WorldWideScience

Sample records for stage comparative models

  1. Palaeotemperature reconstructions of the European permafrost zone during Oxygen Isotope Stage 3 compared with climate model results.

    NARCIS (Netherlands)

    van Huissteden, J.; Vandenberghe, J.; Pollard, D.

    2003-01-01

    A palaeotemperature reconstruction based on periglacial phenomena in Europe north of approximately 51 °N, is compared with high-resolution regional climate model simulations of the marine oxygen isotope Stage 3 (Stage 3) palaeoclimate. The experiments represent Stage 3 warm (interstadial), Stage 3

  2. Turbine stage model

    International Nuclear Information System (INIS)

    Kazantsev, A.A.

    2009-01-01

    A model of turbine stage for calculations of NPP turbine department dynamics in real time was developed. The simulation results were compared with manufacturer calculations for NPP low-speed and fast turbines. The comparison results have shown that the model is valid for real time simulation of all modes of turbines operation. The model allows calculating turbine stage parameters with 1% accuracy. It was shown that the developed turbine stage model meets the accuracy requirements if the data of turbine blades setting angles for all turbine stages are available [ru

  3. Melanoma costs: a dynamic model comparing estimated overall costs of various clinical stages.

    Science.gov (United States)

    Alexandrescu, Doru Traian

    2009-11-15

    The rapidly increasing incidence of melanoma occurs at the same time as an increase in general healthcare costs, particularly the expenses associated with cancer care. Previous cost estimates in melanoma have not utilized a dynamic model considering the evolution of the disease and have not integrated the multiple costs associated with different aspects of medical interventions and patient-related factors. Futhermore, previous calculations have not been updated to reflect the modern tendencies in healthcare costs. We designed a comprehensive model of expenses in melanoma that considers the dynamic costs generated by the natural progression of the disease, which produces costs associated with treatment, surveillance, loss of income, and terminal care. The complete range of initial clinical (TNM) stages of the disease and initial tumor stages were analyzed in this model and the total healthcare costs for the five years following melanoma presentation at each particular stage were calculated. We have observed dramatic incremental total costs associated with progressively higher initial stages of the disease, ranging from a total of $4,648.48 for in situ tumors to $159,808.17 for Stage IV melanoma. By stage, early lesions associate 30-55 percent of their costs for the treatment of the primary tumor, due to a low rate of recurrence (local, regional, or distant), which limits the need for additional interventions. For in situ melanoma, T1a, and T1b, surveillance is an important contributor to the medical costs, accounting for more than 25 percent of the total cost over 5 years. In contrast, late lesions incur a much larger proportion of their associated costs (up to 80-85%) from the diagnosis and treatment of metastatic disease because of the increased propensity of those lesions to disseminate. This cost increases with increasing tumor stage (from $2,442.17 for T1a to $6,678.00 for T4b). The most expensive items in the medical care of patients with melanoma consist of

  4. Comparative effectiveness of one-stage versus two-stage basilic vein transposition arteriovenous fistulas.

    Science.gov (United States)

    Ghaffarian, Amir A; Griffin, Claire L; Kraiss, Larry W; Sarfati, Mark R; Brooke, Benjamin S

    2018-02-01

    Basilic vein transposition (BVT) fistulas may be performed as either a one-stage or two-stage operation, although there is debate as to which technique is superior. This study was designed to evaluate the comparative clinical efficacy and cost-effectiveness of one-stage vs two-stage BVT. We identified all patients at a single large academic hospital who had undergone creation of either a one-stage or two-stage BVT between January 2007 and January 2015. Data evaluated included patient demographics, comorbidities, medication use, reasons for abandonment, and interventions performed to maintain patency. Costs were derived from the literature, and effectiveness was expressed in quality-adjusted life-years (QALYs). We analyzed primary and secondary functional patency outcomes as well as survival during follow-up between one-stage and two-stage BVT procedures using multivariate Cox proportional hazards models and Kaplan-Meier analysis with log-rank tests. The incremental cost-effectiveness ratio was used to determine cost savings. We identified 131 patients in whom 57 (44%) one-stage BVT and 74 (56%) two-stage BVT fistulas were created among 8 different vascular surgeons during the study period that each performed both procedures. There was no significant difference in the mean age, male gender, white race, diabetes, coronary disease, or medication profile among patients undergoing one- vs two-stage BVT. After fistula transposition, the median follow-up time was 8.3 months (interquartile range, 3-21 months). Primary patency rates of one-stage BVT were 56% at 12-month follow-up, whereas primary patency rates of two-stage BVT were 72% at 12-month follow-up. Patients undergoing two-stage BVT also had significantly higher rates of secondary functional patency at 12 months (57% for one-stage BVT vs 80% for two-stage BVT) and 24 months (44% for one-stage BVT vs 73% for two-stage BVT) of follow-up (P < .001 using log-rank test). However, there was no significant difference

  5. A staged service innovation model

    NARCIS (Netherlands)

    Song, L.Z.; Song, Michael; Benedetto, Di A.C.

    2009-01-01

    Drawing from the new product development (NPD) literature, service quality literature (SERVQUAL), and empirically grounded research with 53 service innovation decision makers, we develop a staged service innovation model (SIM) for decision makers. We tested the model using empirical data from 329

  6. Accuracy of the One-Stage and Two-Stage Impression Techniques: A Comparative Analysis.

    Science.gov (United States)

    Jamshidy, Ladan; Mozaffari, Hamid Reza; Faraji, Payam; Sharifi, Roohollah

    2016-01-01

    Introduction . One of the main steps of impression is the selection and preparation of an appropriate tray. Hence, the present study aimed to analyze and compare the accuracy of one- and two-stage impression techniques. Materials and Methods . A resin laboratory-made model, as the first molar, was prepared by standard method for full crowns with processed preparation finish line of 1 mm depth and convergence angle of 3-4°. Impression was made 20 times with one-stage technique and 20 times with two-stage technique using an appropriate tray. To measure the marginal gap, the distance between the restoration margin and preparation finish line of plaster dies was vertically determined in mid mesial, distal, buccal, and lingual (MDBL) regions by a stereomicroscope using a standard method. Results . The results of independent test showed that the mean value of the marginal gap obtained by one-stage impression technique was higher than that of two-stage impression technique. Further, there was no significant difference between one- and two-stage impression techniques in mid buccal region, but a significant difference was reported between the two impression techniques in MDL regions and in general. Conclusion . The findings of the present study indicated higher accuracy for two-stage impression technique than for the one-stage impression technique.

  7. Accuracy of the One-Stage and Two-Stage Impression Techniques: A Comparative Analysis

    Directory of Open Access Journals (Sweden)

    Ladan Jamshidy

    2016-01-01

    Full Text Available Introduction. One of the main steps of impression is the selection and preparation of an appropriate tray. Hence, the present study aimed to analyze and compare the accuracy of one- and two-stage impression techniques. Materials and Methods. A resin laboratory-made model, as the first molar, was prepared by standard method for full crowns with processed preparation finish line of 1 mm depth and convergence angle of 3-4°. Impression was made 20 times with one-stage technique and 20 times with two-stage technique using an appropriate tray. To measure the marginal gap, the distance between the restoration margin and preparation finish line of plaster dies was vertically determined in mid mesial, distal, buccal, and lingual (MDBL regions by a stereomicroscope using a standard method. Results. The results of independent test showed that the mean value of the marginal gap obtained by one-stage impression technique was higher than that of two-stage impression technique. Further, there was no significant difference between one- and two-stage impression techniques in mid buccal region, but a significant difference was reported between the two impression techniques in MDL regions and in general. Conclusion. The findings of the present study indicated higher accuracy for two-stage impression technique than for the one-stage impression technique.

  8. Comparative myoanatomy of cycliophoran life cycle stages

    DEFF Research Database (Denmark)

    Neves, Ricardo C.; Cunha, Maria R.; Funch, Peter

    2010-01-01

    The metazoan phylum Cycliophora includes small cryptic epibionts that live attached to the mouthparts of clawed lobsters. The life cycle is complex, with alternating sexual and asexual generations, and involves several sessile and free-living stages. So far, the morphological and genetic characte......The metazoan phylum Cycliophora includes small cryptic epibionts that live attached to the mouthparts of clawed lobsters. The life cycle is complex, with alternating sexual and asexual generations, and involves several sessile and free-living stages. So far, the morphological and genetic...

  9. Comparative Proteomic Analysis of Hymenolepis diminuta Cysticercoid and Adult Stages

    Directory of Open Access Journals (Sweden)

    Anna Sulima

    2018-01-01

    Full Text Available Cestodiases are common parasitic diseases of animals and humans. As cestodes have complex lifecycles, hexacanth larvae, metacestodes (including cysticercoids, and adults produce proteins allowing them to establish invasion and to survive in the hostile environment of the host. Hymenolepis diminuta is the most commonly used model cestode in experimental parasitology. The aims of the present study were to perform a comparative proteomic analysis of two consecutive developmental stages of H. diminuta (cysticercoid and adult and to distinguish proteins which might be characteristic for each of the stages from those shared by both stages. Somatic proteins of H. diminuta were isolated from 6-week-old cysticercoids and adult tapeworms. Cysticercoids were obtained from experimentally infected beetles, Tenebrio molitor, whereas adult worms were collected from experimentally infected rats. Proteins were separated by GeLC-MS/MS (one dimensional gel electrophoresis coupled with liquid chromatography and tandem mass spectrometry. Additionally protein samples were digested in-liquid and identified by LC-MS/MS. The identified proteins were classified according to molecular function, cellular components and biological processes. Our study showed a number of differences and similarities in the protein profiles of cysticercoids and adults; 233 cysticercoid and 182 adult proteins were identified. From these proteins, 131 were present only in the cysticercoid and 80 only in the adult stage samples. Both developmental stages shared 102 proteins; among which six represented immunomodulators and one is a potential drug target. In-liquid digestion and LC-MS/MS complemented and confirmed some of the GeLC-MS/MS identifications. Possible roles and functions of proteins identified with both proteomic approaches are discussed.

  10. Stage-specific predictive models for breast cancer survivability.

    Science.gov (United States)

    Kate, Rohit J; Nadig, Ramya

    2017-01-01

    Survivability rates vary widely among various stages of breast cancer. Although machine learning models built in past to predict breast cancer survivability were given stage as one of the features, they were not trained or evaluated separately for each stage. To investigate whether there are differences in performance of machine learning models trained and evaluated across different stages for predicting breast cancer survivability. Using three different machine learning methods we built models to predict breast cancer survivability separately for each stage and compared them with the traditional joint models built for all the stages. We also evaluated the models separately for each stage and together for all the stages. Our results show that the most suitable model to predict survivability for a specific stage is the model trained for that particular stage. In our experiments, using additional examples of other stages during training did not help, in fact, it made it worse in some cases. The most important features for predicting survivability were also found to be different for different stages. By evaluating the models separately on different stages we found that the performance widely varied across them. We also demonstrate that evaluating predictive models for survivability on all the stages together, as was done in the past, is misleading because it overestimates performance. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  11. Expanding Comparative Literature into Comparative Sciences Clusters with Neutrosophy and Quad-stage Method

    Directory of Open Access Journals (Sweden)

    Fu Yuhua

    2016-08-01

    Full Text Available By using Neutrosophy and Quad-stage Method, the expansions of comparative literature include: comparative social sciences clusters, comparative natural sciences clusters, comparative interdisciplinary sciences clusters, and so on. Among them, comparative social sciences clusters include: comparative literature, comparative history, comparative philosophy, and so on; comparative natural sciences clusters include: comparative mathematics, comparative physics, comparative chemistry, comparative medicine, comparative biology, and so on.

  12. Comparable Short- and Long-term Outcomes in Living Donor and Deceased Donor Liver Transplantations for Patients With Model for End-stage Liver Disease Scores ≥35 in a Hepatitis-B Endemic Area.

    Science.gov (United States)

    Chok, Kenneth S H; Fung, James Y Y; Chan, Albert C Y; Dai, Wing Chiu; Sharr, William W; Cheung, Tan To; Chan, See Ching; Lo, Chung Mau

    2017-01-01

    To evaluate if living donor liver transplantation (LDLT) should be offered to patients with Model for End-stage Liver Disease (MELD) scores ≥35. No data was available to support LDLT of such patients. Data of 672 consecutive adult liver transplant recipients from 2005 to 2014 at our center were reviewed. Patients with MELD scores ≥35 were divided into the deceased donor liver transplantation (DDLT) group and the LDLT group and were compared. Univariate analysis was performed to identify risk factors affecting survival. The LDLT group (n = 54) had younger (33 yrs vs 50 yrs, P standard-liver-volume rates (51.28% vs 99.76%, P Hong Kong, where most waitlisted patients have acute-on-chronic liver failure from hepatitis B, LDLT is a wise alternative to DDLT.

  13. RESEARCH OF EARLY STAGES OF MODELING

    Directory of Open Access Journals (Sweden)

    Andrey Borisovich Nikolaev

    2017-05-01

    Full Text Available In represented article the questions of estimate of accuracy of an average integral characteristics of random process in the course of imitation modeling is considered. For the purposes of analytical treatment of initial stage of modeling a conditionally nonstationary Gaussian process is analyzed as stationary Gaussian process with boundary prehistory. A model of approximant autocorrelation function is recommended. Analytical expression for variance and mathematical expectation of average integral estimation are obtained. Statistical estimation efficiency criterion, the probability of belonging to correct parameter interval is introduced. Dependences of closeness in estimation statistics clearing interval at transient behavior are researched for various types of processes.

  14. Comparative diagnostic study of staging in renal cell carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Masaharu; Mori, Masaki; Ito, Sachiko and others

    1986-04-01

    A comparative diagnostic study was carried out on 56 patients with pathologically proven renal cell carcinoma which had been staged by CT, US, angiography (AG) and lymphography (LG) between June, 1980, and May, 1985. The confirmation of the tumor extent was established by surgery and microscopic examination in all patients except three, in whom the extent of the tumor was determined at autopsy. CT and AG were performed in all cases. It was also studied how far various factors such as histologic architecture, cell type, grade, growth mode, tumor necrosis and bleeding were related with prognosis, and how to evaluate them in imaging modality. Concerning the T factor, there was no difference in diagnostic ability between images, and since prognosis of T4 was inferior to those of T2 and T3, diagnosis of T4 was seen to require particular attention. Drawing ability of N and V factors was poor in US. In LG, evaluation of regional lymph nodes was difficult, so this seems to be an unnecessary examination because CT can provide sufficient evaluation. By imaging modality, diagnosis of architecture and cell type was difficult. By AG, avascular to hypovascular tumors were of solid type, and there were many spindle or pleomorphic cell types and combination of tubular-granular types, while the papillary type was few. By macroscopic growth mode, the infiltrating type was poor in prognosis, and the presence or absence of halo was evaluated by CT and AG. Prognosis was favorable in cases having no necrosis in the tumor or accompanied by hemorrhage. For the purpose of diagnosis, CT was found to be sufficient, and it was concluded that AG may be used only for the purpose of renal arterial embolization as a preoperative treatment of low-stage cases subjected to nephrectomy. US is sufficient only if satisfying the role of screening. (J.P.N.).

  15. Single-Staged Compared With Multi-Staged PCI in Multivessel NSTEMI Patients: The SMILE Trial.

    Science.gov (United States)

    Sardella, Gennaro; Lucisano, Luigi; Garbo, Roberto; Pennacchi, Mauro; Cavallo, Erika; Stio, Rocco Edoardo; Calcagno, Simone; Ugo, Fabrizio; Boccuzzi, Giacomo; Fedele, Francesco; Mancone, Massimo

    2016-01-26

    A lack of clarity exists about the role of complete coronary revascularization in patients presenting with non-ST-segment elevation myocardial infarction. The aim of our study was to compare long-term outcomes in terms of major adverse cardiovascular and cerebrovascular events of 2 different complete coronary revascularization strategies in patients with non-ST-segment elevation myocardial infarction and multivessel coronary artery disease: 1-stage percutaneous coronary intervention (1S-PCI) during the index procedure versus multistage percutaneous coronary intervention (MS-PCI) complete coronary revascularization during the index hospitalization. In the SMILE (Impact of Different Treatment in Multivessel Non ST Elevation Myocardial Infarction Patients: One Stage Versus Multistaged Percutaneous Coronary Intervention) trial, 584 patients were randomly assigned in a 1:1 manner to 1S-PCI or MS-PCI. The primary study endpoint was the incidence of major adverse cardiovascular and cerebrovascular events, which were defined as cardiac death, death, reinfarction, rehospitalization for unstable angina, repeat coronary revascularization (target vessel revascularization), and stroke at 1 year. The occurrence of the primary endpoint was significantly lower in the 1-stage group (1S-PCI: n = 36 [13.63%] vs. MS-PCI: n = 61 [23.19%]; hazard ratio [HR]: 0.549 [95% confidence interval (CI): 0.363 to 0.828]; p = 0.004). The 1-year rate of target vessel revascularization was significantly higher in the MS-PCI group (1S-PCI: n = 22 [8.33%] vs. MS-PCI: n = 40 [15.20%]; HR: 0.522 [95% CI: 0.310 to 0.878]; p = 0.01; p log-rank = 0.013). When the analyses were limited to cardiac death (1S-PCI: n = 9 [3.41%] vs. MS-PCI: n = 14 [5.32%]; HR: 0.624 [95% CI: 0.270 to 1.441]; p = 0.27) and myocardial infarction (1S-PCI: n = 7 [2.65%] vs. MS-PCI: n = 10 [3.80%]; HR: 0.678 [95% CI: 0.156 to 2.657]; p = 0.46), no significant differences were observed between groups. In multivessel

  16. Stage-by-Stage and Parallel Flow Path Compressor Modeling for a Variable Cycle Engine

    Science.gov (United States)

    Kopasakis, George; Connolly, Joseph W.; Cheng, Larry

    2015-01-01

    This paper covers the development of stage-by-stage and parallel flow path compressor modeling approaches for a Variable Cycle Engine. The stage-by-stage compressor modeling approach is an extension of a technique for lumped volume dynamics and performance characteristic modeling. It was developed to improve the accuracy of axial compressor dynamics over lumped volume dynamics modeling. The stage-by-stage compressor model presented here is formulated into a parallel flow path model that includes both axial and rotational dynamics. This is done to enable the study of compressor and propulsion system dynamic performance under flow distortion conditions. The approaches utilized here are generic and should be applicable for the modeling of any axial flow compressor design.

  17. Thermal properties Forsmark. Modelling stage 2.3 Complementary analysis and verification of the thermal bedrock model, stage 2.

    Energy Technology Data Exchange (ETDEWEB)

    Sundberg, Jan; Wrafter, John; Laendell, Maerta (Geo Innova AB (Sweden)); Back, Paer-Erik; Rosen, Lars (Sweco AB (Sweden))

    2008-11-15

    This report present the results of thermal modelling work for the Forsmark area carried out during modelling stage 2.3. The work complements the main modelling efforts carried out during modelling stage 2.2. A revised spatial statistical description of the rock mass thermal conductivity for rock domain RFM045 is the main result of this work. Thermal modelling of domain RFM045 in Forsmark model stage 2.2 gave lower tail percentiles of thermal conductivity that were considered to be conservatively low due to the way amphibolite, the rock type with the lowest thermal conductivity, was modelled. New and previously available borehole data are used as the basis for revised stochastic geological simulations of domain RFM045. By defining two distinct thermal subdomains, these simulations have succeeded in capturing more of the lithological heterogeneity present. The resulting thermal model for rock domain RFM045 is, therefore, considered to be more realistic and reliable than that presented in model stage 2.2. The main conclusions of modelling efforts in model stage 2.3 are: - Thermal modelling indicates a mean thermal conductivity for domain RFM045 at the 5 m scale of 3.56 W/(mK). This is slightly higher than the value of 3.49 W/(mK) derived in model stage 2.2. - The variance decreases and the lower tail percentiles increase as the scale of observation increases from 1 to 5 m. Best estimates of the 0.1 percentile of thermal conductivity for domain RFM045 are 2.24 W/(mK) for the 1 m scale and 2.36 W/(mK) for the 5 m scale. This can be compared with corresponding values for domain RFM029 of 2.30 W/(mK) for the 1 m scale and 2.87 W/(mK)for the 5 m scale. - The reason for the pronounced lower tail in the thermal conductivity distribution for domain RFM045 is the presence of large bodies of the low-conductive amphibolite. - The modelling results for domain RFM029 presented in model stage 2.2 are still applicable. - As temperature increases, the thermal conductivity decreases

  18. The Generality of Adult Development Stages and Transformations: Comparing Meaning-making and Logical Reasoning

    Directory of Open Access Journals (Sweden)

    Tom Hagström

    2015-09-01

    Full Text Available Human development theories differ in “context sensitivity,” covering those stressing development stages and those stressing continuously progressing changes. The former theories differ in whether, how and why the stages are regarded as being generalized across domains, i.e. their generality claims. Piaget’s developmental stage theory of logical complexity of children and adolescents fulfill “strong” such claims, including fixed stage sequentiality of increasing complexity levels and higher stage structures integrating earlier ones. His theory has inspired a number of adult development stage theories with varying generality claims. These provide suggestions of stages and stage transitions reaching beyond “pure” cognition, integrating more of e.g. emotional, value and moral dimensions. From a neo-Piagetian perspective, core generality aspects seem to concern on the one hand logical reasoning and on the other hand meaning-making. This raises questions of how these aspects are related to each other in terms of stage structures and transformations. The aim of the article is to discern general features in adult development stage structures and transitions, in terms of logical reasoning and meaning making. This is carried out by a “thought experiment” interrelating two theories that differ in these respects but that are both based on Piaget’s theory, namely Robert Kegan’s constructive developmental Subject-Object Theory (SOT and Michael Common´s behaviouristic Model of Hierarchical Complexity (MHC. This comparing approach concerns the 3rd, 4th and 5th order of consciousness as well as transitions between these according to SOT, and order 9 to 12 and corresponding transitions according to MHC. The thought experiment indicates that the generality claims of both models can be argued for without one of them necessarily being subordinated to the other one. Both theories are interpreted as differing but partly overlapping structures of

  19. Stages of Change or Changes of Stage? Predicting Transitions in Transtheoretical Model Stages in Relation to Healthy Food Choice

    Science.gov (United States)

    Armitage, Christopher J.; Sheeran, Paschal; Conner, Mark; Arden, Madelynne A.

    2004-01-01

    Relatively little research has examined factors that account for transitions between transtheoretical model (TTM) stages of change. The present study (N=787) used sociodemographic, TTM, and theory of planned behavior (TPB) variables, as well as theory-driven interventions to predict changes in stage. Longitudinal analyses revealed that…

  20. Chronic infections in hip arthroplasties: comparing risk of reinfection following one-stage and two-stage revision: a systematic review and meta-analysis

    Directory of Open Access Journals (Sweden)

    Lange J

    2012-03-01

    Full Text Available Jeppe Lange1,2, Anders Troelsen3, Reimar W Thomsen4, Kjeld Søballe1,51Lundbeck Foundation Centre for Fast-Track Hip and Knee Surgery, Aarhus C, 2Center for Planned Surgery, Silkeborg Regional Hospital, Silkeborg, 3Department of Orthopaedics, Hvidovre Hospital, Hvidovre, 4Department of Clinical Epidemiology, Aarhus University Hospital, Aalborg, 5Department of Orthopaedics, Aarhus University Hospital, Aarhus C, DenmarkBackground: Two-stage revision is regarded by many as the best treatment of chronic infection in hip arthroplasties. Some international reports, however, have advocated one-stage revision. No systematic review or meta-analysis has ever compared the risk of reinfection following one-stage and two-stage revisions for chronic infection in hip arthroplasties.Methods: The review was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis. Relevant studies were identified using PubMed and Embase. We assessed studies that included patients with a chronic infection of a hip arthroplasty treated with either one-stage or two-stage revision and with available data on occurrence of reinfections. We performed a meta-analysis estimating absolute risk of reinfection using a random-effects model.Results: We identified 36 studies eligible for inclusion. None were randomized controlled trials or comparative studies. The patients in these studies had received either one-stage revision (n = 375 or two-stage revision (n = 929. Reinfection occurred with an estimated absolute risk of 13.1% (95% confidence interval: 10.0%–17.1% in the one-stage cohort and 10.4% (95% confidence interval: 8.5%–12.7% in the two-stage cohort. The methodological quality of most included studies was considered low, with insufficient data to evaluate confounding factors.Conclusions: Our results may indicate three additional reinfections per 100 reimplanted patients when performing a one-stage versus two-stage revision. However, the

  1. Stages as models of scene geometry.

    Science.gov (United States)

    Nedović, Vladimir; Smeulders, Arnold W M; Redert, André; Geusebroek, Jan-Mark

    2010-09-01

    Reconstruction of 3D scene geometry is an important element for scene understanding, autonomous vehicle and robot navigation, image retrieval, and 3D television. We propose accounting for the inherent structure of the visual world when trying to solve the scene reconstruction problem. Consequently, we identify geometric scene categorization as the first step toward robust and efficient depth estimation from single images. We introduce 15 typical 3D scene geometries called stages, each with a unique depth profile, which roughly correspond to a large majority of broadcast video frames. Stage information serves as a first approximation of global depth, narrowing down the search space in depth estimation and object localization. We propose different sets of low-level features for depth estimation, and perform stage classification on two diverse data sets of television broadcasts. Classification results demonstrate that stages can often be efficiently learned from low-dimensional image representations.

  2. Comparative assessment of single-stage and two-stage anaerobic digestion for the treatment of thin stillage.

    Science.gov (United States)

    Nasr, Noha; Elbeshbishy, Elsayed; Hafez, Hisham; Nakhla, George; El Naggar, M Hesham

    2012-05-01

    A comparative evaluation of single-stage and two-stage anaerobic digestion processes for biomethane and biohydrogen production using thin stillage was performed to assess the impact of separating the acidogenic and methanogenic stages on anaerobic digestion. Thin stillage, the main by-product from ethanol production, was characterized by high total chemical oxygen demand (TCOD) of 122 g/L and total volatile fatty acids (TVFAs) of 12 g/L. A maximum methane yield of 0.33 L CH(4)/gCOD(added) (STP) was achieved in the two-stage process while a single-stage process achieved a maximum yield of only 0.26 L CH(4)/gCOD(added) (STP). The separation of acidification stage increased the TVFAs to TCOD ratio from 10% in the raw thin stillage to 54% due to the conversion of carbohydrates into hydrogen and VFAs. Comparison of the two processes based on energy outcome revealed that an increase of 18.5% in the total energy yield was achieved using two-stage anaerobic digestion. Copyright © 2012 Elsevier Ltd. All rights reserved.

  3. A two stage data envelopment analysis model with undesirable output

    Science.gov (United States)

    Shariff Adli Aminuddin, Adam; Izzati Jaini, Nur; Mat Kasim, Maznah; Nawawi, Mohd Kamal Mohd

    2017-09-01

    The dependent relationship among the decision making units (DMU) is usually assumed to be non-existent in the development of Data Envelopment Analysis (DEA) model. The dependency can be represented by the multi-stage DEA model, where the outputs from the precedent stage will be the inputs for the latter stage. The multi-stage DEA model evaluate both the efficiency score for each stages and the overall efficiency of the whole process. The existing multi stage DEA models do not focus on the integration with the undesirable output, in which the higher input will generate lower output unlike the normal desirable output. This research attempts to address the inclusion of such undesirable output and investigate the theoretical implication and potential application towards the development of multi-stage DEA model.

  4. Comparing flood loss models of different complexity

    Science.gov (United States)

    Schröter, Kai; Kreibich, Heidi; Vogel, Kristin; Riggelsen, Carsten; Scherbaum, Frank; Merz, Bruno

    2013-04-01

    Any deliberation on flood risk requires the consideration of potential flood losses. In particular, reliable flood loss models are needed to evaluate cost-effectiveness of mitigation measures, to assess vulnerability, for comparative risk analysis and financial appraisal during and after floods. In recent years, considerable improvements have been made both concerning the data basis and the methodological approaches used for the development of flood loss models. Despite of that, flood loss models remain an important source of uncertainty. Likewise the temporal and spatial transferability of flood loss models is still limited. This contribution investigates the predictive capability of different flood loss models in a split sample cross regional validation approach. For this purpose, flood loss models of different complexity, i.e. based on different numbers of explaining variables, are learned from a set of damage records that was obtained from a survey after the Elbe flood in 2002. The validation of model predictions is carried out for different flood events in the Elbe and Danube river basins in 2002, 2005 and 2006 for which damage records are available from surveys after the flood events. The models investigated are a stage-damage model, the rule based model FLEMOps+r as well as novel model approaches which are derived using data mining techniques of regression trees and Bayesian networks. The Bayesian network approach to flood loss modelling provides attractive additional information concerning the probability distribution of both model predictions and explaining variables.

  5. STAGES OF A STRATEGIC MANAGEMENT MODEL

    OpenAIRE

    Mihaela – Lavinia CIOBANICA

    2014-01-01

    In the literature dedicated to strategic management there is no unitary vision of the authors regarding the sequence of actions that give content to the respective process and what their stages are. With all existing differences, the visions of different authors nevertheless observe the unitary logic of developing a series of actions. These actions begin with the competitive environment analysis in which the organization operates and with the establishment of its strategic mission and th...

  6. Streamlining environmental product declarations: a stage model

    Science.gov (United States)

    Lefebvre, Elisabeth; Lefebvre, Louis A.; Talbot, Stephane; Le Hen, Gael

    2001-02-01

    General public environmental awareness and education is increasing, therefore stimulating the demand for reliable, objective and comparable information about products' environmental performances. The recently published standard series ISO 14040 and ISO 14025 are normalizing the preparation of Environmental Product Declarations (EPDs) containing comprehensive information relevant to a product's environmental impact during its life cycle. So far, only a few environmentally leading manufacturing organizations have experimented the preparation of EPDs (mostly from Europe), demonstrating its great potential as a marketing weapon. However the preparation of EPDs is a complex process, requiring collection and analysis of massive amounts of information coming from disparate sources (suppliers, sub-contractors, etc.). In a foreseeable future, the streamlining of the EPD preparation process will require product manufacturers to adapt their information systems (ERP, MES, SCADA) in order to make them capable of gathering, and transmitting the appropriate environmental information. It also requires strong functional integration all along the product supply chain in order to ensure that all the information is made available in a standardized and timely manner. The goal of the present paper is two fold: first to propose a transitional model towards green supply chain management and EPD preparation; second to identify key technologies and methodologies allowing to streamline the EPD process and subsequently the transition toward sustainable product development

  7. Dynamic Modeling of Starting Aerodynamics and Stage Matching in an Axi-Centrifugal Compressor

    Science.gov (United States)

    Wilkes, Kevin; OBrien, Walter F.; Owen, A. Karl

    1996-01-01

    A DYNamic Turbine Engine Compressor Code (DYNTECC) has been modified to model speed transients from 0-100% of compressor design speed. The impetus for this enhancement was to investigate stage matching and stalling behavior during a start sequence as compared to rotating stall events above ground idle. The model can simulate speed and throttle excursions simultaneously as well as time varying bleed flow schedules. Results of a start simulation are presented and compared to experimental data obtained from an axi-centrifugal turboshaft engine and companion compressor rig. Stage by stage comparisons reveal the front stages to be operating in or near rotating stall through most of the start sequence. The model matches the starting operating line quite well in the forward stages with deviations appearing in the rearward stages near the start bleed. Overall, the performance of the model is very promising and adds significantly to the dynamic simulation capabilities of DYNTECC.

  8. STAGES OF A STRATEGIC MANAGEMENT MODEL

    Directory of Open Access Journals (Sweden)

    Mihaela – Lavinia CIOBANICA

    2014-06-01

    Full Text Available In the literature dedicated to strategic management there is no unitary vision of the authors regarding the sequence of actions that give content to the respective process and what their stages are. With all existing differences, the visions of different authors nevertheless observe the unitary logic of developing a series of actions. These actions begin with the competitive environment analysis in which the organization operates and with the establishment of its strategic mission and they end with the performance evaluation after the strategy has been applied and, if appropriate, with the reconsidering of this strategy and the making of the necessary corrections to it. Such a basic structure of the process is adopted in most organizations that practice the strategic management. But noticeable differences appear in the degree of the formalization of the process and in the involvement of different managerial levels in the designing and detailing of its components.

  9. Geology Forsmark. Site descriptive modelling Forsmark - stage 2.2

    Energy Technology Data Exchange (ETDEWEB)

    Stephens, Michael B. [Geological Survey of Sweden, Uppsala (Sweden); Fox, Aaron; La Pointe, Paul [Golder Associates Inc (United States); Simeonov, Assen [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden); Isaksson, Hans [GeoVista AB, Luleaa (Sweden); Hermanson, Jan; Oehman, Johan [Golder Associates AB, Stockholm (Sweden)

    2007-10-15

    , spatial correlations and models, and other parameters (lithology and scaling corrections, termination matrices) that are necessary to build stochastic models. Primarily due to the establishment of additional fixed point intersections for rock domain boundaries at depth, adjustments have been made to earlier regional and local rock domain models. These adjustments are only minor in character. Compared with the earlier stage 2.1 model, adjustments in the regional deformation zone model are also, in general, highly limited in character. More important differences, which also affect the local model for deformation zones, concern zones ZFMA2, ZFMF1 and ZFMA8 in the gently dipping set. Significant changes in the modelling of deformation zones also concern the steeply dipping zones with surface trace lengths between 1 and 3 km in the local model volume. A totally revised geological DFN model is presented compared with the latest model (version 1.2). In particular, conceptually distinct alternatives are presented for fracture size modelling.

  10. Geology Forsmark. Site descriptive modelling Forsmark - stage 2.2

    International Nuclear Information System (INIS)

    Stephens, Michael B.; Fox, Aaron; La Pointe, Paul; Simeonov, Assen; Isaksson, Hans; Hermanson, Jan; Oehman, Johan

    2007-10-01

    , spatial correlations and models, and other parameters (lithology and scaling corrections, termination matrices) that are necessary to build stochastic models. Primarily due to the establishment of additional fixed point intersections for rock domain boundaries at depth, adjustments have been made to earlier regional and local rock domain models. These adjustments are only minor in character. Compared with the earlier stage 2.1 model, adjustments in the regional deformation zone model are also, in general, highly limited in character. More important differences, which also affect the local model for deformation zones, concern zones ZFMA2, ZFMF1 and ZFMA8 in the gently dipping set. Significant changes in the modelling of deformation zones also concern the steeply dipping zones with surface trace lengths between 1 and 3 km in the local model volume. A totally revised geological DFN model is presented compared with the latest model (version 1.2). In particular, conceptually distinct alternatives are presented for fracture size modelling

  11. Possibilities Of Opening Up the Stage-Gate Model

    Directory of Open Access Journals (Sweden)

    Biljana Stošić

    2014-12-01

    Full Text Available The paper presents basic elements of the Stage-Gate and Open innovation models, and possible connection of these two, resulting in what is frequently called an “Open Stage-Gate” model. This connection is based on opening up the new product development process and integration of the open innovation principles with the Stage-Gate concept, facilitating the import and export of information and technologies. Having in mind that the Stage Gate has originally been classified as the third generation model of innovation, the paper is dealing with the capabilities for applying the sixth generation Open innovation principles in today’s improved and much more flexible phases and gates of the Stage Gate. Lots of innovative companies are actually using both models in their NPD practice, looking for the most appropriate means of opening up the well-known closed innovation, especially in the domain of ideation through co-creation.

  12. Comparing a single-stage geocoding method to a multi-stage geocoding method: how much and where do they disagree?

    Directory of Open Access Journals (Sweden)

    Rice Kenneth

    2007-03-01

    Full Text Available Abstract Background Geocoding methods vary among spatial epidemiology studies. Errors in the geocoding process and differential match rates may reduce study validity. We compared two geocoding methods using 8,157 Washington State addresses. The multi-stage geocoding method implemented by the state health department used a sequence of local and national reference files. The single-stage method used a single national reference file. For each address geocoded by both methods, we measured the distance between the locations assigned by each method. Area-level characteristics were collected from census data, and modeled as predictors of the discordance between geocoded address coordinates. Results The multi-stage method had a higher match rate than the single-stage method: 99% versus 95%. Of 7,686 addresses were geocoded by both methods, 96% were geocoded to the same census tract by both methods and 98% were geocoded to locations within 1 km of each other by the two methods. The distance between geocoded coordinates for the same address was higher in sparsely populated and low poverty areas, and counties with local reference files. Conclusion The multi-stage geocoding method had a higher match rate than the single-stage method. An examination of differences in the location assigned to the same address suggested that study results may be most sensitive to the choice of geocoding method in sparsely populated or low-poverty areas.

  13. Short term load forecasting: two stage modelling

    Directory of Open Access Journals (Sweden)

    SOARES, L. J.

    2009-06-01

    Full Text Available This paper studies the hourly electricity load demand in the area covered by a utility situated in the Seattle, USA, called Puget Sound Power and Light Company. Our proposal is put into proof with the famous dataset from this company. We propose a stochastic model which employs ANN (Artificial Neural Networks to model short-run dynamics and the dependence among adjacent hours. The model proposed treats each hour's load separately as individual single series. This approach avoids modeling the intricate intra-day pattern (load profile displayed by the load, which varies throughout days of the week and seasons. The forecasting performance of the model is evaluated in similiar mode a TLSAR (Two-Level Seasonal Autoregressive model proposed by Soares (2003 using the years of 1995 and 1996 as the holdout sample. Moreover, we conclude that non linearity is present in some series of these data. The model results are analyzed. The experiment shows that our tool can be used to produce load forecasting in tropical climate places.

  14. Energy demand in Portuguese manufacturing: a two-stage model

    International Nuclear Information System (INIS)

    Borges, A.M.; Pereira, A.M.

    1992-01-01

    We use a two-stage model of factor demand to estimate the parameters determining energy demand in Portuguese manufacturing. In the first stage, a capital-labor-energy-materials framework is used to analyze the substitutability between energy as a whole and other factors of production. In the second stage, total energy demand is decomposed into oil, coal and electricity demands. The two stages are fully integrated since the energy composite used in the first stage and its price are obtained from the second stage energy sub-model. The estimates obtained indicate that energy demand in manufacturing responds significantly to price changes. In addition, estimation results suggest that there are important substitution possibilities among energy forms and between energy and other factors of production. The role of price changes in energy-demand forecasting, as well as in energy policy in general, is clearly established. (author)

  15. Treatment outcome in patients with triple negative early stage breast cancers compared with other molecular subtypes

    International Nuclear Information System (INIS)

    Kim, Ja Young; Chang, Sei Kyung; Lee, Bo Mi; Shin, Hyun Soo; Park, Heily

    2012-01-01

    To determine whether triple negative (TN) early stage breast cancers have poorer survival rates compared with other molecular types. Between August 2000 and July 2006, patients diagnosed with stage I, II early stage breast cancers, in whom all three markers (estrogen receptor, progesterone receptor, and human epidermal growth factor receptor [HER]-2) were available and treated with modified radical mastectomy or breast conserving surgery followed by radiotherapy, were retrospectively reviewed. Of 446 patients, 94 (21.1%) were classified as TN, 57 (12.8%) as HER-2 type, and 295 (66.1%) as luminal. TN was more frequently associated with young patients younger than 35 years old (p = 0.002), higher histologic grade (p 0.05). We found that patients with TN early stage breast cancers had no difference in survival rates compared with other molecular subtypes. Prospective study in homogeneous treatment group will need for a prognosis of TN early stage breast cancer.

  16. A stage-based model of design teaching

    DEFF Research Database (Denmark)

    Beier, Sofie

    2014-01-01

    With a focus on the teaching of design students in higher education, the article will present a teaching approach model that follows the stages of the design process. The model suggests that at the Definition stage, the supervisor can focus on leading the student into a more thorough elaboration ...... apply an approach inspired by the master–apprentice relationship, where the student learns by observing the master at work....

  17. Two-stage dental implants inserted in a one-stage procedure : a prospective comparative clinical study

    NARCIS (Netherlands)

    Heijdenrijk, Kees

    2002-01-01

    The results of this study indicate that dental implants designed for a submerged implantation procedure can be used in a single-stage procedure and may be as predictable as one-stage implants. Although one-stage implant systems and two-stage.

  18. Analysis of Three-dimension Viscous Flow in the Model Axial Compressor Stage K1002L

    Science.gov (United States)

    Tribunskaia, K.; Kozhukhov, Y. V.

    2017-08-01

    The main investigation subject considered in this paper is axial compressor model stage K1002L. Three simulation models were designed: Scheme 1 - inlet stage model consisting of IGV (Inlet Guide Vane), rotor and diffuser; Scheme 2 - two-stage model: IGV, first-stage rotor, first-stage diffuser, second-stage rotor, EGV (Exit Guide Vane); Scheme 3 - full-round model: IGV, rotor, diffuser. Numerical investigation of the model stage was held for four circumferential velocities at the outer diameter (Uout=125,160,180,210 m/s) within the range of flow coefficient: ϕ = 0.4 - 0.6. The computational domain was created with ANSYS CFX Workbench. According to simulation results, there were constructed aerodynamic characteristic curves of adiabatic efficiency and the adiabatic head coefficient calculated for total parameters were compared with data from the full-scale test received at the Central Boiler and Turbine Institution (CBTI), thus, verification of the calculated data was carried out. Moreover, there were conducted the following studies: comparison of aerodynamic characteristics of the schemes 1, 2; comparison of the sector and full-round models. The analysis and conclusions are supplemented by gas-dynamic method calculation for axial compressor stages.

  19. Comparative study of nasopharyngeal carcinoma staging system between the chinese 2008 and '92 Fuzhou

    International Nuclear Information System (INIS)

    Zong Jingfeng; Lin Shaojun; Zhang Yu; Chen Yunbin; Guo Qiaojuan; Pan Jianji

    2010-01-01

    Objective: To carry out a comparative study between the Chinese 2008 and '92 staging system of nasopharyngeal carcinoma (NPC). Methods: A total of 777 patients presented with untreated non disseminated NPC who had received MRI scan of nasopharynx and neck were studied retrospectively. The clinical materials and information of imaging were collected. All patients were restaged according to the Chinese 2008 and 92 staging system of nasopharyngeal carcinoma. Distribution of T, N stage, survival and prognostic value were compared. 513 patients of the 777 cases were treated with conventional radiotherapy, 264 cases with intensity modulated radiation therapy. Results: The 3-year follow-up rate was 97.6%. The consistency of T stages was 95.0%. T, N and clinical stage distributions in two systems were similar ( Kappa = 0.93, P = 0.000; Kappa = 0.58, P = 0.000; Kappa = 0.74, P = 0.000). Local failure-free survival and disease specific survival were also similar. There was no difference of distant metastasis between N 0 and N 1 (χ 2 = 1.94, P=0. 164), and a marginal difference between N 1 and N 2 (χ 2 =3.83, P=0.051) in the Chinese '92 staging system. However, although there was also no difference of distant metastasis-free survival between N 0 and N 1a (χ 2 =0.07, P =0.797), ) the difference of overall survival among N 1b , N 2 , and N 3 were significant (χ 2 = 4.95, P = 0.026; χ 2 = 6.74, P = 0.009) in the Chinese 2008 staging system. Conventional radiotherapy or intensity modulated radiation therapy was not a prognostic factor for survival (χ 2 = 3.60, P =0.058). It is reasonable for the Chinese 2008 staging system integrated lymph node characteristics such as laterality, level and extra nodal neoplastic spread into the N staging criteria (χ 2 = 6.59, P = 0.010; χ 2 =4.78, P=0. 029; χ 2 =9.32, P=0.002). Conclusions: For the Chinese 2008 staging system, it was reasonable to simplify the previous T stage. The N stage showed a better predictive role of distant

  20. Stage wise modeling of liquid-extraction column (RDC)

    International Nuclear Information System (INIS)

    Bastani, B.

    2004-01-01

    Stage wise forward mixing model considering coalescence and re dispersion of drops was used to predict the performance of Rotating Disk Liquid Extraction Contactors. Experimental data previously obtained in two RDC columns of 7-62 cm diameter, 73.6 cm height and 21.9 cm diameter,150 cm height were used to evaluate the model predications. Drops-side mass transfer coefficients were predicted applying Hand los-baron drop model and onley's model was used to predict velocities. According to the results obtained the followings could be concluded: (1) If the height of coalescence and re dispersion i.e.:h=h p Q p / Q could be estimated, the stage wise forward mixing with coalescence and re dispersion model will predict the column height and efficiency with the acceptable accuracy, (2) The stage wise modeling predictions are highly dependent on the number of stages used when the number of stages is less than 10 and (3) Application of continuous phase mass transfer axial dispersion coefficients (k c and E c ) obtained from the solute concentration profile along the column height will predict the column performance more accurately than the Calder bank and moo-young (for K c ) and Kumar-Heartland (for E c ) correlations

  1. A kinetic model for the first stage of pygas upgrading

    Directory of Open Access Journals (Sweden)

    J. L. de Medeiros

    2007-03-01

    Full Text Available Pyrolysis gasoline - PYGAS - is an intermediate boiling product of naphtha steam cracking with a high octane number and high aromatic/unsaturated contents. Due to stabilization concerns, PYGAS must be hydrotreated in two stages. The first stage uses a mild trickle-bed conversion for removing extremely reactive species (styrene, dienes and olefins prior to the more severe second stage where sulfured and remaining olefins are hydrogenated in gas phase. This work addresses the reaction network and two-phase kinetic model for the first stage of PYGAS upgrading. Nonlinear estimation was used for model tuning with kinetic data obtained in bench-scale trickle-bed hydrogenation with a commercial Pd/Al2O3 catalyst. On-line sampling experiments were designed to study the influence of variables - temperature and spatial velocity - on the conversion of styrene, dienes and olefins.

  2. Cost-effectiveness of kidney transplantation compared with chronic dialysis in end-stage renal disease

    Directory of Open Access Journals (Sweden)

    Diego Rosselli

    2015-01-01

    Full Text Available To estimate the costs and effectiveness measured in quality-adjusted life years (QALY of kidney transplantation compared with dialysis in adults suffering from end-stage renal disease from the perspective of the Colombian healthcare system, we designed a Markov model with monthly cycles over a five-year time horizon and eight transitional states, including death as an absorbing state. Transition probabilities were obtained from international registries, costs from different local sources [case studies, official tariffs (ISS 2001 + 35% for procedures and SISMED for medications]. Data were validated by an expert panel and we performed univariate, multivariate and probabilistic sensitivity analyses. Effectiveness indicators were months of life gained, months of dialysis averted and deaths prevented. The annual discount rate was 3% and the cost-utility threshold (willingness to pay was three times gross domestic product (GDP = USD 20,000 per QALY. The costs were adopted in US dollars (USD using the 2012 average exchange rate (1 USD = COP$ 1798. The discounted average total cost for five years was USD 76,718 for transplantation and USD 76,891 for dialysis, with utilities 2.98 and 2.10 QALY, respectively. Additionally, renal transplantation represented 6.9 months gained, 35 months in dialysis averted per patient and one death averted for each of the five patients transplanted in five years. We conclude that renal transplantation improves the overall survival rates and quality of life and is a cost-saving alternative compared with dialysis.

  3. Comparative responses to endocrine disrupting compounds in early life stages of Atlantic salmon, Salmo salar

    Science.gov (United States)

    Duffy, Tara A.; Iwanowicz, Luke R.; McCormick, Stephen D.

    2014-01-01

    Atlantic salmon (Salmo salar) are endangered anadromous fish that may be exposed to feminizing endocrine disrupting compounds (EDCs) during early development, potentially altering physiological capacities, survival and fitness. To assess differential life stage sensitivity to common EDCs, we carried out short-term (four day) exposures using three doses each of 17α-ethinylestradiol (EE2), 17β-estradiol (E2), and nonylphenol (NP) on four early life stages; embryos, yolk-sac larvae, feeding fry and one year old smolts. Differential response was compared using vitellogenin (Vtg, a precursor egg protein) gene transcription. Smolts were also examined for impacts on plasma Vtg, cortisol, thyroid hormones (T4/T3) and hepatosomatic index (HSI). Compound-related mortality was not observed in any life stage, but Vtg mRNA was elevated in a dose-dependent manner in yolk-sac larvae, fry and smolts but not in embyos. The estrogens EE2 and E2 were consistently stronger inducers of Vtg than NP. Embryos responded significantly to the highest concentration of EE2 only, while older life stages responded to the highest doses of all three compounds, as well as intermediate doses of EE2 and E2. Maximal transcription was greater for fry among the three earliest life stages, suggesting fry may be the most responsive life stage in early development. Smolt plasma Vtg was also significantly increased, and this response was observed at lower doses of each compound than was detected by gene transcription suggesting this is a more sensitive indicator at this life stage. HSI was increased at the highest doses of EE2 and E2 and plasma T3 decreased at the highest dose of EE2. Our results indicate that all life stages after hatching are potentially sensitive to endocrine disruption by estrogenic compounds and that physiological responses were altered over a short window of exposure, indicating the potential for these compounds to impact fish in the wild.

  4. Two-step two-stage fission gas release model

    International Nuclear Information System (INIS)

    Kim, Yong-soo; Lee, Chan-bock

    2006-01-01

    Based on the recent theoretical model, two-step two-stage model is developed which incorporates two stage diffusion processes, grain lattice and grain boundary diffusion, coupled with the two step burn-up factor in the low and high burn-up regime. FRAPCON-3 code and its in-pile data sets have been used for the benchmarking and validation of this model. Results reveals that its prediction is in better agreement with the experimental measurements than that by any model contained in the FRAPCON-3 code such as ANS 5.4, modified ANS5.4, and Forsberg-Massih model over whole burn-up range up to 70,000 MWd/MTU. (author)

  5. On A Two-Stage Supply Chain Model In The Manufacturing Industry ...

    African Journals Online (AJOL)

    We model a two-stage supply chain where the upstream stage (stage 2) always meet demand from the downstream stage (stage 1).Demand is stochastic hence shortages will occasionally occur at stage 2. Stage 2 must fill these shortages by expediting using overtime production and/or backordering. We derive optimal ...

  6. Comparative study on developmental stages of the clavicle by postmortem MRI and CT imaging

    DEFF Research Database (Denmark)

    Larsen, Sara Tangmose; Lynnerup, Niels; Jensen, K.E.

    2013-01-01

    Objectives: The developmental stages of the clavicles are important for forensic age estimation purposes in adolescents. This study compares the 4-stage system to evaluate the ossification of the medial end of the clavicle as visualized by magnetic resonance imaging (MRI) and computed tomography...... (CT). As several forensic institutes routinely perform CT scans, the large amount of available data may serve as reference sample for MRI in specific cases. Material and methods: This prospective study included an MRI and CT scan of 47 autopsy cases performed prior to medico-legal autopsy (age range...

  7. Stability patterns for a size-structured population model and its stage-structured counterpart

    DEFF Research Database (Denmark)

    Zhang, Lai; Pedersen, Michael; Lin, Zhigui

    2015-01-01

    In this paper we compare a general size-structured population model, where a size-structured consumer feeds upon an unstructured resource, to its simplified stage-structured counterpart in terms of equilibrium stability. Stability of the size-structured model is understood in terms of an equivale...... to the population level....

  8. Numerical modelling of the HAB Energy Buoy: Stage 1

    DEFF Research Database (Denmark)

    Kurniawan, Adi

    This report presents the results of the first stage of the project "Numerical modelling of the HAB Energy Buoy". The objectives of this stage are to develop a numerical model of the HAB Energy Buoy, a self-reacting wave energy device consisting of two heaving bodies, and to investigate a number...... and a summary of the main findings is presented. A numerical model of the HAB Energy Buoy has been developed in the frequency domain using two alternative formulations of the equations of motion. The model is capable of predicting the power capture, motion response, and power take-off loads of the device...... configuration are imposed to give a more realistic prediction of the power capture and help ensure a fair comparison. Recommendations with regard to the HAB design are finally suggested....

  9. Immediate compared with delayed pushing in the second stage of labor: a systematic review and meta-analysis.

    Science.gov (United States)

    Tuuli, Methodius G; Frey, Heather A; Odibo, Anthony O; Macones, George A; Cahill, Alison G

    2012-09-01

    To estimate whether immediate or delayed pushing in the second stage of labor optimizes spontaneous vaginal delivery and other perinatal outcomes. We searched electronic databases MEDLINE and CINHAL through August 2011 without restrictions. The search terms used were MeSH headings, text words, and word variations of the words or phrases labor, laboring down, passive descent, passive second stage, physiologic second stage, spontaneous pushing, pushing, or bearing down. We searched for randomized controlled trials comparing immediate with delayed pushing in the second stage of labor. The primary outcome was spontaneous vaginal delivery. Secondary outcomes were instrumental delivery, cesarean delivery, duration of the second stage, duration of active pushing, and other maternal and neonatal outcomes. Heterogeneity was assessed using the Q test and I2. Pooled relative risks (RRs) and weighted mean differences were calculated using random-effects models. Twelve randomized controlled trials (1,584 immediate and 1,531 delayed pushing) met inclusion criteria. Overall, delayed pushing was associated with an increased rate of spontaneous vaginal delivery compared with immediate pushing (61.5% compared with 56.9%, pooled RR 1.09, 95% confidence interval [CI] 1.03-1.15). This increase was smaller and not statistically significant among high-quality studies (59.0% compared with 54.9%, pooled RR 1.07, 95% CI 0.98-1.26) but larger and statistically significant in lower-quality studies (81.0% compared with 71.0%%, pooled RR 1.13, 95% CI 1.02-1.24). Operative vaginal delivery rates were high in most studies and not significantly different between the two groups (33.7% compared with 37.4%, pooled RR 0.89, 95% CI 0.76-1.06). Delayed pushing was associated with prolongation of the second stage (weighted mean difference 56.92 minutes, 95% CI 42.19-71.64) and shortened duration of active pushing (weighted mean difference -21.98 minutes, 95% CI -31.29 to -12.68). Studies to date suggest

  10. The Study on Stage Financing Model of IT Project Investment

    Directory of Open Access Journals (Sweden)

    Si-hua Chen

    2014-01-01

    Full Text Available Stage financing is the basic operation of venture capital investment. In investment, usually venture capitalists use different strategies to obtain the maximum returns. Due to its advantages to reduce the information asymmetry and agency cost, stage financing is widely used by venture capitalists. Although considerable attentions are devoted to stage financing, very little is known about the risk aversion strategies of IT projects. This paper mainly addresses the problem of risk aversion of venture capital investment in IT projects. Based on the analysis of characteristics of venture capital investment of IT projects, this paper introduces a real option pricing model to measure the value brought by the stage financing strategy and design a risk aversion model for IT projects. Because real option pricing method regards investment activity as contingent decision, it helps to make judgment on the management flexibility of IT projects and then make a more reasonable evaluation about the IT programs. Lastly by being applied to a real case, it further illustrates the effectiveness and feasibility of the model.

  11. The Study on Stage Financing Model of IT Project Investment

    Science.gov (United States)

    Xu, Sheng-hua; Xiong, Neal N.

    2014-01-01

    Stage financing is the basic operation of venture capital investment. In investment, usually venture capitalists use different strategies to obtain the maximum returns. Due to its advantages to reduce the information asymmetry and agency cost, stage financing is widely used by venture capitalists. Although considerable attentions are devoted to stage financing, very little is known about the risk aversion strategies of IT projects. This paper mainly addresses the problem of risk aversion of venture capital investment in IT projects. Based on the analysis of characteristics of venture capital investment of IT projects, this paper introduces a real option pricing model to measure the value brought by the stage financing strategy and design a risk aversion model for IT projects. Because real option pricing method regards investment activity as contingent decision, it helps to make judgment on the management flexibility of IT projects and then make a more reasonable evaluation about the IT programs. Lastly by being applied to a real case, it further illustrates the effectiveness and feasibility of the model. PMID:25147845

  12. The study on stage financing model of IT project investment.

    Science.gov (United States)

    Chen, Si-hua; Xu, Sheng-hua; Lee, Changhoon; Xiong, Neal N; He, Wei

    2014-01-01

    Stage financing is the basic operation of venture capital investment. In investment, usually venture capitalists use different strategies to obtain the maximum returns. Due to its advantages to reduce the information asymmetry and agency cost, stage financing is widely used by venture capitalists. Although considerable attentions are devoted to stage financing, very little is known about the risk aversion strategies of IT projects. This paper mainly addresses the problem of risk aversion of venture capital investment in IT projects. Based on the analysis of characteristics of venture capital investment of IT projects, this paper introduces a real option pricing model to measure the value brought by the stage financing strategy and design a risk aversion model for IT projects. Because real option pricing method regards investment activity as contingent decision, it helps to make judgment on the management flexibility of IT projects and then make a more reasonable evaluation about the IT programs. Lastly by being applied to a real case, it further illustrates the effectiveness and feasibility of the model.

  13. The protection motivation theory within the stages of the transtheoretical model - stage-specific interplay of variables and prediction of exercise stage transitions.

    Science.gov (United States)

    Lippke, Sonia; Plotnikoff, Ronald C

    2009-05-01

    Two different theories of health behaviour have been chosen with the aim of theory integration: a continuous theory (protection motivation theory, PMT) and a stage model (transtheoretical model, TTM). This is the first study to test whether the stages of the TTM moderate the interrelation of PMT-variables and the mediation of motivation, as well as PMT-variables' interactions in predicting stage transitions. Hypotheses were tested regarding (1) mean patterns, stage pair-comparisons and nonlinear trends using ANOVAs; (2) prediction-patterns for the different stage groups employing multi-group structural equation modelling (MSEM) and nested model analyses; and (3) stage transitions using binary logistic regression analyses. Adults (N=1,602) were assessed over a 6 month period on their physical activity stages, PMT-variables and subsequent behaviour. (1) Particular mean differences and nonlinear trends in all test variables were found. (2) The PMT adequately fitted the five stage groups. The MSEM revealed that covariances within threat appraisal and coping appraisal were invariant and all other constrains were stage-specific, i.e. stage was a moderator. Except for self-efficacy, motivation fully mediated the relationship between the social-cognitive variables and behaviour. (3) Predicting stage transitions with the PMT-variables underscored the importance of self-efficacy. Only when threat appraisal and coping appraisal were high, stage movement was more likely in the preparation stage. Results emphasize stage-specific differences of the PMT mechanisms, and hence, support the stage construct. The findings may guide further theory building and research integrating different theoretical approaches.

  14. Systematic Compared With Targeted Staging with Endobronchial Ultrasound in Patients with Lung Cancer.

    Science.gov (United States)

    Sanz-Santos, José; Serra, Pere; Torky, Mohamed; Andreo, Felipe; Centeno, Carmen; Mendiluce, Leire; Martínez-Barenys, Carlos; López de Castro, Pedro; Ruiz-Manzano, Juan

    2018-04-06

    To evaluate the accuracy of systematic mediastinal staging by endobronchial ultrasound transbronchial needle aspiration (EBUS-TBNA) (sampling of all visible nodes measuring ≥5mm from stations N3 to N1 regardless of their positron emission tomography/computed tomography (PET/CT) features) and compare this staging approach with targeted EBUS-TBNA staging (sampling only 18F-fluorodeoxyglucose (FDG)-avid nodes) in patients with N2 non-small cell lung cancer (NSCLC) on PET/CT. Retrospective study of 107 patients who underwent systematic EBUS-TBNA mediastinal staging. The results were compared with those of a hypothetical scenario where only FDG-avid nodes on PET/CT would be sampled. Systematic EBUS-TBNA sampling demonstrated N3 disease in 3 patients, N2 disease in 60 (42 single-station or N2a, 18 multiple-station or N2b) and N0/N1 disease in 44. Of these 44, seven underwent mediastinoscopy, which did not show mediastinal disease; six of the seven proceeded to lung resection, which also showed no mediastinal disease. Thirty-four N0/N1 patients after EBUS-TBNA underwent lung resection directly: N0/N1 was found in 30 and N2 in four (one N2b with a PET/CT showing N2a disease, three N2a). Sensitivity, specificity, negative predictive value, positive predictive value, and overall accuracy of systematic EBUS-TBNA were 94%, 100%, 90%, 100% and 96%, respectively. Compared to targeted EBUS-TBNA, systematic EBUS-TBNA sampling provided additional important clinical information in 14 cases (13%): three N3 cases would have passed unnoticed, and 11 N2b cases would have been staged as N2a. In clinical practice, systematic sampling of the mediastinum by EBUS-TBNA, regardless of PET/CT features, is to be recommended over targeted sampling. Copyright © 2018. Published by Elsevier Inc.

  15. Unilateral vs one stage bilateral total knee replacement in rheumatoid and osteoarthritis - A comparative study

    Directory of Open Access Journals (Sweden)

    Kiran E

    2005-01-01

    Full Text Available Background : A controversy exists regarding simultaneous or staged bilateral total knee replacement. Methods: Fifty patients undergoing simultaneous bilateral and 50 undergoing unilateral total knee arthroplasty were evaluated prospectively to compare the clinical, radiological results and complication rates. Eighty-four patients belonged to ASA category II or III preoperatively. The study included a high proportion of rheumatoid patients and osteoarthritis patients with severe deformities. Results: Bilateral group had greater blood loss and required more blood transfusion, but there was no difference in requirement of postoperative intensive care and the complication rates. Rheumatoid knees had lower pre and postoperative knee score and functional score as compared to osteoarthritic knees. Morbidity and mortality of one stage bilateral knee replacement was no greater than unilateral operation. Conclusion: Simultaneous bilateral knee replacement in younger patients with advanced rheumatoid arthritis is safe and effective

  16. Comparative copper sensitivity between life stages of common subantarctic marine invertebrates.

    Science.gov (United States)

    Holan, Jessica R; King, Catherine K; Davis, Andrew R

    2018-03-01

    The development of environmental guidelines in the Antarctic and subantarctic is essential, because expansion of research, tourism, and fishing is placing these regions at increasing risk of contamination. Data are currently insufficient to create the region-specific guidelines needed for the unique conditions in these areas. To develop the most appropriate environmental guidelines, data from the most sensitive life stages of a species should be included to ensure effective protection throughout its life cycle. It is generally accepted that early life stages are more sensitive to contaminants. We compared the toxicity of copper between juvenile and adult life stages of 4 subantarctic marine invertebrates using sublethal and lethal endpoints. For 2 of the species tested, juveniles were more sensitive than adults. (The 7-d median effect concentration [EC50] values for the gastropod Laevilittorina caliginosa were 79 μg/L at the juvenile stage and 125 μg/L at the adult; for the flatworm Obrimoposthia ohlini, values were 190 μg/L at the juvenile stage and 300 μg/L at the adult.) For the isopod Limnoria stephenseni, juveniles were either more sensitive or of equal sensitivity to adults (7-d EC50 values: juvenile 278 μg/L and adult 320 μg/L). In contrast, for the bivalve Gaimardia trapesina, adults appeared to be more sensitive than young adults (7-d EC50 values: juvenile 23 μg/L and adult life history stages was observed, the present study contributes important information for the development of water quality guidelines in polar regions. Environ Toxicol Chem 2018;37:807-815. © 2017 SETAC. © 2017 SETAC.

  17. Feature ranking and rank aggregation for automatic sleep stage classification: a comparative study.

    Science.gov (United States)

    Najdi, Shirin; Gharbali, Ali Abdollahi; Fonseca, José Manuel

    2017-08-18

    Nowadays, sleep quality is one of the most important measures of healthy life, especially considering the huge number of sleep-related disorders. Identifying sleep stages using polysomnographic (PSG) signals is the traditional way of assessing sleep quality. However, the manual process of sleep stage classification is time-consuming, subjective and costly. Therefore, in order to improve the accuracy and efficiency of the sleep stage classification, researchers have been trying to develop automatic classification algorithms. Automatic sleep stage classification mainly consists of three steps: pre-processing, feature extraction and classification. Since classification accuracy is deeply affected by the extracted features, a poor feature vector will adversely affect the classifier and eventually lead to low classification accuracy. Therefore, special attention should be given to the feature extraction and selection process. In this paper the performance of seven feature selection methods, as well as two feature rank aggregation methods, were compared. Pz-Oz EEG, horizontal EOG and submental chin EMG recordings of 22 healthy males and females were used. A comprehensive feature set including 49 features was extracted from these recordings. The extracted features are among the most common and effective features used in sleep stage classification from temporal, spectral, entropy-based and nonlinear categories. The feature selection methods were evaluated and compared using three criteria: classification accuracy, stability, and similarity. Simulation results show that MRMR-MID achieves the highest classification performance while Fisher method provides the most stable ranking. In our simulations, the performance of the aggregation methods was in the average level, although they are known to generate more stable results and better accuracy. The Borda and RRA rank aggregation methods could not outperform significantly the conventional feature ranking methods. Among

  18. Hydrogeological conceptual model development and numerical modelling using CONNECTFLOW, Forsmark modelling stage 2.3

    Energy Technology Data Exchange (ETDEWEB)

    Follin, Sven (SF GeoLogic AB, Taeby (Sweden)); Hartley, Lee; Jackson, Peter; Roberts, David (Serco TAP (United Kingdom)); Marsic, Niko (Kemakta Konsult AB, Stockholm (Sweden))

    2008-05-15

    Three versions of a site descriptive model (SDM) have been completed for the Forsmark area. Version 0 established the state of knowledge prior to the start of the site investigation programme. Version 1.1 was essentially a training exercise and was completed during 2004. Version 1.2 was a preliminary site description and concluded the initial site investigation work (ISI) in June 2005. Three modelling stages are planned for the complete site investigation work (CSI). These are labelled stage 2.1, 2.2 and 2.3, respectively. An important component of each of these stages is to address and continuously try to resolve discipline-specific uncertainties of importance for repository engineering and safety assessment. Stage 2.1 included an updated geological model for Forsmark and aimed to provide a feedback from the modelling working group to the site investigation team to enable completion of the site investigation work. Stage 2.2 described the conceptual understanding and the numerical modelling of the bedrock hydrogeology in the Forsmark area based on data freeze 2.2. The present report describes the modelling based on data freeze 2.3, which is the final data freeze in Forsmark. In comparison, data freeze 2.3 is considerably smaller than data freeze 2.2. Therefore, stage 2.3 deals primarily with model confirmation and uncertainty analysis, e.g. verification of important hypotheses made in stage 2.2 and the role of parameter uncertainty in the numerical modelling. On the whole, the work reported here constitutes an addendum to the work reported in stage 2.2. Two changes were made to the CONNECTFLOW code in stage 2.3. These serve to: 1) improve the representation of the hydraulic properties of the regolith, and 2) improve the conditioning of transmissivity of the deformation zones against single-hole hydraulic tests. The changes to the modelling of the regolith were made to improve the consistency with models made with the MIKE SHE code, which involved the introduction

  19. Comparative responses to endocrine disrupting compounds in early life stages of Atlantic salmon, Salmo salar.

    Science.gov (United States)

    Duffy, T A; Iwanowicz, L R; McCormick, S D

    2014-07-01

    Atlantic salmon (Salmo salar) are endangered anadromous fish that may be exposed to feminizing endocrine disrupting compounds (EDCs) during early development, potentially altering physiological capacities, survival and fitness. To assess differential life stage sensitivity to common EDCs, we carried out short-term (4 day) exposures using three doses each of 17 α-ethinylestradiol (EE2), 17 β-estradiol (E2), and nonylphenol (NP) on four early life stages; embryos, yolk-sac larvae, feeding fry and 1 year old smolts. Differential response was compared using vitellogenin (Vtg, a precursor egg protein) gene transcription. Smolts were also examined for impacts on plasma Vtg, cortisol, thyroid hormones (T4/T3) and hepatosomatic index (HSI). Compound-related mortality was not observed in any life stage, but Vtg mRNA was elevated in a dose-dependent manner in yolk-sac larvae, fry and smolts but not in embryos. The estrogens EE2 and E2 were consistently stronger inducers of Vtg than NP. Embryos responded significantly to the highest concentration of EE2 only, while older life stages responded to the highest doses of all three compounds, as well as intermediate doses of EE2 and E2. Maximal transcription was greater for fry among the three earliest life stages, suggesting fry may be the most responsive life stage in early development. Smolt plasma Vtg was also significantly increased, and this response was observed at lower doses of each compound than was detected by gene transcription suggesting plasma Vtg is a more sensitive indicator at this life stage. HSI was increased at the highest doses of EE2 and E2, and plasma T3 was decreased at the highest dose of EE2. Our results indicate that all life stages are potentially sensitive to endocrine disruption by estrogenic compounds and that physiological responses were altered over a short window of exposure, indicating the potential for these compounds to impact fish in the wild. Copyright © 2014 Elsevier B.V. All rights

  20. Comparative Influences of Precipitation and River Stage on Groundwater Levels in Near-River Areas

    Directory of Open Access Journals (Sweden)

    Incheol Kim

    2015-12-01

    Full Text Available The sustainable performance of foundations of various urban buildings and infrastructures is strongly affected by groundwater level (GWL, as GWL causes changes in the stress state within soil. In the present study, the components affecting GWL were investigated, focusing on the effects of precipitation and river stage. These components were analyzed using a six-year database established for hydrological and groundwater monitoring data. Five study regions for which daily measured precipitation, river stage, and GWL data were available were compared. Different periods of precipitation, geographical characteristics, and local surface conditions were considered in the analysis. The results indicated that key influence components on GWL are different depending on the hydrological, geological, and geographical characteristics of the target regions. River stage had the strongest influence on GWL in urban areas near large rivers with a high ratio of paved surface. In rural areas, where the paved surface area ratio and soil permeability were low, the moving average showed a closer correlation to GWL than river stage. A moving average-based method to predict GWL variation with time was proposed for regions with a low ratio of paved surface area and low permeability soils.

  1. A Population-Based Comparative Effectiveness Study of Radiation Therapy Techniques in Stage III Non-Small Cell Lung Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Harris, Jeremy P. [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California (United States); Murphy, James D. [Department of Radiation Medicine and Applied Science, University of California– San Diego, Moores Cancer Center, La Jolla, California (United States); Hanlon, Alexandra L. [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California (United States); University of Pennsylvania School of Nursing, Philadelphia, Pennsylvania (United States); Le, Quynh-Thu [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California (United States); Stanford Cancer Institute, Stanford University School of Medicine, Stanford, California (United States); Loo, Billy W., E-mail: BWLoo@Stanford.edu [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California (United States); Stanford Cancer Institute, Stanford University School of Medicine, Stanford, California (United States); Diehn, Maximilian, E-mail: diehn@Stanford.edu [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California (United States); Stanford Cancer Institute, Stanford University School of Medicine, Stanford, California (United States); Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, California (United States)

    2014-03-15

    Purpose: Concerns have been raised about the potential for worse treatment outcomes because of dosimetric inaccuracies related to tumor motion and increased toxicity caused by the spread of low-dose radiation to normal tissues in patients with locally advanced non-small cell lung cancer (NSCLC) treated with intensity modulated radiation therapy (IMRT). We therefore performed a population-based comparative effectiveness analysis of IMRT, conventional 3-dimensional conformal radiation therapy (3D-CRT), and 2-dimensional radiation therapy (2D-RT) in stage III NSCLC. Methods and Materials: We used the Surveillance, Epidemiology, and End Results (SEER)-Medicare database to identify a cohort of patients diagnosed with stage III NSCLC from 2002 to 2009 treated with IMRT, 3D-CRT, or 2D-RT. Using Cox regression and propensity score matching, we compared survival and toxicities of these treatments. Results: The proportion of patients treated with IMRT increased from 2% in 2002 to 25% in 2009, and the use of 2D-RT decreased from 32% to 3%. In univariate analysis, IMRT was associated with improved overall survival (OS) (hazard ratio [HR] 0.90, P=.02) and cancer-specific survival (CSS) (HR 0.89, P=.02). After controlling for confounders, IMRT was associated with similar OS (HR 0.94, P=.23) and CSS (HR 0.94, P=.28) compared with 3D-CRT. Both techniques had superior OS compared with 2D-RT. IMRT was associated with similar toxicity risks on multivariate analysis compared with 3D-CRT. Propensity score matched model results were similar to those from adjusted models. Conclusions: In this population-based analysis, IMRT for stage III NSCLC was associated with similar OS and CSS and maintained similar toxicity risks compared with 3D-CRT.

  2. Comparing the Discrete and Continuous Logistic Models

    Science.gov (United States)

    Gordon, Sheldon P.

    2008-01-01

    The solutions of the discrete logistic growth model based on a difference equation and the continuous logistic growth model based on a differential equation are compared and contrasted. The investigation is conducted using a dynamic interactive spreadsheet. (Contains 5 figures.)

  3. Two stage neural network modelling for robust model predictive control.

    Science.gov (United States)

    Patan, Krzysztof

    2018-01-01

    The paper proposes a novel robust model predictive control scheme realized by means of artificial neural networks. The neural networks are used twofold: to design the so-called fundamental model of a plant and to catch uncertainty associated with the plant model. In order to simplify the optimization process carried out within the framework of predictive control an instantaneous linearization is applied which renders it possible to define the optimization problem in the form of constrained quadratic programming. Stability of the proposed control system is also investigated by showing that a cost function is monotonically decreasing with respect to time. Derived robust model predictive control is tested and validated on the example of a pneumatic servomechanism working at different operating regimes. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  4. Geology - Background complementary studies. Forsmark modelling stage 2.2

    Energy Technology Data Exchange (ETDEWEB)

    Stephens, Michael B. [Geological Survey of Sweden, Uppsala (Sweden); Skagius, Kristina [Kemakta Konsult AB, Stockholm (Sweden)] (eds.)

    2007-09-15

    During Forsmark model stage 2.2, seven complementary geophysical and geological studies were initiated by the geological modelling team, in direct connection with and as a background support to the deterministic modelling of deformation zones. One of these studies involved a field control on the character of two low magnetic lineaments with NNE and NE trends inside the target volume. The interpretation of these lineaments formed one of the late deliveries to SKB that took place after the data freeze for model stage 2.2 and during the initial stage of the modelling work. Six studies involved a revised processing and analysis of reflection seismic, refraction seismic and selected oriented borehole radar data, all of which had been presented earlier in connection with the site investigation programme. A prime aim of all these studies was to provide a better understanding of the geological significance of indirect geophysical data to the geological modelling team. Such essential interpretative work was lacking in the material acquired in connection with the site investigation programme. The results of these background complementary studies are published together in this report. The titles and authors of the seven background complementary studies are presented below. Summaries of the results of each study, with a focus on the implications for the geological modelling of deformation zones, are presented in the master geological report, SKB-R--07-45. The sections in the master report, where reference is made to each background complementary study and where the summaries are placed, are also provided. The individual reports are listed in the order that they are referred to in the master geological report and as they appear in this report. 1. Scan line fracture mapping and magnetic susceptibility measurements across two low magnetic lineaments with NNE and NE trend, Forsmark. Jesper Petersson, Ulf B. Andersson and Johan Berglund. 2. Integrated interpretation of surface and

  5. Geology - Background complementary studies. Forsmark modelling stage 2.2

    International Nuclear Information System (INIS)

    Stephens, Michael B.; Skagius, Kristina

    2007-09-01

    During Forsmark model stage 2.2, seven complementary geophysical and geological studies were initiated by the geological modelling team, in direct connection with and as a background support to the deterministic modelling of deformation zones. One of these studies involved a field control on the character of two low magnetic lineaments with NNE and NE trends inside the target volume. The interpretation of these lineaments formed one of the late deliveries to SKB that took place after the data freeze for model stage 2.2 and during the initial stage of the modelling work. Six studies involved a revised processing and analysis of reflection seismic, refraction seismic and selected oriented borehole radar data, all of which had been presented earlier in connection with the site investigation programme. A prime aim of all these studies was to provide a better understanding of the geological significance of indirect geophysical data to the geological modelling team. Such essential interpretative work was lacking in the material acquired in connection with the site investigation programme. The results of these background complementary studies are published together in this report. The titles and authors of the seven background complementary studies are presented below. Summaries of the results of each study, with a focus on the implications for the geological modelling of deformation zones, are presented in the master geological report, SKB-R--07-45. The sections in the master report, where reference is made to each background complementary study and where the summaries are placed, are also provided. The individual reports are listed in the order that they are referred to in the master geological report and as they appear in this report. 1. Scan line fracture mapping and magnetic susceptibility measurements across two low magnetic lineaments with NNE and NE trend, Forsmark. Jesper Petersson, Ulf B. Andersson and Johan Berglund. 2. Integrated interpretation of surface and

  6. Comparative Analysis between preoperative Radiotherapy and postoperative Radiotherapy in Clinical Stage I and II Endometrial Carcinoma

    International Nuclear Information System (INIS)

    Keum, Ki Chang; Lee, Chang Geol; Chung, Eun Ji; Lee, Sang Wook; Kim, Woo Cheol; Chang, Sei Kyung; Oh, Young Taek; Suh, Chang Ok; Kim, Gwi Eon

    1995-01-01

    Purpose : To obtain the optical treatment method in patients with endometrial carcinoma(clinical stage FIGO I, II) by comparative analysis between preoperative radiotherapy(pre-op R) and postoperative radiotherapy(post-op RT). Materials and Methods : A retrospective review of 62 endometrial carcinoma patients referred to the Yonsei Cancer Center for radiotherapy between 1985 and 1991 was undertaken. Of 62 patients, 19 patients(Stage I; 12 patients, Stage II; 7 patients) received pre-op RT before TAH(Total Abdominal Hysterectomy) and BSO(Bilateral Salphingoophorectomy) (Group 1) and 43 patients( Stage 1; 32 patients, Stage 2; 11 patients) received post-op RT after TAH and BSO (Group 2). Pre-op irradiation was given 4-6 weeks prior to surgery and post-op RT was administered on 4-5 weeks following surgery. All patients exept 1 patient(Group2; ICR alone) received external irradiation. Seventy percent(13/19) of pre-op RT group and 54 percent(23/42) of post-op RT group received external pelvic irradiation and intracavitary radiation therapy(ICR). External radiation dose was 39.6-55Gy(median 45Gy) in 5-6 week through opposed AP/PA fields or 4-field box technique treating daily, five days per week, 180cGy per fraction. ICR doses were prescribed to point A(20-39.6 Gy, median 39Gy) in Group 1 and 0.5cm depth from vaginal surface (18-30 Gy, median 21Gy) in Group2. Results : The overall 5 year survival rate was 95%. No survival difference between pre-op and post-op RT group.(89.3% vs 97.7%, p>0.1) There was no survival difference by stage, grade and histology between two groups. The survival rate was not affected by presence of residual tumor of surgical specimen after pre-op RT in Group 1(p>0.1), but affected by presence of lymph node metastasis in post-op RT group(p<0.5). The complication rate of pre-op RT group was higher than post-op RT.(16% vs 5%) Conclusion : Post-op radiotherapy offers the advantages of accurate surgical-pathological staging and low complication rate

  7. 18F-FDG PET/CT for initial staging in breast cancer patients. Is there a relevant impact on treatment planning compared to conventional staging modalities?

    International Nuclear Information System (INIS)

    Krammer, J.; Schnitzer, A.; Kaiser, C.G.; Buesing, K.A.; Schoenberg, S.O.; Wasser, K.; Sperk, E.; Brade, J.; Wasgindt, S.; Suetterlin, M.; Sutton, E.J.

    2015-01-01

    To evaluate the impact of whole-body 18 F-FDG PET/CT on initial staging of breast cancer in comparison to conventional staging modalities. This study included 102 breast cancer patients, 101 patients were eligible for evaluation. Preoperative whole-body staging with PET/CT was performed in patients with clinical stage ≥ T2 tumours or positive local lymph nodes (n = 91). Postoperative PET/CT was performed in patients without these criteria but positive sentinel lymph node biopsy (n = 10). All patients underwent PET/CT and a conventional staging algorithm, which included bone scan, chest X-ray and abdominal ultrasound. PET/CT findings were compared to conventional staging and the impact on therapeutic management was evaluated. PET/CT led to an upgrade of the N or M stage in overall 19 patients (19 %) and newly identified manifestation of breast cancer in two patients (2 %). PET/CT findings caused a change in treatment of 11 patients (11 %). This is within the range of recent studies, all applying conventional inclusion criteria based on the initial T and N status. PET/CT has a relevant impact on initial staging and treatment of breast cancer when compared to conventional modalities. Further studies should assess inclusion criteria beyond the conventional T and N status, e.g. tumour grading and receptor status. (orig.)

  8. GENERALISED MODEL BASED CONFIDENCE INTERVALS IN TWO STAGE CLUSTER SAMPLING

    Directory of Open Access Journals (Sweden)

    Christopher Ouma Onyango

    2010-09-01

    Full Text Available Chambers and Dorfman (2002 constructed bootstrap confidence intervals in model based estimation for finite population totals assuming that auxiliary values are available throughout a target population and that the auxiliary values are independent. They also assumed that the cluster sizes are known throughout the target population. We now extend to two stage sampling in which the cluster sizes are known only for the sampled clusters, and we therefore predict the unobserved part of the population total. Jan and Elinor (2008 have done similar work, but unlike them, we use a general model, in which the auxiliary values are not necessarily independent. We demonstrate that the asymptotic properties of our proposed estimator and its coverage rates are better than those constructed under the model assisted local polynomial regression model.

  9. Comparative spring-staging ecology of sympatric arctic-nesting geese in south-central Nebraska

    Science.gov (United States)

    Pearse, Aaron T.; Krapu, Gary L.; Cox, Robert R.

    2013-01-01

    The Rainwater Basin in Nebraska has been a historic staging area for midcontinent greater white-fronted geese (Anser albifrons frontalis) since the 1950s and, in the mid-1990s, millions of midcontinent lesser snow geese (Chen caerulescens caerulescens) expanded their spring migration route to include this region. In response to speculation that snow geese may be in direct competition with white-fronted geese, we compared staging ecology by quantifying diet, habitat use, movement patterns, and time budgets during springs 1998–1999. Collected white-fronted geese (n  =  190) and snow geese (n  =  203) consumed primarily corn (Zea mays; 97–98% aggregate dry mass) while staging in Nebraska; thus, diet overlap was nearly complete. Both species used cornfields most frequently during the morning (54–55%) and wetlands more during the afternoon (51–65%). When found grouped together, snow goose abundance was greater than white-fronted goose abundance by an average of 57 times (se  =  11, n  =  131 groups) in crop fields and 28 times (se  =  9, n  =  84 groups) in wetlands. Snow geese and white-fronted geese flew similar distances between roosting and feeding sites, leaving and returning to wetland roost sties at similar times in mornings and afternoons. Overlap in habitat-specific time budgets was high; resting was the most common behavior on wetlands, and foraging was a common behavior in fields. We observed 111 interspecific agonistic interactions while observing white-fronted and snow geese. White-fronted geese initiated and dominated more interactions with other waterfowl species than did snow geese (32 vs. 14%). Certain aspects of spring-staging niches (i.e., diet, habitat use, movement patterns, and habitat-specific behavior) of white-fronted and snow geese overlapped greatly at this mid-latitude staging site, creating opportunity for potential food- and habitat-based competition between species. Snow geese did not consistently dominate

  10. Comparative Analysis of Direct Hospital Care Costs between Aseptic and Two-Stage Septic Knee Revision

    Science.gov (United States)

    Kasch, Richard; Merk, Sebastian; Assmann, Grit; Lahm, Andreas; Napp, Matthias; Merk, Harry; Flessa, Steffen

    2017-01-01

    Background The most common intermediate and long-term complications of total knee arthroplasty (TKA) include aseptic and septic failure of prosthetic joints. These complications cause suffering, and their management is expensive. In the future the number of revision TKA will increase, which involves a greater financial burden. Little concrete data about direct costs for aseptic and two-stage septic knee revisions with an in depth-analysis of septic explantation and implantation is available. Questions/Purposes A retrospective consecutive analysis of the major partial costs involved in revision TKA for aseptic and septic failure was undertaken to compare 1) demographic and clinical characteristics, and 2) variable direct costs (from a hospital department’s perspective) between patients who underwent single-stage aseptic and two-stage septic revision of TKA in a hospital providing maximum care. We separately analyze the explantation and implantation procedures in septic revision cases and identify the major cost drivers of knee revision operations. Methods A total of 106 consecutive patients (71 aseptic and 35 septic) was included. All direct costs of diagnosis, surgery, and treatment from the hospital department’s perspective were calculated as real purchase prices. Personnel involvement was calculated in units of minutes. Results Aseptic versus septic revisions differed significantly in terms of length of hospital stay (15.2 vs. 39.9 days), number of reported secondary diagnoses (6.3 vs. 9.8) and incision-suture time (108.3 min vs. 193.2 min). The management of septic revision TKA was significantly more expensive than that of aseptic failure ($12,223.79 vs. $6,749.43) (p costs of explantation stage ($4,540.46) were lower than aseptic revision TKA ($6,749.43) which were again lower than those of the septic implantation stage ($7,683.33). All mean costs of stays were not comparable as they differ significantly (p cost drivers were the cost of the implant and

  11. A Comparative of business process modelling techniques

    Science.gov (United States)

    Tangkawarow, I. R. H. T.; Waworuntu, J.

    2016-04-01

    In this era, there is a lot of business process modeling techniques. This article is the research about differences of business process modeling techniques. For each technique will explain about the definition and the structure. This paper presents a comparative analysis of some popular business process modelling techniques. The comparative framework is based on 2 criteria: notation and how it works when implemented in Somerleyton Animal Park. Each technique will end with the advantages and disadvantages. The final conclusion will give recommend of business process modeling techniques that easy to use and serve the basis for evaluating further modelling techniques.

  12. COMPARATIVE ANALYSIS OF SOFTWARE DEVELOPMENT MODELS

    OpenAIRE

    Sandeep Kaur*

    2017-01-01

    No geek is unfamiliar with the concept of software development life cycle (SDLC). This research deals with the various SDLC models covering waterfall, spiral, and iterative, agile, V-shaped, prototype model. In the modern era, all the software systems are fallible as they can’t stand with certainty. So, it is tried to compare all aspects of the various models, their pros and cons so that it could be easy to choose a particular model at the time of need

  13. A two-stage stochastic rule-based model to determine pre-assembly buffer content

    Science.gov (United States)

    Gunay, Elif Elcin; Kula, Ufuk

    2018-01-01

    This study considers instant decision-making needs of the automobile manufactures for resequencing vehicles before final assembly (FA). We propose a rule-based two-stage stochastic model to determine the number of spare vehicles that should be kept in the pre-assembly buffer to restore the altered sequence due to paint defects and upstream department constraints. First stage of the model decides the spare vehicle quantities, where the second stage model recovers the scrambled sequence respect to pre-defined rules. The problem is solved by sample average approximation (SAA) algorithm. We conduct a numerical study to compare the solutions of heuristic model with optimal ones and provide following insights: (i) as the mismatch between paint entrance and scheduled sequence decreases, the rule-based heuristic model recovers the scrambled sequence as good as the optimal resequencing model, (ii) the rule-based model is more sensitive to the mismatch between the paint entrance and scheduled sequences for recovering the scrambled sequence, (iii) as the defect rate increases, the difference in recovery effectiveness between rule-based heuristic and optimal solutions increases, (iv) as buffer capacity increases, the recovery effectiveness of the optimization model outperforms heuristic model, (v) as expected the rule-based model holds more inventory than the optimization model.

  14. Developmental stages of an African child and their psychological implications: a comparative study

    OpenAIRE

    2008-01-01

    D. Phil. Human development is a universal phenomenon, characterized by various stages. These stages differ from one culture to the other. Furthermore, each developmental stage tends to bring about expectations that are in accordance with a particular culture. In addition, in each culture there exist problems that are specific to a given stage as well as to the manner in which these problems are resolved. Erikson=s stages of human development are generally regarded as universal. The univers...

  15. Para-aortic lymphadenectomy in advanced stage cervical cancer, a protocol for comparing safety, feasibility and diagnostic accuracy of surgical staging versus PET-CT; PALDISC trial.

    Science.gov (United States)

    Tax, Casper; Abbink, Karin; Rovers, Maroeska M; Bekkers, Ruud L M; Zusterzeel, Petra L M

    2018-01-01

    Currently, a PET-CT is used to assess the need for extended field radiotherapy of para-aortic lymph nodes (PALN) in International Federation of Gynaecology and Obstetrics (FIGO) stage IB2, IIA2-IVA (locally advanced stage) cervical cancer. A small study established a sensitivity and specificity estimate for PALN metastases of 50% (95% CI; 7-93%) and 83% (95% CI; 52-98%), respectively. Surgical staging of PALN may lead to a higher diagnostic accuracy. However, surgical staging of para-aortic lymph nodes in locally advanced stage cervical cancer is not common practice. Therefore, a phase 2 randomised controlled trial is needed to assess its safety and feasibility. In addition to standard imaging (MRI or CT scan) with PET-CT, 30 adult women with FIGO stage IB2, IIA2-IVA cervical cancer will be randomised to receive either surgical staging or usual PET-CT staging. Administering extended field radiotherapy will be based on lymphadenectomy results for the intervention group and on the PET-CT results for the control group. Follow-up visits at 0, 3, 6, 9 and 12 months will assess health-related quality of life and progression-free survival.Primary safety and feasibility outcomes of surgical staging will be assessed by calculating means with 95% confidence intervals for duration of surgery, number of complications, blood loss, nodal yield after para-aortic lymphadenectomy and treatment delay due to surgical staging. Secondary patient-centred outcomes on quality of life and first year survival will be documented and compared between the two groups. Estimates of sensitivity, specificity and negative and positive predictive values of MRI, PET-CT and surgical staging will be presented with 95% CI.. All analysis will be performed according to the intention to treat principle. This study will assess safety and feasibility, expressed as the number and severity of complications, effect on quality of life and the treatment delay due to surgically staging para-aortic lymph nodes in

  16. Is it Worth Comparing Different Bankruptcy Models?

    Directory of Open Access Journals (Sweden)

    Miroslava Dolejšová

    2015-01-01

    Full Text Available The aim of this paper is to compare the performance of small enterprises in the Zlín and Olomouc Regions. These enterprises were assessed using the Altman Z-Score model, the IN05 model, the Zmijewski model and the Springate model. The batch selected for this analysis included 16 enterprises from the Zlín Region and 16 enterprises from the Olomouc Region. Financial statements subjected to the analysis are from 2006 and 2010. The statistical data analysis was performed using the one-sample z-test for proportions and the paired t-test. The outcomes of the evaluation run using the Altman Z-Score model, the IN05 model and the Springate model revealed the enterprises to be financially sound, but the Zmijewski model identified them as being insolvent. The one-sample z-test for proportions confirmed that at least 80% of these enterprises show a sound financial condition. A comparison of all models has emphasized the substantial difference produced by the Zmijewski model. The paired t-test showed that the financial performance of small enterprises had remained the same during the years involved. It is recommended that small enterprises assess their financial performance using two different bankruptcy models. They may wish to combine the Zmijewski model with any bankruptcy model (the Altman Z-Score model, the IN05 model or the Springate model to ensure a proper method of analysis.

  17. Wellness Model of Supervision: A Comparative Analysis

    Science.gov (United States)

    Lenz, A. Stephen; Sangganjanavanich, Varunee Faii; Balkin, Richard S.; Oliver, Marvarene; Smith, Robert L.

    2012-01-01

    This quasi-experimental study compared the effectiveness of the Wellness Model of Supervision (WELMS; Lenz & Smith, 2010) with alternative supervision models for developing wellness constructs, total personal wellness, and helping skills among counselors-in-training. Participants were 32 master's-level counseling students completing their…

  18. Early‐Stage Capital Cost Estimation of Biorefinery Processes: A Comparative Study of Heuristic Techniques

    Science.gov (United States)

    Couturier, Jean‐Luc; Kokossis, Antonis; Dubois, Jean‐Luc

    2016-01-01

    Abstract Biorefineries offer a promising alternative to fossil‐based processing industries and have undergone rapid development in recent years. Limited financial resources and stringent company budgets necessitate quick capital estimation of pioneering biorefinery projects at the early stages of their conception to screen process alternatives, decide on project viability, and allocate resources to the most promising cases. Biorefineries are capital‐intensive projects that involve state‐of‐the‐art technologies for which there is no prior experience or sufficient historical data. This work reviews existing rapid cost estimation practices, which can be used by researchers with no previous cost estimating experience. It also comprises a comparative study of six cost methods on three well‐documented biorefinery processes to evaluate their accuracy and precision. The results illustrate discrepancies among the methods because their extrapolation on biorefinery data often violates inherent assumptions. This study recommends the most appropriate rapid cost methods and urges the development of an improved early‐stage capital cost estimation tool suitable for biorefinery processes. PMID:27484398

  19. Efficacy and safety of a diode laser in second-stage implant surgery: a comparative study.

    Science.gov (United States)

    El-Kholey, K E

    2014-05-01

    For more than a decade, peri-implant tissues have been treated with soft tissue lasers to create a bloodless flap for implant placement and to uncover implants with minimal bleeding, trauma, and anaesthesia. This study was designed to assess if dental implant uncovering is possible with a diode laser without anaesthesia, and to compare its performance with traditional cold scalpel surgery. Thirty patients with a total of 45 completely osseointegrated implants participated in this study. Patients were divided into two groups. For the study group, second-stage implant surgery was done with a 970nm diode laser. For the control group, the implants were exposed with a surgical blade. Certain parameters were used for evaluation of the two techniques. The use of the diode laser obviated the need for local anaesthesia; there was a significant difference between the two groups regarding the need for anaesthesia (Pdiode laser can be used effectively for second-stage implant surgery, providing both the dentist and the patient with additional advantages over the conventional methods used for implant exposure. Copyright © 2013 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  20. A Dual-Stage Two-Phase Model of Selective Attention

    Science.gov (United States)

    Hubner, Ronald; Steinhauser, Marco; Lehle, Carola

    2010-01-01

    The dual-stage two-phase (DSTP) model is introduced as a formal and general model of selective attention that includes both an early and a late stage of stimulus selection. Whereas at the early stage information is selected by perceptual filters whose selectivity is relatively limited, at the late stage stimuli are selected more efficiently on a…

  1. A two-stage stochastic programming model for the optimal design of distributed energy systems

    International Nuclear Information System (INIS)

    Zhou, Zhe; Zhang, Jianyun; Liu, Pei; Li, Zheng; Georgiadis, Michael C.; Pistikopoulos, Efstratios N.

    2013-01-01

    Highlights: ► The optimal design of distributed energy systems under uncertainty is studied. ► A stochastic model is developed using genetic algorithm and Monte Carlo method. ► The proposed system possesses inherent robustness under uncertainty. ► The inherent robustness is due to energy storage facilities and grid connection. -- Abstract: A distributed energy system is a multi-input and multi-output energy system with substantial energy, economic and environmental benefits. The optimal design of such a complex system under energy demand and supply uncertainty poses significant challenges in terms of both modelling and corresponding solution strategies. This paper proposes a two-stage stochastic programming model for the optimal design of distributed energy systems. A two-stage decomposition based solution strategy is used to solve the optimization problem with genetic algorithm performing the search on the first stage variables and a Monte Carlo method dealing with uncertainty in the second stage. The model is applied to the planning of a distributed energy system in a hotel. Detailed computational results are presented and compared with those generated by a deterministic model. The impacts of demand and supply uncertainty on the optimal design of distributed energy systems are systematically investigated using proposed modelling framework and solution approach.

  2. Bladder cancer staging in CT urography: effect of stage labels on statistical modeling of a decision support system

    Science.gov (United States)

    Gandikota, Dhanuj; Hadjiiski, Lubomir; Cha, Kenny H.; Chan, Heang-Ping; Caoili, Elaine M.; Cohan, Richard H.; Weizer, Alon; Alva, Ajjai; Paramagul, Chintana; Wei, Jun; Zhou, Chuan

    2018-02-01

    In bladder cancer, stage T2 is an important threshold in the decision of administering neoadjuvant chemotherapy. Our long-term goal is to develop a quantitative computerized decision support system (CDSS-S) to aid clinicians in accurate staging. In this study, we examined the effect of stage labels of the training samples on modeling such a system. We used a data set of 84 bladder cancers imaged with CT Urography (CTU). At clinical staging prior to treatment, 43 lesions were staged as below stage T2 and 41 were stage T2 or above. After cystectomy and pathological staging that is considered the gold standard, 10 of the lesions were upstaged to stage T2 or above. After correcting the stage labels, 33 lesions were below stage T2, and 51 were stage T2 or above. For the CDSS-S, the lesions were segmented using our AI-CALS method and radiomic features were extracted. We trained a linear discriminant analysis (LDA) classifier with leave-one-case-out cross validation to distinguish between bladder lesions of stage T2 or above and those below stage T2. The CDSS-S was trained and tested with the corrected post-cystectomy labels, and as a comparison, CDSS-S was also trained with understaged pre-treatment labels and tested on lesions with corrected labels. The test AUC for the CDSS-S trained with corrected labels was 0.89 +/- 0.04. For the CDSS-S trained with understaged pre-treatment labels and tested on the lesions with corrected labels, the test AUC was 0.86 +/- 0.04. The likelihood of stage T2 or above for 9 out of the 10 understaged lesions was correctly increased for the CDSS-S trained with corrected labels. The CDSS-S is sensitive to the accuracy of stage labeling. The CDSS-S trained with correct labels shows promise in prediction of the bladder cancer stage.

  3. Comparative toxicity of four crude oils to the early life stages of rainbow trout (Oncorhynchus mykiss)

    International Nuclear Information System (INIS)

    Clarke, L.M.J.; Khan, C.W.; Akhtar, P.; Hodson, P.V.; Short, J.W.

    2004-01-01

    Crude oil is a source of polycyclic aromatic hydrocarbons (PAH) in aquatic ecosystems. Fish that are chronically exposed to alkyl PAHs show dioxin-like toxicity characterized by the presence of blue sac disease (BSD) and the induction of cytochrome P4501A (CYP1A). This study compared the relative toxicity of four crude oils (Scotian Light Crude, MESA, the synthetic Federated Crude, and Alaska North Slope Crude) to early life stages of rainbow trout (Oncorhynchus mykiss). The study examined the influence of the four crudes in causing the disease in rainbow trout embryos living in simulated spawning beds with hydrocarbon-contaminated gravel. Each oil had different chemical characteristics and PAH concentrations. Mortality in the direct exposure experiment increased as the oil concentration increased. The same trend was observed for the BSD prevalence. The study showed that Scotian Light Crude was the least toxic, with BSD increasing only at the highest concentration. 7 refs., 2 tabs., 1 fig

  4. Investigating the performance of directional boundary layer model through staged modeling method

    Science.gov (United States)

    Jeong, Moon-Gyu; Lee, Won-Chan; Yang, Seung-Hune; Jang, Sung-Hoon; Shim, Seong-Bo; Kim, Young-Chang; Suh, Chun-Suk; Choi, Seong-Woon; Kim, Young-Hee

    2011-04-01

    BLM since the feasibility of the BLM has been investigated in many papers[4][5][6]. Instead of fitting the parameters to the wafer critical dimensions (CD) directly, we tried to use the aerial image (AI) from the rigorous simulator with the electromagnetic field (EMF) solver. Usually that kind of method is known as the staged modeling method. To see the advantages of this method we conducted several experiments and observed the results comparing the method of fitting to the wafer CD directly. Through the tests we could observe some remarkable results and confirmed that the staged modeling had better performance in many ways.

  5. Screening for a Chronic Disease: A Multiple Stage Duration Model with Partial Observability.

    Science.gov (United States)

    Mroz, Thomas A; Picone, Gabriel; Sloan, Frank; Yashkin, Arseniy P

    2016-08-01

    We estimate a dynamic multi-stage duration model to investigate how early detection of diabetes can delay the onset of lower extremity complications and death. We allow for partial observability of the disease stage, unmeasured heterogeneity, and endogenous timing of diabetes screening. Timely diagnosis appears important. We evaluate the effectiveness of two potential policies to reduce the monetary costs of frequent screening in terms of lost longevity. Compared to the status quo, the more restrictive policy yields an implicit value for an additional year of life of about $50,000, while the less restrictive policy implies a value of about $120,000.

  6. Comparative evaluation of sea-urchin larval stage sensitivity to ocean acidification.

    Science.gov (United States)

    Passarelli, M C; Cesar, A; Riba, I; DelValls, T A

    2017-10-01

    Changes in the marine carbonate system may affect various calcifying organisms. This study is aimed to compare the sensitivity of embryo-larval development of two species of sea urchins (Paracentrutos lividus and Lytechinus variegatus) collected and exposed to samples from different coastal zone (Spain and Brazil) to ocean acidification. The results showed that the larval stages are very sensitive to small changes in the seawater's pH. The larvae from P. lividus species showed to be more sensitive to acidified elutriate sediments than larvae from L. variegatus sea urchin. Furthermore, this study has demonstrated that the CO 2 enrichment in aquatic ecosystems cause changes on the mobility of the metals: Zn, Cu, Fe, Al and As, which was presented different behavior among them. Although an increase on the mobility of metals was found, the results using the principal component analysis showed that the pH reduction show the highest correlations with the toxicity and is the main cause of embryo-larval development inhibition. In this comparative study it is demonstrated that both species are able to assess potential effects of the ocean acidification related to CO 2 enrichment by both near future scenarios and the risk associated with CO 2 leakages in the Carbon Capture and Storage (CCS) process, and the importance of comparative studies in different zones to improve the understanding of the impacts caused by ocean acidification. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Comparative effects of mesenchymal stem cell therapy in distinct stages of chronic renal failure.

    Science.gov (United States)

    Caldas, Heloisa Cristina; de Paula Couto, Thaís Amarante Peres; Fernandes, Ida Maria Maximina; Baptista, Maria Alice Sperto Ferreira; Kawasaki-Oyama, Rosa Sayoko; Goloni-Bertollo, Eny Maria; Braile, Domingo Marcolino; Abbud-Filho, Mario

    2015-10-01

    The therapeutic potential of adult stem cells in the treatment of chronic diseases is becoming increasingly evident. In the present study, we sought to assess whether treatment with mesenchymal stem cells (MSCs) efficiently retards progression of chronic renal failure (CRF) when administered to experimental models of less severe CRF. We used two renal mass reduction models to simulate different stages of CRF (5/6 or 2/3 mass renal reduction). Renal functional parameters measured were serum creatinine (SCr), creatinine clearance (CCr), rate of decline in CCr (RCCr), and 24-h proteinuria (PT24h). We also evaluated renal morphology by histology and immunohistochemistry. MSCs were obtained from bone marrow aspirates and injected into the renal parenchyma of the remnant kidneys of both groups of rats with CRF (MSC5/6 or MSC2/3). Animals from groups MSC5/6 and CRF2/3 seemed to benefit from MSC therapy because they showed significantly reduction in SCr and PT24h, increase in CCr and slowed the RCCr after 90 days. Treatment reduced glomerulosclerosis but significant improvement did occur in the tubulointerstitial compartment with much less fibrosis and atrophy. MSC therapy reduced inflammation by decreasing macrophage accumulation proliferative activity (PCNA-positive cells) and fibrosis (α-SM-actin). Comparisons of renal functional and morphological parameters responses between the two groups showed that rats MSC2/3 were more responsive to MSC therapy than MSC5/6. This study showed that MSC therapy is efficient to retard CRF progression and might be more effective when administered during less severe stages of CRF.

  8. Constructing stage-structured matrix population models from life tables: comparison of methods

    Directory of Open Access Journals (Sweden)

    Masami Fujiwara

    2017-10-01

    Full Text Available A matrix population model is a convenient tool for summarizing per capita survival and reproduction rates (collectively vital rates of a population and can be used for calculating an asymptotic finite population growth rate (λ and generation time. These two pieces of information can be used for determining the status of a threatened species. The use of stage-structured population models has increased in recent years, and the vital rates in such models are often estimated using a life table analysis. However, potential bias introduced when converting age-structured vital rates estimated from a life table into parameters for a stage-structured population model has not been assessed comprehensively. The objective of this study was to investigate the performance of methods for such conversions using simulated life histories of organisms. The underlying models incorporate various types of life history and true population growth rates of varying levels. The performance was measured by comparing differences in λ and the generation time calculated using the Euler-Lotka equation, age-structured population matrices, and several stage-structured population matrices that were obtained by applying different conversion methods. The results show that the discretization of age introduces only small bias in λ or generation time. Similarly, assuming a fixed age of maturation at the mean age of maturation does not introduce much bias. However, aggregating age-specific survival rates into a stage-specific survival rate and estimating a stage-transition rate can introduce substantial bias depending on the organism’s life history type and the true values of λ. In order to aggregate survival rates, the use of the weighted arithmetic mean was the most robust method for estimating λ. Here, the weights are given by survivorship curve after discounting with λ. To estimate a stage-transition rate, matching the proportion of individuals transitioning, with λ used

  9. Comparing linear probability model coefficients across groups

    DEFF Research Database (Denmark)

    Holm, Anders; Ejrnæs, Mette; Karlson, Kristian Bernt

    2015-01-01

    of the following three components: outcome truncation, scale parameters and distributional shape of the predictor variable. These results point to limitations in using linear probability model coefficients for group comparisons. We also provide Monte Carlo simulations and real examples to illustrate......This article offers a formal identification analysis of the problem in comparing coefficients from linear probability models between groups. We show that differences in coefficients from these models can result not only from genuine differences in effects, but also from differences in one or more...... these limitations, and we suggest a restricted approach to using linear probability model coefficients in group comparisons....

  10. Comparative analysis among X-ray mammographic findings, nuclear and histologic grading, and TNM staging of breast carcinoma

    International Nuclear Information System (INIS)

    Park, Jin Sook; Sung, Ki Joon; Cho, Mee Yon; Hong, In Soo; Kim, Myung Soon; Oh, Ki Keun

    1996-01-01

    The purpose of this study was to evaluate the prognosis of breast carcinoma by comparison with X-ray mammographic findings, nuclear and histologic grade, and TNM staging. We retrospectively reviewed 114 cases (113 patients) of breast carcinoma, analysing X-ray mammographic findings of all cases with regard to mass, calcification, and spiculation. In 80 cases of scirrhous invasive ductal breast carcinoma. Black's nuclear and Bloom-Richardson's histologic grade were also evaluated. Mammographic findings and nuclear and histologic grade were compared with TNM staging which might suggest the prognosis of breast carcinoma. X-ray mammographic findings (mass, calcification and spiculation) did not significantly correlate with T staging, but the clinical staging of the spiculation was advanced. These X-ray findings did not significantly correlate with the nuclear grading and the histologic grading. Nuclear grade did not correlate with T and M staging, but correlated significantly with N staging and clinical stage(p < 0.05). Histologic grade did not significantly correlate with TNM staging. The clinical staging of spiculation was advanced and nuclear grade correlated significantly with N stage and clinical staging. X-ray mammographic findings did not directly correlate with nuclear and histologic grading, but combined studies of the evaluation of mammographic findings and nuclear and histologic grade were useful for prognosing breast carcinoma

  11. Kinetic Energy Losses and Efficiency of an Axial Turbine Stage in Numerical Modeling of Unsteady Flows

    Directory of Open Access Journals (Sweden)

    A. S. Laskin

    2015-01-01

    Full Text Available The article presents the results of numerical investigation of kinetic energy (KE loss and blading efficiency of the single-stage axial turbine under different operating conditions, characterized by the ratio u/C0. The calculations are performed by stationary (Stage method and nonstationary (Transient method methods using ANSYS CFX. The novelty of this work lies in the fact that the numerical simulation of steady and unsteady flows in a turbine stage is conducted, and the results are obtained to determine the loss of KE, both separately by the elements of the flow range and their total values, in the stage efficiency as well. The results obtained are compared with the calculated efficiency according to one-dimensional theory.To solve these problems was selected model of axial turbine stage with D/l = 13, blade profiles of rotor and stator of constant cross-section, similar to tested ones in inverted turbine when = 0.3. The degree of reactivity ρ = 0.27, the rotor speed was varied within the range 1000 ÷ 1800 rev/min.Results obtained allow us to draw the following conclusions:1. The level of averaged coefficients of total KE losses in the range of from 0.48 to 0.75 is from 18% to 21% when calculating by the Stage method and from 21% to 25% by the Transient one.2. The level of averaged coefficients of KE losses with the output speed of in the specified range is from 9% to 13%, and almost the same when in calculating by Stage and Transient methods.3. Levels of averaged coefficients of KE loss in blade tips (relative to the differential enthalpies per stage are changed in the range: from 4% to 3% (Stage and are stored to be equal to 5% (Transient; from 5% to 6% (Stage and from 6% to 8% (Transient.4. Coefficients of KE losses in blade tips GV and RB are higher in calculations of the model stage using the Transient method than the Stage one, respectively, by = 1.5 ÷ 2.5% and = 4 ÷ 5% of the absolute values. These are values to characterize the KE

  12. Model atmospheres for novae during the early stages

    International Nuclear Information System (INIS)

    Wehrse, R.; Hauschildt, P.H.; Shaviv, G.; Starrfield, S.; Arizona State Univ., Tempe, AZ

    1989-01-01

    Continuum and line blanketing models for the photospheres of novae in the early stages of their outbursts are presented. The expanding envelopes are characterized by a very slow increase of density with decreasing radius which leads to very large geometrical extensions and large temperature differences between the inner and outer parts. The spectra show a large IR excess and a small Balmer jump which may be either in absorption or in emission. For the parameters considered (T eff = 10 4 , 1.5 x 10 4 , 2 x 10 4 K, R = 10 11 cm, solar composition), most lines are in absorption. The effects of both modifications in the temperature structure (e.g. by heating from shock fronts) and changes in the abundances of the heavy elements on the emergent spectra are briefly discussed. 13 refs., 11 figs

  13. Modelling of the initial stage of the surface discharge development

    International Nuclear Information System (INIS)

    Gibalov, V.; Pietsch, G.

    1998-01-01

    Computer modelling of the initial stage of the surface discharge was performed by solving numerically the coupled continuity, the Poisson and Townsend ionization equations and taking into account the ionization, attachment and detachment processes. The potential distribution at the dielectric surface and at the boundaries which surround the integration region have been calculated with the charge-image method in a 3D approach. In order to eliminate numerical diffusion effects, the solution of the continuity equation was corrected using a flux correction transport routine. At the positive voltage the development of the discharge channel is determined mainly by the shape of the electrode tip. At the negative voltage the following phases of the discharge may be distinguished: the initial phase, the cathode directed streamer phase resulting in the cathode layer formation, and the propagating phase. The physical processes governing each discharge phase are described in detail. (J.U.)

  14. Comparative study of void fraction models

    International Nuclear Information System (INIS)

    Borges, R.C.; Freitas, R.L.

    1985-01-01

    Some models for the calculation of void fraction in water in sub-cooled boiling and saturated vertical upward flow with forced convection have been selected and compared with experimental results in the pressure range of 1 to 150 bar. In order to know the void fraction axial distribution it is necessary to determine the net generation of vapour and the fluid temperature distribution in the slightly sub-cooled boiling region. It was verified that the net generation of vapour was well represented by the Saha-Zuber model. The selected models for the void fraction calculation present adequate results but with a tendency to super-estimate the experimental results, in particular the homogeneous models. The drift flux model is recommended, followed by the Armand and Smith models. (F.E.) [pt

  15. Two-Stage Electricity Demand Modeling Using Machine Learning Algorithms

    Directory of Open Access Journals (Sweden)

    Krzysztof Gajowniczek

    2017-10-01

    Full Text Available Forecasting of electricity demand has become one of the most important areas of research in the electric power industry, as it is a critical component of cost-efficient power system management and planning. In this context, accurate and robust load forecasting is supposed to play a key role in reducing generation costs, and deals with the reliability of the power system. However, due to demand peaks in the power system, forecasts are inaccurate and prone to high numbers of errors. In this paper, our contributions comprise a proposed data-mining scheme for demand modeling through peak detection, as well as the use of this information to feed the forecasting system. For this purpose, we have taken a different approach from that of time series forecasting, representing it as a two-stage pattern recognition problem. We have developed a peak classification model followed by a forecasting model to estimate an aggregated demand volume. We have utilized a set of machine learning algorithms to benefit from both accurate detection of the peaks and precise forecasts, as applied to the Polish power system. The key finding is that the algorithms can detect 96.3% of electricity peaks (load value equal to or above the 99th percentile of the load distribution and deliver accurate forecasts, with mean absolute percentage error (MAPE of 3.10% and resistant mean absolute percentage error (r-MAPE of 2.70% for the 24 h forecasting horizon.

  16. Mathematical modeling of a single stage ultrasonically assisted distillation process.

    Science.gov (United States)

    Mahdi, Taha; Ahmad, Arshad; Ripin, Adnan; Abdullah, Tuan Amran Tuan; Nasef, Mohamed M; Ali, Mohamad W

    2015-05-01

    The ability of sonication phenomena in facilitating separation of azeotropic mixtures presents a promising approach for the development of more intensified and efficient distillation systems than conventional ones. To expedite the much-needed development, a mathematical model of the system based on conservation principles, vapor-liquid equilibrium and sonochemistry was developed in this study. The model that was founded on a single stage vapor-liquid equilibrium system and enhanced with ultrasonic waves was coded using MATLAB simulator and validated with experimental data for ethanol-ethyl acetate mixture. The effects of both ultrasonic frequency and intensity on the relative volatility and azeotropic point were examined, and the optimal conditions were obtained using genetic algorithm. The experimental data validated the model with a reasonable accuracy. The results of this study revealed that the azeotropic point of the mixture can be totally eliminated with the right combination of sonication parameters and this can be utilized in facilitating design efforts towards establishing a workable ultrasonically intensified distillation system. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Comparing coefficients of nested nonlinear probability models

    DEFF Research Database (Denmark)

    Kohler, Ulrich; Karlson, Kristian Bernt; Holm, Anders

    2011-01-01

    In a series of recent articles, Karlson, Holm and Breen have developed a method for comparing the estimated coeffcients of two nested nonlinear probability models. This article describes this method and the user-written program khb that implements the method. The KHB-method is a general decomposi......In a series of recent articles, Karlson, Holm and Breen have developed a method for comparing the estimated coeffcients of two nested nonlinear probability models. This article describes this method and the user-written program khb that implements the method. The KHB-method is a general...... decomposition method that is unaffected by the rescaling or attenuation bias that arise in cross-model comparisons in nonlinear models. It recovers the degree to which a control variable, Z, mediates or explains the relationship between X and a latent outcome variable, Y*, underlying the nonlinear probability...

  18. Comparative Study of Bancruptcy Prediction Models

    Directory of Open Access Journals (Sweden)

    Isye Arieshanti

    2013-09-01

    Full Text Available Early indication of bancruptcy is important for a company. If companies aware of  potency of their bancruptcy, they can take a preventive action to anticipate the bancruptcy. In order to detect the potency of a bancruptcy, a company can utilize a a model of bancruptcy prediction. The prediction model can be built using a machine learning methods. However, the choice of machine learning methods should be performed carefully. Because the suitability of a model depends on the problem specifically. Therefore, in this paper we perform a comparative study of several machine leaning methods for bancruptcy prediction. According to the comparative study, the performance of several models that based on machine learning methods (k-NN, fuzzy k-NN, SVM, Bagging Nearest Neighbour SVM, Multilayer Perceptron(MLP, Hybrid of MLP + Multiple Linear Regression, it can be showed that fuzzy k-NN method achieve the best performance with accuracy 77.5%

  19. Comparing VA and private sector healthcare costs for end-stage renal disease.

    Science.gov (United States)

    Hynes, Denise M; Stroupe, Kevin T; Fischer, Michael J; Reda, Domenic J; Manning, Willard; Browning, Margaret M; Huo, Zhiping; Saban, Karen; Kaufman, James S

    2012-02-01

    Healthcare for end-stage renal disease (ESRD) is intensive, expensive, and provided in both the public and private sector. Using a societal perspective, we examined healthcare costs and health outcomes for Department of Veterans Affairs (VA) ESRD patients comparing those who received hemodialysis care at VA versus private sector facilities. Dialysis patients were recruited from 8 VA medical centers from 2001 through 2003 and followed for 12 months in a prospective cohort study. Patient demographics, clinical characteristics, quality of life, healthcare use, and cost data were collected. Healthcare data included utilization (VA), claims (Medicare), and patient self-report. Costs included VA calculated costs, Medicare dialysis facility reports and reimbursement rates, and patient self-report. Multivariable regression was used to compare costs between patients receiving dialysis at VA versus private sector facilities. The cohort comprised 334 patients: 170 patients in the VA dialysis group and 164 patients in the private sector group. The VA dialysis group had more comorbidities at baseline, outpatient and emergency visits, prescriptions, and longer hospital stays; they also had more conservative anemia management and lower baseline urea reduction ratio (67% vs. 72%; Pprivate sector dialysis group (Pprivate sector settings is critical in informing health policy options for patients with complex chronic illnesses such as ESRD.

  20. A human life-stage physiologically based pharmacokinetic and pharmacodynamic model for chlorpyrifos: development and validation.

    Science.gov (United States)

    Smith, Jordan Ned; Hinderliter, Paul M; Timchalk, Charles; Bartels, Michael J; Poet, Torka S

    2014-08-01

    Sensitivity to some chemicals in animals and humans are known to vary with age. Age-related changes in sensitivity to chlorpyrifos have been reported in animal models. A life-stage physiologically based pharmacokinetic and pharmacodynamic (PBPK/PD) model was developed to predict disposition of chlorpyrifos and its metabolites, chlorpyrifos-oxon (the ultimate toxicant) and 3,5,6-trichloro-2-pyridinol (TCPy), as well as B-esterase inhibition by chlorpyrifos-oxon in humans. In this model, previously measured age-dependent metabolism of chlorpyrifos and chlorpyrifos-oxon were integrated into age-related descriptions of human anatomy and physiology. The life-stage PBPK/PD model was calibrated and tested against controlled adult human exposure studies. Simulations suggest age-dependent pharmacokinetics and response may exist. At oral doses ⩾0.6mg/kg of chlorpyrifos (100- to 1000-fold higher than environmental exposure levels), 6months old children are predicted to have higher levels of chlorpyrifos-oxon in blood and higher levels of red blood cell cholinesterase inhibition compared to adults from equivalent doses. At lower doses more relevant to environmental exposures, simulations predict that adults will have slightly higher levels of chlorpyrifos-oxon in blood and greater cholinesterase inhibition. This model provides a computational framework for age-comparative simulations that can be utilized to predict chlorpyrifos disposition and biological response over various postnatal life stages. Copyright © 2013 Elsevier Inc. All rights reserved.

  1. A Multi-Stage Maturity Model for Long-Term IT Outsourcing Relationship Success

    Science.gov (United States)

    Luong, Ming; Stevens, Jeff

    2015-01-01

    The Multi-Stage Maturity Model for Long-Term IT Outsourcing Relationship Success, a theoretical stages-of-growth model, explains long-term success in IT outsourcing relationships. Research showed the IT outsourcing relationship life cycle consists of four distinct, sequential stages: contract, transition, support, and partnership. The model was…

  2. Comparative effectiveness of primary tumor resection in patients with stage IV colon cancer.

    Science.gov (United States)

    Alawadi, Zeinab; Phatak, Uma R; Hu, Chung-Yuan; Bailey, Christina E; You, Y Nancy; Kao, Lillian S; Massarweh, Nader N; Feig, Barry W; Rodriguez-Bigas, Miguel A; Skibber, John M; Chang, George J

    2017-04-01

    Although the safety of combination chemotherapy without primary tumor resection (PTR) in patients with stage IV colon cancer has been established, questions remain regarding a potential survival benefit with PTR. The objective of this study was to compare mortality rates in patients who had colon cancer with unresectable metastases who did and did not undergo PTR. An observational cohort study was conducted among patients with unresectable metastatic colon cancer identified from the National Cancer Data Base (2003-2005). Multivariate Cox regression analyses with and without propensity score weighting (PSW) were performed to compare survival outcomes. Instrumental variable analysis, using the annual hospital-level PTR rate as the instrument, was used to account for treatment selection bias. To account for survivor treatment bias, in situations in which patients might die soon after diagnosis from different reasons, a landmark method was used. In the total cohort, 8641 of 15,154 patients (57%) underwent PTR, and 73.8% of those procedures (4972 of 6735) were at landmark. PTR was associated with a significant reduction in mortality using Cox regression (hazard ratio [HR], 0.45; 95% confidence interval [CI], 0.44-0.47) or PSW (HR, 0.46; 95% CI, 0. 44-0.49). However, instrumental variable analysis revealed a much smaller effect (relative mortality rate, 0.91; 95% CI, 0.87-0.96). Although a smaller benefit was observed with the landmark method using Cox regression (HR, 0.6; 95% CI, 0.55-0.64) and PSW (HR, 0.59; 95% CI, 0.54-0.64), instrumental variable analysis revealed no survival benefit (relative mortality rate, 0.97; 95% CI, 0.87-1.06). Among patients with unresectable metastatic colon cancer, after adjustment for confounder effects, PTR was not associated with improved survival compared with systemic chemotherapy; therefore, routine noncurative PTR is not recommended. Cancer 2017;123:1124-1133. © 2016 American Cancer Society. © 2016 American Cancer Society.

  3. Safety Outcomes of Apixaban Compared With Warfarin in Patients With End-Stage Renal Disease.

    Science.gov (United States)

    Sarratt, Stefanie C; Nesbit, Ross; Moye, Robert

    2017-06-01

    Current guidelines make no specific recommendations on the selection of direct oral anticoagulants for the prevention and treatment of venous thromboembolism in patients with end-stage renal disease (ESRD) receiving hemodialysis. Based on these guidelines, warfarin remains the anticoagulant of choice in these patients. To compare bleeding rates in patients receiving apixaban or warfarin with ESRD undergoing chronic hemodialysis. This was a single-center, retrospective, institutional review board-approved cohort analysis. Patients with ESRD undergoing chronic hemodialysis and receiving anticoagulation therapy with either apixaban or warfarin were included in this study. All data were collected from paper charts and electronic medical records and included documentation of bleeding events and related interventions. The primary outcome of this study was clinically relevant major bleeding events. Secondary outcomes included clinically relevant nonmajor bleeding events and minor bleeding events. A total of 160 patients were included in this study (warfarin group, n = 120; apixaban group, n = 40). There were 7 major bleeding events in the warfarin group compared with zero in the apixaban group ( P = 0.34). There were similar rates of clinically relevant nonmajor bleeding events (12.5% vs 5.8%, P = 0.17) and minor bleeding (2.5% vs 2.5%, P = 0.74) events in patients receiving apixaban and warfarin. There were no observed differences in bleeding rates in patients receiving apixaban compared with those receiving warfarin. Apixaban may be a cautious consideration in hemodialysis patients until there is further insight into the effect of subsequent, multiple doses on drug accumulation and clinical outcomes.

  4. Trypanosoma cruzi alkaline 2-DE: Optimization and application to comparative proteome analysis of flagellate life stages

    Directory of Open Access Journals (Sweden)

    Santana Jaime M

    2008-09-01

    Full Text Available Abstract Background Trypanosoma cruzi, a flagellate protozoan, is the etiological agent of Chagas disease, a chronic illness that causes irreversible damage to heart and digestive tract in humans. Previous 2-DE analyses of T. cruzi proteome have not focused on basic proteins, possibly because of inherent difficulties for optimizing 2-DE in the alkaline pH range. However, T. cruzi wide pH range 2-DE gels have shown few visible spots in the alkaline region, indicating that the parasite either did not have an appreciable amount of alkaline proteins or that these proteins were underrepresented in the 2-DE gels. Results Different IEF conditions using 6–11 pH gradient strips were tested for separation of T. cruzi alkaline proteins. The optimized methodology described here was performed using anodic "paper bridge" sample loading supplemented by increased concentration of DTT and Triton X-100 on Multiphor II (GE Healthcare equipment and an electrode pad embedded in DTT- containing solution near the cathode in order to avoid depletion of reducing agent during IEF. Landmark proteins were identified by peptide mass fingerprinting allowing the production of an epimastigote 2-DE map. Most identified proteins corresponded to metabolic enzymes, especially those related to amino acid metabolism. The optimized 2-DE protocol was applied in combination with the "two-in-one gel" method to verify the relative expression of the identified proteins between samples from epimastigote and trypomastigote life stages. Conclusion High resolution 2-DE gels of T. cruzi life forms were achieved using the optimized methodology and a partial epimastigote alkaline 2-DE map was built. Among 700 protein spots detected, 422 were alkaline with a pI above 7.0. The "two-in-one gel" method simplified the comparative analysis between T. cruzi life stages since it minimized variations in spot migration and silver-stained spot volumes. The comparative data were in agreement with

  5. Self-consistent electronic structure of a model stage-1 graphite acceptor intercalate

    International Nuclear Information System (INIS)

    Campagnoli, G.; Tosatti, E.

    1981-04-01

    A simple but self-consistent LCAO scheme is used to study the π-electronic structure of an idealized stage-1 ordered graphite acceptor intercalate, modeled approximately on C 8 AsF 5 . The resulting non-uniform charge population within the carbon plane, band structure, optical and energy loss properties are discussed and compared with available spectroscopic evidence. The calculated total energy is used to estimate migration energy barriers, and the intercalate vibration mode frequency. (author)

  6. A stage-based model of manatee population dynamics

    Science.gov (United States)

    Runge, M.C.; Langtimm, C.A.; Kendall, W.L.

    2004-01-01

    A stage-structured population model for the Florida manatee (Trichechus manatus latirostris) was developed that explicitly incorporates uncertainty in parameter estimates. The growth rates calculated with this model reflect the status of the regional populations over the most recent 10-yr period. The Northwest and Upper St. Johns River regions have growth rates (8) of 1.037 (95% interval, 1.016?1.056) and 1.062 (1.037?1.081), respectively. The Southwest region has a growth rate of 0.989 (0.946?1.024), suggesting this population has been declining at about 1.1% per year. The estimated growth rate in the Atlantic region is 1.010 (0.988?1.029), but there is some uncertainty about whether adult survival rates have been constant over the last 10 yr; using the mean survival rates from the most recent 5-yr period, the estimated growth rate in this region is 0.970 (0.938?0.998). Elasticity analysis indicates that the most effective management actions should seek to increase adult survival rates. Decomposition of the uncertainty in the growth rates indicates that uncertainty about population status can best be reduced through increased monitoring of adult survival rate.

  7. Prediction of Pathological Stage in Patients with Prostate Cancer: A Neuro-Fuzzy Model.

    Directory of Open Access Journals (Sweden)

    Georgina Cosma

    Full Text Available The prediction of cancer staging in prostate cancer is a process for estimating the likelihood that the cancer has spread before treatment is given to the patient. Although important for determining the most suitable treatment and optimal management strategy for patients, staging continues to present significant challenges to clinicians. Clinical test results such as the pre-treatment Prostate-Specific Antigen (PSA level, the biopsy most common tumor pattern (Primary Gleason pattern and the second most common tumor pattern (Secondary Gleason pattern in tissue biopsies, and the clinical T stage can be used by clinicians to predict the pathological stage of cancer. However, not every patient will return abnormal results in all tests. This significantly influences the capacity to effectively predict the stage of prostate cancer. Herein we have developed a neuro-fuzzy computational intelligence model for classifying and predicting the likelihood of a patient having Organ-Confined Disease (OCD or Extra-Prostatic Disease (ED using a prostate cancer patient dataset obtained from The Cancer Genome Atlas (TCGA Research Network. The system input consisted of the following variables: Primary and Secondary Gleason biopsy patterns, PSA levels, age at diagnosis, and clinical T stage. The performance of the neuro-fuzzy system was compared to other computational intelligence based approaches, namely the Artificial Neural Network, Fuzzy C-Means, Support Vector Machine, the Naive Bayes classifiers, and also the AJCC pTNM Staging Nomogram which is commonly used by clinicians. A comparison of the optimal Receiver Operating Characteristic (ROC points that were identified using these approaches, revealed that the neuro-fuzzy system, at its optimal point, returns the largest Area Under the ROC Curve (AUC, with a low number of false positives (FPR = 0.274, TPR = 0.789, AUC = 0.812. The proposed approach is also an improvement over the AJCC pTNM Staging Nomogram (FPR

  8. Model of unplanned smoking initiation of children and adolescents: an integrated stage model of smoking behavior.

    Science.gov (United States)

    Kremers, S P J; Mudde, A N; De Vries, H

    2004-05-01

    Two lines of psychological research have attempted to spell out the stages of adolescent smoking initiation. The first has focused on behavioral stages of smoking initiation, while the second line emphasized motivational stages. A large international sample of European adolescents (N = 10,170, mean age = 13.3 years) was followed longitudinally. Self-reported motivational and behavioral stages of smoking initiation were integrated, leading to the development of the Model of Unplanned Smoking Initiation of Children and Adolescents (MUSICA). The MUSICA postulates that youngsters experiment with smoking while they are in an unmotivated state as regards their plans for smoking regularly in the future. More than 95% of the total population resided in one of the seven stages distinguished by MUSICA. The probability of starting to smoke regularly during the 12 months follow-up period increased with advanced stage assignment at baseline. Unique social cognitive predictors of stage progression from the various stages were identified, but effect sizes of predictors of transitions were small. The integration of motivational and behavioral dimensions improves our understanding of the process of smoking initiation. In contrast to current theories of smoking initiation, adolescent uptake of smoking behavior was found to be an unplanned action.

  9. Comparative Transcriptional Profiling of Two Contrasting Barley Genotypes under Salinity Stress during the Seedling Stage

    Directory of Open Access Journals (Sweden)

    Runhong Gao

    2013-01-01

    Full Text Available Salinity is one of the major abiotic stresses that affect crop productivity. Identification of the potential novel genes responsible for salt tolerance in barley will contribute to understanding the molecular mechanism of barley responses to salt stress. We compared changes in transcriptome between Hua 11 (a salt-tolerant genotype and Hua 30 (a salt sensitive genotype in response to salt stress at the seedling stage using barley cDNA microarrays. In total, 557 and 247 salt-responsive genes were expressed exclusively in the shoot and root tissue of the salt-tolerant genotype, respectively. Among these genes, a number of signal-related genes, transcription factors and compatible solutes were identified and some of these genes were carefully discussed. Notably, a LysM RLK was firstly found involved in salt stress response. Moreover, key enzymes in the pathways of jasmonic acid biosynthesis, lipid metabolism and indole-3-acetic acid homeostasis were specifically affected by salt stress in salt tolerance genotype. These salt-responsive genes and biochemical pathways identified in this study could provide further information for understanding the mechanisms of salt tolerance in barley.

  10. Comparative overview of primary sedimentation-based mechanical stage in some Romanian wastewater treatment systems

    Science.gov (United States)

    Zaharia, C.

    2017-08-01

    Nowadays, wastewater (WW) treatment facilities are considered significant exposure pathways for solid particles, and also significant concerns of any quality conscious manufacturer. Most solid particles have some forms of organic coating either used as active material or to suspend and/or stabilize different present solid materials, having increase in toxicity that must be reduced, or sometimes even totally eliminated, especially if effluent is either discharged directly to surface water, or distributed through industrial water supplies. Representatives providing innovative technologies, comprehensive supports and expertise in wastewater and sludge treatment field are known, each one using modern treatment technology and facilities. Mechanical treatment is indispensable in primary treatment steps of both municipal and industrial WW applications, its main goal being separation of floating, settling and suspended materials (especially into a primary sedimentation-based treatment step). The aim of this work is to present comparatively the performance in solids removal of conventional mechanical WW treatment stages, especially those based on primary sedimentation, or sedimentation-like operations applied for Romanian urban WW treatment plants (serving two towns with ca 18,000 inhabitants), industrial WW treatment plants (deserving industries of vegetal food processing and organic chemicals’ manufacturing) and additional information on valorisation of separated solid material and improvement possibilities.

  11. Radical surgery compared with intracavitary cesium followed by radical surgery in cervical carcinoma stage IB

    Energy Technology Data Exchange (ETDEWEB)

    Tinga, D.J.; Bouma, J.; Aalders, J.G. (Dept. of Obstetrics and Gynaecology, State Univ. Hospital, Groningen (Netherlands)); Hollema, H. (Dept. of Pathology, State Univ. Hospital, Groningen (Netherlands))

    1990-01-01

    Forty-nine patients aged {le} 45 years, with cervical carcinoma stage IB ({le} 3 cm) were treated with either primary radical surgery (n = 26), or intracavitary irradiation followed by radical surgery (n = 23). With primary surgery, ovarian function had been preserved in 15 of the 25 patients, who were alive and well. Seven of the primary surgery patients were irradiated postoperatively and 2 others with a central recurrence were cured by irradiation. One other patient, who was not irradiated postoperatively, had an intestinal metastasis and died of the disease. If any of the adverse prognostic factors (as reported in the literature) had been considered as an indication for postoperative irradiation, 17 patients instead of 7 would have been irradiated after primary radical surgery. In the comparable group of 23 patients treated by intracavitary irradiation and radical surgery (and in 4 cases postoperative irradiation as well) there was no recurrence. There was no significant statistical difference between the treatment results in the cesium + surgery group and those who underwent primary radical surgery. Young patients with early cervical carcinoma without prognostic indicators for postoperative irradiation can benefit from primary radical surgery, because their ovarian function can be preserved. (authors).

  12. Radical surgery compared with intracavitary cesium followed by radical surgery in cervical carcinoma stage IB

    International Nuclear Information System (INIS)

    Tinga, D.J.; Bouma, J.; Aalders, J.G.; Hollema, H.

    1990-01-01

    Forty-nine patients aged ≤ 45 years, with cervical carcinoma stage IB (≤ 3 cm) were treated with either primary radical surgery (n = 26), or intracavitary irradiation followed by radical surgery (n = 23). With primary surgery, ovarian function had been preserved in 15 of the 25 patients, who were alive and well. Seven of the primary surgery patients were irradiated postoperatively and 2 others with a central recurrence were cured by irradiation. One other patient, who was not irradiated postoperatively, had an intestinal metastasis and died of the disease. If any of the adverse prognostic factors (as reported in the literature) had been considered as an indication for postoperative irradiation, 17 patients instead of 7 would have been irradiated after primary radical surgery. In the comparable group of 23 patients treated by intracavitary irradiation and radical surgery (and in 4 cases postoperative irradiation as well) there was no recurrence. There was no significant statistical difference between the treatment results in the cesium + surgery group and those who underwent primary radical surgery. Young patients with early cervical carcinoma without prognostic indicators for postoperative irradiation can benefit from primary radical surgery, because their ovarian function can be preserved. (authors)

  13. Mortality prediction in chronic obstructive pulmonary disease comparing the GOLD 2007 and 2011 staging systems

    DEFF Research Database (Denmark)

    Soriano, Joan B; Lamprecht, Bernd; Ramírez, Ana S

    2015-01-01

    BACKGROUND: There is no universal consensus on the best staging system for chronic obstructive pulmonary disease (COPD). Although documents (eg, the Global Initiative for Chronic Obstructive Lung Disease [GOLD] 2007) have traditionally used forced expiratory volume in 1 s (FEV1) for staging, clin...

  14. Stages of driving behavior change within the Transtheoretical Model (TM).

    Science.gov (United States)

    Kowalski, Kristina; Jeznach, Anna; Tuokko, Holly Anna

    2014-09-01

    Many older adults voluntarily restrict their driving or stop driving of their own accord. Driving behavior change may occur in stages, as predicted by the Transtheoretical Model of Behavior Change (TM). This study explored the process of older driver behavior change within the TM framework using interviews/focus groups with drivers and former drivers aged 71-94 years. Within those groups of drivers, driving behavior was divided into two classes: those who changed their driving with age and those who did not. Those who changed their driving as they aged included people gradually imposing restrictions ("gradual restrictors") and those making plans in anticipation of stopping driving ("preparers"). Participants who did not change their driving included those who employed lifelong driving restrictions ("consistent") and those who made no changes ("non-changers"). Preliminary support for TM within the driving context was found; however, further exploration of driving behavior change within this framework is warranted. It is important to continue to investigate the factors that might influence driving behavior in older adults. By promoting self-regulation in individuals, it may be possible to help older adults continue to drive, thereby improving older adult's mobility and quality of life. Copyright © 2014 National Safety Council and Elsevier Ltd. All rights reserved.

  15. Retail gentrification. Staged spaces and the gourmet market model

    Directory of Open Access Journals (Sweden)

    Luz de Lourdes Cordero Gómez del Campo

    2017-12-01

    Full Text Available Retail gentrification is understood as a process in which commercial activity is transformed to meet the needs of a sector of the population with higher incomes resulting in the displacement of merchants and products, seen from the implementation of the model of the gourmet market. This process, which is seen in the interest of copying the commercial formats of successful cases from gourmet markets such as the San Miguel Market in Madrid or the Borough Market in London, is linked to an offer aimed at satisfying consumption demands produced by a sector of the population that although not being equivalent concepts, different authors identify as cultural omnivores or creative class, coinciding in that these groups have a high cultural and economic capital. In the present work it is discussed how in Mexico City in the absence of the transformation of public markets into gourmet markets and with the inauguration of the Roma Market in 2014, the staging of commercial spaces labeled as gourmet markets has intensified and they are inserted in neighborhoods where they seek to generate development and links with the community, but because of their prices and the characteristics of the products they offer, they are beyond the reach of the local population.

  16. Hydrogeological characterisation and modelling of deformation zones and fracture domains, Forsmark modelling stage 2.2

    Energy Technology Data Exchange (ETDEWEB)

    Follin, Sven (SF GeoLogic AB, Taeby (SE)); Leven, Jakob (Swedish Nuclear Fuel and Waste Management Co., Stockholm (SE)); Hartley, Lee; Jackson, Peter; Joyce, Steve; Roberts, David; Swift, Ben (Serco Assurance, Harwell (GB))

    2007-09-15

    categories of steeply-dipping deformation zones may be due to the anisotropy in the stress field, where the maximum stress is horizontal and has an azimuth of c. 140 deg. The hypothesis is supported by the deformation zones that strike WNW and NW. These two categories of steeply-dipping deformation zones have, relatively speaking, higher mean transmissivities than steeply dipping deformation zones in other directions. Key hydrogeological aspects of the fracture domains modelled are: We find the geological division of the bedrock in between the deterministically deformation zones to fall into six fracture domains useful from a hydrogeological point of view. In fact, the suggested division is consistent with the hydrogeological modelling approach reported for modelling stage 1.2. The key aspect for Forsmark is that the corrected conductive fracture frequency for the potential fracture domain FFM01 shows very strong variations with depth, and so it is suggested that the Hydro-DFN be split into three layers: above the elevation -200, between the elevations -200 and -400, and below the elevation -400. FFM01 is also very anisotropic, being dominated by the HZ set, and only with a small contribution from the NE and NS sets. The top layer of fracture domain FFM01 is similar to the Hydro-DFN parameters for fracture domain FFM02. FFM03 has less variation with depth and is comparable to the middle section of FFM01, but is more isotropic. Data for fracture domain FFM06, which is also a part of the potential target bedrock, will be treated in modelling stage 2.3. Pending this information, it is envisaged that fracture domain FFM06 can be modelled in the same fashion as fracture domain FFM01. Fracture domains FFM04 and FFM05 lie in the periphery of the candidate area. Based on the statistical analysis, FFM05 seems to be similar to FFM03, while FFM04 is of slightly higher hydraulic conductivity, but the statistical significance of the data for these fracture domains is very limited, being

  17. Comparative study of essential oil content and composition of Ducrosia anethifolia at two phenologocal stage

    Directory of Open Access Journals (Sweden)

    Z. Karimi*

    2017-11-01

    Full Text Available Background and objectives: Ducrosia anethifolia is one species which belongs to Apiaceae family that is used to improve the odor of foods and drinks. It is used also to treat catarrh, headache and backache in folk medicine. The herb is also reported to relax the mind and body and induce a peaceful sleep. The growing stage has an important role in quantity and quality of medicinal plants metabolite. In this study, the oil content and composition of D. anethifolia at two growth stages (full flowering and seed formation were studied. Methods: Oil content of this plant was isolated by hydrodistillation method by Clevenger type apparatus. Chemical composition was detected by GC and GC/MS analysis. Results: The results showed that the phenological stage had significant effect on the oil content and composition. Oil content at seed formation was more than the flowering stage (0.24 and 0.96% v/w, respectively. At the flowering stage, n-dodecanal (14.43%, dodecanal (13.30% and n-decanoic acid (11.61% were the major constituents while in the seed formation stage, they were detected slightly. Besides, at seed formation stage cis-chrysanthenyl acetae (39.06%, cubenol (7.97% and p-cymene-7-ol (4.30% were identified as the main composition. Conclusion: The results showed depending on our goal for each plant usage, the harvest time could be different; during seed formation the oil content increased significantly.

  18. Comparing numerically exact and modelled static friction

    Directory of Open Access Journals (Sweden)

    Krengel Dominik

    2017-01-01

    Full Text Available Currently there exists no mechanically consistent “numerically exact” implementation of static and dynamic Coulomb friction for general soft particle simulations with arbitrary contact situations in two or three dimension, but only along one dimension. We outline a differential-algebraic equation approach for a “numerically exact” computation of friction in two dimensions and compare its application to the Cundall-Strack model in some test cases.

  19. A match-mismatch test of a stage model of behaviour change in tobacco smoking

    NARCIS (Netherlands)

    Dijkstra, A; Conijn, B; De Vries, H

    Aims An innovation offered by stage models of behaviour change is that of stage-matched interventions. Match-mismatch studies are the primary test of this idea but also the primary test of the validity of stage models. This study aimed at conducting such a test among tobacco smokers using the Social

  20. A prognostic scoring model for survival after locoregional therapy in de novo stage IV breast cancer.

    Science.gov (United States)

    Kommalapati, Anuhya; Tella, Sri Harsha; Goyal, Gaurav; Ganti, Apar Kishor; Krishnamurthy, Jairam; Tandra, Pavan Kumar

    2018-05-02

    The role of locoregional treatment (LRT) remains controversial in de novo stage IV breast cancer (BC). We sought to analyze the role of LRT and prognostic factors of overall survival (OS) in de novo stage IV BC patients treated with LRT utilizing the National Cancer Data Base (NCDB). The objective of the current study is to create and internally validate a prognostic scoring model to predict the long-term OS for de novo stage IV BC patients treated with LRT. We included de novo stage IV BC patients reported to NCDB between 2004 and 2015. Patients were divided into LRT and no-LRT subsets. We randomized LRT subset to training and validation cohorts. In the training cohort, a seventeen-point prognostic scoring system was developed based on the hazard ratios calculated using Cox-proportional method. We stratified both training and validation cohorts into two "groups" [group 1 (0-7 points) and group 2 (7-17 points)]. Kaplan-Meier method and log-rank test were used to compare OS between the two groups. Our prognostic score was validated internally by comparing the OS between the respective groups in both the training and validation cohorts. Among 67,978 patients, LRT subset (21,200) had better median OS as compared to that of no-LRT (45 vs. 24 months; p < 0.0001). The group 1 and group 2 in the training cohort showed a significant difference in the 3-year OS (p < 0.0001) (68 vs. 26%). On internal validation, comparable OS was seen between the respective groups in each cohort (p = 0.77). Our prognostic scoring system will help oncologists to predict the prognosis in de novo stage IV BC patients treated with LRT. Although firm treatment-related conclusions cannot be made due to the retrospective nature of the study, LRT appears to be associated with a better OS in specific subgroups.

  1. Comparative analysis of Goodwin's business cycle models

    Science.gov (United States)

    Antonova, A. O.; Reznik, S.; Todorov, M. D.

    2016-10-01

    We compare the behavior of solutions of Goodwin's business cycle equation in the form of neutral delay differential equation with fixed delay (NDDE model) and in the form of the differential equations of 3rd, 4th and 5th orders (ODE model's). Such ODE model's (Taylor series expansion of NDDE in powers of θ) are proposed in N. Dharmaraj and K. Vela Velupillai [6] for investigation of the short periodic sawthooth oscillations in NDDE. We show that the ODE's of 3rd, 4th and 5th order may approximate the asymptotic behavior of only main Goodwin's mode, but not the sawthooth modes. If the order of the Taylor series expansion exceeds 5, then the approximate ODE becomes unstable independently of time lag θ.

  2. Comparative Transcriptomic Analysis of Grape Berry in Response to Root Restriction during Developmental Stages

    Directory of Open Access Journals (Sweden)

    Feng Leng

    2016-10-01

    Full Text Available Root restriction improved berry quality by being involved in diverse aspects of grapevine life. However, the molecular mechanism driving this process is not understood very well. In this study, the ‘Summer Black’ grape berry (Vitis vinifera × V. labrusca under root restriction was investigated, which showed an increase of total soluble solids (TSS, color index of red grapes (CIRG value, anthocyanins accumulation, total phenolics and total procyanidins contents during berry development compared with those in control berries. The transcriptomic changes induced by root restriction in ‘Summer Black’ grape over the course of berry development were analyzed by RNA-Seq method. A total of 29,971 genes were generated in ‘Summer Black’ grape berry during development, among which, 1606 genes were significantly responded to root restriction. Furthermore, 1264, 313, 141, 246 and 19 sequences were significantly changed at S1, S2, S3, S4 and S5 sample points, respectively. The gene (VIT_04s0023g02290 predicted as a salicylate O-methyltransferase was differentially expressed in all developmental stages. Gene Ontology (GO enrichment showed that response to organic nitrogen, response to endogenous stimulus, flavonoid metabolic process, phenylpropanoid biosynthetic process and cell wall macromolecule metabolic process were the main significant differential categories. Kyoto Encyclopedia of Genes and Genomes (KEGG pathway enrichment revealed plant–pathogen interaction, plant hormone signal transduction, flavone and flavonol biosynthesis, flavonoid biosynthesis and glucosinolate biosynthesis were the main significant differential pathways. The results of the present study provided a genetic base for the understanding of grape berry fruit quality improvement under root restriction.

  3. A COMPARATIVE STUDY OF OXYTOCIN/MISOPROSTOL/METHYLERGOMETRINE FOR ACTIVE MANAGEMENT OF THE THIRD STAGE OF LABOUR

    Directory of Open Access Journals (Sweden)

    Mundlapaty Sabitha

    2017-08-01

    Full Text Available BACKGROUND The third stage of labour is indeed the unforgiving stage of the labour and in it lurks more unheralded treachery than in both the other stages of labour combined. Many lifesaving drugs have been discovered and used for the management of this stage of labour. According to the WHO multicentric randomised trial using oral misoprostol with oxytocic, they concluded that oral misoprostol was associated with significantly high incidence of side effects like shivering and rise in body temperature and hence oxytocin is preferred to 600 mg of oral misoprostol in management of 3rd stage of labour in hospital settings, but still misoprostol has been suggested for the management of third stage of labour in developing countries, because it has strong uterotonic effects, can be given orally, inexpensive and does not need refrigeration. The aim of the study is to compare oxytocin, misoprostol, methylergometrine for active management of the third stage of labour. MATERIALS AND METHODS A total of 300 women of 37 weeks to 42 weeks of gestation delivering vaginally in Konaseema Institute of Medical Sciences, Amalapuram, Andhra Pradesh. 300 women allocated into 3 groups of 100 each to receive 10 IU I.M. oxytocin, 600 mcg sublingual misoprostol or 200 mcg I.M. methylergometrine, respectively. Primary outcome measure was blood loss in the third stage of labor; secondary measures were duration of the third stage, side effects and complications. RESULTS Subjects who received 600 mcg of misoprostol had the least blood loss (113 mL, followed by oxytocin and methylergometrine. The shortest mean duration of the third stage was with misoprostol (4.34 mins.. Shivering and pyrexia were observed in misoprostol group and raised blood pressure in methylergometrine group. CONCLUSION Misoprostol is as effective as oxytocin and both are more effective than methylergometrine in active management of the third stage of labour. Misoprostol therefore can be used in places

  4. [Comparative analysis of one- and two-stage augmentation urethroplasty with dorsal INLAY buccal graft for extended stricturesof spongious urethra].

    Science.gov (United States)

    Kogan, M I; Glukhov, V P; Mitusov, V V; Krasulin, V V; Ilyash, A V

    2018-03-01

    Urethral reconstructive surgery is in constant development. At present, reconstructive urethroplasty with buccal mucosa is increasingly being used. The study aimed to compare the results of a one- and two-stage augmentation urethroplasty with dorsal inlay buccal graft for strictures of the spongious urethra. The study comprised 72 patients aged 19-64 with urethral strictures 3-18 cm long. In 34 (47.2%) patients, the stricture was localized in the penile urethra, in 30 patients (41.6%) in the penile-bulbous urethra and in 8 patients (11%) in the bulbous urethra. All patients underwent augmentation urethroplasty with dorsal inlay buccal graft. The results were evaluated separately in 55 (76.4%, group 1) and 17 (23.6%, group 2) patients who underwent one-stage and two-stage surgery, respectively. The incidence rate of early postoperative complications was higher after one-stage (23.6%) compared two-stage surgery (11.8%) (purethroplasty with dorsal inlay buccal graft was achieved in 88.9% of patients; treatment effectiveness in the group 1 was 89.1%, in the group 2 - 88.2% (p>0.05). The final effectiveness of the operation, achieved with the use of additional surgical interventions, is estimated at 98.6%. The results of augmentation urethroplasty with dorsal inlay buccal graft do not depend on the number of stages, but fewer complications accompany two-stage surgery.

  5. Cancerous Tumour Model Analysis and Constructing schemes of Anti-angiogenesis Therapy at an Early Stage

    Directory of Open Access Journals (Sweden)

    O. Yu. Mukhomorova

    2015-01-01

    Full Text Available Anti-angiogenesis therapy is an alternative and successfully employed method for treatment of cancerous tumour. However, this therapy isn't widely used in medicine because of expensive drugs. It leads naturally to elaboration of such treatment regimens which use minimum amount of drugs.The aim of the paper is to investigate the model of development of illness and elaborate appropriate treatment regimens in the case of early diagnosis of the disease. The given model reflects the therapy at an intermediate stage of the disease treatment. Further treatment is aimed to destroy cancer cells and may be continued by other means, which are not reflected in the model.Analysis of the main properties of the model was carried out with consideration of two types of auxiliary systems. In the first case, the system is considered without control, as a model of tumour development in the absence of medical treatment. The study of the equilibrium point and determination of its type allowed us to describe disease dynamics and to determine tumour size resulting in death. In the second case a model with a constant control was investigated. The study of its equilibrium point showed that continuous control is not sufficient to support satisfactory patient's condition, and it is necessary to elaborate more complex treatment regimens. For this purpose, we used the method of terminal problems consisting in the search for such program control which forces system to a given final state. Selecting the initial and final states is due to medical grounds.As a result, we found two treatment regimens | one-stage treatment regimen and multi-stage one. The properties of each treatment regimen are analyzed and compared. The total amount of used drugs was a criterion for comparing these two treatment regimens. The theoretical conclusions obtained in this work are supported by computer modeling in MATLAB environment.

  6. A Human Life-Stage Physiologically Based Pharmacokinetic and Pharmacodynamic Model for Chlorpyrifos: Development and Validation

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Jordan N.; Hinderliter, Paul M.; Timchalk, Charles; Bartels, M. J.; Poet, Torka S.

    2014-08-01

    Sensitivity to chemicals in animals and humans are known to vary with age. Age-related changes in sensitivity to chlorpyrifos have been reported in animal models. A life-stage physiologically based pharmacokinetic and pharmacodynamic (PBPK/PD) model was developed to computationally predict disposition of CPF and its metabolites, chlorpyrifos-oxon (the ultimate toxicant) and 3,5,6-trichloro-2-pyridinol (TCPy), as well as B-esterase inhibition by chlorpyrifos-oxon in humans. In this model, age-dependent body weight was calculated from a generalized Gompertz function, and compartments (liver, brain, fat, blood, diaphragm, rapid, and slow) were scaled based on body weight from polynomial functions on a fractional body weight basis. Blood flows among compartments were calculated as a constant flow per compartment volume. The life-stage PBPK/PD model was calibrated and tested against controlled adult human exposure studies. Model simulations suggest age-dependent pharmacokinetics and response may exist. At oral doses ≥ 0.55 mg/kg of chlorpyrifos (significantly higher than environmental exposure levels), 6 mo old children are predicted to have higher levels of chlorpyrifos-oxon in blood and higher levels of red blood cell cholinesterase inhibition compared to adults from equivalent oral doses of chlorpyrifos. At lower doses that are more relevant to environmental exposures, the model predicts that adults will have slightly higher levels of chlorpyrifos-oxon in blood and greater cholinesterase inhibition. This model provides a computational framework for age-comparative simulations that can be utilized to predict CPF disposition and biological response over various postnatal life-stages.

  7. A framework for testing and comparing binaural models.

    Science.gov (United States)

    Dietz, Mathias; Lestang, Jean-Hugues; Majdak, Piotr; Stern, Richard M; Marquardt, Torsten; Ewert, Stephan D; Hartmann, William M; Goodman, Dan F M

    2018-03-01

    Auditory research has a rich history of combining experimental evidence with computational simulations of auditory processing in order to deepen our theoretical understanding of how sound is processed in the ears and in the brain. Despite significant progress in the amount of detail and breadth covered by auditory models, for many components of the auditory pathway there are still different model approaches that are often not equivalent but rather in conflict with each other. Similarly, some experimental studies yield conflicting results which has led to controversies. This can be best resolved by a systematic comparison of multiple experimental data sets and model approaches. Binaural processing is a prominent example of how the development of quantitative theories can advance our understanding of the phenomena, but there remain several unresolved questions for which competing model approaches exist. This article discusses a number of current unresolved or disputed issues in binaural modelling, as well as some of the significant challenges in comparing binaural models with each other and with the experimental data. We introduce an auditory model framework, which we believe can become a useful infrastructure for resolving some of the current controversies. It operates models over the same paradigms that are used experimentally. The core of the proposed framework is an interface that connects three components irrespective of their underlying programming language: The experiment software, an auditory pathway model, and task-dependent decision stages called artificial observers that provide the same output format as the test subject. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Comparative transcriptome analysis of two races of Heterodera glycines at different developmental stages.

    Directory of Open Access Journals (Sweden)

    Gaofeng Wang

    Full Text Available The soybean cyst nematode, Heterodera glycines, is an important pest of soybeans. Although resistance is available against this nematode, selection for virulent races can occur, allowing the nematode to overcome the resistance of cultivars. There are abundant field populations, however, little is known about their genetic diversity. In order to elucidate the differences between races, we investigated the transcriptional diversity within race 3 and race 4 inbred lines during their compatible interactions with the soybean host Zhonghuang 13. Six different race-enriched cDNA libraries were constructed with limited nematode samples collected from the three sedentary stages, parasitic J2, J3 and J4 female, respectively. Among 689 putative race-enriched genes isolated from the six libraries with functional annotations, 92 were validated by quantitative RT-PCR (qRT-PCR, including eight putative effector encoding genes. Further race-enriched genes were validated within race 3 and race 4 during development in soybean roots. Gene Ontology (GO analysis of all the race-enriched genes at J3 and J4 female stages showed that most of them functioned in metabolic processes. Relative transcript level analysis of 13 selected race-enriched genes at four developmental stages showed that the differences in their expression abundance took place at either one or more developmental stages. This is the first investigation into the transcript diversity of H. glycines races throughout their sedentary stages, increasing the understanding of the genetic diversity of H. glycines.

  9. Comparing Realistic Subthalamic Nucleus Neuron Models

    Science.gov (United States)

    Njap, Felix; Claussen, Jens C.; Moser, Andreas; Hofmann, Ulrich G.

    2011-06-01

    The mechanism of action of clinically effective electrical high frequency stimulation is still under debate. However, recent evidence points at the specific activation of GABA-ergic ion channels. Using a computational approach, we analyze temporal properties of the spike trains emitted by biologically realistic neurons of the subthalamic nucleus (STN) as a function of GABA-ergic synaptic input conductances. Our contribution is based on a model proposed by Rubin and Terman and exhibits a wide variety of different firing patterns, silent, low spiking, moderate spiking and intense spiking activity. We observed that most of the cells in our network turn to silent mode when we increase the GABAA input conductance above the threshold of 3.75 mS/cm2. On the other hand, insignificant changes in firing activity are observed when the input conductance is low or close to zero. We thus reproduce Rubin's model with vanishing synaptic conductances. To quantitatively compare spike trains from the original model with the modified model at different conductance levels, we apply four different (dis)similarity measures between them. We observe that Mahalanobis distance, Victor-Purpura metric, and Interspike Interval distribution are sensitive to different firing regimes, whereas Mutual Information seems undiscriminative for these functional changes.

  10. Two-stage stochastic programming model for the regional-scale electricity planning under demand uncertainty

    International Nuclear Information System (INIS)

    Huang, Yun-Hsun; Wu, Jung-Hua; Hsu, Yu-Ju

    2016-01-01

    Traditional electricity supply planning models regard the electricity demand as a deterministic parameter and require the total power output to satisfy the aggregate electricity demand. But in today's world, the electric system planners are facing tremendously complex environments full of uncertainties, where electricity demand is a key source of uncertainty. In addition, electricity demand patterns are considerably different for different regions. This paper developed a multi-region optimization model based on two-stage stochastic programming framework to incorporate the demand uncertainty. Furthermore, the decision tree method and Monte Carlo simulation approach are integrated into the model to simplify electricity demands in the form of nodes and determine the values and probabilities. The proposed model was successfully applied to a real case study (i.e. Taiwan's electricity sector) to show its applicability. Detail simulation results were presented and compared with those generated by a deterministic model. Finally, the long-term electricity development roadmap at a regional level could be provided on the basis of our simulation results. - Highlights: • A multi-region, two-stage stochastic programming model has been developed. • The decision tree and Monte Carlo simulation are integrated into the framework. • Taiwan's electricity sector is used to illustrate the applicability of the model. • The results under deterministic and stochastic cases are shown for comparison. • Optimal portfolios of regional generation technologies can be identified.

  11. Multi-stage IT project evaluation: The flexibility value obtained by implementing and resolving Berk, Green and Naik (2004) model

    Science.gov (United States)

    Abid, Fathi; Guermazi, Dorra

    2009-11-01

    In this paper, we evaluate a multi-stage information technology investment project, by implementing and resolving Berk, Green and Naik's (2004) model, which takes into account specific features of IT projects and considers the real option to suspend investment at each stage. We present a particular case of the model where the project value is the solution of an optimal control problem with a single state variable. In this case, the model is more intuitive and tractable. The case study confirms the practical potential of the model and highlights the importance of the real-option approach compared to classical discounted cash flow techniques in the valuation of IT projects.

  12. Comparative Study of Clinical Staging of Oral Submucous Fibrosis with Qualitative Analysis of Collagen Fibers Under Polarized Microscopy.

    Science.gov (United States)

    Modak, Neha; Tamgadge, Sandhya; Tamgadge, Avinash; Bhalerao, Sudhir

    2015-01-01

    Oral submucous fibrosis (OSMF) is a condition where excessive deposition of dense collagen fibers occurred in the connective tissue of oral mucosa. An alteration of collagen necessitates an in depth understanding of collagen in oral tissues as no breakthrough studies have been reported. T herefore the aim was to correlate the clinical, functional and histopathological staging and to analyze the polarization colors and thickness of the collagen fibers in different stages of OSMF using picrosirius red stain under polarizing microscopy so as to assess the severity of disease. The study was conducted in the department of Oral Pathology and Microbiology at Padm. Dr. D. Y Patil Dental and Hospital, Navi Mumbai, India (2012-13). A sample size was of a total 40 subjects, of which 30 patients had OSMF, and 10 were in control group. Clinical, functional and histopathological staging were done depending upon definite criteria. Collagen fibers were analyzed for polarizing colors and thickness. Further clinical, functional and histopathological stages as well as qualitative parameters of collagen fibers were compared. The correlation between clinical and functional staging was not significant ( P >0.05) whereas the comparison of the functional staging with histopathological staging was more reliable ( P qualitative change in the collagen fibers of OSMF patients using polarized microscopy would help to assess its role in diagnostic evaluation, to determine the prognosis of the disease as well as to provide useful predictive treatment modalities to them.

  13. Comparative hydraulic architecture of tropical tree species representing a range of successional stages and wood density

    Science.gov (United States)

    Katherine A. McCulloh; Frederick C. Meinzer; John S. Sperry; Barbara Lachenbruch; Steven L. Voelker; David R. Woodruff; Jean-Christophe Domec

    2011-01-01

    Plant hydraulic architecture (PHA) has been linked to water transport sufficiency, photosynthetic rates, growth form and attendant carbon allocation. Despite its influence on traits central to conferring an overall competitive advantage in a given environment, few studies have examined whether key aspects of PHA are indicative of successional stage, especially within...

  14. Differential diagnosis and staging of urological tumors by magnetic resonance imaging compared with computed tomography

    International Nuclear Information System (INIS)

    Nishimura, Kazuo; Okada, Yusaku; Takeuchi, Hideo; Miyakawa, Mieko; Okada, Kenichiro; Yoshida, Osamu; Nishimura, Kazumasa

    1987-01-01

    Magnetic resonance imaging (MRI) was performed on 49 urological tumors (11 renal cell carcinomas, 3 renal pelvic cancers, 2 renal angiomyolipomas, 1 renal leiomyosarcoma, 1 large renal cvst, 4 adrenal tumors, 11 bladder cancers, 2 bone metastasis from bladder cancer, 10 prostatic cancers, 1 prostatic sarcoma, 1 urethral cancer, 1 penile cancer and 1 perivesical granuloma) since October 1985 to September 1986. MRI was performed using a Signa (G.E.) with a 1.5 T superconductive magnet and 3 images, including T1 weighted image, T2 weighted image, and proton density image, were obtained. In conclusion MRI is a noninvasive examination and gives more information than computed tomography despite its high cost. In renal cell carcinoma, the chemical shift in MRI and clear visualization of tumor thrombus enable accurate staging. Differential diagnosis from other renal mass lesions may be possible by the T2 weighted image. In adrenal disease, most of the adrenal masses can be differentiated, but in some cases it is impossible. In bladder cancer, wall invasion of tumor may be evaluated in T2 weighted image, and MRI is suitable for staging of locally advanced tumor. In prostatic cancer, visualization of periprostatic plexus and differentiation between internal and external gland may enable local staging and identification of low stage tumors. (author)

  15. A decade of comparative dose planning studies for early-stage Hodgkin lymphoma

    DEFF Research Database (Denmark)

    Maraldo, Maja V; Specht, Lena

    2014-01-01

    , especially in young patients with a long life expectancy. In this study, we review the current evidence for modern radiation therapy planning and delivery techniques in the treatment of early-stage Hodgkin lymphoma with a focus on a reduced delivered dose, a reduced irradiated volume, and a more conformal...

  16. Fetal Origins of Life Stage Disease: A Zebrafish Model for the ...

    Science.gov (United States)

    In the U.S., childhood obesity has more than doubled in children and quadrupled in adolescents in the past 30 years, affects 35% of adults, and costs the U.S. healthcare industry >$200 billion annually. The chemical environment in the womb may cause susceptibility to different life-stage and life-long metabolic diseases including obesity. The challenge is to understand if exposures during developmentally sensitive windows impact life-stage disease, such as obesity, by increasing adipose tissue mass. In vitro models lack the integrated systems approach needed to assess adipose development, while mammalian models are impractical in a screen of thousands of chemicals. Therefore, an obesogen screening method was developed to interrogate bioactivity using a full systems approach, in a vertebrate zebrafish model with complete metabolic activity, at a time when the full signaling repertoire is expressed and active, to optimally examine how chemical dose and duration impact life-stage adipose mass. A time-line for adipose depot formation was mapped in zebrafish 6−14 days post fertilization (dpf) using the lipophilic dye, Nile Red, in combination with fluorescent microscopy. Those time points were then used to investigate the impact of embryonic tributyltin chloride (TBT, a known obesogen) exposure (10nM daily renewal, 0−5dpf) on adipose mass. Fluorescent microscopy revealed adipose depots that were larger and appeared 2 days earlier in TBT treated compared to contro

  17. A preventive maintenance model with a two-level inspection policy based on a three-stage failure process

    International Nuclear Information System (INIS)

    Wang, Wenbin; Zhao, Fei; Peng, Rui

    2014-01-01

    Inspection is always an important preventive maintenance (PM) activity and can have different depths and cover all or part of plant systems. This paper introduces a two-level inspection policy model for a single component plant system based on a three-stage failure process. Such a failure process divides the system′s life into three stages: good, minor defective and severe defective stages. The first level of inspection, the minor inspection, can only identify the minor defective stage with a certain probability, but can always reveal the severe defective stage. The major inspection can however identify both defective stages perfectly. Once the system is found to be in the minor defective stage, a shortened inspection interval is adopted. If however the system is found to be in the severe defective stage, we may delay the maintenance action if the time to the next planned PM window is less than a threshold level, but otherwise, replace immediately. This corresponds to the well adopted maintenance policy in practice such as periodic inspections with planned PMs. A numerical example is presented to demonstrate the proposed model by comparing with other models. - Highlights: • The system′s deterioration goes through a three-stage process, namely, normal, minor defective and severe defective. • Two levels of inspections are proposed, e.g., minor and major inspections. • Once the minor defective stage is found, instead of taking a maintenance action, a shortened inspection interval is recommended. • When the severe defective stage is found, we delay the maintenance according to the threshold to the next PM. • The decision variables are the inspection intervals and the threshold to PM

  18. Evolutionary Stages of e-Tailors and Retailers: Firm Value Determinants Model

    OpenAIRE

    Jae K. Lee; Heegoo Kang; Hoe K. Lee; Han S. Lee

    2002-01-01

    We have studied the evolutionary stages of pure e-tailers, click & mortar (C&M) and brick & mortar (B&M) retailers for three points of time: June 1999, June 2000, and June 2001. To evaluate the dynamic stages of e-tailing business as an innovative venture, we propose four stages: exploration, breakeven, growth, and maturity. The stages are measured by the impact of revenue and income on the firm value, and a regression model is adopted to formulate the model. To empirically examine the stages...

  19. Comparative Analysis of Flower Volatiles from Nine Citrus at Three Blooming Stages

    Directory of Open Access Journals (Sweden)

    Muhammad Azam

    2013-11-01

    Full Text Available Volatiles from flowers at three blooming stages of nine citrus cultivars were analyzed by headspace-solid phase microextraction (HS-SPME-GC-MS. Up to 110 volatiles were detected, with 42 tentatively identified from citrus flowers for the first time. Highest amounts of volatiles were present in fully opened flowers of most citrus, except for pomelos. All cultivars were characterized by a high percentage of either oxygenated monoterpenes or monoterpene hydrocarbons, and the presence of a high percentage of nitrogen containing compounds was also observed. Flower volatiles varied qualitatively and quantitatively among citrus types during blooming. Limonene was the most abundant flower volatile only in citrons; α-citral and β-citral ranked 2nd and 3rd only for Bergamot, and unopened flowers of Ponkan had a higher amount of linalool and β-pinene while much lower amount of γ-terpinene and p-cymene than Satsuma. Taking the average of all cultivars, linalool and limonene were the top two volatiles for all blooming stages; β-pinene ranked 3rd in unopened flowers, while indole ranked 3rd for half opened and fully opened flower volatiles. As flowers bloomed, methyl anthranilate increased while 2-hexenal and p-cymene decreased. In some cases, a volatile could be high in both unopened and fully opened flowers but low in half opened ones. Through multivariate analysis, the nine citrus cultivars were clustered into three groups, consistent with the three true citrus types. Furthermore, an influence of blooming stages on clustering was observed, especially with hybrids Satsuma and Huyou. Altogether, it was suggested that flower volatiles can be suitable markers for revealing the genetic relationships between citrus cultivars but the same blooming stage needs to be strictly controlled.

  20. Small Launch Vehicle Design Approaches: Clustered Cores Compared with Multi-Stage Inline Concepts

    Science.gov (United States)

    Waters, Eric D.; Beers, Benjamin; Esther, Elizabeth; Philips, Alan; Threet, Grady E., Jr.

    2013-01-01

    In an effort to better define small launch vehicle design options two approaches were investigated from the small launch vehicle trade space. The primary focus was to evaluate a clustered common core design against a purpose built inline vehicle. Both designs focused on liquid oxygen (LOX) and rocket propellant grade kerosene (RP-1) stages with the terminal stage later evaluated as a LOX/methane (CH4) stage. A series of performance optimization runs were done in order to minimize gross liftoff weight (GLOW) including alternative thrust levels, delivery altitude for payload, vehicle length to diameter ratio, alternative engine feed systems, re-evaluation of mass growth allowances, passive versus active guidance systems, and rail and tower launch methods. Additionally manufacturability, cost, and operations also play a large role in the benefits and detriments for each design. Presented here is the Advanced Concepts Office's Earth to Orbit Launch Team methodology and high level discussion of the performance trades and trends of both small launch vehicle solutions along with design philosophies that shaped both concepts. Without putting forth a decree stating one approach is better than the other; this discussion is meant to educate the community at large and let the reader determine which architecture is truly the most economical; since each path has such a unique set of limitations and potential payoffs.

  1. Comparative antennal transcriptome of Apis cerana cerana from four developmental stages.

    Science.gov (United States)

    Zhao, Huiting; Peng, Zhu; Du, Yali; Xu, Kai; Guo, Lina; Yang, Shuang; Ma, Weihua; Jiang, Yusuo

    2018-03-21

    Apis cerana cerana, an important endemic honey bee species in China, possesses valuable characteristics such as a sensitive olfactory system, good foraging ability, and strong resistance to parasitic mites. Here, we performed transcriptome sequencing of the antenna, the major chemosensory organ of the bee, using an Illumina sequencer, to identify typical differentially expressed genes (DEGs) in adult worker bees of different ages, namely, T1 (1 day); T2 (10 days); T3 (15 days); and T4 (25 days). Surprisingly, the expression levels of DEGs changed significantly between the T1 period and the other three periods. All the DEGs were classified into 26 expression profiles by trend analysis. Selected trend clusters were analyzed, and valuable information on gene expression patterns was obtained. We found that the expression levels of genes encoding cuticle proteins declined after eclosion, while those of immunity-related genes increased. In addition, genes encoding venom proteins and major royal jelly proteins were enriched at the T2 stage; small heat shock proteins showed significantly higher expression at the T3 stage; and some metabolism-related genes were more highly expressed at the T4 stage. The DEGs identified in this study may serve as a valuable resource for the characterization of expression patterns of antennal genes in A. cerana cerana. Furthermore, this study provides insights into the relationship between labor division in social bees and gene function. Copyright © 2017. Published by Elsevier B.V.

  2. An experimentally validated simulation model for a four-stage spray dryer

    DEFF Research Database (Denmark)

    Petersen, Lars Norbert; Poulsen, Niels Kjølstad; Niemann, Hans Henrik

    2017-01-01

    mathematical model is an index-1 differential algebraic equation (DAE) model with 12 states, 9 inputs, 8 disturbances, and 30 parameters. The parameters in the model are identified from well-excited experimental data obtained from the industrialtype spray dryer. The simulated outputs ofthe model are validated...... is divided into four consecutive stages: a primary spray drying stage, two heated fluid bed stages, and a cooling fluid bed stage. Each of these stages in the model is assumed ideally mixed and the dynamics are described by mass- and energy balances. These balance equations are coupled with constitutive...... equations such as a thermodynamic model, the water evaporation rate, the heat transfer rates, and an equation for the stickiness of the powder (glass transition temperature). Laboratory data is used to model the equilibrium moisture content and the glass transition temperature of the powder. The resulting...

  3. Development of PBPK models for PFOA and PFOS for human pregnancy and lactation life stages.

    Science.gov (United States)

    Loccisano, Anne E; Longnecker, Matthew P; Campbell, Jerry L; Andersen, Melvin E; Clewell, Harvey J

    2013-01-01

    Perfluoroalkyl acid carboxylates and sulfonates (PFAA) have many consumer and industrial applications. Developmental toxicity studies in animals have raised concern about potential reproductive/developmental effects of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS); however, in humans conflicting results have been reported for associations between maternal PFAA levels and these outcomes. Risk assessments and interpretation of available human data during gestation and lactation are hindered due to lack of a framework for understanding and estimating maternal, fetal, and neonatal pharmacokinetics (PK). Physiologically based pharmacokinetic (PBPK) models were developed for PFOA and PFOS for the gestation and lactation life stages in humans to understand how the physiological changes associated with development affect pharmacokinetics of these compounds in the mother, fetus, and infant. These models were derived from PBPK models for PFOA/PFOS that were previously developed for adult humans and rats during gestation and lactation and from existing human pregnancy and lactation models developed for other chemicals. The models simulated PFOA and PFOS concentrations in fetal, infant, and maternal plasma and milk, were compared to available data in humans, and also were used to estimate maternal exposure. The models reported here identified several research needs, which include (1) the identification of transporters involved in renal resorption to explain the multiyear half-lives of these compounds in humans, (2) factors affecting clearance of PFOA/PFOS during gestation and lactation, and (3) data to estimate clearance of PFOA/PFOS in infants. These models may help address concerns regarding possible adverse health effects due to PFOA/PFOS exposure in the fetus and infant and may be useful in comparing pharmacokinetics across life stages.

  4. Comparative Glycoproteome Analysis: Dynamics of Protein Glycosylation during Metamorphic Transition from Pelagic to Benthic Life Stages in Three Invertebrates

    KAUST Repository

    Chandramouli, Kondethimmanahalli; Zhang, Yu; Wong, Yue Him; Qian, Pei Yuan

    2012-01-01

    The life cycle of most benthic marine invertebrates has two distinct stages: the pelagic larval stage and the sessile juvenile stage. The transition between the larval stage and the juvenile stage is often abrupt and may be triggered by post

  5. A Comparative Study on the Stages of Myths Where Nature Appears Sympathetic in Greek & Persian Myths

    Directory of Open Access Journals (Sweden)

    Hiam Gerdabi

    2015-04-01

    Full Text Available During a mythical quest, a typical hero undergoes certain ordeals to achieve the heroic goal which sets him/her on the path of adventure in the first place. Facing the difficulties, the narrator offers help not only through the internal powers of the hero’s soul but also through a variety of external forces (natural/supernatural. In Greek and Persian mythology, heroes sometimes receive help from nature as a source of independent power which can bring about changes. The current study aims to hold out a few cases of natural changes in legendary quests that take ordinary natural phenomena out of their path affecting the quest results. Joseph Campbell’s list of stages of a myth is to be used for juxtaposing the natural phenomena in the myths in order to decide about the part of the legend where nature leaves a mark. The result of the study is expected to categorize different types of heroes that appear in Greek and Persian myths. Furthermore, the relationship between heroes and nature will be examined; as the Persian hero receives the natural interference during the ongoing stages of their quest as help, while the Greek hero receives the effect of nature after their death. All these are supposed to reveal the reward mechanism and how it reflects on the type of measures taken by nature. Keywords: Archetypes, Mythical Hero, Structure of Myths, Reward, Persian Hero, Greek Hero

  6. A two-stage storage routing model for green roof runoff detention.

    Science.gov (United States)

    Vesuviano, Gianni; Sonnenwald, Fred; Stovin, Virginia

    2014-01-01

    Green roofs have been adopted in urban drainage systems to control the total quantity and volumetric flow rate of runoff. Modern green roof designs are multi-layered, their main components being vegetation, substrate and, in almost all cases, a separate drainage layer. Most current hydrological models of green roofs combine the modelling of the separate layers into a single process; these models have limited predictive capability for roofs not sharing the same design. An adaptable, generic, two-stage model for a system consisting of a granular substrate over a hard plastic 'egg box'-style drainage layer and fibrous protection mat is presented. The substrate and drainage layer/protection mat are modelled separately by previously verified sub-models. Controlled storm events are applied to a green roof system in a rainfall simulator. The time-series modelled runoff is compared to the monitored runoff for each storm event. The modelled runoff profiles are accurate (mean Rt(2) = 0.971), but further characterization of the substrate component is required for the model to be generically applicable to other roof configurations with different substrate.

  7. Estimated GFR (eGFR by prediction equation in staging of chronic kidney disease compared to gamma camera GFR

    Directory of Open Access Journals (Sweden)

    Mohammad Masum Alam

    2016-07-01

    Full Text Available Background: Glomerular filtration rate is an effective tool for diagnosis and staging of chronic kidney disease. The effect ofrenal insufficiency by different method of this tool among patients with CKD is controversial.Objective: The objec­tive of this study was to evaluate the performance of eGFR in staging of CKD compared to gamma camera based GFR.Methods: This cross sectional analytical study was conducted in the Department of Biochemistry Bangabandhu Sheikh Mujib Medical University (BSMMU with the collaboration with National Institute of Nuclear Medicine and Allied Sciences, BSMMU during the period of January 2011 to December 2012. Gama camera based GFR was estimated from DTP A reno gram and eGFR was estimated by three prediction equations. Comparison was done by Bland Altman agree­ment test to see the agreement on the measurement of GFR between three equation based eGFR method and gama camera based GFR method. Staging comparison was done by Kappa analysis to see the agreement between the stages identified by those different methods.Results: Bland-Altman agreement analysis between GFR measured by gamma camera, CG equation ,CG equation corrected by BSA and MDRD equation shows statistically significant. CKD stages determined by CG GFR, CG GFR corrected by BSA , MDRD GFR and gamma camera based GFR was compared by Kappa statistical analysis .The kappa value was 0.66, 0.77 and 0.79 respectively.Conclusions: This study findings suggest that GFR estimation by MDRD equation in CKD patients shows good agreement with gamma camera based GFR and for staging of CKD patients, eGFR by MDRD formula may be used as very effective tool in Bangladeshi population.

  8. Comparing holographic dark energy models with statefinder

    International Nuclear Information System (INIS)

    Cui, Jing-Lei; Zhang, Jing-Fei

    2014-01-01

    We apply the statefinder diagnostic to the holographic dark energy models, including the original holographic dark energy (HDE) model, the new holographic dark energy model, the new agegraphic dark energy (NADE) model, and the Ricci dark energy model. In the low-redshift region the holographic dark energy models are degenerate with each other and with the ΛCDM model in the H(z) and q(z) evolutions. In particular, the HDE model is highly degenerate with the ΛCDM model, and in the HDE model the cases with different parameter values are also in strong degeneracy. Since the observational data are mainly within the low-redshift region, it is very important to break this lowredshift degeneracy in the H(z) and q(z) diagnostics by using some quantities with higher order derivatives of the scale factor. It is shown that the statefinder diagnostic r(z) is very useful in breaking the low-redshift degeneracies. By employing the statefinder diagnostic the holographic dark energy models can be differentiated efficiently in the low-redshift region. The degeneracy between the holographic dark energy models and the ΛCDM model can also be broken by this method. Especially for the HDE model, all the previous strong degeneracies appearing in the H(z) and q(z) diagnostics are broken effectively. But for the NADE model, the degeneracy between the cases with different parameter values cannot be broken, even though the statefinder diagnostic is used. A direct comparison of the holographic dark energy models in the r-s plane is also made, in which the separations between the models (including the ΛCDM model) can be directly measured in the light of the current values {r 0 , s 0 } of the models. (orig.)

  9. Comparative hydraulic architecture of tropical tree species representing a range of successional stages and wood density.

    Science.gov (United States)

    McCulloh, Katherine A; Meinzer, Frederick C; Sperry, John S; Lachenbruch, Barbara; Voelker, Steven L; Woodruff, David R; Domec, Jean-Christophe

    2011-09-01

    Plant hydraulic architecture (PHA) has been linked to water transport sufficiency, photosynthetic rates, growth form and attendant carbon allocation. Despite its influence on traits central to conferring an overall competitive advantage in a given environment, few studies have examined whether key aspects of PHA are indicative of successional stage, especially within mature individuals. While it is well established that wood density (WD) tends to be lower in early versus late successional tree species, and that WD can influence other aspects of PHA, the interaction of WD, successional stage and the consequent implications for PHA have not been sufficiently explored. Here, we studied differences in PHA at the scales of wood anatomy to whole-tree hydraulic conductance in species in early versus late successional Panamanian tropical forests. Although the trunk WD was indistinguishable between the successional groups, the branch WD was lower in the early successional species. Across all species, WD correlated negatively with vessel diameter and positively with vessel packing density. The ratio of branch:trunk vessel diameter, branch sap flux and whole-tree leaf-specific conductance scaled negatively with branch WD across species. Pioneer species showed greater sap flux in branches than in trunks and a greater leaf-specific hydraulic conductance, suggesting that pioneer species can move greater quantities of water at a given tension gradient. In combination with the greater water storage capacitance associated with lower WD, these results suggest these pioneer species can save on the carbon expenditure needed to build safer xylem and instead allow more carbon to be allocated to rapid growth.

  10. Costs of conservative management of early-stage prostate cancer compared to radical prostatectomy–a claims data analysis

    Directory of Open Access Journals (Sweden)

    Alina Brandes

    2016-11-01

    Full Text Available Abstract Background Due to widespread PSA testing incidence rates of localized prostate cancer increase but curative treatment is often not required. Overtreatment imposes a substantial economic burden on health care systems. We compared the direct medical costs of conservative management and radical therapy for the management of early-stage prostate cancer in routine care. Methods An observational study design is chosen based on claims data of a German statutory health insurance fund for the years 2008–2011. Three hundred fifty-three age-matched men diagnosed with prostate cancer and treated with conservative management and radical prostatectomy, are included. Individuals with diagnoses of metastases or treatment of advanced prostate cancer are excluded. In an excess cost approach direct medical costs are considered from an insured community perspective for in- and outpatient care, pharmaceuticals, physiotherapy, and assistive technologies. Generalized linear models adjust for comorbidity by Charlson comorbidity score and recycled predictions method calculates per capita costs per treatment strategy. Results After follow-up of 2.5 years per capita costs of conservative management are €6611 lower than costs of prostatectomy ([−9734;−3547], p < 0.0001. Complications increase costs of assistive technologies by 30% (p = 0.0182, but do not influence any other costs. Results are robust to cost outliers and incidence of prostate cancer diagnosis. The short time horizon does not allow assessing long-term consequences of conservative management. Conclusions At a time horizon of 2.5 years, conservative management is preferable to radical prostatectomy in terms of costs. Claims data analysis is limited in the selection of comparable treatment groups, as clinical information is scarce and bias due to non-randomization can only be partly mitigated by matching and confounder adjustment.

  11. A proposed model of psychodynamic psychotherapy linked to Erik Erikson's eight stages of psychosocial development.

    Science.gov (United States)

    Knight, Zelda Gillian

    2017-09-01

    Just as Freud used stages of psychosexual development to ground his model of psychoanalysis, it is possible to do the same with Erik Erikson's stages of development with regards to a model of psychodynamic psychotherapy. This paper proposes an eight-stage model of psychodynamic psychotherapy linked to Erik Erikson's eight stages of psychosocial development. Various suggestions are offered. One such suggestion is that as each of Erikson's developmental stages is triggered by a crisis, in therapy it is triggered by the client's search. The resolution of the search often leads to the development of another search, which implies that the therapy process comprises a series of searches. This idea of a series of searches and resolutions leads to the understanding that identity is developmental and therapy is a space in which a new sense of identity may emerge. The notion of hope is linked to Erikson's stage of Basic Trust and the proposed model of therapy views hope and trust as essential for the therapy process. Two clinical vignettes are offered to illustrate these ideas. Psychotherapy can be approached as an eight-stage process and linked to Erikson's eight stages model of development. Psychotherapy may be viewed as a series of searches and thus as a developmental stage resolution process, which leads to the understanding that identity is ongoing throughout the life span. Copyright © 2017 John Wiley & Sons, Ltd.

  12. Comparing treatment outcomes of different chemotherapy sequences during intensity modulated radiotherapy for advanced N-stage nasopharyngeal carcinoma patients

    International Nuclear Information System (INIS)

    Sun, Xueming; Zeng, Lei; Chen, Chunyan; Huang, Ying; Han, Fei; Xiao, Weiwei; Liu, Shuai; Lu, Taixiang

    2013-01-01

    N-stage is related to distant metastasis of nasopharyngeal carcinoma (NPC) patients. We performed this study to compare the efficacy of different chemotherapy sequences in advanced N-stage (N2 and N3) NPC patients treated with intensity modulated radiotherapy (IMRT). From 2001 to 2008, 198 advanced N-stage NPC patients were retrospectively analyzed. Thirty-three patients received IMRT alone. Concurrent chemoradiotherapy (CCRT) was delivered to 72 patients, neoadjuvant chemotherapy (NACT) + CCRT to 82 patients and CCRT + adjuvant chemotherapy (AC) to 11 patients. The 5-year overall survival rate, recurrence-free survival rate, distant metastasis-free survival rate and progress-free survival rate were 47.7% and 73.1%(p<0.001), 74.5% and 91.3% (p = 0.004), 49.2% and 68.5% (p = 0.018), 37.5% and 63.8% (p<0.001) in IMRT alone and chemoradiotherapy group. Subgroup analyses indicated that there were no significant differences among the survival curves of CCRT, NACT + CCRT and CCRT + AC groups. The survival benefit mainly came from CCRT. However, there was only an improvement attendency in distant metastasis-free survival rate of CCRT group (p = 0.107) when compared with RT alone group, and NACT + CCRT could significantly improve distant metastasis-free survival (p = 0.017). For advanced N-stage NPC patients, NACT + CCRT might be a reasonable treatment strategy

  13. Integrating Growth Stage Deficit Irrigation into a Process Based Crop Model

    Science.gov (United States)

    Lopez, Jose R.; Winter, Jonathan M.; Elliott, Joshua; Ruane, Alex C.; Porter, Cheryl; Hoogenboom, Gerrit

    2017-01-01

    Current rates of agricultural water use are unsustainable in many regions, creating an urgent need to identify improved irrigation strategies for water limited areas. Crop models can be used to quantify plant water requirements, predict the impact of water shortages on yield, and calculate water productivity (WP) to link water availability and crop yields for economic analyses. Many simulations of crop growth and development, especially in regional and global assessments, rely on automatic irrigation algorithms to estimate irrigation dates and amounts. However, these algorithms are not well suited for water limited regions because they have simplistic irrigation rules, such as a single soil-moisture based threshold, and assume unlimited water. To address this constraint, a new modeling framework to simulate agricultural production in water limited areas was developed. The framework consists of a new automatic irrigation algorithm for the simulation of growth stage based deficit irrigation under limited seasonal water availability; and optimization of growth stage specific parameters. The new automatic irrigation algorithm was used to simulate maize and soybean in Gainesville, Florida, and first used to evaluate the sensitivity of maize and soybean simulations to irrigation at different growth stages and then to test the hypothesis that water productivity calculated using simplistic irrigation rules underestimates WP. In the first experiment, the effect of irrigating at specific growth stages on yield and irrigation water use efficiency (IWUE) in maize and soybean was evaluated. In the reproductive stages, IWUE tended to be higher than in the vegetative stages (e.g. IWUE was 18% higher than the well watered treatment when irrigating only during R3 in soybean), and when rainfall events were less frequent. In the second experiment, water productivity (WP) was significantly greater with optimized irrigation schedules compared to non-optimized irrigation schedules in

  14. Chemval project report on stage 1: verification of speciation models

    International Nuclear Information System (INIS)

    Read, D.; Broyd, T.W.

    1989-01-01

    CHEMVAL is an international geochemical exercise, which aims at applicating and validating predictive computer programmes describing the chemistry of radionuclides in the geosphere. As a component of the CEC project MIRAGE- second phase (on migration of radionuclides in the geosphere), CHEMVAL is carried out in the framework of the third community R and D programme of radioactive waste management and storage. The present report is the first of a series devoted to the verification and validation of aqueous speciation and coupled chemical transport codes. Five cases systems are studied, namely, cement, clay, sandstore, granite and limestone. Overall, good agreement was obtained. Reasons for divergence in results have been explored and recommendations are made at the appropriate stages for enhancement of the thermodynamic data base. A listing of the preliminary CHEMVAL Project Data Base is provided

  15. Model Development for Atomic Force Microscope Stage Mechanisms

    National Research Council Canada - National Science Library

    Smith, Ralph C; Hatch, Andrew G; De, Tathagata; Salapaka, Murti V; Raye, Julie K; del Rosario, Ricardo C

    2005-01-01

    In this paper, we develop nonlinear constitutive equations and resulting system models quantifying the nonlinear and hysteretic field-displacement relations inherent to lead zirconate titanate (PZT...

  16. A transition-constrained discrete hidden Markov model for automatic sleep staging

    Directory of Open Access Journals (Sweden)

    Pan Shing-Tai

    2012-08-01

    Full Text Available Abstract Background Approximately one-third of the human lifespan is spent sleeping. To diagnose sleep problems, all-night polysomnographic (PSG recordings including electroencephalograms (EEGs, electrooculograms (EOGs and electromyograms (EMGs, are usually acquired from the patient and scored by a well-trained expert according to Rechtschaffen & Kales (R&K rules. Visual sleep scoring is a time-consuming and subjective process. Therefore, the development of an automatic sleep scoring method is desirable. Method The EEG, EOG and EMG signals from twenty subjects were measured. In addition to selecting sleep characteristics based on the 1968 R&K rules, features utilized in other research were collected. Thirteen features were utilized including temporal and spectrum analyses of the EEG, EOG and EMG signals, and a total of 158 hours of sleep data were recorded. Ten subjects were used to train the Discrete Hidden Markov Model (DHMM, and the remaining ten were tested by the trained DHMM for recognition. Furthermore, the 2-fold cross validation was performed during this experiment. Results Overall agreement between the expert and the results presented is 85.29%. With the exception of S1, the sensitivities of each stage were more than 81%. The most accurate stage was SWS (94.9%, and the least-accurately classified stage was S1 ( Conclusion The results of the experiments demonstrate that the proposed method significantly enhances the recognition rate when compared with prior studies.

  17. Enhancing the Predicting Accuracy of the Water Stage Using a Physical-Based Model and an Artificial Neural Network-Genetic Algorithm in a River System

    Directory of Open Access Journals (Sweden)

    Wen-Cheng Liu

    2014-06-01

    Full Text Available Accurate simulations of river stages during typhoon events are critically important for flood control and are necessary for disaster prevention and water resources management in Taiwan. This study applies two artificial neural network (ANN models, including the back propagation neural network (BPNN and genetic algorithm neural network (GANN techniques, to improve predictions from a one-dimensional flood routing hydrodynamic model regarding the water stages during typhoon events in the Danshuei River system in northern Taiwan. The hydrodynamic model is driven by freshwater discharges at the upstream boundary conditions and by the water levels at the downstream boundary condition. The model provides a sound physical basis for simulating water stages along the river. The simulated results of the hydrodynamic model show that the model cannot reproduce the water stages at different stations during typhoon events for the model calibration and verification phases. The BPNN and GANN models can improve the simulated water stages compared with the performance of the hydrodynamic model. The GANN model satisfactorily predicts water stages during the training and verification phases and exhibits the lowest values of mean absolute error, root-mean-square error and peak error compared with the simulated results at different stations using the hydrodynamic model and the BPNN model. Comparison of the simulated results shows that the GANN model can be successfully applied to predict the water stages of the Danshuei River system during typhoon events.

  18. Generating a robust prediction model for stage I lung adenocarcinoma recurrence after surgical resection.

    Science.gov (United States)

    Wu, Yu-Chung; Wei, Nien-Chih; Hung, Jung-Jyh; Yeh, Yi-Chen; Su, Li-Jen; Hsu, Wen-Hu; Chou, Teh-Ying

    2017-10-03

    Lung cancer mortality remains high even after successful resection. Adjuvant treatment benefits stage II and III patients, but not stage I patients, and most studies fail to predict recurrence in stage I patients. Our study included 211 lung adenocarcinoma patients (stages I-IIIA; 81% stage I) who received curative resections at Taipei Veterans General Hospital between January 2001 and December 2012. We generated a prediction model using 153 samples, with validation using an additional 58 clinical outcome-blinded samples. Gene expression profiles were generated using formalin-fixed, paraffin-embedded tissue samples and microarrays. Data analysis was performed using a supervised clustering method. The prediction model generated from mixed stage samples successfully separated patients at high vs. low risk for recurrence. The validation tests hazard ratio (HR = 4.38) was similar to that of the training tests (HR = 4.53), indicating a robust training process. Our prediction model successfully distinguished high- from low-risk stage IA and IB patients, with a difference in 5-year disease-free survival between high- and low-risk patients of 42% for stage IA and 45% for stage IB ( p model for identifying lung adenocarcinoma patients at high risk for recurrence who may benefit from adjuvant therapy. Our prediction performance of the difference in disease free survival between high risk and low risk groups demonstrates more than two fold improvement over earlier published results.

  19. [Analysis of clinical outcomes of different embryo stage biopsy in array comparative genomic hybridization based preimplantation genetic diagnosis and screening].

    Science.gov (United States)

    Shen, J D; Wu, W; Shu, L; Cai, L L; Xie, J Z; Ma, L; Sun, X P; Cui, Y G; Liu, J Y

    2017-12-25

    Objective: To evaluate the efficiency of the application of array comparative genomic hybridization (array-CGH) in preimplantation genetic diagnosis or screening (PGD/PGS), and compare the clinical outcomes of different stage embryo biopsy. Methods: The outcomes of 381 PGD/PGS cycles referred in the First Affiliated Hospital of Nanjing Medical University from July 2011 to August 2015 were retrospectively analyzed. There were 320 PGD cycles with 156 cleavage-stage-biopsy cycles and 164 trophectoderm-biopsy cycles, 61 PGS cycles with 23 cleavage-stage-biopsy cycles and 38 trophectoderm-biopsy cycles. Chromosomal analysis was performed by array-CGH technology combined with whole genome amplification. Single embryo transfer was performed in all transfer cycles. Live birth rate was calculated as the main clinical outcomes. Results: The embryo diagnosis rate of PGD/PGS by array-CGH were 96.9%-99.1%. In PGD biopsy cycles, the live birth rate per embryo transfer cycle and live birth rate per embryo biopsy cycle were 50.0%(58/116) and 37.2%(58/156) in cleavage-stage-biopsy group, 67.5%(85/126) and 51.8%(85/164) in trophectoderm-biopsy group (both P 0.05). Conclusions: High diagnosis rate and idea live birth rate are achieved in PGD/PGS cycles based on array-CGH technology. The live birth rate of trophectoderm-biopsy group is significantly higher than that of cleavage-stage-biopsy group in PGD cycles; the efficiency of trophectoderm-biopsy is better.

  20. Comparative Analysis of Investment Decision Models

    Directory of Open Access Journals (Sweden)

    Ieva Kekytė

    2017-06-01

    Full Text Available Rapid development of financial markets resulted new challenges for both investors and investment issues. This increased demand for innovative, modern investment and portfolio management decisions adequate for market conditions. Financial market receives special attention, creating new models, includes financial risk management and investment decision support systems.Researchers recognize the need to deal with financial problems using models consistent with the reality and based on sophisticated quantitative analysis technique. Thus, role mathematical modeling in finance becomes important. This article deals with various investments decision-making models, which include forecasting, optimization, stochatic processes, artificial intelligence, etc., and become useful tools for investment decisions.

  1. Computer modelling of structures with account of the construction stages and the time dependent material properties

    Directory of Open Access Journals (Sweden)

    Traykov Alexander

    2015-01-01

    Full Text Available Numerical studies are performed on computer models taking into account the stages of construction and time dependent material properties defined in two forms. A 2D model of three storey two spans frame is created. The first form deals with material defined in the usual design practice way - without taking into account the time dependent properties of the concrete. The second form creep and shrinkage of the concrete are taken into account. Displacements and internal forces in specific elements and sections are reported. The influence of the time dependent material properties on the displacement and the internal forces in the main structural elements is tracked down. The results corresponding to the two forms of material definition are compared together as well as with the results obtained by the usual design calculations. Conclusions on the influence of the concrete creep and shrinkage during the construction towards structural behaviour are made.

  2. Time Delayed Stage-Structured Predator-Prey Model with Birth Pulse and Pest Control Tactics

    Directory of Open Access Journals (Sweden)

    Mei Yan

    2014-01-01

    Full Text Available Normally, chemical pesticides kill not only pests but also their natural enemies. In order to better control the pests, two-time delayed stage-structured predator-prey models with birth pulse and pest control tactics are proposed and analyzed by using impulsive differential equations in present work. The stability threshold conditions for the mature prey-eradication periodic solutions of two models are derived, respectively. The effects of key parameters including killing efficiency rate, pulse period, the maximum birth effort per unit of time of natural enemy, and maturation time of prey on the threshold values are discussed in more detail. By comparing the two threshold values of mature prey-extinction, we provide the fact that the second control tactic is more effective than the first control method.

  3. Classification of iRBD and Parkinson's patients using a general data-driven sleep staging model built on EEG

    DEFF Research Database (Denmark)

    Koch, Henriette; Christensen, Julie Anja Engelhard; Frandsen, Rune

    2013-01-01

    Sleep analysis is an important diagnostic tool for sleep disorders. However, the current manual sleep scoring is time-consuming as it is a crude discretization in time and stages. This study changes Esbroeck and Westover's [1] latent sleep staging model into a global model. The proposed data......-driven method trained a topic mixture model on 10 control subjects and was applied on 10 other control subjects, 10 iRBD patients and 10 Parkinson's patients. In that way 30 topic mixture diagrams were obtained from which features reflecting distinct sleep architectures between control subjects and patients...... were extracted. Two features calculated on basis of two latent sleep states classified subjects as “control” or “patient” by a simple clustering algorithm. The mean sleep staging accuracy compared to classical AASM scoring was 72.4% for control subjects and a clustering of the derived features resulted...

  4. Improving staging accuracy in colon and rectal cancer by sentinel lymph node mapping: A comparative study

    NARCIS (Netherlands)

    van der Zaag, E. S.; Buskens, C. J.; Kooij, N.; Akol, H.; Peters, H. M.; Bouma, W. H.; Bemelman, W. A.

    2009-01-01

    Aim: To compare the predictive value of sentinel lymph node (SN) mapping between patients with colon and rectal cancer. Patients and methods: An ex vivo SN procedure was performed in 100 patients with colon and 32 patients with rectal cancer. If the sentinel node was negative, immunohistochemical

  5. A TWO-STAGE MODEL OF RADIOLOGICAL INSPECTION: SPENDING TIME

    International Nuclear Information System (INIS)

    BROWN, W.S.

    2000-01-01

    The paper describes a model that visually portrays radiological survey performance as basic parameters (surveyor efficiency and criteria, duration of pause, and probe speed) are varied; field and laboratory tests provided typical parameter values. The model is used to illustrate how practical constraints on the time allotted to the task can affect radiological inspection performance. Similar analyses are applicable to a variety of other tasks (airport baggage inspection, and certain types of non-destructive testing) with similar characteristics and constraints

  6. Stereotactic Body Radiotherapy (SBRT) for Operable Stage I Non-Small-Cell Lung Cancer: Can SBRT Be Comparable to Surgery?

    Energy Technology Data Exchange (ETDEWEB)

    Onishi, Hiroshi, E-mail: honishi@yamanashi.ac.jp [School of Medicine, Yamanashi University, Yamanashi (Japan); Shirato, Hiroki [School of Medicine, Hokkaido University, Sapporo (Japan); Nagata, Yasushi [School of Medicine, Hiroshima University, Hiroshima (Japan); Hiraoka, Masahiro [School of Medicine, Kyoto University, Kyoto (Japan); Fujino, Masaharu [School of Medicine, Hokkaido University, Sapporo (Japan); School of Medicine, Yamanashi University, Yamanashi (Japan); Gomi, Kotaro [Cancer Institute Suwa Red-Cross Hospital, Suwa (Japan); Karasawa, Katsuyuki [Tokyo Metropolitan Komagome Hospital, Tokyo (Japan); Hayakawa, Kazushige; Niibe, Yuzuru [Kitasato University, Kanagawa (Japan); Takai, Yoshihiro [School of Medicine, Hirosaki University, Hirosaki (Japan); Kimura, Tomoki [School of Medicine, Kagawa University, Hiroshima (Japan); Takeda, Atsuya [Ofuna Chuo Hospital, Kanagawa (Japan); Ouchi, Atsushi [Keijinkai Hospital, Sapporo (Japan); Hareyama, Masato [Sapporo Medical University, Sapporo (Japan); Kokubo, Masaki [Institute of Biomedical Research and Innovation, Kobe (Japan); Kozuka, Takuyo [School of Cancer Institute Ariake Hospital, Tokyo (Japan); Arimoto, Takuro [Kitami Red Cross Hospital, Kitami (Japan); Hara, Ryusuke [National Institute of Radiological Science, Chiba (Japan); Itami, Jun [National Cancer Center, Tokyo (Japan); Araki, Tsutomu [School of Medicine, Yamanashi University, Yamanashi (Japan)

    2011-12-01

    Purpose: To review treatment outcomes for stereotactic body radiotherapy (SBRT) in medically operable patients with Stage I non-small-cell lung cancer (NSCLC), using a Japanese multi-institutional database. Patients and Methods: Between 1995 and 2004, a total of 87 patients with Stage I NSCLC (median age, 74 years; T1N0M0, n = 65; T2N0M0, n = 22) who were medically operable but refused surgery were treated using SBRT alone in 14 institutions. Stereotactic three-dimensional treatment was performed using noncoplanar dynamic arcs or multiple static ports. Total dose was 45-72.5 Gy at the isocenter, administered in 3-10 fractions. Median calculated biological effective dose was 116 Gy (range, 100-141 Gy). Data were collected and analyzed retrospectively. Results: During follow-up (median, 55 months), cumulative local control rates for T1 and T2 tumors at 5 years after SBRT were 92% and 73%, respectively. Pulmonary complications above Grade 2 arose in 1 patient (1.1%). Five-year overall survival rates for Stage IA and IB subgroups were 72% and 62%, respectively. One patient who developed local recurrences safely underwent salvage surgery. Conclusion: Stereotactic body radiotherapy is safe and promising as a radical treatment for operable Stage I NSCLC. The survival rate for SBRT is potentially comparable to that for surgery.

  7. Stereotactic Body Radiotherapy (SBRT) for Operable Stage I Non–Small-Cell Lung Cancer: Can SBRT Be Comparable to Surgery?

    International Nuclear Information System (INIS)

    Onishi, Hiroshi; Shirato, Hiroki; Nagata, Yasushi; Hiraoka, Masahiro; Fujino, Masaharu; Gomi, Kotaro; Karasawa, Katsuyuki; Hayakawa, Kazushige; Niibe, Yuzuru; Takai, Yoshihiro; Kimura, Tomoki; Takeda, Atsuya; Ouchi, Atsushi; Hareyama, Masato; Kokubo, Masaki; Kozuka, Takuyo; Arimoto, Takuro; Hara, Ryusuke; Itami, Jun; Araki, Tsutomu

    2011-01-01

    Purpose: To review treatment outcomes for stereotactic body radiotherapy (SBRT) in medically operable patients with Stage I non–small-cell lung cancer (NSCLC), using a Japanese multi-institutional database. Patients and Methods: Between 1995 and 2004, a total of 87 patients with Stage I NSCLC (median age, 74 years; T1N0M0, n = 65; T2N0M0, n = 22) who were medically operable but refused surgery were treated using SBRT alone in 14 institutions. Stereotactic three-dimensional treatment was performed using noncoplanar dynamic arcs or multiple static ports. Total dose was 45–72.5 Gy at the isocenter, administered in 3–10 fractions. Median calculated biological effective dose was 116 Gy (range, 100–141 Gy). Data were collected and analyzed retrospectively. Results: During follow-up (median, 55 months), cumulative local control rates for T1 and T2 tumors at 5 years after SBRT were 92% and 73%, respectively. Pulmonary complications above Grade 2 arose in 1 patient (1.1%). Five-year overall survival rates for Stage IA and IB subgroups were 72% and 62%, respectively. One patient who developed local recurrences safely underwent salvage surgery. Conclusion: Stereotactic body radiotherapy is safe and promising as a radical treatment for operable Stage I NSCLC. The survival rate for SBRT is potentially comparable to that for surgery.

  8. DeepSleepNet: A Model for Automatic Sleep Stage Scoring Based on Raw Single-Channel EEG.

    Science.gov (United States)

    Supratak, Akara; Dong, Hao; Wu, Chao; Guo, Yike

    2017-11-01

    This paper proposes a deep learning model, named DeepSleepNet, for automatic sleep stage scoring based on raw single-channel EEG. Most of the existing methods rely on hand-engineered features, which require prior knowledge of sleep analysis. Only a few of them encode the temporal information, such as transition rules, which is important for identifying the next sleep stages, into the extracted features. In the proposed model, we utilize convolutional neural networks to extract time-invariant features, and bidirectional-long short-term memory to learn transition rules among sleep stages automatically from EEG epochs. We implement a two-step training algorithm to train our model efficiently. We evaluated our model using different single-channel EEGs (F4-EOG (left), Fpz-Cz, and Pz-Oz) from two public sleep data sets, that have different properties (e.g., sampling rate) and scoring standards (AASM and R&K). The results showed that our model achieved similar overall accuracy and macro F1-score (MASS: 86.2%-81.7, Sleep-EDF: 82.0%-76.9) compared with the state-of-the-art methods (MASS: 85.9%-80.5, Sleep-EDF: 78.9%-73.7) on both data sets. This demonstrated that, without changing the model architecture and the training algorithm, our model could automatically learn features for sleep stage scoring from different raw single-channel EEGs from different data sets without utilizing any hand-engineered features.

  9. Thermal properties. Site descriptive modelling Forsmark - stage 2.2

    International Nuclear Information System (INIS)

    Back, Paer-Erik; Wrafter, John; Sundberg, Jan; Rosen, L ars

    2007-09-01

    The lithological data acquired from boreholes and mapping of the rock surface need to be reclassified into thermal rock classes, TRCs. The main reason is to simplify the simulations. The lithological data are used to construct models of the transition between different TRCs, thus describing the spatial statistical structure of each TRC. The result is a set of transition probability models that are used in the simulation of TRCs. The intermediate result of this first stochastic simulation is a number of realisations of the geology, each one equally probable. Based on the thermal data, a spatial statistical thermal model is constructed for each TRC. It consists of a statistical distribution and a variogram for each TRC. These are used in the stochastic simulation of thermal conductivity and the result is a number of equally probable realisations of thermal conductivity for the domain. In the next step, the realisations of TRCs (lithology) and thermal conductivity are merged, i.e. each realisation of geology is filled with simulated thermal conductivity values. The result is a set of realisations of thermal conductivity that considers both the difference in thermal properties between different TRCs, and the variability within each TRC. If the result is desired in a scale different from the simulation scale, i.e. the canister scale, upscaling of the realisations can be performed. The result is a set of equally probable realisations of thermal properties. The presented methodology was applied to rock domain RFM029 and RFM045. The main results are sets of realisations of thermal properties that can be used for further processing, most importantly for statistical analysis and numerical temperature simulations for the design of repository layout (distances between deposition holes). The main conclusions of the thermal modelling are: The choice of scale has a profound influence on the distribution of thermal conductivity values. The variance decreases and the lower tail

  10. Thermal properties. Site descriptive modelling Forsmark - stage 2.2

    Energy Technology Data Exchange (ETDEWEB)

    Back, Paer-Erik; Wrafter, John; Sundberg, Jan [Geo Innova AB (Sweden); Rosen, L ars [Sweco Viak AB (Sweden)

    2007-09-15

    The lithological data acquired from boreholes and mapping of the rock surface need to be reclassified into thermal rock classes, TRCs. The main reason is to simplify the simulations. The lithological data are used to construct models of the transition between different TRCs, thus describing the spatial statistical structure of each TRC. The result is a set of transition probability models that are used in the simulation of TRCs. The intermediate result of this first stochastic simulation is a number of realisations of the geology, each one equally probable. Based on the thermal data, a spatial statistical thermal model is constructed for each TRC. It consists of a statistical distribution and a variogram for each TRC. These are used in the stochastic simulation of thermal conductivity and the result is a number of equally probable realisations of thermal conductivity for the domain. In the next step, the realisations of TRCs (lithology) and thermal conductivity are merged, i.e. each realisation of geology is filled with simulated thermal conductivity values. The result is a set of realisations of thermal conductivity that considers both the difference in thermal properties between different TRCs, and the variability within each TRC. If the result is desired in a scale different from the simulation scale, i.e. the canister scale, upscaling of the realisations can be performed. The result is a set of equally probable realisations of thermal properties. The presented methodology was applied to rock domain RFM029 and RFM045. The main results are sets of realisations of thermal properties that can be used for further processing, most importantly for statistical analysis and numerical temperature simulations for the design of repository layout (distances between deposition holes). The main conclusions of the thermal modelling are: The choice of scale has a profound influence on the distribution of thermal conductivity values. The variance decreases and the lower tail

  11. Life-Stage Physiologically-Based Pharmacokinetic (PBPK) Model Applications to Screen Environmental Hazards.

    Science.gov (United States)

    This presentation discusses methods used to extrapolate from in vitro high-throughput screening (HTS) toxicity data for an endocrine pathway to in vivo for early life stages in humans, and the use of a life stage PBPK model to address rapidly changing physiological parameters. A...

  12. Relations of Transtheoretical Model Stage, Self-Efficacy, and Voluntary Physical Activity in African American Preadolescents

    Science.gov (United States)

    Annesi, James J.; Faigenbaum, Avery D.; Westcott, Wayne L.

    2010-01-01

    The transtheoretical model (TTM; Prochaska, DiClemente, & Norcross, 1992) suggests that, at any point, an individual is in one of five stages-of-change related to adopting a behavior. People sequentially advance in stage but may also maintain or even regress, based on personal and environmental factors (Nigg, 2005). A classic study published in…

  13. An empirical test of stage models of e-government development: evidence from Dutch municipalities

    NARCIS (Netherlands)

    Rooks, G.; Matzat, U.; Sadowski, B.M.

    2017-01-01

    In this article we empirically test stage models of e-government development. We use Lee's classification to make a distinction between four stages of e-government: informational, requests, personal, and e-democracy. We draw on a comprehensive data set on the adoption and development of e-government

  14. Two-Stage Hidden Markov Model in Gesture Recognition for Human Robot Interaction

    Directory of Open Access Journals (Sweden)

    Nhan Nguyen-Duc-Thanh

    2012-07-01

    Full Text Available Hidden Markov Model (HMM is very rich in mathematical structure and hence can form the theoretical basis for use in a wide range of applications including gesture representation. Most research in this field, however, uses only HMM for recognizing simple gestures, while HMM can definitely be applied for whole gesture meaning recognition. This is very effectively applicable in Human-Robot Interaction (HRI. In this paper, we introduce an approach for HRI in which not only the human can naturally control the robot by hand gesture, but also the robot can recognize what kind of task it is executing. The main idea behind this method is the 2-stages Hidden Markov Model. The 1st HMM is to recognize the prime command-like gestures. Based on the sequence of prime gestures that are recognized from the 1st stage and which represent the whole action, the 2nd HMM plays a role in task recognition. Another contribution of this paper is that we use the output Mixed Gaussian distribution in HMM to improve the recognition rate. In the experiment, we also complete a comparison of the different number of hidden states and mixture components to obtain the optimal one, and compare to other methods to evaluate this performance.

  15. Clinical value of FDG hybrid-PET in staging and restaging of malignant lymphoma. Compared with conventional diagnostic methods

    International Nuclear Information System (INIS)

    Pichler, R.; Maschek, W.; Hatzl-Griesenhofer, M.; Huber, H.; Wimmer, G.; Wahl, G.; Fridrik, M.

    2000-01-01

    Aim of the present retrospective study was to validate the clinical value of F-18-FDG PET imaging in lymphoma patients with a dual head camera modified for coincidence detection. Staging before and after oncological treatment was compared with a conservative diagnostic approach. Methods: 48 patients (28 non-Hodgkin lymphoma, 20 Hodgkin's disease) received FDG-Hybrid-PET scans. Pretherapeutic staging was realized in 28 patients, 9 of them had control studies after they had completed therapy. Totally 29 persons were examined for posttherapeutic restaging. Computed tomography imaging and lymph node sonography was performed in all cases. Results were validated by clinical follow-up, in three cases a recidive was proven by biopsy. Results: CT and ultrasound detected 77 lesions in 28 patients compared with 100 visualized by PET, but this difference in pretherapeutic staging did not reach significance at p>0.05 by Fisher's t-test. Hybrid-PET obtained a sensitivity of 93%, a specifity of 79%, a positive of 82% and a negative predictive value of 92% for detection of residual disease. The values for CT+US were 87%, 64%, 72% and 88% respectively. Conclusion: FDG Hybrid-PET is as or even more accurate than standard morphologic diagnostic methods for prestaging in malignant lymphoma. Additionally, there is a substancial benefit for therapy monitoring of residual disease using coincidence detection PET with a 3/4-inch crystal gamma camera. (orig.) [de

  16. Comparing models of offensive cyber operations

    CSIR Research Space (South Africa)

    Grant, T

    2012-03-01

    Full Text Available Group Fallback only No Damballa, 2008 Crime Case studies Lone No No Owens et al, 2009 Warfare Literature Group Yes Yes Croom, 2010 Crime (APT) Case studies Group No No Dreijer, 2011 Warfare Previous models and case studies Group Yes No Van... be needed by a geographically or functionally distributed group of attackers. While some of the models describe the installation of a backdoor or an advanced persistent threat (APT), none of them describe the behaviour involved in returning to a...

  17. Tumor Control Probability Modeling for Stereotactic Body Radiation Therapy of Early-Stage Lung Cancer Using Multiple Bio-physical Models

    Science.gov (United States)

    Liu, Feng; Tai, An; Lee, Percy; Biswas, Tithi; Ding, George X.; El Naqa, Isaam; Grimm, Jimm; Jackson, Andrew; Kong, Feng-Ming (Spring); LaCouture, Tamara; Loo, Billy; Miften, Moyed; Solberg, Timothy; Li, X Allen

    2017-01-01

    Purpose To analyze pooled clinical data using different radiobiological models and to understand the relationship between biologically effective dose (BED) and tumor control probability (TCP) for stereotactic body radiotherapy (SBRT) of early-stage non-small cell lung cancer (NSCLC). Method and Materials The clinical data of 1-, 2-, 3-, and 5-year actuarial or Kaplan-Meier TCP from 46 selected studies were collected for SBRT of NSCLC in the literature. The TCP data were separated for Stage T1 and T2 tumors if possible, otherwise collected for combined stages. BED was calculated at isocenters using six radiobiological models. For each model, the independent model parameters were determined from a fit to the TCP data using the least chi-square (χ2) method with either one set of parameters regardless of tumor stages or two sets for T1 and T2 tumors separately. Results The fits to the clinic data yield consistent results of large α/β ratios of about 20 Gy for all models investigated. The regrowth model that accounts for the tumor repopulation and heterogeneity leads to a better fit to the data, compared to other 5 models where the fits were indistinguishable between the models. The models based on the fitting parameters predict that the T2 tumors require about additional 1 Gy physical dose at isocenters per fraction (≤5 fractions) to achieve the optimal TCP when compared to the T1 tumors. Conclusion This systematic analysis of a large set of published clinical data using different radiobiological models shows that local TCP for SBRT of early-stage NSCLC has strong dependence on BED with large α/β ratios of about 20 Gy. The six models predict that a BED (calculated with α/β of 20) of 90 Gy is sufficient to achieve TCP ≥ 95%. Among the models considered, the regrowth model leads to a better fit to the clinical data. PMID:27871671

  18. Comparing models of offensive cyber operations

    CSIR Research Space (South Africa)

    Grant, T

    2015-10-01

    Full Text Available would be needed by a Cyber Security Operations Centre in order to perform offensive cyber operations?". The analysis was performed, using as a springboard seven models of cyber-attack, and resulted in the development of what is described as a canonical...

  19. Comparative Distributions of Hazard Modeling Analysis

    Directory of Open Access Journals (Sweden)

    Rana Abdul Wajid

    2006-07-01

    Full Text Available In this paper we present the comparison among the distributions used in hazard analysis. Simulation technique has been used to study the behavior of hazard distribution modules. The fundamentals of Hazard issues are discussed using failure criteria. We present the flexibility of the hazard modeling distribution that approaches to different distributions.

  20. Modelling Pseudocalanus elongatus stage-structured population dynamics embedded in a water column ecosystem model for the northern North Sea

    Science.gov (United States)

    Moll, Andreas; Stegert, Christoph

    2007-01-01

    This paper outlines an approach to couple a structured zooplankton population model with state variables for eggs, nauplii, two copepodites stages and adults adapted to Pseudocalanus elongatus into the complex marine ecosystem model ECOHAM2 with 13 state variables resolving the carbon and nitrogen cycle. Different temperature and food scenarios derived from laboratory culture studies were examined to improve the process parameterisation for copepod stage dependent development processes. To study annual cycles under realistic weather and hydrographic conditions, the coupled ecosystem-zooplankton model is applied to a water column in the northern North Sea. The main ecosystem state variables were validated against observed monthly mean values. Then vertical profiles of selected state variables were compared to the physical forcing to study differences between zooplankton as one biomass state variable or partitioned into five population state variables. Simulated generation times are more affected by temperature than food conditions except during the spring phytoplankton bloom. Up to six generations within the annual cycle can be discerned in the simulation.

  1. Concerning modeling of double-stage water evaporation cooling

    Science.gov (United States)

    Shatskiy, V. P.; Fedulova, L. I.; Gridneva, I. V.

    2018-03-01

    The matter of need for setting technical norms for production, as well as acceptable microclimate parameters, such as temperature and humidity, at the work place, remains urgent. Use of certain units should be economically sound and that should be taken into account for construction, assembly, operation, technological, and environmental requirements. Water evaporation coolers are simple to maintain, environmentally friendly, and quite cheap, but the development of the most efficient solutions requires mathematical modeling of the heat and mass transfer processes that take place in them.

  2. Laparoscopic surgery compared to traditional abdominal surgery in the management of early stage cervical cancer.

    Science.gov (United States)

    Simsek, T; Ozekinci, M; Saruhan, Z; Sever, B; Pestereli, E

    2012-01-01

    The purpose of the study was to compare laparoscopic total radical hysterectomy with classic radical hysterectomy regarding parametrial, and vaginal resection, and lymphadenectomy. Laparoscopic or laparotomic total radical hysterectomy with advantages and disadvantages was offered to the patients diagnosed as having operable cervical cancer between 2007 and 2010. Lymph node status, resection of the parametria and vagina, and margin positivity were recorded for both groups. Data were collected prospectively. Statistical analysis was performed with the SPSS statistical software program. Totally, 53 cases had classical abdominal radical hysterectomy and 35 laparoscopic radical hysterectomy, respectively. Parametrial involvement was detected in four (11.4%) cases in laparoscopic radical surgery versus nine (16.9%) in laparatomic surgery. All the cases with parametrial involvement had free surgical margins of tumor. Also there were no significant statistical differences in lymph node number and metastasis between the two groups. There is no difference in anatomical considerations between laparoscopic and laparatomic radical surgery in the surgical management of cervical cancer.

  3. A two-phase inspection model for a single component system with three-stage degradation

    International Nuclear Information System (INIS)

    Wang, Huiying; Wang, Wenbin; Peng, Rui

    2017-01-01

    This paper presents a two-phase inspection schedule and an age-based replacement policy for a single plant item contingent on a three-stage degradation process. The two phase inspection schedule can be observed in practice. The three stages are defined as the normal working stage, low-grade defective stage and critical defective stage. When an inspection detects that an item is in the low-grade defective stage, we may delay the preventive replacement action if the time to the age-based replacement is less than or equal to a threshold level. However, if it is above this threshold level, the item will be replaced immediately. If the item is found in the critical defective stage, it is replaced immediately. A hybrid bee colony algorithm is developed to find the optimal solution for the proposed model which has multiple decision variables. A numerical example is conducted to show the efficiency of this algorithm, and simulations are conducted to verify the correctness of the model. - Highlights: • A two-phase inspection model is studied. • The failure process has three stages. • The delayed replacement is considered.

  4. Staging workers' use of hearing protection devices: application of the transtheoretical model.

    Science.gov (United States)

    Raymond, Delbert M; Lusk, Sally L

    2006-04-01

    The threat of noise-induced hearing loss is a serious concern for many workers. This study explores use of the transtheoretical model as a framework for defining stages of workers' acceptance of hearing protection devices. A secondary analysis was performed using a cross-section of data from a randomized, controlled clinical trial of an intervention to increase use of hearing protection. Use of hearing protection devices was well distributed across the theorized stages of change. Chi-square analysis and analysis of variance revealed significant differences between stages for the variables studied. Discrete stages of hearing protection device use can be identified, laying the foundation for further work investigating use of the transtheoretical model for promoting hearing protection device use. The model can provide a framework for tailoring interventions and evaluating their effects. With further development of the transtheoretical model, nurses may be able to easily identify workers' readiness to use hearing protection devices and tailor training toward that goal.

  5. Modelling early stages of relativistic heavy-ion collisions

    Directory of Open Access Journals (Sweden)

    Ruggieri M.

    2016-01-01

    Full Text Available In this study we model early time dynamics of relativistic heavy ion collisions by an initial color-electric field which then decays to a plasma by the Schwinger mechanism. The dynamics of the many particles system produced by the decay is described by relativistic kinetic theory, taking into account the backreaction on the color field by solving self-consistently the kinetic and the field equations. Our main results concern isotropization and thermalization for a 1+1D expanding geometry. In case of small η/s (η/s ≲ 0.3 we find τisotropization ≈ 0.8 fm/c and τthermalization ≈ 1 fm/c in agreement with the common lore of hydrodynamics.

  6. [Quantitative models between canopy hyperspectrum and its component features at apple tree prosperous fruit stage].

    Science.gov (United States)

    Wang, Ling; Zhao, Geng-xing; Zhu, Xi-cun; Lei, Tong; Dong, Fang

    2010-10-01

    Hyperspectral technique has become the basis of quantitative remote sensing. Hyperspectrum of apple tree canopy at prosperous fruit stage consists of the complex information of fruits, leaves, stocks, soil and reflecting films, which was mostly affected by component features of canopy at this stage. First, the hyperspectrum of 18 sample apple trees with reflecting films was compared with that of 44 trees without reflecting films. It could be seen that the impact of reflecting films on reflectance was obvious, so the sample trees with ground reflecting films should be separated to analyze from those without ground films. Secondly, nine indexes of canopy components were built based on classified digital photos of 44 apple trees without ground films. Thirdly, the correlation between the nine indexes and canopy reflectance including some kinds of conversion data was analyzed. The results showed that the correlation between reflectance and the ratio of fruit to leaf was the best, among which the max coefficient reached 0.815, and the correlation between reflectance and the ratio of leaf was a little better than that between reflectance and the density of fruit. Then models of correlation analysis, linear regression, BP neural network and support vector regression were taken to explain the quantitative relationship between the hyperspectral reflectance and the ratio of fruit to leaf with the softwares of DPS and LIBSVM. It was feasible that all of the four models in 611-680 nm characteristic band are feasible to be used to predict, while the model accuracy of BP neural network and support vector regression was better than one-variable linear regression and multi-variable regression, and the accuracy of support vector regression model was the best. This study will be served as a reliable theoretical reference for the yield estimation of apples based on remote sensing data.

  7. Scrum integration in stage-gate models for collaborative product development

    DEFF Research Database (Denmark)

    Sommer, Anita Friis; Slavensky, Andreas; Nguyen, Vivi Thuy

    2013-01-01

    to differentiate from low-cost competitors and increase PD performance, some industrial manufacturers now seek competitive advantage by experimenting with new ways for collaborative PD. This includes integrating customer-focused agile process models, like Scrum, from the software industry into their existing PD...... models. Thus, instead of replacing traditional stage-gate models agile methods are currently integrated in existing PD models generating hybrid solution for collaborative PD. This paper includes a study of three industrial cases that have successfully integrated Scrum into a stage-gate process model...

  8. Numerical and experimental modelling of the centrifugal compressor stage – setting the model of impellers with 2D blades

    Directory of Open Access Journals (Sweden)

    Matas Richard

    2017-01-01

    Full Text Available The article deals with a description of results from research and development of a radial compressor stage. The experimental compressor and used numerical models are briefly described. In the first part, the comparisons of characteristics obtained experimentally and by numerical simulations for stage with vaneless diffuser are described. In the second part, the results for stage with vanned diffuser are presented. The results are relevant for next studies in research and development process.

  9. Numerical and experimental modelling of the centrifugal compressor stage - setting the model of impellers with 2D blades

    Science.gov (United States)

    Matas, Richard; Syka, Tomáš; Luňáček, Ondřej

    The article deals with a description of results from research and development of a radial compressor stage. The experimental compressor and used numerical models are briefly described. In the first part, the comparisons of characteristics obtained experimentally and by numerical simulations for stage with vaneless diffuser are described. In the second part, the results for stage with vanned diffuser are presented. The results are relevant for next studies in research and development process.

  10. Modele bicamerale comparate. Romania: Monocameralism versus bicameralism

    Directory of Open Access Journals (Sweden)

    Cynthia Carmen CURT

    2007-06-01

    Full Text Available The paper attempts to evaluate the Romanian bicameral model as well as to identify and critically asses which are the options our country has in choosing between unicameral and bicameral system. The analysis attempts to observe the characteristics of some Second Chambers that are related to Romanian bicameralism by influencing the configuration of the Romanian bicameral legislature, or which devised constitutional mechanisms can be used in order to preserve an efficient bicameral formula. Also the alternative of giving up the bicameral formula due to some arguments related to the simplification and the efficiency of the legislative procedure is explored.

  11. A Model for Comparing Free Cloud Platforms

    Directory of Open Access Journals (Sweden)

    Radu LIXANDROIU

    2014-01-01

    Full Text Available VMware, VirtualBox, Virtual PC and other popular desktop virtualization applications are used only by a few users of IT techniques. This article attempts to make a comparison model for choosing the best cloud platform. Many virtualization applications such as VMware (VMware Player, Oracle VirtualBox and Microsoft Virtual PC are free for home users. The main goal of the virtualization software is that it allows users to run multiple operating systems simultane-ously on one virtual environment, using one computer desktop.

  12. Comparative Effectiveness of 5 Treatment Strategies for Early-Stage Non-Small Cell Lung Cancer in the Elderly

    Energy Technology Data Exchange (ETDEWEB)

    Shirvani, Shervin M. [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Jiang, Jing [Department of Biostatistics and Applied Mathematics, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Chang, Joe Y.; Welsh, James W.; Gomez, Daniel R. [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Swisher, Stephen [Department of Thoracic and Cardiovascular Surgery, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Buchholz, Thomas A. [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Smith, Benjamin D., E-mail: bsmith3@mdanderson.org [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)

    2012-12-01

    Purpose: The incidence of early-stage non-small cell lung cancer (NSCLC) among older adults is expected to increase because of demographic trends and computed tomography-based screening; yet, optimal treatment in the elderly remains controversial. Using the Surveillance, Epidemiology, and End Results (SEER)-Medicare cohort spanning 2001-2007, we compared survival outcomes associated with 5 strategies used in contemporary practice: lobectomy, sublobar resection, conventional radiation therapy, stereotactic ablative radiation therapy (SABR), and observation. Methods and Materials: Treatment strategy and covariates were determined in 10,923 patients aged {>=}66 years with stage IA-IB NSCLC. Cox regression, adjusted for patient and tumor factors, compared overall and disease-specific survival for the 5 strategies. In a second exploratory analysis, propensity-score matching was used for comparison of SABR with other options. Results: The median age was 75 years, and 29% had moderate to severe comorbidities. Treatment distribution was lobectomy (59%), sublobar resection (11.7%), conventional radiation (14.8%), observation (12.6%), and SABR (1.1%). In Cox regression analysis with a median follow-up time of 3.2 years, SABR was associated with the lowest risk of death within 6 months of diagnosis (hazard ratio [HR] 0.48; 95% confidence interval [CI] 0.38-0.63; referent is lobectomy). After 6 months, lobectomy was associated with the best overall and disease-specific survival. In the propensity-score matched analysis, survival after SABR was similar to that after lobectomy (HR 0.71; 95% CI 0.45-1.12; referent is SABR). Conventional radiation and observation were associated with poor outcomes in all analyses. Conclusions: In this population-based experience, lobectomy was associated with the best long-term outcomes in fit elderly patients with early-stage NSCLC. Exploratory analysis of SABR early adopters suggests efficacy comparable with that of surgery in select populations

  13. Can the localization of primary colonic tumors be improved by staging CT without specific bowel preparation compared to optical colonoscopy?

    International Nuclear Information System (INIS)

    Feuerlein, Sebastian; Grimm, Lars J.; Davenport, Matthew S.; Haystead, Clare M.; Miller, Chad M.; Neville, Amy M.; Jaffe, Tracy A.

    2012-01-01

    Objectives: To investigate the ability of staging computed tomography (CT) without bowel preparation to accurately localize colonic tumors compared to optical colonoscopy. Methods: The local institutional review board approved this retrospective and HIPAA-compliant study. Forty-six patients with colonic adenocarcinoma, preoperative colonoscopy, and staging CT within 60 days of resection were included. Patients underwent contrast enhanced CT imaging without bowel preparation or oral contrast. The colon was divided into four segments with the operative reports used as the standard. Rectal and cecal cancers were excluded. CT scans were reviewed by 5 readers in a segmental binary fashion using a 5-point confidence scale in two sessions blinded and unblinded to the colonoscopy report. Results: At surgery 49 tumors were found in 46 patients. Readers detected 86.1%, 74.3%, and 66.9% of lesions with 92.0%, 94.1%, and 95.4% accuracy for confidence scores of ≥3, ≥4, and 5. CT interobserver agreement was good (κ = 0.82) for the unblinded and moderate (κ = 0.60) for the blinded read. Colonoscopic localization was only 78.7% accurate with 2 tumors undiscovered. Colonoscopic accuracy was low in the descending colon (57.1%) and the transverse colon (55.6%). Conclusions: Preoperative staging CT is more accurate than colonoscopy in the localization of colonic tumors

  14. Comparative proteomic analysis of a high-tillering dwarf mutant induced by spaceflight at different tillering stages

    International Nuclear Information System (INIS)

    Wang Wei; Wei Lijun; Wang Junmin; Xu Jianlong; Sun Yeqing

    2011-01-01

    To investigate changes of proteins during rice tiller development, a comparative proteomic analysis between a high-tillering dwarf mutant R955 induced by spaceflight and its ground control was performed at three developmental stages during the vegetative growth, i. e. at days 14 (no tiller appearance), 21 (initial tillering) and 55 (maximum tillering) after sowing. Analysis of the protein spots on two-dimensional fluorescence difference gel electrophoresis 2-D DIGE images revealed 97 proteins that were differentially expressed at the three stages. Among them, 59 unique proteins were successfully identified by mass spectrometry. Through functional and quantitative analysis of proteomic data, it was found that biological processes including energy pathway, photosynthesis, protein metabolism, nitrogen assimilation, amino acid metabolism and stimulus response were mainly involved in tiller development in mutant plant. K-means clustering revealed that proteins regulated at different stages tended to be involved in different biological processes. Two-way analysis of variance (Two-way ANOVA) showed that S-like was directly correlated RNase with the high-tillering ability. (authors)

  15. An inexact mixed risk-aversion two-stage stochastic programming model for water resources management under uncertainty.

    Science.gov (United States)

    Li, W; Wang, B; Xie, Y L; Huang, G H; Liu, L

    2015-02-01

    Uncertainties exist in the water resources system, while traditional two-stage stochastic programming is risk-neutral and compares the random variables (e.g., total benefit) to identify the best decisions. To deal with the risk issues, a risk-aversion inexact two-stage stochastic programming model is developed for water resources management under uncertainty. The model was a hybrid methodology of interval-parameter programming, conditional value-at-risk measure, and a general two-stage stochastic programming framework. The method extends on the traditional two-stage stochastic programming method by enabling uncertainties presented as probability density functions and discrete intervals to be effectively incorporated within the optimization framework. It could not only provide information on the benefits of the allocation plan to the decision makers but also measure the extreme expected loss on the second-stage penalty cost. The developed model was applied to a hypothetical case of water resources management. Results showed that that could help managers generate feasible and balanced risk-aversion allocation plans, and analyze the trade-offs between system stability and economy.

  16. Impact of two-stage turbocharging architectures on pumping losses of automotive engines based on an analytical model

    International Nuclear Information System (INIS)

    Galindo, J.; Serrano, J.R.; Climent, H.; Varnier, O.

    2010-01-01

    Present work presents an analytical study of two-stage turbocharging configuration performance. The aim of this work is to understand the influence of different two-stage-architecture parameters to optimize the use of exhaust manifold gases energy and to aid decision making process. An analytical model giving the relationship between global compression ratio and global expansion ratio is developed as a function of basic engine and turbocharging system parameters. Having an analytical solution, the influence of different variables, such as expansion ratio between HP and LP turbine, intercooler efficiency, turbochargers efficiency, cooling fluid temperature and exhaust temperature are studied independently. Engine simulations with proposed analytical model have been performed to analyze the influence of these different parameters on brake thermal efficiency and pumping mean effective pressure. The results obtained show the overall performance of the two-stage system for the whole operative range and characterize the optimum control of the elements for each operative condition. The model was also used to compare single-stage and two-stage architectures performance for the same engine operative conditions. Benefits and limits in terms of breathing capabilities and brake thermal efficiency of each type of system have been presented and analyzed.

  17. Provisional safety analyses for SGT stage 2 -- Models, codes and general modelling approach

    International Nuclear Information System (INIS)

    2014-12-01

    In the framework of the provisional safety analyses for Stage 2 of the Sectoral Plan for Deep Geological Repositories (SGT), deterministic modelling of radionuclide release from the barrier system along the groundwater pathway during the post-closure period of a deep geological repository is carried out. The calculated radionuclide release rates are interpreted as annual effective dose for an individual and assessed against the regulatory protection criterion 1 of 0.1 mSv per year. These steps are referred to as dose calculations. Furthermore, from the results of the dose calculations so-called characteristic dose intervals are determined, which provide input to the safety-related comparison of the geological siting regions in SGT Stage 2. Finally, the results of the dose calculations are also used to illustrate and to evaluate the post-closure performance of the barrier systems under consideration. The principal objective of this report is to describe comprehensively the technical aspects of the dose calculations. These aspects comprise: · the generic conceptual models of radionuclide release from the solid waste forms, of radionuclide transport through the system of engineered and geological barriers, of radionuclide transfer in the biosphere, as well as of the potential radiation exposure of the population, · the mathematical models for the explicitly considered release and transport processes, as well as for the radiation exposure pathways that are included, · the implementation of the mathematical models in numerical codes, including an overview of these codes and the most relevant verification steps, · the general modelling approach when using the codes, in particular the generic assumptions needed to model the near field and the geosphere, along with some numerical details, · a description of the work flow related to the execution of the calculations and of the software tools that are used to facilitate the modelling process, and · an overview of the

  18. Provisional safety analyses for SGT stage 2 -- Models, codes and general modelling approach

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2014-12-15

    In the framework of the provisional safety analyses for Stage 2 of the Sectoral Plan for Deep Geological Repositories (SGT), deterministic modelling of radionuclide release from the barrier system along the groundwater pathway during the post-closure period of a deep geological repository is carried out. The calculated radionuclide release rates are interpreted as annual effective dose for an individual and assessed against the regulatory protection criterion 1 of 0.1 mSv per year. These steps are referred to as dose calculations. Furthermore, from the results of the dose calculations so-called characteristic dose intervals are determined, which provide input to the safety-related comparison of the geological siting regions in SGT Stage 2. Finally, the results of the dose calculations are also used to illustrate and to evaluate the post-closure performance of the barrier systems under consideration. The principal objective of this report is to describe comprehensively the technical aspects of the dose calculations. These aspects comprise: · the generic conceptual models of radionuclide release from the solid waste forms, of radionuclide transport through the system of engineered and geological barriers, of radionuclide transfer in the biosphere, as well as of the potential radiation exposure of the population, · the mathematical models for the explicitly considered release and transport processes, as well as for the radiation exposure pathways that are included, · the implementation of the mathematical models in numerical codes, including an overview of these codes and the most relevant verification steps, · the general modelling approach when using the codes, in particular the generic assumptions needed to model the near field and the geosphere, along with some numerical details, · a description of the work flow related to the execution of the calculations and of the software tools that are used to facilitate the modelling process, and · an overview of the

  19. Phototaxis during the slug stage of Dictyostelium discoideum: a model study

    NARCIS (Netherlands)

    Marée, A.F.M.; Panfilov, A.V.; Hogeweg, P.

    1999-01-01

    During the slug stage, the cellular slime mould Dictyostelium discoideum moves towards light sources. We have modelled this phototactic behaviour using a hybrid cellular automata/partial differential equation model. In our model, individual amoebae are not able to measure the direction from which

  20. 78 FR 8535 - Medicare Program: Comprehensive End-Stage Renal Disease Care Model Announcement

    Science.gov (United States)

    2013-02-06

    ... develop and test innovative health care payment and service delivery models that show promise of reducing... test innovative payment and service delivery models that reduce spending under Medicare, Medicaid or...] Medicare Program: Comprehensive End-Stage Renal Disease Care Model Announcement AGENCY: Centers for...

  1. Internal stress model for pre-primary stage of low-stress creep

    International Nuclear Information System (INIS)

    Kloc, L

    2010-01-01

    Initial transient stage in low-stress creep experiments was observed in all such experiments. Recently, evidences were presented that this stage cannot be considered as a normal creep primary stage, though the shape of the creep curve is similar. The strain reached during this so called pre-primary stage is fully recoverable upon unloading; the internal stresses must play important role in the effect. Model of standard linear anelastic solid was modified by introduction of creeping body instead of viscous dashpot. Both power law and hyperbolic sine creep law were used to fit observed creep curves of model and structural materials. Mainly the model using hyeprbolic sine creep law provides good fit to individual creep curves and sets of creep curves at different stresses.

  2. A Four-Stage Hybrid Model for Hydrological Time Series Forecasting

    Science.gov (United States)

    Di, Chongli; Yang, Xiaohua; Wang, Xiaochao

    2014-01-01

    Hydrological time series forecasting remains a difficult task due to its complicated nonlinear, non-stationary and multi-scale characteristics. To solve this difficulty and improve the prediction accuracy, a novel four-stage hybrid model is proposed for hydrological time series forecasting based on the principle of ‘denoising, decomposition and ensemble’. The proposed model has four stages, i.e., denoising, decomposition, components prediction and ensemble. In the denoising stage, the empirical mode decomposition (EMD) method is utilized to reduce the noises in the hydrological time series. Then, an improved method of EMD, the ensemble empirical mode decomposition (EEMD), is applied to decompose the denoised series into a number of intrinsic mode function (IMF) components and one residual component. Next, the radial basis function neural network (RBFNN) is adopted to predict the trend of all of the components obtained in the decomposition stage. In the final ensemble prediction stage, the forecasting results of all of the IMF and residual components obtained in the third stage are combined to generate the final prediction results, using a linear neural network (LNN) model. For illustration and verification, six hydrological cases with different characteristics are used to test the effectiveness of the proposed model. The proposed hybrid model performs better than conventional single models, the hybrid models without denoising or decomposition and the hybrid models based on other methods, such as the wavelet analysis (WA)-based hybrid models. In addition, the denoising and decomposition strategies decrease the complexity of the series and reduce the difficulties of the forecasting. With its effective denoising and accurate decomposition ability, high prediction precision and wide applicability, the new model is very promising for complex time series forecasting. This new forecast model is an extension of nonlinear prediction models. PMID:25111782

  3. A four-stage hybrid model for hydrological time series forecasting.

    Science.gov (United States)

    Di, Chongli; Yang, Xiaohua; Wang, Xiaochao

    2014-01-01

    Hydrological time series forecasting remains a difficult task due to its complicated nonlinear, non-stationary and multi-scale characteristics. To solve this difficulty and improve the prediction accuracy, a novel four-stage hybrid model is proposed for hydrological time series forecasting based on the principle of 'denoising, decomposition and ensemble'. The proposed model has four stages, i.e., denoising, decomposition, components prediction and ensemble. In the denoising stage, the empirical mode decomposition (EMD) method is utilized to reduce the noises in the hydrological time series. Then, an improved method of EMD, the ensemble empirical mode decomposition (EEMD), is applied to decompose the denoised series into a number of intrinsic mode function (IMF) components and one residual component. Next, the radial basis function neural network (RBFNN) is adopted to predict the trend of all of the components obtained in the decomposition stage. In the final ensemble prediction stage, the forecasting results of all of the IMF and residual components obtained in the third stage are combined to generate the final prediction results, using a linear neural network (LNN) model. For illustration and verification, six hydrological cases with different characteristics are used to test the effectiveness of the proposed model. The proposed hybrid model performs better than conventional single models, the hybrid models without denoising or decomposition and the hybrid models based on other methods, such as the wavelet analysis (WA)-based hybrid models. In addition, the denoising and decomposition strategies decrease the complexity of the series and reduce the difficulties of the forecasting. With its effective denoising and accurate decomposition ability, high prediction precision and wide applicability, the new model is very promising for complex time series forecasting. This new forecast model is an extension of nonlinear prediction models.

  4. One- and two-stage Arrhenius models for pharmaceutical shelf life prediction.

    Science.gov (United States)

    Fan, Zhewen; Zhang, Lanju

    2015-01-01

    One of the most challenging aspects of the pharmaceutical development is the demonstration and estimation of chemical stability. It is imperative that pharmaceutical products be stable for two or more years. Long-term stability studies are required to support such shelf life claim at registration. However, during drug development to facilitate formulation and dosage form selection, an accelerated stability study with stressed storage condition is preferred to quickly obtain a good prediction of shelf life under ambient storage conditions. Such a prediction typically uses Arrhenius equation that describes relationship between degradation rate and temperature (and humidity). Existing methods usually rely on the assumption of normality of the errors. In addition, shelf life projection is usually based on confidence band of a regression line. However, the coverage probability of a method is often overlooked or under-reported. In this paper, we introduce two nonparametric bootstrap procedures for shelf life estimation based on accelerated stability testing, and compare them with a one-stage nonlinear Arrhenius prediction model. Our simulation results demonstrate that one-stage nonlinear Arrhenius method has significant lower coverage than nominal levels. Our bootstrap method gave better coverage and led to a shelf life prediction closer to that based on long-term stability data.

  5. A Risk-Based Interval Two-Stage Programming Model for Agricultural System Management under Uncertainty

    Directory of Open Access Journals (Sweden)

    Ye Xu

    2016-01-01

    Full Text Available Nonpoint source (NPS pollution caused by agricultural activities is main reason that water quality in watershed becomes worse, even leading to deterioration. Moreover, pollution control is accompanied with revenue’s fall for agricultural system. How to design and generate a cost-effective and environmentally friendly agricultural production pattern is a critical issue for local managers. In this study, a risk-based interval two-stage programming model (RBITSP was developed. Compared to general ITSP model, significant contribution made by RBITSP model was that it emphasized importance of financial risk under various probabilistic levels, rather than only being concentrated on expected economic benefit, where risk is expressed as the probability of not meeting target profit under each individual scenario realization. This way effectively avoided solutions’ inaccuracy caused by traditional expected objective function and generated a variety of solutions through adjusting weight coefficients, which reflected trade-off between system economy and reliability. A case study of agricultural production management with the Tai Lake watershed was used to demonstrate superiority of proposed model. Obtained results could be a base for designing land-structure adjustment patterns and farmland retirement schemes and realizing balance of system benefit, system-failure risk, and water-body protection.

  6. Differences of Tc-99m HMPAO SPECT imaging in the early stage of subcortical vascular dementia compared with Alzheimer's disease

    International Nuclear Information System (INIS)

    Park, Kyung Won; Kang, Do Young; Park, Min Jeong; Cheon, Sang Myung; Cha, Jae Kwan; Kim, Sang Ho; Kim, Jae Woo

    2007-01-01

    The aim of this study is to assess the specific patterns of regional cerebral blood flow (rCBF) in patients with the early stage of subcortical vascular dementia (SVaD) and Alzheimer's disease (AD) using Tc-99m HMPAO SPECT, and to compare the differences between the two conditions. Sixteen SVaD, 46 AD and 12 control subjects participated in this study. We included the patients with SVaD and AD according to NINCDS-ADRDA and NINDS-AIREN criteria. They were all matched for age, education and clinical dementia rating scores. Three groups were evaluated by Tc-99m HMPAO SPECT using statistical parametric mapping (SPM) for measuring rCBF. The SPECT data of patients with SVaD and AD were compared with those of normal control subjects and then compared with each other. SPM analysis of the SPECT image showed significant perfusion deficits on the right temporal region and thalamus, left insula and superior temporal gyrus, both cingulate gyri and frontal subgyri in patients with SVaD and on the left supramarginal gyrus, superior temporal gyrus, postcentral gyrus and inferior parietal lobule, right fugiform gyrus and both cingulate gyri in AD compared with control subjects (uncorrected ρ < 0.01). SVaD patients revealed significant hypoperfusion in the right parahippocampal gyrus with cingulated gyrus, left insula and both frontal subgyral regions compared with AD (uncorrected ρ < 0.01). Our study shows characteristic and different pattern of perfusion deficits in patients with SVaD and AD, and these results may be helpful to discriminate the two conditions in the early stage of illness

  7. Comparative Morphological Analysis of the Immature Stages of the Grass Blue Butterflies Zizeeria and Zizina (Lepidoptera: Lycaenidae).

    Science.gov (United States)

    Gurung, Raj D; Iwata, Masaki; Hiyama, Atsuki; Taira, Wataru; Degnan, Bernard; Degnan, Sandie; Otaki, Joji M

    2016-08-01

    The pale grass blue butterfly has been used to assess the biological effects of the Fukushima nuclear accident. Zizeeria and Zizina are two closely related genera of grass blue butterflies that are widely distributed in tropical to temperate Asia, Australia, and Africa, making them suitable environmental indicators for these areas. However, the morphological features of the immature stages have been examined only in fragmentary fashion. Here, we reared Zizeeria maha argia, Zizeeria maha okinawana, Zizeeria karsandra karsandra, Zizina emelina emelina, Zizina otis labradus, and Zizina otis riukuensis using a standard rearing method that was developed for Zizeeria maha, and comparatively identified morphological traits to effectively classify the immature stages of species or subspecies. Morphological information on these and other subspecies including Zizeeria knysna knysna and Zizina otis antanossa from Africa was also collected from literature. The subspecies were all reared successfully. The subspecies all had dorsal nectary and tentacle organs with similar morphology. For the subspecies of Zizeeria maha, only minor morphological differences were noted. Similarly, the subspecies of Zizina otis shared many traits. Most importantly, Zizeeria and Zizina differed in the shape of the sensory hairs that accompany the dorsal nectary organ; Zizeeriahad pointed hairs, and Zizina had blunt or rounded hairs. However, Zizina emelina exhibited several intermediate features between these two genera. Overall, the morphological traits did not completely reflect the conventional systematic relationships. This comparative study describes the efficient rearing of the grass blue butterflies and provides a morphological basis for the use of these species as environmental indicators.

  8. A comparative study of external radiotherapy alone versus external radiotherapy + brachytherapy in carcinoma cervix stage III B

    International Nuclear Information System (INIS)

    Bardia, M.R.; Bhargava, S.C.; Chaudhary, R.K.; Agrawal, V.K.; Singh, K.; Vyas, R.

    1987-01-01

    Carcinoma of the cervix is the commonest cancer seen in women at Sardar Patel Medical College, Bikaner (Rajasthan). In the present study external radio-therapy and brachytherapy are used in carcinoma cervix stage III B. After 4000 to 4500 rads to pelvis by external radio-therapy, patient was assessed for intra cavitary application. Total given dose to point A was 7500 rads, to point B was 5000 rads. If patient was not suitable a split course was given where patient was asked to come after 3 weeks for intracavitary application. A comparative study of both methods was done. There was significant improvement in the control of central disease by applying intracavitary source. Radiation reactions were comparable. (author). 4 tables, 10 refs

  9. [Using (1)H-nuclear magnetic resonance metabolomics and gene ontology to establish pathological staging model for esophageal cancer patients].

    Science.gov (United States)

    Chen, X; Wang, K; Chen, W; Jiang, H; Deng, P C; Li, Z J; Peng, J; Zhou, Z Y; Yang, H; Huang, G X; Zeng, J

    2016-07-01

    By combining the metabolomics and computational biology, to explore the relationship between metabolic phenotype and pathological stage in esophageal cancer patients, to find the mechanism of metabolic network disturbance and develop a new method for fast preoperative clinical staging. A prospective cohort study (from April 2013 to January 2016) was conducted. The preoperative patients from Sichuan Provincial People's Hospital, who were diagnosed with esophageal cancer from May 2013 to April 2014 were included, and their serum samples were collected to detect (1)H-nuclear magnetic resonance (NMR) metabolomics for the purpose of drawing the metabolic fingerprinting in different stages of patients with esophageal cancer. The data were processed with these methods-principal components analysis: partial least squares regression and support vector machine, for the exploration of the enzyme-gene network regulatory mechanism in abnormal esophageal cancer metabolic network regulation and to build the quantitative prediction model of esophageal cancer staging in the end. All data were processed on high-performance computing platforms Matalab. The comparison of data had used Wilcoxon test, variance analysis, χ(2) test and Fisher exact test. Twenty patients with different stages of esophageal cancer were included; and their serum metabolic fingerprinting could differentiate different tumor stages. There were no difference among the five teams in the age (F=1.086, P>0.05), the body mass index (F=1.035, P>0.05), the distance from the incisors to tumor (F=1.078, P>0.05). Among the patients with different TNM stages, there was a significant difference in plasma metabolome. Compared to ⅡB, ⅢA, Ⅳstage patients, increased levels of butanone, ethanol amine, homocysteine, hydroxy acids and estriol, together with decreased levels of glycoprotein, creatine, choline, isobutyricacid, alanine, leucine, valine, were observed inⅠB, ⅡA stage patients. Four metabolic markers

  10. An Enhanced Preventive Maintenance Optimization Model Based on a Three-Stage Failure Process

    Directory of Open Access Journals (Sweden)

    Ruifeng Yang

    2015-01-01

    Full Text Available Nuclear power plants are highly complex systems and the issues related to their safety are of primary importance. Probabilistic safety assessment is regarded as the most widespread methodology for studying the safety of nuclear power plants. As maintenance is one of the most important factors for affecting the reliability and safety, an enhanced preventive maintenance optimization model based on a three-stage failure process is proposed. Preventive maintenance is still a dominant maintenance policy due to its easy implementation. In order to correspond to the three-color scheme commonly used in practice, the lifetime of system before failure is divided into three stages, namely, normal, minor defective, and severe defective stages. When the minor defective stage is identified, two measures are considered for comparison: one is that halving the inspection interval only when the minor defective stage is identified at the first time; the other one is that if only identifying the minor defective stage, the subsequent inspection interval is halved. Maintenance is implemented immediately once the severe defective stage is identified. Minimizing the expected cost per unit time is our objective function to optimize the inspection interval. Finally, a numerical example is presented to illustrate the effectiveness of the proposed models.

  11. Distributed activation energy model for kinetic analysis of multi-stage hydropyrolysis of coal

    Energy Technology Data Exchange (ETDEWEB)

    Liu, X.; Li, W.; Wang, N.; Li, B. [Chinese Academy of Sciences, Taiyuan (China). Inst. of Coal Chemistry

    2003-07-01

    Based on the new analysis of distributed activation energy model, a bicentral distribution model was introduced to the analysis of multi-stage hydropyrolysis of coal. The hydropyrolysis for linear temperature programming with and without holding stage were mathematically described and the corresponding kinetic expressions were achieved. Based on the kinetics, the hydropyrolysis (HyPr) and multi-stage hydropyrolysis (MHyPr) of Xundian brown coal was simulated. The results shows that both Mo catalyst and 2-stage holding can lower the apparent activation energy of hydropyrolysis and make activation energy distribution become narrow. Besides, there exists an optimum Mo loading of 0.2% for HyPy of Xundian lignite. 10 refs.

  12. Agil Stage-Gate®: ny model for udviklingsprojekter i mellemstore virksomheder

    DEFF Research Database (Denmark)

    Vedsmand, Tomas; Edwards, Kasper; Hvidt, Nicoline

    Lær at udvikle nye produkter hurtigere og med større træfsikkerhed – ved at arbejde i sprint med agile metoder og træffe de rigtige beslutninger med Stage-Gate® Se også tilhørende: "Værktøjskasse til Agil Stage-Gate®: Ny model for udviklingsprojekter i mellemstore virksomheder" på http://dx.doi.org...

  13. Reconsidering Clinical Staging Model: A Case of Genetic High Risk for Schizophrenia

    OpenAIRE

    Lee, Tae Young; Kim, Minah; Kim, Sung Nyun; Kwon, Jun Soo

    2016-01-01

    The clinical staging model is considered a useful and practical method not only in dealing with the early stage of psychosis overcoming the debate about diagnostic boundaries but also in emerging mood disorder. However, its one limitation is that it cannot discriminate the heterogeneity of individuals at clinical high risk for psychosis, but lumps them all together. Even a healthy offspring of schizophrenia can eventually show clinical symptoms and progress to schizophrenia under the influenc...

  14. Stage-by-Stage and Parallel Flow Path Compressor Modeling for a Variable Cycle Engine, NASA Advanced Air Vehicles Program - Commercial Supersonic Technology Project - AeroServoElasticity

    Science.gov (United States)

    Kopasakis, George; Connolly, Joseph W.; Cheng, Larry

    2015-01-01

    This paper covers the development of stage-by-stage and parallel flow path compressor modeling approaches for a Variable Cycle Engine. The stage-by-stage compressor modeling approach is an extension of a technique for lumped volume dynamics and performance characteristic modeling. It was developed to improve the accuracy of axial compressor dynamics over lumped volume dynamics modeling. The stage-by-stage compressor model presented here is formulated into a parallel flow path model that includes both axial and rotational dynamics. This is done to enable the study of compressor and propulsion system dynamic performance under flow distortion conditions. The approaches utilized here are generic and should be applicable for the modeling of any axial flow compressor design accurate time domain simulations. The objective of this work is as follows. Given the parameters describing the conditions of atmospheric disturbances, and utilizing the derived formulations, directly compute the transfer function poles and zeros describing these disturbances for acoustic velocity, temperature, pressure, and density. Time domain simulations of representative atmospheric turbulence can then be developed by utilizing these computed transfer functions together with the disturbance frequencies of interest.

  15. Why Are There Developmental Stages in Language Learning? A Developmental Robotics Model of Language Development.

    Science.gov (United States)

    Morse, Anthony F; Cangelosi, Angelo

    2017-02-01

    Most theories of learning would predict a gradual acquisition and refinement of skills as learning progresses, and while some highlight exponential growth, this fails to explain why natural cognitive development typically progresses in stages. Models that do span multiple developmental stages typically have parameters to "switch" between stages. We argue that by taking an embodied view, the interaction between learning mechanisms, the resulting behavior of the agent, and the opportunities for learning that the environment provides can account for the stage-wise development of cognitive abilities. We summarize work relevant to this hypothesis and suggest two simple mechanisms that account for some developmental transitions: neural readiness focuses on changes in the neural substrate resulting from ongoing learning, and perceptual readiness focuses on the perceptual requirements for learning new tasks. Previous work has demonstrated these mechanisms in replications of a wide variety of infant language experiments, spanning multiple developmental stages. Here we piece this work together as a single model of ongoing learning with no parameter changes at all. The model, an instance of the Epigenetic Robotics Architecture (Morse et al 2010) embodied on the iCub humanoid robot, exhibits ongoing multi-stage development while learning pre-linguistic and then basic language skills. Copyright © 2016 Cognitive Science Society, Inc.

  16. Modeling screening, prevention, and delaying of Alzheimer's disease: an early-stage decision analytic model

    Directory of Open Access Journals (Sweden)

    Siemers Eric R

    2010-04-01

    Full Text Available Abstract Background Alzheimer's Disease (AD affects a growing proportion of the population each year. Novel therapies on the horizon may slow the progress of AD symptoms and avoid cases altogether. Initiating treatment for the underlying pathology of AD would ideally be based on biomarker screening tools identifying pre-symptomatic individuals. Early-stage modeling provides estimates of potential outcomes and informs policy development. Methods A time-to-event (TTE simulation provided estimates of screening asymptomatic patients in the general population age ≥55 and treatment impact on the number of patients reaching AD. Patients were followed from AD screen until all-cause death. Baseline sensitivity and specificity were 0.87 and 0.78, with treatment on positive screen. Treatment slowed progression by 50%. Events were scheduled using literature-based age-dependent incidences of AD and death. Results The base case results indicated increased AD free years (AD-FYs through delays in onset and a reduction of 20 AD cases per 1000 screened individuals. Patients completely avoiding AD accounted for 61% of the incremental AD-FYs gained. Total years of treatment per 1000 screened patients was 2,611. The number-needed-to-screen was 51 and the number-needed-to-treat was 12 to avoid one case of AD. One-way sensitivity analysis indicated that duration of screening sensitivity and rescreen interval impact AD-FYs the most. A two-way sensitivity analysis found that for a test with an extended duration of sensitivity (15 years the number of AD cases avoided was 6,000-7,000 cases for a test with higher sensitivity and specificity (0.90,0.90. Conclusions This study yielded valuable parameter range estimates at an early stage in the study of screening for AD. Analysis identified duration of screening sensitivity as a key variable that may be unavailable from clinical trials.

  17. Modeling screening, prevention, and delaying of Alzheimer's disease: an early-stage decision analytic model.

    Science.gov (United States)

    Furiak, Nicolas M; Klein, Robert W; Kahle-Wrobleski, Kristin; Siemers, Eric R; Sarpong, Eric; Klein, Timothy M

    2010-04-30

    Alzheimer's Disease (AD) affects a growing proportion of the population each year. Novel therapies on the horizon may slow the progress of AD symptoms and avoid cases altogether. Initiating treatment for the underlying pathology of AD would ideally be based on biomarker screening tools identifying pre-symptomatic individuals. Early-stage modeling provides estimates of potential outcomes and informs policy development. A time-to-event (TTE) simulation provided estimates of screening asymptomatic patients in the general population age > or =55 and treatment impact on the number of patients reaching AD. Patients were followed from AD screen until all-cause death. Baseline sensitivity and specificity were 0.87 and 0.78, with treatment on positive screen. Treatment slowed progression by 50%. Events were scheduled using literature-based age-dependent incidences of AD and death. The base case results indicated increased AD free years (AD-FYs) through delays in onset and a reduction of 20 AD cases per 1000 screened individuals. Patients completely avoiding AD accounted for 61% of the incremental AD-FYs gained. Total years of treatment per 1000 screened patients was 2,611. The number-needed-to-screen was 51 and the number-needed-to-treat was 12 to avoid one case of AD. One-way sensitivity analysis indicated that duration of screening sensitivity and rescreen interval impact AD-FYs the most. A two-way sensitivity analysis found that for a test with an extended duration of sensitivity (15 years) the number of AD cases avoided was 6,000-7,000 cases for a test with higher sensitivity and specificity (0.90,0.90). This study yielded valuable parameter range estimates at an early stage in the study of screening for AD. Analysis identified duration of screening sensitivity as a key variable that may be unavailable from clinical trials.

  18. A Decade of Comparative Dose Planning Studies for Early-Stage Hodgkin Lymphoma: What Can We Learn?

    Energy Technology Data Exchange (ETDEWEB)

    Maraldo, Maja V., E-mail: dra.maraldo@gmail.com [Department of Oncology, Section of Radiotherapy, Rigshospitalet, University of Copenhagen, Copenhagen (Denmark); Specht, Lena [Department of Oncology, Section of Radiotherapy, Rigshospitalet, University of Copenhagen, Copenhagen (Denmark); Department of Hematology, Rigshospitalet, University of Copenhagen, Copenhagen (Denmark)

    2014-12-01

    During the past 4 decades, the treatment of Hodgkin lymphoma has changed dramatically, and combined modality treatment is now considered the standard of care for patients with early-stage disease. However, the risk of late effects has led to concerns regarding the use of radiation therapy, especially in young patients with a long life expectancy. In this study, we review the current evidence for modern radiation therapy planning and delivery techniques in the treatment of early-stage Hodgkin lymphoma with a focus on a reduced delivered dose, a reduced irradiated volume, and a more conformal dose distribution. Although studies are difficult to compare because of differences in field technique, prescribed dose, target volumes, patient population, and reported dosimetric and plan evaluation parameters, modern radiation therapy significantly reduces exposure to normal tissues and thereby the estimated risk of late effects. However, there is no such thing as a single best modern delivery technique when multiple organs at risk are considered simultaneously because of the heterogeneity in patient anatomy and disease location, and the choice of radiation therapy technique should be made individually for each patient.

  19. Hourly cooling load forecasting using time-indexed ARX models with two-stage weighted least squares regression

    International Nuclear Information System (INIS)

    Guo, Yin; Nazarian, Ehsan; Ko, Jeonghan; Rajurkar, Kamlakar

    2014-01-01

    Highlights: • Developed hourly-indexed ARX models for robust cooling-load forecasting. • Proposed a two-stage weighted least-squares regression approach. • Considered the effect of outliers as well as trend of cooling load and weather patterns. • Included higher order terms and day type patterns in the forecasting models. • Demonstrated better accuracy compared with some ARX and ANN models. - Abstract: This paper presents a robust hourly cooling-load forecasting method based on time-indexed autoregressive with exogenous inputs (ARX) models, in which the coefficients are estimated through a two-stage weighted least squares regression. The prediction method includes a combination of two separate time-indexed ARX models to improve prediction accuracy of the cooling load over different forecasting periods. The two-stage weighted least-squares regression approach in this study is robust to outliers and suitable for fast and adaptive coefficient estimation. The proposed method is tested on a large-scale central cooling system in an academic institution. The numerical case studies show the proposed prediction method performs better than some ANN and ARX forecasting models for the given test data set

  20. Stage-specific adhesion of Leishmania promastigotes to sand fly midguts assessed using an improved comparative binding assay.

    Directory of Open Access Journals (Sweden)

    Raymond Wilson

    2010-09-01

    Full Text Available The binding of Leishmania promastigotes to the midgut epithelium is regarded as an essential part of the life-cycle in the sand fly vector, enabling the parasites to persist beyond the initial blood meal phase and establish the infection. However, the precise nature of the promastigote stage(s that mediate binding is not fully understood.To address this issue we have developed an in vitro gut binding assay in which two promastigote populations are labelled with different fluorescent dyes and compete for binding to dissected sand fly midguts. Binding of procyclic, nectomonad, leptomonad and metacyclic promastigotes of Leishmania infantum and L. mexicana to the midguts of blood-fed, female Lutzomyia longipalpis was investigated. The results show that procyclic and metacyclic promastigotes do not bind to the midgut epithelium in significant numbers, whereas nectomonad and leptomonad promastigotes both bind strongly and in similar numbers. The assay was then used to compare the binding of a range of different parasite species (L. infantum, L. mexicana, L. braziliensis, L. major, L. tropica to guts dissected from various sand flies (Lu. longipalpis, Phlebotomus papatasi, P. sergenti. The results of these comparisons were in many cases in line with expectations, the natural parasite binding most effectively to its natural vector, and no examples were found where a parasite was unable to bind to its natural vector. However, there were interesting exceptions: L. major and L. tropica being able to bind to Lu. longipalpis better than L. infantum; L. braziliensis was able to bind to P. papatasi as well as L. major; and significant binding of L. major to P. sergenti and L. tropica to P. papatasi was observed.The results demonstrate that Leishmania gut binding is strictly stage-dependent, is a property of those forms found in the middle phase of development (nectomonad and leptomonad forms, but is absent in the early blood meal and final stages (procyclic

  1. Deleterious effects of lymphocytes at the early stage of neurodegeneration in an animal model of amyotrophic lateral sclerosis

    Directory of Open Access Journals (Sweden)

    Nakatsuji Yuji

    2011-02-01

    Full Text Available Abstract Background Non-neuronal cells, such as microglia and lymphocytes, are thought to be involved in the pathogenesis of amyotrophic lateral sclerosis (ALS. Previous studies have demonstrated neuroprotective effects of lymphocytes at the end stage of ALS, partly through induction of alternatively activated microglia (M2 microglia, which are neuroprotective. In this study, we investigated the role of lymphocytes in the early stage of the disease using an animal model of inherited ALS. Methods We established a transgenic mouse line overexpressing the familial ALS-associated G93A-SOD1 mutation (harboring a single amino acid substitution of glycine to alanine at codon 93 with depletion of the Rag2 gene (mSOD1/RAG2-/- mice, an animal model of inherited ALS lacking mature lymphocytes. Body weights, clinical scores and motor performance (hanging wire test of mSOD1/RAG2-/- mice were compared to those of mutant human SOD1 transgenic mice (mSOD1/RAG2+/+ mice. Activation of glial cells in the spinal cords of these mice was determined immunohistochemically, and the expression of mRNA for various inflammatory and anti-inflammatory molecules was evaluated. Results Clinical onset in mSOD1/RAG2-/- mice was significantly delayed, and the number of lectin-positive cells in spinal cord was increased at the early stage of disease when compared to mSOD1/RAG2+/+ mice. Quantitative RT-PCR confirmed that mRNA for Ym1, an M2 microglial-related molecule, was significantly increased in mSOD1/RAG2-/- mouse spinal cords at the early disease stage. Conclusions Compared with mSOD1/RAG2+/+ mice, mSOD1/RAG2-/- mice displayed delayed onset and increased M2 microglial activation at the early stage of disease. Thus, lymphocytes at the early pathological phase of ALS display a deleterious effect via inhibition of M2 microglial activation.

  2. Waterhammer modeling for the Ares I Upper Stage Reaction Control System cold flow development test article

    Science.gov (United States)

    Williams, Jonathan Hunter

    The Upper Stage Reaction Control System provides in-flight three-axis attitude control for the Ares I Upper Stage. The system design must accommodate rapid thruster firing to maintain proper launch trajectory and thus allow for the possibility to pulse multiple thrusters simultaneously. Rapid thruster valve closure creates an increase in static pressure, known as waterhammer, which propagates throughout the propellant system at pressures exceeding nominal design values. A series of development tests conducted at Marshall Space Flight Center in 2009 were performed using a water-flow test article to better understand fluid characteristics of the Upper Stage Reaction Control System. A subset of the tests examined the waterhammer pressure and frequency response in the flight-representative system and provided data to anchor numerical models. This thesis presents a comparison of waterhammer test results with numerical model and analytical results. An overview of the flight system, test article, modeling and analysis are also provided.

  3. Modeling condom-use stage of change in low-income, single, urban women.

    Science.gov (United States)

    Morrison-Beedy, Dianne; Carey, Michael P; Lewis, Brian P

    2002-04-01

    This study was undertaken to identify and test a model of the cognitive antecedents to condom use stage of change in low-income, single, urban women. A convenience sample of 537 women (M=30 years old) attending two urban primary health care settings in western New York State anonymously completed questionnaires based primarily on two leading social-cognitive models, the transtheoretical model and the information-motivation-behavioral skills model. We used structural equation modeling to examine the direct and indirect effects of HIV-related knowledge, social norms of discussing HIV risk and prevention, familiarity with HIV-infected persons, general readiness to change sexual behaviors, perceived vulnerability to HIV, and pros and cons of condom use on condom-use stage of change. The results indicated two models that differ by partner type. Condom-use stage of change in women with steady main partners was influenced most by social norms and the pros of condom use. Condom-use stage of change in women with "other" types (multiple, casual, or new) of sexual partners was influenced by HIV-related knowledge, general readiness to change sexual behaviors, and the pros of condom use. These findings suggest implications for developing gender-relevant HIV-prevention interventions. Copyright 2002 Wiley Periodicals, Inc.

  4. Characteristic pattern of cerebral perfusion in patients with the early stage of subcortical vascular dementia compared with Alzheimer's disease

    International Nuclear Information System (INIS)

    Jeong, Young Jin; Kang, Do Young; Park, Kyung Won; Cheon, Sang Myung; Kim, Jong Kuk; Kim, Jae Woo

    2004-01-01

    Brain perfusion SPECT has been commonly used to evaluate several different types of dementia. The aim of this study is to assess the specific patterns of regional cerebral blood flow (rCBF) in patients with the early stage of subcortical vascular dementia (SVD) and Alzheimer's disease (AD) using Tc-99m HMPAO SPECT, and to compare the differences between the two conditions. Sixteen SVD (mean age; 68.0±7.0 years, educational period; 6.3±5.6 years, CDR; 0.80±0.26). 46 AD (mean age; 69.9±7.4 years, educational period; 5.4±4.7 years, CDR; 0.86±0.23) and 12 normal control subjects (mean age; 67.1±7.7 years, educational period; 6.2±4.2 years) participated in this study. We included the patients with SVD and AD according to NINCDS-ADRDA criteria for probable AD and NINDS-AIREN criteria for probable or possible VD. They were all matched for age, education and clinical dementia scale scores. SPM analysis of the SPECT image showed significant perfusion deficits on the right temporal region and right thalamus, left insula and superior temporal gyrus, both cingulate gyri and frontal subgyral regions in patients with SVD and on the left supramarginal gyrus, superior temporal gyrus, postcentral gyrus and inferior parietal lobule, right fugiform gyrus and both cingulate gyri in patients with AD compared with control subjects (uncorrected p<0.01). SVD patients revealed significant hypoperfusion in the right parahippocampal gyrus, right cingulated gyrus, left insula, and both frontal subgyral regions compared with AD patients (uncorrected p<0.01). SVD patients revealed significant hyperperfusion in right superior frontal gyrus, left pre- and postcentral gyri, left paracentral lobule, left precuneus and both medial frontal gyri compared with AD patients (uncorrected p<0.01). Our study shows characteristic and different pattern of perfusion deficits in patients with SVD and AD, and these results may be helpful to discriminate the two conditions in the early stage of illness

  5. Effects of the stages of change model-based education and motivational interview on exercise behavior in diabetic women.

    Science.gov (United States)

    Sekerci, Yasemin Gümüs; Kitis, Yeter

    2018-05-08

    In this study, we examined the effects of exercise education and a motivational interview program, based on the stages of change model (SCM), on stage of change, using cognitive and behavioral methods, perceived benefits and barriers and self-confidence in Turkish women with diabetes. This intervention study was carried out in 2015 on 55 women selected from a family health centers' population. An exercise guide was prepared based on the SCM for the intervention group. The intervention group was followed seven times at 1-month intervals via home visits, and exercise education and the motivational interview program were conducted to identify changes in behavior. The control group received no intervention. Data were collected from both groups using a personal description form, Exercise Stages of Change Scale, Exercise Processes of Change Scale, Exercise Decisional Balance Scale, and Exercise Self-Efficacy Scale. After the exercise program, each group was re-subjected to the same scales. We used a chi-square test and independent and paired sample t-tests to analyze the data. The stages of change, using cognitive and behavioral methods, perceived benefits and self-confidence for exercise in the intervention group significantly improved compared with that in the control group (p interview program based on SCM positively affected stages of change, using cognitive and behavioral methods, perceived benefits, perceived barriers, and self-confidence for exercise behavior in women with diabetes. We conclude that the education and motivational interview program based on SCM are effective in promoting exercise habit.

  6. Establishment of a rat model of early-stage liver failure and Th17/Treg imbalance

    OpenAIRE

    LI Dong; LU Zhonghua; GAN Jianhe

    2016-01-01

    ObjectiveTo investigate the methods for establishing a rat model of early-stage liver failure and the changes in Th17, Treg, and Th17/Treg after dexamethasone and thymosin interventions. MethodsA total of 64 rats were randomly divided into carbon tetrachloride (CCl4) group and endotoxin [lipopolysaccharide (LPS)]/D-galactosamine (D-GalN) combination group to establish the rat model of early-stage liver failure. The activities of the rats and changes in liver function and whole blood Th17 and ...

  7. Modelling of Two-Stage Methane Digestion With Pretreatment of Biomass

    Science.gov (United States)

    Dychko, A.; Remez, N.; Opolinskyi, I.; Kraychuk, S.; Ostapchuk, N.; Yevtieieva, L.

    2018-04-01

    Systems of anaerobic digestion should be used for processing of organic waste. Managing the process of anaerobic recycling of organic waste requires reliable predicting of biogas production. Development of mathematical model of process of organic waste digestion allows determining the rate of biogas output at the two-stage process of anaerobic digestion considering the first stage. Verification of Konto's model, based on the studied anaerobic processing of organic waste, is implemented. The dependencies of biogas output and its rate from time are set and may be used to predict the process of anaerobic processing of organic waste.

  8. Clinical Prediction Models for Cardiovascular Disease: Tufts Predictive Analytics and Comparative Effectiveness Clinical Prediction Model Database.

    Science.gov (United States)

    Wessler, Benjamin S; Lai Yh, Lana; Kramer, Whitney; Cangelosi, Michael; Raman, Gowri; Lutz, Jennifer S; Kent, David M

    2015-07-01

    Clinical prediction models (CPMs) estimate the probability of clinical outcomes and hold the potential to improve decision making and individualize care. For patients with cardiovascular disease, there are numerous CPMs available although the extent of this literature is not well described. We conducted a systematic review for articles containing CPMs for cardiovascular disease published between January 1990 and May 2012. Cardiovascular disease includes coronary heart disease, heart failure, arrhythmias, stroke, venous thromboembolism, and peripheral vascular disease. We created a novel database and characterized CPMs based on the stage of development, population under study, performance, covariates, and predicted outcomes. There are 796 models included in this database. The number of CPMs published each year is increasing steadily over time. Seven hundred seventeen (90%) are de novo CPMs, 21 (3%) are CPM recalibrations, and 58 (7%) are CPM adaptations. This database contains CPMs for 31 index conditions, including 215 CPMs for patients with coronary artery disease, 168 CPMs for population samples, and 79 models for patients with heart failure. There are 77 distinct index/outcome pairings. Of the de novo models in this database, 450 (63%) report a c-statistic and 259 (36%) report some information on calibration. There is an abundance of CPMs available for a wide assortment of cardiovascular disease conditions, with substantial redundancy in the literature. The comparative performance of these models, the consistency of effects and risk estimates across models and the actual and potential clinical impact of this body of literature is poorly understood. © 2015 American Heart Association, Inc.

  9. An experimental two-stage rat model of lung carcinoma initiated by radon exposure

    International Nuclear Information System (INIS)

    Poncy, J.L.; Laroque, P.; Fritsch, P.; Monchaux, G.; Masse, R.; Chameaud, J.

    1992-01-01

    We present the results of a two-stage biological model of lung carcinogenesis in rats. The histogenesis of these tumors was examined, and DNA content of lung cells was measured by flow cytometry during the evolving neoplastic stage. Tumors were induced in rat lungs after radon inhalation (1600 WLM) followed by a promoter treatment; six intramuscular injections of 5,6-benzoflavone (25 mg/kg of body weight/injection) every 2 wk. Less than 3 mo after the first injection of benzoflavone, squamous cell carcinoma was observed in the lungs of all rats exposed to radon. The preneoplastic lesions gradually developed as follows: hyperplastic bronchiolar-type cells migrated to the alveoli from cells that proliferated in bronchioles and alveolar ducts; initial lesions were observed in almost all respiratory bronchioles. From some hyperplasias, epidermoid metaplasias arose distally, forming nodular epidermoid lesions in alveoli, which progressed to form squamous papilloma and, finally, epidermoid carcinomas. The histogenesis of these experimentally induced epidermoid carcinomas showed the bronchioloalveolar origin of the tumor. This factor must be considered when comparing these with human lesions; in humans, lung epidermoid carcinomas are thought to arise mainly in the first bronchial generations. The labeling index of pulmonary tissue after incorporation of 3 H-thymidine by the cells was 0.2% in control rats. This index reached a value of 1 to 2% in the hyperplastic area of the bronchioles and 10 to 15% in epidermoid nodules and epidermoid tumors, respectively. DNA cytometric analysis was performed on cell suspensions obtained after enzymatic treatment of paraffin sections of lungs from rats sacrificed during different stags of neoplastic transformations. Data showed the early appearance of a triploid cell population that grew during the evolution of nodular epidermoid lesions to epidermoid carcinomas

  10. Comparative genomic hybridization (CGH) analysis of stage 4 neuroblastoma reveals high frequency of 11q deletion in tumors lacking MYCN amplification

    NARCIS (Netherlands)

    Plantaz, D.; Vandesompele, J.; van Roy, N.; Lastowska, M.; Bown, N.; Combaret, V.; Favrot, M. C.; Delattre, O.; Michon, J.; Bénard, J.; Hartmann, O.; Nicholson, J. C.; Ross, F. M.; Brinkschmidt, C.; Laureys, G.; Caron, H.; Matthay, K. K.; Feuerstein, B. G.; Speleman, F.

    2001-01-01

    We have studied the occurrence and association of 11q deletions with other chromosomal imbalances in Stage 4 neuroblastomas. To this purpose we have performed comparative genomic hybridization (CGH) analysis on 50 Stage 4 neuroblastomas and these data were analyzed together with those from 33

  11. Automated EEG sleep staging in the term-age baby using a generative modelling approach

    Science.gov (United States)

    Pillay, Kirubin; Dereymaeker, Anneleen; Jansen, Katrien; Naulaers, Gunnar; Van Huffel, Sabine; De Vos, Maarten

    2018-06-01

    Objective. We develop a method for automated four-state sleep classification of preterm and term-born babies at term-age of 38-40 weeks postmenstrual age (the age since the last menstrual cycle of the mother) using multichannel electroencephalogram (EEG) recordings. At this critical age, EEG differentiates from broader quiet sleep (QS) and active sleep (AS) stages to four, more complex states, and the quality and timing of this differentiation is indicative of the level of brain development. However, existing methods for automated sleep classification remain focussed only on QS and AS sleep classification. Approach. EEG features were calculated from 16 EEG recordings, in 30 s epochs, and personalized feature scaling used to correct for some of the inter-recording variability, by standardizing each recording’s feature data using its mean and standard deviation. Hidden Markov models (HMMs) and Gaussian mixture models (GMMs) were trained, with the HMM incorporating knowledge of the sleep state transition probabilities. Performance of the GMM and HMM (with and without scaling) were compared, and Cohen’s kappa agreement calculated between the estimates and clinicians’ visual labels. Main results. For four-state classification, the HMM proved superior to the GMM. With the inclusion of personalized feature scaling, mean kappa (±standard deviation) was 0.62 (±0.16) compared to the GMM value of 0.55 (±0.15). Without feature scaling, kappas for the HMM and GMM dropped to 0.56 (±0.18) and 0.51 (±0.15), respectively. Significance. This is the first study to present a successful method for the automated staging of four states in term-age sleep using multichannel EEG. Results suggested a benefit in incorporating transition information using an HMM, and correcting for inter-recording variability through personalized feature scaling. Determining the timing and quality of these states are indicative of developmental delays in both preterm and term-born babies that may

  12. Preimplantation genetic diagnosis for chromosomal rearrangements with the use of array comparative genomic hybridization at the blastocyst stage.

    Science.gov (United States)

    Christodoulou, Christodoulos; Dheedene, Annelies; Heindryckx, Björn; van Nieuwerburgh, Filip; Deforce, Dieter; De Sutter, Petra; Menten, Björn; Van den Abbeel, Etienne

    2017-01-01

    To establish the value of array comparative genomic hybridization (CGH) for preimplantation genetic diagnosis (PGD) in embryos of translocation carriers in combination with vitrification and frozen embryo transfer in nonstimulated cycles. Retrospective data analysis study. Academic centers for reproductive medicine and genetics. Thirty-four couples undergoing PGD for chromosomal rearrangements from October 2013 to December 2015. Trophectoderm biopsy at day 5 or day 6 of embryo development and subsequently whole genome amplification and array CGH were performed. This approach revealed a high occurrence of aneuploidies and structural rearrangements unrelated to the parental rearrangement. Nevertheless, we observed a benefit in pregnancy rates of these couples. We detected chromosomal abnormalities in 133/207 embryos (64.2% of successfully amplified), and 74 showed a normal microarray profile (35.7%). In 48 of the 133 abnormal embryos (36.1%), an unbalanced rearrangement originating from the parental translocation was identified. Interestingly, 34.6% of the abnormal embryos (46/133) harbored chromosome rearrangements that were not directly linked to the parental translocation in question. We also detected a combination of unbalanced parental-derived rearrangements and aneuploidies in 27 of the 133 abnormal embryos (20.3%). The use of trophectoderm biopsy at the blastocyst stage is less detrimental to the survival of the embryo and leads to a more reliable estimate of the genomic content of the embryo than cleavage-stage biopsy. In this small cohort PGD study, we describe the successful implementation of array CGH analysis of blastocysts in patients with a chromosomal rearrangement to identify euploid embryos for transfer. Copyright © 2016 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  13. Dynamic models of staged gasification processes. Documentation of gasification simulator; Dynamiske modeller a f trinopdelte forgasningsprocesser. Dokumentation til forgasser simulator

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-02-15

    In connection with the ERP project 'Dynamic modelling of staged gasification processes' a gasification simulator has been constructed. The simulator consists of: a mathematical model of the gasification process developed at Technical University of Denmark, a user interface programme, IGSS, and a communication interface between the two programmes. (BA)

  14. Development and validation of a preoperative prediction model for colorectal cancer T-staging based on MDCT images and clinical information.

    Science.gov (United States)

    Sa, Sha; Li, Jing; Li, Xiaodong; Li, Yongrui; Liu, Xiaoming; Wang, Defeng; Zhang, Huimao; Fu, Yu

    2017-08-15

    This study aimed to establish and evaluate the efficacy of a prediction model for colorectal cancer T-staging. T-staging was positively correlated with the level of carcinoembryonic antigen (CEA), expression of carbohydrate antigen 19-9 (CA19-9), wall deformity, blurred outer edges, fat infiltration, infiltration into the surrounding tissue, tumor size and wall thickness. Age, location, enhancement rate and enhancement homogeneity were negatively correlated with T-staging. The predictive results of the model were consistent with the pathological gold standard, and the kappa value was 0.805. The total accuracy of staging improved from 51.04% to 86.98% with the proposed model. The clinical, imaging and pathological data of 611 patients with colorectal cancer (419 patients in the training group and 192 patients in the validation group) were collected. A spearman correlation analysis was used to validate the relationship among these factors and pathological T-staging. A prediction model was trained with the random forest algorithm. T staging of the patients in the validation group was predicted by both prediction model and traditional method. The consistency, accuracy, sensitivity, specificity and area under the curve (AUC) were used to compare the efficacy of the two methods. The newly established comprehensive model can improve the predictive efficiency of preoperative colorectal cancer T-staging.

  15. Large animal model of functional tricuspid regurgitation in pacing induced end-stage heart failure.

    Science.gov (United States)

    Malinowski, Marcin; Proudfoot, Alistair G; Langholz, David; Eberhart, Lenora; Brown, Michael; Schubert, Hans; Wodarek, Jeremy; Timek, Tomasz A

    2017-06-01

    Functional tricuspid regurgitation (FTR) is common in patients with advanced heart failure and frequently complicates left ventricular assist device implantation yet remains poorly understood. We set out to establish large animal model of FTR that could serve as a research platform to investigate the pathogenesis of FTR associated with end-stage heart failure. : Through right thoracotomy, ten adult sheep underwent implantation of pacemaker with epicardial LV lead, five sonomicrometry crystals on the right ventricle, and left and right ventricular telemetry pressure sensors during a beating heart off-pump procedure. After 5 ± 1 days of recovery, baseline haemodynamic, echocardiographic and sonomicrometry data were collected. Animals were paced thereafter at a rate of 220-240 beats/min until the development of heart failure and concomitant tricuspid regurgitation. : Three animals died during early recovery period and one during the pacing phase. Six surviving animals were paced for a mean of 14 ± 5 days. Cardiac function was significantly depressed compared to baseline, with LV ejection fraction falling from 69 ± 2% to 22 ± 4% ( P  tricuspid annulus (from 29.5 ± 1.6 to 36.5 ± 4.5 mm; P  = 0.01) and right ventricle (from 21.9 ± 0.2 to 30.3 ± 0.6 mm; P  = 0.03). Sonomicrometry derived contractility of RV free wall was depressed and at least moderate tricuspid insufficiency developed in all animals. : Biventricular dysfunction, tricuspid annular dilatation and significant FTR were observed in our model of ovine tachycardia induced cardiomyopathy. This animal model reflects the clinical situation of end-stage heart failure patients presenting for mechanical support. © The Author 2017. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

  16. What makes us think? A three-stage dual-process model of analytic engagement.

    Science.gov (United States)

    Pennycook, Gordon; Fugelsang, Jonathan A; Koehler, Derek J

    2015-08-01

    The distinction between intuitive and analytic thinking is common in psychology. However, while often being quite clear on the characteristics of the two processes ('Type 1' processes are fast, autonomous, intuitive, etc. and 'Type 2' processes are slow, deliberative, analytic, etc.), dual-process theorists have been heavily criticized for being unclear on the factors that determine when an individual will think analytically or rely on their intuition. We address this issue by introducing a three-stage model that elucidates the bottom-up factors that cause individuals to engage Type 2 processing. According to the model, multiple Type 1 processes may be cued by a stimulus (Stage 1), leading to the potential for conflict detection (Stage 2). If successful, conflict detection leads to Type 2 processing (Stage 3), which may take the form of rationalization (i.e., the Type 1 output is verified post hoc) or decoupling (i.e., the Type 1 output is falsified). We tested key aspects of the model using a novel base-rate task where stereotypes and base-rate probabilities cued the same (non-conflict problems) or different (conflict problems) responses about group membership. Our results support two key predictions derived from the model: (1) conflict detection and decoupling are dissociable sources of Type 2 processing and (2) conflict detection sometimes fails. We argue that considering the potential stages of reasoning allows us to distinguish early (conflict detection) and late (decoupling) sources of analytic thought. Errors may occur at both stages and, as a consequence, bias arises from both conflict monitoring and decoupling failures. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. Two-stage residual inclusion estimation: addressing endogeneity in health econometric modeling.

    Science.gov (United States)

    Terza, Joseph V; Basu, Anirban; Rathouz, Paul J

    2008-05-01

    The paper focuses on two estimation methods that have been widely used to address endogeneity in empirical research in health economics and health services research-two-stage predictor substitution (2SPS) and two-stage residual inclusion (2SRI). 2SPS is the rote extension (to nonlinear models) of the popular linear two-stage least squares estimator. The 2SRI estimator is similar except that in the second-stage regression, the endogenous variables are not replaced by first-stage predictors. Instead, first-stage residuals are included as additional regressors. In a generic parametric framework, we show that 2SRI is consistent and 2SPS is not. Results from a simulation study and an illustrative example also recommend against 2SPS and favor 2SRI. Our findings are important given that there are many prominent examples of the application of inconsistent 2SPS in the recent literature. This study can be used as a guide by future researchers in health economics who are confronted with endogeneity in their empirical work.

  18. COMPAR

    International Nuclear Information System (INIS)

    Kuefner, K.

    1976-01-01

    COMPAR works on FORTRAN arrays with four indices: A = A(i,j,k,l) where, for each fixed k 0 ,l 0 , only the 'plane' [A(i,j,k 0 ,l 0 ), i = 1, isub(max), j = 1, jsub(max)] is held in fast memory. Given two arrays A, B of this type COMPAR has the capability to 1) re-norm A and B ind different ways; 2) calculate the deviations epsilon defined as epsilon(i,j,k,l): =[A(i,j,k,l) - B(i,j,k,l)] / GEW(i,j,k,l) where GEW (i,j,k,l) may be chosen in three different ways; 3) calculate mean, standard deviation and maximum in the array epsilon (by several intermediate stages); 4) determine traverses in the array epsilon; 5) plot these traverses by a printer; 6) simplify plots of these traverses by the PLOTEASY-system by creating input data blocks for this system. The main application of COMPAR is given (so far) by the comparison of two- and three-dimensional multigroup neutron flux-fields. (orig.) [de

  19. A Comparison of Two-Stage Approaches for Fitting Nonlinear Ordinary Differential Equation Models with Mixed Effects.

    Science.gov (United States)

    Chow, Sy-Miin; Bendezú, Jason J; Cole, Pamela M; Ram, Nilam

    2016-01-01

    Several approaches exist for estimating the derivatives of observed data for model exploration purposes, including functional data analysis (FDA; Ramsay & Silverman, 2005 ), generalized local linear approximation (GLLA; Boker, Deboeck, Edler, & Peel, 2010 ), and generalized orthogonal local derivative approximation (GOLD; Deboeck, 2010 ). These derivative estimation procedures can be used in a two-stage process to fit mixed effects ordinary differential equation (ODE) models. While the performance and utility of these routines for estimating linear ODEs have been established, they have not yet been evaluated in the context of nonlinear ODEs with mixed effects. We compared properties of the GLLA and GOLD to an FDA-based two-stage approach denoted herein as functional ordinary differential equation with mixed effects (FODEmixed) in a Monte Carlo (MC) study using a nonlinear coupled oscillators model with mixed effects. Simulation results showed that overall, the FODEmixed outperformed both the GLLA and GOLD across all the embedding dimensions considered, but a novel use of a fourth-order GLLA approach combined with very high embedding dimensions yielded estimation results that almost paralleled those from the FODEmixed. We discuss the strengths and limitations of each approach and demonstrate how output from each stage of FODEmixed may be used to inform empirical modeling of young children's self-regulation.

  20. Modelling the enigmatic Late Pliocene Glacial Event - Marine Isotope Stage M2

    Science.gov (United States)

    Dolan, Aisling M.; Haywood, Alan M.; Hunter, Stephen J.; Tindall, Julia C.; Dowsett, Harry J.; Hill, Daniel J.; Pickering, Steven J.

    2015-01-01

    The Pliocene Epoch (5.2 to 2.58 Ma) has often been targeted to investigate the nature of warm climates. However, climate records for the Pliocene exhibit significant variability and show intervals that apparently experienced a cooler than modern climate. Marine Isotope Stage (MIS) M2 (~ 3.3 Ma) is a globally recognisable cooling event that disturbs an otherwise relatively (compared to present-day) warm background climate state. It remains unclear whether this event corresponds to significant ice sheet build-up in the Northern and Southern Hemisphere. Estimates of sea level for this interval vary, and range from modern values to estimates of 65 m sea level fall with respect to present day. Here we implement plausible M2 ice sheet configurations into a coupled atmosphere–ocean climate model to test the hypothesis that larger-than-modern ice sheet configurations may have existed at M2. Climate model results are compared with proxy climate data available for M2 to assess the plausibility of each ice sheet configuration. Whilst the outcomes of our data/model comparisons are not in all cases straight forward to interpret, there is little indication that results from model simulations in which significant ice masses have been prescribed in the Northern Hemisphere are incompatible with proxy data from the North Atlantic, Northeast Arctic Russia, North Africa and the Southern Ocean. Therefore, our model results do not preclude the possibility of the existence of larger ice masses during M2 in the Northern or Southern Hemisphere. Specifically they are not able to discount the possibility of significant ice masses in the Northern Hemisphere during the M2 event, consistent with a global sea-level fall of between 40 m and 60 m. This study highlights the general need for more focused and coordinated data generation in the future to improve the coverage and consistency in proxy records for M2, which will allow these and future M2 sensitivity tests to be interrogated

  1. COMPARING OF DEPOSIT MODEL AND LIFE INSURANCE MODEL IN MACEDONIA

    Directory of Open Access Journals (Sweden)

    TATJANA ATANASOVA-PACHEMSKA

    2016-02-01

    Full Text Available In conditions of the continuous decline of the interest rates for bank deposits, and at a time when uncertainty about the future is increasing, physical and legal persons have doubts how to secure their future or how and where to invest their funds and thus to “fertilize” and increase their savings. Individuals usually choose to put their savings in the bank for a certain period, and for that period to receive certain interest, or decide to invest their savings in different types of life insurance and thus to "take care" of their life, their future and the future of their families. In mathematics are developed many models that relate to the compounding and the insurance. This paper is a comparison of the deposit model and the model of life insurance

  2. Modeling and Nonlinear Control of Electric Power Stage in Hybrid Electric Vehicle

    DEFF Research Database (Denmark)

    Tahri, A.; El Fadil, H.; Guerrero, Josep M.

    2014-01-01

    This paper deals with the problem of modeling and controlling the electric power stage of hybrid electric vehicle. The controlled system consists of a fuel cell (FC) as a main source, a supercapacitor as an auxiliary source, two DC-DC power converters, an inverter and a traction induction motor...

  3. Numerical simulation of brain tumor growth model using two-stage ...

    African Journals Online (AJOL)

    In the recent years, the study of glioma growth to be an active field of research Mathematical models that describe the proliferation and diffusion properties of the growth have been developed by many researchers. In this work, the performance analysis of two-stage Gauss-Seidel (TSGS) method to solve the glioma growth ...

  4. Analysing outsourcing policies in an asset management context : A six-stage model

    NARCIS (Netherlands)

    Schoenmaker, R.; Verlaan, J.G.

    2013-01-01

    Asset managers of civil infrastructure are increasingly outsourcing their maintenance. Whereas maintenance is a cyclic process, decisions to outsource decisions are often project-based, and confusing the discussion on the degree of outsourcing. This paper presents a six-stage model that facilitates

  5. Using Five Stage Model to Design of Collaborative Learning Environments in Second Life

    Science.gov (United States)

    Orhan, Sevil; Karaman, M. Kemal

    2014-01-01

    Specifically Second Life (SL) among virtual worlds draws attention of researchers to form collaborative learning environments (Sutcliffe & Alrayes, 2012) since it could be used as a rich platform to simulate a real environment containing many collaborative learning characteristics and interaction tools within itself. Five Stage Model (FSM)…

  6. Violent Victimization and Perpetration during Adolescence: Developmental Stage Dependent Ecological Models

    Science.gov (United States)

    Matjasko, Jennifer L.; Needham, Belinda L.; Grunden, Leslie N.; Farb, Amy Feldman

    2010-01-01

    Using a variant of the ecological-transactional model and developmental theories of delinquency on a nationally representative sample of adolescents, the current study explored the ecological predictors of violent victimization, perpetration, and both for three different developmental stages during adolescence. We examined the relative influence…

  7. Cognitive behavioral interventions for alcohol and drug use disorders: Through the stage model and back again.

    Science.gov (United States)

    Carroll, Kathleen M; Kiluk, Brian D

    2017-12-01

    Cognitive-behavioral therapy (CBT) approaches have among the highest level of empirical support for the treatment of drug and alcohol use disorders. As Psychology of Addictive Behaviors marks its 30th anniversary, we review the evolution of CBT for the addictions through the lens of the Stage Model of Behavioral Therapies Development. The large evidence base from Stage II randomized clinical trials indicates a modest effect size with evidence of relatively durable effects, but limited diffusion in clinical practice, as is the case for most empirically validated approaches for mental health and addictive disorders. Technology may provide a means for CBT interventions to circumvent the "implementation cliff" in Stages III-V by offering a flexible, low-cost, standardized means of disseminating CBT in a range of novel settings and populations. Moreover, returning to Stage I to reconnect clinical applications of CBT to recent developments in cognitive science and neuroscience holds great promise for accelerating understanding of mechanisms of action. It is critical that CBT not be considered as a static intervention, but rather 1 that constantly evolves and is refined through the stage model until the field achieves a maximally powerful intervention that addresses core features of the addictions. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  8. Comparative analysis of expressed sequence tags from three castes and two life stages of the termite Reticulitermes flavipes

    Directory of Open Access Journals (Sweden)

    Steller Matthew M

    2010-08-01

    Full Text Available Abstract Background Termites (Isoptera are eusocial insects whose colonies consist of morphologically and behaviorally specialized castes of sterile workers and soldiers, and reproductive alates. Previous studies on eusocial insects have indicated that caste differentiation and behavior are underlain by differential gene expression. Although much is known about gene expression in the honey bee, Apis mellifera, termites remain relatively understudied in this regard. Therefore, our objective was to assemble an expressed sequence tag (EST data base for the eastern subterranean termite, Reticulitermes flavipes, for future gene expression studies. Results Soldier, worker, and alate caste and two larval cDNA libraries were constructed, and approximately 15,000 randomly chosen clones were sequenced to compile an EST data base. Putative gene functions were assigned based on a BLASTX Swissprot search. Categorical in silico expression patterns for each library were compared using the R-statistic. A significant proportion of the ESTs of each caste and life stages had no significant similarity to those in existing data bases. All cDNA libraries, including those of non-reproductive worker and soldier castes, contained sequences with putative reproductive functions. Genes that showed a potential expression bias among castes included a putative antibacterial humoral response and translation elongation protein in soldiers and a chemosensory protein in alates. Conclusions We have expanded upon the available sequences for R. flavipes and utilized an in silico method to compare gene expression in different castes of an eusocial insect. The in silico analysis allowed us to identify several genes which may be differentially expressed and involved in caste differences. These include a gene overrepresented in the alate cDNA library with a predicted function of neurotransmitter secretion or cholesterol absorption and a gene predicted to be involved in protein

  9. Describing the Process of Adopting Nutrition and Fitness Apps: Behavior Stage Model Approach.

    Science.gov (United States)

    König, Laura M; Sproesser, Gudrun; Schupp, Harald T; Renner, Britta

    2018-03-13

    Although mobile technologies such as smartphone apps are promising means for motivating people to adopt a healthier lifestyle (mHealth apps), previous studies have shown low adoption and continued use rates. Developing the means to address this issue requires further understanding of mHealth app nonusers and adoption processes. This study utilized a stage model approach based on the Precaution Adoption Process Model (PAPM), which proposes that people pass through qualitatively different motivational stages when adopting a behavior. To establish a better understanding of between-stage transitions during app adoption, this study aimed to investigate the adoption process of nutrition and fitness app usage, and the sociodemographic and behavioral characteristics and decision-making style preferences of people at different adoption stages. Participants (N=1236) were recruited onsite within the cohort study Konstanz Life Study. Use of mobile devices and nutrition and fitness apps, 5 behavior adoption stages of using nutrition and fitness apps, preference for intuition and deliberation in eating decision-making (E-PID), healthy eating style, sociodemographic variables, and body mass index (BMI) were assessed. Analysis of the 5 behavior adoption stages showed that stage 1 ("unengaged") was the most prevalent motivational stage for both nutrition and fitness app use, with half of the participants stating that they had never thought about using a nutrition app (52.41%, 533/1017), whereas less than one-third stated they had never thought about using a fitness app (29.25%, 301/1029). "Unengaged" nonusers (stage 1) showed a higher preference for an intuitive decision-making style when making eating decisions, whereas those who were already "acting" (stage 4) showed a greater preference for a deliberative decision-making style (F 4,1012 =21.83, Pdigital interventions. This study highlights that new user groups might be better reached by apps designed to address a more intuitive

  10. Travelling wave and convergence in stage-structured reaction-diffusion competitive models with nonlocal delays

    International Nuclear Information System (INIS)

    Xu Rui; Chaplain, M.A.J.; Davidson, F.A.

    2006-01-01

    In this paper, we first investigate a stage-structured competitive model with time delays, harvesting, and nonlocal spatial effect. By using an iterative technique recently developed by Wu and Zou (Wu J, Zou X. Travelling wave fronts of reaction-diffusion systems with delay. J Dynam Differen Equat 2001;13:651-87), sufficient conditions are established for the existence of travelling front solution connecting the two boundary equilibria in the case when there is no positive equilibrium. The travelling wave front corresponds to an invasion by a stronger species which drives the weaker species to extinction. Secondly, we consider a stage-structured competitive model with time delays and nonlocal spatial effect when the domain is finite. We prove the global stability of each of the nonnegative equilibria and demonstrate that the more complex model studied here admits three possible long term behaviors: coexistence, bistability and dominance as is the case for the standard Lotka-Voltera competitive model

  11. A Comparative Study Of Stock Price Forecasting Using Nonlinear Models

    Directory of Open Access Journals (Sweden)

    Diteboho Xaba

    2017-03-01

    Full Text Available This study compared the in-sample forecasting accuracy of three forecasting nonlinear models namely: the Smooth Transition Regression (STR model, the Threshold Autoregressive (TAR model and the Markov-switching Autoregressive (MS-AR model. Nonlinearity tests were used to confirm the validity of the assumptions of the study. The study used model selection criteria, SBC to select the optimal lag order and for the selection of appropriate models. The Mean Square Error (MSE, Mean Absolute Error (MAE and Root Mean Square Error (RMSE served as the error measures in evaluating the forecasting ability of the models. The MS-AR models proved to perform well with lower error measures as compared to LSTR and TAR models in most cases.

  12. A Two-Stage Queue Model to Optimize Layout of Urban Drainage System considering Extreme Rainstorms

    OpenAIRE

    He, Xinhua; Hu, Wenfa

    2017-01-01

    Extreme rainstorm is a main factor to cause urban floods when urban drainage system cannot discharge stormwater successfully. This paper investigates distribution feature of rainstorms and draining process of urban drainage systems and uses a two-stage single-counter queue method M/M/1→M/D/1 to model urban drainage system. The model emphasizes randomness of extreme rainstorms, fuzziness of draining process, and construction and operation cost of drainage system. Its two objectives are total c...

  13. Dynamics of a Stage Structured Pest Control Model in a Polluted Environment with Pulse Pollution Input

    OpenAIRE

    Liu, Bing; Xu, Ling; Kang, Baolin

    2013-01-01

    By using pollution model and impulsive delay differential equation, we formulate a pest control model with stage structure for natural enemy in a polluted environment by introducing a constant periodic pollutant input and killing pest at different fixed moments and investigate the dynamics of such a system. We assume only that the natural enemies are affected by pollution, and we choose the method to kill the pest without harming natural enemies. Sufficient conditions for global attractivity ...

  14. Bifurcation analysis on a delayed SIS epidemic model with stage structure

    Directory of Open Access Journals (Sweden)

    Kejun Zhuang

    2007-05-01

    Full Text Available In this paper, a delayed SIS (Susceptible Infectious Susceptible model with stage structure is investigated. We study the Hopf bifurcations and stability of the model. Applying the normal form theory and the center manifold argument, we derive the explicit formulas determining the properties of the bifurcating periodic solutions. The conditions to guarantee the global existence of periodic solutions are established. Also some numerical simulations for supporting the theoretical are given.

  15. Three Stage Maturity Model in SME’s towards Industry 4.0

    OpenAIRE

    Ganzarain, Jaione; Errasti, Nekane

    2016-01-01

    Purpose: To address the challenges regarding the concept of Industry 4.0 and the diversification methodology and based on the strategic guidance towards Industry 4.0, we propose a process model as a guiding framework for Industry 4.0 collaborative diversification vision, strategy and action building. In this paper we suggest a stage process model to guide and train companies to identify new opportunities for diversification within Industry 4.0. Systematically carrying out the s...

  16. Mechanical and mathematical models of multi-stage horizontal fracturing strings and their application

    Directory of Open Access Journals (Sweden)

    Zhanghua Lian

    2015-03-01

    Full Text Available Multi-stage SRV fracturing in horizontal wells is a new technology developed at home and abroad in recent years to effectively develop shale gas or low-permeability reservoirs, but on the other hand makes the mechanical environment of fracturing strings more complicated at the same time. In view of this, based on the loading features of tubing strings during the multi-stage fracturing of a horizontal well, mechanical models were established for three working cases of multiple packer setting, open differential-pressure sliding sleeve, and open ball-injection sliding sleeve under a hold-down packer. Moreover, mathematical models were respectively built for the above three cases. According to the Lame formula and Von Mises stress calculation formula for the thick-walled cylinder in the theory of elastic mechanics, a mathematical model was also established to calculate the equivalent stress for tubing string safety evaluation when the fracturing string was under the combined action of inner pressure, external squeezing force and axial stress, and another mathematical model was built for the mechanical strength and safety evaluation of multi-stage fracturing strings. In addition, a practical software was developed for the mechanical safety evaluation of horizontal well multi-stage fracturing strings according to the mathematical model developed for the mechanical calculation of the multi-packer string in horizontal wells. The research results were applied and verified in a gas well of Tahe Oilfield in the Tarim Basin with excellent effects, providing a theoretical basis and a simple and reliable technical means for optimal design and safety evaluation of safe operational parameters of multi-stage fracturing strings in horizontal wells.

  17. Report on Stage 1 of project CHEMVAL/MIRAGE: verification of speciation models

    International Nuclear Information System (INIS)

    Read, D.; Broyd, T.W.

    1989-01-01

    This report describes the results of CHEMVAL Stage 1, an international chemical model verification exercise involving the active participation of 14 organisations within the CEC countries, Sweden, Switzerland and Finland. Five case systems were studied, namely, cement, clay, sandstone, granite and limestone. Overall, good agreement was obtained even for conceptually difficult geochemical simulations. Reasons for divergence in results have been explored and recommendations are made at the appropriate stages for enhancement of the thermodynamic database. A listing of the preliminary CHEMVAL Project Database is provided. (author)

  18. Comparative incidences of decompression illness in repetitive, staged, mixed-gas decompression diving: is 'dive fitness' an influencing factor?

    Science.gov (United States)

    Sayer, Martin Dj; Akroyd, Jim; Williams, Guy D

    2008-06-01

    Wreck diving at Bikini Atoll consists of a relatively standard series of decompression dives with maximum depths in the region of 45-55 metres' sea water (msw). In a typical week of diving at Bikini, divers can perform up to 12 decompression dives to these depths over seven days; on five of those days, divers can perform two decompression dives per day. All the dives employ multi-level, staged decompression schedules using air and surface-supplied nitrox containing 80% oxygen. Bikini is serviced by a single diving operator and so a relatively precise record exists both of the actual number of dives undertaken and of the decompression illness incidents both for customer divers and the dive guides. The dive guides follow exactly the dive profiles and decompression schedules of the customers. Each dive guide will perform nearly 400 decompression dives a year, with maximum depths mostly around 50 msw, compared with an average of 10 (maximum of 12) undertaken typically by each customer diver in a week. The incidence of decompression illness for the customer population (presumed in the absence of medical records) is over ten times higher than that for the dive guides. The physiological reasons for such a marked difference are discussed in terms of customer demographics and dive-guide acclimatization to repetitive decompression stress. The rates of decompression illness for a range of diving populations are reviewed.

  19. Comparing four volumetric modulated arc therapy beam arrangements for the treatment of early-stage prostate cancer

    International Nuclear Information System (INIS)

    Elith, Craig A; Dempsey, Shane E; Warren-Forward, Helen M

    2014-01-01

    This study compared four different volumetric modulated arc therapy (VMAT) beam arrangements for the treatment of early-stage prostate cancer examining plan quality and the impact on a radiotherapy department's resources. Twenty prostate cases were retrospectively planned using four VMAT beam arrangements (1) a partial arc (PA), (2) one arc (1A), (3) one arc plus a partial arc (1A + PA) and (4) two arcs (2A). The quality of the dose distributions generated were compared by examining the overall plan quality, the homogeneity and conformity to the planning target volume (PTV), the number of monitor units and the dose delivered to the organs at risk. Departmental resources were considered by recording the planning time and beam delivery time. Each technique produced a plan of similar quality that was considered adequate for treatment; though some differences were noted. The 1A, 1A + PA and 2A plans demonstrated a better conformity to the PTV which correlated to improved sparing of the rectum in the 60–70 Gy range for the 1A + PA and 2A techniques. The time needed to generate the plans was different for each technique ranging from 13.1 min for 1A + PA to 17.8 min for 1A. The PA beam delivery time was fastest with a mean time of 0.9 min. Beam-on times then increased with an increase in the number of arcs up to an average of 2.2 min for the 2A technique. Which VMAT technique is best suited for clinical implementation for the treatment of prostate cancer may be dictated by the individual patient and the availability of departmental resources

  20. A Comparative Study of the Management of Stage 2 hypertension by Combined therapy with Losartan, Amlodipine and Hydrochlorothiazide

    Directory of Open Access Journals (Sweden)

    Reza Jafarzadeh Esfehani

    2012-09-01

    Full Text Available Background: The most effective and accurate treatment of hypertensive patients reduces cardiovascular events and improves the quality of life. Objective: This study compared the efficacy and safety of combined (combination therapy with an angiotensin-receptor blocker (ARB a calcium-channel blocker (CCB (Losartan / Amloidipine 50/10mg vs maximal combination doses of ARB with hydrochlorothiazide (Losartan /HCTZ 100/25 mg and maximal combination doses of CCB with HCTZ (Amlodipine /HCTZ 10/25 mg in the management of stage 2 hypertension. Methods: This randomized clinical trial (RTC comprised 478 hypertensive patients with mean age 50.5±5.21 years, and took place between January 2010 and December 2011 in Vasei Hospital clinic in Sabzevar. Antihypertensive drugs were washed out after 5 days of discontinuation of drugs and the patients with mean blood pressure in sitting position ≥ 160 and <200 mmHg in systole and ≥ 100 and <110 mmHg in diastole were randomized into three groups: Losartan / Amlodipine 50/10 mg (n =164 , Losartan / HCTZ 100/25 mg (n =155 and Amlodipine / HCTZ 10/25 mg (n =159. The end point was reaching the blood pressure below 140/90 within 56 days of treatment in each group. Results: There was a significant difference in systolic blood pressure reductions between treatment groups (P<0.001 and also there was a significant difference between groups in reducing diastolic blood pressure (P<0.01. The highest systolic and diastolic blood pressure reduction respectively was found in Amlodipine/losartane and losartane/HTCZ group. The ANCOVA analysis revealed that only treatment regimen had a significant effect (P=0.01 and other factor including Age, Gender, Diabetes Mellitus, Smoking and High serum cholesterol didn’t have significant effect on blood pressure reduction. Conclusion: ARB/CCB combination therapy reduced blood pressure more effectively than the maximal doses of ARB or CCB with HCTZ in stage 2 hypertensive patients within

  1. Model based simulation of alternative transmission concepts in early stages of product development process; Einsatz von Simulationsmodellen zur Beurteilung von alternativen Getriebekonzepten in fruehen Phasen des Produktentstehungsprozesses

    Energy Technology Data Exchange (ETDEWEB)

    Albers, A.; Ott, S.; Seifermann, A. [Karlsruhe Univ. (Germany). IPEK - Inst. fuer Produktentwicklung

    2006-07-01

    The contribution describes a method for assessing the new transmission concepts and investigate their advantages in alternative powertrain systems. Simulation models of different powertrains were used in order to make the different concepts comparable in an early stage of the product developmentprocess. Further, it is shown how the Contact and Channel Model (C and CM) can be used for modelling individual transmission concepts. These models can help to identify and assess interdependences between part systems and components. (orig.)

  2. A Comprehensive Method for Comparing Mental Models of Dynamic Systems

    OpenAIRE

    Schaffernicht, Martin; Grösser, Stefan N.

    2011-01-01

    Mental models are the basis on which managers make decisions even though external decision support systems may provide help. Research has demonstrated that more comprehensive and dynamic mental models seem to be at the foundation for improved policies and decisions. Eliciting and comparing such models can systematically explicate key variables and their main underlying structures. In addition, superior dynamic mental models can be identified. This paper reviews existing studies which measure ...

  3. Numerical modeling of the initial fluctuation condensation stage with charge drops

    Science.gov (United States)

    Averina, T. A.; Zmievskaya, G. I.

    2016-11-01

    This paper deals with a mathematical model of the phase transition of the first kind at the initial stage of forming drops in a liquid or in melted state in a volume of steam with a fixed charge on drops. The model of the process is represented by superposition of random diffusion and jump stochastic processes. The algorithms for solving stochastic differential equations (SDEs) of the model of processes, which form the cluster size, allow one to calculate a distribution function of drops according to their size. The kinetic approach makes possible evaluate the role of the Rayleigh capillary instability at the initial condensation stage and to employ the analysis of electrodispersion mechanisms in the production of metal and semiconductor powders.

  4. Positron emission tomography with selected mediastinoscopy compared to routine mediastinoscopy offers cost and clinical outcome benefits for pre-operative staging of non-small cell lung cancer

    International Nuclear Information System (INIS)

    Yap, Kelvin K.; Yap, Kenneth S.K.; Byrne, Amanda J.; Berlangieri, Salvatore U.; Poon, Aurora; Harris, Anthony; Tauro, Andrew; Mitchell, Paul; Knight, Simon R.; Clarke, Peter C.; Rowe, Christopher C.; Scott, Andrew M.

    2005-01-01

    18 F-fluorodeoxyglucose positron emission tomography (FDG-PET) imaging is an important staging procedure in patients with non-small cell lung cancer (NSCLC). We aimed to demonstrate, through a decision tree model and the incorporation of real costs of each component, that routine FDG-PET imaging as a prelude to curative surgery will reduce requirements for routine mediastinoscopy and overall hospital costs. A decision tree model comparing routine whole-body FDG-PET imaging to routine staging mediastinoscopy was used, with baseline variables of sensitivity, specificity and prevalence of non-operable and metastatic disease obtained from institutional data and a literature review. Costings for hospital admissions for mediastinoscopy and thoracotomy of actual patients with NSCLC were determined. The overall and average cost of managing patients was then calculated over a range of FDG-PET costs to derive projected cost savings to the community. The prevalence of histologically proven mediastinal involvement in patients with NSCLC presenting for surgical assessment at our institution is 20%, and the prevalence of distant metastatic disease is 6%. Based on literature review, the pooled sensitivity and specificity of FDG-PET for detection of mediastinal spread are 84% and 89% respectively, and for mediastinoscopy, 81% and 100%. The average cost of mediastinoscopy for NSCLC in our institution is AUD$4,160, while that of thoracotomy is AUD$15,642. The cost of an FDG-PET scan is estimated to be AUD$1,500. Using these figures and the decision tree model, the average cost saving is AUD$2,128 per patient. Routine FDG-PET scanning with selective mediastinoscopy will save AUD$2,128 per patient and will potentially reduce inappropriate surgery. These cost savings remain robust over a wide range of disease prevalence and FDG-PET costs. (orig.)

  5. comparative analysis of some existing kinetic models with proposed

    African Journals Online (AJOL)

    IGNATIUS NWIDI

    two statistical parameters namely; linear regression coefficient of correlation (R2) and ... Keynotes: Heavy metals, Biosorption, Kinetics Models, Comparative analysis, Average Relative Error. 1. ... If the flow rate is low, a simple manual batch.

  6. Regulatory activity based risk model identifies survival of stage II and III colorectal carcinoma.

    Science.gov (United States)

    Liu, Gang; Dong, Chuanpeng; Wang, Xing; Hou, Guojun; Zheng, Yu; Xu, Huilin; Zhan, Xiaohui; Liu, Lei

    2017-11-17

    Clinical and pathological indicators are inadequate for prognosis of stage II and III colorectal carcinoma (CRC). In this study, we utilized the activity of regulatory factors, univariate Cox regression and random forest for variable selection and developed a multivariate Cox model to predict the overall survival of Stage II/III colorectal carcinoma in GSE39582 datasets (469 samples). Patients in low-risk group showed a significant longer overall survival and recurrence-free survival time than those in high-risk group. This finding was further validated in five other independent datasets (GSE14333, GSE17536, GSE17537, GSE33113, and GSE37892). Besides, associations between clinicopathological information and risk score were analyzed. A nomogram including risk score was plotted to facilitate the utilization of risk score. The risk score model is also demonstrated to be effective on predicting both overall and recurrence-free survival of chemotherapy received patients. After performing Gene Set Enrichment Analysis (GSEA) between high and low risk groups, we found that several cell-cell interaction KEGG pathways were identified. Funnel plot results showed that there was no publication bias in these datasets. In summary, by utilizing the regulatory activity in stage II and III colorectal carcinoma, the risk score successfully predicts the survival of 1021 stage II/III CRC patients in six independent datasets.

  7. Integrating life stages into ecological niche models: a case study on tiger beetles.

    Science.gov (United States)

    Taboada, Angela; von Wehrden, Henrik; Assmann, Thorsten

    2013-01-01

    Detailed understanding of a species' natural history and environmental needs across spatial scales is a primary requisite for effective conservation planning, particularly for species with complex life cycles in which different life stages occupy different niches and respond to the environment at different scales. However, niche models applied to conservation often neglect early life stages and are mostly performed at broad spatial scales. Using the endangered heath tiger beetle (Cicindela sylvatica) as a model species, we relate presence/absence and abundance data of locally dispersing adults and sedentary larvae to abiotic and biotic variables measured in a multiscale approach within the geographic extent relevant to active conservation management. At the scale of hundreds of meters, fine-grained abiotic conditions (i.e., vegetation structure) are fundamental determinants of the occurrence of both life stages, whereas the effect of biotic factors is mostly contained in the abiotic signature. The combination of dense heath vegetation and bare ground areas is thus the first requirement for the species' preservation, provided that accessibility to the suitable habitat is ensured. At a smaller scale (centimetres), the influence of abiotic factors on larval occurrence becomes negligible, suggesting the existence of important additional variables acting within larval proximity. Sustained significant correlations between neighbouring larvae in the models provide an indication of the potential impact of neighbourhood crowding on the larval niche within a few centimetres. Since the species spends the majority of its life cycle in the larval stage, it is essential to consider the hierarchical abiotic and biotic processes affecting the larvae when designing practical conservation guidelines for the species. This underlines the necessity for a more critical evaluation of the consequences of disregarding niche variation between life stages when estimating niches and

  8. The healing stages of an intramedullary implanted tibia: A stress strain comparative analysis of the calcification process

    Science.gov (United States)

    Filardi, Vincenzo

    2015-01-01

    Aims The extended usage of unreamed tibial nailing resulted in reports of an increased rate of complications, especially for the distal portion of the tibia. Unreamed nailing favours biology at the expense of the achievable mechanical stability, it is therefore of interest to define the limits of the clinical indications for this method. Extra-articular fractures of the distal tibial metaphysis, meta-diaphyseal junction, and adjacent diaphysis are distinct in their management from impaction derived ‘‘pilon’’ type fractures and mid-diaphyseal fractures. The goals of this work were to gain a thorough understanding of the load-sharing mechanism between unreamed nail and bones in a fractured tibia. With this purpose a complete model of the human leg was realised, simulating a mid-diaphyseal fracture, classified as A2 type 1, according to the AO classification. The analysis of the entire chain allows to have a complete picture of the stress distribution and of the most stressed bones and soft tissues, but, more importantly can overcome problems connected with boundary conditions imposed at single bony components. Methods Model consists of six bony structures: pelvis, femur, patella, fibula, tibia, and a simplified lump of the feet, configured in a standing up position. Their articular cartilage layers, were simulated by 3D membranes of opportune stiffness connecting the different segments. Moreover an unreamed intra-medullary nail Expert Tibial Nail (DePuy Synthes®) stabilized the fractured tibia. A load of 700 N has been applied at the top of pelvis and a part the feet, at the tip, was rigidly fixed. Five different contact interfaces have been imposed at the different bony surfaces in contact. Results Three different conditions were analysed: the initially healthy tibia, the A2 type 1 fractured tibia with the Expert tibial nail implanted, and the follow up stage after complete healing of tibia. Non-linear finite element analysis of the models were performed

  9. Weibull aging models for the single protective channel unavailability analysis by the device of stages

    International Nuclear Information System (INIS)

    Nunes, M.E.C.; Noriega, H.C.; Melo, P.F.F.

    1997-01-01

    Among the features to take into account in the unavailability analysis of protective channels, there is one that plays a dominant role - that of considering the equipment aging. In this sense, the exponential failure model is not adequate, since some transition rates are no more constant. As a consequence, Markovian models cannot be used anymore. As an alternative, one may use the device of stages that allows for transforming a Non Markovian model into an equivalent Markovian one by insertion of a fictitious states set, called stages. For a given time-dependent transition rate, its failure density is analysed as to the best combination of exponential distributions and then the moments of the original distribution and those of the combination are matched to estimate the necessary parameters. In this paper, the aging of the protective channel is supposed to follow Weibull distributions. Typical means and variances for the times to failure are considered and combinations of stages are checked. Initial conditions features are discussed in connection with states that are fictitious and to check the validity of the developed models. Alternative solutions by the discretization of the failure rates are generated. The results obtained agree quite well. (author). 7 refs., 6 figs

  10. Comparative anatomy and histology of developmental and parasitic stages in the life cycle of the lined sea anemone Edwardsiella lineata.

    Science.gov (United States)

    Reitzel, Adam M; Daly, Marymegan; Sullivan, James C; Finnerty, John R

    2009-02-01

    The evolution of parasitism is often accompanied by profound changes to the developmental program. However, relatively few studies have directly examined the developmental evolution of parasitic species from free-living ancestors. The lined sea anemone Edwardsiella lineata is a relatively recently evolved parasite for which closely related free-living outgroups are known, including the starlet sea anemone Nematostella vectensis. The larva of E. lineata parasitizes the ctenophore Mnemiopsis leidyi, and, once embedded in its host, the anemone assumes a novel vermiform body plan. That we might begin to understand how the developmental program of this species has been transformed during the evolution of parasitism, we characterized the gross anatomy, histology, and cnidom of the parasitic stage, post-parasitic larval stage, and adult stage of the E. lineata life cycle. The distinct parasitic stage of the life cycle differs from the post-parasitic larva with respect to overall shape, external ciliation, cnida frequency, and tissue architecture. The parasitic stage and planula both contain holotrichs, a type of cnida not previously reported in Edwardsiidae. The internal morphology of the post-parasitic planula is extremely similar to the adult morphology, with a complete set of mesenterial tissue and musculature despite this stage having little external differentiation. Finally, we observed 2 previously undocumented aspects of asexual reproduction in E. lineata: (1) the parasitic stage undergoes transverse fission via physal pinching, the first report of asexual reproduction in a pre-adult stage in the Edwardsiidae; and (2) the juvenile polyp undergoes transverse fission via polarity reversal, the first time this form of fission has been reported in E. lineata.

  11. Thermal stability and hot-stage Raman spectroscopic study of Ca-montmorillonite modified with different surfactants: A comparative study

    International Nuclear Information System (INIS)

    Sun, Zhiming; Park, Yuri; Zheng, Shuilin; Ayoko, Godwin A.; Frost, Ray L.

    2013-01-01

    Highlights: • A typical Ca-montmorillonite was modified with three surfactants through ion exchange. • The organoclays were characterized by XRD, TG and hot stage Raman. • The structural geometry and thermal properties of organoclays were analyzed. • The prepared organoclays show potential prospects in the environmental remediation. - Abstract: Three long chain cationic surfactants were intercalated into Ca-montmorillonite through ion exchange and the obtained organoclays were characterized by X-ray diffraction (XRD), high resolution thermogravimetric analysis (TG) and Raman spectroscopy. The intercalation of surfactants not only changes the surface properties of clay from hydrophilic to hydrophobic but also greatly increases the basal spacing of the interlayers based on XRD analysis. The thermal stability of organoclays intercalated with three surfactants (TTAB, DTAB and CTAB) and the different arrangements of the surfactant molecules intercalated into Ca-montmorillonite were determined by TG-DTG analysis. A Raman spectroscopic study on the Ca-montmorillonite modified by three surfactants prepared at different concentrations provided the detailed conformational ordering of different intercalated long-chain surfactants under different conditions. The wavenumber of the antisymmetric stretching mode is more sensitive than that of the symmetric stretching mode to the mobility of the tail of the amine chain. At room temperature, the conformational ordering is more easily affected by the packing density in the lateral model. With the increase of the temperature, the positions of both the antisymmetric and symmetric stretching bands shift to higher wavenumbers, which indicates a decrease of conformational ordering. This study offers new insights into the structure and properties of Ca-montmorillonite modified with different long chain surfactants. Moreover, the experimental results confirm the potential applications of organic Ca-montmorillonites for the removal

  12. Comparative Glycoproteome Analysis: Dynamics of Protein Glycosylation during Metamorphic Transition from Pelagic to Benthic Life Stages in Three Invertebrates

    KAUST Repository

    Chandramouli, Kondethimmanahalli

    2012-02-03

    The life cycle of most benthic marine invertebrates has two distinct stages: the pelagic larval stage and the sessile juvenile stage. The transition between the larval stage and the juvenile stage is often abrupt and may be triggered by post-translational modification of proteins. Glycosylation, a very important post-translational modification, influences the biological activity of proteins. We used two-dimensional gel electrophoresis (2-DE) followed by glycoprotein-specific fluorescence staining and mass spectrometry with the goal of identifying glycosylation pattern changes during larval settlement and metamorphosis in barnacles, bryozoans, and polychaetes. Our results revealed substantial changes in the protein glycosylation patterns from larval to juvenile stages. Before metamorphosis, the degree of protein glycosylation was high in the barnacle Balanus (=Amphibalanus) amphitrite and the spionid polychaete Pseudopolydora vexillosa, whereas it increased after metamorphosis in the bryozoan Bugula neritina. We identified 19 abundant and differentially glycosylated proteins in these three species. Among the proteins, cellular stress- and metabolism-related proteins exhibited distinct glycosylation in B. amphitrite and B. neritina, whereas fatty acid metabolism-related proteins were abundantly glycosylated in P. vexillosa. Furthermore, the protein and gene expression analysis of some selected glycoproteins revealed that the degree of protein glycosylation did not always complement with transcriptional and translational changes associated with the larval-juvenile transition. The current study provides preliminary information on protein glycosylation in marine invertebrates that will serve as a solid basis for future comprehensive analysis of glycobiology during larval settlement and metamorphosis. © 2011 American Chemical Society.

  13. Comparing Structural Brain Connectivity by the Infinite Relational Model

    DEFF Research Database (Denmark)

    Ambrosen, Karen Marie Sandø; Herlau, Tue; Dyrby, Tim

    2013-01-01

    The growing focus in neuroimaging on analyzing brain connectivity calls for powerful and reliable statistical modeling tools. We examine the Infinite Relational Model (IRM) as a tool to identify and compare structure in brain connectivity graphs by contrasting its performance on graphs from...

  14. Multi-criteria comparative evaluation of spallation reaction models

    Science.gov (United States)

    Andrianov, Andrey; Andrianova, Olga; Konobeev, Alexandr; Korovin, Yury; Kuptsov, Ilya

    2017-09-01

    This paper presents an approach to a comparative evaluation of the predictive ability of spallation reaction models based on widely used, well-proven multiple-criteria decision analysis methods (MAVT/MAUT, AHP, TOPSIS, PROMETHEE) and the results of such a comparison for 17 spallation reaction models in the presence of the interaction of high-energy protons with natPb.

  15. Comparative analysis of various methods for modelling permanent magnet machines

    NARCIS (Netherlands)

    Ramakrishnan, K.; Curti, M.; Zarko, D.; Mastinu, G.; Paulides, J.J.H.; Lomonova, E.A.

    2017-01-01

    In this paper, six different modelling methods for permanent magnet (PM) electric machines are compared in terms of their computational complexity and accuracy. The methods are based primarily on conformal mapping, mode matching, and harmonic modelling. In the case of conformal mapping, slotted air

  16. Rock Mechanics Forsmark. Site descriptive modelling Forsmark stage 2.2

    Energy Technology Data Exchange (ETDEWEB)

    Glamheden, Rune; Fredriksson, Anders (Golder Associates AB (SE)); Roeshoff, Kennert; Karlsson, Johan (Berg Bygg Konsult AB (SE)); Hakami, Hossein (Itasca Geomekanik AB (SE)); Christiansson, Rolf (Swedish Nuclear Fuel and Waste Management Co., Stockholm (SE))

    2007-12-15

    The Swedish Nuclear Fuel and Waste Management Company (SKB) is undertaking site characterisation at two different locations, Forsmark and Laxemar/Simpevarp, with the objective of siting a geological repository for spent nuclear fuel. The characterisation of a site is an integrated work carried out by several disciplines including geology, rock mechanics, thermal properties, hydrogeology, hydrogeochemistry and surface systems. This report presents the rock mechanics model of the Forsmark site up to stage 2.2. The scope of work has included compilation and analysis of primary data of intact rock and fractures, estimation of the rock mass mechanical properties and estimation of the in situ state of stress at the Forsmark site. The laboratory results on intact rock and fractures in the target volume demonstrate a good quality rock mass that is strong, stiff and relatively homogeneous. The homogeneity is also supported by the lithological and the hydrogeological models. The properties of the rock mass have been initially estimated by two separate modelling approaches, one empirical and one theoretical. An overall final estimate of the rock mass properties were achieved by integrating the results from the two models via a process termed 'Harmonization'. Both the tensile tests, carried out perpendicular and parallel to the foliation, and the theoretical analyses of the rock mass properties in directions parallel and perpendicular to the major principal stress, result in parameter values almost independent of direction. This indicates that the rock mass in the target volume is isotropic. The rock mass quality in the target volume appears to be of high and uniform quality. Those portions with reduced rock mass quality that do exist are mainly related to sections with increased fracture frequency. Such sections are associated with deformation zones according to the geological description. The results of adjacent rock domains and fracture domains of the target

  17. A Comparative Study between SVM and Fuzzy Inference System for the Automatic Prediction of Sleep Stages and the Assessment of Sleep Quality

    Directory of Open Access Journals (Sweden)

    John Gialelis

    2015-11-01

    Full Text Available This paper compares two supervised learning algorithms for predicting the sleep stages based on the human brain activity. The first step of the presented work regards feature extraction from real human electroencephalography (EEG data together with its corresponding sleep stages that are utilized for training a support vector machine (SVM, and a fuzzy inference system (FIS algorithm. Then, the trained algorithms are used to predict the sleep stages of real human patients. Extended comparison results are demonstrated which indicate that both classifiers could be utilized as a basis for an unobtrusive sleep quality assessment.

  18. Building fast well-balanced two-stage numerical schemes for a model of two-phase flows

    Science.gov (United States)

    Thanh, Mai Duc

    2014-06-01

    We present a set of well-balanced two-stage schemes for an isentropic model of two-phase flows arisen from the modeling of deflagration-to-detonation transition in granular materials. The first stage is to absorb the source term in nonconservative form into equilibria. Then in the second stage, these equilibria will be composed into a numerical flux formed by using a convex combination of the numerical flux of a stable Lax-Friedrichs-type scheme and the one of a higher-order Richtmyer-type scheme. Numerical schemes constructed in such a way are expected to get the interesting property: they are fast and stable. Tests show that the method works out until the parameter takes on the value CFL, and so any value of the parameter between zero and this value is expected to work as well. All the schemes in this family are shown to capture stationary waves and preserves the positivity of the volume fractions. The special values of the parameter 0,1/2,1/(1+CFL), and CFL in this family define the Lax-Friedrichs-type, FAST1, FAST2, and FAST3 schemes, respectively. These schemes are shown to give a desirable accuracy. The errors and the CPU time of these schemes and the Roe-type scheme are calculated and compared. The constructed schemes are shown to be well-balanced and faster than the Roe-type scheme.

  19. Crack-tip chemistry modeling of stage I stress corrosion cracking

    International Nuclear Information System (INIS)

    Jones, R.H.; Simonen, E.P.

    1991-10-01

    Stage I stress corrosion cracking usually exhibits a very strong K dependence with Paris law exponents of up to 30. 2 Model calculations indicate that the crack velocity in this regime is controlled by transport through a salt film and that the K dependence results from crack opening controlled salt film dissolution. An ionic transport model that accounts for both electromigration through the resistive salt film and Fickian diffusion through the aqueous solution was used for these predictions. Predicted crack growth rates are in excellent agreement with measured values for Ni with P segregated to the grain boundaries and tested in IN H 2 SO 4 at +900 mV. This salt film dissolution may be applicable to stage I cracking of other materials

  20. Delineation of geochemical anomalies based on stream sediment data utilizing fractal modeling and staged factor analysis

    Science.gov (United States)

    Afzal, Peyman; Mirzaei, Misagh; Yousefi, Mahyar; Adib, Ahmad; Khalajmasoumi, Masoumeh; Zarifi, Afshar Zia; Foster, Patrick; Yasrebi, Amir Bijan

    2016-07-01

    Recognition of significant geochemical signatures and separation of geochemical anomalies from background are critical issues in interpretation of stream sediment data to define exploration targets. In this paper, we used staged factor analysis in conjunction with the concentration-number (C-N) fractal model to generate exploration targets for prospecting Cr and Fe mineralization in Balvard area, SE Iran. The results show coexistence of derived multi-element geochemical signatures of the deposit-type sought and ultramafic-mafic rocks in the NE and northern parts of the study area indicating significant chromite and iron ore prospects. In this regard, application of staged factor analysis and fractal modeling resulted in recognition of significant multi-element signatures that have a high spatial association with host lithological units of the deposit-type sought, and therefore, the generated targets are reliable for further prospecting of the deposit in the study area.

  1. Trading stages

    DEFF Research Database (Denmark)

    Steiner, Uli; Tuljapurkar, Shripad; Coulson, Tim

    2012-01-01

    Interest in stage-and age structured models has recently increased because they can describe quantitative traits such as size that are left out of age-only demography. Available methods for the analysis of effects of vital rates on lifespan in stage-structured models have not been widely applied ...... examples. Much of our approach relies on trading of time and mortality risk in one stage for time and risk in others. Our approach contributes to the new framework of the study of age- and stage-structured biodemography....

  2. Methods and models used in comparative risk studies

    International Nuclear Information System (INIS)

    Devooght, J.

    1983-01-01

    Comparative risk studies make use of a large number of methods and models based upon a set of assumptions incompletely formulated or of value judgements. Owing to the multidimensionality of risks and benefits, the economic and social context may notably influence the final result. Five classes of models are briefly reviewed: accounting of fluxes of effluents, radiation and energy; transport models and health effects; systems reliability and bayesian analysis; economic analysis of reliability and cost-risk-benefit analysis; decision theory in presence of uncertainty and multiple objectives. Purpose and prospect of comparative studies are assessed in view of probable diminishing returns for large generic comparisons [fr

  3. Waterhammer Modeling for the Ares I Upper Stage Reaction Control System Cold Flow Development Test Article

    Science.gov (United States)

    Williams, Jonathan H.

    2010-01-01

    The Upper Stage Reaction Control System provides three-axis attitude control for the Ares I launch vehicle during active Upper Stage flight. The system design must accommodate rapid thruster firing to maintain the proper launch trajectory and thus allow for the possibility to pulse multiple thrusters simultaneously. Rapid thruster valve closure creates an increase in static pressure, known as waterhammer, which propagates throughout the propellant system at pressures exceeding nominal design values. A series of development tests conducted in the fall of 2009 at Marshall Space Flight Center were performed using a water-flow test article to better understand fluid performance characteristics of the Upper Stage Reaction Control System. A subset of the tests examined waterhammer along with the subsequent pressure and frequency response in the flight-representative system and provided data to anchor numerical models. This thesis presents a comparison of waterhammer test results with numerical model and analytical results. An overview of the flight system, test article, modeling and analysis are also provided.

  4. Adaptive Urban Stormwater Management Using a Two-stage Stochastic Optimization Model

    Science.gov (United States)

    Hung, F.; Hobbs, B. F.; McGarity, A. E.

    2014-12-01

    In many older cities, stormwater results in combined sewer overflows (CSOs) and consequent water quality impairments. Because of the expense of traditional approaches for controlling CSOs, cities are considering the use of green infrastructure (GI) to reduce runoff and pollutants. Examples of GI include tree trenches, rain gardens, green roofs, and rain barrels. However, the cost and effectiveness of GI are uncertain, especially at the watershed scale. We present a two-stage stochastic extension of the Stormwater Investment Strategy Evaluation (StormWISE) model (A. McGarity, JWRPM, 2012, 111-24) to explicitly model and optimize these uncertainties in an adaptive management framework. A two-stage model represents the immediate commitment of resources ("here & now") followed by later investment and adaptation decisions ("wait & see"). A case study is presented for Philadelphia, which intends to extensively deploy GI over the next two decades (PWD, "Green City, Clean Water - Implementation and Adaptive Management Plan," 2011). After first-stage decisions are made, the model updates the stochastic objective and constraints (learning). We model two types of "learning" about GI cost and performance. One assumes that learning occurs over time, is automatic, and does not depend on what has been done in stage one (basic model). The other considers learning resulting from active experimentation and learning-by-doing (advanced model). Both require expert probability elicitations, and learning from research and monitoring is modelled by Bayesian updating (as in S. Jacobi et al., JWRPM, 2013, 534-43). The model allocates limited financial resources to GI investments over time to achieve multiple objectives with a given reliability. Objectives include minimizing construction and O&M costs; achieving nutrient, sediment, and runoff volume targets; and community concerns, such as aesthetics, CO2 emissions, heat islands, and recreational values. CVaR (Conditional Value at Risk) and

  5. The stage-value model: Implications for the changing standards of care.

    Science.gov (United States)

    Görtz, Daniel Patrik; Commons, Michael Lamport

    2015-01-01

    The standard of care is a legal and professional notion against which doctors and other medical personnel are held liable. The standard of care changes as new scientific findings and technological innovations within medicine, pharmacology, nursing and public health are developed and adopted. This study consists of four parts. Part 1 describes the problem and gives concrete examples of its occurrence. The second part discusses the application of the Model of Hierarchical Complexity on the field, giving examples of how standards of care are understood at different behavioral developmental stage. It presents the solution to the problem of standards of care at a Paradigmatic Stage 14. The solution at this stage is a deliberative, communicative process based around why certain norms should or should not apply in each specific case, by the use of "meta-norms". Part 3 proposes a Cross-Paradigmatic Stage 15 view of how the problem of changing standards of care can be solved. The proposed solution is to found the legal procedure in each case on well-established behavioral laws. We maintain that such a behavioristic, scientifically based justice would be much more proficient at effecting restorative legal interventions that create desired behaviors. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. A Three-Stage Mechanistic Model for Solidification Cracking During Welding of Steel

    Science.gov (United States)

    Aucott, L.; Huang, D.; Dong, H. B.; Wen, S. W.; Marsden, J.; Rack, A.; Cocks, A. C. F.

    2018-03-01

    A three-stage mechanistic model for solidification cracking during TIG welding of steel is proposed from in situ synchrotron X-ray imaging of solidification cracking and subsequent analysis of fracture surfaces. Stage 1—Nucleation of inter-granular hot cracks: cracks nucleate inter-granularly in sub-surface where maximum volumetric strain is localized and volume fraction of liquid is less than 0.1; the crack nuclei occur at solute-enriched liquid pockets which remain trapped in increasingly impermeable semi-solid skeleton. Stage 2—Coalescence of cracks via inter-granular fracture: as the applied strain increases, cracks coalesce through inter-granular fracture; the coalescence path is preferential to the direction of the heat source and propagates through the grain boundaries to solidifying dendrites. Stage 3—Propagation through inter-dendritic hot tearing: inter-dendritic hot tearing occurs along the boundaries between solidifying columnar dendrites with higher liquid fraction. It is recommended that future solidification cracking criterion shall be based on the application of multiphase mechanics and fracture mechanics to the failure of semi-solid materials.

  7. A Comparative Assessment of Aerodynamic Models for Buffeting and Flutter of Long-Span Bridges

    Directory of Open Access Journals (Sweden)

    Igor Kavrakov

    2017-12-01

    Full Text Available Wind-induced vibrations commonly represent the leading criterion in the design of long-span bridges. The aerodynamic forces in bridge aerodynamics are mainly based on the quasi-steady and linear unsteady theory. This paper aims to investigate different formulations of self-excited and buffeting forces in the time domain by comparing the dynamic response of a multi-span cable-stayed bridge during the critical erection condition. The bridge is selected to represent a typical reference object with a bluff concrete box girder for large river crossings. The models are viewed from a perspective of model complexity, comparing the influence of the aerodynamic properties implied in the aerodynamic models, such as aerodynamic damping and stiffness, fluid memory in the buffeting and self-excited forces, aerodynamic nonlinearity, and aerodynamic coupling on the bridge response. The selected models are studied for a wind-speed range that is typical for the construction stage for two levels of turbulence intensity. Furthermore, a simplified method for the computation of buffeting forces including the aerodynamic admittance is presented, in which rational approximation is avoided. The critical flutter velocities are also compared for the selected models under laminar flow. Keywords: Buffeting, Flutter, Long-span bridges, Bridge aerodynamics, Bridge aeroelasticity, Erection stage

  8. Chemval project report on stage 2: application of speciation models to laboratory and field data sets

    International Nuclear Information System (INIS)

    Read, D.

    1990-01-01

    This report describes the results of Chemval Stage 2, an international chemical model validation exercise involving the active participation of 14 organizations within EC countries, Sweden, Switzerland and Finland. Four different sites have been studied, representing a range of host rock types and proposed disposal facilities. It details the methodology employed and results obtained for 19 test cases of varying complexity, devised to allow comparison between modelling results and experimental measurements. Recommendations are made for enhancement of models and thermodynamic databases employed, as well as for the collection of field/laboratory data geared to the needs of model validation. This report complements a previous one, ref. EUR 12237 EN, devoted to the verification of speciation models. The work is part of the Community's Mirage project - Second phase, on migration of radionuclides in the geosphere

  9. A fractal derivative constitutive model for three stages in granite creep

    Directory of Open Access Journals (Sweden)

    R. Wang

    Full Text Available In this paper, by replacing the Newtonian dashpot with the fractal dashpot and considering damage effect, a new constitutive model is proposed in terms of time fractal derivative to describe the full creep regions of granite. The analytic solutions of the fractal derivative creep constitutive equation are derived via scaling transform. The conventional triaxial compression creep tests are performed on MTS 815 rock mechanics test system to verify the efficiency of the new model. The granite specimen is taken from Beishan site, the most potential area for the China’s high-level radioactive waste repository. It is shown that the proposed fractal model can characterize the creep behavior of granite especially in accelerating stage which the classical models cannot predict. The parametric sensitivity analysis is also conducted to investigate the effects of model parameters on the creep strain of granite. Keywords: Beishan granite, Fractal derivative, Damage evolution, Scaling transformation

  10. A two-stage predictive model to simultaneous control of trihalomethanes in water treatment plants and distribution systems: adaptability to treatment processes.

    Science.gov (United States)

    Domínguez-Tello, Antonio; Arias-Borrego, Ana; García-Barrera, Tamara; Gómez-Ariza, José Luis

    2017-10-01

    The trihalomethanes (TTHMs) and others disinfection by-products (DBPs) are formed in drinking water by the reaction of chlorine with organic precursors contained in the source water, in two consecutive and linked stages, that starts at the treatment plant and continues in second stage along the distribution system (DS) by reaction of residual chlorine with organic precursors not removed. Following this approach, this study aimed at developing a two-stage empirical model for predicting the formation of TTHMs in the water treatment plant and subsequently their evolution along the water distribution system (WDS). The aim of the two-stage model was to improve the predictive capability for a wide range of scenarios of water treatments and distribution systems. The two-stage model was developed using multiple regression analysis from a database (January 2007 to July 2012) using three different treatment processes (conventional and advanced) in the water supply system of Aljaraque area (southwest of Spain). Then, the new model was validated using a recent database from the same water supply system (January 2011 to May 2015). The validation results indicated no significant difference in the predictive and observed values of TTHM (R 2 0.874, analytical variance distribution systems studied, proving the adaptability of the new model to the boundary conditions. Finally the predictive capability of the new model was compared with 17 other models selected from the literature, showing satisfactory results prediction and excellent adaptability to treatment processes.

  11. Comparing estimates of genetic variance across different relationship models.

    Science.gov (United States)

    Legarra, Andres

    2016-02-01

    Use of relationships between individuals to estimate genetic variances and heritabilities via mixed models is standard practice in human, plant and livestock genetics. Different models or information for relationships may give different estimates of genetic variances. However, comparing these estimates across different relationship models is not straightforward as the implied base populations differ between relationship models. In this work, I present a method to compare estimates of variance components across different relationship models. I suggest referring genetic variances obtained using different relationship models to the same reference population, usually a set of individuals in the population. Expected genetic variance of this population is the estimated variance component from the mixed model times a statistic, Dk, which is the average self-relationship minus the average (self- and across-) relationship. For most typical models of relationships, Dk is close to 1. However, this is not true for very deep pedigrees, for identity-by-state relationships, or for non-parametric kernels, which tend to overestimate the genetic variance and the heritability. Using mice data, I show that heritabilities from identity-by-state and kernel-based relationships are overestimated. Weighting these estimates by Dk scales them to a base comparable to genomic or pedigree relationships, avoiding wrong comparisons, for instance, "missing heritabilities". Copyright © 2015 Elsevier Inc. All rights reserved.

  12. Comparing live and remote models in eating conformity research.

    Science.gov (United States)

    Feeney, Justin R; Polivy, Janet; Pliner, Patricia; Sullivan, Margot D

    2011-01-01

    Research demonstrates that people conform to how much other people eat. This conformity occurs in the presence of other people (live model) and when people view information about how much food prior participants ate (remote models). The assumption in the literature has been that remote models produce a similar effect to live models, but this has never been tested. To investigate this issue, we randomly paired participants with a live or remote model and compared their eating to those who ate alone. We found that participants exposed to both types of model differed significantly from those in the control group, but there was no significant difference between the two modeling procedures. Crown Copyright © 2010. Published by Elsevier Ltd. All rights reserved.

  13. Comparative calculations and validation studies with atmospheric dispersion models

    International Nuclear Information System (INIS)

    Paesler-Sauer, J.

    1986-11-01

    This report presents the results of an intercomparison of different mesoscale dispersion models and measured data of tracer experiments. The types of models taking part in the intercomparison are Gaussian-type, numerical Eulerian, and Lagrangian dispersion models. They are suited for the calculation of the atmospherical transport of radionuclides released from a nuclear installation. For the model intercomparison artificial meteorological situations were defined and corresponding arithmetical problems were formulated. For the purpose of model validation real dispersion situations of tracer experiments were used as input data for model calculations; in these cases calculated and measured time-integrated concentrations close to the ground are compared. Finally a valuation of the models concerning their efficiency in solving the problems is carried out by the aid of objective methods. (orig./HP) [de

  14. Modeling of thin films growth processes in the early stage for atoms with covalent bonds

    International Nuclear Information System (INIS)

    Tupik, V A; Margolin, V I; Su, Chu Trong

    2017-01-01

    Computer simulation for obtaining thin film’s growth process at an early stage with the proposed model of atoms with isotropic and anisotropic interactions been considered. Carrying out the procedure for analyzing the problem on the basis of the program being implemented, computer simulation of thin film growth processes has been carried out on several examples. The results of computer simulation of the growth process of thin film on a given substrate and an aggregate in a vacuum condition are shown. Some characteristic distributions of the obtained structure have been carried out to evaluate the proposed adequate model and to reflect the high complexity of thin films growth process. (paper)

  15. Simulation model of a single-stage lithium bromide-water absorption cooling unit

    Science.gov (United States)

    Miao, D.

    1978-01-01

    A computer model of a LiBr-H2O single-stage absorption machine was developed. The model, utilizing a given set of design data such as water-flow rates and inlet or outlet temperatures of these flow rates but without knowing the interior characteristics of the machine (heat transfer rates and surface areas), can be used to predict or simulate off-design performance. Results from 130 off-design cases for a given commercial machine agree with the published data within 2 percent.

  16. Weak instruments and the first stage F-statistic in IV models with a nonscalar error covariance structure

    NARCIS (Netherlands)

    Bun, M.; de Haan, M.

    2010-01-01

    We analyze the usefulness of the first stage F-statistic for detecting weak instruments in the IV model with a nonscalar error covariance structure. More in particular, we question the validity of the rule of thumb of a first stage F-statistic of 10 or higher for models with correlated errors

  17. Subset Analysis of a Multicenter, Randomized Controlled Trial to Compare Magnifying Chromoendoscopy with Endoscopic Ultrasonography for Stage Diagnosis of Early Stage Colorectal Cancer.

    Directory of Open Access Journals (Sweden)

    Tomonori Yamada

    Full Text Available Our recent prospective study found equivalent accuracy of magnifying chromoendoscopy (MC and endoscopic ultrasonography (EUS for diagnosing the invasion depth of colorectal cancer (CRC; however, whether these tools show diagnostic differences in categories such as tumor size and morphology remains unclear. Hence, we conducted detailed subset analysis of the prospective data.In this multicenter, prospective, comparative trial, a total of 70 patients with early, flat CRC were enrolled from February 2011 to December 2012, and the results of 66 lesions were finally analyzed. Patients were randomly allocated to primary MC followed by EUS or to primary EUS followed by MC. Diagnoses of invasion depth by each tool were divided into intramucosal to slight submucosal invasion (invasion depth <1000 μm and deep submucosal invasion (invasion depth ≥1000 μm, and then compared with the final pathological diagnosis by an independent pathologist blinded to clinical data. To standardize diagnoses among examiners, this trial was started after achievement of a mean κ value of ≥0.6 which was calculated from the average of κ values between each pair of participating endoscopists.Both MC and EUS showed similar diagnostic outcomes, with no significant differences in prediction of invasion depth in subset analyses according to tumor size, location, and morphology. Lesions that were consistently diagnosed as Tis/T1-SMS or ≥T1-SMD with both tools revealed accuracy of 76-78%. Accuracy was low in borderline lesions with irregular pit pattern in MC and distorted findings of the third layer in EUS (MC, 58.5%; EUS, 50.0%.MC and EUS showed the same limited accuracy for predicting invasion depth in all categories of early CRC. Since the irregular pit pattern in MC, distorted findings to the third layer in EUS and inconsistent diagnosis between both tools were associated with low accuracy, further refinements or even novel methods are still needed for such lesions

  18. A comparative review of radiation-induced cancer risk models

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seung Hee; Kim, Ju Youl [FNC Technology Co., Ltd., Yongin (Korea, Republic of); Han, Seok Jung [Risk and Environmental Safety Research Division, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2017-06-15

    With the need for a domestic level 3 probabilistic safety assessment (PSA), it is essential to develop a Korea-specific code. Health effect assessments study radiation-induced impacts; in particular, long-term health effects are evaluated in terms of cancer risk. The objective of this study was to analyze the latest cancer risk models developed by foreign organizations and to compare the methodology of how they were developed. This paper also provides suggestions regarding the development of Korean cancer risk models. A review of cancer risk models was carried out targeting the latest models: the NUREG model (1993), the BEIR VII model (2006), the UNSCEAR model (2006), the ICRP 103 model (2007), and the U.S. EPA model (2011). The methodology of how each model was developed is explained, and the cancer sites, dose and dose rate effectiveness factor (DDREF) and mathematical models are also described in the sections presenting differences among the models. The NUREG model was developed by assuming that the risk was proportional to the risk coefficient and dose, while the BEIR VII, UNSCEAR, ICRP, and U.S. EPA models were derived from epidemiological data, principally from Japanese atomic bomb survivors. The risk coefficient does not consider individual characteristics, as the values were calculated in terms of population-averaged cancer risk per unit dose. However, the models derived by epidemiological data are a function of sex, exposure age, and attained age of the exposed individual. Moreover, the methodologies can be used to apply the latest epidemiological data. Therefore, methodologies using epidemiological data should be considered first for developing a Korean cancer risk model, and the cancer sites and DDREF should also be determined based on Korea-specific studies. This review can be used as a basis for developing a Korean cancer risk model in the future.

  19. A framework for 2-stage global sensitivity analysis of GastroPlus™ compartmental models.

    Science.gov (United States)

    Scherholz, Megerle L; Forder, James; Androulakis, Ioannis P

    2018-04-01

    Parameter sensitivity and uncertainty analysis for physiologically based pharmacokinetic (PBPK) models are becoming an important consideration for regulatory submissions, requiring further evaluation to establish the need for global sensitivity analysis. To demonstrate the benefits of an extensive analysis, global sensitivity was implemented for the GastroPlus™ model, a well-known commercially available platform, using four example drugs: acetaminophen, risperidone, atenolol, and furosemide. The capabilities of GastroPlus were expanded by developing an integrated framework to automate the GastroPlus graphical user interface with AutoIt and for execution of the sensitivity analysis in MATLAB ® . Global sensitivity analysis was performed in two stages using the Morris method to screen over 50 parameters for significant factors followed by quantitative assessment of variability using Sobol's sensitivity analysis. The 2-staged approach significantly reduced computational cost for the larger model without sacrificing interpretation of model behavior, showing that the sensitivity results were well aligned with the biopharmaceutical classification system. Both methods detected nonlinearities and parameter interactions that would have otherwise been missed by local approaches. Future work includes further exploration of how the input domain influences the calculated global sensitivity measures as well as extending the framework to consider a whole-body PBPK model.

  20. Subset Analysis of a Multicenter, Randomized Controlled Trial to Compare Magnifying Chromoendoscopy with Endoscopic Ultrasonography for Stage Diagnosis of Early Stage Colorectal Cancer.

    Science.gov (United States)

    Yamada, Tomonori; Shimura, Takaya; Ebi, Masahide; Hirata, Yoshikazu; Nishiwaki, Hirotaka; Mizushima, Takashi; Asukai, Koki; Togawa, Shozo; Takahashi, Satoru; Joh, Takashi

    2015-01-01

    Our recent prospective study found equivalent accuracy of magnifying chromoendoscopy (MC) and endoscopic ultrasonography (EUS) for diagnosing the invasion depth of colorectal cancer (CRC); however, whether these tools show diagnostic differences in categories such as tumor size and morphology remains unclear. Hence, we conducted detailed subset analysis of the prospective data. In this multicenter, prospective, comparative trial, a total of 70 patients with early, flat CRC were enrolled from February 2011 to December 2012, and the results of 66 lesions were finally analyzed. Patients were randomly allocated to primary MC followed by EUS or to primary EUS followed by MC. Diagnoses of invasion depth by each tool were divided into intramucosal to slight submucosal invasion (invasion depth final pathological diagnosis by an independent pathologist blinded to clinical data. To standardize diagnoses among examiners, this trial was started after achievement of a mean κ value of ≥0.6 which was calculated from the average of κ values between each pair of participating endoscopists. Both MC and EUS showed similar diagnostic outcomes, with no significant differences in prediction of invasion depth in subset analyses according to tumor size, location, and morphology. Lesions that were consistently diagnosed as Tis/T1-SMS or ≥T1-SMD with both tools revealed accuracy of 76-78%. Accuracy was low in borderline lesions with irregular pit pattern in MC and distorted findings of the third layer in EUS (MC, 58.5%; EUS, 50.0%). MC and EUS showed the same limited accuracy for predicting invasion depth in all categories of early CRC. Since the irregular pit pattern in MC, distorted findings to the third layer in EUS and inconsistent diagnosis between both tools were associated with low accuracy, further refinements or even novel methods are still needed for such lesions. University hospital Medical Information Network Clinical Trials Registry UMIN 000005085.

  1. Dispersion Modeling Using Ensemble Forecasts Compared to ETEX Measurements.

    Science.gov (United States)

    Straume, Anne Grete; N'dri Koffi, Ernest; Nodop, Katrin

    1998-11-01

    Numerous numerical models are developed to predict long-range transport of hazardous air pollution in connection with accidental releases. When evaluating and improving such a model, it is important to detect uncertainties connected to the meteorological input data. A Lagrangian dispersion model, the Severe Nuclear Accident Program, is used here to investigate the effect of errors in the meteorological input data due to analysis error. An ensemble forecast, produced at the European Centre for Medium-Range Weather Forecasts, is then used as model input. The ensemble forecast members are generated by perturbing the initial meteorological fields of the weather forecast. The perturbations are calculated from singular vectors meant to represent possible forecast developments generated by instabilities in the atmospheric flow during the early part of the forecast. The instabilities are generated by errors in the analyzed fields. Puff predictions from the dispersion model, using ensemble forecast input, are compared, and a large spread in the predicted puff evolutions is found. This shows that the quality of the meteorological input data is important for the success of the dispersion model. In order to evaluate the dispersion model, the calculations are compared with measurements from the European Tracer Experiment. The model manages to predict the measured puff evolution concerning shape and time of arrival to a fairly high extent, up to 60 h after the start of the release. The modeled puff is still too narrow in the advection direction.

  2. Structured model of bacterial growth and tests with activated sludge in a one-stage and two-stage chemostat

    NARCIS (Netherlands)

    Harder, A.

    1979-01-01

    A kinetic model for a growing culture of micro-organisms was developed that correlated the biochemical structure of cells with quantitative physiological behaviour. The three-compartment model was adequate for simulation of continuous, batch and transient experiments with activated sludge fed on

  3. Applying the Health Belief Model in Explaining the Stages of Exercise Change in Older Adults

    Directory of Open Access Journals (Sweden)

    Sas-Nowosielski Krzysztof

    2016-12-01

    Full Text Available Introduction. The benefits of physical activity (PA have been so well documented that there is no doubt about the significance of PA for personal and social health. Several theoretical models have been proposed with a view to understanding the phenomenon of PA and other health behaviours. The purpose of this study was to evaluate if and how the variables suggested in the Health Belief Model (HBM determine physical activity stages of change in older adults. Material and methods. A total of 172 students of Universities of the Third Age aged 54 to 75 (mean = 62.89 ± 4.83 years agreed to participate in the study, filling out an anonymous survey measuring their stage of exercise change and determinants of health behaviours proposed by the HBM, including: perceived benefits of physical activity, perceived barriers to physical activity, perceived severity of diseases associated with sedentary lifestyle, perceived susceptibility to these diseases, and self-efficacy. Results. The results only partially support the hypothesis that the HBM predicts intentions and behaviours related to the physical activity of older adults. Only two variables were moderately-to-strongly related to stages of exercise change, namely perceived barriers and self-efficacy. Conclusion. Interventions aimed at informing older adults about the benefits of physical activity and the threats associated with sedentary lifestyle can be expected to have rather a weak influence on their readiness for physical activity.

  4. Disaggregation of Rainy Hours: Compared Performance of Various Models.

    Science.gov (United States)

    Ben Haha, M.; Hingray, B.; Musy, A.

    In the urban environment, the response times of catchments are usually short. To de- sign or to diagnose waterworks in that context, it is necessary to describe rainfall events with a good time resolution: a 10mn time step is often necessary. Such in- formation is not always available. Rainfall disaggregation models have thus to be applied to produce from rough rainfall data that short time resolution information. The communication will present the performance obtained with several rainfall dis- aggregation models that allow for the disaggregation of rainy hours into six 10mn rainfall amounts. The ability of the models to reproduce some statistical character- istics of rainfall (mean, variance, overall distribution of 10mn-rainfall amounts; ex- treme values of maximal rainfall amounts over different durations) is evaluated thanks to different graphical and numerical criteria. The performance of simple models pre- sented in some scientific papers or developed in the Hydram laboratory as well as the performance of more sophisticated ones is compared with the performance of the basic constant disaggregation model. The compared models are either deterministic or stochastic; for some of them the disaggregation is based on scaling properties of rainfall. The compared models are in increasing complexity order: constant model, linear model (Ben Haha, 2001), Ormsbee Deterministic model (Ormsbee, 1989), Ar- tificial Neuronal Network based model (Burian et al. 2000), Hydram Stochastic 1 and Hydram Stochastic 2 (Ben Haha, 2001), Multiplicative Cascade based model (Olsson and Berndtsson, 1998), Ormsbee Stochastic model (Ormsbee, 1989). The 625 rainy hours used for that evaluation (with a hourly rainfall amount greater than 5mm) were extracted from the 21 years chronological rainfall series (10mn time step) observed at the Pully meteorological station, Switzerland. The models were also evaluated when applied to different rainfall classes depending on the season first and on the

  5. 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

  6. Comparative susceptibilities of different life stages of the tarnished plant bug (Hemiptera: miridae) to three classes of insecticide

    Science.gov (United States)

    Insecticidal control of the tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), is targeted at the adult and nymphal stages, but there is little information on relative susceptibilities of these insects to insecticides. Tarnished plant bug adults were collected from various locations in Mi...

  7. Comparative proteomics analysis of silkworm hemolymph during the stages of metamorphosis via liquid chromatography and mass spectrometry.

    Science.gov (United States)

    Hou, Yong; Zhang, Yan; Gong, Jing; Tian, Sha; Li, Jianwei; Dong, Zhaoming; Guo, Chao; Peng, Li; Zhao, Ping; Xia, Qingyou

    2016-05-01

    The silkworm is a lepidopteran insect that has an open circulatory system with hemolymph consisting of blood and lymph fluid. Hemolymph is not only considered as a depository of nutrients and energy, but it also plays a key role in substance transportation, immunity response, and proteolysis. In this study, we used LC-MS/MS to analyze the hemolymph proteins of four developmental stages during metamorphosis. A total of 728 proteins were identified from the hemolymph of the second day of wandering stage, first day of pupation, ninth day of pupation, and first day as an adult moth. GO annotations and categories showed that silkworm hemolymph proteins were enriched in carbohydrate metabolism, proteolysis, protein binding, and antibacterial humoral response. The levels of nutrient, immunity-related, and structural proteins changed significantly during development and metamorphosis. Some, such as cuticle, odorant-binding, and chemosensory proteins, showed stage-specific expression in the hemolymph. In addition, the expression of several antimicrobial peptides exhibited their highest level of abundance in the hemolymph of the early pupal stage. These findings provide a comprehensive proteomic insight of the silkworm hemolymph and suggest additional molecular targets for studying insect metamorphosis. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Design model for bending vibrations of single-stage tunnel fan rotor

    Science.gov (United States)

    Krasyuk, AM; Kosykh, PV

    2018-03-01

    Using of one-mass model of tunnel fan rotor is justified for estimation calculation of the natural bending vibrations frequency during the design stage. It’s shown that the evaluative computation of the main axial tunnel fan at the early design stage yields the acceptable accuracy. It is shown that after completion of the design, the mass of the stepped-type shaft differs from the mass of the calculated uniform-diameter shaft no more than by 40%. Inclusion of this additional mass in the estimation calculation makes it possible to improve the calculation accuracy. The region of the dimensionless rotor design parameters at which the relative difference of frequency in the evaluative and verification calculations is not higher than 5 % is determined.

  9. End-to-End Deep Learning Model For Automatic Sleep Staging Using Raw PSG Waveforms

    DEFF Research Database (Denmark)

    Olesen, Alexander Neergaard; Peppard, P. E.; Sorensen, H. B.

    2018-01-01

    Deep learning has seen significant progress over the last few years, especially in computer vision, where competitions such as the ImageNet challenge have been the driving factor behind many new model architectures far superior to humans in image recognition. We propose a novel method for automatic...... accuracy, precision and recall were 84.93%, 97.42% and 97.02%, respectively. Evaluating on the validation set yielded an overall accuracy of 85.07% and overall precision/recall of 98.54% and 95.72%, respectively. Conclusion: Preliminary results indicate that state of the art deep learning models can...... sleep staging, which relies on current advances in computer vision models eliminating the need for feature engineering or other transformations of input data. By exploiting the high capacity for complex learning in a state of the art object recognition model, we can effectively use raw PSG signals...

  10. Comparing the line broadened quasilinear model to Vlasov code

    International Nuclear Information System (INIS)

    Ghantous, K.; Berk, H. L.; Gorelenkov, N. N.

    2014-01-01

    The Line Broadened Quasilinear (LBQ) model is revisited to study its predicted saturation level as compared with predictions of a Vlasov solver BOT [Lilley et al., Phys. Rev. Lett. 102, 195003 (2009) and M. Lilley, BOT Manual. The parametric dependencies of the model are modified to achieve more accuracy compared to the results of the Vlasov solver both in regards to a mode amplitude's time evolution to a saturated state and its final steady state amplitude in the parameter space of the model's applicability. However, the regions of stability as predicted by LBQ model and BOT are found to significantly differ from each other. The solutions of the BOT simulations are found to have a larger region of instability than the LBQ simulations

  11. Comparing the line broadened quasilinear model to Vlasov code

    Energy Technology Data Exchange (ETDEWEB)

    Ghantous, K. [Laboratoire de Physique des Plasmas, Ecole Polytechnique, 91128 Palaiseau Cedex (France); Princeton Plasma Physics Laboratory, P.O. Box 451, Princeton, New Jersey 08543-0451 (United States); Berk, H. L. [Institute for Fusion Studies, University of Texas, 2100 San Jacinto Blvd, Austin, Texas 78712-1047 (United States); Gorelenkov, N. N. [Princeton Plasma Physics Laboratory, P.O. Box 451, Princeton, New Jersey 08543-0451 (United States)

    2014-03-15

    The Line Broadened Quasilinear (LBQ) model is revisited to study its predicted saturation level as compared with predictions of a Vlasov solver BOT [Lilley et al., Phys. Rev. Lett. 102, 195003 (2009) and M. Lilley, BOT Manual. The parametric dependencies of the model are modified to achieve more accuracy compared to the results of the Vlasov solver both in regards to a mode amplitude's time evolution to a saturated state and its final steady state amplitude in the parameter space of the model's applicability. However, the regions of stability as predicted by LBQ model and BOT are found to significantly differ from each other. The solutions of the BOT simulations are found to have a larger region of instability than the LBQ simulations.

  12. Comparing the line broadened quasilinear model to Vlasov code

    Science.gov (United States)

    Ghantous, K.; Berk, H. L.; Gorelenkov, N. N.

    2014-03-01

    The Line Broadened Quasilinear (LBQ) model is revisited to study its predicted saturation level as compared with predictions of a Vlasov solver BOT [Lilley et al., Phys. Rev. Lett. 102, 195003 (2009) and M. Lilley, BOT Manual. The parametric dependencies of the model are modified to achieve more accuracy compared to the results of the Vlasov solver both in regards to a mode amplitude's time evolution to a saturated state and its final steady state amplitude in the parameter space of the model's applicability. However, the regions of stability as predicted by LBQ model and BOT are found to significantly differ from each other. The solutions of the BOT simulations are found to have a larger region of instability than the LBQ simulations.

  13. Comparing the staffing models of outsourcing in selected companies

    OpenAIRE

    Chaloupková, Věra

    2010-01-01

    This thesis deals with problems of takeover of employees in outsourcing. The capital purpose is to compare the staffing model of outsourcing in selected companies. To compare in selected companies I chose multi-criteria analysis. This thesis is dividend into six chapters. The first charter is devoted to the theoretical part. In this charter describes the basic concepts as outsourcing, personal aspects, phase of the outsourcing projects, communications and culture. The rest of thesis is devote...

  14. Comparative Assessment of Nonlocal Continuum Solvent Models Exhibiting Overscreening

    Directory of Open Access Journals (Sweden)

    Ren Baihua

    2017-01-01

    Full Text Available Nonlocal continua have been proposed to offer a more realistic model for the electrostatic response of solutions such as the electrolyte solvents prominent in biology and electrochemistry. In this work, we review three nonlocal models based on the Landau-Ginzburg framework which have been proposed but not directly compared previously, due to different expressions of the nonlocal constitutive relationship. To understand the relationships between these models and the underlying physical insights from which they are derive, we situate these models into a single, unified Landau-Ginzburg framework. One of the models offers the capacity to interpret how temperature changes affect dielectric response, and we note that the variations with temperature are qualitatively reasonable even though predictions at ambient temperatures are not quantitatively in agreement with experiment. Two of these models correctly reproduce overscreening (oscillations between positive and negative polarization charge densities, and we observe small differences between them when we simulate the potential between parallel plates held at constant potential. These computations require reformulating the two models as coupled systems of local partial differential equations (PDEs, and we use spectral methods to discretize both problems. We propose further assessments to discriminate between the models, particularly in regards to establishing boundary conditions and comparing to explicit-solvent molecular dynamics simulations.

  15. New tips for structure prediction by comparative modeling

    Science.gov (United States)

    Rayan, Anwar

    2009-01-01

    Comparative modelling is utilized to predict the 3-dimensional conformation of a given protein (target) based on its sequence alignment to experimentally determined protein structure (template). The use of such technique is already rewarding and increasingly widespread in biological research and drug development. The accuracy of the predictions as commonly accepted depends on the score of sequence identity of the target protein to the template. To assess the relationship between sequence identity and model quality, we carried out an analysis of a set of 4753 sequence and structure alignments. Throughout this research, the model accuracy was measured by root mean square deviations of Cα atoms of the target-template structures. Surprisingly, the results show that sequence identity of the target protein to the template is not a good descriptor to predict the accuracy of the 3-D structure model. However, in a large number of cases, comparative modelling with lower sequence identity of target to template proteins led to more accurate 3-D structure model. As a consequence of this study, we suggest new tips for improving the quality of omparative models, particularly for models whose target-template sequence identity is below 50%. PMID:19255646

  16. Modeling Remote I/O versus Staging Tradeoff in Multi-Data Center Computing

    International Nuclear Information System (INIS)

    Suslu, Ibrahim H

    2014-01-01

    In multi-data center computing, data to be processed is not always local to the computation. This is a major challenge especially for data-intensive Cloud computing applications, since large amount of data would need to be either moved the local sites (staging) or accessed remotely over the network (remote I/O). Cloud application developers generally chose between staging and remote I/O intuitively without making any scientific comparison specific to their application data access patterns since there is no generic model available that they can use. In this paper, we propose a generic model for the Cloud application developers which would help them to choose the most appropriate data access mechanism for their specific application workloads. We define the parameters that potentially affect the end-to-end performance of the multi-data center Cloud applications which need to access large datasets over the network. To test and validate our models, we implemented a series of synthetic benchmark applications to simulate the most common data access patterns encountered in Cloud applications. We show that our model provides promising results in different settings with different parameters, such as network bandwidth, server and client capabilities, and data access ratio

  17. Modeling of existing cooling towers in ASPEN PLUS using an equilibrium stage method

    International Nuclear Information System (INIS)

    Queiroz, João A.; Rodrigues, Vitor M.S.; Matos, Henrique A.; Martins, F.G.

    2012-01-01

    Highlights: ► Simulation of cooling tower performance under different operating conditions. ► Cooling tower performance is simulated using ASPEN PLUS. ► Levenberg–Marquardt method used to adjust model parameters. ► Air and water outlet temperatures are in good accordance with experimental data. - Abstract: Simulation of cooling tower performance considering operating conditions away from design is typically based on the geometrical parameters provided by the cooling tower vendor, which are often unavailable or outdated. In this paper a different approach for cooling tower modeling based on equilibrium stages and Murphree efficiencies to describe heat and mass transfer is presented. This approach is validated with published data and with data collected from an industrial application. Cooling tower performance is simulated using ASPEN PLUS. Murphree stage efficiency values for the process simulator model were optimized by minimizing the squared difference between the experimental and calculated data using the Levenberg–Marquardt method. The minimization algorithm was implemented in Microsoft Excel with Visual Basic for Applications, integrated with the process simulator (ASPEN PLUS) using Aspen Simulation Workbook. The simulated cooling tower air and water outlet temperatures are in good accordance with experimental data when applying only the outlet water temperature to calibrate the model. The methodology is accurate for simulating cooling towers at different operational conditions.

  18. Modelling of Two-Stage Anaerobic Treating Wastewater from a Molasses-Based Ethanol Distillery with the IWA Anaerobic Digestion Model No.1

    Directory of Open Access Journals (Sweden)

    Kittikhun Taruyanon

    2010-03-01

    Full Text Available This paper presents the application of ADM1 model to simulate the dynamic behaviour of a two-stage anaerobic treatment process treating the wastewater generated from the ethanol distillery process. The laboratory-scale process comprised an anaerobic continuous stirred tank reactor (CSTR and an upflow anaerobic sludge blanket (UASB connecting in series, was used to treat wastewater from the ethanol distillery process. The CSTR and UASB hydraulic retention times (HRT were 12 and 70 hours, respectively. The model was developed based on ADM1 basic structure and implemented with the simulation software AQUASIM. The simulated results were compared with measured data obtained from using the laboratory-scale two-stage anaerobic treatment process to treat wastewater. The sensitivity analysis identified maximum specific uptake rate (km and half-saturation constant (Ks of acetate degrader and sulfate reducing bacteria as the kinetic parameters which highly affected the process behaviour, which were further estimated. The study concluded that the model could predict the dynamic behaviour of a two-stage anaerobic treatment process treating the ethanol distillery process wastewater with varying strength of influents with reasonable accuracy.

  19. Bayesian models for comparative analysis integrating phylogenetic uncertainty

    Directory of Open Access Journals (Sweden)

    Villemereuil Pierre de

    2012-06-01

    Full Text Available Abstract Background Uncertainty in comparative analyses can come from at least two sources: a phylogenetic uncertainty in the tree topology or branch lengths, and b uncertainty due to intraspecific variation in trait values, either due to measurement error or natural individual variation. Most phylogenetic comparative methods do not account for such uncertainties. Not accounting for these sources of uncertainty leads to false perceptions of precision (confidence intervals will be too narrow and inflated significance in hypothesis testing (e.g. p-values will be too small. Although there is some application-specific software for fitting Bayesian models accounting for phylogenetic error, more general and flexible software is desirable. Methods We developed models to directly incorporate phylogenetic uncertainty into a range of analyses that biologists commonly perform, using a Bayesian framework and Markov Chain Monte Carlo analyses. Results We demonstrate applications in linear regression, quantification of phylogenetic signal, and measurement error models. Phylogenetic uncertainty was incorporated by applying a prior distribution for the phylogeny, where this distribution consisted of the posterior tree sets from Bayesian phylogenetic tree estimation programs. The models were analysed using simulated data sets, and applied to a real data set on plant traits, from rainforest plant species in Northern Australia. Analyses were performed using the free and open source software OpenBUGS and JAGS. Conclusions Incorporating phylogenetic uncertainty through an empirical prior distribution of trees leads to more precise estimation of regression model parameters than using a single consensus tree and enables a more realistic estimation of confidence intervals. In addition, models incorporating measurement errors and/or individual variation, in one or both variables, are easily formulated in the Bayesian framework. We show that BUGS is a useful, flexible

  20. Bayesian models for comparative analysis integrating phylogenetic uncertainty

    Science.gov (United States)

    2012-01-01

    Background Uncertainty in comparative analyses can come from at least two sources: a) phylogenetic uncertainty in the tree topology or branch lengths, and b) uncertainty due to intraspecific variation in trait values, either due to measurement error or natural individual variation. Most phylogenetic comparative methods do not account for such uncertainties. Not accounting for these sources of uncertainty leads to false perceptions of precision (confidence intervals will be too narrow) and inflated significance in hypothesis testing (e.g. p-values will be too small). Although there is some application-specific software for fitting Bayesian models accounting for phylogenetic error, more general and flexible software is desirable. Methods We developed models to directly incorporate phylogenetic uncertainty into a range of analyses that biologists commonly perform, using a Bayesian framework and Markov Chain Monte Carlo analyses. Results We demonstrate applications in linear regression, quantification of phylogenetic signal, and measurement error models. Phylogenetic uncertainty was incorporated by applying a prior distribution for the phylogeny, where this distribution consisted of the posterior tree sets from Bayesian phylogenetic tree estimation programs. The models were analysed using simulated data sets, and applied to a real data set on plant traits, from rainforest plant species in Northern Australia. Analyses were performed using the free and open source software OpenBUGS and JAGS. Conclusions Incorporating phylogenetic uncertainty through an empirical prior distribution of trees leads to more precise estimation of regression model parameters than using a single consensus tree and enables a more realistic estimation of confidence intervals. In addition, models incorporating measurement errors and/or individual variation, in one or both variables, are easily formulated in the Bayesian framework. We show that BUGS is a useful, flexible general purpose tool for

  1. Image based 3D city modeling : Comparative study

    Directory of Open Access Journals (Sweden)

    S. P. Singh

    2014-06-01

    Full Text Available 3D city model is a digital representation of the Earth’s surface and it’s related objects such as building, tree, vegetation, and some manmade feature belonging to urban area. The demand of 3D city modeling is increasing rapidly for various engineering and non-engineering applications. Generally four main image based approaches were used for virtual 3D city models generation. In first approach, researchers were used Sketch based modeling, second method is Procedural grammar based modeling, third approach is Close range photogrammetry based modeling and fourth approach is mainly based on Computer Vision techniques. SketchUp, CityEngine, Photomodeler and Agisoft Photoscan are the main softwares to represent these approaches respectively. These softwares have different approaches & methods suitable for image based 3D city modeling. Literature study shows that till date, there is no complete such type of comparative study available to create complete 3D city model by using images. This paper gives a comparative assessment of these four image based 3D modeling approaches. This comparative study is mainly based on data acquisition methods, data processing techniques and output 3D model products. For this research work, study area is the campus of civil engineering department, Indian Institute of Technology, Roorkee (India. This 3D campus acts as a prototype for city. This study also explains various governing parameters, factors and work experiences. This research work also gives a brief introduction, strengths and weakness of these four image based techniques. Some personal comment is also given as what can do or what can’t do from these softwares. At the last, this study shows; it concluded that, each and every software has some advantages and limitations. Choice of software depends on user requirements of 3D project. For normal visualization project, SketchUp software is a good option. For 3D documentation record, Photomodeler gives good

  2. Comparing several boson mappings with the shell model

    International Nuclear Information System (INIS)

    Menezes, D.P.; Yoshinaga, Naotaka; Bonatsos, D.

    1990-01-01

    Boson mappings are an essential step in establishing a connection between the successful phenomenological interacting boson model and the shell model. The boson mapping developed by Bonatsos, Klein and Li is applied to a single j-shell and the resulting energy levels and E2 transitions are shown for a pairing plus quadrupole-quadrupole Hamiltonian. The results are compared to the exact shell model calculation, as well as to these obtained through use of the Otsuka-Arima-Iachello mapping and the Zirnbauer-Brink mapping. In all cases good results are obtained for the spherical and near-vibrational cases

  3. An examination of adaptive cellular protective mechanisms using a multi-stage carcinogenesis model

    International Nuclear Information System (INIS)

    Schollnberger, H.; Stewart, R. D.; Mitchel, R. E. J.; Hofmann, W.

    2004-01-01

    A multi-stage cancer model that describes the putative rate-limiting steps in carcinogenesis was developed and used to investigate the potential impact on lung cancer incidence of the hormesis mechanisms suggested by Feinendegen and Pollycove. In this deterministic cancer model, radiation and endogenous processes damage the DNA of target cells in the lung. Some fraction of the misrepaired our unrepaired DNA damage induces genomic instability and, ultimately, leads to the accumulation of malignant cells. The model accounts for cell birth and death processes. Ita also includes a rate of malignant transformation and a lag period for tumour formation. Cellular defence mechanisms are incorporated into the model by postulating dose and dose rate dependent radical scavenging. The accuracy of DNA damage repair also depends on dose and dose rate. Sensitivity studies were conducted to identify critical model inputs and to help define the shapes of the cumulative lung cancer incidence curves that may arise when dose and dose rate dependent cellular defence mechanisms are incorporated into a multi-stage cancer model. For lung cancer, both linear no-threshold (LNT) and non-LNT shaped responses can be obtained. The reported studied clearly show that it is critical to know whether or not and to what extent multiply damaged DNA sites are formed by endogenous processes. Model inputs that give rise to U-shaped responses are consistent with an effective cumulative lung cancer incidence threshold that may be as high as 300 mGy (4 mGy per year for 75 years). (Author) 11 refs

  4. Towards consensus in comparative chemical characterization modeling for LCIA

    DEFF Research Database (Denmark)

    Hauschild, Michael Zwicky; Bachmann, Till; Huijbregts, Mark

    2006-01-01

    work within, for instance, the OECD, and guidance from a series of expert workshops held between 2002 and 2005, preliminary guidelines focusing on chemical fate, and human and ecotoxic effects were established. For further elaboration of the fate-, exposure- and effect-sides of the modeling, six models...... by the Task Force and the model providers. While the compared models and their differences are important tools to further advance LCA science, the consensus model is intended to provide a generally agreed and scientifically sound method to calculate consistent characterization factors for use in LCA practice...... and to be the basis of the “recommended practice” for calculation of characterization factors for chemicals under authority of the UNEP/SETAC Life Cycle Initiative....

  5. Comparative studies on intestine ultrastructure of third-stage larvae and adults of Cystidicoloides ephemeridarum (Nematoda, Cystidicolidae).

    Science.gov (United States)

    Frantová, Denisa; Moravec, Frantisek

    2004-11-01

    The intestinal epithelium of third-stage larvae and adults of Cystidicoloides ephemeridarum from haemocoel of mayflies and stomach of brown trout was studied by electron microscopy and cytochemistry. In section, the intestine of both stages is composed of a single layer of about ten undifferentiated intestinal cells in a ring. A labyrinth of deep invaginations is present in the basal region of each cell. The apical surface is modified into well developed, regularly arranged microvilli. These, together with numerous organelles engaged in metabolism and a well defined gut lumen filled with unidentifiable material suggest that the intestine may function in digestion and absorption during both stages. The adults seem to feed upon the semifluid content of the stomach of brown trout. Fortuitous oral infection with undetermined bacteria in vitro led to degenerative changes in the intestinal tissue and probably caused death of the infected specimens. Up to 75% of the cell volume in the L(3) is occupied by glycogen deposits. In the adults, a minor portion of glycogen, together with lipid droplets, has been observed. The adults are considered to rely more on aerobic metabolism, whereas anaerobic metabolism (glycolysis) may prevail in L(3).

  6. Modeling two-stage bunch compression with wakefields: Macroscopic properties and microbunching instability

    Directory of Open Access Journals (Sweden)

    R. A. Bosch

    2008-09-01

    Full Text Available In a two-stage compression and acceleration system, where each stage compresses a chirped bunch in a magnetic chicane, wakefields affect high-current bunches. The longitudinal wakes affect the macroscopic energy and current profiles of the compressed bunch and cause microbunching at short wavelengths. For macroscopic wavelengths, impedance formulas and tracking simulations show that the wakefields can be dominated by the resistive impedance of coherent edge radiation. For this case, we calculate the minimum initial bunch length that can be compressed without producing an upright tail in phase space and associated current spike. Formulas are also obtained for the jitter in the bunch arrival time downstream of the compressors that results from the bunch-to-bunch variation of current, energy, and chirp. Microbunching may occur at short wavelengths where the longitudinal space-charge wakes dominate or at longer wavelengths dominated by edge radiation. We model this range of wavelengths with frequency-dependent impedance before and after each stage of compression. The growth of current and energy modulations is described by analytic gain formulas that agree with simulations.

  7. Non-ideal magnetohydrodynamic simulations of the two-stage fragmentation model for cluster formation

    International Nuclear Information System (INIS)

    Bailey, Nicole D.; Basu, Shantanu

    2014-01-01

    We model molecular cloud fragmentation with thin-disk, non-ideal magnetohydrodynamic simulations that include ambipolar diffusion and partial ionization that transitions from primarily ultraviolet-dominated to cosmic-ray-dominated regimes. These simulations are used to determine the conditions required for star clusters to form through a two-stage fragmentation scenario. Recent linear analyses have shown that the fragmentation length scales and timescales can undergo a dramatic drop across the column density boundary that separates the ultraviolet- and cosmic-ray-dominated ionization regimes. As found in earlier studies, the absence of an ionization drop and regular perturbations leads to a single-stage fragmentation on pc scales in transcritical clouds, so that the nonlinear evolution yields the same fragment sizes as predicted by linear theory. However, we find that a combination of initial transcritical mass-to-flux ratio, evolution through a column density regime in which the ionization drop takes place, and regular small perturbations to the mass-to-flux ratio is sufficient to cause a second stage of fragmentation during the nonlinear evolution. Cores of size ∼0.1 pc are formed within an initial fragment of ∼pc size. Regular perturbations to the mass-to-flux ratio also accelerate the onset of runaway collapse.

  8. Lack of miRNA misregulation at early pathological stages in Drosophila neurodegenerative disease models

    Directory of Open Access Journals (Sweden)

    Anita eReinhardt

    2012-10-01

    Full Text Available Late onset neurodegenerative diseases represent a major public health concern as the population in many countries ages. Both frequent diseases such as Alzheimer disease (AD, 14% incidence for 80-84 year old Europeans or Parkinson disease (PD, 1.4% prevalence for > 55 years old share, with other low-incidence neurodegenerative pathologies such as spinocerebellar ataxias (SCAs, 0.01% prevalence and frontotemporal lobar degeneration (FTLD, 0.02% prevalence, a lack of efficient treatment in spite of important research efforts. Besides significant progress, studies with animal models have revealed unexpected complexities in the degenerative process, emphasizing a need to better understand the underlying pathological mechanisms. Recently, microRNAs, a class of small regulatory non-coding RNAs, have been implicated in some neurodegenerative diseases. The current data supporting a role of miRNAs in PD, tauopathies, dominant ataxias and FTLD will first be discussed to emphasize the different levels of the pathological processes which may be affected by miRNAs. To investigate a potential involvement of miRNA dysregulation in the early stages of these neurodegenerative diseases we have used Drosophila models for 7 diseases (PD, 3 FTLD, 3 dominant ataxias that recapitulate many features of the human diseases. We performed deep sequencing of head small RNAs after 3 days of pathological protein expression in the fly head neurons. We found no evidence for a statistically significant difference in miRNA expression in this early stage of the pathological process. In addition, we could not identify small non coding CAG repeat RNAs (sCAG in polyQ disease models. Thus our data suggest that transcriptional deregulation of miRNAs or sCAG is unlikely to play a significant role in the initial stages of neurodegenerative diseases.

  9. Liver fibrosis detection and staging: a comparative study of T1ρ MR imaging and 2D real-time shear-wave elastography.

    Science.gov (United States)

    Li, Ruo-Kun; Ren, Xin-Pin; Yan, Fu-Hua; Qiang, Jin-Wei; Lin, Hui-Min; Tao Wang; Zhao, Hong-Fei; Chen, Wei-Bo

    2017-12-02

    To compare the results of T1ρ MR imaging and 2D real-time shear-wave elastography (SWE) for liver fibrosis detection and staging. Twenty-nine rabbit models of CCl 4 -induced liver fibrosis were established and six untreated rabbits served as controls. T1ρ MR imaging and 2D real-time SWE examination were performed at 2, 4, 6, 8, 10, and 12 weeks. T1ρ values and liver stiffness (LS) values were measured. Fibrosis was staged according to the METAVIR scoring system. Correlation test was performed among T1ρ values, LS values, and fibrosis stage. Receiver operating characteristic (ROC) analysis was performed for assessing diagnostic performance of T1ρ and SWE in detection of no fibrosis (F0), substantial fibrosis (≥ F2), severe fibrosis (≥ F3), and cirrhosis (F4). There was moderate positive correlation between fibrosis stage and T1ρ values (r = 0.566; 95% CI 0.291-0.754; P < 0.0001), and LS value (r = 0.726; 95% CI 0.521-0.851; P = 0.003). T1ρ values showed moderate positive correlations with LS values [r = 0.693; 95% confidence interval (CI) 0.472-0.832; P < 0.0001]. Areas Under ROC (AUROCs) were 0.861 (95% CI 0.705-0.953) for SWE and 0.856 (95% CI 0.698-0.950) for T1ρ (P = 0.940), 0.906 (95% CI 0.762-0.978) for SWE and 0.849 (95% CI 0.691-0.946) for T1ρ (P = 0.414), 0.870 (95% CI 0.716-0.958) for SWE and 0.799 (95% CI 0.632-0.913) for T1ρ (P = 0.422), and 0.846 (95% CI 0.687-0.944) for SWE and 0.692 (95% CI 0.517-0.835) for T1ρ (P = 0.137), when diagnosing liver fibrosis with ≥ F1, ≥ F2, ≥ F3, and F4, respectively. There was moderate positive correlation between inflammatory activity and T1ρ values (r = 0.520; 95% CI 0.158-0.807; P = 0.013). T1ρ imaging has potential for liver fibrosis detection and staging with good diagnostic capability similar to that of ultrasonography elastography.

  10. Modelling of an air-cooled two-stage Rankine cycle for electricity production

    International Nuclear Information System (INIS)

    Liu, Bo

    2014-01-01

    This work considers a two stage Rankine cycle architecture slightly different from a standard Rankine cycle for electricity generation. Instead of expanding the steam to extremely low pressure, the vapor leaves the turbine at a higher pressure then having a much smaller specific volume. It is thus possible to greatly reduce the size of the steam turbine. The remaining energy is recovered by a bottoming cycle using a working fluid which has a much higher density than the water steam. Thus, the turbines and heat exchangers are more compact; the turbine exhaust velocity loss is lower. This configuration enables to largely reduce the global size of the steam water turbine and facilitate the use of a dry cooling system. The main advantage of such an air cooled two stage Rankine cycle is the possibility to choose the installation site of a large or medium power plant without the need of a large and constantly available water source; in addition, as compared to water cooled cycles, the risk regarding future operations is reduced (climate conditions may affect water availability or temperature, and imply changes in the water supply regulatory rules). The concept has been investigated by EDF R and D. A 22 MW prototype was developed in the 1970's using ammonia as the working fluid of the bottoming cycle for its high density and high latent heat. However, this fluid is toxic. In order to search more suitable working fluids for the two stage Rankine cycle application and to identify the optimal cycle configuration, we have established a working fluid selection methodology. Some potential candidates have been identified. We have evaluated the performances of the two stage Rankine cycles operating with different working fluids in both design and off design conditions. For the most acceptable working fluids, components of the cycle have been sized. The power plant concept can then be evaluated on a life cycle cost basis. (author)

  11. Numerical simulation model of hyperacute/acute stage white matter infarction.

    Science.gov (United States)

    Sakai, Koji; Yamada, Kei; Oouchi, Hiroyuki; Nishimura, Tsunehiko

    2008-01-01

    Although previous studies have revealed the mechanisms of changes in diffusivity (apparent diffusion coefficient [ADC]) in acute brain infarction, changes in diffusion anisotropy (fractional anisotropy [FA]) in white matter have not been examined. We hypothesized that membrane permeability as well as axonal swelling play important roles, and we therefore constructed a simulation model using random walk simulation to replicate the diffusion of water molecules. We implemented a numerical diffusion simulation model of normal and infarcted human brains using C++ language. We constructed this 2-pool model using simple tubes aligned in a single direction. Random walk simulation diffused water. Axon diameters and membrane permeability were then altered in step-wise fashion. To estimate the effects of axonal swelling, axon diameters were changed from 6 to 10 microm. Membrane permeability was altered from 0% to 40%. Finally, both elements were combined to explain increasing FA in the hyperacute stage of white matter infarction. The simulation demonstrated that simple water shift into the intracellular space reduces ADC and increases FA, but not to the extent expected from actual human cases (ADC approximately 50%; FA approximately +20%). Similarly, membrane permeability alone was insufficient to explain this phenomenon. However, a combination of both factors successfully replicated changes in diffusivity indices. Both axonal swelling and reduced membrane permeability appear important in explaining changes in ADC and FA based on eigenvalues in hyperacute-stage white matter infarction.

  12. Modelling and Control of the Multi-Stage Cable Pulley-Driven Flexible-Joint Robot

    Directory of Open Access Journals (Sweden)

    Phongsaen Pitakwatchara

    2014-07-01

    Full Text Available This work is concerned with the task space impedance control of a robot driven through a multi-stage nonlinear flexible transmission system. Specifically, a two degrees-of-freedom cable pulley-driven flexible-joint robot is considered. Realistic modelling of the system is developed within the bond graph modelling framework. The model captures the nonlinear compliance behaviour of the multi-stage cable pulley transmission system, the spring effect of the augmented counterbalancing mechanism, the major loss throughout the system elements, and the typical inertial dynamics of the robot. Next, a task space impedance controller based on limited information about the angle and the current of the motors is designed. The motor current is used to infer the transmitted torque, by which the motor inertia may be modulated. The motor angle is employed to estimate the stationary distal robot link angle and the robot joint velocity. They are used in the controller to generate the desired damping force and to shape the potential energy of the flexible joint robot system to the desired configuration. Simulation and experimental results of the controlled system signify the competency of the proposed control law.

  13. Modeling the fine fragmentation following the triggering stage of a vapor explosion

    International Nuclear Information System (INIS)

    Darbord, I.

    1997-01-01

    In the frame of PWR severe accidents, where the core melt, this thesis studies one of the stages of an FCI (fuel coolant interaction) or vapor explosion. An FCI is a rapid evaporation of a coolant when it comes into contact with a hot liquid. More precisely, the subject of this study is the triggering stage of the FCI, when a fuel drop of diameter around one centimeter breaks up into many fragments, diameter of which is around a hundred micrometers. The model describes the cyclic collapse and growth of a vapor bubble around the fuel droplet and its fragmentation. The main features of the model are: - the destabilization of the film or the vapor bubble due to the growth of Rayleigh-Taylor instabilities (those form coolant jets that contact the fuel surface); - The mechanisms of fragmentation, following the contacts (in the case of entrapment of a certain amount of coolant in the fuel, the entrapped coolant evaporates violently after it has been heated to the homogeneous nucleation temperature); - the transient heat transfer from the fragments to the coolant and the elevated vapor production, which leads to an important expansion of the bubble (about this point, the cooling of the fragments has been described by a transient heat transfer coefficient linked to nucleate boiling). The results of the model show good agreement with experimental data. (Author)

  14. Maximum likelihood estimation of signal detection model parameters for the assessment of two-stage diagnostic strategies.

    Science.gov (United States)

    Lirio, R B; Dondériz, I C; Pérez Abalo, M C

    1992-08-01

    The methodology of Receiver Operating Characteristic curves based on the signal detection model is extended to evaluate the accuracy of two-stage diagnostic strategies. A computer program is developed for the maximum likelihood estimation of parameters that characterize the sensitivity and specificity of two-stage classifiers according to this extended methodology. Its use is briefly illustrated with data collected in a two-stage screening for auditory defects.

  15. A two-stage value chain model for vegetable marketing chain efficiency evaluation: A transaction cost approach

    OpenAIRE

    Lu Hualiang

    2006-01-01

    We applied a two-stage value chain model to investigate the effects of input application and occasional transaction costs on vegetable marketing chain efficiencies with a farm household-level data set. In the first stage, the production efficiencies with the combination of resource endowments, capital and managerial inputs, and production techniques were evaluated; then at the second stage, the marketing technical efficiencies were determined under the marketing value of the vegetables for th...

  16. Significant reduction of normal tissue dose by proton radiotherapy compared with three-dimensional conformal or intensity-modulated radiation therapy in Stage I or Stage III non-small-cell lung cancer

    International Nuclear Information System (INIS)

    Chang, Joe Y.; Zhang Xiaodong; Wang Xiaochun; Kang Yixiu; Riley, Beverly C.; Bilton, Stephen C.; Mohan, Radhe; Komaki, Ritsuko; Cox, James D.

    2006-01-01

    Purpose: To compare dose-volume histograms (DVH) in patients with non-small-cell lung cancer (NSCLC) treated by photon or proton radiotherapy. Methods and Materials: Dose-volume histograms were compared between photon, including three-dimensional conformal radiation therapy (3D-CRT), intensity-modulated radiation therapy (IMRT), and proton plans at doses of 66 Gy, 87.5 Gy in Stage I (n = 10) and 60-63 Gy, and 74 Gy in Stage III (n 15). Results: For Stage I, the mean total lung V5, V10, and V20 were 31.8%, 24.6%, and 15.8%, respectively, for photon 3D-CRT with 66 Gy, whereas they were 13.4%, 12.3%, and 10.9%, respectively, with proton with dose escalation to 87.5 cobalt Gray equivalents (CGE) (p = 0.002). For Stage III, the mean total lung V5, V10, and V20 were 54.1%, 46.9%, and 34.8%, respectively, for photon 3D-CRT with 63 Gy, whereas they were 39.7%, 36.6%, and 31.6%, respectively, for proton with dose escalation to 74 CGE (p = 0.002). In all cases, the doses to lung, spinal cord, heart, esophagus, and integral dose were lower with proton therapy even compared with IMRT. Conclusions: Proton treatment appears to reduce dose to normal tissues significantly, even with dose escalation, compared with standard-dose photon therapy, either 3D-CRT or IMRT

  17. Statistical geological discrete fracture network model. Forsmark modelling stage 2.2

    International Nuclear Information System (INIS)

    Fox, Aaron; La Pointe, Paul; Simeonov, Assen; Hermanson, Jan; Oehman, Johan

    2007-11-01

    The Swedish Nuclear Fuel and Waste Management Company (SKB) is performing site characterization at two different locations, Forsmark and Laxemar, in order to locate a site for a final geologic repository for spent nuclear fuel. The program is built upon the development of Site Descriptive Models (SDMs) at specific timed data freezes. Each SDM is formed from discipline-specific reports from across the scientific spectrum. This report describes the methods, analyses, and conclusions of the geological modeling team with respect to a geological and statistical model of fractures and minor deformation zones (henceforth referred to as the geological DFN), version 2.2, at the Forsmark site. The geological DFN builds upon the work of other geological modelers, including the deformation zone (DZ), rock domain (RD), and fracture domain (FD) models. The geological DFN is a statistical model for stochastically simulating rock fractures and minor deformation zones as a scale of less than 1,000 m (the lower cut-off of the DZ models). The geological DFN is valid within four specific fracture domains inside the local model region, and encompassing the candidate volume at Forsmark: FFM01, FFM02, FFM03, and FFM06. The models are build using data from detailed surface outcrop maps and the cored borehole record at Forsmark. The conceptual model for the Forsmark 2.2 geological revolves around the concept of orientation sets; for each fracture domain, other model parameters such as size and intensity are tied to the orientation sets. Two classes of orientation sets were described; Global sets, which are encountered everywhere in the model region, and Local sets, which represent highly localized stress environments. Orientation sets were described in terms of their general cardinal direction (NE, NW, etc). Two alternatives are presented for fracture size modeling: - the tectonic continuum approach (TCM, TCMF) described by coupled size-intensity scaling following power law distributions

  18. Statistical geological discrete fracture network model. Forsmark modelling stage 2.2

    Energy Technology Data Exchange (ETDEWEB)

    Fox, Aaron; La Pointe, Paul [Golder Associates Inc (United States); Simeonov, Assen [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden); Hermanson, Jan; Oehman, Johan [Golder Associates AB, Stockholm (Sweden)

    2007-11-15

    The Swedish Nuclear Fuel and Waste Management Company (SKB) is performing site characterization at two different locations, Forsmark and Laxemar, in order to locate a site for a final geologic repository for spent nuclear fuel. The program is built upon the development of Site Descriptive Models (SDMs) at specific timed data freezes. Each SDM is formed from discipline-specific reports from across the scientific spectrum. This report describes the methods, analyses, and conclusions of the geological modeling team with respect to a geological and statistical model of fractures and minor deformation zones (henceforth referred to as the geological DFN), version 2.2, at the Forsmark site. The geological DFN builds upon the work of other geological modelers, including the deformation zone (DZ), rock domain (RD), and fracture domain (FD) models. The geological DFN is a statistical model for stochastically simulating rock fractures and minor deformation zones as a scale of less than 1,000 m (the lower cut-off of the DZ models). The geological DFN is valid within four specific fracture domains inside the local model region, and encompassing the candidate volume at Forsmark: FFM01, FFM02, FFM03, and FFM06. The models are build using data from detailed surface outcrop maps and the cored borehole record at Forsmark. The conceptual model for the Forsmark 2.2 geological revolves around the concept of orientation sets; for each fracture domain, other model parameters such as size and intensity are tied to the orientation sets. Two classes of orientation sets were described; Global sets, which are encountered everywhere in the model region, and Local sets, which represent highly localized stress environments. Orientation sets were described in terms of their general cardinal direction (NE, NW, etc). Two alternatives are presented for fracture size modeling: - the tectonic continuum approach (TCM, TCMF) described by coupled size-intensity scaling following power law distributions

  19. A stage structure pest management model with impulsive state feedback control

    Science.gov (United States)

    Pang, Guoping; Chen, Lansun; Xu, Weijian; Fu, Gang

    2015-06-01

    A stage structure pest management model with impulsive state feedback control is investigated. We get the sufficient condition for the existence of the order-1 periodic solution by differential equation geometry theory and successor function. Further, we obtain a new judgement method for the stability of the order-1 periodic solution of the semi-continuous systems by referencing the stability analysis for limit cycles of continuous systems, which is different from the previous method of analog of Poincarè criterion. Finally, we analyze numerically the theoretical results obtained.

  20. EGovernment Stage Model: Evaluating the Rate of Web Development Progress of Government Websites in Saudi Arabia

    OpenAIRE

    Osama Alfarraj; Steve Drew; Rayed Abdullah AlGhamdi

    2011-01-01

    This paper contributes to the issue of eGovernment implementation in Saudi Arabia by discussing the current situation of ministry websites. It evaluates the rate of web development progress of vital government websites in Saudi Arabia using the eGovernment stage model. In 2010, Saudi Arabia ranked 58th in the world and 4th in the Gulf region in eGovernment readiness according to United Nations reports. In particular, Saudi Arabia has ranked 75th worldwide for its online service index and its ...

  1. Dynamic modeling of a three-stage low-temperature ethanol reformer for fuel cell application

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, Vanesa M; Serra, Maria [Institut de Robotica i Informatica Industrial (CSIC-UPC), Llorens i Artigas 4-6, 08028 Barcelona (Spain); Lopez, Eduardo; Llorca, Jordi [Institut de Tecniques Energetiques, Universitat Politecnica de Catalunya, Diagonal 647, ed. ETSEIB, 08028 Barcelona (Spain)

    2009-07-01

    A low-temperature ethanol reformer based on a cobalt catalyst for the production of hydrogen has been designed aiming the feed of a fuel cell for an autonomous low-scale power production unit. The reformer comprises three stages: ethanol dehydrogenation to acetaldehyde and hydrogen over SnO{sub 2} followed by acetaldehyde steam reforming over Co(Fe)/ZnO catalyst and water gas shift reaction. Kinetic data have been obtained under different experimental conditions and a dynamic model has been developed for a tubular reformer loaded with catalytic monoliths for the production of the hydrogen required to feed a 1 kW PEMFC. (author)

  2. Comparing staging by positron emission tomography with contrast-enhanced computed tomography and by pathology in head and neck squamous cell carcinoma.

    Science.gov (United States)

    Qualliotine, J R; Mydlarz, W K; Chan, J Y K; Zhou, X; Wang, H; Agrawal, N

    2015-12-01

    This study aimed to evaluate the ability of positron emission tomography with contrast-enhanced computed tomography to correctly stage head and neck squamous cell carcinomas, in comparison with pathological staging. Positron emission tomography computed tomography was used to determine the tumour-node-metastasis classification and overall cancer stage in 85 head and neck squamous cell carcinoma patients who underwent pre-operative imaging using this modality and primary surgery between July 2010 and January 2013. Staging by positron emission tomography computed tomography was retrospectively compared with staging using pathological specimens. Agreement between imaging stage and pathological stage was examined by univariate and multivariate analysis both overall and for each primary tumour site. This imaging modality was 87.5 per cent sensitive and 44.8 per cent specific in identifying regional cervical metastases, and had false positive and false negative rates of 18.8 per cent and 8.2 per cent, respectively. The positive predictive and negative predictive values were 75.4 per cent and 65.0 per cent, respectively. Univariate and multivariate analyses revealed a significant agreement between positron emission tomography computed tomography and pathological node classification in older patients and for the oral cavity primary tumour site. There was significant agreement between both methods in the overall classification only for tumours classified as T3 or greater. Positron emission tomography computed tomography should be used with caution for the pre-operative staging of head and neck cancers because of its high false positive and false negative rates.

  3. Mathematical modelling of the maternal cardiovascular system in the three stages of pregnancy.

    Science.gov (United States)

    Corsini, Chiara; Cervi, Elena; Migliavacca, Francesco; Schievano, Silvia; Hsia, Tain-Yen; Pennati, Giancarlo

    2017-09-01

    In this study, a mathematical model of the female circulation during pregnancy is presented in order to investigate the hemodynamic response to the cardiovascular changes associated with each trimester of pregnancy. First, a preliminary lumped parameter model of the circulation of a non-pregnant female was developed, including the heart, the systemic circulation with a specific block for the uterine district and the pulmonary circulation. The model was first tested at rest; then heart rate and vascular resistances were individually varied to verify the correct response to parameter alterations characterising pregnancy. In order to simulate hemodynamics during pregnancy at each trimester, the main changes applied to the model consisted in reducing vascular resistances, and simultaneously increasing heart rate and ventricular wall volumes. Overall, reasonable agreement was found between model outputs and in vivo data, with the trends of the cardiac hemodynamic quantities suggesting correct response of the heart model throughout pregnancy. Results were reported for uterine hemodynamics, with flow tracings resembling typical Doppler velocity waveforms at each stage, including pulsatility indexes. Such a model may be used to explore the changes that happen during pregnancy in female with cardiovascular diseases. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

  4. Comparative analysis of used car price evaluation models

    Science.gov (United States)

    Chen, Chuancan; Hao, Lulu; Xu, Cong

    2017-05-01

    An accurate used car price evaluation is a catalyst for the healthy development of used car market. Data mining has been applied to predict used car price in several articles. However, little is studied on the comparison of using different algorithms in used car price estimation. This paper collects more than 100,000 used car dealing records throughout China to do empirical analysis on a thorough comparison of two algorithms: linear regression and random forest. These two algorithms are used to predict used car price in three different models: model for a certain car make, model for a certain car series and universal model. Results show that random forest has a stable but not ideal effect in price evaluation model for a certain car make, but it shows great advantage in the universal model compared with linear regression. This indicates that random forest is an optimal algorithm when handling complex models with a large number of variables and samples, yet it shows no obvious advantage when coping with simple models with less variables.

  5. A microbial model of economic trading and comparative advantage.

    Science.gov (United States)

    Enyeart, Peter J; Simpson, Zachary B; Ellington, Andrew D

    2015-01-07

    The economic theory of comparative advantage postulates that beneficial trading relationships can be arrived at by two self-interested entities producing the same goods as long as they have opposing relative efficiencies in producing those goods. The theory predicts that upon entering trade, in order to maximize consumption both entities will specialize in producing the good they can produce at higher efficiency, that the weaker entity will specialize more completely than the stronger entity, and that both will be able to consume more goods as a result of trade than either would be able to alone. We extend this theory to the realm of unicellular organisms by developing mathematical models of genetic circuits that allow trading of a common good (specifically, signaling molecules) required for growth in bacteria in order to demonstrate comparative advantage interactions. In Conception 1, the experimenter controls production rates via exogenous inducers, allowing exploration of the parameter space of specialization. In Conception 2, the circuits self-regulate via feedback mechanisms. Our models indicate that these genetic circuits can demonstrate comparative advantage, and that cooperation in such a manner is particularly favored under stringent external conditions and when the cost of production is not overly high. Further work could involve implementing the models in living bacteria and searching for naturally occurring cooperative relationships between bacteria that conform to the principles of comparative advantage. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  6. Three stage maturity model in SME’s toward industry 4.0

    Energy Technology Data Exchange (ETDEWEB)

    Ganzarain, J.; Errasti, N.

    2016-07-01

    To address the challenges regarding the concept of Industry 4.0 and the diversification methodology and based on the strategic guidance towards Industry 4.0, we propose a process model as a guiding framework for Industry 4.0 collaborative diversification vision, strategy and action building. In this paper we suggest a stage process model to guide and train companies to identify new opportunities for diversification within Industry 4.0. Systematically carrying out the stages will take a company to their individual specific vision and collaborative vision between different companies in the Industry 4.0 scenario. Design/methodology/approach: This new collaborative diversification methodology involves industry within the pilot program; from the diversification and capacity assessment analysis of the companys profile, skills and technologies that dominates, to identify the diversification opportunity map and its business modeling within the Industry 4.0 paradigm. Findings: The application of maturity models to the Industry 4.0 may help organizations to integrate this methodology into their culture. Results show a real need for guided support in developing a company-specific Industry 4.0 vision and specific project planning. Originality/value: Industry 4.0 promotes a vision where recent developments in information technology are expected to enable entirely new forms of cooperative engineering and manufacturing. The vision of industry 4.0 describes a whole new approach to business operations, and especially the production industries. To address the challenges regarding the concept of Industry 4.0 and the diversification methodology discussed above, and based on the strategic guidance towards Industry 4.0, we propose a unique process model as a guiding framework for Industry 4.0 collaborative diversification vision, strategy and action building.

  7. Three stage maturity model in SME’s toward industry 4.0

    International Nuclear Information System (INIS)

    Ganzarain, J.; Errasti, N.

    2016-01-01

    To address the challenges regarding the concept of Industry 4.0 and the diversification methodology and based on the strategic guidance towards Industry 4.0, we propose a process model as a guiding framework for Industry 4.0 collaborative diversification vision, strategy and action building. In this paper we suggest a stage process model to guide and train companies to identify new opportunities for diversification within Industry 4.0. Systematically carrying out the stages will take a company to their individual specific vision and collaborative vision between different companies in the Industry 4.0 scenario. Design/methodology/approach: This new collaborative diversification methodology involves industry within the pilot program; from the diversification and capacity assessment analysis of the companys profile, skills and technologies that dominates, to identify the diversification opportunity map and its business modeling within the Industry 4.0 paradigm. Findings: The application of maturity models to the Industry 4.0 may help organizations to integrate this methodology into their culture. Results show a real need for guided support in developing a company-specific Industry 4.0 vision and specific project planning. Originality/value: Industry 4.0 promotes a vision where recent developments in information technology are expected to enable entirely new forms of cooperative engineering and manufacturing. The vision of industry 4.0 describes a whole new approach to business operations, and especially the production industries. To address the challenges regarding the concept of Industry 4.0 and the diversification methodology discussed above, and based on the strategic guidance towards Industry 4.0, we propose a unique process model as a guiding framework for Industry 4.0 collaborative diversification vision, strategy and action building.

  8. Chemical analysis of simulated high level waste glasses to support stage III sulfate solubility modeling

    Energy Technology Data Exchange (ETDEWEB)

    Fox, K. M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-03-17

    The U.S. Department of Energy (DOE), Office of Environmental Management (EM) is sponsoring an international, collaborative project to develop a fundamental model for sulfate solubility in nuclear waste glass. The solubility of sulfate has a significant impact on the achievable waste loading for nuclear waste forms within the DOE complex. These wastes can contain relatively high concentrations of sulfate, which has low solubility in borosilicate glass. This is a significant issue for low-activity waste (LAW) glass and is projected to have a major impact on the Hanford Tank Waste Treatment and Immobilization Plant (WTP). Sulfate solubility has also been a limiting factor for recent high level waste (HLW) sludge processed at the Savannah River Site (SRS) Defense Waste Processing Facility (DWPF). The low solubility of sulfate in glass, along with melter and off-gas corrosion constraints, dictate that the waste be blended with lower sulfate concentration waste sources or washed to remove sulfate prior to vitrification. The development of enhanced borosilicate glass compositions with improved sulfate solubility will allow for higher waste loadings and accelerate mission completion.The objective of the current scope being pursued by SHU is to mature the sulfate solubility model to the point where it can be used to guide glass composition development for DWPF and WTP, allowing for enhanced waste loadings and waste throughput at these facilities. A series of targeted glass compositions was selected to resolve data gaps in the model and is identified as Stage III. SHU fabricated these glasses and sent samples to SRNL for chemical composition analysis. SHU will use the resulting data to enhance the sulfate solubility model and resolve any deficiencies. In this report, SRNL provides chemical analyses for the Stage III, simulated HLW glasses fabricated by SHU in support of the sulfate solubility model development.

  9. ALPPS Improves Resectability Compared With Conventional Two-stage Hepatectomy in Patients With Advanced Colorectal Liver Metastasis

    DEFF Research Database (Denmark)

    Sandström, Per; Røsok, Bård I; Sparrelid, Ernesto

    2018-01-01

    resection offers the only chance of a cure for patients with metastatic colorectal cancer. Patients with colorectal liver metastasis (CRLM) and an insufficient future liver remnant (FLR) volume are traditionally treated with chemotherapy with portal vein embolization or ligation followed by hepatectomy (TSH...... of patients completing both stages of the treatment. Secondary outcomes were complications, radicality, and 90-day mortality measured from the final intervention. RESULTS: Baseline characteristics, besides body mass index, did not differ between the groups. The RR was 92% [95% confidence interval (CI) 84...

  10. Spatial Distribution of Hydrologic Ecosystem Service Estimates: Comparing Two Models

    Science.gov (United States)

    Dennedy-Frank, P. J.; Ghile, Y.; Gorelick, S.; Logsdon, R. A.; Chaubey, I.; Ziv, G.

    2014-12-01

    We compare estimates of the spatial distribution of water quantity provided (annual water yield) from two ecohydrologic models: the widely-used Soil and Water Assessment Tool (SWAT) and the much simpler water models from the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) toolbox. These two models differ significantly in terms of complexity, timescale of operation, effort, and data required for calibration, and so are often used in different management contexts. We compare two study sites in the US: the Wildcat Creek Watershed (2083 km2) in Indiana, a largely agricultural watershed in a cold aseasonal climate, and the Upper Upatoi Creek Watershed (876 km2) in Georgia, a mostly forested watershed in a temperate aseasonal climate. We evaluate (1) quantitative estimates of water yield to explore how well each model represents this process, and (2) ranked estimates of water yield to indicate how useful the models are for management purposes where other social and financial factors may play significant roles. The SWAT and InVEST models provide very similar estimates of the water yield of individual subbasins in the Wildcat Creek Watershed (Pearson r = 0.92, slope = 0.89), and a similar ranking of the relative water yield of those subbasins (Spearman r = 0.86). However, the two models provide relatively different estimates of the water yield of individual subbasins in the Upper Upatoi Watershed (Pearson r = 0.25, slope = 0.14), and very different ranking of the relative water yield of those subbasins (Spearman r = -0.10). The Upper Upatoi watershed has a significant baseflow contribution due to its sandy, well-drained soils. InVEST's simple seasonality terms, which assume no change in storage over the time of the model run, may not accurately estimate water yield processes when baseflow provides such a strong contribution. Our results suggest that InVEST users take care in situations where storage changes are significant.

  11. Modeling of filling gas centrifuge cascade for nickel isotope separation by feed flow input to different stages

    Directory of Open Access Journals (Sweden)

    Orlov Alexey A.

    2017-01-01

    Full Text Available The article presents results of research filling gas centrifuge cascade by process gas fed into different stages. The modeling of filling cascade was done for nickel isotope separation. Analysis of the research results shows that nickel isotope concentrations of light and heavy fraction flows after filling cascade depend on feed stage number.

  12. Validated Competing Event Model for the Stage I-II Endometrial Cancer Population

    Energy Technology Data Exchange (ETDEWEB)

    Carmona, Ruben; Gulaya, Sachin; Murphy, James D. [Department of Radiation Medicine and Applied Sciences, University of California San Diego, La Jolla, California (United States); Rose, Brent S. [Harvard Radiation Oncology Program, Harvard Medical School, Boston, Massachusetts (United States); Wu, John; Noticewala, Sonal [Department of Radiation Medicine and Applied Sciences, University of California San Diego, La Jolla, California (United States); McHale, Michael T. [Department of Reproductive Medicine, Division of Gynecologic Oncology, University of California San Diego, La Jolla, California (United States); Yashar, Catheryn M. [Department of Radiation Medicine and Applied Sciences, University of California San Diego, La Jolla, California (United States); Vaida, Florin [Department of Family and Preventive Medicine, Biostatistics and Bioinformatics, University of California San Diego Medical Center, San Diego, California (United States); Mell, Loren K., E-mail: lmell@ucsd.edu [Department of Radiation Medicine and Applied Sciences, University of California San Diego, La Jolla, California (United States)

    2014-07-15

    Purpose/Objectives(s): Early-stage endometrial cancer patients are at higher risk of noncancer mortality than of cancer mortality. Competing event models incorporating comorbidity could help identify women most likely to benefit from treatment intensification. Methods and Materials: 67,397 women with stage I-II endometrioid adenocarcinoma after total hysterectomy diagnosed from 1988 to 2009 were identified in Surveillance, Epidemiology, and End Results (SEER) and linked SEER-Medicare databases. Using demographic and clinical information, including comorbidity, we sought to develop and validate a risk score to predict the incidence of competing mortality. Results: In the validation cohort, increasing competing mortality risk score was associated with increased risk of noncancer mortality (subdistribution hazard ratio [SDHR], 1.92; 95% confidence interval [CI], 1.60-2.30) and decreased risk of endometrial cancer mortality (SDHR, 0.61; 95% CI, 0.55-0.78). Controlling for other variables, Charlson Comorbidity Index (CCI) = 1 (SDHR, 1.62; 95% CI, 1.45-1.82) and CCI >1 (SDHR, 3.31; 95% CI, 2.74-4.01) were associated with increased risk of noncancer mortality. The 10-year cumulative incidences of competing mortality within low-, medium-, and high-risk strata were 27.3% (95% CI, 25.2%-29.4%), 34.6% (95% CI, 32.5%-36.7%), and 50.3% (95% CI, 48.2%-52.6%), respectively. With increasing competing mortality risk score, we observed a significant decline in omega (ω), indicating a diminishing likelihood of benefit from treatment intensification. Conclusion: Comorbidity and other factors influence the risk of competing mortality among patients with early-stage endometrial cancer. Competing event models could improve our ability to identify patients likely to benefit from treatment intensification.

  13. Validated Competing Event Model for the Stage I-II Endometrial Cancer Population

    International Nuclear Information System (INIS)

    Carmona, Ruben; Gulaya, Sachin; Murphy, James D.; Rose, Brent S.; Wu, John; Noticewala, Sonal; McHale, Michael T.; Yashar, Catheryn M.; Vaida, Florin; Mell, Loren K.

    2014-01-01

    Purpose/Objectives(s): Early-stage endometrial cancer patients are at higher risk of noncancer mortality than of cancer mortality. Competing event models incorporating comorbidity could help identify women most likely to benefit from treatment intensification. Methods and Materials: 67,397 women with stage I-II endometrioid adenocarcinoma after total hysterectomy diagnosed from 1988 to 2009 were identified in Surveillance, Epidemiology, and End Results (SEER) and linked SEER-Medicare databases. Using demographic and clinical information, including comorbidity, we sought to develop and validate a risk score to predict the incidence of competing mortality. Results: In the validation cohort, increasing competing mortality risk score was associated with increased risk of noncancer mortality (subdistribution hazard ratio [SDHR], 1.92; 95% confidence interval [CI], 1.60-2.30) and decreased risk of endometrial cancer mortality (SDHR, 0.61; 95% CI, 0.55-0.78). Controlling for other variables, Charlson Comorbidity Index (CCI) = 1 (SDHR, 1.62; 95% CI, 1.45-1.82) and CCI >1 (SDHR, 3.31; 95% CI, 2.74-4.01) were associated with increased risk of noncancer mortality. The 10-year cumulative incidences of competing mortality within low-, medium-, and high-risk strata were 27.3% (95% CI, 25.2%-29.4%), 34.6% (95% CI, 32.5%-36.7%), and 50.3% (95% CI, 48.2%-52.6%), respectively. With increasing competing mortality risk score, we observed a significant decline in omega (ω), indicating a diminishing likelihood of benefit from treatment intensification. Conclusion: Comorbidity and other factors influence the risk of competing mortality among patients with early-stage endometrial cancer. Competing event models could improve our ability to identify patients likely to benefit from treatment intensification

  14. Stage-dependent analgesia of electro-acupuncture in a mouse model of cutaneous cancer pain.

    Science.gov (United States)

    Mao-Ying, Qi-Liang; Cui, Ke-Mi; Liu, Qiong; Dong, Zhi-Qiang; Wang, Wei; Wang, Jun; Sha, Hong; Wu, Gen-Cheng; Wang, Yan-Qing

    2006-11-01

    Acupuncture is one of the most effective alternative medical treatments in pain management with the advantages of simple application, low cost and minimal side effects. However its scientific evidence and laws of action are not very clear in cancer pain relieving. The aim of this study was to examine the immediate and therapeutic anti-hyperalgesic effect of electro-acupuncture (EA) on a mouse model of cutaneous cancer pain. B16-BL6 melanoma cells were inoculated into the plantar region of unilateral hind paw and the thermal hyperalgesia was measured by using radiant heat test and hot plate test. C57BL/6 mice showed moderate and marked hyperalgesia during days 8-12 and from day 14 after the orthotopic inoculation of B16-BL6 melanoma cells into the hind paw. Single EA on day 8 after inoculation showed significant analgesic effect immediately after the treatment, the analgesic effect reached its maximum within 15-30min and declined to its minimum at 50min after EA treatment. Single EA treatment on day 20 showed no significant analgesic effect; Repeated EA treatments (started from day 8, once every other day) showed therapeutic analgesic effect, while it showed no therapeutic effect when started from day 16, a relatively late stage of this cancer pain model. The results demonstrated that EA had anti-hyperalgesic effect on early stage of cutaneous cancer pain but not on late stage. These results indicated a tight correlation of EA anti-hyperalgesic effects with the time window of cancer pain.

  15. Use of a high resolution melting (HRM assay to compare gag, pol, and env diversity in adults with different stages of HIV infection.

    Directory of Open Access Journals (Sweden)

    Matthew M Cousins

    Full Text Available Cross-sectional assessment of HIV incidence relies on laboratory methods to discriminate between recent and non-recent HIV infection. Because HIV diversifies over time in infected individuals, HIV diversity may serve as a biomarker for assessing HIV incidence. We used a high resolution melting (HRM diversity assay to compare HIV diversity in adults with different stages of HIV infection. This assay provides a single numeric HRM score that reflects the level of genetic diversity of HIV in a sample from an infected individual.HIV diversity was measured in 203 adults: 20 with acute HIV infection (RNA positive, antibody negative, 116 with recent HIV infection (tested a median of 189 days after a previous negative HIV test, range 14-540 days, and 67 with non-recent HIV infection (HIV infected >2 years. HRM scores were generated for two regions in gag, one region in pol, and three regions in env.Median HRM scores were higher in non-recent infection than in recent infection for all six regions tested. In multivariate models, higher HRM scores in three of the six regions were independently associated with non-recent HIV infection.The HRM diversity assay provides a simple, scalable method for measuring HIV diversity. HRM scores, which reflect the genetic diversity in a viral population, may be useful biomarkers for evaluation of HIV incidence, particularly if multiple regions of the HIV genome are examined.

  16. Use of a high resolution melting (HRM) assay to compare gag, pol, and env diversity in adults with different stages of HIV infection.

    Science.gov (United States)

    Cousins, Matthew M; Laeyendecker, Oliver; Beauchamp, Geetha; Brookmeyer, Ronald; Towler, William I; Hudelson, Sarah E; Khaki, Leila; Koblin, Beryl; Chesney, Margaret; Moore, Richard D; Kelen, Gabor D; Coates, Thomas; Celum, Connie; Buchbinder, Susan P; Seage, George R; Quinn, Thomas C; Donnell, Deborah; Eshleman, Susan H

    2011-01-01

    Cross-sectional assessment of HIV incidence relies on laboratory methods to discriminate between recent and non-recent HIV infection. Because HIV diversifies over time in infected individuals, HIV diversity may serve as a biomarker for assessing HIV incidence. We used a high resolution melting (HRM) diversity assay to compare HIV diversity in adults with different stages of HIV infection. This assay provides a single numeric HRM score that reflects the level of genetic diversity of HIV in a sample from an infected individual. HIV diversity was measured in 203 adults: 20 with acute HIV infection (RNA positive, antibody negative), 116 with recent HIV infection (tested a median of 189 days after a previous negative HIV test, range 14-540 days), and 67 with non-recent HIV infection (HIV infected >2 years). HRM scores were generated for two regions in gag, one region in pol, and three regions in env. Median HRM scores were higher in non-recent infection than in recent infection for all six regions tested. In multivariate models, higher HRM scores in three of the six regions were independently associated with non-recent HIV infection. The HRM diversity assay provides a simple, scalable method for measuring HIV diversity. HRM scores, which reflect the genetic diversity in a viral population, may be useful biomarkers for evaluation of HIV incidence, particularly if multiple regions of the HIV genome are examined.

  17. Evaluating the number of stages in development of squamous cell and adenocarcinomas across cancer sites using human population-based cancer modeling.

    Directory of Open Access Journals (Sweden)

    Julia Kravchenko

    Full Text Available BACKGROUND: Adenocarcinomas (ACs and squamous cell carcinomas (SCCs differ by clinical and molecular characteristics. We evaluated the characteristics of carcinogenesis by modeling the age patterns of incidence rates of ACs and SCCs of various organs to test whether these characteristics differed between cancer subtypes. METHODOLOGY/PRINCIPAL FINDINGS: Histotype-specific incidence rates of 14 ACs and 12 SCCs from the SEER Registry (1973-2003 were analyzed by fitting several biologically motivated models to observed age patterns. A frailty model with the Weibull baseline was applied to each age pattern to provide the best fit for the majority of cancers. For each cancer, model parameters describing the underlying mechanisms of carcinogenesis including the number of stages occurring during an individual's life and leading to cancer (m-stages were estimated. For sensitivity analysis, the age-period-cohort model was incorporated into the carcinogenesis model to test the stability of the estimates. For the majority of studied cancers, the numbers of m-stages were similar within each group (i.e., AC and SCC. When cancers of the same organs were compared (i.e., lung, esophagus, and cervix uteri, the number of m-stages were more strongly associated with the AC/SCC subtype than with the organ: 9.79±0.09, 9.93±0.19 and 8.80±0.10 for lung, esophagus, and cervical ACs, compared to 11.41±0.10, 12.86±0.34 and 12.01±0.51 for SCCs of the respective organs (p<0.05 between subtypes. Most SCCs had more than ten m-stages while ACs had fewer than ten m-stages. The sensitivity analyses of the model parameters demonstrated the stability of the obtained estimates. CONCLUSIONS/SIGNIFICANCE: A model containing parameters capable of representing the number of stages of cancer development occurring during individual's life was applied to the large population data on incidence of ACs and SCCs. The model revealed that the number of m-stages differed by cancer subtype

  18. Evaluating the number of stages in development of squamous cell and adenocarcinomas across cancer sites using human population-based cancer modeling.

    Science.gov (United States)

    Kravchenko, Julia; Akushevich, Igor; Abernethy, Amy P; Lyerly, H Kim

    2012-01-01

    Adenocarcinomas (ACs) and squamous cell carcinomas (SCCs) differ by clinical and molecular characteristics. We evaluated the characteristics of carcinogenesis by modeling the age patterns of incidence rates of ACs and SCCs of various organs to test whether these characteristics differed between cancer subtypes. Histotype-specific incidence rates of 14 ACs and 12 SCCs from the SEER Registry (1973-2003) were analyzed by fitting several biologically motivated models to observed age patterns. A frailty model with the Weibull baseline was applied to each age pattern to provide the best fit for the majority of cancers. For each cancer, model parameters describing the underlying mechanisms of carcinogenesis including the number of stages occurring during an individual's life and leading to cancer (m-stages) were estimated. For sensitivity analysis, the age-period-cohort model was incorporated into the carcinogenesis model to test the stability of the estimates. For the majority of studied cancers, the numbers of m-stages were similar within each group (i.e., AC and SCC). When cancers of the same organs were compared (i.e., lung, esophagus, and cervix uteri), the number of m-stages were more strongly associated with the AC/SCC subtype than with the organ: 9.79±0.09, 9.93±0.19 and 8.80±0.10 for lung, esophagus, and cervical ACs, compared to 11.41±0.10, 12.86±0.34 and 12.01±0.51 for SCCs of the respective organs (p<0.05 between subtypes). Most SCCs had more than ten m-stages while ACs had fewer than ten m-stages. The sensitivity analyses of the model parameters demonstrated the stability of the obtained estimates. A model containing parameters capable of representing the number of stages of cancer development occurring during individual's life was applied to the large population data on incidence of ACs and SCCs. The model revealed that the number of m-stages differed by cancer subtype being more strongly associated with ACs/SCCs histotype than with organ/site.

  19. Comparative modeling of InP solar cell structures

    Science.gov (United States)

    Jain, R. K.; Weinberg, I.; Flood, D. J.

    1991-01-01

    The comparative modeling of p(+)n and n(+)p indium phosphide solar cell structures is studied using a numerical program PC-1D. The optimal design study has predicted that the p(+)n structure offers improved cell efficiencies as compared to n(+)p structure, due to higher open-circuit voltage. The various cell material and process parameters to achieve the maximum cell efficiencies are reported. The effect of some of the cell parameters on InP cell I-V characteristics was studied. The available radiation resistance data on n(+)p and p(+)p InP solar cells are also critically discussed.

  20. Comparing the Effects of Symbiotic Algae (Symbiodinium) Clades C1 and D on Early Growth Stages of Acropora tenuis

    Science.gov (United States)

    Yuyama, Ikuko; Higuchi, Tomihiko

    2014-01-01

    Reef-building corals switch endosymbiotic algae of the genus Symbiodinium during their early growth stages and during bleaching events. Clade C Symbiodinium algae are dominant in corals, although other clades — including A and D — have also been commonly detected in juvenile Acroporid corals. Previous studies have been reported that only molecular data of Symbiodinium clade were identified within field corals. In this study, we inoculated aposymbiotic juvenile polyps with cultures of clades C1 and D Symbiodinium algae, and investigated the different effect of these two clades of Symbiodinium on juvenile polyps. Our results showed that clade C1 algae did not grow, while clade D algae grew rapidly during the first 2 months after inoculation. Polyps associated with clade C1 algae exhibited bright green fluorescence across the body and tentacles after inoculation. The growth rate of polyp skeletons was lower in polyps associated with clade C1 algae than those associated with clade D algae. On the other hand, antioxidant activity (catalase) of corals was not significantly different between corals with clade C1 and clade D algae. Our results suggested that clade D Symbiodinium algae easily form symbiotic relationships with corals and that these algae could contribute to coral growth in early symbiosis stages. PMID:24914677

  1. THE IMPLEMENTATION OF THE 5E MODEL STAGES TO BUILD STUDENTS’ VOCABULARY

    Directory of Open Access Journals (Sweden)

    Muhammad Rochman

    2015-12-01

    Full Text Available There are stages of human to learn something. In early ages, they will learn simplest things to the complicated ones. A learning process of human is started with and introductory and it tries to connect with their prior knowledge to the new one. Children begin to curious about what they want to know and start to make some questions about what they want to know. In the process of finding the answers of their own questions, they will interact with others and try to share the knowledge in this process. The result of this study illustrates that the implementation of the 5E model in teaching vocabulary that can enhance the students’ vocabulary achievement and successfully encourages them to actively and enthusiastically take part in the teaching-learning process of vocabulary through group task. Keywords: implementation, vocabulary, vocabulary course, and 5E model

  2. Delimitation of the user in the creation stages, modeling and prototyping of the clothing product

    Directory of Open Access Journals (Sweden)

    Elen Makara

    2016-12-01

    Full Text Available Because of complaints of clothes that do not fit well and bother, or even the difficulty of acquiring a suitable outfit for an occasion, to the clothing industry may be failing to consider the user in developing their products. The aim of this paper was to determine whether the steps for creating, modeling and prototyping of garment products the user is being considered, as for a design project is right to consider it at all stages of development. For this a literature review and interviews with professionals was held. With the results we can see the difficulty that professionals have to define the public to create the pieces. We also found that most professionals understand the importance of measures table however end up adjusting the empirically, and the realization of prototype testing many choose models that does not match the reality of the public company

  3. Elastic models: a comparative study applied to retinal images.

    Science.gov (United States)

    Karali, E; Lambropoulou, S; Koutsouris, D

    2011-01-01

    In this work various methods of parametric elastic models are compared, namely the classical snake, the gradient vector field snake (GVF snake) and the topology-adaptive snake (t-snake), as well as the method of self-affine mapping system as an alternative to elastic models. We also give a brief overview of the methods used. The self-affine mapping system is implemented using an adapting scheme and minimum distance as optimization criterion, which is more suitable for weak edges detection. All methods are applied to glaucomatic retinal images with the purpose of segmenting the optical disk. The methods are compared in terms of segmentation accuracy and speed, as these are derived from cross-correlation coefficients between real and algorithm extracted contours and segmentation time, respectively. As a result, the method of self-affine mapping system presents adequate segmentation time and segmentation accuracy, and significant independence from initialization.

  4. Comparative assessment of PV plant performance models considering climate effects

    DEFF Research Database (Denmark)

    Tina, Giuseppe; Ventura, Cristina; Sera, Dezso

    2017-01-01

    . The methodological approach is based on comparative tests of the analyzed models applied to two PV plants installed respectively in north of Denmark (Aalborg) and in the south of Italy (Agrigento). The different ambient, operating and installation conditions allow to understand how these factors impact the precision...... the performance of the studied PV plants with others, the efficiency of the systems has been estimated by both conventional Performance Ratio and Corrected Performance Ratio...

  5. New tips for structure prediction by comparative modeling

    OpenAIRE

    Rayan, Anwar

    2009-01-01

    Comparative modelling is utilized to predict the 3-dimensional conformation of a given protein (target) based on its sequence alignment to experimentally determined protein structure (template). The use of such technique is already rewarding and increasingly widespread in biological research and drug development. The accuracy of the predictions as commonly accepted depends on the score of sequence identity of the target protein to the template. To assess the relationship between sequence iden...

  6. Comparing Neural Networks and ARMA Models in Artificial Stock Market

    Czech Academy of Sciences Publication Activity Database

    Krtek, Jiří; Vošvrda, Miloslav

    2011-01-01

    Roč. 18, č. 28 (2011), s. 53-65 ISSN 1212-074X R&D Projects: GA ČR GD402/09/H045 Institutional research plan: CEZ:AV0Z10750506 Keywords : neural networks * vector ARMA * artificial market Subject RIV: AH - Economics http://library.utia.cas.cz/separaty/2011/E/krtek-comparing neural networks and arma models in artificial stock market.pdf

  7. Comparing modelling techniques when designing VPH gratings for BigBOSS

    Science.gov (United States)

    Poppett, Claire; Edelstein, Jerry; Lampton, Michael; Jelinsky, Patrick; Arns, James

    2012-09-01

    BigBOSS is a Stage IV Dark Energy instrument based on the Baryon Acoustic Oscillations (BAO) and Red Shift Distortions (RSD) techniques using spectroscopic data of 20 million ELG and LRG galaxies at 0.5VPH) gratings have been identified as a key technology which will enable the efficiency requirement to be met, however it is important to be able to accurately predict their performance. In this paper we quantitatively compare different modelling techniques in order to assess the parameter space over which they are more capable of accurately predicting measured performance. Finally we present baseline parameters for grating designs that are most suitable for the BigBOSS instrument.

  8. The genealogical decomposition of a matrix population model with applications to the aggregation of stages.

    Science.gov (United States)

    Bienvenu, François; Akçay, Erol; Legendre, Stéphane; McCandlish, David M

    2017-06-01

    Matrix projection models are a central tool in many areas of population biology. In most applications, one starts from the projection matrix to quantify the asymptotic growth rate of the population (the dominant eigenvalue), the stable stage distribution, and the reproductive values (the dominant right and left eigenvectors, respectively). Any primitive projection matrix also has an associated ergodic Markov chain that contains information about the genealogy of the population. In this paper, we show that these facts can be used to specify any matrix population model as a triple consisting of the ergodic Markov matrix, the dominant eigenvalue and one of the corresponding eigenvectors. This decomposition of the projection matrix separates properties associated with lineages from those associated with individuals. It also clarifies the relationships between many quantities commonly used to describe such models, including the relationship between eigenvalue sensitivities and elasticities. We illustrate the utility of such a decomposition by introducing a new method for aggregating classes in a matrix population model to produce a simpler model with a smaller number of classes. Unlike the standard method, our method has the advantage of preserving reproductive values and elasticities. It also has conceptually satisfying properties such as commuting with changes of units. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. A comparative study of the constitutive models for silicon carbide

    Science.gov (United States)

    Ding, Jow-Lian; Dwivedi, Sunil; Gupta, Yogendra

    2001-06-01

    Most of the constitutive models for polycrystalline silicon carbide were developed and evaluated using data from either normal plate impact or Hopkinson bar experiments. At ISP, extensive efforts have been made to gain detailed insight into the shocked state of the silicon carbide (SiC) using innovative experimental methods, viz., lateral stress measurements, in-material unloading measurements, and combined compression shear experiments. The data obtained from these experiments provide some unique information for both developing and evaluating material models. In this study, these data for SiC were first used to evaluate some of the existing models to identify their strength and possible deficiencies. Motivated by both the results of this comparative study and the experimental observations, an improved phenomenological model was developed. The model incorporates pressure dependence of strength, rate sensitivity, damage evolution under both tension and compression, pressure confinement effect on damage evolution, stiffness degradation due to damage, and pressure dependence of stiffness. The model developments are able to capture most of the material features observed experimentally, but more work is needed to better match the experimental data quantitatively.

  10. Comparative evaluation of phenoloxidase activity in different larval stages of four lepidopteran pests after exposure to Bacillus thuringiensis.

    Science.gov (United States)

    Valadez-Lira, J A; Alcocer-Gonzalez, J M; Damas, G; Nuñez-Mejía, G; Oppert, B; Rodriguez-Padilla, C; Tamez-Guerra, P

    2012-01-01

    Microbial entomopathogen-based bioinsecticides are recognized as alternatives to synthetic pesticides. Insects defend themselves against microbial pathogens by innate mechanisms, including increased phenoloxidase (PO) activity, but its relationship with microbial bioinsecticides efficacy is little known. This study evaluated the differences in PO activity at different developmental stages of the tobacco budworm Heliothis virescens Fabricius (Lepidoptera: Noctuidae), Indian meal moth Plodia interpunctella (Hübner) (Pyralidae), beet armyworm Spodoptera exigua (Hübner) (Noctuidae), and cabbage looper Trichoplusia ni (Hübner) (Noctuidae). Additionally, 2(nd)- and 4(th)-instars were exposed to the LC(50) value of the commercial Bacillus thuringiensis (Bt) spray, Biobit(®). The percentage of insecticidal activity (IA%) on 2(nd)-instar Biobit-exposed larvae was approximately the predicted 50 % mortality for all species except S. exigua. With all 4(th) instar Biobit-exposed larvae, mortality was not significantly different from that of unexposed larvae. Unexposed insects had a significantly higher PO activity in pre-pupae and pupae than early-instar larvae and adults, whereas PO activity was higher in adult females than in males. Correlation analysis between IA% and PO activity revealed significant r-values (p < 0.01) in 2(nd) instar H. virescens (r = 0.979) and P. interpunctella (r = 0.930). Second instar Biobit-exposed P. interpunctella had 10 times more PO activity than unexposed larvae. Similarly, the amount of total protein was lower in 4(th) instar Biobit-exposed H. virescens and higher in S. exigua. Therefore, the results indicated a relationship between Biobit susceptibility and PO activity in some cases. This information may be useful if the Biobit application period is timed for a developmental stage with low PO activity. However, more studies are needed to determine the correlation of each insect with a particular bioinsecticide.

  11. Knee Joint Distraction Compared to Total Knee Arthroplasty for Treatment of End Stage Osteoarthritis: Simulating Long-Term Outcomes and Cost-Effectiveness.

    Science.gov (United States)

    van der Woude, J A D; Nair, S C; Custers, R J H; van Laar, J M; Kuchuck, N O; Lafeber, F P J G; Welsing, P M J

    2016-01-01

    In end-stage knee osteoarthritis the treatment of choice is total knee arthroplasty (TKA). An alternative treatment is knee joint distraction (KJD), suggested to postpone TKA. Several studies reported significant and prolonged clinical improvement of KJD. To make an appropriate decision regarding the position of this treatment, a cost-effectiveness and cost-utility analysis from healthcare perspective for different age and gender categories was performed. A treatment strategy starting with TKA and a strategy starting with KJD for patients of different age and gender was simulated. To extrapolate outcomes to long-term health and economic outcomes a Markov (Health state) model was used. The number of surgeries, QALYs, and treatment costs per strategy were calculated. Costs-effectiveness is expressed using the cost-effectiveness plane and cost-effectiveness acceptability curves. Starting with KJD the number of knee replacing procedures could be reduced, most clearly in the younger age categories; especially revision surgery. This resulted in the KJD strategy being dominant (more effective with cost-savings) in about 80% of simulations (with only inferiority in about 1%) in these age categories when compared to TKA. At a willingness to pay of 20.000 Euro per QALY gained, the probability of starting with KJD to be cost-effective compared to starting with a TKA was already found to be over 75% for all age categories and over 90-95% for the younger age categories. A treatment strategy starting with knee joint distraction for knee osteoarthritis has a large potential for being a cost-effective intervention, especially for the relatively young patient.

  12. Statistical study of clone survival curves after irradiation in one or two stages. Comparison and generalization of different models

    International Nuclear Information System (INIS)

    Lachet, Bernard.

    1975-01-01

    A statistical study was carried out on 208 survival curves for chlorella subjected to γ or particle radiations. The computing programmes used were written in Fortran. The different experimental causes contributing to the variance of a survival rate are analyzed and consequently the experiments can be planned. Each curve was fitted to four models by the weighted least squares method applied to non-linear functions. The validity of the fits obtained can be checked by the F test. It was possible to define the confidence and prediction zones around an adjusted curve by weighting of the residual variance, in spite of error on the doses delivered; the confidence limits can them be fixed for a dose estimated from an exact or measured survival. The four models adopted were compared for the precision of their fit (by a non-parametric simultaneous comparison test) and the scattering of their adjusted parameters: Wideroe's model gives a very good fit with the experimental points in return for a scattering of its parameters, which robs them of their presumed meaning. The principal component analysis showed the statistical equivalence of the 1 and 2 hit target models. Division of the irradiation into two doses, the first fixed by the investigator, leads to families of curves for which the equation was established from that of any basic model expressing the dose survival relationship in one-stage irradiation [fr

  13. Integration of Life-Stage Physiologically Based Pharmacokinetic Models with Adverse Outcome Pathways and Environmental Exposure Models to Screen for Environmental Hazards

    Science.gov (United States)

    A Life-stage Physiologically-Based Pharmacokinetic (PBPK) model was developed to include descriptions of several life-stage events such as pregnancy, fetal development, the neonate and child growth. The overall modeling strategy was used for in vitro to in vivo (IVIVE) extrapolat...

  14. Comparative analysis of existing models for power-grid synchronization

    International Nuclear Information System (INIS)

    Nishikawa, Takashi; Motter, Adilson E

    2015-01-01

    The dynamics of power-grid networks is becoming an increasingly active area of research within the physics and network science communities. The results from such studies are typically insightful and illustrative, but are often based on simplifying assumptions that can be either difficult to assess or not fully justified for realistic applications. Here we perform a comprehensive comparative analysis of three leading models recently used to study synchronization dynamics in power-grid networks—a fundamental problem of practical significance given that frequency synchronization of all power generators in the same interconnection is a necessary condition for a power grid to operate. We show that each of these models can be derived from first principles within a common framework based on the classical model of a generator, thereby clarifying all assumptions involved. This framework allows us to view power grids as complex networks of coupled second-order phase oscillators with both forcing and damping terms. Using simple illustrative examples, test systems, and real power-grid datasets, we study the inherent frequencies of the oscillators as well as their coupling structure, comparing across the different models. We demonstrate, in particular, that if the network structure is not homogeneous, generators with identical parameters need to be modeled as non-identical oscillators in general. We also discuss an approach to estimate the required (dynamical) system parameters that are unavailable in typical power-grid datasets, their use for computing the constants of each of the three models, and an open-source MATLAB toolbox that we provide for these computations. (paper)

  15. A New Unified Solution for Circular Tunnel Based on a Four-Stage Constitutive Model considering the Intermediate Principal Stress

    Directory of Open Access Journals (Sweden)

    Liang Chen

    2018-01-01

    Full Text Available Based on the triaxial test, the elasto-perfectly plastic strain-softening damage model (EPSDM is proposed as a new four-stage constitutive model. Compared with traditional models, such as the elasto-brittle-plastic model (EBM, elasto-strain-softening model (ESM, elasto-perfectly plastic model (EPM, and elasto-peak plastic-brittle plastic model (EPBM, this model incorporates both the plastic bearing capacity and strain-softening characteristics of rock mass. Moreover, a new closed-form solution of the circular tunnel is presented for the stress and displacement distribution, and a plastic shear strain increment is introduced to define the critical condition where the strain-softening zone begins to occur. The new analysis solution obtained in this paper is a series of results rather than one specific solution; hence, it is suitable for a wide range of rock masses and engineering structures. The numerical simulation has been used to verify the correctness of the EPSDM. The parametric studies are also conducted to investigate the effects of supporting resistance, residual cohesion, dilation angle, strain-softening coefficient, plastic shear strain increment, and yield parameter on the result. It is shown that when the supporting resistance is fully released, both the post-peak failure radii and surface displacement could be summarized as EBM > EPBM > ESM > EPSDM > EPM; the dilation angle in the damage zone had the highest influence on the surface displacement, whereas the dilation angle in the perfectly plastic zone had the lowest influence; the strain-softening coefficient had the most significant effect on the damage zone radii; the EPSDM is recommended as the optimum model for support design and stability evaluation of the circular tunnel excavated in the perfectly plastic strain-softening rock mass.

  16. Saccharomyces cerevisiae as a model organism: a comparative study.

    Directory of Open Access Journals (Sweden)

    Hiren Karathia

    Full Text Available BACKGROUND: Model organisms are used for research because they provide a framework on which to develop and optimize methods that facilitate and standardize analysis. Such organisms should be representative of the living beings for which they are to serve as proxy. However, in practice, a model organism is often selected ad hoc, and without considering its representativeness, because a systematic and rational method to include this consideration in the selection process is still lacking. METHODOLOGY/PRINCIPAL FINDINGS: In this work we propose such a method and apply it in a pilot study of strengths and limitations of Saccharomyces cerevisiae as a model organism. The method relies on the functional classification of proteins into different biological pathways and processes and on full proteome comparisons between the putative model organism and other organisms for which we would like to extrapolate results. Here we compare S. cerevisiae to 704 other organisms from various phyla. For each organism, our results identify the pathways and processes for which S. cerevisiae is predicted to be a good model to extrapolate from. We find that animals in general and Homo sapiens in particular are some of the non-fungal organisms for which S. cerevisiae is likely to be a good model in which to study a significant fraction of common biological processes. We validate our approach by correctly predicting which organisms are phenotypically more distant from S. cerevisiae with respect to several different biological processes. CONCLUSIONS/SIGNIFICANCE: The method we propose could be used to choose appropriate substitute model organisms for the study of biological processes in other species that are harder to study. For example, one could identify appropriate models to study either pathologies in humans or specific biological processes in species with a long development time, such as plants.

  17. Værktøjskasse til Agil Stage-Gate®: Ny model for udviklingsprojekter i mellemstore virksomheder

    DEFF Research Database (Denmark)

    Vedsmand, Tomas; Edwards, Kasper; Hvidt, Nicoline

    Denne værktøjskasse er et tillæg for guiden Agil Stage-Gate: Ny model for udviklingsprojekter i mellemstore virksomheder. (http://dx.doi.org/10.11581/DTU:00000028)......Denne værktøjskasse er et tillæg for guiden Agil Stage-Gate: Ny model for udviklingsprojekter i mellemstore virksomheder. (http://dx.doi.org/10.11581/DTU:00000028)...

  18. Model for Physical Education Content Standards at Early Stages of Primary Education in the Republic of Macedonia

    OpenAIRE

    Klincarov, Ilija; Popeska, Biljana

    2011-01-01

    The aim of this article is to propose a model for designing national physical education content standards in early stages of primary education in the Republic of Macedonia. Proposed model is based on the findings about motor structure of children at the early stage of primary education obtained in researches realized in 5 primary schools in Skopje, the Republic of Macedonia, in relation with Macedonian PE curriculum, and overarching standards for children at this age in California, USA,chosen...

  19. A Smoothing Algorithm for a New Two-Stage Stochastic Model of Supply Chain Based on Sample Average Approximation

    OpenAIRE

    Liu Yang; Yao Xiong; Xiao-jiao Tong

    2017-01-01

    We construct a new two-stage stochastic model of supply chain with multiple factories and distributors for perishable product. By introducing a second-order stochastic dominance (SSD) constraint, we can describe the preference consistency of the risk taker while minimizing the expected cost of company. To solve this problem, we convert it into a one-stage stochastic model equivalently; then we use sample average approximation (SAA) method to approximate the expected values of the underlying r...

  20. Market splitting in Germany – New evidence from a three-stage numerical model of Europe

    International Nuclear Information System (INIS)

    Trepper, Katrin; Bucksteeg, Michael; Weber, Christoph

    2015-01-01

    With the sharp increase in redispatch measures seen during recent years, the importance of an efficient congestion management has increased, particularly in Germany. As the current market design, with a single bidding area, ignores the physical constraints of the transmission grid, there is an ongoing discussion about introducing price zones. Against this background, we develop a three-stage approach to model redispatch and market splitting for Germany while considering interactions with interconnected countries. We identify an increasing spatial imbalance between generation and load and delays in grid extension as being the main drivers for the increase of modeled redispatch volumes from 2012 to 2020. We show that market splitting reduces imminent congestion although results are sensitive to the zonal delimitation and corresponding net transfer capacities. The overall welfare effect is negligible, but price differences between the bidding areas investigated, i.e. one Northern and Southern price zone, result in considerable distributional effects. While consumers in Northern Germany would benefit – producer rents and in particular the value of wind energy would decrease – the opposite is true for Southern Germany. We conclude that market splitting constitutes a solution to reduce redispatch measures as long as transmission grid expansion is further delayed. - Highlights: • A three-stage approach to model redispatch and zonal pricing is proposed. • Energy transition will lead to a tripling of congestion in Germany until 2020. • Market splitting in Germany substantially reduces redispatch measures. • Overall welfare gain is negligible, but considerable distributional effects occur. • The beneficial effects of market splitting depend strongly on its design.

  1. Mechanical modelling of the Singoe deformation zone. Site descriptive modelling Forsmark stage 2.1

    Energy Technology Data Exchange (ETDEWEB)

    Glamheden, Rune; Maersk Hansen, Lars; Fredriksson, Anders; Bergkvist, Lars; Markstroem, Ingemar; Elfstroem, Mats [Golder Associates AB (Sweden)

    2007-02-15

    This project aims at demonstrating the theoretical approach developed by SKB for determination of mechanical properties of large deformation zones, in particular the Singoe deformation zone. Up to now, only bedrock and minor deformation zones have been characterized by means of this methodology, which has been modified for this project. The Singoe deformation zone is taken as a reference object to get a more comprehensive picture of the structure, which could be incorporated in a future version of the SDM of Forsmark. Furthermore, the Singoe Zone has been chosen because of available data from four tunnels. Scope of work has included compilation and analysis of geological information from site investigations and documentation of existing tunnels. Results have been analyzed and demonstrated by means of RVS-visualization. Numerical modelling has been used to obtain mechanical properties. Numerical modelling has also been carried out in order to verify the results by comparison of calculated and measured deformations. Compilation of various structures in the four tunnels coincides largely with a magnetic anomaly and also with the estimated width. Based on the study it is clear that the Singoe deformation zone has a heterogeneous nature. The number of fracture zones associated with the deformation zone varies on either side of the zone, as does the transition zone between host rock and the Singoe zone. The overall impression from the study is that the results demonstrate that the methodology used for simulating of equivalent mechanical properties is an applicable and adequate method, also in case of large deformation zones. Typical rock mechanical parameters of the Singoe deformations that can be used in the regional stress model considering the zone to be a single fracture are: 200 MPa/m in normal stiffness, 10-15 MPa/m in shear stiffness, 0.4 MPa in cohesion and 31.5 degrees in friction angle.

  2. Mechanical modelling of the Singoe deformation zone. Site descriptive modelling Forsmark stage 2.1

    International Nuclear Information System (INIS)

    Glamheden, Rune; Maersk Hansen, Lars; Fredriksson, Anders; Bergkvist, Lars; Markstroem, Ingemar; Elfstroem, Mats

    2007-02-01

    This project aims at demonstrating the theoretical approach developed by SKB for determination of mechanical properties of large deformation zones, in particular the Singoe deformation zone. Up to now, only bedrock and minor deformation zones have been characterized by means of this methodology, which has been modified for this project. The Singoe deformation zone is taken as a reference object to get a more comprehensive picture of the structure, which could be incorporated in a future version of the SDM of Forsmark. Furthermore, the Singoe Zone has been chosen because of available data from four tunnels. Scope of work has included compilation and analysis of geological information from site investigations and documentation of existing tunnels. Results have been analyzed and demonstrated by means of RVS-visualization. Numerical modelling has been used to obtain mechanical properties. Numerical modelling has also been carried out in order to verify the results by comparison of calculated and measured deformations. Compilation of various structures in the four tunnels coincides largely with a magnetic anomaly and also with the estimated width. Based on the study it is clear that the Singoe deformation zone has a heterogeneous nature. The number of fracture zones associated with the deformation zone varies on either side of the zone, as does the transition zone between host rock and the Singoe zone. The overall impression from the study is that the results demonstrate that the methodology used for simulating of equivalent mechanical properties is an applicable and adequate method, also in case of large deformation zones. Typical rock mechanical parameters of the Singoe deformations that can be used in the regional stress model considering the zone to be a single fracture are: 200 MPa/m in normal stiffness, 10-15 MPa/m in shear stiffness, 0.4 MPa in cohesion and 31.5 degrees in friction angle

  3. The carbon fluxes in different successional stages: modelling the dynamics of tropical montane forests in South Ecuador

    Directory of Open Access Journals (Sweden)

    Sebastian Paulick

    2017-05-01

    Full Text Available Background Tropical forests play an important role in the global carbon (C cycle. However, tropical montane forests have been studied less than tropical lowland forests, and their role in carbon storage is not well understood. Montane forests are highly endangered due to logging, land-use and climate change. Our objective was to analyse how the carbon balance changes during forest succession. Methods In this study, we used a method to estimate local carbon balances that combined forest inventory data with process-based forest models. We utilised such a forest model to study the carbon balance of a tropical montane forest in South Ecuador, comparing two topographical slope positions (ravines and lower slopes vs upper slopes and ridges. Results The simulation results showed that the forest acts as a carbon sink with a maximum net ecosystem exchange (NEE of 9.3 Mg C∙(ha∙yr−1 during its early successional stage (0–100 years. In the late successional stage, the simulated NEE fluctuated around zero and had a variation of 0.77 Mg C∙(ha∙yr –1. The simulated variability of the NEE was within the range of the field data. We discovered several forest attributes (e.g., basal area or the relative amount of pioneer trees that can serve as predictors for NEE for young forest stands (0–100 years but not for those in the late successional stage (500–1,000 years. In case of young forest stands these correlations are high, especially between stand basal area and NEE. Conclusion In this study, we used an Ecuadorian study site as an example of how to successfully link a forest model with forest inventory data, for estimating stem-diameter distributions, biomass and aboveground net primary productivity. To conclude, this study shows that process-based forest models can be used to investigate the carbon balance of tropical montane forests. With this model it is possible to find hidden relationships between forest attributes and forest carbon fluxes

  4. Transcriptome profiling of the cysticercus stage of the laboratory model Taenia crassiceps, strain ORF.

    Science.gov (United States)

    García-Montoya, Gisela M; Mesa-Arango, Jairo A; Isaza-Agudelo, Juan P; Agudelo-Lopez, Sonia P; Cabarcas, Felipe; Barrera, Luis F; Alzate, Juan F

    2016-02-01

    Neurocysticercosis (NC) is a serious public health problem mainly in developing countries. NC caused by the cysticercus stage from cestode Taenia solium is considered by the WHO and ITFDE as a potentially eradicable disease. Definitive diagnosis of NC is challenging because of the unspecific clinical manifestations such as the non-definitive evidence presented by neuroimaging (in most cases) and the lack of definitive serological test. Taenia crassiceps (ORF strain) is a cestode closely related to T. solium and it has frequently been used as a source of antigens for immunodiagnostics. A murine model to study host immune response to infection has also been established by using T. crassiceps. Despite the extensive use of T. crassiceps for research, molecular information for this cestode is scarce in public databases. With the aim of providing more extensive information on T. crassiceps biology, an RNA-seq experiment and subsequent bioinformatic transcriptome processing of this cestode parasite mRNA in its cysticercus stage were carried out. A total of 227,082 read/ESTs were sequenced using the 454-GS FLX Titanium technology and assembled into 10,787 contigs. This transcriptome dataset represents new and valuable molecular information of the cestode T. crassiceps (ORF). This information will substantially improve public information and will help to achieve a better understanding of the biology of T. crassiceps and to identify target proteins for serodiagnosis and vaccination. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Modeling bacterial attachment to surfaces as an early stage of biofilm development.

    Science.gov (United States)

    El Moustaid, Fadoua; Eladdadi, Amina; Uys, Lafras

    2013-06-01

    Biofilms are present in all natural, medical and industrial surroundings where bacteria live. Biofilm formation is a key factor in the growth and transport of both beneficial and harmful bacteria. While much is known about the later stages of biofilm formation, less is known about its initiation which is an important first step in the biofilm formation. In this paper, we develop a non-linear system of partial differential equations of Keller-Segel type model in one-dimensional space, which couples the dynamics of bacterial movement to that of the sensing molecules. In this case, bacteria perform a biased random walk towards the sensing molecules. We derive the boundary conditions of the adhesion of bacteria to a surface using zero-Dirichlet boundary conditions, while the equation describing sensing molecules at the interface needed particular conditions to be set. The numerical results show the profile of bacteria within the space and the time evolution of the density within the free-space and on the surface. Testing different parameter values indicate that significant amount of sensing molecules present on the surface leads to a faster bacterial movement toward the surface which is the first step of biofilm initiation. Our work gives rise to results that agree with the biological description of the early stages of biofilm formation.

  6. COMPARATIVE STUDY ON MAIN SOLVENCY ASSESSMENT MODELS FOR INSURANCE FIELD

    Directory of Open Access Journals (Sweden)

    Daniela Nicoleta SAHLIAN

    2015-07-01

    Full Text Available During the recent financial crisis of insurance domain, there were imposed new aspects that have to be taken into account concerning the risks management and surveillance activity. The insurance societies could develop internal models in order to determine the minimum capital requirement imposed by the new regulations that are to be adopted on 1 January 2016. In this respect, the purpose of this research paper is to offer a real presentation and comparing with the main solvency regulation systems used worldwide, the accent being on their common characteristics and current tendencies. Thereby, we would like to offer a better understanding of the similarities and differences between the existent solvency regimes in order to develop the best regime of solvency for Romania within the Solvency II project. The study will show that there are clear differences between the existent Solvency I regime and the new approaches based on risk and will also point out the fact that even the key principles supporting the new solvency regimes are convergent, there are a lot of approaches for the application of these principles. In this context, the question we would try to find the answer is "how could the global solvency models be useful for the financial surveillance authority of Romania for the implementation of general model and for the development of internal solvency models according to the requirements of Solvency II" and "which would be the requirements for the implementation of this type of approach?". This thing makes the analysis of solvency models an interesting exercise.

  7. Atterberg Limits Prediction Comparing SVM with ANFIS Model

    Directory of Open Access Journals (Sweden)

    Mohammad Murtaza Sherzoy

    2017-03-01

    Full Text Available Support Vector Machine (SVM and Adaptive Neuro-Fuzzy inference Systems (ANFIS both analytical methods are used to predict the values of Atterberg limits, such as the liquid limit, plastic limit and plasticity index. The main objective of this study is to make a comparison between both forecasts (SVM & ANFIS methods. All data of 54 soil samples are used and taken from the area of Peninsular Malaysian and tested for different parameters containing liquid limit, plastic limit, plasticity index and grain size distribution and were. The input parameter used in for this case are the fraction of grain size distribution which are the percentage of silt, clay and sand. The actual and predicted values of Atterberg limit which obtained from the SVM and ANFIS models are compared by using the correlation coefficient R2 and root mean squared error (RMSE value.  The outcome of the study show that the ANFIS model shows higher accuracy than SVM model for the liquid limit (R2 = 0.987, plastic limit (R2 = 0.949 and plastic index (R2 = 0966. RMSE value that obtained for both methods have shown that the ANFIS model has represent the best performance than SVM model to predict the Atterberg Limits as a whole.

  8. Mathematical Model of the One-stage Magneto-optical Sensor Based on Faraday Effect

    Science.gov (United States)

    Babaev, O. G.; Paranin, V. D.; Sinitsin, L. I.

    2018-01-01

    The aim of this work is to refine a model of magneto-optical sensors based on Faraday’s longitudinal magneto-optical effect. The tasks of the study include computer modeling and analysis of the transfer characteristic of a single-stage magneto-optical sensor for various polarization of the input beam and non-ideal optical components. The proposed mathematical model and software make it possible to take into account the non-ideal characteristics of film polaroids observed in operation in the near infrared region and at increased temperatures. On the basis of the results of the model analysis it was found that the dependence of normalized transmission T(γ2) has periodic nature. Choosing the angle (γ 2-γ 1) makes it possible to shift the initial operation point and change the sensitivity dT/dγ 2. The influence of the input beam polarization increases with the increase of polaroid parameter deviation from ideal and shows itself as reduction of modulation depth and angular shift of the sensor conversion response.

  9. Computational Modelling of Large Scale Phage Production Using a Two-Stage Batch Process

    Directory of Open Access Journals (Sweden)

    Konrad Krysiak-Baltyn

    2018-04-01

    Full Text Available Cost effective and scalable methods for phage production are required to meet an increasing demand for phage, as an alternative to antibiotics. Computational models can assist the optimization of such production processes. A model is developed here that can simulate the dynamics of phage population growth and production in a two-stage, self-cycling process. The model incorporates variable infection parameters as a function of bacterial growth rate and employs ordinary differential equations, allowing application to a setup with multiple reactors. The model provides simple cost estimates as a function of key operational parameters including substrate concentration, feed volume and cycling times. For the phage and bacteria pairing examined, costs and productivity varied by three orders of magnitude, with the lowest cost found to be most sensitive to the influent substrate concentration and low level setting in the first vessel. An example case study of phage production is also presented, showing how parameter values affect the production costs and estimating production times. The approach presented is flexible and can be used to optimize phage production at laboratory or factory scale by minimizing costs or maximizing productivity.

  10. Autobiography and Anorexia: A Qualitative Alternative to Prochaska and DiClemente's Stages of Change Model

    Directory of Open Access Journals (Sweden)

    Félix Díaz

    2012-11-01

    Full Text Available In this article, we propose a qualitative approach to the study of the ways in which people face good and poor health issues. During the last 30 years, Prochaska and DiClemente's "trans-theoretical model" (1982, 1983, 1984, 1986, 1992 has gained relevance as a model to assess disposition for change in patients. We revise the features of the model and its common techniques to assess stages of change, underlining its methodological and conceptual problems. Particularly, we discuss the paradoxes set by "pre-contemplation" as a concept; the exogenous definition of human problems in terms of institutional and clinical criteria; and the ambiguity of the model, where the purpose of accompanying and orienting the patient contrasts with the imposition of problem definitions and solution strategies. We propose a narrative analysis of autobiographies of patients as an alternative that recasts their own notions of "change," "problem," and "vital trajectory." We illustrate this possibility with the analysis of an autobiographic interview with a woman who has a history of anorexia. URN: http://nbn-resolving.de/urn:nbn:de:0114-fqs1203209

  11. A cooperation model based on CVaR measure for a two-stage supply chain

    Science.gov (United States)

    Xu, Xinsheng; Meng, Zhiqing; Shen, Rui

    2015-07-01

    In this paper, we introduce a cooperation model (CM) for the two-stage supply chain consisting of a manufacturer and a retailer. In this model, it is supposed that the objective of the manufacturer is to maximise his/her profit while the objective of the retailer is to minimise his/her CVaR while controlling the risk originating from fluctuation in market demand. In reality, the manufacturer and the retailer would like to choose their own decisions as to wholesale price and order quantity to optimise their own objectives, resulting the fact that the expected decision of the manufacturer and that of the retailer may conflict with each other. Then, to achieve cooperation, the manufacturer and the retailer both need to give some concessions. The proposed model aims to coordinate the decisions of the manufacturer and the retailer, and balance the concessions of the two in their cooperation. We introduce an s* - optimal equilibrium solution in this model, which can decide the minimum concession that the manufacturer and the retailer need to give for their cooperation, and prove that the s* - optimal equilibrium solution can be obtained by solving a goal programming problem. Further, the case of different concessions made by the manufacturer and the retailer is also discussed. Numerical results show that the CM is efficient in dealing with the cooperations between the supplier and the retailer.

  12. Risk model in stage IB1-IIB cervical cancer with positive node after radical hysterectomy

    Directory of Open Access Journals (Sweden)

    Chen Z

    2016-05-01

    Full Text Available Zhilan Chen,1,2,* Kecheng Huang,1,* Zhiyong Lu,1,3 Song Deng,1,4 Jiaqiang Xiong,1 Jia Huang,1 Xiong Li,5 Fangxu Tang,1 Zhihao Wang,6 Haiying Sun,1 Lin Wang,1 Shasha Zhou,1 Xiaoli Wang,1 Yao Jia,1 Ting Hu,1 Juan Gui,7 Dongyi Wan,1 Ding Ma,1 Shuang Li,1 Shixuan Wang11Department of Obstetrics and Gynecology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Techonology, Wuhan, 2Department of Obstetrics and Gynecology, Wuhan General Hospital of Guangzhou Military Command, Wuhan, 3Hubei Key Laboratory of Embryonic Stem Cell Research, Tai-He Hospital, Hubei University of Medicine, Shiyan, Hubei, 4Department of Obstetrics and Gynecology, University Hospital of Hubei University for Nationalities, Enshi, Hubei, 5Department of Obstetrics and Gynecology, Wuhan Central Hospital, Wuhan, 6Department of Pathology and Pathophysiology, Key Laboratory of Ministry of Education of China for Neurological Disorders, Huazhong University of Science and Techonology, Wuhan, 7Department of Obstetrics and Gynecology, Renmin Hospital, Wuhan University, Wuhan, People’s Republic of China*These authors contributed equally to this workAbstract: The purpose of this study was to identify risk factors in patients with surgically treated node-positive IB1-IIB cervical cancer and to establish a risk model for disease-free survival (DFS and overall survival (OS. A total of 170 patients who underwent radical hysterectomy and bilateral pelvic lymphadenectomy as primary treatment for node-positive International Federation of Gynaecology and Obstetrics (FIGO stage IB1-IIB cervical cancer from January 2002 to December 2008 were retrospectively analyzed. Five published risk models were evaluated in this population. The variables, including common iliac lymph node metastasis and parametrial invasion, were independent predictors of outcome in a multivariate analysis using a Cox regression model. Three distinct prognostic groups (low, intermediate, and high risk

  13. Dinucleotide controlled null models for comparative RNA gene prediction

    Directory of Open Access Journals (Sweden)

    Gesell Tanja

    2008-05-01

    Full Text Available Abstract Background Comparative prediction of RNA structures can be used to identify functional noncoding RNAs in genomic screens. It was shown recently by Babak et al. [BMC Bioinformatics. 8:33] that RNA gene prediction programs can be biased by the genomic dinucleotide content, in particular those programs using a thermodynamic folding model including stacking energies. As a consequence, there is need for dinucleotide-preserving control strategies to assess the significance of such predictions. While there have been randomization algorithms for single sequences for many years, the problem has remained challenging for multiple alignments and there is currently no algorithm available. Results We present a program called SISSIz that simulates multiple alignments of a given average dinucleotide content. Meeting additional requirements of an accurate null model, the randomized alignments are on average of the same sequence diversity and preserve local conservation and gap patterns. We make use of a phylogenetic substitution model that includes overlapping dependencies and site-specific rates. Using fast heuristics and a distance based approach, a tree is estimated under this model which is used to guide the simulations. The new algorithm is tested on vertebrate genomic alignments and the effect on RNA structure predictions is studied. In addition, we directly combined the new null model with the RNAalifold consensus folding algorithm giving a new variant of a thermodynamic structure based RNA gene finding program that is not biased by the dinucleotide content. Conclusion SISSIz implements an efficient algorithm to randomize multiple alignments preserving dinucleotide content. It can be used to get more accurate estimates of false positive rates of existing programs, to produce negative controls for the training of machine learning based programs, or as standalone RNA gene finding program. Other applications in comparative genomics that require

  14. Dinucleotide controlled null models for comparative RNA gene prediction.

    Science.gov (United States)

    Gesell, Tanja; Washietl, Stefan

    2008-05-27

    Comparative prediction of RNA structures can be used to identify functional noncoding RNAs in genomic screens. It was shown recently by Babak et al. [BMC Bioinformatics. 8:33] that RNA gene prediction programs can be biased by the genomic dinucleotide content, in particular those programs using a thermodynamic folding model including stacking energies. As a consequence, there is need for dinucleotide-preserving control strategies to assess the significance of such predictions. While there have been randomization algorithms for single sequences for many years, the problem has remained challenging for multiple alignments and there is currently no algorithm available. We present a program called SISSIz that simulates multiple alignments of a given average dinucleotide content. Meeting additional requirements of an accurate null model, the randomized alignments are on average of the same sequence diversity and preserve local conservation and gap patterns. We make use of a phylogenetic substitution model that includes overlapping dependencies and site-specific rates. Using fast heuristics and a distance based approach, a tree is estimated under this model which is used to guide the simulations. The new algorithm is tested on vertebrate genomic alignments and the effect on RNA structure predictions is studied. In addition, we directly combined the new null model with the RNAalifold consensus folding algorithm giving a new variant of a thermodynamic structure based RNA gene finding program that is not biased by the dinucleotide content. SISSIz implements an efficient algorithm to randomize multiple alignments preserving dinucleotide content. It can be used to get more accurate estimates of false positive rates of existing programs, to produce negative controls for the training of machine learning based programs, or as standalone RNA gene finding program. Other applications in comparative genomics that require randomization of multiple alignments can be considered. SISSIz

  15. Comparative Proteomic Analysis of Two Uveitis Models in Lewis Rats.

    Science.gov (United States)

    Pepple, Kathryn L; Rotkis, Lauren; Wilson, Leslie; Sandt, Angela; Van Gelder, Russell N

    2015-12-01

    Inflammation generates changes in the protein constituents of the aqueous humor. Proteins that change in multiple models of uveitis may be good biomarkers of disease or targets for therapeutic intervention. The present study was conducted to identify differentially-expressed proteins in the inflamed aqueous humor. Two models of uveitis were induced in Lewis rats: experimental autoimmune uveitis (EAU) and primed mycobacterial uveitis (PMU). Differential gel electrophoresis was used to compare naïve and inflamed aqueous humor. Differentially-expressed proteins were separated by using 2-D gel electrophoresis and excised for identification with matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF). Expression of select proteins was verified by Western blot analysis in both the aqueous and vitreous. The inflamed aqueous from both models demonstrated an increase in total protein concentration when compared to naïve aqueous. Calprotectin, a heterodimer of S100A8 and S100A9, was increased in the aqueous in both PMU and EAU. In the vitreous, S100A8 and S100A9 were preferentially elevated in PMU. Apolipoprotein E was elevated in the aqueous of both uveitis models but was preferentially elevated in EAU. Beta-B2-crystallin levels decreased in the aqueous and vitreous of EAU but not PMU. The proinflammatory molecules S100A8 and S100A9 were elevated in both models of uveitis but may play a more significant role in PMU than EAU. The neuroprotective protein β-B2-crystallin was found to decline in EAU. Therapies to modulate these proteins in vivo may be good targets in the treatment of ocular inflammation.

  16. Comparing pharmacophore models derived from crystallography and NMR ensembles

    Science.gov (United States)

    Ghanakota, Phani; Carlson, Heather A.

    2017-11-01

    NMR and X-ray crystallography are the two most widely used methods for determining protein structures. Our previous study examining NMR versus X-Ray sources of protein conformations showed improved performance with NMR structures when used in our Multiple Protein Structures (MPS) method for receptor-based pharmacophores (Damm, Carlson, J Am Chem Soc 129:8225-8235, 2007). However, that work was based on a single test case, HIV-1 protease, because of the rich data available for that system. New data for more systems are available now, which calls for further examination of the effect of different sources of protein conformations. The MPS technique was applied to Growth factor receptor bound protein 2 (Grb2), Src SH2 homology domain (Src-SH2), FK506-binding protein 1A (FKBP12), and Peroxisome proliferator-activated receptor-γ (PPAR-γ). Pharmacophore models from both crystal and NMR ensembles were able to discriminate between high-affinity, low-affinity, and decoy molecules. As we found in our original study, NMR models showed optimal performance when all elements were used. The crystal models had more pharmacophore elements compared to their NMR counterparts. The crystal-based models exhibited optimum performance only when pharmacophore elements were dropped. This supports our assertion that the higher flexibility in NMR ensembles helps focus the models on the most essential interactions with the protein. Our studies suggest that the "extra" pharmacophore elements seen at the periphery in X-ray models arise as a result of decreased protein flexibility and make very little contribution to model performance.

  17. Comparative assessment of condensation models for horizontal tubes

    International Nuclear Information System (INIS)

    Schaffrath, A.; Kruessenberg, A.K.; Lischke, W.; Gocht, U.; Fjodorow, A.

    1999-01-01

    The condensation in horizontal tubes plays an important role e.g. for the determination of the operation mode of horizontal steam generators of VVER reactors or passive safety systems for the next generation of nuclear power plants. Two different approaches (HOTKON and KONWAR) for modeling this process have been undertaken by Forschungszentrum Juelich (FZJ) and University for Applied Sciences Zittau/Goerlitz (HTWS) and implemented into the 1D-thermohydraulic code ATHLET, which is developed by the Gesellschaft fuer Anlagen- und Reaktorsicherheit (GRS) mbH for the analysis of anticipated and abnormal transients in light water reactors. Although the improvements of the condensation models are developed for different applications (VVER steam generators - emergency condenser of the SWR1000) with strongly different operation conditions (e.g. the temperature difference over the tube wall in HORUS is up to 30 K and in NOKO up to 250 K, the heat flux density in HORUS is up to 40 kW/m 2 and in NOKO up to 1 GW/m 2 ) both models are now compared and assessed by Forschungszentrum Rossendorf FZR e.V. Therefore, post test calculations of selected HORUS experiments were performed with ATHLET/KONWAR and compared to existing ATHLET and ATHLET/HOTKON calculations of HTWS. It can be seen that the calculations with the extension KONWAR as well as HOTKON improve significantly the agreement between computational and experimental data. (orig.) [de

  18. Comparative Modelling of the Spectra of Cool Giants

    Science.gov (United States)

    Lebzelter, T.; Heiter, U.; Abia, C.; Eriksson, K.; Ireland, M.; Neilson, H.; Nowotny, W; Maldonado, J; Merle, T.; Peterson, R.; hide

    2012-01-01

    Our ability to extract information from the spectra of stars depends on reliable models of stellar atmospheres and appropriate techniques for spectral synthesis. Various model codes and strategies for the analysis of stellar spectra are available today. Aims. We aim to compare the results of deriving stellar parameters using different atmosphere models and different analysis strategies. The focus is set on high-resolution spectroscopy of cool giant stars. Methods. Spectra representing four cool giant stars were made available to various groups and individuals working in the area of spectral synthesis, asking them to derive stellar parameters from the data provided. The results were discussed at a workshop in Vienna in 2010. Most of the major codes currently used in the astronomical community for analyses of stellar spectra were included in this experiment. Results. We present the results from the different groups, as well as an additional experiment comparing the synthetic spectra produced by various codes for a given set of stellar parameters. Similarities and differences of the results are discussed. Conclusions. Several valid approaches to analyze a given spectrum of a star result in quite a wide range of solutions. The main causes for the differences in parameters derived by different groups seem to lie in the physical input data and in the details of the analysis method. This clearly shows how far from a definitive abundance analysis we still are.

  19. Precipitation modeling of inclusions at different stages of the steel making process

    International Nuclear Information System (INIS)

    Carreno, V.; Morales, R.D.; Romeero, A.; Hernandez, M.; Morales, R.D.

    1998-01-01

    Steel making processes are continuously improved in order to attend the increasing requirements of the cleanness of the liquid metal. At the refining stages, as deoxidation and desulphuration, the formation of inclusions of oxides and sulphides is promoted, which on the other hand, are the most frequent inclusions. In this work a mathematical simulator of the precipitation and chemical composition of non-metallic inclusions at different steps of the steel making process is presented. To this purpose, it is assumed that inclusions formed by reoxidation can be simulated by increasing arbitrarily the oxygen levels consumed by the residual elements (aluminium, calcium, etc) and starting the chemical reaction with less powerful deoxidants (silicium and manganese). Accordingly, different operative conditions can be simulated. Numerical predictions are compared with experimental results of industrial trials, as well as results included in the bibliography. (Author) 7 refs

  20. Comparing Productivity Simulated with Inventory Data Using Different Modelling Technologies

    Science.gov (United States)

    Klopf, M.; Pietsch, S. A.; Hasenauer, H.

    2009-04-01

    The Lime Stone National Park in Austria was established in 1997 to protect sensible lime stone soils from degradation due to heavy forest management. Since 1997 the management activities were successively reduced and standing volume and coarse woody debris (CWD) increased and degraded soils began to recover. One option to study the rehabilitation process towards natural virgin forest state is the use of modelling technology. In this study we will test two different modelling approaches for their applicability to Lime Stone National Park. We will compare standing tree volume simulated resulting from (i) the individual tree growth model MOSES, and (ii) the species and management sensitive adaptation of the biogeochemical-mechanistic model Biome-BGC. The results from the two models are compared with filed observations form repeated permanent forest inventory plots of the Lime Stone National Park in Austria. The simulated CWD predictions of the BGC-model were compared with dead wood measurements (standing and lying dead wood) recorded at the permanent inventory plots. The inventory was established between 1994 and 1996 and remeasured from 2004 to 2005. For this analysis 40 plots of this inventory were selected which comprise the required dead wood components and are dominated by a single tree species. First we used the distance dependant individual tree growth model MOSES to derive the standing timber and the amount of mortality per hectare. MOSES is initialized with the inventory data at plot establishment and each sampling plot is treated as forest stand. The Biome-BGC is a process based biogeochemical model with extensions for Austrian tree species, a self initialization and a forest management tool. The initialization for the actual simulations with the BGC model was done as follows: We first used spin up runs to derive a balanced forest vegetation, similar to an undisturbed forest. Next we considered the management history of the past centuries (heavy clear cuts

  1. The activities of current antimalarial drugs on the life cycle stages of Plasmodium: a comparative study with human and rodent parasites.

    Science.gov (United States)

    Delves, Michael; Plouffe, David; Scheurer, Christian; Meister, Stephan; Wittlin, Sergio; Winzeler, Elizabeth A; Sinden, Robert E; Leroy, Didier

    2012-02-01

    Malaria remains a disease of devastating global impact, killing more than 800,000 people every year-the vast majority being children under the age of 5. While effective therapies are available, if malaria is to be eradicated a broader range of small molecule therapeutics that are able to target the liver and the transmissible sexual stages are required. These new medicines are needed both to meet the challenge of malaria eradication and to circumvent resistance. Little is known about the wider stage-specific activities of current antimalarials that were primarily designed to alleviate symptoms of malaria in the blood stage. To overcome this critical gap, we developed assays to measure activity of antimalarials against all life stages of malaria parasites, using a diverse set of human and nonhuman parasite species, including male gamete production (exflagellation) in Plasmodium falciparum, ookinete development in P. berghei, oocyst development in P. berghei and P. falciparum, and the liver stage of P. yoelii. We then compared 50 current and experimental antimalarials in these assays. We show that endoperoxides such as OZ439, a stable synthetic molecule currently in clinical phase IIa trials, are strong inhibitors of gametocyte maturation/gamete formation and impact sporogony; lumefantrine impairs development in the vector; and NPC-1161B, a new 8-aminoquinoline, inhibits sporogony. These data enable objective comparisons of the strengths and weaknesses of each chemical class at targeting each stage of the lifecycle. Noting that the activities of many compounds lie within achievable blood concentrations, these results offer an invaluable guide to decisions regarding which drugs to combine in the next-generation of antimalarial drugs. This study might reveal the potential of life-cycle-wide analyses of drugs for other pathogens with complex life cycles.

  2. The Activities of Current Antimalarial Drugs on the Life Cycle Stages of Plasmodium: A Comparative Study with Human and Rodent Parasites

    Science.gov (United States)

    Delves, Michael; Plouffe, David; Scheurer, Christian; Meister, Stephan; Wittlin, Sergio; Winzeler, Elizabeth A.; Sinden, Robert E.; Leroy, Didier

    2012-01-01

    Background Malaria remains a disease of devastating global impact, killing more than 800,000 people every year—the vast majority being children under the age of 5. While effective therapies are available, if malaria is to be eradicated a broader range of small molecule therapeutics that are able to target the liver and the transmissible sexual stages are required. These new medicines are needed both to meet the challenge of malaria eradication and to circumvent resistance. Methods and Findings Little is known about the wider stage-specific activities of current antimalarials that were primarily designed to alleviate symptoms of malaria in the blood stage. To overcome this critical gap, we developed assays to measure activity of antimalarials against all life stages of malaria parasites, using a diverse set of human and nonhuman parasite species, including male gamete production (exflagellation) in Plasmodium falciparum, ookinete development in P. berghei, oocyst development in P. berghei and P. falciparum, and the liver stage of P. yoelii. We then compared 50 current and experimental antimalarials in these assays. We show that endoperoxides such as OZ439, a stable synthetic molecule currently in clinical phase IIa trials, are strong inhibitors of gametocyte maturation/gamete formation and impact sporogony; lumefantrine impairs development in the vector; and NPC-1161B, a new 8-aminoquinoline, inhibits sporogony. Conclusions These data enable objective comparisons of the strengths and weaknesses of each chemical class at targeting each stage of the lifecycle. Noting that the activities of many compounds lie within achievable blood concentrations, these results offer an invaluable guide to decisions regarding which drugs to combine in the next-generation of antimalarial drugs. This study might reveal the potential of life-cycle–wide analyses of drugs for other pathogens with complex life cycles. Please see later in the article for the Editors' Summary PMID

  3. An integrated multi-stage supply chain inventory model with imperfect production process

    Directory of Open Access Journals (Sweden)

    Soumita Kundu

    2015-09-01

    Full Text Available This paper deals with an integrated multi-stage supply chain inventory model with the objective of cost minimization by synchronizing the replenishment decisions for procurement, production and delivery activities. The supply chain structure examined here consists of a single manufacturer with multi-buyer where manufacturer orders a fixed quantity of raw material from outside suppliers, processes the materials and delivers the finished products in unequal shipments to each customer. In this paper, we consider an imperfect production system, which produces defective items randomly and assumes that all defective items could be reworked. A simple algorithm is developed to obtain an optimal production policy, which minimizes the expected average total cost of the integrated production-inventory system.

  4. Hemodialysis Reliable Outflow (HeRO) device in end-stage dialysis access: a decision analysis model.

    Science.gov (United States)

    Dageforde, Leigh Anne; Bream, Peter R; Moore, Derek E

    2012-09-01

    The Hemodialysis Reliable Outflow (HeRO) dialysis access device is a permanent tunneled dialysis graft connected to a central venous catheter and is used in patients with end-stage dialysis access (ESDA) issues secondary to central venous stenosis. The safety and effectiveness of the HeRO device has previously been proven, but no study thus far has compared the cost of its use with tunneled dialysis catheters (TDCs) and thigh grafts in patients with ESDA. A decision analytic model was developed to simulate outcomes for patients with ESDA undergoing placement of a HeRO dialysis access device, TDC, or thigh graft. Outcomes of interest were infection, thrombosis, and ischemic events. Baseline values, ranges, and costs were determined from a systematic review of the literature. Total costs were based on 1 year of post-procedure outcomes. Sensitivity analyses were conducted to test model strength. The HeRO dialysis access device is the least costly dialysis access with an average 1-year cost of $6521. The 1-year cost for a TDC was $8477. A thigh graft accounted for $9567 in a 1-year time period. The HeRO dialysis access device is the least costly method of ESDA. The primary determinants of cost in this model are infection in TDCs and leg ischemia necessitating amputation in thigh grafts. Further study is necessary to incorporate patient preference and quality of life into the model. Copyright © 2012 Elsevier Inc. All rights reserved.

  5. The relative efficiency of Iranian's rural traffic police: a three-stage DEA model.

    Science.gov (United States)

    Rahimi, Habibollah; Soori, Hamid; Nazari, Seyed Saeed Hashemi; Motevalian, Seyed Abbas; Azar, Adel; Momeni, Eskandar; Javartani, Mehdi

    2017-10-13

    Road traffic Injuries (RTIs) as a health problem imposes governments to implement different interventions. Target achievement in this issue required effective and efficient measures. Efficiency evaluation of traffic police as one of the responsible administrators is necessary for resource management. Therefore, this study conducted to measure Iran's rural traffic police efficiency. This was an ecological study. To obtain pure efficiency score, three-stage DEA model was conducted with seven inputs and three output variables. At the first stage, crude efficiency score was measured with BCC-O model. Next, to extract the effects of socioeconomic, demographic, traffic count and road infrastructure as the environmental variables and statistical noise, the Stochastic Frontier Analysis (SFA) model was applied and the output values were modified according to similar environment and statistical noise conditions. Then, the pure efficiency score was measured using modified outputs and BCC-O model. In total, the efficiency score of 198 police stations from 24 provinces of 31 provinces were measured. The annual means (standard deviation) of damage, injury and fatal accidents were 247.7 (258.4), 184.9 (176.9), and 28.7 (19.5), respectively. Input averages were 5.9 (3.0) patrol teams, 0.5% (0.2) manpower proportions, 7.5 (2.9) patrol cars, 0.5 (1.3) motorcycles, 77,279.1 (46,794.7) penalties, 90.9 (2.8) cultural and educational activity score, 0.7 (2.4) speed cameras. The SFA model showed non-significant differences between police station performances and the most differences attributed to the environmental and random error. One-way main road, by road, traffic count and the number of household owning motorcycle had significant positive relations with inefficiency score. The length of freeway/highway and literacy rate variables had negative relations, significantly. Pure efficiency score was with mean of 0.95 and SD of 0.09. Iran's traffic police has potential opportunity to reduce

  6. Increased risk of dialysis and end-stage renal disease among HIV patients in Denmark compared with the background population

    DEFF Research Database (Denmark)

    Rasch, Magnus G; Helleberg, Marie; Feldt-Rasmussen, Bo

    2014-01-01

    BACKGROUND: HIV patients have increased risk of impaired renal function. We aimed to estimate the incidence of any renal replacement therapy (aRRT) and start of chronic renal replacement therapy (cRRT) among HIV patients compared with population controls. METHODS: In a nationwide, population......-based cohort study we analysed incidence rates (IR), incidence rate ratios (IRR) and risk factors for aRRT and cRRT among HIV patients compared with an age- and gender-matched population control cohort using Poisson regression. RESULTS: We identified 5300 HIV patients and 53 000 population controls. The IRs...

  7. Comparative testing of six antigen-based malaria vaccine candidates directed toward merozoite-stage Plasmodium falciparum

    DEFF Research Database (Denmark)

    Arnot, David E; Cavanagh, David R; Remarque, Edmond J

    2008-01-01

    Immunogenicity testing of Plasmodium falciparum antigens being considered as malaria vaccine candidates was undertaken in rabbits. The antigens compared were recombinant baculovirus MSP-1(19) and five Pichia pastoris candidates, including two versions of MSP-1(19), AMA-1 (domains I and II), AMA-1......G concentrations. The two P. pastoris-produced MSP-1(19)-induced IgGs conferred the lowest growth inhibition. Comparative analysis of immunogenicity of vaccine antigens can be used to prioritize candidates before moving to expensive GMP production and clinical testing. The assays used have given discriminating...

  8. Two-Stage orders sequencing system for mixed-model assembly

    Science.gov (United States)

    Zemczak, M.; Skolud, B.; Krenczyk, D.

    2015-11-01

    In the paper, the authors focus on the NP-hard problem of orders sequencing, formulated similarly to Car Sequencing Problem (CSP). The object of the research is the assembly line in an automotive industry company, on which few different models of products, each in a certain number of versions, are assembled on the shared resources, set in a line. Such production type is usually determined as a mixed-model production, and arose from the necessity of manufacturing customized products on the basis of very specific orders from single clients. The producers are nowadays obliged to provide each client the possibility to determine a huge amount of the features of the product they are willing to buy, as the competition in the automotive market is large. Due to the previously mentioned nature of the problem (NP-hard), in the given time period only satisfactory solutions are sought, as the optimal solution method has not yet been found. Most of the researchers that implemented inaccurate methods (e.g. evolutionary algorithms) to solving sequencing problems dropped the research after testing phase, as they were not able to obtain reproducible results, and met problems while determining the quality of the received solutions. Therefore a new approach to solving the problem, presented in this paper as a sequencing system is being developed. The sequencing system consists of a set of determined rules, implemented into computer environment. The system itself works in two stages. First of them is connected with the determination of a place in the storage buffer to which certain production orders should be sent. In the second stage of functioning, precise sets of sequences are determined and evaluated for certain parts of the storage buffer under certain criteria.

  9. Comparative dynamic analysis of the full Grossman model.

    Science.gov (United States)

    Ried, W

    1998-08-01

    The paper applies the method of comparative dynamic analysis to the full Grossman model. For a particular class of solutions, it derives the equations implicitly defining the complete trajectories of the endogenous variables. Relying on the concept of Frisch decision functions, the impact of any parametric change on an endogenous variable can be decomposed into a direct and an indirect effect. The focus of the paper is on marginal changes in the rate of health capital depreciation. It also analyses the impact of either initial financial wealth or the initial stock of health capital. While the direction of most effects remains ambiguous in the full model, the assumption of a zero consumption benefit of health is sufficient to obtain a definite for any direct or indirect effect.

  10. A method for extending stage-discharge relationships using a hydrodynamic model and quantifying the associated uncertainty

    Science.gov (United States)

    Shao, Quanxi; Dutta, Dushmanta; Karim, Fazlul; Petheram, Cuan

    2018-01-01

    Streamflow discharge is a fundamental dataset required to effectively manage water and land resources. However, developing robust stage - discharge relationships called rating curves, from which streamflow discharge is derived, is time consuming and costly, particularly in remote areas and especially at high stage levels. As a result stage - discharge relationships are often heavily extrapolated. Hydrodynamic (HD) models are physically based models used to simulate the flow of water along river channels and over adjacent floodplains. In this paper we demonstrate a method by which a HD model can be used to generate a 'synthetic' stage - discharge relationship at high stages. The method uses a both-side Box-Cox transformation to calibrate the synthetic rating curve such that the regression residuals are as close to the normal distribution as possible. By doing this both-side transformation, the statistical uncertainty in the synthetically derived stage - discharge relationship can be calculated. This enables people trying to make decisions to determine whether the uncertainty in the synthetically generated rating curve at high stage levels is acceptable for their decision. The proposed method is demonstrated in two streamflow gauging stations in north Queensland, Australia.

  11. Comparative Transcriptome Analysis between Broccoli (Brassica oleracea var. italica) and Wild Cabbage (Brassica macrocarpa Guss.) in Response to Plasmodiophora brassicae during Different Infection Stages.

    Science.gov (United States)

    Zhang, Xiaoli; Liu, Yumei; Fang, Zhiyuan; Li, Zhansheng; Yang, Limei; Zhuang, Mu; Zhang, Yangyong; Lv, Honghao

    2016-01-01

    Clubroot, one of the most devastating diseases to the Brassicaceae family, is caused by the obligate biotrophic pathogen Plasmodiophora brassicae . However, studies of the molecular basis of disease resistance are still poor especially in quantitative resistance. In the present paper, two previously identified genotypes, a clubroot-resistant genotype (wild cabbage, B2013) and a clubroot-susceptible genotype (broccoli, 90196) were inoculated by P. brassicae for 0 (T0), 7 (T7), and 14 (T14) day after inoculation (DAI). Gene expression pattern analysis suggested that response changes in transcript level of two genotypes under P. brassicae infection were mainly activated at the primary stage (T7). Based on the results of DEGs functional enrichments from two infection stages, genes associated with cell wall biosynthesis, glucosinolate biosynthesis, and plant hormone signal transduction showed down-regulated at T14 compared to T7, indicating that defense responses to P. brassicae were induced earlier, and related pathways were repressed at T14. In addition, the genes related to NBS-LRR proteins, SA signal transduction, cell wall and phytoalexins biosynthesis, chitinase, Ca 2+ signals and RBOH proteins were mainly up-regulated in B2013 by comparing those of 90196, indicating the pathways of response defense to clubroot were activated in the resistant genotype. This is the first report about comparative transcriptome analysis for broccoli and its wild relative during the different stages of P. brassicae infection and the results should be useful for molecular assisted screening and breeding of clubroot-resistant genotypes.

  12. Adherence rates to ferric citrate as compared to active control in patients with end stage kidney disease on dialysis.

    Science.gov (United States)

    Jalal, Diana; McFadden, Molly; Dwyer, Jamie P; Umanath, Kausik; Aguilar, Erwin; Yagil, Yoram; Greco, Barbara; Sika, Mohammed; Lewis, Julia B; Greene, Tom; Goral, Simin

    2017-04-01

    Oral phosphate binders are the main stay of treatment of hyperphosphatemia. Adherence rates to ferric citrate, a recently approved phosphate binder, are unknown. We conducted a post-hoc analysis to evaluate whether adherence rates were different for ferric citrate vs. active control in 412 subjects with end stage kidney disease (ESKD) who were randomized to ferric citrate vs. active control (sevelamer carbonate and/or calcium acetate). Adherence was defined as percent of actual number of pills taken to total number of pills prescribed. There were no significant differences in baseline characteristics including gender, race/ethnicity, and age between the ferric citrate and active control groups. Baseline phosphorus, calcium, and parathyroid hormone levels were similar. Mean (SD) adherence was 81.4% (17.4) and 81.7% (15.9) in the ferric citrate and active control groups, respectively (P = 0.88). Adherence remained similar between both groups after adjusting for gender, race/ethnicity, age, cardiovascular disease (CVD), and diabetic nephropathy (mean [95% CI]: 81.4% [78.2, 84.6] and 81.5% [77.7, 85.2] for ferric citrate and active control, respectively). Gender, race/ethnicity, age, and diagnosis of diabetic nephropathy did not influence adherence to the prescribed phosphate binder. Subjects with CVD had lower adherence rates to phosphate binder; this was significant only in the active control group. Adherence rates to the phosphate binder, ferric citrate, were similar to adherence rates to active control. Similar adherence rates to ferric citrate are notable since tolerance to active control was an entry criteria and the study was open label. Gender, race/ethnicity, nor age influenced adherence. © 2016 International Society for Hemodialysis.

  13. MRI, PET/CT and ultrasound in the preoperative staging of endometrial cancer - A multicenter prospective comparative study

    DEFF Research Database (Denmark)

    Antonsen, Sofie Leisby; Jensen, Lisa Neerup; Loft, Annika

    2012-01-01

    OBJECTIVES: The aim of this prospective multicenter study was to evaluate and compare the diagnostic performance of PET/CT, MRI and transvaginal two-dimensional ultrasound (2DUS) in the preoperative assessment of endometrial cancer (EC). METHODS: 318 consecutive women with EC were included when...

  14. One year of adjuvant tamoxifen compared with chemotherapy and tamoxifen in postmenopausal patients with stage II breast cancer

    DEFF Research Database (Denmark)

    Ejlertsen, Bent; Jensen, Maj-Britt; Elversang, Johanna

    2013-01-01

    We report the long-term results of a randomised trial comparing tamoxifen with tamoxifen plus cyclophosphamide, methotrexate and fluorouracil (CMF) in postmenopausal high-risk breast cancer patients. In addition, we analyse the prognostic and predictive value of centrally assessed subtypes....

  15. Comparing soil moisture memory in satellite observations and models

    Science.gov (United States)

    Stacke, Tobias; Hagemann, Stefan; Loew, Alexander

    2013-04-01

    A major obstacle to a correct parametrization of soil processes in large scale global land surface models is the lack of long term soil moisture observations for large parts of the globe. Currently, a compilation of soil moisture data derived from a range of satellites is released by the ESA Climate Change Initiative (ECV_SM). Comprising the period from 1978 until 2010, it provides the opportunity to compute climatological relevant statistics on a quasi-global scale and to compare these to the output of climate models. Our study is focused on the investigation of soil moisture memory in satellite observations and models. As a proxy for memory we compute the autocorrelation length (ACL) of the available satellite data and the uppermost soil layer of the models. Additional to the ECV_SM data, AMSR-E soil moisture is used as observational estimate. Simulated soil moisture fields are taken from ERA-Interim reanalysis and generated with the land surface model JSBACH, which was driven with quasi-observational meteorological forcing data. The satellite data show ACLs between one week and one month for the greater part of the land surface while the models simulate a longer memory of up to two months. Some pattern are similar in models and observations, e.g. a longer memory in the Sahel Zone and the Arabian Peninsula, but the models are not able to reproduce regions with a very short ACL of just a few days. If the long term seasonality is subtracted from the data the memory is strongly shortened, indicating the importance of seasonal variations for the memory in most regions. Furthermore, we analyze the change of soil moisture memory in the different soil layers of the models to investigate to which extent the surface soil moisture includes information about the whole soil column. A first analysis reveals that the ACL is increasing for deeper layers. However, its increase is stronger in the soil moisture anomaly than in its absolute values and the first even exceeds the

  16. A Two-Stage Queue Model to Optimize Layout of Urban Drainage System considering Extreme Rainstorms

    Directory of Open Access Journals (Sweden)

    Xinhua He

    2017-01-01

    Full Text Available Extreme rainstorm is a main factor to cause urban floods when urban drainage system cannot discharge stormwater successfully. This paper investigates distribution feature of rainstorms and draining process of urban drainage systems and uses a two-stage single-counter queue method M/M/1→M/D/1 to model urban drainage system. The model emphasizes randomness of extreme rainstorms, fuzziness of draining process, and construction and operation cost of drainage system. Its two objectives are total cost of construction and operation and overall sojourn time of stormwater. An improved genetic algorithm is redesigned to solve this complex nondeterministic problem, which incorporates with stochastic and fuzzy characteristics in whole drainage process. A numerical example in Shanghai illustrates how to implement the model, and comparisons with alternative algorithms show its performance in computational flexibility and efficiency. Discussions on sensitivity of four main parameters, that is, quantity of pump stations, drainage pipe diameter, rainstorm precipitation intensity, and confidence levels, are also presented to provide guidance for designing urban drainage system.

  17. A stage-structured, spatially explicit migration model for Myotis bats: mortality location affects system dynamics

    Science.gov (United States)

    Erickson, Richard A.; Thogmartin, Wayne E.; Russell, Robin E.; Diffendorfer, James E.; Szymanski, Jennifer A.

    2014-01-01

    Bats are ecologically and economically important species because they consume insects, transport nutrients, and pollinate flowers.  Many species of bats, including those in the Myotis genus, are facing population decline and increased extinction risk.  Despite these conservation concerns, few models exist for providing insight into the population dynamics of bats in a spatially explicit context.  We developed a model for bats by considering the stage-structured colonial life history of Myotis bats with their annual migration behavior.  This model provided insight into network dynamics.  We specifically focused on two Myotis species living in the eastern United States: the Indiana bat (M. sodalis), which is a Federally listed endangered species, and the little brown bat (M. lucifugus), which is under consideration for listing as an endangered species.  We found that multiple equilibria exist for the local, migratory subpopulations even though the total population was constant.  These equilibria suggest the location and magnitude of stressors such as White-nose Syndrome, meteorological phenomena, or impacts of wind turbines on survival influence system dynamics and risk of population extirpation in difficult to predict ways.

  18. Roadmap for Lean implementation in Indian automotive component manufacturing industry: comparative study of UNIDO Model and ISM Model

    Science.gov (United States)

    Jadhav, J. R.; Mantha, S. S.; Rane, S. B.

    2015-06-01

    The demands for automobiles increased drastically in last two and half decades in India. Many global automobile manufacturers and Tier-1 suppliers have already set up research, development and manufacturing facilities in India. The Indian automotive component industry started implementing Lean practices to fulfill the demand of these customers. United Nations Industrial Development Organization (UNIDO) has taken proactive approach in association with Automotive Component Manufacturers Association of India (ACMA) and the Government of India to assist Indian SMEs in various clusters since 1999 to make them globally competitive. The primary objectives of this research are to study the UNIDO-ACMA Model as well as ISM Model of Lean implementation and validate the ISM Model by comparing with UNIDO-ACMA Model. It also aims at presenting a roadmap for Lean implementation in Indian automotive component industry. This paper is based on secondary data which include the research articles, web articles, doctoral thesis, survey reports and books on automotive industry in the field of Lean, JIT and ISM. ISM Model for Lean practice bundles was developed by authors in consultation with Lean practitioners. The UNIDO-ACMA Model has six stages whereas ISM Model has eight phases for Lean implementation. The ISM-based Lean implementation model is validated through high degree of similarity with UNIDO-ACMA Model. The major contribution of this paper is the proposed ISM Model for sustainable Lean implementation. The ISM-based Lean implementation framework presents greater insight of implementation process at more microlevel as compared to UNIDO-ACMA Model.

  19. Demographics and Outcomes of Stage I-II Merkel Cell Carcinoma Treated with Mohs Micrographic Surgery Compared with Wide Local Excision in the National Cancer Data Base.

    Science.gov (United States)

    Singh, Babu; Qureshi, Muhammad M; Truong, Minh Tam; Sahni, Debjani

    2018-02-03

    The optimal surgical approach (wide local excision (WLE) vs. Mohs micrographic surgery (MOHS)) for treating Merkel cell carcinoma (MCC) is yet to be determined. To compare survival outcomes in patients with early stage MCC treated with MOHS versus WLE. A retrospective review of all cases in the National Cancer Data Base (NCDB) of MCC of clinical Stage I-II MCC treated with WLE or MOHS was performed. 1,795 cases of Stage I-II MCC were identified who underwent WLE (N=1,685) or MOHS (N=110). There was no difference in residual tumor on surgical margins between the two treatment groups (p=0.588). On multivariate analysis, there was no difference in overall survival between the treatment modalities (adjusted HR 1.02; 95% CI 0.72-1.45, p=0.897). There was no difference in overall survival between the two groups on propensity score matched analysis. Disease specific survival was not reported as this data in not available in the NCDB. MOHS appears to be as effective as WLE in treating early stage MCC. Copyright © 2018. Published by Elsevier Inc.

  20. A comparative study of proliferative activity and tumor stage of pregnancy-associated melanoma (PAM) and non-PAM in gestational age women.

    Science.gov (United States)

    Merkel, Emily A; Martini, Mary C; Amin, Sapna M; Yélamos, Oriol; Lee, Christina Y; Sholl, Lauren M; Rademaker, Alfred W; Guitart, Joan; Gerami, Pedram

    2016-01-01

    The influence of pregnancy on the development, progression, and prognosis of melanoma is controversial. We sought to compare clinical characteristics, histologic features, and proliferative activity in pregnancy-associated melanoma (PAM) and melanoma in nonpregnant women of reproductive age (non-PAM). In this retrospective cohort study, we reviewed medical records and pathology reports from women given a diagnosis of melanoma between 2006 and 2015. We also examined tumor proliferation rates using mitotic count and 2 immunohistochemical markers of proliferation, phosphohistone H3 and Ki-67. In 50 PAM and 122 non-PAM cases, a diagnosis of melanoma in situ was associated with PAM. Among invasive melanomas, there was no difference in proliferative activity between groups. Pregnancy status was also not associated with age at diagnosis, tumor site, Breslow depth, Clark level, ulceration, or overall stage. This was a retrospective study with a small sample size of mostly patients with early-stage melanoma. In our study of primarily early-stage melanoma, pregnancy did not have a significant impact on tumor proliferation. Particularly for patients given a diagnosis of stage I melanoma who are undergoing close surveillance, a history of PAM should not outweigh traditional factors, such as advanced maternal age, in planning future pregnancies. Copyright © 2015 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.

  1. Comparative analysis of methods of training and dietary habits of skilled bodybuilders in the run-general preparatory stage

    Directory of Open Access Journals (Sweden)

    Dzhym V.Y.

    2015-02-01

    Full Text Available Purpose : comparative analysis of the characteristics of methods of training and nutrition bodybuilders in the run-general of the preparatory phase (duration 4 - 5 months or 20 microcycles. Analyzed the characteristics of different methods of training bodybuilders to increase muscle mass. Material : the study involved 8 skilled bodybuilders, are included in the team of the Kharkiv region. Results : a comparative characteristic of the most commonly used methods of exercise and nutrition in bodybuilding. Discovered and proved the optimal technique for athletes depending on the original form at the beginning of general-preparatory phase of training. Driven changes in body weight, depending on the amount used Athlete of carbohydrates, proteins and fats. Conclusions : throughout the training period was characterized by severe protein diet orientation. The proportion of the nutrient was 40% in the first quarter, 50% - in the second, 60% in the third. Only in the last two microcycle decreased to 50%.

  2. Bevacizumab compared with Diode Laser in stage 3 posterior retinopathy of prematurity: a 5 year follow-up

    LENUS (Irish Health Repository)

    O’Keeffe, N

    2016-02-01

    We conducted a prospective randomized study to compare outcomes of intravitreal Bevacizumab versus diode laser in thirty eyes of fifteen premature babies with zone 1 or posterior zone 2 retinopathy of prematurity (ROP). We recorded complications, regression\\/reactivation of ROP, visual outcome, refractive error and systemic complications. The Bevacizumab-treated eyes showed rapid regression of the ROP with resolution of plus disease and flattening of the ridge at 48 hours post injection. In 3 Bevacizumab-treated eyes, reactivation occurred and were treated with laser (3 eyes) or a further Bevacizumab injection (1 eye). Of the diode laser treated eyes, one showed progression and was treated with Bevacizumab. At 5-year follow-up, good outcomes were observed in both treatment groups. However, less myopia was found in the Bevacizumab compared with the diode laser treated eyes.

  3. Comparing Numerical Spall Simulations with a Nonlinear Spall Formation Model

    Science.gov (United States)

    Ong, L.; Melosh, H. J.

    2012-12-01

    Spallation accelerates lightly shocked ejecta fragments to speeds that can exceed the escape velocity of the parent body. We present high-resolution simulations of nonlinear shock interactions in the near surface. Initial results show the acceleration of near-surface material to velocities up to 1.8 times greater than the peak particle velocity in the detached shock, while experiencing little to no shock pressure. These simulations suggest a possible nonlinear spallation mechanism to produce the high-velocity, low show pressure meteorites from other planets. Here we pre-sent the numerical simulations that test the production of spall through nonlinear shock interactions in the near sur-face, and compare the results with a model proposed by Kamegai (1986 Lawrence Livermore National Laboratory Report). We simulate near-surface shock interactions using the SALES_2 hydrocode and the Murnaghan equation of state. We model the shock interactions in two geometries: rectangular and spherical. In the rectangular case, we model a planar shock approaching the surface at a constant angle phi. In the spherical case, the shock originates at a point below the surface of the domain and radiates spherically from that point. The angle of the shock front with the surface is dependent on the radial distance of the surface point from the shock origin. We model the target as a solid with a nonlinear Murnaghan equation of state. This idealized equation of state supports nonlinear shocks but is tem-perature independent. We track the maximum pressure and maximum velocity attained in every cell in our simula-tions and compare them to the Hugoniot equations that describe the material conditions in front of and behind the shock. Our simulations demonstrate that nonlinear shock interactions in the near surface produce lightly shocked high-velocity material for both planar and cylindrical shocks. The spall is the result of the free surface boundary condi-tion, which forces a pressure gradient

  4. Comparative study of computational model for pipe whip analysis

    International Nuclear Information System (INIS)

    Koh, Sugoong; Lee, Young-Shin

    1993-01-01

    Many types of pipe whip restraints are installed to protect the structural components from the anticipated pipe whip phenomena of high energy lines in nuclear power plants. It is necessary to investigate these phenomena accurately in order to evaluate the acceptability of the pipe whip restraint design. Various research programs have been conducted in many countries to develop analytical methods and to verify the validity of the methods. In this study, various calculational models in ANSYS code and in ADLPIPE code, the general purpose finite element computer programs, were used to simulate the postulated pipe whips to obtain impact loads and the calculated results were compared with the specific experimental results from the sample pipe whip test for the U-shaped pipe whip restraints. Some calculational models, having the spring element between the pipe whip restraint and the pipe line, give reasonably good transient responses of the restraint forces compared with the experimental results, and could be useful in evaluating the acceptability of the pipe whip restraint design. (author)

  5. Does breast screening offer a survival benefit? A retrospective comparative study of oncological outcomes of screen-detected and symptomatic early stage breast cancer cases.

    Science.gov (United States)

    Újhelyi, M; Pukancsik, D; Kelemen, P; Kovács, E; Kenessey, I; Udvarhelyi, N; Bak, M; Kovács, T; Mátrai, Z

    2016-12-01

    Mammography screening reduces breast cancer mortality by up to 32%. However, some recent studies have questioned the impact of non-palpable breast cancer detection on mortality reduction. The aim of this study was to analyse the clinicopathological and long-term follow-up data of early stage screened and symptomatic breast cancer patients. The institutional prospectively led database was systematically analysed for breast cancer cases diagnosed via the mammography screening program from 2002 to 2009. As a control group, symptomatic early stage breast cancer patients were collected randomly from the same database and matched for age and follow-up period. All medical records were reviewed retrospectively. Data from 298 breast cancer patients were collected from 47,718 mammography screenings. In addition, 331 symptomatic breast cancer patients were randomly selected. The screened group presented a significantly lower median tumour size (P screened group (P screened group did not exhibit better overall (P = 0.717) or disease-free survival (P = 0.081) compared to the symptomatic group. Our results do not suggest that mammography screening does not reduce breast cancer mortality but the mammography screening did not bring any significant improvement in patient overall or disease-free survival for the early stage breast cancer patients compared to the symptomatic group. The drawback of symptomatic early stage tumours compared to non-palpable tumours could be equalized by modern multimodality oncology treatments. Copyright © 2016 Elsevier Ltd, BASO ~ the Association for Cancer Surgery, and the European Society of Surgical Oncology. All rights reserved.

  6. Spleen dynamic contrast-enhanced magnetic resonance imaging as a new method for staging liver fibrosis in a piglet model.

    Directory of Open Access Journals (Sweden)

    Li Zhou

    Full Text Available OBJECTIVE: To explore spleen hemodynamic alteration in liver fibrosis with dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI, and to determine how to stage liver fibrosis with spleen DCE-MRI parameters. MATERIALS AND METHODS: Sixteen piglets were prospectively used to model liver fibrosis staged by liver biopsy, and underwent spleen DCE-MRI on 0, 5th, 9th, 16th and 21st weekend after modeling this disease. DCE-MRI parameters including time to peak (TTP, positive enhancement integral (PEI, maximum slope of increase (MSI and maximum slope of decrease (MSD of spleen were measured, and statistically analyzed to stage this disease. RESULTS: Spearman's rank correlation tests showed that TTP tended to increase with increasing stages of liver fibrosis (r = 0.647, P0.05, and decreased from stage 2 to 4 (P0.05. Mann-Whitney tests demonstrated that TTP and PEI could classify fibrosis between stage 0 and 1-4, between 0-1 and 2-4, between 0-2 and 3-4, or between 0-3 and 4 (all P<0.01. MSD could discriminate between 0-2 and 3-4 (P = 0.006, or between 0-3 and 4 (P = 0.012. MSI could not differentiate between any two stages. Receiver operating characteristic analysis illustrated that area under receiver operating characteristic curve (AUC of TTP was larger than of PEI for classifying stage ≥1 and ≥2 (AUC = 0.851 and 0.783, respectively. PEI could best classify stage ≥3 and 4 (AUC = 0.903 and 0.96, respectively. CONCLUSION: Spleen DCE-MRI has potential to monitor spleen hemodynamic alteration and classify liver fibrosis stages.

  7. THE PROPAGATION OF UNCERTAINTIES IN STELLAR POPULATION SYNTHESIS MODELING. II. THE CHALLENGE OF COMPARING GALAXY EVOLUTION MODELS TO OBSERVATIONS

    International Nuclear Information System (INIS)

    Conroy, Charlie; Gunn, James E.; White, Martin

    2010-01-01

    Models for the formation and evolution of galaxies readily predict physical properties such as star formation rates, metal-enrichment histories, and, increasingly, gas and dust content of synthetic galaxies. Such predictions are frequently compared to the spectral energy distributions of observed galaxies via the stellar population synthesis (SPS) technique. Substantial uncertainties in SPS exist, and yet their relevance to the task of comparing galaxy evolution models to observations has received little attention. In the present work, we begin to address this issue by investigating the importance of uncertainties in stellar evolution, the initial stellar mass function (IMF), and dust and interstellar medium (ISM) properties on the translation from models to observations. We demonstrate that these uncertainties translate into substantial uncertainties in the ultraviolet, optical, and near-infrared colors of synthetic galaxies. Aspects that carry significant uncertainties include the logarithmic slope of the IMF above 1 M sun , dust attenuation law, molecular cloud disruption timescale, clumpiness of the ISM, fraction of unobscured starlight, and treatment of advanced stages of stellar evolution including blue stragglers, the horizontal branch, and the thermally pulsating asymptotic giant branch. The interpretation of the resulting uncertainties in the derived colors is highly non-trivial because many of the uncertainties are likely systematic, and possibly correlated with the physical properties of galaxies. We therefore urge caution when comparing models to observations.

  8. Stage-dependent alterations of progenitor cell proliferation and neurogenesis in an animal model of Wernicke-Korsakoff syndrome.

    Science.gov (United States)

    Vetreno, Ryan P; Klintsova, Anna; Savage, Lisa M

    2011-05-19

    Alcohol-induced Wernicke-Korsakoff syndrome (WKS) culminates in bilateral diencephalic lesion and severe amnesia. Using the pyrithiamine-induced thiamine deficiency (PTD) animal paradigm of WKS, our laboratory has demonstrated hippocampal dysfunction in the absence of gross anatomical pathology. Extensive literature has revealed reduced hippocampal neurogenesis following a neuropathological insult, which might contribute to hippocampus-based learning and memory impairments. Thus, the current investigation was conducted to determine whether PTD treatment altered hippocampal neurogenesis in a stage-dependent fashion. Male Sprague-Dawley rats were assigned to one of 4 stages of thiamine deficiency based on behavioral symptoms: pre-symptomatic stage, ataxic stage, early post-opisthotonus stage, or the late post-opisthotonus stage. The S-phase mitotic marker 5'-bromo-2'-deoxyuridine (BrdU) was administered at the conclusion of each stage following thiamine restoration and subjects were perfused 24 hours or 28 days after BrdU to assess cellular proliferation or neurogenesis and survival, respectively. Dorsal hippocampal sections were immunostained for BrdU (proliferating cell marker), NeuN (neurons), GFAP (astrocytes), Iba-1 (microglia), and O4 (oligodendrocytes). The PTD treatment increased progenitor cell proliferation and survival during the early post-opisthotonus stage. However, levels of neurogenesis were reduced during this stage as well as the late post-opisthotonus stage where there was also an increase in astrocytogenesis. The diminished numbers of newly generated neurons (BrdU/NeuN co-localization) was paralleled by increased BrdU cells that did not co-localize with any of the phenotypic markers during these later stages. These data demonstrate that long-term alterations in neurogenesis and gliogenesis might contribute to the observed hippocampal dysfunction in the PTD model and human WKS. Published by Elsevier B.V.

  9. THE FLAT TAX - A COMPARATIVE STUDY OF THE EXISTING MODELS

    Directory of Open Access Journals (Sweden)

    Schiau (Macavei Laura - Liana

    2011-07-01

    Full Text Available In the two last decades the flat tax systems have spread all around the globe from East and Central Europe to Asia and Central America. Many specialists consider this phenomenon a real fiscal revolution, but others see it as a mistake as long as the new systems are just a feint of the true flat tax designed by the famous Stanford University professors Robert Hall and Alvin Rabushka. In this context this paper tries to determine which of the existing flat tax systems resemble the true flat tax model by comparing and contrasting their main characteristics with the features of the model proposed by Hall and Rabushka. The research also underlines the common features and the differences between the existing models. The idea of this kind of study is not really new, others have done it but the comparison was limited to one country. For example Emil Kalchev from New Bulgarian University has asses the Bulgarian income system, by comparing it with the flat tax and concluding that taxation in Bulgaria is not simple, neutral and non-distortive. Our research is based on several case studies and on compare and contrast qualitative and quantitative methods. The study starts form the fiscal design drawn by the two American professors in the book The Flat Tax. Four main characteristics of the flat tax system were chosen in order to build the comparison: fiscal design, simplicity, avoidance of double taxation and uniformity of the tax rates. The jurisdictions chosen for the case study are countries all around the globe with fiscal systems which are considered flat tax systems. The results obtained show that the fiscal design of Hong Kong is the only flat tax model which is built following an economic logic and not a legal sense, being in the same time a simple and transparent system. Others countries as Slovakia, Albania, Macedonia in Central and Eastern Europe fulfill the requirement regarding the uniformity of taxation. Other jurisdictions avoid the double

  10. Animal Models for Evaluation of Bone Implants and Devices: Comparative Bone Structure and Common Model Uses.

    Science.gov (United States)

    Wancket, L M

    2015-09-01

    Bone implants and devices are a rapidly growing field within biomedical research, and implants have the potential to significantly improve human and animal health. Animal models play a key role in initial product development and are important components of nonclinical data included in applications for regulatory approval. Pathologists are increasingly being asked to evaluate these models at the initial developmental and nonclinical biocompatibility testing stages, and it is important to understand the relative merits and deficiencies of various species when evaluating a new material or device. This article summarizes characteristics of the most commonly used species in studies of bone implant materials, including detailed information about the relevance of a particular model to human bone physiology and pathology. Species reviewed include mice, rats, rabbits, guinea pigs, dogs, sheep, goats, and nonhuman primates. Ultimately, a comprehensive understanding of the benefits and limitations of different model species will aid in rigorously evaluating a novel bone implant material or device. © The Author(s) 2015.

  11. A comparison of two-component and quadratic models to assess survival of irradiated stage-7 oocytes of Drosophila melanogaster

    International Nuclear Information System (INIS)

    Peres, C.A.; Koo, J.O.

    1981-01-01

    In this paper, the quadratic model to analyse data of this kind, i.e. S/S 0 = exp(-αD-bD 2 ), where S and Ssub(o) are defined as before is proposed is shown that the same biological interpretation can be given to the parameters α and A and to the parameters β and B. Furthermore it is shown that the quadratic model involves one probabilistic stage more than the two-component model, and therefore the quadratic model would perhaps be more appropriate as a dose-response model for survival of irradiated stage-7 oocytes of Drosophila melanogaster. In order to apply these results, the data presented by Sankaranarayanan and Sankaranarayanan and Volkers are reanalysed using the quadratic model. It is shown that the quadratic model fits better than the two-component model to the data in most situations. (orig./AJ)

  12. Global Analysis of a Model of Viral Infection with Latent Stage and Two Types of Target Cells

    Directory of Open Access Journals (Sweden)

    Shuo Liu

    2013-01-01

    Full Text Available By introducing the probability function describing latency of infected cells, we unify some models of viral infection with latent stage. For the case that the probability function is a step function, which implies that the latency period of the infected cells is constant, the corresponding model is a delay differential system. The model with delay of latency and two types of target cells is investigated, and the obtained results show that when the basic reproduction number is less than or equal to unity, the infection-free equilibrium is globally stable, that is, the in-host free virus will be cleared out finally; when the basic reproduction number is greater than unity, the infection equilibrium is globally stable, that is, the viral infection will be chronic and persist in-host. And by comparing the basic reproduction numbers of ordinary differential system and the associated delayed differential system, we think that it is necessary to elect an appropriate type of probability function for predicting the final outcome of viral infection in-host.

  13. Multi-objective optimization of generalized reliability design problems using feature models-A concept for early design stages

    International Nuclear Information System (INIS)

    Limbourg, Philipp; Kochs, Hans-Dieter

    2008-01-01

    Reliability optimization problems such as the redundancy allocation problem (RAP) have been of considerable interest in the past. However, due to the restrictions of the design space formulation, they may not be applicable in all practical design problems. A method with high modelling freedom for rapid design screening is desirable, especially in early design stages. This work presents a novel approach to reliability optimization. Feature modelling, a specification method originating from software engineering, is applied for the fast specification and enumeration of complex design spaces. It is shown how feature models can not only describe arbitrary RAPs but also much more complex design problems. The design screening is accomplished by a multi-objective evolutionary algorithm for probabilistic objectives. Comparing averages or medians may hide the true characteristics of this distributions. Therefore the algorithm uses solely the probability of a system dominating another to achieve the Pareto optimal set. We illustrate the approach by specifying a RAP and a more complex design space and screening them with the evolutionary algorithm

  14. An appreciation of Bruce and Young's (1986) serial stage model of face naming after 25 years.

    Science.gov (United States)

    Hanley, J Richard

    2011-11-01

    The current status of Bruce and Young's (1986) serial model of face naming is discussed 25 years after its original publication. In the first part of the paper, evidence for and against the serial model is reviewed. It is argued that there is no compelling reason why we should abandon Bruce and Young's claim that recall of a name is contingent upon prior retrieval of semantic information about the person. The current status of the claim that people's names are more difficult to recall than the names of objects is then evaluated. Finally, an account of the anatomical location in the brain of Bruce and Young's three processing stages (face familiarity, retrieval of semantic information, retrieval of names) is suggested. In particular, there is evidence that biographical knowledge about familiar people is stored in the right anterior temporal lobes (ATL) and that the left temporal pole (TP) is heavily involved in retrieval of the names of familiar people. The issue of whether these brain areas play a similar role in object processing is also discussed. ©2011 The British Psychological Society.

  15. A 3-stage model of patient-centered communication for addressing cancer patients' emotional distress.

    Science.gov (United States)

    Dean, Marleah; Street, Richard L

    2014-02-01

    To describe pathways through which clinicians can more effectively respond to patients' emotions in ways that contribute to betterment of the patient's health and well-being. A representative review of literature on managing emotions in clinical consultations was conducted. A three-stage, conceptual model for assisting clinicians to more effectively address the challenges of recognizing, exploring, and managing cancer patients' emotional distress in the clinical encounter was developed. To enhance and enact recognition of patients' emotions, clinicians can engage in mindfulness, self-situational awareness, active listening, and facilitative communication. To enact exploration, clinicians can acknowledge and validate emotions and provide empathy. Finally, clinicians can provide information empathetically, identify therapeutic resources, and give referrals and interventions as needed to help lessen patients' emotional distress. This model serves as a framework for future research examining pathways that link clinicians' emotional cue recognition to patient-centered responses exploring a patient's emotional distress to therapeutic actions that contribute to improved psychological and emotional health. Specific communicative and cognitive strategies are presented that can help clinicians better recognize a patient's emotional distress and respond in ways that have therapeutic value. Published by Elsevier Ireland Ltd.

  16. Two-stage collaborative global optimization design model of the CHPG microgrid

    Science.gov (United States)

    Liao, Qingfen; Xu, Yeyan; Tang, Fei; Peng, Sicheng; Yang, Zheng

    2017-06-01

    With the continuous developing of technology and reducing of investment costs, renewable energy proportion in the power grid is becoming higher and higher because of the clean and environmental characteristics, which may need more larger-capacity energy storage devices, increasing the cost. A two-stage collaborative global optimization design model of the combined-heat-power-and-gas (abbreviated as CHPG) microgrid is proposed in this paper, to minimize the cost by using virtual storage without extending the existing storage system. P2G technology is used as virtual multi-energy storage in CHPG, which can coordinate the operation of electric energy network and natural gas network at the same time. Demand response is also one kind of good virtual storage, including economic guide for the DGs and heat pumps in demand side and priority scheduling of controllable loads. Two kinds of storage will coordinate to smooth the high-frequency fluctuations and low-frequency fluctuations of renewable energy respectively, and achieve a lower-cost operation scheme simultaneously. Finally, the feasibility and superiority of proposed design model is proved in a simulation of a CHPG microgrid.

  17. Simulation of the Two Stages Stretch-Blow Molding Process: Infrared Heating and Blowing Modeling

    International Nuclear Information System (INIS)

    Bordival, M.; Schmidt, F. M.; Le Maoult, Y.; Velay, V.

    2007-01-01

    In the Stretch-Blow Molding (SBM) process, the temperature distribution of the reheated perform affects drastically the blowing kinematic, the bottle thickness distribution, as well as the orientation induced by stretching. Consequently, mechanical and optical properties of the final bottle are closely related to heating conditions. In order to predict the 3D temperature distribution of a rotating preform, numerical software using control-volume method has been developed. Since PET behaves like a semi-transparent medium, the radiative flux absorption was computed using Beer Lambert law. In a second step, 2D axi-symmetric simulations of the SBM have been developed using the finite element package ABAQUS registered . Temperature profiles through the preform wall thickness and along its length were computed and applied as initial condition. Air pressure inside the preform was not considered as an input variable, but was automatically computed using a thermodynamic model. The heat transfer coefficient applied between the mold and the polymer was also measured. Finally, the G'sell law was used for modeling PET behavior. For both heating and blowing stage simulations, a good agreement has been observed with experimental measurements. This work is part of the European project ''APT P ACK'' (Advanced knowledge of Polymer deformation for Tomorrow's PACKaging)

  18. Simulation of the Two Stages Stretch-Blow Molding Process: Infrared Heating and Blowing Modeling

    Science.gov (United States)

    Bordival, M.; Schmidt, F. M.; Le Maoult, Y.; Velay, V.

    2007-05-01

    In the Stretch-Blow Molding (SBM) process, the temperature distribution of the reheated perform affects drastically the blowing kinematic, the bottle thickness distribution, as well as the orientation induced by stretching. Consequently, mechanical and optical properties of the final bottle are closely related to heating conditions. In order to predict the 3D temperature distribution of a rotating preform, numerical software using control-volume method has been developed. Since PET behaves like a semi-transparent medium, the radiative flux absorption was computed using Beer Lambert law. In a second step, 2D axi-symmetric simulations of the SBM have been developed using the finite element package ABAQUS®. Temperature profiles through the preform wall thickness and along its length were computed and applied as initial condition. Air pressure inside the preform was not considered as an input variable, but was automatically computed using a thermodynamic model. The heat transfer coefficient applied between the mold and the polymer was also measured. Finally, the G'sell law was used for modeling PET behavior. For both heating and blowing stage simulations, a good agreement has been observed with experimental measurements. This work is part of the European project "APT_PACK" (Advanced knowledge of Polymer deformation for Tomorrow's PACKaging).

  19. Comparative effect of fixed dose combination of Amlodipine + Bisoprolol versus Amlodipine and Bisoprolol alone on blood pressure in stage-2 essential hypertensive patients.

    Directory of Open Access Journals (Sweden)

    Shirure PA,Tadvi NA, Bajait CS, Baig MS, Gade PR

    2012-09-01

    Full Text Available Background: Employment of low dose combinations of two antihypertensives, with different mode of action has gained acceptance worldwide for the treatment of mild to moderate hypertension. However, most studies in hypertensive disease have focused on monotherapy. The combination therapy in the treatment of hypertension is largely extrapolated from these monotherapy studies. Objectives: To study and compare the effect of amlodipine, bisoprolol and fixed dose combination of amlodipine + bisoprolol on blood pressure in stage-2 essential hypertensive patients. Methods: The present study was carried out in Department of Pharmacology in collaboration with Department of Medicine at Government Medical College and Hospital, Aurangabad. Results and Conclusion : Amlodipine + bisoprolol in fixed dose combination have showed significant blood pressure control in patients of stage-2 essential hypertension and the antihypertensive effect was greater than individual monotherapy study groups.

  20. An audit comparing the reporting of staging MRI scans for rectal cancer with the London Cancer Alliance (LCA) guidelines.

    Science.gov (United States)

    Siddiqui, M R S; Shanmuganandan, A P; Rasheed, S; Tekkis, P; Brown, G; Abulafi, A M

    2017-11-01

    This article focuses on the audit and assessment of clinical practice before and after introduction of MRI reporting guidelines. Standardised proforma based reporting may improve quality of MRI reports. Uptake of the use may be facilitated by endorsement from regional and national cancer organisations. This audit was divided into 2 phases. MRI reports issued between April 2014 and June 2014 were included in the first part of our audit. Phase II included MRI reports issued between April 2015 and June 2015. 14 out of 15 hospitals that report MRI scans in the LCA responded to our audit proposal. The completion rate of key MRI metrics/metrics was better in proforma compared to prose reports both before (98% vs 73%; p < 0.05) and after introduction of the guidelines (98% vs 71%; p < 0.05). There was an approximate doubling of proforma reporting after the introduction of guidelines and workshop interventions (39% vs 65%; p < 0.05). Evaluation of locally advanced cancers (tumours extending to or beyond the circumferential resection margin) for beyond TME surgery was reported in 3% of prose reports vs. 42% in proformas. Incorporation of standardised reporting in official guidelines improved the uptake of proforma based reporting. Proforma based reporting captured more MRI reportable items compared to prose summaries, before and after the implementation of guidelines. MRI reporting of advanced cancers for beyond TME surgery falls short of acceptable standards but is more detailed in proforma based reports. Further work to improve completion especially in beyond TME reporting is required. Copyright © 2017 Elsevier Ltd, BASO ~ The Association for Cancer Surgery, and the European Society of Surgical Oncology. All rights reserved.

  1. Utility-free heuristic models of two-option choice can mimic predictions of utility-stage models under many conditions

    Directory of Open Access Journals (Sweden)

    Steven T Piantadosi

    2015-04-01

    Full Text Available Economists often model choices as if decision-makers assign each option a scalar value variable, known as utility, and then select the option with the highest utility. It remains unclear whether as-if utility models describe real mental and neural steps in choice. Although choices alone cannot prove the existence of a utility stage in choice, utility transformations are often taken to provide the most parsimonious or psychologically plausible explanation for choice data. Here, we show that it is possible to mathematically transform a large set of common utility-stage two-option choice models (specifically ones in which dimensions are linearly separable into a psychologically plausible heuristic model (specifically, a dimensional prioritization heuristic that has no utility computation stage. We then show that under a range of plausible assumptions, both classes of model predict similar neural responses. These results highlight the difficulties in using neuroeconomic data to infer the existence of a value stage in choice.

  2. Utility-free heuristic models of two-option choice can mimic predictions of utility-stage models under many conditions

    Science.gov (United States)

    Piantadosi, Steven T.; Hayden, Benjamin Y.

    2015-01-01

    Economists often model choices as if decision-makers assign each option a scalar value variable, known as utility, and then select the option with the highest utility. It remains unclear whether as-if utility models describe real mental and neural steps in choice. Although choices alone cannot prove the existence of a utility stage, utility transformations are often taken to provide the most parsimonious or psychologically plausible explanation for choice data. Here, we show that it is possible to mathematically transform a large set of common utility-stage two-option choice models (specifically ones in which dimensions are can be decomposed into additive functions) into a heuristic model (specifically, a dimensional prioritization heuristic) that has no utility computation stage. We then show that under a range of plausible assumptions, both classes of model predict similar neural responses. These results highlight the difficulties in using neuroeconomic data to infer the existence of a value stage in choice. PMID:25914613

  3. Comparative benefit of malaria chemoprophylaxis modelled in United Kingdom travellers.

    Science.gov (United States)

    Toovey, Stephen; Nieforth, Keith; Smith, Patrick; Schlagenhauf, Patricia; Adamcova, Miriam; Tatt, Iain; Tomianovic, Danitza; Schnetzler, Gabriel

    2014-01-01

    .3% decrease in estimated infections. The number of travellers experiencing moderate adverse events (AE) or those requiring medical attention or drug withdrawal per case prevented is as follows: C ± P 170, Mq 146, Dx 114, AP 103. The model correctly predicted the number of malaria deaths, providing a robust and reliable estimate of the number of imported malaria cases in the UK, and giving a measure of benefit derived from chemoprophylaxis use against the likely adverse events generated. Overall numbers needed to prevent a malaria infection are comparable among the four options and are sensitive to changes in the background infection rates. Only a limited impact on the number of infections can be expected if Mq is substituted by AP.

  4. Tracking cognitive processing stages with MEG : A spatio-temporal model of associative recognition in the brain

    NARCIS (Netherlands)

    Borst, Jelmer P; Ghuman, Avniel S; Anderson, John R

    2016-01-01

    In this study, we investigated the cognitive processing stages underlying associative recognition using MEG. Over the last four decades, a model of associative recognition has been developed in the ACT-R cognitive architecture. This model was first exclusively based on behavior, but was later

  5. Re-thinking stages of cognitive development: an appraisal of connectionist models on the balance scale task

    NARCIS (Netherlands)

    Quinlan, P.T.; van der Maas, H.L.J.; Jansen, B.R.J.; Booij, O.; Rendell, M.

    2007-01-01

    The present paper re-appraises connectionist attempts to explain how human cognitive development appears to progress through a series of sequential stages. Models of performance on the Piagetian balance scale task are the focus of attention. Limitations of these models are discussed and replications

  6. Two-stage Lagrangian modeling of ignition processes in ignition quality tester and constant volume combustion chambers

    KAUST Repository

    Alfazazi, Adamu; Kuti, Olawole Abiola; Naser, Nimal; Chung, Suk-Ho; Sarathy, Mani

    2016-01-01

    The ignition characteristics of isooctane and n-heptane in an ignition quality tester (IQT) were simulated using a two-stage Lagrangian (TSL) model, which is a zero-dimensional (0-D) reactor network method. The TSL model was also used to simulate

  7. An idealized model for tree-grass coexistence in savannas : The role of life stage structure and fire disturbances

    NARCIS (Netherlands)

    Baudena, Mara|info:eu-repo/dai/nl/340303867; D'Andrea, Fabio; Provenzale, A.

    2010-01-01

    1. We discuss a simple implicit-space model for the competition of trees and grasses in an idealized savanna environment. The model represents patch occupancy dynamics within the habitat and introduces life stage structure in the tree population, namely adults and seedlings. A tree can be

  8. Assessing vanadium and arsenic exposure of people living near a petrochemical complex with two-stage dispersion models

    International Nuclear Information System (INIS)

    Chio, Chia-Pin; Yuan, Tzu-Hsuen; Shie, Ruei-Hao; Chan, Chang-Chuan

    2014-01-01

    Highlights: • Two-stage dispersion models can estimate exposures to hazardous air pollutants. • Spatial distribution of V levels is derived for sources without known emission rates. • A distance-to-source gradient is found for V levels from a petrochemical complex. • Two-stage dispersion is useful for modeling air pollution in resource-limited areas. - Abstract: The goal of this study is to demonstrate that it is possible to construct a two-stage dispersion model empirically for the purpose of estimating air pollution levels in the vicinity of petrochemical plants. We studied oil refineries and coal-fired power plants in the No. 6 Naphtha Cracking Complex, an area of 2,603-ha situated on the central west coast of Taiwan. The pollutants targeted were vanadium (V) from oil refineries and arsenic (As) from coal-fired power plants. We applied a backward fitting method to determine emission rates of V and As, with 192 PM 10 filters originally collected between 2009 and 2012. Our first-stage model estimated emission rates of V and As (median and 95% confidence intervals at 0.0202 (0.0040–0.1063) and 0.1368 (0.0398–0.4782) g/s, respectively. In our second stage model, the predicted zone-average concentrations showed a strong correlation with V, but a poor correlation with As. Our findings show that two-stage dispersion models are relatively precise for estimating V levels at residents’ addresses near the petrochemical complex, but they did not work as well for As levels. In conclusion, our model-based approach can be widely used for modeling exposure to air pollution from industrial areas in countries with limited resources

  9. A comparative study of machine learning models for ethnicity classification

    Science.gov (United States)

    Trivedi, Advait; Bessie Amali, D. Geraldine

    2017-11-01

    This paper endeavours to adopt a machine learning approach to solve the problem of ethnicity recognition. Ethnicity identification is an important vision problem with its use cases being extended to various domains. Despite the multitude of complexity involved, ethnicity identification comes naturally to humans. This meta information can be leveraged to make several decisions, be it in target marketing or security. With the recent development of intelligent systems a sub module to efficiently capture ethnicity would be useful in several use cases. Several attempts to identify an ideal learning model to represent a multi-ethnic dataset have been recorded. A comparative study of classifiers such as support vector machines, logistic regression has been documented. Experimental results indicate that the logical classifier provides a much accurate classification than the support vector machine.

  10. Comparative molecular analysis of early and late cancer cachexia-induced muscle wasting in mouse models.

    Science.gov (United States)

    Sun, Rulin; Zhang, Santao; Lu, Xing; Hu, Wenjun; Lou, Ning; Zhao, Yan; Zhou, Jia; Zhang, Xiaoping; Yang, Hongmei

    2016-12-01

    Cancer-induced muscle wasting, which commonly occurs in cancer cachexia, is characterized by impaired quality of life and poor patient survival. To identify an appropriate treatment, research on the mechanism underlying muscle wasting is essential. Thus far, studies on muscle wasting using cancer cachectic models have generally focused on early cancer cachexia (ECC), before severe body weight loss occurs. In the present study, we established models of ECC and late cancer cachexia (LCC) and compared different stages of cancer cachexia using two cancer cachectic mouse models induced by colon-26 (C26) adenocarcinoma or Lewis lung carcinoma (LLC). In each model, tumor-bearing (TB) and control (CN) mice were injected with cancer cells and PBS, respectively. The TB and CN mice, which were euthanized on the 24th day or the 36th day after injection, were defined as the ECC and ECC-CN mice or the LCC and LCC-CN mice. In addition, the tissues were harvested and analyzed. We found that both the ECC and LCC mice developed cancer cachexia. The amounts of muscle loss differed between the ECC and LCC mice. Moreover, the expression of some molecules was altered in the muscles from the LCC mice but not in those from the ECC mice compared with their CN mice. In conclusion, the molecules with altered expression in the muscles from the ECC and LCC mice were not exactly the same. These findings may provide some clues for therapy which could prevent the muscle wasting in cancer cachexia from progression to the late stage.

  11. Circuit models and three-dimensional electromagnetic simulations of a 1-MA linear transformer driver stage

    Directory of Open Access Journals (Sweden)

    D. V. Rose

    2010-09-01

    Full Text Available A 3D fully electromagnetic (EM model of the principal pulsed-power components of a high-current linear transformer driver (LTD has been developed. LTD systems are a relatively new modular and compact pulsed-power technology based on high-energy density capacitors and low-inductance switches located within a linear-induction cavity. We model 1-MA, 100-kV, 100-ns rise-time LTD cavities [A. A. Kim et al., Phys. Rev. ST Accel. Beams 12, 050402 (2009PRABFM1098-440210.1103/PhysRevSTAB.12.050402] which can be used to drive z-pinch and material dynamics experiments. The model simulates the generation and propagation of electromagnetic power from individual capacitors and triggered gas switches to a radially symmetric output line. Multiple cavities, combined to provide voltage addition, drive a water-filled coaxial transmission line. A 3D fully EM model of a single 1-MA 100-kV LTD cavity driving a simple resistive load is presented and compared to electrical measurements. A new model of the current loss through the ferromagnetic cores is developed for use both in circuit representations of an LTD cavity and in the 3D EM simulations. Good agreement between the measured core current, a simple circuit model, and the 3D simulation model is obtained. A 3D EM model of an idealized ten-cavity LTD accelerator is also developed. The model results demonstrate efficient voltage addition when driving a matched impedance load, in good agreement with an idealized circuit model.

  12. Comparative study: Oral mucosal lesions, signs and symptoms in diabetes mellitus patients with end stage renal disease with analogous findings in diabetes mellitus patients with non-end stage renal disease

    Directory of Open Access Journals (Sweden)

    Balasubramani Senthil

    2017-01-01

    Full Text Available Aim: The aim of this study is to compare oral signs, symptoms and oral lesions type and prevalence, in end stage renal disease (ESRD with non-end stage renal disease (NESRD in diabetes mellitus (DM patients. Methodology: Two groups of DM patients were studied, Group 1 includes 100 patients with ESRD, who were under hemodialysis therapy, and Group 2 includes100 patients with NESRD whose serum creatinine level is <2.0 mg/dl. The DM status and other laboratory investigations were recorded, with the patients consent and thorough oral examination was performed and the findings were recorded. All the data were entered into Microsoft Excel sheets. Statistical analysis including Pearson's correlation analysis, Chi-square test, and t-test were done using SPSS software SYSTAT version 7.0. Results: On thorough clinical examination, the prevalence of oral lesions was found to be higher in ESRD patients. The most common lesions such as saburral tongue (P ≤ 0.002, petechiae/ecchymoses (P ≤ 0.000, pale mucosa (P ≤ 0.000, stomatitis medicamentosa (P ≤ 0.043 fissured tongue, smooth tongue, candidiasis, dry and fissured lips, angular cheilitis, uremic stomatitis, signs such as uremic fetor (P ≤ 0.000, xerostomia and symptoms like burning tongue, unpleasant taste are noted. Conclusion: The high prevalence of uremic fetor, saburral tongue, pale mucosa, and petechiae/ecchymoses in ESRD patient group can be considered as a possible sign of undiagnosed advanced stage of renal disease in other diabetic patients.

  13. Two-stage model of development of heterogeneous uranium-lead systems in zircon

    International Nuclear Information System (INIS)

    Mel'nikov, N.N.; Zevchenkov, O.A.

    1985-01-01

    Behaviour of isotope systems of multiphase zircons at their two-stage distortion is considered. The results of calculations testify to the fact that linear correlations on the diagram with concordance can be explained including two-stage discovery of U-Pb systems of cogenetic zircons if zircon is considered physically heterogeneous and losing in its different part different ratios of accumulated radiogenic lead. ''Metamorphism ages'' obtained by these two-stage opening zircons are intermediate, and they not have geochronological significance while ''crystallization ages'' remain rather close to real ones. Two-stage opening zircons in some cases can be diagnosed by discordance of their crystal component

  14. Validity and reliability of an application review process using dedicated reviewers in one stage of a multi-stage admissions model.

    Science.gov (United States)

    Zeeman, Jacqueline M; McLaughlin, Jacqueline E; Cox, Wendy C

    2017-11-01

    With increased emphasis placed on non-academic skills in the workplace, a need exists to identify an admissions process that evaluates these skills. This study assessed the validity and reliability of an application review process involving three dedicated application reviewers in a multi-stage admissions model. A multi-stage admissions model was utilized during the 2014-2015 admissions cycle. After advancing through the academic review, each application was independently reviewed by two dedicated application reviewers utilizing a six-construct rubric (written communication, extracurricular and community service activities, leadership experience, pharmacy career appreciation, research experience, and resiliency). Rubric scores were extrapolated to a three-tier ranking to select candidates for on-site interviews. Kappa statistics were used to assess interrater reliability. A three-facet Many-Facet Rasch Model (MFRM) determined reviewer severity, candidate suitability, and rubric construct difficulty. The kappa statistic for candidates' tier rank score (n = 388 candidates) was 0.692 with a perfect agreement frequency of 84.3%. There was substantial interrater reliability between reviewers for the tier ranking (kappa: 0.654-0.710). Highest construct agreement occurred in written communication (kappa: 0.924-0.984). A three-facet MFRM analysis explained 36.9% of variance in the ratings, with 0.06% reflecting application reviewer scoring patterns (i.e., severity or leniency), 22.8% reflecting candidate suitability, and 14.1% reflecting construct difficulty. Utilization of dedicated application reviewers and a defined tiered rubric provided a valid and reliable method to effectively evaluate candidates during the application review process. These analyses provide insight into opportunities for improving the application review process among schools and colleges of pharmacy. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Mid-term follow-up outcomes of 2-staged hybrid coronary revascularization compared with off-pump coronary artery bypass for patients with multivessel coronary artery disease.

    Science.gov (United States)

    Wu, Song; Ling, Yunpeng; Fu, Yuanhao; Zhang, Lufeng; Yang, Hang; Guo, Lijun; Gao, Wei; Wan, Feng

    2017-06-01

    Two-staged hybrid coronary revascularization (HCR) is a novel procedure in selected patients with multivessel coronary artery disease. However, few studies are available on the mid-term or long-term outcomes of this 2-staged procedure as compared to off-pump coronary artery bypass (OPCAB). To compare in-hospital and mid-term follow-up outcomes of 2-staged HCR with OPCAB in patients with multivessel coronary artery disease. The present retrospective study analyzed the data from 73 patients who underwent the 2-staged HCR (HCR group) during 2012-2014 at the heart center. Three hundred and eighty-three patients who underwent conventional OPCAB by the same surgeon were selected for the comparative analysis performed on in-hospital and mid-term follow-up outcomes between the two groups. No significant difference was observed in the preoperative outcome between the two groups. The HCR group had a shorter operation duration (152.9 ±43.8 vs. 262.6 ±51.8 min, p < 0.05), less bleeding (558.6 ±441.3 vs. 1035.5 ±613.3 ml, p < 0.05), shorter mechanical ventilation (9.4 ±7.4 vs. 19.0 ±18.3 h, p < 0.05), and less blood transfusion (12 (16.4%) vs. 200 (52.2%), p < 0.05). The mean follow-up duration was 25.0 ±9.6 months in the HCR group and 22.8 ±10.6 months in the OPCAB group. The incidence of major adverse cardiac or cerebrovascular events (MACCE) was similar in both groups (4 (5.5%) vs. 10 (2.8%), p = 0.408). The estimated 3-year survival was similar in both groups (log-rank χ 2 = 1.041, p = 0.308). The 2-staged HCR is a safe and effective surgical procedure and may offer similar mid-term follow-up outcomes to OPCAB.

  16. Comparative metabolomics of drought acclimation in model and forage legumes.

    Science.gov (United States)

    Sanchez, Diego H; Schwabe, Franziska; Erban, Alexander; Udvardi, Michael K; Kopka, Joachim

    2012-01-01

    Water limitation has become a major concern for agriculture. Such constraints reinforce the urgent need to understand mechanisms by which plants cope with water deprivation. We used a non-targeted metabolomic approach to explore plastic systems responses to non-lethal drought in model and forage legume species of the Lotus genus. In the model legume Lotus. japonicus, increased water stress caused gradual increases of most of the soluble small molecules profiled, reflecting a global and progressive reprogramming of metabolic pathways. The comparative metabolomic approach between Lotus species revealed conserved and unique metabolic responses to drought stress. Importantly, only few drought-responsive metabolites were conserved among all species. Thus we highlight a potential impediment to translational approaches that aim to engineer traits linked to the accumulation of compatible solutes. Finally, a broad comparison of the metabolic changes elicited by drought and salt acclimation revealed partial conservation of these metabolic stress responses within each of the Lotus species, but only few salt- and drought-responsive metabolites were shared between all. The implications of these results are discussed with regard to the current insights into legume water stress physiology. © 2011 Blackwell Publishing Ltd.

  17. Static response of deformable microchannels: a comparative modelling study

    Science.gov (United States)

    Shidhore, Tanmay C.; Christov, Ivan C.

    2018-02-01

    We present a comparative modelling study of fluid-structure interactions in microchannels. Through a mathematical analysis based on plate theory and the lubrication approximation for low-Reynolds-number flow, we derive models for the flow rate-pressure drop relation for long shallow microchannels with both thin and thick deformable top walls. These relations are tested against full three-dimensional two-way-coupled fluid-structure interaction simulations. Three types of microchannels, representing different elasticity regimes and having been experimentally characterized previously, are chosen as benchmarks for our theory and simulations. Good agreement is found in most cases for the predicted, simulated and measured flow rate-pressure drop relationships. The numerical simulations performed allow us to also carefully examine the deformation profile of the top wall of the microchannel in any cross section, showing good agreement with the theory. Specifically, the prediction that span-wise displacement in a long shallow microchannel decouples from the flow-wise deformation is confirmed, and the predicted scaling of the maximum displacement with the hydrodynamic pressure and the various material and geometric parameters is validated.

  18. Comparing Transformation Possibilities of Topological Functioning Model and BPMN in the Context of Model Driven Architecture

    Directory of Open Access Journals (Sweden)

    Solomencevs Artūrs

    2016-05-01

    Full Text Available The approach called “Topological Functioning Model for Software Engineering” (TFM4SE applies the Topological Functioning Model (TFM for modelling the business system in the context of Model Driven Architecture. TFM is a mathematically formal computation independent model (CIM. TFM4SE is compared to an approach that uses BPMN as a CIM. The comparison focuses on CIM modelling and on transformation to UML Sequence diagram on the platform independent (PIM level. The results show the advantages and drawbacks the formalism of TFM brings into the development.

  19. A coupling model for the two-stage core calculation method with subchannel analysis for boiling water reactors

    International Nuclear Information System (INIS)

    Mitsuyasu, Takeshi; Aoyama, Motoo; Yamamoto, Akio

    2017-01-01

    Highlights: • A coupling model of the two-stage core calculation with subchannel analysis. • BWR fuel assembly parameters are assumed and verified. • The model was evaluated for heterogeneous problems. - Abstract: The two-stage core analysis method is widely used for BWR core analysis. The purpose of this study is to develop a core analysis model coupled with subchannel analysis within the two-stage calculation scheme using an assembly-based thermal-hydraulics calculation in the core analysis. The model changes the 2D lattice physics scheme, and couples with 3D subchannel analysis which evaluates the thermal-hydraulics characteristics within the coolant flow area divided as some subchannel regions. In order to couple with these two analyses, some BWR fuel assembly parameters are assumed and verified. The developed model is evaluated for the heterogeneous problem with and without a control rod. The present model is especially effective for the control rod inserted condition. The present model can incorporate the subchannel effect into the current two-stage core calculation method.

  20. A two-stage method for microcalcification cluster segmentation in mammography by deformable models

    International Nuclear Information System (INIS)

    Arikidis, N.; Kazantzi, A.; Skiadopoulos, S.; Karahaliou, A.; Costaridou, L.; Vassiou, K.

    2015-01-01

    Purpose: Segmentation of microcalcification (MC) clusters in x-ray mammography is a difficult task for radiologists. Accurate segmentation is prerequisite for quantitative image analysis of MC clusters and subsequent feature extraction and classification in computer-aided diagnosis schemes. Methods: In this study, a two-stage semiautomated segmentation method of MC clusters is investigated. The first stage is targeted to accurate and time efficient segmentation of the majority of the particles of a MC cluster, by means of a level set method. The second stage is targeted to shape refinement of selected individual MCs, by means of an active contour model. Both methods are applied in the framework of a rich scale-space representation, provided by the wavelet transform at integer scales. Segmentation reliability of the proposed method in terms of inter and intraobserver agreements was evaluated in a case sample of 80 MC clusters originating from the digital database for screening mammography, corresponding to 4 morphology types (punctate: 22, fine linear branching: 16, pleomorphic: 18, and amorphous: 24) of MC clusters, assessing radiologists’ segmentations quantitatively by two distance metrics (Hausdorff distance—HDIST cluster , average of minimum distance—AMINDIST cluster ) and the area overlap measure (AOM cluster ). The effect of the proposed segmentation method on MC cluster characterization accuracy was evaluated in a case sample of 162 pleomorphic MC clusters (72 malignant and 90 benign). Ten MC cluster features, targeted to capture morphologic properties of individual MCs in a cluster (area, major length, perimeter, compactness, and spread), were extracted and a correlation-based feature selection method yielded a feature subset to feed in a support vector machine classifier. Classification performance of the MC cluster features was estimated by means of the area under receiver operating characteristic curve (Az ± Standard Error) utilizing tenfold cross

  1. Impact of river stage prediction methods on stream-aquifer exchanges in a hydro(geo)logical model at the regional scale

    Science.gov (United States)

    Saleh, F.; Flipo, N.; de Fouquet, C.

    2012-04-01

    The main objective of this study is to provide a realistic simulation of river stage in regional river networks in order to improve the quantification of stream-aquifer exchanges and better assess the associated aquifer responses that are often impacted by the magnitude and the frequency of the river stage fluctuations. The study focuses on the Oise basin (17 000 km2, part of the 65 000 km2 Seine basin in Northern France) where stream-aquifer exchanges cannot be assessed directly by experimental methods. Nowadays numerical methods are the most appropriate approaches for assessing stream-aquifer exchanges at this scale. A regional distributed process-based hydro(geo)logical model, Eau-Dyssée, is used, which aims at the integrated modeling of the hydrosystem to manage the various elements involved in the quantitative and qualitative aspects of water resources. Eau-Dyssée simulates pseudo 3D flow in aquifer systems solving the diffusivity equation with a finite difference numerical scheme. River flow is simulated with a Muskingum model. In addition to the in-stream discharge, a river stage estimate is needed to calculate the water exchange at the stream-aquifer interface using the Darcy law. Three methods for assessing in-stream river stages are explored to determine the most appropriate representation at regional scale over 25 years (1980-2005). The first method consists in defining rating curves for each cell of a 1D Saint-Venant hydraulic model. The second method consists in interpolating observed rating curves (at gauging stations) onto the river cells of the hydro(geo)logical model. The interpolation technique is based on geostatistics. The last method assesses river stage using Manning equation with a simplified rectangular cross-section (water depth equals the hydraulic radius). Compared to observations, the geostatistical and the Manning methodologies lead to slightly less accurate (but still acceptable) results offering a low computational cost opportunity

  2. The survival of patients with Stage III Colon Cancer is improved in HNPCC compared with sporadic cases. A Danish registry based study

    DEFF Research Database (Denmark)

    Brixen, Line Merrild; Bernstein, Inge Thomsen; Bülow, Steffen

    2013-01-01

    AIM: Patients with hereditary non-polyposis colorectal cancer (HNPCC) seem to have a better prognosis than those with sporadic colon cancer (CC)s. The aim was to compare survival after stage III CC in patients with HNPCC with those having sporadic CC. METHOD: 230 patients with hereditary cancer...... from The Danish HNPCC-Register and 3557 patients with sporadic CC from The Danish Colorectal Cancer Database, diagnosed during May 2001-December 2008 were included. HNPCC patients were classified according to Mismatch Repair mutation status and family pedigree. Sporadic cases had no known family...... history of cancer. Patient characteristics, geographic differences and survival data were analyzed. RESULTS: The overall survival (OS) was better in HNPCC patients compared to sporadic CC after stratification for sex and age (p=0.02; CI 1.04-1.7). The 5-year survival was 70% in HNPCC patients compared...

  3. Mathematical modeling of a continuous alcoholic fermentation process in a two-stage tower reactor cascade with flocculating yeast recycle.

    Science.gov (United States)

    de Oliveira, Samuel Conceição; de Castro, Heizir Ferreira; Visconti, Alexandre Eliseu Stourdze; Giudici, Reinaldo

    2015-03-01

    Experiments of continuous alcoholic fermentation of sugarcane juice with flocculating yeast recycle were conducted in a system of two 0.22-L tower bioreactors in series, operated at a range of dilution rates (D 1 = D 2 = 0.27-0.95 h(-1)), constant recycle ratio (α = F R /F = 4.0) and a sugar concentration in the feed stream (S 0) around 150 g/L. The data obtained in these experimental conditions were used to adjust the parameters of a mathematical model previously developed for the single-stage process. This model considers each of the tower bioreactors as a perfectly mixed continuous reactor and the kinetics of cell growth and product formation takes into account the limitation by substrate and the inhibition by ethanol and biomass, as well as the substrate consumption for cellular maintenance. The model predictions agreed satisfactorily with the measurements taken in both stages of the cascade. The major differences with respect to the kinetic parameters previously estimated for a single-stage system were observed for the maximum specific growth rate, for the inhibition constants of cell growth and for the specific rate of substrate consumption for cell maintenance. Mathematical models were validated and used to simulate alternative operating conditions as well as to analyze the performance of the two-stage process against that of the single-stage process.

  4. Neutrino masses in the SO(10) model with intermediate stage of the symmetry breaking

    International Nuclear Information System (INIS)

    Svetovoj, V.B.

    1982-01-01

    An effect for the neutrino masses of an intermediate stage in the symmetry spontaneous breaking, different from SU(5), is investigated in some detail for the SO(1O) model. There are two possibilities depending on the composition of the Higgs sector: i) msub(ν) approximately msub(f)(Msub(W)/Msub(1)); ii) msub(ν) approximately msub(f)sub(b)/Msub(1))(M/Msub(1)), where M, M 1 and Msub) are the scales of the breaking of the original SO(10) simmetry, the intermediate symmetry, and the standard SUsub(c)(3)xSUsub(L)(2)xU(1) symmetry, respectively, and msub(f) is a typical fermion mass. It as shown that a Majorana mass of the right neutrino (νsub(R)) of a purely loop origin would result in a too large mass of the usual neutrinos, so a tree-graph contribution to the mass of νsub(R) is necessary. Numerical estimates for the neutrino masses are discussed [ru

  5. Neutrino masses in an SO(10) model with an intermediate stage of symmetry breaking

    International Nuclear Information System (INIS)

    Svetovoi, V.B.

    1982-01-01

    The effect on neutrino masses of an intermediate stage in symmetry breaking different from SU(5) is investigated in detail for the SO(10) model. There are two possibilities depending on the contents of the Higgs sector: i) m/sub ν/approx.m/sub f/(M/sub W//M 1 ); ii) m/sub ν/approx.m/sub f/(M/sub W//M 1 )(M/M 1 ), where M, M 1 and M/sub W/ are the scales of the breaking of the original SO(10) symmetry, the intermediate symmetry, and the standard SU/sub c/(3) x SU/sub L/(2) x U(1) symmetry, respectively, and m/sub f/ is a typical fermion mass. It is shown that a Majorana mass of the right-handed-neutrino (ν/sub R/) of a purely loop origin would result in too large a mass of the usual neutrinos, so a tree-graph contribution to the mass of ν/sub R/ is necessary. Numerical estimates for the neutrino masses are discussed

  6. Evaluation of carcinogenic potential of diuron in a rat mammary two-stage carcinogenesis model.

    Science.gov (United States)

    Grassi, Tony Fernando; Rodrigues, Maria Aparecida Marchesan; de Camargo, João Lauro Viana; Barbisan, Luís Fernando

    2011-04-01

    This study aimed to evaluate the carcinogenic potential of the herbicide Diuron in a two-stage rat medium-term mammary carcinogenesis model initiated by 7,12-dimethylbenz(a)anthracene (DMBA). Female seven-week-old Sprague-Dawley (SD) rats were allocated to six groups: groups G1 to G4 received intragastrically (i.g.) a single 50 mg/kg dose of DMBA; groups G5 and G6 received single administration of canola oil (vehicle of DMBA). Groups G1 and G5 received a basal diet, and groups G2, G3, G4, and G6 were fed the basal diet with the addition of Diuron at 250, 1250, 2500, and 2500 ppm, respectively. After twenty-five weeks, the animals were euthanized and mammary tumors were histologically confirmed and quantified. Tumor samples were also processed for immunohistochemical evaluation of the expressions of proliferating cell nuclear antigen (PCNA), cleaved caspase-3, estrogen receptor-α (ER-α), p63, bcl-2, and bak. Diuron treatment did not increase the incidence or multiplicity of mammary tumors (groups G2 to G4 versus Group G1). Also, exposure to Diuron did not alter tumor growth (cell proliferation and apoptosis indexes) or immunoreactivity to ER-α, p63 (myoephitelial marker), or bcl-2 and bak (apoptosis regulatory proteins). These findings indicate that Diuron does not have a promoting potential on mammary carcinogenesis in female SD rats initiated with DMBA.

  7. Implications of the two stage clonal expansion model to radiation risk estimation

    International Nuclear Information System (INIS)

    Curtis, S.B.; Hazelton, W.D.; Luebeck, E.G.; Moolgavkar, S.H.

    2003-01-01

    The Two Stage Clonal Expansion Model of carcinogenesis has been applied to the analysis of several cohorts of persons exposed to chronic exposures of high and low LET radiation. The results of these analyses are: (1) the importance of radiation-induced initiation is small and, if present at all, contributes to cancers only late in life and only if exposure begins early in life, (2) radiation-induced promotion dominates and produces the majority of cancers by accelerating proliferation of already-initiated cells, and (3) radiation-induced malignant conversion is important only during and immediately after exposure ceases and tends to dominate only late in life, acting on already initiated and promoted cells. Two populations, the Colorado Plateau miners (high-LET, radon exposed) and the Canadian radiation workers (low-LET, gamma ray exposed) are used as examples to show the time dependence of the hazard function and the relative importance of the three hypothesized processes (initiation, promotion and malignant conversion) for each radiation quality

  8. Effects of melatonin in experimental stroke models in acute, sub-acute, and chronic stages

    Directory of Open Access Journals (Sweden)

    Hsiao-Wen Lin

    2009-03-01

    Full Text Available Hsiao-Wen Lin, E-Jian LeeNeurophysiology Laboratory, Neurosurgical Service, Department of Surgery, National Cheng Kung University Medical Center and Medical School, Tainan, TaiwanAbstract: Melatonin (N-acetyl-5-methoxy-tryptamine, a naturally occurring indole produced mainly by the pineal gland, is a well known antioxidant. Stroke (cerebral ischemia is the second leading cause of death worldwide. To date, however, effective and safe treatment for stroke remains unavailable. Melatonin is both lipid- and water-soluble and readily crosses the blood–brain barrier (BBB. Increasing evidence has shown that, in animal stroke models, administering melatonin significantly reduces infarct volume, edema, and oxidative damage and improves electrophysiological and behavioral performance. Here, we reviewed studies that assess effects of melatonin on cerebral ischemia in acute, sub-acute, and chronic stages. In addition to its potent antioxidant properties, melatonin exerts antiapoptotic, antiexcitotoxic, anti-inflammatory effects and promotes mitochondrial functions in animals with cerebral ischemia. Given that melatonin shows almost no toxicity to humans and possesses multifaceted protective capacity against cerebral ischemia, it is valuable to consider using melatonin in clinical trials on patients suffering from stroke.Keywords: cerebral ischemia, melatonin, stroke, neuroprotection

  9. Optimal pulse fishing policy in stage-structured models with birth pulses

    International Nuclear Information System (INIS)

    Gao Shujing; Chen Lansun; Sun Lihua

    2005-01-01

    In this paper, we propose exploited models with stage structure for the dynamics in a fish population for which periodic birth pulse and pulse fishing occur at different fixed time. Using the stroboscopic map, we obtain an exact cycle of system, and obtain the threshold conditions for its stability. Bifurcation diagrams are constructed with the birth rate (or pulse fishing time or harvesting effort) as the bifurcation parameter, and these are observed to display complex dynamic behaviors, including chaotic bands with period windows, period-doubling, multi-period-halving and incomplete period-doubling bifurcation, pitch-fork and tangent bifurcation, non-unique dynamics (meaning that several attractors or attractor and chaos coexist) and attractor crisis. This suggests that birth pulse and pulse fishing provide a natural period or cyclicity that make the dynamical behaviors more complex. Moreover, we show that the pulse fishing has a strong impact on the persistence of the fish population, on the volume of mature fish stock and on the maximum annual-sustainable yield. An interesting result is obtained that, after the birth pulse, the population can sustain much higher harvesting effort if the mature fish is removed as early as possible

  10. Center variation in the use of nonstandardized model for end-stage liver disease exception points.

    Science.gov (United States)

    Goldberg, David S; Makar, George; Bittermann, Therese; French, Benjamin

    2013-12-01

    The Model for End-Stage Liver Disease (MELD) score is an imperfect prognosticator of waitlist dropout, so transplant centers may apply for exception points to increase a waitlist candidate's priority on the waitlist. Exception applications are categorized as recognized exceptional diagnoses (REDs; eg, hepatocellular carcinoma) and non-REDs (eg, cholangitis). Although prior work has demonstrated regional variation in the use of exceptions, no work has examined the between-center variability. We analyzed all new waitlist candidates from February 27, 2002 to June 3, 2011 to explore variations in the use of non-REDs, for which no strict exception criteria exist. There were 58,641 new waitlist candidates, and 4356 (7.4%) applied for a non-RED exception. The number of applications increased steadily o