013.

  20. Electrochemistry-based Battery Modeling for Prognostics

    Science.gov (United States)

    Daigle, Matthew J.; Kulkarni, Chetan Shrikant

    2013-01-01

    Batteries are used in a wide variety of applications. In recent years, they have become popular as a source of power for electric vehicles such as cars, unmanned aerial vehicles, and commericial passenger aircraft. In such application domains, it becomes crucial to both monitor battery health and performance and to predict end of discharge (EOD) and end of useful life (EOL) events. To implement such technologies, it is crucial to understand how batteries work and to capture that knowledge in the form of models that can be used by monitoring, diagnosis, and prognosis algorithms. In this work, we develop electrochemistry-based models of lithium-ion batteries that capture the significant electrochemical processes, are computationally efficient, capture the effects of aging, and are of suitable accuracy for reliable EOD prediction in a variety of usage profiles. This paper reports on the progress of such a model, with results demonstrating the model validity and accurate EOD predictions.

  1. Mannheim Peritonitis Index (MPI) and elderly population: prognostic evaluation in acute secondary peritonitis.

    Science.gov (United States)

    Salamone, G; Licari, L; Falco, N; Augello, G; Tutino, R; Campanella, S; Guercio, G; Gulotta, G

    2016-01-01

    Acute Secondary Peritonitis due to abdominal visceral perforation is characterized by high mortality and morbidity risk. Risk stratification allows prognosis prediction to adopt the best surgical treatment and clinical care support therapy. In Western countries elderly people represent a significant percentage of population Aim. Evaluation of Mannheim Peritonitis Index (MPI) and consideration upon old people. Retrospective study on 104 patients admitted and operated for "Acute Secondary Peritonitis due to visceral perforation". MPI was scored. In our study we want to demonstrate efficacy of MPI and the possibility to consider older age an independent prognostic factor. Mortality was 25.96%. Greatest sensitivity and specificity for the MPI score as a predictor of mortality was at the score of 20. MPI score of 22. Patients with MPI score 17-21 had 0.46 times lower risk of mortality compared to patients with MPI score >21. In the group of patients with MPI score of >20 the mortality rate was 48.5% for patients older than 80 years old and 12.1% for younger patients (p < 0.005); in the group with MPI score of < 20 mortality rate was respectively 8.4% and 1.4% (p < 0.005). Data confirm the accuracy of the test. MPI score and age over 80 years old resulted independent predictors of mortality at multivariate analysis.

  2. Prognosis Prediction for Postoperative Esophageal Cancer Patients Using Onodera's Prognostic Nutritional Index.

    Science.gov (United States)

    Matsumoto, Hideo; Okamoto, Yuko; Kawai, Akimasa; Ueno, Daisuke; Kubota, Hisako; Murakami, Haruaki; Higashida, Masaharu; Hirai, Toshihiro

    2017-01-01

    Preoperative nutritional status may impact surgical outcome and prognosis. We evaluated the predictive value of Onodera's prognostic nutritional index (O's-PNI) of surgical outcome following esophagectomy in esophageal cancer patients. In total, 144 patients undergoing esophagectomy for esophageal cancer from April 2010 to May 2015 were evaluated, retrospectively. Eighty-four patients were enrolled in this study. O's-PNIs were calculated before surgery, discharge, and 1, 2, and 6 mo after discharge. The relationship between O's-PNI and occurrence of complications as classified by the Clavien-Dindo (C-D) classification, length of hospital stay, and survival time was investigated. The mean O's-PNI for patients with complications of more than Grade 2 by the C-D classification was 37.4, which was significantly lower than that for Grades 0 or 1 (40.5, P = 0.0094). A negative correlation was obtained between O's-PNI and hospital stay length (P = 0.0006), whereas a positive correlation was obtained for O's-PNI at 6 mo postsurgery and overall survival (P = 0.0171, P = 0.0201). O's-PNI may represent a useful indicator of the occurrence of complications and length of hospital stay, and may influence overall survival at 6 mo postsurgery. Nutritional management during the perioperative period could therefore contribute to satisfactory outcomes following esophagectomy in esophageal cancer patients.

  3. Prognostic Value of the Nutritional Risk Index in Heart Transplant Recipients.

    Science.gov (United States)

    Barge-Caballero, Eduardo; García-López, Fernando; Marzoa-Rivas, Raquel; Barge-Caballero, Gonzalo; Couto-Mallón, David; Paniagua-Martín, María J; Solla-Buceta, Miguel; Velasco-Sierra, Carlos; Pita-Gutiérrez, Francisco; Herrera-Noreña, José M; Cuenca-Castillo, José J; Vázquez-Rodríguez, José Manuel; Crespo-Leiro, María G

    2017-08-01

    To study the prognostic impact of preoperative nutritional status, as assessed through the nutritional risk index (NRI), on postoperative outcomes after heart transplantation (HT). We conducted a retrospective, single-center study of 574 patients who underwent HT from 1991 to 2014. Preoperative NRI was calculated as 1.519 × serum albumin (g/L) + 41.7 × (body weight [kg] / ideal body weight [kg]). The association between preoperative NRI and postoperative outcomes was analyzed by means of multivariable logistic regression and multivariable Cox regression. Mean NRI before HT was 100.9 ± 9.9. According to this parameter, the prevalence of severe nutritional risk (NRI nutritional risk (83.5 ≤ NRI nutritional risk (97.5 ≤ NRI risk of postoperative infection (adjusted OR, 0.97; 95%CI, 0.95-1.00; P = .027) and prolonged postoperative ventilator support (adjusted OR, 0.96; 95%CI, 0.94-0.98; P = .001). Patients at moderate or severe nutritional risk had significantly higher 1-year post-HT mortality (adjusted HR, 1.55; 95%CI, 1.22-1.97; P risk of postoperative complications and mortality after HT. Preoperative NRI determination may help to identify HT candidates who might benefit from nutritional intervention. Copyright © 2016 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

  4. Prognostic model for survival in patients with metastatic renal cell carcinoma: results from the international kidney cancer working group.

    Science.gov (United States)

    Manola, Judith; Royston, Patrick; Elson, Paul; McCormack, Jennifer Bacik; Mazumdar, Madhu; Négrier, Sylvie; Escudier, Bernard; Eisen, Tim; Dutcher, Janice; Atkins, Michael; Heng, Daniel Y C; Choueiri, Toni K; Motzer, Robert; Bukowski, Ronald

    2011-08-15

    To develop a single validated model for survival in metastatic renal cell carcinoma (mRCC) using a comprehensive international database. A comprehensive database of 3,748 patients including previously reported clinical prognostic factors was established by pooling patient-level data from clinical trials. Following quality control and standardization, descriptive statistics were generated. Univariate analyses were conducted using proportional hazards models. Multivariable analysis using a log-logistic model stratified by center and multivariable fractional polynomials was conducted to identify independent predictors of survival. Missing data were handled using multiple imputation methods. Three risk groups were formed using the 25th and 75th percentiles of the resulting prognostic index. The model was validated using an independent data set of 645 patients treated with tyrosine kinase inhibitor (TKI) therapy. Median survival in the favorable, intermediate and poor risk groups was 26.9 months, 11.5 months, and 4.2 months, respectively. Factors contributing to the prognostic index included treatment, performance status, number of metastatic sites, time from diagnosis to treatment, and pretreatment hemoglobin, white blood count, lactate dehydrogenase, alkaline phosphatase, and serum calcium. The model showed good concordance when tested among patients treated with TKI therapy (C statistic = 0.741, 95% CI: 0.714-0.768). Nine clinical factors can be used to model survival in mRCC and form distinct prognostic groups. The model shows utility among patients treated in the TKI era. ©2011 AACR.

  5. A Physics-Based Modeling Framework for Prognostic Studies

    Science.gov (United States)

    Kulkarni, Chetan S.

    2014-01-01

    Prognostics and Health Management (PHM) methodologies have emerged as one of the key enablers for achieving efficient system level maintenance as part of a busy operations schedule, and lowering overall life cycle costs. PHM is also emerging as a high-priority issue in critical applications, where the focus is on conducting fundamental research in the field of integrated systems health management. The term diagnostics relates to the ability to detect and isolate faults or failures in a system. Prognostics on the other hand is the process of predicting health condition and remaining useful life based on current state, previous conditions and future operating conditions. PHM methods combine sensing, data collection, interpretation of environmental, operational, and performance related parameters to indicate systems health under its actual application conditions. The development of prognostics methodologies for the electronics field has become more important as more electrical systems are being used to replace traditional systems in several applications in the aeronautics, maritime, and automotive fields. The development of prognostics methods for electronics presents several challenges due to the great variety of components used in a system, a continuous development of new electronics technologies, and a general lack of understanding of how electronics fail. Similarly with electric unmanned aerial vehicles, electrichybrid cars, and commercial passenger aircraft, we are witnessing a drastic increase in the usage of batteries to power vehicles. However, for battery-powered vehicles to operate at maximum efficiency and reliability, it becomes crucial to both monitor battery health and performance and to predict end of discharge (EOD) and end of useful life (EOL) events. We develop an electrochemistry-based model of Li-ion batteries that capture the significant electrochemical processes, are computationally efficient, capture the effects of aging, and are of suitable

  6. Adding items that assess changes in activities of daily living does not improve the predictive accuracy of the Palliative Prognostic Index.

    Science.gov (United States)

    Hamano, Jun; Tokuda, Yasuharu; Kawagoe, Shohei; Shinjo, Takuya; Shirayama, Hiroto; Ozawa, Taketoshi; Shishido, Hideki; Otomo, Sen; Nagayama, Jun; Baba, Mika; Tei, Yo; Hiramoto, Shuji; Suga, Akihiko; Hisanaga, Takayuki; Ishihara, Tatsuhiko; Iwashita, Tomoyuki; Kaneishi, Keisuke; Kuriyama, Toshiyuki; Maeda, Takashi; Morita, Tatsuya

    2017-03-01

    Changes in activities of daily living in cancer patients may predict their survival. The Palliative Prognostic Index is a useful tool to evaluate cancer patients, and adding an item about activities of daily living changes might improve its predictive value. To clarify whether adding an item about activities of daily living changes improves the accuracy of Palliative Prognostic Index. Multicenter prospective cohort study. A total of 58 palliative care services in Japan. Patients aged >20 years diagnosed with locally extensive or metastatic cancer (including hematological neoplasms) who had been admitted to palliative care units, were receiving care by hospital-based palliative care teams, or were receiving home-based palliative care. Palliative care physicians recorded clinical variables at the first assessment and followed up patients 6 months later. A total of 2425 subjects were recruited and 2343 of these had analyzable data. The C-statistic of the original Palliative Prognostic Index was 0.801, and those of modified Palliative Prognostic Indices ranged from 0.793 to 0.805 at 3 weeks. For 6-week survival predictions, the C-statistic of the original Palliative Prognostic Index was 0.802, and those of modified Palliative Prognostic Indices ranged from 0.791 to 0.799. The weighted kappa of the original Palliative Prognostic Index was 0.510, and those of modified Palliative Prognostic Indices ranged from 0.484 to 0.508. Adding items about activities of daily living changes to the Palliative Prognostic Index did not improve prognostic value in advanced cancer patients.

  7. External validation of prognostic models to predict risk of gestational diabetes mellitus in one Dutch cohort: prospective multicentre cohort study.

    Science.gov (United States)

    Lamain-de Ruiter, Marije; Kwee, Anneke; Naaktgeboren, Christiana A; de Groot, Inge; Evers, Inge M; Groenendaal, Floris; Hering, Yolanda R; Huisjes, Anjoke J M; Kirpestein, Cornel; Monincx, Wilma M; Siljee, Jacqueline E; Van 't Zelfde, Annewil; van Oirschot, Charlotte M; Vankan-Buitelaar, Simone A; Vonk, Mariska A A W; Wiegers, Therese A; Zwart, Joost J; Franx, Arie; Moons, Karel G M; Koster, Maria P H

    2016-08-30

     To perform an external validation and direct comparison of published prognostic models for early prediction of the risk of gestational diabetes mellitus, including predictors applicable in the first trimester of pregnancy.  External validation of all published prognostic models in large scale, prospective, multicentre cohort study.  31 independent midwifery practices and six hospitals in the Netherlands.  Women recruited in their first trimester (diabetes mellitus of any type were excluded.  Discrimination of the prognostic models was assessed by the C statistic, and calibration assessed by calibration plots.  3723 women were included for analysis, of whom 181 (4.9%) developed gestational diabetes mellitus in pregnancy. 12 prognostic models for the disorder could be validated in the cohort. C statistics ranged from 0.67 to 0.78. Calibration plots showed that eight of the 12 models were well calibrated. The four models with the highest C statistics included almost all of the following predictors: maternal age, maternal body mass index, history of gestational diabetes mellitus, ethnicity, and family history of diabetes. Prognostic models had a similar performance in a subgroup of nulliparous women only. Decision curve analysis showed that the use of these four models always had a positive net benefit.  In this external validation study, most of the published prognostic models for gestational diabetes mellitus show acceptable discrimination and calibration. The four models with the highest discriminative abilities in this study cohort, which also perform well in a subgroup of nulliparous women, are easy models to apply in clinical practice and therefore deserve further evaluation regarding their clinical impact. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  8. Beyond Body Mass Index. Is the Body Cell Mass Index (BCMI) a useful prognostic factor to describe nutritional, inflammation and muscle mass status in hospitalized elderly?: Body Cell Mass Index links in elderly.

    Science.gov (United States)

    Rondanelli, Mariangela; Talluri, Jacopo; Peroni, Gabriella; Donelli, Chiara; Guerriero, Fabio; Ferrini, Krizia; Riggi, Emilia; Sauta, Elisabetta; Perna, Simone; Guido, Davide

    2017-03-24

    The aim of this study was to establish the effectiveness of Body Cell Mass Index (BCMI) as a prognostic index of (mal)nutrition, inflammation and muscle mass status in the elderly. A cross-sectional observational study has been conducted on 114 elderly patients (80 women and 34 men), with mean age equal to 81.07 ± 6.18 years. We performed a multivariate regression model by Structural Equation Modelling (SEM) framework. We detected the effects over a Mini Nutritional Assessment (MNA) stratification, by performing a multi-group multivariate regression model (via SEM) in two MNA nutritional strata, less and bigger (or equal) than 17. BCMI had a significant effect on albumin (β = +0.062, P = 0.001), adjusting for the other predictors of the model as Body Mass Index (BMI), age, sex, fat mass and cognitive condition. An analogous result is maintained in MNAmass (FFM) (β = +0.480, P Index (SMI) (β = +0.265, P < 0.001), assessed by DXA. BCMI also returned suggestive evidences (0.05 < P < 0.10) for both the effect on FFM and on SMI in overall sample. The main result of this study is that the BCMI, compared to BMI, proved to be significantly related to an important marker as albumin in geriatric population. Then, assessing the BCMI could be a valuable, inexpensive, easy to perform tool to investigate the inflammation status of elderly patients. Copyright © 2017 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

  9. Confirmation of the mantle-cell lymphoma International Prognostic Index in randomized trials of the European Mantle-Cell Lymphoma Network

    DEFF Research Database (Denmark)

    Hoster, Eva; Klapper, Wolfram; Hermine, Olivier

    2014-01-01

    PURPOSE: Mantle-cell lymphoma (MCL) is a distinct B-cell lymphoma associated with poor outcome. In 2008, the MCL International Prognostic Index (MIPI) was developed as the first prognostic stratification tool specifically directed to patients with MCL. External validation was planned.......9) and 2.6 (2.0 to 3.3), respectively. MIPI was similarly prognostic for TTF. All four clinical baseline characteristics constituting the MIPI, age, performance status, lactate dehydrogenase level, and WBC count, were confirmed as independent prognostic factors for OS and TTF. The validity of MIPI...

  10. Prognostic value of the bone scan index using a computer-aided diagnosis system for bone scans in hormone-naive prostate cancer patients with bone metastases.

    Science.gov (United States)

    Miyoshi, Yasuhide; Yoneyama, Shuko; Kawahara, Takashi; Hattori, Yusuke; Teranishi, Jun-ichi; Kondo, Keiichi; Moriyama, Masatoshi; Takebayashi, Shigeo; Yokomizo, Yumiko; Yao, Masahiro; Uemura, Hiroji; Noguchi, Kazumi

    2016-02-19

    The bone scan index (BSI) using a computer-aided diagnosis system for bone scans is expected to be an objective and quantitative clinical tool for evaluating bone metastatic prostate cancer. This study aimed to evaluate the pretreatment BSI as a prognostic factor in hormone-naive prostate cancer patients with bone metastases. The study included 60 patients with hormone-naive, bone metastatic prostate cancer that was initially treated with combined androgen blockade therapy. The BONENAVI system was used for calculating the BSI. We evaluated the correlation between overall survival (OS) and pretreatment clinicopathological characteristics, including patients' age, initial prostate-specific antigen (PSA) value, Gleason scores, clinical TNM stage, and the BSI. Cox proportional hazards regression models were used for statistical analysis. The median follow-up duration was 21.4 months. Clinical or PSA progression occurred in 37 (61.7%) patients and 18 (30.0%) received docetaxel. Death occurred in 16 (26.7%) patients. Of these deaths, 15 (25.0%) were due to prostate cancer. The median OS was not reached. In multivariate analysis, age and the BSI were independent prognostic factors for OS. We evaluated the discriminatory ability of our models, including or excluding BSI by quantifying the C-index. The BSI improved the C-index from 0.751 to 0.801 for OS. Median OS was not reached in patients with a BSI ≤ 1.9 and median OS was 34.8 months in patients with a BSI >1.9 (p = 0.039). The pretreatment BSI and patients' age are independent prognostic factors for patients with hormone-naive, bone metastatic prostate cancer.

  11. The preoperative alkaline phosphatase-to-platelet ratio index is an independent prognostic factor for hepatocellular carcinoma after hepatic resection.

    Science.gov (United States)

    Yu, Ya-Qun; Li, Jun; Liao, Yan; Chen, Qian; Liao, Wei-Jia; Huang, Jian

    2016-12-01

    A simple, inexpensive, and readily available prognostic index is highly needed to accurately predict the prognosis of hepatocellular carcinoma (HCC). This study aimed to develop a simple prognostic index using routine laboratory tests, alkaline phosphatase-to-platelet count ratio index (APPRI), to predict the likelihood of postoperative survival in HCC patients.A total of 246 patients with HCC undergoing curative resection were retrospectively analyzed. Cutoff point for APPRI was calculated using receiver operating characteristic curve analysis, and then the patients were divided into the low-APPRI group (APPRI ≤ 4.0) and the high-APPRI group (APPRI > 4.0). The influences of APPRI on disease-free survival (DFS) and overall survival (OS) were tested by the Kaplan-Meier method, and multivariate analysis using Cox regression. Elevated APPRI was associated with age, cirrhosis, and aspartate aminotransferase (AST) in HCC. Univariate analysis showed that APPRI > 4.0, tumor size >6 cm, multiple tumors, Barcelona-clinic liver cancer stages B to C, and AST > 40 U/L were significant predictors of worse DFS and OS. A multivariate analysis suggested that APPRI > 4.0 was an independent factor for DFS (hazard ratio [HR] = 1.689; 95% confidence interval [CI], 1.139-2.505; P = 0.009) and OS (HR = 1.664; 95% CI, 1.123-2.466; P = 0.011). Preoperative APPRI > 4.0 was a powerful prognostic predictor of adverse DFS and OS in HCC after surgery. The APPRI may be a promising prognostic marker for HCC after surgical resection.

  12. Development of an oncological-multidimensional prognostic index (Onco-MPI) for mortality prediction in older cancer patients.

    Science.gov (United States)

    Brunello, Antonella; Fontana, Andrea; Zafferri, Valeria; Panza, Francesco; Fiduccia, Pasquale; Basso, Umberto; Copetti, Massimiliano; Lonardi, Sara; Roma, Anna; Falci, Cristina; Monfardini, Silvio; Cella, Alberto; Pilotto, Alberto; Zagonel, Vittorina

    2016-05-01

    A multidimensional prognostic index (MPI) based on a comprehensive geriatric assessment (CGA) has been developed and validated in independent cohorts of older patients demonstrating good accuracy in predicting one-year mortality. The aim of this study was to develop a cancer-specific modified MPI (Onco-MPI) for mortality prediction in older cancer patients. We enrolled 658 new cancer subjects ≥70 years (mean age 77.1 years, 433 females, 65.8 %) attending oncological outpatient services from September 2004 to June 2011. The Onco-MPI was calculated according to a validated algorithm as a weighted linear combination of the following CGA domains: age, sex, basal and instrumental activities of daily living, Eastern Cooperative Oncology Group performance status, mini-mental state examination, body mass index, Cumulative Illness Rating Scale, number of drugs and the presence of caregiver. Cancer sites (breast 46.5 %, colorectal 21.3 %, lung 6.4 %, prostate 5.5 %, urinary tract 5.0 %, other 15.3 %) and cancer stages (I 37 %, II 22 %, III 19 %, IV 22 %) were also included in the model. All-cause mortality was recorded. Three grades of severity of the Onco-MPI score (low risk: 0.0-0.46, medium risk: 0.47-0.63, high risk: 0.64-1.0) were calculated using RECPAM method. Discriminatory power and calibration were assessed by estimating survival C-indices, along with 95 % confidence interval (CI) and the survival-based Hosmer-Lemeshow (HL) measures. One-year mortality incidence rate was 17.4 %. A significant difference in mortality rates was observed in Onco-MPI low risk compared to medium- and high-risk patients (2.1 vs. 17.7 vs. 80.8 %, p patients that can be useful for clinical decision making in this age group.

  13. Ki67 index is an independent prognostic factor in epithelioid but not in non-epithelioid malignant pleural mesothelioma: a multicenter study.

    Science.gov (United States)

    Ghanim, B; Klikovits, T; Hoda, M A; Lang, G; Szirtes, I; Setinek, U; Rozsas, A; Renyi-Vamos, F; Laszlo, V; Grusch, M; Filipits, M; Scheed, A; Jakopovic, M; Samarzija, M; Brcic, L; Stancic-Rokotov, D; Kern, I; Rozman, A; Dekan, G; Klepetko, W; Berger, W; Glasz, T; Dome, B; Hegedus, B

    2015-03-03

    Estimating the prognosis in malignant pleural mesothelioma (MPM) remains challenging. Thus, the prognostic relevance of Ki67 was studied in MPM. Ki67 index was determined in a test cohort of 187 cases from three centres. The percentage of Ki67-positive tumour cells was correlated with clinical variables and overall survival (OS). The prognostic power of Ki67 index was compared with other prognostic factors and re-evaluated in an independent cohort (n=98). Patients with Ki67 higher than median (>15%) had significantly (P<0.001) shorter median OS (7.5 months) than those with low Ki67 (19.1 months). After multivariate survival analyses, Ki67 proved to be-beside histology and treatment-an independent prognostic marker in MPM (hazard ratio (HR): 2.1, P<0.001). Interestingly, Ki67 was prognostic exclusively in epithelioid (P<0.001) but not in non-epithelioid subtype. Furthermore, Ki67 index was significantly lower in post-chemotherapy samples when compared with chemo-naive cases. The prognostic power was comparable to other recently published prognostic factors (CRP, fibrinogen, neutrophil-to-leukocyte ratio (NLR) and nuclear grading score) and was recapitulated in the validation cohort (P=0.048). This multicentre study demonstrates that Ki67 is an independent and reproducible prognostic factor in epithelioid but not in non-epithelioid MPM and suggests that induction chemotherapy decreases the proliferative capacity of MPM.

  14. A novel prognostic indicator for in-hospital and 4-year outcomes in patients with pulmonary embolism: TIMI risk index.

    Science.gov (United States)

    Keskin, Muhammed; Güvenç, Tolga Sinan; Hayıroğlu, Mert İlker; Kaya, Adnan; Tatlısu, Mustafa Adem; Avşar, Şahin; Öz, Ahmet; Keskin, Taha; Uzun, Ahmet Okan; Kozan, Ömer

    2017-10-01

    Thrombolysis in Myocardial Infarction (TIMI) risk index (TRI) was recently evaluated in patients with acute myocardial infarction and found as an important prognostic index. In the current study, we evaluated the prognostic value of TRI in patients with moderate-high and high risk pulmonary embolism (PE) who were treated with thrombolytic agents. We retrospectively evaluated the in-hospital and long-term (4-year) prognostic impact of TRI in a total number of 456 patients with moderate-high and high risk PE. Patients were stratified by quartiles (Q) of admission TRI. In-hospital analysis revealed significantly higher rates of in-hospital death for patients with TRI in Q4. After adjustment for confounding baseline variables, TRI in Q4 was associated with 2.8-fold hazard of in-hospital death. Upon multivariate analysis, admission TRI in Q4 vs. Q1-3 was associated with 3.1 fold hazard of 4-year mortality rate. TRI in Q4, as compared to Q1-3, was significantly predictive of short term and long-term outcomes in PE patients who treated with thrombolytic agents. Our data suggest TRI to be an independent, feasible, and cost-effective tool for rapid risk stratification in moderate-high and high risk PE patients who treated with thrombolytic agents. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Physics based Degradation Modeling and Prognostics of Electrolytic Capacitors under Electrical Overstress Conditions

    Data.gov (United States)

    National Aeronautics and Space Administration — This paper proposes a physics based degradation modeling and prognostics approach for electrolytic capacitors. Electrolytic capacitors are critical components in...

  16. Prognostics Health Management and Physics based failure Models for Electrolytic Capacitors

    Data.gov (United States)

    National Aeronautics and Space Administration — This paper proposes first principles based modeling and prognostics approach for electrolytic capacitors. Electrolytic capacitors and MOSFETs are the two major...

  17. Routine use of ancillary investigations in staging diffuse large B-cell lymphoma improves the International Prognostic Index (IPI).

    Science.gov (United States)

    Talaulikar, Dipti; Shadbolt, Bruce; Dahlstrom, Jane E; McDonald, Anne

    2009-11-22

    The International Prognostic Index (IPI) is used to determine prognosis in diffuse large B-cell lymphoma (DLBCL). One of the determinants of IPI is the stage of disease with bone marrow involvement being classified as stage IV. For the IPI, involvement on bone marrow is traditionally defined on the basis of histology with ancillary investigations used only in difficult cases to aid histological diagnosis. This study aimed to determine the effect of the routine use of flow cytometry, immunohistochemistry and molecular studies in bone marrow staging upon the IPI. Bone marrow trephines of 156 histologically proven DLBCL cases at initial diagnosis were assessed on routine histology, and immunohistochemistry using two T-cell markers (CD45RO and CD3), two B-cell markers (CD20 and CD79a) and kappa and lambda light chains. Raw flow cytometry data on all samples were reanalysed and reinterpreted blindly. DNA extracted from archived paraffin-embedded trephine biopsy samples was used for immunoglobulin heavy chain and light chain gene rearrangement analysis. Using immunophenotyping (flow cytometry and immunohistochemistry), 30 (19.2%) cases were upstaged to stage IV. A further 8 (5.1%) cases were upstaged using molecular studies. A change in IPI was noted in 18 cases (11.5%) on immunophenotyping alone, and 22 (14.1%) cases on immunophenotyping and molecular testing. Comparison of two revised IPI models, 1) using immunophenotyping alone, and 2) using immunophenotyping with molecular studies, was performed with baseline IPI using a Cox regression model. It showed that the revised IPI model using immunophenotyping provides the best differentiation between the IPI categories. Improved bone marrow staging using flow cytometry and immunohistochemistry improves the predictive value of the IPI in patients with DLBCL and should be performed routinely in all cases.

  18. Routine use of ancillary investigations in staging diffuse large B-cell lymphoma improves the International Prognostic Index (IPI

    Directory of Open Access Journals (Sweden)

    Shadbolt Bruce

    2009-11-01

    Full Text Available Abstract Background The International Prognostic Index (IPI is used to determine prognosis in diffuse large B-cell lymphoma (DLBCL. One of the determinants of IPI is the stage of disease with bone marrow involvement being classified as stage IV. For the IPI, involvement on bone marrow is traditionally defined on the basis of histology with ancillary investigations used only in difficult cases to aid histological diagnosis. This study aimed to determine the effect of the routine use of flow cytometry, immunohistochemistry and molecular studies in bone marrow staging upon the IPI. Results Bone marrow trephines of 156 histologically proven DLBCL cases at initial diagnosis were assessed on routine histology, and immunohistochemistry using two T-cell markers (CD45RO and CD3, two B-cell markers (CD20 and CD79a and kappa and lambda light chains. Raw flow cytometry data on all samples were reanalysed and reinterpreted blindly. DNA extracted from archived paraffin-embedded trephine biopsy samples was used for immunoglobulin heavy chain and light chain gene rearrangement analysis. Using immunophenotyping (flow cytometry and immunohistochemistry, 30 (19.2% cases were upstaged to stage IV. A further 8 (5.1% cases were upstaged using molecular studies. A change in IPI was noted in 18 cases (11.5% on immunophenotyping alone, and 22 (14.1% cases on immunophenotyping and molecular testing. Comparison of two revised IPI models, 1 using immunophenotyping alone, and 2 using immunophenotyping with molecular studies, was performed with baseline IPI using a Cox regression model. It showed that the revised IPI model using immunophenotyping provides the best differentiation between the IPI categories. Conclusion Improved bone marrow staging using flow cytometry and immunohistochemistry improves the predictive value of the IPI in patients with DLBCL and should be performed routinely in all cases.

  19. Evaluation of an Optimal Cut-Off Point for the Ki-67 Index as a Prognostic Factor in Primary Breast Cancer: A Retrospective Study.

    Directory of Open Access Journals (Sweden)

    Rumiko Tashima

    Full Text Available The Ki-67 index is an important biomarker for indicating the proliferation of cancer cells and is considered to be an effective prognostic factor for breast cancer. However, a standard cut-off point for the Ki-67 index has not yet been established. Therefore, the aim of this retrospective study was to determine an optimal cut-off point in order to establish it as a more accurate prognostic factor. Immunohistochemical analysis of the Ki-67 index was performed on 4329 patients with primary breast cancer from August 1987 to March 2012. Out of this sample, there were 3186 consecutive cases from September 1997 with simultaneous evaluations of ER, PgR and HER2 status. Cox's proportional hazard model was used to perform univariate and multivariate analyses of the factors related to OS. The hazard ratios (HR and the p values were then compared to determine the optimal cut-off point for the Ki-67 index. The median Ki-67 index value was 20.5% (mean value 26.2%. The univariate analysis revealed that there was a statistically significant negative correlation with DFS and OS and the multivariate analysis revealed that the Ki-67 index value was a significant factor for DFS and OS. The top seven cut-off points were then carefully chosen based on the results of the univariate analysis using the lowest p-values and the highest HR as the main selection criteria. The multivariate analysis of the factors for OS showed that the cut-off point of 20% had the highest HR in all of the cases. However, the cutoff point of 20% was only a significant factor for OS in the Luminal/HER2- subtype. There was no correlation between the Ki-67 index value and OS in any of the other subtypes. These data indicate that the optimal cut-off point of 20% is the most effective prognostic factor for Luminal/HER2- breast cancer.

  20. Geoinformational prognostic model of mudflows hazard and mudflows risk for the territory of Ukrainian Carpathians

    Science.gov (United States)

    Chepurna, Tetiana B.; Kuzmenko, Eduard D.; Chepurnyj, Igor V.

    2017-06-01

    The article is devoted to the geological issue of the space-time regional prognostication of mudflow hazard. The methodology of space-time prediction of mudflows hazard by creating GIS predictive model has been developed. Using GIS technologies the relevant and representative complex of significant influence of spatial and temporal factors, adjusted to use in the regional prediction of mudflows hazard, were selected. Geological, geomorphological, technological, climatic, and landscape factors have been selected as spatial mudflow factors. Spatial analysis is based on detection of a regular connection of spatial factor characteristics with spatial distribution of the mudflow sites. The function of a standard complex spatial index (SCSI) of the probability of the mudflow sites distribution has been calculated. The temporal, long-term prediction of the mudflows activity was based on the hypothesis of the regular reiteration of natural processes. Heliophysical, seismic, meteorological, and hydrogeological factors have been selected as time mudflow factors. The function of a complex index of long standing mudflow activity (CIMA) has been calculated. The prognostic geoinformational model of mudflow hazard up to 2020 year, a year of the next peak of the mudflows activity, has been created. Mudflow risks have been counted and carogram of mudflow risk assessment within the limits of administrative-territorial units has been built for 2020 year.

  1. Prognostic significance of Ki67 proliferation index, HIF1 alpha index and microvascular density in patients with non-small cell lung cancer brain metastases

    Energy Technology Data Exchange (ETDEWEB)

    Berghoff, A.S. [Medical University of Vienna, Institute of Neurology, Vienna (Austria); Medical University of Vienna, Comprehensive Cancer Center CNS Tumors Unit, Vienna (Austria); Medical University of Vienna, Department of Medicine I, Vienna (Austria); Ilhan-Mutlu, A.; Preusser, M. [Medical University of Vienna, Comprehensive Cancer Center CNS Tumors Unit, Vienna (Austria); Medical University of Vienna, Department of Medicine I, Vienna (Austria); Woehrer, A.; Hainfellner, J.A. [Medical University of Vienna, Institute of Neurology, Vienna (Austria); Medical University of Vienna, Comprehensive Cancer Center CNS Tumors Unit, Vienna (Austria); Hackl, M. [Austrian National Cancer Registry, Statistics Austria, Vienna (Austria); Widhalm, G. [Medical University of Vienna, Comprehensive Cancer Center CNS Tumors Unit, Vienna (Austria); Medical University of Vienna, Department of Neurosurgery, Vienna (Austria); Dieckmann, K. [Medical University of Vienna, Comprehensive Cancer Center CNS Tumors Unit, Vienna (Austria); Medical University of Vienna, Department of Radiotherapy, Vienna (Austria); Melchardt, T. [Paracelsus Medical University Hospital Salzburg, Third Medical Department, Salzburg (Austria); Dome, B. [Medical University of Vienna, Department of Surgery, Vienna (Austria); Heinzl, H. [Medical University of Vienna, Comprehensive Cancer Center CNS Tumors Unit, Vienna (Austria); Medical University of Vienna, Center for Medical Statistics, Informatics, and Intelligent Systems, Vienna (Austria); Birner, P. [Medical University of Vienna, Comprehensive Cancer Center CNS Tumors Unit, Vienna (Austria); Medical University of Vienna, Institute of Clinical Pathology, Vienna (Austria)

    2014-07-15

    Survival upon diagnosis of brain metastases (BM) in patients with non-small cell lung cancer (NSCLC) is highly variable and established prognostic scores do not include tissue-based parameters. Patients who underwent neurosurgical resection as first-line therapy for newly diagnosed NSCLC BM were included. Microvascular density (MVD), Ki67 tumor cell proliferation index and hypoxia-inducible factor 1 alpha (HIF-1 alpha) index were determined by immunohistochemistry. NSCLC BM specimens from 230 patients (151 male, 79 female; median age 56 years; 199 nonsquamous histology) and 53/230 (23.0 %) matched primary tumor samples were available. Adjuvant whole-brain radiation therapy (WBRT) was given to 153/230 (66.5 %) patients after neurosurgical resection. MVD and HIF-1 alpha indices were significantly higher in BM than in matched primary tumors. In patients treated with adjuvant WBRT, low BM HIF-1 alpha expression was associated with favorable overall survival (OS), while among patients not treated with adjuvant WBRT, BM HIF-1 alpha expression did not correlate with OS. Low diagnosis-specific graded prognostic assessment score (DS-GPA), low Ki67 index, high MVD, low HIF-1 alpha index and administration of adjuvant WBRT were independently associated with favorable OS. Incorporation of tissue-based parameters into the commonly used DS-GPA allowed refined discrimination of prognostic subgroups. Ki67 index, MVD and HIF-1 alpha index have promising prognostic value in BM and should be validated in further studies. (orig.) [German] Die Ueberlebensprognose von Patienten mit zerebralen Metastasen eines nicht-kleinzelligen Lungenkarzinoms (NSCLC) ist sehr variabel. Bisher werden gewebsbasierte Parameter nicht in die prognostische Beurteilung inkludiert. Neurochirurgische Resektate zerebraler NSCLC-Metastasen wurden in dieser Studie untersucht. Die Gefaessdichte (''microvascular density'', MVD), der Ki67-Proliferationsindex sowie der HIF-1α-Index wurden mittels

  2. Proliferative activity (MIB-1 index) is an independent prognostic parameter in patients with high-grade soft tissue sarcomas of subtypes other than malignant fibrous histiocytomas

    DEFF Research Database (Denmark)

    Jensen, V; Sørensen, Flemming Brandt; Bentzen, S M

    1998-01-01

    . Univariate analysis identified patient age, tumour size, histological grade of malignancy, MIB-1 index and p53 accumulation as significant prognostic parameters. Multivariate Cox analysis, including tests for interaction terms between histological subtypes and MIB-1 index, showed independent prognostic....... The proliferative activity was assessed by use of the monoclonal antibody MIB-1 and evaluated in multiple, random systematic sampled fields of vision. The percentage of proliferating cells (the MIB-1 index) ranged between 1% and 85% (median 12%). A significant increase in mean MIB-1 index was seen with increasing...

  3. Accounting for treatment use when validating a prognostic model: a simulation study

    Directory of Open Access Journals (Sweden)

    Romin Pajouheshnia

    2017-07-01

    Full Text Available Abstract Background Prognostic models often show poor performance when applied to independent validation data sets. We illustrate how treatment use in a validation set can affect measures of model performance and present the uses and limitations of available analytical methods to account for this using simulated data. Methods We outline how the use of risk-lowering treatments in a validation set can lead to an apparent overestimation of risk by a prognostic model that was developed in a treatment-naïve cohort to make predictions of risk without treatment. Potential methods to correct for the effects of treatment use when testing or validating a prognostic model are discussed from a theoretical perspective.. Subsequently, we assess, in simulated data sets, the impact of excluding treated individuals and the use of inverse probability weighting (IPW on the estimated model discrimination (c-index and calibration (observed:expected ratio and calibration plots in scenarios with different patterns and effects of treatment use. Results Ignoring the use of effective treatments in a validation data set leads to poorer model discrimination and calibration than would be observed in the untreated target population for the model. Excluding treated individuals provided correct estimates of model performance only when treatment was randomly allocated, although this reduced the precision of the estimates. IPW followed by exclusion of the treated individuals provided correct estimates of model performance in data sets where treatment use was either random or moderately associated with an individual's risk when the assumptions of IPW were met, but yielded incorrect estimates in the presence of non-positivity or an unobserved confounder. Conclusions When validating a prognostic model developed to make predictions of risk without treatment, treatment use in the validation set can bias estimates of the performance of the model in future targeted individuals, and

  4. Updating and prospective validation of a prognostic model for high sickness absence

    NARCIS (Netherlands)

    Roelen, C.A.M.; Heymans, M.W.; Twisk, J.W.R.; van Rhenen, W.; Pallesen, S.; Bjorvatn, B.; Moen, B.E.; Mageroy, N.

    2015-01-01

    Objectives To further develop and validate a Dutch prognostic model for high sickness absence (SA). Methods Three-wave longitudinal cohort study of 2,059 Norwegian nurses. The Dutch prognostic model was used to predict high SA among Norwegian nurses at wave 2. Subsequently, the model was updated by

  5. On prognostic models, artificial intelligence and censored observations.

    Science.gov (United States)

    Anand, S S; Hamilton, P W; Hughes, J G; Bell, D A

    2001-03-01

    The development of prognostic models for assisting medical practitioners with decision making is not a trivial task. Models need to possess a number of desirable characteristics and few, if any, current modelling approaches based on statistical or artificial intelligence can produce models that display all these characteristics. The inability of modelling techniques to provide truly useful models has led to interest in these models being purely academic in nature. This in turn has resulted in only a very small percentage of models that have been developed being deployed in practice. On the other hand, new modelling paradigms are being proposed continuously within the machine learning and statistical community and claims, often based on inadequate evaluation, being made on their superiority over traditional modelling methods. We believe that for new modelling approaches to deliver true net benefits over traditional techniques, an evaluation centric approach to their development is essential. In this paper we present such an evaluation centric approach to developing extensions to the basic k-nearest neighbour (k-NN) paradigm. We use standard statistical techniques to enhance the distance metric used and a framework based on evidence theory to obtain a prediction for the target example from the outcome of the retrieved exemplars. We refer to this new k-NN algorithm as Censored k-NN (Ck-NN). This reflects the enhancements made to k-NN that are aimed at providing a means for handling censored observations within k-NN.

  6. Stage Separation Failure: Model Based Diagnostics and Prognostics

    Science.gov (United States)

    Luchinsky, Dmitry; Hafiychuk, Vasyl; Kulikov, Igor; Smelyanskiy, Vadim; Patterson-Hine, Ann; Hanson, John; Hill, Ashley

    2010-01-01

    Safety of the next-generation space flight vehicles requires development of an in-flight Failure Detection and Prognostic (FD&P) system. Development of such system is challenging task that involves analysis of many hard hitting engineering problems across the board. In this paper we report progress in the development of FD&P for the re-contact fault between upper stage nozzle and the inter-stage caused by the first stage and upper stage separation failure. A high-fidelity models and analytical estimations are applied to analyze the following sequence of events: (i) structural dynamics of the nozzle extension during the impact; (ii) structural stability of the deformed nozzle in the presence of the pressure and temperature loads induced by the hot gas flow during engine start up; and (iii) the fault induced thrust changes in the steady burning regime. The diagnostic is based on the measurements of the impact torque. The prognostic is based on the analysis of the correlation between the actuator signal and fault-induced changes in the nozzle structural stability and thrust.

  7. Prognostic value of body mass index before treatment for laryngeal squamous cell carcinoma.

    Science.gov (United States)

    Li, Zhao-Qu; Zou, Lan; Liu, Tian-Run; Yang, An-Kui

    2015-12-01

    Patients with head and neck cancer often suffer from malnutrition. This study aims to investigate the influence of body mass index (BMI) on the prognosis of laryngeal squamous cell carcinoma (LSCC). A total of 473 patients with LSCC initially treated at Sun Yat-sen University Cancer Center between January 2005 and July 2009 were retrospectively reviewed. Survival analysis was performed by the Kaplan-Meier method and Cox regression model. Low BMI before treatment was significantly associated with poor overall survival in patients with LSCC (Pnutritional status is favorable to improve survival in patients with LSCC.

  8. Uncertainty Representation and Interpretation in Model-Based Prognostics Algorithms Based on Kalman Filter Estimation

    Science.gov (United States)

    Galvan, Jose Ramon; Saxena, Abhinav; Goebel, Kai Frank

    2012-01-01

    This article discusses several aspects of uncertainty representation and management for model-based prognostics methodologies based on our experience with Kalman Filters when applied to prognostics for electronics components. In particular, it explores the implications of modeling remaining useful life prediction as a stochastic process, and how it relates to uncertainty representation, management and the role of prognostics in decision-making. A distinction between the interpretations of estimated remaining useful life probability density function is explained and a cautionary argument is provided against mixing interpretations for two while considering prognostics in making critical decisions.

  9. [Clinical application value of prognostic nutritional index for predicting survival in patients with advanced non-small cell lung cancer].

    Science.gov (United States)

    Xu, W J; Kang, Y M; Zhou, L; Chen, F F; Song, Y H; Zhang, C Q

    2017-02-23

    Objective: To explore the clinical application value of prognostic nutritional index(PNI) for predicting overall survival(OS) in patients with advanced non-small cell lung cancer (NSCLC). Methods: 123 patients with histologically confirmed non-small cell lung cancer were enrolled in this study, and their clinical and laboratory data were reviewed. The PNI was calculated as 10×serum albumin value+ 5×total lymphocyte countin peripheral blood.Univariate and multivariate analyses were used to identify the potential prognostic factors for advanced NSCLC. Results: PNI of the 123 NSCLC patients was 46.24±6.56. PNI was significantly associated with age, weight loss and pleural effusion (Prelationship with sex, smoking, hemoptysis, chest pain, dyspnea, histological type, clinical stage, and administration of chemotherapy (P>0.05). The median OS of the 123 patients was 19.5 months. The median OS in the higher PNI group (PNI≥46.24) and lower PNI group(PNI<46.24) were 25.2 months and 16.4 months, respectively.The 1-year survival rates were 80.6% and 63.9%, and 2-year survival rates were 54.8% and 19.6%, respectively (P<0.01). Univariate analysis showed that PNI, age, dyspnea, and weight loss were related to the OS of the advanced NSCLC patients (P<0.05). Multivariate analysis identified PNI as an independent prognostic factor for OS of advanced NSCLC (P<0.001). Conclusion: PNI can be easily calculated, and may be used as a relatively new prognostic indicator for advanced NSCLC in clinical practice.

  10. Prognostic models in acute pulmonary embolism: a systematic review and meta-analysis

    Science.gov (United States)

    Elias, Antoine; Mallett, Susan; Daoud-Elias, Marie; Poggi, Jean-Noël; Clarke, Mike

    2016-01-01

    Objective To review the evidence for existing prognostic models in acute pulmonary embolism (PE) and determine how valid and useful they are for predicting patient outcomes. Design Systematic review and meta-analysis. Data sources OVID MEDLINE and EMBASE, and The Cochrane Library from inception to July 2014, and sources of grey literature. Eligibility criteria Studies aiming at constructing, validating, updating or studying the impact of prognostic models to predict all-cause death, PE-related death or venous thromboembolic events up to a 3-month follow-up in patients with an acute symptomatic PE. Data extraction Study characteristics and study quality using prognostic criteria. Studies were selected and data extracted by 2 reviewers. Data analysis Summary estimates (95% CI) for proportion of risk groups and event rates within risk groups, and accuracy. Results We included 71 studies (44 298 patients). Among them, 17 were model construction studies specific to PE prognosis. The most validated models were the PE Severity Index (PESI) and its simplified version (sPESI). The overall 30-day mortality rate was 2.3% (1.7% to 2.9%) in the low-risk group and 11.4% (9.9% to 13.1%) in the high-risk group for PESI (9 studies), and 1.5% (0.9% to 2.5%) in the low-risk group and 10.7% (8.8% to12.9%) in the high-risk group for sPESI (11 studies). PESI has proved clinically useful in an impact study. Shifting the cut-off or using novel and updated models specifically developed for normotensive PE improves the ability for identifying patients at lower risk for early death or adverse outcome (0.5–1%) and those at higher risk (up to 20–29% of event rate). Conclusions We provide evidence-based information about the validity and utility of the existing prognostic models in acute PE that may be helpful for identifying patients at low risk. Novel models seem attractive for the high-risk normotensive PE but need to be externally validated then be assessed in impact studies. PMID

  11. A Discussion on Uncertainty Representation and Interpretation in Model-Based Prognostics Algorithms based on Kalman Filter Estimation Applied to Prognostics of Electronics Components

    Science.gov (United States)

    Celaya, Jose R.; Saxen, Abhinav; Goebel, Kai

    2012-01-01

    This article discusses several aspects of uncertainty representation and management for model-based prognostics methodologies based on our experience with Kalman Filters when applied to prognostics for electronics components. In particular, it explores the implications of modeling remaining useful life prediction as a stochastic process and how it relates to uncertainty representation, management, and the role of prognostics in decision-making. A distinction between the interpretations of estimated remaining useful life probability density function and the true remaining useful life probability density function is explained and a cautionary argument is provided against mixing interpretations for the two while considering prognostics in making critical decisions.

  12. Investigating the Effect of Damage Progression Model Choice on Prognostics Performance

    Data.gov (United States)

    National Aeronautics and Space Administration — The success of model-based approaches to systems health management depends largely on the quality of the underly- ing models. In model-based prognostics, it is...

  13. A Comparison of Filter-based Approaches for Model-based Prognostics

    Data.gov (United States)

    National Aeronautics and Space Administration — Model-based prognostics approaches use domain knowledge about a system and its failure modes through the use of physics-based models. Model-based prognosis is...

  14. The art versus science of predicting prognosis: can a prognostic index predict short-term mortality better than experienced nurses do?

    Science.gov (United States)

    Casarett, David J; Farrington, Sue; Craig, Teresa; Slattery, Julie; Harrold, Joan; Oldanie, Betty; Roy, Jason; Biehl, Richard; Teno, Joan

    2012-06-01

    To determine whether a prognostic index could predict one-week mortality more accurately than hospice nurses can. An electronic health record-based retrospective cohort study of 21,074 hospice patients was conducted in three hospice programs in the Southeast, Northeast, and Midwest United States. Model development used logistic regression with bootstrapped confidence intervals and multiple imputation to account for missing data. The main outcome measure was mortality within 7 days of hospice enrollment. A total of 21,074 patients were admitted to hospice between October 1, 2008 and May 31, 2011, and 5562 (26.4%) died within 7 days. An optimal predictive model included the Palliative Performance Scale (PPS) score, admission from a hospital, and gender. The model had a c-statistic of 0.86 in the training sample and 0.84 in the validation sample, which was greater than that of nurses' predictions (0.72). The index's performance was best for patients with pulmonary disease (0.89) and worst for patients with cancer and dementia (both 0.80). The index's predictions of mortality rates in each index category were within 5.0% of actual rates, whereas nurses underestimated mortality by up to 18.9%. Using the optimal index threshold (<3), the index's predictions had a better c-statistic (0.78 versus 0.72) and higher sensitivity (74.4% versus 47.8%) than did nurses' predictions but a lower specificity (80.6% versus 95.1%). Although nurses can often identify patients who will die within 7 days, a simple model based on available clinical information offers improved accuracy and could help to identify those patients who are at high risk for short-term mortality.

  15. Calpain-1 Expression in Triple-Negative Breast Cancer: A Potential Prognostic Factor Independent of the Proliferative/Apoptotic Index

    Directory of Open Access Journals (Sweden)

    Shadia M. Al-Bahlani

    2017-01-01

    Full Text Available Triple-negative breast cancer (TNBC is an aggressive type of breast cancer in which calpain system plays an important role in its cellular processes including apoptosis and proliferation. Although such roles have been assessed in tumor pathogenesis, the correlation of its expression to the proliferating/apoptotic index has not been studied yet. Immunohistochemical staining of calpain-1 was performed on paraffin-embedded tissues to correlate its expression with clinicopathological variables and outcome. The proliferation activity was determined by calculating the percentage of cells expressing the Ki-67 antigen. The apoptotic index was assessed morphologically and biochemically using Haematoxylin & Eosin method and Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay, respectively. Calpain-1 was significantly expressed in TNBC tissues varying from low to high with a significant correlation to lymph node status but not with the other clinicopathological variables, suggesting its role as a prognostic factor. In addition, a positive correlation was found between both apoptotic counts assays (P<0.001, r=0.547 as well as with proliferation (P=0.045. Calpain-1 expression had no significant correlation with either proliferation (P=0.29 or apoptotic indices (P=0.071 and P=0.100. Determining calpain-1 expression may provide relevant prognostic value for TNBC cancer patients.

  16. Prognostic Impact of the Geriatric Nutritional Risk Index on Long-Term Outcomes in Patients Who Underwent Percutaneous Coronary Intervention.

    Science.gov (United States)

    Wada, Hideki; Dohi, Tomotaka; Miyauchi, Katsumi; Doi, Shinichiro; Naito, Ryo; Konishi, Hirokazu; Tsuboi, Shuta; Ogita, Manabu; Kasai, Takatoshi; Hassan, Ahmed; Okazaki, Shinya; Isoda, Kikuo; Suwa, Satoru; Daida, Hiroyuki

    2017-06-01

    Malnutrition has been identified as an important predictor of poor clinical outcomes in patients with heart failure. The aim of this study is to examine the prognostic impact of nutritional status in patients with coronary artery disease (CAD) who underwent percutaneous coronary intervention (PCI). The impact of nutrition, assessed using the geriatric nutritional risk index (GNRI) calculated by serum albumin and body mass index, was evaluated in 2,853 patients with CAD who underwent their first PCI between 2000 and 2011. Patients were assigned to tertiles based on their GNRI levels. The incidences of all-cause death and cardiac death were assessed. The median GNRI values were 101 (interquartile range 95 to 106). Lower GNRI levels were associated with older age and higher prevalence of acute coronary syndrome and chronic kidney disease. During the median follow-up period of 7.4 years, Kaplan-Meier curves showed ongoing divergence in rates of mortality among tertiles (GNRI nutritional status was associated with long-term clinical outcomes in CAD patients after PCI. Evaluation of GNRI carries important prognostic information and may guide the therapeutic approach to such patients. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Efficacy of NETDC (New England Trophoblastic Disease Center prognostic index score to predict gestational trophoblastic tumor from hydatidiform mole

    Directory of Open Access Journals (Sweden)

    Khrismawan Khrismawan

    2004-03-01

    Full Text Available A prospective longitudinal analytic study assessing the efficacy of NETDC (New England Trophoblastic Disease Center prognostic index score in predicting malignancy after hydatidiform mole had been performed. Of the parameter evaluated; age of patients, type of hydatidiform mole, uterine enlargement, serum hCG level, lutein cyst, and presence of complicating factors were significant risk factors for malignancy after hydatidiform mole were evacuated (p<0.032. The study were done on 50 women diagnosed with hydatidiform mole with 1 year observation (January 2001-December 2002 at the Department of Obstetrics and Gynecology, Mohammad Hoesin Hospital, Palembang. The results showed that the NETDC prognostic index score predicted malignancy in 50% of high risk group and 10% in low risk group (p<0.05. This showed a higher number than that found by the WHO (19%-30%. The risk for incidence of  malignancy after hydatidiform mole in the high risk group is 9.0 times higher compared to that of the low risk group (CI: 1.769-45.786. (Med J Indones 2004; 13: 40-6 Keywords: New England Trophoblastic Disease Center (NETDC, gestational trophoblastic tumor, hydatidiform mole, high and low risk

  18. Neuromagnetic index of hemispheric asymmetry prognosticating the outcome of sudden hearing loss.

    Science.gov (United States)

    Li, Lieber Po-Hung; Shiao, An-Suey; Chen, Kuang-Chao; Lee, Po-Lei; Niddam, David M; Chang, Shyue-Yih; Hsieh, Jen-Chuen

    2012-01-01

    The longitudinal relationship between central plastic changes and clinical presentations of peripheral hearing impairment remains unknown. Previously, we reported a unique plastic pattern of "healthy-side dominance" in acute unilateral idiopathic sudden sensorineural hearing loss (ISSNHL). This study aimed to explore whether such hemispheric asymmetry bears any prognostic relevance to ISSNHL along the disease course. Using magnetoencephalography (MEG), inter-hemispheric differences in peak dipole amplitude and latency of N100m to monaural tones were evaluated in 21 controls and 21 ISSNHL patients at two stages: initial and fixed stage (1 month later). Dynamics/Prognostication of hemispheric asymmetry were assessed by the interplay between hearing level/hearing gain and ipsilateral/contralateral ratio (I/C) of N100m latency and amplitude. Healthy-side dominance of N100m amplitude was observed in ISSNHL initially. The pattern changed with disease process. There is a strong correlation between the hearing level at the fixed stage and initial I/C(amplitude) on affected-ear stimulation in ISSNHL. The optimal cut-off value with the best prognostication effect for the hearing improvement at the fixed stage was an initial I/C(latency) on affected-ear stimulation of 1.34 (between subgroups of complete and partial recovery) and an initial I/C(latency) on healthy-ear stimulation of 0.76 (between subgroups of partial and no recovery), respectively. This study suggested that a dynamic process of central auditory plasticity can be induced by peripheral lesions. The hemispheric asymmetry at the initial stage bears an excellent prognostic potential for the treatment outcomes and hearing level at the fixed stage in ISSNHL. Our study demonstrated that such brain signature of central auditory plasticity in terms of both N100m latency and amplitude at defined time can serve as a prognostication predictor for ISSNHL. Further studies are needed to explore the long-term temporal scenario

  19. Physics Based Modeling and Prognostics of Electrolytic Capacitors

    Science.gov (United States)

    Kulkarni, Chetan; Ceyla, Jose R.; Biswas, Gautam; Goebel, Kai

    2012-01-01

    This paper proposes first principles based modeling and prognostics approach for electrolytic capacitors. Electrolytic capacitors have become critical components in electronics systems in aeronautics and other domains. Degradations and faults in DC-DC converter unit propagates to the GPS and navigation subsystems and affects the overall solution. Capacitors and MOSFETs are the two major components, which cause degradations and failures in DC-DC converters. This type of capacitors are known for its low reliability and frequent breakdown on critical systems like power supplies of avionics equipment and electrical drivers of electromechanical actuators of control surfaces. Some of the more prevalent fault effects, such as a ripple voltage surge at the power supply output can cause glitches in the GPS position and velocity output, and this, in turn, if not corrected will propagate and distort the navigation solution. In this work, we study the effects of accelerated aging due to thermal stress on different sets of capacitors under different conditions. Our focus is on deriving first principles degradation models for thermal stress conditions. Data collected from simultaneous experiments are used to validate the desired models. Our overall goal is to derive accurate models of capacitor degradation, and use them to predict performance changes in DC-DC converters.

  20. Multidisciplinary Rehabilitation Treatment of Patients With Chronic Low Back Pain: A Prognostic Model for Its Outcome

    NARCIS (Netherlands)

    van der Hulst, Marije; Vollenbroek-Hutten, Miriam Marie Rosé; Groothuis-Oudshoorn, Catharina Gerarda Maria; Hermens, Hermanus J.

    Objectives: (1) To determine if treatment outcome in chronic low back pain can be predicted by a predefined multivariate prognostic model based on consistent predictors from the literature and (2) to explore the value of potentially prognostic factors further. Methods: Data were derived from a

  1. Systematic review of multivariable prognostic models for mild traumatic brain injury.

    Science.gov (United States)

    Silverberg, Noah D; Gardner, Andrew J; Brubacher, Jeffrey R; Panenka, William J; Li, Jun Jian; Iverson, Grant L

    2015-04-15

    Prognostic models can guide clinical management and increase statistical power in clinical trials. The availability and adequacy of prognostic models for mild traumatic brain injury (MTBI) is uncertain. The present study aimed to (1) identify and evaluate multivariable prognostic models for MTBI, and (2) determine which pre-, peri-, and early post-injury variables have independent prognostic value in the context of multivariable models. An electronic search of MEDLINE, PsycINFO, PubMed, EMBASE, and CINAHL databases for English-language MTBI cohort studies from 1970-2013 was supplemented by Web of Science citation and hand searching. This search strategy identified 7789 articles after removing duplicates. Of 182 full-text articles reviewed, 26 met eligibility criteria including (1) prospective inception cohort design, (2) prognostic information collected within 1 month post-injury, and (3) 2+variables combined to predict clinical outcome (e.g., post-concussion syndrome) at least 1 month later. Independent reviewers extracted sample characteristics, study design features, clinical outcome variables, predictor selection methods, and prognostic model discrimination, calibration, and cross-validation. These data elements were synthesized qualitatively. The present review found no multivariable prognostic model that adequately predicts individual patient outcomes from MTBI. Suboptimal methodology limits their reproducibility and clinical usefulness. The most robust prognostic factors in the context of multivariable models were pre-injury mental health and early post-injury neuropsychological functioning. Women and adults with early post-injury anxiety also have worse prognoses. Relative to these factors, the severity of MTBI had little long-term prognostic value. Future prognostic studies should consider a broad range of biopsychosocial predictors in large inception cohorts.

  2. Improving Computational Efficiency of Prediction in Model-based Prognostics Using the Unscented Transform

    Data.gov (United States)

    National Aeronautics and Space Administration — Model-based prognostics captures system knowledge in the form of physics-based models of components, and how they fail, in order to obtain accurate predictions of...

  3. Aircraft Anomaly Prognostics Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Ridgetop Group will leverage its proven Electromechanical Actuator (EMA) prognostics methodology to develop an advanced model-based actuator prognostic reasoner...

  4. Plaque Brachytherapy for Uveal Melanoma: A Vision Prognostication Model

    Energy Technology Data Exchange (ETDEWEB)

    Khan, Niloufer [Department of Radiation Oncology, Taussig Cancer Center, Cleveland Clinic, Cleveland, Ohio (United States); Khan, Mohammad K. [Department of Radiation Oncology, Emory University School of Medicine, Atlanta, Georgia (United States); Bena, James [Department of Quantitative Health Sciences, Cleveland Clinic, Cleveland, Ohio (United States); Macklis, Roger [Department of Radiation Oncology, Taussig Cancer Center, Cleveland Clinic, Cleveland, Ohio (United States); Singh, Arun D., E-mail: singha@ccf.org [Department of Ophthalmic Oncology, Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio (United States)

    2012-11-01

    Purpose: To generate a vision prognostication model after plaque brachytherapy for uveal melanoma. Methods and Materials: All patients with primary single ciliary body or choroidal melanoma treated with iodine-125 or ruthenium-106 plaque brachytherapy between January 1, 2005, and June 30, 2010, were included. The primary endpoint was loss of visual acuity. Only patients with initial visual acuity better than or equal to 20/50 were used to evaluate visual acuity worse than 20/50 at the end of the study, and only patients with initial visual acuity better than or equal to 20/200 were used to evaluate visual acuity worse than 20/200 at the end of the study. Factors analyzed were sex, age, cataracts, diabetes, tumor size (basal dimension and apical height), tumor location, and radiation dose to the tumor apex, fovea, and optic disc. Univariate and multivariable Cox proportional hazards were used to determine the influence of baseline patient factors on vision loss. Kaplan-Meier curves (log rank analysis) were used to estimate freedom from vision loss. Results: Of 189 patients, 92% (174) were alive as of February 1, 2011. At presentation, visual acuity was better than or equal to 20/50 and better than or equal to 20/200 in 108 and 173 patients, respectively. Of these patients, 44.4% (48) had post-treatment visual acuity of worse than 20/50 and 25.4% (44) had post-treatment visual acuity worse than 20/200. By multivariable analysis, increased age (hazard ratio [HR] of 1.01 [1.00-1.03], P=.05), increase in tumor height (HR of 1.35 [1.22-1.48], P<.001), and a greater total dose to the fovea (HR of 1.01 [1.00-1.01], P<.001) were predictive of vision loss. This information was used to develop a nomogram predictive of vision loss. Conclusions: By providing a means to predict vision loss at 3 years after treatment, our vision prognostication model can be an important tool for patient selection and treatment counseling.

  5. [Using the CRIB as an early prognostic index for very low birthweight infants, treated in neonatal intensive care unites].

    Science.gov (United States)

    Vakrilova, L; Emilova, Z; Slŭncheva, B; Kalaĭdzhieva, M; Pramatarova, T; Iarŭkova, N

    2007-01-01

    The illness severity by admission in NICU reflects the intensity of the therapy, the prognosis for the newborn and the hospital costs. Using the CRIB (Clinical Risk Index for Babies) as an objective and easy method for measuring the illness severity in the first 12 h of life allows assessing the risk of death until discharge. To apply the CRIB for assessing the illness severity and to investigate its prognostic value for life and risk of permanent disabilities among very low birthweight (VLBW) and gestational age (VLGA) infants. The study includes the inborn babies in the Specialized Obstetrics & Gynaecology Hospital "Maichin dom" with birthweight 15. The infants with permanent disabilities were with significantly higher CRIB scores too: 11.7 / 11.4% among the infants with IVH III-IV compared to 6.2 / 5.2 without; 9.6 / 10.1 among infants with CLD compared to 5.7 /5.2 without; 10.1 / 10 among infants with ROP compared to 5.5 / 5.1 without. The CRIB score is useful and easy to apply early and objective prognostic criterion about the risk of in hospital death and permanent disabilities among VLBW newborns. It can be used as a basis for comparing the results of the different NICUs too.

  6. [The Association Française de Chirurgie (AFC) colorectal index: a reliable preoperative prognostic index in colorectal surgery].

    Science.gov (United States)

    Duval, H; Dumont, F; Vibert, E; Manaouil, D; Verhaeghe, P; Fuks, D; Bounicaud, D; Riboulot, M; Chatelain, D; Yzet, T; Mauvais, F; Lapôtre-Ledoux, B; Regimbeau, J-M

    2006-01-01

    Evaluation of outcome after colorectal surgery is always necessary. A new index which permits to appreciate preoperatively postoperative mortality after colorectal resection in colorectal cancer (CRC) and in diverticular disease has been published (i.e., Association Française de Chirurgie, AFC colorectal index). From November 2002 to July 2004, in-hospital mortality was analysed on 253 patients who underwent colic resection (N = 220, 87%) or rectal resection, with anastomosis (N = 175, 70%). Mortality was analysed according to emergency resection, neurological co morbidity, lost of weight more than 10% of weight, age older than 70 years. Mean age of patients was 63 +/- 18 years (17-92) (45% older than 70 years), 26% of patients were ASA >or= III, 35% underwent surgery in emergency, and 12% underwent laparoscopic surgery. One hundred and fifteen (45%) patients underwent surgery for CRC and 50 (20%), for diverticular disease and 11 patients underwent surgery for ischemic colitis. Overall mortality rate was 10% (N = 26), it was 19% in emergency surgery versus 5% after elective surgery. Global morbidity was 38%, percentage of anastomotic leak was 8% (N = 14/175), reoperation was necessary in 14%. The mean length of stay was 13 +/- 8 days. Ten percent of patients necessitated unplanned readmission. After surgery for CCR or diverticular disease. -i) overall mortality was 9% - ii) among patients who had 0, 1, 2, or 3 predictive risk factors of mortality; mortality was 0% , 5% 15% and 33%. After surgery for other aetiology than CCR or diverticular disease, among patients who had 0, 1, 2, or 3 predictive risk factors of mortality; mortality was 0%, 12% 36% and 25%. These results showed the reproducibility of the AFC colorectal index and its potential application in all aetiologies after colorectal surgery.

  7. Modified BODE indexes: Agreement between multidimensional prognostic systems based on oxygen uptake

    Directory of Open Access Journals (Sweden)

    José Luis Lopez-Campos

    2010-05-01

    Full Text Available José Luis Lopez-Campos, Pilar Cejudo, Eduardo Marquez, Francisco Ortega, Esther Quintana, Carmen Carmona, Emilia BarrotUnidad Médico-Quirúrgica de Enfermedades Respiratorias, Hospitales Universitarios Virgen del Rocío, Seville, SpainAim: It has been recently shown that the original BODE index has a high degree of correlation with two modified BODE indexes using maximal oxygen uptake expressed either as mL/min/kg (mBODE or as the percentage predicted (mBODE%. In this study we investigated the agreement between the two modified BODE indexes (mBODE and mBODE% in patients with stable chronic obstructive pulmonary disease (COPD.Methods: A total of 169 patients with stable COPD were enrolled in this cross-sectional study. Differences between the two mBODE indexes were assessed using kappa coefficients and Bland-Altman plots. One out of every three patients underwent the six-minute walking test to investigate the agreement with the original BODE index.Results: Correlations between the two mBODE indexes with each other (r = 0.96, P < 0.001 and with the original BODE index (mBODE r = 0.88, P < 0.001; mBODE% r = 0.93, P < 0.001 were excellent. However, the two mBODE indexes were significantly different from each other (mBODE 5.27 ± 2.3 versus mBODE% 4.31 ± 2.5; P < 0.001. The kappa coefficients were significantly lower (entire study group k = 0.5, P < 0.001 for every GOLD stage. The mean difference between the two mBODE indexes was 0.8 ± 0.6 units. Differences with the original BODE were higher for the mBODE (1.8 ± 0.9 than for the mBODE% (0.6 ± 0.8.Conclusions: The new mBODE indexes are highly correlated but significantly different from each other. The differences between the novel indexes deserve further scrutiny.Keywords: BODE index, chronic obstructive pulmonary disease, exercise testing, multidimensional evaluation, oxygen uptake

  8. Prognostic nutritional index serves as a predicative marker of survival and associates with systemic inflammatory response in metastatic intrahepatic cholangiocarcinoma

    Directory of Open Access Journals (Sweden)

    Zhang C

    2016-10-01

    Full Text Available Chenyue Zhang,1,2 Haiyong Wang,1,3 Zhouyu Ning,1,2 Litao Xu,1,2 Liping Zhuang,1,2 Peng Wang,1,2 Zhiqiang Meng1,2 1Department of Integrative Oncology, Fudan University Shanghai Cancer Center, 2Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, 3Department of Radiation Oncology, Shandong Cancer Hospital and Institute, Jinan, People’s Republic of China Objective: The significance of the prognostic nutritional index (PNI has been widely reported and confirmed in many types of cancers. However, few studies are available indicating its prognostic power in patients with intrahepatic cholangiocarcinoma (ICC. Thus, we investigated its relationship with overall survival (OS to evaluate its role in predicting survival in patients with ICC. Patients and methods: Between October 2011 and October 2015, 173 consecutive patients with pathologically confirmed locally advanced or metastatic ICC were enrolled. First, the correlations between PNI and clinical factors were analyzed among these patients. Next, univariate and multivariate analyses were conducted to evaluate the association between PNI and OS among these patients with ICC. In addition, the relationships between PNI and three typical systemic inflammatory response (SIR markers – the neutrophil/lymphocyte ratio (NLR, the platelet/lymphocyte ratio (PLR, and the lymphocyte/monocyte ratio (LMR – were also assessed. Results: A lower PNI was linked with a shorter OS in patients with ICC, as reflected obviously in the Kaplan–Meier analyses. The patients with ICC were divided into the locally advanced group and the metastatic group. Further analyses revealed that PNI is not associated with OS in the locally advanced group. However, in the subgroup of patients with metastatic ICC, a lower PNI significantly correlated with a worsened OS. The OS for patients with a low PNI is 5 months, whereas the OS is 10.17 months for patients with a high PNI. Multivariate analyses revealed

  9. Uncertainty Representation and Interpretation in Model-based Prognostics Algorithms based on Kalman Filter Estimation

    Data.gov (United States)

    National Aeronautics and Space Administration — This article discusses several aspects of uncertainty represen- tation and management for model-based prognostics method- ologies based on our experience with Kalman...

  10. Clinical Risk Factors and Prognostic Model for Primary Graft Dysfunction after Lung Transplantation in Patients with Pulmonary Hypertension.

    Science.gov (United States)

    Porteous, Mary K; Lee, James C; Lederer, David J; Palmer, Scott M; Cantu, Edward; Shah, Rupal J; Bellamy, Scarlett L; Lama, Vibha N; Bhorade, Sangeeta M; Crespo, Maria M; McDyer, John F; Wille, Keith M; Localio, A Russell; Orens, Jonathan B; Shah, Pali D; Weinacker, Ann B; Arcasoy, Selim; Wilkes, David S; Ware, Lorraine B; Christie, Jason D; Kawut, Steven M; Diamond, Joshua M

    2017-10-01

    Pulmonary hypertension from pulmonary arterial hypertension or parenchymal lung disease is associated with an increased risk for primary graft dysfunction after lung transplantation. We evaluated the clinical determinants of severe primary graft dysfunction in pulmonary hypertension and developed and validated a prognostic model. We conducted a retrospective cohort study of patients in the multicenter Lung Transplant Outcomes Group with pulmonary hypertension at transplant listing. Severe primary graft dysfunction was defined as PaO2/FiO2 ≤200 with allograft infiltrates at 48 or 72 hours after transplantation. Donor, recipient, and operative characteristics were evaluated in a multivariable explanatory model. A prognostic model derived using donor and recipient characteristics was then validated in a separate cohort. In the explanatory model of 826 patients with pulmonary hypertension, donor tobacco smoke exposure, higher recipient body mass index, female sex, listing mean pulmonary artery pressure, right atrial pressure and creatinine at transplant, cardiopulmonary bypass use, transfusion volume, and reperfusion fraction of inspired oxygen were associated with primary graft dysfunction. Donor obesity was associated with a lower risk for primary graft dysfunction. Using a 20% threshold for elevated risk, the prognostic model had good negative predictive value in both derivation and validation cohorts (89.1% [95% confidence interval, 85.3-92.8] and 83.3% [95% confidence interval, 78.5-88.2], respectively), but low positive predictive value. Several recipient, donor, and operative characteristics were associated with severe primary graft dysfunction in patients with pulmonary hypertension, including several risk factors not identified in the overall transplant population. A prognostic model with donor and recipient clinical risk factors alone had low positive predictive value, but high negative predictive value, to rule out high risk for primary graft dysfunction.

  11. Long-term prognostic value of a comprehensive assessment of cardiac magnetic resonance indexes after an ST-segment elevation myocardial infarction.

    Science.gov (United States)

    Merlos, Pilar; López-Lereu, Maria P; Monmeneu, Jose V; Sanchis, Juan; Núñez, Julio; Bonanad, Clara; Valero, Ernesto; Miñana, Gema; Chaustre, Fabián; Gómez, Cristina; Oltra, Ricardo; Palacios, Lorena; Bosch, Maria J; Navarro, Vicente; Llácer, Angel; Chorro, Francisco J; Bodí, Vicente

    2013-08-01

    A variety of cardiac magnetic resonance indexes predict mid-term prognosis in ST-segment elevation myocardial infarction patients. The extent of transmural necrosis permits simple and accurate prediction of systolic recovery. However, its long-term prognostic value beyond a comprehensive clinical and cardiac magnetic resonance evaluation is unknown. We hypothesized that a simple semiquantitative assessment of the extent of transmural necrosis is the best resonance index to predict long-term outcome soon after a first ST-segment elevation myocardial infarction. One week after a first ST-segment elevation myocardial infarction we carried out a comprehensive quantification of several resonance parameters in 206 consecutive patients. A semiquantitative assessment (altered number of segments in the 17-segment model) of edema, baseline and post-dobutamine wall motion abnormalities, first pass perfusion, microvascular obstruction, and the extent of transmural necrosis was also performed. During follow-up (median 51 months), 29 patients suffered a major adverse cardiac event (8 cardiac deaths, 11 nonfatal myocardial infarctions, and 10 readmissions for heart failure). Major cardiac events were associated with more severely altered quantitative and semiquantitative resonance indexes. After a comprehensive multivariate adjustment, the extent of transmural necrosis was the only resonance index independently related to the major cardiac event rate (hazard ratio=1.34 [1.19-1.51] per each additional segment displaying>50% transmural necrosis, P<.001). A simple and non-time consuming semiquantitative analysis of the extent of transmural necrosis is the most powerful cardiac magnetic resonance index to predict long-term outcome soon after a first ST-segment elevation myocardial infarction. Copyright © 2013 Sociedad Española de Cardiología. Published by Elsevier Espana. All rights reserved.

  12. Development and validation of logistic prognostic models by predefined SAS-macros

    Directory of Open Access Journals (Sweden)

    Ziegler, Christoph

    2006-02-01

    Full Text Available In medical decision making about therapies or diagnostic procedures in the treatment of patients the prognoses of the course or of the magnitude of diseases plays a relevant role. Beside of the subjective attitude of the clinician mathematical models can help in providing such prognoses. Such models are mostly multivariate regression models. In the case of a dichotomous outcome the logistic model will be applied as the standard model. In this paper we will describe SAS-macros for the development of such a model, for examination of the prognostic performance, and for model validation. The rational for this developmental approach of a prognostic modelling and the description of the macros can only given briefly in this paper. Much more details are given in. These 14 SAS-macros are a tool for setting up the whole process of deriving a prognostic model. Especially the possibility of validating the model by a standardized software tool gives an opportunity, which is not used in general in published prognostic models. Therefore, this can help to develop new models with good prognostic performance for use in medical applications.

  13. [Prognostic factors of postoperative delayed gastric emptying after pancreaticoduodenectomy: a predictive model].

    Science.gov (United States)

    Tan, H T; Zong, Y; Zhao, Z Q; Wu, L F; Liu, J; Sun, B; Jiang, H C

    2017-05-01

    Objective: To study the prognostic factors of delayed gastric emptying(DGE) after pancreaticoduodenectomy(PD) and construct a prognostic predictive model for clinical application. Methods: Clinic data of 401 consecutive patients who underwent PD between January 2012 and July 2016 in the First Affiliated Hospital of Harbin Medical University were retrospectively collected and analyzed. The patients were randomly selected to modeling group(n=299) and validation group(n=102) at a ratio of 3∶1. The data of modeling group were subjected to univariate and multivariate analysis for prognostic factors and to construct a prognostic predictive model of DGE after PD. The data of validation group were applied to test the prognostic predictive model. Results: DGE after PD occurred in 35 of 299 patients(11.7%) in the modeling group. The multivariate analysis of the modeling group showed that upper abdominal operation history(χ(2)=6.533, P=0.011), diabetes mellitus(χ(2)=17.872, P=0.000), preoperative hemoglobin predictive model of DGE after PD was constructed based on these factors and successfully tested. The area under the receiver operating characteristic(ROC) curve was 0.761(95%CI: 0.666-0.856) of the modeling group and 0.750(95% CI: 0.577-0.923) of the validation group. Conclusions: Upper abdominal operation history, diabetes mellitus, preoperative hemoglobinmodel is a valid tool to take precautions against DGE after PD.

  14. Prognostic immune-related gene models for breast cancer: a pooled analysis.

    Science.gov (United States)

    Zhao, Jianli; Wang, Ying; Lao, Zengding; Liang, Siting; Hou, Jingyi; Yu, Yunfang; Yao, Herui; You, Na; Chen, Kai

    2017-01-01

    Breast cancer, the most common cancer among women, is a clinically and biologically heterogeneous disease. Numerous prognostic tools have been proposed, including gene signatures. Unlike proliferation-related prognostic gene signatures, many immune-related gene signatures have emerged as principal biology-driven predictors of breast cancer. Diverse statistical methods and data sets were used for building these immune-related prognostic models, making it difficult to compare or use them in clinically meaningful ways. This study evaluated successfully published immune-related prognostic gene signatures through systematic validations of publicly available data sets. Eight prognostic models that were built upon immune-related gene signatures were evaluated. The performances of these models were compared and ranked in ten publicly available data sets, comprising a total of 2,449 breast cancer cases. Predictive accuracies were measured as concordance indices (C-indices). All tests of statistical significance were two-sided. Immune-related gene models performed better in estrogen receptor-negative (ER-) and lymph node-positive (LN+) breast cancer subtypes. The three top-ranked ER- breast cancer models achieved overall C-indices of 0.62-0.63. Two models predicted better than chance for ER+ breast cancer, with C-indices of 0.53 and 0.59, respectively. For LN+ breast cancer, four models showed predictive advantage, with C-indices between 0.56 and 0.61. Predicted prognostic values were positively correlated with ER status when evaluated using univariate analyses in most of the models under investigation. Multivariate analyses indicated that prognostic values of the three models were independent of known clinical prognostic factors. Collectively, these analyses provided a comprehensive evaluation of immune-related prognostic gene signatures. By synthesizing C-indices in multiple independent data sets, immune-related gene signatures were ranked for ER+, ER-, LN+, and LN- breast

  15. A Framework for Model-Based Diagnostics and Prognostics of Switched-Mode Power Supplies

    Science.gov (United States)

    2014-10-02

    consumption, MOSFET voltage, diode reverse voltage, and 47K resistance consumption. ANNUAL CONFERENCE OF THE PROGNOSTICS AND HEALTH MANAGEMENT...methodology based on an equivalent circuit system simulation model developed from a commercially available switch-mode power supply, and empirical...of an integrated simulation model combining two empirical models in the application of SMPS: a circuit -based SMPS simulation model and the

  16. Blood pyrrole-protein adducts as a diagnostic and prognostic index in pyrrolizidine alkaloid-hepatic sinusoidal obstruction syndrome.

    Science.gov (United States)

    Gao, Hong; Ruan, Jianqing Q; Chen, Jie; Li, Na; Ke, Changqiang Q; Ye, Yang; Lin, Ge; Wang, Jiyao Y

    2015-01-01

    The diagnosis of hepatic sinusoidal obstruction syndrome (HSOS) induced by pyrrolizidine alkaloids is mainly based on clinical investigation. There is currently no prognostic index. This study evaluated the quantitative measurement of blood pyrrole-protein adducts (PPAs) as a diagnostic and prognostic index for pyrrolizidine alkaloid-induced HSOS. Suspected drug-induced liver injury patients were prospectively recruited. Blood PPAs were quantitatively measured using ultra-performance liquid chromatography-tandem mass spectrometry. Patients' age, sex, biochemistry test results, and a detailed drug history were recorded. The patients were divided into two groups, ie, those with HSOS induced by pyrrolizidine alkaloid-containing drugs and those with liver injury induced by drugs without pyrrolizidine alkaloids. The relationship between herb administration, clinical outcomes, blood sampling time, and blood PPA concentration in pyrrolizidine alkaloid-associated HSOS patients was analyzed using multiple linear regression analysis. Forty patients met the entry criteria, among whom 23 had pyrrolizidine alkaloid-associated HSOS and 17 had liver injury caused by drugs without pyrrolizidine alkaloids. Among the 23 patients with pyrrolizidine alkaloid-associated HSOS, ten recovered, four developed chronic disease, eight died, and one underwent liver transplantation within 6 months after onset. Blood PPAs were detectable in 24 of 40 patients with concentrations from 0.05 to 74.4 nM. Sensitivity and specificity of the test for diagnosis of pyrrolizidine alkaloid-associated HSOS were 100% (23/23) and 94.1% (23/24), respectively. The positive predictive value was 95.8% and the negative predictive value was 100%, whereas the positive likelihood ratio was 23.81. The level of blood PPAs in the severe group (died or received liver transplantation) was significantly higher than that in the recovery/chronicity group (P=0.004). Blood PPAs measured by ultra-performance liquid

  17. A prognostic model for lung adenocarcinoma patient survival with a focus on four miRNAs.

    Science.gov (United States)

    Li, Xianqiu; An, Zhaoling; Li, Peihui; Liu, Haihua

    2017-09-01

    There is currently no effective biomarker for determining the survival of patients with lung adenocarcinoma. The purpose of the present study was to construct a prognostic survival model using microRNA (miRNA) expression data from patients with lung adenocarcinoma. miRNA data were obtained from The Cancer Genome Atlas, and patients with lung adenocarcinoma were divided into either the training or validation set based on the random allocation principle. The prognostic model focusing on miRNA was constructed, and patients were divided into high-risk or low-risk groups as per the scores, to assess their survival time. The 5-year survival rate from the subgroups within the high- and low-risk groups was assessed. P-values of the prognostic model in the total population, the training set and validation set were 0.0017, 0.01986 and 0.02773, respectively, indicating that the survival time of the lung adenocarcinoma high-risk group was less than that of the low-risk group. Thus, the model had a good assessment effectiveness for the untreated group (P=0.00088) and the Caucasian patient group (P=0.00043). In addition, the model had the best prediction effect for the 5-year survival rate of the Caucasian patient group (AUC=0.629). In conclusion, the prognostic model developed in the present study can be used as an independent prognostic model for patients with lung adenocarcinoma.

  18. Evaluation of body mass index as a prognostic factor in osteoarthrosis of the knee

    Directory of Open Access Journals (Sweden)

    Fabrício Bolpato Loures

    2016-08-01

    Full Text Available ABSTRACT OBJECTIVE: To evaluate the relationship between patients' body mass index (BMI and the degree of radiographic severity of knee osteoarthrosis. METHOD: 117 patients with gonarthrosis were evaluated prospectively. The patients' BMI was calculated and their knee arthrosis was classified in accordance with the modified Ahlbäck criteria. Kruskal-Wallis analysis of variance (ANOVA was used to evaluate the relationship between these two variables. RESULTS: The group classified as Ahlbäck grade V had significantly higher BMI than the others. CONCLUSION: There is a direct relationship between BMI and the degree of radiographic severity of gonarthrosis. Obesity appears to be directly related to the progression of knee osteoarthrosis.

  19. Blood pyrrole-protein adducts as a diagnostic and prognostic index in pyrrolizidine alkaloid-hepatic sinusoidal obstruction syndrome

    Directory of Open Access Journals (Sweden)

    Gao H

    2015-08-01

    Full Text Available Hong Gao,1,* Jianqing Q Ruan,2,* Jie Chen,1 Na Li,2 Changqiang Q Ke,3 Yang Ye,3–5 Ge Lin,2,4,5 Jiyao Y Wang1,61Department of Gastroenterology, Zhongshan Hospital, Fudan University, Shanghai, People’s Republic of China; 2School of Biomedical Sciences, Chinese University of Hong Kong, Hong Kong; 3Shanghai Institute of Materia Medica, Shanghai, People’s Republic of China; 4Joint Research Laboratory for Promoting Globalization of Traditional Chinese Medicines, Shanghai Institute of Materia Medica, 5Chinese University of Hong Kong, Hong Kong; 6Center of Evidence-Based Medicine Fudan University, Shanghai, People’s Republic of China*These authors contributed equally to this work and share first authorship Background: The diagnosis of hepatic sinusoidal obstruction syndrome (HSOS induced by pyrrolizidine alkaloids is mainly based on clinical investigation. There is currently no prognostic index. This study evaluated the quantitative measurement of blood pyrrole-protein adducts (PPAs as a diagnostic and prognostic index for pyrrolizidine alkaloid-induced HSOS.Methods: Suspected drug-induced liver injury patients were prospectively recruited. Blood PPAs were quantitatively measured using ultra-performance liquid chromatography-tandem mass spectrometry. Patients’ age, sex, biochemistry test results, and a detailed drug history were recorded. The patients were divided into two groups, ie, those with HSOS induced by pyrrolizidine alkaloid-containing drugs and those with liver injury induced by drugs without pyrrolizidine alkaloids. The relationship between herb administration, clinical outcomes, blood sampling time, and blood PPA concentration in pyrrolizidine alkaloid-associated HSOS patients was analyzed using multiple linear regression analysis.Results: Forty patients met the entry criteria, among whom 23 had pyrrolizidine alkaloid-associated HSOS and 17 had liver injury caused by drugs without pyrrolizidine alkaloids. Among the 23

  20. The search for stable prognostic models in multiple imputed data sets

    NARCIS (Netherlands)

    Vergouw, D.; Heijmans, M.W.; Peat, G.M.; Kuijpers, T.; Croft, P.R.; de Vet, H.C.W.; van der Horst, H.E.; van der Windt, D.A.W.M.

    2010-01-01

    Background: In prognostic studies model instability and missing data can be troubling factors. Proposed methods for handling these situations are bootstrapping (B) and Multiple imputation (MI). The authors examined the influence of these methods on model composition. Methods: Models were constructed

  1. Maximal amniotic fluid index as a prognostic factor in pregnancies complicated by polyhydramnios.

    Science.gov (United States)

    Pri-Paz, S; Khalek, N; Fuchs, K M; Simpson, L L

    2012-06-01

    Polyhydramnios is present in approximately 2% of pregnancies and has been associated with a variety of adverse pregnancy outcomes. Our aim was to evaluate the association between the maximal amniotic fluid index (AFI) and the frequency of specific adverse outcomes. This was a retrospective chart review of 524 singleton pregnancies diagnosed with polyhydramnios and delivered in a single tertiary referral center between 2003 and 2008. Polyhydramnios was defined as either AFI ≥ 25 cm or a maximum vertical pocket (MVP) ≥ 8 cm even in the presence of AFI polyhydramnios, as based on the maximal AFI (≥ 35 cm; n = 67), was associated with the highest rates of prenatally diagnosed congenital anomalies (79%), preterm delivery (46%), small-for-gestational-age neonate (16%), aneuploidy (13%) and perinatal mortality (27%). No significant association between degree of polyhydramnios and adverse outcome was demonstrated in cases of idiopathic polyhydramnios (n = 253). There is an association between the frequencies of a variety of adverse pregnancy outcomes and the severity of polyhydramnios as reflected by the maximal AFI. Copyright © 2012 ISUOG. Published by John Wiley & Sons, Ltd.

  2. Melanoma prognostic model using tissue microarrays and genetic algorithms.

    Science.gov (United States)

    Gould Rothberg, Bonnie E; Berger, Aaron J; Molinaro, Annette M; Subtil, Antonio; Krauthammer, Michael O; Camp, Robert L; Bradley, William R; Ariyan, Stephan; Kluger, Harriet M; Rimm, David L

    2009-12-01

    As a result of the questionable risk-to-benefit ratio of adjuvant therapies, stage II melanoma is currently managed by observation because available clinicopathologic parameters cannot identify the 20% to 60% of such patients likely to develop metastatic disease. Here, we propose a multimarker molecular prognostic assay that can help triage patients at increased risk of recurrence. Protein expression for 38 candidates relevant to melanoma oncogenesis was evaluated using the automated quantitative analysis (AQUA) method for immunofluorescence-based immunohistochemistry in formalin-fixed, paraffin-embedded specimens from a cohort of 192 primary melanomas collected during 1959 to 1994. The prognostic assay was built using a genetic algorithm and validated on an independent cohort of 246 serial primary melanomas collected from 1997 to 2004. Multiple iterations of the genetic algorithm yielded a consistent five-marker solution. A favorable prognosis was predicted by ATF2 ln(non-nuclear/nuclear AQUA score ratio) of more than -0.052, p21(WAF1) nuclear compartment AQUA score of more than 12.98, p16(INK4A) ln(non-nuclear/nuclear AQUA score ratio) of < or = -0.083, beta-catenin total AQUA score of more than 38.68, and fibronectin total AQUA score of < or = 57.93. Primary tumors that met at least four of these five conditions were considered a low-risk group, and those that met three or fewer conditions formed a high-risk group (log-rank P < .0001). Multivariable proportional hazards analysis adjusting for clinicopathologic parameters shows that the high-risk group has significantly reduced survival on both the discovery (hazard ratio = 2.84; 95% CI, 1.46 to 5.49; P = .002) and validation (hazard ratio = 2.72; 95% CI, 1.12 to 6.58; P = .027) cohorts. This multimarker prognostic assay, an independent determinant of melanoma survival, might be beneficial in improving the selection of stage II patients for adjuvant therapy.

  3. Prognostic significance of ankle-brachial index, brachial-ankle pulse wave velocity, flow-mediated dilation, and nitroglycerin-mediated dilation in end-stage renal disease.

    Science.gov (United States)

    Morimoto, Satoshi; Yurugi, Takatomi; Aota, Yasuko; Sakuma, Takao; Jo, Fusakazu; Nishikawa, Mitsushige; Iwasaka, Toshiji; Maki, Kei

    2009-01-01

    Identifying patients at high risk of cardiovascular disease is important in managing patients undergoing hemodialysis. We evaluated a series of prognostic values: flow-mediated dilation (FMD) and nitrogen-mediated dilation (NMD), an index of endothelium-dependent and endothelium-independent function, respectively, ankle-brachial index (ABI), and brachial-ankle pulse wave velocity (baPWV) in patients undergoing chronic hemodialysis. A cohort of 199 patients was studied. At entry, these values were examined and the prognostic significances were investigated. In estimating the significance of baPWV, patients with ABI hemodialysis patients by means of ABI and baPWV but not FMD or NMD provides complementary information in identifying a high-risk population in these patients.

  4. Analytical correlation of routing table length index and routing path length index in hierarchical routing model

    OpenAIRE

    Lu, Tingrong

    2008-01-01

    In Kleinrock and Kamoun's paper, the inverse relation of routing table length index and routing path length index in hierarchical routing model is illustrated. In this paper we give the analytical correlation of routing table length index and routing path length index in hierarchical routing model.

  5. Enhanced Prognostic Model for Lithium Ion Batteries Based on Particle Filter State Transition Model Modification

    Directory of Open Access Journals (Sweden)

    Buddhi Arachchige

    2017-11-01

    Full Text Available This paper focuses on predicting the End of Life and End of Discharge of Lithium ion batteries using a battery capacity fade model and a battery discharge model. The proposed framework will be able to estimate the Remaining Useful Life (RUL and the Remaining charge through capacity fade and discharge models. A particle filter is implemented that estimates the battery’s State of Charge (SOC and State of Life (SOL by utilizing the battery’s physical data such as voltage, temperature, and current measurements. The accuracy of the prognostic framework has been improved by enhancing the particle filter state transition model to incorporate different environmental and loading conditions without retuning the model parameters. The effect of capacity fade in the reduction of the EOD (End of Discharge time with cycling has also been included, integrating both EOL (End of Life and EOD prediction models in order to get more accuracy in the estimations.

  6. Population-specific prognostic models are needed to stratify outcomes for African-Americans with diffuse large B-cell lymphoma.

    Science.gov (United States)

    Chen, Qiushi; Ayer, Turgay; Nastoupil, Loretta J; Koff, Jean L; Staton, Ashley D; Chhatwal, Jagpreet; Flowers, Christopher R

    2016-01-01

    Diffuse large B-cell lymphoma (DLBCL) demonstrates significant racial differences in age of onset, stage, and survival. To examine whether population-specific models improve prediction of outcomes for African-American (AA) patients with DLBCL, we utilized Surveillance, Epidemiology, and End Results data and compared stratification by the international prognostic index (IPI) in general and AA populations. We also constructed and compared prognostic models for general and AA populations using multivariable logistic regression (LR) and artificial neural network approaches. While the IPI adequately stratified outcomes for the general population, it failed to separate AA DLBCL patients into distinct risk groups. Our AA LR model identified age ≥ 55 (odds ratio 0.45, [95% CI: 0.36, 0.56], male sex (0.75, [0.60, 0.93]), and stage III/IV disease (0.43, [0.34, 0.54]) as adverse predictors of 5-year survival for AA patients. In addition, general-population prognostic models were poorly calibrated for AAs with DLBCL, indicating a need for validated AA-specific prognostic models.

  7. THE ROBUSTNESS OF SINGLE INDEX MODELS IN CROP MARKETS: A MULTIPLE INDEX MODEL TEST

    OpenAIRE

    Blank, Steven C.

    1991-01-01

    The single index model (SIM), developed for analysis of financial assets, is assessed as a tool for evaluating the risk-return tradeoff faced in agricultural enterprise selection. This study tests whether some of the hypotheses underlying the SIM are valid when the SIM is used in agricultural cropping decisions. Empirical evidence from county level data does not support SIM hypotheses, indicating that more robust results might come from multiple index models.

  8. Clinical prediction of 5-year survival in systemic sclerosis: validation of a simple prognostic model in EUSTAR centres

    NARCIS (Netherlands)

    Fransen, J.; Popa-Diaconu, D.A.; Hesselstrand, R.; Carreira, P.; Valentini, G.; Beretta, L.; Airo, P.; Inanc, M.; Ullman, S.; Balbir-Gurman, A.; Sierakowski, S.; Allanore, Y.; Czirjak, L.; Riccieri, V.; Giacomelli, R.; Gabrielli, A.; Riemekasten, G.; Matucci-Cerinic, M.; Farge, D.; Hunzelmann, N.; Hoogen, F.H. Van den; Vonk, M.C.

    2011-01-01

    OBJECTIVE: Systemic sclerosis (SSc) is associated with a significant reduction in life expectancy. A simple prognostic model to predict 5-year survival in SSc was developed in 1999 in 280 patients, but it has not been validated in other patients. The predictions of a prognostic model are usually

  9. Prognostic models for physical capacity at discharge and 1 year postdischarge from rehabilitation in persons with spinal cord injury

    NARCIS (Netherlands)

    Haisma, J.A.; van der Woude, L.H.V.; Stam, H.J.; Bergen, M.P.; Sluis, T.A.; de Groot, S.; Dallmeijer, A.J.; Bussmann, J.B.J.

    2007-01-01

    Haisma JA, van der Woude LH, Stam HJ, Bergen MP, Sluis TA, de Groot S, Dallmeijer AJ, Bussmann JB. Prognostic models for physical capacity at discharge and 1 year postdischarge from rehabilitation in persons with spinal cord injury. Objective: To develop prognostic models for physical capacity at

  10. External validation of prognostic models to predict risk of gestational diabetes mellitus in one Dutch cohort : prospective multicentre cohort study

    NARCIS (Netherlands)

    Lamain-de Ruiter, Marije; Kwee, Anneke; Naaktgeboren, Christiana A; de Groot, Inge; Evers, Inge M; Groenendaal, Floris; Hering, Yolanda R; Huisjes, Anjoke J M; Kirpestein, Cornel; Monincx, Wilma M; Siljee, Jacqueline E; Van 't Zelfde, Annewil; van Oirschot, Charlotte M; Vankan-Buitelaar, Simone A; Vonk, Mariska A A W; Wiegers, Therese A; Zwart, Joost J; Franx, Arie; Moons, Karel G M; Koster, Maria P H

    2016-01-01

    OBJECTIVE: To perform an external validation and direct comparison of published prognostic models for early prediction of the risk of gestational diabetes mellitus, including predictors applicable in the first trimester of pregnancy. DESIGN: External validation of all published prognostic models in

  11. The prognostic value of pre-operative serum tetranectin, CA-125 and a combined index in women with primary ovarian cancer

    DEFF Research Database (Denmark)

    Høgdall, Claus K; Nørgaard-Pedersen, Bent; Mogensen, Ole

    2002-01-01

    OBJECTIVE: To study the prognostic value of pre-operative serum tetranectin (TN), CA125 levels and a mathematical formula (Index1) in primary ovarian cancer. MATERIALS AND METHODS: The study group consisted of sixty-six patients with varying FIGO stages I-IV. The end-point was death from ovarian....../l (relative hazard for FIGO stages = 3.3 and for TN = 2.6). CONCLUSION: TN was a strong prognostic variable in patients with advanced ovarian cancer. To the contrary, CA125 was a strong prognostic factor in patients with a localised ovarian cancer and of no prognostic value in patients with advanced cancer...... cancer. Evaluation was by univariate life-tables analyses and the multivariate Cox analysis. In the Cox analyses, the variables were tested respectively in actual values and as dichotomy variables with different cut-off levels: 6.7, 7.3 and 8.2 mg/l for TN, 35, 65, 100 and 165 U/ml for CA125. RESULTS...

  12. Improving Clinical Risk Stratification at Diagnosis in Primary Prostate Cancer: A Prognostic Modelling Study.

    Directory of Open Access Journals (Sweden)

    Vincent J Gnanapragasam

    2016-08-01

    new five-stratum risk stratification system was produced, and its prognostic power was compared against the current system, with PCSM as the outcome. The results were analysed using a Cox hazards model, the log-rank test, Kaplan-Meier curves, competing-risks regression, and concordance indices. In the training set, the new risk stratification system identified distinct subgroups with different risks of PCSM in pair-wise comparison (p < 0.0001. Specifically, the new classification identified a very low-risk group (Group 1, a subgroup of intermediate-risk cancers with a low PCSM risk (Group 2, hazard ratio [HR] 1.62 [95% CI 0.96-2.75], and a subgroup of intermediate-risk cancers with an increased PCSM risk (Group 3, HR 3.35 [95% CI 2.04-5.49] (p < 0.0001. High-risk cancers were also sub-classified by the new system into subgroups with lower and higher PCSM risk: Group 4 (HR 5.03 [95% CI 3.25-7.80] and Group 5 (HR 17.28 [95% CI 11.2-26.67] (p < 0.0001, respectively. These results were recapitulated in the testing set and remained robust after inclusion of competing risks. In comparison to the current risk stratification system, the new system demonstrated improved prognostic performance, with a concordance index of 0.75 (95% CI 0.72-0.77 versus 0.69 (95% CI 0.66-0.71 (p < 0.0001. In an external cohort, the new system achieved a concordance index of 0.79 (95% CI 0.75-0.84 for predicting PCSM versus 0.66 (95% CI 0.63-0.69 (p < 0.0001 for the current NICE risk stratification system. The main limitations of the study were that it was registry based and that follow-up was relatively short.A novel and simple five-stratum risk stratification system outperforms the standard three-stratum risk stratification system in predicting the risk of PCSM at diagnosis in men with primary non-metastatic prostate cancer, even when accounting for competing risks. This model also allows delineation of new clinically relevant subgroups of men who might potentially receive more appropriate

  13. Prognostic Model for Survival in Patients With Early Stage Cervical Cancer

    NARCIS (Netherlands)

    Biewenga, Petra; van der Velden, Jacobus; Mol, Ben Willem J.; Stalpers, Lukas J. A.; Schilthuis, Marten S.; van der Steeg, Jan Willem; Burger, Matthé P. M.; Buist, Marrije R.

    2011-01-01

    BACKGROUND: In the management of early stage cervical cancer, knowledge about the prognosis is critical. Although many factors have an impact on survival, their relative importance remains controversial. This study aims to develop a prognostic model for survival in early stage cervical cancer

  14. Prognostic model for chronic hypertension in women with a history of hypertensive pregnancy disorders at term

    NARCIS (Netherlands)

    van der Velde-Visser, S.D.; Hermes, W.; Twisk, J; Franx, A.|info:eu-repo/dai/nl/157009939; Pampus, M.G.; Koopmans, C.; Mol, B. W J; de Groot, J.C.M.J.

    2017-01-01

    Introduction The association between hypertensive pregnancy disorders and cardiovascular disease later in life is well described. In this study we aim to develop a prognostic model from patients characteristics known before, early in, during and after pregnancy to identify women at increased risk of

  15. Prognostic model for survival in patients with early stage cervical cancer.

    Science.gov (United States)

    Biewenga, Petra; van der Velden, Jacobus; Mol, Ben Willem J; Stalpers, Lukas J A; Schilthuis, Marten S; van der Steeg, Jan Willem; Burger, Matthé P M; Buist, Marrije R

    2011-02-15

    In the management of early stage cervical cancer, knowledge about the prognosis is critical. Although many factors have an impact on survival, their relative importance remains controversial. This study aims to develop a prognostic model for survival in early stage cervical cancer patients and to reconsider grounds for adjuvant treatment. A multivariate Cox regression model was used to identify the prognostic weight of clinical and histological factors for disease-specific survival (DSS) in 710 consecutive patients who had surgery for early stage cervical cancer (FIGO [International Federation of Gynecology and Obstetrics] stage IA2-IIA). Prognostic scores were derived by converting the regression coefficients for each prognostic marker and used in a score chart. The discriminative capacity was expressed as the area under the curve (AUC) of the receiver operating characteristic. The 5-year DSS was 92%. Tumor diameter, histological type, lymph node metastasis, depth of stromal invasion, lymph vascular space invasion, and parametrial extension were independently associated with DSS and were included in a Cox regression model. This prognostic model, corrected for the 9% overfit shown by internal validation, showed a fair discriminative capacity (AUC, 0.73). The derived score chart predicting 5-year DSS showed a good discriminative capacity (AUC, 0.85). In patients with early stage cervical cancer, DSS can be predicted with a statistical model. Models, such as that presented here, should be used in clinical trials on the effects of adjuvant treatments in high-risk early cervical cancer patients, both to stratify and to include patients. Copyright © 2010 American Cancer Society.

  16. The search for stable prognostic models in multiple imputed data sets

    Directory of Open Access Journals (Sweden)

    de Vet Henrica CW

    2010-09-01

    Full Text Available Abstract Background In prognostic studies model instability and missing data can be troubling factors. Proposed methods for handling these situations are bootstrapping (B and Multiple imputation (MI. The authors examined the influence of these methods on model composition. Methods Models were constructed using a cohort of 587 patients consulting between January 2001 and January 2003 with a shoulder problem in general practice in the Netherlands (the Dutch Shoulder Study. Outcome measures were persistent shoulder disability and persistent shoulder pain. Potential predictors included socio-demographic variables, characteristics of the pain problem, physical activity and psychosocial factors. Model composition and performance (calibration and discrimination were assessed for models using a complete case analysis, MI, bootstrapping or both MI and bootstrapping. Results Results showed that model composition varied between models as a result of how missing data was handled and that bootstrapping provided additional information on the stability of the selected prognostic model. Conclusion In prognostic modeling missing data needs to be handled by MI and bootstrap model selection is advised in order to provide information on model stability.

  17. Secondary Cutaneous Diffuse Large B-cell Lymphoma has a Higher International Prognostic Index Score and Worse Prognosis Than Diffuse Large B-cell Lymphoma, Leg Type.

    Science.gov (United States)

    Lee, Woo Jin; Won, Kwang Hee; Won, Chong Hyun; Chang, Sung Eun; Choi, Jee Ho; Moon, Kee Chan; Park, Chan-Sik; Huh, Jooryung; Suh, Cheolwon; Lee, Mi Woo

    2016-02-01

    Diffuse large B-cell lymphoma (DLBCL) can be separated into 2 groups: nodal and extranodal disease. The aim of this study was to analyse the clinical features of skin lesions and survival outcomes of cutaneous DLBCL according to the primary tumour site. A total of 44 patients with cutaneous DLBCL were classified as primary cutaneous DLBCL, leg type or cutaneous DLBCL secondary to primary disease. Although skin lesion characteristics did not differ significantly between groups, extensive cutaneous lesions were more often observed in secondary cutaneous DLBCL compared with DLBCL, leg type. Secondary cutaneous DLBCL was more commonly associated with an advanced stage and higher International Prognostic Index score than DLBCL, leg type. DLBCL, leg type demonstrated a better survival outcome than secondary cutaneous DLBCL. The multiplicity of skin lesions and time-point of cutaneous involvement were associated with prognosis in secondary cutaneous DLBCL. Survival outcomes and prognostic factors differ depending on the primary tumour site of cutaneous DLBCL.

  18. The optimal cut-off value of the preoperative prognostic nutritional index for the survival differs according to the TNM stage in hepatocellular carcinoma.

    Science.gov (United States)

    Okamura, Yukiyasu; Sugiura, Teiichi; Ito, Takaaki; Yamamoto, Yusuke; Ashida, Ryo; Uesaka, Katsuhiko

    2017-08-01

    To establish the optimal cut-off value of the preoperative prognostic nutritional index (PNI) for prognosis according to the Tumor Node Metastasis (TNM) stage of hepatocellular carcinoma (HCC) after curative resection. This retrospective study reviewed the records of 375 patients. The optimal cut-off value of the PNI was established according to the TNM stage, and overall survival was compared between the low and high PNI groups. The optimal cut-off value of the PNI decreased with increasing TNM stage, with 52, 47, and 43 patients having stage I, II, and III HCC, respectively. A low preoperative PNI predicted a poorer overall survival than did a high PNI for stage I (P cut-off value for the PNI for prognosis differs among the TNM stages and that the preoperative PNI is a favorable prognostic factor for stage I HCC.

  19. Updating and prospective validation of a prognostic model for high sickness absence.

    Science.gov (United States)

    Roelen, C A M; Heymans, M W; Twisk, J W R; van Rhenen, W; Pallesen, S; Bjorvatn, B; Moen, B E; Magerøy, N

    2015-01-01

    To further develop and validate a Dutch prognostic model for high sickness absence (SA). Three-wave longitudinal cohort study of 2,059 Norwegian nurses. The Dutch prognostic model was used to predict high SA among Norwegian nurses at wave 2. Subsequently, the model was updated by adding person-related (age, gender, marital status, children at home, and coping strategies), health-related (BMI, physical activity, smoking, and caffeine and alcohol intake), and work-related (job satisfaction, job demands, decision latitude, social support at work, and both work-to-family and family-to-work spillover) variables. The updated model was then prospectively validated for predictions at wave 3. 1,557 (77 %) nurses had complete data at wave 2 and 1,342 (65 %) at wave 3. The risk of high SA was under-estimated by the Dutch model, but discrimination between high-risk and low-risk nurses was fair after re-calibration to the Norwegian data. Gender, marital status, BMI, physical activity, smoking, alcohol intake, job satisfaction, job demands, decision latitude, support at the workplace, and work-to-family spillover were identified as potential predictors of high SA. However, these predictors did not improve the model's discriminative ability, which remained fair at wave 3. The prognostic model correctly identifies 73 % of Norwegian nurses at risk of high SA, although additional predictors are needed before the model can be used to screen working populations for risk of high SA.

  20. Urbanization Effects on air Quality and Climate in the Acapulco Area Using a Prognostic Meteorological and air Quality Model

    Science.gov (United States)

    Ortinez, A. A.; Garcia, A. R.; Jazcilevich, A. D.; Caetano, E.; Moya, M. N.; Delgado, J. C.

    2007-05-01

    The effects of urbanization growth on the Acapulco coastal metropolitan area were estimated by using a prognostic meteorological and air quality model. To this end three urbanization scenarios are proposed: The current Acapulco urban area that we call "Control Scenario" and two possible urban growths that we call "Scenario 1" and "Scenario 2". We estimated the urban growth of scenarios 1 and 2, using economic factors, population distribution and historical data. The urban distribution in the "Control Scenario" was taken from the aerial photographs of Acapulco and processed by a Geographic Information System (GIS).The variables devised for the scenarios comparison was a Comfort Index based on humidity and temperature and the Potential Exposure Index for Ozone. The model used was the Penn State/NCAR MM5 mesoscale meteorological model and the Multiscale Climate and Chemistry Model (MCCM). Since there is no local information, the emissions were estimated by using data of similar socio- economic urban areas where emission data is available. The meteorology and air quality models were calibrated using data of a measuring campaign performed in December 2005. This is a preliminary effort to propose a planned urban expansion for Acapulco from the point of view of air quality and urban climate.

  1. A prognostic factor index for overall survival in patients receiving first-line chemotherapy for HER2-negative advanced breast cancer: an analysis of the ATHENA trial.

    Science.gov (United States)

    Llombart-Cussac, Antonio; Pivot, Xavier; Biganzoli, Laura; Cortes-Funes, Hernan; Pritchard, Kathleen I; Pierga, Jean-Yves; Smith, Ian; Thomssen, Christoph; Srock, Stefanie; Sampayo, Miguel; Cortes, Javier

    2014-10-01

    Evidence-based definitions of 'poor-prognosis' or 'aggressive' advanced breast cancer are lacking. We developed a prognostic factor index using data from 2203 patients treated with first-line chemotherapy plus bevacizumab for HER2-negative advanced breast cancer. The risk factors most closely associated with worse OS were: disease-free interval ≤24 months; liver metastases or ≥3 involved organ sites; prior anthracycline and/or taxane therapy; triple-negative breast cancer (TNBC); and performance status 2 or prior analgesic/corticosteroid treatment. Risk of death was increased threefold in patients with ≥3 versus ≤1 risk factors (hazard ratio 3.0 [95% CI 2.6-3.4; p < 0.001]; median 16.0 vs 38.8 months, respectively). This prognostic index may enable identification of patients with a poorer prognosis in whom more intensive systemic regimens may be appropriate. The index may also be considered in designing new trials, although it requires validation in other datasets before extrapolation to non-bevacizumab-containing therapy. ClinicalTrials.gov identifier: NCT00448591. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Physics Based Electrolytic Capacitor Degradation Models for Prognostic Studies under Thermal Overstress

    Science.gov (United States)

    Kulkarni, Chetan S.; Celaya, Jose R.; Goebel, Kai; Biswas, Gautam

    2012-01-01

    Electrolytic capacitors are used in several applications ranging from power supplies on safety critical avionics equipment to power drivers for electro-mechanical actuators. This makes them good candidates for prognostics and health management research. Prognostics provides a way to assess remaining useful life of components or systems based on their current state of health and their anticipated future use and operational conditions. Past experiences show that capacitors tend to degrade and fail faster under high electrical and thermal stress conditions that they are often subjected to during operations. In this work, we study the effects of accelerated aging due to thermal stress on different sets of capacitors under different conditions. Our focus is on deriving first principles degradation models for thermal stress conditions. Data collected from simultaneous experiments are used to validate the desired models. Our overall goal is to derive accurate models of capacitor degradation, and use them to predict performance changes in DC-DC converters.

  3. Prognostic significance of serum uric acid in outpatients with chronic heart failure is complex and related to body mass index: data from the IN-CHF Registry.

    Science.gov (United States)

    Baldasseroni, S; Urso, R; Maggioni, A P; Orso, F; Fabbri, G; Marchionni, N; Tavazzi, L

    2012-05-01

    In the field of cardiovascular diseases, elevated levels of serum uric acid (UA) reflect a marked activation of the xanthine oxidase pathway with increase in free radicals production; it is often associated with an inflammatory state, oxygen consumption and endothelial dysfunction. All these associations have been also confirmed in heart failure (HF) but the pathophysiological role of UA in this setting is not well understood. The aim of this study was to evaluate the prognostic role of UA in outpatients enrolled in the Italian Registry of Congestive Heart Failure (IN-CHF). All patients met the European Society of Cardiology (ESC) criteria for diagnosis of HF. We considered patients with complete clinical data and UA level available at the baseline and at 1-year follow-up. The study population was composed of 877 patients aged 63 ± 12 years. One-year mortality was 10.8% and dead patients had a higher level of UA than survivors (7.1 mg dl⁻¹ vs 6.6 mg dl⁻¹, p < 0.0207). In multivariable full model of analysis, UA did not result in an independent predictor of death in overall population, but only in patients with low body mass index (BMI) (≤22 kg m⁻²) (hazard ratio (HR): 2.38, 95% confidence interval (CI) 1.36-4.18). In this subgroup, a statistically significant gradual relationship between UA and survival was detected starting from values higher than 8 mg dl⁻¹. Elevated level of UA is not an independent predictor of mortality in chronic HF, but it markedly worsens outcome if associated with low level of BMI. This association is likely an indicator of chronic inflammatory and catabolic state. Copyright © 2010 Elsevier B.V. All rights reserved.

  4. Physical Modeling for Anomaly Diagnostics and Prognostics Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Ridgetop developed an innovative, model-driven anomaly diagnostic and fault characterization system for electromechanical actuator (EMA) systems to mitigate...

  5. A Prognostic Model for Development of Profound Shock among Children Presenting with Dengue Shock Syndrome.

    Directory of Open Access Journals (Sweden)

    Phung Khanh Lam

    Full Text Available To identify risk factors and develop a prediction model for the development of profound and recurrent shock amongst children presenting with dengue shock syndrome (DSS.We analyzed data from a prospective cohort of children with DSS recruited at the Paediatric Intensive Care Unit of the Hospital for Tropical Disease in Ho Chi Minh City, Vietnam. The primary endpoint was "profound DSS", defined as ≥2 recurrent shock episodes (for subjects presenting in compensated shock, or ≥1 recurrent shock episodes (for subjects presenting initially with decompensated/hypotensive shock, and/or requirement for inotropic support. Recurrent shock was evaluated as a secondary endpoint. Risk factors were pre-defined clinical and laboratory variables collected at the time of presentation with shock. Prognostic model development was based on logistic regression and compared to several alternative approaches.The analysis population included 1207 children of whom 222 (18% progressed to "profound DSS" and 433 (36% had recurrent shock. Independent risk factors for both endpoints included younger age, earlier presentation, higher pulse rate, higher temperature, higher haematocrit and, for females, worse hemodynamic status at presentation. The final prognostic model for "profound DSS" showed acceptable discrimination (AUC=0.69 for internal validation and calibration and is presented as a simple score-chart.Several risk factors for development of profound or recurrent shock among children presenting with DSS were identified. The score-chart derived from the prognostic models should improve triage and management of children presenting with DSS in dengue-endemic areas.

  6. An updated PREDICT breast cancer prognostication and treatment benefit prediction model with independent validation.

    Science.gov (United States)

    Candido Dos Reis, Francisco J; Wishart, Gordon C; Dicks, Ed M; Greenberg, David; Rashbass, Jem; Schmidt, Marjanka K; van den Broek, Alexandra J; Ellis, Ian O; Green, Andrew; Rakha, Emad; Maishman, Tom; Eccles, Diana M; Pharoah, Paul D P

    2017-05-22

    PREDICT is a breast cancer prognostic and treatment benefit model implemented online. The overall fit of the model has been good in multiple independent case series, but PREDICT has been shown to underestimate breast cancer specific mortality in women diagnosed under the age of 40. Another limitation is the use of discrete categories for tumour size and node status resulting in 'step' changes in risk estimates on moving between categories. We have refitted the PREDICT prognostic model using the original cohort of cases from East Anglia with updated survival time in order to take into account age at diagnosis and to smooth out the survival function for tumour size and node status. Multivariable Cox regression models were used to fit separate models for ER negative and ER positive disease. Continuous variables were fitted using fractional polynomials and a smoothed baseline hazard was obtained by regressing the baseline cumulative hazard for each patients against time using fractional polynomials. The fit of the prognostic models were then tested in three independent data sets that had also been used to validate the original version of PREDICT. In the model fitting data, after adjusting for other prognostic variables, there is an increase in risk of breast cancer specific mortality in younger and older patients with ER positive disease, with a substantial increase in risk for women diagnosed before the age of 35. In ER negative disease the risk increases slightly with age. The association between breast cancer specific mortality and both tumour size and number of positive nodes was non-linear with a more marked increase in risk with increasing size and increasing number of nodes in ER positive disease. The overall calibration and discrimination of the new version of PREDICT (v2) was good and comparable to that of the previous version in both model development and validation data sets. However, the calibration of v2 improved over v1 in patients diagnosed under the age

  7. A prognostic pollen emissions model for climate models (PECM1.0)

    Science.gov (United States)

    Wozniak, Matthew C.; Steiner, Allison L.

    2017-11-01

    We develop a prognostic model called Pollen Emissions for Climate Models (PECM) for use within regional and global climate models to simulate pollen counts over the seasonal cycle based on geography, vegetation type, and meteorological parameters. Using modern surface pollen count data, empirical relationships between prior-year annual average temperature and pollen season start dates and end dates are developed for deciduous broadleaf trees (Acer, Alnus, Betula, Fraxinus, Morus, Platanus, Populus, Quercus, Ulmus), evergreen needleleaf trees (Cupressaceae, Pinaceae), grasses (Poaceae; C3, C4), and ragweed (Ambrosia). This regression model explains as much as 57 % of the variance in pollen phenological dates, and it is used to create a climate-flexible phenology that can be used to study the response of wind-driven pollen emissions to climate change. The emissions model is evaluated in the Regional Climate Model version 4 (RegCM4) over the continental United States by prescribing an emission potential from PECM and transporting pollen as aerosol tracers. We evaluate two different pollen emissions scenarios in the model using (1) a taxa-specific land cover database, phenology, and emission potential, and (2) a plant functional type (PFT) land cover, phenology, and emission potential. The simulated surface pollen concentrations for both simulations are evaluated against observed surface pollen counts in five climatic subregions. Given prescribed pollen emissions, the RegCM4 simulates observed concentrations within an order of magnitude, although the performance of the simulations in any subregion is strongly related to the land cover representation and the number of observation sites used to create the empirical phenological relationship. The taxa-based model provides a better representation of the phenology of tree-based pollen counts than the PFT-based model; however, we note that the PFT-based version provides a useful and climate-flexible emissions model for the

  8. A prognostic pollen emissions model for climate models (PECM1.0

    Directory of Open Access Journals (Sweden)

    M. C. Wozniak

    2017-11-01

    Full Text Available We develop a prognostic model called Pollen Emissions for Climate Models (PECM for use within regional and global climate models to simulate pollen counts over the seasonal cycle based on geography, vegetation type, and meteorological parameters. Using modern surface pollen count data, empirical relationships between prior-year annual average temperature and pollen season start dates and end dates are developed for deciduous broadleaf trees (Acer, Alnus, Betula, Fraxinus, Morus, Platanus, Populus, Quercus, Ulmus, evergreen needleleaf trees (Cupressaceae, Pinaceae, grasses (Poaceae; C3, C4, and ragweed (Ambrosia. This regression model explains as much as 57 % of the variance in pollen phenological dates, and it is used to create a climate-flexible phenology that can be used to study the response of wind-driven pollen emissions to climate change. The emissions model is evaluated in the Regional Climate Model version 4 (RegCM4 over the continental United States by prescribing an emission potential from PECM and transporting pollen as aerosol tracers. We evaluate two different pollen emissions scenarios in the model using (1 a taxa-specific land cover database, phenology, and emission potential, and (2 a plant functional type (PFT land cover, phenology, and emission potential. The simulated surface pollen concentrations for both simulations are evaluated against observed surface pollen counts in five climatic subregions. Given prescribed pollen emissions, the RegCM4 simulates observed concentrations within an order of magnitude, although the performance of the simulations in any subregion is strongly related to the land cover representation and the number of observation sites used to create the empirical phenological relationship. The taxa-based model provides a better representation of the phenology of tree-based pollen counts than the PFT-based model; however, we note that the PFT-based version provides a useful and climate-flexible emissions

  9. Creation of a Prognostic Index for Spine Metastasis to Stratify Survival in Patients Treated With Spinal Stereotactic Radiosurgery: Secondary Analysis of Mature Prospective Trials

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Chad [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Hess, Kenneth [Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Bishop, Andrew J.; Pan, Hubert Y.; Christensen, Eva N. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Yang, James N. [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Tannir, Nizar [Department of Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Amini, Behrang [Department of Diagnostic Radiology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Tatsui, Claudio; Rhines, Laurence [Department of Neurosurgery, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Brown, Paul [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Ghia, Amol, E-mail: ajghia@mdanderson.org [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States)

    2015-09-01

    Purpose: There exists uncertainty in the prognosis of patients following spinal metastasis treatment. We sought to create a scoring system that stratifies patients based on overall survival. Methods and Materials: Patients enrolled in 2 prospective trials investigating stereotactic spine radiation surgery (SSRS) for spinal metastasis with ≥3-year follow-up were analyzed. A multivariate Cox regression model was used to create a survival model. Pretreatment variables included were race, sex, age, performance status, tumor histology, extent of vertebrae involvement, previous therapy at the SSRS site, disease burden, and timing of diagnosis and metastasis. Four survival groups were generated based on the model-derived survival score. Results: Median follow-up in the 206 patients included in this analysis was 70 months (range: 37-133 months). Seven variables were selected: female sex (hazard ratio [HR] = 0.7, P=.02), Karnofsky performance score (HR = 0.8 per 10-point increase above 60, P=.007), previous surgery at the SSRS site (HR = 0.7, P=.02), previous radiation at the SSRS site (HR = 1.8, P=.001), the SSRS site as the only site of metastatic disease (HR = 0.5, P=.01), number of organ systems involved outside of bone (HR = 1.4 per involved system, P<.001), and >5 year interval from initial diagnosis to detection of spine metastasis (HR = 0.5, P<.001). The median survival among all patients was 25.5 months and was significantly different among survival groups (in group 1 [excellent prognosis], median survival was not reached; group 2 reached 32.4 months; group 3 reached 22.2 months; and group 4 [poor prognosis] reached 9.1 months; P<.001). Pretreatment symptom burden was significantly higher in the patient group with poor survival than in the group with excellent survival (all metrics, P<.05). Conclusions: We developed the prognostic index for spinal metastases (PRISM) model, a new model that identified patient subgroups with poor and excellent prognoses.

  10. Model Updating and Uncertainty Management for Aircraft Prognostic Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This proposal addresses the integration of physics-based damage propagation models with diagnostic measures of current state of health in a mathematically rigorous...

  11. Introduction of prognostic rain in ECHAM5: design and Single Column Model simulations

    OpenAIRE

    Posselt, R.; Lohmann, U.

    2007-01-01

    International audience; Prognostic equations for the rain mass mixing ratio and the rain drop number concentration are introduced into the large-scale cloud microphysics parameterization of the ECHAM5 general circulation model (ECHAM5-PROG). To this end, a rain flux from one level to the next with the appropriate fall speed is introduced. This maintains rain water in the atmosphere to be available for the next time step. Rain formation in ECHAM5-PROG is, therefore, less dependent on the autoc...

  12. Bayesian based Prognostic Model for Predictive Maintenance of Offshore Wind Farms

    DEFF Research Database (Denmark)

    Asgarpour, Masoud

    2017-01-01

    The operation and maintenance costs of offshore wind farms can be significantly reduced if existing corrective actions are performed as efficient as possible and if future corrective actions are avoided by performing sufficient preventive actions. In this paper a prognostic model for degradation...... monitoring, fault detection and predictive maintenance of offshore wind components is defined. The diagnostic model defined in this paper is based on degradation, remaining useful lifetime and hybrid inspection threshold models. The defined degradation model is based on an exponential distribution...

  13. Portfolio optimization for index tracking modelling in Malaysia stock market

    Science.gov (United States)

    Siew, Lam Weng; Jaaman, Saiful Hafizah; Ismail, Hamizun

    2016-06-01

    Index tracking is an investment strategy in portfolio management which aims to construct an optimal portfolio to generate similar mean return with the stock market index mean return without purchasing all of the stocks that make up the index. The objective of this paper is to construct an optimal portfolio using the optimization model which adopts regression approach in tracking the benchmark stock market index return. In this study, the data consists of weekly price of stocks in Malaysia market index which is FTSE Bursa Malaysia Kuala Lumpur Composite Index from January 2010 until December 2013. The results of this study show that the optimal portfolio is able to track FBMKLCI Index at minimum tracking error of 1.0027% with 0.0290% excess mean return over the mean return of FBMKLCI Index. The significance of this study is to construct the optimal portfolio using optimization model which adopts regression approach in tracking the stock market index without purchasing all index components.

  14. Prognostic factors for urachal cancer: a bayesian model-averaging approach.

    Science.gov (United States)

    Kim, In Kyong; Lee, Joo Yong; Kwon, Jong Kyou; Park, Jae Joon; Cho, Kang Su; Ham, Won Sik; Hong, Sung Joon; Yang, Seung Choul; Choi, Young Deuk

    2014-09-01

    This study was conducted to evaluate prognostic factors and cancer-specific survival (CSS) in a cohort of 41 patients with urachal carcinoma by use of a Bayesian model-averaging approach. Our cohort included 41 patients with urachal carcinoma who underwent extended partial cystectomy, total cystectomy, transurethral resection, chemotherapy, or radiotherapy at a single institute. All patients were classified by both the Sheldon and the Mayo staging systems according to histopathologic reports and preoperative radiologic findings. Kaplan-Meier survival curves and Cox proportional-hazards regression models were carried out to investigate prognostic factors, and a Bayesian model-averaging approach was performed to confirm the significance of each variable by using posterior probabilities. The mean age of the patients was 49.88 ± 13.80 years and the male-to-female ratio was 24:17. The median follow-up was 5.42 years (interquartile range, 2.8-8.4 years). Five- and 10-year CSS rates were 55.9% and 43.4%, respectively. Lower Sheldon (p=0.004) and Mayo (pcancer-specific mortality in urachal carcinoma. The Mayo staging system might be more effective than the Sheldon staging system. In addition, the multivariate analyses suggested that tumor size may be a prognostic factor for urachal carcinoma.

  15. Watershed modeling tools and data for prognostic and diagnostic

    Science.gov (United States)

    Chambel-Leitao, P.; Brito, D.; Neves, R.

    2009-04-01

    When eutrophication is considered an important process to control it can be accomplished reducing nitrogen and phosphorus losses from both point and nonpoint sources and helping to assess the effectiveness of the pollution reduction strategy. HARP-NUT guidelines (Guidelines on Harmonized Quantification and Reporting Procedures for Nutrients) (Borgvang & Selvik, 2000) are presented by OSPAR as the best common quantification and reporting procedures for calculating the reduction of nutrient inputs. In 2000, OSPAR HARP-NUT guidelines on a trial basis. They were intended to serve as a tool for OSPAR Contracting Parties to report, in a harmonized manner, their different commitments, present or future, with regard to nutrients under the OSPAR Convention, in particular the "Strategy to Combat Eutrophication". HARP-NUT Guidelines (Borgvang and Selvik, 2000; Schoumans, 2003) were developed to quantify and report on the individual sources of nitrogen and phosphorus discharges/losses to surface waters (Source Orientated Approach). These results can be compared to nitrogen and phosphorus figures with the total riverine loads measured at downstream monitoring points (Load Orientated Approach), as load reconciliation. Nitrogen and phosphorus retention in river systems represents the connecting link between the "Source Orientated Approach" and the "Load Orientated Approach". Both approaches are necessary for verification purposes and both may be needed for providing the information required for the various commitments. Guidelines 2,3,4,5 are mainly concerned with the sources estimation. They present a set of simple calculations that allow the estimation of the origin of loads. Guideline 6 is a particular case where the application of a model is advised, in order to estimate the sources of nutrients from diffuse sources associated with land use/land cover. The model chosen for this was SWAT (Arnold & Fohrer, 2005) model because it is suggested in the guideline 6 and because it

  16. A Consistent Pricing Model for Index Options and Volatility Derivatives

    DEFF Research Database (Denmark)

    Kokholm, Thomas

    We propose and study a flexible modeling framework for the joint dynamics of an index and a set of forward variance swap rates written on this index, allowing options on forward variance swaps and options on the underlying index to be priced consistently. Our model reproduces various empirically ...

  17. Introduction of prognostic rain in ECHAM5: design and single column model simulations

    Directory of Open Access Journals (Sweden)

    R. Posselt

    2008-06-01

    Full Text Available Prognostic equations for the rain mass mixing ratio and the rain drop number concentration are introduced into the large-scale cloud microphysics parameterization of the ECHAM5 general circulation model (ECHAM5-PROG. To this end, a rain flux from one level to the next with the appropriate fall speed is introduced. This maintains rain water in the atmosphere to be available for the next time step. Rain formation in ECHAM5-PROG is, therefore, less dependent on the autoconversion rate than the standard ECHAM5 but shifts the emphasis towards the accretion rates in accordance with observations. ECHAM5-PROG is tested and evaluated with Single Column Model (SCM simulations for two cases: the marine stratocumulus study EPIC (October 2001 and the continental mid-latitude ARM Cloud IOP (shallow frontal cloud case – March 2000. In case of heavy precipitation events, the prognostic equations for rain hardly affect the amount and timing of precipitation at the surface in different SCM simulations because heavy rain depends mainly on the large-scale forcing. In case of thin, drizzling clouds (i.e., stratocumulus, surface precipitation is sensitive to the number of sub-time steps used in the prognostic rain scheme. Cloud microphysical quantities, such as cloud liquid and rain water within the atmosphere, are sensitive to the number of sub-time steps in both considered cases. This results from the decreasing autoconversion rate and increasing accretion rate.

  18. Climate feedbacks in a general circulation model incorporating prognostic clouds

    Energy Technology Data Exchange (ETDEWEB)

    Colman, R.; Fraser, J. [Bureau of Meteorology Research Centre, Melbourne, Vic. (Australia); Rotstayn, L. [CSIRO Atmospheric Research, Aspendale (Australia)

    2001-11-01

    This study performs a comprehensive feedback analysis on the Bureau of Meteorology Research Centre General Circulation Model, quantifying all important feedbacks operating under an increase in atmospheric CO{sub 2}. The individual feedbacks are analysed in detail, using an offline radiation perturbation method, looking at long- and shortwave components, latitudinal distributions, cloud impacts, non-linearities under 2xCO{sub 2} and 4xCO{sub 2} warmings and at interannual variability. The water vapour feedback is divided into terms due to moisture height and amount changes. The net cloud feedback is separated into terms due to cloud amount, height, water content, water phase, physical thickness and convective cloud fraction. Globally the most important feedbacks were found to be (from strongest positive to strongest negative) those due to water vapour, clouds, surface albedo, lapse rate and surface temperature. For the longwave (LW) response the most important term of the cloud 'optical property' feedbacks is due to the water content. In the shortwave (SW), both water content and water phase changes are important. Cloud amount and height terms are also important for both LW and SW. Feedbacks due to physical cloud thickness and convective cloud fraction are found to be relatively small. All cloud component feedbacks (other than height) produce conflicting LW/SW feedbacks in the model. Furthermore, the optical property and cloud fraction feedbacks are also of opposite sign. The result is that the net cloud feedback is the (relatively small) product of conflicting physical processes. Non-linearities in the feedbacks are found to be relatively small for all but the surface albedo response and some cloud component contributions. The cloud impact on non-cloud feedbacks is also discussed: greatest impact is on the surface albedo, but impact on water vapour feedback is also significant. The analysis method here proves to be a powerful tool for detailing the

  19. A simplified prognostic model to predict mortality in patients with acute variceal bleeding.

    Science.gov (United States)

    Lee, Han Hee; Park, Jae Myung; Han, Seunghoon; Park, Sung Min; Kim, Hee Yeon; Oh, Jung Hwan; Kim, Chang Wook; Yoon, Seung Kew; Choi, Myung-Gyu

    2017-11-24

    Acute variceal bleeding (AVB) is a major cause of death in patients with liver cirrhosis. The aim of this study was to investigate mortality predictors and develop a new simple prognostic model using easily verified factors at admission in AVB patients. Between January 2009 and May 2015, 333 consecutive patients with AVB were included. A simplified prognostic model was developed using multiple logistic regression after identifying significant predictors of 6-week mortality. Mortality prediction accuracy was assessed with area under the receiver operating characteristic (AUROC) curve. We compared the new model to existing models of model for end-stage liver disease (MELD) and Child-Pugh scores. The 6-week overall mortality rate was 12.9%. Multivariate analysis showed that C-reactive protein (CRP), total bilirubin, and the international normalized ratio were independent predictors of mortality. A new logistic model using these variables was developed. This model's AUROC was 0.834, which was significantly higher than that of MELD (0.764) or Child-Pugh scores (0.699). Two external validation studies showed that the AUROC of our model was consistently higher than 0.8. Our new simplified model accurately and consistently predicted 6-week mortality in patients with AVB using objective variables measured at admission. Our system can be used to identify high risk AVB patients. Copyright © 2017 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

  20. A prognostic model of triple-negative breast cancer based on miR-27b-3p and node status.

    Directory of Open Access Journals (Sweden)

    Songjie Shen

    Full Text Available Triple-negative breast cancer (TNBC is an aggressive but heterogeneous subtype of breast cancer. This study aimed to identify and validate a prognostic signature for TNBC patients to improve prognostic capability and to guide individualized treatment.We retrospectively analyzed the prognostic performance of clinicopathological characteristics and miRNAs in a training set of 58 patients with invasive ductal TNBC diagnosed between 2002 and 2012. A prediction model was developed based on independent clinicopathological and miRNA covariates. The prognostic value of the model was further validated in a separate set of 41 TNBC patients diagnosed between 2007 and 2008.Only lymph node status was marginally significantly associated with poor prognosis of TNBC (P = 0.054, whereas other clinicopathological factors, including age, tumor size, histological grade, lymphovascular invasion, P53 status, Ki-67 index, and type of surgery, were not. The expression levels of miR-27b-3p, miR-107, and miR-103a-3p were significantly elevated in the metastatic group compared with the disease-free group (P value: 0.008, 0.005, and 0.050, respectively. The Cox proportional hazards regression analysis revealed that lymph node status and miR-27b-3p were independent predictors of poor prognosis (P value: 0.012 and 0.027, respectively. A logistic regression model was developed based on these two independent covariates, and the prognostic value of the model was subsequently confirmed in a separate validation set. The two different risk groups, which were stratified according to the model, showed significant differences in the rates of distant metastasis and breast cancer-related death not only in the training set (P value: 0.001 and 0.040, respectively but also in the validation set (P value: 0.013 and 0.012, respectively.This model based on miRNA and node status covariates may be used to stratify TNBC patients into different prognostic subgroups for potentially

  1. Reduced nonlinear prognostic model construction from high-dimensional data

    Science.gov (United States)

    Gavrilov, Andrey; Mukhin, Dmitry; Loskutov, Evgeny; Feigin, Alexander

    2017-04-01

    Construction of a data-driven model of evolution operator using universal approximating functions can only be statistically justified when the dimension of its phase space is small enough, especially in the case of short time series. At the same time in many applications real-measured data is high-dimensional, e.g. it is space-distributed and multivariate in climate science. Therefore it is necessary to use efficient dimensionality reduction methods which are also able to capture key dynamical properties of the system from observed data. To address this problem we present a Bayesian approach to an evolution operator construction which incorporates two key reduction steps. First, the data is decomposed into a set of certain empirical modes, such as standard empirical orthogonal functions or recently suggested nonlinear dynamical modes (NDMs) [1], and the reduced space of corresponding principal components (PCs) is obtained. Then, the model of evolution operator for PCs is constructed which maps a number of states in the past to the current state. The second step is to reduce this time-extended space in the past using appropriate decomposition methods. Such a reduction allows us to capture only the most significant spatio-temporal couplings. The functional form of the evolution operator includes separately linear, nonlinear (based on artificial neural networks) and stochastic terms. Explicit separation of the linear term from the nonlinear one allows us to more easily interpret degree of nonlinearity as well as to deal better with smooth PCs which can naturally occur in the decompositions like NDM, as they provide a time scale separation. Results of application of the proposed method to climate data are demonstrated and discussed. The study is supported by Government of Russian Federation (agreement #14.Z50.31.0033 with the Institute of Applied Physics of RAS). 1. Mukhin, D., Gavrilov, A., Feigin, A., Loskutov, E., & Kurths, J. (2015). Principal nonlinear dynamical

  2. Forecasting Analysis of Shanghai Stock Index Based on ARIMA Model

    Directory of Open Access Journals (Sweden)

    Li Chenggang

    2017-01-01

    Full Text Available Prediction and analysis of the Shanghai Composite Index is conducive for investors to investing in the stock market, and providing investors with reference. This paper selects Shanghai Composite Index monthly closing price from Jan, 2005 to Oct, 2016 to construct ARIMA model. This paper carries on the forecast of the last three monthly closing price of Shanghai Stock Index that have occurred, and compared it with the actual value, which tests the accuracy and feasibility of the model in the short term Shanghai Stock Index forecast. At last, this paper uses the ARIMA model to forecast the Shanghai Composite Index closing price of the last two months in 2016.

  3. No prognostic value added by vitamin D pathway SNPs to current prognostic system for melanoma survival.

    Science.gov (United States)

    Luo, Li; Orlow, Irene; Kanetsky, Peter A; Thomas, Nancy E; Fang, Shenying; Lee, Jeffrey E; Berwick, Marianne; Lee, Ji-Hyun

    2017-01-01

    The prognostic improvement attributed to genetic markers over current prognostic system has not been well studied for melanoma. The goal of this study is to evaluate the added prognostic value of Vitamin D Pathway (VitD) SNPs to currently known clinical and demographic factors such as age, sex, Breslow thickness, mitosis and ulceration (CDF). We utilized two large independent well-characterized melanoma studies: the Genes, Environment, and Melanoma (GEM) and MD Anderson studies, and performed variable selection of VitD pathway SNPs and CDF using Random Survival Forest (RSF) method in addition to Cox proportional hazards models. The Harrell's C-index was used to compare the performance of model predictability. The population-based GEM study enrolled 3,578 incident cases of cutaneous melanoma (CM), and the hospital-based MD Anderson study consisted of 1,804 CM patients. Including both VitD SNPs and CDF yielded C-index of 0.85, which provided slight but not significant improvement by CDF alone (C-index = 0.83) in the GEM study. Similar results were observed in the independent MD Anderson study (C-index = 0.84 and 0.83, respectively). The Cox model identified no significant associations after adjusting for multiplicity. Our results do not support clinically significant prognostic improvements attributable to VitD pathway SNPs over current prognostic system for melanoma survival.

  4. No prognostic value added by vitamin D pathway SNPs to current prognostic system for melanoma survival.

    Directory of Open Access Journals (Sweden)

    Li Luo

    Full Text Available The prognostic improvement attributed to genetic markers over current prognostic system has not been well studied for melanoma. The goal of this study is to evaluate the added prognostic value of Vitamin D Pathway (VitD SNPs to currently known clinical and demographic factors such as age, sex, Breslow thickness, mitosis and ulceration (CDF. We utilized two large independent well-characterized melanoma studies: the Genes, Environment, and Melanoma (GEM and MD Anderson studies, and performed variable selection of VitD pathway SNPs and CDF using Random Survival Forest (RSF method in addition to Cox proportional hazards models. The Harrell's C-index was used to compare the performance of model predictability. The population-based GEM study enrolled 3,578 incident cases of cutaneous melanoma (CM, and the hospital-based MD Anderson study consisted of 1,804 CM patients. Including both VitD SNPs and CDF yielded C-index of 0.85, which provided slight but not significant improvement by CDF alone (C-index = 0.83 in the GEM study. Similar results were observed in the independent MD Anderson study (C-index = 0.84 and 0.83, respectively. The Cox model identified no significant associations after adjusting for multiplicity. Our results do not support clinically significant prognostic improvements attributable to VitD pathway SNPs over current prognostic system for melanoma survival.

  5. Simplified prognostic model for critically ill patients in resource limited settings in South Asia.

    Science.gov (United States)

    Haniffa, Rashan; Mukaka, Mavuto; Munasinghe, Sithum Bandara; De Silva, Ambepitiyawaduge Pubudu; Jayasinghe, Kosala Saroj Amarasiri; Beane, Abi; de Keizer, Nicolette; Dondorp, Arjen M

    2017-10-17

    Current critical care prognostic models are predominantly developed in high-income countries (HICs) and may not be feasible in intensive care units (ICUs) in lower- and middle-income countries (LMICs). Existing prognostic models cannot be applied without validation in LMICs as the different disease profiles, resource availability, and heterogeneity of the population may limit the transferability of such scores. A major shortcoming in using such models in LMICs is the unavailability of required measurements. This study proposes a simplified critical care prognostic model for use at the time of ICU admission. This was a prospective study of 3855 patients admitted to 21 ICUs from Bangladesh, India, Nepal, and Sri Lanka who were aged 16 years and over and followed to ICU discharge. Variables captured included patient age, admission characteristics, clinical assessments, laboratory investigations, and treatment measures. Multivariate logistic regression was used to develop three models for ICU mortality prediction: model 1 with clinical, laboratory, and treatment variables; model 2 with clinical and laboratory variables; and model 3, a purely clinical model. Internal validation based on bootstrapping (1000 samples) was used to calculate discrimination (area under the receiver operating characteristic curve (AUC)) and calibration (Hosmer-Lemeshow C-Statistic; higher values indicate poorer calibration). Comparison was made with the Acute Physiology and Chronic Health Evaluation (APACHE) II and Simplified Acute Physiology Score (SAPS) II models. Model 1 recorded the respiratory rate, systolic blood pressure, Glasgow Coma Scale (GCS), blood urea, haemoglobin, mechanical ventilation, and vasopressor use on ICU admission. Model 2, named TropICS (Tropical Intensive Care Score), included emergency surgery, respiratory rate, systolic blood pressure, GCS, blood urea, and haemoglobin. Model 3 included respiratory rate, emergency surgery, and GCS. AUC was 0.818 (95% confidence

  6. A hybrid prognostic model for multistep ahead prediction of machine condition

    Science.gov (United States)

    Roulias, D.; Loutas, T. H.; Kostopoulos, V.

    2012-05-01

    Prognostics are the future trend in condition based maintenance. In the current framework a data driven prognostic model is developed. The typical procedure of developing such a model comprises a) the selection of features which correlate well with the gradual degradation of the machine and b) the training of a mathematical tool. In this work the data are taken from a laboratory scale single stage gearbox under multi-sensor monitoring. Tests monitoring the condition of the gear pair from healthy state until total brake down following several days of continuous operation were conducted. After basic pre-processing of the derived data, an indicator that correlated well with the gearbox condition was obtained. Consecutively the time series is split in few distinguishable time regions via an intelligent data clustering scheme. Each operating region is modelled with a feed-forward artificial neural network (FFANN) scheme. The performance of the proposed model is tested by applying the system to predict the machine degradation level on unseen data. The results show the plausibility and effectiveness of the model in following the trend of the timeseries even in the case that a sudden change occurs. Moreover the model shows ability to generalise for application in similar mechanical assets.

  7. Predicting Overall Survival After Stereotactic Ablative Radiation Therapy in Early-Stage Lung Cancer: Development and External Validation of the Amsterdam Prognostic Model

    Energy Technology Data Exchange (ETDEWEB)

    Louie, Alexander V., E-mail: Dr.alexlouie@gmail.com [Department of Radiation Oncology, VU University Medical Center, Amsterdam (Netherlands); Department of Radiation Oncology, London Regional Cancer Program, University of Western Ontario, London, Ontario (Canada); Department of Epidemiology, Harvard School of Public Health, Harvard University, Boston, Massachusetts (United States); Haasbeek, Cornelis J.A. [Department of Radiation Oncology, VU University Medical Center, Amsterdam (Netherlands); Mokhles, Sahar [Department of Cardio-Thoracic Surgery, Erasmus University Medical Center, Rotterdam (Netherlands); Rodrigues, George B. [Department of Radiation Oncology, London Regional Cancer Program, University of Western Ontario, London, Ontario (Canada); Stephans, Kevin L. [Department of Radiation Oncology, Taussig Cancer Institute, Cleveland Clinic, Cleveland, Ohio (United States); Lagerwaard, Frank J. [Department of Radiation Oncology, VU University Medical Center, Amsterdam (Netherlands); Palma, David A. [Department of Radiation Oncology, London Regional Cancer Program, University of Western Ontario, London, Ontario (Canada); Videtic, Gregory M.M. [Department of Radiation Oncology, Taussig Cancer Institute, Cleveland Clinic, Cleveland, Ohio (United States); Warner, Andrew [Department of Radiation Oncology, London Regional Cancer Program, University of Western Ontario, London, Ontario (Canada); Takkenberg, Johanna J.M. [Department of Cardio-Thoracic Surgery, Erasmus University Medical Center, Rotterdam (Netherlands); Reddy, Chandana A. [Department of Radiation Oncology, Taussig Cancer Institute, Cleveland Clinic, Cleveland, Ohio (United States); Maat, Alex P.W.M. [Department of Cardio-Thoracic Surgery, Erasmus University Medical Center, Rotterdam (Netherlands); Woody, Neil M. [Department of Radiation Oncology, Taussig Cancer Institute, Cleveland Clinic, Cleveland, Ohio (United States); Slotman, Ben J.; Senan, Suresh [Department of Radiation Oncology, VU University Medical Center, Amsterdam (Netherlands)

    2015-09-01

    Purpose: A prognostic model for 5-year overall survival (OS), consisting of recursive partitioning analysis (RPA) and a nomogram, was developed for patients with early-stage non-small cell lung cancer (ES-NSCLC) treated with stereotactic ablative radiation therapy (SABR). Methods and Materials: A primary dataset of 703 ES-NSCLC SABR patients was randomly divided into a training (67%) and an internal validation (33%) dataset. In the former group, 21 unique parameters consisting of patient, treatment, and tumor factors were entered into an RPA model to predict OS. Univariate and multivariate models were constructed for RPA-selected factors to evaluate their relationship with OS. A nomogram for OS was constructed based on factors significant in multivariate modeling and validated with calibration plots. Both the RPA and the nomogram were externally validated in independent surgical (n=193) and SABR (n=543) datasets. Results: RPA identified 2 distinct risk classes based on tumor diameter, age, World Health Organization performance status (PS) and Charlson comorbidity index. This RPA had moderate discrimination in SABR datasets (c-index range: 0.52-0.60) but was of limited value in the surgical validation cohort. The nomogram predicting OS included smoking history in addition to RPA-identified factors. In contrast to RPA, validation of the nomogram performed well in internal validation (r{sup 2}=0.97) and external SABR (r{sup 2}=0.79) and surgical cohorts (r{sup 2}=0.91). Conclusions: The Amsterdam prognostic model is the first externally validated prognostication tool for OS in ES-NSCLC treated with SABR available to individualize patient decision making. The nomogram retained strong performance across surgical and SABR external validation datasets. RPA performance was poor in surgical patients, suggesting that 2 different distinct patient populations are being treated with these 2 effective modalities.

  8. Predicting Overall Survival After Stereotactic Ablative Radiation Therapy in Early-Stage Lung Cancer: Development and External Validation of the Amsterdam Prognostic Model.

    Science.gov (United States)

    Louie, Alexander V; Haasbeek, Cornelis J A; Mokhles, Sahar; Rodrigues, George B; Stephans, Kevin L; Lagerwaard, Frank J; Palma, David A; Videtic, Gregory M M; Warner, Andrew; Takkenberg, Johanna J M; Reddy, Chandana A; Maat, Alex P W M; Woody, Neil M; Slotman, Ben J; Senan, Suresh

    2015-09-01

    A prognostic model for 5-year overall survival (OS), consisting of recursive partitioning analysis (RPA) and a nomogram, was developed for patients with early-stage non-small cell lung cancer (ES-NSCLC) treated with stereotactic ablative radiation therapy (SABR). A primary dataset of 703 ES-NSCLC SABR patients was randomly divided into a training (67%) and an internal validation (33%) dataset. In the former group, 21 unique parameters consisting of patient, treatment, and tumor factors were entered into an RPA model to predict OS. Univariate and multivariate models were constructed for RPA-selected factors to evaluate their relationship with OS. A nomogram for OS was constructed based on factors significant in multivariate modeling and validated with calibration plots. Both the RPA and the nomogram were externally validated in independent surgical (n = 193) and SABR (n = 543) datasets. RPA identified 2 distinct risk classes based on tumor diameter, age, World Health Organization performance status (PS) and Charlson comorbidity index. This RPA had moderate discrimination in SABR datasets (c-index range: 0.52-0.60) but was of limited value in the surgical validation cohort. The nomogram predicting OS included smoking history in addition to RPA-identified factors. In contrast to RPA, validation of the nomogram performed well in internal validation (r(2) = 0.97) and external SABR (r(2) = 0.79) and surgical cohorts (r(2) = 0.91). The Amsterdam prognostic model is the first externally validated prognostication tool for OS in ES-NSCLC treated with SABR available to individualize patient decision making. The nomogram retained strong performance across surgical and SABR external validation datasets. RPA performance was poor in surgical patients, suggesting that 2 different distinct patient populations are being treated with these 2 effective modalities. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Prognostic significance of the complex "Visceral Adiposity Index" vs. simple anthropometric measures: Tehran lipid and glucose study.

    Science.gov (United States)

    Mohammadreza, Bozorgmanesh; Farzad, Hadaegh; Davoud, Khalili; Fereidoun Prof, Azizi Fereidoun

    2012-03-07

    Visceral adiposity index (VAI) has recently been suggested to be used as a surrogate of visceral adiposity. We examined if VAI could improve predictive performances for CVD of the Framingham's general CVD algorithm (a multivariate model incorporating established CVD risk factors). We compared the predictive abilities of the VAI with those of simple anthropometric measures i.e. BMI, waist-to-height ratio (WHtR) or waist-to-hip ratio (WHpR). In a nine-year population-based follow-up, 6,407 (2,778 men) participants, free of CVD at baseline, aged≥30 years were eligible for the current analysis. The risk of CVD was estimated by incorporating VAI, BMI, WHpR, and WHtR, one at a time, into multivariate accelerated failure time models. We documented 534 CVD events with the annual incidence rate (95%CIs) being 7.3 (6.4-8.3) among women and 13.0 (11.7-14.6) among men. Risk of future CVD increased with increasing levels of VAI among both men and women. VAI was associated with multivariate-adjusted increased risk of incident CVD among women. However, the magnitude of risk conferred by VAI was not significantly higher than those conferred by BMI, WHpR, or WHtR. Among men, after adjustment for established CVD risk factors, VAI was no longer associated with increased risk of CVD. VAI failed to add to the predictive ability of the Framingham general CVD algorithm. Using VAI instead of simple anthropometric measures may lead to loss of much information needed for predicting incident CVD.

  10. A Hidden Semi-Markov Model with Duration-Dependent State Transition Probabilities for Prognostics

    Directory of Open Access Journals (Sweden)

    Ning Wang

    2014-01-01

    Full Text Available Realistic prognostic tools are essential for effective condition-based maintenance systems. In this paper, a Duration-Dependent Hidden Semi-Markov Model (DD-HSMM is proposed, which overcomes the shortcomings of traditional Hidden Markov Models (HMM, including the Hidden Semi-Markov Model (HSMM: (1 it allows explicit modeling of state transition probabilities between the states; (2 it relaxes observations’ independence assumption by accommodating a connection between consecutive observations; and (3 it does not follow the unrealistic Markov chain’s memoryless assumption and therefore it provides a more powerful modeling and analysis capability for real world problems. To facilitate the computation of the proposed DD-HSMM methodology, new forward-backward algorithm is developed. The demonstration and evaluation of the proposed methodology is carried out through a case study. The experimental results show that the DD-HSMM methodology is effective for equipment health monitoring and management.

  11. Modeling Philippine Stock Exchange Composite Index Using Time Series Analysis

    Science.gov (United States)

    Gayo, W. S.; Urrutia, J. D.; Temple, J. M. F.; Sandoval, J. R. D.; Sanglay, J. E. A.

    2015-06-01

    This study was conducted to develop a time series model of the Philippine Stock Exchange Composite Index and its volatility using the finite mixture of ARIMA model with conditional variance equations such as ARCH, GARCH, EG ARCH, TARCH and PARCH models. Also, the study aimed to find out the reason behind the behaviorof PSEi, that is, which of the economic variables - Consumer Price Index, crude oil price, foreign exchange rate, gold price, interest rate, money supply, price-earnings ratio, Producers’ Price Index and terms of trade - can be used in projecting future values of PSEi and this was examined using Granger Causality Test. The findings showed that the best time series model for Philippine Stock Exchange Composite index is ARIMA(1,1,5) - ARCH(1). Also, Consumer Price Index, crude oil price and foreign exchange rate are factors concluded to Granger cause Philippine Stock Exchange Composite Index.

  12. Prognostic Significance of Bcl-2 and p53 Protein Expressions and Ki67 Proliferative Index in Diffuse Large B-cell Lymphoma

    Directory of Open Access Journals (Sweden)

    Betül Bolat Küçükzeybek

    2013-09-01

    Full Text Available Objective: Diffuse large B-cell lymphoma (DLBCL is a high-grade neoplasm that has heterogeneous properties in clinical, morphological, and immunophenotypic aspects. In the present study the effects of p53, Bcl-2, and Ki67 on prognosis and their relationships with clinical parameters were examined. Materials and Methods: Thirty-five patients who had been diagnosed with nodally located DLBCL at İzmir Atatürk Training and Research Hospital between January 1999 and June 2006 were included in the study. The Ann Arbor classification system was used to determine the stage of the patients. The patients were evaluated according to age, sex, stage, B symptoms, extranodal involvement, and lactate dehydrogenase (LDH level as well as immunohistochemically. P53 protein and Bcl-2 oncoprotein expressions and Ki67 proliferation index were assessed immunohistochemically. Results: High Bcl-2 expression was found in 9 patients (25.7%, high p53 expression was found in 10 patients (28.6%, and high Ki67 was observed in 23 patients (65.7%. There was no significant correlation between p53 expression, Bcl-2 expression, or Ki67 proliferation index and age, sex, stage, B symptoms, extranodal involvement, LDH level, and overall survival (p>0.05. We did not find a relationship among p53 expression, Bcl-2 expression, Ki67 proliferation index, and prognosis (p>0.05. There was no significant relationship between overall survival and age, sex, stage, B symptoms, extranodal involvement, or LDH level (p>0.05. Our results revealed that Bcl-2 and p53 protein expressions and Ki67 proliferation index have no effect on overall survival of patients with DLBCL. Conclusion: The prognostic importance of p53 and Bcl-2 protein expressions and Ki67 proliferation index in DLBCL, which has biological and clinical heterogeneity, can be understood in a large series of studies that have subclasses and immunohistochemical markers with optimal cut-off values.

  13. A Consistent Pricing Model for Index Options and Volatility Derivatives

    DEFF Research Database (Denmark)

    Cont, Rama; Kokholm, Thomas

    We propose and study a flexible modeling framework for the joint dynamics of an index and a set of forward variance swap rates written on this index, allowing options on forward variance swaps and options on the underlying index to be priced consistently. Our model reproduces various empirically ...... on S&P 500 across strikes and maturities as well as options on the VIX volatility index. The calibration of the model is done in two steps, first by matching VIX option prices and then by matching prices of options on the underlying....

  14. A Derivative Based Estimator for Semiparametric Index Models

    NARCIS (Netherlands)

    Donkers, A.C.D.; Schafgans, M.

    2003-01-01

    This paper proposes a semiparametric estimator for single- and multiple index models.It provides an extension of the average derivative estimator to the multiple index model setting.The estimator uses the average of the outer product of derivatives and is shown to be root-N consistent and

  15. Model-based prognostics for batteries which estimates useful life and uses a probability density function

    Science.gov (United States)

    Saha, Bhaskar (Inventor); Goebel, Kai F. (Inventor)

    2012-01-01

    This invention develops a mathematical model to describe battery behavior during individual discharge cycles as well as over its cycle life. The basis for the form of the model has been linked to the internal processes of the battery and validated using experimental data. Effects of temperature and load current have also been incorporated into the model. Subsequently, the model has been used in a Particle Filtering framework to make predictions of remaining useful life for individual discharge cycles as well as for cycle life. The prediction performance was found to be satisfactory as measured by performance metrics customized for prognostics for a sample case. The work presented here provides initial steps towards a comprehensive health management solution for energy storage devices.

  16. Glasgow outcome scale at hospital discharge as a prognostic index in patients with severe traumatic brain injury

    Directory of Open Access Journals (Sweden)

    Rosmari A.R.A. Oliveira

    2012-08-01

    Full Text Available OBJECTIVE: Evaluate the Glasgow outcome scale (GOS at discharge (GOS-HD as a prognostic indicator in patients with traumatic brain injury (TBI. METHOD: Retrospective data were collected of 45 patients, with Glasgow coma scale <8, age 25±10 years, 36 men, from medical records. Later, at home visit, two measures were scored: GOS-HD (according to information from family members and GOS LATE (12 months after TBI. RESULTS: At discharge, the ERG showed: vegetative state (VS in 2 (4%, severe disability (SD in 27 (60%, moderate disability (MD in 15 (33% and good recovery (GR in 1 (2%. After 12 months: death in 5 (11%, VS in 1 (2%, SD in 7 (16%, MD in 9 (20% and GR in 23 (51%. Variables associated with poor outcome were: worse GOS-HD (p=0.03, neurosurgical procedures (p=0.008 and the kind of brain injury (p=0.009. CONCLUSION: The GOS-HD was indicator of prognosis in patients with severe TBI.

  17. The prognostic value of tip-to-apex distance (TAD index in intertrochanteric fractures fixed by dynamic hip screw

    Directory of Open Access Journals (Sweden)

    Ali Sadighi

    2012-11-01

    Full Text Available Intertrochanteric fractures (ITFs are the most common type of fractures requiring surgical intervention. They also have the highest surgical mortality among orthopedic operations. Among the many different techniques used for fixation of this type of fracture, use of the Dynamic Hip Screw (DHS has gained wide acceptance. This current study was designed to assess positive predictive value of tip-to-apex distance (TAD index in the prognosis of patients treated with DHS. The study was designed according to a descriptive-analytic protocol, made up of 100 cases of ITFs caused by falling, treated in the Shohada Orthopedic Center, Tabriz, Iran. All patients underwent lateral and antero-posterior hip X-ray to measure TAD index. The cohort was followed for three months after DHS placement. Of a total of 100 cases (53 male, 47 female with a mean age of 76.7 years (range 29-100 years, 43% had grade 4, 29% grade 3, 21% grade 5, 5% grade 2 and 2% grade 6 osteoporosis. The screw position was postero-inferior in 57%, central in 40% and superior in 3% of patients. Minimum and maximum TAD index were 20 and 28 mm, respectively. Mean TAD was 23.5 mm. There were no post-operative complications in 84% of cases. Screw failure was the most common complication in the remaining 16% of patients. The study shows a statistically significant correlation between TAD index and cut-off rate in patients with intertrochanteric fractures of femoral bone treated by DHS. This validates the use of TAD index in determining the prognosis of patients treated by DHS.

  18. A Prognostic Model for One-year Mortality in Patients Requiring Prolonged Mechanical Ventilation

    Science.gov (United States)

    Carson, Shannon S.; Garrett, Joanne; Hanson, Laura C.; Lanier, Joyce; Govert, Joe; Brake, Mary C.; Landucci, Dante L.; Cox, Christopher E.; Carey, Timothy S.

    2009-01-01

    Objective A measure that identifies patients who are at high risk of mortality after prolonged ventilation will help physicians communicate prognosis to patients or surrogate decision-makers. Our objective was to develop and validate a prognostic model for 1-year mortality in patients ventilated for 21 days or more. Design Prospective cohort study. Setting University-based tertiary care hospital Patients 300 consecutive medical, surgical, and trauma patients requiring mechanical ventilation for at least 21 days were prospectively enrolled. Measurements and Main Results Predictive variables were measured on day 21 of ventilation for the first 200 patients and entered into logistic regression models with 1-year and 3-month mortality as outcomes. Final models were validated using data from 100 subsequent patients. One-year mortality was 51% in the development set and 58% in the validation set. Independent predictors of mortality included requirement for vasopressors, hemodialysis, platelet count ≤150 ×109/L, and age ≥50. Areas under the ROC curve for the development model and validation model were 0.82 (se 0.03) and 0.82 (se 0.05) respectively. The model had sensitivity of 0.42 (se 0.12) and specificity of 0.99 (se 0.01) for identifying patients who had ≥90% risk of death at 1 year. Observed mortality was highly consistent with both 3- and 12-month predicted mortality. These four predictive variables can be used in a simple prognostic score that clearly identifies low risk patients (no risk factors, 15% mortality) and high risk patients (3 or 4 risk factors, 97% mortality). Conclusions Simple clinical variables measured on day 21 of mechanical ventilation can identify patients at highest and lowest risk of death from prolonged ventilation. PMID:18552692

  19. Role of bispectral index monitoring and burst suppression in prognostication following out-of-hospital cardiac arrest: a systematic review protocol.

    Science.gov (United States)

    Eveson, Leanne; Vizcaychipi, Marcela; Patil, Shashank

    2017-09-25

    Out-of-hospital cardiac arrest (OHCA) is associated with significant mortality or may have a poor neurological outcome. Various community-training programmes have improved practices like bystander cardiopulmonary resuscitation (CPR) and early defibrillation using automated external defibrillator (AED). Post-resuscitation care has also changed significantly in the millennium. Interventions like targeted temperature management (TTM), avoidance of hyperoxia and emergency cardiac catheterisation have given patients a chance of a better neurological outcome. Despite these timely interventions, it is still very difficult to predict neurological outcome. The European Resuscitation Council and European Society of Intensive Care Medicine (ERC-ESICM) published guidance in 2015 with a strong recommendation to delay prognostication for at least 72 h and with an emphasis to adapt a multimodal approach, which includes neurological examination, biomarkers, electroencephalogram (EEG) and radiological tests. These interventions not only have cost attached to them, but the unpredictability has a significant emotional impact on family members. Bispectral index (BIS) monitoring device acts on the principle of EEG and converts the waveform into an absolute number and also measures the burst suppression. We hypothesize that patients who have a low BIS value and high burst suppression within 24 h of presentation will have a poor neurological outcome. The primary objective of this review is to look at BIS monitor as a tool, which could help bring forward the timing of prognostication. Electronic databases will be systematically searched for randomised controlled trials and prospective or retrospective cohort studies with no language restrictions. The search will be supplemented with grey literature searches of thesis, dissertations and hand searching of relevant journals. Two independent reviewers will screen, select and perform analysis according to the Preferred Reporting Items for

  20. Cross-National Validation of Prognostic Models Predicting Sickness Absence and the Added Value of Work Environment Variables

    NARCIS (Netherlands)

    Roelen, Corne A. M.; Stapelfeldt, Christina M.; Heymans, Martijn W.; van Rhenen, Willem; Labriola, Merete; Nielsen, Claus V.; Bultmann, Ute; Jensen, Chris

    Purpose To validate Dutch prognostic models including age, self-rated health and prior sickness absence (SA) for ability to predict high SA in Danish eldercare. The added value of work environment variables to the models' risk discrimination was also investigated. Methods 2,562 municipal eldercare

  1. Prognostic factors for survival in adult patients with recurrent glioblastoma: a decision-tree-based model.

    Science.gov (United States)

    Audureau, Etienne; Chivet, Anaïs; Ursu, Renata; Corns, Robert; Metellus, Philippe; Noel, Georges; Zouaoui, Sonia; Guyotat, Jacques; Le Reste, Pierre-Jean; Faillot, Thierry; Litre, Fabien; Desse, Nicolas; Petit, Antoine; Emery, Evelyne; Lechapt-Zalcman, Emmanuelle; Peltier, Johann; Duntze, Julien; Dezamis, Edouard; Voirin, Jimmy; Menei, Philippe; Caire, François; Dam Hieu, Phong; Barat, Jean-Luc; Langlois, Olivier; Vignes, Jean-Rodolphe; Fabbro-Peray, Pascale; Riondel, Adeline; Sorbets, Elodie; Zanello, Marc; Roux, Alexandre; Carpentier, Antoine; Bauchet, Luc; Pallud, Johan

    2017-11-20

    We assessed prognostic factors in relation to OS from progression in recurrent glioblastomas. Retrospective multicentric study enrolling 407 (training set) and 370 (external validation set) adult patients with a recurrent supratentorial glioblastoma treated by surgical resection and standard combined chemoradiotherapy as first-line treatment. Four complementary multivariate prognostic models were evaluated: Cox proportional hazards regression modeling, single-tree recursive partitioning, random survival forest, conditional random forest. Median overall survival from progression was 7.6 months (mean, 10.1; range, 0-86) and 8.0 months (mean, 8.5; range, 0-56) in the training and validation sets, respectively (p = 0.900). Using the Cox model in the training set, independent predictors of poorer overall survival from progression included increasing age at histopathological diagnosis (aHR, 1.47; 95% CI [1.03-2.08]; p = 0.032), RTOG-RPA V-VI classes (aHR, 1.38; 95% CI [1.11-1.73]; p = 0.004), decreasing KPS at progression (aHR, 3.46; 95% CI [2.10-5.72]; p < 0.001), while independent predictors of longer overall survival from progression included surgical resection (aHR, 0.57; 95% CI [0.44-0.73]; p < 0.001) and chemotherapy (aHR, 0.41; 95% CI [0.31-0.55]; p < 0.001). Single-tree recursive partitioning identified KPS at progression, surgical resection at progression, chemotherapy at progression, and RTOG-RPA class at histopathological diagnosis, as main survival predictors in the training set, yielding four risk categories highly predictive of overall survival from progression both in training (p < 0.0001) and validation (p < 0.0001) sets. Both random forest approaches identified KPS at progression as the most important survival predictor. Age, KPS at progression, RTOG-RPA classes, surgical resection at progression and chemotherapy at progression are prognostic for survival in recurrent glioblastomas and should inform the treatment decisions.

  2. Multicollinearity in prognostic factor analyses using the EORTC QLQ-C30: identification and impact on model selection.

    Science.gov (United States)

    Van Steen, Kristel; Curran, Desmond; Kramer, Jocelyn; Molenberghs, Geert; Van Vreckem, Ann; Bottomley, Andrew; Sylvester, Richard

    2002-12-30

    Clinical and quality of life (QL) variables from an EORTC clinical trial of first line chemotherapy in advanced breast cancer were used in a prognostic factor analysis of survival and response to chemotherapy. For response, different final multivariate models were obtained from forward and backward selection methods, suggesting a disconcerting instability. Quality of life was measured using the EORTC QLQ-C30 questionnaire completed by patients. Subscales on the questionnaire are known to be highly correlated, and therefore it was hypothesized that multicollinearity contributed to model instability. A correlation matrix indicated that global QL was highly correlated with 7 out of 11 variables. In a first attempt to explore multicollinearity, we used global QL as dependent variable in a regression model with other QL subscales as predictors. Afterwards, standard diagnostic tests for multicollinearity were performed. An exploratory principal components analysis and factor analysis of the QL subscales identified at most three important components and indicated that inclusion of global QL made minimal difference to the loadings on each component, suggesting that it is redundant in the model. In a second approach, we advocate a bootstrap technique to assess the stability of the models. Based on these analyses and since global QL exacerbates problems of multicollinearity, we therefore recommend that global QL be excluded from prognostic factor analyses using the QLQ-C30. The prognostic factor analysis was rerun without global QL in the model, and selected the same significant prognostic factors as before. Copyright 2002 John Wiley & Sons, Ltd.

  3. External validation of prognostic models to predict risk of gestational diabetes mellitus in one Dutch cohort: prospective multicentre cohort study.

    NARCIS (Netherlands)

    Lamain-de Ruiter, M.; Kwee, A.; Naaktgeboren, C.A.; Groot, I. de; Evers, I.M.; Groenendaal, F.; Hering, Y.R.; Huisjes, A.J.M.; Kirpestein, C.; Monincx, W.M.; Siljee, J.E.; Zelfde, A. van't; Oirschot, C.M. van; Vankan-Buitelaar, S.A.; Vonk, M.A.A.W.; Wiegers, T.A.; Zwart, J.J.; Franx, A.; Moons, K.G.M.; Koster, M.P.H.

    2016-01-01

    Objective: To perform an external validation and direct comparison of published prognostic models for early prediction of the risk of gestational diabetes mellitus, including predictors applicable in the first trimester of pregnancy. Design: External validation of all published prognostic models in

  4. An Index for Intersecting Branes in Matrix Models

    Directory of Open Access Journals (Sweden)

    Harold Steinacker

    2013-11-01

    Full Text Available We introduce an index indicating the occurrence of chiral fermions at the intersection of branes in matrix models. This allows to discuss the stability of chiral fermions under perturbations of the branes.

  5. Diagnostic and prognostic values of the V-index, a novel ECG marker quantifying spatial heterogeneity of ventricular repolarization, in patients with symptoms suggestive of non-ST-elevation myocardial infarction.

    Science.gov (United States)

    Abächerli, Roger; Twerenbold, Raphael; Boeddinghaus, Jasper; Nestelberger, Thomas; Mächler, Patrick; Sassi, Roberto; Rivolta, Massimo W; Roonizi, Ebadollah Kheirati; Mainardi, Luca T; Kozhuharov, Nikola; Rubini Giménez, Maria; Wildi, Karin; Grimm, Karin; Sabti, Zaid; Hillinger, Petra; Puelacher, Christian; Strebel, Ivo; Cupa, Janosch; Badertscher, Patrick; Roux, Isabelle; Schmid, Ramun; Leber, Remo; Osswald, Stefan; Mueller, Christian; Reichlin, Tobias

    2017-06-01

    The V-index is an ECG marker quantifying spatial heterogeneity of ventricular repolarization. We prospectively assessed the diagnostic and prognostic values of the V-index in patients with suspected non-ST-elevation myocardial infarction (NSTEMI). We prospectively enrolled 497 patients presenting with suspected NSTEMI to the emergency department (ED). Digital 12-lead ECGs of five-minute duration were recorded at presentation. The V-index was automatically calculated in a blinded fashion. Patients with a QRS duration >120ms were ruled out from analysis. The final diagnosis was adjudicated by two independent cardiologists. The prognostic endpoint was all-cause mortality during 24months of follow-up. NSTEMI was the final diagnosis in 14% of patients. V-index levels were higher in patients with AMI compared to other causes of chest pain (median 23ms vs. 18ms, pV-index in addition to conventional ECG-criteria improved the diagnostic accuracy for the diagnosis of NSTEMI as quantified by area under the ROC curve from 0.66 to 0.73 (p=0.001) and the sensitivity of the ECG for AMI from 41% to 86% (pV-index (pV-index remained an independent predictor of death. The V-index, an ECG marker quantifying spatial heterogeneity of ventricular repolarization, significantly improves the accuracy and sensitivity of the ECG for the diagnosis of NSTEMI and independently predicts mortality during follow-up. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. A prognostic model of therapy-related myelodysplastic syndrome for predicting survival and transformation to acute myeloid leukemia.

    Science.gov (United States)

    Quintás-Cardama, Alfonso; Daver, Naval; Kim, Hawk; Dinardo, Courtney; Jabbour, Elias; Kadia, Tapan; Borthakur, Gautam; Pierce, Sherry; Shan, Jianqin; Cardenas-Turanzas, Marylou; Cortes, Jorge; Ravandi, Farhad; Wierda, William; Estrov, Zeev; Faderl, Stefan; Wei, Yue; Kantarjian, Hagop; Garcia-Manero, Guillermo

    2014-10-01

    We evaluated the characteristics of a cohort of patients with myelodysplastic syndrome (MDS) related to therapy (t-MDS) to create a prognostic model. We identified 281 patients with MDS who had received previous chemotherapy and/or radiotherapy for previous malignancy. Potential prognostic factors were determined using univariate and multivariate analyses. Multivariate Cox regression analysis identified 7 factors that independently predicted short survival in t-MDS: age ≥ 65 years (hazard ratio [HR], 1.63), Eastern Cooperative Oncology Group performance status 2-4 (HR, 1.86), poor cytogenetics (-7 and/or complex; HR, 2.47), World Health Organization MDS subtype (RARs or RAEB-1/2; HR, 1.92), hemoglobin (HR, 2.24), platelets (HR, 2.01), and transfusion dependency (HR, 1.59). These risk factors were used to create a prognostic model that segregated patients into 3 groups with distinct median overall survival: good (0-2 risk factors; 34 months), intermediate (3-4 risk factors; 12 months), and poor (5-7 risk factors; 5 months) (P < .001) and 1-year leukemia-free survival (96%, 84%, and 72%, respectively, P = .003). This model also identified distinct survival groups according to t-MDS therapy. In summary, we devised a prognostic model specifically for patients with t-MDS that predicted overall survival and leukemia-free survival. This model might facilitate the development of risk-adapted therapeutic strategies. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. Prognostics for Microgrid Components

    Science.gov (United States)

    Saxena, Abhinav

    2012-01-01

    Prognostics is the science of predicting future performance and potential failures based on targeted condition monitoring. Moving away from the traditional reliability centric view, prognostics aims at detecting and quantifying the time to impending failures. This advance warning provides the opportunity to take actions that can preserve uptime, reduce cost of damage, or extend the life of the component. The talk will focus on the concepts and basics of prognostics from the viewpoint of condition-based systems health management. Differences with other techniques used in systems health management and philosophies of prognostics used in other domains will be shown. Examples relevant to micro grid systems and subsystems will be used to illustrate various types of prediction scenarios and the resources it take to set up a desired prognostic system. Specifically, the implementation results for power storage and power semiconductor components will demonstrate specific solution approaches of prognostics. The role of constituent elements of prognostics, such as model, prediction algorithms, failure threshold, run-to-failure data, requirements and specifications, and post-prognostic reasoning will be explained. A discussion on performance evaluation and performance metrics will conclude the technical discussion followed by general comments on open research problems and challenges in prognostics.

  8. Prognostic factors in gastric cancer evaluated by using Cox regression model.

    Science.gov (United States)

    Ghiandoni, G; Rocchi, M B; Signoretti, P; Belbusti, F

    1998-06-01

    To identify the most relevant short-term predictor variables in gastric cancer removal. A retrospective survival analysis executed by using the Cox regression model; the follow-up period is included between 18 and 90 months. A district general hospital surgery unit: "Divisione di Chirurgia Generale, Ospedale Civile di Urbino" (Marche, Italy). One hundred and twenty nine consecutive patients operated for gastric cancer. Surgery (total or subtotal gastrectomy). Survival times. Lymph node involvement (N) (p extension (T) (p < 0.001) and the age of the patients (p < 0.05) have been recognized as significant prognostic factors. Results show that the short-term prognosis largely depends on both the earliness of the diagnosis and the age of the patients.

  9. A Consistent Pricing Model for Index Options and Volatility Derivatives

    DEFF Research Database (Denmark)

    Kokholm, Thomas

    We propose a flexible modeling framework for the joint dynamics of an index and a set of forward variance swap rates written on this index. Our model reproduces various empirically observed properties of variance swap dynamics and enables volatility derivatives and options on the underlying index...... to be priced consistently, while allowing for jumps in volatility and returns. An affine specification using Lévy processes as building blocks leads to analytically tractable pricing formulas for volatility derivatives, such as VIX options, as well as efficient numerical methods for pricing of European options...

  10. A Consistent Pricing Model for Index Options and Volatility Derivatives

    DEFF Research Database (Denmark)

    Cont, Rama; Kokholm, Thomas

    2013-01-01

    We propose a flexible modeling framework for the joint dynamics of an index and a set of forward variance swap rates written on this index. Our model reproduces various empirically observed properties of variance swap dynamics and enables volatility derivatives and options on the underlying index...... to be priced consistently, while allowing for jumps in volatility and returns. An affine specification using Lévy processes as building blocks leads to analytically tractable pricing formulas for volatility derivatives, such as VIX options, as well as efficient numerical methods for pricing of European options...

  11. PROGNOSTIC VALUE OF THE BASELINE VALUES OF SERUM TESTOSTERONE AND FREE ANDROGEN INDEX IN PATIENTS WITH PROSTATE CANCER

    Directory of Open Access Journals (Sweden)

    M. E. Grigoryev

    2012-01-01

    Full Text Available The growing incidence of prostate cancer (PC and its variable nature are an important problem today. PC is distinguished by its latent ability in many cases, which makes its screening difficult.Prostate-specific antigen (PSA is one of the most common tumor markers of PC, which are used for mass male screening. However, the detection rate of PC in men with normal PSA values is also very high. This promotes an active search for new markers and predictors of PC.The effect of androgens on hormonal carcinogenesis in the prostate suggests that the analysis of serum testosterone concentrations and free androgen index may be made in patients with low PSA levels in the early diagnosis and prognosis of PC.

  12. The prognostic influence of body mass index, resting energy expenditure and fasting blood glucose on postoperative patients with esophageal cancer.

    Science.gov (United States)

    Wu, Ning; Zhu, Yongjun; Kadel, Dhruba; Pang, Liewen; Chen, Gang; Chen, Zhiming

    2016-12-21

    Body mass index (BMI), resting energy expenditure (REE) and fasting blood glucose (FBG) are major preoperative assessments of patients' nutrition and metabolic state. The relations and effects of these indices on esophageal cancer patients' postoperative short-term and long-term outcomes remain controversial and unclear. We aimed to study the impact of BMI, REE and FBG in esophageal cancer patients undergoing esophagectomy. Three hundred and six esophageal cancer patients who underwent esophagectomy were observed retrospectively. Clinical characteristics, postoperative complications and survival analysis were compared among different BMI, REE and FBG groups. There were significant linear relationships between REE, BMI and FBG indices, patients with low BMI tended to have low REE (p cancer undergoing esophagectomy and preoperative evaluation of these indices help to determine the prognosis in these patients.

  13. A Novel Inflammation- and Nutrition-Based Prognostic System for Patients with Laryngeal Squamous Cell Carcinoma: Combination of Red Blood Cell Distribution Width and Body Mass Index (COR-BMI.

    Directory of Open Access Journals (Sweden)

    Yan Fu

    Full Text Available Laryngeal squamous cell carcinoma (LSCC is a head and neck cancer type. In this study, we introduced a novel inflammation- and nutrition-based prognostic system, referred to as COR-BMI (Combination of red blood cell distribution width and body mass index, for LSCC patients.A total of 807 LSCC patients (784 male and 23 female, 22-87 y of age who underwent surgery were enrolled in this retrospective cohort study. The patients were stratified by COR-BMI into three groups: COR-BMI (0 (RDW ≤ 13.1 and BMI ≥ 25; COR-BMI (1 (RDW ≤ 13.1 and BMI 13.1 and 18.5 ≤ BMI 13.1 and BMI < 18.5. Cox regression models were used to investigate the association between COR-BMI and cancer-specific survival (CSS rate among LSCC patients.The 5-y, 10-y, and 15-y CSS rates were 71.6%, 60.1%, and 55.4%, respectively. There were significant differences among the COR-BMI groups in age (< 60 versus ≥ 60 y; P = 0.005 and T stage (T1, T2, T3, or T4; P = 0.013. Based on the results, COR-BMI (1 versus 0: HR = 1.76; 95% CI = 0.98-3.15; 2 versus 0: HR = 2.91; 95% CI = 1.53-5.54, P = 0.001 was a significant independent predictor of CSS.COR-BMI is a novel inflammation- and nutrition-based prognostic system, which could predict long-term survival in LSCC patients who underwent surgery.

  14. Perspectives in using a remotely sensed dryness index in distributed hydrological models at river basin scale

    DEFF Research Database (Denmark)

    Andersen, J.; Sandholt, Inge; Jensen, Karsten Høgh

    2002-01-01

    Remote Sensing, hydrological modelling, dryness index, surface temperature, vegetation index, Africa, Senegal, soil moisture......Remote Sensing, hydrological modelling, dryness index, surface temperature, vegetation index, Africa, Senegal, soil moisture...

  15. Evaluation of habitat suitability index models for assessing biotic resources

    Science.gov (United States)

    John C. Rennie; Joseph D. Clark; James M. Sweeney

    2000-01-01

    Existing habitat suitability index (HSI) models are evaluated for assessing the biotic resources on Champion International Corporation (CIC) lands with data from a standard and an expanded timber inventory. Forty HSI models for 34 species that occur in the Southern Appalachians have been identified from the literature. All of the variables for 14 models are provided (...

  16. A prognostic model to predict the success of artificial insemination in dairy cows based on readily available data

    NARCIS (Netherlands)

    Rutten, C.J.; Steeneveld, W.; Vernooij, J.C.M.; Huijps, K.; Nielen, M.; Hogeveen, H.

    2016-01-01

    A prognosis of the likelihood of insemination success is valuable information for the decision to start inseminating a cow. This decision is important for the reproduction management of dairy farms. The aim of this study was to develop a prognostic model for the likelihood of successful first

  17. A prognostic model to predict the success of artificial insemination in dairy cows based on readily available data

    NARCIS (Netherlands)

    Rutten, C J|info:eu-repo/dai/nl/353551031; Steeneveld, W|info:eu-repo/dai/nl/304833169; Vernooij, J C M|info:eu-repo/dai/nl/340304596; Huijps, K|info:eu-repo/dai/nl/304837881; Nielen, M|info:eu-repo/dai/nl/123535298; Hogeveen, H|info:eu-repo/dai/nl/126322864

    2016-01-01

    A prognosis of the likelihood of insemination success is valuable information for the decision to start inseminating a cow. This decision is important for the reproduction management of dairy farms. The aim of this study was to develop a prognostic model for the likelihood of successful first

  18. Predicting stabilizing treatment outcomes for complex posttraumatic stress disorder and dissociative identity disorder: an expertise-based prognostic model

    NARCIS (Netherlands)

    Baars, E.W.; van der Hart, O.; Nijenhuis, E.R.S.; Chu, J.A.; Glas, G.; Draaijer, N.

    2011-01-01

    The purpose of this study was to develop an expertise-based prognostic model for the treatment of complex posttraumatic stress disorder (PTSD) and dissociative identity disorder (DID).We developed a survey in 2 rounds: In the first round we surveyed 42 experienced therapists (22 DID and 20 complex

  19. Modification of Simplified Pulmonary Embolism Severity Index and its Prognostic Value in Patients with Acute Pulmonary Embolism.

    Science.gov (United States)

    Ostovan, Mohammad Ali; Ghaffari, Samad; Pourafkari, Leili; Dehghani, Pooyan; Hajizadeh, Reza; Nadiri, Mehdi; Ghaffari, Mohammad Reza

    2016-02-01

    Various risk stratification systems have been used to predict the clinical outcome of patients with pulmonary embolism (PE). In this study we present a modification of the simplified Pulmonary Embolism Severity Index (S-PESI) score and evaluate its accuracy in predicting the outcome of these patients. Patients older than 18 years with documented PE were enrolled in this study. S-PESI was calculated in all patients. We added electrocardiographic evidence of right ventricular strain as a new criteria and replaced the O2 saturation of <90% in S-PESI score with PaO2 /PaCO2 ratio obtained from the arterial blood gas analysis as two newly modified criteria to define a modified form of S-PESI system (modified s-PESI). Patients were followed for about one year in outpatient clinics. Any deaths attributable to PE or for unknown reasons were considered as PE related. We defined Major Adverse Cardio-Pulmonary Events (MACPE) as sum of one-year mortality, need for thrombolysis and mechanical ventilation during index hospitalisation. Among 300 enrolled patients, in-hospital mortality occurred in 38 (12.7%) and one-year mortality in 73 (24.3%) patients. Considering a cut-off point of 3, modified s-PESI score had a lower sensitivity (49.3% vs. 89%) and higher specificity (79.4% vs. 37.7%) than S-PESI to predict one-year mortality. Area Under Curve (AUC) to predict MACPE was significantly higher for modified s-PESI (0.692 vs 0.730, P=0.012). The modified s-PESI is superior to S-PESI in predicting one-year outcome in patients with PE and can be used for more accurate risk stratification of these patients. Copyright © 2015 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.

  20. Implementation of Remaining Useful Lifetime Transformer Models in the Fleet-Wide Prognostic and Health Management Suite

    Energy Technology Data Exchange (ETDEWEB)

    Agarwal, Vivek [Idaho National Lab. (INL), Idaho Falls, ID (United States); Lybeck, Nancy J. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Pham, Binh [Idaho National Lab. (INL), Idaho Falls, ID (United States); Rusaw, Richard [Electric Power Research Inst. (EPRI), Palo Alto, CA (United States); Bickford, Randall [Expert Microsystems, Orangevale, CA (United States)

    2015-02-01

    Research and development efforts are required to address aging and reliability concerns of the existing fleet of nuclear power plants. As most plants continue to operate beyond the license life (i.e., towards 60 or 80 years), plant components are more likely to incur age-related degradation mechanisms. To assess and manage the health of aging plant assets across the nuclear industry, the Electric Power Research Institute has developed a web-based Fleet-Wide Prognostic and Health Management (FW-PHM) Suite for diagnosis and prognosis. FW-PHM is a set of web-based diagnostic and prognostic tools and databases, comprised of the Diagnostic Advisor, the Asset Fault Signature Database, the Remaining Useful Life Advisor, and the Remaining Useful Life Database, that serves as an integrated health monitoring architecture. The main focus of this paper is the implementation of prognostic models for generator step-up transformers in the FW-PHM Suite. One prognostic model discussed is based on the functional relationship between degree of polymerization, (the most commonly used metrics to assess the health of the winding insulation in a transformer) and furfural concentration in the insulating oil. The other model is based on thermal-induced degradation of the transformer insulation. By utilizing transformer loading information, established thermal models are used to estimate the hot spot temperature inside the transformer winding. Both models are implemented in the Remaining Useful Life Database of the FW-PHM Suite. The Remaining Useful Life Advisor utilizes the implemented prognostic models to estimate the remaining useful life of the paper winding insulation in the transformer based on actual oil testing and operational data.

  1. A preoperative low nutritional prognostic index correlates with the incidence of incisional surgical site infections after bowel resection in patients with Crohn's disease.

    Science.gov (United States)

    Maeda, Kiyoshi; Nagahara, Hisashi; Shibutani, Masatsune; Otani, Hiroshi; Sakurai, Katsunobu; Toyokawa, Takahiro; Tanaka, Hiroaki; Kubo, Naoshi; Muguruma, Kazuya; Kamata, Noriko; Yamagami, Hirokazu; Hirakawa, Kosei

    2015-11-01

    The incidence of incisional surgical site infections (SSIs) is reported to be higher among patients with Crohn's disease (CD) than among those with colorectal cancer. It has also been reported that the preoperative nutritional and inflammatory status is associated with the frequency of postoperative complications. Onodera's prognostic nutritional index (OPNI) is a simple and useful parameter for determining the nutritional and inflammatory status. In the present study, we retrospectively investigated the correlation between the OPNI and the incidence of incisional SSI in patients with CD who had undergone bowel resection. A total of 177 CD patients who underwent abdominal surgery were enrolled. Various clinical factors and the OPNI values were evaluated to identify risk factors for incisional SSIs. The incidence of incisional SSIs was 19.8 %. A multivariate analysis indicated that the OPNI was an independent risk factor for incisional SSIs. The results of this retrospective study suggest that the OPNI is an independent risk factor for incisional SSIs in patients with a history of bowel resection for CD.

  2. Prognostic factors in acute mesenteric ischemia and evaluation with Mannheim Peritonitis Index and platelet-to-lymphocyte ratio.

    Science.gov (United States)

    Yılmaz, Eyüp Murat; Cartı, Erdem Barış

    2017-07-01

    Acute mesenteric ischemia (AMI) is a disease that has a very high mortality rate and for which the diagnosis is frequently delayed. The aim of the present study was to assess the predictive value of the Mannheim Peritonitis Index (MPI) and platelet-to-lymphocyte (P/L) ratio in the prognosis of AMI. The files of 34 patients diagnosed with AMI between September 2014 and April 2016 were retrospectively examined. The patients were divided into 2 groups based on survival. The parameters of MPI and P/L ratio, demographic data, and duration of hospitalization were recorded and compared. In all, 19 (55.9%) patients were male, and 15 (44.1%) were female. Total of 19 patients (55.9%) were discharged with a complete recovery, while 15 (44.1%) died. MPI mean value was 21.13±7.55 and 16.00±5.24 in those who died and survived, respectively (p=0.026). P/L ratio was 288.48±233.01 and 373.82±389.62 in those who survived and died, respectively (p=0.045). MPI and P/L ratio are simple and reliable methods to predict the prognosis of AMI.

  3. Multidimensional Geriatric Prognostic Index, Based on a Geriatric Assessment, for Long-Term Survival in Older Adults in Korea.

    Directory of Open Access Journals (Sweden)

    Hee-Won Jung

    Full Text Available The patient´s survival estimate is important for clinical decision-making, especially in frail patients with multimorbidities. We aimed to develop a multidimensional geriatric prognosis index (GPI for 3- and 5-year mortality in community-dwelling elderly and to validate the GPI in a separate hospital-based population. The GPI was constructed using data for 988 participants in the Korean Longitudinal Study on Health and Aging (KLoSHA and cross-validated with 1109 patients who underwent a geriatric assessment at the Seoul National University Bundang Hospital (SNUBH. The GPI, with a total possible score of 8, included age, gender, activities of daily living, instrumental activities of daily living, comorbidities, mood, cognitive function, and nutritional status. During the 5-year observation period, 179 KLoSHA participants (18.1% and 340 SNUBH patients (30.7% died. The c-indices for 3- and 5-year mortality were 0.78 and 0.80, respectively, in the KLoSHA group and 0.73 and 0.80, respectively, in the SNUBH group. Positive linear trends were observed for GPI scores and both 3- and 5-year mortality in both groups. In conclusions, using common components of a geriatric assessment, the GPI can stratify the risk of 3- and 5-year mortality in Korean elderly people both in the community and hospital.

  4. Intercomparisons of Prognostic, Diagnostic, and Inversion Modeling Approaches for Estimation of Net Ecosystem Exchange over the Pacific Northwest Region

    Science.gov (United States)

    Turner, D. P.; Jacobson, A. R.; Nemani, R. R.

    2013-12-01

    The recent development of large spatially-explicit datasets for multiple variables relevant to monitoring terrestrial carbon flux offers the opportunity to estimate the terrestrial land flux using several alternative, potentially complimentary, approaches. Here we developed and compared regional estimates of net ecosystem exchange (NEE) over the Pacific Northwest region of the U.S. using three approaches. In the prognostic modeling approach, the process-based Biome-BGC model was driven by distributed meteorological station data and was informed by Landsat-based coverages of forest stand age and disturbance regime. In the diagnostic modeling approach, the quasi-mechanistic CFLUX model estimated net ecosystem production (NEP) by upscaling eddy covariance flux tower observations. The model was driven by distributed climate data and MODIS FPAR (the fraction of incident PAR that is absorbed by the vegetation canopy). It was informed by coarse resolution (1 km) data about forest stand age. In both the prognostic and diagnostic modeling approaches, emissions estimates for biomass burning, harvested products, and river/stream evasion were added to model-based NEP to get NEE. The inversion model (CarbonTracker) relied on observations of atmospheric CO2 concentration to optimize prior surface carbon flux estimates. The Pacific Northwest is heterogeneous with respect to land cover and forest management, and repeated surveys of forest inventory plots support the presence of a strong regional carbon sink. The diagnostic model suggested a stronger carbon sink than the prognostic model, and a much larger sink that the inversion model. The introduction of Landsat data on disturbance history served to reduce uncertainty with respect to regional NEE in the diagnostic and prognostic modeling approaches. The FPAR data was particularly helpful in capturing the seasonality of the carbon flux using the diagnostic modeling approach. The inversion approach took advantage of a global

  5. Preliminary prediction model for the ROTI index at high latitude

    Science.gov (United States)

    Rochel Grimald, Sandrine; Boscher, Daniel; Fabbro, Vincent; Rougerie, Sébastien

    2017-04-01

    The variation of electron density can be described by the ROTI index (i.e. the Rate of change of Total electron content Index). This index is indicative of the electron density gradients which can be responsible of loss of satellite communications or loss of lock of GNSS system.. At high latitude, the ionosphere is connected to the magnetosphere through the magnetic field lines. When the magnetic activity increases, particles from the magnetosphere are injected in the ionosphere along the magnetic field lines. They disturb the ionospheric layer and are responsible of changes in the ROTI index. In this paper, we will use the NOAA POES satellites data to study the link between the ROTI index value and the particles flux in the inner magnetosphere. Then we will use the results to developp a preliminary ROTI model.

  6. Prognostic Modeling in Pathologic N1 Breast Cancer Without Elective Nodal Irradiation After Current Standard Systemic Management.

    Science.gov (United States)

    Yu, Jeong Il; Park, Won; Choi, Doo Ho; Huh, Seung Jae; Nam, Seok Jin; Kim, Seok Won; Lee, Jeong Eon; Kil, Won Ho; Im, Young-Hyuck; Ahn, Jin Seok; Park, Yeon Hee; Cho, Eun Yoon

    2015-08-01

    This study was conducted to establish a prognostic model in patients with pathologic N1 (pN1) breast cancer who have not undergone elective nodal irradiation (ENI) under the current standard management and to suggest possible indications for ENI. We performed a retrospective study with patients with pN1 breast cancer who received the standard local and preferred adjuvant chemotherapy treatment without neoadjuvant chemotherapy and ENI from January 2005 to June 2011. Most of the indicated patients received endocrine and trastuzumab therapy. In 735 enrolled patients, the median follow-up period was 58.4 months (range, 7.2-111.3 months). Overall, 55 recurrences (7.4%) developed, and locoregional recurrence was present in 27 patients (3.8%). Recurrence-free survival was significantly related to lymphovascular invasion (P = .04, hazard ratio [HR], 1.83; 95% confidence interval [CI], 1.03-2.88), histologic grade (P = .03, HR, 2.57; 95% CI, 1.05-6.26), and nonluminal A subtype (P = .02, HR, 3.04; 95% CI, 1.23-7.49) in multivariate analysis. The prognostic model was established by these 3 prognostic factors. Recurrence-free survival was less than 90% at 5 years in cases with 2 or 3 factors. The prognostic model has stratified risk groups in pN1 breast cancer without ENI. Patients with 2 or more factors should be considered for ENI. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. Predicting stabilizing treatment outcomes for complex posttraumatic stress disorder and dissociative identity disorder: an expertise-based prognostic model.

    Science.gov (United States)

    Baars, Erik W; van der Hart, Onno; Nijenhuis, Ellert R S; Chu, James A; Glas, Gerrit; Draijer, Nel

    2011-01-01

    The purpose of this study was to develop an expertise-based prognostic model for the treatment of complex posttraumatic stress disorder (PTSD) and dissociative identity disorder (DID). We developed a survey in 2 rounds: In the first round we surveyed 42 experienced therapists (22 DID and 20 complex PTSD therapists), and in the second round we surveyed a subset of 22 of the 42 therapists (13 DID and 9 complex PTSD therapists). First, we drew on therapists' knowledge of prognostic factors for stabilization-oriented treatment of complex PTSD and DID. Second, therapists prioritized a list of prognostic factors by estimating the size of each variable's prognostic effect; we clustered these factors according to content and named the clusters. Next, concept mapping methodology and statistical analyses (including principal components analyses) were used to transform individual judgments into weighted group judgments for clusters of items. A prognostic model, based on consensually determined estimates of effect sizes, of 8 clusters containing 51 factors for both complex PTSD and DID was formed. It includes the clusters lack of motivation, lack of healthy relationships, lack of healthy therapeutic relationships, lack of other internal and external resources, serious Axis I comorbidity, serious Axis II comorbidity, poor attachment, and self-destruction. In addition, a set of 5 DID-specific items was constructed. The model is supportive of the current phase-oriented treatment model, emphasizing the strengthening of the therapeutic relationship and the patient's resources in the initial stabilization phase. Further research is needed to test the model's statistical and clinical validity.

  8. Cross-national validation of prognostic models predicting sickness absence and the added value of work environment variables.

    Science.gov (United States)

    Roelen, Corné A M; Stapelfeldt, Christina M; Heymans, Martijn W; van Rhenen, Willem; Labriola, Merete; Nielsen, Claus V; Bültmann, Ute; Jensen, Chris

    2015-06-01

    To validate Dutch prognostic models including age, self-rated health and prior sickness absence (SA) for ability to predict high SA in Danish eldercare. The added value of work environment variables to the models' risk discrimination was also investigated. 2,562 municipal eldercare workers (95% women) participated in the Working in Eldercare Survey. Predictor variables were measured by questionnaire at baseline in 2005. Prognostic models were validated for predictions of high (≥30) SA days and high (≥3) SA episodes retrieved from employer records during 1-year follow-up. The accuracy of predictions was assessed by calibration graphs and the ability of the models to discriminate between high- and low-risk workers was investigated by ROC-analysis. The added value of work environment variables was measured with Integrated Discrimination Improvement (IDI). 1,930 workers had complete data for analysis. The models underestimated the risk of high SA in eldercare workers and the SA episodes model had to be re-calibrated to the Danish data. Discrimination was practically useful for the re-calibrated SA episodes model, but not the SA days model. Physical workload improved the SA days model (IDI = 0.40; 95% CI 0.19-0.60) and psychosocial work factors, particularly the quality of leadership (IDI = 0.70; 95% CI 053-0.86) improved the SA episodes model. The prognostic model predicting high SA days showed poor performance even after physical workload was added. The prognostic model predicting high SA episodes could be used to identify high-risk workers, especially when psychosocial work factors are added as predictor variables.

  9. Delta neutrophil index as a promising prognostic marker of emergent surgical intervention for acute diverticulitis in the emergency department.

    Science.gov (United States)

    Kang, Hee Seung; Cha, Yong Sung; Park, Kyung Hye; Hwang, Sung Oh

    2017-01-01

    Early identification of patients with acute diverticulitis who require emergent surgical intervention in the emergency department (ED) is important to the physician. Although computed tomography (CT) has an important role in evaluating the severity of diverticulitis, its findings alone may not predict the need for emergent surgical intervention in all patients with acute diverticulitis in the ED. Serum inflammation markers may help to differentiate severity of acute diverticulitis and predict the need for surgical intervention in clinical practice. No information is currently available on the clinical usefulness of the delta neutrophil index (DNI), with respect to the prediction of emergent surgical intervention in patients with acute diverticulitis at the ED. This was a retrospective observational study of consecutive adult patients with acute diverticulitis confirmed by CT in the ED, between January 2014 and December 2016. Recruited patients were divided into two groups: emergent surgical intervention and no surgical intervention. The following laboratory serum parameters were examined in the ED: DNI value, C-reactive protein (CRP) levels, white blood cell count, neutrophil count, and neutrophil-to-lymphocyte ratio (NLR). The patients were also examined for the presence or absence of complications by CT. A total of 132 patients were finally included in the study, with the emergent surgical intervention group constituting 52 patients. The median DNI value, CRP levels, neutrophil count, and NLR were significantly higher in the emergent surgical intervention group than in the no surgical intervention group. The area under the curve for predicting emergent surgical intervention, using the DNI was significantly higher than that of CRP levels, neutrophil count, or NLR. Moreover, the combination of initial DNI and CT was most powerful diagnostic modality. DNI values measured at the ED combined with CT were good predictors for emergent surgical intervention in acute

  10. A note on prognostic accuracy evaluation of regression models applied to longitudinal autocorrelated binary data

    Directory of Open Access Journals (Sweden)

    Giulia Barbati

    2014-11-01

    Full Text Available Background: Focus of this work was on evaluating the prognostic accuracy of two approaches for modelling binary longitudinal outcomes, a Generalized Estimating Equation (GEE and a likelihood based method, Marginalized Transition Model (MTM, in which a transition model is combined with a marginal generalized linear model describing the average response as a function of measured predictors.Methods: A retrospective study on cardiovascular patients and a prospective study on sciatic pain were used to evaluate discrimination by computing the Area Under the Receiver-Operating-Characteristics curve, (AUC, the Integrated Discrimination Improvement (IDI and the Net Reclassification Improvement (NRI at different time occasions. Calibration was also evaluated. A simulation study was run in order to compare model’s performance in a context of a perfect knowledge of the data generating mechanism. Results: Similar regression coefficients estimates and comparable calibration were obtained; an higher discrimination level for MTM was observed. No significant differences in calibration and MSE (Mean Square Error emerged in the simulation study, that instead confirmed the MTM higher discrimination level. Conclusions: The choice of the regression approach should depend on the scientific question being addressed, i.e. if the overall population-average and calibration or the subject-specific patterns and discrimination are the objectives of interest, and some recently proposed discrimination indices are useful in evaluating predictive accuracy also in a context of longitudinal studies.

  11. A simple prognostic model for overall survival in metastatic renal cell carcinoma

    Science.gov (United States)

    Assi, Hazem I.; Patenaude, Francois; Toumishey, Ethan; Ross, Laura; Abdelsalam, Mahmoud; Reiman, Tony

    2016-01-01

    Introduction: The primary purpose of this study was to develop a simpler prognostic model to predict overall survival for patients treated for metastatic renal cell carcinoma (mRCC) by examining variables shown in the literature to be associated with survival. Methods: We conducted a retrospective analysis of patients treated for mRCC at two Canadian centres. All patients who started first-line treatment were included in the analysis. A multivariate Cox proportional hazards regression model was constructed using a stepwise procedure. Patients were assigned to risk groups depending on how many of the three risk factors from the final multivariate model they had. Results: There were three risk factors in the final multivariate model: hemoglobin, prior nephrectomy, and time from diagnosis to treatment. Patients in the high-risk group (two or three risk factors) had a median survival of 5.9 months, while those in the intermediate-risk group (one risk factor) had a median survival of 16.2 months, and those in the low-risk group (no risk factors) had a median survival of 50.6 months. Conclusions: In multivariate analysis, shorter survival times were associated with hemoglobin below the lower limit of normal, absence of prior nephrectomy, and initiation of treatment within one year of diagnosis. PMID:27217858

  12. Incorporating a prognostic representation of marine nitrogen fixers into the global ocean biogeochemical model HAMOCC

    Science.gov (United States)

    Paulsen, Hanna; Ilyina, Tatiana; Six, Katharina D.; Stemmler, Irene

    2017-03-01

    Nitrogen (N2) fixation is a major source of bioavailable nitrogen to the euphotic zone, thereby exerting an important control on ocean biogeochemical cycling. This paper presents the incorporation of prognostic N2 fixers into the HAMburg Ocean Carbon Cycle model (HAMOCC), a component of the Max Planck Institute Earth System Model (MPI-ESM). Growth dynamics of N2 fixers in the model are based on physiological characteristics of the cyanobacterium Trichodesmium. The applied temperature dependency confines diazotrophic growth and N2 fixation to the tropical and subtropical ocean roughly between 40°S and 40°N. Simulated large-scale spatial patterns compare well with observations, and the global N2 fixation rate of 135.6 Tg N yr-1 is within the range of current estimates. The vertical distribution of N2 fixation also matches well the observations, with a major fraction of about 85% occurring in the upper 20 m. The observed seasonal variability at the stations BATS and ALOHA is reasonably reproduced, with highest fixation rates in northern summer/fall. Iron limitation was found to be an important factor in controlling the simulated distribution of N2 fixation, especially in the Pacific Ocean. The new model component considerably improves the representation of present-day N2 fixation in HAMOCC. It provides the basis for further studies on the role of diazotrophs in global biogeochemical cycles, as well as on the response of N2 fixation to changing environmental conditions.

  13. A flexible alternative to the Cox proportional hazards model for assessing the prognostic accuracy of hospice patient survival.

    Directory of Open Access Journals (Sweden)

    Branko Miladinovic

    Full Text Available Prognostic models are often used to estimate the length of patient survival. The Cox proportional hazards model has traditionally been applied to assess the accuracy of prognostic models. However, it may be suboptimal due to the inflexibility to model the baseline survival function and when the proportional hazards assumption is violated. The aim of this study was to use internal validation to compare the predictive power of a flexible Royston-Parmar family of survival functions with the Cox proportional hazards model. We applied the Palliative Performance Scale on a dataset of 590 hospice patients at the time of hospice admission. The retrospective data were obtained from the Lifepath Hospice and Palliative Care center in Hillsborough County, Florida, USA. The criteria used to evaluate and compare the models' predictive performance were the explained variation statistic R(2, scaled Brier score, and the discrimination slope. The explained variation statistic demonstrated that overall the Royston-Parmar family of survival functions provided a better fit (R(2 =0.298; 95% CI: 0.236-0.358 than the Cox model (R(2 =0.156; 95% CI: 0.111-0.203. The scaled Brier scores and discrimination slopes were consistently higher under the Royston-Parmar model. Researchers involved in prognosticating patient survival are encouraged to consider the Royston-Parmar model as an alternative to Cox.

  14. Quantitative modeling of clinical, cellular, and extracellular matrix variables suggest prognostic indicators in cancer: a model in neuroblastoma.

    Science.gov (United States)

    Tadeo, Irene; Piqueras, Marta; Montaner, David; Villamón, Eva; Berbegall, Ana P; Cañete, Adela; Navarro, Samuel; Noguera, Rosa

    2014-02-01

    Risk classification and treatment stratification for cancer patients is restricted by our incomplete picture of the complex and unknown interactions between the patient's organism and tumor tissues (transformed cells supported by tumor stroma). Moreover, all clinical factors and laboratory studies used to indicate treatment effectiveness and outcomes are by their nature a simplification of the biological system of cancer, and cannot yet incorporate all possible prognostic indicators. A multiparametric analysis on 184 tumor cylinders was performed. To highlight the benefit of integrating digitized medical imaging into this field, we present the results of computational studies carried out on quantitative measurements, taken from stromal and cancer cells and various extracellular matrix fibers interpenetrated by glycosaminoglycans, and eight current approaches to risk stratification systems in patients with primary and nonprimary neuroblastoma. New tumor tissue indicators from both fields, the cellular and the extracellular elements, emerge as reliable prognostic markers for risk stratification and could be used as molecular targets of specific therapies. The key to dealing with personalized therapy lies in the mathematical modeling. The use of bioinformatics in patient-tumor-microenvironment data management allows a predictive model in neuroblastoma.

  15. Delta neutrophil index as a promising prognostic marker of emergent surgical intervention for acute diverticulitis in the emergency department.

    Directory of Open Access Journals (Sweden)

    Hee Seung Kang

    Full Text Available Early identification of patients with acute diverticulitis who require emergent surgical intervention in the emergency department (ED is important to the physician. Although computed tomography (CT has an important role in evaluating the severity of diverticulitis, its findings alone may not predict the need for emergent surgical intervention in all patients with acute diverticulitis in the ED. Serum inflammation markers may help to differentiate severity of acute diverticulitis and predict the need for surgical intervention in clinical practice. No information is currently available on the clinical usefulness of the delta neutrophil index (DNI, with respect to the prediction of emergent surgical intervention in patients with acute diverticulitis at the ED.This was a retrospective observational study of consecutive adult patients with acute diverticulitis confirmed by CT in the ED, between January 2014 and December 2016. Recruited patients were divided into two groups: emergent surgical intervention and no surgical intervention. The following laboratory serum parameters were examined in the ED: DNI value, C-reactive protein (CRP levels, white blood cell count, neutrophil count, and neutrophil-to-lymphocyte ratio (NLR. The patients were also examined for the presence or absence of complications by CT.A total of 132 patients were finally included in the study, with the emergent surgical intervention group constituting 52 patients. The median DNI value, CRP levels, neutrophil count, and NLR were significantly higher in the emergent surgical intervention group than in the no surgical intervention group. The area under the curve for predicting emergent surgical intervention, using the DNI was significantly higher than that of CRP levels, neutrophil count, or NLR. Moreover, the combination of initial DNI and CT was most powerful diagnostic modality.DNI values measured at the ED combined with CT were good predictors for emergent surgical intervention

  16. Elevated neutrophil and monocyte counts in peripheral blood are associated with poor survival in patients with metastatic melanoma: a prognostic model

    DEFF Research Database (Denmark)

    Schmidt, H; Bastholt, L; Geertsen, P

    2005-01-01

    We aimed to create a prognostic model in metastatic melanoma based on independent prognostic factors in 321 patients receiving interleukin-2 (IL-2)-based immunotherapy with a median follow-up time for patients currently alive of 52 months (range 15-189 months). The patients were treated as part...... factors in univariate analyses. Subsequently, a multivariate Cox's regression analysis identified elevated LDH (P

  17. System Interdependency Modeling in the Design of Prognostic and Health Management Systems in Smart Manufacturing.

    Science.gov (United States)

    Malinowski, M L; Beling, P A; Haimes, Y Y; LaViers, A; Marvel, J A; Weiss, B A

    2015-01-01

    The fields of risk analysis and prognostics and health management (PHM) have developed in a largely independent fashion. However, both fields share a common core goal. They aspire to manage future adverse consequences associated with prospective dysfunctions of the systems under consideration due to internal or external forces. This paper describes how two prominent risk analysis theories and methodologies - Hierarchical Holographic Modeling (HHM) and Risk Filtering, Ranking, and Management (RFRM) - can be adapted to support the design of PHM systems in the context of smart manufacturing processes. Specifically, the proposed methodologies will be used to identify targets - components, subsystems, or systems - that would most benefit from a PHM system in regards to achieving the following objectives: minimizing cost, minimizing production/maintenance time, maximizing system remaining usable life (RUL), maximizing product quality, and maximizing product output. HHM is a comprehensive modeling theory and methodology that is grounded on the premise that no system can be modeled effectively from a single perspective. It can also be used as an inductive method for scenario structuring to identify emergent forced changes (EFCs) in a system. EFCs connote trends in external or internal sources of risk to a system that may adversely affect specific states of the system. An important aspect of proactive risk management includes bolstering the resilience of the system for specific EFCs by appropriately controlling the states. Risk scenarios for specific EFCs can be the basis for the design of prognostic and diagnostic systems that provide real-time predictions and recognition of scenario changes. The HHM methodology includes visual modeling techniques that can enhance stakeholders' understanding of shared states, resources, objectives and constraints among the interdependent and interconnected subsystems of smart manufacturing systems. In risk analysis, HHM is often paired

  18. Prognostic models based on patient snapshots and time windows: Predicting disease progression to assisted ventilation in Amyotrophic Lateral Sclerosis.

    Science.gov (United States)

    Carreiro, André V; Amaral, Pedro M T; Pinto, Susana; Tomás, Pedro; de Carvalho, Mamede; Madeira, Sara C

    2015-12-01

    Amyotrophic Lateral Sclerosis (ALS) is a devastating disease and the most common neurodegenerative disorder of young adults. ALS patients present a rapidly progressive motor weakness. This usually leads to death in a few years by respiratory failure. The correct prediction of respiratory insufficiency is thus key for patient management. In this context, we propose an innovative approach for prognostic prediction based on patient snapshots and time windows. We first cluster temporally-related tests to obtain snapshots of the patient's condition at a given time (patient snapshots). Then we use the snapshots to predict the probability of an ALS patient to require assisted ventilation after k days from the time of clinical evaluation (time window). This probability is based on the patient's current condition, evaluated using clinical features, including functional impairment assessments and a complete set of respiratory tests. The prognostic models include three temporal windows allowing to perform short, medium and long term prognosis regarding progression to assisted ventilation. Experimental results show an area under the receiver operating characteristics curve (AUC) in the test set of approximately 79% for time windows of 90, 180 and 365 days. Creating patient snapshots using hierarchical clustering with constraints outperforms the state of the art, and the proposed prognostic model becomes the first non population-based approach for prognostic prediction in ALS. The results are promising and should enhance the current clinical practice, largely supported by non-standardized tests and clinicians' experience. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. A prognostic model for platinum-doublet as second-line chemotherapy in advanced non-small-cell lung cancer patients.

    Science.gov (United States)

    Mo, Hongnan; Hao, Xuezhi; Liu, Yutao; Wang, Lin; Hu, Xingsheng; Xu, Jianping; Yang, Sheng; Xing, Puyuan; Shi, Youwu; Jia, Bo; Wang, Yan; Li, Junling; Wang, Hongyu; Wang, Ziping; Sun, Yan; Shi, Yuankai

    2016-06-01

    Poor prognosis of advanced non-small-cell lung cancer (NSCLC) patients and the promising therapeutic effect of platinum urge the oncologists to evaluate the role of platinum doublet as second-line chemotherapy and establish the definition of platinum sensitivity in NSCLC. We retrospectively analyzed 364 advanced NSCLC patients who received platinum-doublet regimens as second-line chemotherapy after platinum-based first-line treatment. Patients were divided into four groups by their time-to-progression (TTP) after first-line chemotherapy: 0-3, 4-6, 7-12, and >12-month group, respectively. Treatment efficacy of patients' overall survival (OS), progression-free survival (PFS), and response rate (RR), as well as treatment-related toxicity, were compared among the four groups. A prognosis score system and a nomogram were established by Cox proportional hazard model, and validated by concordance index (c-index). Median OS was 14.0, 16.0, 20.0, 25.0 months for patients in the 0-3, 4-6, 7-12, >12-month group, respectively. Age ≤60 years (P = 0.002), female (P = 0.019), and TTP>12 months (P = 0.003) were independent prognostic factors. Prognostic score was calculated by adding 1 point each for any of the above three indicators, with a c-index of 0.590 (95% confidential interval [CI], 0.552-0.627). Median OS were equal to 25.0, 16.0, and 11.0 months for best (2-3 points), intermediate (1 point) and worst (0 point) category, respectively (P chemotherapy in advanced NSCLCpatients. © 2016 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.

  20. GPU Accelerated Prognostics

    Science.gov (United States)

    Gorospe, George E., Jr.; Daigle, Matthew J.; Sankararaman, Shankar; Kulkarni, Chetan S.; Ng, Eley

    2017-01-01

    Prognostic methods enable operators and maintainers to predict the future performance for critical systems. However, these methods can be computationally expensive and may need to be performed each time new information about the system becomes available. In light of these computational requirements, we have investigated the application of graphics processing units (GPUs) as a computational platform for real-time prognostics. Recent advances in GPU technology have reduced cost and increased the computational capability of these highly parallel processing units, making them more attractive for the deployment of prognostic software. We present a survey of model-based prognostic algorithms with considerations for leveraging the parallel architecture of the GPU and a case study of GPU-accelerated battery prognostics with computational performance results.

  1. Prognostic modeling of oral cancer by gene profiles and clinicopathological co-variables.

    Science.gov (United States)

    Mes, Steven W; Te Beest, Dennis; Poli, Tito; Rossi, Silvia; Scheckenbach, Kathrin; van Wieringen, Wessel N; Brink, Arjen; Bertani, Nicoletta; Lanfranco, Davide; Silini, Enrico M; van Diest, Paul J; Bloemena, Elisabeth; Leemans, C René; van de Wiel, Mark A; Brakenhoff, Ruud H

    2017-08-29

    Accurate staging and outcome prediction is a major problem in clinical management of oral cancer patients, hampering high precision treatment and adjuvant therapy planning. Here, we have built and validated multivariable models that integrate gene signatures with clinical and pathological variables to improve staging and survival prediction of patients with oral squamous cell carcinoma (OSCC). Gene expression profiles from 249 human papillomavirus (HPV)-negative OSCCs were explored to identify a 22-gene lymph node metastasis signature (LNMsig) and a 40-gene overall survival signature (OSsig). To facilitate future clinical implementation and increase performance, these signatures were transferred to quantitative polymerase chain reaction (qPCR) assays and validated in an independent cohort of 125 HPV-negative tumors. When applied in the clinically relevant subgroup of early-stage (cT1-2N0) OSCC, the LNMsig could prevent overtreatment in two-third of the patients. Additionally, the integration of RT-qPCR gene signatures with clinical and pathological variables provided accurate prognostic models for oral cancer, strongly outperforming TNM. Finally, the OSsig gene signature identified a subpopulation of patients, currently considered at low-risk for disease-related survival, who showed an unexpected poor prognosis. These well-validated models will assist in personalizing primary treatment with respect to neck dissection and adjuvant therapies.

  2. Accelerated Aging with Electrical Overstress and Prognostics for Power MOSFETs

    Science.gov (United States)

    Saha, Sankalita; Celaya, Jose Ramon; Vashchenko, Vladislav; Mahiuddin, Shompa; Goebel, Kai F.

    2011-01-01

    Power electronics play an increasingly important role in energy applications as part of their power converter circuits. Understanding the behavior of these devices, especially their failure modes as they age with nominal usage or sudden fault development is critical in ensuring efficiency. In this paper, a prognostics based health management of power MOSFETs undergoing accelerated aging through electrical overstress at the gate area is presented. Details of the accelerated aging methodology, modeling of the degradation process of the device and prognostics algorithm for prediction of the future state of health of the device are presented. Experiments with multiple devices demonstrate the performance of the model and the prognostics algorithm as well as the scope of application. Index Terms Power MOSFET, accelerated aging, prognostics

  3. Prognostic scoring systems for mortality in intensive care units--the APACHE model.

    Science.gov (United States)

    Niewiński, Grzegorz; Starczewska, Małgorzata; Kański, Andrzej

    2014-01-01

    The APACHE (Acute Physiology and Chronic Health Evaluation) scoring system is time consuming. The mean time for introducing a patient's data to APACHE IV is 37.3 min. Nevertheless, statisticians have known for years that the higher the number of variables the mathematical model describes, the more accurate the model. Because of the necessity of gathering data over a 24-hour period and of determining one cause for ICU admission, the system is troublesome and prone to mistakes. The evolution of the APACHE scoring system is an example of unfulfilled hopes for accurately estimating the risk of death for patients admitted to the ICU; satisfactory prognostic effects resulting from the use of APACHE II and III have been recently studied in patients undergoing liver transplantations. Because no increase in the predictive properties of successive versions has been observed, the search for other solutions continues. The APACHE IV scoring system is helpful; however, its use without prepared spreadsheets is almost impractical. Therefore, although many years have passed since its original publication, APACHE II or its extension APACHE III is currently used in clinical practice.

  4. Systematic review of prognostic roles of body mass index for patients undergoing lung cancer surgery: does the 'obesity paradox' really exist?

    Science.gov (United States)

    Li, Shuangjiang; Wang, Zhiqiang; Huang, Jian; Fan, Jun; Du, Heng; Liu, Lunxu; Che, Guowei

    2017-05-01

    The paradoxical benefit of obesity, the 'obesity paradox', has been recently identified in surgical populations. Our goal was to evaluate by a systematic review with meta-analysis the prognostic role of body mass index (BMI) and to identify whether the 'obesity paradox' exists in lung cancer surgery. Comprehensive literature retrieval was conducted in PubMed to identify the eligible articles. The odds ratios (OR) and hazard ratios (HR) with the corresponding 95% confidence intervals (CI) were used to synthesize in-hospital and long-term survival outcomes, respectively. The heterogeneity level and publication bias between studies were also estimated. Finally, 25 observational studies with 78 143 patients were included in this review. The pooled analyses showed a significantly better long-term survival rate in patients with higher BMI, but no significant benefit of increased BMI was found for in-hospital morbidity. The pooled analyses also showed that overall morbidity (OR: 0.84; 95% CI: 0.73-0.98; P  =   0.025) and in-hospital mortality (OR: 0.78; 95% CI: 0.63-0.98; P  =   0.031) were significantly decreased in obese patients. Obesity could be a strong predictor of the favourable long-term prognosis of lung cancer patients (HR: 0.69; 95% CI: 0.56-0.86; P  =   0.001). The robustness of these pooled estimates was strong. No publication bias was detected. In summary, obesity has favourable effects on in-hospital outcomes and long-term survival of surgical patients with lung cancer. The 'obesity paradox' does have the potential to exist in lung cancer surgery.

  5. Advanced Methods for Determining Prediction Uncertainty in Model-Based Prognostics with Application to Planetary Rovers

    Science.gov (United States)

    Daigle, Matthew J.; Sankararaman, Shankar

    2013-01-01

    Prognostics is centered on predicting the time of and time until adverse events in components, subsystems, and systems. It typically involves both a state estimation phase, in which the current health state of a system is identified, and a prediction phase, in which the state is projected forward in time. Since prognostics is mainly a prediction problem, prognostic approaches cannot avoid uncertainty, which arises due to several sources. Prognostics algorithms must both characterize this uncertainty and incorporate it into the predictions so that informed decisions can be made about the system. In this paper, we describe three methods to solve these problems, including Monte Carlo-, unscented transform-, and first-order reliability-based methods. Using a planetary rover as a case study, we demonstrate and compare the different methods in simulation for battery end-of-discharge prediction.

  6. A Modeling Framework for Prognostic Decision Making and its Application to UAV Mission Planning

    Data.gov (United States)

    National Aeronautics and Space Administration — The goal of prognostic decision making (PDM) is to utilize information on anticipated system health changes in selecting future actions. One of the key challenges in...

  7. Verification of a prognostic meteorological and air pollution model for year-long predictions in the Kwinana industrial region of Western Australia

    Energy Technology Data Exchange (ETDEWEB)

    Hurley, P.J. [CSIRO Atmospheric Research, Aspendale, Vic (Australia); Blockley, A.; Rayner, K. [Department of Environmental Protection, Perth, WA (Australia)

    2001-04-01

    A prognostic air pollution model (TAPM) has been used to predict meteorology and sulphur dioxide concentration in the Kwinana industrial region of Western Australia for 1997, with a view to verifying TAPM for use in environmental impact assessments and associated air pollution studies. The regulatory plume model, DISPMOD, developed for the Kwinana region has also been run using both an observationally based meteorological file (denoted DISPMOD-O) and using a TAPM-based meteorological file (denoted DISPMOD-T). TAPM predictions of the meteorology for 1997 compare well with the observed values at each of the five monitoring sites. Root mean square error and index of agreement values for temperature and winds indicate that TAPM performs well at predicting the meteorology, compared to the performance of similar models from other studies. The yearly average, 99.9 percentile, maximum and mean of the top 10 ground-level sulphur dioxide concentrations for 1997 were predicted well by all of the model runs, although DISPMOD-O and DISPMOD-T tended to overpredict extreme statistics at sites furthest from the sources. Overall, TAPM performed better than DISPMOD-O, which in turn performed better than DISPMOD-T, for all statistics considered, but we consider that all three sets of results are sufficiently accurate for regulatory applications. The mean of the top ten concentrations is generally considered to be a robust performance statistic for air pollution applications, and we show that compared to the site-averaged observed value of 95{mu}gm{sup -3}, TAPM predicted 94{mu}gm{sup -3}, DISPMOD-O predicted 111{mu}gm{sup -3} and DISPMOD-T predicted 125{mu}gm{sup -3}. The results indicate that the prognostic meteorological and air pollution approach to regulatory modelling used by TAPM, gives comparable or better results than the current regulatory approach used in the Kwinana region (DISPMOD), and also indicates that the approach of using a currently accepted regulatory model with a

  8. Indexed

    CERN Document Server

    Hagy, Jessica

    2008-01-01

    Jessica Hagy is a different kind of thinker. She has an astonishing talent for visualizing relationships, capturing in pictures what is difficult for most of us to express in words. At indexed.blogspot.com, she posts charts, graphs, and Venn diagrams drawn on index cards that reveal in a simple and intuitive way the large and small truths of modern life. Praised throughout the blogosphere as “brilliant,” “incredibly creative,” and “comic genius,” Jessica turns her incisive, deadpan sense of humor on everything from office politics to relationships to religion. With new material along with some of Jessica’s greatest hits, this utterly unique book will thrill readers who demand humor that makes them both laugh and think.

  9. Modelling refractive index changes due to molecular interactions

    Science.gov (United States)

    Varma, Manoj

    2016-03-01

    There are a large number of sensing techniques which use optical changes to monitor interactions between molecules. In the absence of fluorophores or other labels, the basic signal transduction mechanism relies on refractive index changes arising from the interactions of the molecules involved. A quantitative model incorporating molecular transport, reaction kinetics and optical mixing is presented which reveals important insights concerning the optimal detection of molecular interactions optically. Although conceptually simple, a comprehensive model such as this has not been reported anywhere. Specifically, we investigate the pros and cons of detecting molecular interactions in free solution relative to detecting molecular interactions on surfaces using surface bound receptor molecules such as antibodies. The model reveals that the refractive index change produced in surface based sensors is 2-3 orders of magnitude higher than that from interactions in free solution. On the other hand, the model also reveals that it is indeed possible to distinguish specific molecular interactions from non-specific ones based on free-solution bulk refractometry without any washing step necessary in surface based sensors. However, the refractive index change for free solution interactions predicted by the model is smaller than 10-7 RIU, even for large proteins such as IgG in sufficiently high concentrations. This value is smaller than the typical 10-6 RIU detection limit of most state of the art optical sensing techniques therefore requiring techniques with substantially higher index sensitivity such as Back Scattering Interferometry.

  10. Comparison of the prognostic value of liver biopsy and FIB-4 index in patients coinfected with HIV and hepatitis C virus.

    Science.gov (United States)

    Berenguer, Juan; Zamora, Francisco X; Aldámiz-Echevarría, Teresa; Von Wichmann, Miguel A; Crespo, Manel; López-Aldeguer, José; Carrero, Ana; Montes, Marisa; Quereda, Carmen; Téllez, María J; Galindo, María J; Sanz, José; Santos, Ignacio; Guardiola, Josep M; Barros, Carlos; Ortega, Enrique; Pulido, Federico; Rubio, Rafael; Mallolas, Josep; Tural, Cristina; Jusdado, Juan J; Pérez, Gloria; Díez, Cristina; Álvarez-Pellicer, Julio; Esteban, Herminia; Bellón, José M; González-García, Juan

    2015-03-15

    We compared the prognostic value of liver biopsy (LB) and FIB-4 index in patients with human immunodeficiency virus (HIV)/hepatitis C virus (HCV) coinfection. We studied patients from the Grupo de Estudio del SIDA 3603 study cohort, in whom fibrosis was evaluated at baseline using both LB (Metavir score) and FIB-4 index. We assessed overall death (OD) and liver-related events (LREs), defined as decompensation or hepatocellular carcinoma, whichever occurred first. We used receiver operating characteristic (ROC) curves to determine the ability of LB and FIB-4 to predict outcomes. We also assessed the association between advanced fibrosis-LB (F3 or greater) or FIB-4 (≥3.25)-and outcomes using multivariate Cox regression analysis. The study sample comprised 903 patients (328 with sustained virologic response [SVR]). Baseline fibrosis by LB was as follows: F0, n = 71; F1, n = 242; F2, n = 236; F3, n = 236; F4, n = 118. Fibrosis by FIB-4 was as follows: ≤1, n = 148; >1 to <3.25, n = 597; ≥3.25, n = 158. After a median follow-up of 62 months, there were 46 deaths and 71 LREs. The area under the ROC curves for OD/LREs was 0.648 and 0.742 for LB and FIB-4, respectively (P = .006). Similar results were found for patients without SVR and for OD and LREs separately. The adjusted hazard ratios of OD or LRE were 1.740 (95% confidence interval [CI], 1.119-2.7.06; P = .014) for advanced fibrosis assessed by LB and 3.896 (95% CI, 2.463-6.160; P < .001) assessed by FIB-4. FIB-4 outperformed LB as a predictor of OD and LRE. These findings are of relevance for clinical practice and research and call into question the role of LB as a gold standard for assessing prognosis in HIV/HCV coinfection. © The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  11. [Molecular biological evaluation of prognostic parameters in GIST. Development of an integrative model of tumor progression].

    Science.gov (United States)

    Haller, F

    2010-10-01

    Prognosis evaluation in gastrointestinal stromal tumors (GIST) is currently based on tumor diameter, mitotic counts and anatomic localisation. There are two risk classifications as well as the first ever TNM classification for GISTs, whereby the risk classification according to the Armed Forces Institute of Pathology (AFIP) has the best correlation with clinical follow-up according to own experiences. "Very low/low risk" GISTs are almost benign, while the majority of "high risk" GISTs metastasize and benefit from adjuvant therapy. Careful evaluation of mitotic counts in 50 high-power fields is of particular relevance for correct risk classification. Apart from these classical prognostic factors, many molecular genetic parameters with correlation to follow-up have been evaluated and may help to improve prognosis evaluation of GISTs in the future. Since most of the molecular genetic parameters are associated or even determined by the clinico-pathological parameters, an integrated model for tumor progression of GISTs is helpful to interpret the different factors in correlation to one another. In particular for "intermediate risk" GISTs, additional parameters are needed for improved prognosis evaluation.

  12. Modeling Using Dryness Index to Predict Evapotranspiration in a ...

    African Journals Online (AJOL)

    Based on crop-climate studies from the viewpoint of modeling and predictability, this paper presents a new dryness index (DI), the ratio of rainfall over reference evapotranspiration (ET), for Ilorin (8.48o N) in the transition zone between humid and semi-arid climatic belts in Nigeria. The ET values were computed using the ...

  13. Step-indexed Kripke models over recursive worlds

    DEFF Research Database (Denmark)

    Birkedal, Lars; Reus, Bernhard; Schwinghammer, Jan

    2011-01-01

    worlds that are recursively defined in a category of metric spaces. In this paper, we broaden the scope of this technique from the original domain-theoretic setting to an elementary, operational one based on step indexing. The resulting method is widely applicable and leads to simple, succinct models...

  14. A Confidence Index for expressing geological model uncertainty

    Science.gov (United States)

    Mathers, Steve; Lark, Murray; Marchant, Andrew; Hulbert, Andrew

    2015-04-01

    A Confidence Index has been developed that expresses the confidence of experts in the quality of a 3-D model as a representation of the subsurface at particular locations. The Confidence Index is based on the notion that the variation of the height of a particular geological surface represents general geological variability and local variability. The general variability comprises simple trends which allow the modeller to project surface structure at locations remote from direct observations. The local variability limits the extent to which hard data constrain inferences which the modeller can make concerning local fluctuations around the broad trends. The general and local geological variability of particular contacts are modelled in terms of simple trend surfaces and variogram models. These are then used to extend measures of confidence that reflect expert opinion so as to assign a confidence value to any location where a particular contact is represented in a model. The index is illustrated for individual model surfaces and ther thickness of units with examples from the East Midlands region of England.

  15. Prognostic value of blood-biomarkers related to hypoxia, inflammation, immune response and tumour load in non-small cell lung cancer - A survival model with external validation.

    Science.gov (United States)

    Carvalho, Sara; Troost, Esther G C; Bons, Judith; Menheere, Paul; Lambin, Philippe; Oberije, Cary

    2016-06-01

    Improve the prognostic prediction of clinical variables for non-small cell lung cancer (NSCLC), by selecting from blood-biomarkers, non-invasively describing hypoxia, inflammation and tumour load. Model development and validation included 182 and 181 inoperable stage I-IIIB NSCLC patients treated radically with radiotherapy (55.2%) or chemo-radiotherapy (44.8%). Least absolute shrinkage and selection operator (LASSO), selected from blood-biomarkers related to hypoxia [osteopontin (OPN) and carbonic anhydrase IX (CA-IX)], inflammation [interleukin-6 (IL-6), IL-8, and C-reactive protein (CRP)], and tumour load [carcinoembryonic antigen (CEA), and cytokeratin fragment 21-1 (Cyfra 21-1)]. Sequent model extension selected from alpha-2-macroglobulin (α2M), serum interleukin-2 receptor (sIL2r), toll-like receptor 4 (TLR4), and vascular endothelial growth factor (VEGF). Discrimination was reported by concordance-index. OPN and Cyfra 21-1 (hazard ratios of 3.3 and 1.7) significantly improved a clinical model comprising gender, World Health Organization performance-status, forced expiratory volume in 1s, number of positive lymph node stations, and gross tumour volume, from a concordance-index of 0.66 to 0.70 (validation=0.62 and 0.66). Extension of the validated model yielded a concordance-index of 0.67, including α2M, sIL2r and VEGF (hazard ratios of 4.6, 3.1, and 1.4). Improvement of a clinical model including hypoxia and tumour load blood-biomarkers was validated. New immunological markers were associated with overall survival. Data and models can be found at www.cancerdata.org (http://dx.doi.org/10.17195/candat.2016.04.1) and www.predictcancer.org. Copyright © 2016 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

  16. Prediction of overall survival for patients with metastatic castration-resistant prostate cancer: development of a prognostic model through a crowdsourced challenge with open clinical trial data

    OpenAIRE

    Guinney, Justin; Tao WANG; Laajala, Teemu D; Winner, Kimberly Kanigel; Bare, J. Christopher; Neto, Elias Chaibub; Khan, Suleiman A.; Peddinti, Gopal; Airola, Antti; Pahikkala, Tapio; Mirtti, Tuomas; Yu, Thomas; Bot, Brian M.; Shen, Liji; Abdallah, Kald

    2017-01-01

    Background: Improvements to prognostic models in metastatic castration-resistant prostate cancer have the potential to augment clinical trial design and guide treatment strategies. In partnership with Project Data Sphere, a not-for-profit initiative allowing data from cancer clinical trials to be shared broadly with researchers, we designed an open-data, crowdsourced, DREAM (Dialogue for Reverse Engineering Assessments and Methods) challenge to not only identify a better prognostic model for ...

  17. CA 19-9 to peritoneal carcinomatosis index (PCI) ratio is prognostic in patients with epithelial appendiceal mucinous neoplasms and peritoneal dissemination undergoing cytoreduction surgery and intraperitoneal chemotherapy: A retrospective cohort study.

    Science.gov (United States)

    Kozman, Mathew A; Fisher, Oliver M; Rebolledo, Bree-Anne J; Valle, Sarah J; Alzahrani, Nayef; Liauw, Winston; Morris, David L

    2017-12-01

    Serum tumour levels have been shown to be prognostic in patients with epithelial appendiceal mucinous neoplasms with peritoneal dissemination (pseudomyxoma peritonei (PMP)). A singular index which incorporates both tumour activity (as depicted by serum tumour marker levels) and tumour volume (as depicted by peritoneal carcinomatosis index (PCI)), may give a more precise surrogate of tumour biological behaviour. The prognostic implication of this index has not yet been reported. A retrospective cohort study of all patients with PMP managed from 1996 to 2016 with cytoreductive surgery (CRS) and intraperitoneal chemotherapy (IPC) was performed by analysing the survival effect of the ratio of preoperative serum CEA, CA19.9 and CA125 to PCI. Three hundred and eighty-six patients were included. In patients with low-grade PMP, elevated CA19-9/PCI ratio resulted in poorer median overall survival times (104 months vs NR, 95%CI 83 - NR, log-rank p < 0.001) and was an independent predictor of reduced overall survival on multivariable analysis (adjusted HR 5.60, 95%CI 1.60-19.68, p = 0.007). In patients with high-grade PMP, no statistically significant difference in survival was recognised. CA19-9/PCI ratio is an independent prognostic factor for overall survival in patients with low-grade PMP undergoing CRS and IPC. By accounting for both tumour activity and tumour volume simultaneously, this novel index behaves as a surrogate of tumour biology and provides a useful adjunct for decisions regarding treatment allocation in this patient group. Copyright © 2017 Elsevier Ltd, BASO ~ The Association for Cancer Surgery, and the European Society of Surgical Oncology. All rights reserved.

  18. A Price Index Model for Road Freight Transportation and Its Empirical analysis in China

    OpenAIRE

    Liu Zhishuo; Zhao Kuan; Ma Jingmiao; Wang Chunfang

    2017-01-01

    The aim of price index for road freight transportation (RFT) is to reflect the changes of price in the road transport market. Firstly, a price index model for RFT based on the sample data from Alibaba logistics platform is built. This model is a three levels index system including total index, classification index and individual index and the Laspeyres method is applied to calculate these indices. Finally, an empirical analysis of the price index for RFT market in Zhejiang Province is perform...

  19. Empirical modelling to predict the refractive index of human blood.

    Science.gov (United States)

    Yahya, M; Saghir, M Z

    2016-02-21

    Optical techniques used for the measurement of the optical properties of blood are of great interest in clinical diagnostics. Blood analysis is a routine procedure used in medical diagnostics to confirm a patient's condition. Measuring the optical properties of blood is difficult due to the non-homogenous nature of the blood itself. In addition, there is a lot of variation in the refractive indices reported in the literature. These are the reasons that motivated the researchers to develop a mathematical model that can be used to predict the refractive index of human blood as a function of concentration, temperature and wavelength. The experimental measurements were conducted on mimicking phantom hemoglobin samples using the Abbemat Refractometer. The results analysis revealed a linear relationship between the refractive index and concentration as well as temperature, and a non-linear relationship between refractive index and wavelength. These results are in agreement with those found in the literature. In addition, a new formula was developed based on empirical modelling which suggests that temperature and wavelength coefficients be added to the Barer formula. The verification of this correlation confirmed its ability to determine refractive index and/or blood hematocrit values with appropriate clinical accuracy.

  20. Generic Software Architecture for Prognostics (GSAP) User Guide

    Science.gov (United States)

    Teubert, Christopher Allen; Daigle, Matthew John; Watkins, Jason; Sankararaman, Shankar; Goebel, Kai

    2016-01-01

    The Generic Software Architecture for Prognostics (GSAP) is a framework for applying prognostics. It makes applying prognostics easier by implementing many of the common elements across prognostic applications. The standard interface enables reuse of prognostic algorithms and models across systems using the GSAP framework.

  1. Infinite Ergodic Index of the Ehrenfest Wind-Tree Model

    Science.gov (United States)

    Málaga Sabogal, Alba; Troubetzkoy, Serge Eugene

    2017-12-01

    The set of all possible configurations of the Ehrenfest wind-tree model endowed with the Hausdorff topology is a compact metric space. For a typical configuration we show that the wind-tree dynamics has infinite ergodic index in almost every direction. In particular some ergodic theorems can be applied to show that if we start with a large number of initially parallel particles their directions decorrelate as the dynamics evolve, answering the question posed by the Ehrenfests.

  2. Various forms of indexing HDMR for modelling multivariate classification problems

    Science.gov (United States)

    Aksu, ćaǧrı; Tunga, M. Alper

    2014-12-01

    The Indexing HDMR method was recently developed for modelling multivariate interpolation problems. The method uses the Plain HDMR philosophy in partitioning the given multivariate data set into less variate data sets and then constructing an analytical structure through these partitioned data sets to represent the given multidimensional problem. Indexing HDMR makes HDMR be applicable to classification problems having real world data. Mostly, we do not know all possible class values in the domain of the given problem, that is, we have a non-orthogonal data structure. However, Plain HDMR needs an orthogonal data structure in the given problem to be modelled. In this sense, the main idea of this work is to offer various forms of Indexing HDMR to successfully model these real life classification problems. To test these different forms, several well-known multivariate classification problems given in UCI Machine Learning Repository were used and it was observed that the accuracy results lie between 80% and 95% which are very satisfactory.

  3. Various forms of indexing HDMR for modelling multivariate classification problems

    Energy Technology Data Exchange (ETDEWEB)

    Aksu, Çağrı [Bahçeşehir University, Information Technologies Master Program, Beşiktaş, 34349 İstanbul (Turkey); Tunga, M. Alper [Bahçeşehir University, Software Engineering Department, Beşiktaş, 34349 İstanbul (Turkey)

    2014-12-10

    The Indexing HDMR method was recently developed for modelling multivariate interpolation problems. The method uses the Plain HDMR philosophy in partitioning the given multivariate data set into less variate data sets and then constructing an analytical structure through these partitioned data sets to represent the given multidimensional problem. Indexing HDMR makes HDMR be applicable to classification problems having real world data. Mostly, we do not know all possible class values in the domain of the given problem, that is, we have a non-orthogonal data structure. However, Plain HDMR needs an orthogonal data structure in the given problem to be modelled. In this sense, the main idea of this work is to offer various forms of Indexing HDMR to successfully model these real life classification problems. To test these different forms, several well-known multivariate classification problems given in UCI Machine Learning Repository were used and it was observed that the accuracy results lie between 80% and 95% which are very satisfactory.

  4. The prognostic value of FET PET at radiotherapy planning in newly diagnosed glioblastoma

    Energy Technology Data Exchange (ETDEWEB)

    Hoejklint Poulsen, Sidsel [The Finsen Center, Rigshospitalet, Department of Radiation Biology, Copenhagen (Denmark); Center of Diagnostic Investigation, Rigshospitalet, Department of Clinical Physiology, Nuclear Medicine and PET, Copenhagen (Denmark); Urup, Thomas; Grunnet, Kirsten; Skovgaard Poulsen, Hans [The Finsen Center, Rigshospitalet, Department of Radiation Biology, Copenhagen (Denmark); The Finsen Center, Rigshospitalet, Department of Oncology, Copenhagen (Denmark); Jarle Christensen, Ib [University of Copenhagen, Hvidovre Hospital, Laboratory of Gastroenterology, Copenhagen (Denmark); Larsen, Vibeke Andree [Center of Diagnostic Investigation, Rigshospitalet, Department of Radiology, Copenhagen (Denmark); Lundemann Jensen, Michael; Munck af Rosenschoeld, Per [The Finsen Center, Rigshospitalet, Department of Oncology, Copenhagen (Denmark); The Finsen Center, Rigshospitalet, Section of Radiotherapy, Copenhagen (Denmark); Law, Ian [Center of Diagnostic Investigation, Rigshospitalet, Department of Clinical Physiology, Nuclear Medicine and PET, Copenhagen (Denmark)

    2017-03-15

    Glioblastoma patients show a great variability in progression free survival (PFS) and overall survival (OS). To gain additional pretherapeutic information, we explored the potential of O-(2-{sup 18}F-fluoroethyl)-L-tyrosine (FET) PET as an independent prognostic biomarker. We retrospectively analyzed 146 consecutively treated, newly diagnosed glioblastoma patients. All patients were treated with temozolomide and radiation therapy (RT). CT/MR and FET PET scans were obtained postoperatively for RT planning. We used Cox proportional hazards models with OS and PFS as endpoints, to test the prognostic value of FET PET biological tumor volume (BTV). Median follow-up time was 14 months, and median OS and PFS were 16.5 and 6.5 months, respectively. In the multivariate analysis, increasing BTV (HR = 1.17, P < 0.001), poor performance status (HR = 2.35, P < 0.001), O(6)-methylguanine-DNA methyltransferase protein status (HR = 1.61, P = 0.024) and higher age (HR = 1.32, P = 0.013) were independent prognostic factors of poor OS. For poor PFS, only increasing BTV (HR = 1.18; P = 0.002) was prognostic. A prognostic index for OS was created based on the identified prognostic factors. Large BTV on FET PET is an independent prognostic factor of poor OS and PFS in glioblastoma patients. With the introduction of FET PET, we obtain a prognostic index that can help in glioblastoma treatment planning. (orig.)

  5. A variable polytrope index applied to planet and material models

    Science.gov (United States)

    Thielen, Kevin; Weppner, Stephen; Zielinski, Alexander

    2016-01-01

    We introduce a new approach to a century-old assumption which enhances not only planetary interior calculations but also high-pressure material physics. We show that the polytropic index is the derivative of the bulk modulus with respect to pressure. We then augment the traditional polytrope theory by including a variable polytrope index within the confines of the Lane-Emden differential equation. To investigate the possibilities of this method, we create a high-quality universal equation of state, transforming the traditional polytrope method to a tool with the potential for excellent predictive power. The theoretical foundation of our equation of state is the same elastic observable which we found equivalent to the polytrope index, the derivative of the bulk modulus with respect to pressure. We calculate the density-pressure of six common materials up to 1018 Pa, mass-radius relationships for the same materials, and produce plausible density-radius models for the rocky planets of our Solar system. We argue that the bulk modulus and its derivatives have been underutilized in previous planet formation methods. We constrain the material surface observables for the inner core, outer core, and mantle of planet Earth in a systematic way including pressure, bulk modulus, and the polytrope index in the analysis. We believe that this variable polytrope method has the necessary apparatus to be extended further to gas giants and stars. As supplemental material we provide computer code to calculate multi-layered planets.

  6. Baseline elevated leukocyte count in peripheral blood is associated with poor survival in patients with advanced non-small cell lung cancer: a prognostic model.

    Science.gov (United States)

    Tibaldi, C; Vasile, E; Bernardini, I; Orlandini, C; Andreuccetti, M; Falcone, A

    2008-10-01

    We aimed to investigate the prognostic significance of several baseline variables in stage IIIB-IV non-small cell lung cancer to create a model based on independent prognostic factors. A total of 320 patients were treated with last generation chemotherapy regimens. The majority of patients received treatment with cisplatin + gemcitabine or gemcitabine alone if older than 70 years or with an ECOG performance status (PS) = 2. Performance status of 2, squamous histology, number of metastatic sites >2, presence of bone, brain, liver and contralateral lung metastases and elevated leukocyte count in peripheral blood were all statistically significant prognostic factors in univariate analyses whereas the other tested variables (sex, stage, age, presence of adrenal gland and skin metastases) were not. Subsequently, a multivariate Cox's regression analysis identified PS 2 (P leukocyte count (P Leukocyte count resulted the stronger factor after performance status. If prospectly validated, the proposed prognostic model could be useful to stratify performance status 2 patients in specific future trials.

  7. Prognostic impact of absolute lymphocyte count/absolute monocyte count ratio and prognostic score in patients with nasal-type, extranodal natural killer/T-cell lymphoma.

    Science.gov (United States)

    Li, Na; Zhang, Li; Song, Hao-Lan; Zhang, Jing; Weng, Hua-Wei; Zou, Li-Qun

    2017-05-01

    count prognostic score to the International Prognostic Index and Korean Prognostic Index model, additional prognostic information was found. These results suggest that absolute lymphocyte count/absolute monocyte count ratio and absolute lymphocyte count/absolute monocyte count prognostic score might be useful prognostic factors in extranodal natural killer/T-cell lymphoma.

  8. Single-Index Additive Vector Autoregressive Time Series Models

    KAUST Repository

    LI, YEHUA

    2009-09-01

    We study a new class of nonlinear autoregressive models for vector time series, where the current vector depends on single-indexes defined on the past lags and the effects of different lags have an additive form. A sufficient condition is provided for stationarity of such models. We also study estimation of the proposed model using P-splines, hypothesis testing, asymptotics, selection of the order of the autoregression and of the smoothing parameters and nonlinear forecasting. We perform simulation experiments to evaluate our model in various settings. We illustrate our methodology on a climate data set and show that our model provides more accurate yearly forecasts of the El Niño phenomenon, the unusual warming of water in the Pacific Ocean. © 2009 Board of the Foundation of the Scandinavian Journal of Statistics.

  9. Prognostic values of pneumonia severity index, CURB-65 and expanded CURB-65 scores in community-acquired pneumonia in Zagazig University Hospitals

    Directory of Open Access Journals (Sweden)

    Samah M. Shehata

    2017-07-01

    Conclusions: Expanded CURB-65 score is simple, objective and more accurate scoring system for evaluation of CAP severity and can improve the efficiency of predicting the mortality in CAP patients, better than CURB-65 and PSI scores. Also, Expanded CUEB-65 may generate new therapeutic and prognostic modality in CAP especially in patients with liver cirrhosis.

  10. A Novel Inflammation- and Nutrition-Based Prognostic System for Patients with Laryngeal Squamous Cell Carcinoma: Combination of Red Blood Cell Distribution Width and Body Mass Index (COR-BMI)

    OpenAIRE

    Yan Fu; Yize Mao; Shiqi Chen; Ankui Yang; Quan Zhang

    2016-01-01

    Background Laryngeal squamous cell carcinoma (LSCC) is a head and neck cancer type. In this study, we introduced a novel inflammation- and nutrition-based prognostic system, referred to as COR-BMI (Combination of red blood cell distribution width and body mass index), for LSCC patients. Methods A total of 807 LSCC patients (784 male and 23 female, 22?87 y of age) who underwent surgery were enrolled in this retrospective cohort study. The patients were stratified by COR-BMI into three groups: ...

  11. Polychotomization of continuous variables in regression models based on the overall C index

    Directory of Open Access Journals (Sweden)

    Bax Leon

    2006-12-01

    Full Text Available Abstract Background When developing multivariable regression models for diagnosis or prognosis, continuous independent variables can be categorized to make a prediction table instead of a prediction formula. Although many methods have been proposed to dichotomize prognostic variables, to date there has been no integrated method for polychotomization. The latter is necessary when dichotomization results in too much loss of information or when central values refer to normal states and more dispersed values refer to less preferable states, a situation that is not unusual in medical settings (e.g. body temperature, blood pressure. The goal of our study was to develop a theoretical and practical method for polychotomization. Methods We used the overall discrimination index C, introduced by Harrel, as a measure of the predictive ability of an independent regressor variable and derived a method for polychotomization mathematically. Since the naïve application of our method, like some existing methods, gives rise to positive bias, we developed a parametric method that minimizes this bias and assessed its performance by the use of Monte Carlo simulation. Results The overall C is closely related to the area under the ROC curve and the produced di(polychotomized variable's predictive performance is comparable to the original continuous variable. The simulation shows that the parametric method is essentially unbiased for both the estimates of performance and the cutoff points. Application of our method to the predictor variables of a previous study on rhabdomyolysis shows that it can be used to make probability profile tables that are applicable to the diagnosis or prognosis of individual patient status. Conclusion We propose a polychotomization (including dichotomization method for independent continuous variables in regression models based on the overall discrimination index C and clarified its meaning mathematically. To avoid positive bias in

  12. Pulsar Braking Index: A Test of Emission Models?

    Science.gov (United States)

    Xu, R. X.; Qiao, G. J.

    2001-11-01

    Pulsar braking torques due to magnetodipole radiation and the unipolar generator are considered, which results in a braking index n of less than 3 and could be employed to test the emission models. Improved equations for the pulsar braking index and magnetic field are presented, which are true if the rotation energy-loss rate equals the sum of the energy-loss rate of dipole radiation and of relativistic particles powered by a unipolar generator. The magnetic field calculated conventionally could be good enough, but only if it were modified by a factor of at most ~0.6. Both inner and outer gaps may coexist in the magnetosphere of the Vela pulsar.

  13. Prognostic meta-signature of breast cancer developed by two-stage mixture modeling of microarray data

    Directory of Open Access Journals (Sweden)

    Ghosh Debashis

    2004-12-01

    Full Text Available Abstract Background An increasing number of studies have profiled tumor specimens using distinct microarray platforms and analysis techniques. With the accumulating amount of microarray data, one of the most intriguing yet challenging tasks is to develop robust statistical models to integrate the findings. Results By applying a two-stage Bayesian mixture modeling strategy, we were able to assimilate and analyze four independent microarray studies to derive an inter-study validated "meta-signature" associated with breast cancer prognosis. Combining multiple studies (n = 305 samples on a common probability scale, we developed a 90-gene meta-signature, which strongly associated with survival in breast cancer patients. Given the set of independent studies using different microarray platforms which included spotted cDNAs, Affymetrix GeneChip, and inkjet oligonucleotides, the individually identified classifiers yielded gene sets predictive of survival in each study cohort. The study-specific gene signatures, however, had minimal overlap with each other, and performed poorly in pairwise cross-validation. The meta-signature, on the other hand, accommodated such heterogeneity and achieved comparable or better prognostic performance when compared with the individual signatures. Further by comparing to a global standardization method, the mixture model based data transformation demonstrated superior properties for data integration and provided solid basis for building classifiers at the second stage. Functional annotation revealed that genes involved in cell cycle and signal transduction activities were over-represented in the meta-signature. Conclusion The mixture modeling approach unifies disparate gene expression data on a common probability scale allowing for robust, inter-study validated prognostic signatures to be obtained. With the emerging utility of microarrays for cancer prognosis, it will be important to establish paradigms to meta

  14. Extreme value modelling of Ghana stock exchange index.

    Science.gov (United States)

    Nortey, Ezekiel N N; Asare, Kwabena; Mettle, Felix Okoe

    2015-01-01

    Modelling of extreme events has always been of interest in fields such as hydrology and meteorology. However, after the recent global financial crises, appropriate models for modelling of such rare events leading to these crises have become quite essential in the finance and risk management fields. This paper models the extreme values of the Ghana stock exchange all-shares index (2000-2010) by applying the extreme value theory (EVT) to fit a model to the tails of the daily stock returns data. A conditional approach of the EVT was preferred and hence an ARMA-GARCH model was fitted to the data to correct for the effects of autocorrelation and conditional heteroscedastic terms present in the returns series, before the EVT method was applied. The Peak Over Threshold approach of the EVT, which fits a Generalized Pareto Distribution (GPD) model to excesses above a certain selected threshold, was employed. Maximum likelihood estimates of the model parameters were obtained and the model's goodness of fit was assessed graphically using Q-Q, P-P and density plots. The findings indicate that the GPD provides an adequate fit to the data of excesses. The size of the extreme daily Ghanaian stock market movements were then computed using the value at risk and expected shortfall risk measures at some high quantiles, based on the fitted GPD model.

  15. A Price Index Model for Road Freight Transportation and Its Empirical analysis in China

    Directory of Open Access Journals (Sweden)

    Liu Zhishuo

    2017-01-01

    Full Text Available The aim of price index for road freight transportation (RFT is to reflect the changes of price in the road transport market. Firstly, a price index model for RFT based on the sample data from Alibaba logistics platform is built. This model is a three levels index system including total index, classification index and individual index and the Laspeyres method is applied to calculate these indices. Finally, an empirical analysis of the price index for RFT market in Zhejiang Province is performed. In order to demonstrate the correctness and validity of the exponential model, a comparative analysis with port throughput and PMI index is carried out.

  16. Diagnostic and prognostic simulations with a full Stokes model accounting for superimposed ice of Midtre Lovénbreen, Svalbard

    Directory of Open Access Journals (Sweden)

    T. Zwinger

    2009-11-01

    Full Text Available We present steady state (diagnostic and transient (prognostic simulations of Midtre Lovénbreen, Svalbard performed with the thermo-mechanically coupled full-Stokes code Elmer. This glacier has an extensive data set of geophysical measurements available spanning several decades, that allow for constraints on model descriptions. Consistent with this data set, we included a simple model accounting for the formation of superimposed ice. Diagnostic results indicated that a dynamic adaptation of the free surface is necessary, to prevent non-physically high velocities in a region of under determined bedrock depths. Observations from ground penetrating radar of the basal thermal state agree very well with model predictions, while the dip angles of isochrones in radar data also match reasonably well with modelled isochrones, despite the numerical deficiencies of estimating ages with a steady state model.

    Prognostic runs for 53 years, using a constant accumulation/ablation pattern starting from the steady state solution obtained from the configuration of the 1977 DEM show that: 1 the unrealistic velocities in the under determined parts of the DEM quickly damp out; 2 the free surface evolution matches well measured elevation changes; 3 the retreat of the glacier under this scenario continues with the glacier tongue in a projection to 2030 being situated ≈500 m behind the position in 1977.

  17. Bounds and Inequalities Relating h-Index, g-Index, e-Index and Generalized Impact Factor: An Improvement over Existing Models

    Science.gov (United States)

    Abbas, Ash Mohammad

    2012-01-01

    In this paper, we describe some bounds and inequalities relating -index, -index, -index, and generalized impact factor. We derive the bounds and inequalities relating these indexing parameters from their basic definitions and without assuming any continuous model to be followed by any of them. We verify the theorems using citation data for five Price Medalists. We observe that the lower bound for -index given by Theorem 2, , comes out to be more accurate as compared to Schubert-Glanzel relation for a proportionality constant of , where is the number of citations and is the number of papers referenced. Also, the values of -index obtained using Theorem 2 outperform those obtained using Egghe-Liang-Rousseau power law model for the given citation data of Price Medalists. Further, we computed the values of upper bound on -index given by Theorem 3, , where denotes the value of -index. We observe that the upper bound on -index given by Theorem 3 is reasonably tight for the given citation record of Price Medalists. PMID:22496760

  18. Bounds and inequalities relating h-index, g-index, e-index and generalized impact factor: an improvement over existing models.

    Directory of Open Access Journals (Sweden)

    Ash Mohammad Abbas

    Full Text Available In this paper, we describe some bounds and inequalities relating h-index, g-index, e-index, and generalized impact factor. We derive the bounds and inequalities relating these indexing parameters from their basic definitions and without assuming any continuous model to be followed by any of them. We verify the theorems using citation data for five Price Medalists. We observe that the lower bound for h-index given by Theorem 2, [formula: see text], g ≥ 1, comes out to be more accurate as compared to Schubert-Glanzel relation h is proportional to C(2/3P(-1/3 for a proportionality constant of 1, where C is the number of citations and P is the number of papers referenced. Also, the values of h-index obtained using Theorem 2 outperform those obtained using Egghe-Liang-Rousseau power law model for the given citation data of Price Medalists. Further, we computed the values of upper bound on g-index given by Theorem 3, g ≤ (h + e, where e denotes the value of e-index. We observe that the upper bound on g-index given by Theorem 3 is reasonably tight for the given citation record of Price Medalists.

  19. Bounds and inequalities relating h-index, g-index, e-index and generalized impact factor: an improvement over existing models.

    Science.gov (United States)

    Abbas, Ash Mohammad

    2012-01-01

    In this paper, we describe some bounds and inequalities relating h-index, g-index, e-index, and generalized impact factor. We derive the bounds and inequalities relating these indexing parameters from their basic definitions and without assuming any continuous model to be followed by any of them. We verify the theorems using citation data for five Price Medalists. We observe that the lower bound for h-index given by Theorem 2, [formula: see text], g ≥ 1, comes out to be more accurate as compared to Schubert-Glanzel relation h is proportional to C(2/3)P(-1/3) for a proportionality constant of 1, where C is the number of citations and P is the number of papers referenced. Also, the values of h-index obtained using Theorem 2 outperform those obtained using Egghe-Liang-Rousseau power law model for the given citation data of Price Medalists. Further, we computed the values of upper bound on g-index given by Theorem 3, g ≤ (h + e), where e denotes the value of e-index. We observe that the upper bound on g-index given by Theorem 3 is reasonably tight for the given citation record of Price Medalists.

  20. Electrohydraulic Servomechanisms Affected by Multiple Failures: A Model-Based Prognostic Method Using Genetic Algorithms

    OpenAIRE

    Dalla Vedova, Matteo Davide Lorenzo; Maggiore, Paolo

    2016-01-01

    In order to detect incipient failures due to a progressive wear of a primary flight command electro hydraulic actuator (EHA), prognostics could employ several approaches; the choice of the best ones is driven by the efficacy shown in failure detection, since not all the algorithms might be useful for the proposed purpose. In other words, some of them could be suitable only for certain applications while they could not give useful results for others. Developing a fault detection algorithm able...

  1. Evaluation of Simulated Marine Aerosol Production Using the WaveWatchIII Prognostic Wave Model Coupled to the Community Atmosphere Model within the Community Earth System Model

    Energy Technology Data Exchange (ETDEWEB)

    Long, M. S. [Harvard Univ., Cambridge, MA (United States). School of Engineering and Applied Sciences; Keene, William C. [Univ. of Virginia, Charlottesville, VA (United States). Dept. of Environmental Sciences; Zhang, J. [Univ. of North Dakota, Grand Forks, ND (United States). Dept. of Atmospheric Sciences; Reichl, B. [Univ. of Rhode Island, Narragansett, RI (United States). Graduate School of Oceanography; Shi, Y. [Univ. of North Dakota, Grand Forks, ND (United States). Dept. of Atmospheric Sciences; Hara, T. [Univ. of Rhode Island, Narragansett, RI (United States). Graduate School of Oceanography; Reid, J. S. [Naval Research Lab. (NRL), Monterey, CA (United States); Fox-Kemper, B. [Brown Univ., Providence, RI (United States). Earth, Environmental and Planetary Sciences; Craig, A. P. [National Center for Atmospheric Research, Boulder, CO (United States); Erickson, D. J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Computer Science and Mathematics Division; Ginis, I. [Univ. of Rhode Island, Narragansett, RI (United States). Graduate School of Oceanography; Webb, A. [Univ. of Tokyo (Japan). Dept. of Ocean Technology, Policy, and Environment

    2016-11-08

    Primary marine aerosol (PMA) is emitted into the atmosphere via breaking wind waves on the ocean surface. Most parameterizations of PMA emissions use 10-meter wind speed as a proxy for wave action. This investigation coupled the 3rd generation prognostic WAVEWATCH-III wind-wave model within a coupled Earth system model (ESM) to drive PMA production using wave energy dissipation rate – analogous to whitecapping – in place of 10-meter wind speed. The wind speed parameterization did not capture basin-scale variability in relations between wind and wave fields. Overall, the wave parameterization did not improve comparison between simulated versus measured AOD or Na+, thus highlighting large remaining uncertainties in model physics. Results confirm the efficacy of prognostic wind-wave models for air-sea exchange studies coupled with laboratory- and field-based characterizations of the primary physical drivers of PMA production. No discernible correlations were evident between simulated PMA fields and observed chlorophyll or sea surface temperature.

  2. Validation and Extension of the Prolonged Mechanical Ventilation Prognostic Model (ProVent) Score for Predicting 1-Year Mortality after Prolonged Mechanical Ventilation.

    Science.gov (United States)

    Udeh, Chiedozie I; Hadder, Brent; Udeh, Belinda L

    2015-12-01

    Prognostic models can inform management decisions for patients requiring prolonged mechanical ventilation. The Prolonged Mechanical Ventilation Prognostic model (ProVent) score was developed to predict 1-year mortality in these patients. External evaluation of such models is needed before they are adopted for routine use. The goal was to perform an independent external validation of the modified ProVent score and assess for spectrum extension at 14 days of mechanical ventilation. This was a retrospective cohort analysis of patients who received prolonged mechanical ventilation at the University of Iowa Hospitals. Patients who received 14 or more days of mechanical ventilation were identified from a database. Manual review of their medical records was performed to abstract relevant data including the four model variables at Days 14 and 21 of mechanical ventilation. Vital status at 1 year was checked in the medical records or the social security death index. Logistic regressions examined the associations between the different variables and mortality. Model performance at 14 to 20 days and 21+ days was assessed for discrimination by calculating the area under the receiver operating characteristic curve, and calibration was assessed using the Hosmer-Lemeshow goodness-of-fit test. A total of 180 patients (21+ d) and 218 patients (14-20 d) were included. Overall, 75% were surgical patients. One-year mortality was 51% for 21+ days and 32% for 14 to 20 days of mechanical ventilation. Age greater than 65 years was the strongest predictor of mortality at 1 year in all cohorts. There was no significant difference between predicted and observed mortality rates for patients stratified by ProVent score. There was near-perfect specificity for mortality in the groups with higher ProVent scores. Areas under the curve were 0.69 and 0.75 for the 21+ days and the 14 to 20 days cohorts respectively. P values for the Hosmer-Lemeshow statistics were 0.24 for 21+ days and 0.22 for 14 to

  3. Bivariate sub-Gaussian model for stock index returns

    Science.gov (United States)

    Jabłońska-Sabuka, Matylda; Teuerle, Marek; Wyłomańska, Agnieszka

    2017-11-01

    Financial time series are commonly modeled with methods assuming data normality. However, the real distribution can be nontrivial, also not having an explicitly formulated probability density function. In this work we introduce novel parameter estimation and high-powered distribution testing methods which do not rely on closed form densities, but use the characteristic functions for comparison. The approach applied to a pair of stock index returns demonstrates that such a bivariate vector can be a sample coming from a bivariate sub-Gaussian distribution. The methods presented here can be applied to any nontrivially distributed financial data, among others.

  4. Usefulness of Geriatric Nutritional Risk Index for Assessing Nutritional Status and Its Prognostic Impact in Patients Aged ≥65 Years With Acute Heart Failure.

    Science.gov (United States)

    Honda, Yasuyuki; Nagai, Toshiyuki; Iwakami, Naotsugu; Sugano, Yasuo; Honda, Satoshi; Okada, Atsushi; Asaumi, Yasuhide; Aiba, Takeshi; Noguchi, Teruo; Kusano, Kengo; Ogawa, Hisao; Yasuda, Satoshi; Anzai, Toshihisa

    2016-08-15

    Malnutrition is becoming one of the most important determinants of worse clinical outcomes in patients with acute heart failure (AHF). However, appropriate tools for evaluating the nutritional status in patients aged ≥65 years with AHF remain unclear. We examined 490 consecutive patients aged ≥65 years with AHF. They were divided into 2 groups according to Geriatric Nutritional Risk Index (GNRI; cut-off value = 92). During a median period of 189 days, the mortality rate was significantly higher in the lower GNRI group than the higher GNRI group (p nutritional indexes. Adding GNRI to an existing outcome prediction model for mortality in AHF significantly increased the C-statistic from 0.68 to 0.74 (p = 0.017). The net reclassification improvement afforded by GNRI was 60% overall, 27% for events, and 33% for nonevents (p nutritional parameters. Furthermore, the assessment of nutritional status using GNRI is very helpful for risk stratification. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Towards A Model-based Prognostics Methodology for Electrolytic Capacitors: A Case Study Based on Electrical Overstress Accelerated Aging

    Directory of Open Access Journals (Sweden)

    Gautam Biswas

    2012-12-01

    Full Text Available This paper presents a model-driven methodology for predict- ing the remaining useful life of electrolytic capacitors. This methodology adopts a Kalman filter approach in conjunction with an empirical state-based degradation model to predict the degradation of capacitor parameters through the life of the capacitor. Electrolytic capacitors are important components of systems that range from power supplies on critical avion- ics equipment to power drivers for electro-mechanical actuators. These devices are known for their comparatively low reliability and given their critical role in the system, they are good candidates for component level prognostics and health management. Prognostics provides a way to assess remain- ing useful life of a capacitor based on its current state of health and its anticipated future usage and operational conditions. This paper proposes and empirical degradation model and discusses experimental results for an accelerated aging test performed on a set of identical capacitors subjected to electrical stress. The data forms the basis for developing the Kalman-filter based remaining life prediction algorithm.

  6. Prognostic factors for metachronous contralateral breast cancer: a comparison of the linear Cox regression model and its artificial neural network extension.

    Science.gov (United States)

    Mariani, L; Coradini, D; Biganzoli, E; Boracchi, P; Marubini, E; Pilotti, S; Salvadori, B; Silvestrini, R; Veronesi, U; Zucali, R; Rilke, F

    1997-06-01

    The purpose of the present study was to assess prognostic factor for metachronous contralateral recurrence of breast cancer (CBC). Two factors were of particular interest, namely estrogen (ER) and progesterone (PgR) receptors assayed with the biochemical method in primary tumor tissue. Information was obtained from a prospective clinical database for 1763 axillary node-negative women who had received curative surgery, mostly of the conservative type, and followed-up for a median of 82 months. The analysis was performed based on both a standard (linear) Cox model and an artificial neural network (ANN) extension of this model proposed by Faraggi and Simon. Furthermore, to assess the prognostic importance of the factors considered, model predictive ability was computed. In agreement with already published studies, the results of our analysis confirmed the prognostic role of age at surgery, histology, and primary tumor site, in that young patients (extensive intraductal component, and a lower hazard in infiltrating lobular carcinoma or other histotypes. In spite of the above findings, the predictive value of both the standard and ANN Cox models was relatively low, thus suggesting an intrinsic limitation of the prognostic variables considered, rather than their suboptimal modeling. Research for better prognostic variables should therefore continue.

  7. Development and internal validation of a prognostic model to predict recurrence free survival in patients with adult granulosa cell tumors of the ovary

    NARCIS (Netherlands)

    van Meurs, Hannah S.; Schuit, Ewoud; Horlings, Hugo M.; van der Velden, Jacobus; van Driel, Willemien J.; Mol, Ben Willem J.; Kenter, Gemma G.; Buist, Marrije R.

    2014-01-01

    Models to predict the probability of recurrence free survival exist for various types of malignancies, but a model for recurrence free survival in individuals with an adult granulosa cell tumor (GCT) of the ovary is lacking. We aimed to develop and internally validate such a prognostic model. We

  8. Significance of stromal-1 and stromal-2 signatures and biologic prognostic model in diffuse large B-cell lymphoma

    Science.gov (United States)

    Abdou, Asmaa Gaber; Asaad, Nancy; Kandil, Mona; Shabaan, Mohammed; Shams, Asmaa

    2017-01-01

    Objective : Diffuse Large B Cell Lymphoma (DLBCL) is a heterogeneous group of tumors with different biological and clinical characteristics that have diverse clinical outcomes and response to therapy. Stromal-1 signature of tumor microenvironment of DLBCL represents extracellular matrix deposition and histiocytic infiltrate, whereas stromal-2 represents angiogenesis that could affect tumor progression. Methods : The aim of the present study is to assess the significance of stromal-1 signature using SPARC-1 and stromal-2 signature using CD31 expression and then finally to construct biologic prognostic model (BPM) in 60 cases of DLBCL via immunohistochemistry. Results : Microvessel density (PBPM showed that 42 cases (70%) were of low biologic score (0–1) and 18 cases (30%) were of high biologic score (2–3). Low BPM cases showed less probability for splenic involvement (P=0.04) and a higher rate of complete response to therapy compared with high score cases (P=0.08). Conclusions : The DLBCL microenvironment could modulate tumor progression behavior since angiogenesis and SPARC positive stromal cells promote dissemination by association with spleen involvement and capsular invasion. Biologic prognostic models, including modified BPM, which considered cell origin of DLBCL and stromal signature pathways, could determine DLBCL progression and response to therapy. PMID:28607806

  9. Composite prognostic models across the non-alcoholic fatty liver disease spectrum: Clinical application in developing countries

    Science.gov (United States)

    Lückhoff, Hilmar K; Kruger, Frederik C; Kotze, Maritha J

    2015-01-01

    Heterogeneity in clinical presentation, histological severity, prognosis and therapeutic outcomes characteristic of non-alcoholic fatty liver disease (NAFLD) necessitates the development of scientifically sound classification schemes to assist clinicians in stratifying patients into meaningful prognostic subgroups. The need for replacement of invasive liver biopsies as the standard method whereby NAFLD is diagnosed, graded and staged with biomarkers of histological severity injury led to the development of composite prognostic models as potentially viable surrogate alternatives. In the present article, we review existing scoring systems used to (1) confirm the presence of undiagnosed hepatosteatosis; (2) distinguish between simple steatosis and NASH; and (3) predict advanced hepatic fibrosis, with particular emphasis on the role of NAFLD as an independent cardio-metabolic risk factor. In addition, the incorporation of functional genomic markers and application of emerging imaging technologies are discussed as a means to improve the diagnostic accuracy and predictive performance of promising composite models found to be most appropriate for widespread clinical adoption. PMID:26019735

  10. Use of remotely sensed precipitation and leaf area index in a distributed hydrological model

    DEFF Research Database (Denmark)

    Andersen, Jens; Dybkjær, Gorm Ibsen; Jensen, Karsten Høgh

    2002-01-01

    distributed hydrological modelling, remote sensing, precipitation, leaf area index, NOAA AVHRR, cold cloud duration......distributed hydrological modelling, remote sensing, precipitation, leaf area index, NOAA AVHRR, cold cloud duration...

  11. Performance and evaluation of a coupled prognostic model TAPM over a mountainous complex terrain industrial area

    Science.gov (United States)

    Matthaios, Vasileios N.; Triantafyllou, Athanasios G.; Albanis, Triantafyllos A.; Sakkas, Vasileios; Garas, Stelios

    2017-04-01

    Atmospheric modeling is considered an important tool with several applications such as prediction of air pollution levels, air quality management, and environmental impact assessment studies. Therefore, evaluation studies must be continuously made, in order to improve the accuracy and the approaches of the air quality models. In the present work, an attempt is made to examine the air pollution model (TAPM) efficiency in simulating the surface meteorology, as well as the SO2 concentrations in a mountainous complex terrain industrial area. Three configurations under different circumstances, firstly with default datasets, secondly with data assimilation, and thirdly with updated land use, ran in order to investigate the surface meteorology for a 3-year period (2009-2011) and one configuration applied to predict SO2 concentration levels for the year of 2011.The modeled hourly averaged meteorological and SO2 concentration values were statistically compared with those from five monitoring stations across the domain to evaluate the model's performance. Statistical measures showed that the surface temperature and relative humidity are predicted well in all three simulations, with index of agreement (IOA) higher than 0.94 and 0.70 correspondingly, in all monitoring sites, while an overprediction of extreme low temperature values is noted, with mountain altitudes to have an important role. However, the results also showed that the model's performance is related to the configuration regarding the wind. TAPM default dataset predicted better the wind variables in the center of the simulation than in the boundaries, while improvement in the boundary horizontal winds implied the performance of TAPM with updated land use. TAPM assimilation predicted the wind variables fairly good in the whole domain with IOA higher than 0.83 for the wind speed and higher than 0.85 for the horizontal wind components. Finally, the SO2 concentrations were assessed by the model with IOA varied from 0

  12. Prognostic breast cancer signature identified from 3D culture model accurately predicts clinical outcome across independent datasets

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Katherine J.; Patrick, Denis R.; Bissell, Mina J.; Fournier, Marcia V.

    2008-10-20

    One of the major tenets in breast cancer research is that early detection is vital for patient survival by increasing treatment options. To that end, we have previously used a novel unsupervised approach to identify a set of genes whose expression predicts prognosis of breast cancer patients. The predictive genes were selected in a well-defined three dimensional (3D) cell culture model of non-malignant human mammary epithelial cell morphogenesis as down-regulated during breast epithelial cell acinar formation and cell cycle arrest. Here we examine the ability of this gene signature (3D-signature) to predict prognosis in three independent breast cancer microarray datasets having 295, 286, and 118 samples, respectively. Our results show that the 3D-signature accurately predicts prognosis in three unrelated patient datasets. At 10 years, the probability of positive outcome was 52, 51, and 47 percent in the group with a poor-prognosis signature and 91, 75, and 71 percent in the group with a good-prognosis signature for the three datasets, respectively (Kaplan-Meier survival analysis, p<0.05). Hazard ratios for poor outcome were 5.5 (95% CI 3.0 to 12.2, p<0.0001), 2.4 (95% CI 1.6 to 3.6, p<0.0001) and 1.9 (95% CI 1.1 to 3.2, p = 0.016) and remained significant for the two larger datasets when corrected for estrogen receptor (ER) status. Hence the 3D-signature accurately predicts breast cancer outcome in both ER-positive and ER-negative tumors, though individual genes differed in their prognostic ability in the two subtypes. Genes that were prognostic in ER+ patients are AURKA, CEP55, RRM2, EPHA2, FGFBP1, and VRK1, while genes prognostic in ER patients include ACTB, FOXM1 and SERPINE2 (Kaplan-Meier p<0.05). Multivariable Cox regression analysis in the largest dataset showed that the 3D-signature was a strong independent factor in predicting breast cancer outcome. The 3D-signature accurately predicts breast cancer outcome across multiple datasets and holds prognostic

  13. Prognostics of Power MOSFET

    Science.gov (United States)

    Celaya, Jose Ramon; Saxena, Abhinav; Vashchenko, Vladislay; Saha, Sankalita; Goebel, Kai Frank

    2011-01-01

    This paper demonstrates how to apply prognostics to power MOSFETs (metal oxide field effect transistor). The methodology uses thermal cycling to age devices and Gaussian process regression to perform prognostics. The approach is validated with experiments on 100V power MOSFETs. The failure mechanism for the stress conditions is determined to be die-attachment degradation. Change in ON-state resistance is used as a precursor of failure due to its dependence on junction temperature. The experimental data is augmented with a finite element analysis simulation that is based on a two-transistor model. The simulation assists in the interpretation of the degradation phenomena and SOA (safe operation area) change.

  14. Using a Simple Parcel Model to Investigate the Haines Index

    Science.gov (United States)

    Mary Ann Jenkins; Steven K. Krueger; Ruiyu Sun

    2003-01-01

    The Haines Index (Haines 1988) ia fire-weather index based on stability and moisture conditions of the lower atmosphere that rates the potential for large fire growth or extreme fire behavior. The Hained Index is calculated by adding a temperature term a to a moisture term b.

  15. Right Heart End-Systolic Remodeling Index Strongly Predicts Outcomes in Pulmonary Arterial Hypertension: Comparison With Validated Models.

    Science.gov (United States)

    Amsallem, Myriam; Sweatt, Andrew J; Aymami, Marie C; Kuznetsova, Tatiana; Selej, Mona; Lu, HongQuan; Mercier, Olaf; Fadel, Elie; Schnittger, Ingela; McConnell, Michael V; Rabinovitch, Marlene; Zamanian, Roham T; Haddad, Francois

    2017-06-01

    Right ventricular (RV) end-systolic dimensions provide information on both size and function. We investigated whether an internally scaled index of end-systolic dimension is incremental to well-validated prognostic scores in pulmonary arterial hypertension. From 2005 to 2014, 228 patients with pulmonary arterial hypertension were prospectively enrolled. RV end-systolic remodeling index (RVESRI) was defined by lateral length divided by septal height. The incremental values of RV free wall longitudinal strain and RVESRI to risk scores were determined. Mean age was 49±14 years, 78% were female, 33% had connective tissue disease, 52% were in New York Heart Association class ≥III, and mean pulmonary vascular resistance was 11.2±6.4 WU. RVESRI and right atrial area were strongly connected to the other right heart metrics. Three zones of adaptation (adapted, maladapted, and severely maladapted) were identified based on the RVESRI to RV systolic pressure relationship. During a mean follow-up of 3.9±2.4 years, the primary end point of death, transplant, or admission for heart failure was reached in 88 patients. RVESRI was incremental to risk prediction scores in pulmonary arterial hypertension, including the Registry to Evaluate Early and Long-Term PAH Disease Management score, the Pulmonary Hypertension Connection equation, and the Mayo Clinic model. Using multivariable analysis, New York Heart Association class III/IV, RVESRI, and log NT-proBNP (N-Terminal Pro-B-Type Natriuretic Peptide) were retained (χ 2 , 62.2; P right heart metrics, RVESRI demonstrated the best test-retest characteristics. RVESRI is a simple reproducible prognostic marker in patients with pulmonary arterial hypertension. © 2017 American Heart Association, Inc.

  16. A Generic Software Architecture For Prognostics

    Science.gov (United States)

    Teubert, Christopher; Daigle, Matthew J.; Sankararaman, Shankar; Goebel, Kai; Watkins, Jason

    2017-01-01

    Prognostics is a systems engineering discipline focused on predicting end-of-life of components and systems. As a relatively new and emerging technology, there are few fielded implementations of prognostics, due in part to practitioners perceiving a large hurdle in developing the models, algorithms, architecture, and integration pieces. As a result, no open software frameworks for applying prognostics currently exist. This paper introduces the Generic Software Architecture for Prognostics (GSAP), an open-source, cross-platform, object-oriented software framework and support library for creating prognostics applications. GSAP was designed to make prognostics more accessible and enable faster adoption and implementation by industry, by reducing the effort and investment required to develop, test, and deploy prognostics. This paper describes the requirements, design, and testing of GSAP. Additionally, a detailed case study involving battery prognostics demonstrates its use.

  17. Modeling pedestrian gap crossing index under mixed traffic condition.

    Science.gov (United States)

    Naser, Mohamed M; Zulkiple, Adnan; Al Bargi, Walid A; Khalifa, Nasradeen A; Daniel, Basil David

    2017-12-01

    There are a variety of challenges faced by pedestrians when they walk along and attempt to cross a road, as the most recorded accidents occur during this time. Pedestrians of all types, including both sexes with numerous aging groups, are always subjected to risk and are characterized as the most exposed road users. The increased demand for better traffic management strategies to reduce the risks at intersections, improve quality traffic management, traffic volume, and longer cycle time has further increased concerns over the past decade. This paper aims to develop a sustainable pedestrian gap crossing index model based on traffic flow density. It focusses on the gaps accepted by pedestrians and their decision for street crossing, where (Log-Gap) logarithm of accepted gaps was used to optimize the result of a model for gap crossing behavior. Through a review of extant literature, 15 influential variables were extracted for further empirical analysis. Subsequently, data from the observation at an uncontrolled mid-block in Jalan Ampang in Kuala Lumpur, Malaysia was gathered and Multiple Linear Regression (MLR) and Binary Logit Model (BLM) techniques were employed to analyze the results. From the results, different pedestrian behavioral characteristics were considered for a minimum gap size model, out of which only a few (four) variables could explain the pedestrian road crossing behavior while the remaining variables have an insignificant effect. Among the different variables, age, rolling gap, vehicle type, and crossing were the most influential variables. The study concludes that pedestrians' decision to cross the street depends on the pedestrian age, rolling gap, vehicle type, and size of traffic gap before crossing. The inferences from these models will be useful to increase pedestrian safety and performance evaluation of uncontrolled midblock road crossings in developing countries. Copyright © 2017 National Safety Council and Elsevier Ltd. All rights reserved.

  18. Prognostic role of left atrial strain and its combination index with transmitral E-wave velocity in patients with atrial fibrillation.

    Science.gov (United States)

    Hsu, Po-Chao; Lee, Wen-Hsien; Chu, Chun-Yuan; Lee, Hung-Hao; Lee, Chee-Siong; Yen, Hsueh-Wei; Lin, Tsung-Hsien; Voon, Wen-Chol; Lai, Wen-Ter; Sheu, Sheng-Hsiung; Su, Ho-Ming

    2016-02-01

    Left atrial (LA) strain can reflect LA remodeling and is reduced in atrial fibrillation (AF) patients with prior stroke. This study sought to examine the ability of LA strain in predicting subsequent stroke event in AF and also evaluated whether E/LA strain could predict cardiovascular (CV) events in these patients. In 190 persistent AF patients, we performed comprehensive echocardiography with assessment of LA strain. There were 69 CV events including 19 CV death, 32 hospitalizations for heart failure, 3 myocardial infarctions, and 15 strokes during an average follow-up of 29 months. Multivariate analysis showed old age, chronic heart failure, increased left ventricular (LV) mass index, and increased E/LA strain were associated with CV events and decreased LA strain was associated with subsequent stroke event. The addition of E/LA strain and LA strain to a model containing CHA2DS2-VASc score and LV function significantly improved the values in predicting CV events and subsequent stroke event, respectively. In conclusion, E/LA strain and LA strain were respectively useful in predicting CV events and subsequent stroke event in AF. E/LA strain and LA strain could provide incremental values for CV outcome and subsequent stroke outcome prediction over conventional clinical and echocardiographic parameters in AF, respectively.

  19. A Novel Inflammation- and Nutrition-Based Prognostic System for Patients with Laryngeal Squamous Cell Carcinoma: Combination of Red Blood Cell Distribution Width and Body Mass Index (COR-BMI).

    Science.gov (United States)

    Fu, Yan; Mao, Yize; Chen, Shiqi; Yang, Ankui; Zhang, Quan

    Laryngeal squamous cell carcinoma (LSCC) is a head and neck cancer type. In this study, we introduced a novel inflammation- and nutrition-based prognostic system, referred to as COR-BMI (Combination of red blood cell distribution width and body mass index), for LSCC patients. A total of 807 LSCC patients (784 male and 23 female, 22-87 y of age) who underwent surgery were enrolled in this retrospective cohort study. The patients were stratified by COR-BMI into three groups: COR-BMI (0) (RDW ≤ 13.1 and BMI ≥ 25); COR-BMI (1) (RDW ≤ 13.1 and BMI 13.1 and 18.5 ≤ BMI 13.1 and BMI cancer-specific survival (CSS) rate among LSCC patients. The 5-y, 10-y, and 15-y CSS rates were 71.6%, 60.1%, and 55.4%, respectively. There were significant differences among the COR-BMI groups in age (nutrition-based prognostic system, which could predict long-term survival in LSCC patients who underwent surgery.

  20. Noncutaneous malignant melanoma: a prognostic model from a retrospective multicenter study

    Directory of Open Access Journals (Sweden)

    Kim Jung Han

    2010-04-01

    Full Text Available Abstract Background We performed multicenter study to define clinical characteristics of noncutaneous melanomas and to establish prognostic factors patients who received curative resection. Methods Of the 141 patients who were diagnosed of non-cutaneous melanoma at 4 institutions in Korea between June 1992 and May 2005, 129 (91.5% satisfied the selection criteria. Results Of the 129 noncutaneous melanoma patients, 14 patients had ocular melanoma and 115 patients had mucosal melanoma. For mucosal melanoma, anorectum was the most common anatomic site (n = 39, 30.2% which was followed by nasal cavity (n = 30, 23.3%, genitourinary (n = 21, 16.3%, oral cavity (n = 14, 10.9%, upper gastrointestinal tract (n = 6, 4.7% and maxillary sinus (n = 5, 3.9% in the order of frequency. With the median 64.5 (range 4.3-213.0 months follow-up, the median overall survival were 24.4 months (95% CI 13.2-35.5 for all patients, and 34.6 (95% CI 24.5-44.7 months for curatively resected mucosal melanoma patients. Adverse prognostic factors of survival for 87 curatively resected mucosal melanoma patients were complete resection (R1 resection margin, and age > 50 years. For 14 ocular melanoma, Survival outcome was much better than mucosal melanoma with 73.3% of 2 year OS and 51.2 months of median OS (P = .04. Conclusion Prognosis differed according to primary sites of noncutaneous melanoma. Based on our study, noncutaneous melanoma patients should be treated differently to improve survival outcome.

  1. Multidimensional Prognostic Index in Association with Future Mortality and Number of Hospital Days in a Population-Based Sample of Older Adults: Results of the EU Funded MPI_AGE Project.

    Science.gov (United States)

    Angleman, Sara B; Santoni, Giola; Pilotto, Alberto; Fratiglioni, Laura; Welmer, Anna-Karin

    2015-01-01

    The Multidimensional Prognostic Index (MPI) has been found to predict mortality in patients with a variety of clinical conditions. We aimed to assess the association of the MPI with future mortality and number of in-hospital days for the first time in a population-based cohort. The study population consisted of 2472 persons, aged 66-99 years, from the Swedish National Study on Aging and Care in Kungsholmen, Sweden, who underwent the baseline visit 2001-4, and were followed up >10 years for in-hospital days and >12 years for mortality. The MPI was a modified version of the original and aggregated seven domains (personal and instrumental activities of daily living, cognitive function, illness severity and comorbidity, number of medications, co-habitation status, and nutritional status). The MPI score was divided into risk groups: low, medium and high. Number of in-hospital days (within 1, 3 and 10 years) and mortality data were derived from official registries. All analyses were age-stratified (sexagenarians, septuagenarians, octogenarians, nonagenarians). During the follow-up 1331 persons (53.8%) died. Laplace regression models, suggested that median survival in medium risk groups varied by age from 2.2-3.6 years earlier than for those in the corresponding low risk groups (p = 0.002-p<0.001), and median survival in high risk groups varied by age from 3.8-9.0 years earlier than for corresponding low risk groups (p<0.001). For nonagenarians, the median age at death was 3.8 years earlier in the high risk group than for the low risk group (p<0.001). The mean number of in-hospital days increased significantly with higher MPI risk score within 1 and 3 years for people of each age group. For the first time, the effectiveness of MPI has been verified in a population-based cohort. Higher MPI risk scores associated with more days in hospital and with fewer years of survival, across a broad and stratified age range.

  2. Multidimensional Prognostic Index in Association with Future Mortality and Number of Hospital Days in a Population-Based Sample of Older Adults: Results of the EU Funded MPI_AGE Project.

    Directory of Open Access Journals (Sweden)

    Sara B Angleman

    Full Text Available The Multidimensional Prognostic Index (MPI has been found to predict mortality in patients with a variety of clinical conditions. We aimed to assess the association of the MPI with future mortality and number of in-hospital days for the first time in a population-based cohort.The study population consisted of 2472 persons, aged 66-99 years, from the Swedish National Study on Aging and Care in Kungsholmen, Sweden, who underwent the baseline visit 2001-4, and were followed up >10 years for in-hospital days and >12 years for mortality. The MPI was a modified version of the original and aggregated seven domains (personal and instrumental activities of daily living, cognitive function, illness severity and comorbidity, number of medications, co-habitation status, and nutritional status. The MPI score was divided into risk groups: low, medium and high. Number of in-hospital days (within 1, 3 and 10 years and mortality data were derived from official registries. All analyses were age-stratified (sexagenarians, septuagenarians, octogenarians, nonagenarians.During the follow-up 1331 persons (53.8% died. Laplace regression models, suggested that median survival in medium risk groups varied by age from 2.2-3.6 years earlier than for those in the corresponding low risk groups (p = 0.002-p<0.001, and median survival in high risk groups varied by age from 3.8-9.0 years earlier than for corresponding low risk groups (p<0.001. For nonagenarians, the median age at death was 3.8 years earlier in the high risk group than for the low risk group (p<0.001. The mean number of in-hospital days increased significantly with higher MPI risk score within 1 and 3 years for people of each age group.For the first time, the effectiveness of MPI has been verified in a population-based cohort. Higher MPI risk scores associated with more days in hospital and with fewer years of survival, across a broad and stratified age range.

  3. [Developing a predictive model for the caregiver strain index].

    Science.gov (United States)

    Álvarez-Tello, Margarita; Casado-Mejía, Rosa; Praena-Fernández, Juan Manuel; Ortega-Calvo, Manuel

    Patient homecare with multiple morbidities is an increasingly common occurrence. The caregiver strain index is tool in the form of questionnaire that is designed to measure the perceived burden of those who care for their families. The aim of this study is to construct a diagnostic nomogram of informal caregiver burden using data from a predictive model. The model was drawn up using binary logistic regression and the questionnaire items as dichotomous factors. The dependent variable was the final score obtained with the questionnaire but categorised in accordance with that in the literature. Scores between 0 and 6 were labelled as "no" (no caregiver stress) and at or greater than 7 as "yes". The version 3.1.1R statistical software was used. To construct confidence intervals for the ROC curve 2000 boot strap replicates were used. A sample of 67 caregivers was obtained. A diagnosing nomogram was made up with its calibration graph (Brier scaled = 0.686, Nagelkerke R2=0.791), and the corresponding ROC curve (area under the curve=0.962). The predictive model generated using binary logistic regression and the nomogram contain four items (1, 4, 5 and 9) of the questionnaire. R plotting functions allow a very good solution for validating a model like this. The area under the ROC curve (0.96; 95% CI: 0.994-0.941) achieves a high discriminative value. Calibration also shows high goodness of fit values, suggesting that it may be clinically useful in community nursing and geriatric establishments. Copyright © 2015 SEGG. Publicado por Elsevier España, S.L.U. All rights reserved.

  4. Generalized Functional Linear Models With Semiparametric Single-Index Interactions

    KAUST Repository

    Li, Yehua

    2010-06-01

    We introduce a new class of functional generalized linear models, where the response is a scalar and some of the covariates are functional. We assume that the response depends on multiple covariates, a finite number of latent features in the functional predictor, and interaction between the two. To achieve parsimony, the interaction between the multiple covariates and the functional predictor is modeled semiparametrically with a single-index structure. We propose a two step estimation procedure based on local estimating equations, and investigate two situations: (a) when the basis functions are pre-determined, e.g., Fourier or wavelet basis functions and the functional features of interest are known; and (b) when the basis functions are data driven, such as with functional principal components. Asymptotic properties are developed. Notably, we show that when the functional features are data driven, the parameter estimates have an increased asymptotic variance, due to the estimation error of the basis functions. Our methods are illustrated with a simulation study and applied to an empirical data set, where a previously unknown interaction is detected. Technical proofs of our theoretical results are provided in the online supplemental materials.

  5. MESH FREE ESTIMATION OF THE STRUCTURE MODEL INDEX

    Directory of Open Access Journals (Sweden)

    Joachim Ohser

    2011-05-01

    Full Text Available The structure model index (SMI is a means of subsuming the topology of a homogeneous random closed set under just one number, similar to the isoperimetric shape factors used for compact sets. Originally, the SMI is defined as a function of volume fraction, specific surface area and first derivative of the specific surface area, where the derivative is defined and computed using a surface meshing. The generalised Steiner formula yields however a derivative of the specific surface area that is – up to a constant – the density of the integral of mean curvature. Consequently, an SMI can be defined without referring to a discretisation and it can be estimated from 3D image data without need to mesh the surface but using the number of occurrences of 2×2×2 pixel configurations, only. Obviously, it is impossible to completely describe a random closed set by one number. In this paper, Boolean models of balls and infinite straight cylinders serve as cautionary examples pointing out the limitations of the SMI. Nevertheless, shape factors like the SMI can be valuable tools for comparing similar structures. This is illustrated on real microstructures of ice, foams, and paper.

  6. Prognostic, quantitative histopathologic variables in lobular carcinoma of the breast

    DEFF Research Database (Denmark)

    Ladekarl, M; Sørensen, Flemming Brandt

    1993-01-01

    of disease, vv(nuc), MI, and NI were of significant independent, prognostic value. On the basis of the multivariate analyses, a prognostic index with highly distinguishing capacity between prognostically poor and favorable cases was constructed. CONCLUSION: Quantitative histopathologic variables are of value...

  7. Measuring broadband in Europe: : development of a market model and performance index using structural equations modelling

    NARCIS (Netherlands)

    Lemstra, W.; Voogt, B.; Gorp, van N.

    2015-01-01

    This contribution reports on the development of a performance index and underlying market model with application to broadband developments in the European Union. The Structure–Conduct–Performance paradigm provides the theoretical grounding. Structural equations modelling was applied to determine the

  8. Indexed semi-Markov process for wind speed modeling.

    Science.gov (United States)

    Petroni, F.; D'Amico, G.; Prattico, F.

    2012-04-01

    -order Markov chain with different number of states, and Weibull distribution. All this model use Markov chains to generate synthetic wind speed time series but the search for a better model is still open. Approaching this issue, we applied new models which are generalization of Markov models. More precisely we applied semi-Markov models to generate synthetic wind speed time series. In a previous work we proposed different semi-Markov models, showing their ability to reproduce the autocorrelation structures of wind speed data. In that paper we showed also that the autocorrelation is higher with respect to the Markov model. Unfortunately this autocorrelation was still too small compared to the empirical one. In order to overcome the problem of low autocorrelation, in this paper we propose an indexed semi-Markov model. More precisely we assume that wind speed is described by a discrete time homogeneous semi-Markov process. We introduce a memory index which takes into account the periods of different wind activities. With this model the statistical characteristics of wind speed are faithfully reproduced. The wind is a very unstable phenomenon characterized by a sequence of lulls and sustained speeds, and a good wind generator must be able to reproduce such sequences. To check the validity of the predictive semi-Markovian model, the persistence of synthetic winds were calculated, then averaged and computed. The model is used to generate synthetic time series for wind speed by means of Monte Carlo simulations and the time lagged autocorrelation is used to compare statistical properties of the proposed models with those of real data and also with a time series generated though a simple Markov chain. [1] A. Shamshad, M.A. Bawadi, W.M.W. Wan Hussin, T.A. Majid, S.A.M. Sanusi, First and second order Markov chain models for synthetic generation of wind speed time series, Energy 30 (2005) 693-708. [2] H. Nfaoui, H. Essiarab, A.A.M. Sayigh, A stochastic Markov chain model for simulating

  9. Thrombocytosis portends adverse prognostic significance in patients with stage II colorectal carcinoma [v2; ref status: indexed, http://f1000r.es/4k6

    Directory of Open Access Journals (Sweden)

    Tianhua Guo

    2014-10-01

    Full Text Available Thrombocytosis portends adverse prognostic significance in many types of cancers including ovarian and lung carcinoma. In this study, we determined the prevalence and prognostic significance of thrombocytosis (defined as platelet count in excess of 400 × 103/μl in patients with colorectal cancer. We performed a retrospective analysis of 310 consecutive patients diagnosed at our Institution between 2004 and 2013. The patients (48.7% male and 51.3% female had a mean age of 69.9 years (+/- 12.7 years at diagnosis. Thrombocytosis was found in a total of 25 patients, with a higher incidence in those with stage III and IV disease (14.4% of patients. Although the mean platelet count increased with the depth of tumor invasion (pT, its values remained within normal limits in the whole patient cohort. No patient with stage I cancer (n=57 had elevated platelet count at diagnosis. By contrast, five of the 78 patients (6.4% with stage II cancer showed thrombocytosis, and four of these patients showed early recurrence and/or metastatic disease, resulting in shortened survival (they died within one year after surgery. The incidence of thrombocytosis increased to 12.2% and 20.6%, respectively, in patients with stage III and IV disease. The overall survival rate of patients with thrombocytosis was lower than those without thrombocytosis in the stage II and III disease groups, but this difference disappeared in patients with stage IV cancer who did poorly regardless of their platelet count. We concluded that thrombocytosis at diagnosis indicates adverse clinical outcome in colorectal cancer patients with stage II or III disease. This observation is especially intriguing in stage II patients because the clinical management of these patients is controversial. If our data are confirmed in larger studies, stage II colon cancer patients with thrombocytosis may be considered for adjuvant chemotherapy.

  10. A clinical prognostic model for the identification of low-risk patients with acute symptomatic pulmonary embolism and active cancer.

    Science.gov (United States)

    den Exter, Paul L; Gómez, Vicente; Jiménez, David; Trujillo-Santos, Javier; Muriel, Alfonso; Huisman, Menno V; Monreal, Manuel

    2013-01-01

    Physicians need a specific risk-stratification tool to facilitate safe and cost-effective approaches to the management of patients with cancer and acute pulmonary embolism (PE). The objective of this study was to develop a simple risk score for predicting 30-day mortality in patients with PE and cancer by using measures readily obtained at the time of PE diagnosis. Investigators randomly allocated 1,556 consecutive patients with cancer and acute PE from the international multicenter Registro Informatizado de la Enfermedad TromboEmbólica to derivation (67%) and internal validation (33%) samples. The external validation cohort for this study consisted of 261 patients with cancer and acute PE. Investigators compared 30-day all-cause mortality and nonfatal adverse medical outcomes across the derivation and two validation samples. In the derivation sample, multivariable analyses produced the risk score, which contained six variables: age > 80 years, heart rate ≥ 110/min, systolic BP < 100 mm Hg, body weight < 60 kg, recent immobility, and presence of metastases. In the internal validation cohort (n = 508), the 22.2% of patients (113 of 508) classified as low risk by the prognostic model had a 30-day mortality of 4.4% (95% CI, 0.6%-8.2%) compared with 29.9% (95% CI, 25.4%-34.4%) in the high-risk group. In the external validation cohort, the 18% of patients (47 of 261) classified as low risk by the prognostic model had a 30-day mortality of 0%, compared with 19.6% (95% CI, 14.3%-25.0%) in the high-risk group. The developed clinical prediction rule accurately identifies low-risk patients with cancer and acute PE.

  11. The added value that increasing levels of diagnostic information provide in prognostic models to estimate hospital mortality for adult intensive care patients

    NARCIS (Netherlands)

    de Keizer, N. F.; Bonsel, G. J.; Goldfad, C.; Rowan, K. M.

    2000-01-01

    To investigate in a systematic, reproducible way the potential of adding increasing levels of diagnostic information to prognostic models for estimating hospital mortality. Prospective cohort study. Thirty UK intensive care units (ICUs) participating in the ICNARC Case Mix Programme. Eight thousand

  12. Enhanced index tracking modeling in portfolio optimization with mixed-integer programming z approach

    Science.gov (United States)

    Siew, Lam Weng; Jaaman, Saiful Hafizah Hj.; Ismail, Hamizun bin

    2014-09-01

    Enhanced index tracking is a popular form of portfolio management in stock market investment. Enhanced index tracking aims to construct an optimal portfolio to generate excess return over the return achieved by the stock market index without purchasing all of the stocks that make up the index. The objective of this paper is to construct an optimal portfolio using mixed-integer programming model which adopts regression approach in order to generate higher portfolio mean return than stock market index return. In this study, the data consists of 24 component stocks in Malaysia market index which is FTSE Bursa Malaysia Kuala Lumpur Composite Index from January 2010 until December 2012. The results of this study show that the optimal portfolio of mixed-integer programming model is able to generate higher mean return than FTSE Bursa Malaysia Kuala Lumpur Composite Index return with only selecting 30% out of the total stock market index components.

  13. A new enhanced index tracking model in portfolio optimization with sum weighted approach

    Science.gov (United States)

    Siew, Lam Weng; Jaaman, Saiful Hafizah; Hoe, Lam Weng

    2017-04-01

    Index tracking is a portfolio management which aims to construct the optimal portfolio to achieve similar return with the benchmark index return at minimum tracking error without purchasing all the stocks that make up the index. Enhanced index tracking is an improved portfolio management which aims to generate higher portfolio return than the benchmark index return besides minimizing the tracking error. The objective of this paper is to propose a new enhanced index tracking model with sum weighted approach to improve the existing index tracking model for tracking the benchmark Technology Index in Malaysia. The optimal portfolio composition and performance of both models are determined and compared in terms of portfolio mean return, tracking error and information ratio. The results of this study show that the optimal portfolio of the proposed model is able to generate higher mean return than the benchmark index at minimum tracking error. Besides that, the proposed model is able to outperform the existing model in tracking the benchmark index. The significance of this study is to propose a new enhanced index tracking model with sum weighted apporach which contributes 67% improvement on the portfolio mean return as compared to the existing model.

  14. Interaction between body mass index and hormone-receptor status as a prognostic factor in lymph-node-positive breast cancer.

    Directory of Open Access Journals (Sweden)

    Il Yong Chung

    Full Text Available The aim of this study was to determine the relationship between the body mass index (BMI at a breast cancer diagnosis and various factors including the hormone-receptor, menopause, and lymph-node status, and identify if there is a specific patient subgroup for which the BMI has an effect on the breast cancer prognosis. We retrospectively analyzed the data of 8,742 patients with non-metastatic invasive breast cancer from the research database of Asan Medical Center. The overall survival (OS and breast-cancer-specific survival (BCSS outcomes were compared among BMI groups using the Kaplan-Meier method and Cox proportional-hazards regression models with an interaction term. There was a significant interaction between BMI and hormone-receptor status for the OS (P = 0.029, and BCSS (P = 0.013 in lymph-node-positive breast cancers. Obesity in hormone-receptor-positive breast cancer showed a poorer OS (adjusted hazard ratio [HR] = 1.51, 95% confidence interval [CI] = 0.92 to 2.48 and significantly poorer BCSS (HR = 1.80, 95% CI = 1.08 to 2.99. In contrast, a high BMI in hormone-receptor-negative breast cancer revealed a better OS (HR = 0.44, 95% CI = 0.16 to 1.19 and BCSS (HR = 0.53, 95% CI = 0.19 to 1.44. Being underweight (BMI < 18.50 kg/m2 with hormone-receptor-negative breast cancer was associated with a significantly worse OS (HR = 1.98, 95% CI = 1.00-3.95 and BCSS (HR = 2.24, 95% CI = 1.12-4.47. There was no significant interaction found between the BMI and hormone-receptor status in the lymph-node-negative setting, and BMI did not interact with the menopause status in any subgroup. In conclusion, BMI interacts with the hormone-receptor status in a lymph-node-positive setting, thereby playing a role in the prognosis of breast cancer.

  15. Mucins as diagnostic and prognostic biomarkers in a fish-parasite model: transcriptional and functional analysis.

    Directory of Open Access Journals (Sweden)

    Jaume Pérez-Sánchez

    Full Text Available Mucins are O-glycosylated glycoproteins present on the apex of all wet-surfaced epithelia with a well-defined expression pattern, which is disrupted in response to a wide range of injuries or challenges. The aim of this study was to identify mucin gene sequences of gilthead sea bream (GSB, to determine its pattern of distribution in fish tissues and to analyse their transcriptional regulation by dietary and pathogenic factors. Exhaustive search of fish mucins was done in GSB after de novo assembly of next-generation sequencing data hosted in the IATS transcriptome database (www.nutrigroup-iats.org/seabreamdb. Six sequences, three categorized as putative membrane-bound mucins and three putative secreted-gel forming mucins, were identified. The transcriptional tissue screening revealed that Muc18 was the predominant mucin in skin, gills and stomach of GSB. In contrast, Muc19 was mostly found in the oesophagus and Muc13 was along the entire intestinal tract, although the posterior intestine exhibited a differential pattern with a high expression of an isoform that does not share a clear orthologous in mammals. This mucin was annotated as intestinal mucin (I-Muc. Its RNA expression was highly regulated by the nutritional background, whereas the other mucins, including Muc2 and Muc2-like, were expressed more constitutively and did not respond to high replacement of fish oil (FO by vegetable oils (VO in plant protein-based diets. After challenge with the intestinal parasite Enteromyxum leei, the expression of a number of mucins was decreased mainly in the posterior intestine of infected fish. But, interestingly, the highest down-regulation was observed for the I-Muc. Overall, the magnitude of the changes reflected the intensity and progression of the infection, making mucins and I-Muc, in particular, reliable markers of prognostic and diagnostic value of fish intestinal health.

  16. The prognostic value of the neoadjuvant response index in triple-negative breast cancer : validation and comparison with pathological complete response as outcome measure

    NARCIS (Netherlands)

    Jebbink, M.; van Werkhoven, E.; Mandjes, I. A. M.; Wesseling, J.; Lips, E. H.; Peeters, M. -J. T. D. F. Vrancken; Loo, C. E.; Sonke, G. S.; Linn, S. C.; Falo Zamora, C.; Rodenhuis, S.

    The Neoadjuvant response index (NRI) has been proposed as a simple measure of downstaging by neoadjuvant treatment in breast cancer. It was previously found to predict recurrence-free survival (RFS) in triple-negative (TN) breast cancer. It was at least as accurate as the standard binary system, the

  17. Work ability as prognostic risk marker of disability pension : Single-item work ability score versus multi-item work ability index

    NARCIS (Netherlands)

    Roelen, C.A.M.; Rhenen, van W.; Groothoff, J.W.; Klink, van der J.J.L.; Twisk, W.R.; Heymans, M.W.

    2014-01-01

    Work ability predicts future disability pension (DP). A single-item work ability score (WAS) is emerging as a measure for work ability. This study compared single-item WAS with the multi-item work ability index (WAI) in its ability to identify workers at risk of DP.

  18. Serial changes and prognostic implications of a Doppler-derived index of combined left ventricular systolic and diastolic myocardial performance in acute myocardial infarction

    DEFF Research Database (Denmark)

    Poulsen, Steen H; Jensen, Svend E; Nielsen, Jens C

    2000-01-01

    relaxation time divided by ejection time was measured from mitral inflow and left ventricular outflow Doppler velocity profiles. The index was significantly higher in patients with AMI than in control subjects at days 1 and 360 (day 1, 0.58 +/- 0.09 vs 0.41 +/- 0.08, p

  19. Water absorption in a refractive index model for bacterial spores

    Science.gov (United States)

    Siegrist, K. M.; Thrush, E.; Airola, M.; Carr, A. K.; Limsui, D. M.; Boggs, N. T.; Thomas, M. E.; Carter, C. C.

    2009-05-01

    The complexity of biological agents can make it difficult to identify the important factors impacting scattering characteristics among variables such as size, shape, internal structure and biochemical composition, particle aggregation, and sample additives. This difficulty is exacerbated by the environmentally interactive nature of biological organisms. In particular, bacterial spores equilibrate with environmental humidity by absorption/desorption of water which can affect both the complex refractive index and the size/shape distributions of particles - two factors upon which scattering characteristics depend critically. Therefore accurate analysis of experimental data for determination of refractive index must take account of particle water content. First, spectral transmission measurements to determine visible refractive index done on suspensions of bacterial spores must account for water (or other solvent) uptake. Second, realistic calculations of aerosol scattering cross sections should consider effects of atmospheric humidity on particle water content, size and shape. In this work we demonstrate a method for determining refractive index of bacterial spores bacillus atropheus (BG), bacillus thuringiensis (BT) and bacillus anthracis Sterne (BAs) which accounts for these effects. Visible index is found from transmission measurements on aqueous and DMSO suspensions of particles, using an anomalous diffraction approximation. A simplified version of the anomalous diffraction theory is used to eliminate the need for knowledge of particle size. Results using this approach indicate the technique can be useful in determining the visible refractive index of particles when size and shape distributions are not well known but fall within the region of validity of anomalous dispersion theory.

  20. Development of prognostic model for predicting survival after retrograde placement of ureteral stent in advanced gastrointestinal cancer patients and its evaluation by decision curve analysis.

    Science.gov (United States)

    Kawano, Shingo; Komai, Yoshinobu; Ishioka, Junichiro; Sakai, Yasuyuki; Fuse, Nozomu; Ito, Masaaki; Kihara, Kazunori; Saito, Norio

    2016-10-01

    The aim of this study was to determine risk factors for survival after retrograde placement of ureteral stents and develop a prognostic model for advanced gastrointestinal tract (GIT: esophagus, stomach, colon and rectum) cancer patients. We examined the clinical records of 122 patients who underwent retrograde placement of a ureteral stent against malignant extrinsic ureteral obstruction. A prediction model for survival after stenting was developed. We compared its clinical usefulness with our previous model based on the results from nephrostomy cases by decision curve analysis. Median follow-up period was 201 days (8-1490) and 97 deaths occurred. The 1-year survival rate in this cohort was 29%. Based on multivariate analysis, primary site of colon origin, absence of retroperitoneal lymph node metastasis and serum albumin >3g/dL were significantly associated with a prolonged survival time. To develop a prognostic model, we divided the patients into 3 risk groups of favorable: 0-1 factors (N.=53), intermediate: 2 risk factors (N.=54), and poor: 3 risk factors (N.=15). There were significant differences in the survival profiles of these 3 risk groups (P<0.0001). Decision curve analyses revealed that the current model has a superior net benefit than our previous model for most of the examined probabilities. We have developed a novel prognostic model for GIT cancer patients who were treated with retrograde placement of a ureteral stent. The current model should help urologists and medical oncologists to predict survival in cases of malignant extrinsic ureteral obstruction.

  1. Prognostic value of the seventh AJCC/UICC TNM classification of intestinal-type ethmoid adenocarcinoma: Systematic review and risk prediction model.

    Science.gov (United States)

    Fiaux-Camous, Domitille; Chevret, Sylvie; Oker, Natalie; Turri-Zanoni, Mario; Lombardi, Davide; Choussy, Olivier; Duprez, Frederic; Jorissen, Marc; de Gabory, Ludovic; Malard, Olivier; Herman, Philippe; Nicolai, Piero; Castelnuovo, Paolo; Verillaud, Benjamin

    2017-04-01

    The purpose of this study was to propose a prognostic classification of intestinal-type adenocarcinoma (ITAC) based on literature search and prognostic modeling of cohort data. We first conducted a literature search to assess the homogeneity of the reported estimates of 5-year survival and to identify the influence of T classification. We then pooled prospective data from 3 large French and Italian series to predict time to all-cause mortality. The sample was randomly split to derive and then to validate the proposed prognostic model. Literature analysis confirmed the heterogeneity in 5-year survival rates, partly explained in subsets of homogeneous T-values. The sample included 223 patients, randomly separated into a derivation (n = 141) and a validation set (n = 82). Invasion of the sphenoid lateral and/or posterior walls and dura/cerebral invasion were systematically associated with a poor survival. The incorporation of the invasion of the sphenoid lateral or posterior walls should be considered for ITAC management and prognostication. © 2017 Wiley Periodicals, Inc. Head Neck 39: 668-678, 2017. © 2017 Wiley Periodicals, Inc.

  2. Establishment and evaluation of a prognostic model for surgical outcomes of patients with atlanto-axial dislocations.

    Science.gov (United States)

    Guo, Shuai; Chen, Jie; Yang, Baohui; Li, Haopeng

    2016-12-01

    Objective Atlanto-axial dislocations (AADs) are potentially fatal disturbances with high spinal cord compression syndrome. As surgeons are still uncertain who is likely to benefit the most from surgery, a prediction tool is needed to provide decision-making support. Methods The model was established based on 108 patients with AADs using multiple binary logistic regression analysis and evaluated by calibration plot and the area under the receiver operating curve (AUC). Bootstrapping was used for internal validation. Results The prognostic model can be expressed as: logit(P) = -2.2428 + 0.3168SCOPE - 2.0375SIGNAL, in which two covariates were accepted (SCORE represents the preoperative modified Japanese Orthopedic Association (mJOA) score and SIGNAL represents the intramedullary hyperintense T2-weighted imaging (T2WI) with AUC = 0.8081). Conclusions The model was internally valid, and the preoperative mJOA score and hyperintense T2WI were important predictors of outcomes. The threshold was defined as logit(P) = -0.7282 according to the receiver operating curve (ROC).

  3. Standardized uptake value for (18)F-fluorodeoxyglucose is correlated with a high International Prognostic Index and the presence of extranodal involvement in patients with diffuse large B-cell lymphoma.

    Science.gov (United States)

    Akkas, B E; Vural, G U

    2014-01-01

    The aim of this study was to evaluate whether the maximum standardized uptake value (SUVmax) of (18)F-fluorodeoxyglucose (FDG) correlates with the International Prognostic Index (IPI) and the presence of extranodal involvement in patients with Diffuse Large B-Cell Lymphoma (DLBCL). 77 patients (age: 57.2±18.5, 40F, 37M) with DLBCL who underwent FDG PET/CT for initial staging were included. SUVmax of the predominant lesions were compared to Ann Arbor stage, IPI scores, the presence of extranodal involvement and the number extranodal sites. PET/CT detected nodal (n:25) and extranodal involvement (n:52) in all the patients. In 27 patients, extranodal disease could only be detected by PET. SUVmax of the predominant lesion in patients with extranodal disease was significantly higher than that of the patients who had only nodal disease (25±12 vs. 15.3±10 respectively, p=0.001). SUVmax significantly correlated with IPI scores; the average SUVmax was significantly correlated with the IPI: Mean SUVmax of the predominant lesion was 13.9±9.5 in patients with low risk (IPI=0-1), 14.2±8.8 in low-intermediate risk group (IPI=2) whereas 26.6±9.5 in high-intermediate risk group (IPI=3) and 25±13.6 in high risk group patients (IPI=4-5) (p=0.002). SUVmax was not correlated with clinical stage, the number of extranodal sites and serum LDH levels. FDG uptake correlates with IPI and the presence of extranodal involvement in DLBCL. PET is a powerful method to detect extranodal disease in DLBCL. The correlation of SUVmax with these prognostic factors may highlight the importance of pretreatment FDG uptake as a metabolic marker of poor prognosis for patients with DLBCL. Copyright © 2013 Elsevier España, S.L. and SEMNIM. All rights reserved.

  4. Predicting hydrological signatures in ungauged catchments using spatial interpolation, index model, and rainfall-runoff modelling

    Science.gov (United States)

    Zhang, Yongqiang; Vaze, Jai; Chiew, Francis H. S.; Teng, Jin; Li, Ming

    2014-09-01

    Understanding a catchment's behaviours in terms of its underlying hydrological signatures is a fundamental task in surface water hydrology. It can help in water resource management, catchment classification, and prediction of runoff time series. This study investigated three approaches for predicting six hydrological signatures in southeastern Australia. These approaches were (1) spatial interpolation with three weighting schemes, (2) index model that estimates hydrological signatures using catchment characteristics, and (3) classical rainfall-runoff modelling. The six hydrological signatures fell into two categories: (1) long-term aggregated signatures - annual runoff coefficient, mean of log-transformed daily runoff, and zero flow ratio, and (2) signatures obtained from daily flow metrics - concavity index, seasonality ratio of runoff, and standard deviation of log-transformed daily flow. A total of 228 unregulated catchments were selected, with half the catchments randomly selected as gauged (or donors) for model building and the rest considered as ungauged (or receivers) to evaluate performance of the three approaches. The results showed that for two long-term aggregated signatures - the log-transformed daily runoff and runoff coefficient, the index model and rainfall-runoff modelling performed similarly, and were better than the spatial interpolation methods. For the zero flow ratio, the index model was best and the rainfall-runoff modelling performed worst. The other three signatures, derived from daily flow metrics and considered to be salient flow characteristics, were best predicted by the spatial interpolation methods of inverse distance weighting (IDW) and kriging. Comparison of flow duration curves predicted by the three approaches showed that the IDW method was best. The results found here provide guidelines for choosing the most appropriate approach for predicting hydrological behaviours at large scales.

  5. There’s Risk, and Then There’s RISK: The Latest Clinical Prognostic Risk Stratification Models in Myelodysplastic Syndromes

    OpenAIRE

    Zeidan, Amer M.; Komrokji, Rami S.

    2013-01-01

    Myelodysplastic syndromes (MDS) include a diverse group of clonal hematopoietic disorders characterized by progressive cytopenias and propensity for leukemic progression. The biologic heterogeneity that underlies MDS translates clinically in wide variations of clinical outcomes. Several prognostic schemes were developed to predict the natural course of MDS, counsel patients, and allow evidence-based, risk-adaptive implementation of therapeutic strategies. The prognostic schemes divide patient...

  6. Two novel mixed effects models for prognostics of rolling element bearings

    Science.gov (United States)

    Wang, Dong; Tsui, Kwok-Leung

    2018-01-01

    Rolling element bearings are widely used in various machines to support rotating shafts. Due to harsh working environments, the health condition of a bearing degrades over time. A typical bearing degradation process includes two phases. In Phase I, the health condition of the bearing is in normal and it exhibits a stable trend. In Phase II, the health condition of the bearing degrades exponentially. To analytically model the bearing degradation process, two novel mixed effects models are proposed in this paper. Each of the two mixed effects models is able to simultaneously model Phases I and II of the bearing degradation process. The main difference between the two mixed effects models is that different error assumptions including multiplicative normal random error and multiplicative Brownian motion error are respectively considered in the two mixed effects models. Consequently, two different closed-form distributions of bearing remaining useful life are derived from the two mixed effects models via Bayes' theorem once real-time bearing condition monitoring data are available. 25 sets of bearing degradation data collected from an experimental machine are used to illustrate how the two mixed effects models work. Comparisons are conducted to show that the mixed effects model with multiplicative Brownian motion error results in lower prediction errors than the mixed effects model with multiplicative normal random error for bearing remaining useful life prediction.

  7. External validation of a prognostic model for predicting survival of cirrhotic patients with refractory ascites.

    Science.gov (United States)

    Guardiola, Jordi; Baliellas, Carme; Xiol, Xavier; Fernandez Esparrach, Glòria; Ginès, Pere; Ventura, Pere; Vazquez, Santiago

    2002-09-01

    Cirrhotic patients with refractory ascites (RA) have a poor prognosis, although individual survival varies greatly. A model that could predict survival for patients with RA would be helpful in planning treatment. Moreover, in cases of potential liver transplantation, a model of these characteristics would provide the bases for establishing priorities of organ allocation and the selection of patients for a living donor graft. Recently, we developed a model to predict survival of patients with RA. The aim of this study was to establish its generalizability for predicting the survival of patients with RA. The model was validated by assessing its performance in an external cohort of patients with RA included in a multicenter, randomized, controlled trial that compared large-volume paracentesis and peritoneovenous shunt. The values for actual and model-predicted survival of three risk groups of patients, established according to the model, were compared graphically and by means of the one-sample log-rank test. The model provided a very good fit to the survival data of the three risk groups in the validation cohort. We also found good agreement between the survival predicted from the model and the observed survival when patients treated with peritoneovenous shunt and with paracentesis were considered separately. Our survival model can be used to predict the survival of patients with RA and may be a useful tool in clinical decision making, especially in deciding priority for liver transplantation.

  8. Prediction of complications in early-onset pre-eclampsia (PREP): development and external multinational validation of prognostic models.

    Science.gov (United States)

    Thangaratinam, Shakila; Allotey, John; Marlin, Nadine; Dodds, Julie; Cheong-See, Fiona; von Dadelszen, Peter; Ganzevoort, Wessel; Akkermans, Joost; Kerry, Sally; Mol, Ben W; Moons, Karl G M; Riley, Richard D; Khan, Khalid S

    2017-03-30

    Unexpected clinical deterioration before 34 weeks gestation is an undesired course in early-onset pre-eclampsia. To safely prolong preterm gestation, accurate and timely prediction of complications is required. Women with confirmed early onset pre-eclampsia were recruited from 53 maternity units in the UK to a large prospective cohort study (PREP-946) for development of prognostic models for the overall risk of experiencing a complication using logistic regression (PREP-L), and for predicting the time to adverse maternal outcome using a survival model (PREP-S). External validation of the models were carried out in a multinational cohort (PIERS-634) and another cohort from the Netherlands (PETRA-216). Main outcome measures were C-statistics to summarise discrimination of the models and calibration plots and calibration slopes. A total of 169 mothers (18%) in the PREP dataset had adverse outcomes by 48 hours, and 633 (67%) by discharge. The C-statistics of the models for predicting complications by 48 hours and by discharge were 0.84 (95% CI, 0.81-0.87; PREP-S) and 0.82 (0.80-0.84; PREP-L), respectively. The PREP-S model included maternal age, gestation, medical history, systolic blood pressure, deep tendon reflexes, urine protein creatinine ratio, platelets, serum alanine amino transaminase, urea, creatinine, oxygen saturation and treatment with antihypertensives or magnesium sulfate. The PREP-L model included the above except deep tendon reflexes, serum alanine amino transaminase and creatinine. On validation in the external PIERS dataset, the reduced PREP-S model showed reasonable calibration (slope 0.80) and discrimination (C-statistic 0.75) for predicting adverse outcome by 48 hours. Reduced PREP-L model showed excellent calibration (slope: 0.93 PIERS, 0.90 PETRA) and discrimination (0.81 PIERS, 0.75 PETRA) for predicting risk by discharge in the two external datasets. PREP models can be used to obtain predictions of adverse maternal outcome risk, including

  9. Comparison of the predictive qualities of three prognostic models of colorectal cancer

    Science.gov (United States)

    Anderson, Billie; Hardin, J. Michael; Alexander, Dominik D.; Meleth, Sreelatha; Grizzle, William E.; Manne, Upender

    2013-01-01

    Most discoveries of cancer biomarkers involve construction of a single model to determine predictions of survival. ‘Data-mining’ techniques, such as artificial neural networks (ANNs), perform better than traditional methods, such as logistic regression. In this study, the quality of multiple predictive models built on a molecular data set for colorectal cancer (CRC) was evaluated. Predictive models (logistic regressions, ANNs, and decision trees) were compared, and the effect of techniques for variable selection on the predictive quality of these models was investigated. The Kolmogorov-Smirnoff (KS) statistic was used to compare the models. Overall, the logistic regression and ANN methods outperformed use of a decision tree. In some instances (e.g., for a model that included ‘all variables without tumor stage’ and use of a decision tree for variable selection), the ANN marginally outperformed logistic regression, although the difference between the accuracy of the KS statistic was minimal (0.80 versus 0.82). Regardless of the variable(s) and the methods for variable selection, all three predictive models identified survivors and non-survivors with the same level of statistical accuracy. PMID:20515758

  10. Comparison of the prognostic value of Chronic Liver Failure Consortium scores and traditional models for predicting mortality in patients with cirrhosis.

    Science.gov (United States)

    Antunes, Artur Gião; Teixeira, Cristina; Vaz, Ana Margarida; Martins, Cláudio; Queirós, Patrícia; Alves, Ana; Velasco, Francisco; Peixe, Bruno; Oliveira, Ana Paula; Guerreiro, Horácio

    2017-04-01

    Recently, the European Association for the Study of the Liver - Chronic Liver Failure (CLIF) Consortium defined two new prognostic scores, according to the presence or absence of acute-on-chronic liver failure (ACLF): the CLIF Consortium ACLF score (CLIF-C ACLFs) and the CLIF-C Acute Decompensation score (CLIF-C ADs). We sought to compare their accuracy in predicting 30- and 90-day mortality with some of the existing models: Child-Turcotte-Pugh (CTP), Model for End-Stage Liver Disease (MELD), MELD-Na, integrated MELD (iMELD), MELD to serum sodium ratio index (MESO), Refit MELD and Refit MELD-Na. Retrospective cohort study that evaluated all admissions due to decompensated cirrhosis in 2 centers between 2011 and 2014. At admission each score was assessed, and the discrimination ability was compared by measuring the area under the ROC curve (AUROC). A total of 779 hospitalizations were evaluated. Two hundred and twenty-two patients met criteria for ACLF (25.9%). The 30- and 90-day mortality were respectively 17.7 and 37.3%. CLIF-C ACLFs presented an AUROC for predicting 30- and 90-day mortality of 0.684 (95% CI: 0.599-0.770) and 0.666 (95% CI: 0.588-0.744) respectively. No statistically significant differences were found when compared to traditional models. For patients without ACLF, CLIF-C ADs had an AUROC for predicting 30- and 90-day mortality of 0.689 (95% CI: 0.614-0.763) and 0.672 (95% CI: 0.624-0.720) respectively. When compared to other scores, it was only statistically superior to MELD for predicting 30-day mortality (p=0.0296). The new CLIF-C scores were not statistically superior to the traditional models, with the exception of CLIF-C ADs for predicting 30-day mortality. Copyright © 2017 Elsevier España, S.L.U., AEEH y AEG. All rights reserved.

  11. Model-based prognostics for batteries which estimates useful life and uses a probability density function

    Data.gov (United States)

    National Aeronautics and Space Administration — This invention develops a mathematical model to describe battery behavior during individual discharge cycles as well as over its cycle life. The basis for the form...

  12. A mathematical model describes the malignant transformation of low grade gliomas: Prognostic implications.

    Directory of Open Access Journals (Sweden)

    Magdalena U Bogdańska

    Full Text Available Gliomas are the most frequent type of primary brain tumours. Low grade gliomas (LGGs, WHO grade II gliomas may grow very slowly for the long periods of time, however they inevitably cause death due to the phenomenon known as the malignant transformation. This refers to the transition of LGGs to more aggressive forms of high grade gliomas (HGGs, WHO grade III and IV gliomas. In this paper we propose a mathematical model describing the spatio-temporal transition of LGGs into HGGs. Our modelling approach is based on two cellular populations with transitions between them being driven by the tumour microenvironment transformation occurring when the tumour cell density grows beyond a critical level. We show that the proposed model describes real patient data well. We discuss the relationship between patient prognosis and model parameters. We approximate tumour radius and velocity before malignant transformation as well as estimate the onset of this process.

  13. A radiobiological model of radiotherapy response and its correlation with prognostic imaging variables

    Science.gov (United States)

    Crispin-Ortuzar, Mireia; Jeong, Jeho; Fontanella, Andrew N.; Deasy, Joseph O.

    2017-04-01

    Radiobiological models of tumour control probability (TCP) can be personalized using imaging data. We propose an extension to a voxel-level radiobiological TCP model in order to describe patient-specific differences and intra-tumour heterogeneity. In the proposed model, tumour shrinkage is described by means of a novel kinetic Monte Carlo method for inter-voxel cell migration and tumour deformation. The model captures the spatiotemporal evolution of the tumour at the voxel level, and is designed to take imaging data as input. To test the performance of the model, three image-derived variables found to be predictive of outcome in the literature have been identified and calculated using the model’s own parameters. Simulating multiple tumours with different initial conditions makes it possible to perform an in silico study of the correlation of these variables with the dose for 50% tumour control (\\text{TC}{{\\text{D}}50} ) calculated by the model. We find that the three simulated variables correlate with the calculated \\text{TC}{{\\text{D}}50} . In addition, we find that different variables have different levels of sensitivity to the spatial distribution of hypoxia within the tumour, as well as to the dynamics of the migration mechanism. Finally, based on our results, we observe that an adequate combination of the variables may potentially result in higher predictive power.

  14. Prognostic Value of Ankle-Brachial Index in Patients Undergoing Percutaneous Coronary Intervention: In-Hospital and 1-Year Outcomes From the SHINANO Registry.

    Science.gov (United States)

    Hashizume, Naoto; Miura, Takashi; Miyashita, Yusuke; Motoki, Hirohiko; Ebisawa, Soichiro; Izawa, Atsushi; Koyama, Jun; Ikeda, Uichi; Kuwahara, Koichiro

    2017-11-01

    Concomitant coronary and peripheral artery disease is associated with higher periprocedural and long-term percutaneous coronary intervention (PCI) complication rates. We evaluated in-hospital and 1-year clinical outcomes of patients with low or borderline ankle-brachial indexes (ABIs) undergoing PCIs in the drug-eluting stent era. We divided 1370 SHINANO registry patients into 3 groups-low (ABI ≤ 0.9), borderline (0.9 < ABI ≤ 1.0), and normal (1.0 ≤ ABI < 1.4). During the 1-year follow-up, more PCI-related complications occurred in the low and borderline ABI groups than in the normal ABI group (7.7% vs 8.8% vs 4.0%, respectively). Low ABI patients were more likely to experience adverse clinical events (6.3% vs 3.6% vs 3.0%, respectively; log-rank P = .020 for low vs normal ABI), with a hazard ratio of 2.27 (95% confidence interval, 1.12-4.61; P = .023), compared with patients with normal ABIs. Patients with abnormal ABIs had a significantly higher incidence of PCI-related complications and a less favorable 1-year prognosis. Routine ABI measurement before PCI may help predict PCI-related complication incidence and 1-year prognosis.

  15. Prognostic role of a new risk index for the prediction of 30-day cardiovascular mortality in patients with acute pulmonary embolism: the Age-Mean Arterial Pressure Index (AMAPI).

    Science.gov (United States)

    Zuin, Marco; Rigatelli, Gianluca; Picariello, Claudio; Carraro, Mauro; Zonzin, Pietro; Roncon, Loris

    2017-12-01

    Acute pulmonary embolism (PE) is the third cause of cardiovascular (CV) mortality. We evaluated a new risk index, named Age-Mean Arterial Pressure Index (AMAPI), to predict 30-day CV mortality in patients with acute PE. Data of 209 patients (44.0% male and 56.0% female, mean age 70.58 ± 14.14 years) with confirmed acute PE were retrospectively analysed. AMAPI was calculated as the ratio between age and mean arterial pressure (MAP), which was defined as [systolic blood pressure + (2 × diastolic blood pressure)]/3. To test AMAPI accuracy, a comparison with shock index (SI) and simplified pulmonary embolism severity index (sPESI) was performed. Patients were divided in two groups according their hemodynamic stability, or not, at admission. 30-day mortality rate, in all cases for CV events, was 10.5% (n = 22). Hemodynamically unstable patients had a higher AMAPI compare to those without hypotension at admission (1.28 ± 0.39 vs 0.78 ± 0.27, p < 0.0001). Receiving operative curve analyses (ROC) found the optimal cut-off for AMAPI in hemodynamically stable and unstable patients ≥0.9 and ≥0.92, respectively. In both groups, patients with an AMAPI over the cut-off were significantly older, hypotensive (both systolic and diastolic blood pressure), with a higher SI and lower MAP. In hemodynamically stable patients, 30-day CV mortality risk prediction was improved adding AMAPI ≥0.9 to both SI and sPESI (net reclassification improvement-NRI-of 14.2%, p = 0.0006 and 11.5%, p = 0.0002, respectively). In hemodynamically unstable patients NRI was 19.2%, p = 0.006. Mantel-Cox analysis revealed a statistical significant difference in the distribution of survival between hemodynamically stable patients with an AMAPI index ≥0.9 compared to those with an AMAPI <0.89 [log rank (Mantel-Cox) p < 0.0001] and in hemodynamically unstable patients with an AMAPI ≥0.92 [log rank (Mantel-Cox) p = 0.001]. AMAPI ≥0.90 and ≥0.92 predict 30-day CV mortality

  16. Implicit coupling of turbulent diffusion with chemical reaction mechanisms for prognostic atmospheric dispersion models

    Energy Technology Data Exchange (ETDEWEB)

    Berlowitz, D.R.

    1996-11-01

    In the last few decades the negative impact by humans on the thin atmospheric layer enveloping the earth, the basis for life on this planet, has increased steadily. In order to halt, or at least slow down this development, the knowledge and study of these anthropogenic influence has to be increased and possible remedies have to be suggested. An important tool for these studies are computer models. With their help the atmospheric system can be approximated and the various processes, which have led to the current situation can be quantified. They also serve as an instrument to assess short or medium term strategies to reduce this human impact. However, to assure efficiency as well as accuracy, a careful analysis of the numerous processes involved in the dispersion of pollutants in the atmosphere is called for. This should help to concentrate on the essentials and also prevent excessive usage of sometimes scarce computing resources. The basis of the presented work is the EUMAC Zooming Model (ETM), and particularly the component calculating the dispersion of pollutants in the atmosphere, the model MARS. The model has two main parts: an explicit solver, where the advection and the horizontal diffusion of pollutants are calculated, and an implicit solution mechanism, allowing the joint computation of the change of concentration due to chemical reactions, coupled with the respective influence of the vertical diffusion of the species. The aim of this thesis is to determine particularly the influence of the horizontal components of the turbulent diffusion on the existing implicit solver of the model. Suggestions for a more comprehensive inclusion of the full three dimensional diffusion operator in the implicit solver are made. This is achieved by an appropriate operator splitting. A selection of numerical approaches to tighten the coupling of the diffusion processes with the calculation of the applied chemical reaction mechanisms are examined. (author) figs., tabs., refs.

  17. Assessing the utility of a prognostication model to predict 1-year mortality in patients receiving radiation therapy for spinal metastases.

    Science.gov (United States)

    Shi, Diana D; Chen, Yu-Hui; Lam, Tai Chung; Leonard, Dana; Balboni, Tracy Anne; Schoenfeld, Andrew; Skamene, Sonia; Cagney, Daniel N; Chi, John H; Cho, Charles H; Harris, Mitchel; Ferrone, Marco L; Hertan, Lauren M

    2017-10-12

    Predicting survival outcomes after radiation therapy alone for metastatic disease of the spine is a challenging task that is important to guiding treatment decisions (e.g., determining dose fractionation and intensity). The New England Spinal Metastasis Score (NESMS) was recently introduced and validated in independent cohorts as a tool to predict 1-year survival following surgery for spinal metastases. This metric is composed of 3 factors: pre-operative albumin, ambulatory status, and modified Bauer score, with the total score ranging from 0 to 3. The purpose of this study is to assess the applicability of the NESMS model to predict 1-year survival among patients treated with radiation therapy alone for spinal metastases. This study is a retrospective analysis. This sample included 290 patients who underwent conventional radiation therapy alone for spinal metastases. Patients' NESMS scores (comprised of ambulatory status, pre-treatment serum albumin, and modified Bauer score) were assessed as well as their 1-year overall survival rates following radiation for metastatic disease of the spine. This study is a single-institution retrospective analysis of 290 patients treated with conventional radiation alone for spinal metastases from 2008 to 2013. The predictive value of the NESMS was assessed using multivariable logistic regression modeling, adjusted for potential confounding variables. This analysis indicated that patients with lower NESMS scores had higher rates of 1-year mortality. Multivariable analysis demonstrated a strong association between lower NESMS scores and lower rates of survival. The NESMS score is a simple prognostic scheme that requires clinical data that is often readily available and has been validated in independent cohorts of surgical patients. This study serves to validate the utility of the NESMS composite score to predict 1-year mortality in patients treated with radiation alone for spinal metastases. Copyright © 2017 Elsevier Inc. All

  18. Prognostic evaluation of DNA index in HIV-HPV co-infected women cervical samples attending in reference centers for HIV-AIDS in Recife.

    Directory of Open Access Journals (Sweden)

    Albert Eduardo Silva Martins

    Full Text Available INTRODUCTION: Persistence of cervical infection caused by human papillomavirus (HPV types with high oncogenic risk may lead to cervical intraepithelial neoplasia (CIN. The aim of the present study was to evaluate whether, in HIV-positive women, the presence of aneuploidy in cervical cell samples is associated with presence and evolution of CIN. METHODS: The present study had two stages. In the first stage, comprising a cross-sectional study, the association between the presence of aneuploidy seen via flow cytometry and sociodemographic characteristics, habits and characteristics relating to HPV and HIV infection was analyzed. In the second stage, comprising a cohort study, it was investigated whether aneuploidy was predictive of CIN evolution. RESULTS: No association was observed between the presence of aneuploidy and HPV infection, or between its presence and alterations seen in oncotic cytological analysis. On the other hand, aneuploidy was associated with the presence of CIN (p = 0.030 in histological analysis and with nonuse of antiretroviral therapy (p = 0.001. Most of the HIV-positive women (234/272 presented normal CD4+ T lymphocyte counts (greater than 350 cells/mm3 and showed a greater aneuploidy regression rate (77.5% than a progression rate (23.9% over a follow-up of up to two years. CONCLUSION: Although there was an association between the presence of cervical tissue lesions and the DNA index, the latter was not predictive of progression of the cervical lesion. This suggests that progression of the cervical lesion to cancer in HIV-positive women may also be changed through improvement of the immunological state enabled by using antiretroviral therapy.

  19. Model for clinical management using body mass index of diabetes ...

    African Journals Online (AJOL)

    Three models were used for comparison: a model that used weight of diabetes patient as a covariate, a second that used both weight and admitting blood sugar reading of diabetes patients as covariates and the third separate models for each of the three weight groups of diabetes patient as covariate. Results showed that ...

  20. A Discussion on Uncertainty Representation and Interpretation in Model-based Prognostics Algorithms based on Kalman Filter Estimation Applied to Prognostics of Electronics Components

    Data.gov (United States)

    National Aeronautics and Space Administration — This article presented a discussion on uncertainty representation and management for model-based prog- nostics methodologies based on the Bayesian tracking framework...

  1. [Expression and prognostic significance of microenvironment related prognostic factors in patients with classical Hodgkin's lymphoma].

    Science.gov (United States)

    Wang, T T; Li, S X; Xia, B; Zhao, H F; Xu, W; Yang, H L; Wang, X F; Yu, Y; Sun, B C; Zhang, Y Z

    2017-05-16

    Objective: To observe the expression of three microenvironment related prognostic factors, i. e. programmed death 1 (PD-1), forkhead box protein 3(FOXP3) and colony-stimulating factor 1 receptor(CSF-1R) protein in classical Hodgkin's lymphoma (CHL) patients, and to explore the correlation between the protein expression and the prognosis of the patients. Methods: A total of 45 cases of CHL patients, who had been admitted to the Tianjin Medical University Cancer Institute and Hospital and Chinese PLA General Hospital from February 2005 to August 2010 were analyzed, including clinical features, prognostic factors, and treatment regimens. CHL patients' specimens were collected and the expression of PD-1, FOXP3, and CSF-1R proteins analyzed by immunohistochemical staining. Epstein-Barr virus encoded mRNA (EBER) was detected by in situ hybridization analysis. The relationship between the protein expression of PD-1, FOXP3 and CSF-1R and the patients' outcome was analyzed with clinical and follow-up data. Survival analysis was performed by Kaplan-Meier method, the Cox proportional hazard model was used to perform multivariate analysis. Results: In this cohort of 45 CHL patients, PD-1 positive was found in 7 cases (15.6%), FOXP3 high expression in 23 cases (51.1%), CSF-1R positive in 18 cases (40.0%). In the univariate analysis, the expression of FOXP3 and CSF-1R, International Prognostic Index (IPI) score, Ann Arbor stage and EBER were related with the patients' 5-year overall survival (OS); IPI score, the expression of FOXP3 and EBER were related with the patients' 5-year progress-free survival (PFS). Multivariate analysis indicated that CSF-1R protein expression was the independent prognostic factor affecting the patients' 5-year OS(HR: 8.918, P=0.020), and FOXP3 protein expression was the independent prognostic factor affecting the patients' 5-year PFS (HR: 0.122, PCSF-1R and EBV may be independent prognostic factors of CHL and this study may provide novel strategies

  2. A copula-multifractal volatility hedging model for CSI 300 index futures

    Science.gov (United States)

    Wei, Yu; Wang, Yudong; Huang, Dengshi

    2011-11-01

    In this paper, we propose a new hedging model combining the newly introduced multifractal volatility (MFV) model and the dynamic copula functions. Using high-frequency intraday quotes of the spot Shanghai Stock Exchange Composite Index (SSEC), spot China Securities Index 300 (CSI 300), and CSI 300 index futures, we compare the direct and cross hedging effectiveness of the copula-MFV model with several popular copula-GARCH models. The main empirical results show that the proposed copula-MFV model obtains better hedging effectiveness than the copula-GARCH-type models in general. Furthermore, the hedge operating strategy based MFV hedging model involves fewer transaction costs than those based on the GARCH-type models. The finding of this paper indicates that multifractal analysis may offer a new way of quantitative hedging model design using financial futures.

  3. γ-H2AX: A Novel Prognostic Marker in a Prognosis Prediction Model of Patients with Early Operable Non-Small Cell Lung Cancer

    Directory of Open Access Journals (Sweden)

    E. Chatzimichail

    2014-01-01

    Full Text Available Cancer is a leading cause of death worldwide and the prognostic evaluation of cancer patients is of great importance in medical care. The use of artificial neural networks in prediction problems is well established in human medical literature. The aim of the current study was to assess the prognostic value of a series of clinical and molecular variables with the addition of γ-H2AX—a new DNA damage response marker—for the prediction of prognosis in patients with early operable non-small cell lung cancer by comparing the γ-H2AX-based artificial network prediction model with the corresponding LR one. Two prognostic models of 96 patients with 27 input variables were constructed by using the parameter-increasing method in order to compare the predictive accuracy of neural network and logistic regression models. The quality of the models was evaluated by an independent validation data set of 11 patients. Neural networks outperformed logistic regression in predicting the patient’s outcome according to the experimental results. To assess the importance of the two factors p53 and γ-H2AX, models without these two variables were also constructed. JR and accuracy of these models were lower than those of the models using all input variables, suggesting that these biological markers are very important for optimal performance of the models. This study indicates that neural networks may represent a potentially more useful decision support tool than conventional statistical methods for predicting the outcome of patients with non-small cell lung cancer and that some molecular markers, such as γ-H2AX, enhance their predictive ability.

  4. Chronic lymphocytic leukemia: A prognostic model comprising only two biomarkers (IGHV mutational status and FISH cytogenetics) separates patients with different outcome and simplifies the CLL-IPI.

    Science.gov (United States)

    Delgado, Julio; Doubek, Michael; Baumann, Tycho; Kotaskova, Jana; Molica, Stefano; Mozas, Pablo; Rivas-Delgado, Alfredo; Morabito, Fortunato; Pospisilova, Sarka; Montserrat, Emili

    2017-04-01

    Rai and Binet staging systems are important to predict the outcome of patients with chronic lymphocytic leukemia (CLL) but do not reflect the biologic diversity of the disease nor predict response to therapy, which ultimately shape patients' outcome. We devised a biomarkers-only CLL prognostic system based on the two most important prognostic parameters in CLL (i.e., IGHV mutational status and fluorescence in situ hybridization [FISH] cytogenetics), separating three different risk groups: (1) low-risk (mutated IGHV + no adverse FISH cytogenetics [del(17p), del(11q)]); (2) intermediate-risk (either unmutated IGHV or adverse FISH cytogenetics) and (3) high-risk (unmutated IGHV + adverse FISH cytogenetics). In 524 unselected subjects with CLL, the 10-year overall survival was 82% (95% CI 76%-88%), 52% (45%-62%), and 27% (17%-42%) for the low-, intermediate-, and high-risk groups, respectively. Patients with low-risk comprised around 50% of the series and had a life expectancy comparable to the general population. The prognostic model was fully validated in two independent cohorts, including 417 patients representative of general CLL population and 337 patients with Binet stage A CLL. The model had a similar discriminatory value as the CLL-IPI. Moreover, it applied to all patients with CLL independently of age, and separated patients with different risk within Rai or Binet clinical stages. The biomarkers-only CLL prognostic system presented here simplifies the CLL-IPI and could be useful in daily practice and to stratify patients in clinical trials. © 2017 Wiley Periodicals, Inc.

  5. A new process sensitivity index to identify important system processes under process model and parametric uncertainty

    Energy Technology Data Exchange (ETDEWEB)

    Dai, Heng [Pacific Northwest National Laboratory, Richland Washington USA; Ye, Ming [Department of Scientific Computing, Florida State University, Tallahassee Florida USA; Walker, Anthony P. [Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge Tennessee USA; Chen, Xingyuan [Pacific Northwest National Laboratory, Richland Washington USA

    2017-04-01

    Hydrological models are always composed of multiple components that represent processes key to intended model applications. When a process can be simulated by multiple conceptual-mathematical models (process models), model uncertainty in representing the process arises. While global sensitivity analysis methods have been widely used for identifying important processes in hydrologic modeling, the existing methods consider only parametric uncertainty but ignore the model uncertainty for process representation. To address this problem, this study develops a new method to probe multimodel process sensitivity by integrating the model averaging methods into the framework of variance-based global sensitivity analysis, given that the model averaging methods quantify both parametric and model uncertainty. A new process sensitivity index is derived as a metric of relative process importance, and the index includes variance in model outputs caused by uncertainty in both process models and model parameters. For demonstration, the new index is used to evaluate the processes of recharge and geology in a synthetic study of groundwater reactive transport modeling. The recharge process is simulated by two models that converting precipitation to recharge, and the geology process is also simulated by two models of different parameterizations of hydraulic conductivity; each process model has its own random parameters. The new process sensitivity index is mathematically general, and can be applied to a wide range of problems in hydrology and beyond.

  6. Site index model for naturally regenerated even-aged longleaf pine

    Science.gov (United States)

    Dwight K. Lauer; John S. Kush

    2013-01-01

    Data from the Regional Longleaf Growth Study (339 permanent sample plots) were used to develop a site index model for naturally regenerated, even-aged longleaf pine (Pinus palustris Mill.). The site index equation was derived using the generalized algebraic difference approach and is base-age invariant. Using height as a measure of site productivity...

  7. A two-dimensional volatility basis set – Part 3: Prognostic modeling and NOx dependence

    Directory of Open Access Journals (Sweden)

    W. K. Chuang

    2016-01-01

    Full Text Available When NOx is introduced to organic emissions, aerosol production is sometimes, but not always, reduced. Under certain conditions, these interactions will instead increase aerosol concentrations. We expanded the two-dimensional volatility basis set (2D-VBS to include the effects of NOx on aerosol formation. This includes the formation of organonitrates, where the addition of a nitrate group contributes to a decrease of 2.5 orders of magnitude in volatility. With this refinement, we model outputs from experimental results, such as the atomic N : C ratio, organonitrate mass, and nitrate fragments in Aerosol Mass Spectrometer (AMS measurements. We also discuss the mathematical methods underlying the implementation of the 2D-VBS and provide the complete code in the Supplement. A developer version is available on Bitbucket, an online community repository.

  8. A two-dimensional volatility basis set - Part 3: Prognostic modeling and NOx dependence

    Science.gov (United States)

    Chuang, W. K.; Donahue, N. M.

    2016-01-01

    When NOx is introduced to organic emissions, aerosol production is sometimes, but not always, reduced. Under certain conditions, these interactions will instead increase aerosol concentrations. We expanded the two-dimensional volatility basis set (2D-VBS) to include the effects of NOx on aerosol formation. This includes the formation of organonitrates, where the addition of a nitrate group contributes to a decrease of 2.5 orders of magnitude in volatility. With this refinement, we model outputs from experimental results, such as the atomic N : C ratio, organonitrate mass, and nitrate fragments in Aerosol Mass Spectrometer (AMS) measurements. We also discuss the mathematical methods underlying the implementation of the 2D-VBS and provide the complete code in the Supplement. A developer version is available on Bitbucket, an online community repository.

  9. Basic critical care echocardiography by pulmonary fellows: learning trajectory and prognostic impact using a minimally resourced training model*.

    Science.gov (United States)

    See, Kay Choong; Ong, Venetia; Ng, Jeffrey; Tan, Rou An; Phua, Jason

    2014-10-01

    The spread of basic critical care echocardiography may be limited by training resources. Another barrier is the lack of information about the learning trajectory and prognostic impact of individual basic critical care echocardiography domains like acute cor pulmonale determination and left ventricular function estimation. We thus developed a minimally resourced training model and studied the latter outcomes. Prospective observational study. Twenty-bed medical ICU. Echocardiography-naive trainees enrolled in the first year of our Pulmonary Medicine Fellowship Program from September 2012 to September 2013. We described the learning trajectory in six basic critical care echocardiography domains (adequate views, pericardial effusion, acute cor pulmonale, left ventricular ejection fraction, mitral regurgitation, and inferior vena cava variability) and correlated abnormalities in selected basic critical care echocardiography domains with clinical outcomes (mortality and length of stay). Three-hundred forty-three basic critical care echocardiography scans were done for 318 patients by seven fellows (median of 40 scans per fellow; range, 34-105). Only one-third patients had normal basic critical care echocardiography studies. Accuracy in various basic critical care echocardiography domains was high (> 90%), especially beyond the first 30 examinations. Acute cor pulmonale was associated with ICU mortality when adjusted for Acute Physiology and Chronic Health Evaluation II score and presence of sepsis, whereas mitral regurgitation was associated with longer hospitalization only on univariate analysis. Basic critical care echocardiography training using minimal resources is feasible. New trainees can achieve reasonable competency in most basic critical care echocardiography domains after performing about 30 examinations within the first year. The relatively high prevalence of abnormalities and the significant association of acute cor pulmonale with ICU mortality support the

  10. Prognostic and symptomatic aspects of rapid eye movement sleep in a mouse model of posttraumatic stress disorder

    Directory of Open Access Journals (Sweden)

    Stephanie A. Polta

    2013-05-01

    Full Text Available Not every individual develops Posttraumatic Stress Disorder (PTSD after the exposure to a potentially traumatic event. Therefore, the identification of pre-existing risk factors and early diagnostic biomarkers is of high medical relevance. However, no objective biomarker has yet progressed into clinical practice. Sleep disturbances represent commonly reported complaints in PTSD patients. In particular, changes in rapid eye movement sleep (REMS properties are frequently observed in PTSD patients. Here, we examined in a mouse model of PTSD whether (1 mice developed REMS alterations after trauma and (2 whether REMS architecture before and/or shortly after trauma predicted the development of PTSD-like symptoms. We monitored sleep-wake behavior via combined EEG/EMG recordings immediately before (24 h pre, immediately after (0-48 h post and two months after exposure to an electric foot shock in male C57BL/6N mice (n=15. PTSD-like symptoms, including hyperarousal, contextual and generalized fear, were assessed one month post-trauma.Shocked mice showed early-onset and sustained elevation of REMS compared to non-shocked controls. In addition, REMS architecture before trauma was correlated with the intensity of acoustic startle responses, but not contextual fear, one month after trauma.Our data suggest REMS as prognostic (pre-trauma and symptomatic (post-trauma marker of PTSD-like symptoms in mice. Translated to the situation in humans, REMS may constitute a viable, objective and non-invasive biomarker in PTSD and other trauma-related psychiatric disorders, which could guide pharmacological interventions in humans at high risk.

  11. A Prognostic Model of Surgical Site Infection Using Daily Clinical Wound Assessment.

    Science.gov (United States)

    Sanger, Patrick C; van Ramshorst, Gabrielle H; Mercan, Ezgi; Huang, Shuai; Hartzler, Andrea L; Armstrong, Cheryl A L; Lordon, Ross J; Lober, William B; Evans, Heather L

    2016-08-01

    Surgical site infection (SSI) remains a common, costly, and morbid health care-associated infection. Early detection can improve outcomes, yet previous risk models consider only baseline risk factors (BF) not incorporating a proximate and timely data source-the wound itself. We hypothesize that incorporation of daily wound assessment improves the accuracy of SSI identification compared with traditional BF alone. A prospective cohort of 1,000 post open abdominal surgery patients at an academic teaching hospital were examined daily for serial features (SF), for example, wound characteristics and vital signs, in addition to standard BF, for example, wound class. Using supervised machine learning, we trained 3 Naïve Bayes classifiers (BF, SF, and BF+SF) using patient data from 1 to 5 days before diagnosis to classify SSI on the following day. For comparison, we also created a simplified SF model that used logistic regression. Control patients without SSI were matched on 5 similar consecutive postoperative days to avoid confounding by length of stay. Accuracy, sensitivity/specificity, and area under the receiver operating characteristic curve were calculated on a training and hold-out testing set. Of 851 patients, 19.4% had inpatient SSIs. Univariate analysis showed differences in C-reactive protein, surgery duration, and contamination, but no differences in American Society of Anesthesiologists scores, diabetes, or emergency surgery. The BF, SF, and BF+SF classifiers had area under the receiver operating characteristic curves of 0.67, 0.76, and 0.76, respectively. The best-performing classifier (SF) had optimal sensitivity of 0.80, specificity of 0.64, positive predictive value of 0.35, and negative predictive value of 0.93. Features most associated with subsequent SSI diagnosis were granulation degree, exudate amount, nasogastric tube presence, and heart rate. Serial features provided moderate positive predictive value and high negative predictive value for early

  12. Evaluation of the International Prognostic Score (IPS-7) and a Simpler Prognostic Score (IPS-3) for advanced Hodgkin lymphoma in the modern era.

    Science.gov (United States)

    Diefenbach, Catherine S; Li, Hailun; Hong, Fangxin; Gordon, Leo I; Fisher, Richard I; Bartlett, Nancy L; Crump, Michael; Gascoyne, Randy D; Wagner, Henry; Stiff, Patrick J; Cheson, Bruce D; Stewart, Douglas A; Kahl, Brad S; Friedberg, Jonathan W; Blum, Kristie A; Habermann, Thomas M; Tuscano, Joseph M; Hoppe, Richard T; Horning, Sandra J; Advani, Ranjana H

    2015-11-01

    The International Prognostic Score (IPS-7) is the most commonly used risk stratification tool for advanced Hodgkin lymphoma (HL), however recent studies suggest the IPS-7 is less discriminating due to improved outcomes with contemporary therapy. We evaluated the seven variables for IPS-7 recorded at study entry for 854 patients enrolled on Eastern Cooperative Oncology Group 2496 trial. Univariate and multivariate Cox models were used to assess their prognostic ability for freedom from progression (FFP) and overall survival (OS). The IPS-7 remained prognostic however its prognostic range has narrowed. On multivariate analysis, two factors (age, stage) remained significant for FFP and three factors (age, stage, haemoglobin level) for OS. An alternative prognostic index, the IPS-3, was constructed using age, stage and haemoglobin level, which provided four distinct risk groups [FFP (P = 0·0001) and OS (P IPS-3 outperformed the IPS-7 on risk prediction for both FFP and OS by model fit and discrimination criteria. Using reclassification calibration, 18% of IPS-7 low risk patients were re-classified as intermediate risk and 13% of IPS-7 intermediate risk patients as low risk. For patients with advanced HL, the IPS-3 may provide a simpler and more accurate framework for risk assessment in the modern era. Validation of these findings in other large data sets is planned. © 2015 John Wiley & Sons Ltd.

  13. Bus Operation Monitoring Oriented Public Transit Travel Index System and Calculation Models

    Directory of Open Access Journals (Sweden)

    Jiancheng Weng

    2013-01-01

    Full Text Available This study proposed a two-dimensional index system which is concerned essentially with urban travel based on travel modes and user satisfaction. First, the public transit was taken as an example to describe the index system establishing process. In consideration of convenience, rapid, reliability, comfort, and safety, a bus service evaluation index system was established. The indicators include the N-minute coverage of bus stops, average travel speed, and fluctuation of travel time between stops and bus load factor which could intuitively describe the characteristics of public transport selected to calculate bus travel indexes. Then, combined with the basic indicators, the calculation models of Convenience Index (CI, Rapid Index (RI, Reliability Index (RBI, and Comfort Index (CTI were established based on the multisource data of public transit including the real-time bus GPS data and passenger IC card data. Finally, a case study of Beijing bus operation evaluation and analysis was conducted by taking real bus operation data including GPS data and passenger transaction recorder (IC card data. The results showed that the operation condition of the public transit was well reflected and scientifically classified by the bus travel index models.

  14. A model of social influence on body mass index.

    Science.gov (United States)

    Hammond, Ross A; Ornstein, Joseph T

    2014-12-01

    In this paper, we develop an agent-based model of social influence on body weight. The model's assumptions are grounded in theory and evidence from physiology, social psychology, and behavioral science, and its outcomes are tested against longitudinal data from American youth. We discuss the implementation of the model, the insights it generates, and its implications for public health policy. By explicating a well-grounded dynamic mechanism, our analysis helps clarify important dependencies for both efforts to leverage social influence for obesity intervention and efforts to interpret clustering of BMI in networks. © 2014 New York Academy of Sciences.

  15. Temperature-Dependent Conformations of Model Viscosity Index Improvers

    Energy Technology Data Exchange (ETDEWEB)

    Ramasamy, Uma Shantini; Cosimbescu, Lelia; Martini, Ashlie

    2015-05-01

    Lubricants are comprised of base oils and additives where additives are chemicals that are deliberately added to the oil to enhance properties and inhibit degradation of the base oils. Viscosity index (VI) improvers are an important class of additives that reduce the decline of fluid viscosity with temperature [1], enabling optimum lubricant performance over a wider range of operating temperatures. These additives are typically high molecular weight polymers, such as, but not limited to, polyisobutylenes, olefin copolymer, and polyalkylmethacrylates, that are added in concentrations of 2-5% (w/w). Appropriate polymers, when dissolved in base oil, expand from a coiled to an uncoiled state with increasing temperature [2]. The ability of VI additives to increase their molar volume and improve the temperature-viscosity dependence of lubricants suggests there is a strong relationship between molecular structure and additive functionality [3]. In this work, we aim to quantify the changes in polymer size with temperature for four polyisobutylene (PIB) based molecular structures at the nano-scale using molecular simulation tools. As expected, the results show that the polymers adopt more conformations at higher temperatures, and there is a clear indication that the expandability of a polymer is strongly influenced by molecular structure.

  16. Habitat suitability index model for black bear (Ursus americanus)

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This descriptive model applies only to black bear in the coastal forests and adjacent vegetative communities, which extend from Afognak Island and the shores of...

  17. The sequential organ failure assessment (SOFA) score is prognostically superior to the model for end-stage liver disease (MELD) and MELD variants following paracetamol (acetaminophen) overdose.

    Science.gov (United States)

    Craig, D G N; Reid, T W D J; Wright, E C; Martin, K G; Davidson, J S; Hayes, P C; Simpson, K J

    2012-03-01

    The prognostic value of the model for end-stage liver disease (MELD) and sodium-based MELD variants in predicting survival following paracetamol overdose remains unclear. To examine the prognostic accuracy of sodium-based MELD variants in paracetamol-induced acute liver injury compared with the sequential organ failure assessment (SOFA) score. Retrospective analysis of 138 single time point paracetamol overdoses admitted to a tertiary liver centre. Individual laboratory samples were correlated with the corresponding clinical parameters in relation to time post-overdose, and the daily MELD, MELD-Na, MELDNa, MESO, iMELD, UKELD, updated MELD and SOFA scores were calculated. Sixty-six (47.8%) patients developed hepatic encephalopathy, of whom 7 were transplanted and 21 died without liver transplantation. SOFA had a significantly greater area under the receiver operator characteristic for the prediction of spontaneous survival compared with MELD at both 72 (P = 0.024) and 96 (P = 0.017) h post-overdose. None of the sodium-based MELD variants improved the prognostic accuracy of MELD. A SOFA score >6 by 72 h or >7 by 96 h, post-overdose predicted death/transplantation with a negative predictive value of 96.9 (95% CI 90.2-99.4) and 98.8 (95% CI 93.6-99.9) respectively. SOFA and MELD had similar accuracy for predicting the development of hepatic encephalopathy (P = 0.493). The SOFA score is superior to MELD in predicting spontaneous survival following paracetamol-induced acute liver injury. Modification of the MELD score to include serum sodium does not improve prognostic accuracy in this setting. SOFA may have potential as a quantitative triage marker following paracetamol overdose. © 2012 Blackwell Publishing Ltd.

  18. Predicting the Direction of Stock Market Index Movement Using an Optimized Artificial Neural Network Model.

    Directory of Open Access Journals (Sweden)

    Mingyue Qiu

    Full Text Available In the business sector, it has always been a difficult task to predict the exact daily price of the stock market index; hence, there is a great deal of research being conducted regarding the prediction of the direction of stock price index movement. Many factors such as political events, general economic conditions, and traders' expectations may have an influence on the stock market index. There are numerous research studies that use similar indicators to forecast the direction of the stock market index. In this study, we compare two basic types of input variables to predict the direction of the daily stock market index. The main contribution of this study is the ability to predict the direction of the next day's price of the Japanese stock market index by using an optimized artificial neural network (ANN model. To improve the prediction accuracy of the trend of the stock market index in the future, we optimize the ANN model using genetic algorithms (GA. We demonstrate and verify the predictability of stock price direction by using the hybrid GA-ANN model and then compare the performance with prior studies. Empirical results show that the Type 2 input variables can generate a higher forecast accuracy and that it is possible to enhance the performance of the optimized ANN model by selecting input variables appropriately.

  19. Predicting the Direction of Stock Market Index Movement Using an Optimized Artificial Neural Network Model.

    Science.gov (United States)

    Qiu, Mingyue; Song, Yu

    2016-01-01

    In the business sector, it has always been a difficult task to predict the exact daily price of the stock market index; hence, there is a great deal of research being conducted regarding the prediction of the direction of stock price index movement. Many factors such as political events, general economic conditions, and traders' expectations may have an influence on the stock market index. There are numerous research studies that use similar indicators to forecast the direction of the stock market index. In this study, we compare two basic types of input variables to predict the direction of the daily stock market index. The main contribution of this study is the ability to predict the direction of the next day's price of the Japanese stock market index by using an optimized artificial neural network (ANN) model. To improve the prediction accuracy of the trend of the stock market index in the future, we optimize the ANN model using genetic algorithms (GA). We demonstrate and verify the predictability of stock price direction by using the hybrid GA-ANN model and then compare the performance with prior studies. Empirical results show that the Type 2 input variables can generate a higher forecast accuracy and that it is possible to enhance the performance of the optimized ANN model by selecting input variables appropriately.

  20. ECONOMETRIC’S MODEL: THE DEPENDENCE OF PFTS INDEX FROM ECONOMICS RANKS

    Directory of Open Access Journals (Sweden)

    K. Cherkashyna

    2013-11-01

    Full Text Available Dynamics of stock index is an indicator of market efficiency. We use the strong form of market efficiency, where prices reflect all available information, – both public and private. National index PFTS and main world indexes such as Dow Jones industrial, Standard & Poor’s 500, Nasdaq composite, Japan’s Nikkei index, Hong Kong’s Hang Seng index are very volatility. Last week all of the major U.S. stock indexes were in the red. Data dependence index PFTS from many exogenous and internal factors is analyzed in the article. The main exogenous factors are Dow Jones industrial, Nasdaq composite, growth rate of world GDP, price of gold, price of oil. The main internal factors are the exchange rate, the international investment position of Ukraine, the external debt of Ukraine. Index PFTS is malleable from the international investment position, the exchange rate and the price of gold. It is very difficult to forecast the dynamic of stock index. There is an approximation error. It is 6,82%. It is less than 10% and it is allowable. The econometric model makes it possible to predict the dynamics of the PFTS on the next years. But we must have in mind asymmetry of information and moral hazard.

  1. Modeling of preventive maintenance changes influence upon flight safety indexes

    Directory of Open Access Journals (Sweden)

    А.В. Гончаренко

    2004-03-01

    Full Text Available  It is considered a simplified model of connection between the catastrophic events flow frequency and both preventive maintenance changes periodicity and diagnosis depth of aviation equipment. It is deduced specific formulas for computing the changes and diagnostics parameters influence upon the values of both the catastrophic events flow frequency and technical-economical control factor criterion of flight safety levels.

  2. Evaluation of MM5 model resolution when applied to prediction of national fire danger rating indexes

    Science.gov (United States)

    Jeanne L. Hoadley; Miriam L. Rorig; Larry Bradshaw; Sue A. Ferguson; Kenneth J. Westrick; Scott L. Goodrick; Paul Werth

    2006-01-01

    Weather predictions from the MM5 mesoscale model were used to compute gridded predictions of National Fire Danger Rating System (NFDRS) indexes. The model output was applied to a case study of the 2000 fire season in Northern Idaho and Western Montana to simulate an extreme event. To determine the preferred resolution for automating NFD RS predictions, model...

  3. Use of the generalized linear models in data related to dental caries index

    Directory of Open Access Journals (Sweden)

    Javali S

    2007-01-01

    Full Text Available The aim of this study is to encourage and initiate the application of generalized linear models (GLMs in the analysis of the covariates of decayed, missing, and filled teeth (DMFT index data, which is not necessarily normally distributed. GLMs can be performed assuming underlying many distributions; in fact Poisson distribution with log built-in link function and binomial distribution with Logit and Probit built-in link functions are considered. The Poisson model is used for modeling the DMFT index data and the Logit and Probit models are employed to model the dichotomous outcome of DMFT = 0 and DMFT ≠ 0 (caries free/caries present. The data comprised 7188 subjects aged 18-30 years from the study on the oral health status of Karnataka state conducted by SDM College of Dental Sciences and Hospital, Dharwad, Karnataka, India. The Poisson model and binomial models (Logit and Probit displayed dissimilarity in the outcome of results at 5% level of significance ( P < 0.05. The binomial models were a poor fit, whereas the Poisson model showed a good fit for the DMFT index data. Therefore, a suitable modeling approach for DMFT index data is to use a Poisson model for the DMFT response and a binomial model for the caries free and caries present (DMFT = 0 and DMFT ≠ 0. These GLMs allow separate estimation of those covariates which influence the magnitude of caries.

  4. Modeling of Ship Collision Risk Index Based on Complex Plane and Its Realization

    Directory of Open Access Journals (Sweden)

    Xiaoqin Xu

    2016-07-01

    Full Text Available Ship collision risk index is the basic and important concept in the domain of ship collision avoidance. In this paper, the advantages and deficiencies of the various calculation methods of ship collision risk index are pointed out. Then the ship collision risk model based on complex plane, which can well make up for the deficiencies of the widely-used evaluation model proposed by Kearon.J and Liu ruru is proposed. On this basis, the calculation method of collision risk index under the encountering situation of multi-ships is constructed, then the three-dimensional image and spatial curve of the risk index are figured out. Finally, single chip microcomputer is used to realize the model. And attaching this single chip microcomputer to ARPA is helpful to the decision-making of the marine navigators.

  5. An agent-based model for the bibliometric h-index

    Science.gov (United States)

    Ionescu, Georgia; Chopard, Bastien

    2013-10-01

    We model a virtual scientific community in which authors publish and cite articles. Citations are attributed according to a preferential attachment mechanism. From the numerical simulations, the h-index can be computed. This bottom-up approach reproduces well real bibliometric data. We consider two versions of our model. (1) The single-scientist is controlled by two parameters which can be tuned to reproduce the value of the h-index of many real scientists. Moreover, this model shows how the h-index grows with the number of citations, for a fixed number of articles. We also define an average h-index that can be used to compare the scientific productivity of institutions of different sizes. (2) The multi-scientist model considers a population of scientists and allows us to study the impact of removing citations from the low h-index researchers on the community. Simulations on real bibilometric data, as well as the predictions of the model, show that the h-index eco-system can be strongly affected by such a filtering.

  6. Index-aware model order reduction methods applications to differential-algebraic equations

    CERN Document Server

    Banagaaya, N; Schilders, W H A

    2016-01-01

    The main aim of this book is to discuss model order reduction (MOR) methods for differential-algebraic equations (DAEs) with linear coefficients that make use of splitting techniques before applying model order reduction. The splitting produces a system of ordinary differential equations (ODE) and a system of algebraic equations, which are then reduced separately. For the reduction of the ODE system, conventional MOR methods can be used, whereas for the reduction of the algebraic systems new methods are discussed. The discussion focuses on the index-aware model order reduction method (IMOR) and its variations, methods for which the so-called index of the original model is automatically preserved after reduction.

  7. A multi-factorial genetic model for prognostic assessment of high risk melanoma patients receiving adjuvant interferon.

    Directory of Open Access Journals (Sweden)

    Ena Wang

    Full Text Available PURPOSE: IFNa was the first cytokine to demonstrate anti-tumor activity in advanced melanoma. Despite the ability of high-dose IFNa reducing relapse and mortality by up to 33%, large majority of patients experience side effects and toxicity which outweigh the benefits. The current study attempts to identify genetic markers likely to be associated with benefit from IFN-a2b treatment and predictive for survival. EXPERIMENTAL DESIGN: We tested the association of variants in FOXP3 microsatellites, CTLA4 SNPs and HLA genotype in 284 melanoma patients and their association with prognosis and survival of melanoma patients who received IFNa adjuvant therapy. RESULTS: Univariate survival analysis suggested that patients bearing either the DRB1*15 or HLA-Cw7 allele suffered worse OS while patients bearing either HLA-Cw6 or HLA-B44 enjoyed better OS. DRB1*15 positive patients suffered also worse RFS and conversely HLA-Cw6 positive patients had better RFS. Multivariate analysis revealed that a five-marker genotyping signature was prognostic of OS independent of disease stage. In the multivariate Cox regression model, HLA-B38 (p = 0.021, HLA-C15 (p = 0.025, HLA-C3 (p = 0.014, DRB1*15 (p = 0.005 and CT60*G/G (0.081 were significantly associated with OS with risk ratio of 0.097 (95% CI, 0.013-0.709, 0.387 (95% CI, 0.169-0.889, 0.449 (95% CI, 0.237-0.851, 1.948 (95% CI, 1.221-3.109 and 1.484 (95% IC, 0.953-2.312 respectively. CONCLUSION: These results suggest that gene polymorphisms relevant to a biological occurrence are more likely to be informative when studied in concert to address potential redundant or conflicting functions that may limit each gene individual contribution. The five markers identified here exemplify this concept though prospective validation in independent cohorts is needed.

  8. External validation of a proposed prognostic model for the prediction of 1-year postoperative eGFR after living donor nephrectomy.

    Science.gov (United States)

    Kulik, Ulf; Gwiasda, Jill; Oldhafer, Felix; Kaltenborn, Alexander; Arelin, Viktor; Gueler, Faikah; Richter, Nicolas; Klempnauer, Juergen; Schrem, Harald

    2017-11-01

    The goal of this study was to externally validate the recently proposed prognostic model for the prediction of estimated glomerular filtration rate (eGFR) < 60 ml/min/1.73 m(2) 1 year after living donor nephrectomy. 130 living kidney donors (median age at donation 52.3 years, range 24.7-75.6 years) were investigated before and after donation between March 2000 and April 2016. Preoperative eGFR values varied between 61.7 and 148.4 ml/min (mean: 89, median: 88). Observed eGFR 1 year after transplantation (±45 days) ranged between 36.3 and 97.1 ml/min (mean: 55, median: 53). 70.8% of donors displayed eGFR values < 60 ml/min 1 year after donation. Predicted eGFR 1 year after donation was determined using the prognostic model proposed by Benoit et al. (Int Urol Nephrol 49(5):793-801. doi: 10.1007/s11255-017-1559-1 , 2017): postoperative eGFR ml/min/1.73 m(2) = 31.71 + (0.521 × eGFR in ml/min prior to donation -0.314 × Age in years at donation). Pearson correlation and receiver operating characteristics curve (ROC-curve) were used to assess external validity of the proposed prognostic model to predict postoperative eGFR in ml/min and eGFR < 60 ml/min. The correlation between predicted and observed eGFR 1 year after donation was significant (p < 0.001; R (2) = 0.594). The area under the ROC-curve (AUROC) demonstrated a high sensitivity and specificity for predicted eGFR values < 60 ml/min (AUROC = 0.866). The proposed prognostic model for the prediction of postoperative eGFR was successfully validated in our cohort. We therefore consider the model as generally applicable.

  9. A prognostic model for development of significant liver fibrosis in HIV-hepatitis C co-infection.

    Directory of Open Access Journals (Sweden)

    Nasheed Moqueet

    Full Text Available Liver fibrosis progresses rapidly in HIV-Hepatitis C virus (HCV co-infected individuals partially due to heightened inflammation. Immune markers targeting stages of fibrogenesis could aid in prognosis of fibrosis.A case-cohort study was nested in the prospective Canadian Co-infection Cohort (n = 1119. HCV RNA positive individuals without fibrosis, end-stage liver disease or chronic Hepatitis B at baseline (n = 679 were eligible. A random subcohort (n = 236 was selected from those eligible. Pro-fibrogenic markers and Interferon Lambda (IFNL rs8099917 genotype were measured from first available sample in all fibrosis cases (APRI ≥ 1.5 during follow-up and the subcohort. We used Cox proportional hazards and compared Model 1 (selected clinical predictors only to Model 2 (Model 1 plus selected markers for predicting 3-year risk of liver fibrosis using weighted Harrell's C and Net Reclassification Improvement indices.113 individuals developed significant liver fibrosis over 1300 person-years (8.63 per 100 person-years 95% CI: 7.08, 10.60. Model 1 (age, sex, current alcohol use, HIV RNA, baseline APRI, HCV genotype was nested in model 2, which also included IFNL genotype and IL-8, sICAM-1, RANTES, hsCRP, and sCD14. The C indexes (95% CI for model 1 vs. model 2 were 0.720 (0.649, 0.791 and 0.756 (0.688, 0.825, respectively. Model 2 classified risk more appropriately (overall net reclassification improvement, p<0.05.Including IFNL genotype and inflammatory markers IL-8, sICAM-1, RANTES, hs-CRP, and sCD14 enabled better prediction of the 3-year risk of significant liver fibrosis over clinical predictors alone. Whether this modest improvement in prediction justifies their additional cost requires further cost-benefit analyses.

  10. A novel water poverty index model for evaluation of Chinese regional water security

    Science.gov (United States)

    Gong, L.; Jin, C. L.; Li, Y. X.; Zhou, Z. L.

    2017-08-01

    This study proposed an improved Water Poverty Index (WPI) model employed in evaluating Chinese regional water security. Firstly, the Chinese WPI index system was constructed, in which the indicators were obtained according to China River reality. A new mathematical model was then established for WPI values calculation on the basis of Center for Ecology and Hydrology (CEH) model. Furthermore, this new model was applied in Shiyanghe River (located in western China). It turned out that the Chinese index system could clearly reflect the indicators threatening security of river water and the Chinese WPI model is feasible. This work has also developed a Water Security Degree (WSD) standard which is able to be regarded as a scientific basis for further water resources utilization and water security warning mechanism formulation.

  11. Can metabolic tumor parameters on primary staging18F-FDG PET/CT aid in risk stratification of primary central nervous system lymphomas for patient management as a prognostic model?

    Science.gov (United States)

    Okuyucu, K; Alagoz, E; Ince, S; Ozaydin, S; Arslan, N

    Primary central nervous system (CNS) lymphoma is an aggressive and fatal extranodal non-Hodgkin lymphoma jailed in CNS at initial diagnosis. Its prognosis is poor and the disease has a fatal outcome when compared with systemic non-Hodgkin lymphoma. A few baseline risk stratification scoring systems have been suggested to estimate the prognosis mainly based on serum lactate dehydrogenase level,age, Karnofsky performance score, involvement of deep brain structures and cerebrospinal fluid protein concentration. 18 F-FDG PET/CT has a high prognostic value with respect to overall survival and disease-free survival in many cancers and lymphomas. We aimed to investigate metabolic tumor indexes on primary staging 18 F-FDG PET/CT as prognostic markers in primary CNS lymphoma. Fourteen patients with primary CNS diffuse large B-cell lymphoma (stage i) were enrolled in this retrospective cohort study. Primary staging 18 F-FDG PET/CT was performed and quantitative parameters like maximum standardized uptake value, average standardized uptake value, metabolic tumor volume and total lesion glycolysis (TLG) were calculated for all patients before the treatment. Cox regression models were performed to determine their relation with survival time. In the evaluation of all potential risk factors impacting recurrence/metastases (age, sex, serum lactate dehydrogenase, involvement of deep brain structures, maximum standardized uptake value, average standardized uptake value, metabolic tumor volume, and TLG) with univariate analysis, TLG remained statistically significant (P=.02). Metabolic tumor parameters are useful in prognosis estimation of primary CNS lymphomas, especially TLG, which is the most important one and may play a role in patient management. Copyright © 2017 Elsevier España, S.L.U. y SEMNIM. All rights reserved.

  12. Skeletal muscle depletion is an independent prognostic factor for hepatocellular carcinoma.

    Science.gov (United States)

    Iritani, Soichi; Imai, Kenji; Takai, Koji; Hanai, Tatsunori; Ideta, Takayasu; Miyazaki, Tsuneyuki; Suetsugu, Atsushi; Shiraki, Makoto; Shimizu, Masahito; Moriwaki, Hisataka

    2015-03-01

    Skeletal muscle depletion or sarcopenia has been identified as a poor prognostic factor for various diseases. The aim of this study is to determine whether muscle depletion is a prognostic factor for hepatocellular carcinoma (HCC). We evaluated 217 consecutive patients with primary HCC. The skeletal muscle cross-sectional area was measured by computed tomography at the third lumbar vertebra (L3), from which the total body fat-free mass (FFM) and L3 skeletal muscle index (L3 SMI) were obtained. The factors contributing to overall survival (OS) were analyzed by univariate and multivariate Cox proportional hazards model. In univariate analysis, FFM (P = 0.0422), Child-Pugh classification (P = 0.0058), serum albumin level (P 22) died earlier (P = 0.0129). Skeletal muscle depletion is an independent prognostic factor. Intervention to prevent muscle wasting might be an effective strategy for improving the outcome of HCC.

  13. Feasibility of transitioning from APACHE II to SAPS III as prognostic model in a Brazilian general intensive care unit. A retrospective study.

    Science.gov (United States)

    Serpa Neto, Ary; Assunção, Murillo Santucci Cesar de; Pardini, Andréia; Silva, Eliézer

    2015-01-01

    Prognostic models reflect the population characteristics of the countries from which they originate. Predictive models should be customized to fit the general population where they will be used. The aim here was to perform external validation on two predictive models and compare their performance in a mixed population of critically ill patients in Brazil. Retrospective study in a Brazilian general intensive care unit (ICU). This was a retrospective review of all patients admitted to a 41-bed mixed ICU from August 2011 to September 2012. Calibration (assessed using the Hosmer-Lemeshow goodness-of-fit test) and discrimination (assessed using area under the curve) of APACHE II and SAPS III were compared. The standardized mortality ratio (SMR) was calculated by dividing the number of observed deaths by the number of expected deaths. A total of 3,333 ICU patients were enrolled. The Hosmer-Lemeshow goodness-of-fit test showed good calibration for all models in relation to hospital mortality. For in-hospital mortality there was a worse fit for APACHE II in clinical patients. Discrimination was better for SAPS III for in-ICU and in-hospital mortality (P = 0.042). The SMRs for the whole population were 0.27 (confidence interval [CI]: 0.23 - 0.33) for APACHE II and 0.28 (CI: 0.22 - 0.36) for SAPS III. In this group of critically ill patients, SAPS III was a better prognostic score, with higher discrimination and calibration power.

  14. Predicting intracranial hemorrhage after traumatic brain injury in low and middle-income countries: A prognostic model based on a large, multi-center, international cohort

    Directory of Open Access Journals (Sweden)

    Subaiya Saleena

    2012-11-01

    Full Text Available Abstract Background Traumatic brain injury (TBI affects approximately 10 million people annually, of which intracranial hemorrhage is a devastating sequelae, occurring in one-third to half of cases. Patients in low and middle-income countries (LMIC are twice as likely to die following TBI as compared to those in high-income countries. Diagnostic capabilities and treatment options for intracranial hemorrhage are limited in LMIC as there are fewer computed tomography (CT scanners and neurosurgeons per patient as in high-income countries. Methods The Medical Research Council CRASH-1 trial was utilized to build this model. The study cohort included all patients from LMIC who received a CT scan of the brain (n = 5669. Prognostic variables investigated included age, sex, time from injury to randomization, pupil reactivity, cause of injury, seizure and the presence of major extracranial injury. Results There were five predictors that were included in the final model; age, Glasgow Coma Scale, pupil reactivity, the presence of a major extracranial injury and time from injury to presentation. The model demonstrated good discrimination and excellent calibration (c-statistic 0.71. A simplified risk score was created for clinical settings to estimate the percentage risk of intracranial hemorrhage among TBI patients. Conclusion Simple prognostic models can be used in LMIC to estimate the risk of intracranial hemorrhage among TBI patients. Combined with clinical judgment this may facilitate risk stratification, rapid transfer to higher levels of care and treatment in resource-poor settings.

  15. A dynamic prognostic model to predict survival in primary myelofibrosis: a study by the IWG-MRT (International Working Group for Myeloproliferative Neoplasms Research and Treatment).

    Science.gov (United States)

    Passamonti, Francesco; Cervantes, Francisco; Vannucchi, Alessandro Maria; Morra, Enrica; Rumi, Elisa; Pereira, Arturo; Guglielmelli, Paola; Pungolino, Ester; Caramella, Marianna; Maffioli, Margherita; Pascutto, Cristiana; Lazzarino, Mario; Cazzola, Mario; Tefferi, Ayalew

    2010-03-04

    Age older than 65 years, hemoglobin level lower than 100 g/L (10 g/dL), white blood cell count greater than 25 x 10(9)/L, peripheral blood blasts 1% or higher, and constitutional symptoms have been shown to predict poor survival in primary myelofibrosis (PMF) at diagnosis. To investigate whether the acquisition of these factors during follow-up predicts survival, we studied 525 PMF patients regularly followed. All 5 variables had a significant impact on survival when analyzed as time-dependent covariates in a multivariate Cox proportional hazard model and were included in 2 separate models, 1 for all patients (Dynamic International Prognostic Scoring System [DIPSS]) and 1 for patients younger than 65 years (age-adjusted DIPSS). Risk factors were assigned score values based on hazard ratios (HRs). Risk categories were low, intermediate-1, intermediate-2, and high in both models. Survival was estimated by the HR. When shifting to the next risk category, the HR was 4.13 for low risk, 4.61 for intermediate-1, and 2.54 for intermediate-2 according to DIPSS; 3.97 for low risk, 2.84 for intermediate-1, and 1.81 for intermediate-2 according to the age-adjusted DIPSS. The novelty of these models is the prognostic assessment of patients with PMF anytime during their clinical course, which may be useful for treatment decision-making.

  16. Agent-based model for the h-index - Exact solution

    CERN Document Server

    Żogała-Siudem, Barbara; Cena, Anna; Gagolewski, Marek

    2015-01-01

    The Hirsch's $h$-index is perhaps the most popular citation-based measure of the scientific excellence. In 2013 G. Ionescu and B. Chopard proposed an agent-based model for this index to describe a publications and citations generation process in an abstract scientific community. With such an approach one can simulate a single scientist's activity, and by extension investigate the whole community of researchers. Even though this approach predicts quite well the $h$-index from bibliometric data, only a solution based on simulations was given. In this paper, we complete their results with exact, analytic formulas. What is more, due to our exact solution we are able to simplify the Ionescu-Chopard model which allows us to obtain a compact formula for $h$-index. Moreover, a simulation study designed to compare both, approximated and exact, solutions is included. The last part of this paper presents evaluation of the obtained results on a real-word data set.

  17. Proliferation index: a continuous model to predict prognosis in patients with tumours of the Ewing's sarcoma family.

    Directory of Open Access Journals (Sweden)

    Samantha Brownhill

    Full Text Available The prognostic value of proliferation index (PI and apoptotic index (AI, caspase-8, -9 and -10 expression have been investigated in primary Ewing's sarcoma family of tumours (ESFT. Proliferating cells, detected by immunohistochemistry for Ki-67, were identified in 91% (91/100 of tumours with a median PI of 14 (range 0-87. Apoptotic cells, identified using the TUNEL assay, were detected in 96% (76/79 of ESFT; the median AI was 3 (range 0-33. Caspase-8 protein expression was negative (0 in 14% (11/79, low (1 in 33% (26/79, medium (2 in 38% (30/79 and high (3 in 15% (12/79 of tumours, caspase-9 expression was low (1 in 66% (39/59 and high (3 in 34% (20/59, and caspase-10 protein was low (1 in 37% (23/62 and negative (0 in 63% (39/62 of primary ESFT. There was no apparent relationship between caspase-8, -9 and -10 expression, PI and AI. PI was predictive of relapse-free survival (RFS; p = 0.011 and overall survival (OS; p = <0.001 in a continuous model, whereas AI did not predict outcome. Patients with tumours expressing low levels of caspase-9 protein had a trend towards a worse RFS than patients with tumours expressing higher levels of caspase-9 protein (p = 0.054, log rank test, although expression of caspases-8, -9 and/or -10 did not significantly predict RFS or OS. In a multivariate analysis model that included tumour site, tumour volume, the presence of metastatic disease at diagnosis, PI and AI, PI independently predicts OS (p = 0.003. Consistent with previous publications, patients with pelvic tumours had a significantly worse OS than patients with tumours at other sites (p = 0.028; patients with a pelvic tumour and a PI≥20 had a 6 fold-increased risk of death. These studies advocate the evaluation of PI in a risk model of outcome for patients with ESFT.

  18. Prediction of overall survival for patients with metastatic castration-resistant prostate cancer: development of a prognostic model through a crowdsourced challenge with open clinical trial data.

    Science.gov (United States)

    Guinney, Justin; Wang, Tao; Laajala, Teemu D; Winner, Kimberly Kanigel; Bare, J Christopher; Neto, Elias Chaibub; Khan, Suleiman A; Peddinti, Gopal; Airola, Antti; Pahikkala, Tapio; Mirtti, Tuomas; Yu, Thomas; Bot, Brian M; Shen, Liji; Abdallah, Kald; Norman, Thea; Friend, Stephen; Stolovitzky, Gustavo; Soule, Howard; Sweeney, Christopher J; Ryan, Charles J; Scher, Howard I; Sartor, Oliver; Xie, Yang; Aittokallio, Tero; Zhou, Fang Liz; Costello, James C

    2017-01-01

    Improvements to prognostic models in metastatic castration-resistant prostate cancer have the potential to augment clinical trial design and guide treatment strategies. In partnership with Project Data Sphere, a not-for-profit initiative allowing data from cancer clinical trials to be shared broadly with researchers, we designed an open-data, crowdsourced, DREAM (Dialogue for Reverse Engineering Assessments and Methods) challenge to not only identify a better prognostic model for prediction of survival in patients with metastatic castration-resistant prostate cancer but also engage a community of international data scientists to study this disease. Data from the comparator arms of four phase 3 clinical trials in first-line metastatic castration-resistant prostate cancer were obtained from Project Data Sphere, comprising 476 patients treated with docetaxel and prednisone from the ASCENT2 trial, 526 patients treated with docetaxel, prednisone, and placebo in the MAINSAIL trial, 598 patients treated with docetaxel, prednisone or prednisolone, and placebo in the VENICE trial, and 470 patients treated with docetaxel and placebo in the ENTHUSE 33 trial. Datasets consisting of more than 150 clinical variables were curated centrally, including demographics, laboratory values, medical history, lesion sites, and previous treatments. Data from ASCENT2, MAINSAIL, and VENICE were released publicly to be used as training data to predict the outcome of interest-namely, overall survival. Clinical data were also released for ENTHUSE 33, but data for outcome variables (overall survival and event status) were hidden from the challenge participants so that ENTHUSE 33 could be used for independent validation. Methods were evaluated using the integrated time-dependent area under the curve (iAUC). The reference model, based on eight clinical variables and a penalised Cox proportional-hazards model, was used to compare method performance. Further validation was done using data from a

  19. Block Empirical Likelihood for Longitudinal Single-Index Varying-Coefficient Model

    Directory of Open Access Journals (Sweden)

    Yunquan Song

    2013-01-01

    Full Text Available In this paper, we consider a single-index varying-coefficient model with application to longitudinal data. In order to accommodate the within-group correlation, we apply the block empirical likelihood procedure to longitudinal single-index varying-coefficient model, and prove a nonparametric version of Wilks’ theorem which can be used to construct the block empirical likelihood confidence region with asymptotically correct coverage probability for the parametric component. In comparison with normal approximations, the proposed method does not require a consistent estimator for the asymptotic covariance matrix, making it easier to conduct inference for the model's parametric component. Simulations demonstrate how the proposed method works.

  20. Improving Stochastic Modelling of Daily Rainfall Using the ENSO Index: Model Development and Application in Chile

    Directory of Open Access Journals (Sweden)

    Diego Urdiales

    2018-02-01

    Full Text Available Stochastic weather simulation, or weather generators (WGs, have gained a wide acceptance and been used for a variety of purposes, including climate change studies and the evaluation of climate variability and uncertainty effects. The two major challenges in WGs are improving the estimation of interannual variability and reducing overdispersion in the synthetic series of simulated weather. The objective of this work is to develop a WG model of daily rainfall, incorporating a covariable that accounts for interannual variability, and apply it in three climate regions (arid, Mediterranean, and temperate of Chile. Precipitation occurrence was modeled using a two-stage, first-order Markov chain, whose parameters are fitted with a generalized lineal model (GLM using a logistic function. This function considers monthly values of the observed Sea Surface Temperature Anomalies of the Region 3.4 of El Niño-Southern Oscillation (ENSO index as a covariable. Precipitation intensity was simulated with a mixed exponential distribution, fitted using a maximum likelihood approach. The stochastic simulation shows that the application of the approach to Mediterranean and arid climates largely eliminates the overdispersion problem, resulting in a much improved interannual variability in the simulated values.

  1. Leaf area index uncertainty estimates for model-data fusion applications

    Science.gov (United States)

    Andrew D. Richardson; D. Bryan Dail; D.Y. Hollinger

    2011-01-01

    Estimates of data uncertainties are required to integrate different observational data streams as model constraints using model-data fusion. We describe an approach with which random and systematic uncertainties in optical measurements of leaf area index [LAI] can be quantified. We use data from a measurement campaign at the spruce-dominated Howland Forest AmeriFlux...

  2. The partial duration series method in regional index-flood modeling

    DEFF Research Database (Denmark)

    Madsen, Henrik; Rosbjerg, Dan

    1997-01-01

    A regional index-flood method based on the partial duration series model is introduced. The model comprises the assumptions of a Poisson-distributed number of threshold exceedances and generalized Pareto (GP) distributed peak magnitudes. The regional T-year event estimator is based on a regional...

  3. Detecting Growth Shape Misspecifications in Latent Growth Models: An Evaluation of Fit Indexes

    Science.gov (United States)

    Leite, Walter L.; Stapleton, Laura M.

    2011-01-01

    In this study, the authors compared the likelihood ratio test and fit indexes for detection of misspecifications of growth shape in latent growth models through a simulation study and a graphical analysis. They found that the likelihood ratio test, MFI, and root mean square error of approximation performed best for detecting model misspecification…

  4. An Explanation of the Effectiveness of Latent Semantic Indexing by Means of a Bayesian Regression Model.

    Science.gov (United States)

    Story, Roger E.

    1996-01-01

    Discussion of the use of Latent Semantic Indexing to determine relevancy in information retrieval focuses on statistical regression and Bayesian methods. Topics include keyword searching; a multiple regression model; how the regression model can aid search methods; and limitations of this approach, including complexity, linearity, and…

  5. Multiplex polymerase chain reaction-based prognostic models in diffuse large B-cell lymphoma patients treated with R-CHOP

    DEFF Research Database (Denmark)

    Green, Tina M.; Jensen, Andreas K.; Holst, René

    2016-01-01

    We present a multiplex analysis for genes known to have prognostic value in an attempt to design a clinically useful classification model in patients with diffuse large B-cell lymphoma (DLBCL). Real-time polymerase chain reaction was used to measure transcript levels of 28 relevant genes in 194 de...... models. The best model was validated in data from an online available R-CHOP treated cohort. With progression-free survival (PFS) as primary endpoint, the best performing IPI independent model incorporated the LMO2 and HLADQA1 as well as gene interactions for GCSAMxMIB1, GCSAMxCTGF and FOXP1xPDE4B....... 82% for low risk group (P new drug trials....

  6. Implementation of a GNSS Meteorological model to the estimation of the Haines Index

    Science.gov (United States)

    Fernandez, Laura Isabel; Aragon-Paz, Juan Manuel; Mendoza, Luciano Pedro Oscar; Meza, Amalia Margarita

    2017-04-01

    Wildfire indexes evaluate the risk of forest fire occurrences and the dangerousness of its large and erratic propagation. In this context, the widely used Haines Index assesses the potential contribution of the atmosphere in forecasting and monitoring the behavior of the plume-dominated wildfires. The main goal of this study is the analysis of advantages in applying the GPT2w, an empirical model originally developed for Global Navigation Satellite System (GNSS) Meteorology, to the estimation of the Haines Index. To this aim, a statistical analysis of the differences between this estimation and the real values from radiosondes was performed. The selected area comprises a region of South America between latitudes 15° S and 35° S. This area was chosen due to the availability of the radiosonde launches required for validation during the year of study (2011). Previously, for characterizing the expected regional performance of the Haines Index, the Climatology was developed by using data from the European Centre for Medium-Range Weather Forecast (ECMWF) reanalysis model (ERA Interim) for the period 2000-2011. Afterwards a statistical analysis of the differences between the index estimation from the application of the GPT2w with respect to the real index values, that is: Haines index calculated from radiosonde measurements was performed. Moreover, the additional estimation of the Haines Index by using multi-level data from ERA Interim at the same control stations was also provided. Because the GPT2w model is freely available, the analysis of the results discusses the advantages of using this approach where radiosonde launches are scarce. Likewise, strategies for improving the deficiencies of this estimate are also presented.

  7. Prognostic model for advanced breast carcinoma with luminal subtype and impact of hormonal maintenance: Implications for post-progression and conditional survival.

    Science.gov (United States)

    Carbognin, Luisa; Sperduti, Isabella; Ciccarese, Mariangela; Fabi, Alessandra; Petrucelli, Luciana; Vari, Sabrina; Forcignanò, Rosa Chiara; Nortilli, Rolando; Vicentini, Cecilia; Pilotto, Sara; Merler, Sara; Zampiva, Ilaria; Brunelli, Matteo; Manfrin, Erminia; Giannarelli, Diana; Tortora, Giampaolo; Bria, Emilio

    2016-10-01

    The aim of this analysis was to develop and validate a prognostic model for advanced breast cancer (ABC) with luminal subtype based on the combination of clinical, pathological and therapeutic predictors to provide a practical tool to evaluate patients' prognosis. Clinical and pathological data were retrospectively correlated to progression-free and overall survival (PFS/OS) using a Cox model. Significant treatment variables were adjusted with the propensity score analysis. A continuous score to identify risk classes was derived according to model ratios. The performance of the risk-class model was tested for post-progression survival (PPS) and conditional survival (CS) as well. Data from 335 patients (3 institutions) were gathered (median follow-up 58 months). At multivariate analysis Ki67, Performance Status (PS) and number of metastatic sites were significant predictors for PFS, whereas Ki67, PS, brain metastases, PFS after 1st-line therapy, number of chemotherapy lines, hormonal therapy and maintenance were significant predictors for OS. The hormonal maintenance resulted to be prognostic after adjustment with propensity score analysis. A two-class model significantly differentiated low-risk and high-risk patients for 2-year PFS (31.5% and 11.0%, p model separated low risk, intermediate-risk, and high-risk patients for 2-year PFS (40.8%, 24.4%, and 11.0%, p models equally discriminate the luminal ABC prognosis in terms of PPS and CS. A risk stratification model including 'easy-to-obtain' clinical, pathological and therapeutic parameters accurately separates luminal ABC patients into different risk classes. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Perspectives in using a remotely sensed dryness index in distributed hydrological models at river basin scale

    DEFF Research Database (Denmark)

    Andersen, Jens Asger; Sandholt, Inge; Jensen, Karsten Høgh

    2002-01-01

    In a previous study a spatially distributed hydrological model, based on the MIKE SHE code, was constructed and validated for the 375 000 km2 Senegal River basin in West Africa. The model was constructed using spatial data on topography, soil types and vegetation characteristics together with time......-series of precipitation from 112 stations in the basin. The model was calibrated and validated based on river discharge data from nine stations in the basin for 11 years. Calibration and validation results suggested that the spatial resolution of the input data in parts of the area was not sufficient for a satisfactory...... examines a remotely sensed dryness index for its relationship to simulated soil moisture and evaporation for six days in the wet season 1990. The index is derived from observations of surface temperature and vegetation index as measured by the NOAA Advanced Very High Resolution Radiometer (AVHRR) sensor...

  9. Cytogenetic Prognostication Within Medulloblastoma Subgroups

    Science.gov (United States)

    Shih, David J.H.; Northcott, Paul A.; Remke, Marc; Korshunov, Andrey; Ramaswamy, Vijay; Kool, Marcel; Luu, Betty; Yao, Yuan; Wang, Xin; Dubuc, Adrian M.; Garzia, Livia; Peacock, John; Mack, Stephen C.; Wu, Xiaochong; Rolider, Adi; Morrissy, A. Sorana; Cavalli, Florence M.G.; Jones, David T.W.; Zitterbart, Karel; Faria, Claudia C.; Schüller, Ulrich; Kren, Leos; Kumabe, Toshihiro; Tominaga, Teiji; Shin Ra, Young; Garami, Miklós; Hauser, Peter; Chan, Jennifer A.; Robinson, Shenandoah; Bognár, László; Klekner, Almos; Saad, Ali G.; Liau, Linda M.; Albrecht, Steffen; Fontebasso, Adam; Cinalli, Giuseppe; De Antonellis, Pasqualino; Zollo, Massimo; Cooper, Michael K.; Thompson, Reid C.; Bailey, Simon; Lindsey, Janet C.; Di Rocco, Concezio; Massimi, Luca; Michiels, Erna M.C.; Scherer, Stephen W.; Phillips, Joanna J.; Gupta, Nalin; Fan, Xing; Muraszko, Karin M.; Vibhakar, Rajeev; Eberhart, Charles G.; Fouladi, Maryam; Lach, Boleslaw; Jung, Shin; Wechsler-Reya, Robert J.; Fèvre-Montange, Michelle; Jouvet, Anne; Jabado, Nada; Pollack, Ian F.; Weiss, William A.; Lee, Ji-Yeoun; Cho, Byung-Kyu; Kim, Seung-Ki; Wang, Kyu-Chang; Leonard, Jeffrey R.; Rubin, Joshua B.; de Torres, Carmen; Lavarino, Cinzia; Mora, Jaume; Cho, Yoon-Jae; Tabori, Uri; Olson, James M.; Gajjar, Amar; Packer, Roger J.; Rutkowski, Stefan; Pomeroy, Scott L.; French, Pim J.; Kloosterhof, Nanne K.; Kros, Johan M.; Van Meir, Erwin G.; Clifford, Steven C.; Bourdeaut, Franck; Delattre, Olivier; Doz, François F.; Hawkins, Cynthia E.; Malkin, David; Grajkowska, Wieslawa A.; Perek-Polnik, Marta; Bouffet, Eric; Rutka, James T.; Pfister, Stefan M.; Taylor, Michael D.

    2014-01-01

    Purpose Medulloblastoma comprises four distinct molecular subgroups: WNT, SHH, Group 3, and Group 4. Current medulloblastoma protocols stratify patients based on clinical features: patient age, metastatic stage, extent of resection, and histologic variant. Stark prognostic and genetic differences among the four subgroups suggest that subgroup-specific molecular biomarkers could improve patient prognostication. Patients and Methods Molecular biomarkers were identified from a discovery set of 673 medulloblastomas from 43 cities around the world. Combined risk stratification models were designed based on clinical and cytogenetic biomarkers identified by multivariable Cox proportional hazards analyses. Identified biomarkers were tested using fluorescent in situ hybridization (FISH) on a nonoverlapping medulloblastoma tissue microarray (n = 453), with subsequent validation of the risk stratification models. Results Subgroup information improves the predictive accuracy of a multivariable survival model compared with clinical biomarkers alone. Most previously published cytogenetic biomarkers are only prognostic within a single medulloblastoma subgroup. Profiling six FISH biomarkers (GLI2, MYC, chromosome 11 [chr11], chr14, 17p, and 17q) on formalin-fixed paraffin-embedded tissues, we can reliably and reproducibly identify very low-risk and very high-risk patients within SHH, Group 3, and Group 4 medulloblastomas. Conclusion Combining subgroup and cytogenetic biomarkers with established clinical biomarkers substantially improves patient prognostication, even in the context of heterogeneous clinical therapies. The prognostic significance of most molecular biomarkers is restricted to a specific subgroup. We have identified a small panel of cytogenetic biomarkers that reliably identifies very high-risk and very low-risk groups of patients, making it an excellent tool for selecting patients for therapy intensification and therapy de-escalation in future clinical trials. PMID

  10. Preoperative multivariable prognostic models for prediction of survival and major complications following surgical resection of renal cell carcinoma with suprahepatic caval tumor thrombus.

    Science.gov (United States)

    Haddad, Ahmed Q; Leibovich, Bradley C; Abel, Edwin Jason; Luo, Jun-Hang; Krabbe, Laura-Maria; Thompson, Robert Houston; Heckman, Jennifer E; Merrill, Megan M; Gayed, Bishoy A; Sagalowsky, Arthur I; Boorjian, Stephen A; Wood, Christopher G; Margulis, Vitaly

    2015-09-01

    Surgical resection for renal cell carcinoma (RCC) with suprahepatic inferior vena cava tumor thrombus is associated with significant morbidity, yet there are currently no tools for preoperative prognostic evaluation. Our goal was to develop a preoperative multivariable model for prediction of survival and risk of major complications in patients with suprahepatic thrombi. We identified patients who underwent surgery for RCC with suprahepatic tumor thrombus extension from 2000 to 2013 at 4 tertiary centers. A Cox proportional hazard model was used for analysis of overall survival (OS) and logistic regression was used for major complications within 90 days of surgery (Clavien ≥ 3A). Nomograms were internally calibrated by bootstrap resampling method. A total of 49 patients with level III thrombus and 83 patients with level IV thrombus were identified. During median follow-up of 24.5 months, 80 patients (60.6%) died and 46 patients (34.8%) experienced major complication. Independent prognostic factors for OS included distant metastases at presentation (hazard ratio = 2.52, P = 0.002) and Eastern Cooperative Oncology Group (ECOG) performance status (hazard ratio = 1.84, Pmodels for the prediction of survival and major complications in patients with RCC who have a suprahepatic inferior vena cava thrombus. If externally validated, these tools may aid in patient selection for surgical intervention. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. Prognostic Performance Metrics

    Data.gov (United States)

    National Aeronautics and Space Administration — This chapter presents several performance metrics for offline evaluation of prognostics algorithms. A brief overview of different methods employed for performance...

  12. Prognostic model to identify patients with myelofibrosis at the highest risk of transformation to acute myeloid leukemia.

    Science.gov (United States)

    Quintás-Cardama, Alfonso; Kantarjian, Hagop; Pierce, Sherry; Cortes, Jorge; Verstovsek, Srdan

    2013-06-01

    Some patients with myelofibrosis (MF) progress to acute myeloid leukemia (AML). Current prognostic tools were not devised to assess risk of AML transformation. Multivariate analysis in 649 patients followed for a median of 19 months (range, 1-180 months). We identified age > 60 (P = .004; hazard ratio [HR], 1.63), platelets HR, 1.62), bone marrow blast > 10% (P = .002; HR, 2.18), high-risk karyotype (P HR, 2.44), transfusion dependency (P HR, 2.64), performance status > 1 (P = .003; HR, 1.47), lactate dehydrogenase > 2000 U/L (P HR, 1.62), previous hydroxyurea (P HR, 1.69), and male sex (P = .005; HR, 1.41) as independent poor prognostic factors for survival. Using the same baseline variables we identified bone marrow blasts >10% and worst karyotype as independent risk factors for AML transformation. Patients with 1 or both of these risk factors (n = 80; 12%) had a median survival of 10 months and a 1-year AML transformation rate of 13% (2% if none of those factors, P = .001). We have identified risk factors that predict high risk of transformation from MF to AML. Copyright © 2013 Elsevier Inc. All rights reserved.

  13. Modeling and computing of stock index forecasting based on neural network and Markov chain.

    Science.gov (United States)

    Dai, Yonghui; Han, Dongmei; Dai, Weihui

    2014-01-01

    The stock index reflects the fluctuation of the stock market. For a long time, there have been a lot of researches on the forecast of stock index. However, the traditional method is limited to achieving an ideal precision in the dynamic market due to the influences of many factors such as the economic situation, policy changes, and emergency events. Therefore, the approach based on adaptive modeling and conditional probability transfer causes the new attention of researchers. This paper presents a new forecast method by the combination of improved back-propagation (BP) neural network and Markov chain, as well as its modeling and computing technology. This method includes initial forecasting by improved BP neural network, division of Markov state region, computing of the state transition probability matrix, and the prediction adjustment. Results of the empirical study show that this method can achieve high accuracy in the stock index prediction, and it could provide a good reference for the investment in stock market.

  14. Stochastic modeling of soundtrack for efficient segmentation and indexing of video

    Science.gov (United States)

    Naphade, Milind R.; Huang, Thomas S.

    1999-12-01

    Tools for efficient and intelligent management of digital content are essential for digital video data management. An extremely challenging research area in this context is that of multimedia analysis and understanding. The capabilities of audio analysis in particular for video data management are yet to be fully exploited. We present a novel scheme for indexing and segmentation of video by analyzing the audio track. This analysis is then applied to the segmentation and indexing of movies. We build models for some interesting events in the motion picture soundtrack. The models built include music, human speech and silence. We propose the use of hidden Markov models to model the dynamics of the soundtrack and detect audio-events. Using these models we segment and index the soundtrack. A practical problem in motion picture soundtracks is that the audio in the track is of a composite nature. This corresponds to the mixing of sounds from different sources. Speech in foreground and music in background are common examples. The coexistence of multiple individual audio sources forces us to model such events explicitly. Experiments reveal that explicit modeling gives better result than modeling individual audio events separately.

  15. Semiempirical modeling of the nocturnal boundary layer Application to the calculation of the refractive index profile

    Science.gov (United States)

    Klapisz, C.; Weill, A.

    1985-12-01

    A method for calculating the evolution of the refractive index profile at night is proposed with the purpose of predicting when and how multipath propagation will occur. Data obtained during the PACEM 1 campaign in the summer of 1982 are used in the calculations. The proposed semiempirical model of the nocturnal boundary layer is found to require is less-computing time.

  16. Dynamic base-age invariant site index models for Tectona grandis ...

    African Journals Online (AJOL)

    Data from 27 remeasured sample plots were used to evaluate dynamic base-age invariant site index models for teak (Tectona grandis) forests in Karnataka, India. The data were obtained in observational field studies covering a wide range of sites in Karnataka and provided up to three interval measurements per plot.

  17. Identification and estimation of nonseparable single-index models in panel data with correlated random effects

    NARCIS (Netherlands)

    Cizek, Pavel; Lei, Jinghua

    The identification in a nonseparable single-index models with correlated random effects is considered in panel data with a fixed number of time periods. The identification assumption is based on the correlated random effects structure. Under this assumption, the parameters of interest are identified

  18. Identification and Estimation of Nonseparable Single-Index Models in Panel Data with Correlated Random Effects

    NARCIS (Netherlands)

    Cizek, P.; Lei, J.

    2013-01-01

    Abstract: The identification of parameters in a nonseparable single-index models with correlated random effects is considered in the context of panel data with a fixed number of time periods. The identification assumption is based on the correlated random-effect structure: the distribution of

  19. Independent screening for single-index hazard rate models with ultrahigh dimensional features

    DEFF Research Database (Denmark)

    Gorst-Rasmussen, Anders; Scheike, Thomas

    2013-01-01

    can be viewed as the natural survival equivalent of correlation screening. We state conditions under which the method admits the sure screening property within a class of single-index hazard rate models with ultrahigh dimensional features and describe the generally detrimental effect of censoring...

  20. Hemorheology index changes in a rat acute blood stasis model: a ...

    African Journals Online (AJOL)

    Background: Blood stasis has received increasing attention in research related to traditional Chinese medicine (TCM) and integrative Chinese and Western medicine. More than 90% of research studies use hemorheology indexes to evaluate the establishment of animal blood stasis models rather than pathological methods ...

  1. Description and evaluation of a net energy intake model as a function of dietary chewing index

    DEFF Research Database (Denmark)

    Jensen, L.M.; Markussen, B.; Nielsen, N.I.

    2016-01-01

    Previously, a linear relationship has been found between net energy intake (NEI) and dietary chewing index (CI) of the diet for different types of cattle. Therefore, we propose to generalize and calibrate this relationship into a new model for direct prediction of NEI by dairy cows from CI values...

  2. Stock Index Returns' Density Prediction using GARCH Models: Frequentist or Bayesian Estimation?

    NARCIS (Netherlands)

    L.F. Hoogerheide (Lennart); D. David (David); N. Corre (Nienke)

    2011-01-01

    textabstractUsing well-known GARCH models for density prediction of daily S&P 500 and Nikkei 225 index returns, a comparison is provided between frequentist and Bayesian estimation. No significant difference is found between the qualities of the forecasts of the whole density, whereas the Bayesian

  3. On-farm evaluation of the Salmon Welfare Index Model (SWIM 1.0)

    NARCIS (Netherlands)

    Folkedal, O.; Pettersen, J.M.; Bracke, M.B.; Stien, L.H.; Nilsson, J.; Martins, C.; Breck, O.; Midtlyng, P.J.; Kristiansen, T.

    2016-01-01

    The present study investigated the operational feasibility of the recently developed Salmon Welfare Index Model (SWIM 1.0) designed for Atlantic salmon (Salmo salar L) in production cages. Ten salmon farms containing spring smolts were visited twice, first between May and June the first year in

  4. 心力衰竭预后评估模型与评价%Different prognostic models of heart failure and their evaluation

    Institute of Scientific and Technical Information of China (English)

    黄樱硕; 孙颖

    2013-01-01

    Heart failure is the end-stage of various cardiomyopathy, and is of characteristics with difficult therapeutic options, poor prognosis and very high mortality. Many studies reported a wide variety of risk factors associated to heart failure. So, clinical physicians have to face some important decisions, such as, optimal therapeutic option, left ventricular assisted devices, and priority groups for heart transplantation, and prognosis and death risk. Though prognostic models of heart failure are helpful to assess prognosis, different models have their own characteristics, and are suitable for different population. This article introduced several prognostic models of heart failure.%心力衰竭是各种器质性心脏病的终末阶段,其治疗难度大、预后差、死亡率高。已有很多研究分析了心力衰竭的危险因素。选择正确的治疗措施,识别左室辅助装置及心脏移植的优先人群,正确判断预后及死亡风险,是临床医师面临的重要问题。心力衰竭的风险预后模型有助于评估预后,但现有模型各有特点,适用于不同人群。本文分别介绍心力衰竭的几种预后评估模型。

  5. Composite Estimation for Single-Index Models with Responses Subject to Detection Limits

    KAUST Repository

    Tang, Yanlin

    2017-11-03

    We propose a semiparametric estimator for single-index models with censored responses due to detection limits. In the presence of left censoring, the mean function cannot be identified without any parametric distributional assumptions, but the quantile function is still identifiable at upper quantile levels. To avoid parametric distributional assumption, we propose to fit censored quantile regression and combine information across quantile levels to estimate the unknown smooth link function and the index parameter. Under some regularity conditions, we show that the estimated link function achieves the non-parametric optimal convergence rate, and the estimated index parameter is asymptotically normal. The simulation study shows that the proposed estimator is competitive with the omniscient least squares estimator based on the latent uncensored responses for data with normal errors but much more efficient for heavy-tailed data under light and moderate censoring. The practical value of the proposed method is demonstrated through the analysis of a human immunodeficiency virus antibody data set.

  6. Evaluating and Quantifying the Climate-Driven Interannual Variability in Global Inventory Modeling and Mapping Studies (GIMMS) Normalized Difference Vegetation Index (NDVI3g) at Global Scales

    Science.gov (United States)

    Zeng, Fanwei; Collatz, George James; Pinzon, Jorge E.; Ivanoff, Alvaro

    2013-01-01

    Satellite observations of surface reflected solar radiation contain informationabout variability in the absorption of solar radiation by vegetation. Understanding thecauses of variability is important for models that use these data to drive land surface fluxesor for benchmarking prognostic vegetation models. Here we evaluated the interannualvariability in the new 30.5-year long global satellite-derived surface reflectance index data,Global Inventory Modeling and Mapping Studies normalized difference vegetation index(GIMMS NDVI3g). Pearsons correlation and multiple linear stepwise regression analyseswere applied to quantify the NDVI interannual variability driven by climate anomalies, andto evaluate the effects of potential interference (snow, aerosols and clouds) on the NDVIsignal. We found ecologically plausible strong controls on NDVI variability by antecedent precipitation and current monthly temperature with distinct spatial patterns. Precipitation correlations were strongest for temperate to tropical water limited herbaceous systemswhere in some regions and seasons 40 of the NDVI variance could be explained byprecipitation anomalies. Temperature correlations were strongest in northern mid- to-high-latitudes in the spring and early summer where up to 70 of the NDVI variance was explained by temperature anomalies. We find that, in western and central North America,winter-spring precipitation determines early summer growth while more recent precipitation controls NDVI variability in late summer. In contrast, current or prior wetseason precipitation anomalies were correlated with all months of NDVI in sub-tropical herbaceous vegetation. Snow, aerosols and clouds as well as unexplained phenomena still account for part of the NDVI variance despite corrections. Nevertheless, this study demonstrates that GIMMS NDVI3g represents real responses of vegetation to climate variability that are useful for global models.

  7. Validation of an Austrian forecasting model for biologically effective UV radiation (UV index); Validierung des oesterreichischen Vorhersagemodells fuer die biologisch-effektive UV Strahlung (UV Index)

    Energy Technology Data Exchange (ETDEWEB)

    Schauberger, G.; Schmalwieser, A. [Veterinaermedizinische Univ., Vienna (Austria). Inst. fuer Medizinische Physik

    1999-07-01

    Since October 1995 there has been an Austrian forecasting service for the next day's UV index for the three model domains Austria, Europe and world. This forecasting model uses spectral irradiation intensity data measured for 16 specific wavelengths, taking into account solar altitude, height above sea level and atmospheric ozone concentration. Weighting spectral irradiation intensity according to the spectral erythematous effect curve yields a measure of biologically effective UV radiation, and subsequent normalisation with respect to 25 mW{sub biol}/m-2 relates the result to the dimension figure for the UV index. The model has been validated by means of data obtained by continuous measurement with Robertson-Berger measuring devices (site of the Vienna Veterinary Hospital: 48 15 15.47'N; 16 25.98E; elevation 153 amsl). The spectral sensitivity of these instruments is approximately the same as that of the human skin to reddening. Combining the UV index with the expected UV dose for the day permits issuing recommendations for the most suitable sun protection factor in sunblock creams as a function of users' photobiological skin type. Users of the UV index are expected to have enough personal initiative to select the UV index that most closely corresponds to their local population situation. According to the principles of UV radiation protection the performance of the model is considered poor if the measured UV index is greater than the forecast index. This happens in approx. 12% of all cases. The error frequency of positive errors (forecast values greater than measured values) reflects the degree to which extinction of UV radiation through the population occurs, as the present model does not take this factor into account. [German] Seit Oktober 1995 wird in Oesterreich taeglich eine Prognose des UV-Index fuer die drei Modelldomaenen: Oesterreich, Europa und weltweit, geltend fuer den darauf folgenden Tag, erstellt. Das oesterreichische Prognosemodell

  8. Index-based groundwater vulnerability mapping models using hydrogeological settings: A critical evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Prashant, E-mail: prashantkumar@csio.res.in [CSIR-Central Scientific Instruments Organisation, Chandigarh 160030 (India); Academy of Scientific and Innovative Research—CSIO, Chandigarh 160030 (India); Bansod, Baban K.S.; Debnath, Sanjit K. [CSIR-Central Scientific Instruments Organisation, Chandigarh 160030 (India); Academy of Scientific and Innovative Research—CSIO, Chandigarh 160030 (India); Thakur, Praveen Kumar [Indian Institute of Remote Sensing (ISRO), Dehradun 248001 (India); Ghanshyam, C. [CSIR-Central Scientific Instruments Organisation, Chandigarh 160030 (India); Academy of Scientific and Innovative Research—CSIO, Chandigarh 160030 (India)

    2015-02-15

    Groundwater vulnerability maps are useful for decision making in land use planning and water resource management. This paper reviews the various groundwater vulnerability assessment models developed across the world. Each model has been evaluated in terms of its pros and cons and the environmental conditions of its application. The paper further discusses the validation techniques used for the generated vulnerability maps by various models. Implicit challenges associated with the development of the groundwater vulnerability assessment models have also been identified with scientific considerations to the parameter relations and their selections. - Highlights: • Various index-based groundwater vulnerability assessment models have been discussed. • A comparative analysis of the models and its applicability in different hydrogeological settings has been discussed. • Research problems of underlying vulnerability assessment models are also reported in this review paper.

  9. Matching-index-of-refraction of transparent 3D printing models for flow visualization

    Energy Technology Data Exchange (ETDEWEB)

    Song, Min Seop; Choi, Hae Yoon; Seong, Jee Hyun; Kim, Eung Soo, E-mail: kes7741@snu.ac.kr

    2015-04-01

    Matching-index-of-refraction (MIR) has been used for obtaining high-quality flow visualization data for the fundamental nuclear thermal-hydraulic researches. By this method, distortions of the optical measurements such as PIV and LDV have been successfully minimized using various combinations of the model materials and the working fluids. This study investigated a novel 3D printing technology for manufacturing models and an oil-based working fluid for matching the refractive indices. Transparent test samples were fabricated by various rapid prototyping methods including selective layer sintering (SLS), stereolithography (SLA), and vacuum casting. As a result, the SLA direct 3D printing was evaluated to be the most suitable for flow visualization considering manufacturability, transparency, and refractive index. In order to match the refractive indices of the 3D printing models, a working fluid was developed based on the mixture of herb essential oils, which exhibit high refractive index, high transparency, high density, low viscosity, low toxicity, and low price. The refractive index and viscosity of the working fluid range 1.453–1.555 and 2.37–6.94 cP, respectively. In order to validate the MIR method, a simple test using a twisted prism made by the SLA technique and the oil mixture (anise and light mineral oil) was conducted. The experimental results show that the MIR can be successfully achieved at the refractive index of 1.51, and the proposed MIR method is expected to be widely used for flow visualization studies and CFD validation for the nuclear thermal-hydraulic researches.

  10. Prediction of outcome after moderate and severe traumatic brain injury: External validation of the International Mission on Prognosis and Analysis of Clinical Trials (IMPACT) and Corticoid Randomisation after Significant Head injury (CRASH) prognostic models

    NARCIS (Netherlands)

    B. Roozenbeek (Bob); H.F. Lingsma (Hester); F.E. Lecky (Fiona); J. Lu (Juan); J. Weir (James); I. Butcher (Isabella); G.S. McHugh (Gillian); G.D. Murray (Gordon); P. Perel (Pablo); A.I.R. Maas (Andrew); E.W. Steyerberg (Ewout)

    2012-01-01

    textabstractObjective: The International Mission on Prognosis and Analysis of Clinical Trials and Corticoid Randomisation After Significant Head injury prognostic models predict outcome after traumatic brain injury but have not been compared in large datasets. The objective of this is study is to

  11. Model of Recommendation System for for Indexing and Retrieving the Learning Object based on Multiagent System

    Directory of Open Access Journals (Sweden)

    Ronaldo Lima Rocha Campos

    2012-07-01

    Full Text Available This paper proposes a multiagent system application model for indexing, retrieving and recommendation learning objects stored in different and heterogeneous repositories. The objects within these repositories are described by filled fields using different metadata standards. The searching mechanism covers several different learning object repositories and the same object can be described in these repositories by the use of different types of fields. Aiming to improve accuracy and coverage in terms of recovering a learning object and improve the signification of the results we propose an information retrieval model based on the multiagent system approach and an ontological model to describe the knowledge domain covered.

  12. Partially Linear Single Index Cox Regression Model in Nested Case-Control Studies.

    Science.gov (United States)

    Shang, Shulian; Liu, Mengling; Zeleniuch-Jacquotte, Anne; Clendenen, Tess V; Krogh, Vittorio; Hallmans, Goran; Lu, Wenbin

    2013-11-01

    The nested case-control (NCC) design is widely used in epidemiologic studies as a cost-effective subcohort sampling method to study the association between a disease and its potential risk factors. NCC data are commonly analyzed using Thomas' partial likelihood approach under the Cox proportional hazards model assumption. However, the linear modeling form in the Cox model may be insufficient for practical applications, especially when there are a large number of risk factors under investigation. In this paper, we consider a partially linear single index proportional hazard model, which includes a linear component for covariates of interest to yield easily interpretable results and a nonparametric single index component to adjust for multiple confounders effectively. We propose to approximate the nonparametric single index function by polynomial splines and estimate the parameters of interest using an iterative algorithm based on the partial likelihood. Asymptotic properties of the resulting estimators are established. The proposed methods are evaluated using simulations and applied to an NCC study of ovarian cancer.

  13. A Distributed Approach to System-Level Prognostics

    Science.gov (United States)

    Daigle, Matthew J.; Bregon, Anibal; Roychoudhury, Indranil

    2012-01-01

    Prognostics, which deals with predicting remaining useful life of components, subsystems, and systems, is a key technology for systems health management that leads to improved safety and reliability with reduced costs. The prognostics problem is often approached from a component-centric view. However, in most cases, it is not specifically component lifetimes that are important, but, rather, the lifetimes of the systems in which these components reside. The system-level prognostics problem can be quite difficult due to the increased scale and scope of the prognostics problem and the relative Jack of scalability and efficiency of typical prognostics approaches. In order to address these is ues, we develop a distributed solution to the system-level prognostics problem, based on the concept of structural model decomposition. The system model is decomposed into independent submodels. Independent local prognostics subproblems are then formed based on these local submodels, resul ting in a scalable, efficient, and flexible distributed approach to the system-level prognostics problem. We provide a formulation of the system-level prognostics problem and demonstrate the approach on a four-wheeled rover simulation testbed. The results show that the system-level prognostics problem can be accurately and efficiently solved in a distributed fashion.

  14. Assessing the cost effectiveness of using prognostic biomarkers with decision models: case study in prioritising patients waiting for coronary artery surgery.

    Science.gov (United States)

    Henriksson, Martin; Palmer, Stephen; Chen, Ruoling; Damant, Jacqueline; Fitzpatrick, Natalie K; Abrams, Keith; Hingorani, Aroon D; Stenestrand, Ulf; Janzon, Magnus; Feder, Gene; Keogh, Bruce; Shipley, Martin J; Kaski, Juan-Carlos; Timmis, Adam; Sculpher, Mark; Hemingway, Harry

    2010-01-19

    To determine the effectiveness and cost effectiveness of using information from circulating biomarkers to inform the prioritisation process of patients with stable angina awaiting coronary artery bypass graft surgery. Decision analytical model comparing four prioritisation strategies without biomarkers (no formal prioritisation, two urgency scores, and a risk score) and three strategies based on a risk score using biomarkers: a routinely assessed biomarker (estimated glomerular filtration rate), a novel biomarker (C reactive protein), or both. The order in which to perform coronary artery bypass grafting in a cohort of patients was determined by each prioritisation strategy, and mean lifetime costs and quality adjusted life years (QALYs) were compared. Swedish Coronary Angiography and Angioplasty Registry (9935 patients with stable angina awaiting coronary artery bypass grafting and then followed up for cardiovascular events after the procedure for 3.8 years), and meta-analyses of prognostic effects (relative risks) of biomarkers. The observed risk of cardiovascular events while on the waiting list for coronary artery bypass grafting was 3 per 10,000 patients per day within the first 90 days (184 events in 9935 patients). Using a cost effectiveness threshold of pound20,000- pound30,000 (euro22,000-euro33,000; $32,000-$48,000) per additional QALY, a prioritisation strategy using a risk score with estimated glomerular filtration rate was the most cost effective strategy (cost per additional QALY was < pound410 compared with the Ontario urgency score). The impact on population health of implementing this strategy was 800 QALYs per 100,000 patients at an additional cost of pound 245,000 to the National Health Service. The prioritisation strategy using a risk score with C reactive protein was associated with lower QALYs and higher costs compared with a risk score using estimated glomerular filtration rate. Evaluating the cost effectiveness of prognostic biomarkers is

  15. Development of JPSS VIIRS Global Gridded Vegetation Index products for NOAA NCEP Environmental Modeling Systems

    Science.gov (United States)

    Vargas, Marco; Miura, Tomoaki; Csiszar, Ivan; Zheng, Weizhong; Wu, Yihua; Ek, Michael

    2017-04-01

    The first Joint Polar Satellite System (JPSS) mission, the Suomi National Polar-orbiting Partnership (S-NPP) satellite, was successfully launched in October, 2011, and it will be followed by JPSS-1, slated for launch in 2017. JPSS provides operational continuity of satellite-based observations and products for NOAA's Polar Operational Environmental Satellites (POES). Vegetation products derived from satellite measurements are used for weather forecasting, land modeling, climate research, and monitoring the environment including drought, the health of ecosystems, crop monitoring and forest fires. The operationally produced S-NPP VIIRS Vegetation Index (VI) Environmental Data Record (EDR) includes two vegetation indices: the Top of the Atmosphere (TOA) Normalized Difference Vegetation Index (NDVI), and the Top of the Canopy (TOC) Enhanced Vegetation Index (EVI). For JPSS-1, the S-NPP Vegetation Index EDR algorithm has been updated to include the TOC NDV. The current JPSS operational VI products are generated in granule style at 375 meter resolution at nadir, but these products in granule format cannot be ingested into NOAA operational monitoring and decision making systems. For that reason, the NOAA JPSS Land Team is developing a new global gridded Vegetation Index (VI) product suite for operational use by the NOAA National Centers for Environmental Prediction (NCEP). The new global gridded VIs will be used in the Multi-Physics (MP) version of the Noah land surface model (Noah-MP) in NCEP NOAA Environmental Modeling System (NEMS) for plant growth and data assimilation and to describe vegetation coverage and density in order to model the correct surface energy partition. The new VI 4km resolution global gridded products (TOA NDVI, TOC NDVI and TOC EVI) are being designed to meet the needs of directly ingesting vegetation index variables without the need to develop local gridding and compositing procedures. These VI products will be consistent with the already

  16. Community-Wide Validation of Geospace Model Local K-Index Predictions to Support Model Transition to Operations

    Science.gov (United States)

    Glocer, A.; Rastaetter, L.; Kuznetsova, M.; Pulkkinen, A.; Singer, H. J.; Balch, C.; Weimer, D.; Welling, D.; Wiltberger, M.; Raeder, J.; hide

    2016-01-01

    We present the latest result of a community-wide space weather model validation effort coordinated among the Community Coordinated Modeling Center (CCMC), NOAA Space Weather Prediction Center (SWPC), model developers, and the broader science community. Validation of geospace models is a critical activity for both building confidence in the science results produced by the models and in assessing the suitability of the models for transition to operations. Indeed, a primary motivation of this work is supporting NOAA/SWPCs effort to select a model or models to be transitioned into operations. Our validation efforts focus on the ability of the models to reproduce a regional index of geomagnetic disturbance, the local K-index. Our analysis includes six events representing a range of geomagnetic activity conditions and six geomagnetic observatories representing midlatitude and high-latitude locations. Contingency tables, skill scores, and distribution metrics are used for the quantitative analysis of model performance. We consider model performance on an event-by-event basis, aggregated over events, at specific station locations, and separated into high-latitude and midlatitude domains. A summary of results is presented in this report, and an online tool for detailed analysis is available at the CCMC.

  17. Application of DOI index to analysis of selected examples of resistivity imaging models in Quaternary sediments

    Directory of Open Access Journals (Sweden)

    Glazer Michał

    2014-12-01

    Full Text Available Interpretation of resistivity cross sections may be in many cases unreliable due to the presence of artifacts left by the inversion process. One way to avoid erroneous conclusions about geological structure is creation of Depth of Investigation (DOI index maps, which describe durability of prepared model with respect to variable parameters of inversion. To assess the usefulness of this interpretation methodology in resistivity imaging method over quaternary sediments, it has been used to one synthetic data set and three investigation sites. Two of the study areas were placed in the Upper Silesian Industrial District region: Bytom - Karb, Chorzów - Chorzow Stary; and one in the Southern Pomeranian Lake District across Piława River Valley. Basing on the available geological information the results show high utility of DOI index in analysis of received resistivity models, on which areas poorly constrained by data has been designated.

  18. Science dynamics and research production indicators, indexes, statistical laws and mathematical models

    CERN Document Server

    Vitanov, Nikolay K

    2016-01-01

    This book deals with methods to evaluate scientific productivity. In the book statistical methods, deterministic and stochastic models and numerous indexes are discussed that will help the reader to understand the nonlinear science dynamics and to be able to develop or construct systems for appropriate evaluation of research productivity and management of research groups and organizations. The dynamics of science structures and systems is complex, and the evaluation of research productivity requires a combination of qualitative and quantitative methods and measures. The book has three parts. The first part is devoted to mathematical models describing the importance of science for economic growth and systems for the evaluation of research organizations of different size. The second part contains descriptions and discussions of numerous indexes for the evaluation of the productivity of researchers and groups of researchers of different size (up to the comparison of research productivities of research communiti...

  19. Modeling Philippine Stock Exchange Composite Index Using Weighted Geometric Brownian Motion Forecasts

    Directory of Open Access Journals (Sweden)

    Gayo Willy

    2016-01-01

    Full Text Available Philippine Stock Exchange Composite Index (PSEi is the main stock index of the Philippine Stock Exchange (PSE. PSEi is computed using a weighted mean of the top 30 publicly traded companies in the Philippines, called component stocks. It provides a single value by which the performance of the Philippine stock market is measured. Unfortunately, these weights, which may vary for every trading day, are not disclosed by the PSE. In this paper, we propose a model of forecasting the PSEi by estimating the weights based on historical data and forecasting each component stock using Monte Carlo simulation based on a Geometric Brownian Motion (GBM assumption. The model performance is evaluated and its forecast compared is with the results using a direct GBM forecast of PSEi over different forecast periods. Results showed that the forecasts using WGBM will yield smaller error compared to direct GBM forecast of PSEi.

  20. PROBADO3D – Towards an automatic multimedia indexing workflow for architectural 3D models

    OpenAIRE

    R. Berndt; I. Blümel; R. Wessel

    2010-01-01

    In this paper, we describe a repository for architectural 3D-CAD models which is currently set up at the German National Library of Science and Technology (TIB), Hannover, as part of the larger German PROBADO digital library initiative: The proposed PROBADO-framework is integrating different types of multimedia content-repositories and adding features available in text-based digital libraries. A workflow for automated content-based data analysis and indexing is proposed.

  1. Prognostics of Power MOSFET

    Data.gov (United States)

    National Aeronautics and Space Administration — This paper demonstrates how to apply prognostics to power MOSFETs (metal oxide field effect transistor). The methodology uses thermal cycling to age devices and...

  2. Determining the Best Arch/Garch Model and Comparing JKSE with Stock Index in Developed Countries

    Directory of Open Access Journals (Sweden)

    Kharisya Ayu Effendi

    2015-09-01

    Full Text Available The slow movement of Indonesia economic growth in 2014 due to several factors, in internal factors; due to the high interest rates in Indonesia and external factors from the US which will raise the fed rate this year. However, JKSE shows a sharp increase trend from the beginning of 2014 until the second quarter of 2015 although it remains fluctuate but insignificant. The purpose of this research is to determine the best ARCH/ GARCH model in JKSE and stock index in developed countries (FTSE, Nasdaq and STI and then compare the JKSE with the stock index in developed countries (FTSE, Nasdaq and STI. The results obtained in this study is to determine the best model of ARCH / GARCH, it is obtained that JKSE is GARCH (1,2, while the FTSE obtains GARCH (2,2, NASDAQ produces the best model which is GARCH (1,1 and STI with GARCH (2,1, and the results of the comparison of JKSE with FTSE, NASDAQ and STI are that even though JKSE fluctuates with moderate levels but the trend shown upward trend. This is different with other stock indexes fluctuated highly and tends to have a downward trend.

  3. Modeling Travel Time Reliability of Road Network Considering Connected Vehicle Guidance Characteristics Indexes

    Directory of Open Access Journals (Sweden)

    Jiangfeng Wang

    2017-01-01

    Full Text Available Travel time reliability (TTR is one of the important indexes for effectively evaluating the performance of road network, and TTR can effectively be improved using the real-time traffic guidance information. Compared with traditional traffic guidance, connected vehicle (CV guidance can provide travelers with more timely and accurate travel information, which can further improve the travel efficiency of road network. Five CV characteristics indexes are selected as explanatory variables including the Congestion Level (CL, Penetration Rate (PR, Compliance Rate (CR, release Delay Time (DT, and Following Rate (FR. Based on the five explanatory variables, a TTR model is proposed using the multilogistic regression method, and the prediction accuracy and the impact of characteristics indexes on TTR are analyzed using a CV guidance scenario. The simulation results indicate that 80% of the RMSE is concentrated within the interval of 0 to 0.0412. The correlation analysis of characteristics indexes shows that the influence of CL, PR, CR, and DT on the TTR is significant. PR and CR have a positive effect on TTR, and the average improvement rate is about 77.03% and 73.20% with the increase of PR and CR, respectively, while CL and DT have a negative effect on TTR, and TTR decreases by 31.21% with the increase of DT from 0 to 180 s.

  4. Analytical Modelling of a Refractive Index Sensor Based on an Intrinsic Micro Fabry-Perot Interferometer

    Directory of Open Access Journals (Sweden)

    Everardo Vargas-Rodriguez

    2015-10-01

    Full Text Available In this work a refractive index sensor based on a combination of the non-dispersive sensing (NDS and the Tunable Laser Spectroscopy (TLS principles is presented. Here, in order to have one reference and one measurement channel a single-beam dual-path configuration is used for implementing the NDS principle. These channels are monitored with a couple of identical optical detectors which are correlated to calculate the overall sensor response, called here the depth of modulation. It is shown that this is useful to minimize drifting errors due to source power variations. Furthermore, a comprehensive analysis of a refractive index sensing setup, based on an intrinsic micro Fabry-Perot Interferometer (FPI is described. Here, the changes over the FPI pattern as the exit refractive index is varied are analytically modelled by using the characteristic matrix method. Additionally, our simulated results are supported by experimental measurements which are also provided. Finally it is shown that by using this principle a simple refractive index sensor with a resolution in the order of 2.15 × 10−4 RIU can be implemented by using a couple of standard and low cost photodetectors.

  5. PRELIMINARY INDIVIDUAL TREE GROWTH MODEL, SITE INDEX MODEL «MORTALITY» MODEL FOR ALEPPO PINE (Pinus halepensis MILL. IN CHALKIDIKI (NORTHERN GREECE

    Directory of Open Access Journals (Sweden)

    Kyriaki Kitikidou

    2016-01-01

    Full Text Available Preliminary height models, a volume model, a site index model and a survival analysis for Pinus halepensis Mill. in Chalkidiki (Northern Greece were preliminarily developed based on measurements of 20 experimental plots established in 2010. The data for the height, volume and ‘mortality’ models consisted of 790 observations taken from 40 trees (20 dominant and 20 co-dominant. An equation derived from the hyperbolic function was selected to model the dominant height and the volume development. The height growth model was used as a guide curve to develop two site index curves. Mean dominant and codominant height was estimated at 10m (site I and 7m (site II (base age of 17 years. Kaplan-Meier survival and hazard functions applied for the ‘mortality’ analysis, confirmed the site index curves developed from the height model (SI10 and SI7.

  6. Palliative medicine review: prognostication.

    Science.gov (United States)

    Glare, Paul A; Sinclair, Christian T

    2008-01-01

    Prognostication, along with diagnosis and treatment, is a traditional core clinical skill of the physician. Many patients and families receiving palliative care want information about life expectancy to help plan realistically for their futures. Although underappreciated, prognosis is, or at least should be, part of every clinical decision. Despite this crucial role, expertise in the art and science of prognostication diminished during the twentieth century, due largely to the ascendancy of accurate diagnostic tests and effective therapies. Consequently, "Doctor, how long do I have?" is a question most physicians find unprepared to answer effectively. As we focus on palliative care in the twenty-first century, prognostication will need to be restored as a core clinical proficiency. The discipline of palliative medicine can provide leadership in this direction. This paper begins by discussing a framework for understanding prognosis and how its different domains might be applied to all patients with life limiting illness, although the main focus of the paper is predicting survival in patients with cancer. Examples of prognostic tools are provided, although the subjective assessment of prognosis remains important in the terminally ill. Other issues addressed include: the importance of prognostication in terms of clinical decision-making, discharge planning, and care planning; the impact of prognosis on hospice referrals and patient/family satisfaction; and physicians' willingness to prognosticate.

  7. Prognostic Model for Resected Squamous-Cell Lung Cancer: External Multicenter Validation and Propensity Score Analysis exploring the Impact of Adjuvant and Neoadjuvant Treatment.

    Science.gov (United States)

    Pilotto, Sara; Sperduti, Isabella; Leuzzi, Giovanni; Chiappetta, Marco; Mucilli, Felice; Ratto, Giovanni Battista; Lococo, Filippo; Filosso, Pierluigi; Spaggiari, Lorenzo; Novello, Silvia; Milella, Michele; Santo, Antonio; Scarpa, Aldo; Infante, Maurizio; Tortora, Giampaolo; Facciolo, Francesco; Bria, Emilio

    2017-12-18

    We developed one of the first clinicopathological prognostic nomograms for resected squamous cell lung cancer (SQLC). Herein, we validate the model in a larger multicenter cohort and we explore the impact of adjuvant/neoadjuvant treatment (ANT). Resected SQLC patients from January 2002 to December 2012 in six institutions were eligible. To each patient was assigned a prognostic score based on those clinicopathological factors included in the model (age, T-descriptor according to TNM 7th edition, lymph nodes, grading). Kaplan-Meier analysis for disease-free/cancer-specific/overall survival (DFS/CSS/OS) was performed according to three-class risk model. Harrell's C-statistics were adopted for model validation. The effect of ANT was adjusted with propensity score (PS). Data from 1,375 patients was gathered (median age: 68 years; male: 86.8%; T-descriptor 1-2/3-4: 71.7%/24.9%; nodes negative/positive: 53.4%/46.6%; grading 1-2/3: 35.0%/41.1%). Data for survival analysis was available for 1,097 patients. With a median follow-up of 55 months, patients at low risk had a significantly longer DFS versus intermediate (HR 1.67, 95% CI 1.40-2.01) and high risk (HR 2.46, 95% CI 1.90-3.19), as well as for CSS (HR 2.46, 95% CI 1.80-3.36; HR 4.30, 95% CI 2.92-6.33) and OS (HR 1.79, 95% CI 1.48-2.17; HR 2.33, 95% CI 1.76-3.07). A trend in favor of ANT was observed for intermediate/high risk patients, particularly for CSS (p=0.06; 5-year CSS 72.7% versus 60.8%). A model based on a combination of easily available clinicopathological factors effectively stratifies resected SQLC patients in three-risk classes. Copyright © 2017 International Association for the Study of Lung Cancer. Published by Elsevier Inc. All rights reserved.

  8. Survival after resection of perihilar cholangiocarcinoma-development and external validation of a prognostic nomogram.

    Science.gov (United States)

    Groot Koerkamp, B; Wiggers, J K; Gonen, M; Doussot, A; Allen, P J; Besselink, M G H; Blumgart, L H; Busch, O R C; D'Angelica, M I; DeMatteo, R P; Gouma, D J; Kingham, T P; van Gulik, T M; Jarnagin, W R

    2015-09-01

    The objective of this study was to derive and validate a prognostic nomogram to predict disease-specific survival (DSS) after a curative intent resection of perihilar cholangiocarcinoma (PHC). A nomogram was developed from 173 patients treated at Memorial Sloan Kettering Cancer Center (MSKCC), New York, USA. The nomogram was externally validated in 133 patients treated at the Academic Medical Center (AMC), Amsterdam, The Netherlands. Prognostic accuracy was assessed with concordance estimates and calibration, and compared with the American Joint Committee on Cancer (AJCC) staging system. The nomogram will be available as web-based calculator at mskcc.org/nomograms. For all 306 patients, the median overall survival (OS) was 40 months and the median DSS 41 months. Median follow-up for patients alive at last follow-up was 48 months. Lymph node involvement, resection margin status, and tumor differentiation were independent prognostic factors in the derivation cohort (MSKCC). A nomogram with these prognostic factors had a concordance index of 0.73 compared with 0.66 for the AJCC staging system. In the validation cohort (AMC), the concordance index was 0.72, compared with 0.60 for the AJCC staging system. Calibration was good in the derivation cohort; in the validation cohort patients had a better median DSS than predicted by the model. The proposed nomogram to predict DSS after curative intent resection of PHC had a better prognostic accuracy than the AJCC staging system. Calibration was suboptimal because DSS differed between the two institutions. The nomogram can inform patients and physicians, guide shared decision making for adjuvant therapy, and stratify patients in future randomized, controlled trials. © The Author 2015. Published by Oxford University Press on behalf of the European Society for Medical Oncology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  9. Management Index Systems and Energy Efficiency Diagnosis Model for Power Plant: Cases in China

    Directory of Open Access Journals (Sweden)

    Jing-Min Wang

    2016-01-01

    Full Text Available In recent years, the energy efficiency of thermal power plant largely contributes to that of the industry. A thorough understanding of influencing factors, as well as the establishment of scientific and comprehensive diagnosis model, plays a key role in the operational efficiency and competitiveness for the thermal power plant. Referring to domestic and abroad researches towards energy efficiency management, based on Cloud model and data envelopment analysis (DEA model, a qualitative and quantitative index system and a comprehensive diagnostic model (CDM are construed. To testify rationality and usability of CDM, case studies of large-scaled Chinese thermal power plants have been conducted. In this case, CDM excavates such qualitative factors as technology, management, and so forth. The results shows that, compared with conventional model, which only considered production running parameters, the CDM bears better adaption to reality. It can provide entities with efficient instruments for energy efficiency diagnosis.

  10. A method to create simplified versions of existing habitat suitability index (HSI) models

    Science.gov (United States)

    Wakeley, James S.

    1988-01-01

    The habitat evaluation procedures (HEP), developed by the US Fish and Wildlife Service, are widely used in the United States to determine the impacts of major construction projects on fish and wildlife habitats. HEP relies heavily on habitat suitability index (HSI) models that use measurements of important habitat characteristics to rate habitat quality for a species on a scale of 0 (unsuitable) to 1.0 (optimal). This report describes a method to simplify existing HSI models to reduce the time and expense involved in sampling habitat variables. Simplified models for three species produced HSI values within 0.2 of those predicted by the original models 90% of the time. Simplified models are particularly useful for rapid habitat inventories and evaluations, wildlife management, and impact assessments in extensive areas or with limited time and personnel.

  11. Vehicle Integrated Prognostic Reasoner (VIPR) Metric Report

    Science.gov (United States)

    Cornhill, Dennis; Bharadwaj, Raj; Mylaraswamy, Dinkar

    2013-01-01

    This document outlines a set of metrics for evaluating the diagnostic and prognostic schemes developed for the Vehicle Integrated Prognostic Reasoner (VIPR), a system-level reasoner that encompasses the multiple levels of large, complex systems such as those for aircraft and spacecraft. VIPR health managers are organized hierarchically and operate together to derive diagnostic and prognostic inferences from symptoms and conditions reported by a set of diagnostic and prognostic monitors. For layered reasoners such as VIPR, the overall performance cannot be evaluated by metrics solely directed toward timely detection and accuracy of estimation of the faults in individual components. Among other factors, overall vehicle reasoner performance is governed by the effectiveness of the communication schemes between monitors and reasoners in the architecture, and the ability to propagate and fuse relevant information to make accurate, consistent, and timely predictions at different levels of the reasoner hierarchy. We outline an extended set of diagnostic and prognostics metrics that can be broadly categorized as evaluation measures for diagnostic coverage, prognostic coverage, accuracy of inferences, latency in making inferences, computational cost, and sensitivity to different fault and degradation conditions. We report metrics from Monte Carlo experiments using two variations of an aircraft reference model that supported both flat and hierarchical reasoning.

  12. Generalized least squares and empirical Bayes estimation in regional partial duration series index-flood modeling

    DEFF Research Database (Denmark)

    Madsen, Henrik; Rosbjerg, Dan

    1997-01-01

    A regional estimation procedure that combines the index-flood concept with an empirical Bayes method for inferring regional information is introduced. The model is based on the partial duration series approach with generalized Pareto (GP) distributed exceedances. The prior information of the model...... families of prior distributions. The regional method is applied to flood records from 48 New Zealand catchments. In the case of a strongly heterogeneous intersite correlation structure, the GLS procedure provides a more efficient estimate of the regional GP shape parameter as compared to the usually...

  13. Numerical Modeling of Limiting Oxygen Index Apparatus for Film Type Fuels

    Directory of Open Access Journals (Sweden)

    Amit Kumar

    2012-12-01

    Full Text Available A detailed three-dimensional numerical model is used to compute the flow pattern and the flame behavior of thin solid fuels in a rectangular column that resembles a standard Limiting Oxygen Index (LOI device. The model includes full Navier-Stokes equations for mixed buoyant-forced flow and finite rate combustion and pyrolysis reactions so that the sample LOI can be computed to study the effect of feeding flow rate, sample width and gravity levels. In addition to the above parameters, the sample location in the column and the column cross-sectional area are also investigated on their effect on the ambient air entrainment from the top.

  14. Daily air quality index forecasting with hybrid models: A case in China.

    Science.gov (United States)

    Zhu, Suling; Lian, Xiuyuan; Liu, Haixia; Hu, Jianming; Wang, Yuanyuan; Che, Jinxing

    2017-12-01

    Air quality is closely related to quality of life. Air pollution forecasting plays a vital role in air pollution warnings and controlling. However, it is difficult to attain accurate forecasts for air pollution indexes because the original data are non-stationary and chaotic. The existing forecasting methods, such as multiple linear models, autoregressive integrated moving average (ARIMA) and support vector regression (SVR), cannot fully capture the information from series of pollution indexes. Therefore, new effective techniques need to be proposed to forecast air pollution indexes. The main purpose of this research is to develop effective forecasting models for regional air quality indexes (AQI) to address the problems above and enhance forecasting accuracy. Therefore, two hybrid models (EMD-SVR-Hybrid and EMD-IMFs-Hybrid) are proposed to forecast AQI data. The main steps of the EMD-SVR-Hybrid model are as follows: the data preprocessing technique EMD (empirical mode decomposition) is utilized to sift the original AQI data to obtain one group of smoother IMFs (intrinsic mode functions) and a noise series, where the IMFs contain the important information (level, fluctuations and others) from the original AQI series. LS-SVR is applied to forecast the sum of the IMFs, and then, S-ARIMA (seasonal ARIMA) is employed to forecast the residual sequence of LS-SVR. In addition, EMD-IMFs-Hybrid first separately forecasts the IMFs via statistical models and sums the forecasting results of the IMFs as EMD-IMFs. Then, S-ARIMA is employed to forecast the residuals of EMD-IMFs. To certify the proposed hybrid model, AQI data from June 2014 to August 2015 collected from Xingtai in China are utilized as a test case to investigate the empirical research. In terms of some of the forecasting assessment measures, the AQI forecasting results of Xingtai show that the two proposed hybrid models are superior to ARIMA, SVR, GRNN, EMD-GRNN, Wavelet-GRNN and Wavelet-SVR. Therefore, the

  15. Use of remotely sensed precipitation and leaf area index in a distributed hydrological model

    DEFF Research Database (Denmark)

    Andersen, J.; Dybkjær, G.; Jensen, Karsten Høgh

    2002-01-01

    Remotely sensed precipitation from METEOSAT data and leaf area index (LAI) from NOAA AVHRR data is used as input data to the distributed hydrological modelling of three sub catchments (82.000 km(2)) in the Senegal River Basin. Further, root depths of annual vegetation are related to the temporal...... and spatial variation of LAI. The modelling results are compared with results based on conventional input of precipitation and vegetation characteristics. The introduction of remotely sensed LAI shows improvements in the simulated hydrographs, a marked change in the relative proportions of actual...

  16. Binomial Markov-Switching Multifractal model with Skewed t innovations and applications to Chinese SSEC Index

    Science.gov (United States)

    Liu, Yufang; Zhang, Weiguo; Fu, Junhui

    2016-11-01

    This paper presents the Binomial Markov-switching Multifractal (BMSM) model of asset returns with Skewed t innovations (BMSM-Skewed t for short), which considers the fat tails, skewness and multifractality in asset returns simultaneously. The parameters of BMSM-Skewed t model can be estimated by Maximum Likelihood (ML) methods, and volatility forecasting can be accomplished via Bayesian updating. In order to evaluate the performance of BMSM-Skewed t model, BMSM model with Normal innovations (BMSM-N), BMSM model with Student-t innovations (BMSM-t) and GARCH(1,1) models (GARCH-N, GARCH-t and GARCH-Skewed t) are chosen for comparison. Through empirical studies on Shanghai Stock Exchange Composite Index (SSEC), we find that for sample estimation, BMSM models outperform the GARCH(1,1) models through BIC and AIC rules, and BMSM-Skewed t performs the best among all the models due to its fat tails, skewness and multifractality. In addition, BMSM-Skewed t model dominates other models at most forecasting horizons for out-of-sample volatility forecasts in terms of MSE, MAE and SPA test.

  17. Normality index of ventricular contraction based on a statistical model from FADS.

    Science.gov (United States)

    Jiménez-Ángeles, Luis; Valdés-Cristerna, Raquel; Vallejo, Enrique; Bialostozky, David; Medina-Bañuelos, Verónica

    2013-01-01

    Radionuclide-based imaging is an alternative to evaluate ventricular function and synchrony and may be used as a tool for the identification of patients that could benefit from cardiac resynchronization therapy (CRT). In a previous work, we used Factor Analysis of Dynamic Structures (FADS) to analyze the contribution and spatial distribution of the 3 most significant factors (3-MSF) present in a dynamic series of equilibrium radionuclide angiography images. In this work, a probability density function model of the 3-MSF extracted from FADS for a control group is presented; also an index, based on the likelihood between the control group's contraction model and a sample of normal subjects is proposed. This normality index was compared with those computed for two cardiopathic populations, satisfying the clinical criteria to be considered as candidates for a CRT. The proposed normality index provides a measure, consistent with the phase analysis currently used in clinical environment, sensitive enough to show contraction differences between normal and abnormal groups, which suggests that it can be related to the degree of severity in the ventricular contraction dyssynchrony, and therefore shows promise as a follow-up procedure for patients under CRT.

  18. Femtosecond laser fabricated all-optical fiber sensors with ultrahigh refractive index sensitivity: modeling and experiment

    Science.gov (United States)

    Jiang, Lan; Zhao, Longjiang; Wang, Sumei; Yang, Jinpeng; Xiao, Hai

    2011-08-01

    All-optical fiber sensors based on ultracompact fiber inline Mach-Zehnder interferometer (MZI) are fabricated by side-ablating a U-shape microcavity in a single-mode optical fiber with the fiber core partially removed using femtosecond (fs) laser pulses, in which the two light paths are accordingly formed in the remaining D-type fiber core and the U-shape microcavity. Beam propagation method (BPM) analysis is utilized to illustrate the dependences of good transmission spectra on parameters including the ablation depth, ablation length and the refractive index of U-shape micocavity, which gives some guidelines to optimize parameters for fs laser micromachining and predicts RI (refractive index) sensitivities within given RI ranges. The modeling results of ultrahigh RI sensitivities for gases and solutions are -3243.75 ± 0.65nm/RIU (refractive index unit) and -10789.29 ± 18.91nm/RIU, respectively. In RI testing experiments, the sensor exhibits ultrahigh RI sensitivities of -3754.79 ± 44.24nm/RIU with refractive indices ranging from 1.0001143 to 1.0002187 by testing different mixture ratios of N2 and He gases, and -12162.01 ± 173.92nm/RIU with refractive indices ranging from 1.3330 to 1.33801 by testing different concentrations of sucrose solutions, which is essentially in agreement with the modeling results.

  19. Normality Index of Ventricular Contraction Based on a Statistical Model from FADS

    Directory of Open Access Journals (Sweden)

    Luis Jiménez-Ángeles

    2013-01-01

    Full Text Available Radionuclide-based imaging is an alternative to evaluate ventricular function and synchrony and may be used as a tool for the identification of patients that could benefit from cardiac resynchronization therapy (CRT. In a previous work, we used Factor Analysis of Dynamic Structures (FADS to analyze the contribution and spatial distribution of the 3 most significant factors (3-MSF present in a dynamic series of equilibrium radionuclide angiography images. In this work, a probability density function model of the 3-MSF extracted from FADS for a control group is presented; also an index, based on the likelihood between the control group's contraction model and a sample of normal subjects is proposed. This normality index was compared with those computed for two cardiopathic populations, satisfying the clinical criteria to be considered as candidates for a CRT. The proposed normality index provides a measure, consistent with the phase analysis currently used in clinical environment, sensitive enough to show contraction differences between normal and abnormal groups, which suggests that it can be related to the degree of severity in the ventricular contraction dyssynchrony, and therefore shows promise as a follow-up procedure for patients under CRT.

  20. Normality Index of Ventricular Contraction Based on a Statistical Model from FADS

    Science.gov (United States)

    Jiménez-Ángeles, Luis; Valdés-Cristerna, Raquel; Vallejo, Enrique; Bialostozky, David; Medina-Bañuelos, Verónica

    2013-01-01

    Radionuclide-based imaging is an alternative to evaluate ventricular function and synchrony and may be used as a tool for the identification of patients that could benefit from cardiac resynchronization therapy (CRT). In a previous work, we used Factor Analysis of Dynamic Structures (FADS) to analyze the contribution and spatial distribution of the 3 most significant factors (3-MSF) present in a dynamic series of equilibrium radionuclide angiography images. In this work, a probability density function model of the 3-MSF extracted from FADS for a control group is presented; also an index, based on the likelihood between the control group's contraction model and a sample of normal subjects is proposed. This normality index was compared with those computed for two cardiopathic populations, satisfying the clinical criteria to be considered as candidates for a CRT. The proposed normality index provides a measure, consistent with the phase analysis currently used in clinical environment, sensitive enough to show contraction differences between normal and abnormal groups, which suggests that it can be related to the degree of severity in the ventricular contraction dyssynchrony, and therefore shows promise as a follow-up procedure for patients under CRT. PMID:23634177

  1. Modeling and Computing of Stock Index Forecasting Based on Neural Network and Markov Chain

    Directory of Open Access Journals (Sweden)

    Yonghui Dai

    2014-01-01

    Full Text Available The stock index reflects the fluctuation of the stock market. For a long time, there have been a lot of researches on the forecast of stock index. However, the traditional method is limited to achieving an ideal precision in the dynamic market due to the influences of many factors such as the economic situation, policy changes, and emergency events. Therefore, the approach based on adaptive modeling and conditional probability transfer causes the new attention of researchers. This paper presents a new forecast method by the combination of improved back-propagation (BP neural network and Markov chain, as well as its modeling and computing technology. This method includes initial forecasting by improved BP neural network, division of Markov state region, computing of the state transition probability matrix, and the prediction adjustment. Results of the empirical study show that this method can achieve high accuracy in the stock index prediction, and it could provide a good reference for the investment in stock market.

  2. Prognostic radiographic aspects of spondylolisthesis

    Energy Technology Data Exchange (ETDEWEB)

    Saraste, H.; Brostroem, L.A.; Aparisi, T.

    1984-01-01

    A series of 202 patients (133 men, 69 women) with lumbar spondylolysis were examined radiographically on two occasions, first at the time of diagnosis and later at a follow-up, after an observation period of 20 years or more. The films from patients in groups without and with moderate and severe olisthesis were evaluated with respect to variables describing lumbosacral lordosis, wedging of the spondylolytic vertebra, lengths of the transverse processes and iliolumbar ligaments, disk height, progression of slipping, and influence on measured olisthesis of lumbar spine flexion and extension at the radiographic examination. The evaluation was made with special attention to possible signs which could be predictive for the prognosis of vertebral slipping. Progression of slipping did not differ between patients diagnosed as adults or adolescents. Reduction of disk height was correlated to the degree of slipping present at the initial examination and to the progression of olisthesis. Flexion and extension of the lumbar spine did not modify the degree of olisthesis. Data concerning the lengths of the transverse processes and the iliolumbar ligaments, and lumbar lordosis, cannot be used for prognostic purposes. The lumbar index reflecting the degree of wedge deformity of the spondylolytic vertebra was shown to be the only variable of prognostic value for the development of vertebral slipping.

  3. Potential energy landscape of the two-dimensional XY model: Higher-index stationary points

    Science.gov (United States)

    Mehta, D.; Hughes, C.; Kastner, M.; Wales, D. J.

    2014-06-01

    The application of numerical techniques to the study of energy landscapes of large systems relies on sufficient sampling of the stationary points. Since the number of stationary points is believed to grow exponentially with system size, we can only sample a small fraction. We investigate the interplay between this restricted sample size and the physical features of the potential energy landscape for the two-dimensional XY model in the absence of disorder with up to N = 100 spins. Using an eigenvector-following technique, we numerically compute stationary points with a given Hessian index I for all possible values of I. We investigate the number of stationary points, their energy and index distributions, and other related quantities, with particular focus on the scaling with N. The results are used to test a number of conjectures and approximate analytic results for the general properties of energy landscapes.

  4. Prognostic value of cardiac time intervals measured by tissue Doppler imaging M-mode in the general population

    DEFF Research Database (Denmark)

    Biering-Sørensen, Tor; Mogelvang, Rasmus; Jensen, Jan Skov

    2015-01-01

    echocardiographic parameters resulted in a significant increase in the c-statistics (0.76 vs 0.75 pimproved reclassification significantly when added to the clinical predictors (p... adjustment for clinical predictors and conventional echocardiography, only the combined indexes, including information on both systolic and diastolic performance (IVRT/ET and MPI), remained significant prognosticators (pAdding IVRT/ET or MPI to a model already including all other...

  5. A theoretical model of the relationship between the h-index and other simple citation indicators.

    Science.gov (United States)

    Bertoli-Barsotti, Lucio; Lando, Tommaso

    2017-01-01

    Of the existing theoretical formulas for the h-index, those recently suggested by Burrell (J Informetr 7:774-783, 2013b) and by Bertoli-Barsotti and Lando (J Informetr 9(4):762-776, 2015) have proved very effective in estimating the actual value of the h-index Hirsch (Proc Natl Acad Sci USA 102:16569-16572, 2005), at least at the level of the individual scientist. These approaches lead (or may lead) to two slightly different formulas, being based, respectively, on a "standard" and a "shifted" version of the geometric distribution. In this paper, we review the genesis of these two formulas-which we shall call the "basic" and "improved" Lambert-W formula for the h-index-and compare their effectiveness with that of a number of instances taken from the well-known Glänzel-Schubert class of models for the h-index (based, instead, on a Paretian model) by means of an empirical study. All the formulas considered in the comparison are "ready-to-use", i.e., functions of simple citation indicators such as: the total number of publications; the total number of citations; the total number of cited paper; the number of citations of the most cited paper. The empirical study is based on citation data obtained from two different sets of journals belonging to two different scientific fields: more specifically, 231 journals from the area of "Statistics and Mathematical Methods" and 100 journals from the area of "Economics, Econometrics and Finance", totaling almost 100,000 and 20,000 publications, respectively. The citation data refer to different publication/citation time windows, different types of "citable" documents, and alternative approaches to the analysis of the citation process ("prospective" and "retrospective"). We conclude that, especially in its improved version, the Lambert-W formula for the h-index provides a quite robust and effective ready-to-use rule that should be preferred to other known formulas if one's goal is (simply) to derive a reliable estimate of the h-index.

  6. Effect of ageing and Mg content on the quality index of two model Al--Cu--Si--Mg alloys

    Energy Technology Data Exchange (ETDEWEB)

    Caceres, C.H. [Queensland Univ., Brisbane, Qld. (Australia). Dept. of Min., Miner. and Mater. Eng.; Sokolowski, J.H.; Gallo, P. [Department of Mechanical and Materials Engineering, Ford IRC in Light Metals Casting Technology, University of Windsor, Windsor (Canada)

    1999-11-01

    The evolution of the quality index of two Al-1%Cu-4.5%Si--Mg alloys as the materials are aged is examined. When underaged and up to the peak ageing condition the yield strength of the alloys increases while the ductility decreases. The quality index is high and remains approximately constant. At moderate overageing the strength of the alloys decreases rapidly without increase in the ductility and the quality index falls. As the degree of overageing increases the ductility increases again and the quality index tends to increase marginally. The quality index has been related to the material properties using an analytical model. Using this model it is possible to generate a quality index chart that takes into account the change in strain hardening characteristics of the materials with ageing. (orig.)

  7. CONCEPTUAL MODEL OF FINANCIAL INDEXES FOR INFORMATIVE SYSTEM IN NAPS OF UKRAINE

    Directory of Open Access Journals (Sweden)

    Alla V. Kilchenko

    2011-10-01

    Full Text Available The actual task of modern information society forming is a construction and introduction of the information systems in educational management. The article contains the analysis of subject domain of the informative system in the National Academy of Pedagogical Sciences of Ukraine, description of financial documents and facilities for automations of their treatment in the integrated environment of Windows SharePoint Services – Microsoft Word. The conceptual model of information is presented, it is shown, as on its basis facilities of automation of work are built with financial documents. The CRT forms of document life cycle are resulted in the information system: conceptual model of information, logical model of data, physical model of data, template, a document, eventual document with the automatic filling of indexes of financial documents.

  8. Regional drought assessment using a distributed hydrological model coupled with Standardized Runoff Index

    Directory of Open Access Journals (Sweden)

    H. Shen

    2015-05-01

    Full Text Available Drought assessment is essential for coping with frequent droughts nowadays. Owing to the large spatio-temporal variations in hydrometeorology in most regions in China, it is very necessary to use a physically-based hydrological model to produce rational spatial and temporal distributions of hydro-meteorological variables for drought assessment. In this study, the large-scale distributed hydrological model Variable Infiltration Capacity (VIC was coupled with a modified standardized runoff index (SRI for drought assessment in the Weihe River basin, northwest China. The result indicates that the coupled model is capable of reasonably reproducing the spatial distribution of drought occurrence. It reflected the spatial heterogeneity of regional drought and improved the physical mechanism of SRI. This model also has potential for drought forecasting, early warning and mitigation, given that accurate meteorological forcing data are available.

  9. Scalability of the muscular action in a parametric 3D model of the index finger.

    Science.gov (United States)

    Sancho-Bru, Joaquín L; Vergara, Margarita; Rodríguez-Cervantes, Pablo-Jesús; Giurintano, David J; Pérez-González, Antonio

    2008-01-01

    A method for scaling the muscle action is proposed and used to achieve a 3D inverse dynamic model of the human finger with all its components scalable. This method is based on scaling the physiological cross-sectional area (PCSA) in a Hill muscle model. Different anthropometric parameters and maximal grip force data have been measured and their correlations have been analyzed and used for scaling the PCSA of each muscle. A linear relationship between the normalized PCSA and the product of the length and breadth of the hand has been finally used for scaling, with a slope of 0.01315 cm(-2), with the length and breadth of the hand expressed in centimeters. The parametric muscle model has been included in a parametric finger model previously developed by the authors, and it has been validated reproducing the results of an experiment in which subjects from different population groups exerted maximal voluntary forces with their index finger in a controlled posture.

  10. Prognostic value of tumor necrosis at CT in diffuse large B-cell lymphoma.

    Science.gov (United States)

    Adams, Hugo J A; de Klerk, John M H; Fijnheer, Rob; Dubois, Stefan V; Nievelstein, Rutger A J; Kwee, Thomas C

    2015-03-01

    To determine the prognostic value of tumor necrosis at computed tomography (CT) in newly diagnosed diffuse large B-cell lymphoma (DLBCL). This retrospective study included 51 patients with newly diagnosed DLBCL who had undergone both unenhanced and intravenous contrast-enhanced CT before R-CHOP (rituximab, cyclophosphamide, hydroxydaunorubicin, oncovin and prednisolone) chemo-immunotherapy. Presence of tumor necrosis was visually and quantitatively assessed at CT. Associations between tumor necrosis status at CT and the National Comprehensive Cancer Network (NCCN) International Prognostic Index (IPI) factors were assessed. Cox regression analysis was used to determine the prognostic impact of NCCN-IPI scores and tumor necrosis status at CT. There were no correlations between tumor necrosis status at CT and the NCCN-IPI factors categorized age (ρ=-0.042, P=0.765), categorized lactate dehydrogenase (LDH) ratio (ρ=0.201, P=0.156), extranodal disease in major organs (φ=-0.245, P=0.083), Ann Arbor stage III/IV disease (φ=-0.208, P=0.141), and Eastern Cooperative Oncology Group (ECOG) performance status (φ=0.015, P=0.914). In the multivariate Cox proportional hazards model, only tumor necrosis status at CT was an independent predictive factor of progression-free survival (P=0.003) and overall survival (P=0.004). The findings of this study indicate the prognostic potential of tumor necrosis at CT in newly diagnosed DLBCL. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  11. Implementing targeted expectant management in fertility care using prognostic modelling: a cluster randomized trial with a multifaceted strategy.

    Science.gov (United States)

    Kersten, F A M; Nelen, W L D M; van den Boogaard, N M; van Rumste, M M; Koks, C A; IntHout, J; Verhoeve, H R; Pelinck, M J; Boks, D E S; Gianotten, J; Broekmans, F J M; Goddijn, M; Braat, D D M; Mol, B W J; Hermens, R P G M

    2017-08-01

    What is the effectiveness of a multifaceted implementation strategy compared to usual care on improving the adherence to guideline recommendations on expectant management for couples with unexplained infertility? The multifaceted implementation strategy did not significantly increase adherence to guideline recommendations on expectant management compared to care as usual. Intrauterine insemination (IUI) with or without ovarian hyperstimulation has no beneficial effect compared to no treatment for 6 months after the fertility work-up for couples with unexplained infertility and a good prognosis of natural conception. Therefore, various professionals and policy makers have advocated the use of prognostic profiles and expectant management in guideline recommendations. A cluster randomized controlled trial in 25 clinics in the Netherlands was conducted between March 2013 and May 2014. Clinics were randomized between the implementation strategy (intervention, n = 13) and care as usual (control, n = 12). The effect of the implementation strategy was evaluated by comparing baseline and effect measurement data. Data collection was retrospective and obtained from medical record research and a patient questionnaire. A total of 544 couples were included at baseline and 485 at the effect measurement (247 intervention group/238 control group). Guideline adherence increased from 49 to 69% (OR 2.66; 95% CI 1.45-4.89) in the intervention group, and from 49 to 61% (OR 2.03; 95% CI 1.38-3.00) in the control group. Multilevel analysis with case-mix adjustment showed that the difference of 8% was not statistically significant (OR 1.31; 95% CI 0.67-2.59). The ongoing pregnancy rate within six months after fertility work-up did not significantly differ between intervention and control group (25% versus 27%: OR 0.72; 95% CI 0.40-1.27). There is a possible selection bias, couples included in the study had a higher socio-economic status than non-responders. How this affects guideline

  12. Developing grey-box model to diagnose asphaltene stability in crude oils: Application of refractive index

    Directory of Open Access Journals (Sweden)

    Mahdi Zeinali Hasanvand

    2016-12-01

    Full Text Available Asphaltene precipitation can cause serious problems in petroleum industry while diagnosing the asphaltene stability conditions in crude oil system is still a challenge and has been subject of many investigations. To monitor and diagnose asphaltene stability, high performance intelligent approaches based bio-inspired science like artificial neural network which have been optimized by various optimization techniques have been carried out. The main purpose of the implemented optimization algorithms is to decide high accurate interconnected weights of proposed neural network model. The proposed intelligent approaches are examined by using extensive experimental data reported in open literature. Moreover, to highlight robustness and precision of the addressed approaches, two different regression models have been developed and results obtained from the aforementioned intelligent models and regression approaches are compared with the corresponding refractive index data measured in laboratory. Based on the results, hybrid of genetic algorithm and particle swarm optimization have high performance and average relative absolute deviation between the model outputs and the relevant experimental data was found to be less than 0.2%. Routs from this work indicate that implication of HGAPSO-ANN in monitoring refractive index can lead to more reliable estimation of addressed issue which can lead to design of more reliable phase behavior simulation and further plans of oil production.

  13. NEOPLANTA: A Short Description of the First Serbian UV Index Model

    Science.gov (United States)

    Malinovic, S.; Mihailovic, D. T.; Kapor, D.; Mijatovic, Z.; Arsenic, I. D.

    2006-08-01

    A numerical model called “NEOPLANTA” for estimating solar UV irradiance and UV index under cloud-free conditions is being developed and tested at the University of Novi Sad in Serbia. In this paper, the model features, calculation procedure, and input parameters are described. Effects of the absorption of UV radiation by O3, SO2, and NO2 and absorption and scattering by aerosol as well as the air molecules in the atmosphere are included. The performance of the model has been tested with respect to its capability of UV index, which is a weighted integral between 280 and 400 nm of the solar irradiance reaching the ground. For this test 10-day data measured during the spring and summer in 2003, 2004, and 2005 are used. Data are recorded by the Yankee UVB-1 biometer located at the Novi Sad university campus (45.33°N, 19.85°E; 84 m MSL). Error analyses indicate that the modeled values agree well with the observations.

  14. Validation of the problem gambling severity index using confirmatory factor analysis and rasch modelling.

    Science.gov (United States)

    Miller, Natalie V; Currie, Shawn R; Hodgins, David C; Casey, David

    2013-09-01

    The Problem Gambling Severity Index (PGSI), a screening tool used to measure the severity of gambling problems in general population research, was subjected to confirmatory factor analysis and Rasch modelling to (a) confirm the one-factor structure; (b) assess how well the items measure the continuum of problem gambling severity; (c) identify sources of differential item functioning among relevant subpopulations of gamblers. Analyses were conducted on a nationally representative sample of over 25,000 gamblers compiled by merging data from the Canadian Community Health Survey and Canadian Problem Gambling Index (CPGI) integrated datasets. Results provided support for a one-factor model that was invariant across gender, age, income level, and gambler type. Rasch modelling revealed a well-fitting, unidimensional model with no miss-fitting items. The average severity assessed by the PGSI is consistent with moderately severe problem gambling. The PGSI is therefore weak in assessing low to moderate problem severity, a notable limitation of most brief gambling screens. Evidence of clinically significant differential item functioning was found with only one item, borrowing money to gamble, which behaved differently in gamblers who play electronic gaming machines or casino games compared to gamblers who avoid these games. Copyright © 2013 John Wiley & Sons, Ltd.

  15. Load index model: An advanced tool to support decision making during mass-casualty incidents.

    Science.gov (United States)

    Adini, Bruria; Aharonson-Daniel, Limor; Israeli, Avi

    2015-03-01

    In mass-casualty events, accessing information concerning hospital congestion levels is crucial to improving patient distribution and optimizing care. The study aimed to develop a decision support tool for distributing casualties to hospitals in an emergency scenario involving multiple casualties. A comprehensive literature review and structured interviews with 20 content experts produced a shortlist of relevant criteria for inclusion in the model. A "load index model" was prepared, incorporating results of a modified Delphi survey of 100 emergency response experts. The model was tested in three simulation exercises in which an emergency scenario was presented to six groups of senior emergency managers. Information was provided regarding capacities of 11 simulated admitting hospitals in the region, and evacuation destinations were requested for 600 simulated casualties. Of the three simulation rounds, two were performed without the model and one after its presentation. Following simulation experiments and implementation during a real-life security threat, the efficacy of the model was assessed. Variability between experts concerning casualties' evacuation destinations decreased significantly following the model's introduction. Most responders (92%) supported the need for standardized data, and 85% found that the model improved policy setting regarding casualty evacuation in an emergency situation. These findings were reaffirmed in a real-life emergency scenario. The proposed model improved capacity to ensure evacuation of patients to less congested medical facilities in emergency situations, thereby enhancing lifesaving medical services. The model supported decision-making processes in both simulation exercises and an actual emergency situation.

  16. Permafrost Favorability Index: Spatial Modeling in the French Alps Using a Rock Glacier Inventory

    Directory of Open Access Journals (Sweden)

    Marco Marcer

    2017-12-01

    Full Text Available In the present study we used the first rock glacier inventory for the entire French Alps to model spatial permafrost distribution in the region. Climatic and topographic data evaluated at the rock glacier locations were used as predictor variables in a Generalized Linear Model. Model performances are strong, suggesting that, in agreement with several previous studies, this methodology is able to model accurately rock glacier distribution. A methodology to estimate model uncertainties is proposed, revealing that the subjectivity in the interpretation of rock glacier activity and contours may substantially bias the model. The model highlights a North-South trend in the regional pattern of permafrost distribution which is attributed to the climatic influences of the Atlantic and Mediterranean climates. Further analysis suggest that lower amounts of precipitation in the early winter and a thinner snow cover, as typically found in the Mediterranean area, could contribute to the existence of permafrost at higher temperatures compared to the Northern Alps. A comparison with the Alpine Permafrost Index Map (APIM shows no major differences with our model, highlighting the very good predictive power of the APIM despite its tendency to slightly overestimate permafrost extension with respect to our database. The use of rock glaciers as indicators of permafrost existence despite their time response to climate change is discussed and an interpretation key is proposed in order to ensure the proper use of the model for research as well as for operational purposes.

  17. An enhanced temperature index model for debris-covered glaciers accounting for thickness effect

    Science.gov (United States)

    Carenzo, M.; Pellicciotti, F.; Mabillard, J.; Reid, T.; Brock, B. W.

    2016-08-01

    Debris-covered glaciers are increasingly studied because it is assumed that debris cover extent and thickness could increase in a warming climate, with more regular rockfalls from the surrounding slopes and more englacial melt-out material. Debris energy-balance models have been developed to account for the melt rate enhancement/reduction due to a thin/thick debris layer, respectively. However, such models require a large amount of input data that are not often available, especially in remote mountain areas such as the Himalaya, and can be difficult to extrapolate. Due to their lower data requirements, empirical models have been used extensively in clean glacier melt modelling. For debris-covered glaciers, however, they generally simplify the debris effect by using a single melt-reduction factor which does not account for the influence of varying debris thickness on melt and prescribe a constant reduction for the entire melt across a glacier. In this paper, we present a new temperature-index model that accounts for debris thickness in the computation of melt rates at the debris-ice interface. The model empirical parameters are optimized at the point scale for varying debris thicknesses against melt rates simulated by a physically-based debris energy balance model. The latter is validated against ablation stake readings and surface temperature measurements. Each parameter is then related to a plausible set of debris thickness values to provide a general and transferable parameterization. We develop the model on Miage Glacier, Italy, and then test its transferability on Haut Glacier d'Arolla, Switzerland. The performance of the new debris temperature-index (DETI) model in simulating the glacier melt rate at the point scale is comparable to the one of the physically based approach, and the definition of model parameters as a function of debris thickness allows the simulation of the nonlinear relationship of melt rate to debris thickness, summarised by the

  18. An enhanced temperature index model for debris-covered glaciers accounting for thickness effect.

    Science.gov (United States)

    Carenzo, M; Pellicciotti, F; Mabillard, J; Reid, T; Brock, B W

    2016-08-01

    Debris-covered glaciers are increasingly studied because it is assumed that debris cover extent and thickness could increase in a warming climate, with more regular rockfalls from the surrounding slopes and more englacial melt-out material. Debris energy-balance models have been developed to account for the melt rate enhancement/reduction due to a thin/thick debris layer, respectively. However, such models require a large amount of input data that are not often available, especially in remote mountain areas such as the Himalaya, and can be difficult to extrapolate. Due to their lower data requirements, empirical models have been used extensively in clean glacier melt modelling. For debris-covered glaciers, however, they generally simplify the debris effect by using a single melt-reduction factor which does not account for the influence of varying debris thickness on melt and prescribe a constant reduction for the entire melt across a glacier. In this paper, we present a new temperature-index model that accounts for debris thickness in the computation of melt rates at the debris-ice interface. The model empirical parameters are optimized at the point scale for varying debris thicknesses against melt rates simulated by a physically-based debris energy balance model. The latter is validated against ablation stake readings and surface temperature measurements. Each parameter is then related to a plausible set of debris thickness values to provide a general and transferable parameterization. We develop the model on Miage Glacier, Italy, and then test its transferability on Haut Glacier d'Arolla, Switzerland. The performance of the new debris temperature-index (DETI) model in simulating the glacier melt rate at the point scale is comparable to the one of the physically based approach, and the definition of model parameters as a function of debris thickness allows the simulation of the nonlinear relationship of melt rate to debris thickness, summarised by the

  19. Getting RID of the blues: Formulating a Risk Index for Depression (RID) using structural equation modeling.

    Science.gov (United States)

    Dipnall, Joanna F; Pasco, Julie A; Berk, Michael; Williams, Lana J; Dodd, Seetal; Jacka, Felice N; Meyer, Denny

    2017-11-01

    While risk factors for depression are increasingly known, there is no widely utilised depression risk index. Our objective was to develop a method for a flexible, modular, Risk Index for Depression using structural equation models of key determinants identified from previous published research that blended machine-learning with traditional statistical techniques. Demographic, clinical and laboratory variables from the National Health and Nutrition Examination Study (2009-2010, N = 5546) were utilised. Data were split 50:50 into training:validation datasets. Generalised structural equation models, using logistic regression, were developed with a binary outcome depression measure (Patient Health Questionnaire-9 score ⩾ 10) and previously identified determinants of depression: demographics, lifestyle-environs, diet, biomarkers and somatic symptoms. Indicative goodness-of-fit statistics and Areas Under the Receiver Operator Characteristic Curves were calculated and probit regression checked model consistency. The generalised structural equation model was built from a systematic process. Relative importance of the depression determinants were diet (odds ratio: 4.09; 95% confidence interval: [2.01, 8.35]), lifestyle-environs (odds ratio: 2.15; 95% CI: [1.57, 2.94]), somatic symptoms (odds ratio: 2.10; 95% CI: [1.58, 2.80]), demographics (odds ratio:1.46; 95% CI: [0.72, 2.95]) and biomarkers (odds ratio:1.39; 95% CI: [1.00, 1.93]). The relationships between demographics and lifestyle-environs and depression indicated a potential indirect path via somatic symptoms and biomarkers. The path from diet was direct to depression. The Areas under the Receiver Operator Characteristic Curves were good (logistic:training = 0.850, validation = 0.813; probit:training = 0.849, validation = 0.809). The novel Risk Index for Depression modular methodology developed has the flexibility to add/remove direct/indirect risk determinants paths to depression using a

  20. Integrated Diagnostics and Prognostics of Rotating Machinery

    Directory of Open Access Journals (Sweden)

    Kam W. Ng

    1999-01-01

    Full Text Available This paper provides an overview of current research efforts in integrated diagnostics and prognostics of rotating machinery. Specifically, the following topics are discussed: sensing techniques and sensors; signal detection, identification and extraction; classification of faults; predictive failure models; data/model fusion; information management; and man–machine interface. Technical issues, recommendations, and future research directions are also addressed.

  1. A Neural Network Architecture For Rapid Model Indexing In Computer Vision Systems

    Science.gov (United States)

    Pawlicki, Ted

    1988-03-01

    Models of objects stored in memory have been shown to be useful for guiding the processing of computer vision systems. A major consideration in such systems, however, is how stored models are initially accessed and indexed by the system. As the number of stored models increases, the time required to search memory for the correct model becomes high. Parallel distributed, connectionist, neural networks' have been shown to have appealing content addressable memory properties. This paper discusses an architecture for efficient storage and reference of model memories stored as stable patterns of activity in a parallel, distributed, connectionist, neural network. The emergent properties of content addressability and resistance to noise are exploited to perform indexing of the appropriate object centered model from image centered primitives. The system consists of three network modules each of which represent information relative to a different frame of reference. The model memory network is a large state space vector where fields in the vector correspond to ordered component objects and relative, object based spatial relationships between the component objects. The component assertion network represents evidence about the existence of object primitives in the input image. It establishes local frames of reference for object primitives relative to the image based frame of reference. The spatial relationship constraint network is an intermediate representation which enables the association between the object based and the image based frames of reference. This intermediate level represents information about possible object orderings and establishes relative spatial relationships from the image based information in the component assertion network below. It is also constrained by the lawful object orderings in the model memory network above. The system design is consistent with current psychological theories of recognition by component. It also seems to support Marr's notions

  2. [Identification of cutoff points for Homeostatic Model Assessment for Insulin Resistance index in adolescents: systematic review].

    Science.gov (United States)

    Andrade, Maria Izabel Siqueira de; Oliveira, Juliana Souza; Leal, Vanessa Sá; Lima, Niedja Maria da Silva; Costa, Emília Chagas; Aquino, Nathalia Barbosa de; Lira, Pedro Israel Cabral de

    2016-06-01

    To identify cutoff points of the Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) index established for adolescents and discuss their applicability for the diagnosis of insulin resistance in Brazilian adolescents. A systematic review was performed in the PubMed, Lilacs and SciELO databases, using the following descriptors: "Adolescents", "insulin resistance" and "ROC curve". Original articles carried out with adolescents published between 2005 and 2015 in Portuguese, English or Spanish languages, which included the statistical analysis using ROC curve to determine the index cutoff (HOMA-IR) were included. A total of 184 articles were identified and after the study phases were applied, seven articles were selected for the review. All selected studies established their cutoffs using a ROC curve, with the lowest observed cutoff of 1.65 for girls and 1.95 for boys and the highest of 3.82 for girls and 5.22 for boys. Of the studies analyzed, one proposed external validity, recommending the use of the HOMA-IR cutoff >2.5 for both genders. The HOMA-IR index constitutes a reliable method for the detection of insulin resistance in adolescents, as long as it uses cutoffs that are more adequate for the reality of the study population, allowing early diagnosis of insulin resistance and enabling multidisciplinary interventions aiming at health promotion of this population. Copyright © 2015 Sociedade de Pediatria de São Paulo. Publicado por Elsevier Editora Ltda. All rights reserved.

  3. Derivation of a Vacuum Refractive Index in a Stringy Space-Time Foam Model

    CERN Document Server

    Ellis, Jonathan Richard; Nanopoulos, D V

    2008-01-01

    It has been suggested that energetic photons propagating in vacuo should experience a non-trivial refractive index due to the foamy structure of space-time induced by quantum-gravitational fluctuations. The sensitivity of recent astrophysical observations, particularly of AGN Mk501 by the MAGIC Collaboration, approaches the Planck scale for a refractive index depending linearly on the photon energy. We present here a new derivation of this quantum-gravitational vacuum refraction index, based on a stringy analogue of the interaction of a photon with internal degrees of freedom in a conventional medium. We model the space-time foam as a gas of D-particles in the bulk space-time of a higher-dimensional cosmology where the observable Universe is a D3-brane. The interaction of an open string representing a photon with a D-particle stretches and excites the string, which subsequently decays and re-emits the photon with a time delay that increases linearly with the photon energy and is related to stringy uncertainty...

  4. Spoke Model for Calculating Reliability Index and Safety Factor of Slopes

    Directory of Open Access Journals (Sweden)

    Ping Wang

    2013-01-01

    Full Text Available Considering the disadvantages of the slice method commonly employed in reliability analysis of slopes, a novel method (Spoke model was proposed for reliability analysis and safety factor calculation of slopes in this work based on geometrical relationship among slices. The safety factor and the coefficients of limit state function of slopes could be achieved with the Gaussian integral method. The minimum safety factor and the minimum reliability index, as well as their corresponding coordinates on the slip surface, can be calculated with the improved JC method and the searching method. A novel and practical method for reliability analysis of slopes has been achieved. With this method the slice process could be avoided, which helps to eliminate some calculation errors caused by oversimplified assumption. Moreover, the explicit expression of safety factor in this method requires no repeated iterative solution, which is employed in traditional slice methods, as well as can be developed into a limit state function required by calculation of the reliability index. It is demonstrated that this method works efficiently and succinctly in evaluation of reliability index and safety factor for soil slopes.

  5. Potential Negative Impact of DG on Reliability Index: A Study Based on Time-Domain Modeling

    Science.gov (United States)

    Ran, Xuanchang

    This thesis presents an original insight of the negative impact of distributed generation on reliability index based on dynamic time-domain modeling. Models for essential power system components, such as protective devices and synchronous generators, were developed and tested. A 4 kV distribution loop which carries relatively high power demand was chosen for the analysis. The characteristic curves of all protective devices were extracted from utility database and applied to the time domain relay model. The performance of each device was investigated in details. The negative effect on reliability is due to the fuse opening caused by the installation of DG at the wrong location and inappropriate relay setup. Over 50% of the possible DG locations can produce an undesirable impact. The study conclusion is that there exists a significant potential for the installation of DG to negatively affect the reliability of power systems.

  6. An Ionospheric Index Model based on Linear Regression and Neural Network Approaches

    Science.gov (United States)

    Tshisaphungo, Mpho; McKinnell, Lee-Anne; Bosco Habarulema, John

    2017-04-01

    The ionosphere is well known to reflect radio wave signals in the high frequency (HF) band due to the present of electron and ions within the region. To optimise the use of long distance HF communications, it is important to understand the drivers of ionospheric storms and accurately predict the propagation conditions especially during disturbed days. This paper presents the development of an ionospheric storm-time index over the South African region for the application of HF communication users. The model will result into a valuable tool to measure the complex ionospheric behaviour in an operational space weather monitoring and forecasting environment. The development of an ionospheric storm-time index is based on a single ionosonde station data over Grahamstown (33.3°S,26.5°E), South Africa. Critical frequency of the F2 layer (foF2) measurements for a period 1996-2014 were considered for this study. The model was developed based on linear regression and neural network approaches. In this talk validation results for low, medium and high solar activity periods will be discussed to demonstrate model's performance.

  7. Detection performance and risk stratification using a model-based shape index characterizing heart rate turbulence.

    Science.gov (United States)

    Martínez, Juan Pablo; Cygankiewicz, Iwona; Smith, Danny; Bayés de Luna, Antonio; Laguna, Pablo; Sörnmo, Leif

    2010-10-01

    A detection-theoretic approach to quantify heart rate turbulence (HRT) following a ventricular premature beat is proposed and validated using an extended integral pulse frequency modulation (IPFM) model which accounts for HRT. The modulating signal of the extended IPFM model is projected into a three-dimensional subspace spanned by the Karhunen-Loève basis functions, characterizing HRT shape. The presence or absence of HRT is decided by means of a likelihood ratio test, the Neyman-Pearson detector, resulting in a quadratic detection statistic. Using a labeled dataset built from different interbeat interval series, detection performance is assessed and found to outperform the two widely used indices: turbulence onset (TO) and turbulence slope (TS). The ability of the proposed method to predict the risk of cardiac death is evaluated in a population of patients (n = 90) with ischemic cardiomyopathy and mild-to-moderate congestive heart failure. While both TS and the novel HRT index differ significantly in survivors and cardiac death patients, mortality analysis shows that the latter index exhibits much stronger association with risk of cardiac death (hazard ratio = 2.8, CI = 1.32-5.97, p = 0.008). It is also shown that the model-based shape indices, but not TO and TS, remain predictive of cardiac death in our population when computed from 4-h instead of 24-h ambulatory ECGs.

  8. An empirical model of L-band scintillation S4 index constructed by using FORMOSAT-3/COSMIC data

    Science.gov (United States)

    Chen, Shih-Ping; Bilitza, Dieter; Liu, Jann-Yenq; Caton, Ronald; Chang, Loren C.; Yeh, Wen-Hao

    2017-09-01

    Modern society relies heavily on the Global Navigation Satellite System (GNSS) technology for applications such as satellite communication, navigation, and positioning on the ground and/or aviation in the troposphere/stratosphere. However, ionospheric scintillations can severely impact GNSS systems and their related applications. In this study, a global empirical ionospheric scintillation model is constructed with S4-index data obtained by the FORMOSAT-3/COSMIC (F3/C) satellites during 2007-2014 (hereafter referred to as the F3CGS4 model). This model describes the S4-index as a function of local time, day of year, dip-latitude, and solar activity using the index PF10.7. The model reproduces the F3/C S4-index observations well, and yields good agreement with ground-based reception of satellite signals. This confirms that the constructed model can be used to forecast global L-band scintillations on the ground and in the near surface atmosphere.

  9. Multivariate Modeling of Body Mass Index, Pulse Pressure, Systolic and Diastolic Blood Pressure in Chinese Twins

    DEFF Research Database (Denmark)

    Wu, Yili; Zhang, Dongfeng; Pang, Zengchang

    2015-01-01

    Systolic and diastolic blood pressure, pulse pressure (PP), and body mass index (BMI) are heritable traits in human metabolic health but their common genetic and environmental backgrounds are not well investigated. The aim of this article was to explore the phenotypic and genetic associations among...... PP, systolic blood pressure (SBP), diastolic blood pressure (DBP), and BMI. The studied sample contained 615 twin pairs (17-84 years) collected in the Qingdao municipality. Univariate and multivariate structural equation models were fitted for assessing the genetic and environmental contributions...

  10. Development of a Habitat Suitability Index Model for the Sage Sparrow on the Hanford Site

    Energy Technology Data Exchange (ETDEWEB)

    Duberstein, Corey A.; Simmons, Mary Ann; Sackschewsky, Michael R.; Becker, James M.

    2008-01-01

    Mitigation threshold guidelines for the Hanford Site are based on habitat requirements of the sage sparrow (Amphispiza belli) and only apply to areas with a mature sagebrush (Artemisia tridentata) overstory and a native understory. The sage sparrow habitat requirements are based on literature values and are not specific to the Hanford Site. To refine these guidelines for the Site, a multi-year study was undertaken to quantify habitat characteristics of sage sparrow territories. These characteristics were then used to develop a habitat suitability index (HSI) model which can be used to estimate the habitat value of specific locations on the Site.

  11. Assessment of oyster habitat in Mobile Bay, Alabama using index modeling, geographic information systems, and computational fluid dynamic modeling

    Science.gov (United States)

    Rodgers, Leonard James

    The need to quantify habitat and to index the salient qualities of habitat is growing in importance in resource management. One method is to use habitat suitability index models (HSI) to spatially delineate the essential habitat through its key features. This dissertation implements an HSI for Eastern oysters (Crassostrea virginica) in an estuarine environment. Typically, extremely simplified methods have been incorporated into HSI models, such as, using the mean of monthly water samples from a very limited number of fixed sights. These methods are inadequate. How then should the investigator estimate highly dynamic spatial variables such as: temperature, salinity, and hydraulic flux? The current study employed a two dimensional computational fluid dynamic (CFD) model to calculate a measure of central tendency and a variance for major hydrodynamic variables of oyster habitat. Spatial data from several sources were combined with the CFD to determine suitability indices. Using the U.S. Fish and Wildlife Service geometric mean method an HSI was calculated. Dynamic HSI models were calculated annually and seasonally over three river discharge scenarios to test and demonstrate the concept. The results were plotted using a Geographical Information System (GIS). The model functioned as expected, and the results conformed to the observed distributions and abundances of oysters in Mobile Bay. This methodology, while complex and computer intensive, is potentially useful in resource management and planning. It could also be used as a predictive tool, forecasting the effects of such things as channel dredging, dam discharge, and possibly even global climate change on living estuarine resources.

  12. Adaptation of a 3-factor model for the Pittsburgh Sleep Quality Index in Portuguese older adults.

    Science.gov (United States)

    Becker, Nathália Brandolim; de Neves Jesus, Saul

    2017-05-01

    The present study examined the factor structure of the Pittsburgh Sleep Quality Index (PSQI) in a sample of older Portuguese adults using a cross-validation approach. Design is a cross-sectional. A convenience sample of 204 community-dwelling older adults (M=70.05, SD=7.15) were included. The global sleep quality (GSQ) score ranged from 0 to 18 with a mean of 5.98 (SD±3.45). The distribution showed that gender and perception of oneself as healthy influences GSQ in this sample. Cronbach's α was 0.69, but increased to 0.70 if the "use of sleep medication" component was deleted. Exploratory factor analysis (EFA) demonstrated two factor model is better than one factor, and a model fit with good indices (chi-square=8.649, df=8, p=0.373). Confirmatory factor analysis (CFA) was performed on the single factor, two factor, and three factor models, with and without the "use of sleep medications" component. The best model was the 3-factor model without the "use of sleep medications" component (chi-square=1.214, df=6, GFI=0.997, AGFI=0.918, CFI=0.986, RMSEA=0.046). The adaptation of the model is similar to the original model, with the only change being the exclusion of the "use of medications to sleep" component. We suggest using that component as a complementary qualitative assessment of health. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

  13. Prognostic Disclosures to Children: A Historical Perspective.

    Science.gov (United States)

    Sisk, Bryan A; Bluebond-Langner, Myra; Wiener, Lori; Mack, Jennifer; Wolfe, Joanne

    2016-09-01

    Prognostic disclosure to children has perpetually challenged clinicians and parents. In this article, we review the historical literature on prognostic disclosure to children in the United States using cancer as an illness model. Before 1948, there was virtually no literature focused on prognostic disclosure to children. As articles began to be published in the 1950s and 1960s, many clinicians and researchers initially recommended a "protective" approach to disclosure, where children were shielded from the harms of bad news. We identified 4 main arguments in the literature at this time supporting this "protective" approach. By the late 1960s, however, a growing number of clinicians and researchers were recommending a more "open" approach, where children were included in discussions of diagnosis, which at the time was often synonymous with a terminal prognosis. Four different arguments in the literature were used at this time supporting this "open" approach. Then, by the late 1980s, the recommended approach to prognostic disclosure in pediatrics shifted largely from "never tell" to "always tell." In recent years, however, there has been a growing appreciation for the complexity of prognostic disclosure in pediatrics. Current understanding of pediatric disclosure does not lead to simple "black-and-white" recommendations for disclosure practices. As with most difficult questions, we are left to balance competing factors on a case-by-case basis. We highlight 4 categories of current considerations related to prognostic disclosure in pediatrics, and we offer several approaches to prognostic disclosure for clinicians who care for these young patients and their families. Copyright © 2016 by the American Academy of Pediatrics.

  14. Clinical-sonographic index (CSI): a novel transcranial Doppler diagnostic model for middle cerebral artery stenosis.

    Science.gov (United States)

    Jung, Keun-Hwa; Lee, Yong-Seok

    2008-07-01

    Transcranial Doppler sonography is useful for the diagnosis of middle cerebral artery (MCA) stenosis. Although the previous studies have focused on the elevated mean flow velocity (MFV) or asymmetry of MFV, the lack of clinical correlation might limit diagnostic accuracy. We try to develop and validate a new diagnostic model including more comprehensive clinical and sonographic parameters. Consecutive patients with magnetic resonance angiography (MRA)-verified MCA stenosis were included, and compared with control subjects with normal MCA. The age, sex, corresponding symptoms (CS) to sonographic side, diabetes mellitus (DM), and hypertension were included for analysis. As sonographic parameters, MFV (cm/sec), asymmetry index (AI,%), and difference of pulsatility index (DeltaPI) were analyzed. Clinical-sonographic index (CSI) model was built with significant parameters by multivariate logistic regression analysis. One hundred and seven patients (M:F = 53:54, age: 61.6 +/- 11.6 years), and 100 control subjects (M:F = 49:51, age: 54.9 +/- 14.5 years) were included. In logistic regression, MFV (odds ratio [OR], 1.057; 95% confidence interval [95% CI], 1.030-1.084), AI (OR, 1.067; 95% CI, 1.031-1.104), DeltaPI (OR, 41.754; 95% CI, 2.771-626.999), CS (OR, 15.904; 95% CI, 5.055-50.042), and DM (OR, 3.949; 95% CI, 1.132-13.783) were independent predictors of MCA stenosis. CSI was simplified for clinical use, CSI = MFV(cm/sec) + 3 * AI (%) + 180 *DeltaPI + 90 * CS(presence = 1, absence = 0) + 30 * DM (presence = 1, absence = 0). The area under the receiver operator characteristic (ROC) curve of MCA stenosis versus MFV, DeltaPI, AI, and CSI was .641, .668, .865 and .953. According to ROC curve, cut-off point for MCA stenosis was suggested as CSI > 180 (sensitivity: 87%, specificity: 92%). CSI might be useful to enhance diagnostic accuracy.

  15. Delta model for end-stage liver disease and delta clinical prognostic indicator as predictors of mortality in patients with viral acute liver failure.

    Science.gov (United States)

    Pannu, Ashok Kumar; Bhalla, Ashish; Rao, Chelapati; Singh, Charanpreet

    2017-01-01

    The objective of the study is to compare the model for end-stage liver disease (MELD) with clinical prognostic indicators (CPI) specifically the change in these parameters after 48 h of admission in predicting the mortality in patients with acute liver failure (ALF) due to acute viral hepatitis. An open label, investigator-initiated prospective study was conducted that included 41 patients with acute viral hepatitis with ALF. The cases were followed prospectively till death or discharge. The MELD and CPI were calculated at admission and 48 h of admission. Patients having no change or worsening in CPI score, i.e., delta CPI more negative had a higher mortality over the next 48 h compared to patients having an improvement in their respective CPI score. Delta CPI predicted adverse outcome better than the presence of any three CPI on admission (P = 0.019). Patients having no change or a worsening in MELD score, i.e., delta MELD more negative, had a higher mortality in the next 48 h compared to the patients having improvement in their respective MELD score. However, MELD >33 on admission was superior to delta MELD in predicting the adverse outcome (P = 0.019). Among the patients with ALF due to viral hepatitis, delta CPI was found to be superior to delta MELD in predicting the adverse outcome in patients with viral ALF (P < 0.0001).

  16. PBT assessment and prioritization by PBT Index and consensus modeling: comparison of screening results from structural models.

    Science.gov (United States)

    Gramatica, Paola; Cassani, Stefano; Sangion, Alessandro

    2015-04-01

    The limited availability of comprehensive data for Persistence, Bioaccumulation and Toxicity (PBT) of chemicals is a serious hindrance to the assignment of compounds to the categories of PBT and vPvB; REACH regulation requires authorization for the use of such chemicals, and additionally plans for safer alternatives. In the context of screening and priority-setting tools for PBT-assessment, the cumulative PBT Index model, implemented in QSARINS (QSAR-INSUBRIA), new software tool for the development and validation of multiple linear regression QSAR models, offers a new holistic approach for the identification of chemicals with cumulative PBT properties directly from their molecular structure. In this study the Insubria PBT Index